Cover member, imaging plate assembly, processing apparatus, program, and image merging method

Abstract

This technology provides a way to easily and accurately align multiple radiographic images read from multiple imaging plates used in intraoral radiography when combining them. [Solution] The cover member covers multiple imaging plates used for intraoral radiography and is placed in the oral cavity together with the multiple imaging plates. The cover member has at least one mark for alignment when combining multiple radiographic images read from each of the multiple imaging plates. When radiation is irradiated onto the multiple imaging plates through the cover member, the multiple radiographic images include a mark image corresponding to at least one mark.

Description

Technical Field

[0005]

[0001] The present disclosure relates to an imaging plate used for intraoral radiography.

Background Art

[0002] Patent Document 1 discloses a technique for performing intraoral imaging using a plurality of imaging plates.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When imaging inside the oral cavity is performed using a plurality of imaging plates simultaneously, a plurality of radiation images respectively read from the plurality of imaging plates may be combined to generate an overall image, and the generated overall image may be displayed.

[0005] Conventionally, in intraoral imaging using a plurality of imaging plates, when generating a composite image from a plurality of image data, it was necessary to comprehensively search for feature points of each tooth, which is the subject, by a program, and perform an image data combining (composite) process using the feature points as a clue. In such a process, a complex program was required, and the processing time tended to be long. Also, when the oral cavity of the subject is edentulous, there are almost no anatomical clues, so there are few feature points, and the combining process was very difficult.

[0006] Furthermore, in dental X-ray imaging using imaging plates, when a relatively wide area of ​​the oral cavity is being photographed (for example, occlusal imaging), if a large-format imaging plate is selected, a reader equipped with a larger-than-usual sensor is required to read the large imaging plate.

[0007] This disclosure aims to provide a technology that enables easy, quick, and appropriate alignment of multiple radiographic images read from multiple imaging plates used in intraoral radiography, and to provide a technology that can handle image processing using various imaging methods with conventional imaging plate readers. [Means for solving the problem]

[0008] One embodiment of the cover member covers a plurality of imaging plates used in intraoral radiography and is placed in the oral cavity together with the plurality of imaging plates. One embodiment of the cover member has at least one mark for alignment when combining a plurality of radiographic images read from each of the plurality of imaging plates. When radiation is irradiated onto the plurality of imaging plates through the cover member, the plurality of radiographic images include a mark image corresponding to at least one mark.

[0009] One embodiment of the processing apparatus includes an image processing unit that aligns multiple radiation images read from multiple imaging plates covered by the above-mentioned cover member based on mark images contained in the multiple radiation images, and combines the multiple radiation images after alignment.

[0010] One aspect of the program is a program that causes a computer device to perform the following processes: aligning multiple radiation images read from multiple imaging plates covered by the above-mentioned cover member, based on mark images contained in the multiple radiation images; and combining the multiple radiation images after alignment.

[0011] One embodiment of the image merging method involves aligning multiple radiation images read from multiple imaging plates covered by the above-mentioned cover member, based on mark images contained in the multiple radiation images, and then merging the multiple radiation images after alignment. [Effects of the Invention]

[0012] This technology makes it possible to easily, quickly, and accurately align multiple radiographic images when combining them, based on the mark images contained within those images. Furthermore, it enables diverse imaging techniques to accommodate various cases using, for example, relatively small imaging plates. [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic diagram showing an example of an imaging plate assembly. [Figure 2] This is a schematic diagram showing an example of an imaging plate assembly. [Figure 3] This is a schematic diagram showing an example of an imaging plate assembly. [Figure 4] This is a schematic diagram showing an example of an imaging plate assembly. [Figure 5] This is a schematic diagram showing an example of an imaging plate assembly. [Figure 6] This is a schematic diagram showing an example of an imaging plate assembly. [Figure 7] This is a schematic diagram showing an example of an imaging plate assembly. [Figure 8] This is a schematic diagram showing an example of an imaging plate assembly. [Figure 9] This is a schematic diagram showing an example of an imaging plate assembly. [Figure 10] This is a schematic diagram showing an example of a reading device. [Figure 11] This is a schematic diagram showing an example of a reading device. [Figure 12] This is a schematic diagram showing an example of a reading device. [Figure 13] It is a schematic diagram showing an example of a reading device. [Figure 14] It is a schematic diagram showing an example of the configuration of a control unit. [Figure 15] It is a schematic diagram for explaining an example of the operation of an image processing unit. [Figure 16] It is a schematic diagram showing an example of a holding member. [Figure 17] It is a schematic diagram showing an example of a radiation image recorded on an imaging plate. [Figure 18] It is a schematic diagram showing an example of a read radiation image. [Figure 19] It is a schematic diagram showing an example of a first layout diagram. [Figure 20] It is a schematic diagram for explaining an example of the operation of an image processing unit. [Figure 21] It is a schematic diagram for explaining an example of the operation of an image processing unit. [Figure 22] It is a schematic diagram for explaining an example of an overall image. [Figure 23] It is a schematic diagram showing an example of a radiation image recorded on an imaging plate. [Figure 24] It is a schematic diagram for explaining an example of the operation of an image processing unit. [Figure 25] It is a schematic diagram for explaining an example of an overall image. [Figure 26] It is a schematic diagram showing an example of a holding member. [Figure 27] It is a schematic diagram showing an example of a holding member. [Figure 28] It is a schematic diagram showing an example of a holding member. [Figure 29] It is a schematic diagram showing an example of a holding member. [Figure 30] It is a schematic diagram showing an example of a radiation image recorded on an imaging plate. [Figure 31] It is a schematic diagram for explaining an example of the operation of an image processing unit. [Figure 32] It is a schematic diagram showing an example of a holding member. [Figure 33] It is a schematic diagram showing an example of a holding member. [Figure 34] This is a schematic diagram showing an example of a retaining member. [Figure 35] This is a schematic diagram showing an example of a retaining member. [Figure 36] This is a schematic diagram showing an example of a second layout diagram. [Figure 37] This is a schematic diagram illustrating an example of the operation of the image processing unit. [Figure 38] This is a schematic diagram showing an example of a readable radiographic image. [Figure 39] This is a schematic diagram showing an example of a retaining member. [Figure 40] This is a schematic diagram illustrating an example of the operation of the image processing unit. [Figure 41] This is a schematic diagram showing an example of a retaining member. [Figure 42] This is a schematic diagram showing an example of a readable radiographic image. [Figure 43] This is a schematic diagram illustrating an example of the operation of the image processing unit. [Figure 44] This is a schematic diagram illustrating an example of the operation of the image processing unit. [Figure 45] This is a schematic diagram showing an example of a retaining member. [Figure 46] This is a schematic diagram showing an example of a retaining member. [Figure 47] This is a schematic diagram illustrating an example of the operation of the image processing unit. [Figure 48] This is a schematic diagram showing an example of alignment of read radiographic images. [Figure 49] This is a schematic diagram showing an example of a retaining member. [Figure 50] This is a schematic diagram showing an example of a readable radiographic image. [Figure 51] This is a schematic diagram showing an example of a retaining member. [Figure 52] This is a schematic diagram showing an example of a retaining member. [Figure 53] This is a schematic diagram showing an example of a retaining member. [Figure 54] This is a schematic diagram showing an example of a retaining member. [Figure 55]This is a schematic diagram showing an example of a retaining member. [Figure 56] This is a schematic diagram showing an example of a retaining member. [Figure 57] This is a schematic diagram showing an example of a retaining member. [Figure 58] This is a schematic diagram showing an example of a retaining member. [Figure 59] This is a schematic diagram showing an example of a retaining member. [Figure 60] This is a schematic diagram showing an example of a retaining member. [Figure 61] This is a schematic diagram showing an example of an overall view. [Figure 62] This is a schematic diagram showing an example of imaging plate arrangement. [Figure 63] This is a schematic diagram showing an example of a radiographic image recorded on an imaging plate. [Figure 64] This is a schematic diagram showing an example of a readable radiographic image. [Figure 65] This is a schematic diagram showing an example of the overall picture. [Figure 66] This is a schematic diagram showing an example of a retaining member. [Figure 67] This is a schematic diagram showing an example of a retaining member. [Figure 68] This is a schematic diagram showing an example of a readable radiographic image. [Figure 69] This is a schematic diagram showing an example of a readable radiographic image. [Figure 70] This is a schematic diagram showing an example of a retaining member. [Figure 71] This is a schematic diagram showing an example of a retaining member. [Figure 72] This is a schematic diagram showing an example of a readable radiographic image. [Figure 73] This is a schematic diagram showing an example of a readable radiographic image. [Figure 74] This is a schematic diagram showing an example of a retaining member. [Figure 75] This is a schematic diagram showing an example of a retaining member. [Figure 76] This is a schematic diagram showing an example of a retaining member. [Figure 77]This is a schematic diagram showing an example of an imaging plate assembly. [Figure 78] This is a schematic diagram showing an example of an imaging plate assembly. [Figure 79] This is a schematic diagram showing an example of an imaging plate assembly. [Figure 80] This is a schematic diagram showing an example of how the reading device and the display unit are connected. [Figure 81] This is a schematic diagram showing an example of how the reading device and processing device are connected. [Modes for carrying out the invention]

[0014] <Example configuration of an imaging plate assembly> Figures 1 and 2 are schematic diagrams showing an example of an imaging plate assembly 1 (also called an IP assembly 1) comprising multiple imaging plates 2. Figure 1 shows an example of an IP assembly 1 before assembly, and Figure 2 shows an example of an IP assembly 1 after assembly. The IP assembly 1 is placed, for example, in the oral cavity of a person and used for imaging of the oral cavity. The IP assembly 1 is used, for example, in occlusal imaging. However, the uses of the IP assembly 1 are not limited to these.

[0015] As shown in Figures 1 and 2, the IP assembly 1 comprises, for example, multiple imaging plates 2 used for intraoral imaging, and an imaging plate protection assembly 3 capable of housing the multiple imaging plates 2. In the example shown in Figures 1 and 2, there are two imaging plates 2, but there may be three or more imaging plates 2. The IP assembly 1 can also be used with only a single imaging plate 2 housed within it.

[0016] The imaging plate protection assembly 3 (also called the protection assembly 3) comprises, for example, a plurality of waterproof bags 4 that each individually house a plurality of imaging plates 2, and a holding member 5 that holds the plurality of imaging plates 2 housed in the plurality of waterproof bags 4 in a predetermined position. The protection assembly 3 also comprises, for example, a plurality of cover members 6 that each cover a plurality of imaging plates 2. The waterproof bags 4 house the imaging plates 2 covered by the cover members 6.

[0017] The imaging plate 2 is a flat recording medium having a radiation-forming layer 20, and is used to record radiation images. The imaging plate 2 has a front surface on which the radiation-forming layer 20 is located, and a back surface opposite to the front surface. The imaging plate 2 has, for example, a roughly rectangular flat shape with rounded corners. The radiation-forming layer 20 is a layer that stores the energy of the irradiated radiation and emits a photocatalytic light corresponding to the stored energy. The imaging plate 2 has a film made of resin. The film has a front surface on which the radiation-forming layer 20 is provided, and a back surface opposite to the front surface. The radiation-forming layer 20 is composed of, for example, a photocatalytic phosphor coated on the front surface of the film. X-rays are used as the radiation irradiated onto the radiation-forming layer 20. When X-rays from the X-ray generator, which is the radiation source, pass through the object to be photographed (also called the subject) and irradiate the imaging plate 2, energy corresponding to the intensity of the X-rays on the imaging plate 2 is accumulated in the radiation image forming layer 20. Since the intensity of the X-rays is based on the distribution of the X-ray absorption region in the object to be photographed, the distribution of energy accumulated in the radiation image forming layer 20 is the radiation image of the object to be photographed with X-rays. In this way, the imaging plate 2 records, for example, the radiation image of the object to be photographed with X-rays as a latent image.

[0018] Figure 2 shows an example of how multiple imaging plates 2, each housed in multiple waterproof bags 4, are held by a retaining member 5. The IP assembly 1, in the state shown in Figure 2, is placed, for example, in the oral cavity of a person. There are, for example, several sizes of imaging plates 2. Depending on the subject to be photographed, the type and number of imaging plates 2 used for imaging are appropriately selected.

[0019] In dental X-ray imaging using imaging plates, smaller imaging plates are generally used more frequently than larger ones. This trend stems from the fact that scanning large imaging plates with conventional detectors used in the field of dental X-ray imaging presents many challenges and high technical hurdles. Conversely, incorporating detectors capable of scanning large imaging plates would result in larger equipment, higher equipment costs, or over-specced equipment for detecting commonly used (small) imaging plates. Therefore, if it were possible to perform the same imaging using small imaging plates as with large imaging plates, it would enable a wider range of dental X-ray imaging applications even with conventional equipment, expanding its range of uses.

[0020] The terms "small size imaging plate" and "large size imaging plate" used here are merely convenient terms to distinguish between sizes that can be read by conventional scanning with a typical detector and sizes that cannot. For example, small size imaging plates include those labeled "size 0," "size 1," "size 2," and "size 3." Large size imaging plates include those larger than "size 3." In dental radiography, "size 0" imaging plates are generally used for standard pediatric radiography, and "size 1" imaging plates are generally used for bite-wing radiography in children. "Size 2" imaging plates are generally used for standard adult radiography, and "size 3" imaging plates are generally used for bite-wing radiography in adults. Larger imaging plates include "size 4" and "size 5," which are commonly used in dental X-ray imaging for occlusal imaging of children and adults.

[0021] When multiple imaging plates 2 are used, as in the IP assembly 1 disclosed in the embodiment shown in Figure 1, for example, large-area occlusal imaging, which conventionally required an imaging plate larger than size 3, becomes possible even with a smaller imaging plate.

[0022] During intraoral imaging, the IP assembly 1 is placed inside the oral cavity, and radiation is irradiated onto the radiographic layer 20 of each imaging plate 2 of the IP assembly 1. The radiographic layer 20 of each imaging plate 2 of the IP assembly 1 records the subject (in other words, the subject to be photographed) inside the oral cavity. The radiographic layer 20 records, for example, at least one tooth (for example, a dentition forming part of the dental arch), soft tissue such as the gums, and the jawbone as subjects. If the subject includes edentulous individuals, teeth will not be recorded on the radiographic layer 20. Furthermore, when an IP assembly 1 with multiple imaging plates 2 is placed inside the oral cavity, not all of the IP assembly 1 may fit inside the oral cavity, and a part of the IP assembly 1 may be located outside the oral cavity. In other words, a part of the outer retaining member 5 of the IP assembly 1 may be located outside the oral cavity.

[0023] The radiographic image recorded on the imaging plate 2 is read by a reading device 100 (see Figure 10), which will be described later. For example, one imaging plate 2 from each IP assembly 1 is inserted into the reading device 100. The reading device 100 reads the radiographic image from the radiographic image forming layer 20 of the inserted imaging plate 2. The radiographic image read from each imaging plate 2 (also called the read radiographic image) shows subjects such as teeth that make up a part of the dental arch. The reading device 100 combines (in other words, synthesizes) the multiple radiographic images read from multiple imaging plates 2 from each IP assembly 1 to generate a single overall image representing the oral cavity. Subjects such as the dental arch are shown in the overall image. The overall image is sometimes called an occlusal image. The reading device 100 displays the generated overall image on a display unit, for example. Hereafter, the front surface of the imaging plate 2 will be referred to as the reading target surface 21. Furthermore, the back surface of the imaging plate 2 is called the non-readable surface 22.

[0024] The cover member 6 is a member that protects the imaging plate 2. The cover member 6 has a structure in which, for example, a sheet-like material is folded and is openable and closable. The cover member 6 can cover the imaging plate 2 by sandwiching it between the cover member 6 and the imaging plate 2. For example, in the cover member 6, at least the portion that comes into contact with the reading surface 21 of the imaging plate 2 is made of a radiotransparent material. The cover member 6 is also made of, for example, a material that has light-shielding properties against visible light. The cover member 6 is made of, for example, paper.

[0025] For example, when no external force is applied to the cover member 6, it is in an open state as shown in Figure 1. On the other hand, when the cover member 6 is pinched from the outside with fingers, the cover member 6 closes, and the imaging plate 2 is held between the cover member 6. Figure 3 is a schematic diagram showing an example of how the imaging plate 2 is positioned on the inner surface of the open cover member 6.

[0026] In this way, the imaging plate 2 is less susceptible to mechanical damage when covered by the cover member 6. For example, when the IP assembly 1 placed in the oral cavity is bitten by a person's teeth during dental X-ray imaging, or when it curves to conform to the dentition and comes into contact with the dentition, the imaging plate 2 is less likely to be damaged. The cover member 6 is also called, for example, a bite cover, IP cover, or carton.

[0027] Furthermore, since the imaging plate 2 is covered with a cover member 6 made of a material such as paper that does not easily transmit visible light, visible light or ambient light emitted from surrounding lighting devices (e.g., fluorescent lamps or LEDs (light-emitting diodes)) is less likely to hit the imaging plate 2. As a result, information from the radiographic image is less likely to be lost from the imaging plate 2.

[0028] The configuration of the cover member 6 is not limited to the example described above. For example, the cover member 6 may be in a closed state when no external force is applied. Also, the cover member 6 may be made of a material other than paper. Furthermore, the protective assembly 3 does not necessarily have to include the cover member 6.

[0029] The waterproof bag 4 is a protective material for the imaging plate 2 and the cover member 6. The waterproof bag 4 contains the imaging plate 2, which is covered by the cover member 6. The waterproof bag 4 can also be said to be a cover member that covers the imaging plate 2, similar to the cover member 6.

[0030] The waterproof bag 4 is designed to prevent bodily fluids (saliva, blood, viruses, bacteria, etc.) from penetrating or flowing into the interior of the waterproof bag 4, so as not to adhere to the imaging plate 2 and cover member 6 placed in the oral cavity during imaging. Furthermore, when the waterproof bag 4 is washed after imaging, it is designed to prevent disinfectants from entering the interior of the waterproof bag 4. The waterproof bag 4 is also called, for example, a protective bag, an IP protective bag, or a hygienic pouch.

[0031] The waterproof bag 4 comprises, for example, a waterproof bag-shaped main body 40 and an adhesive member 48 for sealing the main body 40. The adhesive member 48 is provided on the main body 40. The adhesive member 48 is made of, for example, a radiotransparent material. The adhesive member 48 is made of, for example, double-sided tape. The adhesive member 48 has an adhesive surface to which a part of the main body 40 is attached. In an unused waterproof bag 4, for example, the adhesive surface of the adhesive member 48 is covered with release paper or release film (also called a protective sheet).

[0032] The main body 40 is, for example, a hygienic component made of a biocompatible material. Alternatively, the main body 40 may be made of, for example, a radiotransparent material. The main body 40 may also be made of, for example, a soft material such as resin. The main body 40 may also be made of, for example, a resin such as PVC (Polyvinyl Chloride) or EVA (Ethylene-Vinylacetate Copolymer).

[0033] The main body 40 has an opening 44 through which the imaging plate 2 is inserted and removed, and a lid 43 that can close the opening 44. The lid 43 has a mounting target portion 43a and a handle portion 43b that are attached to the adhesive surface of the adhesive member 48. The assembler of the IP assembly 1 grasps the handle portion 43b of the lid 43 with their fingers, bends the lid 43 toward the adhesive member 48, and attaches the mounting target portion 43a to the adhesive surface of the adhesive member 48.

[0034] The imaging plate 2 is inserted into the main body 40 through the opening 44, for example, while being sandwiched between the cover member 6. The assembler holds the cover member 6 (see Figure 3), on which the imaging plate 2 is positioned on the inner surface, with their fingers from the outside, and inserts the imaging plate 2 and the cover member 6 into the main body 40 through the opening 44. Figure 4 is a schematic diagram showing an example of how the imaging plate 2 and the cover member 6 are inserted into the main body 40 through the opening 44.

[0035] After the imaging plate 2 and cover member 6 are housed in the main body 40, the release paper or release film covering the adhesive surface of the adhesive member 48 is removed. Then, the assembly worker, while holding the knob 43b of the lid 43 with their fingers, bends the lid 43 toward the adhesive member 48, attaching the mounting target portion 43a of the lid 43 to the adhesive surface of the adhesive member 48. As a result, the opening 44 is covered by the lid 43, and the main body 40 is sealed in a watertight manner. Consequently, the assembly of assembly 7 (also called unit assembly 7), which consists of the imaging plate 2, the cover member 6 covering it, and the waterproof bag 4 housing the imaging plate 2 and cover member 6, is completed.

[0036] Figure 5 is a schematic diagram showing an example of how the opening 44 is covered by the lid 43 and the main body 40 is sealed. Two unit assemblies 7 are shown in Figure 5. The assembler assembles multiple unit assemblies 7. If the protective assembly 3 does not have a cover member 6, the unit assembly 7 does not include a cover member 6.

[0037] In this way, by housing the imaging plate 2 in the waterproof bag 4, the imaging plate 2 is less likely to be contaminated with bodily fluids such as saliva or blood when the IP assembly 1 is placed in the oral cavity. This reduces the likelihood of cross-infection.

[0038] Alternatively, a hardening adhesive may be used instead of the adhesive member 48. The lid 43 may also be folded and welded to the main body 40. Furthermore, the waterproof bag 4 may not have a lid 43 and consist only of a bag-shaped main body 40. In this case, the adhesive member 48 may be provided on the inner surface of the main body 40, or the area around the opening 44 of the main body 40 may be heat-sealed, or the opening 44 may be closed with a zipper-type structure similar to that of a freezer bag.

[0039] At least a portion of the main body 40 of the waterproof bag 4 may have light-shielding properties against visible light. In this case, for example, visible light or ambient light emitted from ambient lighting devices will be less likely to hit the imaging plate 2, thus reducing the loss of radiation image information from the imaging plate 2. As a method for providing light-shielding properties against visible light to at least a portion of the main body 40, for example, at least a portion of the surface of the main body 40 may be made black. In this case, for example, at least one of the outer or inner surfaces of the portion of the main body 40 that faces the reading target surface 21 of the imaging plate 2 within the main body 40 may be black. This reduces the amount of ambient visible light that hits the imaging plate 2, especially the radiation image forming layer 20. Alternatively, at least one of the outer or inner surfaces of the portion of the main body 40 that faces the non-reading surface 22 of the imaging plate 2 within the main body 40 may be black. Even in this case, ambient visible light will be less likely to hit the imaging plate 2. Additionally, at least one of the two sides of the lid 43 may be black. In this case, ambient visible light is less likely to hit the imaging plate 2. At the very least, the assembly of the unit assembly 7 should be carried out so that the light-shielding portion of the waterproof bag 4 and the reading surface 21 of the imaging plate 2 face each other.

[0040] The holding member 5 holds multiple unit assemblies 7 in predetermined positions. The holding member 5 is also called, for example, a positioning device, an IP positioning device, or a container. The holding member 5 holds multiple unit assemblies 7 so that they are lined up in a predetermined direction. It can also be said that the holding member 5 holds multiple imaging plates 2 so that they are lined up in a predetermined direction. It can also be said that the holding member 5 holds multiple waterproof bags 4 so that they are lined up in a predetermined direction. The holding member 5 holds the multiple unit assemblies 7 so as to cover them. It can also be said that the holding member 5 holds the multiple imaging plates 2 so as to cover them. The holding member 5 can also be said to be a cover member that covers the multiple imaging plates 2. Hereafter, the multiple imaging plates 2 held by the holding member 5 may be referred to as a combined imaging plate. A combined imaging plate can also be viewed as one large imaging plate composed of multiple imaging plates 2.

[0041] The holding member 5 holds multiple imaging plates 2 such that two adjacent imaging plates 2 partially overlap. For example, the holding member 5 holds multiple imaging plates 2 such that the short edges (in other words, the long edges) of two adjacent imaging plates 2 overlap each other. Two imaging plates 2 held by the holding member 5 are aligned along their short edges.

[0042] This disclosure describes several types of retaining members 5. Hereafter, one example of the retaining member 5 shown in Figures 1 to 5 will be referred to as retaining member 5A.

[0043] The retaining member 5A is openable and closable. Figure 1 shows the retaining member 5A in the open state, and Figure 2 shows the retaining member 5A in the closed state. The retaining member 5A comprises, for example, a base material 50 that covers a plurality of unit assemblies 7, and a mounting portion 58 for attaching the plurality of unit assemblies 7 to the base material 50. The base material 50 covers a plurality of waterproof bags 4. The base material 50 can also be called the main body.

[0044] The base material 50 has a structure in which, for example, a sheet-like member is folded and is openable and closable. The base material 50 has, for example, a fixed portion 51 in which a plurality of unit assemblies 7 are arranged and fixed, and a cover portion 52 that covers the plurality of unit assemblies 7 fixed to the fixed portion 51. The plurality of unit assemblies 7 are fixed to the fixed portion 51 by mounting portions 58. Waterproof bags 4 of the plurality of unit assemblies 7 are fixed to the fixed portion 51. The cover portion 52 covers the plurality of waterproof bags 4 fixed to the fixed portion 51.

[0045] The fixed portion 51 and the cover portion 52 are each, for example, in the form of a sheet. The cover portion 52 is connected to the fixed portion 51 and can be opened and closed relative to the fixed portion 51, with the connection point with the fixed portion 51 as the pivot point (in other words, the opening / closing axis).

[0046] When no external force is applied to the base 50, for example, the cover portion 52 is open relative to the fixed portion 51, and the base 50 is in an open state. When an external force is applied to at least one of the fixed portion 51 and the cover portion 52 so that they move closer to each other, the base 50 closes, and the multiple unit assemblies 7 are sandwiched between the fixed portion 51 and the cover portion 52. For example, if the fixed portion 51 and the cover portion 52 are pinched from the outside with fingers, the base 50 closes. When the multiple unit assemblies 7 are sandwiched between the fixed portion 51 and the cover portion 52, the base 50 faces both sides of the imaging plate 2 of the multiple unit assemblies 7 (i.e., the reading surface 21 and the non-reading surface 22). The base 50 may also be in a closed state when no external force is applied.

[0047] The fixed portion 51 and the cover portion 52 each have a pair of knobs 51a and 52a. The knob 51a is provided on the fixed portion 51 at the end opposite to the connection end with the cover portion 52. The knob 52a is provided on the cover portion 52 at the end opposite to the connection end with the fixed portion 51. When the base material 50 is in the closed state, the pair of knobs 51a and 52a face each other. The assembler can maintain the closed state of the base material 50 by pinching the pair of knobs 51a and 52a with their fingers from the outside. When the base material 50 is in the closed state with the unit assembly 7 fixed to the fixed portion 51, the imaging plate 2 of the unit assembly 7 is not located between the pair of knobs 51a and 52a. Note that the holding member 5 does not necessarily have to have knobs 51a and 52a.

[0048] The base material 50 is, for example, a hygienic component made of a biocompatible material (for example, a material conforming to ISO standard 10993-1, etc.). Alternatively, the base material 50 may be made of a radiotransparent material. Alternatively, the base material 50 may be made of a soft material such as resin. The base material 50 may be made of a resin such as PVC or EVA. The base material 50 may be made of the same material as the main body 40 of the waterproof bag 4, or it may be made of a different material than the main body 40. Alternatively, the base material 50 may be made of paper instead of resin. Alternatively, the base material 50 may be made of paper and resin. In this case, for example, the base material 50 may be made by coating a base material (also called the main body) made of paper with a resin such as vinyl. As the material for the base material 50, various other materials with high radiotransparency, such as carbon fiber material, can be used.

[0049] On the inner surface 51b of the fixed portion 51, that is, the fixed surface 51b to which the multiple unit assemblies 7 are fixed, location information 51c indicating the placement locations of the multiple unit assemblies 7 is indicated by printing or other means. The location information 51c indicates the placement locations of the multiple waterproof bags 4, each containing a multiple imaging plate 2. The location information 51c can also be said to indicate the layout of the multiple unit assemblies 7 on the fixed surface 51b, or the layout of the multiple imaging plates 2 on the fixed surface 51b.

[0050] In the examples in Figures 1-5, the placement information 51c includes the numbers 1 and 2, indicating that two unit assemblies 7 are placed on the fixed surface 51b. The direction in which the numbers 1 and 2 are arranged indicates the direction in which the two unit assemblies 7 are arranged. The location where the number 1 is shown indicates the approximate placement location of one unit assembly 7, and the location where the number 2 is shown indicates the approximate placement location of the other unit assembly 7. It can also be said that the location where the number 1 is shown indicates the approximate placement location of the imaging plate 2 of one unit assembly 7, and the location where the number 2 is shown indicates the approximate placement location of the imaging plate 2 of the other unit assembly 7.

[0051] Furthermore, the placement information 51c also includes a dotted line 51ca indicating the detailed placement location of one of the unit assemblies 7. The dotted line 51ca is shown around the number 1. The dotted line 51ca has a shape corresponding to the shape of the unit assembly 7. It can also be said that the dotted line 51ca has a shape corresponding to the shape of the imaging plate 2. The dotted line 51ca can also be said to be information indicating the detailed placement location of the imaging plate 2 of one of the unit assemblies 7.

[0052] The configuration of the placement location information 51c is not limited to the example above. The placement location information 51c may indicate the positions of three or more unit assemblies 7, or it may indicate the direction in which three or more unit assemblies 7 are arranged. In other words, the placement location information 51c may indicate the layout of three or more unit assemblies 7 on the fixed surface 51b. The placement location information 51c may also be indicated using lines other than dotted lines. The placement location information 51c may also be indicated using at least one of several types of marks, such as lines, symbols, letters, and figures. The placement location information 51c should at least be configured to show the user the arrangement (in other words, layout) of each imaging plate 2 that is suitable for the imaging method in which the IP assembly 1 is used.

[0053] The mounting portion 58, which attaches the fixed portion 51 and the multiple waterproof bags 4 to each other, is made of, for example, a radiotransparent material. Before the multiple unit assemblies 7 are fixed to the fixed portion 51, i.e., in the unused retaining member 5A, the mounting portion 58 is provided on, for example, the fixed surface 51b. The mounting portion 58 is, for example, an adhesive member. As this adhesive member, for example, translucent or transparent double-sided tape is used. In the unused retaining member 5A, release paper or release film may be attached to the mounting portion 58. The mounting portion 58 is provided on at least a part of the fixed surface 51b. In the example of Figures 1-5, the mounting portion 58 is provided on most of the fixed surface 51b. The placement information 51c is visible through the mounting portion 58. Each of the multiple unit assemblies 7 is, for example, detachable from the fixed surface 51b.

[0054] For example, when two unit assemblies 7 are fixed to the fixed portion 51 of the holding member 5A, first, one unit assembly 7 is positioned and fixed to the fixed surface 51b at the location indicated by the number 1. Specifically, one unit assembly 7 is positioned and fixed to the area of ​​the fixed surface 51b indicated by the dotted line 51ca around the number 1. More specifically, one unit assembly 7 is positioned in a roughly rectangular area enclosed by the dotted line 51ca shown on the fixed surface 51b and the outer edge of the fixed surface 51b connected to the dotted line 51ca. Figure 6 is a schematic diagram showing an example of this arrangement. The unit assembly 7 is fixed to the fixed surface 51b, for example, such that the non-readable surface 22 of the imaging plate 2 included in the unit assembly 7 is located on the fixed surface 51b side. Furthermore, the unit assembly 7 is fixed to the fixing surface 51b such that, for example, the bottom of the waterproof bag 4 of the unit assembly 7 is located on the connection end side between the cover portion 52 and the fixing portion 51, and the lid portion 43 of the waterproof bag 4 is located on the side of the knob portion 51a.

[0055] Here, on the fixed surface 51b, the direction along the direction from the knob portion 51a toward the connection end between the cover portion 52 and the fixed portion 51 (approximately the left-right direction in Figure 1) is defined as the vertical direction of the fixed surface 51b, and the direction perpendicular to this vertical direction is defined as the horizontal direction of the fixed surface 51b. When the unit assembly 7 is placed in the area indicated by the dotted line 51ca on the fixed surface 51b, the longitudinal direction of the unit assembly 7 becomes aligned with the vertical direction of the fixed surface 51b. Therefore, the longitudinal direction of the imaging plate 2 becomes aligned with the vertical direction of the fixed surface 51b.

[0056] After one unit assembly 7 is fixed to the surface to be fixed 51b, the other unit assembly 7 is placed and fixed to the surface to be fixed 51b. Specifically, the other unit assembly 7 is placed and fixed to the location on the surface to be fixed 51b indicated by the number 2. At this time, the other unit assembly 7 is placed on the surface to be fixed 51b such that its longitudinal direction is aligned with the longitudinal direction of the surface to be fixed 51b, similar to the first unit assembly 7 that is already fixed to the surface to be fixed 51b.

[0057] Once the multiple unit assemblies 7 are fixed to the surface 51b as described above, the assembly of the IP assembly 1 is complete. Figure 7 is a schematic diagram showing an example of a completed IP assembly 1.

[0058] In Figure 7, the imaging plate 2 is shown by a dashed line. Two unit assemblies 7 are fixed to the fixing part 51 such that the two imaging plates 2 contained in each of the two unit assemblies 7 partially overlap each other. For example, the two unit assemblies 7 are fixed to the fixing surface 51b by the mounting part 58 such that one end 25 in the short direction (in other words, one end 25 on the long side) of the imaging plate 2 of the second unit assembly 7 is positioned on one end 25 in the short direction (in other words, one end 25 on the long side) of the imaging plate 2 of the first unit assembly 7 to be fixed. One end 25 of the imaging plate 2 can be said to be the overlapping portion that overlaps with the other imaging plate 2. The two imaging plates 2 are basically stacked by the assembly worker so that their long sides are parallel and their short sides are aligned in a straight line.

[0059] As can be understood from the above explanation, the dotted line 51ca shown on the fixed surface 51b indicates that the unit assembly 7 should be positioned on the fixed surface 51b such that its longitudinal direction aligns with the longitudinal direction of the fixed surface 51b. In other words, the dotted line 51ca indicates the orientation (also called orientation information) that the multiple imaging plates 2 should take with respect to the holding member 5A. The assembly worker of the IP assembly 1 can determine from the dotted line 51ca shown on the holding member 5A how the multiple imaging plates 2 should be positioned with respect to the holding member 5A. In other words, the assembly worker can determine the orientation that the multiple imaging plates 2 should be set to relative to the holding member 5A from the orientation information shown on the holding member 5A. This makes it easier for the assembly worker to set the orientation of the multiple imaging plates 2 with respect to the holding member 5A to the appropriate orientation.

[0060] Furthermore, the numbers 1 and 2 shown on the fixed surface 51b can be said to be information (also called overlapping relationship information) indicating the overlapping vertical relationship that the two imaging plates 2 covered by the holding member 5 should have. The assembly worker of IP assembly 1 can determine from the numbers 1 and 2 how the overlapping vertical relationship of the two imaging plates 2 should be arranged. Alternatively, the assembly worker can determine from the numbers 1 and 2 in what order the two imaging plates 2 should be placed on the fixed surface 51b. The numbers 1 and 2 can also be said to be information indicating in what order the two imaging plates 2 should be placed (in other words, fixed) on the fixed surface 51b. The assembly worker can determine from the overlapping relationship information shown on the holding member 5A the overlapping vertical relationship that should be set for multiple imaging plates 2 on the holding member 5A. This makes it easier for the assembly worker to set the overlapping vertical relationship of the two imaging plates 2 to an appropriate vertical relationship.

[0061] Even when three or more unit assemblies 7 are fixed to the fixing part 51, each unit assembly 7 is fixed to the fixing part 51 in order. For example, after the first unit assembly 7 is fixed to the fixing part 51, the second unit assembly 7 is fixed to the fixing part 51 such that one end of the imaging plate 2 in the short direction of the second unit assembly 7 overlaps with one end of the imaging plate 2 in the short direction of the first unit assembly 7. Next, the third unit assembly 7 is fixed to the fixing part 51 such that one end of the imaging plate 2 in the short direction of the third unit assembly 7 overlaps with the other end of the imaging plate 2 in the short direction of the second unit assembly 7. Thereafter, the fourth and subsequent unit assemblies 7 are fixed to the fixing part 51 in the same manner. Figure 9 is a schematic diagram showing an example of how three unit assemblies 7 are fixed to the fixing part 51. In the example shown in Figure 9, one end of another imaging plate is positioned above one end of the central imaging plate 2, and one end of yet another imaging plate is positioned below the other end of the central imaging plate 2.

[0062] Furthermore, when three or more unit assemblies 7 are fixed to the fixing part 51, the way in which the imaging plates 2 of the multiple unit assemblies 7 are stacked is not limited to the example in Figure 9. For example, one end in the short direction of two other imaging plates 2 may be positioned above both ends in the short direction of one imaging plate 2. Alternatively, one end in the short direction of two other imaging plates 2 may be positioned below both ends in the short direction of one imaging plate 2. In addition, the multiple unit assemblies 7 may be fixed to the fixing part 51 such that no two adjacent imaging plates 2 overlap each other. In other words, the holding member 5A may hold the multiple unit assemblies 7 such that no two adjacent imaging plates 2 overlap each other.

[0063] The configuration of the mounting portion 58 of the retaining member 5A is not limited to the above example. For example, the mounting portion 58 may consist of multiple adhesive members (e.g., double-sided tape or adhesive coating) provided on each of the multiple waterproof bags 4 fixed to the fixed portion 51. Alternatively, the mounting portion 58 may consist of multiple adhesive members provided on each of the multiple waterproof bags 4 and an adhesive member provided on the fixed surface 51b. If the mounting portion 58 is provided only on the multiple waterproof bags 4, it is preferable that the mounting method of the imaging plate 2, i.e., the orientation of the reading target surface 21 and the non-reading surface 22, is not easily confused when fixing the waterproof bag 4 containing the imaging plate 2 to the retaining member 5A. For example, by providing an adhesive member on the non-reading surface 22 side of the main body portion 40 of the waterproof bag 4, the imaging plate 2 can be reliably guided to the correct mounting state with the front and back sides facing each other.

[0064] Furthermore, at least one of the multiple waterproof bags 4 fixed to the fixed portion 51 may be detachable from the fixed portion 51. In this case, for example, the attachment portion 58 may be equipped with a hook-and-loop fastener. Specifically, the attachment portion 58 may be equipped with, for example, a first hook-and-loop fastener provided on the waterproof bag 4 and a second hook-and-loop fastener provided on the fixed surface 51b that engages with the first hook-and-loop fastener.

[0065] Furthermore, at least one of the multiple waterproof bags 4 fixed to the fixed part 51 may be in a manner that prevents it from being detached from the fixed part 51. For example, the mounting part 58 may contain a hardening adhesive, and the waterproof bag 4 and the fixed part 51 may be attached to each other with the adhesive.

[0066] When the assembled IP assembly 1 is placed in a person's oral cavity for imaging, as shown in Figure 8, the imaging operator (also called the imaging operator) grasps the pair of knobs 51a and 52a of the base material 50 of the holding member 5A with their fingers from the outside. Then, while grasping the pair of knobs 51a and 52a, the imaging operator inserts the IP assembly 1 into the subject's oral cavity from the side opposite to the pair of knobs 51a and 52a. The subject bites down on the base material 50 of the holding member 5A in their oral cavity, maintaining the closed state of the base material 50. The radiation image-forming layers 20 of each imaging plate 2, held by the closed holding member 5A, face the cover material 52 of the holding member 5A. After the IP assembly 1 is placed in the oral cavity, radiation is irradiated onto the IP assembly 1 from the cover material 52 side to perform imaging.

[0067] When the maxillary dental arch is being imaged, the IP assembly 1 is positioned in the oral cavity so that the cover portion 52 of the retaining member 5A faces the maxillary dental arch. This positions the IP assembly 1 so that the reading surface 21 (in other words, the radiographic image-forming layer 20) of each imaging plate 2 faces the maxillary dental arch. Radiation is then irradiated onto the IP assembly 1 in the oral cavity from above the maxilla. The radiation passes through the maxilla, the cover portion 52 of the retaining member 5A, the waterproof bag 4, and the cover member 6 in sequence, irradiating the radiographic image-forming layer 20 of each imaging plate 2. As a result, radiographic images of the maxillary dental arch are recorded across the entire radiographic image-forming layer 20 of the multiple imaging plates 2 of the IP assembly 1. In the overlapping portion of two imaging plates 2 held by the retaining member 5A, radiation that has passed through the upper imaging plate 2 irradiates the lower imaging plate 2. A portion of the maxillary dental arch is recorded on each imaging plate 2. In the intraoral IP assembly 1, the lower imaging plate 2, which is fixed first to the fixed surface 51b (in other words, the imaging plate 2 fixed at the location marked 1 on the fixed surface 51b), is located on the left buccal side, and the upper imaging plate 2, which is fixed later to the fixed surface 51b (in other words, the imaging plate 2 fixed at the location marked 2 on the fixed surface 51b), is located on the right buccal side.

[0068] On the other hand, when the mandibular dental arch is being imaged, the IP assembly 1 is positioned in the oral cavity so that the cover portion 52 of the retaining member 5A faces the mandibular dental arch. This positions the IP assembly 1 so that the reading surface 21 of each imaging plate 2 faces the upper and lower dental arches. Radiation is then irradiated onto the IP assembly 1 in the oral cavity from below the mandible. The radiation passes through the mandible, the cover portion 52 of the retaining member 5A, the waterproof bag 4, and the cover member 6 in sequence, irradiating the radiographic image-forming layer 20 of each imaging plate 2. As a result, radiographic images of the mandibular dental arch are recorded across the entire radiographic image-forming layer 20 of the multiple imaging plates 2 of the IP assembly 1. A portion of the mandibular dental arch is recorded on each imaging plate 2. In the IP assembly 1 in the oral cavity, the lower imaging plate 2, which is fixed to the fixed portion 51 first, is located on the right buccal side, and the upper imaging plate 2, which is fixed to the fixed portion 51 later, is located on the left buccal side.

[0069] Thus, in this example, the holding member 5 that holds the multiple imaging plates 2 is inserted into the subject's oral cavity from the side opposite to the pair of knobs 51a and 52a. Therefore, within the oral cavity, the multiple imaging plates are arranged so that their longitudinal directions are aligned with the front-to-back direction (in other words, the depth direction) of the oral cavity. Since the insertion direction of the holding member 5A into the oral cavity is determined by the pair of knobs 51a and 52a, it can be said that the pair of knobs 51a and 52a indicate the insertion direction of the holding member 5A into the oral cavity. The imaging operator can determine the insertion direction of the holding member 5A into the oral cavity from the pair of knobs 51a and 52a. In other words, the imaging operator can determine from the pair of knobs 51a and 52a what direction the holding member 5A should be inserted into the oral cavity. This makes it easier for the imaging operator to insert the holding member 5A into the oral cavity in the appropriate direction.

[0070] Once the imaging is complete, the IP assembly 1 is removed from the subject's oral cavity. Next, for example, multiple unit assemblies 7 are removed from the fixed portion 51 of the retaining member 5A. Then, the imaging plate 2, covered by the cover member 6, is removed from the waterproof bag 4 of each unit assembly 7.

[0071] The imaging plate 2, removed from the waterproof bag 4, is carried to the insertion opening 121 (see Figure 10) of the reading device 100 while sandwiched between the cover member 6. Then, the cover member 6 is opened and the imaging plate 2 is inserted into the insertion opening 121. The reading device 100 reads the radiographic image from the inserted imaging plate 2. Similarly, radiographic images are read from each imaging plate 2 provided in the IP assembly 1. The reading device 100 combines the multiple radiographic images read from each of the multiple imaging plates 2 provided in the IP assembly 1 to generate an overall image (in other words, an occlusal image). The reading device 100 then displays the generated overall image. The overall image may show, for example, the maxillary dental arch or the mandibular dental arch.

[0072] Furthermore, if imaging is performed using only one imaging plate 2 due to reasons such as a narrow imaging range, the unit assembly 7 is placed individually in the oral cavity, and radiation is irradiated to that single unit assembly 7 in the oral cavity. Hereafter, imaging using only one unit assembly 7 will be referred to as IP single-unit imaging.

[0073] As shown in Figures 1-8, the holding member 5 is provided with at least one alignment mark 10 used when combining multiple radiation images read from multiple imaging plates 2 covered by the holding member 5. The mark 10 is made of radiation shielding material. The mark 10 does not completely shield the radiation, but allows some radiation to pass through.

[0074] Mark 10 is provided on the oral cavity retaining member 5 in the portion facing the radiation image forming layer 20 of each imaging plate 2 covered by the retaining member 5. It can be said that Mark 10 is provided on the portion of the retaining member 5 into which radiation is incident. It can also be said that Mark 10 is provided on the oral cavity retaining member 5 in the portion closer to the radiation source than the imaging plate 2.

[0075] In the retaining member 5A shown in Figures 1 and 2, the mark 10 is provided, for example, on the inner surface of the cover portion 52 that faces the radiographic image-forming layer 20 of the imaging plate 2 when the retaining member 5A is closed. The mark 10 is provided on the surface of the retaining member 5A of the intraoral IP assembly 1 that faces the radiographic image-forming layer 20 of the imaging plate 2. The mark 10 may also be provided on the outer surface of the cover portion 52. The same applies to the retaining member 5B shown in Figures 77 and 78, which will be described later.

[0076] When intraoral imaging is performed using the intraoral IP assembly 1, radiation is transmitted through the cover portion 52 of the retaining member 5A and irradiated onto the imaging plate 2. At this time, the portion of the cover portion 52 where the mark 10 is provided has the transmission of radiation obstructed by the mark 10. As a result, the amount of radiation transmitted through the portion of the cover portion 52 where the mark 10 is provided is significantly reduced compared to the amount of radiation transmitted through the portion of the cover portion 52 where the mark 10 is not provided.

[0077] When radiation is irradiated onto the image-forming layers 20 of multiple imaging plates 2 through the holding member 5, a mark image corresponding to at least one mark 10 provided on the holding member 5 is recorded on the multiple imaging plates 2. As a result, the multiple radiation images read from the multiple imaging plates 2 include a mark image corresponding to at least one mark 10 provided on the holding member 5. When the reading device 100 combines the multiple radiation images read from the multiple imaging plates 2, it performs alignment processing to align the multiple radiation images based on the mark images included in the multiple radiation images.

[0078] Hereafter, Mark 10 may be referred to as Alignment Mark 10. Also, the mark image corresponding to Mark 10, included in the radiographic image, may be referred to as the Alignment Mark Image. The Alignment Mark Image can be described as an image representing Alignment Mark 10, or as an image in which Alignment Mark 10 is captured. Alignment Mark 10 and the Alignment Mark Image will be explained in detail later.

[0079] <Example of reader device configuration> Figure 10 is a schematic diagram showing an example of the configuration of the reading device 100. The reading device 100 can also be called a processing device. As shown in Figure 10, the reading device 100 includes, for example, a housing 120. The housing 120 houses a configuration for reading the radiation image from the imaging plate 2. This configuration will be described later.

[0080] The housing 120 is provided with an insertion opening 121 and an outlet 122. The insertion opening 121 is provided, for example, on the top surface of the housing 120. The user of the reading device 100 can insert the imaging plate 2 into the housing 120 through the insertion opening 121. In the example shown in Figure 10, the imaging plate 2 is inserted into the insertion opening 121 from one end in the longitudinal direction (in other words, the short side). Alternatively, the imaging plate 2 may be inserted into the insertion opening 121 from one end in the short direction (in other words, the long side).

[0081] The imaging plate 2 has its radiographic image read inside the housing 120. The outlet 122 is provided, for example, on the lower part of one side of the housing 120. After the radiographic image has been read, the imaging plate 2 (also called the read imaging plate 2) is discharged to the outlet 122. The user of the reading device 100 can retrieve the read imaging plate 2 through the outlet 122.

[0082] The housing 120 is provided with, for example, an operation unit 140 that receives input from the user. The operation unit 140 includes, for example, a plurality of operation buttons 141. Each operation button 141 is, for example, a hardware button. The plurality of operation buttons 141 include, for example, a power button and a start button for instructing the start of reading. The operation unit 140 may also include a touch sensor that detects user touch operations.

[0083] The housing 120 is provided with, for example, a display unit 130. The display unit 130 is composed of, for example, a liquid crystal display panel or an organic EL (electro-luminescence) display panel. The display unit 130 can display various types of information, such as characters, symbols, figures, and images. The display unit 130 may, for example, display a radiation image read from the imaging plate 2, i.e., a read radiation image. In addition to the form of a display panel, the display unit 130 may also include a display unit such as an indicator lamp.

[0084] For example, plate housing cases 160 and 170, capable of accommodating imaging plates 2, are placed on the top surface of the housing 120.

[0085] A cable 151 of the AC adapter 150 extends outward from the housing 120. Power is supplied to each component of the reader 100 from the AC adapter 150. The reader 100 may also be equipped with a battery to supply power to each component of the reader 100, in addition to the AC adapter 150. Alternatively, the reader 100 may be equipped with a battery instead of the AC adapter 150.

[0086] <An example of the internal mechanism of the enclosure> Figures 11 and 12 are schematic diagrams showing an example of the configuration inside the housing 120. Figure 12 shows an example of the structure shown in Figure 11 viewed from below. Figure 13 is a block diagram mainly showing an example of the configuration of the control unit 280 provided in the reading device 100.

[0087] As shown in Figures 11-13, the reading device 100 includes, for example, a mounting member 200 on which the imaging plate 2 is placed, a light source 210, a detector 220, a drive unit 230, an interface unit 240, a control unit 280, and a transport mechanism 250. These components are housed within the housing 120.

[0088] <About the Control Department> The control unit 280 can comprehensively manage the operation of the reading device 100 and can also be described as a control circuit. The control unit 280 can control, for example, the display unit 130, the mounting member 200, the light source 210, the detector 220, the drive unit 230, and the interface unit 240. In addition, the control unit 280 can perform processing in response to user operations received by the operation unit 140.

[0089] As shown in Figure 14, the control unit 280 includes, for example, at least one processor 280a and a storage unit (also called a storage circuit) 280b. The at least one processor 280a may include a CPU (Central Processing Unit) or a processor other than a CPU. In the control unit 280, the various functions described below are realized by the execution of a program 280c in the storage unit 280b by the at least one processor 280a. The control unit 280 can also be described as a computer device.

[0090] In the control unit 280, at least one processor 280a executes the program 280c in the storage unit 280b, thereby forming functional blocks such as an image processing unit 281, a display control unit 282, a drive control unit 283, a holding control unit 284, a detection control unit 285, and a light emission control unit 286.

[0091] The image processing unit 281 can perform image processing on the image indicated by the image signal output from the detector 220, as described later. The display control unit 82 can control the display of the display unit 130. The drive control unit 283 can control the drive unit 230. The holding control unit 284 can control the holding of the imaging plate 2 on the mounting member 200. The detection control unit 285 can control the detector 220. The light emission control unit 286 can control the light source 210.

[0092] Furthermore, some or all of the functions of the control unit 280 may be implemented by hardware circuits that do not require software (in other words, programs) to realize those functions. For example, some or all of the functions of the image processing unit 281 may be implemented by hardware circuits that do not require software to realize those functions. The same applies to the display control unit 282, drive control unit 283, hold control unit 284, detection control unit 285, and light emission control unit 286. In addition, at least one of the image processing unit 281, display control unit 282, drive control unit 283, hold control unit 284, detection control unit 285, and light emission control unit 286 may be configured as a circuit independent of the other components.

[0093] <About the Interface Section> The interface unit 240 is capable of communicating with devices outside the housing 120 (hereinafter also referred to as external devices), and can be, for example, an interface circuit, a communication circuit, or a communication unit. External devices may include personal computers, mobile phones such as smartphones, or other computer devices (for example, tablet terminals). External devices may also include data recording media (for example, flash memory) that can be attached to or detached from the reader 100. The interface unit 240 can receive signals from external devices and input the received signals to the control unit 280. The interface unit 240 can also transmit signals from the control unit 280 to the external devices. For example, the interface unit 240 can transmit an image signal representing an image processed by the image processing unit 281 of the control unit 280 to the external devices. The interface unit 240 may communicate with external devices via wired communication or wireless communication. Communication between the interface unit 240 and the housing may conform to Ethernet, USB (Universal Serial Bus), WiFi, or other standards.

[0094] <Regarding mounting components> The mounting member 200 is on which the imaging plate 2, inserted through the insertion opening 121 of the housing 120, is placed. The mounting member 200 can, for example, hold the mounted imaging plate 2. The mounting member 200 comprises, for example, a mounting plate 201 (which can also be called a stage) on which the imaging plate 2 is placed, and a fixing part 202 that fixes the position of the imaging plate 2 placed on the mounting plate 201.

[0095] The mounting plate 201 includes a main surface 201a (also called the mounting surface 201a) on which the imaging plate 2 is placed from its non-reading surface 22 side, and a back surface on the opposite side of the main surface 201a.

[0096] The fixing portion 202 has, for example, a plurality of fixing portions 202a that approach the peripheral portion of the imaging plate 2. The fixing portion 202 can also be called a fixing member. As shown in Figure 10, the plurality of fixing portions 202a approach the peripheral portion of the imaging plate 2 so as to surround it. This fixes the position (i.e., relative position) and orientation (i.e., relative orientation) of the imaging plate 2 with respect to the mounting plate 201.

[0097] Each fixing part 202a can move between an approaching position, where it is close to the imaging plate 2 supported on the mounting plate 201, and an anticipating position, where it is separated from the imaging plate 2 supported on the mounting plate 201, under the control of the holding control unit 284. The imaging plate 2 is inserted into the housing 120 through the insertion opening 121 and placed on the mounting plate 201 while each fixing part 202a is in the anticipating position. Subsequently, as each fixing part 202a moves from the anticipating position to the approaching position, the position and orientation of the imaging plate 2 are fixed by the fixing part 202. In other words, the imaging plate 2 is held.

[0098] <Regarding the drive unit and conveying mechanism> The transport mechanism 250 can transport the mounting member 200 along a predetermined direction DR10 by being driven by the drive unit 230. As a result, the imaging plate 2 placed on the mounting member 200 can also move along the predetermined direction DR10. It can also be said that the transport mechanism 250 can move the imaging plate 2 along the predetermined direction DR10 through the mounting member 200. The drive unit 230 is controlled by the drive control unit 283. The drive unit 230 is equipped with, for example, a motor. The transport mechanism 250 is driven by the motor provided in the drive unit 230. The rotation of the motor provided in the drive unit 230 is controlled by the drive control unit 283. The predetermined direction DR10 is, for example, the direction along the longitudinal direction of the imaging plate 2 placed on the mounting member 200. Therefore, the imaging plate 2 moves in the direction along the longitudinal direction of the imaging plate 2 as the mounting member 200 moves along the predetermined direction DR10. Hereafter, the predetermined direction DR10 may be referred to as the transport direction DR10 or the movement direction DR10.

[0099] <About the light source and detector> In this example, as shown in Figure 13, the optical measuring instrument 290, which reads a radiation image from the radiation image forming layer 20 of the imaging plate 2, is composed of a light source 210, a light emission control unit 286 that controls it, a detector 220, and a detection control unit 285 that controls it. The light source 210, detector 220, detection control unit 285, and light emission control unit 286 that constitute the optical measuring instrument 290 may be housed in a single case and unitized, or they may not be housed in a single case.

[0100] The light source 210 is capable of irradiating the imaging plate 2, held on the mounting member 200, with excitation light L1 to excite the radiation image forming layer 20. The light source 210 emits the excitation light L1 toward the mounting surface 201a of the mounting member 200. The light source 210 is capable of scanning the excitation light L1 in one direction (also called the main scanning direction DRm) on the imaging plate 2. The main scanning direction DRm is perpendicular to the movement direction DR10 of the mounting member 200. The main scanning direction DRm is along the shorter side of the imaging plate 2 mounted on the mounting member 200.

[0101] The excitation light L1 is, for example, visible light from a laser. The excitation light L1 may be, for example, red laser light or laser light of another color. When the excitation light L1 is irradiated onto the radiation image forming layer 20, the radiation image forming layer 20 emits light according to the energy distribution accumulated in the radiation image forming layer 20, and exhausted light L2 (see Figure 12) is emitted from the radiation image forming layer 20. The exhausted light L2 is, for example, blue visible light. The detector 220 detects the exhausted light L2 from the imaging plate 2 and outputs an electrical signal corresponding to the intensity of the detected exhausted light L2.

[0102] The light source 210 includes, for example, a laser generation unit that generates and outputs excitation light L1, and a laser scanning unit that scans the excitation light L1 on the imaging plate 2 in the main scanning direction DRm. The laser generation unit includes, for example, a semiconductor laser oscillator and is controlled by the light emission control unit 286. The laser generation unit may include a laser diode or other semiconductor laser. The laser scanning unit includes, for example, a MEMS (Micro Electro Mechanical Systems) mirror that reflects the excitation light L1 from the laser generation unit toward the radiation image forming layer 20 of the imaging plate 2. The MEMS mirror changes the reflection angle of the excitation light L1 so that the irradiation point of the excitation light L1 on the radiation image forming layer 20 moves in the main scanning direction DRm, under the control of the light emission control unit 286. The laser scanning unit may include other mirrors instead of the MEMS mirror, such as a galvanometer mirror.

[0103] The detector 220 includes an optical filter 222 into which the exhausted light L2 from the imaging plate 2 is incident, and a sensor 221 that detects the exhausted light L2 emitted from the optical filter 222. The sensor 221 is controlled by a detection control unit 285. The optical filter 222 is located between the sensor 221 and the main surface 201a of the mounting plate 201. The exhausted light L2 from the imaging plate 2 first enters the optical filter 222, and the filtered exhausted light L2 exits the optical filter 222 and enters the sensor 221.

[0104] The sensor 221 can detect the exhausted light L2 transmitted through the optical filter 222 and output an electrical signal corresponding to the intensity of the detected exhausted light L2. The sensor 221 may be composed of, for example, multiple photodiodes or a photomultiplier tube.

[0105] In the reading device 100, when a process (also called reading process) is performed to read a radiation image from the imaging plate 2, the mounting member 200 on which the imaging plate 2 is placed is transported to the reading start position by a transport mechanism 250 driven by a drive unit 230. Then, the optical measuring instrument 290 starts the reading process.

[0106] During the reading process, the light source 210, under the control of the light emission control unit 286, repeatedly performs a process (also called a main scanning direction scan) of scanning the imaging plate 2 in the main scanning direction DRm with excitation light L1. Meanwhile, during the reading process, the transport mechanism 250 moves the mounting member 200 on which the imaging plate 2 is placed in one direction DRs (also called sub-scanning direction DRs) along the transport direction DR10. The sub-scanning direction DRs is perpendicular to the main scanning direction DRm. While the mounting member 200 is moving in the sub-scanning direction DRs, the main scanning direction scan is repeatedly performed, causing the excitation light L1 to irradiate the radiation image forming layer 20 of the imaging plate 2 with a two-dimensional spread, and the radiation image forming layer 20 is raster scanned. As a result, during the reading process, the excitation light L1 is sequentially irradiated over the entire area of ​​the radiation image forming layer 20, and the entire area of ​​the radiation image forming layer 20 is scanned with the excitation light L1. While a raster scan is performed on the radiation image forming layer 20 using excitation light L1, the sensor 221 of the detector 220 detects the exhausted light L2 that arrives sequentially from the radiation image forming layer 20 in response to the raster scan, thereby reading a radiation image from the radiation image forming layer 20.

[0107] The sensor 221 outputs an image signal representing the read radiation image to the detection control unit 285 as a result of detecting the exhausted light L2 during the raster scan of the excitation light L1. This image signal includes the brightness values ​​(in other words, pixel values) of multiple pixels representing the read radiation image. The sensor 221 outputs, for example, a grayscale image signal.

[0108] The optical measuring instrument 290 reads the radiation image recorded on the imaging plate 2 along the longitudinal direction of the imaging plate 2. In other words, the optical measuring instrument 290 reads the radiation image recorded on the imaging plate 2 from one end of the imaging plate 2 in the longitudinal direction (in other words, one short side) toward the other end of the imaging plate 2 in the longitudinal direction (in other words, the other short side).

[0109] The outline of the radiation image read from the imaging plate 2 by the optical measuring instrument 290 will be the same as the outline of the imaging plate 2. The outline of the read radiation image will be, for example, a roughly rectangular shape with rounded corners. One end of the read radiation image in the longitudinal direction (in other words, one short side) will be the starting point for reading by the optical measuring instrument 290, and the other end of the read radiation image in the longitudinal direction (in other words, the other short side) will be the ending point for reading by the optical measuring instrument 290. Alternatively, one long side of the read radiation image may be the starting point for reading by the optical measuring instrument 290, and the other long side of the read radiation image may be the ending point for reading by the optical measuring instrument 290.

[0110] For the sake of explanation, from now on, we will describe the imaging plate 2 and the read radiographic image assuming that both have a rectangular shape.

[0111] The excitation light L1 can be scanned in two dimensions, and the main scanning direction DRm and the sub-scanning direction DRs do not need to be perpendicular to each other. For example, the main scanning direction DRm and the sub-scanning direction DRs may intersect at an angle other than perpendicular. Also, one or both of the main scanning direction DRm and the sub-scanning direction DRs may be set in a curved direction.

[0112] <About the image processing section> The image processing unit 281 of the control unit 280 acquires the image signal output from the sensor 221 through the detection control unit 85. The image processing unit 281 then performs predetermined image processing on the read radiation image shown by the acquired image signal, that is, the radiation image read by the optical measuring instrument 290. The radiation image can be said to be a type of image.

[0113] Here, the reading device 100 has two operating modes: a combined mode (also called a synthesis mode) that combines multiple read radiation images, and a normal mode that does not combine multiple read radiation images. The reading device 100 switches the operating mode according to an operation received by the operation unit 140, for example. When a user inserts an imaging plate 2 of a single unit assembly 7 used in IP single imaging into the reading device 100, they perform a predetermined operation on the operation unit 140 to set the operating mode of the reading device 100 to the normal mode. In the normal mode, the image processing unit 281 performs predetermined image processing on the read radiation image indicated by the image signal output from the sensor 221. Then, the display control unit 82 displays the read radiation image processed by the image processing unit 281 on the display unit 130.

[0114] On the other hand, when the user inserts multiple imaging plates 2 provided by the IP assembly 1 used for occlusal imaging into the reader 100, they perform a predetermined operation on the operation unit 140 to set the operating mode of the reader 100 to the coupling mode. When the operating mode of the reader 100 is set to the coupling mode, the user inserts the multiple imaging plates 2 provided by the IP assembly 1 into the insertion port 121 of the reader 100 in a continuous and sequential manner. Here, the layout of the multiple imaging plates 2 in the holding member 5 is called the IP layout. When the user inserts the multiple imaging plates 2 into the insertion port 121 in order, for example, they insert the imaging plates 2 into the insertion port 121 in order from the top imaging plate 2 of the IP layout (i.e., the imaging plate 2 that is fixed to the holding member 5 last) to the bottom imaging plate 2 of the IP layout (i.e., the imaging plate 2 that is fixed to the holding member 5 first). As shown in the example in Figure 7, when two imaging plates 2 are held by the retaining member 5A, the user first inserts the imaging plate 2 located at the number 2 on the fixed surface 51b (i.e., the top imaging plate 2 in the IP layout) into the insertion opening 121. Then, the user inserts the imaging plate 2 located at the number 1 on the fixed surface 51b (i.e., the bottom imaging plate 2 in the IP layout) into the insertion opening 121.

[0115] Hereafter, the number of imaging plates 2 provided in IP assembly 1 will be represented by N (where N is an integer greater than or equal to 2). Furthermore, among the N imaging plates 2 provided in IP assembly 1, the nth imaging plate 2 from the top of the IP layout (1 ≤ n ≤ N) is sometimes referred to as the nth imaging plate 2. In the example in Figure 7, the imaging plate 2 positioned at the number 2 on the fixed surface 51b is the 1st imaging plate 2, and the imaging plate 2 positioned at the number 1 on the fixed surface 51b is the 2nd imaging plate 2. The nth imaging plate 2 and the (n+1)th imaging plate 2 are adjacent to each other in the IP layout. That is, the nth imaging plate 2 and the (n+1)th imaging plate 2 are fixed to the fixed surface 51b so that they are adjacent to each other. It can also be said that n represents the order in which the N imaging plates 2 are inserted into the reader 100.

[0116] The user inserts N imaging plates 2 into the insertion port 12 from the same direction. Here, when the IP assembly 1 is placed in the oral cavity, the short side of the imaging plate 2 of the IP assembly 1 that is located on the posterior side of the oral cavity (in other words, the back side of the oral cavity or molar side) is called the posterior short side of the oral cavity. Also, when the IP assembly 1 is placed in the oral cavity, the short side of the imaging plate 2 of the IP assembly 1 that is located on the anterior side of the oral cavity (in other words, the front teeth side) is called the anterior short side of the oral cavity. Each imaging plate 2 of the IP assembly 1 is inserted into the insertion port 121 from, for example, the posterior short side of the oral cavity. However, each imaging plate 2 of the IP assembly 1 may also be inserted into the insertion port 121 from the anterior short side of the oral cavity.

[0117] The optical measuring instrument 290 of the reading device 100 reads a radiographic image from the imaging plate 2 each time the imaging plate 2 is inserted. When the imaging plate 2 is inserted into the reading device 100 from the posterior short side of the oral cavity, the optical measuring instrument 290 reads the radiographic image from the posterior short side of the imaging plate 2. In other words, the posterior short side of the imaging plate 2 is the starting side for reading the radiographic image. The image processing unit 281 performs alignment processing to align the N read radiographic images based on the alignment mark images contained in the N read radiographic images read sequentially by the optical measuring instrument 290. After that, the image processing unit 281 combines the N read radiographic images after alignment. This generates an overall image (i.e., an occlusal image) that shows the subject (in other words, the object being photographed), such as the dental arch. The image processing unit 281 performs predetermined image processing on the generated overall image. The display control unit 82 displays the overall image processed by the image processing unit 281 on the display unit 130.

[0118] The image processing unit 281 combines N read radiation images according to the IP layout of the N imaging plates 2. The image processing unit 281 combines two read radiation images read from two adjacent imaging plates 2 in the IP layout.

[0119] Here, two read radiation images from two adjacent imaging plates 2 in the IP layout are called a pair of combined radiation images. The read radiation image from the nth imaging plate 2 is called the nth radiation image. The nth radiation image is the nth radiation image read by the reading device 100 out of the N read radiation images.

[0120] For N readings of radiation images, there are (N-1) pairs of radiation images that can be combined. For example, when N=3, there are two pairs of radiation images that can be combined: one consisting of the first and second radiation images, and another consisting of the second and third radiation images. Similarly, when N=4, there are three pairs of radiation images that can be combined: one consisting of the first and second radiation images, one consisting of the second and third radiation images, and another consisting of the third and fourth radiation images.

[0121] The image processing unit 281 combines the two read radiation images that make up one pair of (N-1) radiation image pairs to be combined. As a result, N read radiation images are combined to generate an overall image.

[0122] For example, consider the case where N=3. In this case, the image processing unit 281 combines the first radiation image (in other words, the first radiation image read) and the second radiation image (in other words, the second radiation image read), and then combines the second radiation image and the third radiation image (in other words, the third radiation image read) to combine the three radiation images. In the case of N=3, it can also be said that the image processing unit 281 combines the first and third radiation images with the second radiation image to generate the overall image.

[0123] As another example, consider the case where N=4. In this case, the image processing unit 281 combines the first radiation image with the second radiation image, combines the second radiation image with the third radiation image, and combines the third radiation image with the fourth radiation image to combine the four radiation images.

[0124] Figure 15 is a schematic diagram illustrating an example of a method for combining N readings of radiation images. The following explanation uses Figure 15 to illustrate an example of a method for combining N readings of radiation images.

[0125] The first imaging plate 2 has an overlapping portion (also called the second IP overlapping portion) that overlaps with the second imaging plate 2 in the IP layout. One end 25 in the shorter direction of the first imaging plate 2 that overlaps with the second imaging plate 2 (see Figure 7) becomes the second IP overlapping portion.

[0126] The nth imaging plate 2 has an overlapping portion (also called the (N-1)th IP overlapping portion) that overlaps with the (N-1)th imaging plate 2 in the IP layout. When 2 ≤ n ≤ N-1, the nth imaging plate 2 has an overlapping portion (also called the (n-1)th IP overlapping portion) that overlaps with the (n+1)th imaging plate 2 in the IP layout, and an overlapping portion (also called the (n+1)th IP overlapping portion) that overlaps with the (n+1)th imaging plate 2 in the IP layout.

[0127] As shown in the upper part of Figure 15, the first radiographic image 310 has a second IP overlap corresponding image 311 that corresponds to the second IP overlap portion of the first imaging plate 2. The second IP overlap corresponding image 311 is an image read from the second IP overlap portion of the first imaging plate 2. One end of the first radiographic image 310 in the short direction (in other words, one end of the long side) constitutes the second IP overlap corresponding image 311.

[0128] The Nth radiographic image has an image corresponding to the (N-1)th IP overlap portion of the Nth imaging plate 2. The (N-1)th IP overlap portion is an image read from the (N-1)th IP overlap portion of the Nth imaging plate 2. One end of the Nth radiographic image in the short direction constitutes the image corresponding to the (N-1)th IP overlap portion.

[0129] For 2 ≤ n ≤ N-1, the nth radiation image has corresponding images for the (n-1)th IP overlap portion and the (n+1)th IP overlap portion of the nth imaging plate 2, respectively. The (n-1)th IP overlap portion corresponding image is the image read from the (n-1)th IP overlap portion of the nth imaging plate 2. The (n+1)th IP overlap portion corresponding image is the image read from the (n+1)th IP overlap portion of the nth imaging plate 2. One end of the nth radiation image in the short direction constitutes the (n-1)th IP overlap portion corresponding image, and the other end of the nth radiation image in the short direction constitutes the (n+1)th IP overlap portion corresponding image. For example, the second radiation image 320 has the first IP overlapping portion corresponding image 321 and the third IP overlapping portion corresponding image 322, as shown in the upper part of Figure 15. Similarly, the third radiation image 330 has the second IP overlapping portion corresponding image 331 and the fourth IP overlapping portion corresponding image 332.

[0130] The (n-1)th IP overlapping portion corresponding image of the nth radiation image and the (n-1)th radiation image both show the same part of the subject. Therefore, the (n-1)th IP overlapping portion corresponding image of the nth radiation image and the (n-1)th radiation image can be said to be the overlapping portion (in other words, the overlapping image) that overlaps between the nth radiation image and the (n-1)th radiation image. For example, the 1st IP overlapping portion corresponding image 321 of the 2nd radiation image 320 and the 2nd IP overlapping portion corresponding image 311 of the 1st radiation image 310 can be said to be the overlapping portion between the 2nd radiation image 320 and the 1st radiation image 310.

[0131] Furthermore, the (n+1)th IP overlapping portion corresponding to the nth radiation image and the nth IP overlapping portion corresponding to the (n+1)th radiation image both depict the same portion of the subject. Therefore, the (n+1)th IP overlapping portion corresponding to the nth radiation image and the nth IP overlapping portion corresponding to the (n+1)th radiation image can be said to be the overlapping portion between the nth radiation image and the (n+1)th radiation image. For example, the third IP overlapping portion corresponding to the second radiation image 320 322 and the second IP overlapping portion corresponding to the third radiation image 330 331 can be said to be the overlapping portion between the second radiation image 320 and the third radiation image 330.

[0132] The image processing unit 281 aligns N radiation images by aligning each of the (N-1) pairs of radiation images to be combined so that the two radiation images constituting one pair of radiation images to be combined partially overlap. Then, the image processing unit 281 combines the N radiation images after alignment to generate an overall image that shows the subject, such as the dental arch.

[0133] When the image processing unit 281 aligns the nth radiation image and the (n+1)th radiation image that constitute a pair of radiation images to be combined, it aligns the nth radiation image and the (n+1)th radiation image so that the (n+1)th IP overlap portion corresponding image of the nth radiation image and the nth IP overlap portion corresponding image of the (n+1)th radiation image overlap each other. At this time, the image processing unit 281 basically aligns the nth radiation image and the (n+1)th radiation image so that they overlap only with the (n+1)th IP overlap portion corresponding image and the nth IP overlap portion corresponding image. Furthermore, the image processing unit 281 aligns the nth radiation image and the (n+1)th radiation image on the nth imaging plate 2 and the (n+1)th imaging plate 2 such that the image corresponding to the (n+1)th IP overlap portion of the nth radiation image read from the upper nth imaging plate 2 is positioned above the image corresponding to the nth IP overlap portion of the (n+1)th radiation image read from the lower (n+1)th imaging plate 2. Alternatively, the nth radiation image and the (n+1)th radiation image may be aligned such that the image corresponding to the (n+1)th IP overlap portion of the nth radiation image is positioned below the image corresponding to the nth IP overlap portion of the (n+1)th radiation image.

[0134] For example, consider the case where the first radiation image 310 and the second radiation image 320, which constitute a pair of radiation images to be combined, are aligned. In this case, as shown in the middle of Figure 15, the image processing unit 281 aligns the first radiation image 310 and the second radiation image 320 so that the image 311 corresponding to the second IP overlap portion of the first radiation image 310 (in other words, the overlapping portion) and the image 321 corresponding to the first IP overlap portion of the second radiation image 320 (in other words, the overlapping portion) overlap each other. At this time, the image processing unit 281 basically aligns the first radiation image 310 and the second radiation image 320 so that they overlap only with the image 311 corresponding to the second IP overlap portion and the image 321 corresponding to the first IP overlap portion. Furthermore, the image processing unit 281 aligns the first radiation image 310 and the second radiation image 320, for example, so that the second IP overlap portion corresponding image 311 of the first radiation image 310 read from the upper first imaging plate 2 is positioned above the first IP overlap portion corresponding image 321 of the second radiation image 320 read from the lower second imaging plate 2.

[0135] As another example, consider the case where the second radiation image 320 and the third radiation image 330, which constitute a pair of radiation images to be combined, are aligned. In this case, as shown in the middle of Figure 15, the image processing unit 281 aligns the second radiation image 320 and the third radiation image 330 so that the third IP overlap portion corresponding image 322 of the second radiation image 320 and the second IP overlap portion corresponding image 331 of the third radiation image 330 overlap with each other. At this time, the image processing unit 281 basically aligns the second radiation image 320 and the third radiation image 330 so that they overlap only with the third IP overlap portion corresponding image 322 and the second IP overlap portion corresponding image 331. Furthermore, the image processing unit 281 aligns the second radiation image 320 and the third radiation image 330, for example, so that the third IP overlap portion corresponding image 322 of the second radiation image 320 read from the upper second imaging plate 2 is positioned above the second IP overlap portion corresponding image 331 of the third radiation image 330 read from the lower third imaging plate 2.

[0136] As described above, the image processing unit 281 aligns N radiation images by aligning the two read radiation images that constitute one pair of radiation images to be combined, so that they partially overlap. The N read radiation images are aligned in numerical order along the short side of the radiation images, and the long sides of two adjacent radiation images overlap. When the image processing unit 281 aligns the two read radiation images that constitute one pair of radiation images to be combined, it aligns the two read radiation images based on at least one alignment mark image contained in each of the two read radiation images. A specific example of alignment using an alignment mark image will be described in detail later.

[0137] Once the alignment of the N read radiation images is complete (see the middle section of Figure 15), the image processing unit 281 combines the aligned N read radiation images to generate the overall image 400 shown at the bottom of Figure 15. Specifically, after aligning the N read radiation images, the image processing unit 281 combines the N read radiation images by combining the two read radiation images that make up one pair of (N-1) pairs of radiation images to be combined.

[0138] When the image processing unit 281 combines the nth radiation image and the (n+1)th radiation image that constitute a pair of radiation images to be combined, for example, it removes the lower of the two overlapping IP overlapping portion corresponding images of the nth radiation image and the (n+1)th radiation image from the (n+1)th radiation image. Then, the image processing unit 281 connects the (n+1)th radiation image from which the nth IP overlapping portion corresponding image has been removed to the nth radiation image. In other words, it connects the edge of the (n+1)th radiation image on the nth radiation image side to the edge of the nth radiation image on the (n+1)th radiation image side. This combines the nth radiation image and the (n+1)th radiation image. The combined image obtained by combining the nth radiation image and the (n+1)th radiation image includes the image corresponding to the (n+1)th IP overlap portion of the nth radiation image, but does not include the image corresponding to the nth IP overlap portion of the (n+1)th radiation image.

[0139] For example, consider the case where the first radiation image 310 and the second radiation image 320, which constitute a pair of radiation images to be combined, are combined. In this case, the image processing unit 281, for example, deletes the lower of the two overlapping images, the first IP overlapping portion corresponding image 321 of the second radiation image 320 and the second IP overlapping portion corresponding image 311 of the first radiation image 310 and the first IP overlapping portion corresponding image 321 of the second radiation image 320, from the second radiation image 320. Then, the image processing unit 281 connects the first radiation image 310 and the second radiation image 320 from which the first IP overlapping portion corresponding image 321 has been deleted. As a result, the first radiation image 310 and the second radiation image 320 are combined. As shown in the lower part of Figure 15, the combined image 401 obtained by combining the first radiation image 310 and the second radiation image 320 includes the image 311 corresponding to the second IP overlap portion of the first radiation image 310, but does not include the image 321 corresponding to the first IP overlap portion of the second radiation image 320.

[0140] Furthermore, consider the case where the second radiation image 320 and the third radiation image 330, which constitute a pair of radiation images to be combined, are combined. In this case, the image processing unit 281 deletes the lower of the two images corresponding to the overlapping portion of the second IP of the second radiation image 330 from the third radiation image 330. Then, the image processing unit 281 connects the third radiation image 330, from which the second IP overlapping portion corresponding image 331 has been deleted, to the second radiation image 320. As a result, the second radiation image 320 and the third radiation image 330 are combined. As shown in the lower part of Figure 15, the combined image 402 obtained by combining the second radiation image 320 and the third radiation image 330 includes the image 322 corresponding to the third IP overlap portion of the second radiation image 320, but does not include the image 331 corresponding to the second IP overlap portion of the third radiation image 330.

[0141] As described above, the image processing unit 281 combines the two read radiographic images that make up one pair of radiographic images to be combined for each of the (N-1) pairs of radiographic images to be combined, to generate an overall image 400 showing the captured dental arch (maxillary or mandibular dental arch). In the case of N=2, the image processing unit 281 combines the first radiographic image 310 and the second radiographic image 320, and the resulting combined image 401 is designated as the overall image 400.

[0142] Furthermore, when the image processing unit 281 combines the nth radiation image and the (n+1)th radiation image that constitute a pair of radiation images to be combined, it may delete the upper (n+1)th IP overlap portion corresponding image of the (n+1)th IP overlap portion corresponding image of the (n+1)th radiation image from the nth radiation image, which overlaps with the other image. In this case, the image processing unit 281 connects the nth radiation image from which the (n+1)th IP overlap portion corresponding image has been deleted to the (n+1)th radiation image, thereby combining the nth radiation image and the (n+1)th radiation image. The combined image obtained by combining the nth radiation image and the (n+1)th radiation image does not include the (n+1)th IP overlap portion corresponding image of the nth radiation image, but does include the nth IP overlap portion corresponding image of the (n+1)th radiation image.

[0143] In the reading device 100, the imaging plate 2 from which the radiation image has been read may be discharged to the outlet 122 of the housing 120 after the radiation image has been erased from the imaging plate 2. In this case, the reading device 100 may be equipped with an erasing light source that irradiates the imaging plate 2 with erasing light to erase the radiation image from the imaging plate 2. The erasing light may be white light, red visible light, or visible light of another color. The erasing light source may be an LED (Light Emission Diode), a halogen lamp, or another light source.

[0144] When the radiographic image is to be erased from the imaging plate 2, once the reading process is complete, the transport mechanism 250 moves the mounting member 200 to the erase position, driven by the drive unit 230. Next, the erasing light source, under the control of the control unit 280, irradiates the entire area of ​​the radiographic image forming layer 20 of the imaging plate 2 with erasing light. This erases the radiographic image from the imaging plate 2. After that, the imaging plate 2 with the radiographic image erased is discharged to the outlet 122.

[0145] In the example above, the reader 100 switched its operating mode in response to an operation received by the operation unit 140, but the method of switching the operating mode of the reader 100 is not limited to this. For example, an external device connected to the reader 100 (e.g., a personal computer or tablet terminal) may receive an instruction from the user to switch the operating mode of the reader 100 and notify the reader 100 of the instruction to switch the operating mode. Alternatively, the initial setting of the operating mode of the reader 100 may be the normal mode, and it may be possible to switch between the normal mode and the composite mode as needed in response to a switching instruction from the user.

[0146] Furthermore, the reading device 100 may combine multiple read radiation images read from multiple imaging plates in normal mode, according to instructions from the user. For example, the reading device 100 displays multiple read radiation images read from multiple imaging plates in normal mode on an external device. The user performs a predetermined operation on the external device to select multiple read radiation images to be combined from among the multiple read radiation images displayed on the external device. The external device notifies the reading device 100 of the selected multiple read radiation images to be combined. The reading device 100 then combines the multiple read radiation images to be combined that were notified by the external device.

[0147] Furthermore, the reading device 100 may, in normal mode, display multiple read radiation images read from multiple imaging plates on the display unit 130, and the user may perform a predetermined operation on the operation unit 140 to select multiple read radiation images to be combined from among the multiple read radiation images displayed on the display unit 130. The reading device 100 may then combine the selected multiple read radiation images to be combined.

[0148] With the above configuration, even if there is an error in the setting of the operating mode, for example, multiple occlusal-acquired radiographic images can be selected from a group of radiographic images read in normal mode and later combined as the radiographic images to be combined, which is advantageous.

[0149] <About alignment marks> As described above, the alignment mark 10 is made of a radiation shielding material. The radiation shielding material constituting the alignment mark 10 may be, for example, a radiation-absorbing material. The material of the alignment mark 10 may be, for example, copper, tungsten, titanium, or iron. The mark 10 does not completely shield from radiation, but transmits some radiation. However, the mark 10 may also completely shield from radiation.

[0150] The method for forming the alignment marks 10 on the retaining member 5 can be any method. For example, the alignment marks 10 may be printed on the retaining member 5. Alternatively, the alignment marks 10 may be made of a sealing material and attached to the retaining member 5, or they may be formed by metal foil stamping. Furthermore, the alignment marks 10 may be detachable from the retaining member 5.

[0151] The image processing unit 281 can easily and appropriately align multiple read radiation images based on mark images corresponding to alignment marks 10 included in the multiple read radiation images. Several examples of alignment marks 10 and alignment processing using them are described below. Below, several examples are described mainly for the case where N=2, that is, when the holding member 5A holds two imaging plates 2, as shown in the example in Figure 7. Also, below, unless otherwise specified, the holding member 5A refers to the holding member 5A in a closed state, as shown in Figures 2 and 8. Furthermore, the vertical direction of the holding member 5A refers to the direction along the vertical direction (left-right direction in Figure 2) of the fixed surface 51b of the holding member 5A in a closed state, and the horizontal direction of the holding member 5A refers to the direction along the horizontal direction (up-down direction in Figure 2) of the fixed surface 51b of the holding member 5A in a closed state. In the holding member 5A, the multiple imaging plates 2 are arranged so that their longitudinal directions are aligned with the vertical direction of the holding member 5A. The vertical direction of the retaining member 5A can also be described as the direction that aligns with the anterior-posterior direction of the oral cavity when the retaining member 5A is placed inside the oral cavity.

[0152] <Example 1 (Use of marks for non-overlapping areas)> In this example, the image processing unit 281 aligns the nth radiation image and the (n+1)th radiation image based on a mark image corresponding to a non-overlapping mark 10 (also called the nth IP non-overlapping mark 10) for recording a mark image in the portion of the nth imaging plate 2 that does not overlap with the (n+1)th imaging plate 2, and a mark image corresponding to a non-overlapping mark 10 (also called the (n+1)th IP non-overlapping mark 10) for recording a mark image in the portion of the (n+1)th imaging plate 2 that does not overlap with the nth imaging plate 2. For example, the image processing unit 281 aligns the nth radiation image and the (n+1)th radiation image based on the position of the mark image corresponding to the nth IP non-overlapping mark 10 and the position of the mark image corresponding to the (n+1)th IP non-overlapping mark 10.

[0153] Figure 16 is a schematic diagram showing an example of a holding member 5A and the first imaging plate 2 and second imaging plate 2 held therein. In the example in Figure 16, the combined imaging plate 420 consists of the first imaging plate 2 and the second imaging plate 2. Hereafter, the first imaging plate 2 may be referred to as the first imaging plate 2a or imaging plate 2a, and the second imaging plate 2 may be referred to as the second imaging plate 2b or imaging plate 2b. In Figure 16, imaging plate 2a is shown by a dashed line, and imaging plate 2b is shown by a dashed line.

[0154] One end 25 in the shorter direction of imaging plate 2a that overlaps with imaging plate 2b becomes the second IP overlap portion. Similarly, one end 25 in the shorter direction of imaging plate 2b that overlaps with imaging plate 2a becomes the first IP overlap portion. Hereafter, the second IP overlap portion may be referred to as overlap portion 25a, and the first IP overlap portion may be referred to as overlap portion 25b.

[0155] In the following, for the sake of explanation, the first and second sides of the retaining member 5A refer to the left and right sides of the retaining member 5A, respectively, when viewed from the cover portion 52 side with the knob portion 52a facing downwards (in other words, with the connection point between the cover portion 52 and the fixed portion 51 facing upwards), as shown in Figure 16. The knob portion 52a side of the retaining member 5A may also be referred to as the fourth side of the retaining member 5A. The side opposite to the fourth side of the retaining member 5A (i.e., the side with the connection point between the cover portion 52 and the fixed portion 51) may also be referred to as the third side of the retaining member 5A.

[0156] The retaining member 5A is positioned in the oral cavity such that its third side is located on the posterior side of the oral cavity (in other words, the molar side) and its fourth side is located on the anterior side of the oral cavity (in other words, the front teeth side). When the maxillary dental arch is photographed, the retaining member 5A is positioned in the oral cavity such that the cover portion 52 is located on the upper side of the oral cavity and the fixed portion 51 is located on the lower side of the oral cavity. As a result, the first side of the retaining member 5A in the oral cavity is located on the right buccal side and the second side of the retaining member 5A in the oral cavity is located on the left buccal side. On the other hand, when the mandibular dental arch is photographed, the retaining member 5A is positioned in the oral cavity such that the cover portion 52 is located on the lower side of the oral cavity and the fixed portion 51 is located on the upper side of the oral cavity. As a result, the first side of the retaining member 5A in the oral cavity is located on the left buccal side and the second side of the retaining member 5A in the oral cavity is located on the right buccal side.

[0157] Furthermore, for the sake of explanation, in the following, the first side and second side of the imaging plate 2 refer to the left and right sides of the imaging plate 2 when the holding member 5A is viewed from the cover portion 52 side with the knob portion 52a of the holding member 5A facing downwards (in other words, with the connection point between the cover portion 52 and the fixed portion 51 facing upwards), as shown in Figure 16. In this example, one long side of the imaging plate 2 is the first side, and the other long side of the imaging plate 2 is the second side.

[0158] Furthermore, for the sake of explanation, the third side of the imaging plate 2 refers to the side where the cover portion 52 and the fixed portion 51 are connected when the imaging plate 2 is held by the holding member 5A. Also, for the sake of explanation, the fourth side of the imaging plate 2 refers to the side with the knob portion 52a when the imaging plate 2 is held by the holding member 5A. In this example, one short side of the imaging plate 2 is the third side, and the other short side of the imaging plate 2 is the fourth side.

[0159] Imaging plate 2 is positioned in the oral cavity such that its third side faces the back of the oral cavity (in other words, the molar side) and its fourth side faces the front of the oral cavity (in other words, the front teeth side). When the maxillary dental arch is being imaged, imaging plate 2 is positioned in the oral cavity such that its first side faces the right buccal side and its second side faces the left buccal side. On the other hand, when the mandibular dental arch is being imaged, imaging plate 2 is positioned in the oral cavity such that its first side faces the left buccal side and its second side faces the right buccal side.

[0160] As described above, in this example, the reading device 100 reads the radiographic image from the posterior short side of the imaging plate 2 inside the oral cavity. Therefore, the third side of the imaging plate 2 becomes the starting side for reading the radiographic image.

[0161] As shown in Figure 16, the imaging plate 2a has an overlapping portion 25a that overlaps with the imaging plate 2b and a non-overlapping portion 26a that does not overlap with the imaging plate 2b. Similarly, the imaging plate 2b has an overlapping portion 25b that overlaps with the imaging plate 2a and a non-overlapping portion 26b that does not overlap with the imaging plate 2a.

[0162] The retaining member 5A includes, for example, a plurality of marks 10. The plurality of marks 10 include, for example, circular marks 10a, 10b, 10c, and 10d. Marks 10a and 10b are marks 10 for recording mark images on the non-overlapping portion 26a of the imaging plate 2a. Marks 10c and 10d are marks 10 for recording mark images on the non-overlapping portion 26b of the imaging plate 2b.

[0163] Marks 10a and 10b, used to record mark images on the non-overlapping portion 26a of imaging plate 2a, can also be called non-overlapping portion marks 10. Similarly, marks 10c and 10d, used to record mark images on the non-overlapping portion 26b of imaging plate 2b, can also be called non-overlapping portion marks 10. Marks 10a and 10b are the first IP non-overlapping portion marks 10, and marks 10c and 10d are the second IP non-overlapping portion marks 10.

[0164] Marks 10a and 10b are provided on the holding member 5A in the portion of the imaging plate 2a facing the radiation image forming layer 20. For example, marks 10a and 10b are provided on the inner surface of the cover portion 52 of the holding member 5A in the portion of the imaging plate 2a facing the radiation image forming layer 20.

[0165] Marks 10a and 10b are provided on the holding member 5A in the portion facing the end (in other words, edge, peripheral edge or periphery) 425 of the combined imaging plate 420, which consists of imaging plates 2a and 2b held by the holding member 5A. The end 425 of the combined imaging plate 420 can be said to be the end of one large imaging plate consisting of imaging plates 2a and 2b held by the holding member 5A. For example, marks 10a and 10b are provided on the inner surface of the cover portion 52 in the portion facing the end 425 of the combined imaging plate 420.

[0166] The imaging plate 2a has four corners 28a. The four corners 28a are included in the end portion 425 of the combined imaging plate 420. Of the four corners 28a, the two corners 28a on the first side are included in the non-overlapping portion 26a, and the two corners 28a on the second side are included in the overlapping portion 25a.

[0167] The cover portion 52 has four first opposing portions that are opposite to each of the four corner portions 28a of the imaging plate 2a. Mark 10a is provided, for example, on the inner surface of the third first opposing portion of the two first opposing portions on the first side of the cover portion 52. Mark 10b is provided, for example, on the inner surface of the fourth first opposing portion of the two first opposing portions on the first side of the cover portion 52.

[0168] Marks 10c and 10d are provided on the holding member 5A in the portion facing the radiation image-forming layer 20 of the imaging plate 2b. For example, marks 10c and 10d are provided on the inner surface of the cover portion 52 of the holding member 5A in the portion facing the radiation image-forming layer 20 of the imaging plate 2b.

[0169] Marks 10c and 10d are provided on the holding member 5A in the portion facing the end 425 of the combined imaging plate 420. For example, marks 10c and 10d are provided on the inner surface of the cover portion 52 in the portion facing the end 425 of the combined imaging plate 420.

[0170] The imaging plate 2b has four corners 28b. The four corners 28b are included in the end portion 425 of the combined imaging plate 420. Of the four corners 28b, the two corners 28b on the first side are included in the non-overlapping portion 26b, and the two corners 28a on the second side are included in the overlapping portion 25b.

[0171] The cover portion 52 has four second opposing portions that are opposite to each of the four corner portions 28b of the imaging plate 2b. Mark 10c is provided, for example, on the inner surface of the second opposing portion on the third side of the two second opposing portions of the cover portion 52. Mark 10d is provided, for example, on the inner surface of the second opposing portion on the fourth side of the two second opposing portions of the cover portion 52.

[0172] Figure 17 schematically shows an example of a radiographic image recorded on the combination imaging plate 420 shown in Figure 16. For ease of explanation, in Figure 17, an example of a radiographic image recorded on the combination imaging plate 420 is shown with a solid line. Figure 17 schematically shows a radiographic image when the subject includes a dental arch. Also, in Figure 17, the illustration of tissues other than teeth that appear in the actual radiographic image (e.g., soft tissues such as gums and hard tissues such as jawbones) is omitted. The same applies to the schematic example of a radiographic image recorded on the combination imaging plate 420 which will be described later.

[0173] The radiographic image recorded on the combined imaging plate 420 (in other words, one large imaging plate) includes four mark images 350, each corresponding to one of the four marks 10 on the holding member 5A. The mark images 350 are images representing the marks 10, or can be said to be images of the marks 10. The shape of the mark image 350 is the same as the shape of the mark 10 corresponding to the mark image 350. In addition, the radiographic image recorded on the combined imaging plate 420 includes a dental arch image 360 ​​representing the dental arch. The dental arch image 360 ​​can be said to be an image of the dental arch as the subject. The dental arch image 360 ​​can also be said to be the subject image or the image being photographed. The mark images 350 have a shape that can be distinguished from the subject image.

[0174] The four mark images 350 include mark images 350a, 350b, 350c, and 350d, which correspond to marks 10a, 10c, 10c, and 10d, respectively. Mark images 350a and 350b are recorded on the non-overlapping portion 26a of imaging plate 2a. Mark images 350c and 350d are recorded on the non-overlapping portion 26b of imaging plate 2b.

[0175] Mark images 350a, 350b, 350c, and 350d are recorded on the end 425 of the combined imaging plate 420. Marks 10a, 10b, 10c, and 10d, which correspond to mark images 350a, 350b, 350c, and 350d, can also be called end marks 10 for recording mark images on the end 425 of the combined imaging plate 420.

[0176] Mark image 350a is recorded on the third corner 28a of the two corners 28a on the first side of the imaging plate 2a, which is included in the end portion 425 of the combined imaging plate 420. Mark image 350b is recorded on the fourth corner 28a of the two corners 28a on the first side of the imaging plate 2a. Marks 10a and 10b, which correspond to mark images 350a and 350b, can also be called corner marks 10 for recording mark images on the corners 28a of the imaging plate 2a.

[0177] Mark image 350c is recorded on the third corner 28b of the second corner 28b of the imaging plate 2b, which is included in the end portion 425 of the combined imaging plate 420. Mark image 350d is recorded on the fourth corner 28b of the second corner 28b of the imaging plate 2b. Marks 10c and 10d, which correspond to mark images 350c and 350d, can also be called corner marks 10 for recording mark images on the corners 28b of the imaging plate 2b.

[0178] In this example, the multiple marks 10 on the holding member 5A are configured such that all of the multiple mark images 350 corresponding to each of the multiple marks 10 are recorded on the end 425 of the combined imaging plate 420. In the example in Figure 17, all of the mark images 350a, 350b, 350c, and 350d included in the radiographic image recorded on the combined imaging plate 420 are recorded on the end 425 of the combined imaging plate 420.

[0179] As can be understood from the above explanation, mark 10 is provided in the holding member 5 in a portion of the radiation image forming layer 20 of the imaging plate 2 that is opposite to the portion where a mark image corresponding to mark 10 is recorded.

[0180] As in this example, when the multiple mark images 350 recorded on the combination imaging plate 420 include a mark image 350 recorded on the end 425 of the combination imaging plate 420, the mark images 350 are less likely to overlap with the dental arch image 360 ​​recorded on the combination imaging plate 420. In other words, the mark images 350 are less likely to overlap with the subject image recorded on the combination imaging plate 420. Therefore, it becomes easier to obtain an appropriate subject image.

[0181] Furthermore, as in this example, when the multiple mark images 350 recorded on the combined imaging plate 420 include a mark image 350 recorded on the corner of the imaging plate 2, the mark images 350 are less likely to overlap with the subject image recorded on the combined imaging plate 420, making it easier to obtain a suitable subject image.

[0182] Furthermore, as in this example, when all of the multiple mark images 350 corresponding to the multiple marks 10 on the holding member 5A are recorded on the end 425 of the combined imaging plate 420, the mark images 350 are less likely to overlap with the subject image recorded on the combined imaging plate 420, making it easier to obtain an appropriate subject image (in other words, the image to be captured). Thus, it is preferable that the mark images 350 be positioned so as not to overlap with the observation target area in the subject image. In other words, it is preferable that the mark images 350 be positioned so as not to interfere with image interpretation.

[0183] Figure 18 is a schematic diagram showing an example of the first radiation image 310 and the second radiation image 320 read from imaging plates 2a and 2b shown in Figure 17. Hereafter, the image 311 corresponding to the overlapping portion of the second IP contained in the first radiation image 310 may be referred to as the overlapping portion 311. Similarly, the image 321 corresponding to the overlapping portion of the first IP contained in the second radiation image 320 may be referred to as the overlapping portion 321.

[0184] In Figure 18, the first radiation image 310 is shown such that the reading start side of the reading device 100 for the first radiation image 310 is at the top of the figure. The same applies to the second radiation image 320.

[0185] As described above, the reading device 100 reads the radiographic image from the third side of the imaging plate 2. Therefore, in the first radiographic image 310, the side where the image read from the third end of the first imaging plate 2a (the image of the molars in the example of Figure 17) is located becomes the starting side of reading for the first radiographic image 310 by the reading device 100. On the other hand, in the first radiographic image 310, the side where the image read from the fourth end of the first imaging plate 2a (the image of the anterior teeth in the example of Figure 17) is located becomes the ending side of reading for the first radiographic image 310 by the reading device 100. The same applies to the second radiographic image 320.

[0186] In the example in Figure 18, the first radiographic image 310 includes mark images 350a and 350b, and a dental image 360a, which is part of the dental arch image 360 ​​shown in Figure 17. The dental image 360a represents the dentition recorded on imaging plate 2a. The second radiographic image 320 includes mark images 350c and 350d, and a dental image 360b, which is part of the dental arch image 360. The dental image 360b represents the dentition recorded on imaging plate 2b. The overlapping portion 311 in the first radiographic image 310 and the overlapping portion 321 in the second radiographic image 320 show the same portion of the subject's dental arch.

[0187] The image processing unit 281 aligns the first radiation image 310 and the second radiation image 320 based on the mark images 350a, 350b, 350c, and 350d so that the overlapping portions 311 and 321 overlap each other. An example of the method for aligning the first radiation image 310 and the second radiation image 320 is described below.

[0188] The memory unit 280b of the control unit 280 has a first layout diagram 460 pre-stored in it, which shows the relative positions of multiple marks 10 on the holding member 5. The image processing unit 281 aligns the first radiation image 310 and the second radiation image 320 based on the first layout diagram 460 in the memory unit 280b and the mark images 350a, 350b, 350c, and 350d.

[0189] Figure 19 is a schematic diagram showing an example of the first layout diagram 460. The relative positions of the multiple marks 10 on the holding member 5 remain constant regardless of the relative positions of the multiple imaging plates 2 held by the holding member 5. Therefore, even if the degree of overlap of the multiple imaging plates 2 on the holding member 5 changes, the relative positions of the multiple marks 10 on the holding member 5 do not change.

[0190] The first layout diagram 460 shows the relative positions 450 of the multiple marks 10 when the holding member 5A is viewed from the side irradiated with radiation, along a direction perpendicular to the reading surface 21 of the imaging plate 2. The first layout diagram 460 can also be said to show the relative positions 450 of the multiple marks 10 when the holding member 5A is viewed from the side of the outer surface of the cover portion 52, along a direction perpendicular to the reading surface 21 of the imaging plate 2. The first layout diagram 460 can also be said to be layout information.

[0191] The first layout diagram 460 shows the positions 450a of mark 10a, 450b of mark 10b, 450c of mark 10c, and 450d of mark 10d. The position 450 of mark 10 shown in the first layout diagram 460 may be, for example, the position of the centroid of mark 10. The shape of the first layout diagram 460 matches, for example, the shape of the holding member 5A when viewed from the side to which radiation is irradiated, along a direction perpendicular to the reading target surface 21 of the imaging plate 2. However, the shape of the first layout diagram 460 is not limited to this. The shape of the first layout diagram 460 does not have to match the shape of the holding member 5A. The first layout diagram 460 only needs to be large enough to encompass the area of ​​the subject that is to be diagnosed (in other words, observed).

[0192] When the IP assembly 1 is viewed from the side irradiated with radiation along a direction perpendicular to the reading surface 21 of the imaging plate 2, the positions of the multiple marks 10 coincide with the recording positions of the multiple mark images 350 on the combined imaging plate 420 held by the holding member 5 (in other words, on a single large imaging plate). Therefore, the first layout figure 460 can also be said to show the relative recording positions of the multiple mark images 350 on the combined imaging plate 420, which is held by the holding member 5, when viewed from the side irradiated with radiation along a direction perpendicular to the reading surface 21 of the imaging plate 2. Furthermore, the first layout figure 460 can also be said to show the relative positional relationship of the multiple marks 10, and the relative positional relationship of the recording positions of the multiple mark images 350 on the combined imaging plate 420 held by the holding member 5A.

[0193] Figures 20 and 21 are schematic diagrams illustrating an example of a method for aligning the first radiation image 310 and the second radiation image 320. As shown in Figure 20, the image processing unit 281 positions the second radiation image 320 on the first layout diagram 460 such that, for example, the position of the mark image 350c corresponding to the mark 10c included in the second radiation image 320 (e.g., the position of the centroid) coincides with the position 450c of the mark 10c in the first layout diagram 460, and the position of the mark image 350d corresponding to the mark 10d included in the second radiation image 320 (e.g., the position of the centroid) coincides with the position 450d of the mark 10d in the first layout diagram 460.

[0194] Next, as shown in Figure 21, the image processing unit 281 positions the first radiation image 310 on the first layout diagram 460 such that, for example, the position of the mark image 350a corresponding to mark 10a included in the first radiation image 310 (e.g., the position of the centroid) coincides with the position 450a of mark 10a in the first layout diagram 460, and the position of the mark image 350b corresponding to mark 10b included in the first radiation image 310 (e.g., the position of the centroid) coincides with the position 450b of mark 10b in the first layout diagram 460. In this way, the first radiation image 310 and the second radiation image 320 are basically aligned so that the overlapping portion 311 of the first radiation image 310 perfectly overlaps the overlapping portion 321 of the second radiation image 320.

[0195] Here, the image processing unit 281 does not know in advance which mark 10 on the holding member 5 corresponds to which mark image 350 included in the read radiation image. In other words, the image processing unit 281 does not know in advance which mark image 350 included in the read radiation image corresponds to which mark 10 position 450 in the first layout diagram 460. Therefore, in order to align the first radiation image 310 and the second radiation image 320 as shown in Figures 20 and 21, the image processing unit 281 needs to identify which mark 10 corresponds to which mark image 350 included in the read radiation image.

[0196] In this example, the image processing unit 281 identifies two mark images 350 contained within the first read radiation image from the optical measuring instrument 290. Then, of the two identified mark images 350, the image processing unit 281 sets the mark image 350 on the reading start side as mark image 350a corresponding to mark 10a, and the mark image 350 on the reading end side as mark image 350b corresponding to mark 10b.

[0197] Furthermore, the image processing unit 281 identifies two mark images 350 contained within the second read radiation image from the optical measuring instrument 290. Then, of the two identified mark images 350, the image processing unit 281 sets the mark image 350 on the reading start side as mark image 350c corresponding to mark 10c, and the mark image 350 on the reading end side as mark image 350d corresponding to mark 10d.

[0198] As described above, the first radiation image read by the optical detector 290 is the first radiation image 310. Also, as shown in Figure 17 above, the mark image 350a corresponding to mark 10a is recorded on the third end of the imaging plate 2a, and the mark image 350b corresponding to mark 10b is recorded on the fourth end of the imaging plate 2a. As described above, the third side of the imaging plate 2 is the starting side of reading by the reader 100, and the fourth side of the imaging plate 2 is the ending side of reading by the reader 100. Therefore, of the two mark images 350 included in the first radiation image read by the optical detector 290, the mark image 350 on the starting side of reading is the mark image 350a corresponding to mark 10a, and the mark image 350 on the ending side of reading is the mark image 350b corresponding to mark 10b. For similar reasons, of the two mark images 350 included in the second reading of the radiation image taken by the optical measuring instrument 290, the mark image 350 on the reading start side becomes mark image 350c corresponding to mark 10c, and the mark image 350 on the reading end side becomes mark image 350d corresponding to mark 10d.

[0199] As shown in Figure 21, the image processing unit 281 aligns the first radiographic image 310 and the second radiographic image 320, and then removes the lower overlapping portion 321 from the second radiographic image 320. The image processing unit 281 then connects the second radiographic image 320 from which the overlapping portion 321 has been removed to the second radiographic image 320 of the first radiographic image 310. As a result, the first radiographic image 310 and the second radiographic image 320 are combined, and as shown in Figure 22, an overall image 400 is generated that includes the dental arch image 360 ​​of the subject to be photographed and the mark images 350a, 350b, 350c, and 350d. Since the overlapping portion 311 taken from the upper imaging plate 2a has better image quality than the overlapping portion 321 read from the lower imaging plate 2b, the image quality of the overall image 400 can be improved by leaving the overlapping portion 311 and removing the overlapping portion 321. The overall image 400 generated by the image processing unit 281 is displayed on the display unit 130.

[0200] Furthermore, when combining the first radiation image 310 and the second radiation image 320, the image processing unit 271 may remove the upper overlapping portion 311 from the first radiation image 310 and then connect the first radiation image 310 from which the overlapping portion 311 has been removed to the second radiation image 320.

[0201] As described above, in the holding member 5A, the imaging plates 2a and 2b are basically stacked so that their long sides are parallel and their short sides are aligned in a straight line. However, in some cases, at least one of the imaging plates 2a and 2b may be positioned slightly misaligned in the holding member 5A, resulting in the long sides of the imaging plates 2a and 2b held by the holding member 5A not being perfectly parallel, or the short sides of the imaging plates 2a and 2b held by the holding member 5A not being perfectly aligned in a straight line. Even if the overlap of the imaging plates 2a and 2b is slightly misaligned in this way, the image processing unit 281 can align the first radiation image 310 and the second radiation image 320 by operating in the same manner as described above, so that the overlapping portion 311 of the first radiation image 310 and the overlapping portion 321 of the second radiation image 320 overlap each other.

[0202] In this disclosure, it is assumed that the overlap of imaging plates 2a and 2b is small. Even if the overlap of imaging plates 2a and 2b is misaligned, it is assumed that the long sides of imaging plates 2a and 2b are generally parallel, and the angle between the long side of imaging plate 2a and the long side of imaging plate 2b is within a few degrees or less. Furthermore, even if the overlap of imaging plates 2a and 2b is misaligned, it is assumed that the short sides of imaging plates 2a and 2b are generally aligned in a straight line, and the longitudinal positional misalignment of imaging plate 2 between the third short side of imaging plate 2a and the third short side of imaging plate 2b (in other words, the positional misalignment between the fourth short side of imaging plate 2a and the fourth short side of imaging plate 2b) is within a few millimeters or less. That is, it is assumed that the mark image 350 will be positioned within a positional misalignment that is approximately around position 450 when compared to the first layout figure 460.

[0203] Figure 23 schematically shows an example of a radiographic image recorded on the combined imaging plate 420 when the overlapping of imaging plates 2a and 2b is slightly misaligned in the holding member 5A.

[0204] Figure 24 is a schematic diagram illustrating an example of a method for aligning the first radiation image 310 and the second radiation image 320 when the radiation images shown in Figure 23 are recorded on the combined imaging plate 420.

[0205] As shown in Figure 24, the image processing unit 281 positions the second radiation image 320 on the first layout diagram 460 such that the position of the mark image 350c corresponding to mark 10c in the second radiation image 320 coincides with the position 450c of mark 10c in the first layout diagram 460, and the position of the mark image 350d corresponding to mark 10d in the second radiation image 320 coincides with the position 450d of mark 10d in the first layout diagram 460. The image processing unit 281 can then identify which mark 10 each mark image 350 in the second radiation image 320 corresponds to.

[0206] Next, as shown in Figure 24, the image processing unit 281 positions the first radiation image 310 on the first layout diagram 460 such that the position of the mark image 350a corresponding to mark 10a in the first radiation image 310 coincides with the position 450a of mark 10a in the first layout diagram 460, and the position of the mark image 350b corresponding to mark 10b in the first radiation image 310 coincides with the position 450b of mark 10b in the first layout diagram 460. In this way, the first radiation image 310 and the second radiation image 320 are aligned so that the overlapping portion 311 of the first radiation image 310 perfectly overlaps the overlapping portion 321 of the second radiation image 320. The image processing unit 281 can identify which mark 10 each mark image 350 in the first radiation image 310 corresponds to in the same manner as described above.

[0207] The image processing unit 281 aligns the first radiographic image 310 and the second radiographic image 320, and then combines them as described above. As a result, an overall image 400 is generated, which includes the dental arch image 360 ​​of the subject to be photographed, and the mark images 350a, 350b, 350c, and 350d, as shown in Figure 25.

[0208] The locations where the mark image 350 is recorded on imaging plate 2 are not limited to the above example. For example, the multiple mark images 350 recorded on imaging plate 2a may include mark images 350 recorded in places other than the corners 28a of imaging plate 2a, or they may not include mark images 350 recorded on the corners 28a of imaging plate 2a. The same applies to imaging plate 2b.

[0209] Furthermore, the multiple mark images 350 recorded on the combined imaging plate 420 may include mark images 350 recorded on parts other than the end 425 of the combined imaging plate 420, or they may not include mark images 350 recorded on the end 425.

[0210] In the example above, Mark 10 is a circle (more specifically, a perfect circle), but it is not limited to this. For example, Mark 10 could be a line segment, a curve, a polygon, a number, a letter such as an alphabet, a symbol, or a pattern.

[0211] Furthermore, the multiple marks 10 on the retaining member 5 may include multiple marks 10 of different shapes. For example, the multiple marks 10 on the retaining member 5 may include line segment (in other words, rod-shaped) marks 10, alphabetic mark 10, and digitic mark 10. Alternatively, the multiple marks 10 may include multiple marks 10 of the same shape but different sizes (for example, short line segments and long line segments).

[0212] Furthermore, the multiple marks 10 on the retaining member 5 may include both marks 10 provided on the inner surface of the cover portion 52 and marks 10 provided on the outer surface of the cover portion 52, or they may not include marks 10 provided on the inner surface of the cover portion 52.

[0213] Figure 26 is a schematic diagram showing another example of the retaining member 5A. In the example in Figure 26, the marks 10a and 10b on the retaining member 5A are line segments instead of circles. Also, the marks 10a and 10b are provided on the outer surface of the cover portion 52, rather than the inner surface.

[0214] In the example shown in Figure 26, the line segment mark images 350a and 350b corresponding to the line segment marks 10a and 10b, respectively, are recorded along the edge of the imaging plate 2a. Specifically, mark image 350a is recorded along the long side of the first side of the imaging plate 2a, and mark image 350b is recorded along the short side of the fourth side of the imaging plate 2a. When the mark images 350 are recorded along the edge of the imaging plate 2a in this way, the mark images 350 are less likely to overlap with the subject image.

[0215] Figure 27 is a schematic diagram showing another example of the retaining member 5A. In the example in Figure 27, the marks 10a, 10b, 10c, and 10d on the retaining member 5A are line segments instead of circles. Also, the marks 10a, 10b, 10c, and 10d are provided on the outer surface of the cover portion 52, rather than the inner surface.

[0216] The line segment marks shown in Figure 27 have a thin shape, which means they do not interfere with the radiographic image of the subject being observed. Therefore, they are a clinically desirable shape.

[0217] In the example shown in Figure 27, the line segment mark images 350a and 350b corresponding to the line segment marks 10a and 10b, respectively, are recorded along the edge of the imaging plate 2a. Specifically, the line segment mark image 350a is recorded along the third edge of the imaging plate 2a, in the center of the imaging plate 2a in the short direction, at the third end of the imaging plate 2a. The line segment mark image 350b is recorded along the fourth edge of the imaging plate 2a, in the center of the imaging plate 2a in the short direction, at the fourth end of the imaging plate 2a.

[0218] The line segment mark images 350c and 350d corresponding to the line segment marks 10c and 10d, respectively, are recorded along the edge of the imaging plate 2b. Specifically, the line segment mark image 350c is recorded along the third edge of the imaging plate 2b at the third end of the imaging plate 2b, in the center of the imaging plate 2b in the short direction. The line segment mark image 350d is recorded along the fourth edge of the imaging plate 2b at the fourth end of the imaging plate 2b, in the center of the imaging plate 2b in the short direction.

[0219] Although the above example was for the case where N=2, even when N≧3 and the holding member 5A holds three or more imaging plates 2, the image processing unit 281 can align the two read radiation images for each of the two or more pairs of radiation images to be combined, based on the multiple mark images 350 included in the two read radiation images that constitute the pair of radiation images to be combined.

[0220] Figure 28 is a schematic diagram showing an example where N=3, consisting of a holding member 5A and the first imaging plate 2a, second imaging plate 2b, and third imaging plate 2 held therein. Hereafter, the third imaging plate 2 may be referred to as the third imaging plate 2c or imaging plate 2c. In Figure 28, imaging plate 2c is shown by a dashed line.

[0221] In the example shown in Figure 28, the retaining member 5A has multiple marks 10, including marks 10a, 10b, 10c, and 10d, as well as two marks 10e and 10f for recording mark images 350 on the imaging plate 2c. The two mark images 350 corresponding to marks 10e and 10f are recorded on the imaging plate 2c in a portion that does not overlap with the imaging plate 2b. The two mark images 350 corresponding to marks 10c and 10d are recorded on the imaging plate 2b in a portion that does not overlap with the imaging plates 2a and 2c.

[0222] The first layout diagram 460 in the memory unit 280b shows the relative positions 450 of marks 10a, 10b, 10c, 10d, 10e, and 10f on the holding member 5A. The image processing unit 281 positions the third radiation image 330 on the first layout diagram 460, for example, so that the positions of the two mark images 350 included in the third radiation image 330 read from the third imaging plate 2c coincide with the positions 450 of the two marks 10 corresponding to the two mark images 350, as shown in the first layout diagram 460. Next, the image processing unit 281 positions the second radiation image 320 on the first layout diagram 460 in the same manner as in Figure 20. This completes the alignment of the second radiation image 320 and the third radiation image 330, which constitute a pair of radiation images to be combined. Then, the image processing unit 281 positions the first radiation image 310 on the first layout diagram 460 in the same manner as in Figure 21. This completes the alignment of the first radiation image 310 and the second radiation image 320, which constitute a pair of radiation images to be combined. As a result, the first radiation image 310, the second radiation image 320, and the third radiation image 330 are aligned so that the third IP overlap portion corresponding image 322 of the second radiation image 320 perfectly overlaps the second IP overlap portion corresponding image 331 of the third radiation image 330, and the second IP overlap portion corresponding image 311 of the first radiation image 310 perfectly overlaps the first IP overlap portion corresponding image 321 of the second radiation image 320. Subsequently, the image processing unit 281 combines the first radiation image 310, the second radiation image 320, and the third radiation image 330 to generate an overall image 400.

[0223] The method for determining which mark 10 corresponds to the mark image 350 included in the third radiation image 310 is the same as the method for determining which mark 10 corresponds to the mark image 350 included in the first radiation image 310 and the mark image 350 included in the second radiation image 320.

[0224] In this example, the image processing unit 281 aligns the nth radiation image and the (n+1)th radiation image based on the position of the mark image 350 corresponding to the nth IP non-overlapping portion mark 10 and the position of the mark image 350 corresponding to the (n+1)th IP non-overlapping portion mark 10. In such a case, the image processing unit 281 can align the nth radiation image and the (n+1)th radiation image in the same manner as described above, using at least two mark images corresponding to the nth IP non-overlapping portion mark 10 and at least two mark images corresponding to the (n+1)th IP non-overlapping portion mark 10. Therefore, for example, when N=2, the holding member 5 may have three or more first IP non-overlapping portion marks 10, or three or more second IP non-overlapping portion marks 10. Also, the number of first IP non-overlapping portion marks 10 and the number of second IP non-overlapping portion marks 10 may be different from each other.

[0225] <Example 2 (Using marks for overlapping areas)> In this example, the image processing unit 281 aligns the nth radiation image and the (n+1)th radiation image using a mark image 350 corresponding to an overlap mark 10 (also called an overlap mark 10 for the nth IP and the (n+1)th IP) for recording a mark image in the overlapping portion of the nth imaging plate 2 and the (n+1)th imaging plate 2. For example, the image processing unit 281 aligns the nth radiation image and the (n+1)th radiation image based on the position of the mark image 350 corresponding to the overlap mark 10 for the nth IP and the (n+1)th IP.

[0226] Figure 29 is a schematic diagram showing an example of a retaining member 5A. In the example of Figure 29, the retaining member 5A has multiple marks 10, including marks 10g and 10h for recording mark images on the overlapping portion 25a of the imaging plate 2a and the overlapping portion 25b of the imaging plate 2b. Marks 10g and 10h can also be called marks 10 for the overlapping portions of the first and second IPs. Marks 10g and 10h are provided, for example, on the inner surface of the cover portion 52, in the portion facing the overlapping portions 25a and 25b.

[0227] The second and third corner 28a (also called the first corner 28a) of the imaging plate 2a and the first and third corner 28b (also called the first corner 28b) of the imaging plate 2b overlap each other. Mark 10g is provided on the inner surface of the cover portion 52 in the portion facing the first corner 28a and the first corner 28b.

[0228] The second and fourth corner 28a (also referred to as the second corner 28a) of the imaging plate 2a and the first and fourth corner 28b (also referred to as the second corner 28b) of the imaging plate 2b overlap each other. Mark 10h is provided on the inner surface of the cover portion 52 in the portion facing the second corner 28a and the second corner 28b.

[0229] Figure 30 schematically shows an example of a radiographic image recorded on the combined imaging plate 420 shown in Figure 29.

[0230] A mark image 350 corresponding to mark 10g is recorded on each of the imaging plates 2a and 2b. Specifically, a mark image 350ga corresponding to mark 10g is recorded on the overlapping portion 25a of imaging plate 2a, and a mark image 350gb corresponding to mark 10g is recorded on the overlapping portion 25b of imaging plate 2b.

[0231] Mark images 350ga and 350gb are recorded at the end 425 of the combined imaging plate 420. Mark image 350ga is recorded at the first corner 28a of imaging plate 2a, and mark image 350gb is recorded at the first corner 28b of imaging plate 2b.

[0232] On each of imaging plates 2a and 2b, a mark image 350 corresponding to mark 10h is recorded. Specifically, a mark image 350ha corresponding to mark 10h is recorded in the overlapping portion 25a of imaging plate 2a, and a mark image 350hb corresponding to mark 10h is recorded in the overlapping portion 25b of imaging plate 2b.

[0233] Mark images 350ha and 350hb are recorded at the end 425 of the combined imaging plate 420. Mark image 350ha is recorded at the second corner 28a of imaging plate 2a, and mark image 350hb is recorded at the second corner 28b of imaging plate 2b.

[0234] FIG. 31 is a schematic diagram for explaining an example of a method of aligning the first radiation image 310 and the second radiation image 320 read from imaging plates 2a and 2b held by the holding member 5A shown in FIG. 29. Above FIG. 31, the first radiation image 310 and the second radiation image 320 before alignment are shown, and below FIG. 31, the first radiation image 310 and the second radiation image 320 after alignment are shown.

[0235] In this example, the image processing unit 281 aligns multiple read radiographs without using the first layout diagram 460. As shown in Figure 31, the image processing unit 281 partially overlaps the first radiograph 310 and the second radiograph 320 so that the positions of the mark images 350ga and 350gb corresponding to the same mark 10g coincide, and the positions of the mark images 350ha and 350hb corresponding to the same mark 10h coincide. At this time, the image processing unit 281 positions, for example, the first radiograph 310 above the second radiograph 320. In this way, the first radiograph 310 and the second radiograph 320 are basically aligned so that the overlapping portion 311 of the first radiograph 310 perfectly overlaps the overlapping portion 321 of the second radiograph 320.

[0236] Here, as described above, the image processing unit 281 does not know in advance which mark 10 on the holding member 5 corresponds to which mark 350 included in each read radiation image. In this example, the image processing unit 281 sets the mark image 350 on the reading start side to mark image 350ga corresponding to mark 10g, and the mark image 350 on the reading end side to mark image 350ha corresponding to mark 10h, in the two mark images 350 included in the first read radiation image read by the optical measuring instrument 290. Furthermore, the image processing unit 281 sets the mark image 350 on the reading start side to mark image 350gb corresponding to mark 10g, and the mark image 350 on the reading end side to mark image 350hb corresponding to mark 10h, in the two mark images 350 included in the second read radiation image read by the optical measuring instrument 290.

[0237] The first read radiation image read by the optical measuring device 290 is the first radiation image 310. Also, as shown in FIG. 30 described above, the mark image 350ga is recorded at the end of the third side of the imaging plate 2a, and the mark image 350ha is recorded at the end of the fourth side of the imaging plate 2a. Then, the third side of the imaging plate 2 becomes the reading start side in the reading device 100, and the fourth side of the imaging plate 2 becomes the reading end side in the reading device 100. Therefore, among the two mark images 350 included in the first read radiation image read by the optical measuring device 290, the mark image 350 on the reading start side becomes the mark image 350ga corresponding to the mark 10g, and the mark image 350 on the reading end side becomes the mark image 350ha corresponding to the mark 10h. For the same reason, among the two mark images 350 included in the second read radiation image read by the optical measuring device 290, the mark image 350 on the reading start side becomes the mark image 350gb corresponding to the mark 10g, and the mark image 350 on the reading end side becomes the mark image 350hb corresponding to the mark 10h.

[0238] As shown on the lower side of FIG. 31, when the image processing unit 281 aligns the first radiation image 310 and the second radiation image 320, the first radiation image 310 and the second radiation image 320 are combined in the same manner as described above to generate the overall image 400. The overall image 400 includes the mark images 350ga and 350ha included in the first radiation image 310, but does not include the mark images 350gb and 350hb included in the second radiation image 320.

[0239] The above example was the case where N = 2. However, even when N ≥ 3 and the holding member 5A holds three or more imaging plates 2, the image processing unit 281, in the same manner as the above alignment of the first radiation image and the second radiation image, for each of two or more pairs of radiation images to be combined, based on the plurality of mark images 350 included in the two read radiation images constituting one pair of radiation images to be combined, can align the positions of the two read radiation images.

[0240] Figure 32 is a schematic diagram showing an example where N=3, consisting of a holding member 5A and the first imaging plate 2a, second imaging plate 2b, and third imaging plate 2c held therein.

[0241] In the example shown in Figure 32, the retaining member 5A has multiple marks 10, including marks 10g and 10h, as well as two marks 10i and 10j for recording mark images 350 on the portion of the imaging plate 2c that overlaps with the imaging plate 2b. The two mark images 350 corresponding to marks 10i and 10j are recorded on the portion of the imaging plate 2c that overlaps with the imaging plate 2b.

[0242] Marks 10g and 10h are marks 10 for recording a mark image in the overlapping portion of imaging plate 2a and imaging plate 2b, and are therefore marks 10 for the overlapping portion in the relationship between imaging plate 2a and imaging plate 2b. On the other hand, marks 10g and 10h can also be said to be marks 10 for recording a mark image in the portion of imaging plate 2b that does not overlap with imaging plate 2c, and are therefore marks 10 for the non-overlapping portion in the relationship between imaging plate 2b and imaging plate 2c.

[0243] The image processing unit 281 partially overlaps the second radiation image 320 and the third radiation image 330 so that, for example, the positions of the two mark images 350 included in the second radiation image 320 and the third radiation image 330, respectively, that correspond to the same mark 10i, coincide, and the positions of the two mark images 350 included in the second radiation image 320 and the third radiation image 330, respectively, that correspond to the same mark 10j, coincide. At this time, the image processing unit 281 ensures that, for example, the second radiation image 320 is positioned above the third radiation image 330. This completes the alignment of the second radiation image 320 and the third radiation image 330 that constitute a pair of radiation images to be combined. Next, the image processing unit 281 aligns the second radiation image 320 above the third radiation image 330 and the first radiation image 310 based on the mark images 350 corresponding to marks 10g and 10h, in the same manner as in Figure 31. This completes the alignment of the first radiation image 310 and the second radiation image 320, which constitute a pair of radiation images to be combined. As a result, the first radiation image 310, the second radiation image 320, and the third radiation image 330 are aligned so that the third IP overlap portion corresponding image 322 of the second radiation image 320 perfectly overlaps the second IP overlap portion corresponding image 321 of the third radiation image 330, and the second IP overlap portion corresponding image 311 of the first radiation image 310 perfectly overlaps the first IP overlap portion corresponding image 321 of the second radiation image 320. Subsequently, the image processing unit 281 combines the first radiation image 310, the second radiation image 320, and the third radiation image 330 to generate an overall image 400.

[0244] As described above, in this example, the image processing unit 281 aligns the nth radiation image and the (n+1)th radiation image based on the position of the mark image 350 corresponding to the overlapping mark 10 of the nth IP and the (n+1)th IP. In such a case, the image processing unit 281 can align the nth radiation image and the (n+1)th radiation image in the same manner as described above, using at least two or more overlapping mark 10 of the nth IP and the (n+1)th IP. Therefore, for example, when N=2, the holding member 5 may be provided with three or more overlapping mark 10 of the 1st IP and the 2nd IP.

[0245] Furthermore, the position of the mark 10 for the overlapping portion of the nth IP and the (n+1)th IP, which is used for aligning the nth radiation image and the (n+1)th radiation image, is not limited to the example above. The position of each mark 10 in this disclosure should be such that it does not interfere with the radiation image being observed during diagnosis. The same applies to the marks described later.

[0246] <Example 3 (Use of marks for non-overlapping and overlapping areas)> In this example, the image processing unit 281 aligns the nth radiation image with the (n+1)th radiation image using the mark image 350 corresponding to the nth IP non-overlapping portion mark 10, the mark image 350 corresponding to the (n+1)th IP non-overlapping portion mark 10, and the mark image 350 corresponding to the overlapping portion mark 10 of the nth IP and the (n+1)th IP. For example, the image processing unit 281 aligns the nth radiation image with the (n+1)th radiation image based on the position of the mark image 350 corresponding to the nth IP non-overlapping portion mark 10, the position of the mark image 350 corresponding to the (n+1)th IP non-overlapping portion mark 10, and the position of the mark image 350 corresponding to the overlapping portion mark 10 of the nth IP and the (n+1)th IP.

[0247] Figure 33 is a schematic diagram showing an example of a retaining member 5A. In the example of Figure 33, the multiple marks 10 on the retaining member 5A include the marks 10b, 10d, and 10g described above.

[0248] The first layout diagram 460 within the memory unit 280b shows the relative positions 450 of marks 10b and 10d on the holding member 5A. The first layout diagram 460 shows the position 450b of mark 10b and the position 450d of mark 10d (see Figure 19). Mark 10b is the mark 10 for the non-overlapping portion of the first IP, and mark 10d is the mark 10 for the non-overlapping portion of the second IP. Mark 10g is the mark 10 for the overlapping portion of the first and second IPs.

[0249] The image processing unit 281 arranges the first radiation image 310 and the second radiation image 320 on the first layout diagram 460 such that, for example, the position of the mark image 350ga (see Figure 31) corresponding to the mark 10g included in the first radiation image 310 and the position of the mark image 350gb (see Figure 31) corresponding to the mark 10g included in the second radiation image 320 coincide with each other, and the mark image 350b (see Figures 21 and 24) corresponding to the mark 10b included in the first radiation image 310 and the mark image 350d (see Figures 21 and 24) corresponding to the mark 10d included in the second radiation image 320 coincide with the positions 450b and 450d shown in the first layout diagram 460. At this time, the first radiation image 310 is positioned above the second radiation image 320. As a result, similar to the lower parts of Figures 21 and 24, the first radiation image 310 and the second radiation image 320 are aligned so that the overlapping portion 311 of the first radiation image 310 perfectly overlaps the overlapping portion 321 of the second radiation image 320.

[0250] The image processing unit 281 sets the mark image 350 on the reading start side to mark image 350ga corresponding to mark 10g, and the mark image 350 on the reading end side to mark image 350b corresponding to mark 10b, in the two mark images 350 included in the first radiation image 310. Similarly, the image processing unit 281 sets the mark image 350 on the reading start side to mark image 350gb corresponding to mark 10g, and the mark image 350 on the reading end side to mark image 350d corresponding to mark 10d, in the two mark images 350 included in the second radiation image 310.

[0251] The position 450 of mark 10g may also be shown in the first layout diagram 460. In this case, the image processing unit 281 places the second radiation image 320 on the first layout diagram 460, for example, so that the positions of the two mark images 350 corresponding to marks 10g and 10d included in the second radiation image 320 coincide with the positions 450 of marks 10g and 10d shown in the first layout diagram 460. Subsequently, the image processing unit 281 places the first radiation image 310 on the first layout diagram 460 so that the positions of the two mark images 350 corresponding to marks 10g and 10b included in the first radiation image 310 coincide with the positions 450 of marks 10g and 10b shown in the first layout diagram 460.

[0252] Although the above example was for the case where N=2, even when N≧3 and the holding member 5A holds three or more imaging plates 2, the image processing unit 281 can align the two read radiation images for each of the two or more pairs of radiation images to be combined, based on the multiple mark images 350 included in the two read radiation images that constitute one pair of radiation images to be combined.

[0253] Figure 34 is a schematic diagram showing an example of a holding member 5A and imaging plates 2a, 2b, and 2c held therein, where N=3. In the example of Figure 34, the multiple marks 10 on the holding member 5A include marks 10b, 10f, 10g, and 10i. The first layout diagram 460 in the storage unit 280b shows, for example, the relative positions 450 of marks 10b, 10f, and 10g on the holding member 5A. In the relationship between imaging plates 2a and 2b, mark 10i becomes the mark 10 for the second non-overlapping portion of the IP, and in the relationship between imaging plates 2b and 2c, mark 10g becomes the mark 10 for the second non-overlapping portion of the IP.

[0254] The image processing unit 281 arranges the second and third radiation images 320 and 330 on the first layout diagram 460 such that, for example, the positions of the two mark images 350 included in the second radiation image 320 and the third radiation image 330, which correspond to the same mark 10i, coincide with each other, the position of the mark image 350 corresponding to mark 10g included in the second radiation image 320 coincides with the position 450 of mark 10g shown in the first layout diagram 460, and the position of the mark image 350 corresponding to mark 10f included in the third radiation image 330 coincides with the position 450 of mark 10f shown in the first layout diagram 460. At this time, the second radiation image is positioned 320 units above the third radiation image 330.

[0255] Next, the image processing unit 281 positions the first radiation image 310 on the first layout diagram 460 such that the position of the mark image 350 corresponding to the mark 10g included in the first radiation image 310 coincides with the position of the mark image 350 corresponding to the mark 10g included in the second radiation image 320 on the first layout diagram 460, and the position of the mark image 350 corresponding to the mark 10b included in the first radiation image 310 coincides with the position 450 of the mark 10b shown in the first layout diagram 460. In other words, the image processing unit 281 positions the first radiation image 310 on the first layout diagram 460 such that the position of the mark image 350 corresponding to the mark 10g included in the first radiation image 310 coincides with the position 450 of the mark 10g shown in the first layout diagram 460, and the position of the mark image 350 corresponding to the mark 10b included in the first radiation image 310 coincides with the position 450 of the mark 10b shown in the first layout diagram 460. As a result, the first radiation image 310, the second radiation image 320, and the third radiation image 330 are aligned so that the third IP overlap portion corresponding image 322 of the second radiation image 320 perfectly overlaps the second IP overlap portion corresponding image 331 of the third radiation image 330, and the second IP overlap portion corresponding image 311 of the first radiation image 310 perfectly overlaps the first IP overlap portion corresponding image 321 of the second radiation image 320. After that, the image processing unit 281 combines the first radiation image 310, the second radiation image 320, and the third radiation image 330 to generate an overall image.

[0256] The position 450 of mark 10i may also be shown in the first layout diagram 460. In this case, the image processing unit 281 places the third radiation image 330 on the first layout diagram 460, for example, so that the positions of the two mark images 350 corresponding to marks 10i and 10f included in the third radiation image 330 coincide with the positions 450 of marks 10i and 10f shown in the first layout diagram 460. Next, the image processing unit 281 places the second radiation image 320 on the first layout diagram 460 so that the positions of the two mark images 350 corresponding to marks 10g and 10i included in the second radiation image 320 coincide with the positions 450 of marks 10g and 10i shown in the first layout diagram 460. Then, the image processing unit 281 places the first radiation image 310 on the first layout diagram 460 such that the positions of the two mark images 350 corresponding to the marks 10g and 10b included in the first radiation image 310 coincide with the positions 450 of the marks 10g and 10b shown in the first layout diagram 460.

[0257] As described above, in this example, the image processing unit 281 aligns the n-th radiation image and the (n + 1)-th radiation image based on the position of the mark image 350 corresponding to the n-th IP non-overlapping portion mark 10, the position of the mark image 350 corresponding to the (n + 1)-th IP non-overlapping portion mark 10, and the position of the mark image 350 corresponding to the overlapping portion mark 10 of the n-th IP and the (n + 1)-th IP. In such a case, the image processing unit 281 can perform the alignment of the n-th radiation image and the (n + 1)-th radiation image in the same manner as above using at least one mark image 350 corresponding to at least one n-th IP non-overlapping portion mark 10, at least one mark image 350 corresponding to at least one (n + 1)-th IP non-overlapping portion mark 10, and at least one mark image 350 corresponding to at least one overlapping portion mark 10 of the n-th IP and the (n + 1)-th IP. Therefore, for example, when N = 2, the holding member 5 may include two or more first IP non-overlapping portion marks 10. Also, the holding member 5 may include two or more second IP non-overlapping portion marks 10. Also, the holding member 5 may include two or more overlapping portion marks 10 of the first IP and the second IP. Also, the number of the first IP non-overlapping portion marks 10 and the number of the second IP non-overlapping portion marks 10 may be different from each other.

[0258] Also, the positions of the n-th IP non-overlapping portion mark 10, the (n + 1)-th IP non-overlapping portion mark 10, and the overlapping portion mark 10 of the n-th IP and the (n + 1)-th IP used for the alignment of the n-th radiation image and the (n + 1)-th radiation image in this example are not limited to the above example.

[0259] <Example 4 (Use of Non-Overlapping Portion Marks)> In this example, the image processing unit 281 aligns the n-th radiation image and the (n + 1)-th radiation image based on the position and orientation of the mark image 350 corresponding to the n-th IP non-overlapping portion mark 10 and the position and orientation of the mark image 350 corresponding to the (n + 1)-th IP non-overlapping portion mark 10.

[0260] Figure 35 is a schematic diagram showing an example of a retaining member 5A. In the example in Figure 35, the retaining member 5A has multiple marks 10, including marks 10a and 10c. In the example in Figure 35, mark 10a is an equilateral triangle, and mark 10c is a star-shaped pentagon.

[0261] The memory unit 280b of the control unit 280 has a second layout diagram 490 pre-stored therein, which shows the relative positions of the multiple marks 10 on the holding member 5 and the relative orientations of the multiple marks 10 on the holding member 5. The image processing unit 281 aligns the first radiation image 310 and the second radiation image 320 based on the second layout diagram 490 in the memory unit 280b and the mark images 350 corresponding to marks 10a and 10c.

[0262] Figure 36 is a schematic diagram showing an example of the second layout diagram 490. In the second layout diagram 490, a mark correspondence diagram 480 that mimics the mark 10 is shown for each mark 10. The shape of the mark correspondence diagram 480 that mimics the mark 10 matches the shape of the mark 10 when the holding member 5A is viewed from the side irradiated with radiation, along a direction perpendicular to the reading target surface 21 of the imaging plate 2. The external shape of the second layout diagram 490 matches, for example, the external shape of the holding member 5A when the holding member 5A is viewed from the side irradiated with radiation, along a direction perpendicular to the reading target surface 21 of the imaging plate 2. Note that the external shape of the second layout diagram 490 is not limited to this.

[0263] The relative positions of the multiple mark correspondence diagrams 480 in the second layout diagram 490 correspond to the relative positions of the multiple marks 10 when the holding member 5A is viewed from the side irradiated with radiation, along a direction perpendicular to the reading surface 21 of the imaging plate 2. Furthermore, the relative orientation of the multiple mark correspondence diagrams 480 in the second layout diagram 490 corresponds to the relative orientation of the multiple marks 10 when the holding member 5A is viewed from the side irradiated with radiation, along a direction perpendicular to the reading surface 21 of the imaging plate 2. The second layout diagram 490 shows a mark correspondence diagram 480a, which simulates mark 10a, and a mark correspondence diagram 480c, which simulates mark 10c.

[0264] Figures 37 and 38 are schematic diagrams showing an example of how to align the first radiation image 310 and the second radiation image 320 in this example. The upper part of Figures 37 and 38 shows an example of the first radiation image 310 and the second radiation image 320 read from imaging plates 2a and 2b shown in Figure 35. Hereafter, when referring to the left and right sides of a read radiation image such as the first radiation image 310, it means the left and right sides of the read radiation image when the read radiation image is positioned so that the reading start side and reading end side of the read radiation image are located on the upper and lower sides, respectively, as shown in the upper part of Figures 37 and 38.

[0265] As shown in the lower part of Figure 37, the image processing unit 281 positions the second radiation image 320 on the second layout diagram 490 such that, for example, the mark image 350c corresponding to the star-shaped pentagon mark 10c included in the second radiation image 320 perfectly overlaps with the mark correspondence diagram 480c, which mimics the mark 10c, as shown in the second layout diagram 490. In other words, the image processing unit 281 positions the second radiation image 320 on the second layout diagram 490 such that the position and orientation of the mark image 350c match the position and orientation of the mark correspondence diagram 480c, which has the same shape as the mark image 350c.

[0266] Next, the image processing unit 281 places the first radiation image 310 on the second layout diagram 490, as shown on the lower side of Figure 38, so that the mark image 350a corresponding to the triangular mark 10a included in the first radiation image 310 perfectly overlaps with the mark correspondence diagram 480a, which mimics the mark 10a, as shown in the second layout diagram 490.

[0267] Here, the shapes of the mark image 350a and the corresponding mark figure 480a are 3-fold rotationally symmetric. Therefore, there are 3 orientations of the mark image 350a such that it perfectly overlaps with the corresponding mark figure 480a in the second layout figure 490. Also, the shapes of the mark image 350c and the corresponding mark figure 480c are 5-fold rotationally symmetric. Therefore, there are 5 orientations of the mark image 350c such that it perfectly overlaps with the corresponding mark figure 480c in the second layout figure 490. Thus, simply placing the first radiation image 310 and the second radiation image 320 on the second layout figure 490 so that the mark images 350a and 350c perfectly overlap with the corresponding mark figures 480a and 480c, respectively, may result in the overlapping portion 311 of the first radiation image 310 and the overlapping portion 321 of the second radiation image 320 not perfectly overlapping each other.

[0268] On the other hand, this example assumes that the overlap of imaging plates 2a and 2b at the holding member 5A is small. Therefore, even if the overlap of imaging plates 2a and 2b is misaligned, in IP assembly 1, the second side end 25a of imaging plate 2a and the first side end 25b of imaging plate 2b overlap, and the long sides of imaging plates 2a and 2b are generally parallel.

[0269] Therefore, when the image processing unit 281 places the first radiation image 310 and the second radiation image 320 on the second layout diagram 490, the right side of the first radiation image 310 is positioned on the second radiation image 320 side, the left side of the second radiation image 320 is positioned on the first radiation image 310 side, and the mark images 350a and 350c are precisely superimposed on the mark correspondence diagrams 480a and 480c, respectively, so that the long sides of the first radiation image 310 and the long sides of the second radiation image 320 are parallel or approximately parallel. At this time, for example, a pattern matching method may be used to superimpose the mark images 350a and 350c onto the mark correspondence diagrams 480a and 480c, respectively. In this way, the first radiation image 310 and the second radiation image 320 are basically aligned so that the overlapping portion 311 of the first radiation image 310 perfectly overlaps the overlapping portion 321 of the second radiation image 320.

[0270] Even if N≧3, the image processing unit 281 can perform alignment of the two read radiation images constituting each of two or more pairs of radiation images to be combined, in the same manner as the alignment of the first and second radiation images described above.

[0271] As in this example, when the image processing unit 281 aligns the nth radiation image and the (n+1)th radiation image based on the position and orientation of the mark image 350 corresponding to the nth IP non-overlapping portion mark 10 and the position and orientation of the mark image 350 corresponding to the (n+1)th IP non-overlapping portion mark 10, the shape of the mark 10 only needs to be such that its rotation can be determined. In other words, the shape of the mark 10 only needs to be such that its orientation can be determined. In this example, marks such as perfect circles, whose rotation cannot be determined (in other words, marks whose orientation cannot be determined), are not used as alignment marks 10.

[0272] Mark 10 may be rotationally symmetric (except for n-fold rotational symmetry, such as a circle, where n is an arbitrary value) or non-rotationally symmetric, as shown in the example in Figure 35. The shape of non-rotationally symmetric Mark 10 may be, for example, the letter "A" or "B", the number "2" or "3", or any other shape. The shape of non-rotationally symmetric Mark 10 can also be described as a shape that allows the rotation to be understood regardless of the value of the rotation angle of Mark 10. For example, Mark 10 may be a partially cut circle, or an asymmetrical figure (e.g., a trapezoid or a smiley face mark).

[0273] Furthermore, as in this example, when the alignment of the nth radiation image and the (n+1)th radiation image is performed based on the position and orientation of the mark image 350 corresponding to the nth IP non-overlapping portion mark 10 and the position and orientation of the mark image 350 corresponding to the (n+1)th IP non-overlapping portion mark 10, the image processing unit 281 can perform the alignment of the nth radiation image and the (n+1)th radiation image in the same manner as described above, using at least one mark image corresponding to the nth IP non-overlapping portion mark 10 and at least one mark image corresponding to the (n+1)th IP non-overlapping portion mark 10. Therefore, for example, when N=2, the holding member 5 may have two or more first IP non-overlapping portion marks 10, or two or more second IP non-overlapping portion marks 10. Also, the number of first IP non-overlapping portion marks 10 and the number of second IP non-overlapping portion marks 10 may be different from each other.

[0274] Furthermore, the positions of the nth IP non-overlapping portion mark 10 and the (n+1)th IP non-overlapping portion mark 10 used for aligning the nth radiation image and the (n+1)th radiation image are not limited to the above example.

[0275] <Example 5 (Use of marks for overlapping areas)> In this example, the image processing unit 281 aligns the nth radiation image and the (n+1)th radiation image based on the position and orientation of the mark image 350 corresponding to the mark 10 for the overlapping portion of the nth IP and the (n+1)th IP.

[0276] Figure 39 is a schematic diagram showing an example of a retaining member 5A. In the example in Figure 39, the retaining member 5A has multiple marks 10, including a mark 10g which is a mark 10 for the overlapping portion of the first IP and the second IP. In the example in Figure 39, the mark 10g is the letter "M" and is not rotationally symmetrical.

[0277] Figure 40 is a schematic diagram illustrating an example of the method for aligning the first radiation image 310 and the second radiation image 320 in this example. The upper part of Figure 40 shows an example of the first radiation image 310 and the second radiation image 320 read from imaging plates 2a and 2b shown in Figure 39. The first radiation image 310 includes a mark image 350ga corresponding to mark 10g, and the second radiation image 320 includes a mark image 350gb corresponding to mark 10g.

[0278] In this example, the image processing unit 281 superimposes the first radiation image 310 onto the second radiation image 320 so that the mark images 350ga and 350gb, which correspond to the same mark 10g, perfectly overlap each other, as shown in the lower part of Figure 40. In other words, the image processing unit 281 superimposes the first radiation image 310 onto the second radiation image 320 so that the position and orientation of the mark image 350ga and the position and orientation of the mark image 350gb, which has the same shape as the mark image 350ga, coincide. In this way, the first radiation image 310 and the second radiation image 320 are basically aligned so that the overlapping portion 311 of the first radiation image 310 perfectly overlaps the overlapping portion 321 of the second radiation image 320.

[0279] If mark 10g is rotationally symmetric, simply overlapping mark image 350ga and mark image 350gb may not result in the overlapping portion 311 of the first radiation image 310 and the overlapping portion 321 of the second radiation image 320 perfectly overlapping each other. If mark image 30g is rotationally symmetric, the image processing unit 281 precisely overlaps mark image 350ga and mark image 350gb such that the right side of the first radiation image 310 is positioned towards the second radiation image 320, the left side of the second radiation image 320 is positioned towards the first radiation image 310, and the long sides of the first radiation image 310 and the long sides of the second radiation image 320 are parallel or approximately parallel. As a result, the overlapping portion 311 of the first radiation image 310 will basically perfectly overlap the overlapping portion 321 of the second radiation image 320.

[0280] Even if N≧3, the image processing unit 281 can perform alignment of the two read radiation images constituting each of two or more pairs of radiation images to be combined, in the same manner as the alignment of the first and second radiation images described above.

[0281] As in this example, when the image processing unit 281 aligns the nth radiation image and the (n+1)th radiation image based on the position and orientation of the mark image 350 corresponding to the overlapping portion mark 10 of the nth IP and the (n+1)th IP, the shape of the mark 10 only needs to be such that its rotation can be determined, as in the fourth example. In this example, marks such as perfect circles, whose rotation cannot be determined, are not used as alignment marks 10.

[0282] Furthermore, as in this example, when the alignment of the nth radiation image and the (n+1)th radiation image is performed based on the position and orientation of the mark image 350 corresponding to the overlapping portion mark 10 of the nth IP and the (n+1)th IP, the image processing unit 281 can perform the alignment of the nth radiation image and the (n+1)th radiation image in the same manner as described above, using at least one mark image corresponding to the overlapping portion mark 10 of the nth IP and the (n+1)th IP. Therefore, for example, when N=2, the holding member 5 may be provided with two or more overlapping portion marks 10 of the 1st IP and the 2nd IP.

[0283] Furthermore, the position of the mark 10 for the overlapping portion of the nth IP and the (n+1)th IP, which is used for aligning the nth radiation image and the (n+1)th radiation image, is not limited to the example above.

[0284] <Example 6 (Use of boundary images)> As described above, the nth imaging plate 2 and the (n+1)th imaging plate 2 are held by the holding member 5A in a state where they partially overlap each other, with the (n+1)th imaging plate 2 on the lower side. Therefore, the (n+1)th radiation image includes a boundary image corresponding to the boundary between the nth imaging plate 2 and the (n+1)th imaging plate 2 on the (n+1)th imaging plate 2. The boundary image included in the (n+1)th radiation image can also be said to be an image of the portion of the periphery (also called the outer edge) of the nth imaging plate 2 that is located on the (n+1)th imaging plate 2.

[0285] In this example, the image processing unit 281 aligns the nth radiation image and the (n+1)th radiation image based on the position of the mark image 350 corresponding to the nth IP non-overlapping portion mark 10, the position of the mark image 350 corresponding to the (n+1)th IP non-overlapping portion mark 10, and the boundary image included in the (n+1)th radiation image. The image processing unit 281 makes it possible to easily and appropriately align the nth radiation image and the (n+1)th radiation image based on the mark image 350 included in the nth radiation image and the (n+1)th radiation image, and the boundary image included in the (n+1)th radiation image.

[0286] Figure 41 is a schematic diagram showing an example of a holding member 5A and the first imaging plate 2 and second imaging plate 2 held therein. In the example of Figure 41, the holding member 5A has multiple marks 10, including a circular mark 10a as the mark 10 for the first non-overlapping portion of the IP and a circular mark 10c as the mark 10 for the second non-overlapping portion of the IP. The storage unit 280b has a first layout diagram 460 pre-stored, which shows the relative positions of marks 10a and 10c on the holding member 5.

[0287] Furthermore, in the example of Figure 41, as in the example of Figure 23 described above, the overlap of the imaging plates 2a and 2b is slightly misaligned in the holding member 5A. The periphery of imaging plate 2a includes a portion 29a located on imaging plate 2b, in other words, a portion 29b that overlaps with imaging plate 2b. Hereafter, portion 29a may be referred to as the overlapping edge 29a. The overlapping edge 29a indicates the boundary 29ab between the first imaging plate 2a and the second imaging plate 2b on the second imaging plate 2b.

[0288] As shown in Figure 16 and other figures, if the overlap of imaging plates 2a and 2b in the holding member 5A is not misaligned, only one of the longer sides 23a (see Figure 41) on the imaging plate 2b side of imaging plate 2a constitutes the overlapping edge 29a. Therefore, if the overlap of imaging plates 2a and 2b in the holding member 5A is not misaligned, the overlapping edge 29a does not include the other longer side 23a of imaging plate 2a or the shorter side 24a of imaging plate 2a.

[0289] On the other hand, as in the example in Figure 41, if the overlap of imaging plates 2a and 2b in the holding member 5A is misaligned, the overlapping edge 29a may include parts of the periphery of imaging plate 2a other than the long side 23a on the imaging plate 2b side. As described above, in this example, even if the overlap of imaging plates 2a and 2b is misaligned, the misalignment is small. Therefore, even if the overlap of imaging plates 2a and 2b is misaligned, the majority of the overlapping edge 29a is composed of one of the long sides 23a on the imaging plate 2b side of imaging plate 2a, and the other long side 23a of imaging plate 2a is not included in the overlapping edge 29a. Furthermore, even if the short side 24b of imaging plate 2a is included in the overlapping edge 29a, the proportion of the short side 24a included in the overlapping edge 29a is much smaller than the proportion of the long side 23a included in the overlapping edge 29a. Hereafter, the long side 23a on the imaging plate 2b side of imaging plate 2a may be referred to as the second IP side long side 23a. All or most of the overlapping edge 29a is composed of the second IP-side long side 23a. The second IP-side long side 23a constitutes all or most of the boundary 29ab.

[0290] Figure 42 is a schematic diagram showing an example of the first radiographic image 310 and the second radiographic image 320 read from the first imaging plate 2a and the second imaging plate 2b shown in Figure 41.

[0291] As shown in Figure 42, the first radiographic image 310 includes a mark image 350a corresponding to mark 10a. The second radiographic image 320 includes a mark image 350c corresponding to mark 10c. The second radiographic image 320 also includes a boundary image 325 corresponding to the boundary 29ab between the first imaging plate 2a and the second imaging plate 2b on the second imaging plate 2b. The boundary image 325 can also be described as an image of the overlapping edge 29a of the first imaging plate 2. The boundary image 325 shows the contour of the overlapping portion 321 (in other words, the image 321 corresponding to the overlapping portion of the first IP). In the second radiographic image 320, the dentition image 360b and the mark image 350c are generally more clearly visible than the boundary image 325. Note that in figures where an explanation of the boundary image 325 is unnecessary, such as the figures above which show an example of the second radiographic image 320, the illustration of the boundary image 325 is omitted.

[0292] The boundary image 325 includes an image 326 (also called the long-side corresponding image 326) corresponding to the second IP-side long side 23a of the imaging plate 2a. The long-side corresponding image 326 is an image of at least a portion of the second IP-side long side 23a. If the overlap of the imaging plates 2a and 2b in the holding member 5A is not misaligned, the long-side corresponding image 326 is an image of the entire second IP-side long side 23a, and the boundary image 325 consists only of the long-side corresponding image 326. On the other hand, if the overlap of the imaging plates 2a and 2b in the holding member 5A is slightly misaligned, as in the example in Figure 41, the long-side corresponding image 326 is an image of a portion of the second IP-side long side 23a, and the majority of the boundary image 325 consists of the long-side corresponding image 326. In the example in Figure 41, the boundary image 325 also includes an image 327 (also called the short-side corresponding image 327) corresponding to the short side 24a of the imaging plate 2a. The proportion of the short-side corresponding image 327 included in the boundary image 325 is much smaller than the proportion of the long-side corresponding image 326 included in the boundary image 325.

[0293] The image processing unit 281 aligns the first radiation image 310 and the second radiation image 320 based on the first layout diagram 460, the mark image 350a included in the first radiation image 310, and the mark image 350c and boundary image 325 included in the second radiation image 320.

[0294] Figure 43 is a schematic diagram illustrating an example of how the first radiation image 310 and the second radiation image 320 are aligned in this example. First, the image processing unit 281, for example, places the reading start side of the first radiation image 310 and the second radiation image 320 upwards, and places the first radiation image 310 and the second radiation image 320 to the left and right, respectively, and aligns them side by side. Next, as shown in the upper part of Figure 43, the image processing unit 281 ensures that the long side 315 of the first radiation image 310 on the second radiation image 320 side (also called the long side 315 of the second radiation image) and the long side corresponding image 326 included in the boundary image 325 of the second radiation image 320 are parallel. The long side 315 of the second radiation image in the first radiation image 310 and the long side corresponding image 326 included in the boundary image 325 each correspond to the long side 23a of the second IP side of the imaging plate 2a.

[0295] If there is no misalignment in the overlap of imaging plates 2a and 2b in the holding member 5A, the boundary image 325 consists only of the long-side corresponding image 326. Then, at the left end of the second radiation image 320, a linear image appears as the long-side corresponding image 326 (in other words, the boundary image 325), extending from one end on the reading start side to the other end on the reading end side of the second radiation image 320. If the left end of the second radiation image 320 contains a linear image extending from one end on the reading start side to the other end on the reading end side of the second radiation image 320, the image processing unit 281 considers this linear image as the long-side corresponding image 326 (i.e., the boundary image 325), and places the first radiation image 310 and the second radiation image 320 side by side so that the long-side corresponding image 326 and the long side 315 of the second radiation image are parallel.

[0296] As described above, in this example, even if a misalignment occurs in the overlap of imaging plates 2a and 2b in the holding member 5A, the misalignment is small. Therefore, even if a misalignment occurs in the overlap of imaging plates 2a and 2b in the holding member 5A, a long linear image appears at the left end of the second radiation image 320 as the long-side corresponding image 326 of the boundary image 325. This long linear image extends roughly from one end of the second radiation image 320 on the reading start side to the one end on the reading end side. When the image processing unit 281 finds that the left end of the second radiation image 320 contains a linear image that extends roughly from one end of the second radiation image 320 on the reading start side to the one end on the reading end side, it uses this linear image as the long-side corresponding image 326 and places the first radiation image 310 and the second radiation image 320 side by side so that the long-side corresponding image 326 and the long side 315 of the second radiation image are parallel.

[0297] Next, as shown in the lower part of Figure 43, the image processing unit 281 positions the second radiation image 320 and the first radiation image 310 on the first layout diagram 460 such that the position of the mark image 350a corresponding to mark 10a in the first radiation image 310 coincides with the position 450a of mark 10a in the first layout diagram 460, and the position of the mark image 350c corresponding to mark 10c in the second radiation image 320 coincides with the position 450c of mark 10c in the first layout diagram 460. At this time, the image processing unit 281 positions the second radiation image 320 lower than the first radiation image 310. As a result, the first radiation image 310 and the second radiation image 320 are basically aligned so that the overlapping portion 311 of the first radiation image 310 perfectly overlaps the overlapping portion 321 of the second radiation image 320.

[0298] The alignment process between the first radiation image 310 and the second radiation image 320 described above can also be described as a process of aligning and overlapping the edges of the first radiation image 310 with the corresponding edges projected onto the second radiation image 320.

[0299] Furthermore, after arranging the first radiation image 310 and the second radiation image 320 on the first layout diagram 460, the image processing unit 281 may change the orientation of at least one of the first radiation image 310 and the second radiation image 320 so that the long side 315 of the first radiation image 310 on the second radiation image side overlaps with the long side corresponding image 326 of the second radiation image 320. Figure 44 is a schematic diagram illustrating an example of how to align the first radiation image 310 and the second radiation image 320 in this case.

[0300] In the example shown in Figure 44, the image processing unit 281 first positions the second radiation image 320 on the first layout diagram 460 such that the position of the mark image 350c corresponding to the mark 10c included in the second radiation image 320 coincides with the position 450c of the mark 10c in the first layout diagram 460. Next, the image processing unit 281 positions the first radiation image 310 on the first layout diagram 460 such that the position of the mark image 350a corresponding to the mark 10a included in the first radiation image 310 coincides with the position 450a of the mark 10a in the first layout diagram 460. As a result, the first radiation image 310 and the second radiation image 320 are positioned on the first layout diagram 460 such that the position of the mark image 350a of the first radiation image 310 coincides with position 450a in the first layout diagram 460, and the position of the mark image 350c of the second radiation image 320 coincides with position 450c in the first layout diagram 460, as shown in the upper part of Figure 44.

[0301] Next, as shown in the lower part of Figure 44, the image processing unit 281 changes the orientation of at least one of the first radiation image 310 and the second radiation image 320 so that the long side 315 of the first radiation image 310 on the second radiation image side and the long side corresponding image 326 of the second radiation image 320 overlap each other, while maintaining the position of the mark images 350a and 350c to coincide with the positions 450a and 450c in the first layout Figure 460, respectively. As a result, similar to the example in Figure 43, the first radiation image 310 and the second radiation image 320 are aligned so that the overlapping portion 311 of the first radiation image 310 perfectly overlaps the overlapping portion 321 of the second radiation image 320.

[0302] As can be understood from the above explanation, in both the example in Figure 43 and the example in Figure 44, the image processing unit 281 aligns the first radiation image 310 and the second radiation image 320 by arranging them on the first layout diagram 460 such that the position of the mark image 350a included in the first radiation image 310 coincides with position 450a, the position of the mark image 350c included in the second radiation image 320 coincides with position 450c, and one of the long sides of the first radiation image 310 and the corresponding long side image 326 of the second radiation image 320 overlap each other.

[0303] The above example was for the case where N=2, but even when N≧3 and the holding member 5A holds three or more imaging plates 2, the image processing unit 281 can align the two read radiation images constituting each of two or more pairs of radiation images to be combined, in the same manner as the alignment of the first and second radiation images described above.

[0304] Figure 45 is a schematic diagram showing an example where N=3, consisting of a holding member 5A and the first imaging plate 2a, second imaging plate 2b, and third imaging plate 2c held therein.

[0305] In the example shown in Figure 45, the retaining member 5A is provided not only with marks 10a and 10c, but also with mark 10e as a third mark 10 for the non-overlapping portion of the IP. The first layout diagram 460 within the storage unit 280b shows the relative positions 450 of marks 10a, 10c, and 10e on the retaining member 5A.

[0306] In the example shown in Figure 45, the overlap of imaging plates 2b and 2c is slightly misaligned in the holding member 5A. The periphery of imaging plate 2b includes a portion 29b located on imaging plate 2c, in other words, a portion 29b that overlaps with imaging plate 2c. Hereafter, portion 29b may be referred to as the overlapping edge 29b. The overlapping edge 29b indicates the boundary 29bc between the second imaging plate 2b and the third imaging plate 2c on the third imaging plate 2c. The overlapping edge 29b includes at least a portion of the longer side 23b of imaging plate 2b on the imaging plate 2c side (also called the longer side 23b on the third IP side).

[0307] The third radiographic image 330, read from the third imaging plate 2c, includes a mark image 350 corresponding to mark 10e. The third radiographic image 330 also includes a boundary image (also called a second boundary image) corresponding to the boundary 29bc between the second imaging plate 2b and the third imaging plate 2c on the third imaging plate 2c. The second boundary image includes an image corresponding to the third IP-side long side 23b of imaging plate 2b (also called a second long side corresponding image). The second long side corresponding image is an image of at least a portion of the third IP-side long side 23b.

[0308] The image processing unit 281 positions the second radiation image 320 and the third radiation image 330 on the first layout diagram 460 such that, for example, the position of the mark image 350c corresponding to mark 10c in the second radiation image 320 coincides with the position 450c of mark 10c in the first layout diagram 460, the position of the mark image 350 corresponding to mark 10e in the third radiation image 330 coincides with the position 450 of mark 10e in the first layout diagram 460, and one of the long sides of the second radiation image 320 and the corresponding image of the second long side included in the second boundary image of the third radiation image 320 overlap each other. At this time, the image processing unit 281 positions the third radiation image 330 below the second radiation image 320. This completes the alignment of the second radiation image 320 and the third radiation image 330, which constitute a pair of radiation images to be combined. The image processing unit 281 can identify the second long-side corresponding image in the same manner as the method for identifying the long-side corresponding image 326.

[0309] Next, the image processing unit 281 positions the first radiation image 310 on the second radiation image 320 on the first layout diagram 460 such that the position of the mark image 350a included in the first radiation image 310 coincides with the position 450a in the first layout diagram 460, the position of the mark image 350c included in the second radiation image 320 coincides with the position 450c in the first layout diagram 460, and one of the long sides of the first radiation image 310 and the corresponding long side image 326 of the second radiation image 320 overlap each other. This completes the alignment of the first radiation image 310 and the second radiation image 320 that constitute a pair of radiation images to be combined. As a result, the first radiation image 310, the second radiation image 320, and the third radiation image 330 are aligned such that the third IP overlapping portion corresponding image 322 of the second radiation image 320 perfectly overlaps the second IP overlapping portion corresponding image 331 of the third radiation image 330, and the second IP overlapping portion corresponding image 311 of the first radiation image 310 perfectly overlaps the first IP overlapping portion corresponding image 321 of the second radiation image 320.

[0310] As in this example, when the alignment of the nth radiation image and the (n+1)th radiation image is performed based on the boundary image corresponding to the boundary between the nth imaging plate 2 and the (n+1)th imaging plate 2 on the (n+1)th imaging plate 2, the position of the mark image corresponding to the nth IP non-overlapping portion mark 10, and the position of the mark image corresponding to the (n+1)th IP non-overlapping portion mark 10, the image processing unit 281 can perform the alignment of the nth radiation image and the (n+1)th radiation image in the same manner as described above, using at least one mark image corresponding to the nth IP non-overlapping portion mark 10 and at least one mark image corresponding to the (n+1)th IP non-overlapping portion mark 10. Therefore, for example, when N=2, the holding member 5 may have two or more first IP non-overlapping portion marks 10, or two or more second IP non-overlapping portion marks 10. Furthermore, the number of marks 10 for the first IP non-overlapping portion and the number of marks 10 for the second IP non-overlapping portion may be different from each other.

[0311] Furthermore, the positions of the nth IP non-overlapping portion mark 10 and the (n+1)th IP non-overlapping portion mark 10 used for aligning the nth radiation image and the (n+1)th radiation image are not limited to the above example.

[0312] <Example 7 (Use of boundary images)> In this example, the image processing unit 281 aligns the nth radiation image with the (n+1)th radiation image based on a boundary image corresponding to the boundary between the nth imaging plate 2 and the (n+1)th imaging plate 2 on the (n+1)th imaging plate 2, which is included in the (n+1)th radiation image, and a mark image 350 corresponding to the overlapping portion mark 10 of the nth IP and the (n+1)th IP.

[0313] Figure 46 is a schematic diagram showing an example of a retaining member 5A. In the example of Figure 46, the retaining member 5A is provided with a mark 10g as a mark 10 for the overlapping portion of the first IP and the second IP. The first radiation image 310 read from the imaging plate 2a includes a mark image 350ga corresponding to the mark 10g. The second radiation image 320 read from the imaging plate 2b includes a mark image 350gb corresponding to the mark 10g and the boundary image 325 described above.

[0314] Figure 47 is a schematic diagram illustrating an example of how the first radiation image 310 and the second radiation image 320 are aligned in this example. First, the image processing unit 281, for example, as in the sixth example described above, places the reading start side of the first radiation image 310 and the second radiation image 320 upwards and arranges them side by side so that the first radiation image 310 and the second radiation image 320 are positioned on the left and right sides, respectively. Next, as shown in the upper part of Figure 47, the image processing unit 281 makes the long side 315 of the first radiation image 310 on the second radiation image side parallel to the long side corresponding image 326 included in the boundary image 325 of the second radiation image 320.

[0315] Next, as shown in the lower part of Figure 47, the image processing unit 281 partially overlaps the first radiation image 310 and the second radiation image 320, while maintaining the parallel state between the long side 315 of the second radiation image and the long side corresponding image 326, so that the positions of the mark image 350ga and the mark image 350gb corresponding to the same mark 10g coincide. At this time, the image processing unit 281 positions, for example, the first radiation image 310 above the second radiation image 320. In this way, the first radiation image 310 and the second radiation image 320 are basically aligned so that the overlapping portion 311 of the first radiation image 310 perfectly overlaps the overlapping portion 321 of the second radiation image 320.

[0316] Furthermore, the image processing unit 281 may partially overlap the first radiation image 310 and the second radiation image 320 so that the positions of the mark image 350ga and the mark image 350gb coincide and the second radiation image 320 is located below the first radiation image 310, and then change the orientation of at least one of the first radiation image 310 and the second radiation image 320 so that the long side 315 of the first radiation image 310 on the second radiation image side overlaps with the long side corresponding image 326 of the second radiation image 320.

[0317] As can be understood from the above explanation, in this example, the image processing unit 281 aligns the first radiation image 310 and the second radiation image 320 so that the positions of the mark image 350ga and the mark image 350gb coincide with each other, and one of the long sides of the first radiation image 310 overlaps with the long side corresponding image 326 of the second radiation image 320.

[0318] Even if N≧3, the image processing unit 281 can perform alignment of the two read radiation images constituting each of two or more pairs of radiation images to be combined, in the same manner as the alignment of the first and second radiation images described above.

[0319] As in this example, when the alignment of the nth radiation image and the (n+1)th radiation image is performed based on a boundary image corresponding to the boundary between the nth imaging plate 2 and the (n+1)th imaging plate 2 on the (n+1)th imaging plate 2, which is included in the (n+1)th radiation image, and a mark image 350 corresponding to the overlapping portion mark 10 of the nth IP and the (n+1)th IP, the image processing unit 281 can perform the alignment of the nth radiation image and the (n+1)th radiation image in the same manner as described above, using at least one overlapping portion mark 10 of the nth IP and the (n+1)th IP. Therefore, for example, when N=2, the holding member 5 may be provided with two or more overlapping portion marks 10 of the first IP and the second IP.

[0320] Furthermore, the positions of the marks 10 for the non-overlapping portion of the nth IP and the (n+1)th IP used for aligning the nth radiation image and the (n+1)th radiation image in this example are not limited to the above example.

[0321] <Example 8 (Identifying the reading direction)> Once the radiography is complete, as described above, the imaging plate 2 is basically inserted into the reading device 100 from the posterior short side of the oral cavity, and the optical measuring instrument 290 reads the radiographic image from the posterior short side of the imaging plate 2 (in other words, the third side).

[0322] However, the imaging plate 2 may sometimes be mistakenly inserted into the reading device 100 from the anterior short side of the oral cavity by the user. In this case, the optical measuring instrument 290 will read the radiographic image from the anterior short side of the oral cavity (in other words, the fourth side) of the imaging plate 2.

[0323] Thus, when the imaging plate 2 is inserted into the reading device 100 from the posterior short side of the oral cavity, the reading direction of the radiographic image from the imaging plate 2 is opposite to when the imaging plate 2 is inserted into the reading device 100 from the anterior short side of the oral cavity. This is because the reading device 100 does not switch to a predetermined reading direction when reading the radiographic image, but always reads the radiographic image from a constant direction.

[0324] Hereafter, for the sake of explanation, the reading direction when the radiographic image is read from the posterior short side of the imaging plate 2 inside the oral cavity may be referred to as the correct reading direction. Conversely, the reading direction when the radiographic image is read from the anterior short side of the imaging plate 2 inside the oral cavity may be referred to as the incorrect reading direction. Furthermore, from now on, when we refer to the image reading direction, we mean the reading direction when the radiographic image is read from the imaging plate 2.

[0325] In the first example described above, the nth radiation image and the (n+1)th radiation image are aligned assuming that the image reading direction of the nth imaging plate 2 and the (n+1)th imaging plate 2 are the correct reading direction. Therefore, if the image reading direction of at least one of the nth imaging plate 2 and the (n+1)th imaging plate 2 is the incorrect reading direction, the image processing unit 281 may not be able to properly combine the nth radiation image and the (n+1)th radiation image, and may not be able to generate a complete image 400 in which the subject is properly captured.

[0326] For example, consider the case where N=2, the image reading direction of the first imaging plate 2 is the correct reading direction, and the image reading direction of the second imaging plate 2 is the incorrect reading direction. In this case, as shown in the upper part of Figure 48, the molar side is the starting side for reading in the first radiographic image 310, and the anterior side is the starting side for reading in the second radiographic image 320. Therefore, when the first radiographic image 310 and the second radiographic image 320 are placed on the first layout figure 460 as in the first example, the overlapping portion 311 of the first radiographic image 310 and the overlapping portion 321 of the second radiographic image 320 do not overlap, as shown in the lower part of Figure 48. Consequently, the image processing unit 81 cannot properly combine the first radiographic image 310 and the second radiographic image 320. As a result, the image processing unit 81 cannot generate an overall image 400 in which the subject, such as the dental arch, is properly captured. Even when the image reading direction of the first imaging plate 2 is the incorrect reading direction and the image reading direction of the second imaging plate 2 is the correct reading direction, the overlapping portion 311 of the first radiation image 310 and the overlapping portion 321 of the second radiation image 320 will not overlap on the first layout diagram 460. Furthermore, even when the image reading directions of both the first imaging plate 2 and the second imaging plate 2 are the incorrect reading directions, the overlapping portion 311 of the first radiation image 310 and the overlapping portion 321 of the second radiation image 320 will not overlap on the first layout diagram 460.

[0327] In this example, the multiple marks 10 provided on the holding member 5 include at least one reading direction identifying mark (also called a first identifying mark) for identifying the image reading direction of the N imaging plates 2 held by the holding member 5 based on the mark image. The image processing unit 281 performs direction identification processing to identify the image reading direction of the N imaging plates 2 based on the mark image 350 corresponding to at least one reading direction identifying mark included in the N reading radiation images. This allows the image processing unit 281 to easily and accurately identify the reading direction of the radiation images from the imaging plates 2. Then, based on the result of the direction identification processing, the image processing unit 281 can easily and appropriately align the N reading radiation images by aligning the N radiation images. As a result, the likelihood of obtaining a complete image in which the target is properly captured increases.

[0328] Figure 49 is a schematic diagram showing an example of a retaining member 5A. The example in Figure 49 is the same as the example in Figure 16 described above, but with the shapes of marks 10a, 10b, 10c, and 10d changed from circles to equilateral triangles.

[0329] In the retaining member 5A, marks 10a, 10b, 10c, and 10d are arranged in the same orientation (in other words, in the same position). For example, marks 10a, 10b, 10c, and 10d are arranged so that one vertex faces the third side. Therefore, when the retaining member 5A is inserted into the oral cavity from the third side, one vertex of each of marks 10a, 10b, 10c, and 10d faces the back of the oral cavity. Marks 10a, 10b, 10c, and 10d are used as reading direction identifying marks to determine the image reading direction of imaging plates 2a and 2b based on the marked image 350.

[0330] Figure 50 is a schematic diagram showing an example of the first radiographic image 310 read from the imaging plate 2a shown in Figure 49. The upper part of Figure 50 shows an example of the first radiographic image 310 when the image reading direction of the imaging plate 2a is the correct reading direction. The lower part of Figure 50 shows an example of the first radiographic image 310 when the image reading direction of the imaging plate 2a is the incorrect reading direction.

[0331] Marks 10a and 10b are configured such that the image reading direction of the imaging plate 2a is determined by the orientation of the corresponding mark images 350a and 350b. When the image reading direction of the imaging plate 2a is the correct reading direction, as shown in the upper part of Figure 50, one vertex of each of the equilateral triangular mark images 350a and 350b, corresponding to marks 10a and 10b, will face the reading start side. Conversely, when the image reading direction of the imaging plate 2a is the incorrect reading direction, as shown in the lower part of Figure 50, one vertex of the mark images 350a and 350b will face the reading end side. As shown in the example in Figure 50, when the first radiation image 310 is positioned with the reading start side facing upwards, the orientation of the mark images 350a and 350b included in the first radiation image 310 when the image reading direction of the imaging plate 2a is the misreading direction will be the same as the orientation of the mark images 350a and 350b included in the first radiation image 310 when the image reading direction of the imaging plate 2a is the correct reading direction, rotated by 180 degrees. Note that in this example, it is assumed that the overlap of imaging plates 2a and 2b in the holding member 5A is small, so the same can be said even if the overlap of imaging plates 2a and 2b is misaligned.

[0332] Marks 10c and 10d are configured so that the image reading direction of the imaging plate 2b is determined from the orientation of the mark images 350c and 350d. When the image reading direction of the imaging plate 2b is the correct reading direction, one vertex of each of the equilateral triangle mark images 350c and 350d, corresponding to marks 10c and 10d, will face the reading start side. Conversely, when the image reading direction of the imaging plate 2b is the incorrect reading direction, one vertex of the mark images 350c and 350d will face the reading end side.

[0333] In the direction determination process, the image processing unit 281 determines the image reading direction of the imaging plate 2a based on the orientation of the mark images 350a and 350b included in the first radiation image 310. Specifically, the image processing unit 281 determines that the image reading direction of the imaging plate 2a is the correct reading direction if one vertex of each of the mark images 350a and 350b included in the first radiation image 310 points toward the reading start side. On the other hand, in the direction determination process, the image processing unit 81 determines that the image reading direction of the imaging plate 2a is the incorrect reading direction if one vertex of each of the mark images 350a and 350b points toward the reading end side.

[0334] Similarly, in the direction determination process, the image processing unit 281 determines that the image reading direction of the imaging plate 2b is the correct reading direction if one vertex of each of the mark images 350c and 350d included in the second radiation image 320 points toward the reading start side. On the other hand, in the direction determination process, the image processing unit 81 determines that the image reading direction of the imaging plate 2b is the incorrect reading direction if one vertex of each of the mark images 350c and 350d points toward the reading end side.

[0335] If the image processing unit 281 determines in the orientation determination process that the image reading direction of the first imaging plate 2a is the correct reading direction, then, similar to the first example, in the two mark images 350 included in the first radiation image 310, the mark image 350 on the reading start side is set to mark image 350a corresponding to mark 10a, and the mark image 350 on the reading end side is set to mark image 350b corresponding to mark 10b. On the other hand, if the image processing unit 281 determines in the orientation determination process that the image reading direction of the first imaging plate 2a is the incorrect reading direction, then in the two mark images 350 included in the first radiation image 310, the mark image 350 on the reading end side is set to mark image 350a corresponding to mark 10a, and the mark image 350 on the reading start side is set to mark image 350b corresponding to mark 10b.

[0336] Similarly, if the image processing unit 281 determines that the image reading direction of the second imaging plate 2b is the correct reading direction, then, as in the first example, in the two mark images 350 included in the second radiographic image 320, the mark image 350 on the reading start side is set to the mark image 350c corresponding to mark 10c, and the mark image 350 on the reading end side is set to the mark image 350d corresponding to mark 10d. On the other hand, if the image processing unit 281 determines that the image reading direction of the second imaging plate 2b is the incorrect reading direction, then in the two mark images 350 included in the second radiographic image 320, the mark image 350 on the reading end side is set to the mark image 350c corresponding to mark 10c, and the mark image 350 on the reading start side is set to the mark image 350d corresponding to mark 10d.

[0337] The image processing unit 281 identifies the correspondence between the mark images 350a, 350b, 350c, and 350d and the positions 450a, 450b, 450c, and 450d in the first layout diagram 460, and then, similar to the first example, places the first radiation image 310 and the second radiation image 320 on the first layout diagram 460. Specifically, the image processing unit 281 places the second radiation image 320 on the first layout diagram 460 such that the position of the mark image 350c included in the second radiation image 320 (e.g., the position of the centroid) coincides with the position 450c of the mark 10c in the first layout diagram 460, and the position of the mark image 350d included in the second radiation image 320 (e.g., the position of the centroid) coincides with the position 450d of the mark 10d in the first layout diagram 460. The image processing unit 281 then positions the first radiation image 310 on the first layout diagram 460 such that the position of the mark image 350a included in the first radiation image 310 coincides with the position 450a of the mark 10a in the first layout diagram 460, and the position of the mark image 350b included in the first radiation image 310 coincides with the position 450b of the mark 10b in the first layout diagram 460. As a result, as shown in the lower part of Figures 21 and 24 above, the first radiation image 310 and the second radiation image 320 are aligned so that the overlapping portion 311 of the first radiation image 310 perfectly overlaps the overlapping portion 321 of the second radiation image 320. Therefore, the image processing unit 281 can generate an overall image 400 in which the target is properly captured, regardless of whether the image reading direction of the imaging plate 2 is the correct reading direction or the incorrect reading direction. In other words, regardless of whether the user of the reading device 100 inserts the imaging plate 2 into the reading device 100 from the posterior short side or the anterior short side, the image processing unit 281 can generate a complete image 400 in which the subject to be photographed is properly captured. As a result, the user does not need to worry about the direction in which they insert the imaging plate 2 into the reading device 100, improving the convenience of the reading device 100.

[0338] The image processing unit 281 may use only one of the marks 10a and 10b as a reading direction identification mark and determine the image reading direction of the imaging plate 2a based on the orientation of the mark image 350 corresponding to that one mark 10. Similarly, the image processing unit 281 may use only one of the marks 10c and 10d as a reading direction identification mark and determine the image reading direction of the imaging plate 2b based on the orientation of the mark image 350 corresponding to that one mark 10.

[0339] The shape of the reading direction identification mark is not limited to the example above. In cases where the image reading direction of the imaging plate 2 is determined based on the orientation of the mark image 350 corresponding to the reading direction identification mark, as in this example, the reading direction identification mark only needs to have a shape that allows for the identification of a 180-degree rotation of the mark. In other words, the reading direction identification mark only needs to have a shape that allows for the distinction between the orientation before rotation (in other words, the orientation) and the orientation after rotation (in other words, the orientation) when the reading direction identification mark is rotated 180 degrees. Therefore, when the image reading direction of the imaging plate 2 is determined based on the orientation of the mark image 350 corresponding to the reading direction identification mark, marks such as perfect circles and rectangles, which do not allow for the identification of a 180-degree rotation, are not adopted as reading direction identification marks. It can also be said that the reading direction identification mark only needs to have a shape that allows for the distinction between the orientation of the mark image 350 corresponding to the reading direction identification mark when the image reading direction of the imaging plate 2 is the correct reading direction and when it is the incorrect reading direction. The reading direction indicator mark may be a rotationally symmetric figure other than an equilateral triangle, or it may be rotationally symmetric. The shape of the marks 10 other than the reading direction indicator mark included in the multiple marks 10 of the holding member 5 may be any shape.

[0340] In the above example, a reading direction indicator mark is used in the first example, but a reading direction indicator mark may also be used in the second example. Figure 51 is a schematic diagram showing an example of the holding member 5A in this case. The example in Figure 51 is the same as in the example in Figure 29 above, but with the shapes of marks 10g and 10h changed from circles to equilateral triangles. In the holding member 5A, marks 10g and 10h are arranged in the same orientation. For example, marks 10g and 10h are arranged so that one vertex faces the third side. Marks 10g and 10h are used as reading direction indicator marks.

[0341] Marks 10g and 10h are configured such that the image reading direction of the imaging plate 2a is determined by the orientation of the corresponding mark images 350ga and 350ha. In the example shown in Figure 51, when the image reading direction of the imaging plate 2a is the correct reading direction, one vertex of each of the equilateral triangle mark images 350ga and 350ha, corresponding to marks 10g and 10h, will face the reading start side. Conversely, when the image reading direction of the imaging plate 2a is the incorrect reading direction, one vertex of the mark images 350ga and 350ha will face the reading end side.

[0342] Furthermore, marks 10g and 10h are configured such that the image reading direction of the imaging plate 2b is determined by the orientation of the corresponding mark images 350gb and 350hb. When the image reading direction of the imaging plate 2b is the correct reading direction, one vertex of each of the equilateral triangle mark images 350gb and 350hb, corresponding to marks 10g and 10h, will face the reading start side. Conversely, when the image reading direction of the imaging plate 2b is the incorrect reading direction, one vertex of the mark images 350gb and 350hb will face the reading end side.

[0343] In the direction determination process, the image processing unit 281 determines that the image reading direction of the imaging plate 2a is the correct reading direction if one vertex of each of the mark images 350ga and 350ha included in the first radiation image 310 faces the reading start side. On the other hand, in the direction determination process, the image processing unit 81 determines that the image reading direction of the imaging plate 2a is the incorrect reading direction if one vertex of each of the mark images 350ga and 350ha faces the reading end side. The image processing unit 281 can similarly determine the image reading direction of the second imaging plate 2b based on the orientation of the mark images 350gb and 350hb.

[0344] If the image processing unit 281 determines that the image reading direction of the first imaging plate 2a is the correct reading direction, then, similar to the second example, in the two mark images 350 included in the first radiation image 310, the mark image 350 on the reading start side is set to mark image 350ga corresponding to mark 10g, and the mark image 350 on the reading end side is set to mark image 350ha corresponding to mark 10h. On the other hand, if the image processing unit 281 determines that the image reading direction of the first imaging plate 2a is the incorrect reading direction, then in the two mark images 350 included in the first radiation image 310, the mark image 350 on the reading start side is set to mark image 350ha corresponding to mark 10h, and the mark image 350 on the reading end side is set to mark image 350ga corresponding to mark 10g.

[0345] Similarly, if the image processing unit 281 determines that the image reading direction of the second imaging plate 2b is the correct reading direction, then in the two mark images 350 included in the second radiographic image 320, the mark image 350 on the reading start side is set to mark image 350gb corresponding to mark 10g, and the mark image 350 on the reading end side is set to mark image 350hb corresponding to mark 10h. On the other hand, if the image processing unit 281 determines that the image reading direction of the first imaging plate 2b is the incorrect reading direction, then in the two mark images 350 included in the second radiographic image 320, the mark image 350 on the reading start side is set to mark image 350hb corresponding to mark 10h, and the mark image 350 on the reading end side is set to mark image 350gb corresponding to mark 10g.

[0346] Subsequently, the image processing unit 281 partially overlaps the first radiation image 310 and the second radiation image 320, similar to the second example, so that the positions of the mark images 350ga and 350gb corresponding to the same mark 10g coincide with each other, and the positions of the mark images 350ha and 350hb corresponding to the same mark 10h coincide with each other.

[0347] Alternatively, the image processing unit 281 may use only one of the marks 10g and 10h, mark 10, as a mark for determining the reading direction, and determine the image reading direction of the imaging plates 2a and 2b based on the orientation of the mark image 350 corresponding to that one mark 10.

[0348] In the third example described above, reading direction indicator marks may be used. Figure 52 is a schematic diagram showing an example of the holding member 5A in this case. The example in Figure 52 is the same as the example in Figure 33 above, but with the shapes of marks 10b, 10d, and 10g changed from circles to equilateral triangles. In the holding member 5A, marks 10b, 10d, and 10g are arranged such that, for example, one vertex faces the third side. Marks 10b, 10d, and 10g are used as reading direction indicator marks.

[0349] In the direction determination process, the image processing unit 281 determines that the image reading direction of the imaging plate 2a is the correct reading direction if one vertex each of the mark images 350b and 10ga included in the first radiation image 310 faces the reading start side. On the other hand, in the direction determination process, the image processing unit 81 determines that the image reading direction of the imaging plate 2a is the incorrect reading direction if one vertex each of the mark images 350b and 350ga faces the reading end side. The image processing unit 281 can similarly determine the image reading direction of the second imaging plate 2b based on the orientation of the mark images 350d and 350gb.

[0350] If the image processing unit 281 determines that the image reading direction of the first imaging plate 2a is the correct reading direction, then in the two mark images 350 included in the first radiographic image 310, the mark image 350 on the reading start side is set to mark image 350ga corresponding to mark 10g, and the mark image 350 on the reading end side is set to mark image 350b corresponding to mark 10b. On the other hand, if the image processing unit 281 determines that the image reading direction of the first imaging plate 2a is the incorrect reading direction, then in the two mark images 350 included in the first radiographic image 310, the mark image 350 on the reading end side is set to mark image 350ga corresponding to mark 10g, and the mark image 350 on the reading start side is set to mark image 350b corresponding to mark 10b.

[0351] Similarly, if the image processing unit 281 determines that the image reading direction of the second imaging plate 2b is the correct reading direction, then in the two mark images 350 included in the second radiographic image 320, the mark image 350 on the reading start side is set to mark image 350gb corresponding to mark 10g, and the mark image 350 on the reading end side is set to mark image 350d corresponding to mark 10d. On the other hand, if the image processing unit 281 determines that the image reading direction of the second imaging plate 2b is the incorrect reading direction, then in the two mark images 350 included in the second radiographic image 320, the mark image 350 on the reading start side is set to mark image 350d corresponding to mark 10d, and the mark image 350 on the reading end side is set to mark image 350gb corresponding to mark 10g.

[0352] Subsequently, the image processing unit 281, in the same manner as in the third example, arranges the first radiation image 310 and the second radiation image 320 on the first layout diagram 460 such that the position of the mark image 350ga corresponding to the mark 10g included in the first radiation image 310 and the position of the mark image 350gb corresponding to the mark 10g included in the second radiation image 320 coincide with each other, and the mark image 350b corresponding to the mark 10b included in the first radiation image 310 and the mark image 350d corresponding to the mark 10d included in the second radiation image 320 coincide with the positions 450b and 450d shown in the first layout diagram 460.

[0353] The image processing unit 281 may use only one of the marks 10b and 10g as a reading direction identification mark and determine the image reading direction of the imaging plate 2a based on the orientation of the mark image 350 corresponding to that one mark 10. Similarly, the image processing unit 281 may use only one of the marks 10d and 10g as a reading direction identification mark and determine the image reading direction of the imaging plate 2b based on the orientation of the mark image 350 corresponding to that one mark 10.

[0354] In the fourth example described above, a reading direction indicator mark may be used. Figure 53 is a schematic diagram showing an example of the holding member 5A in this case. The example in Figure 53 is the same as the example in Figure 35 described above, but with the shape of the mark 10c changed to an equilateral triangle. In the holding member 5A, the marks 10b and 10c are arranged such that, for example, one vertex faces the third side. The marks 10b and 10c are used as reading direction indicator marks.

[0355] In the direction determination process, the image processing unit 281 determines that the image reading direction of the first imaging plate 2a is the correct reading direction if one vertex of the mark image 350a included in the first radiation image 310 points toward the reading start side. On the other hand, in the direction determination process, the image processing unit 281 determines that the image reading direction of the first imaging plate 2a is the incorrect reading direction if one vertex of the mark image 350a included in the first radiation image 310 points toward the reading end side. In the direction determination process, the image processing unit 281 can similarly determine the image reading direction of the second imaging plate 2b based on the orientation of the mark image 350b.

[0356] Next, the alignment process in the image processing unit 281 will be explained. First, consider the case where, in the direction determination process, it is determined that the image reading directions of both imaging plates 2a and 2b are the correct reading directions. In this case, the image processing unit 281 aligns the first radiographic image 310 and the second radiographic image 320 in the same manner as in the fourth example.

[0357] Next, consider the case where, in the direction determination process, the image reading direction of imaging plate 2a is determined to be the correct reading direction, and the image reading direction of imaging plate 2b is determined to be the incorrect reading direction. In this case, when the image processing unit 281 places the first radiation image 310 and the second radiation image 320 on the second layout diagram 490, it rotates the second radiation image 320 by 180 degrees compared to the fourth example. That is, the image processing unit 281 places the right side of the first radiation image 310 on the second radiation image 320 side, the right side of the second radiation image 320 on the first radiation image 310 side, and the long side of the first radiation image 310 and the long side of the second radiation image 320 are parallel or approximately parallel, so that the mark images 350a and 350c are precisely superimposed on the mark correspondence diagrams 480a and 480c of the second layout diagram 490, respectively. This essentially aligns the first radiation image 310 and the second radiation image 320 so that the overlapping portion 311 of the first radiation image 310 perfectly overlaps the overlapping portion 321 of the second radiation image 320. The right and left sides of the first radiation image 310 refer to the right and left sides, respectively, when the first radiation image 310 is positioned with the reading start side at the top and the reading end side at the bottom (see the top of Figure 37), as described above. The same applies to the right and left sides of the second radiation image 320.

[0358] Next, consider the case where, in the direction determination process, the image reading direction of imaging plate 2a is determined to be the incorrect reading direction, and the image reading direction of imaging plate 2b is determined to be the correct reading direction. In this case, when the image processing unit 281 places the first radiation image 310 and the second radiation image 320 on the second layout diagram 490, it rotates the first radiation image 310 by 180 degrees compared to the fourth example. That is, the image processing unit 281 places the left side of the first radiation image 310 on the second radiation image 320 side, the left side of the second radiation image 320 on the first radiation image 310 side, and the mark images 350a and 350c are precisely superimposed on the mark correspondence diagrams 480a and 480c, respectively, so that the long side of the first radiation image 310 and the long side of the second radiation image 320 are parallel or approximately parallel.

[0359] Finally, consider the case where, in the orientation determination process, it is determined that the image reading directions of both imaging plates 2a and 2b are misreading directions. In this case, when the image processing unit 281 places the first radiation image 310 and the second radiation image 320 on the second layout diagram 490, it rotates the first radiation image 310 and the second radiation image 320 by 180 degrees compared to the fourth example. That is, the image processing unit 281 places the left side of the first radiation image 310 on the second radiation image 320 side, the right side of the second radiation image 320 on the first radiation image 310 side, and the mark images 350a and 350c are precisely superimposed on the mark correspondence diagrams 480a and 480c, respectively, so that the long side of the first radiation image 310 and the long side of the second radiation image 320 are parallel or approximately parallel.

[0360] Furthermore, if mark 10a is not rotatable, regardless of whether the image reading direction of imaging plate 2a is the correct or incorrect reading direction, the mark image 350a corresponding to mark 10a will be precisely superimposed on the mark correspondence figure 480a of the second layout figure 490, thereby appropriately positioning the first radiographic image 310 on the second layout figure 490. Therefore, if mark 10a is not rotatable, it is not necessary to determine the image reading direction of imaging plate 2a. Similarly, if mark 10b is not rotatable, it is not necessary to determine the image reading direction of imaging plate 2b.

[0361] In the fifth example described above, a reading direction indicator mark may be used. Figure 54 is a schematic diagram showing an example of the holding member 5A in this case. The example in Figure 54 is the same as the example in Figure 39 above, but with the shape of the mark 10g changed to an equilateral triangle. The mark 10g is used as a reading direction indicator mark.

[0362] In the direction determination process, the image processing unit 281 determines that the image reading direction of the first imaging plate 2a is the correct reading direction if one vertex of the mark image 350ga included in the first radiation image 310 points toward the reading start side. On the other hand, in the direction determination process, the image processing unit 281 determines that the image reading direction of the first imaging plate 2a is the incorrect reading direction if one vertex of the mark image 350ga included in the first radiation image 310 points toward the reading end side. The image processing unit 281 can similarly determine the image reading direction of the second imaging plate 2b based on the orientation of the mark image 350gb.

[0363] Next, the alignment of the imaging plate 2 in the image processing unit 281 will be explained. First, consider the case where the image reading direction of both imaging plates 2a and 2b is determined to be the correct reading direction in the direction determination process. In this case, the image processing unit 281 aligns the first radiographic image 310 and the second radiographic image 320 in the same manner as in the fifth example.

[0364] Next, consider the case where, in the orientation determination process, the image reading direction of imaging plate 2a is determined to be the correct reading direction, and the image reading direction of imaging plate 2b is determined to be the incorrect reading direction. In this case, the image processing unit 281 precisely overlaps the mark image 350ga and the mark image 350gb so that the right side of the first radiation image 310 is positioned towards the second radiation image 320, the right side of the second radiation image 320 is positioned towards the first radiation image 310, and the long sides of the first radiation image 310 and the long sides of the second radiation image 320 are parallel or approximately parallel.

[0365] Next, consider the case where, in the orientation determination process, the image reading direction of imaging plate 2a is determined to be the incorrect reading direction, and the image reading direction of imaging plate 2b is determined to be the correct reading direction. In this case, the image processing unit 281 precisely overlaps the mark image 350ga and the mark image 350gb so that the left side of the first radiation image 310 is positioned towards the second radiation image 320, the left side of the second radiation image 320 is positioned towards the first radiation image 310, and the long sides of the first radiation image 310 and the long sides of the second radiation image 320 are parallel or approximately parallel.

[0366] Finally, consider the case where, during the orientation determination process, it is determined that the image reading directions of both imaging plates 2a and 2b are misreading directions. In this case, the image processing unit 281 precisely overlaps the mark image 350ga and the mark image 350gb so that the left side of the first radiation image 310 is positioned towards the second radiation image 320, the right side of the second radiation image 320 is positioned towards the first radiation image 310, and the long sides of the first radiation image 310 and the long sides of the second radiation image 320 are parallel or approximately parallel.

[0367] Furthermore, if mark 10g is not a rotatable object, regardless of whether the image reading direction of imaging plates 2a and 2b is the correct reading direction or the incorrect reading direction, mark image 350ga and mark image 350gb can be precisely superimposed on each other, so that the overlapping portion 311 of the first radiation image 310 and the overlapping portion 321 of the second radiation image 320 are precisely aligned. Therefore, if mark 10g is not a rotatable object, the direction determination process does not need to be performed.

[0368] In the sixth example described above, the orientation determination process does not need to be performed. In the sixth example, the position of the mark image 350a included in the first radiation image 310 coincides with position 450a on the first layout diagram 460, the position of the mark image 350c included in the second radiation image 320 coincides with position 450c on the first layout diagram 460, and the first radiation image 310 and the second radiation image 320 are arranged on the first layout diagram 460 such that one long side of the first radiation image 310 and the corresponding long side image 326 of the second radiation image 320 overlap each other. As a result, regardless of whether the image reading direction of the imaging plates 2a and 2b is the correct reading direction or the incorrect reading direction, the first radiation image 310 and the second radiation image 320 are properly aligned so that the overlapping portion 311 of the first radiation image 310 and the overlapping portion 321 of the second radiation image 320 perfectly overlap. Therefore, in the sixth example, the orientation determination process does not need to be performed.

[0369] In the seventh example described above, the direction determination process does not need to be performed. In the seventh example, the position of the mark image 350ga included in the first radiation image 310 and the position of the mark image 350gb included in the second radiation image 320 coincide with each other, and the first radiation image 310 and the second radiation image 320 are aligned so that one of the long sides of the first radiation image 310 overlaps with the long side corresponding image 326 of the second radiation image 320. As a result, regardless of whether the image reading direction of the imaging plates 2a and 2b is the correct reading direction or the incorrect reading direction, the first radiation image 310 and the second radiation image 320 are properly aligned so that the overlapping portion 311 of the first radiation image 310 and the overlapping portion 321 of the second radiation image 320 perfectly overlap. Therefore, in the seventh example, the direction determination process does not need to be performed.

[0370] The image processing unit 281 may determine the image reading direction of the imaging plate 2 based on the position of the mark image 350 corresponding to the reading direction identification mark, rather than the orientation of the mark image 350 corresponding to the reading direction identification mark.

[0371] Figure 55 is a schematic diagram showing an example of a holding member 5A in the first example, where the image reading direction of the imaging plate 2 is determined based on the position of the mark image 350 corresponding to the reading direction identification mark.

[0372] The example in Figure 55 is the same as the example in Figure 16 described above, but with the positions of marks 10b and 10d changed. In the example in Figure 55, the mark image 350b corresponding to mark 10b is recorded in the longitudinal center of the imaging plate 2a at the first side end of the imaging plate 2a, unlike in the example in Figure 17 described above. Also, the mark image 350d corresponding to mark 10d is recorded in the longitudinal center of the imaging plate 2b at the second side end of the imaging plate 2b, unlike in the example in Figure 17. Marks 10a, 10b, 10c, and 10d are used as reading direction identification marks.

[0373] Marks 10a and 10b are configured such that the image reading direction of the imaging plate 2a is determined from the positions of the corresponding mark images 350a and 350b. In this example, the layout of the mark images 350a and 350b in the first radiation image 310 differs depending on whether the image reading direction of the imaging plate 2a is the correct reading direction or the incorrect reading direction. When the image reading direction of the imaging plate 2a is the correct reading direction, in the first radiation image 310, the mark image 350a corresponding to mark 10a is located on the reading start side, and the mark image 350b corresponding to mark 10b is located in the longitudinal center of the first radiation image 310. In contrast, when the image reading direction of the imaging plate 2a is the incorrect reading direction, in the first radiation image 310, the mark image 350a is located on the reading end side, and the mark image 350b is located in the longitudinal center of the first radiation image 310.

[0374] Marks 10c and 10d are configured such that the image reading direction of the imaging plate 2b is determined from the positions of the corresponding mark images 350c and 350d. When the image reading direction of the imaging plate 2b is the correct reading direction, in the second radiographic image 320, the mark image 350c corresponding to mark 10c is located on the reading start side, and the mark image 350d corresponding to mark 10d is located in the longitudinal center of the second radiographic image 320. Conversely, when the image reading direction of the imaging plate 2b is the incorrect reading direction, in the second radiographic image 320, the mark image 350c is located on the reading end side, and the mark image 350d is located in the longitudinal center of the second radiographic image 320.

[0375] The image processing unit 281 determines the image reading direction of the imaging plate 2a based on the positions (in other words, layout) of the mark images 350a and 350b included in the first radiation image 310. Specifically, the image processing unit 281 determines that the image reading direction of the imaging plate 2a is the correct reading direction if one of the two mark images 350a and 350b included in the first radiation image 310 is located on the reading start side and the other mark image 350 is located in the longitudinal center of the first radiation image 310. On the other hand, the image processing unit 281 determines that the image reading direction of the imaging plate 2a is the incorrect reading direction if one of the mark images 350 is located on the reading end side and the other mark image 350 is located in the longitudinal center of the first radiation image 310.

[0376] Similarly, the image processing unit 281 determines that the image reading direction of the imaging plate 2b is the correct reading direction if, of the two mark images 350c and 350d included in the second radiation image 320, one mark image 350 is located on the reading start side and the other mark image 350 is located in the longitudinal center of the second radiation image 320. On the other hand, the image processing unit 81 determines that the image reading direction of the imaging plate 2b is the incorrect reading direction if one mark image 350 is located on the reading end side and the other mark image 350 is located in the longitudinal center of the second radiation image 320.

[0377] After the orientation determination process, the image processing unit 281 aligns the first radiation image 310 and the second radiation image 320 in the same manner as in the eighth example described above.

[0378] In the example shown in Figure 55, only mark 10a of marks 10a and 10b may be used as a reading direction identification mark. When the image reading direction of the imaging plate 2a is the correct reading direction, the mark image 350a corresponding to mark 10a is located at the beginning end of the reading of the first radiation image 310. On the other hand, when the image reading direction of the imaging plate 2a is the incorrect reading direction, the mark image 350a corresponding to mark 10a is located at the end of the reading of the first radiation image 310. The image processing unit 281 determines that the image reading direction of the imaging plate 2a is the correct reading direction if the mark image 350 is located at the beginning end of the reading of the first radiation image 310. The image processing unit 281 then determines that the image reading direction of the imaging plate 2a is the incorrect reading direction if the mark image 350 is located at the end of the reading of the first radiation image 310. Similarly, only mark 10c of marks 10c and 10d may be used as a reading direction identification mark.

[0379] The image processing unit 281 can determine the image reading direction of imaging plates 2a and 2b even if the layout of the multiple marks 10a, 10b, 10c, and 10d is as shown in Figures 16 and 49 above. In the example of Figures 16 and 49, when the image reading direction of imaging plate 2a is the correct reading direction, the two mark images 350a and 350b included in the first radiation image 310 are located to the left of the first radiation image 310 (see upper part of Figure 50). On the other hand, when the image reading direction of imaging plate 2a is the incorrect reading direction, the two mark images 350a and 350b included in the first radiation image 310 are located to the right of the first radiation image 310 (see lower part of Figure 50). The same applies to the two mark images 350c and 350d included in the second radiation image 320.

[0380] The image processing unit 281 determines that the image reading direction of the imaging plate 2a is the correct reading direction if the two mark images 350 (i.e., mark images 350a and 350b) included in the first radiation image 310 are located to the left of the first radiation image 310. On the other hand, the image processing unit 281 determines that the image reading direction of the imaging plate 2a is the incorrect reading direction if the two mark images included in the first radiation image 310 are located to the right of the first radiation image 310. The image processing unit 281 can similarly determine the image reading direction of the imaging plate 2b based on the positions (in other words, layout) of the mark images 350c and 350d included in the second radiation image 320.

[0381] As in this example, when the image reading direction of the imaging plate 2 is determined based on the position of the mark image 350, the image processing unit 281 can determine the image reading direction of the imaging plate 2 if the layout of the multiple mark images 350 included in the read radiographic image read from the imaging plate 2 can be distinguished between the correct reading direction and the incorrect reading direction. In other words, if the read radiographic image is rotated 180 degrees, the image processing unit 281 can determine the image reading direction of the imaging plate 2 if the layout of the multiple mark images 350 before rotation and the layout of the multiple mark images 350 after rotation can be distinguished.

[0382] Figure 56 is a schematic diagram showing another example of the retaining member 5A. In the example in Figure 56, the shapes of marks 10a and 10c are changed to equilateral triangles in the example in Figure 16 described above. In the example in Figure 56, the triangular marks 10a and 10c are used as reading direction identification marks.

[0383] In the example shown in Figure 56, the image processing unit 281 determines the image reading direction of the imaging plate 2a based on the position of the mark image 350a corresponding to the mark 10a included in the first radiation image 310. In the example shown in Figure 56, if the image reading direction of the imaging plate 2a is the correct reading direction, the triangular mark image 350a in the first radiation image 310 is located on the reading start side. On the other hand, if the image reading direction of the imaging plate 2a is the incorrect reading direction, the triangular mark image 350a in the first radiation image 310 is located on the reading end side. The image processing unit 281 determines that the image reading direction of the imaging plate 2a is the correct reading direction if the triangular mark image 350 included in the first radiation image 310 is located on the reading start side. The image processing unit 281 also determines that the image reading direction of the imaging plate 2a is the incorrect reading direction if the triangular mark image 350 included in the first radiation image 310 is located on the reading end side. In the example shown in Figure 56, the image processing unit 281 identifies the shape of the mark image 350, and therefore it can be said that it determines the image reading direction of the imaging plate 2a based on the position and shape of the mark image 350a. The image processing unit 281 may similarly determine the image reading direction of the imaging plate 2b based on the position of the mark image 350c corresponding to the mark 10c included in the second radiographic image 320.

[0384] In the example in Figure 56, the circular marks 10b and 10d may be used as reading direction identification marks. When the image reading direction of the imaging plate 2a is the correct reading direction, the circular mark image 350b in the first radiation image 310 is located on the end of the reading side. On the other hand, when the image reading direction of the imaging plate 2a is the wrong reading direction, the circular mark image 350b in the first radiation image 310 is located on the start of the reading side. The image processing unit 281 determines that the image reading direction of the imaging plate 2a is the correct reading direction if the circular mark image 350 included in the first radiation image 310 is located on the end of the reading side. The image processing unit 81 determines that the image reading direction of the imaging plate 2a is the wrong reading direction if the circular mark image 350 included in the first radiation image 310 is located on the start of the reading side. The image processing unit 281 may similarly determine the image reading direction of the imaging plate 2b based on the position of the mark image 350d corresponding to the mark 10d included in the second radiographic image 320.

[0385] Furthermore, in the example shown in Figure 56, the image processing unit 281 may determine the image reading direction of the imaging plate 2a based on the orientation and position of the mark image 350a corresponding to the mark 10a included in the first radiation image 310. In this case, the image processing unit 281 determines that the image reading direction of the imaging plate 2a is the correct reading direction if the triangular mark image 350 included in the first radiation image 310 is located on the reading start side and one vertex of the mark image 350 is facing the reading start side. On the other hand, the image processing unit 281 determines that the image reading direction of the imaging plate 2a is the incorrect reading direction if the triangular mark image 350 included in the first radiation image 310 is located on the reading end side and one vertex of the mark image 350 is facing the reading end side. In the example shown in Figure 56, it can also be said that the mark 10a is configured such that the image reading direction of the imaging plate 2a is determined from the orientation and position of the mark image 350a. The image processing unit 281 may similarly determine the image reading direction of the imaging plate 2b based on the orientation and position of the mark image 350c corresponding to the mark 10c included in the second radiographic image 320.

[0386] In the above examples, in the first example, the image reading direction of the imaging plate 2 is determined based on the position of the mark image 350 corresponding to the reading direction identification mark. However, in the second example, the image reading direction of the imaging plate 2 may also be determined based on the position of the mark image 350 corresponding to the reading direction identification mark. For example, consider the example in Figure 29 above. In this case, the image processing unit 281 determines that the image reading direction of the imaging plate 2a is the correct reading direction if the two mark images 350 included in the first radiation image 310 are located to the right of the first radiation image 310. On the other hand, the image processing unit 281 determines that the image reading direction of the imaging plate 2a is the incorrect reading direction if the two mark images 350 included in the first radiation image 310 are located to the left of the first radiation image 310. Furthermore, the image processing unit 281 determines that the image reading direction of the imaging plate 2b is the correct reading direction if the two mark images 350 included in the second radiation image 320 are located to the left of the second radiation image 320. On the other hand, the image processing unit 281 determines that the image reading direction of the imaging plate 2b is incorrect if the two mark images 350 included in the second radiation image 320 are located to the right of the second radiation image 320. In the second example as well, the image reading direction of the imaging plate 2 may be determined based on the orientation and position of the mark images 350 corresponding to the reading direction identification marks.

[0387] In the third example, the image reading direction of the imaging plate 2 may be determined based on the position of the mark image 350 corresponding to the reading direction identification mark. For example, consider the example in Figure 57. In this case, the image processing unit 281 determines that the image reading direction of the imaging plate 2a is the correct reading direction if the two mark images 350 included in the first radiation image 310 are located on the reading start side of the first radiation image 310. On the other hand, the image processing unit 281 also determines that the image reading direction of the imaging plate 2a is the correct reading direction if the two mark images 350 included in the first radiation image 310 are located on the reading end side of the first radiation image 310. The image processing unit 281 can similarly determine the image reading direction of the imaging plate 2b based on the positions of the two mark images 350 included in the second radiation image 320. In addition, in the third example, the image reading direction of the imaging plate 2 may also be determined based on the orientation and position of the mark image 350 corresponding to the reading direction identification mark.

[0388] In the fourth example, the image reading direction of the imaging plate 2 may be determined based on the position of the mark image 350 corresponding to the reading direction identification mark. For example, consider the example in Figure 35 above. In this case, the image processing unit 281 determines that the image reading direction of the imaging plate 2a is the correct reading direction if the mark image 350 included in the first radiation image 310 is located on the reading start side of the first radiation image 310. On the other hand, the image processing unit 281 determines that the image reading direction of the imaging plate 2a is the correct reading direction if the mark image 350 included in the first radiation image 310 is located on the reading end side of the first radiation image 310. The image processing unit 281 can similarly determine the image reading direction of the imaging plate 2b based on the position of the mark image 350 included in the second radiation image 320. In addition, in the fourth example, the image reading direction of the imaging plate 2 may also be determined based on the orientation and position of the mark image 350 corresponding to the reading direction identification mark.

[0389] In the fifth example, the image reading direction of the imaging plate 2 may be determined based on the position of the mark image 350 corresponding to the reading direction identification mark. For example, consider the example in Figure 39 above. In this case, the image processing unit 281 determines that the image reading direction of the imaging plate 2a is the correct reading direction if the mark image 350 included in the first radiation image 310 is located on the reading start side of the first radiation image 310. On the other hand, the image processing unit 281 determines that the image reading direction of the imaging plate 2a is the correct reading direction if the mark image 350 included in the first radiation image 310 is located on the reading end side of the first radiation image 310. The image processing unit 281 can similarly determine the image reading direction of the imaging plate 2b based on the position of the mark image 350 included in the second radiation image 320. In addition, even in the fifth example, the image reading direction of the imaging plate 2 may be determined based on the orientation and position of the mark image 350 corresponding to the reading direction identification mark.

[0390] The above explanation mainly focused on the case where N=2, but even when N≧3, the image processing unit 281 can similarly determine the image reading direction of the N imaging plates 2 based on the mark images 350 corresponding to the reading direction identification marks included in the N read radiation images.

[0391] As described above, in this example, the image processing unit 281 aligns the N read radiation images based on the reading direction of the radiation image from each of the N imaging plates 2 and the mark images 350 included in the N read radiation images read from the N imaging plates 2, making it possible to align the N read radiation images easily and appropriately.

[0392] <Example 9 (Identifying the hierarchical relationship of overlapping elements)> For example, suppose a user inserts the first imaging plate 2 on the side of the holding member 5A into the reading device 100, and then inserts the second imaging plate 2 on the side of the holding member 5A into the reading device 100. The image processing unit 281 then aligns the read radiation images so that the read radiation image from the later-inserted imaging plate 2 is on top of the read radiation image from the first-inserted imaging plate 2. Furthermore, as shown in the example in Figure 15, the image processing unit 281 removes the overlapping portion of the upper radiation image with the lower radiation image, and leaves the overlapping portion of the lower radiation image with the upper radiation image, and then combines the upper radiation image and the latent image of the lower radiation image.

[0393] In such a case, as in the example above, when the overlapping relationship information indicated by the holding member 5A indicates that the imaging plates 2 should be stacked so that the first imaging plate 2 is positioned above the second imaging plate 2, the image processing unit 281 aligns the first and second radiation images 310 and 320 so that the first radiation image 310 read from the upper first imaging plate 2 is positioned above the second radiation image 320 read from the lower second imaging plate 2. Then, the image processing unit 281 retains the overlapping portion 311 in the upper first radiation image 310 and deletes the overlapping portion 321 in the lower second radiation image 320, thereby combining the first and second radiation images 310 and 320.

[0394] Here, let's assume that the image processing unit 281 ideally aims to improve the image quality of the overall image 400 by retaining the high-quality overlapping portion 311 contained in the first radiation image 310 read from the upper imaging plate 2, and deleting the low-quality overlapping portion 321 contained in the second radiation image 320 read from the lower imaging plate 2, and then combining the first radiation image 310 and the second radiation image 320. In the above example, since the low-quality overlapping portion 321 is deleted when the first radiation image 310 and the second radiation image 320 are combined, a relatively high-quality overall image 400 is generated using the high-quality overlapping portion 311. Note that "high quality" of the overlapping portion 311 means that its image quality is better (superior) compared to the overlapping portion 321. Also, "low quality" of the overlapping portion 321 means that its image quality is worse (inferior) compared to the overlapping portion 311. The same applies below.

[0395] In contrast, when the overlapping relationship information indicated by the holding member 5A indicates that the imaging plates 2 should be stacked so that the second imaging plate 2 is positioned above the first imaging plate 2, the image processing unit 281 aligns the first and second radiation images 310 and 320 so that the second radiation image 320 read from the lower imaging plate 2 is positioned above the first radiation image 310 read from the upper imaging plate 2. Then, the image processing unit 281 retains the overlapping portion 321 in the upper second radiation image 320 and deletes the overlapping portion 311 in the lower first radiation image 310, thereby combining the first and second radiation images 310 and 320. In this case, the image processing unit 281 generates the overall image 400 using the lower quality overlapping portion 321 rather than the higher quality overlapping portion 311, resulting in a relative decrease in the image quality of the overall image 400.

[0396] Thus, if the image processing unit 281 does not understand the overlapping relationship between the two imaging plates 2 held by the holding member 5A, the overlapping portion 311 and 321 that should be deleted may not be deleted, and the first radiographic image 310 and the second radiographic image 320 may be merged.

[0397] In this example, the multiple marks 10 on the holding member 5 include at least one vertical relationship identification mark (also called a fourth identification mark) for identifying the vertical relationship of the overlapping multiple imaging plates 2 on the holding member 5 based on the mark image. In the alignment process, the image processing unit 281 performs a vertical relationship identification process to identify the vertical relationship of the overlapping N imaging plates 2 based on the mark image 350 corresponding to at least one vertical relationship identification mark. This allows the image processing unit 281 to easily and accurately identify the vertical relationship of the overlapping N imaging plates 2. Then, the image processing unit 281 aligns the N read radiation images based on the identified vertical relationship and the mark images 350 included in the N read radiation images. This allows the image processing unit 281 to easily and appropriately align the N read radiation images. As a result, for example, a high-quality overall image 400 can be generated.

[0398] Figure 58 is a schematic diagram showing an example of the holding member 5A. In the example in Figure 58, the shapes of marks 10a and 10b are changed to equilateral triangles, and the shapes of marks 10c and 10d are changed to arrows, compared to the example in Figure 16 described above. Marks 10a, 10b, 10c, and 10d are used as marks 10 for identifying the top / bottom relationship. In the example in Figure 58, the top / bottom relationship of the overlapping two imaging plates 2 is identified from the difference in the shape of the mark images 350 corresponding to the marks 10 for identifying the top / bottom relationship between the two read radiation images read from the two imaging plates 2 held by the holding member 5A.

[0399] Furthermore, in the example shown in Figure 58, the overlapping relationship information indicated by the holding member 5A shows that the imaging plates 2 are stacked such that the imaging plate 2 on the first side is positioned above the imaging plate 2 on the second side. Therefore, in the holding member 5A, the imaging plate 2 on the first side is positioned above the imaging plate 2 on the second side.

[0400] Marks 10a, 10b, 10c, and 10d are configured so that the top-bottom relationship of the overlapping two imaging plates 2 in the holding member 5A can be identified from the shape of the corresponding mark image 350. The triangular marks 10a and 10b for recording the mark image 350 on the first side imaging plate 2 are for recording the mark image on the upper imaging plate 2 of the two imaging plates 2 held by the holding member 5A. Therefore, the read radiation image from the upper imaging plate 2 includes triangular mark images 350a and 350b corresponding to marks 10a and 10b. On the other hand, the arrow marks 10c and 10d for recording the mark image 350 on the second side imaging plate 2 are for recording the mark image on the lower imaging plate 2 of the two imaging plates 2 held by the holding member 5A. Therefore, the read radiation image from the lower imaging plate 2 includes arrow mark images 350c and 350d corresponding to marks 10c and 10d.

[0401] Furthermore, if the overlapping relationship information indicated by the holding member 5A indicates that the imaging plates 2 should be stacked such that the second imaging plate 2 is positioned above the first imaging plate 2, then the shapes of marks 10a and 10b will be arrows, and the shapes of marks 10c and 10d will be equilateral triangles.

[0402] The image processing unit 281 determines the upper and lower relationship of the overlapping two imaging plates 2 held by the holding member 5A based on the shapes of the mark images 350a, 350b, 350c, and 350d corresponding to the marks 10a, 10b, 10c, and 10d. Specifically, if the read radiation image read from a certain imaging plate 2 includes a triangular mark image 350, the image processing unit 281 designates that imaging plate 2 as the upper imaging plate 2 in the holding member 5A. Then, the image processing unit 281 designates the image to be read from that imaging plate 2 as the first radiation image 310 read from the upper imaging plate 2.

[0403] On the other hand, if the image processing unit 281 reads an image of a radiation with an arrow mark 350 from a certain imaging plate 2, it designates that imaging plate 2 as the lower imaging plate 2 in the holding member 5A. Then, the image processing unit 281 designates the image of the radiation read from that imaging plate 2 as the second radiation image 320 read from the lower imaging plate 2.

[0404] The image processing unit 281 identifies the upper and lower relationship of the overlapping two imaging plates 2 in the holding member 5A, and then, as in the first example, aligns the first radiation image 310 and the second radiation image 320 based on the first layout diagram 460 and the mark images 350a, 350b, 350c, and 350d. At this time, the image processing unit 281 places the first radiation image 310 above the second radiation image 320. Subsequently, the image processing unit 281 retains the high-quality overlapping portion 311 in the upper first radiation image 320 and deletes the low-quality overlapping portion 321 in the lower second radiation image 320, thereby combining the first radiation image 310 and the second radiation image 320. As a result, the overlapping portion 321 that was originally intended to be deleted is reliably removed, and a high-quality overall image 400 is obtained.

[0405] In the example above, the overlapping portion 321 was the one to be deleted from the overlapping portion 311 and 321, but it could also be the overlapping portion 311. In other words, the image processing unit 281 may ideally delete the overlapping portion 311 contained in the first radiation image 310 read from the upper imaging plate 2, and leave the overlapping portion 321 contained in the second radiation image 320 read from the lower imaging plate 2, and then combine the first radiation image 310 and the second radiation image 320. In this case, the image processing unit 281 identifies the upper and lower relationship of the overlapping of the two imaging plates 2 in the holding member 5A, then places the first radiation image 310 above the second radiation image 320, deletes the overlapping portion 311 from the upper first radiation image 320, and leaves the overlapping portion 321 from the lower second radiation image 320, and then combines the first radiation image 310 and the second radiation image 320.

[0406] The image processing unit 281 may determine the top-down relationship of the N imaging plates 2 based on the position of the mark image 350 corresponding to the top-down relationship identification mark included in the N read radiation images. Figure 59 is a schematic diagram showing an example of the holding member 5A in this case.

[0407] The example in Figure 59 is the same as the example in Figure 16 described above, but with a change in the position of mark 10b. In the example in Figure 59, the mark image 350b corresponding to mark 10b is recorded in the longitudinal center of the imaging plate 2a at the first side end of the imaging plate 2a, unlike in the example in Figure 17 described above. Marks 10a, 10b, 10c, and 10d are used as marks for determining the top / bottom relationship. In the example in Figure 59, the top / bottom relationship of the overlapping two imaging plates 2 is determined based on the difference in the position of the mark images 350 corresponding to the marks for determining the top / bottom relationship between the two read radiation images read from the two imaging plates 2. Marks 10a, 10b, 10c, and 10d are configured so that the top / bottom relationship of the overlapping two imaging plates 2 in the holding member 5A is determined from the position of the mark images 350 corresponding to them.

[0408] In the example shown in Figure 59, the image processing unit 281 determines that an imaging plate 2 read from a given imaging plate 2 contains a mark image 350 at both its longitudinal end and its longitudinal center, and designates that imaging plate 2 as the upper imaging plate 2 in the holding member 5A. The image processing unit 281 then designates the read imaging plate 2 read from that imaging plate 2 as the first imaging image 310. On the other hand, if an imaging plate 2 reads from a given imaging plate 2 and contains a mark image 350 at both its longitudinal end and its other longitudinal end, the image processing unit 281 determines that an imaging plate 2 read from that imaging plate 2 as the lower imaging plate 2 in the holding member 5A. The image processing unit 281 then designates the read imaging plate 2 read from that imaging plate 2 as the second imaging image 320.

[0409] The image processing unit 281 may determine the overlapping vertical relationship of the N imaging plates 2 based on the number of mark images 350 corresponding to the vertical relationship identification marks included in the N read radiation images. Figure 60 is a schematic diagram showing an example of the holding member 5A in this case.

[0410] The example in Figure 60 is the same as the example in Figure 16 described above, but with the addition of mark 10j to the holding member 5A. In the example in Figure 60, the mark image 350 corresponding to mark 10j is recorded at the first side end of the imaging plate 2a, in the longitudinal center of the imaging plate 2a. Marks 10a, 10b, 10c, 10d, and 10j are used as marks for determining the top / bottom relationship. In the example in Figure 60, the top / bottom relationship of the overlapping two imaging plates 2 is determined based on the difference in the number of mark images 350 corresponding to the marks for determining the top / bottom relationship between the two read radiation images read from the two imaging plates 2 held by the holding member 5A. Marks 10a, 10b, 10c, 10d, and 10j are configured so that the top / bottom relationship of the overlapping two imaging plates 2 in the holding member 5A is determined by the number of mark images 350 corresponding to them.

[0411] In the example shown in Figure 60, if the read radiation image from a certain imaging plate 2 contains three mark images 350, the image processing unit 281 designates that imaging plate 2 as the upper imaging plate 2 in the holding member 5A. The image processing unit 281 then designates the read radiation image from that imaging plate 2 as the first radiation image 310. On the other hand, if the read radiation image from a certain imaging plate 2 contains two mark images 350, the image processing unit 281 designates that imaging plate 2 as the lower imaging plate 2 in the holding member 5A. The image processing unit 281 then designates the read radiation image from that imaging plate 2 as the second radiation image 320.

[0412] The image processing unit 281 may determine the top-down relationship of the N imaging plates 2 based on the shape and position of the mark images 350 corresponding to the top-down relationship identification marks included in the N read radiation images. For example, consider the case in the example of Figure 59 where the shapes of marks 10a and 10b are changed to triangles, and the shapes of marks 10c and 10d are changed to arrows. In this case, the image processing unit 281 determines that an imaging plate 2 is the upper imaging plate 2 in the holding member 5A if a triangular mark image 350 is included at the longitudinal end of the read radiation image read from a certain imaging plate 2, and a triangular mark image 350 is included in the longitudinal center of the read radiation image. On the other hand, the image processing unit 281 determines that an imaging plate 2 is the lower imaging plate 2 in the holding member 5A if an arrow mark image 350 is included at one longitudinal end of the read radiation image read from a certain imaging plate 2, and an arrow mark image 350 is included at the other longitudinal end of the read radiation image.

[0413] The image processing unit 281 may determine the overlapping relationship of the N imaging plates 2 based on the shape and number of mark images 350 corresponding to the top-down relationship identification marks included in the N read radiation images. For example, consider the case in the example of Figure 60 where the shapes of marks 10a, 10b, and 10j are changed to triangles, and the shapes of marks 10c and 10d are changed to arrows. In this case, if the read radiation image read from a certain imaging plate 2 contains three triangular mark images 350, the image processing unit 281 will designate that imaging plate 2 as the upper imaging plate 2 in the holding member 5A. On the other hand, if the read radiation image read from a certain imaging plate 2 contains two arrow mark images 350, the image processing unit 281 will designate that imaging plate 2 as the lower imaging plate 2 in the holding member 5A.

[0414] The image processing unit 281 may determine the overlapping relationship of the N imaging plates 2 based on the position and number of mark images 350 corresponding to the top-down relationship identification marks included in the N read radiation images. For example, in the example of Figure 60, if a read radiation image read from a certain imaging plate 2 contains three mark images 350, and these three mark images 350 consist of a mark image 350 located at one end in the longitudinal direction of the read radiation image, a mark image 350 located at the other end in the longitudinal direction of the read radiation image, and a mark image 350 located at the central end in the longitudinal direction of the read radiation image, then the certain imaging plate 2 is designated as the upper imaging plate 2 in the holding member 5A. On the other hand, if the read radiographic image read from a certain imaging plate 2 includes two mark images 350, and these two mark images 350 consist of a mark image 350 located at one end of the read radiographic image in the longitudinal direction and a mark image 350 located at the other end of the read radiographic image in the longitudinal direction, the image processing unit 281 will designate the certain imaging plate 2 as the lower imaging plate 2 in the holding member 5A.

[0415] The image processing unit 281 may determine the overlapping relationship of the N imaging plates 2 based on the shape, position, and number of mark images 350 corresponding to the top-down relationship identification marks included in the N read radiation images. For example, consider the case in the example of Figure 60 where the shapes of marks 10a, 10b, and 10j are changed to triangles, and the shapes of marks 10c and 10d are changed to arrows. In this case, if the read radiation image read from a certain imaging plate 2 contains three triangular mark images 350, and these three triangular mark images 350 consist of a triangular mark image 350 located at one end in the longitudinal direction of the read radiation image, a triangular mark image 350 located at the other end in the longitudinal direction of the read radiation image, and a triangular mark image 350 located at the central end in the longitudinal direction of the read radiation image, then the image processing unit 281 designates the certain imaging plate 2 as the upper imaging plate 2 in the holding member 5A. On the other hand, the image processing unit 281 determines that the imaging plate 2 read from a certain imaging plate 2 contains two arrow mark images 350, and that the two arrow mark images 350 consist of an arrow mark image 350 located at one end of the longitudinal direction of the read radiation image and an arrow mark image 350 located at the other end of the longitudinal direction of the read radiation image, and then designates the imaging plate 2 as the lower imaging plate 2 in the holding member 5A.

[0416] The above explanation mainly focused on the case where N=2, but even when N≧3, the image processing unit 281 can similarly determine the overlapping vertical relationship of the two imaging plates 2 on which the two readable radiation images are read, based on the mark images 350 corresponding to the vertical relationship identification marks 10 included in the two readable radiation images constituting one pair of combined radiation images. In other words, the image processing unit 281 can similarly determine the overlapping vertical relationship of N imaging plates 2 based on the mark images 350 corresponding to the vertical relationship identification marks 10 included in N readable radiation images.

[0417] Furthermore, in the case where the holding member 5 is equipped with non-overlapping portion marks 10, as in the third, fourth, and sixth examples, the image processing unit 281 can similarly determine the top-down relationship of the overlapping N imaging plates 2 on the holding member 5 based on the mark image 350 corresponding to the top-down relationship determination mark by setting the non-overlapping portion marks 10 to marks for determining the top-down relationship.

[0418] <Example 10 (Identifying the hierarchical relationship of overlapping elements)> Unlike the examples above, if the holding member 5A overlaps and does not indicate an upper-lower relationship, the first imaging plate 2 may be positioned on top of the holding member 5A, or the second imaging plate 2 may be positioned on top. In such a case, the poor-quality overlapping portion 321 included in the second radiographic image 320 may be retained, and the good-quality overlapping portion 311 included in the first radiographic image 310 may be deleted, and the first radiographic image 310 and the second radiographic image 320 may be combined. Furthermore, even if the holding member 5A overlaps and indicates an upper-lower relationship, the two imaging plates 2 may be stacked in the wrong order within the holding member 5A.

[0419] Therefore, in this example, the image processing unit 281 determines the overlapping relationship of the two imaging plates 2 based on the difference in brightness of the mark image 350 corresponding to the overlapping mark 10 between the two read radiation images read from the two adjacent imaging plates 2 in the holding member 5A.

[0420] In this example, as in the second, third, fifth, and seventh examples, when the holding member 5 is equipped with overlapping mark 10, the image processing unit 281 can determine the overlapping relationship of the two imaging plates 2 based on the brightness of the mark image 350 corresponding to the overlapping mark 10 included in the two read radiation images read from the two imaging plates 2 held by the holding member 5A.

[0421] Here, the overlapping portion of the lower imaging plate 2 with the upper imaging plate 2 is irradiated by radiation that has passed through the upper imaging plate 2. Therefore, there is a difference between the brightness of the mark image 350 corresponding to the overlapping portion mark 10 read from the lower imaging plate 2 and the brightness of the mark image 350 corresponding to the overlapping portion mark 10 read from the upper imaging plate 2. Here, for example, the brightness of the mark image 350 corresponding to the overlapping portion mark 10 read from the upper imaging plate 2 is assumed to be greater than the brightness of the mark image 350 corresponding to the overlapping portion mark 10 read from the lower imaging plate 2.

[0422] The image processing unit 281 compares the brightness (also called the first brightness) of the mark image 350 corresponding to the overlapping mark 10 included in the first read radiation image read from the first side imaging plate 2 with the brightness (second brightness) of the mark image 350 corresponding to the said overlapping mark 10 included in the second read radiation image read from the second side imaging plate 2. The image processing unit 281 then determines that if the first brightness is greater than the second brightness, the first side imaging plate 2 is positioned above the second side imaging plate 2. On the other hand, if the second brightness is greater than the first brightness, the image processing unit 281 determines that the second side imaging plate 2 is positioned above the first side imaging plate 2. The processing after the image processing unit 281 has determined the upper and lower relationship of the overlap of the two imaging plates 2 is the same as in the ninth example.

[0423] As described above, the overlapping portion of the lower imaging plate 2 with the upper imaging plate 2 is irradiated by radiation that has passed through the upper imaging plate 2. Therefore, the radiation is scattered by the upper imaging plate 2 before irradiating this overlapping portion. Furthermore, the distance between the radiation source and the lower imaging plate 2 is greater than the distance between the radiation source and the upper imaging plate 2. As a result, the size of the mark image 350 corresponding to the overlapping portion mark 10, as read from the lower imaging plate 2, is larger than the size of the mark image 350 corresponding to the overlapping portion mark 10, as read from the upper imaging plate 2.

[0424] Therefore, the image processing unit 281 may determine the relative height of the overlap between the first imaging plate 2 and the second imaging plate 2 based on the difference between the size of the mark image 350 corresponding to the overlapping mark 10 (also called the first size) included in the first read radiation image read from the first imaging plate 2 and the size of the mark image 350 corresponding to the said overlapping mark 10 (second size) included in the second read radiation image read from the second imaging plate 2. For example, if the first size is smaller than the second size, the image processing unit 281 determines that the first imaging plate 2 is positioned above the second imaging plate 2. On the other hand, if the second size is smaller than the first size, the image processing unit 281 determines that the second imaging plate 2 is positioned above the first imaging plate 2.

[0425] Even if N≧3, the image processing unit 281 can similarly determine the overlapping vertical relationship of the two imaging plates 2 on which the two readable radiation images are read, based on the brightness or size of the mark images 350 corresponding to the overlapping portion marks 10 included in the two readable radiation images constituting one pair of combined radiation images, for each of the (N-1) pairs of radiation images to be combined. In other words, even if N≧3, the image processing unit 281 can similarly determine the overlapping vertical relationship of the N imaging plates 2 in the holding member 5.

[0426] <Identifying the front or back side of the overall picture> Figure 61 is a schematic diagram showing an example of the display of the overall image 400 on the display unit 130. As shown in the example in Figure 61, the display control unit 282 may, for example, display the overall image 400 on the display surface 131 of the display unit 130 with the front teeth facing downwards. In other words, the display control unit 282 may display the overall image 400 on the display surface 131 with the back teeth facing upwards.

[0427] Thus, when the display orientation (in other words, the orientation of the display) of the overall image 400 is automatically determined or set by default based on whether the overall image 400 is on the front or back side, it is necessary to specify whether the overall image 400 is on the front or back side.

[0428] Therefore, in this example, the multiple marks 10 provided on the holding member 5 include at least one identification mark (also called an anterior / posterior identification mark or a second identification mark) for identifying the anterior or posterior side of the overall image 400 based on the mark image. The image processing unit 281 identifies the anterior or posterior side of the overall image 400 based on the mark image 350 corresponding to at least one anterior / posterior identification mark. The display control unit 282 displays the overall image 400 on the display unit 130 in a predetermined orientation (in other words, a predetermined direction), for example, as shown in Figure 61, based on the anterior or posterior side of the overall image 400 identified by the image processing unit 281. However, the display orientation of the overall image 400 is not limited to this. Furthermore, the display orientation of the overall image 400 showing the maxillary dental arch and the display orientation of the overall image 400 showing the mandibular dental arch may be different from each other.

[0429] In this example, if the retaining member 5A shown in Figure 49 above is used in the first example, the marks 10 on the retaining member 5A can be used to identify the anterior or posterior side of the overall image 400. The image processing unit 281 uses the marks 10a, 10b, 10c, and 10d included in the retaining member 5A shown in Figure 49 as marks 10 for identifying the anterior / posterior side.

[0430] Marks 10a, 10b, 10c, and 10d are configured such that the anterior or posterior side of the overall image 400 can be identified based on the orientation of the corresponding mark image 350. When the retaining member 5A shown in Figure 49 is placed in the oral cavity, one vertex of each of ...

Claims

1. A cover member that covers multiple imaging plates used in intraoral radiography and is placed in the oral cavity together with the multiple imaging plates, The system includes at least one mark for alignment when combining multiple radiographic images read from each of the aforementioned multiple imaging plates, A cover member wherein, when radiation is irradiated onto the plurality of imaging plates through the cover member, a mark image corresponding to at least one mark is included in the plurality of radiation images.

2. A cover member according to claim 1, The plurality of imaging plates include a first imaging plate and a second imaging plate that are covered by the cover member in a partially overlapping state, The first imaging plate has a first non-overlapping portion that does not overlap with the second imaging plate. The second imaging plate has a second non-overlapping portion that does not overlap with the first imaging plate. The aforementioned at least one mark is, At least one mark for the first non-overlapping portion for recording a mark image in the first non-overlapping portion, At least one mark for the second non-overlapping portion for recording a mark image in the second non-overlapping portion, A cover component, including the cover member.

3. A cover member according to claim 1, The plurality of imaging plates include a first imaging plate and a second imaging plate that are covered by the cover member in a partially overlapping state, The first imaging plate has a first overlapping portion that overlaps with the second imaging plate, The second imaging plate has a second overlapping portion that overlaps with the first imaging plate, The cover member includes at least one mark for recording a mark image in the first overlapping portion and the second overlapping portion.

4. The cover member according to claim 2, The first imaging plate has a first overlapping portion that overlaps with the second imaging plate, The second imaging plate has a second overlapping portion that overlaps with the first imaging plate, The cover member includes at least one mark for recording a mark image in the first overlapping portion and the second overlapping portion.

5. A cover member according to any one of claims 1 to 4, The cover member includes at least one end mark for recording a mark image on the end of a combined imaging plate comprising the plurality of imaging plates.

6. A cover member according to claim 5, A cover member comprising at least one end mark for recording a mark image at at least one corner of the plurality of imaging plates.

7. A cover member according to claim 5, A cover member in which the at least one mark is configured such that all mark images corresponding to the at least one mark are recorded at the end.

8. A cover member according to any one of claims 1 to 4, A cover member wherein the at least one mark includes at least one first identifying mark for identifying the reading direction of the radiation image from each of the plurality of imaging plates based on the mark image.

9. The cover member according to claim 8, A cover member in which the at least one first identifying mark is configured such that the reading direction is determined from at least one of the orientation and position of the mark image corresponding to the at least one first identifying mark.

10. A cover member according to any one of claims 1 to 4, A cover member wherein the at least one mark includes at least one second identifying mark for identifying the anterior or posterior side of the overall image obtained by combining the plurality of radiographic images, based on the marked image.

11. A cover member according to claim 10, A cover member in which the at least one second identifying mark is configured such that the anterior tooth side or the posterior tooth side of the overall image can be identified from at least one of the orientation and position of the mark image corresponding to the at least one second identifying mark.

12. A cover member according to claim 10, A cover member indicating the direction in which the cover member is inserted into the oral cavity.

13. A cover member according to any one of claims 1 to 4, The cover member wherein the at least one mark includes at least one third identifying mark for identifying the orientation of the plurality of imaging plates relative to the cover member based on the mark image.

14. A cover member according to claim 13, A cover member in which the at least one third identifying mark is configured such that the orientation of the plurality of imaging plates relative to the cover member is determined from at least one of the shape, position, and number of mark images corresponding to the at least one third identifying mark.

15. A cover member according to claim 13, A cover member that indicates the orientation that the plurality of imaging plates should take relative to the cover member.

16. A cover member according to any one of claims 1 to 4, The plurality of imaging plates include a first imaging plate and a second imaging plate that are covered by the cover member in a partially overlapping state, A cover member wherein the at least one mark includes at least one fourth identifying mark for identifying the top-down relationship of the overlapping first imaging plate and the second imaging plate based on the mark image.

17. A cover member according to claim 16, A cover member in which the at least one fourth identifying mark is configured such that the up-down relationship is determined by at least one of the shape, position, and number of mark images corresponding to the at least one fourth identifying mark.

18. A cover member according to claim 16, A cover member that indicates the upper and lower relationship of the overlap that the first imaging plate and the second imaging plate should have.

19. A cover member according to any one of claims 1 to 4, A cover member that holds the first imaging plate and the second imaging plate in predetermined positions.

20. A cover member according to any one of claims 1 to 4, The plurality of imaging plates covered by the cover member and Equipped with an imaging plate assembly.

21. A processing apparatus comprising an image processing unit that aligns a plurality of radiation images read from a plurality of imaging plates covered by a cover member according to any one of claims 1 to 4, based on mark images included in the plurality of radiation images, and combines the plurality of radiation images after alignment.

22. The apparatus according to claim 21, The plurality of imaging plates include a first imaging plate and a second imaging plate. The first imaging plate is positioned above the second imaging plate, and the first imaging plate and the second imaging plate are covered by the cover member in a state where they partially overlap. The plurality of radiographic images include a first radiographic image and a second radiographic image read from the first imaging plate and the second imaging plate, respectively. The second radiographic image includes a boundary image corresponding to the boundary between the first imaging plate and the second imaging plate 2 on the second imaging plate, The image processing unit is a processing device that aligns the first radiation image and the second radiation image based on the boundary image and the mark images included in the first radiation image and the second radiation image.

23. The image processing unit aligns the plurality of radiation images read from the plurality of imaging plates covered by the cover member described in claim 8, based on the mark images included in the plurality of radiation images, and combines the plurality of radiation images after alignment. The aforementioned image processing unit, Based on the mark image corresponding to at least one first identification mark included in the plurality of radiation images, the reading direction of the radiation image from each of the plurality of imaging plates is determined. A processing device that aligns a plurality of radiation images based on the identified reading direction and the mark images included in the plurality of radiation images.

24. The image processing unit aligns the plurality of radiation images read from the plurality of imaging plates covered by the cover member described in claim 10, based on the mark images included in the plurality of radiation images, and combines the plurality of radiation images after alignment. The image processing unit is a processing unit that identifies the anterior tooth side or the posterior tooth side of the overall image obtained by combining the plurality of radiographic images, based on a mark image corresponding to at least one second identification mark included in the plurality of radiographic images.

25. The processing apparatus according to claim 24, The system includes a display control unit that displays the overall image on the display unit, The display control unit is a processing device that determines the display orientation of the overall image based on whether the overall image is on the anterior or posterior side, as identified by the image processing unit.

26. The image processing unit aligns the plurality of radiation images read from the plurality of imaging plates covered by the cover member described in claim 13, based on the mark images included in the plurality of radiation images, and combines the plurality of radiation images after alignment. The image processing unit is a processing device that determines the orientation of the plurality of imaging plates relative to the cover member based on a mark image corresponding to at least one third identifying mark included in the plurality of radiation images.

27. The apparatus according to claim 26, The image processing unit includes a display control unit that displays the overall image obtained by combining the multiple radiation images on a display unit. The display control unit is a processing device that determines the display orientation of the overall image based on the orientation of the plurality of imaging plates relative to the cover member, as identified by the image processing unit.

28. The image processing unit aligns the plurality of radiation images read from the plurality of imaging plates covered by the cover member described in claim 16, based on the mark images included in the plurality of radiation images, and combines the plurality of radiation images after alignment. The plurality of radiation images include a first radiation image and a second radiation image read from the first imaging plate and the second imaging plate, respectively, which are included in the plurality of imaging plates. The aforementioned image processing unit, Based on the mark images corresponding to at least one fourth identifying mark included in the first and second radiation images, the top-down relationship of the overlapping first imaging plate and the second imaging plate is determined. A processing device that aligns the first radiation image and the second radiation image based on the identified vertical relationship and the mark images included in the first radiation image and the second radiation image.

29. The image processing unit aligns the plurality of radiation images read from the plurality of imaging plates covered by the cover member described in claim 3 or claim 4, based on the mark images included in the plurality of radiation images, and combines the plurality of radiation images after alignment. The plurality of radiation images include a first radiation image and a second radiation image read from the first imaging plate and the second imaging plate, respectively, which are included in the plurality of imaging plates. The aforementioned image processing unit, Based on the mark image corresponding to the at least one overlapping portion mark included in the first and second radiation images, the top-down relationship of the overlapping first imaging plate and the second imaging plate is determined. A processing device that aligns the first radiation image and the second radiation image based on the identified vertical relationship and the mark images included in the first radiation image and the second radiation image.

30. The processing apparatus according to claim 29, The image processing unit determines the up-down relationship based on the difference between the brightness of a mark image corresponding to at least one overlapping mark included in the first radiation image and the brightness of a mark image corresponding to at least one overlapping mark included in the second radiation image.

31. The processing apparatus according to claim 29, The image processing unit determines the vertical relationship based on the difference between the size of a mark image corresponding to the at least one overlapping mark included in the first radiation image and the size of a mark image corresponding to the at least one overlapping mark included in the second radiation image.

32. The apparatus according to claim 21, A processing device that reads multiple radiation images from the multiple imaging plates.

33. In a computer device, A process of aligning the plurality of radiation images read from the plurality of imaging plates covered by the cover member according to any one of claims 1 to 4, based on the mark images included in the plurality of radiation images, A process for combining the multiple radiation images after alignment. A program to execute.

34. An image merging method comprising aligning a plurality of radiation images read from a plurality of imaging plates covered by a cover member according to any one of claims 1 to 4, based on mark images included in the plurality of radiation images, and merging the plurality of radiation images after alignment.

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