JP2021153710A - Visual function inspection unit - Google Patents

Abstract

To improve uniformity of brightness of a background image.SOLUTION: A visual function inspection unit comprises: a first light source for emitting laser beam for projecting an inspection target for inspecting a visual function onto a retina of a subject; a second light source for emitting background light for projecting a background image being a background of the inspection target onto the retina of the subject; a scanning part for scanning two-dimensionally, the laser beam emitted from the first light source; a first optical component being arranged on a front side of an eye of the subject for reflecting a plurality of laser beams emitted from the scanning part at different times, converging the plurality of laser beams at a first convergent point in an eye of the subject and then radiating the plurality of laser beams to the retina of the subject; and a second optical component for reflecting the plurality of laser beams reflected in different directions from the scanning part and converging the plurality of laser beams at a second convergent point on the first light source side, and then radiating the plurality of laser beams to the first optical component. The background light emitted from the second light source is reflected on the second optical component, and then reflected on the first optical component and is radiated to the retina of the subject.SELECTED DRAWING: Figure 2

Description

The present invention relates to a visual function test device.

There is a visual field test device as a visual function test device for inspecting the visual function of a subject. This inspection device inspects the visual field of a subject by projecting stimulating light on a projection screen and visually recognizing the projected stimulating light. As such a device, a device that projects a uniform background light onto a projection screen in order to enhance the visibility of the stimulating light is known (for example, Patent Document 1). Further, as a visual field inspection device, there is also known a device that directly projects an index for inspection onto the retina by Maxwell vision instead of a projection screen (for example, Patent Document 2).

Special Table 2004-528943 JP-A-2017-221657

In a visual field inspection device that directly projects stimulating light onto the retina, when a two-dimensionally scanned laser beam is projected onto the retina, the stimulating light (target) and background light can be shared by the projected laser beam. In this case, when the background image is projected by the laser beam scanned in two dimensions, the background image having a uniform brightness is projected due to the difference in scanning speed between the central portion and the edge portion of the background image. Is difficult. In addition, in order to improve the accuracy of inspection, it is necessary to make a difference between the amount of stimulus light (target) and the amount of background light, and the stimulus light requires laser light intensity modulation with an extremely wide dynamic range. Become.

The present invention has been made in view of the above problems, and an object of the present invention is to improve the uniformity of brightness of a background image.

The present invention uses a first light source that emits a laser beam for projecting an inspection target for inspecting visual function onto the retina of the subject, and a background image that serves as a background for the inspection target. A second light source that emits background light for projecting onto the retina, a scanning unit that scans the laser light emitted from the first light source in two dimensions, and a scanning unit that is arranged in front of the subject's eye. The plurality of laser beams emitted from the scanning unit at different times are reflected and converged at the first convergence point in the subject's eye, and then the plurality of laser beams are irradiated to the subject's retina. The first optical component to be caused and the plurality of laser beams reflected in different directions from the scanning unit are reflected and converged at the second convergence point on the first light source side of the first optical component, and then the plurality of laser lights are converged. A second optical component that irradiates the first optical component with laser light is provided, and the background light emitted from the second light source is reflected by the first optical component after being reflected by the second optical component. It is a visual function test device that is irradiated to the retina of the subject.

In the above configuration, the laser beam scanned by the scanning unit and the background light emitted from the second light source include a half mirror arranged between the scanning unit and the second optical component. The structure is such that the half mirror is transmitted or reflected to enter the second optical component, is reflected by the second optical component, and then is reflected by the first optical component to irradiate the subject's retina. Can be done.

In the above configuration, the second light source may be arranged at a position substantially symmetrical to the scanning portion with respect to the half mirror.

In the above configuration, the background light is converted into convergent light by the second optical component, condensed at the first condensing point in front of the first optical component, and then becomes diffused light to the first optical component. It is configured to be incident, converted into focused light by the first optical component, focused at the second focusing point in the subject's eye, and then converted into diffused light to be irradiated to the subject's retina. can do.

In the above configuration, the angle at which the background light is focused on the second focusing point is greater than or equal to the angle at which the plurality of laser beams emitted from the scanning unit at different times converge on the first focusing point. Can be configured to be.

The present invention uses a first light source that emits a laser beam for projecting an inspection target for inspecting visual function onto the retina of the subject, and a background image that serves as a background for the inspection target. A second light source that emits background light for projecting onto the retina, a scanning unit that scans the laser light emitted from the first light source in two dimensions, and a scanning unit that is arranged in front of the subject's eye. The plurality of laser beams emitted from the scanning unit at different times are reflected and converged at the first convergence point in the subject's eye, and then the plurality of laser beams are irradiated to the subject's retina. The first optical component and the plurality of laser beams reflected in different directions from the scanning unit are reflected and converged at the second convergence point on the first light source side of the first optical component, and then the plurality of laser beams are converged. A second optical component that emits laser light to the first optical component is provided, and the background light emitted from the second light source passes through the first optical component and irradiates the subject's retina. It is a visual function test device.

In the above configuration, it is arranged between the first optical component and the second light source arranged on the side opposite to the eye of the subject with respect to the first optical component, and from the second light source. The configuration may include a lens that converts the emitted background light into convergent light or substantially parallel light that is focused in the eyes of the subject.

In the above configuration, between the plurality of second light sources arranged on the side opposite to the eyes of the subject with respect to the first optical component, the plurality of second light sources, and the first optical component. It can be configured to include a lens diffuser that is arranged and a plurality of lenses are randomly provided on the surface.

In the above configuration, the second light source may be an LED light source.

In the above configuration, in the laser beam, the ratio of the optical path length between the second optical component and the second convergence point to the optical path length between the scanning unit and the second optical component is the ratio between the first optical component and the second optical component. The configuration may be substantially the same as the ratio of the optical path length between the second convergence point and the first optical component to the optical path length between the first convergence points.

According to the present invention, by separating the optotype light source and the background light light source, the uniformity of the brightness of the background image is improved without preparing a light source having a large dynamic range, which is technically difficult to configure. Can be made to.

FIG. 1 is a block diagram showing a visual function test apparatus according to the first embodiment. FIG. 2 is a diagram showing an optical system of the visual function test apparatus according to the first embodiment. FIG. 3 is a diagram illustrating a laser beam between the scanning portion and the retina. 4 (a) to 4 (c) are diagrams showing an example of the distribution of laser light emitted from the scanning unit at different times. FIG. 5 is an enlarged view of the projection optical system of FIG. FIG. 6 is a diagram illustrating an image projected on the retina. FIG. 7 is a flowchart showing an example of the visual function test. 8 (a) to 8 (c) are diagrams illustrating an image projected on the retina in the flowchart of FIG. 7. FIG. 9 is a diagram showing an optical system of a visual function test device according to a comparative example. FIG. 10 is a diagram showing an optical system of the visual function test apparatus according to the second embodiment. FIG. 11 is a diagram showing an optical system of the visual function test apparatus according to the third embodiment.

Hereinafter, examples of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing a visual function test apparatus according to the first embodiment. With reference to FIG. 1, the visual function test device 100 of the first embodiment includes a projection unit 10, a control unit 40, an input unit 50, and a display unit 51. The projection unit 10 includes a light source 11, a light source 12, an adjustment unit 13, an adjustment unit 14, a scanning unit 15, a projection optical system 16, a drive circuit 17, and an input circuit 18. The control unit 40 includes an image control unit 41, a signal processing unit 42, and an image creation unit 43.

The image control unit 41 generates an image to be projected on the retina of the subject. An image signal is input to the input circuit 18 from the image control unit 41. The drive circuit 17 drives the light sources 11 and 12 and the scanning unit 15 based on the image signal acquired by the input circuit 18 and the control signal of the image control unit 41.

The light source 11 is a laser diode (LD) light source that emits laser light, and is, for example, a red laser light (wavelength: about 610 nm to 660 nm), a green laser light (wavelength: about 515 nm to 540 nm), and a blue laser light (wavelength: about 540 nm). 440 nm to 480 nm) is emitted. Examples of the light source 11 that emits red, green, and blue laser light include a light source in which an RGB (red, green, and blue) laser diode chip, a three-color synthesis device, and a microcollimating lens are integrated. The light source 11 is one light source and may emit a laser beam having a single wavelength.

The light source 12 is, for example, a light emitting diode (LED) light source, and can emit white LED light or pseudo white LED light. For example, the light source 12 may be a light source having RGB (red, green, blue) LED chips, a light source having a B (blue) LED chip and a yellow phosphor, or a near-ultraviolet light source. A light source including an LED chip and red, green, and blue phosphors may be used, or a light source having other configurations may be used.

The adjusting unit 13 has, for example, a collimating lens, a toric lens, and / or an aperture, and forms a laser beam 60 emitted from the light source 11. The scanning unit 15 (scanner) is, for example, a scanning mirror such as a MEMS (Micro Electro Mechanical System) mirror or a transmissive scanner, and scans the laser beam 60 in a two-dimensional direction. The adjusting unit 14 has, for example, an aperture or the like, and forms the LED light 61 emitted from the light source 12. The projection optical system 16 irradiates the subject's eye 70 with the scanned laser beam 60 and the molded LED light 61.

The input unit 50 is a device for the subject to input a response signal at the time of the visual function test. The input unit 50 is, for example, a response button, but may be other cases. The signal processing unit 42 processes the response signal from the input unit 50 based on the control signal from the image control unit 41. The image creation unit 43 creates a two-dimensional inspection result image based on the signal processed by the signal processing unit 42. The display unit 51 displays the inspection result image. The display unit 51 is, for example, a liquid crystal display or the like.

In the image control unit 41, the signal processing unit 42, and the image creation unit 43, a processor such as a CPU (Central Processing Unit) may cooperate with the program to perform processing. The image control unit 41, the signal processing unit 42, and the image creation unit 43 may be circuits designed exclusively for them. The image control unit 41, the signal processing unit 42, and the image creation unit 43 may be one circuit or different circuits.

FIG. 2 is a diagram showing an optical system of the visual function test apparatus according to the first embodiment. The visual function test device uses Maxwell vision to project an image onto the retina 71 of the subject. With reference to FIG. 2, the numerical aperture (NA) and / or the beam diameter of the laser beam 60 emitted from the light source 11 is adjusted by the adjusting unit 13. The laser beam 60 formed by the adjusting unit 13 is incident on the scanning unit 15. The laser beam 60 is two-dimensionally scanned by the MEMS mirror which is the scanning unit 15.

The scanned laser beam 60 passes through the half mirror 20 and is incident on the mirror 30, and then is reflected by the mirror 30 and incident on the mirror 31. The half mirror 20 may be, for example, a half mirror that reflects and transmits the laser light 60 and the LED light 61 at a ratio of 50:50. The reflective surfaces of the mirrors 30 and 31 are curved surfaces such as free curved surfaces. The mirrors 30 and 31 may be concave mirrors having different focal lengths, or may be concave mirrors having the same focal length. That is, the radius of curvature of the mirror 30 may be the same as or different from the radius of curvature of the mirror 31. The mirrors 30 and 31 are, for example, total reflection mirrors. The mirrors 30 and 31 are components constituting the projection optical system 16 of FIG.

The laser beam 60 emitted from the scanning unit 15 at different times is reflected by the mirror 30, converges at the convergence point 63, and then enters the mirror 31. In this way, the mirror 30 irradiates the mirror 31 after converging the laser light 60 reflected from the scanning unit 15 in different directions at the convergence point 63 on the light source 11 side of the mirror 31 (that is, in front of the mirror 31). 2 This is an example of an optical component. The laser beam 60 incident on the mirror 31 is reflected by the mirror 31 and converges at the convergence point 64 in the subject's eye 70 (for example, in the vicinity of the pupil 72), passes through the crystalline lens 73, and irradiates the retina 71. As described above, the mirror 31 is an example of a first optical component that irradiates the retina 71 after the laser light 60 emitted from the scanning unit 15 at different times is converged at the convergence point 64 in the subject's eye 70. be. The first optical component and the second optical component may be other than the mirror. When the scanned laser beam 60 is applied to the retina 71, an inspection target for inspecting the visual function is projected on the retina 71. The inspection target is, for example, a stimulation target (stimulation light) used for a visual field test.

FIG. 3 is a diagram illustrating a laser beam between the scanning portion and the retina. With reference to FIG. 3, the projection optical system 16 includes a mirror 30 and a mirror 31. The reflective surfaces of the mirror 30 and the mirror 31 are curved surfaces such as a free curved surface. The scanning light 62, which is a collection of laser light 60 scanned by the scanning unit 15 and reflected from the scanning unit 15 in different directions, is incident on the mirror 30. The scanning light 62 is reflected by the mirror 30 and converges at the convergence point 63, and then irradiates the mirror 31. The scanning light 62 irradiated to the mirror 31 is reflected by the mirror 31 and converges at the convergence point 64 near the pupil 72, and then is irradiated to the retina 71.

4 (a) to 4 (c) are diagrams showing an example of the distribution of laser light emitted from the scanning unit at different times. FIG. 4A shows an example of the distribution of the laser beam 60 between the scanning unit 15 and the mirror 30, and FIG. 4B shows an example of the distribution of the laser beam 60 between the mirrors 30 and 31. FIG. 4 (c) shows an example of the distribution of the laser beam 60 between the mirror 31 and the eye 70. As shown in FIG. 4A, between the scanning unit 15 and the mirror 30, the laser beams 60 emitted from the scanning unit 15 at different times are regularly distributed within the rectangular range, and each of the laser beams 60 is distributed. Has approximately the same beam diameter. As shown in FIG. 4B, between the mirrors 30 and 31, the laser beam 60 emitted from the scanning unit 15 at different times due to the positive focusing power of the mirror 30 and the bending angle φ1 (see FIG. 5). The distribution is biased, and the beam diameters of the laser beams 60 are also different. As shown in FIG. 4C, between the mirror 31 and the eye 70, the positive focusing power of the mirror 31 and the bending angle φ2 (see FIG. 5) make the laser with the positive focusing power of the mirror 30 and the bending angle φ1. The influence on the light 60 is canceled out, and the laser light 60 emitted from the scanning unit 15 at different times is distributed in a rectangular range with regularity, and each of the laser light 60 has a beam diameter of substantially the same size. return.

FIG. 5 is an enlarged view of the projection optical system of FIG. With reference to FIG. 5, in the laser beam 60a corresponding to the central pixel of the image projected on the retina 71, the optical path length between the mirror 30 and the convergence point 63 with respect to the optical path length L1 between the scanning unit 15 and the mirror 30. The ratio of L2 is substantially the same as the ratio of the optical path length L3 between the convergence point 63 and the mirror 31 to the optical path length L4 between the mirror 31 and the convergence point 64. That is, the value of the optical path length L2 / optical path length L1 is substantially the same as the value of the optical path amount L3 / optical path length L4. The same applies to the laser light 60 other than the laser light 60a. As a result, the influence of the positive focusing power of the mirror 31 and the bending angle φ2 on the laser light 60 is effectively offset by the influence of the positive focusing power of the mirror 30 and the bending angle φ1 on the laser light 60. Can be done. Therefore, it is possible to project a good image in which distortion is suppressed. The bending angle φ1 of the mirror 30 of the laser beam 60a and the bending angle φ2 of the mirror 31 are substantially the same size. The same applies to the laser light 60 other than the laser light 60a. Here, the bending angle is the sum of the incident angle and the reflection angle. Thereby, the influence of the positive focusing power of the mirror 31 on the laser light 60 can be effectively offset by the influence of the positive focusing power of the mirror 30 on the laser light 60.

The scanning angle θ1 of the laser light 60 by the scanning unit 15, the convergence angle θ2 in which the laser light 60 emitted from the scanning unit 15 at different times converges to the convergence point 63, and the laser light emitted from the scanning unit 15 at different times. The relationship between the emission angle θ3 (emission angle θ3 = convergence angle θ2) emitted from the convergence point 63 by 60 and the convergence angle θ4 in which the laser light 60 emitted from the scanning unit 15 at different times converges at the convergence point 64 is θ1: θ2 = θ4: θ3. Since the convergence points 63 and 64 have a conjugated relationship via the mirror 31, and the scanning unit 15 and the convergence point 64 have a conjugated relationship via the mirrors 30 and 31, θ1 = θ4, θ2 = It is θ3. Here, when θ1 = θ2, the scanning unit 15 and the convergence point 64 have a conjugate relationship of substantially the same magnification, so that the beam diameter of the laser beam 60 when incident on the eye 70 is scanned by the scanning unit 15. The beam diameter of the laser beam 60 can be made substantially the same as the beam diameter. As a result, the beam diameter of the laser beam 60 when it enters the eye 70 can be increased, and a high-resolution image can be projected on the retina 71. Further, if θ1: θ2 = θ4: θ3, and θ1 ≠ θ2 and θ4 ≠ θ3, an optical system that is conjugated but not the same size can be constructed, and the versatility of the projected image can be improved.

The above-mentioned substantially the same is a case where the image quality is substantially the same to the extent that deterioration of image quality is suppressed, and a case where the manufacturing error is substantially the same (the same applies hereinafter). Similarly, the conjugate relationship of approximately the same magnification is approximately the same magnification to the extent that deterioration of image quality is suppressed, and is approximately the same magnification as the manufacturing error.

With reference to FIG. 2, the diameter and the like of the LED light 61 emitted from the light source 12 are adjusted by the adjusting unit 14. The LED light 61 formed by the adjusting unit 14 is reflected by the half mirror 20 and incident on the mirror 30. In the LED light 61, the center of the LED light 61 is located at a position where the laser light 60 located at the center of the plurality of laser lights 60 emitted from the scanning unit 15 at different times is emitted from the half mirror 20, and the LED light 61 is half. It is incident on the mirror 20. The range in which the LED light 61 is incident on the half mirror 20 is the same as or larger than the range in which the plurality of laser lights 60 emitted from the scanning unit 15 at different times are emitted from the half mirror 20.

The LED light 61 is reflected by the mirror 30, is condensed at the condensing point 65 in front of the mirror 31, becomes diffused light, and is incident on the mirror 31. The LED light 61 incident on the mirror 31 is reflected by the mirror 31 and focused at the focusing point 66 in the subject's eye 70 (for example, near the pupil 72), and then becomes diffused light and is irradiated to the retina 71. .. When the LED light 61 irradiates the retina 71, a background image serving as a background of the examination target is projected on the retina 71.

The light source 12 and the scanning unit 15 are arranged at positions substantially line-symmetrical with respect to the half mirror 20. Therefore, at the center of the LED light 61, the ratio of the optical path length between the mirror 30 and the condensing point 65 to the optical path length between the light source 12 and the mirror 30 is the optical path length between the mirror 31 and the condensing point 66. The size is substantially the same as the ratio of the optical path lengths between the focusing point 65 and the mirror 31. As a result, the distortion of the background image projected on the retina 71 by the LED light 61 is suppressed in the same manner as in the case where the distortion of the image projected on the retina 71 by the laser light 60 described above is suppressed.

In the above description, the gathering of the laser beams 60 emitted from the scanning unit 15 at different times at one point is expressed as convergence, and the focusing of the laser light 60 and the LED light 61 is expressed as focusing. .. The condensing point 65 is at substantially the same position as, for example, the converging point 63, but may be different. The focusing point 66 is at substantially the same position as, for example, the focusing point 64, but may be different. The LED light 61 has a convergence angle of the laser light 60 so that the LED light 61 is irradiated to the retina 71 in a region larger than the region where the laser light 60 emitted from the scanning unit 15 at different times is irradiated to the retina 71. It is preferable that the convergent light having an angle of θ4 (see FIG. 5) or more is incident on the eye 70, and it is more preferable that the convergent light having an angle larger than the convergence angle θ4 is incident on the eye 70.

FIG. 6 is a diagram illustrating an image projected on the retina. With reference to FIG. 6, a plurality of regions 81 for projecting the inspection target 80, which is a stimulation target (stimulation light), are set in a tile shape on the retina 71, and the inspection target 80 is projected on the region 81a. In this case, the image control unit 41 projects the inspection target 80 onto the region 81a of the retina 71, and generates an inspection image 82 that does not project the inspection target 80 onto the other regions 81. When the inspection image 82 is projected onto the retina 71, the scanning unit 15 raster-scans the laser beam 60 from the upper left to the lower right as shown by the arrow 84. Even if the scanning unit 15 is driven within the scanning range of the scanning unit 15, the laser light 60 is not irradiated to the retina 71 unless the light source 11 emits the laser light 60. The laser beam 60 is not emitted from the broken line arrow 84 in FIG. The drive circuit 17 synchronizes the light source 11 with the scanning unit 15. As a result, the light source 11 emits the laser beam 60 at the thick solid line 85 in the region 81a, the region 81a is irradiated with the laser beam 60 as the inspection target 80, and the other regions 81 are not irradiated with the laser beam 60. As described above, the inspection image 82 is an image in which the inspection target 80 is projected on the region 81a in the retina 71 and the inspection target 80 is not projected on the other region 81 of the retina 71. The inspection target 80 and the region 81 have, for example, a quadrangular shape, but may have a polygonal shape such as a circular shape, an elliptical shape, or a hexagonal shape. The inspection target 80 may be white light including red, green, and blue laser light, or monochromatic light including laser light of a single wavelength. The size of the region 81 is, for example, 10 μm × 10 μm.

When the LED light 61 emitted from the light source 12 irradiates the retina 71, the background image 83 is projected on the retina 71. The background image 83 is a plain image formed with a brightness low enough not to interfere with the detection of the inspection target 80 by the subject. The background image 83 is, for example, a plain gray image. The background image 83 has substantially uniform brightness over the entire image. The size of the background image 83 is larger than the size of the inspection image 82.

FIG. 7 is a flowchart showing an example of the visual function test. 8 (a) to 8 (c) are diagrams illustrating an image projected on the retina in the flowchart of FIG. 7. With reference to FIG. 7, the image control unit 41 emits the LED light 61 from the light source 12 and projects the background image 83 onto the retina 71 (step S10). The projection of the background image 83 is continuously performed during the following steps S12 to S18. The image control unit 41 emits the laser beam 60 from the light source 11 and projects the inspection image 82 including the inspection target 80 on the retina 71 (step S12). As a result, as shown in FIG. 8A, the background image 83 is projected on the retina 71, and the inspection image 82 including the inspection target 80 projected on the region 81a is projected superimposed on the background image 83. NS. That is, the inspection target 80 is superimposed on the background image 83 and projected onto the retina 71. Although not shown, the inspection image 82 may include a fixation target for directing the line of sight of the subject.

Next, the signal processing unit 42 acquires the response signal from the input unit 50 (step S14). When the subject detects that the inspection target 80 is projected on the area 81a, the subject operates the input unit 50. Therefore, when the subject detects the inspection target 80, the signal processing unit 42 can acquire a response signal from the input unit 50, and when the inspection target 80 cannot be detected, the signal processing unit 42 receives the response signal from the input unit 50. Response signal cannot be obtained.

After a predetermined time has elapsed from the projection of the inspection image 82 in step S12, the image control unit 41 determines whether or not it is the last region (step S16). For example, when all the examinations of the region 81 to be inspected in the retina 71 are completed, it is determined as Yes. When No, the image control unit 41 changes the region 81 on which the inspection target 80 is projected (step S18), and returns to step S12. Steps S12 to S18 are repeated until it is determined to be Yes in step S16. FIG. 8B shows a case where the region on which the inspection target 80 is projected is changed to the region 81b, and FIG. 8C shows a case where the region is changed to the region 81c.

If it is determined to be Yes in step S16, the image creation unit 43 creates an image of the inspection result of the visual function (for example, a visual field defect image) based on the response signal from the input unit 50 in each region 81 of the signal processing unit 42. (Step S20). The display unit 51 displays the inspection result image (step S22).

By confirming the test result image displayed on the display unit 51 by the doctor, the visual function (for example, visual field defect) of the subject can be examined.

FIG. 9 is a diagram showing an optical system of a visual function test device according to a comparative example. With reference to FIG. 9, in the visual function inspection device 500 of the comparative example, the light source 12 is arranged on the side opposite to the mirror 31 with respect to the mirror 30a. The mirror 30a is, for example, a half mirror. The LED light 61 emitted from the light source 12 is converted from diffused light to converged light by the lens 32, then passes through the mirror 30a, is condensed in front of the mirror 31, and then becomes diffused light and is incident on the mirror 31. Since other configurations are the same as those of the visual function test apparatus of the first embodiment, the description thereof will be omitted.

In the comparative example, the LED light 61 emitted from the light source 12 passes through the mirror 30a, is then reflected by the mirror 31, and irradiates the retina 71. In this case, as in the case described in FIG. 4B, the positive focusing power of the mirror 31 causes the intensity distribution of the LED light 61 to be biased, and the brightness of the LED light 61 on the retina 71. Distribution will occur in. That is, the brightness of the background image 83 projected on the retina 71 by the LED light 61 is not uniform and has a distribution in the image. Therefore, when the visual function test is performed by projecting the inspection target 80 on the background image 83, it may be difficult to perform the visual function test with high accuracy.

Further, for example, when the background image 83 is projected on the retina 71 by the laser light 60, the entire image is uniform with low brightness because the brightness range of the laser light 60 is wide in order to project the inspection target 80 which is the stimulation target. It is difficult to project a background image 83 having a high brightness. Further, the laser beam 60 is scanned two-dimensionally by the scanning unit 15, but since the scanning speed differs between the central portion and the edge portion of the background image 83, the brightness of the entire image is uniform in this respect as well. It is difficult to project the background image 83 of.

On the other hand, in the first embodiment, as shown in FIG. 2, the LED light 61 (background light) emitted from the light source 12 (second light source) is reflected by the mirror 30 (second optical component) and then mirror 31 (second optical component). 1 Optical component) is reflected and irradiated to the subject's retina 71. Therefore, the influence of the positive focusing power of the mirror 31 and the bending angle φ2 on the LED light 61 is canceled by the positive focusing power of the mirror 30 and the bending angle φ1, and the LED light 61 having a highly uniform intensity distribution is produced. The retina 71 will be irradiated. Therefore, the uniformity of the brightness of the background image 83 projected on the retina 71 can be improved.

As shown in FIG. 2, the half mirror 20 is arranged between the scanning unit 15 and the mirror 30. The laser light 60 and the LED light 61 pass through or reflect the half mirror 20 and enter the mirror 30, and after being reflected by the mirror 30, are reflected by the mirror 31 and irradiate the retina 71. As a result, distortion of the inspection image 82 projected on the retina 71 by the laser light 60 is suppressed and / or the resolution is increased, and the uniformity of the brightness of the background image 83 projected on the retina 71 by the LED light 61 is improved. And, can be easily achieved at the same time.

In order to suppress the increase in size of the visual function inspection device 100, as shown in FIG. 2, the laser beam 60 scanned by the scanning unit 15 passes through the half mirror 20 and enters the mirror 30, and the LED emitted from the light source 12. The light 61 may be reflected by the half mirror 20 and incident on the mirror 30. The laser light 60 may be reflected by the half mirror 20 and incident on the mirror 30, and the LED light 61 may be transmitted through the half mirror 20 and incident on the mirror 30.

As shown in FIG. 2, the light source 12 is arranged at a position substantially symmetrical with the scanning unit 15 with respect to the half mirror 20. As a result, the distortion of the background image 83 irradiated to the retina 71 by the LED light 61 is suppressed, and the uniformity of the brightness of the background image 83 can be improved.

As shown in FIG. 2, the LED light 61 is converted into convergent light by the mirror 30, focused in front of the mirror 31, becomes diffused light, enters the mirror 31, and is converted into convergent light by the mirror 31. After condensing within 70, it becomes diffused light and irradiates the retina 71. As a result, the influence of the positive focusing power of the mirror 31 on the LED light 61 is effectively offset by the influence of the positive focusing power of the mirror 30 on the LED light 61. Therefore, the uniformity of the brightness of the background image 83 can be improved.

As shown in FIG. 2, the angle at which the LED light 61 focuses at the focusing point 66 is greater than or equal to the angle at which a plurality of laser beams 60 emitted from the scanning unit 15 at different times converge at the focusing point 64. The case is preferable. As a result, the background image 83 is projected over a wider area than the area where the examination target 80 is projected on the retina 71.

FIG. 10 is a diagram showing an optical system of the visual function test apparatus according to the second embodiment. With reference to FIG. 10, in the visual function test apparatus 200 of the second embodiment, the light source 12 is arranged on the side opposite to the eye 70 with respect to the mirror 31a. The mirror 31a is, for example, a half mirror, but the laser light 60 and the LED light 61 may be transmitted and reflected at a ratio other than 50:50. The LED light 61 emitted from the light source 12 is converted from diffused light to focused light by the lens 34 after being molded by the adjusting unit 14, passes through the mirror 31a, and is incident on the eye 70. Since other configurations are the same as those of the visual function test apparatus of the first embodiment, the description thereof will be omitted.

According to the second embodiment, the LED light 61 (background light) emitted from the light source 12 (second light source) passes through the mirror 31a (first optical component) and irradiates the retina 71 of the subject. In this case, since the influence of the LED light 61 on the positive condensing power of the mirror 31a is reduced, the LED light 61 having a highly uniform intensity distribution is applied to the retina 71. Therefore, the uniformity of the brightness of the background image 83 projected on the retina 71 can be improved.

In the second embodiment, the lens 34 is arranged between the light source 12 and the mirror 31a arranged on the side opposite to the eye 70 with respect to the mirror 31a, and the LED light 61 emitted from the light source 12 is inspected by the lens 34. It is converted into convergent light that is focused in the human eye 70. As a result, a Maxwell vision similar to that of the stimulation light group is formed, and the uniformity of the brightness of the projection region is maintained. The LED light 61 emitted from the light source 12 may be converted into substantially parallel light by the lens 34. In this case, the discomfort that the background light disappears even if the line of sight is moved is eliminated.

FIG. 11 is a diagram showing an optical system of the visual function test apparatus according to the third embodiment. With reference to FIG. 11, in the visual function test apparatus 300 of the third embodiment, a plurality of light sources 12 are arranged on a plane on the side opposite to the eye 70 with respect to the mirror 31a. A lens diffuser 35 is arranged between the plurality of light sources 12 and the mirror 31a. The LED lights 61 emitted from the plurality of light sources 12 are formed by the adjusting unit 14, then diffusely formed by the lens diffuser 35, pass through the mirror 31a, and enter the eye 70. The surface of the lens diffuser 35 is formed with minute and random irregularities, whereby a plurality of minute lenses are randomly provided on the surface to form a lens array. Since other configurations are the same as those of the visual function test apparatus of the first embodiment, the description thereof will be omitted.

According to the third embodiment, the LED light 61 (background light) emitted from the plurality of light sources 12 (second light source) is transmitted to the retina 71 of the subject through the mirror 31a (first optical component). NS. Thereby, the uniformity of the brightness of the background image 83 projected on the retina 71 can be improved.

A lens diffuser 35 in which a plurality of lenses are randomly arranged on the surface is arranged between the plurality of light sources 12 arranged on the side opposite to the eye 70 with respect to the mirror 31a and the mirror 31a. As a result, the LED light 61 (background light) emitted from the plurality of light sources 12 passes through the lens diffuser 35, so that the uneven brightness of the LED light 61 irradiated to the retina 71 can be reduced.

Also in the second embodiment, the lens diffuser 35 may be arranged instead of the lens 34.

In Examples 1 to 3, a case where the light source 12 (second light source) that emits background light is an LED light source is shown as an example, but the case is not limited to this case, and the light source is illuminated by an EL light emitting plate or a fluorescent lamp. It may be a white plate.

Although the examples of the present invention have been described in detail above, the present invention is not limited to such specific examples, and various modifications and modifications are made within the scope of the gist of the present invention described in the claims. It can be changed.

10 Projection unit 11, 12 Light source 13, 14 Adjustment unit 15 Scan unit 16 Projection optical system 17 Drive circuit 18 Input circuit 20 Half mirror 30, 30a Mirror 31, 31a Mirror 32 Lens 34 Lens 35 Lens diffuser 40 Control unit 41 Image control Part 42 Signal processing part 43 Image creation part 50 Input part 51 Display part 60, 60a Laser light 61 LED light 62 Scanning light 63, 64 Convergence point 65, 66 Focus point 70 Eye 71 Retina 72 Eye hole 73 Crystal body 80 Inspection target 81 ~ 81c area 82 Inspection image 83 Background image 100, 200, 300, 500 Visual function inspection device

Claims (10)

A first light source that emits a laser beam for projecting an inspection target for inspecting visual function onto the retina of a subject, and
A second light source that emits background light for projecting a background image, which is the background of the inspection target, onto the retina of the subject.
A scanning unit that scans the laser beam emitted from the first light source in two dimensions, and
A plurality of laser beams arranged in front of the subject's eye and emitted from the scanning unit at different times are reflected and converged at a first convergence point in the subject's eye, and then the plurality of laser beams are converged. The first optical component that irradiates the subject's retina with the laser beam of
After reflecting the plurality of laser beams reflected from the scanning unit in different directions and converging them at the second convergence point on the first light source side of the first optical component, the plurality of laser beams are subjected to the first optical. It is equipped with a second optical component that irradiates the component.
A visual function test device in which the background light emitted from the second light source is reflected by the second optical component and then reflected by the first optical component to irradiate the retina of the subject. A half mirror arranged between the scanning unit and the second optical component is provided.
The laser beam scanned by the scanning unit and the background light emitted from the second light source are transmitted or reflected through the half mirror, incident on the second optical component, and reflected by the second optical component. The visual function test apparatus according to claim 1, which is then reflected by the first optical component and irradiated to the retina of the subject. The visual function test apparatus according to claim 2, wherein the second light source is arranged at a position substantially symmetrical to the scanning portion with respect to the half mirror. The background light is converted into convergent light by the second optical component, focused at the first condensing point in front of the first optical component, and then becomes diffused light and enters the first optical component. Claims 1 to 3 which are converted into convergent light by the first optical component, focused at the second condensing point in the subject's eye, and then become diffused light and irradiated to the subject's retina. The visual function test apparatus according to any one of the above. The angle at which the background light is focused on the second focusing point is greater than or equal to the angle at which the plurality of laser beams emitted from the scanning unit at different times converge at the first focusing point. Item 4. The visual function test apparatus according to item 4. A first light source that emits a laser beam for projecting an inspection target for inspecting visual function onto the retina of a subject, and
A second light source that emits background light for projecting a background image, which is the background of the inspection target, onto the retina of the subject.
A scanning unit that scans the laser beam emitted from the first light source in two dimensions, and
A plurality of laser beams arranged in front of the subject's eye and emitted from the scanning unit at different times are reflected and converged at a first convergence point in the subject's eye, and then the plurality of laser beams are converged. The first optical component that irradiates the subject's retina with the laser beam of
After reflecting the plurality of laser beams reflected from the scanning unit in different directions and converging them at the second convergence point on the first light source side of the first optical component, the plurality of laser beams are subjected to the first optical. It is equipped with a second optical component that emits light to the component.
A visual function test device in which the background light emitted from the second light source passes through the first optical component and irradiates the retina of the subject. The first optical component and the second light source arranged on the side opposite to the eye of the subject with respect to the first optical component, and emitted from the second light source. The visual function test apparatus according to claim 6, further comprising a lens that converts background light into convergent light or substantially parallel light that is focused in the eyes of the subject. A plurality of the second light sources arranged on the side opposite to the eyes of the subject with respect to the first optical component,
The visual function test apparatus according to claim 6, further comprising a lens diffuser plate arranged between the plurality of second light sources and the first optical component and randomly provided with a plurality of lenses on the surface. The visual function test apparatus according to any one of claims 1 to 8, wherein the second light source is an LED light source. In the laser beam, the ratio of the optical path length between the second optical component and the second convergence point to the optical path length between the scanning unit and the second optical component is the ratio between the first optical component and the first convergence point. The visual function test apparatus according to any one of claims 1 to 9, which has substantially the same magnitude as the ratio of the optical path length between the second convergence point and the first optical component with respect to the optical path length between the two.

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