Image projection device, visual inspection device, and fundus photography device

Abstract

To make diameters on a retina of a plurality of light beams fall within a prescribed range when a half angle of a field angle being the larger one of the field angle in a horizontal direction and the field angle in a vertical direction in a range where the retina is irradiated with the plurality of light beams is equal to or greater than 10°.SOLUTION: An image projection device comprises: a light source 12; a scan unit 20 which scans a light beam 40 emitted from the light source 12; and an irradiation optical system 30 which projects an image by irradiating a retina 62 of a user with the plurality of light beams 40 emitted in different times from the scan unit 20 after being converged at a convergent point 46 in an eye 60 of the user. When the diameters of the plurality of light beams 40 incident on a cornea 66 of the user is within 0.41 mm±0.05 mm, the diameters on the retina 62 of the plurality of light beams 40 become substantially constant within a range in which the field angle of the projection range of the plurality of light beams 40 projected onto the retina 62 is 30 degrees.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an image projection device, a visual inspection device, and a fundus photography device. [Background technology]

[0002] Image projection devices that utilize Maxwell's vision, in which scanned light rays are converged inside the eye and then irradiated onto the retina, are known (e.g., Patent Documents 1 and 2). Also, a visual inspection device that utilizes Maxwell's vision is known (e.g., Patent Document 3). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-116219 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-102368 [Patent Document 3] International Publication No. 2019 / 069578 Summary of the Invention [Problem to be solved by the invention]

[0004] In Maxwellian vision, multiple light beams emitted from the scanning unit at different times converge at a convergence point inside the eye of a user or the like before being irradiated onto the retina. In this case, it is desirable that the larger half angle of the horizontal and vertical angles of view within the range in which the multiple light beams irradiate the retina at the convergence point inside the eye be 10° or greater. Even when multiple light beams irradiate the retina at such an angle of view, it is desirable that the diameters of the multiple light beams on the retina fall within a predetermined range at any position on the retina.

[0005] The present invention has been made in consideration of the above-mentioned problems, and aims to make the diameters of multiple light rays on the retina fall within a predetermined range when the half angle of the larger of the horizontal and vertical angles of view in the range in which the multiple light rays are irradiated onto the retina is 10° or more. [Means for solving the problem]

[0006] The present invention provides an optical system that includes a light source, a scanning unit that scans light beams emitted from the light source, and an optical system that converges a plurality of light beams emitted from the scanning unit at different times at a convergence point in the eye of a user and then irradiates the light beams onto the retina of the user to project an image, wherein the diameter of the plurality of light beams incident on the cornea of ​​the user is within 0.41 mm±0.05 mm. and , the projection range of the plurality of light rays projected onto the retina The angle between the ray located at the center and the ray located at the edge of the projection range Within a range of 30 degrees, the diameter of the plurality of light rays on the retina is 55μm or more and 77μm or less This is an image projection device.

[0008] The present invention provides an optical system comprising a light source, a scanning unit that scans light beams emitted from the light source, and a plurality of light beams emitted from the scanning unit at different times that are converged at a convergence point in the eye of a user and then projected onto the retina of the user to project an image, wherein the diameter of the plurality of light beams incident on the cornea of ​​the user is within 0.41 mm±0.05 mm, and the angle between the light beam located at the center of the projection range of the plurality of light beams projected onto the retina and the light beam located at the edge of the projection range is within a range of 30 degrees, and The difference between the maximum and minimum diameters is 22 μm or less , an image projection device .

[0011] The present invention provides an optical system comprising a light source, a scanning unit that scans light rays emitted from the light source, an optical system that converges the plurality of light rays emitted at different times from the scanning unit at a convergence point in the eye of the subject and then irradiates the retina of the subject, and an input unit that inputs the subject's response to the plurality of light rays irradiated to the retina, wherein the diameter of the plurality of light rays incident on the cornea of ​​the subject is within 0.41 mm±0.05 mm. and , the projection range of the plurality of light rays projected onto the retina The angle between the ray located at the center and the ray located at the edge of the projection range Within a range of 30 degrees, the diameter of the plurality of light rays on the retina is 55μm or more and 77μm or less This is a visual inspection device. The present invention also provides a visual inspection device comprising: a light source; a scanning unit that scans light rays emitted from the light source; an optical system that converges the multiple light rays emitted from the scanning unit at different times at a convergence point inside the subject's eye and then irradiates the multiple light rays onto the subject's retina; and an input unit that inputs the subject's response to the multiple light rays irradiated onto the retina, wherein the diameters of the multiple light rays incident on the subject's cornea are within 0.41 mm ± 0.05 mm, the angle between the light ray located at the center of a projection range of the multiple light rays projected onto the retina and the light ray located at an edge of the projection range is within a range of 30 degrees, and the difference between the maximum and minimum diameters of the multiple light rays on the retina is 22 μm or less.

[0012] In the above configuration, the subject may respond to each of the plurality of light beams that are sequentially irradiated onto the retina by operating the input unit.

[0013] The present invention provides an optical system that includes a light source, a scanning unit that scans light rays emitted from the light source, an optical system that converges the plurality of light rays emitted from the scanning unit at different times at a convergence point in the eye of the subject and then irradiates the retina of the subject, a detector that detects the plurality of light rays reflected from the retina, and an acquisition unit that acquires an image of the fundus of the subject from the plurality of light rays detected by the detector, wherein the diameter of the plurality of light rays incident on the cornea of ​​the subject is within 0.41 mm±0.05 mm. and , the projection range of the plurality of light rays projected onto the retina The angle between the ray located at the center and the ray located at the edge of the projection range Within a range of 30 degrees, the diameter of the plurality of light rays on the retina is 55μm or more and 77μm or less This is a fundus photography device. The fundus photography device also includes a light source, a scanning unit that scans light rays emitted from the light source, an optical system that converges the multiple light rays emitted from the scanning unit at different times at a convergence point inside the subject's eye and then irradiates the multiple light rays onto the subject's retina, a detector that detects the multiple light rays reflected from the retina, and an acquisition unit that acquires a fundus image of the subject from the multiple light rays detected by the detector, wherein the diameter of the multiple light rays incident on the subject's cornea is within 0.41 mm ± 0.05 mm, the angle between the light ray located at the center of the projection range of the multiple light rays projected onto the retina and the light ray located at the edge of the projection range is within a range of 30 degrees, and the difference between the maximum and minimum diameters of the multiple light rays on the retina is 22 μm or less. [Effects of the Invention]

[0014] According to the present invention, when the half angle of the larger of the horizontal and vertical angles of view in the range in which multiple light rays are irradiated onto the retina is 10° or more, the diameters of the multiple light rays on the retina can be made to fall within a predetermined range. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a block diagram of an image projection device according to a first embodiment. [Figure 2] FIG. 2 is a diagram illustrating an optical system of the image projection device according to the first embodiment. [Figure 3] FIG. 3 is a diagram showing light rays in the first embodiment. [Figure 4] FIG. 4 is a diagram illustrating a method for generating an image in the first embodiment. [Figure 5] 5(a) to 5(d) are graphs showing the results of Simulation 1. [Figure 6] 6(a) to 6(c) are graphs showing simulation results of the spot diameter of the light beam versus the angle α when a light beam of a single wavelength is used. [Figure 7]7(a) to 7(d) are graphs showing the results of Simulation 2. [Figure 8] FIG. 8 is a graph showing the simulation results of the spot diameter of a light beam relative to the diameter of the light beam incident on the cornea. [Figure 9] 9(a) and 9(b) are graphs showing the results of Simulation 3. [Figure 10] FIG. 10 is a block diagram of a visual inspection device according to the second embodiment. [Figure 11] FIG. 11 is a diagram showing an optical system of a visual inspection device according to the second embodiment. [Figure 12] FIG. 12 is a flowchart illustrating an example of an inspection method of the visual inspection device according to the second embodiment. [Figure 13] 13(a) to 13(c) are diagrams for explaining the test images projected onto the retina in the flowchart of FIG. [Figure 14] FIG. 14 is a block diagram of a fundus photographing apparatus according to the third embodiment. [Figure 15] FIG. 15 is a diagram showing an optical system of a fundus photographing apparatus according to the third embodiment. [Figure 16] FIG. 16 is a flowchart illustrating an example of an examination method of the fundus photographing apparatus according to the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments of the present invention will be described with reference to the drawings. [Example]

[0017] 1 is a block diagram of an image projection device 100 according to a first embodiment. As shown in FIG. 1, the image projection device 100 includes a projection unit 10 and a control unit 50. The projection unit 10 includes a light source 12, an adjustment unit 14 including a lens 16 and an aperture 18, a scanning unit 20, a driving circuit 22, an input circuit 24, and an irradiation optical system 30. The control unit 50 includes an image control unit 52.

[0018] Image data is input to the image control unit 52 from a camera and / or a recording device (not shown), etc. The image control unit 52 generates an image signal based on the input image data and outputs it to the input circuit 24. The drive circuit 22 drives the light source 12 and the scanning unit 20 based on the control signal from the image control unit 52 and the image signal acquired by the input circuit 24.

[0019] The light source 12 emits light beams 40 (laser beams) that are visible light, such as red laser beams (wavelength: approximately 610 nm to 660 nm), green laser beams (wavelength: approximately 515 nm to 540 nm), and blue laser beams (wavelength: approximately 440 nm to 480 nm). An example of the light source 12 that emits red, green, and blue laser beams is a light source that integrates, for example, RGB (red, green, and blue) laser diode chips and a three-color combining device. Note that the light source 12 may also emit light beams 40 of a single wavelength.

[0020] The adjustment unit 14 shapes the light beam 40. The scanning unit 20 (scanner) is, for example, a scanning mirror such as a MEMS (Micro Electric Mechanical System) mirror or a transmission scanner, and scans the light beam 40 in two dimensions. The irradiation optical system 30 irradiates the scanned light beam 40 onto the eye 60 of the user.

[0021] The image control unit 52 may be implemented by a processor such as a CPU (Central Processing Unit) working in cooperation with a program. The image control unit 52 may be a circuit designed specifically for that purpose. The image control unit 52 may project an image input from a camera installed at an appropriate position in the user's line of sight onto the user's eye 60. The image control unit 52 may also project an image input from a recording device or the like, or superimpose a camera image on an image from a recording device or the like to project so-called augmented reality (AR).

[0022] Fig. 2 is a diagram showing an optical system of the image projection device 100 according to Example 1. As shown in Fig. 2, the image projection device 100 is a retinal projection head-mounted display that utilizes Maxwellian vision, in which light rays 40 for allowing a user to visually recognize an image are directly irradiated onto the user's retina 62.

[0023] The light source 12 emits a light beam 40 under the control of the image control unit 52 (see FIG. 1). The light beam 40 emitted by the light source 12 passes through the lens 16. The lens 16 is a condenser lens that converts the light beam 40 from diffused light to focused light. The diameter of the light beam 40 that passes through the lens 16 is adjusted by the aperture 18. The light beam 40 that passes through the aperture 18 enters the scanning unit 20. The scanning unit 20 scans the light beam 40 in two dimensions, that is, in the horizontal and vertical directions.

[0024] The plurality of light beams 40 scanned in two dimensions by the scanning unit 20 and emitted from the scanning unit 20 in different directions at different times are incident on the irradiation optical system 30. The irradiation optical system 30 includes a reflecting mirror 32, a projection mirror 34, and a lens 36. The light source 12, the adjustment unit 14, the scanning unit 20, and each component of the irradiation optical system 30 are fixed to, for example, an eyeglass-type frame 42.

[0025] The multiple light beams 40 emitted from the scanning unit 20 are incident on the reflecting mirror 32. The reflecting mirror 32 is a concave mirror having a reflective surface formed of a curved surface such as a free-form surface, and has positive focusing power. The multiple light beams 40 reflected by the reflecting mirror 32 converge at a convergence point 44 in front of the projection mirror 34. A lens 36 is provided at the convergence point 44. The lens 36 is, for example, a biconvex lens. The multiple light beams 40 pass through the lens 36 and enter the projection mirror 34.

[0026] The projection mirror 34 is disposed in front of the user's eye 60. The projection mirror 34 is a concave mirror having a reflective surface formed of a curved surface such as a free-form surface, and has positive focusing power. The projection mirror 34 reflects a plurality of light rays 40 toward the user's eye 60. The plurality of light rays 40 reflected by the projection mirror 34 pass through the pupil 64 of the user's eye 60, converge at a convergence point 46 within the eye 60, and then irradiate the retina 62. The convergence point 46 is located, for example, on or near the crystalline lens 68. The plurality of light rays 40 irradiate the retina 62, allowing the user to view an image.

[0027] FIG. 3 is a diagram showing a light ray 40 in Example 1. As shown in FIG. 3, the light ray 40 emitted by the light source 12 passes through the lens 16. The lens 16 is a condenser lens that converts the light ray 40 from diffuse light to focused light. The diameter of the light ray 40 that passes through the lens 16 is adjusted by the aperture 18. The aperture 18 has an opening that blocks a portion of the light ray 40 and allows the remainder to pass. The opening is fixed to a certain size and has, for example, a substantially circular shape. The diameter of the opening is set so that the diameter of the light ray 40 when it enters the user's cornea 66 falls within a range of 0.36 mm to 0.46 mm. In other words, the diameter of the light ray 40 when it enters the user's cornea 66 falls within a range of ±0.05 mm, with a median value of 0.41 mm, as an actual projection.

[0028] The light beam 40 that passes through the aperture 18 enters the scanning unit 20 in the form of converged light. The multiple light beams 40 that are scanned in two dimensions by the scanning unit 20 and emitted from the scanning unit 20 in different directions at different times are incident on the reflecting mirror 32. Each of the multiple light beams 40 is converged in front of the reflecting mirror 32, then becomes diffused light and enters the reflecting mirror 32. Because the reflecting mirror 32 has a positive focusing power, each of the multiple light beams 40 is converted from diffused light into approximately parallel light by being reflected by the reflecting mirror 32. The lens 16 is provided between the light source 12 and the scanning unit 20 so that the light beams 40 reflected by the reflecting mirror 32 become approximately parallel light.

[0029] The multiple light rays 40 reflected by the reflecting mirror 32 converge at a convergence point 44 in front of the projection mirror 34. A lens 36 is provided at the convergence point 44. The lens 36 is a condenser lens that converts each of the multiple light rays 40 from approximately parallel light into convergent light. Each of the multiple light rays 40 that have passed through the lens 36 is condensed at a convergence point 48 in front of the projection mirror 34, and then becomes diffused light and enters the projection mirror 34.

[0030] Because the projection mirror 34 has a positive focusing power, each of the multiple light rays 40 is converted from diffused light into approximately parallel light by being reflected by the projection mirror 34 and enters the user's eye 60. Therefore, the numerical aperture of each of the multiple light rays 40 when they enter the cornea 66 of the eye 60 is approximately zero. This does not change depending on the user wearing the image projection device 100. The diameter of each of the multiple light rays 40 when they enter the cornea 66 is 0.36 mm to 0.46 mm (0.41 mm ± 0.05 mm). The lens 36 is provided at the convergence point 44 so that each of the multiple light rays 40 reflected by the projection mirror 34 becomes approximately parallel light.

[0031] The multiple light rays 40 converge at a convergence point 46 inside the user's eye 60. Each of the multiple light rays 40 is converted from approximately parallel light into converging light by the crystalline lens 68 and focused near the retina 62. The larger of the horizontal and vertical half angles θ of the angle of view of the range in which the multiple light rays 40 are irradiated onto the retina 62 at the convergence point 46 inside the eye 60 is 10° or more and 30° or less. In other words, the larger of the horizontal and vertical angles between the light ray 40 located at the center of the irradiation range in which the multiple light rays 40 are irradiated onto the retina 62 (corresponding to the light ray 40 corresponding to the center of the projected image projected onto the retina 62) and the light ray 40 located at the edge of the irradiation range (corresponding to the light ray 40 corresponding to the edge of the projected image) is 10° or more and 30° or less. In Example 1, the range over which the multiple light rays 40 are irradiated onto the retina 62 is longer in the horizontal direction than in the vertical direction (for example, an image projection in which the vertical length:horizontal length ratio is 9:16), and the half angle θ of the horizontal field of view is 10° or more and 30°.

[0032] FIG. 4 is a diagram illustrating a method for generating an image in the first embodiment. As shown in FIG. 4, the scanning unit 20 raster-scans the light beam 40 on the retina 62 from the upper left to the lower right as indicated by the arrow 70. As a result, an image 72 is projected onto the retina 62. The range in which the multiple light beams 40 are irradiated onto the retina 62 is longer in the horizontal direction than in the vertical direction, for example, and the image 72 projected onto the retina 62 is a landscape-oriented image with an aspect ratio of 9:16, for example. If the light source 12 does not emit the light beam 40 even when the scanning unit 20 is driven, the light beam 40 is not irradiated onto the retina 62. For example, the light beam 40 is not emitted at the dashed arrow 70 in FIG. 4. The driving circuit 22 synchronizes the emission of the light beam 40 from the light source 12 with the driving of the scanning unit 20. As a result, the light source 12 emits the light beam 40 within a predetermined range (the arrow 70 in the actual drawing) on ​​the retina 62.

[0033] [Simulation 1] In the case where the irradiation range over which a plurality of light rays 40 are irradiated onto the retina 62 is longer in the horizontal direction than in the vertical direction, and the half angle θ of the horizontal angle of view at the convergence point 46 is 30°, a simulation was performed to determine the diameter on the retina 62 of the light rays 40 that are irradiated onto the retina 62 at an angle α (see FIG. 2) relative to the light ray 40 located at the center of the irradiation range. The simulation conditions are as follows. Note that, hereinafter, the diameter of the light ray 40 when it enters the cornea 66 will be referred to as the corneal incidence diameter of the light ray 40, and the diameter of the light ray 40 on the retina 62 will be referred to as the spot diameter of the light ray 40. Simulation conditions: Light 40: White light generated by combining red laser light (wavelength: 640 nm), green laser light (wavelength: 520 nm), and blue laser light (wavelength: 465 nm) Axial length (distance L between the cornea 66 and the retina 62: see Figure 3): 23 mm, 24 mm, 25 mm, 26 mm Corneal entrance diameter for ray 40: 0.25mm, 0.5mm, 1mm, 2mm, 4mm

[0034] Figures 5(a) to 5(d) are graphs showing the results of Simulation 1. In Figures 5(a) to 5(d), the horizontal axis represents the angle α [°], and the vertical axis represents the spot diameter of the light ray 40 [μm]. The thick solid line, solid line, dotted line, dashed-dotted line, and dashed line show the results when the corneal entrance diameter of the light ray 40 is 0.25 mm, 0.5 mm, 1 mm, 2 mm, and 4 mm, respectively. Figure 5(a) shows the results when the axial length is 23 mm, Figure 5(b) shows the results when it is 24 mm, Figure 5(c) shows the results when it is 25 mm, and Figure 5(d) shows the results when it is 26 mm. Note that in Figure 5(d), the thin dashed line shows the case where the corneal entrance diameter of the light ray 40 is 4 mm, and correction is performed so that the spot diameter of the light ray 40 is minimized when the angle α is 0°.

[0035] As shown in Figures 5(a) to 5(d), when the axial length is 23 mm and the corneal entrance diameter of light ray 40 is large, such as 2 mm or 4 mm, the spot diameter of light ray 40 changes significantly when the angle α is 10° or greater. On the other hand, by setting the corneal entrance diameter of light ray 40 to 0.25 mm to 1 mm, the change in the spot diameter of light ray 40 can be kept small when the angle α is in the range of 0° to 30°, regardless of whether the axial length is 23 mm, 24 mm, 25 mm, or 26 mm. Furthermore, even when the axial length is changed to 23 mm, 24 mm, 25 mm, or 26 mm, the change in the spot diameter of light ray 40 when the angle α is 0° can be kept small by setting the corneal entrance diameter of light ray 40 to 0.25 mm to 1 mm. From these facts, it can be said that in FIGS. 5(a) to 5(d), a near field state where the light beam 40 is thin and a far field state where the light beam 40 is thick are mixed together.

[0036] Therefore, the results of Simulation 1 show that by setting the corneal entrance diameter of light ray 40 to 0.25 mm to 1 mm, even if the axial length is different, the spot diameter of light ray 40 itself can be reduced while the amount of change in this diameter can be kept small when the angle α is in the range of 0° to 30°.

[0037] While Figures 5(a) to 5(d) show the case where light beam 40 is white light obtained by combining red, green, and blue laser beams, the following describes the case where light beam 40 is a single-wavelength light beam of red, green, or blue laser beam. Figures 6(a) to 6(c) show the simulation results of the spot diameter of light beam 40 versus angle α when a single-wavelength light beam is used as light beam 40. In Figures 6(a) to 6(c), the horizontal axis represents angle α [°], and the vertical axis represents the spot diameter [μm] of light beam 40. The cases where the corneal incident diameter of light beam 40 is 0.25 mm, 0.5 mm, 1 mm, 2 mm, and 4 mm are shown by the thick solid line, solid line, dotted line, dashed-dotted line, and dashed line, respectively. Figure 6(a) shows the results when the axial length of the eye is 24 mm and red laser light with a wavelength of 640 nm is used as the light ray 40, Figure 6(b) shows the results when the axial length of the eye is 24 mm and green laser light with a wavelength of 520 nm is used as the light ray 40, and Figure 6(c) shows the results when the axial length of the eye is 24 mm and blue laser light with a wavelength of 465 nm is used as the light ray 40.

[0038] 6(a) to 6(c), it can be seen that the change in the spot diameter of the light beam 40 with respect to the angle α exhibits a similar tendency whether a single-wavelength light beam of red laser light, green laser light, or blue laser light is used as the light beam 40 or whether white light obtained by combining red laser light, green laser light, and blue laser light is used as the light beam 40 as shown in FIG. 5(b). It can be seen that the spot diameter of the light beam 40 when white light obtained by combining red laser light, green laser light, and blue laser light is used as the light beam 40 (FIG. 5(b)) corresponds to the largest size of the spot diameter of the light beam 40 when a single-wavelength light beam of red laser light, green laser light, or blue laser light is used as the light beam 40 (FIGS. 6(a) to 6(c)).

[0039] [Simulation 2] From the results of Simulation 1, it was found that the corneal incidence diameter of the light ray 40 is preferably 0.25 mm to 1 mm. Therefore, we simulated the spot diameter of the light ray 40 with respect to the angle α when the corneal incidence diameter of the light ray 40 was finely varied within the range of 0.25 mm to 1 mm. The simulation conditions were as follows: Simulation conditions: Light 40: White light generated by combining red laser light (wavelength: 640 nm), green laser light (wavelength: 520 nm), and blue laser light (wavelength: 465 nm) Eye axis length: 23mm, 24mm, 25mm, 26mm Corneal incidence diameter of ray 40: 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm

[0040] Figures 7(a) to 7(d) are graphs showing the results of Simulation 2. In Figures 7(a) to 7(d), the horizontal axis represents the angle α [°], and the vertical axis represents the spot diameter of light ray 40 [μm]. The thick solid line, solid line, dotted line, dashed-dotted line, and broken line show the results when the corneal entrance diameter of light ray 40 is 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, and 0.7 mm, respectively. Figure 7(a) shows the results when the axial length is 23 mm, Figure 7(b) shows the results when it is 24 mm, Figure 7(c) shows the results when it is 25 mm, and Figure 7(d) shows the results when it is 26 mm.

[0041] 7(a) to 7(d), when the corneal incidence diameter of light ray 40 was 0.3 mm, the change in the spot diameter of light ray 40 was small even when the axial length and angle α were changed, but the spot diameter of light ray 40 itself increased. When the corneal incidence diameter of light ray 40 was 0.7 mm, the change in the spot diameter of light ray 40 due to changes in the axial length and angle α was large, and when the axial length was 26 mm, the spot diameter of light ray 40 was sometimes larger than when the corneal incidence diameter of light ray 40 was 0.3 mm.

[0042] When the axial length was 23 mm (Figure 7(a)), for angles α between 0° and 30°, the spot diameter of light ray 40 was 42 μm to 79 μm when the corneal entrance diameter of light ray 40 was 0.4 mm to 0.6 mm, and 50 μm to 74 μm when it was 0.4 mm to 0.5 mm. When the axial length was 24 mm (Figure 7(b)), for angles α between 0° and 30°, the spot diameter of light ray 40 was 42 μm to 65 μm when the corneal entrance diameter of light ray 40 was 0.4 mm to 0.6 mm, and 52 μm to 65 μm when it was 0.4 mm to 0.5 mm.

[0043] When the axial length was 25 mm (Figure 7(c)), and the angle α was between 0° and 30°, the spot diameter of ray 40 was 44 μm to 66 μm when the corneal entrance diameter of ray 40 was between 0.4 mm and 0.6 mm, and 52 μm to 66 μm when it was between 0.4 mm and 0.5 mm. When the axial length was 26 mm (Figure 7(d)), and the angle α was between 0° and 30°, the spot diameter of ray 40 was 55 μm to 85 μm when the corneal entrance diameter of ray 40 was between 0.4 mm and 0.6 mm, and 55 μm to 78 μm when it was between 0.4 mm and 0.5 mm.

[0044] Therefore, it was found that by setting the corneal incidence diameter of light ray 40 to 0.4 mm to 0.6 mm, the spot diameter of light ray 40 becomes 42 μm to 85 μm when the axial length is 23 mm to 26 mm and the angle α is 0° to 30°. Also, it was found that by setting the corneal incidence diameter of light ray 40 to 0.4 mm to 0.5 mm, the spot diameter of light ray 40 becomes 42 μm to 78 μm when the axial length is 23 mm to 26 mm and the angle α is 0° to 30°.

[0045] Here, the simulation results of the spot diameter of the light ray 40 relative to the corneal incidence diameter of the light ray 40 are shown. The simulation conditions are as follows. Simulation conditions: Light 40: White light generated by combining red laser light (wavelength: 640 nm), green laser light (wavelength: 520 nm), and blue laser light (wavelength: 465 nm) Eye axis length: 24mm

[0046] FIG. 8 is a graph showing the simulation results of the spot diameter of the light ray 40 versus the corneal incidence diameter of the light ray 40. In FIG. 8, the horizontal axis represents the corneal incidence diameter of the light ray 40 [mm], and the vertical axis represents the spot diameter of the light ray 40 [μm]. FIG. 8 shows the spot diameter of the light ray 40 when the corneal incidence diameter of the light ray 40 is 3 mm to 7 mm. A corneal incidence diameter of the light ray 40 of 3 mm to 7 mm corresponds to the case where light passes through the pupil 64 and is irradiated onto the retina 62 in natural vision. In particular, a diameter of approximately 7 mm corresponds to the case where light passes through the pupil 64 and is irradiated onto the retina 62 in a dark place. As the corneal incidence diameter of the light ray 40 increases, the chromatic aberration on the retina 62 increases, and therefore the far-field state becomes dominant with respect to the spot diameter of the light ray 40. When the corneal incidence diameter of the light ray 40 is 7 mm, the spot diameter of the light ray 40 is approximately 85 μm. The spot diameter of the light beam 40 is approximately the same when a broadband light source is used.

[0047] Therefore, considering the diameter of light when it is irradiated onto the retina 62 in natural vision, it is preferable to keep the spot diameter of the light ray 40 to 85 μm or less, regardless of the axial length of the eye and the position on the retina 62. From the results of Simulation 2 above, the spot diameter of the light ray 40 can be set to 42 μm to 85 μm by setting the corneal incidence diameter of the light ray 40 to 0.4 mm to 0.6 mm. Furthermore, the spot diameter of the light ray 40 can be set to 42 μm to 78 μm by setting the corneal incidence diameter of the light ray 40 to 0.4 mm to 0.5 mm.

[0048] A large variation in the spot diameter of light ray 40 with respect to a change in angle α is undesirable in terms of the user perceiving a uniform resolution for the projected image. It is preferable to keep the change in the energy density of light ray 40 on retina 62 to 3 dB or less, and the change in the spot diameter of light ray 40 to 1.5 dB or less.

[0049] The results of Simulation 2 above show that the corneal incidence diameter of light ray 40 is preferably around 0.4 mm in order to keep the spot diameter of light ray 40 at 85 μm or less and to keep the variation in the spot diameter of light ray 40 relative to changes in axial length and angle α small.

[0050] [Simulation 3] As described in Simulation 2 above, it was found that the corneal incidence diameter of light ray 40 is preferably around 0.4 mm. When the corneal incidence diameter of light ray 40 is 0.4 mm, the spot diameter of light ray 40 is approximately 65 μm when the axial length is 24 mm and the angle α is 0°. Using this spot diameter of light ray 40 as a reference, in order for the variation in the spot diameter of light ray 40 to be 1.5 dB or less, in other words, ±0.75 dB or less, the spot diameter of light ray 40 needs to be between 55 μm and 77 μm. Therefore, we simulated the spot diameter of light ray 40 versus the angle α when the corneal incidence diameter of light ray 40 was finely varied around 0.4 mm. The simulation conditions were as follows: Simulation conditions: Light 40: White light generated by combining red laser light (wavelength: 640 nm), green laser light (wavelength: 520 nm), and blue laser light (wavelength: 465 nm) Eye axis length: 23mm, 26mm Corneal incident diameter of ray 40: 0.34mm, 0.36mm, 0.38mm, 0.4mm, 0.42mm, 0.44mm, 0.46mm

[0051] Figures 9(a) and 9(b) are graphs showing the results of Simulation 3. Tables 1 and 2 are tables showing the results of Simulation 3. In Figures 9(a) and 9(b), the horizontal axis represents the angle α [°], and the vertical axis represents the spot diameter of light ray 40 [μm]. The cases where the corneal entrance diameter of light ray 40 is 0.34 mm, 0.36 mm, 0.38 mm, 0.4 mm, 0.42 mm, 0.44 mm, and 0.46 mm are shown by a thick solid line, a solid line, a dotted line, a thick dashed line, a thick broken line, a broken line, and a dashed line, respectively. Figure 9(a) and Table 1 show the results when the axial length is 23 mm, and Figure 9(b) and Table 2 show the results when the axial length is 26 mm. [Table 1] [Table 2]

[0052] As shown in Figures 9(a) and 9(b) and Tables 1 and 2, when the corneal entrance diameter of light ray 40 is 0.34 mm, the spot diameter of light ray 40 is 79.96 μm when the axial length is 26 mm, which falls outside the range of 55 μm to 77 μm for the spot diameter of light ray 40. When the corneal entrance diameter of light ray 40 is 0.46 mm, the change in the spot diameter of light ray 40 is greatest, with the minimum spot diameter being 55.16 μm and the maximum spot diameter being 75.616 μm, and the change amount is 1.37 dB.

[0053] 9(a), 9(b) and Tables 1 and 2, it can be seen that the corneal incidence diameter of light beam 40 is preferably 0.36 mm to 0.46 mm (0.41 mm ± 0.05 mm) in order to keep the spot diameter of light beam 40 within the range of 55 μm to 77 μm. In order to reduce the variation in the spot diameter of light beam 40, it can be seen that the corneal incidence diameter of light beam 40 is preferably 0.36 mm to 0.44 mm, more preferably 0.38 mm to 0.44 mm, and even more preferably 0.38 mm to 0.42 mm.

[0054] As described above, according to the first embodiment, when the half angle θ of the larger of the horizontal and vertical angles of view within the range where the multiple light rays 40 at the convergence point 46 in the eye 60 are irradiated onto the retina 62 is 10° or more and 30° or less, the corneal entrance diameter of the multiple light rays 40 is set to 0.36 mm or more and 0.46 mm or less. As a result, even if the user's axial length (visual acuity) is different, the amount of change in the spot diameter of the multiple light rays 40 within the range where the multiple light rays 40 are irradiated onto the retina 62 is kept small, and the spot diameter of the multiple light rays 40 can be kept within the range of 55 μm or more and 77 μm or less. Therefore, the user can perceive a uniform resolution from the image projected onto the retina 62.

[0055] In the first embodiment, the half angle θ of the larger of the horizontal and vertical angles of view of the range in which the plurality of light beams 40 at the convergence point 46 in the eye 60 irradiate the retina 62 is 10° or more and 30° or less. However, when the half angle θ of the angle of view is 10° or more and the spot diameter of the plurality of light beams 40 is 55 μm or more and 77 μm or less, the upper limit of the half angle θ of the angle of view may be greater than 30°.

[0056] Furthermore, according to the first embodiment, the numerical aperture when the multiple light beams 40 are incident on the user's cornea 66 is approximately zero regardless of the user. As a result, by setting the corneal incidence diameter of the multiple light beams 40 to 0.36 mm or more and 0.46 mm or less, the spot diameter of the multiple light beams 40 can be kept within the range of 55 μm or more and 77 μm or less. "Approximately zero" means -0.0005 or more and +0.0005 or less.

[0057] Furthermore, according to the first embodiment, the plurality of light beams 40 are monochromatic light beams of red laser light, green laser light, or blue laser light, or multiplexed light beams obtained by multiplexing at least two of red laser light, green laser light, and blue laser light. In this case, by setting the diameter of the plurality of light beams 40 when incident on the cornea 66 to 0.36 mm or more and 0.46 mm or less, the spot diameter of the plurality of light beams 40 can be within the range of 55 μm or more and 77 μm or less.

[0058] In Example 1, the corneal incidence diameter of the plurality of light beams 40 is preferably 0.38 mm or more and 0.44 mm or less in order to suppress variations in the spot diameter of the plurality of light beams 40. In this case, the corneal incidence diameter of the plurality of light beams 40 is actually projected within a range of ±0.03 mm with 0.41 mm as the median.

[0059] In Example 1, the image projection device 100 is attached to an eyeglass-type frame 42, but as long as this frame can be worn on the user's face and the image projection device 100 can be placed in front of the user's eyes, it is not limited to eyeglass-type, and may be goggle-type, eye patch-type, ear hook-type, helmet-mounted type, or other types. [Example]

[0060] FIG. 10 is a block diagram of a visual inspection apparatus 200 according to a second embodiment. As shown in FIG. 10, the visual inspection apparatus 200 differs from FIG. 1 of the first embodiment in that the control unit 50 includes a signal processing unit 54 and an image generation unit 56 in addition to the image control unit 52. The image control unit 52 generates an image for inspection to be projected onto the subject's retina 62. The signal processing unit 54 processes a response signal from the input unit 80 based on a control signal from the image control unit 52. The input unit 80 is a device through which the subject inputs a response signal during the visual inspection, and is, for example, a button, but may be other devices. The image generation unit 56 generates an inspection result image based on the signal processed by the signal processing unit 54. The display unit 82 displays the inspection result image. The display unit 82 is, for example, a liquid crystal display.

[0061] The image control unit 52, the signal processing unit 54, and the image generation unit 56 may be processed by a processor such as a CPU working in cooperation with a program. The image control unit 52, the signal processing unit 54, and the image generation unit 56 may be circuits designed specifically for them. The image control unit 52, the signal processing unit 54, and the image generation unit 56 may be a single circuit or different circuits.

[0062] FIG. 11 is a diagram showing the optical system of a visual inspection device 200 according to a second embodiment. As shown in FIG. 11, the visual inspection device 200 projects an image for inspection onto a retina 62 using Maxwell's vision. A light beam 40 emitted by a light source 12 is converted from diffused light into substantially parallel light by a lens 16. The diameter of the light beam 40 that has passed through the lens 16 is adjusted by an aperture 18. The light beam 40 that has passed through the aperture 18 is reflected by a plane mirror 26 and enters the scanning unit 20.

[0063] The plurality of light beams 40 scanned in two dimensions by the scanning unit 20 and emitted in different directions from the scanning unit 20 at different times are incident on the irradiation optical system 30. The irradiation optical system 30 includes a lens 38 and a lens 39. The plurality of light beams 40 are incident on the subject's eye 60 via the lens 38 and the lens 39. The lens 38 is, for example, a condensing lens. The plurality of light beams 40 become approximately parallel to each other by the lens 38, and each of the plurality of light beams 40 is converted from approximately parallel light to convergent light by the lens 38. Each of the plurality of light beams 40 is condensed in front of the lens 39, becomes diffused light, and enters the lens 39. The lens 39 is, for example, a condensing lens. Each of the plurality of light beams 40 is converted from diffused light to approximately parallel light by the lens 39 and enters the subject's eye 60. Therefore, the numerical aperture of each of the plurality of light beams 40 when it enters the cornea 66 is approximately zero. This does not change depending on the subject using the visual inspection device 200. The diameter of the multiple light beams 40 when they are incident on the cornea 66 is 0.36 mm to 0.46 mm (0.41 mm ± 0.05 mm), the same as in Example 1. The multiple light beams 40 converge at a convergence point 46 in the subject's eye 60. The convergence point 46 is located, for example, on the crystalline lens 68 or near the crystalline lens 68. Each of the multiple light beams 40 is converted from parallel light into convergent light by the crystalline lens 68 and focused near the retina 62. The half angle θ of the larger of the horizontal and vertical angles of view of the range in which the multiple light beams 40 are irradiated onto the retina 62 at the convergence point 46 in the eye 60 is 10° or more and 30° or less, the same as in Example 1. The range in which the multiple light beams 40 are irradiated onto the retina 62 is the area onto which a test image for testing the subject's visual function is projected.

[0064] FIG. 12 is a flowchart illustrating an example of an inspection method of the visual inspection device 200 according to the second embodiment. FIGS. 13(a) to 13(c) are diagrams illustrating an inspection image 72 projected onto the retina 62 in the flowchart of FIG. 12. As shown in FIG. 12, the image control unit 52 emits a light beam 40 from the light source 12 to project an inspection image 72 including an inspection target 74 onto the retina 62 (step S10). The light beam 40 is a monochromatic light beam, such as a red laser beam, a green laser beam, or a blue laser beam, or a combined light beam obtained by combining at least two light beams, such as a red laser beam, a green laser beam, and a blue laser beam. In step S10, as shown in FIG. 13(a), the inspection image 72 including the inspection target 74 is projected onto the retina 62 in an area 75a. In this second embodiment, the area 75 is defined as an area onto which the retina 62 is irradiated with a single light beam 40. Note that the area 75 may be an area onto which multiple light beams 40 are irradiated. Although not shown, the test image 72 may include a fixation target to which the subject should direct their gaze.

[0065] Next, the signal processing unit 54 acquires a response signal from the input unit 80 (step S12). When the subject detects that the test optotype 74 has been projected onto the area 75a, the subject operates the input unit 80. Therefore, when the subject detects the test optotype 74, the signal processing unit 54 can acquire a response signal from the input unit 80, and when the test optotype 74 cannot be detected, the signal processing unit 54 cannot acquire a response signal from the input unit 80.

[0066] After a predetermined time has elapsed since the projection of the test image 72 in step S10, the image control unit 52 determines whether or not this is the last region (step S14). For example, if the test of all of the regions 75 to be tested in the retina 62 has been completed, the result is Yes. If the result is No, the image control unit 52 changes the region 75 onto which the test target 74 is projected (step S16) and returns to step S10. Steps S10 to S16 are repeated until the result is Yes in step S14. FIG. 13(b) shows a case where the region onto which the test target 74 is projected has been changed to region 75b, and FIG. 13(c) shows a case where it has been changed to region 75c.

[0067] If the determination in step S14 is Yes, the image generator 56 generates an image of the visual function test result (e.g., an image of visual field defect) based on the response signal from the input unit 80 in each region 75 of the signal processor 54 (step S18). The display unit 82 displays the test result image (step S20).

[0068] According to the second embodiment, as in the first embodiment, when the half angle θ of the larger of the horizontal and vertical angles of view within the range where the multiple light beams 40 are irradiated onto the retina 62 at the convergence point 46 within the eye 60 is 10° or more and 30° or less, the corneal entrance diameter of the multiple light beams 40 is set to 0.36 mm or more and 0.46 mm or less. As a result, even if the axial lengths (visual acuity) of the subjects are different, the amount of change in the spot diameter of the multiple light beams 40 within the range where the multiple light beams 40 are irradiated onto the retina 62 is kept small, and the spot diameter of the multiple light beams 40 can be kept within the range of 55 μm or more and 77 μm or less. Therefore, a visual function test can be performed under the same conditions over a wide range of the retina 62 for subjects with different axial lengths, thereby improving the accuracy of the visual function test.

[0069] In the second embodiment, the case was shown in which the larger of the horizontal and vertical half angles of view θ of the range in which the plurality of light beams 40 at the convergence point 46 in the eye 60 irradiate the retina 62 is 10° or more and 30° or less. However, as in the first embodiment, when the half angle of view θ is 10° or more and the spot diameter of the plurality of light beams 40 is 55 μm or more and 77 μm or less, the upper limit of the half angle of view θ may be greater than 30°.

[0070] 13(a) to 13(c) is an area where one light beam 40 is irradiated onto the retina 62. Therefore, the subject responds to each of the multiple light beams 40 that are sequentially irradiated onto the retina 62 by operating the input unit 80. Since the spot diameters of the multiple light beams 40 are within a predetermined range, the accuracy of the visual function test in which the subject responds to each of the multiple light beams 40 is improved.

[0071] Furthermore, according to the second embodiment, the multiple light beams 40 are monochromatic light beams of red laser light, green laser light, or blue laser light, or multiplexed light beams obtained by multiplexing at least two light beams of red laser light, green laser light, and blue laser light. In this case, as shown in the first embodiment, by setting the diameter of the multiple light beams 40 when incident on the cornea 66 to be 0.36 mm or more and 0.46 mm or less, the spot diameter of the multiple light beams 40 can be set within the range of 55 μm or more and 77 μm or less. By setting the spot diameter of the multiple light beams 40 within this range, the accuracy of the visual function test is improved.

[0072] Also in Example 2, similarly to Example 1, the numerical aperture when the multiple light beams 40 are incident on the cornea 66 of the subject is approximately zero regardless of the subject. As a result, by setting the corneal incidence diameter of the multiple light beams 40 to 0.36 mm or more and 0.46 mm or less, the spot diameter of the multiple light beams 40 can be within the range of 55 μm or more and 77 μm or less.

[0073] In Example 2, similarly to Example 1, in order to suppress variations in the spot diameter of the plurality of light beams 40, the corneal incidence diameter of the plurality of light beams 40 is preferably 0.38 mm or more and 0.44 mm or less (0.41 mm±0.03 mm). [Example]

[0074] FIG. 14 is a block diagram of a fundus imaging device 300 according to a third embodiment. As shown in FIG. 14, in the fundus imaging device 300, similar to the second embodiment, the control unit 50 includes a signal processing unit 54 and an image generation unit 56 in addition to the image control unit 52. The image control unit 52 generates an examination image to be projected onto the subject's retina 62. The signal processing unit 54 processes an output signal from a photodetector 84 based on a control signal from the image control unit 52. The photodetector 84 detects light rays 40 reflected by the retina 62. The photodetector 84 includes an imaging element such as a CMOS image sensor or a CCD image sensor. The image generation unit 56 generates a fundus image based on a signal obtained by processing the output signal from the photodetector 84 by the signal processing unit 54. The display unit 82 displays the fundus image.

[0075] FIG. 15 is a diagram showing the optical system of a fundus imaging device 300 according to Example 3. As shown in FIG. 15, the fundus imaging device 300, like Example 2, irradiates a retina 62 with a light beam 40 using Maxwellian vision. A half mirror 28 is provided on the optical path of the light beam 40 between the aperture 18 and the plane mirror 26. The light beam 40 reflected by the retina 62 passes through a lens 39, a lens 38, a scanning unit 20, and the plane mirror 26 and is incident on the half mirror 28, where it is reflected and incident on the photodetector 84. The other configurations are the same as those shown in FIG. 11 of Example 2, and therefore a description thereof will be omitted. In Example 3, the numerical aperture of each of the multiple light beams 40 when they enter the cornea 66 is approximately zero. This does not change depending on the subject using the fundus imaging device 300. The diameter of the multiple light beams 40 when they enter the cornea 66 is 0.36 mm to 0.46 mm (0.41 mm ± 0.05 mm). The half angle θ of the larger of the horizontal and vertical angles of view of the range in which the multiple light rays 40 at the convergence point 46 in the eye 60 are irradiated onto the retina 62 is 10° or more and 30° or less, as in Example 1.

[0076] FIG. 16 is a flowchart showing an example of an examination method for the fundus imaging device 300 according to the third embodiment. As shown in FIG. 16, the image control unit 52 causes the light source 12 to emit a light beam 40 for fundus imaging and irradiate the light beam 40 onto the retina 62 (step S30). The light beam 40 for fundus imaging is monochromatic light of red laser light, green laser light, and blue laser light, or a combined light obtained by combining at least two light beams of red laser light, green laser light, and blue laser light. The light beam 40 may be invisible light such as infrared laser light. The light beam 40 is raster-scanned over the retina 62 from the upper left to the lower right, and is irradiated onto the retina 62. The light beam 40 reflected by the retina 62 is incident on the photodetector 84, as described with reference to FIG. 15.

[0077] The signal processing unit 54 acquires the output signal of the photodetector 84 (step S32). The image generating unit 56 generates a fundus image based on the signal obtained by processing the output signal of the photodetector 84 by the signal processing unit 54 (step S34). The display unit 82 displays the fundus image generated by the image generating unit 56 (step S36).

[0078] According to the third embodiment, as in the first embodiment, when the half angle θ of the larger of the horizontal and vertical angles of view within the range where the plurality of light rays 40 at the convergence point 46 in the eye 60 are irradiated onto the retina 62 is 10° or more and 30° or less, the corneal entrance diameter of the plurality of light rays 40 is set to 0.36 mm or more and 0.46 mm or less. As a result, even if the axial lengths (visual acuity) of the subjects are different, the amount of change in the spot diameter of the plurality of light rays 40 within the range where the plurality of light rays 40 are irradiated onto the retina 62 is kept small, and the spot diameter of the plurality of light rays 40 can be kept within the range of 55 μm or more and 77 μm or less. Therefore, fundus images captured under the same conditions over a wide range of the retina 62 can be obtained for subjects with different axial lengths.

[0079] In the third embodiment, the case was shown in which the larger of the horizontal and vertical half angles of view θ of the range in which the plurality of light beams 40 at the convergence point 46 inside the eye 60 irradiate the retina 62 is 10° or more and 30° or less. However, as in the first embodiment, when the half angle of view θ is 10° or more and the spot diameter of the plurality of light beams 40 is 55 μm or more and 77 μm or less, the upper limit of the half angle of view θ may be greater than 30°.

[0080] According to the third embodiment, the light beams 40 are monochromatic light beams of red, green, or blue laser light, or a combined light beam obtained by combining at least two of red, green, and blue laser light beams. In this case, as shown in the first embodiment, by setting the diameter of the light beams 40 incident on the cornea 66 to 0.36 mm or more and 0.46 mm or less, the spot diameter of the light beams 40 can be set within the range of 55 μm or more and 77 μm or less. By setting the spot diameter of the light beams 40 within this range, the accuracy of the fundus image can be improved.

[0081] Also in Example 3, similarly to Example 1, the numerical aperture when the multiple light beams 40 are incident on the cornea 66 of the subject is approximately zero regardless of the subject. As a result, by setting the corneal incidence diameter of the multiple light beams 40 to 0.36 mm or more and 0.46 mm or less, the spot diameter of the multiple light beams 40 can be within the range of 55 μm or more and 77 μm or less.

[0082] In Example 3, similarly to Example 1, in order to suppress variations in the spot diameter of the multiple light beams 40, the corneal incidence diameter of the multiple light beams 40 is preferably 0.38 mm or more and 0.44 mm or less (0.41 mm±0.03 mm).

[0083] In the above-described Examples 1 to 3, the half angle θ of the larger of the horizontal and vertical angles of view of the range in which the multiple light beams 40 at the convergence point 46 in the eye 60 irradiate the retina 62 is between 10° and 30°. However, as shown in FIG. 5( a), since the spot diameter of the light beams 40 tends to vary more as the angle α increases, it is preferable that the corneal entrance diameter of the multiple light beams 40 be between 0.36 mm and 0.46 mm when the larger of the horizontal and vertical half angles of view θ is 15° or greater. It is more preferable that the corneal entrance diameter of the multiple light beams 40 be between 0.36 mm and 0.46 mm when the half angle of view θ is 20° or greater. It is even more preferable that the corneal entrance diameter of the multiple light beams 40 be between 0.36 mm and 0.46 mm when the half angle of view θ is 25° or greater.

[0084] In the above-described first to third embodiments, the range where the plurality of light rays 40 are irradiated onto the retina 62 is a rectangle whose horizontal length is longer than its vertical length, but it may also be a rectangle whose vertical length is longer than its horizontal length, or may be a circle, an ellipse, etc. When the range where the plurality of light rays 40 are irradiated onto the retina 62 is a circle, the half angle θ of the larger of the horizontal and vertical angles of view is the half angle of the angle of view at the diameter, and when it is an ellipse, it is the half angle of the angle of view at the major axis.

[0085] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications and variations are possible within the scope of the gist of the present invention as defined in the claims. [Explanation of symbols]

[0086] 10 Projection section 12 light source 14 Adjustment section 16 Lenses 18 aperture 20 Scanning unit 22 Drive circuit 24 Input circuit 26 Plane mirror 28 Half Mirror 30 Irradiation optical system 32 Reflective mirror 34 Projection mirror 36, 38, 39 lenses 40 rays 42 Glasses-type frame 44, 46 Convergence point 50 control section 52 Image control unit 54 Signal Processing Section 56 Image generation unit 60 eyes 62 Retina 64 Pupil 66 Cornea 68 Crystalline Lens 72 images 74 Test Targets 75~75c area 80 Input section 82 Display section 84 Photodetector 100 Image projection device 200 Visual inspection equipment 300 Fundus photography device

Claims

1. A light source and a scanning unit that scans the light beam emitted from the light source; an optical system that converges the plurality of light beams emitted from the scanning unit at different times at a convergence point in the eye of a user and then irradiates the light beams onto the retina of the user to project an image, An image projection device in which the diameter of the multiple light beams incident on the user's cornea is within 0.41 mm ± 0.05 mm, the angle between the light beam located at the center of the projection range of the multiple light beams projected onto the retina and the light beam located at the edge of the projection range is within a range of 30 degrees, and the diameter of the multiple light beams on the retina is 55 μm or more and 77 μm or less.

2. A light source; a scanning unit that scans the light beam emitted from the light source; an optical system that converges the plurality of light beams emitted from the scanning unit at different times at a convergence point in the eye of a user and then irradiates the light beams onto the retina of the user to project an image, An image projection device in which the diameter of the multiple light beams incident on the user's cornea is within 0.41 mm ± 0.05 mm, the angle between the light beam located at the center of the projection range of the multiple light beams projected onto the retina and the light beam located at the edge of the projection range is within a range of 30 degrees, and the difference between the maximum and minimum diameters of the multiple light beams on the retina is 22 μm or less.

3. A light source and a scanning unit that scans the light beam emitted from the light source; an optical system that converges the plurality of light beams emitted from the scanning unit at different times at a convergence point in the eye of the subject and then irradiates the retina of the subject; an input unit into which a response of the subject to the plurality of light beams irradiated onto the retina is input, A visual inspection device wherein the diameter of the plurality of light rays incident on the subject's cornea is within 0.41 mm ± 0.05 mm, the angle between the light ray located at the center of the projection range of the plurality of light rays projected onto the retina and the light ray located at the edge of the projection range is within a range of 30 degrees, and the diameter of the plurality of light rays on the retina is 55 μm or more and 77 μm or less.

4. A light source; a scanning unit that scans the light beam emitted from the light source; an optical system that converges the plurality of light beams emitted from the scanning unit at different times at a convergence point in the eye of the subject and then irradiates the retina of the subject; an input unit into which a response of the subject to the plurality of light beams irradiated onto the retina is input, A visual inspection device wherein the diameters of the plurality of light rays incident on the cornea of ​​the subject are within 0.41 mm ± 0.05 mm, the angle between the light ray located at the center of the projection range of the plurality of light rays projected onto the retina and the light ray located at the edge of the projection range is within a range of 30 degrees, and the difference between the maximum and minimum diameters of the plurality of light rays on the retina is 22 μm or less.

5. 5. The visual inspection device according to claim 3, wherein the subject responds to each of the plurality of light beams that are sequentially irradiated onto the retina by operating the input unit.

6. A light source and a scanning unit that scans the light beam emitted from the light source; an optical system that converges the plurality of light beams emitted from the scanning unit at different times at a convergence point in the eye of the subject and then irradiates the retina of the subject; a detector for detecting the plurality of light rays reflected from the retina; an acquisition unit that acquires a fundus image of the subject from the plurality of light rays detected by the detector, A fundus photography device in which the diameter of the multiple light rays incident on the subject's cornea is within 0.41 mm ± 0.05 mm, the angle between the light ray located at the center of the projection range of the multiple light rays projected onto the retina and the light ray located at the edge of the projection range is within a range of 30 degrees, and the diameter of the multiple light rays on the retina is 55 μm or more and 77 μm or less.

7. A light source; a scanning unit that scans the light beam emitted from the light source; an optical system that converges the plurality of light beams emitted from the scanning unit at different times at a convergence point in the eye of the subject and then irradiates the retina of the subject; a detector for detecting the plurality of light rays reflected from the retina; an acquisition unit that acquires a fundus image of the subject from the plurality of light rays detected by the detector, A fundus photography device in which the diameters of the multiple light rays incident on the subject's cornea are within 0.41 mm ± 0.05 mm, the angle between the light ray located at the center of the projection range of the multiple light rays projected onto the retina and the light ray located at the edge of the projection range is within a range of 30 degrees, and the difference between the maximum and minimum diameters of the multiple light rays on the retina is 22 μm or less.

Images