Camera head and imaging system

Abstract

To address such a desire that, when a camera head is downsized, it may be further useful.SOLUTION: A camera head 10 has an elongated shape and is used to capture an image of an imaging area in the vicinity of a tip part 12 in a longitudinal direction. The camera head 10 includes a camera module 30, two or more light source units disposed at positions farther from the tip part 12 than the camera module 30 in the longitudinal direction, and a light guide unit 60 disposed radially outside an outer surface of the camera module 30 and guiding light emitted from each of the two or more light source units 40 to the vicinity of the tip part so that the light is applied to the imaging area, where at least two light source units 40 out of the two or more light source units 40 are located at different positions in the longitudinal direction. This configuration allows the camera head 10 to be further downsized.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a camera head and an imaging system used for imaging an imaging area in the vicinity of a tip end in a longitudinal direction. [Background technology]

[0002] Conventionally, various types of camera heads have been used in, for example, endoscopes for observing living organisms, industrial endoscopes, etc. Some camera heads have a structure for emitting illumination light and a camera module.

[0003] To reduce the diameter of such camera heads, some have a structure in which a light source is placed behind the imaging module and a light guide guides the light from the light source to the tip (see, for example, Patent Documents 1, 2, 3, 4, and 5 below).

[0004] There are camera heads having a structure in which a plurality of light guides and light emitting parts are arranged at equal intervals around the imaging element (see, for example, Patent Documents 6, 7, and 8 below). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6995659 [Patent Document 2] JP 2005-204944 A [Patent Document 3] Patent No. 4530128 [Patent Document 4] JP 2012-205849 A [Patent Document 5] Japanese Patent Application Publication No. 2-110505 [Patent Document 6] Patent No. 7100171 [Patent Document 7] Patent No. 6020870 [Patent Document 8] Patent No. 6055691 Summary of the Invention [Problem to be solved by the invention]

[0006] If the camera head can be made smaller, the camera head and the imaging system using the camera head will become more useful in several applications.

[0007] An object of the present invention is to provide a smaller camera head and imaging system. [Means for solving the problem]

[0008] The camera head of the first invention has an elongated shape and is used for imaging an imaging area near a tip in the longitudinal direction, and comprises a camera module, two or more light source units arranged at a position farther from the tip in the longitudinal direction than the camera module, and a light guiding unit arranged radially outward from the outer surface of the camera module and guiding light emitted from each of the two or more light source units to the vicinity of the tip so that it is irradiated onto the imaging area, and at least two of the two or more light source units are at different positions in the longitudinal direction.

[0009] With this configuration, it is possible to miniaturize the camera head capable of irradiating the imaging area with light from two or more light source units.

[0010] Furthermore, in contrast to the first invention, the camera head of the second invention is a camera head in which at least two of the two or more light source sections are configured to emit light having different wavelengths from each other.

[0011] With this configuration, it is possible to miniaturize the camera head capable of irradiating the imaging area with light of multiple wavelengths.

[0012] Furthermore, the camera head of the third invention is a camera head in which, compared to the first or second invention, the light guide section has two or more optical fibers corresponding to at least two of the two or more light source sections, and each of the two or more optical fibers is arranged around the camera module so as to be spaced apart from each other in the circumferential direction and aligned in the circumferential direction.

[0013] With this configuration, the light from the light source unit can be irradiated evenly onto the imaging area.

[0014] Furthermore, the camera head of the fourth invention is a camera head in which, compared to the third invention, two or more optical fibers are arranged around the camera module so as to be spaced apart from each other in the circumferential direction, and two or more optical fibers are arranged to guide light of a certain wavelength band, and the light guide section is configured to be able to irradiate the light of the certain wavelength band onto the imaging area from two or more locations spaced apart from each other in the circumferential direction.

[0015] With this configuration, the imaging area can be irradiated with light of one wavelength band evenly.

[0016] In addition, the camera head of the fifth invention is a camera head in which, compared to the third or fourth invention, the camera module has a columnar portion having a polygonal columnar shape, and each of the two or more optical fibers is arranged along the planar side surface of the columnar portion.

[0017] With this configuration, the camera head can be made smaller.

[0018] In addition, the camera head of the sixth invention is a camera head according to any one of the first to fifth inventions, which is provided with a sleeve formed in a tubular shape, and the camera module, light source unit and light guide unit are housed inside the sleeve.

[0019] With this configuration, a camera head that is small and easy to manufacture can be constructed.

[0020] Furthermore, the camera head of the seventh invention is a camera head according to any one of the first to fifth inventions, which comprises a sleeve formed in a tubular shape, the sleeve being a transparent member, the light guiding section being all or part of the sleeve, and the camera module being housed inside the sleeve.

[0021] With this configuration, the camera head can be made smaller.

[0022] A camera head according to an eighth aspect of the present invention is a camera head according to any one of the first to seventh aspects of the present invention, in which the camera module and the light guiding section are integrally configured.

[0023] With this configuration, a camera head that is small and easy to manufacture can be constructed.

[0024] In addition, the camera head of the ninth invention is a camera head in which, compared to any one of the first to eighth inventions, at least two of the two or more light source units that are located at different positions in the longitudinal direction are arranged so as to partially overlap when viewed from the front in the longitudinal direction.

[0025] With this configuration, it is possible to reliably reduce the size of a camera head having at least two light source units.

[0026] In addition, the imaging system of the tenth invention is an imaging system according to any one of the first to ninth inventions, comprising a camera head and an image capture device connected to the camera head and capturing an image captured by the camera head.

[0027] With this configuration, an image can be acquired using a small camera head that can irradiate an imaging area with light from two or more light source units. Effect of the Invention

[0028] According to the present invention, it is possible to provide a smaller camera head and imaging system. [Brief description of the drawings]

[0029] [Figure 1] FIG. 1 is a diagram illustrating a configuration of an imaging system according to an embodiment of the present invention. [Diagram 2] Block diagram of the imaging system [Diagram 3] A side cross-sectional view of the camera head. [Figure 4] Cross section of line AA in Figure 3 [Diagram 5] Cross section of line BB in Figure 3 [Figure 6] Cross section of line CC in Figure 3 [Figure 7] Cross section of line DD in Figure 3 [Figure 8] FIG. 1 is a diagram for explaining the configuration of an illumination filter of the camera head. [Figure 9] FIG. 1 is a diagram for explaining a configuration example of a camera head according to a comparative example of the present embodiment; [Figure 10] FIG. 1 is a diagram for explaining a usage example of an imaging system according to an embodiment of the present invention; [Figure 11] FIG. 1 is a diagram illustrating a configuration example of a camera head according to a first modified example of an embodiment of the present invention. [Figure 12] FIG. 13 is a diagram illustrating a configuration example of a camera head according to a second modified example of an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] Hereinafter, embodiments of a camera head and an imaging system using the same will be described with reference to the drawings. Note that components with the same reference numerals in the embodiments perform similar operations, and therefore repeated description may be omitted.

[0031] In the following description, the direction perpendicular to the longitudinal direction of the tubular camera head may be referred to as the radial direction, and the direction along the arc centered on the central axis of the camera head along the longitudinal direction may be referred to as the circumferential direction. In addition, in the following, the direction toward the tip in the radial direction may be referred to as the "front" and the opposite direction may be referred to as the "rear". For example, as in this example, the shape and positional relationship of each part may be described by indicating a certain direction, but the direction is merely for convenience of explanation and does not limit the orientation or posture of each device, etc., when used according to the present invention. In addition, expressions indicating directions and expressions indicating states such as horizontal, vertical, and orthogonal only indicate that they can be roughly understood as such, and do not necessarily have to be interpreted strictly as such expressions.

[0032] (Embodiment)

[0033] The outline of the embodiment is as follows. The camera head is for capturing an image of an imaging area near the tip in the longitudinal direction. The camera head has a structure in which at least two light source units are arranged at different positions in the longitudinal direction, at a position farther from the tip than the camera module. It is preferable that the at least two light source units are configured to emit light of different wavelengths. The camera head configured in this way and the configuration of an imaging system using the same will be described below.

[0034] Fig. 1 is a diagram illustrating a configuration of an imaging system 1 according to an embodiment of the present invention, and Fig. 2 is a block diagram of the imaging system 1.

[0035] As shown in the figure, the imaging system 1 includes a camera head 10 and an image acquisition device 100. The imaging system 1 can be used as an endoscope for observing and inspecting various organs of living organisms, an industrial endoscope, and the like. The imaging system 1 may be called an imaging device. Note that the use of the imaging system 1 is not limited to this. The imaging system 1 is configured to be able to acquire imaging results of an imaging area near the tip of the camera head 10. The imaging system 1 is configured to be able to record the imaging results as an image, or to output the imaging results to an output device provided inside or outside.

[0036] Note that the image referred to here may be a still image or a moving image. A moving image may be considered to include a plurality of still images. Furthermore, the format of the data recorded or output as the image does not matter.

[0037] Moreover, outputting to an output device includes an expression that includes displaying on a display or the like, printing on a medium by a printer or the like, transmitting information to another device via a network, and the like.

[0038] The camera head 10 has a camera module 30 and a light source unit 40. In the present embodiment, the light source unit 40 has, for example, a first light source unit 41 and a second light source unit 42 that emit light having different wavelengths. There may be more types of light sources. A more specific structure of the camera head 10 will be described later.

[0039] The camera head 10 is connected to the image acquisition device 100 via a cable 19. The cable 19 includes, for example, a signal line for communicating with the camera module 30, and an electric wire for supplying power for driving the camera module 30 and the light source unit 40. The cable 19 is configured to be flexible, but is not limited to this.

[0040] The image acquisition device 100 is, for example, a device including a computer or the like, and configured to be able to drive the camera head 10 to capture an image. In this embodiment, the image acquisition device 100 is configured to be able to record the image capture result, output the image capture result to an external terminal device 600 or the like, and display the image on the display of the terminal device 600 or the like. The image acquisition device 100 may have a display itself and be configured to be able to display the captured image. The image acquisition device 100 may be, for example, a personal computer itself. In this embodiment, the imaging system 1 may be understood to include the terminal device 600.

[0041] In this embodiment, the image acquisition device 100 includes, for example, a storage unit 110, a reception unit 130, an image acquisition unit 140, a camera head driving unit 150, and a communication unit 160.

[0042] The storage unit 110 is preferably a non-volatile recording medium, but may also be a volatile recording medium. The storage unit 110 stores information acquired by the image acquisition device 100. The process by which the information is stored is not limited to a specific process. For example, the information may be stored via a recording medium, information transmitted via a communication line may be stored, or information input via an input device may be stored.

[0043] The reception unit 130 receives the imaging results by the camera head 10, information received by the communication unit 160, and the like as information input to the image acquisition device 100. The received information is temporarily or long-term accumulated in the storage unit 110, or is used in processing by each of the other units.

[0044] The reception unit 130 may be capable of receiving information input by an input means. The input means may be, for example, a numeric keypad, a keyboard, a mouse, a menu screen, or any other means. In this case, the reception unit 130 may be realized by a device driver for an input means such as a numeric keypad or a keyboard, or control software for a menu screen.

[0045] The image acquiring unit 140 acquires an image captured by the camera head 10. That is, the imaging result acquired by the camera module 30 of the camera head 10 and transmitted to the image acquiring device 100 via the cable 19 is acquired as an image. The image acquiring unit 140 is configured to be able to record the acquired image in the storage unit 110.

[0046] The camera head driving section 150 is configured to supply power to the camera module 30 and the light source section 40 of the camera head 10, and to drive and control the operation of each section.

[0047] Image acquisition section 140 and camera head driving section 150 are configured to be operable, for example, by a computer executing a predetermined control program, but are not limited to this.

[0048] The communication unit 160 connects the image acquisition device 100 to an external device so as to be able to communicate with the external device. The communication unit 160 is realized, for example, by a wireless or wired communication means, but may also be realized by a means for receiving broadcasts or a broadcasting means. In this embodiment, the communication unit 160 is configured to be able to communicate, for example, with an external terminal device 600 or the like, and to transmit images that are the imaging results of the camera head 10 to the terminal device 600. In other words, the image acquisition device 100 is able to output images captured using the camera head 10.

[0049] Next, the structure of the camera head 10 according to the present embodiment will be described.

[0050] Fig. 3 is a side cross-sectional view of the camera head 10. Fig. 4 is a cross-sectional view taken along line AA in Fig. 3. Fig. 5 is a cross-sectional view taken along line BB in Fig. 3. Fig. 6 is a cross-sectional view taken along line CC in Fig. 3. Fig. 7 is a cross-sectional view taken along line DD in Fig. 3.

[0051] In these figures and similar cross-sectional views below, hatching indicates cross sections of members, but for convenience of illustration, cross sections of all members are not necessarily hatched.

[0052] As shown in the figure, the camera head 10 has an elongated shape as a whole. In this embodiment, the camera head 10 has a generally cylindrical shape as a whole. The front and rear ends of the camera head 10 may be rounded, or may have partial irregularities. FIG. 3 shows a cross section of the camera head 10 taken along a plane passing through the central axis thereof.

[0053] The camera head 10 includes, for example, a sleeve 20, a camera module 30, a light source unit 40, a light guiding unit 60, and filters 70 and 80. In the present embodiment, the filters 70 and 80 include an illumination filter 70 and an imaging filter 80.

[0054] The sleeve 20 is formed in a cylindrical shape. It may be said that the sleeve 20 is formed in a tubular shape. The material of the sleeve 20 is not important. It may be any material such as metal, ceramic, resin, etc. In this embodiment, each part of the camera head 10 is accommodated inside the sleeve 20. It may be said that each part of the camera head 10 is inside the sleeve 20. It may also be said that each part of the camera head 10 is inside the inner circumferential surface of the sleeve 20 in the radial direction (the direction toward or away from the central axis of the camera head 10). In this embodiment, the inner circumferential surface of the sleeve 20 has a cylindrical shape.

[0055] The camera module 30 is a module in which an imaging element and an optical system such as a lens are packaged. As the camera module 30, for example, one having a known structure can be used. The camera module 30 has a structure in which a light receiving unit 32, which is located at the tip side in the longitudinal direction of the camera head 10 (the left-right direction in FIG. 3 ) and into which light to be imaged is incident, an optical system including a lens, and an imaging element are arranged. A wiring 91 connected to the imaging element is connected to a rear end 34 of the camera module 30, i.e., the rear end 34 of the imaging element. The wiring 91 can be collected into a cable 19 and connected to an image acquisition device 100 or the like.

[0056] In this embodiment, the camera module 30 has a quadrangular prism shape formed such that the longitudinal direction of the camera head 10 corresponds to the height direction as a whole. That is, the outer surface (peripheral side surface) of the camera module 30 is roughly composed of four substantially flat flat portions 35. The cross section of the camera module 30 is substantially square, but may be other rectangular or quadrangular shapes. Note that the camera module 30 is not limited to such a shape, and may have a columnar portion that is a polygonal prism. The flat portions 35 may be said to be planar side surfaces of the columnar portions.

[0057] For example, the camera module 30 is not limited to a quadrangular prism shape, and may be formed to have a triangular prism shape or other polygonal prism shape. That is, the peripheral side surface of the camera module 30 may be composed of three or more substantially flat flat portions 35. The camera module may also have a three-dimensional shape called a twisted column (helix column) in which the bottom surface rotates around a central axis as it progresses in the height direction. The camera module 30 may be a cylinder or have other shapes.

[0058] The light source unit 40 is a light source for irradiating the imaging area when imaging is performed using the camera head 10. The light source unit 40 is, for example, an LED chip, but is not limited thereto. The light source unit 40 may be, for example, a light source using other types of light sources such as a laser diode. The light source unit 40 is connected to, for example, an electric wire (not shown) wired through a cable 19, and is turned on when power is supplied from the image acquisition device 100 or the like. The light source unit 40 has, for example, a rectangular parallelepiped shape as a whole as described later, but is not limited thereto, and may be, for example, a cylindrical shape, a coin shape, a flat plate shape, or other shapes.

[0059] The camera head 10 has two or more light source units 40. For example, in this embodiment, four light source units 40 are provided. Two of the four light source units 40 are first light source units 41, and the other two are second light source units 42. The first light source unit 41 and the second light source unit 42 are, for example, LED chips having a shape that is a substantially rectangular parallelepiped as a whole, and are arranged to emit light from their front surfaces. The first light source unit 41 and the second light source unit 42 are configured to emit light of different wavelengths. In this embodiment, the first light source unit 41 and the second light source unit 42 are provided, so that the structure of the light guide unit 60 that guides the light from each unit forward can be simplified. In addition, the amount of light irradiated from the camera head 10 can be easily adjusted for each wavelength.

[0060] The number of light source units 40 is not limited to this. It is sufficient that two or more light source units 40 are provided. Of the two or more light source units 40, at least two are preferably configured to emit light of different wavelengths as in the present embodiment. For example, the camera head 10 may be provided with one first light source unit 41 and one second light source unit 42. However, this is not limited, and the first light source unit 41 and the second light source unit 42 may be configured to emit light of the same wavelength. In addition, one light source unit 40 or two or more light source units 40 that emit light of the same wavelength may be provided, and the light emitted from the light source unit 40 may pass through a filter that transmits light of different wavelength bands, so that light of two or more wavelengths can be irradiated from the camera head 10.

[0061] As shown in the figure, each light source unit 40 is disposed at a position farther from the tip 12 than the camera module 30 in the longitudinal direction. That is, each light source unit 40 is located behind the camera module 30. It may be said that each light source unit 40 is behind the camera module 30 when viewed from the front (tip 12 side) of the camera head 10 in the longitudinal direction. Since the light source unit 40 is disposed at a position farther from the tip 12, heat generated by the light source unit 40 is less likely to be transmitted to the tip 12, and it is possible to prevent the subject from being affected. In addition, each light source unit 40 is disposed at a position where a part of the light source unit 40 overlaps with the camera module 30 when viewed from the front in the longitudinal direction. This allows each part of the camera head 10 to be accommodated in a smaller-diameter sleeve 20, and the camera head 10 can be made smaller (thinner).

[0062] In addition, in the camera head 10, at least two of the light source units 40 are located at different positions in the longitudinal direction. Of the at least two light source units 40, the rear end of at least one of the light source units 40 is located forward of the front end of the other at least one light source unit 40. Since the at least two light source units 40 are located at different positions in the longitudinal direction in this manner, each light source unit 40 can be housed in a sleeve 20 with a smaller diameter. In other words, the diameter of the camera head 10 can be made smaller. In order to make the diameter smaller, the at least two light source units 40 may be arranged so as to partially overlap each other when viewed from the front in the longitudinal direction.

[0063] In addition, the at least two light source units 40 are located at different positions in the circumferential direction. Since the at least two light source units 40 are located at different positions in the circumferential direction, as described later, a structure for guiding light from each light source unit 40 to the tip portion 12 can be simply configured.

[0064] More specifically, in the present embodiment, the two first light source units 41 of the camera head 10 are located in front of the two second light source units 42. In other words, it may be said that the camera module 30, the two first light source units 41, and the two second light source units 42 are arranged in this order from the side closer to the tip portion 12 in the longitudinal direction. It may be said that each of the two first light source units 41 is sandwiched between the rear end portion 34 of the camera module 30 and the front end portion of the second light source unit 42.

[0065] As shown in Fig. 4, in this embodiment, the two first light source units 41 are disposed radially outward of the cable 19 so as to sandwich the cable 19 between the two first light source units 41. The two first light source units 41 are disposed such that their long sides are substantially parallel to each other when viewed from the front in the longitudinal direction. As shown in Fig. 5, the two second light source units 42 are also disposed radially outward of the cable 19 so as to sandwich the cable 19 between the two second light source units 42. The two second light source units 42 are disposed such that their long sides are substantially parallel to each other when viewed from the front in the longitudinal direction.

[0066] In this embodiment, the first light source unit 41 and the second light source unit 42 are arranged so that the long side of the first light source unit 41 and the long side of the second light source unit 42 are perpendicular to each other when viewed from the front in the longitudinal direction. That is, the first light source unit 41 and the second light source unit 42 are at different positions in the circumferential direction. Also, the first light source unit 41 and the second light source unit 42 are arranged so that they partially overlap when viewed from the front in the longitudinal direction. Here, the expressions "parallel" and "orthogonal to each other" do not necessarily mean that they are in such a strict relationship. They may be roughly parallel or roughly orthogonal. Note that the positional relationship of the first light source unit 41 and the second light source unit 42 when viewed from the front in the longitudinal direction is not limited to this. When viewed from the front in the longitudinal direction, a straight line overlapping the long side of the first light source unit 41 and a straight line overlapping the long side of the second light source unit 42 may intersect at a predetermined angle. It is preferable that two or more light source units 40 at different positions in the longitudinal direction are arranged so that the positions from which light is emitted are different from each other when viewed from the front in the longitudinal direction. This arrangement allows the light guide unit 60 to have a relatively simple configuration. For example, when optical fibers are used as the light guide unit 60 as described below, the optical fibers can be easily wired. When two or more light source units 40 are arranged at different positions in the longitudinal direction, for example, the light source units 40 may be configured to be positioned at positions shifted by a predetermined angle around the center of the camera head 10 when viewed from the front in the longitudinal direction.

[0067] Alternatively, one first light source unit 41 and one second light source unit 42 may be disposed at approximately the same position in the longitudinal direction, and another first light source unit 41 and another second light source unit 42 may be disposed behind them. Alternatively, the first light source unit 41 may be located on the rear side, and the second light source unit 42 may be located on the front side. Alternatively, it is sufficient that one of the first light source unit 41 and the second light source unit 42 is located in front of or behind the other.

[0068] It is preferable that the rear end 34 of the camera module 30 and the first light source unit 41, which is located among the light source units 40 and is located closest to the tip end 12, are close to each other. In this embodiment, of the light source unit 40 located closest to the tip end 12, a part of the front surface on the tip end 12 side faces the rear end 34 of the camera module 30 in the longitudinal direction. With such a structure, that is, a structure in which a part of the light source unit 40 overlaps with the camera module 30 when viewed from the front in the longitudinal direction as shown in Fig. 4, the camera head 10 can be made smaller.

[0069] The light guide unit 60 is disposed radially outward of the outer surface of the camera module 30. In this embodiment, the light guide unit 60 is disposed between the flat portion 35 of the camera module 30 and the inner peripheral surface of the sleeve 20. The light guide unit 60 guides the light emitted from each of the light source units 40 to the vicinity of the tip 12 so that the light is irradiated to the imaging area. It may be said that the light guide unit 60 guides the light to the vicinity of the tip 12. It may also be said that the light guide unit 60 guides the light to the vicinity of the tip 12. The vicinity of the tip 12 may include the tip 12. In this embodiment, the illumination filter 80 through which the guided light passes is provided at the tip 12, and the light guide unit 60 is configured to guide the light to the vicinity of the entrance portion of the light to the illumination filter 80. That is, the entrance portion of the light to the illumination filter 80 is included in the vicinity of the tip 12.

[0070] In addition, when the light guiding section 60 guides the light emitted from the light source section 40 behind the camera module 30 to the vicinity of the tip section 12, it can also be said that the light is guided forward so that it is emitted in front of the camera module 30.

[0071] In this embodiment, the light guide 60 has an optical fiber. Note that an element other than an optical fiber, for example, an optical waveguide made of resin or glass, may be used.

[0072] In this embodiment, the light guiding section 60 has four optical fibers respectively corresponding to each light source section 40. Of the four optical fibers, two are called first light guiding sections 61, and the other two are called second light guiding sections 62. The two first light guiding sections 61 correspond to the two first light source sections 41, and the two second light guiding sections 62 correspond to the two second light source sections 42, respectively. Note that for one light source section 40, two or more elements such as optical fibers that respectively guide light so that the light is emitted from different positions in the radial or circumferential direction may be provided.

[0073] In this embodiment, the four optical fibers of the light guide unit 60 are arranged around the camera module 30 so as to be spaced apart from each other in the circumferential direction and aligned in the circumferential direction. The optical fibers are aligned at approximately equal intervals in the circumferential direction. That is, the four optical fibers are aligned at approximately 90 degree intervals in the circumferential direction.

[0074] More specifically, as shown in Fig. 6, the first light guiding sections 61 and the second light guiding sections 62 are arranged alternately in the circumferential direction. That is, the light guiding section 60 is configured to be able to irradiate the imaging region with light of one wavelength band from two positions separated from each other in the circumferential direction. This allows the light of the respective wavelength bands of the first light source section 41 and the second light source section 42 to be irradiated relatively uniformly onto the imaging region.

[0075] Here, each optical fiber is arranged so as to follow the flat portion 35 of the camera module 30. In this embodiment, one optical fiber is arranged in each of the four spaces generated between each of the four flat portions 35 and the inner peripheral surface of the sleeve 20. By arranging the optical fibers in this manner, each part of the camera head 10 can be accommodated in the smaller diameter sleeve 20, and the diameter of the camera head 10 can be made smaller.

[0076] The imaging filter 70 and the illumination filter 80 are attached to the tip portion 12 of the camera head 10 .

[0077] In this embodiment, the camera head 10 is configured so as to be usable for a bioimaging technique in which, for example, a fluorescent substance is excited by irradiating an imaging region with excitation light of a specific wavelength, and the emitted fluorescence is imaged. In order to enable the camera head 10 to be used for such an application, an imaging filter 70 is disposed on the tip side of the camera module 30, and an illumination filter 80 is disposed on the tip side of the light guide unit 60.

[0078] The illumination filter 80 is, for example, an excitation light filter. The illumination filter 80 passes only light in a specific wavelength range among the light guided by the light guide unit 60, and irradiates the imaging area with the light. This light acts on fluorescent substances and fluorescent markers in tissues and the like in the imaging area, and excites them. The imaging filter 70 is, for example, a fluorescent filter. The imaging filter 70 is configured to pass only fluorescence in a specific wavelength range different from the excitation light, and allows only a certain fluorescent signal generated after excitation to enter the light receiving unit 32 of the camera module 30 with high accuracy.

[0079] The imaging filter 70 is fixed to the camera module 30 so as to cover the front of the light receiving unit 32. The illumination filter 80 is disposed in front of the light guiding unit 60 so as to be shaped to close the gap between the imaging filter 70 and the inner peripheral surface of the sleeve 20. That is, in this embodiment, the tip portion 12 of the camera head 10 is sealed by the filters 70, 80. Note that the rear end portion of the camera head 10 is sealed, for example, using a bonding material or the like as shown by the two-dot chain line in FIG. 3, but is not limited thereto.

[0080] The filters 70 and 80 are not limited to those having the above characteristics. Filters having properties according to the respective applications may be used. In addition, one or both of the filters 70 and 80 may not be used. In this case, a filter for protection purposes may be provided at the tip portion 12, or no optical element may be provided in addition to the camera module 30 and the light guide portion 60. The filters 70 and 80 are so-called optical filters, but they may not be so.

[0081] 7, in this embodiment, a light shielding structure 22 configured to shield light is provided between the filters 70 and 80 so as to prevent light originating from the light emitted from the light source unit 40 from directly entering the camera module 30. In other words, the light shielding structure 22 prevents light different from the light entering from the imaging region from entering the camera module 30. The light shielding structure 22 may be provided around the camera module 30, around the light guide unit 60, or the like.

[0082] The light-shielding structure 22 is, for example, a metal film or a film having light-shielding properties, but is not limited thereto. When the imaging filter 70 or the illumination filter 80 is configured to totally reflect the incident light, such a configuration may be regarded as the light-shielding structure 22. The light-shielding structure 22 may also be a filler having light-shielding properties that is applied or filled into the gaps between members. For example, the filler may be a mixture of an adhesive, a resin that hardens by a chemical reaction, and a pigment. The light-shielding structure 22 is not limited thereto, and various structures that prevent the incidence of light other than the light incident from the imaging region can be used. Note that the light-shielding structure 22 may not be provided depending on the application and configuration of the camera head 10.

[0083] FIG. 8 is a diagram illustrating the configuration of the illumination filter 80 of the camera head 10. As shown in FIG.

[0084] In this embodiment, the illumination filter 80 has a first excitation light filter 81 corresponding to the first light source unit 41 and a second excitation light filter 82 corresponding to the second light source unit 42. Thus, the illumination filter 80 is configured to be able to irradiate excitation light of different wavelengths corresponding to the light emitted from the first light source unit 41 and the second light source unit 42, respectively.

[0085] 8, for example, the illumination filter 80 is configured by combining four members: two first excitation light filters 81 arranged in front of each of the first light guiding sections 61, and two second excitation light filters 82 arranged in front of each of the second light guiding sections 62. The filters 81, 82 are attached to each other so that adjacent filters in the circumferential direction form one illumination filter 80. Note that the configuration of the illumination filter 80 is not limited to this.

[0086] In this embodiment, the imaging filter 70 and the illumination filter 80 are joined together. The camera module 30 is fixed to the imaging filter 70. The light guiding unit 60 is fixed to the illumination filter 80. As a result, the camera module 30 and the light guiding unit 60 are integrally configured. This makes it possible to easily manufacture the camera head 10.

[0087] As described above, by arranging the camera module 30 and the two or more light source units 40 at different positions in the longitudinal direction and spaced apart from each other in the longitudinal direction, rather than arranging them so as to be located on the same cross section, it is possible to configure a small camera head 10 with a built-in light source. More specifically, it is possible to further miniaturize the camera head 10 capable of irradiating the imaging area with light from each of the first light source unit 41 and the second light source unit 42. In particular, in this embodiment, it may be said that the diameter of the camera head 10 can be made thinner.

[0088] Furthermore, since it is possible to configure the camera head 10 with a built-in light source, it is not necessary to bundle optical fibers or the like with the cable 19, and the flexibility of the cable 19 can be improved.

[0089] The fact that the diameter of the camera head 10 can be reduced will now be described with a specific example of dimensions.

[0090] FIG. 9 is a diagram illustrating a configuration example of a camera head according to a comparative example of the present embodiment.

[0091] 9 shows an example of a configuration in which, for example, a 0201 size LED chip is arranged at the tip as the light source unit 840. In order to irradiate light evenly, the light source units 840 are arranged at four locations so as to surround the imaging filter 70 having the same size as that of the present embodiment. Here, the lengths of the two sides of the 0201 size element are 0.6 mm and 0.3 mm when viewed from the front.

[0092] In this comparative example, the dimensions shown in the figure are as follows: L21 is 1.52 mm. L22 is 1.31 mm. L23 is 0.5 mm. L24 is 0.3 mm. L25 is 0.6 mm.

[0093] That is, the inner diameter of sleeve 820 is 1.31 mm, and when the thickness of sleeve 820 is about 0.1 mm, the outer diameter of sleeve 820 is 1.52 mm. That is, the outer diameter of the camera head in this comparative example is 1.52 mm.

[0094] On the other hand, in this embodiment, specific examples of the dimensions shown in Fig. 6 are as follows. Here, it is assumed that the optical fiber of the light guiding section 60 has a diameter of 0.125 mm. In this case, L11 is 1.00 mm. L12 is 0.8 mm. L13 is 0.5 mm. L14 is 0.125 mm. L15 is 0.125 mm.

[0095] When using a sleeve 20 of such a size and an 0201 size LED chip as the light source unit 40, the light source units can be arranged behind the camera module 30, for example at different positions in the longitudinal direction.

[0096] In this manner, in the present embodiment, the camera head 10 can be configured to have a thinner and smaller outer diameter compared to the comparative example.

[0097] If the camera head 10 can be made smaller in size in this way, the camera head 10 and the imaging system 1 using the same will become more useful in several applications.

[0098] FIG. 10 is a diagram illustrating an example of use of the imaging system 1 according to the present embodiment.

[0099] 10 shows an example of use in which an image capturing an image of the state of tissues of a subject animal 9 is captured using an imaging system 1. Here, the imaging system 1 is composed of a camera head 10 and an image capturing device 2100 to which the camera head 10 is connected via a cable 19. The image capturing device 2100 is composed of a transmitting / receiving device 2102 that can be configured to be small enough to be attached to the subject animal 9, and a main body device 2101 having the same functions as the image capturing device 100 described above. That is, in the example shown in the figure, the image capturing device 2100 can wirelessly capture an image showing the imaging result of the camera head 10.

[0100] As described above, the camera head 10 can be configured to have a small diameter of about 1 millimeter. Therefore, it becomes possible to perform an experiment in a less invasive state for the subject animal 9 in which the camera head 10 is embedded than before. In addition, it becomes possible to continuously capture images while the camera head 10 is left embedded in the subject animal 9. Therefore, it becomes possible to perform an experiment under conditions and in observation modes that were difficult to perform when a conventional large camera head was used.

[0101] (Description of Modifications)

[0102] In the above embodiment, an example of the camera head 10 configured to be capable of emitting light of two different wavelengths is shown, but the present invention is not limited to this.

[0103] FIG. 11 is a diagram illustrating a configuration example of a camera head according to a first modified example of the embodiment of the present invention.

[0104] In the figure, a cross-sectional view of the vicinity of tip 12 of camera head 310 configured to be capable of emitting, for example, four different types of light is shown.

[0105] The camera head 310 is provided with, for example, four types of optical fibers 361, 362, 363, and 364 corresponding to four light source units (not shown) that emit light with different wavelength bands, as light guide units. Two of each of the optical fibers 361, 362, 363, and 364 are provided. That is, a total of eight optical fibers 361, 362, 363, and 364 are provided as light guide units. The optical fibers 361, 362, 363, and 364 are arranged in the circumferential direction on the radial outer side of the camera module 30 so as to surround the periphery of the camera module 30. In each of the four gaps between the camera module 30 and the inner circumferential surface of the sleeve 20, two of the optical fibers 361, 362, 363, and 364 corresponding to the light from the different light guide units are arranged as a set.

[0106] By arranging many optical fibers 361, 362, 363, and 364 in this manner, it is possible to configure camera head 310 in a relatively small size.

[0107] In this modification, among the optical fibers 361, 362, 363, and 364, two optical fibers provided to guide light of one wavelength band are arranged around the camera module 30 so as to be separated from each other in the circumferential direction. More specifically, as viewed from the front in the longitudinal direction as shown in the figure, the two optical fibers 361 that guide light of the first wavelength band are arranged at positions that are point-symmetric with respect to the center of the camera head 310. Similarly, the two optical fibers 362 that guide light of the second wavelength band, the two optical fibers 363 that guide light of the third wavelength band, and the two optical fibers 364 that guide light of the fourth wavelength band are each arranged at positions that are point-symmetric with respect to the center of the camera head 310. Note that this is not limited to this, and for example, two optical fibers that guide light of each wavelength band may be arranged in two positions that are not adjacent to each other among the four gaps between the camera module 30 and the inner peripheral surface of the sleeve 20.

[0108] By arranging the optical fibers 361, 362, 363, and 364 in this manner, the imaging area can be relatively uniformly irradiated with light of each wavelength band.

[0109] It should be noted that the camera head 310 is provided with a filter 380 in place of the illumination filter 80. The characteristics and functions of the filter 380 can be set as appropriate.

[0110] FIG. 12 is a diagram illustrating a configuration example of a camera head according to a second modified example of the embodiment of the present invention.

[0111] In the figure, a cross-sectional side view of a camera head 410 shown in a similar manner to FIG. 3 is shown.

[0112] The camera head 410 has a camera module 30, a light source unit 40, an imaging filter 70, and the like, which are configured similarly to the camera head 10 according to the above-described embodiment. That is, in the longitudinal direction, from the tip end portion 12 side, the imaging filter 70, the camera module 30, the first light source unit 41, and the second light source unit 42 are arranged in this order at different positions from each other.

[0113] In the camera head 410, a sleeve 420 is provided in place of the sleeve 20. The camera module 30 and the imaging filter 70 are housed inside the sleeve 420.

[0114] The sleeve 420 is a transparent member, and is configured to function as a light guide that guides light from the light source unit 40 to the tip unit 12. That is, in this modification, the light guide is configured by the entire sleeve 420. The sleeve 420 that functions as the light guide can be configured using, for example, a transparent resin, but is not limited to this. The light guide may be configured to be realized by a part of the sleeve 420. For example, only the part of the sleeve 420 that functions as the light guide may be configured to be an optical waveguide.

[0115] In this modified example, the sleeve 420 is configured by combining, for example, a first member 421 having a light incident portion 421b at the rear end side connected to the first light source unit 41, and a second member 422 having a light incident portion 422b at the rear end side connected to the second light source unit 42. This allows the light emitted from each of the first light source unit 41 and the second light source unit 42 to be irradiated independently.

[0116] The sleeve 420 may be molded as a single member having both the light entrance portions 421b and 422b. The sleeve 420 may be formed so as to accommodate the light source portion 40. That is, the sleeve 420 may be configured to have the light entrance portions 421b and 422b in a part thereof, and the light entrance portions 421b and 422b may not necessarily be provided at the rear end portion of the sleeve 420.

[0117] In this manner, by using sleeve 420 that functions as a light guiding section, camera head 410 can be made smaller.

[0118] (others)

[0119] The computer used in the above-described embodiment may be a single computer or a plurality of computers, that is, centralized processing or distributed processing may be performed.

[0120] In the above-described embodiments, two or more components present in one device may be physically realized on one medium.

[0121] In the above embodiment, each component may be configured by dedicated hardware, or a component that can be realized by software may be realized by executing a program. For example, each component may be realized by a program execution unit such as a CPU reading and executing a software program recorded on a recording medium such as a hard disk or a semiconductor memory. During execution, the program execution unit may execute the program while accessing a storage unit or a recording medium. The program may be executed by being downloaded from a server or the like, or may be executed by reading a program recorded on a predetermined recording medium (for example, an optical disk, a magnetic disk, a semiconductor memory, etc.). The program may be used as a program constituting a program product. The computer that executes the program may be single or multiple. That is, centralized processing may be performed, or distributed processing may be performed.

[0122] Furthermore, in the above embodiments, each process (each function) may be realized by centralized processing by a single device (system), or may be realized by distributed processing by multiple devices (in this case, the entire system made up of multiple devices performing distributed processing can be considered as a single "device").

[0123] In addition, in the above embodiments, the transfer of information between each component may be performed, for example, by one component outputting information and the other component receiving information if the two components transferring the information are physically different, or, if the two components transferring the information are physically the same, by shifting from a processing phase corresponding to one component to a processing phase corresponding to the other component.

[0124] In the above embodiment, information related to the processing performed by each component, such as information accepted, acquired, selected, generated, transmitted, or received by each component, and information such as thresholds, formulas, and addresses used by each component in processing, may be temporarily or long-term stored in a recording medium (not shown) even if not specified in the above description. Furthermore, each component or a storage unit (not shown) may store information in the recording medium (not shown). Furthermore, each component or a reading unit (not shown) may read information from the recording medium (not shown).

[0125] The present invention is not limited to the above-described embodiment, and various modifications are possible, which are also included within the scope of the present invention.

[0126] The components of the above-mentioned embodiments and modifications may be appropriately combined to form an embodiment. For example, each component of the above-mentioned embodiments and modifications may be appropriately replaced or combined with components of other modifications. In addition, some components or functions of the above-mentioned embodiments and modifications may be omitted. [Industrial Applicability]

[0127] INDUSTRIAL APPLICABILITY As described above, the camera head according to the present invention has the effect of enabling the camera head to be made smaller, and is useful as a camera head, etc. [Explanation of symbols]

[0128] 1. Imaging system 10,310,410 Camera head 12 Tip 20,420 Sleeve 30 Camera Module 40 Light source section 41 First light source section 42 Second light source section 60 Light guide section 70 Imaging Filter 80 Lighting Filters 100,2100 Image acquisition device 140 Image acquisition unit 361,362,363,364 Optical fiber 380 Filters

Claims

1. A camera head having an elongated shape and used for capturing an image of an imaging area near a tip end in a longitudinal direction, A camera module; Two or more light source units arranged at a position farther from a tip end portion than the camera module in a longitudinal direction; a light guide unit disposed radially outward of an outer surface of the camera module and configured to guide light emitted from each of the two or more light source units to a vicinity of a tip end portion so that the light is irradiated onto an imaging area; A camera head, wherein at least two of the two or more light source units are located at different positions in a longitudinal direction.

2. The camera head according to claim 1 , wherein at least two of the two or more light source sections are configured to emit light having different wavelengths.

3. 2. The camera head of claim 1, wherein the light guide section has two or more optical fibers corresponding to at least two of the two or more light source sections, and the two or more optical fibers are arranged around the camera module so as to be spaced apart from each other in a circumferential direction and aligned in a circumferential direction.

4. Among the two or more optical fibers, two or more optical fibers provided to guide light of a certain wavelength band are arranged around the camera module so as to be spaced apart from each other in a circumferential direction, The camera head according to claim 3 , wherein the light guiding section is configured to be able to irradiate the imaging region with light of the one wavelength band from two or more locations that are separated from each other in a circumferential direction.

5. The camera module has a columnar portion having a polygonal columnar shape, The camera head according to claim 3 , wherein each of the two or more optical fibers is arranged along a planar side surface of the columnar portion.

6. A sleeve formed in a tubular shape, The camera head according to claim 1 , wherein the camera module, the light source unit, and the light guiding unit are accommodated inside the sleeve.

7. A sleeve formed in a tubular shape, The sleeve is a transparent member, the light guide portion is a part or the whole of the sleeve, The camera head of claim 1 , wherein the camera module is housed inside the sleeve.

8. The camera head according to claim 1 , wherein the camera module and the light guide section are integrally configured.

9. The camera head according to claim 1 , wherein at least two of the two or more light source sections that are at different positions in the longitudinal direction are arranged so as to partially overlap each other when viewed from the front in the longitudinal direction.

10. A camera head according to any one of claims 1 to 9; an image capture device connected to the camera head and capturing an image captured by the camera head;

Images