Fundus photography device

Abstract

A fundus photography device comprises: a projector which performs two-dimensional scanning on a photographic light beam used for fundus photography and then emits it; a first optical component which causes a plurality of photographic light beams emitted from the projector at different times to converge at a first convergence point near a pupil of a subject and then illuminate the subject's retina; a second optical component which causes a plurality of first reflected light beams which are reflected by the subject's retina and pass through the first optical component to converge at a second convergence point; a simulated eye optical system which is arranged at the second convergence point and converts the plurality of first reflected light beams into converged light beams respectively; a light detector which detects the plurality of first reflected light beams which pass through the simulated eye optical system; and an image generating unit which generates a fundus image based on an output signal of the light detector.

Description

Technical Field

[0001] The invention relates to a fundus photography device. Background Art

[0002] An ophthalmic device is known in which an optical system for guiding incident light for fundus photography to the retina of a subject and reflecting light from the retina of the subject to a photodetector is combined with an optical system for guiding scanning light for treatment or a sight mark to the retina of the subject (for example, Patent Document 1). In addition, a scanning laser ophthalmoscope (SLO) is known in which a light is irradiated onto the retina of a subject after scanning, and a fundus image is acquired by detecting reflected light from the retina using a photodetector.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application No. 2011-512916 Summary of the invention

[0006] Problems to be solved by the invention

[0007] There is a known projector that projects an image by two-dimensionally scanning a light beam and then emitting it to the outside. When an ophthalmologic apparatus is constructed using such a projector, it is required to obtain a fundus image using the light beam emitted from the projector after being two-dimensionally scanned.

[0008] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to enable acquisition of a fundus image.

[0009] Means for solving problems

[0010] The present invention is a fundus photography device, which comprises: a projector, which performs two-dimensional scanning on the photographic light used for fundus photography and then emits it; a first optical component, which makes a plurality of the photographic light emitted from the projector at different times converge at a first convergence point near the pupil of the subject and then irradiate the retina of the subject; a second optical component, which makes the plurality of photographic light rays reflected by the retina of the subject and passed through the first optical component converge at a second convergence point; a simulated eye optical system, which is arranged at the second convergence point and converts the plurality of first reflected light rays into converged light respectively; a light detector, which detects the plurality of first reflected light rays that have passed through the simulated eye optical system; and an image generating unit, which generates a fundus image based on the output signal of the light detector.

[0011] In the above configuration, the first convergence point and the second convergence point may be located at substantially conjugate positions, and the subject's retina and the photodetector may be located at substantially conjugate positions.

[0012] In the above structure, it can be set as follows: the first optical component makes the multiple photographic light rays converge at the first convergence point, and converts the multiple photographic light rays from diffuse light to approximately parallel light respectively; the second optical component makes the multiple first reflected light rays converge at the second convergence point, and converts the multiple first reflected light rays from diffuse light to approximately parallel light respectively; the simulated eye optical system converts the multiple first reflected light rays from approximately parallel light to converged light respectively.

[0013] In the above structure, it can be set as follows: a third optical component is arranged between the first optical component and the second optical component, the multiple shooting lights emitted from the projector at different times are reflected by the third optical component and incident on the first optical component, and the multiple first reflected lights reflected by the retina of the subject are transmitted through the first optical component and the third optical component and incident on the second optical component.

[0014] In the above configuration, a configuration may be adopted in which a quarter wavelength plate is provided between the third optical member and the first optical member, and the third optical member is a polarization beam splitter.

[0015] In the above structure, it can be set as follows: it comprises: a light source, which emits background light to illuminate the retina of the subject; and a fourth optical component, which is arranged between the first optical component and the second optical component, and the background light emitted from the light source is reflected by the fourth optical component and is transmitted through the first optical component to illuminate the retina of the subject.

[0016] In the above configuration, a configuration may be adopted in which a fifth optical member is provided, which is disposed between the second optical member and the simulated eye optical system and which bends the plurality of first reflected light rays.

[0017] In the above configuration, a configuration may be adopted in which the focal length of the first optical member is different from the focal length of the second optical member.

[0018] In the above structure, the following structure can be set: an irradiation area adjustment unit, which does not irradiate the second area with the photographic light when irradiating the photographic light to the first area of ​​the first area and the second area obtained by dividing the retina of the subject relative to the center of the retina, and does not irradiate the first area with the photographic light when irradiating the photographic light to the second area; a light shielding component that is movably arranged between the second optical component and the second convergence point; and a driving mechanism, which moves the light shielding component to a first position when irradiating the photographic light only to the first area, the first position being a position where the second reflected light of the photographic light reflected by the cornea of ​​the subject and passing through the first optical component and the second optical component is blocked and the first reflected light passes, and moves the light shielding component to a second position where the second reflected light is blocked and the first reflected light passes when irradiating the photographic light only to the second area, and the image generating unit generates an image based on the output signal of the light detector in each case where the photographic light is irradiated to the first area or the second area, and generates the fundus image by synthesizing the two generated images.

[0019] In the above configuration, the light shielding member may be arranged at or near a focus point where the second reflected light beam is focused close to the second convergence point.

[0020] In the above configuration, the light shielding member may be configured to be movable in a first direction in which the second reflected light is incident on the light shielding member and in a second direction intersecting the first direction.

[0021] In the above configuration, the light shielding member may have a concave U-shaped center portion of the second reflected light beam.

[0022] In the above configuration, the pseudo-eye optical system, the photodetector, and the image generating unit may be a digital camera.

[0023] In the above configuration, the projector may be a detachable general-purpose projector.

[0024] In the above configuration, the distance from the second convergence point to the photodetector is based on the length from the surface of the subject's cornea to the surface of the subject's retina and is within a range of 16 mm to 17 mm.

[0025] In the above structure, it can be set as follows: the multiple photographic lights emitted from the projector are vertically polarized lights, the fundus photography device has a polarizing plate that transmits the vertically polarized lights, the third optical component is a polarization beam splitter that reflects the vertically polarized lights and transmits lights other than the vertically polarized lights, the third optical component transmits the multiple first reflected lights of randomly polarized lights that are reflected by the retina of the subject after the vertically polarized lights pass through the cornea of ​​the subject, and reflects the vertically polarized lights reflected by the cornea of ​​the subject, and the light detector detects the multiple first reflected lights of randomly polarized lights that have passed through the third optical component.

[0026] In the above configuration, the plurality of imaging light beams emitted from the projector may be non-polarized light beams, and the polarizing plate may transmit the non-polarized light beams as vertically polarized light beams.

[0027] The present invention provides an image forming device, characterized in that it comprises: a light source that emits photographic light for fundus photography; a first optical component that causes the photographic light to converge at a first convergence point near the pupil of the subject and then irradiate the retina of the subject; a second optical component that causes the first reflected light that is reflected by the retina of the subject and passes through the first optical component to converge at a second convergence point; a photodetector that detects the first reflected light that passes through the second optical component; an irradiation area adjustment unit that does not irradiate the second area when irradiating the first area of ​​a first area and a second area obtained by dividing the retina of the subject into two parts relative to the center of the retina with the photographic light, and does not irradiate the first area when irradiating the photographic light to the second area;

[0028] A shading component that is movably arranged between the second optical component and the second convergence point; and a driving mechanism that moves the shading component to a first position when only the first area is irradiated with the photographic light, and the first position is a position where the second reflected light from the photographic light reflected by the subject's cornea and passing through the first optical component and the second optical component is blocked and the first reflected light passes, and moves the shading component to a second position where the second reflected light is blocked and the first reflected light passes when only the second area is irradiated with the photographic light, and an image generating unit that generates an image based on an output signal of the light detector in each case where the photographic light irradiates the first area or the second area, and generates a fundus image by synthesizing the two generated images.

[0029] Effects of the Invention

[0030] According to the present invention, a fundus image can be acquired. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a block diagram of the fundus imaging device of the first embodiment.

[0032] Figure 2 1 is a diagram showing an optical system of the fundus imaging device according to Example 1.

[0033] Figure 3 : is a diagram showing a simulated eye optical system.

[0034] Figure 4 A diagram showing light scanning on the retina of a subject.

[0035] Figure 5 : is a flowchart showing an example of fundus imaging processing.

[0036] Figure 6 1 is a diagram showing an optical system of a fundus imaging device according to Example 2.

[0037] Figure 7 1 is a diagram showing an optical system of a fundus imaging device according to a third embodiment.

[0038] Figure 8 1 is a diagram showing an optical system of a fundus imaging device according to a fourth embodiment.

[0039] Fig. 9 (a) is a perspective view of the appearance of the fundus photography device of Example 5, Fig. 9 (b) is along Fig. 9 (a) The appearance of the arrow A, Fig. 9 (c) is along Fig. 9 (a) is the appearance viewed from the arrow B.

[0040] Fig.10 1 is a diagram showing an optical system of a fundus imaging device according to Example 5.

[0041] Fig.11 This is a diagram showing the trajectory of light reflected by the cornea of ​​the subject.

[0042] Fig.12 (a) is a diagram showing the trajectory of light reflected by the retina, Fig.12 (b) Fig.12 (a) is an enlarged view of the vicinity of the simulated eye optical system.

[0043] Fig.13 (a) is a diagram showing the trajectory of light reflected by the cornea, Fig.13 (b) Fig.13 (a) is an enlarged view of the vicinity of the simulated eye optical system.

[0044] Fig.14 (a) is only shown Fig.13 (a) Diagram of the optical axis of a ray, Fig.14 (b) and Fig.14 (c) is shown Fig.13 (a) A diagram showing the trajectories of two of the three rays.

[0045] Fig.15 This is a block diagram of a fundus imaging device according to a sixth embodiment.

[0046] Fig.16 (a) to Fig.16 (d) is a diagram showing an optical system of the fundus imaging device of Example 6;

[0047] Fig.17 This is a diagram showing an example of light reflected from a retina having a shape divided in half.

[0048] Fig.18 : is a flowchart showing an example of fundus imaging processing.

[0049] Fig.19 (a) and Fig.19 (b) is a diagram showing an optical system of a fundus imaging device according to Modification 1 of Example 6.

[0050] Fig. 20 (a) to Fig. 20 (c) is a diagram showing changes in the position of the focal point of the cornea reflected light due to differences in the radius of curvature of the cornea.

[0051] Fig.21 This is a diagram showing an example in which a light shielding plate arranged on a virtual plane has a U-shape.

[0052] Fig. 22 (a) and Fig. 22 (b) is a diagram showing a problem that occurs when a flat-plate-type light shielding plate is used to shield the cornea reflected light.

[0053] Fig.23 1 is a diagram showing an optical system of a fundus imaging device according to Example 7. DETAILED DESCRIPTION

[0054] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0055] Example 1

[0056] Figure 1 1 is a block diagram of a fundus imaging device according to Embodiment 1. Figure 1The fundus photographing device 100 includes a projection unit 10, a control unit 30, and a photodetector 40. The fundus photographing device 100 may include a display unit 41 detachably or integrally. The projection unit 10 includes a light source 11, a scanning unit 12, an optical system 13, a drive circuit 14, and an input circuit 15. The control unit 30 includes an image control unit 31, a signal processing unit 32, and an image generating unit 33. The light source 11, the scanning unit 12, the drive circuit 14, the input circuit 15, and the image control unit 31 are provided in a projector 16 that two-dimensionally scans light and then emits it to the outside. The projector 16 is, for example, a general laser scanning projector.

[0057] The image control unit 31 generates an image to be projected onto the retina of the subject. An image signal is input from the image control unit 31 to the input circuit 15. The drive circuit 14 drives the light source 11 and the scanning unit 12 based on the control signal of the image control unit 31 and the image signal obtained by the input circuit 15.

[0058] The light source 11 may emit invisible light as infrared laser, or may emit visible light of a single wavelength of red laser, green laser or blue laser, or may emit white light including them. The wavelength of the infrared laser may be about 785nm to 1.4μm, the wavelength of the red laser may be about 610nm to 660nm, the wavelength of the green laser may be about 515nm to 540nm, and the wavelength of the blue laser may be about 440nm to 480nm.

[0059] The scanning unit 12 is, for example, a scanning mirror such as a MEMS (Micro Electro Mechanical System) mirror or a transmission-type scanner, and performs two-dimensional scanning on the light beam 50 emitted from the light source 11 .

[0060] The optical system 13 irradiates the light 50 after two-dimensional scanning to the subject's eye 70. The reflected light 51 reflected by the retina of the subject's eye 70 is incident on the photodetector 40 via the optical system 13. The photodetector 40 detects the reflected light 51. The photodetector 40 includes, for example, an imaging element such as a CMOS (Complementary Metal Oxide Semiconductor) image sensor or a CCD (Charge Coupled Device) image sensor.

[0061] The signal processing unit 32 processes the output signal of the photodetector 40 based on the control signal of the image control unit 31. The image generating unit 33 generates a fundus image based on the signal obtained by the signal processing unit 32 processing the output signal of the photodetector 40. The display unit 41 is, for example, a liquid crystal display, and displays the image generated by the image generating unit 33.

[0062] The image control unit 31, the signal processing unit 32, and the image generation unit 33 may be processed by a processor such as a CPU (Central Processing Unit) in cooperation with a program. The image control unit 31, the signal processing unit 32, and the image generation unit 33 may also be specially designed circuits. The image control unit 31, the signal processing unit 32, and the image generation unit 33 may be one circuit or different circuits.

[0063] Figure 2 1 is a diagram showing the optical system of the fundus imaging device of Example 1. Figure 2 In FIG. 5 , the light ray 50 and the reflected light ray 51 are represented by their respective finite beam diameters, and their centers are represented by dotted lines. Figure 2 The projector 16 includes a light source 11, a scanning unit 12, a collimating lens 17, a reflector 18, an optical component 19, and an attenuation filter 20. The light source 11, the scanning unit 12, the collimating lens 17, and the reflector 18 are arranged in a frame 29. The optical component 19 and the attenuation filter 20 are mounted on the outside of the frame 29. In addition, the optical component 19 and the attenuation filter 20 may be arranged in the frame 29, or may not be provided in the projector 16 and may be arranged separately from the frame 29. The light 50 emitted by the light source 11 is converted from diffuse light to approximately parallel light by the collimating lens 17, and then reflected by the reflector 18 and incident on the scanning unit 12. The so-called approximately parallel light is not limited to the case of completely parallel light, but also includes the case of slightly converging or diffusing.

[0064] The light 50 after two-dimensional scanning by the scanning unit 12 passes through the optical component 19 and the attenuation filter 20. The optical component 19 is, for example, a focusing lens, which converts a plurality of light rays 50 emitted from the scanning unit 12 at different times and whose optical axes diffuse with each other into a plurality of light rays 50 whose optical axes are approximately parallel to each other, and converts each light 50 from approximately parallel light into converging light. The plurality of light rays 50 emitted from the scanning unit 12 at different times may also be collectively referred to as scanning light. The attenuation filter 20 is, for example, an ND filter, which adjusts the light amount of the light 50. The projector 16 may also include a plurality of attenuation filters 20 with different light amount adjustment amounts, and may switch the attenuation filter 20 through which the light 50 passes. Thus, the light amount of the light 50 emitted from the projector 16 may be appropriately changed according to the intended use, etc.

[0065] The plurality of light rays 50 emitted from the projector 16 are reflected by the optical component 21 and enter the optical component 22. The optical component 21 is a half mirror. Each of the plurality of light rays 50 is focused in front of the optical component 22 and becomes diffuse light and enters the optical component 22. The optical component 22 is, for example, a condenser lens, which converts the plurality of light rays 50 whose optical axes are substantially parallel to each other into the plurality of light rays 50 whose optical axes converge to each other, and converts each light 50 from diffuse light to substantially parallel light. The substantially parallel light here can be substantially parallel light to the extent that the light rays 50 can be substantially focused on the retina 74 of the subject, and the case where it is simply described as being substantially parallel also includes being substantially parallel. The plurality of light rays 50 that have passed through the optical component 22 converge at a convergence point 52 near the pupil 71 of the subject's eye 70, and are irradiated onto the retina 74 through the lens 72 and the vitreous body 73. The beam diameter (diameter) of each light ray 50 when it enters the cornea 75 is approximately 0.8 mm to 1.65 mm. Each light ray 50 is converted from substantially parallel light to convergent light by the lens 72, and is substantially focused on the retina 74. In this way, the light ray 50 is irradiated onto the retina 74 of the subject by Maxwell observation.

[0066] The light 50 is reflected by the retina 74 of the subject. The reflected light 51 reflected by the retina 74 passes through the optical component 22 and the optical component 21 and enters the optical component 23. The optical component 22 converts the multiple reflected light rays 51 whose optical axes are diffused by the retina 74 into multiple reflected light rays 51 whose optical axes are approximately parallel to each other, and converts each reflected light ray 51 from approximately parallel light to convergent light. After the reflected light ray 51 is focused in front of the optical component 23, it becomes diffuse light and enters the optical component 23. The optical component 23 is, for example, a condenser lens, which converts the multiple reflected light rays 51 whose optical axes are approximately parallel to each other into multiple reflected light rays 51 whose optical axes converge to each other, and converts each reflected light ray 51 from diffuse light to approximately parallel light.

[0067] The simulated eye optical system 24 is arranged at the convergence point 53 where a plurality of reflected light rays 51 that have passed through the optical component 23 converge. The simulated eye optical system 24 is composed of a plurality of lenses, and converts the reflected light rays 51 from approximately parallel light to convergent light. After being converted into convergent light by the simulated eye optical system 24, the reflected light rays 51 are focused on the planar detection surface (imaging surface) 40a of the light detector 40 or near the detection surface 40a. The scanning unit 12, the convergence point 52, and the convergence point 53 are located at approximately conjugate positions. The so-called approximately conjugate position also includes the case where the position deviates from the conjugate position by a degree of manufacturing error, and the case where it is only recorded as conjugate also includes approximately conjugate.

[0068] Figure 3 is a diagram showing a simulated eye optical system. Figure 3 In FIG. 5 , the dotted line indicates the center of the finite beam diameter of the reflected light 51. Figure 3 The simulated eye optical system 24 is composed of, for example, a convex lens 24a, a concave lens 24b, and a convex lens 24c. The reflected light 51 is converted from approximately parallel light to convergent light by the convex lens 24a, converted from convergent light to diffuse light by the concave lens 24b, and converted again from diffuse light to convergent light by the convex lens 24c, and is focused on the detection surface 40a of the light detector 40 or near the detection surface 40a. The convex lens 24a is a plano-convex lens in which the surface on the side where the reflected light 51 is incident is convex and the surface on the side where the reflected light 51 is emitted is flat. The concave lens 24b is a biconcave lens in which both the surface on the side where the reflected light 51 is incident and the surface on the side where the reflected light 51 is emitted are concave. The convex lens 24c is a plano-convex lens in which the surface on the side where the reflected light 51 is incident is flat and the surface on the side where the reflected light 51 is emitted is convex. In addition, the convex lenses 24a and 24c may also be biconvex lenses in which both the surface on the side where the reflected light 51 is incident and the surface on the side where the reflected light 51 is emitted are convex. The concave lens 24b may be a plano-concave lens in which one of the surfaces on the side where the reflected light 51 is incident and the side where the reflected light 51 is emitted is a concave surface and the other surface is a flat surface.

[0069] The convex lens 24a is arranged in contact with the concave lens 24b. The concave lens 24b is arranged separately from the convex lens 24c. In addition, the convex lens 24a and the concave lens 24b can also be arranged separately with a spacing narrower than the spacing between the concave lens 24b and the convex lens 24c. For example, a plurality of reflected light rays 51 converge at the center of the convex surface on which the reflected light rays 51 of the convex lens 24a are incident to form a convergence point 53.

[0070] The length dimension L from the convex surface or convergence point 53 of the convex lens 24a to the detection surface 40a of the light detector 40 is equivalent to the distance corrected for the length dimension from the surface of the lens or cornea of ​​the eye to the surface of the retina in consideration of the refractive index of the human eye, for example, 16 mm to 17 mm.

[0071] Figure 2 The optical components 21, 22, 23 and the simulated eye optical system 24 are equivalent to Figure 1 The optical system 13 in the optical system 13. The optical component 22 and the optical component 23 may also be the same component as the optical component 19 of the projector 16. By making the optical component 22 and the optical component 23 the same component, the manufacturing cost can be reduced. In addition, by making the optical component 21, the optical component 22, the optical component 23, the simulated eye optical system 24 and the light detector 40 as an integrated optical system module, and providing a loading and unloading portion that can be loaded and unloaded relative to the projector 16, the optical system module and the projector 16 can be loaded and unloaded and replaced. Therefore, if the projector 16 is a general-purpose projector that projects onto a wall or a screen, etc., it is possible to use the general-purpose projector as a fundus photography device by connecting it to the optical system module.

[0072] Figure 4 is a diagram showing the scanning of light rays on the retina of the subject. Figure 4 , the scanning unit 12 performs raster scanning of the light 50 from the upper left to the lower right on the retina 74 as indicated by the arrow 55. If the light source 11 does not emit the light 50 even if the scanning unit 12 is driven, the light 50 will not irradiate the retina 74. Figure 4 The dotted arrow 55 does not emit the light 50. The driving circuit 14 synchronizes the emission of the light 50 from the light source 11 with the driving of the scanning unit 12. Thus, the light source 11 emits the light 50 within a predetermined range on the retina 74 (real arrow 55).

[0073] Figure 5 2 is a flowchart showing an example of fundus photography processing. Figure 5 The image control unit 31 controls the driving of the light source 11 and the scanning unit 12, and emits the light 50 for fundus photography from the projector 16, so that the light 50 irradiates the retina 74 (step S10). The light 50 for fundus photography can be an infrared laser, or white light including red laser, green laser and blue laser, or monochromatic light including a single wavelength laser. Figure 5 In the fundus photography process, the light 50 is raster scanned from the upper left to the lower right on the retina 74 and then irradiates the entire retina 74. Figure 2 As described in , when the light 50 is irradiated onto the retina 74 of the subject, the reflected light 51 reflected by the retina 74 enters the photodetector 40 .

[0074] Next, the signal processing unit 32 obtains the output signal of the photodetector 40 (step S12). Next, the image generating unit 33 generates a fundus image based on the signal processed by the signal processing unit 32 on the output signal of the photodetector 40 (step S14). The display unit 41 displays the fundus image generated by the image generating unit 33 (step S16). The doctor can check the fundus condition of the subject by carefully examining the fundus image displayed on the display unit 41.

[0075] According to Example 1, Figure 2As shown, a plurality of light beams 50 (photographic light beams) for fundus photography emitted from the projector 16 at different times converge at a convergence point 52 (first convergence point) near the pupil 71 of the subject through the optical component 22 (first optical component) and then irradiate the retina 74 of the subject. A plurality of reflected light beams 51 (first reflected light beams) reflected by the retina 74 converge at a convergence point 53 (second convergence point) through the optical component 23 (second optical component) after passing through the optical component 22. A simulated eye optical system 24 that converts the reflected light beams 51 into convergent light is arranged at the convergence point 53. The plurality of reflected light beams 51 are detected by the photodetector 40 after passing through the simulated eye optical system 24. The image generation unit 33 generates a fundus image based on the output signal of the photodetector 40. Thus, in the fundus photography device 100 configured using the projector 16 that emits the light beams 50 after two-dimensional scanning, a fundus image can be obtained.

[0076] In order to irradiate the light 50 to the retina 74 of the subject using Maxwell observation and detect the reflected light 51 of the light 50 reflected by the retina 74 using the photodetector 40, it is preferable that the convergence point 52 and the convergence point 53 are in substantially conjugate positions. In addition, in order to focus the light 50 on the retina 74 of the subject and focus the reflected light 51 on the detection surface 40a of the photodetector 40, it is preferable that the retina 74 of the subject and the photodetector 40 are in substantially conjugate positions. The so-called substantially conjugate position also includes the case where the position deviates from the conjugate position by a degree of manufacturing error.

[0077] like Figure 2 As shown, the optical component 22 converges a plurality of light rays 50 at a convergence point 52, and converts each light ray 50 from diffuse light to approximately parallel light. Thus, the light rays 50 can be focused on the retina 74 of the subject. The optical component 23 converges a plurality of reflected light rays 51 at a convergence point 53, and converts each reflected light ray 51 from diffuse light to approximately parallel light, and the simulated eye optical system 24 converts the reflected light rays 51 of approximately parallel light into convergent light. Thus, the reflected light rays 51 can be focused on the detection surface 40a of the light detector 40.

[0078] Preferably, the light 50 emitted from the projector 16 is reflected by the optical component 21 (third optical component) disposed between the optical component 22 and the optical component 23 and enters the optical component 22, and the reflected light 51 reflected by the retina 74 passes through the optical component 22 and the optical component 21 and enters the optical component 23. Thus, the fundus imaging device 100 can be miniaturized.

[0079] Example 2

[0080] Since the block diagram of the fundus imaging device of the second embodiment is similar to that of the first embodiment, Figure 1 The same, therefore the description is omitted. Figure 62 is a diagram showing an optical system of a fundus imaging device according to Embodiment 2. Figure 6 In the fundus imaging device 200 of the second embodiment, a quarter wavelength plate 25 is disposed between the optical component 21a and the optical component 22. The optical component 21a is a polarization beam splitter. The other structures are the same as those of the first embodiment, and thus the description thereof is omitted.

[0081] According to the second embodiment, the optical component 21a is a polarization beam splitter, and the quarter wavelength plate 25 is disposed between the optical component 21a and the optical component 22. Thus, when the light 50 of the S wave is emitted from the projector 16, the light 50 is reflected by the optical component 21a, passes through the quarter wavelength plate 25, becomes circularly polarized light, and irradiates the retina 74. The reflected light 51 reflected by the retina 74 passes through the quarter wavelength plate 25, becomes a P wave, passes through the optical component 21a, and enters the optical component 23. By setting it as such a structure, it is possible to improve the utilization efficiency of light and improve the optical S / N ratio.

[0082] Example 3

[0083] Since the block diagram of the fundus imaging device of the third embodiment is similar to that of the first embodiment, Figure 1 The same, therefore the description is omitted. Figure 7 2 is a diagram showing an optical system of a fundus imaging device according to Embodiment 3. Figure 7 In the fundus photographing device 300 of the third embodiment, the optical component 19 and the optical component 23 are the same components, but the focal length of the optical component 22a is shorter than the focal lengths of the optical components 19 and 23. The other structures are the same as those of the first embodiment, and thus the description thereof is omitted.

[0084] According to the third embodiment, the focal length of the optical component 22a is shorter than that of the optical component 23. As a result, the FOV (Field of View) is expanded, and the range in which the light 50 irradiates the retina 74 can be expanded.

[0085] In the third embodiment, the case where the focal length of the optical component 22a is shorter than that of the optical component 23 is exemplified, but it may be longer. In this case, the beam diameter when the light 50 enters the cornea of ​​the subject can be increased, so the spot diameter of the light 50 on the retina 74 becomes smaller, and the resolution on the retina 74 and the SN ratio of the fundus image can be improved. In this way, the focal length of the optical component 22a can be made different from that of the optical component 23 according to the FOV and the point of the beam diameter when entering the cornea.

[0086] Example 4

[0087] Since the block diagram of the fundus photographing device of the fourth embodiment is the same as that of the first embodiment except that the light source 26 is added, Figure 1 The same, therefore the description is omitted. Figure 82 is a diagram showing an optical system of a fundus imaging device according to Embodiment 4. Figure 8 In the fundus photography device 400 of the fourth embodiment, in addition to the first embodiment Figure 2 In addition to the structure of the embodiment 1, there is also a light source 26 that emits background light 54, and an optical component 27 arranged between the optical component 21 and the optical component 22. The light source 26 is, for example, an LED light source or a laser light source. The optical component 27 is, for example, a half mirror. The background light 54 emitted by the light source 26 is reflected by the optical component 27 and enters the optical component 22. The background light 54 is converted from diffuse light to convergent light by the optical component 22, and after being focused near the pupil 71 of the subject, it is irradiated to the retina 74. The background light 54 from the light source 26 is emitted, for example, when the examiner turns on the light source 26. The other structures are the same as those in Example 1, so the description is omitted.

[0088] According to the fourth embodiment, a light source 26 for emitting background light 54 is provided. With only the light 50, a good fundus image may not be obtained due to insufficient light quantity and / or unevenness caused by scanning, or generation of stray light. By providing the light source 26, the background light 54 is irradiated to the retina 74, and the overall brightness of the retina 74 is improved, so that a good fundus image can be obtained. At this time, an optical component 27 (fourth optical component) is arranged between the optical component 22 and the optical component 23, and the background light 54 emitted from the light source 26 is reflected by the optical component 27 and irradiated to the retina 74 of the subject through the optical component 22. Therefore, the fundus photography device 400 can be prevented from being enlarged.

[0089] Example 5

[0090] Fig. 9 (a) is a perspective view of the appearance of the fundus photography device of Example 5, Fig. 9 (b) is along Fig. 9 (a) is the appearance diagram observed by arrow A, and Fig. 9 (c) is along Fig. 9 (a) The external view as viewed from arrow B. Fig. 9 (a) to Fig. 9 (c) The fundus photographing device 500 of the fifth embodiment is a handheld fundus photographing device, and comprises: a housing 90, which has a projection unit 10, a control unit 30, and a photodetector 40 inside; and a lens barrel 91, which is aligned with the eye 70 of the subject. The width W of the fundus photographing device 500 is about 70 mm to 80 mm. The depth D1 is about 90 mm to 100 mm, and D2 is about 60 mm to 70 mm. The height H is about 150 mm to 160 mm.

[0091] Fig.10 2 is a diagram showing an optical system of a fundus imaging device according to Embodiment 5. Fig.10In the fundus photography device 500 of the fifth embodiment, an optical component 28 for bending the reflected light 51 is arranged between the optical component 23 and the simulated eye optical system 24. The optical component 28 is, for example, a reflector. Therefore, the reflected light 51 passing through the optical component 23 is incident on the simulated eye optical system 24 after being reflected and bent by the optical component 28.

[0092] In addition, the angle at which the direction in which the optical component 22 and the optical component 23 are opposed to each other and the direction in which the light 50 is emitted from the projector 16 intersects is not a right angle. When the imaginary plane including the emission surface of the light 50 of the projector 16 is used as the reference plane, the optical component 22 is arranged to be farther from the imaginary plane than the optical component 23. Therefore, the light 50 emitted from the projector 16 is reflected by the optical component 21 obliquely upward in the direction away from the projector 16 and enters the optical component 22. The other structures are the same as those in the first embodiment, so the description is omitted.

[0093] According to the fifth embodiment, an optical component 28 (fifth optical component) for bending the reflected light 51 is arranged between the optical component 23 and the simulated eye optical system 24. This allows the fundus imaging device 500 to be miniaturized. Fig.10 In this embodiment, the circuits of the signal processing unit 32 and the image generating unit 33 can be arranged on the lower side of the photodetector 40 , and the fundus imaging device 500 can be miniaturized.

[0094] The light emitted from the projector 16 is reflected by the optical component 21 toward the upper direction away from the projector 16 and enters the optical component 22. Fig. 9 As shown in (c), the lens barrel 91 can be directed obliquely upward, and the subject can easily align the eye 70 with the lens barrel 91.

[0095] Example 6

[0096] like Figure 2 As shown, the light 50 emitted from the projector 16 passes through the cornea 75 and irradiates the retina 74. Therefore, a part of the light 50 is reflected by the cornea 75. Fig.11 is a diagram showing the trajectory of light reflected by the cornea of ​​the subject. Fig.11, a part of the light 50 emitted from the projector 16 is reflected by the cornea 75 and becomes a reflected light 56. The reflected light 56 ​​passes through the optical component 22, the optical component 21, the optical component 23 and the simulated eye optical system 24 and is incident on the detection surface 40a of the light detector 40. Hereinafter, the reflected light 56 ​​reflected by the cornea 75 is sometimes referred to as the cornea reflected light 56, and the reflected light 51 reflected by the retina 74 is sometimes referred to as the retina reflected light 51. Since the curvature radius of the surface of the cornea 75 is about 7.8 mm, a plurality of cornea reflected light rays 56 and a plurality of retina reflected light rays 51 are roughly overlapped. That is, the area where the plurality of cornea reflected light rays 56 are incident on the detection surface 40a of the light detector 40 and the area where the plurality of retina reflected light rays 51 are incident on the detection surface 40a of the light detector 40 are roughly overlapped.

[0097] The amount of light reflected from the cornea 56 is several dozen times greater than the amount of light reflected from the retina 51. Therefore, when the cornea reflected light 56 ​​enters the photodetector 40 in addition to the retina reflected light 51, a light spot is generated in the image generated based on the output signal of the photodetector 40, and it is sometimes difficult to capture the fundus image of the retina 74.

[0098] Fig.12 (a) is a diagram showing the trajectory of light reflected by the retina, Fig.12 (b) Fig.12 (a) is an enlarged view of the vicinity of the simulated eye optical system. Fig.13 (a) is a diagram showing the trajectory of light reflected by the cornea, Fig.13 (b) Fig.13 (a) is an enlarged view of the vicinity of the simulated eye optical system. Fig.14 (a) is only shown Fig.13 (a) Diagram of the optical axis of a ray, Fig.14 (b) and Fig.14 (c) is shown Fig.13 (a) A diagram showing the trajectories of two of the three rays. Fig.12 (a) to Fig.14 (c) shows a case where the fundus photographing device is observed from above, and shows a case where the light 50 is irradiated to only one region 74a of regions 74a and 74b obtained by dividing the retina 74 into two parts left and right relative to the center of the retina 74. The direction in which the light 50 is incident on the center of the retina 74 is set as the Z direction, the horizontal direction is set as the X direction, and the vertical direction is set as the Y direction. In addition, the center of the retina 74 is set as the origin, the direction on the region 74a side relative to the center (origin) of the retina 74 is set as the +X direction, and the direction on the region 74b side is set as the -X direction. In the entire fundus photographing device, the region on the +X side is defined as the +X region, and the region on the -X side is defined as the -X region.

[0099] Reference Fig.12 (a) and Fig.12 (b) When the light 50 is irradiated to the area 74a of the retina 74, the light 50 enters the eye 70 from the -X area. The retinal reflected light 51 reflected by the area 74a of the retina 74 returns to the optical component 21 along a trajectory substantially the same as the trajectory of the light 50 entering the eye 70, and then passes through the optical component 21 and the optical component 23 to enter the simulated eye optical system 24. That is, the retinal reflected light 51 is emitted from the eye 70 to the -X area, then passes through the optical component 22 and the optical component 21, and is bent toward the +X area by the optical component 23 to enter the simulated eye optical system 24. In addition, although not shown in the figure, when the light 50 is irradiated to the area 74b of the retina 74, the light 50 enters the eye 70 from the +X area. The retinal reflected light 51 reflected by the area 74b of the retina 74 returns to the optical component 21 along a trajectory substantially the same as the trajectory of the light 50 entering the eye 70, and then passes through the optical component 21 and the optical component 23 to enter the simulated eye optical system 24. That is, the retinal reflected light 51 is emitted from the eye 70 to the +X region, passes through the optical component 22 and the optical component 21 , is bent toward the −X region by the optical component 23 , and enters the pseudo-eye optical system 24 .

[0100] Reference Fig.13 (a) Fig.13 (b) and Fig.14 (a), the light 50 irradiated to the area 74a of the retina 74 is reflected by the cornea 75, and the cornea reflected light 56 ​​is reflected toward the +X area by the convex surface shape of the cornea 75. After passing through the optical component 22 and the optical component 21, the cornea reflected light 56 ​​is bent toward the -X area by the optical component 23 and enters the simulated eye optical system 24. In addition, although the illustration is omitted, when the light 50 irradiates the area 74b of the retina 74, the light 50 enters the eye 70 from the +X area, and the cornea reflected light 56 ​​reflected by the cornea 75 is reflected toward the -X area. After passing through the optical component 22 and the optical component 21, the cornea reflected light 56 ​​is bent toward the +X area by the optical component 23 and enters the simulated eye optical system 24.

[0101] Reference Fig.13 (a) Fig.13 (b) Fig.14 (b) and Fig.14(c) The cornea 75 is in the shape of a convex surface, so the cornea reflected light 56 ​​is reflected by the convex mirror. Since the light 50 is incident on the cornea 75 as approximately parallel light, the cornea reflected light 56 ​​reflected by the cornea 75 becomes diffuse light. After the cornea reflected light 56 ​​is converted from diffuse light to approximately parallel light by the optical component 22, it is converted from approximately parallel light to convergent light by the optical component 23. The cornea reflected light 56 ​​is converted into convergent light by the optical component 23, and is focused at the focus point 57 in front of the simulated eye optical system 24. Since the simulated eye optical system 24 is configured at a convergence point 53 located at a position approximately conjugate with the convergence point 52 where multiple light rays 50 converge near the pupil 71 (the convergence point 52 and the convergence point 53 are Figure 2 The cornea reflected light 56 ​​is focused in front of the simulated eye optical system 24. In other words, when the cornea reflected light 56 ​​is extended into the eye 70, the cornea reflected light 56 ​​has a focus point between the convergence point 52 and the cornea 75, and the focus point is in a substantially conjugate position with the focus point 57.

[0102] like Fig.12 (a) to Fig.13 As shown in (b), when the light 50 is irradiated to the area 74a of the retina 74, the retinal reflected light 51 and the corneal reflected light 56 ​​travel on different paths and enter the simulated eye optical system 24. The same is true when the light 50 is irradiated to the area 74b of the retina 74. Here, the imaginary plane passing through the focus 57 of the corneal reflected light 56 ​​is set as the imaginary plane 58. In the imaginary plane 58, the retinal reflected light 51 is roughly located at a position slightly close to the -X area relative to the origin of the X-axis, while the corneal reflected light 56 ​​is roughly located at a position close to the +X area relative to the origin of the X-axis. Therefore, the following describes an example of using such a difference to suppress the influence of the corneal reflected light 56 ​​on the fundus image.

[0103] Fig.15 2 is a block diagram of a fundus imaging device according to Embodiment 6. Fig.15 , the fundus photography device 600 of Example 6 and Figure 1 Compared with the fundus photography device 100 of the first embodiment, the drive control unit 34 and the drive mechanism 95 are further included. When the image control unit 31 outputs the control signal for fundus photography to the drive circuit 14, the drive control unit 34 outputs the control signal to the drive mechanism 95. The drive mechanism 95 drives the light shielding plate (see the following description) provided in the optical system 13 based on the control signal of the drive control unit 34. Fig.16 (a) to Fig.16 (d)). The driving mechanism 95 includes, for example, a stepping motor. Other structures are the same as those of the first embodiment. Figure 1 The same, therefore the description is omitted.

[0104] Fig.16 (a) to Fig.16 (d) is a diagram showing the optical system of the fundus imaging device of Example 6. Fig.16 (a) and Fig.16 (b) shows the retinal reflected light 51 and the cornea reflected light 56 ​​when the light 50 is incident on the area 74a of the retina 74. Fig.16 (c) and Fig.16 (d) shows the retinal reflected light 51 and the cornea reflected light 56 ​​when the light 50 is incident on the area 74 b of the retina 74 . Fig.16 (a) to Fig.16 (d) shows a state where the fundus imaging device is viewed from above, and for the sake of clarity of the drawing, illustration of the projector 16 is omitted.

[0105] Reference Fig.16 (a) to Fig.16 (d) In the fundus photographing device 600 of the sixth embodiment, a light shielding plate 96 is disposed between the optical component 23 and the simulated eye optical system 24, at a position closer to the simulated eye optical system 24 than the center between the optical component 23 and the simulated eye optical system 24, so as to be movable in the ±X direction as indicated by arrows 92. For example, the light shielding plate 96 is disposed at Fig.12 (a) to Fig.13 (b) is a virtual plane 58 passing through the focal point 57 of the cornea reflected light 56. The light shielding plate 96 is driven in the ±X direction of the arrow 92 by the driving mechanism 95. The other structures are the same as those in the first embodiment, and thus the description thereof is omitted.

[0106] Reference Fig.16 (a) and Fig.16 (b), when the light 50 is incident on the area 74a of the retina 74, the shading plate 96 moves to the first position where all the cornea reflected light 56 ​​are blocked and a part of each of the retina reflected light 51 is passed. Fig.12 (a) to Fig.13 As shown in FIG. 1( b ), in the imaginary plane 58, the plurality of cornea reflected light rays 56 are focused, while the plurality of retinal reflected light rays 51 are roughly converged and each of the plurality of retinal reflected light rays 51 becomes roughly parallel light of roughly the same size as the light 50 incident on the cornea 75. The diameter of the retinal reflected light rays 51 on the imaginary plane 58 is about 0.8 mm to 1.65 mm. If the plurality of cornea reflected light rays 56 are completely blocked by the shading plate 96, the front end of the shading plate 96 slightly protrudes from the origin of the X axis to the -X region. Therefore, the retinal reflected light rays 51 are divided into two halves by the shading plate 96.

[0107] Fig.171 is a diagram showing an example of retinal reflected light beams that are split in half. Since the diameter of the retinal reflected light beams 51 on the virtual plane 58 is about 0.8 mm to 1.65 mm, and the amount by which the light shielding plate 96 protrudes from the origin to the -X region is about 10 μm to 50 μm, even if the retinal reflected light beams 51 are split in half by the light shielding plate 96, there will be no problem in the detection of the light detector 40. Therefore, the plurality of cornea reflected light beams 56 reflected by the cornea 75 are shielded by the light shielding plate 96 to suppress the incidence on the light detector 40, and a portion of each of the plurality of retinal reflected light beams 51 reflected by the region 74a of the retina 74 passes through the light shielding plate 96 and is detected by the light detector 40.

[0108] like Fig.16 (c) and Fig.16 As shown in (d), when the light 50 is incident on the area 74b of the retina 74, the shading plate 96 moves to the second position where all of the plurality of cornea reflected light rays 56 are blocked and a portion of each of the plurality of retinal reflected light rays 51 passes. Thus, the plurality of cornea reflected light rays 56 reflected by the cornea 75 are blocked by the shading plate 96 and are suppressed from entering the photodetector 40, and a portion of each of the plurality of retinal reflected light rays 51 reflected by the area 74b of the retina 74 passes through the shading plate 96 and is detected by the photodetector 40.

[0109] Fig.18 2 is a flowchart showing an example of fundus photography processing. Fig.18 The drive control unit 34 controls the drive mechanism 95 to move the light shielding plate 96 to Fig.16 (a) and Fig.16 (b) (step S30). Next, the image control unit 31 controls the driving of the light source 11 and the scanning unit 12, and emits the light 50 for fundus photography from the projector 16, and irradiates only the area 74a of the areas 74a and 74b obtained by dividing the retina 74 into two parts (step S32). Here, the light 50 is irradiated only to the area 74a, for example, Figure 4 In the scanning of the light 50 on the retina 74 described above, the light 50 may be emitted from the light source 11 only when the scanning unit 12 scans the area 74a. Fig.16 (a) and Fig.16 As shown in (b), a portion of each of the plurality of retinal reflected light rays 51 reflected by the area 74a of the retina 74 is incident on the photodetector 40 and detected, but all of the plurality of cornea reflected light rays 56 reflected by the cornea 75 are blocked by the light shielding plate 96 and are suppressed from entering the photodetector 40. In addition, the order of step S30 and step S32 may be reversed.

[0110] Next, the signal processing unit 32 obtains the output signal of the photodetector 40 (step S34). Next, the image generating unit 33 generates a first image related to the fundus based on the result of the signal processing unit 32 processing the output signal of the photodetector 40 (step S36). The first image is a fundus image related to the area 74a of the retina 74.

[0111] Next, the drive control unit 34 controls the drive mechanism 95 to move the light shielding plate 96 to the position of Fig.16 (c) and Fig.16 (d) The second position shown in step S38. Next, the image control unit 31 controls the driving of the light source 11 and the scanning unit 12, and emits the light 50 for fundus photography from the projector 16, and irradiates only the area 74b of the areas 74a and 74b of the retina 74 (step S40). When the light 50 is irradiated only to the area 74b, it is the same as when the light 50 is irradiated only to the area 74a. For example, the light 50 can be emitted from the light source 11 only when the scanning unit 12 scans the area 74b. Thus, as shown in FIG. Fig.16 (c) and Fig.16 As shown in (d), a part of each of the plurality of retinal reflected light rays 51 reflected by the area 74b of the retina 74 is incident on the photodetector 40 and detected, but all of the plurality of cornea reflected light rays 56 reflected by the cornea 75 are blocked by the light shielding plate 96 and are suppressed from entering the photodetector 40. In addition, the order of step S38 and step S40 may be reversed.

[0112] Next, the signal processing unit 32 obtains the output signal of the photodetector 40 (step S42). Next, the image generating unit 33 generates a second image related to the fundus based on the result of the signal processing unit 32 processing the output signal of the photodetector 40 (step S44). The second image is a fundus image related to the area 74b of the retina 74.

[0113] Next, the image generator 33 synthesizes the first image generated in step S36 and the second image generated in step S44 to generate a fundus image of the entire retina 74 (step S46). The display unit 41 displays the fundus image generated by the image generator 33 (step S48).

[0114] According to Example 6, Fig.16 (a) to Fig.16As shown in (d), the image control unit 31 (irradiation area adjustment unit) does not irradiate area 74b when irradiating area 74a of the two areas 74a and 74b divided into two parts with the retina 74 as the center, and does not irradiate area 74a when irradiating area 74b. The shading plate 96 (shading component) is movably arranged between the optical component 23 and the simulated eye optical system 24. In other words, the shading plate 96 is movably arranged between the optical component 23 and the convergence point 53. The shading plate 96 is movably arranged between the optical component 23 and the convergence point 53 by the driving mechanism 95 (refer to Fig.15 ) Move the light shielding plate 96. Fig.16 (a) and Fig.16 As shown in (b), when the light 50 is irradiated only to the area 74a, the driving mechanism 95 moves the shading plate 96 to the first position where the cornea reflected light 56 ​​is blocked and the retina reflected light 51 is allowed to pass. Fig.16 (c) and Fig.16 As shown in (d), when the light 50 irradiates only the area 74b, the shading plate 96 is moved to the second position where the corneal reflected light 56 ​​is blocked and the retinal reflected light 51 passes. Then, the image generating unit 33 generates an image based on the output signal of the light detector 40 in each case where the light 50 irradiates the area 74a or the area 74b, and synthesizes the two images to generate a fundus image. In this way, the influence of the corneal reflected light 56 ​​on the fundus image can be suppressed, and a good fundus image can be obtained. In addition, in Example 6, the case where the retina 74 is divided into two parts left and right is illustrated, but it is not limited to this case, as long as the retina 74 is divided into two parts up and down, and the retina 74 is divided into two parts relative to the center of the retina 74, other cases may be used.

[0115] In Example 6, the case in which the image control unit 31 assumes the function of the irradiation area adjustment unit for not irradiating area 74b when irradiating light 50 to area 74a among areas 74a and 74b, and not irradiating area 74a when irradiating light 50 to area 74b, is shown as an example, but the present invention is not limited to this case. Fig.19 19(a) and 19(b) are diagrams showing the optical system of the fundus imaging device according to the first modification of the sixth embodiment. Fig.19 (a) and Fig.19(b) It is also possible that the light shielding plate 97 disposed between the optical component 21 and the optical component 22 in a manner movable in the ±X direction functions as the irradiation area adjustment unit. That is, the light shielding plate 97 may be moved to the first position to irradiate the light 50 only to the area 74a, and the light shielding plate 97 may be moved to the second position to irradiate the light 50 only to the area 74b. The light shielding plate 97 may also be driven by the driving mechanism 95. In addition, the light shielding plate 97 is not limited to the case where it is disposed between the optical component 21 and the optical component 22, and may be disposed between the optical component 19 and the optical component 21, or between the optical component 22 and the eye 70.

[0116] The curvature radius of the surface of the cornea 75 varies from person to person, and has a distribution of about 7.8 mm±1.0 mm. When the curvature radius of the cornea 75 varies, the position of the focal point 57 of the cornea reflected light 56 ​​changes. Fig. 20 (a) to Fig. 20 (c) is a diagram showing the change in the position of the focal point of the corneal reflected light caused by the difference in the curvature radius of the cornea. Fig. 20 (b) and Fig. 20 (c) is shown by a dotted line. Fig. 20 (a) is an imaginary plane 58. Fig. 20 (a) is the case where the curvature radius of the cornea 75 is 7.8 mm. When the curvature radius is less than 7.8 mm, Fig. 20 As shown in (b), the focal point 57 of the corneal reflected light 56, i.e., the imaginary plane 58, is close to the simulated eye optical system 24. On the contrary, when the radius of curvature is greater than 7.8 mm, as shown in FIG. Fig. 20 As shown in (c), the focus point 57 of the corneal reflected light 56, that is, the virtual plane 58, is away from the simulated eye optical system 24. For example, when the curvature radius is 6.8 mm, the position of the focus point 57 (the position of the virtual plane 58) is about 0.5 mm closer to the simulated eye optical system 24 than when the curvature radius is 7.8 mm. When the curvature radius is 8.8 mm, the position of the focus point 57 (the position of the virtual plane 58) is about 0.5 mm away from the simulated eye optical system 24 than when the curvature radius is 7.8 mm.

[0117] When the shading plate 96 is offset from the imaginary plane 58, the larger the offset, the larger the beam diameter of the cornea reflected light 56 ​​at the shading plate 96. Fig.16 (b) and Fig.16As shown in (d), when the cornea reflected light 56 ​​is shielded by the shielding plate 96, the amount of protrusion of the front end of the shielding plate 96 toward the -X region or the +X region becomes larger, and as a result, the beam diameter of the retinal reflected light 51 passing through the shielding plate 96 becomes smaller. Therefore, the shielding plate 96 is preferably arranged at the virtual plane 58 or near the virtual plane 58. That is, the shielding plate 96 is preferably arranged at the focus point 57 where the cornea reflected light 56 ​​is focused in front of the simulated eye optical system 24 (that is, in front of the convergence point 53) or near the focus point 57. The vicinity of the focus point 57 refers to, for example, the case where it is within the range of the distance from the focus point 57 to the distance between the focus point 57 and the convergence point 53.

[0118] like Fig. 20 (a) to Fig. 20 As shown in (c), the position of the focus point 57 of the corneal reflected light 56 ​​changes according to the curvature radius of the cornea 75, so it is preferred that the driving mechanism 95 can move the shading plate 96 not only in the ±X direction but also in the ±Z direction. In other words, it is preferred that the shading plate 96 can move in a first direction in which the corneal reflected light 56 ​​is incident on the shading plate 96 and in a second direction intersecting the first direction. In addition, the driving mechanism 95 can also drive the shading plate 96 and the simulated eye optical system 24 in the ±Z direction as a whole.

[0119] In Embodiment 6, the case where the light 50 after two-dimensional scanning is emitted from the projector 16 is exemplified, but it is also possible to emit light that is not two-dimensionally scanned (photographic light for fundus photography). In this case, by using an optical system including the optical component 19, the optical component 21, the optical component 22, the optical component 23, and the light shielding plate 96, the influence of the reflected light of the photographic light reflected by the cornea 75 on the fundus image can be suppressed, and a good fundus image can be obtained. In the case of emitting photographic light that is not two-dimensionally scanned, the optical system does not need to include the simulated eye optical system 24.

[0120] Fig.21 1 is a side view showing an example in which the light shielding plate arranged on the imaginary plane has a U-shaped shape. Fig.21 In the figure, the retinal reflected light 51 and the corneal reflected light 56 ​​reflected by the retina 74 and the cornea 75 at different times are shown, and the corneal reflected light 56 ​​is shaded for clarity (described later). Fig. 22 (a) and Fig. 22 The same is true for (b). Fig.21 As shown in FIG. 1 , regarding the size of the cornea reflected light 56 ​​at the shading plate 96a disposed on the imaginary plane 58, the cornea reflected light 56 ​​at the center is the smallest, and gradually expands as it moves away from the center due to the influence of the aberration of the optical system. In order to block the expanded cornea reflected light 56, it is preferable to make the peripheral side of the shading plate 96a wider.

[0121] Fig. 22 (a) and Fig. 22 (b) is a diagram showing the problem that occurs when a flat-plate shading plate is used to block the light reflected from the cornea. Fig. 22 As shown in (a), if a flat-plate shading plate 96 is arranged at a position to block the cornea reflected light 56 ​​located in the central part, the expanded cornea reflected light 56 ​​located at a position away from the central part cannot be blocked. Fig. 22 As shown in (b), when the light shielding plate 96 is enlarged so as to shield the enlarged cornea reflected light beam 56, shielding of the retina reflected light beam 51 increases, and the light of the fundus image is attenuated.

[0122] like Fig.21 As shown, by using a U-shaped shading plate 96a in which the central portion corresponding to the corneal reflected light 56 ​​is concave and the peripheral portion away from the central portion is protruding, the surrounding enlarged corneal reflected light 56 ​​can be blocked and the dimmer of the retinal reflected light 51 can be suppressed to a smaller level. Fig.16 (a) to Fig.16 The movement of the light shielding plate 96 a from the first position to the second position described in (d) can be performed by rotating the light shielding plate 96 a by 180 degrees by the driving mechanism 95 .

[0123] In the fundus photography apparatus of Embodiments 1 to 6, if the simulated eye optical system 24 and the photodetector 40 are set as a camera lens and the photodetector 40 is set as an imaging sensor, the simulated eye optical system 24, the photodetector 40 and the image generation unit 33 have the same functions as a general digital camera, so the simulated eye optical system 24, the photodetector 40 and the image generation unit 33 can be replaced by a digital camera. Here, in the case of replacing with a digital camera in Embodiment 6, it is sometimes necessary to pay attention to the positional relationship between the camera lens and the light shielding plate 96 or 96a. That is, in order to improve the optical characteristics of the camera lens, by combining a plurality of lenses, etc., the focus point 57 of the optical system of the fundus photography apparatus of Embodiment 6 is sometimes located inside the camera lens. In this case, the camera lens interferes with the light shielding plate 96 or 96a. On the other hand, the focus point 57 of the camera lens used in a smartphone or the like is mostly outside the camera lens, and it is preferable to use such a camera lens in the fundus photography apparatus of Embodiment 6 while miniaturizing. In addition, as described in Embodiment 1, if the projector 16 is a general-purpose projector, a digital camera and a general-purpose projector can be used to constitute the fundus photography apparatus.

[0124] Example 7

[0125] In the sixth embodiment, a structure and a method for reducing the influence of the cornea reflected light 56 ​​are described. In the seventh embodiment, a different structure and a method for reducing the influence of the cornea reflected light 56 ​​are described.

[0126] Fig.23 FIG. 2 is a diagram showing an optical system of a fundus imaging device 700 according to Embodiment 7. Fig.23 In the fundus photographing device 700, a polarizing plate 81 and an optical component 21b are arranged on the optical path of a plurality of light beams 50 emitted from the projector 16. The polarizing plate 81 may be provided between the attenuation filter 20 and the optical component 21b, or between the attenuation filter 20 and the optical component 19.

[0127] When the projector 16 is a laser scanning projector, the emitted light 50 is a linearly polarized laser. The polarizing plate 81 is a polarizing filter that is adjusted in such a way that the linearly polarized light 50 is transmitted as an S wave corresponding to the optical characteristics of the optical component 21b. The polarizing plate 81 makes the linearly polarized light 50 emitted from the projector 16 become an S wave that vibrates perpendicularly to the normal line of the reflection surface of the optical component 21b and the plane of the incident light beam, and enters the optical component 21b. The optical component 21b is a polarization beam splitter that reflects the S wave and transmits waves other than the S wave, and reflects the S wave light 50 that has passed through the polarizing plate 81. In order to efficiently reflect the S wave by the optical component 21b, the polarizing plate 81 and the optical component 21b are adjusted to adjust the optical characteristics including their orientation and / or positional relationship.

[0128] The S-wave light 50 passes through the optical component 22 and is irradiated to the cornea 75 and the retina 74. The cornea 75 transmits most of the irradiated light 50 and reflects a part of it. However, since the cornea 75 is a substantially uniform spherical surface, the irradiated S-wave light 50 remains in the state of an S-wave and a part of it is reflected. The S-wave light 50 irradiated to the retina 74 is not reflected as a fixed polarized light, but is reflected as a random polarized light, because the surface of the retina 74 has fine convexities and concavities.

[0129] The reflected light of the S wave reflected by the cornea 75 and the reflected light of the randomly polarized light reflected by the retina 74 pass through the optical component 22. The reflected light of the S wave reflected by the cornea 75 is reflected by the optical component 21b, does not pass through the optical component 21b, and therefore does not reach the photodetector 40. On the other hand, the reflected light 51 other than the S wave of the randomly polarized light reflected by the retina 74 passes through the optical component 21b and reaches the photodetector 40. Thus, the reflected light of the S wave reflected by the cornea 75 is not detected by the photodetector 40, and the reflected light 51 other than the S wave of the randomly polarized light reflected by the retina 74 is detected by the photodetector 40, so that the influence of the component of the light reflected by the cornea 75 can be reduced, and the reflected light 51 reflected by the retina 74 is mainly detected by the photodetector 40, and the S / N of the fundus image can be improved.

[0130] Here, the polarizing plate 81 is set as a polarizing filter adjusted in a manner to transmit the P wave of the linearly polarized light 50, and the optical component 21b is set as a polarization beam splitter that reflects the P wave that has passed through the polarizing plate 81 and transmits other than the P wave, and the same effect can be obtained by the same operation as described above. In addition, the projector 16 is a laser scanning projector that outputs laser light as linearly polarized light, but in the case of using a projector that emits non-polarized light based on the illumination light instead of laser scanning, it can also be used by adjusting the optical characteristics of the polarizing plate 81 and the optical component 21b to correspond to non-polarized light. For example, in the case where the projector 16 emits non-polarized light, the polarizing plate 81 can also transmit the non-polarized light as vertically polarized light.

[0131] In the fundus photography apparatus of the first to seventh embodiments, in addition to photographing the fundus, a visual function test can be performed by emitting two-dimensionally scanned light for projecting a test target for testing visual function (e.g., visual field) from the projector 16. Thus, it is possible to perform both fundus image acquisition and visual function test using one projector 16.

[0132] As mentioned above, although the embodiment of the present invention is described in detail, the present invention is not limited to the specific embodiment involved, and various modifications and changes can be made within the scope of the gist of the present invention described in the claims.

Claims

1. A fundus photography device, comprising: a light source, which emits light; a scanning unit for performing two-dimensional scanning on the light; and a first optical component configured to converge the plurality of light beams scanned by the scanning unit and emitted at different times at a first convergence point near the pupil of the subject and then irradiate the retina of the subject; a second optical component that causes a plurality of first reflected light rays that are reflected by the retina of the subject and pass through the first optical component to converge at a second convergence point; an optical system, which is disposed at the second convergence point and converts the plurality of first reflected light rays into convergent light respectively; a light detector configured to detect the plurality of first reflected light rays transmitted through the optical system; and An image generating unit generates a fundus image based on an output signal of the photodetector.

2. The fundus photography device according to claim 1, wherein: The first convergence point and the second convergence point are located at conjugate positions, The subject's retina and the photodetector are located at a conjugate position.

3. The fundus photography device according to claim 1, wherein: The scanning portion and the first convergence point are in a conjugate positional relationship.

4. The fundus photography device according to claim 1, wherein: The first optical component converges the plurality of light rays at the first convergence point, and converts the plurality of light rays from diffuse light to parallel light, respectively. The second optical component makes the plurality of first reflected light rays converge at the second convergence point, and converts the plurality of first reflected light rays from diffuse light to parallel light, respectively. The optical system converts the plurality of first reflected light rays from parallel light to convergent light respectively.

5. The fundus photography device according to claim 1, wherein: The plurality of first reflected light rays are focused before the second optical member, become diffused light, and enter the second optical member.

6. The fundus photography device according to claim 1, wherein: The beam diameter of the light incident on the cornea of ​​the subject is greater than or equal to 0.8 mm and less than or equal to 1.65 mm.

7. The fundus photography device according to claim 1, wherein: The fundus imaging device includes a third optical component disposed between the first optical component and the second optical component. A plurality of the light rays are reflected by the third optical component and are incident on the first optical component. The plurality of first reflected light beams reflected by the retina of the subject are transmitted through the first optical component and the third optical component and enter the second optical component.

8. The fundus photography device according to claim 7, wherein: The fundus imaging device includes a quarter wavelength plate disposed between the third optical component and the first optical component. The third optical component is a polarizing beam splitter.

9. The fundus photography device according to claim 1, wherein: The fundus photography device comprises: a light source that emits background light that is irradiated onto the subject's retina; and a fourth optical component, which is arranged between the first optical component and the second optical component, The background light emitted from the light source is reflected by the fourth optical component, passes through the first optical component, and is irradiated onto the retina of the subject.

10. The fundus photography device according to claim 1, wherein: The fundus photographing device includes a fifth optical component that is disposed between the second optical component and the optical system and that bends the plurality of first reflected light rays.

11. The fundus photography device according to claim 1, wherein: The focal length of the first optical component is different from the focal length of the second optical component.

12. The fundus photography device according to claim 1, wherein: The fundus photography device comprises: a light shielding member movably disposed between the second optical member and the second convergence point; and A drive mechanism moves the light shielding member to a first position where a second reflected light beam, in which the light beam is reflected by the cornea of ​​the subject and passes through the first optical member and the second optical member, is blocked and the first reflected light beam passes.

13. The fundus photography device according to claim 1, wherein: The fundus photography device comprises: an irradiation region adjustment unit that, when irradiating the light to a first region of a first region and a second region obtained by dividing the retina of the subject into two parts with respect to the center of the retina, does not irradiate the light to the second region, and when irradiating the light to the second region, does not irradiate the light to the first region; a light shielding member movably disposed between the second optical member and the second convergence point; as well as a driving mechanism for moving the light shielding member to a first position in which the light is reflected by the cornea of ​​the subject and passes through the first optical member and the second optical member, the second reflected light is blocked and the first reflected light passes, when the light is irradiated only to the first area; and for moving the light shielding member to a second position in which the second reflected light is blocked and the first reflected light passes, when the light is irradiated only to the second area. The image generating unit generates an image based on an output signal of the photodetector in each case where the light is irradiated onto the first region or the second region, and generates the fundus image by synthesizing the two generated images.

14. The fundus photography device according to claim 12, wherein: The light shielding member is arranged at or near a focus point where the second reflected light is focused before the second convergence point.

15. The fundus photography device according to claim 12, wherein: The light shielding member is movable in a first direction in which the second reflected light is incident on the light shielding member and in a second direction intersecting the first direction.

16. The fundus photography device according to claim 12, wherein: The light shielding member has a U-shaped shape in which the center portion of the second reflected light is concave.

17. The fundus photography device according to claim 1, wherein: The optical system, the photodetector, and the image generating unit are digital cameras.

18. A fundus photography device comprising: a projector, a projection unit, and an image generation unit, The projector has: a light source, which emits light; a scanning unit for performing two-dimensional scanning on the light; and an emitting portion that emits the scanned light, The projection unit comprises: a first optical component that causes the plurality of light rays emitted from the projector at different times to converge at a first convergence point near the pupil of the subject and then illuminate the retina of the subject; a second optical component that causes a plurality of first reflected light rays that are reflected by the retina of the subject and pass through the first optical component to converge at a second convergence point; an optical system, which is disposed at the second convergence point and converts the plurality of first reflected light rays into convergent light respectively; and a light detector for detecting the plurality of first reflected light rays transmitted through the optical system, The image generating unit generates a fundus image based on an output signal of the photodetector.

19. The fundus photography device according to claim 18, wherein: The first convergence point and the second convergence point are located at conjugate positions, The subject's retina and the photodetector are located at a conjugate position.

20. The fundus photography device according to claim 18, wherein: The scanning portion and the first convergence point are in a conjugate positional relationship.

21. The fundus photography device according to claim 18, wherein: The first optical component converges the plurality of light rays at the first convergence point, and converts the plurality of light rays from diffuse light to parallel light, respectively. The second optical component makes the plurality of first reflected light rays converge at the second convergence point, and converts the plurality of first reflected light rays from diffuse light to parallel light, respectively. The optical system converts the plurality of first reflected light rays from parallel light to convergent light respectively.

22. The fundus photography device according to claim 18, wherein: The plurality of first reflected light rays are focused before the second optical member, become diffused light, and enter the second optical member.

23. The fundus photography device according to claim 18, wherein: The beam diameter of the light incident on the cornea of ​​the subject is greater than or equal to 0.8 mm and less than or equal to 1.65 mm.

24. The fundus photography device according to claim 18, wherein: The fundus imaging device includes a third optical component disposed between the first optical component and the second optical component. A plurality of the light rays are reflected by the third optical component and are incident on the first optical component. The plurality of first reflected light beams reflected by the retina of the subject are transmitted through the first optical component and the third optical component and enter the second optical component.

25. The fundus photography device according to claim 24, wherein: The fundus imaging device includes a quarter wavelength plate disposed between the third optical component and the first optical component. The third optical component is a polarizing beam splitter.

26. The fundus photography device according to claim 18, wherein: The fundus photography device comprises: a light source that emits background light that is irradiated onto the subject's retina; and a fourth optical component, which is arranged between the first optical component and the second optical component, The background light emitted from the light source is reflected by the fourth optical component, passes through the first optical component, and is irradiated onto the retina of the subject.

27. The fundus photography device according to claim 18, wherein: The fundus photographing device includes a fifth optical component that is disposed between the second optical component and the optical system and that bends the plurality of first reflected light rays.

28. The fundus photography device according to claim 18, wherein: The focal length of the first optical component is different from the focal length of the second optical component.

29. The fundus photography device according to claim 18, wherein: The fundus photography device comprises: a light shielding member movably disposed between the second optical member and the second convergence point; and A drive mechanism moves the light shielding member to a first position where a second reflected light beam, in which the light beam is reflected by the cornea of ​​the subject and passes through the first optical member and the second optical member, is blocked and the first reflected light beam passes.

30. The fundus photography device according to claim 18, wherein: The fundus photography device comprises: an irradiation region adjustment unit that, when irradiating the light to a first region of a first region and a second region obtained by dividing the retina of the subject into two parts with respect to the center of the retina, does not irradiate the light to the second region, and when irradiating the light to the second region, does not irradiate the light to the first region; a light shielding member movably disposed between the second optical member and the second convergence point; as well as a driving mechanism for moving the light shielding member to a first position in which the light is reflected by the cornea of ​​the subject and passes through the first optical member and the second optical member, the second reflected light is blocked and the first reflected light passes, when the light is irradiated only to the first area; and for moving the light shielding member to a second position in which the second reflected light is blocked and the first reflected light passes, when the light is irradiated only to the second area. The image generating unit generates an image based on an output signal of the photodetector in each case where the light is irradiated onto the first region or the second region, and generates the fundus image by synthesizing the two generated images.

31. The fundus photography device according to claim 29, wherein: The light shielding member is arranged at or near a focus point where the second reflected light is focused before the second convergence point.

32. The fundus photography device according to claim 29, wherein: The light shielding member is movable in a first direction in which the second reflected light is incident on the light shielding member and in a second direction intersecting the first direction.

33. The fundus photography device according to claim 29, wherein: The light shielding member has a U-shaped shape in which the center portion of the second reflected light is concave.

34. The fundus photography device according to claim 18, wherein: The optical system, the photodetector, and the image generating unit are digital cameras.

35. The fundus photography device according to claim 18, wherein: The projector is a detachable general-purpose projector.

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