Image reading system, image reading device, and image forming system

Abstract

To generate highly accurate composite image data.SOLUTION: An image reading system comprises: a document platen on which a document is placed; a photographing unit that is arranged at a position opposite to the document placed on the document platen, and photographs the document in a plurality of different ranges to generate a plurality of pieces of image data of the document; a detection unit that detects overlapping ranges of the plurality of different ranges in the document photographed by the photographing unit; a selection unit that selects, from the overlapping ranges, an overlapping range of the plurality of ranges photographed at the shortest photographing distance between the photographing unit and the document; and a generation unit that generates composite image data from the photographed different ranges based on the overlapping range of the plurality of ranges photographed at the shortest photographing distance selected by the selection unit.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an image reading system, an image reading apparatus, and an image forming system.

Background Art

[0002] In an image reading system for reading a large-sized document such as an architectural drawing, a large-scale device configuration and a high-resolution imaging device used for reading the document are required. Therefore, there is a technique in which a partial area of the document is photographed with high precision a plurality of times by shifting the photographing range using a low-resolution imaging device, and these image data are combined, so that the large-sized document can be read in a relatively compact configuration and at a low cost.

[0003] For example, Patent Document 1 discloses a technique for generating high-precision overall image data by photographing a plurality of partial images of a document using an imaging device such as a camera and combining these partial image data.

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in photographing by an imaging device, usually, high-precision photographing is possible at the central portion, but low-precision photographing is performed at the peripheral portion. Therefore, in the technique of Patent Document 1, the synthesized overall image data includes a portion with low resolution.

[0005] The present invention has been made in view of the above, and an object thereof is to provide an image reading system, an image reading apparatus, and an image forming system capable of generating high-precision composite image data.

Means for Solving the Problems

[0006] To solve the above-mentioned problems and achieve the objective, the present invention comprises: a document table on which a document is placed; a shooting unit positioned opposite to the document placed on the document table and shooting the document in a plurality of different ranges to generate a plurality of image data of the document; a detection unit for detecting overlapping ranges of the plurality of different ranges of the document shot by the shooting unit; a selection unit for selecting the overlapping range from which the shooting unit and the document are shot at the shortest shooting distance; and a generation unit for generating composite image data from the different ranges shot based on the overlapping range shot at the shortest shooting distance selected by the selection unit. [Effects of the Invention]

[0007] According to the present invention, high-precision composite image data can be generated. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 shows an example of the configuration of the image reading system according to Embodiment 1. [Figure 2] Figure 2 is a diagram illustrating the relationship between the shooting distance and resolution of the shooting unit in the image reading system according to Embodiment 1. [Figure 3] Figure 3 is a block diagram showing an example of the hardware configuration of the image reading system according to Embodiment 1. [Figure 4] Figure 4 is a block diagram showing an example of the functional configuration of the controller according to Embodiment 1. [Figure 5] Figure 5 shows how multiple image data are generated by the image reading system according to Embodiment 1. [Figure 6] Figure 6 shows how composite image data is generated from multiple image data by the image reading system according to Embodiment 1. [Figure 7] Figure 7 is a flowchart showing an example of the procedure for image reading processing in the image reading system according to Embodiment 1. [Figure 8]Figure 8 shows an overview of image reading by the image reading system according to Embodiment 1 and the comparative example. [Figure 9] Figure 9 shows an example of the configuration of an image reading system according to a modified example of Embodiment 1. [Figure 10] Figure 10 shows an example of the configuration of the image reading system according to Embodiment 2. [Figure 11] Figure 11 shows an example of the configuration of an image reading system according to a modified example 1 of Embodiment 2. [Figure 12] Figure 12 is a flowchart showing an example of the procedure for image reading processing in an image reading system according to a modified example 1 of Embodiment 2. [Figure 13] Figure 13 is a block diagram showing an example of the functional configuration of a controller in an image reading system according to a modified example 2 of Embodiment 2. [Figure 14] Figure 14 illustrates the method for calculating the document size using a controller according to a modified example 2 of Embodiment 2. [Figure 15] Figure 15 shows an example of the configuration of the image reading system according to Embodiment 3. [Figure 16] Figure 16 is a flowchart showing an example of the procedure for image reading processing in the image reading system according to Embodiment 3. [Figure 17] Figure 17 shows an example of the configuration of the image forming system according to Embodiment 4. [Modes for carrying out the invention]

[0009] [Embodiment 1] Embodiment 1 will be described below with reference to the drawings.

[0010] (Example of an image reading system configuration) Figure 1 shows an example of the configuration of an image reading system 1 according to Embodiment 1. As shown in Figure 1, the image reading system 1 comprises a controller 10, a document tray 20, an operation unit 21, a shooting unit 22, and an arm unit 23.

[0011] The controller 10 as an image reading device is configured as a computer or the like that controls the entire image reading system 1. The controller 10 also performs a process of generating composite image data by combining a plurality of image data generated by the imaging unit 22. The controller 10 is provided, for example, at an end of the document table 20.

[0012] The document table 20 is, for example, a table on which a document to be read is placed. The document to be read by the image reading system 1 is, for example, a large-sized document such as an architectural drawing.

[0013] The operation unit 21 is an interface with the user. That is, the operation unit 21 is configured to output various information from the image reading system 1 to the user. In addition, the operation unit 21 is configured to be able to receive various operations from the user to the image reading system 1.

[0014] Specifically, the operation unit 21 may have, for example, a monitor, buttons, a touch panel, a buzzer, a speaker, and other physical components.

[0015] The imaging unit 22 is a camera or the like that can image a document placed on the document table 20. The camera used as the imaging unit 222 may be a camera with a relatively low resolution. Even with a low-resolution camera, it is possible to generate high-resolution image data by narrowing the imaging range PA within the area excluding the peripheral portion of the document table 20 and partially imaging a large-sized document.

[0016] The imaging unit 22 images different ranges of the document placed on the document table 20 a plurality of times, thereby dividing and storing the entire document in a plurality of images.

[0017] The imaging unit 22 is attached to the tip of the arm 23, which is fixed to the document table 20. As a result, the imaging unit 22 is positioned opposite the document table 20 at a predetermined distance above it, with its position and orientation fixed relative to the document table 20. The lens of the imaging unit 22 is also parallel to the upper surface of the document table 20.

[0018] The arm portion 23 has a base portion fixed to the document table 20, for example via the controller 10, and a tip portion that extends above the document table 20 and to which the imaging unit 22 is attached, as described above.

[0019] Here, when the imaging unit 22 photographs the document from a predetermined position above the document table 20, the distance from the imaging unit 22 varies depending on the position of the document placed on the document table 20. As a result, the resolution of the central and peripheral parts of the image data will differ. This point will be explained using Figure 2.

[0020] Figure 2 is a diagram illustrating the relationship between the shooting distance SDc,SDe and resolution of the shooting unit 22 of the image reading system 1 according to Embodiment 1.

[0021] As shown in Figure 2, the distance to the imaging unit 22 in the peripheral portion PAe of the imaging range PA of the imaging unit 22, i.e., the imaging distance SDe, is longer than the imaging distance SDc in the central portion PAc.

[0022] Therefore, when photographing a document placed on the document table 20, the image data of the document portion positioned at the periphery PAe will have lower resolution than the image data of the document portion positioned at the center PAc. This is because the size of the document portion that fits within one pixel increases as the shooting distance SD increases. Thus, in a single shot, image data with high resolution in the central part and low resolution in the periphery is obtained.

[0023] (Example hardware configuration for an image reading system) Next, an example of the hardware configuration of the image reading system 1 will be described using Figure 3. Figure 3 is a block diagram showing an example of the hardware configuration of the image reading system 1 according to Embodiment 1.

[0024] As shown in Figure 3, the controller 10, which functions as an image reading device, comprises an arithmetic unit 11, a storage device 12, and an auxiliary storage device 13. These components are connected to each other by an internal bus.

[0025] The arithmetic unit 11 is, for example, a CPU (Central Processing Unit) and controls the entire image reading system 1. The arithmetic unit 11 also performs image processing on the image data generated by the imaging unit 22, such as feature extraction, image matching, and image synthesis.

[0026] The storage device 12 is, for example, ROM (Read Only Memory), RAM (Random Access Memory), etc., and stores programs executed by the arithmetic unit 11, and also serves as the primary storage area when the arithmetic unit 11 executes programs.

[0027] The auxiliary storage device 13 is an HDD (Hard Disk Drive), SSD (Solid State Drive), etc., and stores parameters used by the arithmetic unit 11, as well as image data generated by the imaging unit 22.

[0028] The programs executed by the arithmetic unit 11 are provided as installable or executable files recorded on computer-readable recording media such as CD-ROMs, flexible disks (FDs), CD-Rs, and DVDs (Digital Versatile Discs).

[0029] Furthermore, the program executed by the arithmetic unit 11 may be provided by storing it on a computer connected to a network such as the Internet and allowing it to be downloaded via the network. Alternatively, the program executed by the arithmetic unit 11 may be provided or distributed via a network such as the Internet. Alternatively, the program executed by the arithmetic unit 11 may be provided pre-loaded into ROM or the like.

[0030] The controller 10 is connected to the operation unit 21 and the imaging unit 22 via a bus. The operation unit 21 transmits the details of various operations received from the user to the controller 10. The imaging unit 22 receives commands from the controller 10, performs imaging, and transmits the generated image data back to the controller 10.

[0031] (Example of controller function configuration) Next, an example of the functional configuration of the controller 10 will be described using Figure 4. Figure 4 is a block diagram showing an example of the functional configuration of the controller 10 according to Embodiment 1.

[0032] As shown in Figure 4, the controller 10 includes a detection unit 101, a selection unit 102, a generation unit 103, and a storage unit 104 as functional units.

[0033] The detection unit 101 detects overlapping areas of the original document that are included in some of the multiple image data. When the imaging unit 22 divides the entire original document into multiple images and captures them, some of the image data will include overlapping areas of the original document. The detection unit 101 detects these overlapping areas. The detection unit 101 is realized by the execution of a program by the aforementioned arithmetic unit 11.

[0034] The selection unit 102 selects the overlapping area of ​​the original document that is included in several overlapping image data, specifically the overlapping area captured at the shortest shooting distance. The selection unit 102 is realized by the aforementioned arithmetic unit 11 executing a program.

[0035] The generation unit 103 combines multiple image data, each containing a divided portion of the original document, to generate a single composite image data that includes the entire area of ​​the original document. In this composite image data, overlapping areas of the original document that are included in several image data become connecting portions between different image data. The generation unit 103 connects multiple image data using the overlapping areas of the original document selected by the selection unit 102 as connecting portions to generate composite image data. The generation unit 103 is realized by the execution of a program by the aforementioned arithmetic unit 11.

[0036] The memory unit 104 stores control parameters used by the detection unit 101, the selection unit 102, and the generation unit 103, multiple image data captured by the imaging unit 22, the overlapping range selected by the selection unit 102, and the composite image data generated by the generation unit 103. The memory unit 104 is implemented by an auxiliary storage device 13, etc., which operates under the control of the arithmetic unit 11 that executes the program.

[0037] (Example of generating composite image data) Next, using Figures 5 and 6, we will explain the process by which the image reading system 1 generates composite image data.

[0038] Figure 5 shows how multiple image data are generated by the image reading system 1 according to Embodiment 1. As shown in Figure 5, the imaging unit 22 of the image reading system 1 captures a single document MS in parts multiple times.

[0039] As shown in the side view of Figure 5, in the example of Figure 5, the vertical width of the document MS is approximately equal to the width of the shooting range PA of the shooting unit 22, and fits within the shooting range PA of the shooting unit 22. Also, as shown in the front view of Figure 5, the horizontal width of the document MS is wider than the width of the shooting range PA of the shooting unit 22. In this case, the user moves the document MS horizontally, and the shooting unit 22 sequentially photographs different areas of the document MS.

[0040] In the example shown in Figure 5, the original document MS is placed on the document table 20, and the first image is captured by aligning one lateral end of the document MS with one end of the shooting range PA of the imaging unit 22. Next, the document MS is shifted laterally on the document table 20, and the central part of the document MS is positioned within the shooting range PA of the imaging unit 22 to capture the second image. Next, the document MS is shifted further laterally on the document table 20, and the other end of the document MS is aligned with the other end of the shooting range PA of the imaging unit 22 to generate the third image data.

[0041] This process divides the entire original MS into three parts, generating three separate image data files. The shooting distance at corresponding points within these three separate image data files is constant.

[0042] In other words, for example, the center of each of the three partial image data points was captured at the same distance, and that distance is the shortest of all the points within the partial image data. Also, for example, the four corners of each of the three partial image data points were captured at the same distance, and that distance is the longest of all the points within the partial image data points.

[0043] Figure 6 shows how a composite image data CMab is generated from multiple image data IMa and IMb by the image reading system 1 according to Embodiment 1. In the example in Figure 6, the case in which two of the three image data IMa and IMb described above are concatenated will be explained.

[0044] As shown in Figure 6(a), the detection unit 101 of the controller 10 detects overlapping areas ORa and ORb that are included in the image data IMa and IMb, which are images of adjacent parts of the original document MC. The overlapping area ORa is included in the image data IMa, and the overlapping area ORb is included in the image data IMb. These overlapping areas ORa and ORb are areas where the same area in the original document MS is included in the two image data images IMa and IMb.

[0045] When detecting overlapping ranges ORA and ORb, the detection unit 101 can use methods such as performing image processing on image data IMa and IMb to extract feature points from each image data IMa and IMb, and further performing image matching between the image data IMa and IMb to extract corresponding points.

[0046] As described above, image detection methods using feature points and corresponding points include, for example, Scale-Invariant Feature Transform (SIFT). However, various other methods are known for detecting specific images, and one can choose and use the method that is most likely to yield the desired results from among these.

[0047] Furthermore, if the original document has blank areas, the image data may include blank areas. In this case, the detection unit 101 may perform the image processing including the blank areas in the image data.

[0048] As shown in Figure 6(b), the selection unit 102 of the controller 10 measures the distance from the central part CTa of the image data IMa to multiple points in the overlapping area ORa contained within the image data IMa. The selection unit 102 also measures the distance from the central part CTb of the image data IMb to multiple points in the overlapping area ORb contained within the image data IMb.

[0049] The selection unit 102 selects, from among multiple measurement points in the overlapping ranges ORA and ORb, a point whose distance from the corresponding measurement point in the overlapping range ORb to the central part CTb of the image data IMA is shorter than the distance from the central part CTb of the image data IMA to the corresponding measurement point in the overlapping range ORb.

[0050] Furthermore, the selection unit 102 selects, from among multiple measurement points in the overlapping ranges ORa and ORb, a point whose distance from the corresponding measurement point in the overlapping range ORa to the central part CTa of the image data IMb is shorter than the distance from the central part Cta of the image data IMb.

[0051] In the example in Figure 6(b), among the multiple measurement points within the overlapping area ORa, the measurement point in the overlapping area ORb that corresponds to the point where the distance to the central part CTa of the image data IMa is 3 is the point where the distance to the central part CTb of the image data IMb is 11.

[0052] In other words, among these measurement points in overlapping ranges ORA and ORb, the measurement points in overlapping range ORA are the points where the shooting distance at the time of shooting was shorter than the corresponding measurement points in overlapping range ORb. The selection unit 102 selects the measurement points in overlapping range ORA from among these measurement points in overlapping ranges ORA and ORb.

[0053] Furthermore, among the multiple measurement points within the overlapping area ORA, the measurement point in the overlapping area ORA that corresponds to the point where the distance to the central part CTb of the image data IMb is 5 is the point where the distance to the central part CTa of the image data Ima is 9.

[0054] In other words, among these measurement points in overlapping ranges ORA and ORb, the measurement points in overlapping range ORb are the points where the shooting distance at the time of shooting was shorter than the corresponding measurement points in overlapping range ORA. The selection unit 102 selects the measurement points in overlapping range ORb from among these measurement points in overlapping ranges ORA and ORb.

[0055] Thus, among the multiple measurement points within the overlapping area ORa, for points where the distance to the central part CTa of the image data IMa is 7 or less, the distance to the central part CTa of the image data IMa is shorter than the distance from the corresponding measurement point in the overlapping area ORb to the central part CTa of the image data IMa. In other words, these measurement points in the image data IMa are points where the shooting distance at the time of capture was shorter than that of the corresponding measurement points in the overlapping area ORb.

[0056] Similarly, among the multiple measurement points within the overlapping area ORb, for points where the distance to the central part CTb of the image data IMb is 7 or less, the distance to the central part CTb of the image data IMb is shorter than the distance from the corresponding measurement point in the overlapping area ORa to the central part CTa of the image data Ima. In other words, these measurement points in the image data IMb are points where the shooting distance at the time of capture was shorter than that of the corresponding measurement points in the overlapping area ORa.

[0057] The selection unit 102 selects a measurement point from among multiple measurement points in the overlapping area ORa that is within a distance of 7 to the central part CTa of the image data IMa. Similarly, the selection unit 102 selects a measurement point from among multiple measurement points in the overlapping area ORb that is within a distance of 7 to the central part CTb of the image data IMb.

[0058] In the overlapping areas ORA and ORb, the measurement points where the distance to the central parts CTa and CTb of the respective image data IMa and IMb is 7 correspond to the center position of the width of the overlapping areas ORA and ORb, respectively.

[0059] Furthermore, in the example shown in Figure 6, the selection unit 102 is supposed to determine which image data IMa or IMb point to select for multiple points in the horizontal direction within the overlapping areas ORA and ORb. However, in reality, the selection unit 102 measures the distance to the central parts CTa and CTb of each pixel included within the overlapping areas ORA and ORb, and selects the pixel information of the overlapping area ORA for points where "distance to the central part CTa of image data IMa < distance to the central part CTb of image data IMb", and selects the pixel information of the overlapping area ORb for points where "distance to the central part CTa of image data IMa > distance to the central part CTb of image data IMb".

[0060] As shown in Figure 6(c), the selection unit 102 selects the region within the overlapping area ORa of the image data IMa where the distance to the central part CTa of the image data IMa is 7 or less, as the connecting portion CNa when connecting the image data IMa and IMb.

[0061] The generation unit 103 of the controller 10 discards the region in the overlapping area ORA of the image data IMa where the distance to the central part CTa of the image data IMa exceeds 7, and which was not selected by the selection unit 102, as the unselected portion ORAn.

[0062] Furthermore, the selection unit 102 selects the region within the overlapping range ORb of the image data IMb where the distance to the central portion CTb of the image data IMb is 7 or less, as the concatenation portion CNb when concatenating the image data IMa and IMb.

[0063] The generation unit 103 of the controller 10 discards the region in the overlapping area ORb of the image data IMb where the distance to the central part CTb of the image data IMb exceeds 7, and which was not selected by the selection unit 102, as the unselected portion ORbn.

[0064] As shown in Figure 6(d), the generation unit 103 concatenates the concatenation portion CNa of the image data IMa and the concatenation portion CNb of the image data IMb to generate composite image data CMab, which is a combination of the image data IMa and IMb.

[0065] Each part of the controller 10, following the same procedure as in Figures 6(a) to (d) above, concatenates the remaining image data of the three image data with the composite image data CMab to generate composite image data that includes the entire range of the original MS.

[0066] If the image data includes blank areas, the generation unit 103 may use the image information of the colored areas excluding the blank areas in the image data to perform image data synthesis.

[0067] Furthermore, in the examples shown in Figures 5 and 6 above, the original document MS was divided into three images and then combined. However, depending on the width of the original document MR, the original document MS may be divided into fewer than three images or four or more images. Also, if the vertical width of the original document MR is longer than the vertical width of the imaging range PA of the imaging unit 22, the original document MS may be divided into multiple images in the vertical direction as well.

[0068] However, in order to improve efficiency by reducing the number of times the original MC is photographed, it is preferable to photograph the original MC in such a way that the area of ​​the original MC within each image data is as large as possible.

[0069] Furthermore, there are no particular restrictions on the start position, end position, or order of shooting on the original MC. Therefore, for example, at least one of the start position or end position may be in the central or peripheral part of the original MC. The shooting order can also be appropriately selected so that the direction of travel is linear, spiral, or zigzag. However, in any case, it is more efficient to proceed with shooting in order of adjacent regions.

[0070] Furthermore, when shifting the document MS on the document table 20, the direction and angle of shifting are not limited to vertical or horizontal; for example, it can be shifted diagonally, etc., without any particular restrictions. However, when doing so, the document MS should be shifted so that each image data has an overlapping range at the boundary with other image data, which is also included in the other image data. At this time, by making the overlapping range in each image data 1 / 4 or more, preferably 1 / 2 or more, high-precision composite image data can be generated.

[0071] Furthermore, the overlapping areas contained in each image data may overlap not only in two image data images, but also in three or more image data images. In this case as well, among the overlapping areas contained in three or more image data images, the overlapping area captured at the shortest shooting distance is used as the concatenated portion of the composite image data.

[0072] (Example of processing by an image recognition system) Next, an example of processing in the image reading system 1 will be explained using Figure 7. Figure 7 is a flowchart showing an example of the procedure for image reading processing in the image reading system 1 according to Embodiment 1.

[0073] As shown in Figure 7, first the user places the document on the document glass 20 (step S101). Next, the user instructs the controller 10 to photograph the document via the operation unit 21.

[0074] The operation unit 21 receives a shooting instruction from the user and transmits it to the controller 10. The controller 10, upon receiving the shooting instruction from the user, causes the shooting unit 22 to photograph the document according to the instruction (step S102).

[0075] The user continues to photograph the document with the imaging unit 22 (step S102) by shifting the document as appropriate (step S104) until the entire area of ​​the document has been photographed (step S103: No). When shifting the document, as described above, each image data has an overlapping area at the boundary with other image data that is also included in the other image data.

[0076] Once the entire area within the document has been captured (Step S103: Yes), the user instructs the controller 10 via the operation unit 21 to combine the captured image data.

[0077] The operation unit 21 receives an image synthesis instruction from the user and transmits it to the controller 10, and the detection unit 101 of the controller 10 extracts the overlapping range that is included in several image data (step S105).

[0078] The selection unit 102 selects pixel information from among several overlapping ranges to be used as the concatenated portion of the composite image data, based on the shooting distance of each pixel (step S106).

[0079] The generation unit 103 concatenates multiple image data using the overlapping areas of each figure selected by the selection unit 102 as connecting parts, generates composite image data that includes the entire range of the original document, and saves it to the storage unit 104 (step S107).

[0080] Alternatively, the operation unit 21 may display a message indicating that the composite image data has been saved to the storage unit 104, informing the user that the image reading process is complete.

[0081] Alternatively, the user who receives the notification may decide whether or not to terminate the image reading process and input a command to terminate the process. In this case, if the desired composite image data is not obtained, such as due to low resolution, the user may be able to input a command to repeat the image reading process.

[0082] If the composite image data does not reach the desired resolution, the user can adjust the shifting of the original MC during repeated processing to increase the overlapping area within each image data.

[0083] With the above steps completed, the image reading process in the image reading system 1 of Embodiment 1 is finished.

[0084] (Comparative example) Image recognition systems for scanning large-format documents such as architectural drawings tend to have complex equipment configurations and require high-resolution cameras. Therefore, there is a technique that uses low-resolution cameras to capture multiple images of the large-format document in sections, and then combines these partial image data to generate a complete scanned image of the large-format document. This technique is called stitching and is sometimes used when creating panoramic images.

[0085] As a comparative example, the technology described in Patent Document 1 simplifies the user's work by capturing multiple partial images of a large-format document using a camera or the like, and then combining these images to generate image data of the entire document, in order to read the document with high accuracy. This is shown in the comparative example in Figure 8.

[0086] Figure 8 shows an overview of image reading by the image reading system according to Embodiment 1 and the Comparative Example. In the Comparative Example's image reading system, the original document is photographed multiple times (Figure 8(a)), multiple image data without overlapping areas are obtained (Figure 8(b)), and a composite image data is generated by concatenating the ends of these multiple image data (Figure 8(c)).

[0087] However, in the comparative example's technology, differences in resolution occur at each point in the composite image data depending on the shooting distance. Therefore, there is a problem in that the resolution is reduced in a portion of the composite image data.

[0088] According to the image reading system 1 of Embodiment 1, among multiple overlapping ranges of different ranges, composite image data is generated from the different ranges captured based on the overlapping range where the imaging unit 22 and the original document were captured at the shortest shooting distance.

[0089] In other words, as shown in the embodiment of Figure 8, the original document is photographed multiple times so that parts of it overlap (Figure 8(a)), multiple image data including the overlapping area is obtained (Figure 8(b)), and composite image data is generated by concatenating the overlapping areas of these multiple image data as a concatenation portion (Figure 8(c)).

[0090] This reduces variations in resolution and enables the generation of high-precision composite image data across the entire image.

[0091] (modified version) Next, an image reading system 1a, a modified example of Embodiment 1, will be described using Figure 9. The modified image reading system 1a differs from Embodiment 1 in that it includes an imaging unit 22a that is tilted and facing the document table 20.

[0092] Figure 9 shows an example of the configuration of an image reading system 1a according to a modified example of Embodiment 1. In Figure 9, the same reference numerals are used for components similar to those in Embodiment 1 described above, and their descriptions are omitted.

[0093] As shown in Figure 9, the image reading system 1a includes an imaging unit 22a and a controller 10a, instead of the imaging unit 22 and controller 10 of the embodiment 1 described above.

[0094] The imaging unit 22a is attached to the tip of the arm 23, which is fixed to the document table 20. As a result, the imaging unit 22a is positioned opposite the document table 20 at a predetermined distance above it, with its position and orientation fixed relative to the document table 20. The lens of the imaging unit 22a is tilted at a certain angle with respect to the upper surface of the document table 20.

[0095] In the modified image capture unit 22a, because the lens is in an inclined position, the image capture range PAa of the image capture unit 22a on the document table 20 is trapezoidal, extending from point C on the front side of the image capture unit 22a to point A on the back side.

[0096] Furthermore, even when the modified image capture unit 22a captures an image from a predetermined position above the document table 20, the distance from the image capture unit 22a varies depending on the position of the document placed on the document table 20. As a result, the resolution of the central and peripheral parts of the image data will differ.

[0097] As described above, because the lens is in an inclined position, when the document is photographed by the photographing unit 22a, the photographing distance SDb is shortest at point B, which is directly below the photographing unit 22a on the document table 20. Point B is the point where a line drawn vertically from the photographing unit 22a toward the document table 20 touches the upper surface of the document table 20.

[0098] Furthermore, the shooting distance SDc at point C on the near side of the shooting unit 22a is longer than the shooting distance SDb at point B. Also, the shooting distance SDa at point A on the far side of the shooting unit 22a is even longer than the shooting distance SDc at point C. Note that the point where the shooting distance is longest is the two sides of the large diameter base on the side of point A.

[0099] When points A to C are plotted on the captured image data IM, it can be seen that the resolution of the image data IM is highest at point B, which is shifted laterally from the center of the image data IM. Furthermore, it can be seen that the resolution of the image data IM is slightly lower at the end on the point C side of the image data IM than at point B. Furthermore, it can be seen that the resolution of the image data IM is even lower at the end on the point A side of the image data IM than at point C. Finally, the resolution of the image data IM is lowest at the two ends on the point A side.

[0100] The controller 10a is configured as a computer, similar to the controller 10 in Embodiment 1 described above, and includes, for example, an arithmetic unit, a storage device, and an auxiliary storage device. However, the arithmetic unit of the controller 10a performs the above-mentioned various processing on the image data IM according to an algorithm adapted to the image data IM captured with the lens tilted.

[0101] In other words, when the arithmetic unit of the controller 10a selects pixel information to be used for composite image data from overlapping ranges that are included in several image data, it selects pixel information that is captured at the shortest shooting distance SDb and is the shortest distance from point B with the highest resolution.

[0102] The modified image reading system 1a achieves the same effects as the image reading system 1 of the embodiment 1 described above.

[0103] [Embodiment 2] Embodiment 2 will be described below with reference to the drawings. Embodiment 2 differs from Embodiment 1 described above in that it includes multiple imaging units.

[0104] (Example of an image reading system configuration) Figure 10 shows an example of the configuration of the image reading system 2 according to Embodiment 2. In Figure 10, the same reference numerals are used for components similar to those in Embodiment 1 described above, and their descriptions are omitted.

[0105] As shown in Figure 10, the image reading system 2 includes imaging units 122a to 122c, an arm unit 123, an operation unit 121, and a controller 110, instead of the imaging unit 22, arm unit 23, operation unit 21, and controller 10 of the embodiment 1 described above.

[0106] The imaging unit 122a is attached to one end of the arm 123, which is fixed to the document table 20. As a result, the imaging unit 122a is positioned above the document table 20 at a predetermined distance, facing the document table 20, with its position and orientation fixed relative to the document table 20.

[0107] The imaging unit 122b is attached to the other end of the arm 123, which is fixed to the document table 20. As a result, the imaging unit 122b is positioned above the document table 20 at a predetermined distance, facing the document table 20, with its position and orientation fixed relative to the document table 20.

[0108] The imaging unit 122c is attached to another end of the arm 123, which is fixed to the document table 20. As a result, the imaging unit 122c is positioned above the document table 20 at a predetermined distance, facing the document table 20, with its position and orientation fixed relative to the document table 20.

[0109] Here, the imaging units 122a to 122c are all positioned at a constant angle and distance from the document table, and are arranged in the order of 122a, 122b, and 122c, respectively, from one end to the other in the horizontal direction on the 20 documents.

[0110] In the example shown in Figure 10, the lenses of the imaging units 122a to 122c are all parallel to the upper surface of the document table 20. However, the imaging units 122a to 122c may be mounted on the arm 123 in a position where these lenses are tilted at equal angles to each other with respect to the upper surface of the document table 20.

[0111] As a result, the imaging units 122a to 122c each have imaging ranges PA2a, PA2b, and PA2c, respectively, which are aligned below the imaging units 122a, 122b, and 122c, extending horizontally from one end to the other on the 20-page document stack. The boundaries of these imaging ranges PA2a, PA2b, and PA2c overlap with each other.

[0112] The controller 110 is configured as a computer, similar to the controller 10 in the first embodiment described above, and includes, for example, an arithmetic unit, a storage device, and an auxiliary storage device. The controller 110 is also configured to perform simultaneous imaging by multiple imaging units 122a to 122c in response to a single imaging instruction from the user.

[0113] The operation unit 121 functions as an interface with the user, similar to the operation unit 21 of the embodiment 1 described above. The operation unit 121 is configured to transmit a single shooting command from the user to the controller 110.

[0114] With the configuration described above, the image reading system 2 can capture a wider area of ​​the document in a single pass. Furthermore, since the multiple imaging units 122a to 122c are arranged so that the boundaries of their respective imaging ranges PA2a to PA2c overlap, multiple image data obtained in at least one pass will have overlapping areas at their boundaries without the user having to adjust the overlapping area and shift the document.

[0115] Note that the number of imaging units 122a to 122c in the image reading system 2 is not limited to the example in Figure 10, and may be less than three or four or more.

[0116] In Embodiment 2, the image reading process in the image reading system 2 is performed in the same manner as in Figure 7 of Embodiment 1 described above. However, in the image reading system 2, in the process of step S102 described above, the imaging units 122a to 122c perform imaging all at once with a single imaging instruction from the user. In addition, the number of repetitions of the processes in steps S102 to S104 is expected to be reduced compared to Embodiment 1.

[0117] The image reading system 2 of Embodiment 2 includes multiple imaging units 122a to 122c that are positioned at different locations on the document glass 20, with a constant angle and distance from the document glass 20. This allows for the simultaneous generation of multiple image data with equal resolution at each point, reducing the user's workload and improving work efficiency.

[0118] According to the image reading system 2 of Embodiment 2, the multiple imaging units 122a to 122c are arranged such that the boundary portions of the imaging ranges PA2a to PA2c of adjacent imaging units 122a to 122c overlap each other.

[0119] This allows the overlapping area to be included in the boundaries of each image data, even for multiple image data generated in at least one shot, without the user having to adjust the overlapping area and shift the original document. If the entire area of ​​the original document can be captured in these image data in a single shot, the user's task of shifting the original document can be omitted. Thus, the user's workload can be reduced and work efficiency can be improved.

[0120] The image reading system 2 of Embodiment 2 also provides the same effects as the image reading system 1 of Embodiment 1 described above.

[0121] (Variation 1) Next, an image reading system 2a of the modified embodiment 2, Modified Example 1, will be described with reference to Figures 11 and 12. The image reading system 2a of Modified Example 1 differs from the above-described embodiment 2 in that the document tray 120 has markers 111a to 114a and 111b to 114b.

[0122] Figure 11 shows an example of the configuration of an image reading system 2a according to a modified example 1 of Embodiment 2. In Figure 11, the same reference numerals are used for components similar to those in Embodiment 2 described above, and their descriptions are omitted.

[0123] As shown in Figure 11, the image reading system 2a is equipped with a document glass 120 and a controller 110a, instead of the document glass 20 and controller 10 of the embodiment 2 described above.

[0124] The document tray 120 is equipped with multiple markers 111a to 114a and 111b to 114b on its upper surface. The multiple markers 111a to 114a are provided on one side of the document tray 120 in the vertical direction and are arranged in this order from one end to the other in the horizontal direction of the document tray 120. The multiple markers 111b to 114b are provided on the other side of the document tray 120 in the vertical direction and are arranged in this order from one end to the other in the horizontal direction of the document tray 120.

[0125] In other words, markers 111a and 111b form a pair on both sides of the document table 120 in the vertical direction. Markers 112a and 112b also form a pair on both sides of the document table 120 in the vertical direction. Markers 113a and 113b also form a pair on both sides of the document table 120 in the vertical direction. Markers 114a and 114b also form a pair on both sides of the document table 120 in the vertical direction.

[0126] Furthermore, markers 111a and 114a are paired on both sides of the document tray 120 in the horizontal direction. Markers 111b and 114b are also paired on both sides of the document tray 120 in the horizontal direction.

[0127] The pair of markers 111a and 111b on both sides of the document table 120 in the vertical direction are positioned within the imaging range PA2a of the imaging unit 122a, near the end of the side that does not overlap with the imaging range PA2b of the imaging unit 122b.

[0128] The pair of markers 112a and 112b on both sides of the document table 120 in the vertical direction are located within the shooting range PA2b of the imaging unit 122b, near the end on the side that overlaps with the shooting range PA2a of the imaging unit 122a. The pair of markers 113a and 113b on both sides of the document table 120 in the vertical direction are located within the shooting range PA2b of the imaging unit 122b, near the end on the side that overlaps with the shooting range PA2c.

[0129] The pair of markers 114a and 114b on both sides of the document table 120 in the vertical direction are located within the imaging range PA2c of the imaging unit 122c, and are positioned near the end on the side that overlaps with the imaging range PA2c of the imaging unit 122c.

[0130] These markers 111a-114a and 111b-114b may have any size and shape, as long as they are of a size and shape that makes it easy for the detection unit of the controller 110a, described later, to extract these features.

[0131] The image reading system 2a of the modified example 1 reads documents that fit within the imaging range PA2a to PA2c of the multiple imaging units 122a to 122c. In addition, the documents to be read have a vertical width shorter than the distance between the pairs of markers on both sides of the document glass 120 in the vertical direction, and are sized to be placed on the document glass 120 without obscuring these markers 111a to 114a, 111b to 114b.

[0132] When a document that meets the above conditions is placed on the document table 120 and photographed only once by the imaging units 122a to 122c, multiple image data are generated. These image data will include the entire area of ​​the document as well as multiple markers 111a to 114a and 111b to 114b on the vertical outer edges of the document.

[0133] The controller 110a is configured as a computer, similar to the controller 110 in Embodiment 2 described above, and includes, for example, an arithmetic unit, a storage device, and an auxiliary storage device. Furthermore, while the detection unit 101 in Embodiment 1 directly detects overlapping areas from the original document portions of multiple image data, the detection unit of the controller 110a uses markers 111a to 114a and 111b to 114b included in the multiple image data to detect overlapping areas in these image data.

[0134] More specifically, the detection unit of the controller 110a performs image processing on multiple image data, for example, to extract feature points from markers 111a-114a and 111b-114b contained in each image data, and further performs image data matching between these markers 111a-114a and 111b-114b to extract corresponding points. In this way, the detection unit of the controller 110a detects markers 111a-114a and 111b-114b in the image data.

[0135] However, as mentioned above, the detection methods for markers 111a-114a and 111b-114b are not limited to those described above.

[0136] The detection unit of the controller 110a extracts overlapping ranges that are included in multiple image data based on the detected markers 111a to 114a and 111b to 114b.

[0137] In other words, the image data in which markers 112a and 112b are detected, and the area in that image data where markers 112a and 112b are attached, is the part of the document that was located where the shooting range PA2a of the shooting unit 122a and the shooting range PA2b of the shooting unit 122b overlap, and is an overlapping area that is also included in other image data.

[0138] Similarly, in the image data in which markers 113a and 113b are detected, the area where markers 113a and 113b are attached is the portion of the document that was located where the shooting range PA2b of the shooting unit 122b and the shooting range PA2c of the shooting unit 122c overlap, and is an overlapping area that is also included in other image data.

[0139] As described above, when detecting overlapping areas directly from the original document portion of multiple image data, the detection accuracy depends on the state of the original document, such as the content of the text, the colors used, and the shades of those colors. By using markers 111a~114a and 111b~114b included in the image data, it is possible to detect overlapping areas within the image data without depending on the state of the original document.

[0140] However, the method of detecting overlapping areas within image data using markers 111a~114a, 111b~114b included in the image data is not suitable for larger originals that do not meet the above conditions. In the case of an original document that is too large to fit entirely within the multiple image data generated by the imaging units 122a~122c in a single shot, if the position of the original document on the document table 120 is shifted and multiple shots are taken as described above, the positional relationship between each marker 111a~114a, 111b~114b and the original document will change in the multiple image data, making it impossible to correctly detect overlapping areas within the multiple image data.

[0141] Furthermore, in the method for detecting overlapping areas within image data using markers 111a~114a and 111b~114b contained in the image data, a process is performed to delete parts of the multiple image data that are not the original document, that is, the parts in which markers 111a~114a and 111b~114b are visible.

[0142] The detection unit of the controller 110a performs image processing on multiple image data, for example, by binarizing these image data, to extract the contours of the original document contained within the image data. Known methods for contour extraction by binarization include, for example, the Canny edge detection method. However, various other methods are known for contour detection in image data, and a method that is likely to yield the desired results can be appropriately selected and used from among these.

[0143] When generating composite image data by concatenating multiple image data, the generation unit of the controller 110a generates composite image data in which parts other than the original document are deleted, based on the contour detection results from the detection unit of the controller 110a.

[0144] Figure 12 is a flowchart showing an example of the procedure for image reading processing in the image reading system 2a according to a modified example 1 of Embodiment 2.

[0145] Steps S201 and S202 shown in Figure 12 are the same as the processes in steps S101 and S102 in Figure 7 of Embodiment 1 described above. However, in the image reading system 2a, multiple images are captured simultaneously using multiple imaging units 122a to 122c based on a single shooting instruction from the user.

[0146] As shown in Figure 12, the detection unit of the controller 110a uses the markers 111a to 114a and 111b to 114b contained in the multiple image data to detect overlapping ranges within these image data (step S203).

[0147] The selection unit of the controller 110a, similar to the selection unit 102 of Embodiment 1 described above, selects pixel information to be used as the concatenated portion of the composite image data from among several overlapping ranges, based on the shooting distance of each pixel (step S204).

[0148] The generation unit of the controller 110a combines and synthesizes multiple image data by using the overlapping range of each selected figure as a connecting portion (step S205).

[0149] Furthermore, the generation unit of the controller 110a extracts the document portion from the synthesized image data based on the extracted document contour, generates synthesized image data that includes the entire range of the document, and stores it in the storage unit of the controller 110a (step S206).

[0150] With the above steps, the image reading process in the image reading system 2a of the modified example 1 is completed.

[0151] According to the image reading system 2a of the modified example 1, the document tray 120 has markers 111a~114a, 111b~114b that indicate the range of a document that overlaps in several image data, and the detection unit of the controller 110a detects the overlapping range that overlaps in several image data by detecting the markers 111a~114a, 111b~114b.

[0152] This allows for highly accurate extraction of overlapping areas even in documents where it is difficult to directly detect feature points from multiple image data points.

[0153] The image reading system 2a of the modified example 1 also provides the same effects as the image reading systems 1 and 2 of the embodiments described above.

[0154] (Modification 2) Next, an image reading system of modified embodiment 2 will be described using Figures 13 and 14. The image reading system of modified embodiment 2 differs from that of embodiment 2 in that it can identify the size of the original document.

[0155] Figure 13 is a block diagram showing an example of the functional configuration of the controller 110b included in the image reading system according to a modified example 2 of Embodiment 2.

[0156] As shown in Figure 13, the controller 110b of the modified example 2 includes a detection unit 201, a selection unit 202, a generation unit 203, a storage unit 204, and a calculation unit 205 as functional units.

[0157] The detection unit 201, selection unit 202, and generation unit 203 have the same functions as the detection unit, selection unit, and generation unit of the controller 110a in the modified example 1 described above.

[0158] Similar to the storage unit 104 in Embodiment 1 described above, the storage unit 204 stores various control parameters, multiple image data captured by the imaging units 122a to 122c, the overlapping range selected by the selection unit 202, and the composite image data generated by the generation unit 203.

[0159] Furthermore, the memory unit 204 stores information such as the arrangement of markers 111a~114a, 111b~114b on the document table 120, the distance on the document table 120 between each marker 111a~114a, 111b~114b and other markers, and the number of pixels included between each marker 111a~114a, 111b~114b and other markers when they are captured in the image data.

[0160] The calculation unit 205 uses the above information regarding markers 111a to 114a and 111b to 114b stored in the storage unit 204 to calculate the actual size of the original document from information about the original document included in the composite image data. The method for calculating the original document size by the calculation unit 205 will be explained in detail below with reference to Figure 14.

[0161] Figure 14 illustrates the method for calculating the document size using the controller 110b according to a modified example 2 of Embodiment 2.

[0162] As shown in Figure 14, the calculation unit 205 of the controller 110b calculates the document size using the actual distance RKx between markers 112a and 113a on the document glass 120, the actual distance RKy between markers 111a and 111b, the number of pixels Kx included between markers 112a and 113a when they are captured in the image data, the number of pixels Ky included between markers 111a and 111b, and the number of pixels Mx included in the horizontal direction of the document and the number of pixels My included in the vertical direction of the document in the composite image data.

[0163] The calculation unit 205 counts the number of pixels Mx included in the horizontal direction of the original document within the composite image data, and the number of pixels My included in the vertical direction of the original document.

[0164] Furthermore, as described above, the memory unit 204 pre-stores the actual distance RKx between markers 112a and 113a on the document glass 120, the actual distance RKy between markers 111a and 111b, and the number of pixels Kx and Ky between markers 111a and 111b that would be included in the image data if they were captured.

[0165] The calculation unit 205 refers to the distances RKx, RKy and pixel counts Kx, Ky stored in the storage unit 204, and calculates the actual width RMx and height RMy of the original document using the following equations (1) and (2) from the pixel counts Mx, My obtained from the composite image data.

[0166] Kx:Mx=RKx:RMx RMx = Mx × RKx / Kx ... (1)

[0167] Ky:My=RKy:RMy RMy = My × RKY / Ky ... (2)

[0168] According to the image reading system of modified example 2, the calculation unit 205 calculates the number of pixels Mx between the two ends of the original document in the horizontal direction, calculates the actual horizontal width RMx of the original document based on the calculated number of pixels Mx, the number of pixels Kx and distance RKx between a pair of markers 112a and 113a, calculates the number of pixels My between the two ends of the original document in the vertical direction, and calculates the actual vertical width RMy of the original document based on the calculated number of pixels My, the number of pixels Ky and distance RKy between a pair of markers 111a and 111b.

[0169] In this way, the document size can be automatically detected from the distances RKx and RKy, the number of pixels Kx and Ky stored in the memory unit 204, and the number of pixels Mx and My obtained from the composite image data. This makes it possible to automatically scan documents without, for example, requiring the user to specify the size.

[0170] The image reading system of the modified example 2 also provides the same effects as the image reading systems 1 and 2 of the embodiments described above.

[0171] [Embodiment 3] Embodiment 3 will be described below with reference to the drawings. Embodiment 3 differs from Embodiment 1 described above in that it includes a movable imaging unit.

[0172] (Example of a reading system configuration) Figure 15 shows an example of the configuration of the image reading system 3 according to Embodiment 3. In Figure 15, the same reference numerals are used for components similar to those in Embodiment 1 described above, and their descriptions are omitted.

[0173] As shown in Figure 15, the image reading system 2 includes an arm 223, a rail 224, a drive unit 225, an operation unit 221, and a controller 210, instead of the arm 23, operation unit 21, and controller 10 of the embodiment 1 described above.

[0174] The arm portion 223 has a base portion fixed to the document table 20, for example via a controller 210, and a tip portion that extends above the document table 20 and to which a rail 224 is attached.

[0175] The rail 224 is attached to the tip of the arm 223 at a predetermined height above the document tray 20, so as to be parallel to the top surface of the document tray 20.

[0176] The imaging unit 22 is attached to the rail 224 via a drive unit 225 so that it can move along the rail 224. The drive unit 225 includes, for example, a motor (not shown) and drives the imaging unit 22 to move along the rail 224.

[0177] As a result, the imaging unit 22 can move on the document table 20 while maintaining a constant angle and distance from the document table 20.

[0178] The controller 210 is configured as a computer, similar to the controller 10 in Embodiment 1 described above, and includes, for example, an arithmetic unit, a memory device, and an auxiliary memory device. The controller 210 is also configured to move the imaging unit 22 and perform multiple imaging operations in response to a single imaging instruction from the user. The operation unit 221 is configured to transmit a single imaging instruction from the user to the controller 210.

[0179] When photographing a document, the controller 210 controls the photographing unit 22, which moves along the rail 224, to take photographs at multiple predetermined positions on the document table 20. At this time, the controller 210 controls the timing of the photographs taken by the photographing unit 22 so that the photographing range PA3 of the photographing unit 22 overlaps at the boundaries of each other at the multiple photographing positions. As a result, each of the multiple image data captured will include an overlapping range at the boundary with other image data.

[0180] The controller 210 may adjust the range in which the imaging unit 22 moves along the rail 224, as well as the position and number of times the imaging unit 22 takes a photograph, depending on the size of the document, etc.

[0181] (Example of processing by a reading device) Next, an example of processing in the image reading system 3 will be described using Figure 16. Figure 16 is a flowchart showing an example of the procedure for image reading processing in the image reading system 3 according to Embodiment 3.

[0182] Step S301 shown in Figure 16 is the same as the process in step S101 in Figure 7 of Embodiment 1 described above.

[0183] As shown in Figure 16, the controller 210 starts operating based on a single shooting instruction from the user (step S302). That is, the controller 210 moves along the rail 224 using the drive unit 225 and causes the shooting unit 22 to take a picture at a predetermined position (step S303).

[0184] The controller 210 continues to move the shooting unit 22 by the drive unit 225 (step S305) and repeats the shooting of the original document (step S303) until the shooting unit 22 has finished moving within its movable range on the rail 224 (step S304: No).

[0185] After the shooting unit 22 has finished moving within its movable range on the rail 224 (step S304: Yes), if there are still unphotographed parts of the document (step S306: No), the user adjusts the document as appropriate (step S307) and issues another shooting instruction (step S302), allowing the shooting unit 22 to continue photographing the document (step S303).

[0186] Once the entire area within the document has been captured (step S306: Yes), the user instructs the controller 210 via the operation unit 221 to combine the captured image data.

[0187] The subsequent steps S308 to S310 are the same as the steps S105 to S107 in Figure 7 of Embodiment 1 described above.

[0188] With the above steps, the image reading process in the image reading system 3 of Embodiment 3 is completed.

[0189] In addition, during the process in step S304, the operation unit 221 may display a message or emit a sound to inform the user that the movement of the imaging unit 22 has been completed.

[0190] (Overview) The image reading system 3 of Embodiment 3 includes a rail 224 provided above the document table 20 and parallel to the document table 20, and a drive unit 225 that drives the imaging unit 22 to move along the rail 224.

[0191] This allows the overlapping area to be included in the boundaries of each image data, even for multiple image data generated in at least one shot, without the user having to adjust the overlapping area and shift the original document. If the entire area of ​​the original document can be captured in these image data in a single shot, the user's task of shifting the original document can be omitted. Thus, the user's workload can be reduced and work efficiency can be improved.

[0192] The image reading system 3 of Embodiment 3 also provides the same effects as the image reading systems of Embodiments 1 and 2 described above.

[0193] In the above-described embodiment 3, the imaging unit 22 is moved in the horizontal direction. However, the rails may be arranged so that the imaging unit 22 can be moved not only horizontally but also vertically. Alternatively, the image reading system of modified example 2 may further include, in addition to the above configuration, a rail extending in the vertical direction, another imaging unit attached to the rail, and a drive unit for driving the other imaging unit.

[0194] [Embodiment 4] The image reading systems of embodiments 1 to 3 and their modified versions described above are applicable to image forming apparatuses equipped with, for example, a scanner. Below, an example of an image forming system 100 to which the image reading system 1 of embodiment 1 is applied will be described with reference to Figure 17.

[0195] Figure 17 shows an example of the configuration of the image forming system 100 according to Embodiment 4. Figure 17(a) is a diagram of the image forming system 100 according to Embodiment 4, and Figure 17(b) is a diagram of the image forming apparatus 90a equipped with a scanner function.

[0196] As shown in Figure 17(a), the image forming system 100 comprises an image reading system 1c and an image forming apparatus 90c.

[0197] The image reading system 1c is mounted on the upper end of the image forming apparatus 90c. The configuration of the image reading system 1c is generally as described above.

[0198] However, the controller 10c of the image reading system 1c is housed, for example, within the casing of the image forming apparatus 90c and is also used as a controller for controlling the image forming apparatus 90c. In addition, the operating section 21c of the image reading system 1c is provided, for example, on the entire surface of the image forming system 100 and is also used as an operating section for the image forming apparatus 90c.

[0199] The image forming apparatus 90c includes a paper discharge unit 92, an image forming unit 93, and a paper feeding unit 95.

[0200] The paper feeding unit 95 is configured to store paper to be image formed and supplies paper to the image forming unit 93. The paper feeding unit 95 is located, for example, at the bottom of the image forming apparatus 90c.

[0201] The image forming unit 93 prints by spraying ink or the like onto paper supplied from the paper feeding unit 95, thereby forming image data. The image forming unit 93 is located in the central part of the image forming apparatus 90c, for example, on top of the paper feeding unit 95.

[0202] The paper discharge unit 92 discharges the paper on which the image data has been formed. The paper discharge unit 92 is located at the top of the image forming apparatus 90c, for example, on the image forming unit 93.

[0203] The controller 10c is configured as a computer, similar to the controller 10 in Embodiment 1 described above, and includes, for example, an arithmetic unit, a memory device, and an auxiliary memory device, and controls the entire image forming system 100, which includes the image reading system 1c and the image forming apparatus 90c.

[0204] The controller 10c performs the same control on the image reading system 1c as the controller 10 in Embodiment 1 described above to generate composite image data of a large-format original.

[0205] Furthermore, the controller 10c causes the image forming unit 93 to receive paper from the paper feeding unit 95 of the image forming apparatus 90c, causes the image forming unit 93 to perform image forming processing to print the generated composite image onto the paper, and discharges the paper with the composite image data formed on it from the paper discharge unit 92.

[0206] The operation unit 21c functions as an interface with the user, similar to the operation unit 21 of the embodiment 1 described above, and receives various instructions from the user to the image reading system 1c and the image forming apparatus 90c. The operation unit 21c also outputs various information from the image reading system 1c and the image forming apparatus 90c to the user.

[0207] The image forming system 100 described above can be configured, for example, based on the image forming apparatus 90 shown in Figure 17(b).

[0208] As shown in Figure 17(b), the image forming apparatus 90, which forms the basis of the image forming system 100, includes an operation unit 91, a paper output unit 92, an image forming unit 93, a controller 94, a paper feeding unit 95, and a reading unit 96.

[0209] The paper discharge unit 92, image forming unit 93, and paper feeding unit 95 of the image forming apparatus 90 are configured in the same way as the paper discharge unit 92, image forming unit 93, and paper feeding unit 95 of the image forming apparatus 90c described above. The controller 94 is a controller specific to the image forming apparatus 90 and controls the entire image forming apparatus 90. The operation unit 91 is an operation unit specific to the image forming apparatus 90 and functions as an interface between the user and the image forming apparatus 90.

[0210] The reading unit 96 of the image forming apparatus 90 is, for example, a scanner capable of scanning a document set in the reading unit 96 and importing it into the image forming apparatus 90 as image data. The image data read by the reading unit 96 undergoes image forming processing, such as printing on paper by the image forming unit 93 under the control of the controller 94.

[0211] Based on the image forming apparatus 90 configured in this way, the document table 20, imaging unit 22, and arm unit 23 of the image reading system 1 are mounted on the image forming apparatus 90 in place of the reading unit 96, and the operation unit 91 and controller 94 of the image forming apparatus 90 are integrated with the operation unit 21c and controller 10c to obtain the image forming system 100 described above.

[0212] In the example shown in Figure 17, the image reading system 1 of Embodiment 1 is mounted on the image forming apparatus 90. However, any of the image reading systems from Embodiments 1 to 3 and their modified versions can be mounted on the image forming apparatus 90.

[0213] Although embodiments have been described above, the specific configuration of each part, the details of the processing, etc., are not limited to those described in the embodiments. [Explanation of Symbols]

[0214] 1,2,2a,3 Image reading system 10, 10a, 110, 110a, 110b, 210 controller 20,120 Manuscript holder 22, 22a, 122a, 122b, 122c Photography Department 23,123 Arm 101,201 Detection unit 102,202 Selection section 103,203 Generation part 104,204 Storage section 111a~114a, 111b~114b Markers 205 Calculation Section 224 rails 225 Drive unit [Prior art documents] [Patent Documents]

[0215] [Patent Document 1] Japanese Patent Publication No. 2019-146126

Claims

1. A manuscript stand for placing the manuscript, A shooting unit positioned opposite the document placed on the document table, which photographs the document at multiple different ranges to generate multiple image data of the document, A detection unit for detecting the overlapping range of multiple different ranges in the original document captured by the imaging unit, A selection unit selects the overlapping area from the aforementioned overlapping area in which the imaging unit and the original document are photographed at the shortest shooting distance, The system includes a generation unit that generates composite image data from different captured ranges based on the overlapping range of the image captured at the shortest shooting distance selected by the selection unit, Image recognition system.

2. Each of the aforementioned plurality of image data is, The boundary portion with other image data has the overlapping range which is included in the other image data. The image reading system according to claim 1.

3. The aforementioned imaging unit is The device is configured to be able to move on the document tray while maintaining a constant angle and distance from the document tray. The image reading system according to claim 1 or claim 2.

4. A rail is provided above the document tray, parallel to the document tray, The system further comprises a drive unit that drives the imaging unit to move along the rail, The image reading system according to claim 3.

5. The aforementioned imaging unit is The angle and distance to the document table are constant, and the system includes multiple imaging units positioned at different locations on the document table. The image reading system according to claim 1 or claim 2.

6. The aforementioned multiple imaging units are The boundary lines of the shooting ranges of adjacent shooting sections are arranged so that they overlap with each other. The image reading system according to claim 5.

7. The aforementioned document stand is The aforementioned plurality of image data includes a marker indicating the range of the original document that is included in some of the image data, The detection unit is The overlapping range is detected by detecting the marker. The image reading system according to claim 5 or claim 6.

8. A storage unit that holds information about the marker, The system further includes a calculation unit that calculates the size of the original document based on the composite image data, The aforementioned marker is, A pair of first markers positioned along a first direction of the document placed on the document table, It includes a pair of second markers arranged along a second direction intersecting the first direction of the document placed on the document table, The aforementioned storage unit is As for information regarding the aforementioned marker, The distance between the pair of first markers and the number of pixels, The distance between the pair of second markers and the number of pixels are maintained, The detection unit is The contour of the original document is detected, and the end positions of the original document in the first direction and the end positions in the second direction are identified. The calculation unit described above, The number of pixels between the two ends of the original document in the first direction is calculated, and the actual length of the original document in the first direction is calculated based on the number of pixels between the two ends of the original document in the first direction, the number of pixels between the pair of first markers, and the distance between them. The number of pixels between the two ends of the original document in the second direction is calculated, and the actual length of the original document in the second direction is calculated based on the number of pixels between the two ends of the original document in the second direction, the number of pixels between the pair of second markers, and the distance between them. The image reading system according to claim 7.

9. Image data obtained by photographing parts of the document multiple times from a position facing the document, and a detection unit that detects overlapping areas of multiple different areas in the document from multiple image data that include different areas of the document, A selection unit that selects the overlapping area from the aforementioned overlapping area in which the original document was photographed at the shortest shooting distance, The system includes a generation unit that generates composite image data from different captured ranges based on the overlapping range of the image captured at the shortest shooting distance selected by the selection unit, Image reading device.

10. A document tray on which to place a document, A shooting unit positioned opposite the document placed on the document table, which photographs the document at multiple different ranges to generate multiple image data of the document, A detection unit for detecting the overlapping range of multiple different ranges in the original document captured by the imaging unit, A selection unit selects the overlapping area from the aforementioned overlapping area in which the imaging unit and the original document are photographed at the shortest shooting distance, A generation unit generates composite image data from different captured ranges based on the overlapping range captured at the shortest shooting distance selected by the selection unit, The system includes an image forming unit that prints the composite image data onto a printing medium. Image forming system.

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