ophthalmic devices

Abstract

This method allows for optimal small-pupil imaging without completely losing intraocular information. [Solution] The ophthalmic apparatus includes an objective lens, an illumination optical system that generates slit-shaped illumination light and includes an iris diaphragm positioned at a location substantially conjugate to the pupil of the eye under examination and having two or more apertures, a scanning unit that moves the illumination area of ​​the illumination light in the imaging area of ​​the eye under examination in a predetermined scanning direction, a light-receiving optical system configured to guide the reflected light of the illumination light irradiated onto the eye under examination via the objective lens to an image sensor positioned at a location substantially conjugate to the imaging area, and a branching member positioned at a location substantially conjugate to the pupil between the objective lens and the illumination optical system, which deflects the illumination light to the objective lens and deflects the reflected light guided through the objective lens toward the light-receiving optical system. The illumination optical system includes one or more black dot plates positioned at a location where the illumination light is reflected by the objective lens and an image is formed in the illumination optical system.

Description

Technical Field

[0001] This invention relates to an ophthalmic device.

Background Art

[0002] For ophthalmic devices for screening and treating eye diseases, etc., there is a demand for devices that can easily capture (observe) the fundus of the eye to be examined with a wide field of view. As such an ophthalmic device, there is known a fundus imaging device that scans the fundus with slit-shaped illumination light and forms an image of the fundus by detecting the return light with a light receiving device.

[0003] For example, Patent Document 1 discloses a method of obtaining a clear fundus image without being affected by unnecessary light by synchronizing the irradiation timing of illumination light and the light reception timing of return light using a Nipkow disk.

[0004] For example, Patent Document 2 discloses a method of moving a slit-shaped imaging area on the imaging surface of an imaging device by continuously crossing a plurality of slit openings formed in an optical chopper with respect to the optical path of illumination light and the optical path of return light, and obtaining a clear fundus image.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] In ophthalmic equipment capable of photographing intraocular parts such as the fundus, illumination light is introduced into the eye through the pupil, and reflected light from the fundus (return light, fundus reflected light) is emitted through the pupil. Therefore, in ophthalmic equipment, the image of the illumination aperture through which the illumination light passes and the image of the light-receiving aperture (photographic aperture) through which the reflected light passes are separated at a pupillary conjugate plane that is optically approximately conjugate with the pupil of the eye being examined.

[0007] However, the ophthalmic device disclosed in Patent Document 1 is configured such that a single illumination aperture and a single light-receiving aperture are formed on the pupil conjugate surface. In this case, if the eye being examined has a small pupil, there is a problem in that the image quality of the acquired image deteriorates for the following reasons.

[0008] Figures 15A and 15B show schematic diagrams illustrating the process of photographing the fundus of an eye with a normal pupil diameter using conventional ophthalmic equipment. Figure 15A schematically represents the images of the illumination aperture and the light-receiving aperture in conventional ophthalmic equipment. Figure 15B schematically represents the illumination light and reflected light incident on the eye in the state shown in Figure 15A.

[0009] In ophthalmic devices, to completely separate the illumination beam entering the eye through the pupil from the reflected beam exiting the eye through the pupil, the illumination aperture and the light-receiving aperture are completely separated in the pupil conjugate plane PL, which is optically conjugate to the pupil of the eye E being examined. Specifically, in the pupil conjugate plane PL, an image ILP of the illumination aperture through which the illumination beam IL passes and an image SHP of the light-receiving aperture through which the reflected beam OL from the fundus passes are formed (see Figure 15A).

[0010] In fundus photography of the eye under examination E, illumination light is introduced through the pupil and reflected light is emitted. Therefore, in the pupil conjugate plane PL, it is necessary to contain at least a portion of the illumination aperture image ILP and at least a portion of the light-receiving aperture image SHP within the pupil division range Rp1 corresponding to the pupil diameter φ1 of the eye under examination E (Figure 15A). At this time, the gap between the illumination aperture image and the light-receiving aperture image (the gap between the illumination aperture and the light-receiving aperture at the separation diaphragm) is a predetermined gap length GP1 (>0). Here, the gap is the distance (shortest distance) between the illumination aperture image and the light-receiving aperture image in the direction of alignment of the illumination aperture image and the light-receiving aperture image.

[0011] As shown in Figure 15A, when the gap is a predetermined gap length GP1, as shown in Figure 15B, the illumination beam IL passes through the objective lens OBJ positioned on the optical axis O and is guided to the fundus through the pupil of the eye E being examined. The reflected light beam OL of the illumination beam IL reflected from the fundus exits the eye E being examined through the pupil, passes through the objective lens OBJ, and is guided to the light receiving path (photographic path).

[0012] In contrast, if the eye being examined (E) has a small pupil, the above gap needs to be shortened.

[0013] Figures 16A and 16B show schematic diagrams illustrating the process of photographing the fundus of a subject eye E with a small pupil using a conventional ophthalmic apparatus. Figure 16A schematically represents the images of the illumination aperture and the light-receiving aperture in a conventional ophthalmic apparatus. Figure 16B schematically represents the illumination light and reflected light incident on the subject eye E in the state shown in Figure 16A. In Figures 16A and 16B, the same reference numerals are used for parts that are the same as those in Figures 15A and 15B, and explanations are omitted as appropriate.

[0014] If the eye E under examination is a small pupil eye, it is necessary to fit at least a portion of the image ILP of the illumination aperture and at least a portion of the image SHP of the light-receiving aperture within the pupil division range Rp2 corresponding to the pupil diameter φ2 of the small pupil in the pupil conjugate plane PL (Figure 16A). In this case, the gap between the image of the illumination aperture and the image of the light-receiving aperture is a predetermined gap length GP2( <GP1)となる。

[0015] As shown in Figure 16A, when the gap reaches a predetermined gap length GP2, the illumination beam IL passes near the optical axis of the objective lens OBJ, as shown in Figure 16B. As a result, reflections at the lens apex AP on the optical axis O of the objective lens OBJ (central ghosting) are more likely to enter the light-receiving path, causing flare as an artifact and increasing the likelihood of complete loss of fundus information, at least in part of the imaging area.

[0016] In this case, by placing a black spot plate at a position on the illumination path that is optically conjugate to the lens apex AP of the objective lens OBJ, central ghosting caused by reflection from the lens apex AP can be prevented.

[0017] Figures 17 and 18 show schematic diagrams illustrating the arrangement of a black spot plate in a conventional fundus apparatus. Figure 17 schematically represents the illumination light and reflected light incident on the eye E under examination with the black spot plate in place. Figure 18 schematically represents the fundus image of the eye E under examination acquired in a conventional fundus apparatus with the black spot plate in place. In Figure 17, the same reference numerals are used for parts that are the same as those in Figure 15A or Figure 15B, and explanations are omitted as appropriate.

[0018] As described above, when a black spot plate is positioned on the illumination path optically conjugate to the lens apex AP of the objective lens OBJ, the illumination light passing through the lens apex AP of the objective lens OBJ is blocked by the black spot plate. As a result, the illumination light does not reach the fundus near the lens optical axis of the objective lens OBJ. In this case, as shown in Figure 18, a black spot shadow BS caused by the black spot plate is depicted in the acquired fundus image IMG10. The area where the black spot shadow BS is depicted is in a state of black crush (a state in which grayscale information is lost), and it is an area in which fundus information as intraocular information representing the intraocular morphology is completely lost.

[0019] As described above, conventional ophthalmic equipment has the problem that the image quality of fundus images deteriorates due to the occurrence of flare or the visualization of black spots, resulting in the loss of fundus information in at least a portion of the imaging area. This problem is not limited to when the imaging site is the fundus, but is also true when imaging the inside of the eye being examined.

[0020] Furthermore, in the method disclosed in Patent Document 1, one refractive plane mirror is provided so as to be in contact with the end of the other refractive plane mirror. Therefore, in this method, if multiple illumination apertures or light-receiving apertures are formed on the pupil conjugate surface, it is difficult to guide illumination light to the fundus through the multiple illumination apertures or to receive reflected light from the fundus through the multiple light-receiving apertures.

[0021] In contrast, Patent Document 2 discloses a method that provides multiple illumination apertures and a single light-receiving aperture. However, this presents a problem in that the optical path length (path length) of the illumination light path traversed by the optical chopper differs from the optical path length (path length) of the imaging light path, which complicates the optical design and optical system configuration.

[0022] This invention has been made in view of the above circumstances, and one of its objectives is to provide a new technology for suitably realizing small pupil imaging without completely losing intraocular information. Another objective of this invention is to provide a new technology for suitably realizing small pupil imaging without completely losing intraocular information, while simplifying the optical design and optical system configuration. [Means for solving the problem]

[0023] One aspect of some embodiments includes an objective lens, an illumination optical system, a scanning unit, a light receiving optical system, and a branching member. The illumination optical system includes an iris diaphragm disposed at a position optically substantially conjugate with the pupil of the eye to be examined and having two or more apertures formed therein. The illumination optical system generates slit-shaped illumination light from the illumination light emitted by irradiating the iris diaphragm with light from a light source, or generates slit-shaped illumination light by irradiating the iris diaphragm with slit-shaped light. The scanning unit moves the irradiation region of the illumination light at the imaging site of the eye to be examined in a predetermined scanning direction. The light receiving optical system is configured to guide the return light of the illumination light irradiated onto the eye to be examined through the objective lens to an image sensor disposed at a position optically substantially conjugate with the imaging site. The branching member is disposed at a position optically substantially conjugate with the pupil between the objective lens and the illumination optical system, deflects the illumination light from the illumination optical system and guides it to the objective lens, and deflects the return light guided through the objective lens toward the light receiving optical system. The illumination optical system includes one or more black dot plates disposed at positions where the illumination light forms an image in the illumination optical system when reflected by the objective lens.

Advantages of the Invention

[0024] According to the present invention, it becomes possible to provide a new technique for suitably realizing small pupil imaging without completely losing intraocular information. Further, according to the present invention, it becomes possible to provide a new technique for suitably realizing small pupil imaging while simplifying the optical design and the configuration of the optical system without completely losing intraocular information.

Brief Description of the Drawings

[0025] [Figure 1] It is a schematic diagram showing an example of the configuration of the optical system of an ophthalmic device according to the first embodiment. [Figure 2] It is a schematic diagram for explaining the configuration of the optical system of an ophthalmic device according to the first embodiment. [Figure 3] It is a schematic diagram for explaining the configuration of the optical system of an ophthalmic device according to the first embodiment. [Figure 4A] It is a schematic diagram showing an example of the configuration of the optical system of an ophthalmic device according to the first embodiment. [Figure 4B] This is a schematic diagram showing an example of the configuration of the optical system of an ophthalmic device according to the first embodiment. [Figure 5] This is a schematic diagram illustrating the configuration of the optical system of the ophthalmic apparatus according to the first embodiment. [Figure 6] This is a schematic diagram illustrating the operation of the ophthalmic device according to the first embodiment. [Figure 7] This is a schematic diagram showing an example of the configuration of the processing system of an ophthalmic device according to the first embodiment. [Figure 8] This is a schematic diagram showing an example of the configuration of the processing system of an ophthalmic device according to the first embodiment. [Figure 9] This is a flowchart showing an example of operation of the ophthalmic device according to the first embodiment. [Figure 10A] This is a schematic diagram illustrating the operation of the ophthalmic device according to the first embodiment. [Figure 10B] This is a schematic diagram illustrating the operation of the ophthalmic device according to the first embodiment. [Figure 11] This is a schematic diagram showing an example of the configuration of the optical system of an ophthalmic device according to the second embodiment. [Figure 12] This is a schematic diagram illustrating the configuration of the optical system of an ophthalmic device according to the first embodiment or a first modified example of the second embodiment. [Figure 13] This is a schematic diagram illustrating the operation of an ophthalmic device according to the first embodiment or a first modified example of the second embodiment. [Figure 14] This is a schematic diagram illustrating the configuration of the optical system of an ophthalmic device according to the first embodiment or a second modified example of the second embodiment. [Figure 15A] This is a schematic diagram illustrating conventional ophthalmic equipment. [Figure 15B] This is a schematic diagram illustrating conventional ophthalmic equipment. [Figure 16A] This is a schematic diagram illustrating conventional ophthalmic equipment. [Figure 16B] This is a schematic diagram illustrating conventional ophthalmic equipment. [Figure 17] This is a schematic diagram illustrating conventional ophthalmic equipment. [Figure 18]This is a schematic diagram illustrating conventional ophthalmic equipment. [Modes for carrying out the invention]

[0026] Examples of embodiments of the ophthalmic apparatus according to this invention will be described in detail with reference to the drawings. It is possible to apply the contents of the referenced documents and any prior art cited in this specification to the following embodiments.

[0027] An ophthalmic apparatus according to an embodiment includes an objective lens, an illumination optical system, a scanning unit, a light-receiving optical system, and a branching member. In some embodiments, the illumination optical system includes at least one of the objective lens, the scanning unit, and the branching member.

[0028] The illumination optical system generates slit-shaped illumination light. Specifically, the illumination optical system includes an iris diaphragm (illumination aperture) positioned at a location approximately conjugate to the pupil (iris) of the eye under examination, with two or more openings (illumination apertures) formed therein. Here, the location approximately conjugate to the pupil (iris) of the eye under examination includes the pupil (iris) conjugate location that is optically conjugate to the pupil (iris) of the eye under examination or its vicinity. The illumination optical system can generate slit-shaped illumination light from the illumination light emitted by irradiating the iris diaphragm with light from a light source, or generate slit-shaped illumination light by irradiating the iris diaphragm with slit-shaped light.

[0029] Furthermore, the illumination optical system includes one or more black dot plates positioned at locations where illumination light is reflected by the objective lens and an image is formed in the illumination optical system. In some embodiments, the one or more black dot plates are positioned on the optical axis of the optical system including the objective lens at a position optically conjugate to the lens vertex of the objective lens (lens vertex conjugate position) or near thereto. In some embodiments, the one or more black dot plates are positioned at or near the above-mentioned lens vertex conjugate position or its vicinity at a position where illumination light is reflected by the objective lens and an image is formed.

[0030] The scanning unit moves the illumination area of ​​the illumination light in the imaging area of ​​the eye under examination (e.g., the fundus) in a predetermined scanning direction. In some embodiments, the scanning unit moves the illumination area of ​​the illumination light in the imaging area by deflecting the illumination light with a scanning mirror (deflection mirror).

[0031] In some embodiments, the scanning unit moves the illumination area of ​​the imaging area by continuously traversing a slit opening (slit-shaped opening) across the optical path of the illumination light. For example, the scanning unit includes a slit disk that is rotatable about a rotation axis passing through a predetermined rotation center, and has two or more slit openings, including a first slit opening and a second slit opening, formed in a circumferential direction having a predetermined radius passing through a predetermined rotation center. In this case, the scanning unit is configured such that at least a portion of the second slit opening traverses the optical path of the return light in the light-receiving optical system at the same time that at least a portion of the first slit opening traverses the optical path of the illumination light in the illumination optical system. In some embodiments, the direction in which the rotation axis extends substantially coincides with the direction in which the lens optical axis of the objective lens extends.

[0032] The light-receiving optical system is configured as an imaging optical system to guide the reflected light of illumination light irradiated onto the eye under examination via the objective lens to an image sensor positioned at a location approximately conjugate to the imaging site. Here, if the imaging site is the fundus, the position approximately conjugate to the fundus of the eye under examination includes the fundus conjugate position or its vicinity, which is optically conjugate to the fundus of the eye under examination.

[0033] The branching member is positioned between the objective lens and the illumination optical system, at a location that is approximately optically conjugate to the pupil of the eye being examined. The branching member deflects the illumination light from the illumination optical system and guides it to the objective lens, and also deflects the reflected light that has been guided through the objective lens towards the light-receiving optical system.

[0034] In the configuration described above, the image of the eye obtained by illuminating the area of ​​the eye being examined with illumination light that has passed through two or more openings formed in the iris diaphragm will depict two or more black spots. Here, each of the two or more black spots corresponds to one of the two or more illumination openings. Therefore, each of the black spots contains grayscale information (intraocular information) as fundus information obtained by being illuminated by illumination light that has passed through the remaining illumination openings excluding the corresponding illumination opening. As a result, each of the two or more black spots is not completely blacked out, and each black spot area contains grayscale information corresponding to the amount of illumination light that has passed through the remaining illumination openings.

[0035] For example, by applying a predetermined black spot correction process to the obtained image of the eye under examination, it is possible to avoid the complete loss of tonal information. This makes it possible to acquire an image containing intraocular information of the eye under examination and to perform an appropriate diagnosis of the image of the eye with a small pupil, even when it is necessary to shorten the gap, such as when the eye under examination has a small pupil.

[0036] The control method for the ophthalmic apparatus according to the embodiment includes one or more steps for realizing processing to be performed by one or more processors (computers) in the ophthalmic apparatus according to the embodiment. The program according to the embodiment causes one or more processors to execute each step of the control method for the ophthalmic apparatus according to the embodiment. That is, the program according to the embodiment is a computer program that includes instructions to cause the computer to execute the control method for the ophthalmic apparatus according to the embodiment when the program is executed by the computer. The recording medium (storage medium) according to the embodiment is any non-transitory recording medium that is readable by a computer and on which the program according to the embodiment is recorded (stored). The recording medium may be an electronic medium that utilizes magnetism, light, magneto-optical technology, semiconductors, etc. Typically, recording media include magnetic tapes, magnetic disks, optical disks, magneto-optical disks, flash memory, solid-state drives, etc. Examples of magnetic disks include hard disks, floppy disks, ZIP and other magnetic storage media. Examples of magneto-optical disks include CD-ROMs, DVD-RAMs, DVD-ROMs, MOs, etc. It is also possible to send and receive this program via a network such as the Internet or a LAN.

[0037] In this specification, "processor" means, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), a programmable logic device (e.g., SPLD (Simple Programmable Logic Device), CPLD (Complex Programmable Logic Device), FPGA (Field Programmable Gate Array)), or other circuit. The processor realizes the functions according to the embodiment by, for example, reading and executing a program stored in a memory circuit or memory device.

[0038] The following description will focus on the case where the ophthalmic device according to the embodiment is primarily a fundus imaging device that photographs the fundus as the imaging site. However, the following embodiments can also be applied to ophthalmic devices that photograph areas other than the fundus.

[0039] Furthermore, the following description will focus on the case where the scanning unit according to the embodiment includes a slit disk. However, the following embodiments can also be applied when the functions of the scanning unit according to the embodiment are realized by components other than the slit disk.

[0040] In the following, the position optically conjugate to the fundus of the eye under examination will be referred to as the "fundus conjugate position," and the position approximately optically conjugate to the fundus of the eye under examination will be referred to as the "fundus conjugate position or its vicinity." Similarly, the position optically conjugate to the pupil (iris) of the eye under examination will be referred to as the "pupil (iris) conjugate position," and the position approximately optically conjugate to the pupil (iris) of the eye under examination will be referred to as the "pupil (iris) conjugate position or its vicinity."

[0041] Furthermore, in the following explanation, the optical axis direction (depth direction, front-to-back direction) of the optical system (objective optical system) will be denoted as the z direction, the horizontal direction (left-to-right direction) perpendicular to the z direction will be denoted as the x direction, and the vertical direction (up-down direction) perpendicular to both the z and x directions will be denoted as the y direction.

[0042] <First Embodiment> [Optical system] Figure 1 shows an example of the optical system configuration of an ophthalmic device according to the first embodiment. In Figure 1, the position optically conjugate to the fundus Ef of the eye under examination E is shown as the fundus conjugate position P, and the position optically conjugate to the pupil (iris) Eu of the eye under examination E is shown as the pupil (iris) conjugate position Q.

[0043] The ophthalmic device 1 according to the first embodiment is configured to acquire a fundus image of the eye E by scanning the fundus Ef of the eye E under examination with a slit-shaped illumination light and sequentially receiving the reflected light of the illumination light from the fundus Ef. The reflected light from the fundus Ef is the scattered light (reflected light) of the illumination light from the fundus Ef that was irradiated by the illumination light incident on the eye E under examination. In some embodiments, the reflected light from the fundus Ef includes the scattered light (reflected light) of the illumination light from the fundus Ef, and fluorescence and its scattered light, which uses the illumination light incident on the eye E under examination as excitation light.

[0044] The ophthalmic device 1 includes an illumination optical system 10, a light-receiving optical system 20, an objective optical system 30, a branching member 40, one or more black spot plates 50, and a slit disc 60 for realizing the function of a scanning unit.

[0045] The illumination optical system 10 generates a slit-shaped illumination light that passes through two or more apertures at or near the pupil conjugate position Q, which is optically conjugate to the pupil Eu of the eye under examination, and illuminates the fundus Ef of the eye under examination via the objective optical system 30. The light receiving optical system 20 guides the reflected light from the fundus Ef illuminated by the illumination optical system 10 to the image sensor. The image sensor is positioned at or near the fundus conjugate position P, which is optically conjugate to the fundus Ef of the eye under examination.

[0046] The objective optical system 30 is positioned between the illumination optical system 10 and the eye under examination E, and guides the illumination light from the illumination optical system 10 to the eye under examination E, as well as the reflected light from the illumination light from the eye under examination E to the light receiving optical system 20.

[0047] The branching member 40 guides illumination light from the illumination optical system 10 to the eye under examination E via the objective optical system 30, and also guides the reflected illumination light from the eye under examination E to the light receiving optical system 20.

[0048] Each of the one or more black spot plates 50 is positioned so that the illumination light is reflected by the objective lens (described later) and an image is formed in the illumination optical system 10.

[0049] The slit disk 60 is provided with a ring-shaped slit opening forming region in the circumferential direction of a predetermined rotation center. Two or more slit openings (slit-shaped openings) are formed in the circumferential direction of the slit opening forming region. The slit disk 60 is configured to be rotatable about a rotation axis passing through a predetermined rotation center. The slit disk 60 is configured such that two or more slit openings, including a first slit opening and a second slit opening, continuously cross the optical path of illumination light in the illumination optical system 10 and the optical path of reflected light in the light receiving optical system 20. The first slit opening crosses the optical path of illumination light at or near the fundus conjugate position P, and the second slit opening crosses the optical path of reflected light at or near the fundus conjugate position P. At this time, at least a portion of the first slit opening crosses the optical path of the illumination light, and at least a portion of the second slit opening crosses the optical path of the reflected light. As a result, the reflected light from the fundus Ef of the slit-shaped illumination light formed by the first slit opening is received on the imaging surface of the image sensor exposed by the second slit opening.

[0050] (Illumination optical system 10) The illumination optical system 10 includes a light source 11, a relay lens 12, an iris diaphragm 13, a relay lens 14, a relay lens 15 as a focusing lens, and a deflection mirror 16.

[0051] (Light source 11) The light source 11 outputs light in the visible or infrared wavelength range. For example, the light source 11 includes an LED (Light Emitting Diode) or an LD (Laser Diode).

[0052] In some embodiments, the light source 11 includes two or more light sources that generate light in different wavelength ranges, and it is possible to combine and emit light generated simultaneously from the two or more light sources, or to emit light generated from any one of the two or more light sources.

[0053] (Relay lens 12) The relay lens 12 transmits light from the light source 11 and guides it to the iris diaphragm 13. In some embodiments, the relay lens 12 can increase the amount of light passing through the opening formed in the iris diaphragm 13 by focusing the light from the light source 11 as a condenser lens.

[0054] (Iris diaphragm 13) The iris diaphragm 13 has two or more openings (illumination openings) formed at positions eccentric to the optical axis O of the illumination optical system 10. In this embodiment, the iris diaphragm 13 is assumed to have two openings. The iris diaphragm 13 (specifically, the openings) is positioned at or near the pupil conjugate position Q. The iris diaphragm 13 functions as an illumination diaphragm. The openings formed in the iris diaphragm 13 define the incident position (incidence shape) of the illumination light in the pupil Eu of the eye E being photographed.

[0055] Figure 2 shows an example of the configuration of the iris diaphragm 13 in Figure 1. Figure 2 schematically represents the configuration of the iris diaphragm 13 as viewed from the direction of the optical axis O of the illumination optical system 10. In Figure 2, two apertures are formed in the iris diaphragm 13, but as mentioned above, three or more apertures may be formed in the iris diaphragm 13.

[0056] As shown in Figure 2, the iris diaphragm 13 has two openings (illumination openings) 13a and 13b formed at positions eccentric to the optical axis O. Each of the openings 13a and 13b is a part of a ring-shaped opening centered at a position corresponding to the optical axis O. That is, each of the openings 13a and 13b is a part of a ring-shaped opening having a predetermined width in the radial direction centered at a position corresponding to the optical axis O.

[0057] Furthermore, apertures 13a and 13b are formed in positions that are point-symmetric with respect to the position corresponding to the optical axis O. Both ends of apertures 13a and 13b in the circumferential direction are cut out so that the distance between the two apertures 13a and 13b from the optical axis O in the alignment direction is a predetermined distance.

[0058] In some embodiments, at least one of the openings 13a, 13b is formed in the shape of an arc, a curve, a bow (a shape formed by a part of an arc and a chord connecting both ends of it), or a polygon formed by three or more line segments.

[0059] Light that passes through the apertures 13a and 13b formed in the iris diaphragm 13 is guided to the relay lens 14.

[0060] (Relay lens 14) The relay lens 14 transmits the light that has passed through the apertures 13a and 13b formed in the iris diaphragm 13 and guides it to the relay lens 15.

[0061] A slit disc 60 is positioned on the optical path between relay lens 14 and relay lens 15 such that a slit aperture forming region is located at or near the fundus conjugate position P.

[0062] (Slit disc 60) The slit disk 60 is configured to be rotatable around a rotation axis O1 that is approximately parallel to the optical axis O.

[0063] Figure 3 shows an example of the configuration of the slit disk 60 in Figure 1. Figure 3 schematically represents the general configuration of the slit disk 60 as viewed from the direction of the rotation axis O1 of the slit disk. Note that in Figure 6, eight openings are formed in the slit disk 60, but it is sufficient for the slit disk 60 to have two or more openings.

[0064] As shown in Figure 3, for example, the slit disk 60 has slit openings 61-1 to 61-8 formed in the circumferential direction around a rotation axis O1 passing through a predetermined center of rotation. The direction in which the rotation axis O1 extends is approximately the same as the direction in which the lens optical axis of the objective lens in the objective optical system 30, as described later, extends. Specifically, the rotation axis O1 is approximately the same as the lens optical axis of the objective lens, as described later (the rotation axis O1 is positioned on the extension of the lens optical axis).

[0065] For example, of the slit apertures 61-1 to 61-8, two slit apertures that have an almost point-symmetric relationship with respect to the center of rotation as the center of symmetry are positioned in the optical path of the illumination light in the illumination optical system 10, and the other is positioned in the optical path of the reflected light in the light-receiving optical system 20. In this case, for example, if slit apertures 61-4 and 61-8 have an almost point-symmetric relationship with respect to the center of rotation as the center of symmetry, and slit aperture 61-4 is positioned in the optical path of the illumination light, then slit aperture 61-8 is positioned in the optical path of the reflected light.

[0066] In some embodiments, two slit openings 61-1 to 61-8 that are rotated a predetermined distance around a center of rotation are positioned in the optical path of illumination light in the illumination optical system 10, and the other is positioned in the optical path of return light in the light receiving optical system 20. In this case, for example, slit openings 61-4 and 61-6 are rotated 90 degrees around a center of rotation, and when slit opening 61-4 is positioned in the optical path of illumination light, slit opening 61-6 is positioned in the optical path of return light.

[0067] As described above, when the slit disc 60 rotates and a slit opening is positioned in the optical path between the relay lens 14 and the relay lens 15, the light from the relay lens 14 that passes through the slit opening is guided to the relay lens 15.

[0068] (Relay lens 15) When at least a portion of the slit opening of the rotating slit disc 60 is positioned in the optical path between the relay lens 14 and the relay lens 15, the relay lens 15 transmits the illumination light that has passed through the slit opening and guides it to the deflection mirror 16.

[0069] The relay lens 15 is configured to move in the direction of the optical axis O of the illumination optical system 10 as a focusing lens. By moving the relay lens 15 in the direction of the optical axis O, the slit aperture formed in the slit aperture forming region of the slit disc 60 can be positioned at or near the fundus conjugate position P.

[0070] In some embodiments, the slit disc 60 is configured to be movable in the direction of the optical axis O. In some embodiments, the slit disc 60 and the relay lens 15 are configured to be movable together or independently.

[0071] (Polarization mirror 16) The deflection mirror 16 deflects the illumination light that has passed through the relay lens 15 toward the branching member 40.

[0072] (Branching member 40) The branching member 40 optically couples the illumination optical system 10 and the light-receiving optical system 20 substantially coaxially. The branching member 40 is positioned at or near the pupil conjugate position Q.

[0073] Figures 4A and 4B show examples of the configuration of the branching member 40 in Figure 1. Figure 4A schematically represents the configuration of the branching member 40 when viewed from the objective optical system 30 in the direction of the optical axis O. Figure 4B schematically represents the configuration of the branching member 40 when viewed from the horizontal direction (x direction) perpendicular to the optical axis O. In Figure 4B, the same reference numerals are used for parts that are the same as in Figure 4A, and explanations are omitted as appropriate.

[0074] The branching member 40 includes illumination light branching mirrors 41a and 41b and a return light branching mirror 42. The return light branching mirror 42 is positioned near the illumination light branching mirrors 41a and 41b. For example, the return light branching mirror 42 is positioned between the illumination light branching mirrors 41a and 41b at or near the pupil conjugate position Q.

[0075] The illumination light branching mirrors 41a and 41b deflect the illumination light deflected by the deflection mirror 16 toward the objective optical system 30. For example, each of the illumination light branching mirrors 41a and 41b is provided corresponding to the openings 13a and 13b formed in the iris diaphragm 13. In some embodiments, if two or more openings are formed in the iris diaphragm 13, the branching member 40 includes two or more illumination light branching mirrors.

[0076] The light-reflecting mirror 42 deflects the light-reflecting mirror 42, which has been guided from the fundus Ef through the objective optical system 30, toward the light-receiving optical system 20. The light-reflecting mirror 42 is positioned at or near the pupillary conjugate position Q on the optical axis O.

[0077] This allows for pupillary splitting at the pupillary conjugate position Q or its vicinity, completely separating the illumination beam entering the eye and the return beam exiting the eye at the pupil Eu.

[0078] Figure 5 shows an explanatory diagram of the branching member 40 in Figure 1. Figure 5 schematically represents the cross-sectional shape of the luminous beam of the illumination light and the cross-sectional shape of the luminous beam of the reflected light at the pupil conjugate position Q. In Figure 5, the cross-sectional shape of the luminous beam of the reflected light is shown when the deflection surface of the reflected light branching mirror 42 is circular, but as shown in Figure 4A, the cross-sectional shape of the luminous beam of the reflected light is rectangular when the deflection surface of the reflected light branching mirror 42 is rectangular.

[0079] At the pupillary conjugate plane PL, images ILP1 and ILP2 are formed at apertures 13a and 13b in the iris diaphragm 13, and an image SIP is formed at the deflection surface (broadly speaking, the light-receiving aperture (imaging aperture)) of the light-reflecting mirror 42. The images ILP1 and ILP2 of apertures 13a and 13b are formed at positions eccentric to the optical axis O, and the image SIP of the deflection surface is formed in the central region that includes the position corresponding to the optical axis O. At this time, the image ILP1 of aperture 13a (image ILP2 of aperture 13b) and the image SIP of the deflection surface are formed with a distance of gap GP between them.

[0080] (Objective optical system 30) The objective optical system 30 includes an objective lens 31 and a relay lens 32. Illumination light deflected by illumination light branching mirrors 41a and 41b passes through the relay lens 32, is refracted by the objective lens 31, and is guided to the fundus Ef of the eye under examination E. The reflected illumination light from the fundus Ef passes through the objective lens 31, passes through the relay lens 32, and is guided to the return light branching mirror 42.

[0081] (Receiving optical system 20) The light-receiving optical system 20 guides the reflected light, which has been deflected by the branching member 40 (reflected light branching mirror 42), to the image sensor 23.

[0082] The light-receiving optical system 20 includes a deflection mirror 21 and a relay lens 22 as a focusing lens. In some embodiments, the light-receiving optical system 20 further includes an image sensor 23.

[0083] (Polarizing mirror 21) The deflection mirror 21 deflects the reflected light, which has been deflected by the reflected light branching mirror 42, toward the relay lens 22.

[0084] (Relay lens 22) The relay lens 22 transmits the reflected light deflected by the deflection mirror 21 and guides it to the image sensor 23 (imaging surface).

[0085] In some embodiments, the relay lens 22 is configured to act as a focusing lens and is movable in the optical axis direction of the light-receiving optical system 20. By moving the relay lens 22 in the optical axis direction of the light-receiving optical system 20, the image sensor 23 (imaging surface) can be positioned at or near the conjugate position P of the fundus.

[0086] In some embodiments, the image sensor 23 is configured to be movable in the optical axis direction of the light-receiving optical system 20.

[0087] (Image sensor 23) The image sensor 23 (imaging surface, light-receiving surface, detection surface) can be positioned at or near the conjugate position P of the fundus. The image sensor 23 functions as a two-dimensional image sensor with pixelated light-receiving elements. The image sensor 23 can set a virtually movable light-receiving region (light-receiving area) at or near the conjugate position P of the fundus.

[0088] For example, the light reception result from the image sensor 23 is captured and read out using a rolling shutter method. In some embodiments, the light reception result from the image sensor 23 is captured and read out using a global shutter method that allows the light-receiving area to be changed or moved. In some embodiments, the control unit described later controls the readout of the light reception result by controlling the image sensor 23. In some embodiments, the image sensor 23 can automatically output light reception results for a predetermined line along with information indicating the light reception position.

[0089] Such an image sensor 23 includes, for example, a CMOS (Complementary Metal Oxide Semiconductor) image sensor or a CCD (Charge Coupled Device) image sensor.

[0090] A slit disc 60 is positioned on the optical path between the relay lens 22 and the image sensor 23 such that a slit aperture forming region is located at or near the fundus conjugate position P.

[0091] As described above, when the slit disc 60 rotates and a slit opening is positioned in the optical path between the relay lens 22 and the image sensor 23, the light that has passed through the slit opening and returned from the relay lens 22 is received on the imaging surface of the image sensor 23.

[0092] When one of the slit openings 61-1 to 61-8 formed in the slit disk 60 is positioned in the optical path of the illumination light in the illumination optical system 10, the other slit openings 61-1 to 61-8 are positioned in the optical path of the return light in the light receiving optical system 20.

[0093] In some embodiments, the period T1 during which the slit aperture crosses the optical path of the illumination light (the period from the start timing of the slit aperture crossing to the end timing of the slit aperture crossing) overlaps with the period T2 during which another slit aperture crosses the optical path of the return light. In some embodiments, period T1 is simultaneous (exactly coincidental) or approximately simultaneous with period T2. In some embodiments, period T2 is included in period T1. That is, period T2 starts after the start timing of period T1, and period T1 ends after the end timing of period T2.

[0094] (Black dot plate 50) In the illumination optical system 10, a black spot plate 50 is positioned on the optical axis O between the branching member 40 and the slit disc 60 (slit opening). The black spot plate 50 blocks the light reflected by the objective lens 31 from the illumination light. One or more black spot plates 50 may be positioned on the optical axis O. In this embodiment, the black spot plate 50 is positioned between the branching member 40 and the deflection mirror 16.

[0095] Each of the one or more black dot plates 50 is positioned on the optical path between the branching member 40 and the slit disc 60 (slit opening) at a position (objective lens reflected light imaging position) or near such a position where illumination light is reflected by the objective lens 31 and an image is formed in the illumination optical system 10.

[0096] In some embodiments, each of the one or more black dot plates 50 is positioned on the optical axis O at a position optically conjugate to the lens vertex of the objective lens 31 (lens vertex conjugate position) or in its vicinity. In some embodiments, each of the one or more black dot plates 50 is positioned at the objective lens reflected light imaging position or in its vicinity, on the optical path between the branching member 40 and the slit disc 60 (slit aperture), within the lens vertex conjugate position or its vicinity.

[0097] In some embodiments, each of the one or more black dot plates 50 is positioned so that illumination light is reflected by the objective lens 31 and imaged in the illumination optical system 10, with two or more apertures formed in the iris diaphragm 13 acting as object points. Here, the object points may be, for example, any one of the two or more apertures, or a representative position of the two or more apertures.

[0098] In some embodiments, each of the one or more black dot plates 50 is positioned at at least one location where illumination light is reflected from the front surface of the objective lens 31 to form an image in the illumination optical system 10, and where illumination light is reflected from the rear surface of the objective lens 31 to form an image in the illumination optical system 10. Here, the front surface of the objective lens 31 is the lens surface of the objective lens 31 facing the eye under examination E, and the rear surface of the objective lens 31 is the lens surface of the objective lens 31 on the light source 11 side.

[0099] As described above, when the objective lens 31 includes one or more cemented lenses, each of the one or more black dot plates 50 is positioned at or near a position where it forms an image in the optical path between the branching member 40 and the slit disc 60 due to the reflection of illumination light from one or more cemented surfaces of the one or more cemented lenses.

[0100] In some embodiments, a single black dot plate 50 is positioned on the optical axis O by adjusting the curvature of the lens surface of the objective lens 31, etc., so that two or more positions where the reflected light of the illumination light from the objective lens 31 is imaged are concentrated at a single position in the illumination optical system 10. In Figure 1, a single black dot plate 50 is positioned between the branching member 40 and the slit disc 60.

[0101] In the ophthalmic device 1 having this configuration, light generated by the light source 11 passes through the relay lens 12 and uniformly illuminates the iris diaphragm 13. The light that passes through the opening formed in the iris diaphragm 13 is irradiated onto the slit opening forming region of the slit disc 60. When the slit disc 60 rotates and the slit opening is positioned in the optical path of the illumination light of the illumination optical system 10, the light that passes through the slit opening is guided to the relay lens 15 as slit-shaped illumination light. The illumination light guided to the relay lens 15 passes through the relay lens 15, is deflected by the deflection mirror 16, and is deflected by the illumination light branching mirrors 41a and 41b. The illumination light deflected by the illumination light branching mirrors 41a and 41b passes through the relay lens 32, passes through the objective lens 31, and is irradiated onto the fundus Ef through the pupil Eu.

[0102] The reflected light from the illuminating fundus Ef exits the eye through the pupil Eu, passes through the objective lens 31, passes through the relay lens 32, is deflected by the reflected light branching mirror 42, and is deflected by the deflection mirror 21. The reflected light deflected by the deflection mirror 21 passes through the relay lens 22 and illuminates the slit aperture forming region of the slit disk 60. When the slit disk 60 rotates and the slit aperture is positioned in the optical path of the reflected light of the light-receiving optical system 20, the reflected light that has passed through the slit aperture forms an image on the imaging surface of the image sensor 23.

[0103] Figure 6 shows an explanatory diagram of a fundus Ef scan using the slit disc 60 according to this embodiment. In Figure 6, for the sake of explanation, the illumination regions IL1 to IL8 on the fundus Ef are shown as being illuminated by illumination light passing through the slit openings 61-1 to 61-8, respectively.

[0104] As shown in Figure 6, when slit-shaped illumination light passing through the slit aperture 61-1 irradiates the illumination area IL1 on the fundus Ef, the reflected light from the illumination area IL1 is guided to the photodetector optical system 20. In the photodetector optical system 20, for example, the reflected light that has passed through the slit aperture 61-5, which is traversing the optical path of the reflected light, is received by the imaging surface of the image sensor 23.

[0105] Next, as the slit disc 60 rotates and the slit-shaped illumination light passing through the slit aperture 61-2 is irradiated onto the illumination area IL2 on the fundus Ef, the reflected light from the illumination area IL2 is guided to the light-receiving optical system 20. In the light-receiving optical system 20, for example, the reflected light that has passed through the slit aperture 61-6 as it crosses the optical path of the reflected light is received by the imaging surface of the image sensor 23.

[0106] Similarly, when the slit disc 60 rotates and the slit-shaped illumination light that has passed through the slit aperture 61-8 is irradiated onto the illumination area IL8 on the fundus Ef, the reflected light from the illumination area IL8 is guided to the light-receiving optical system 20. In the light-receiving optical system 20, for example, the reflected light that has passed through the slit aperture 61-4 as it traverses the optical path of the reflected light is received by the imaging surface of the image sensor 23.

[0107] As described above, a predetermined imaging area of ​​the IMR on the fundus Ef is sequentially illuminated by a slit-shaped illumination light, and the reflected light from each illuminated area is sequentially received.

[0108] With this configuration, the optical path length (path length) and optical magnification of the illumination light from the slit aperture located in the optical path of the illumination light to the fundus Ef coincide with the optical path length (path length) and optical magnification of the return light from the fundus Ef to the slit aperture located in the optical path of the return light. This makes it possible to use the same optical components in the illumination optical system 10 and the light-receiving optical system 20, or to simplify the control of the optical system, thereby simplifying the optical design and configuration of the optical system. For example, it becomes possible to use the same optical components for the relay lenses 15 and 22, to unify the control for the relay lenses 15 and 22, or to move or link the relay lenses 15 and 22 together.

[0109] [Processing System] Figures 7 and 8 show an example of the configuration of the processing system of the ophthalmic device 1 according to the first embodiment. In Figure 7, the same reference numerals are used for parts similar to those in Figure 1, and their descriptions are omitted as appropriate. In Figure 8, the same reference numerals are used for parts similar to those in Figure 7, and their descriptions are omitted as appropriate.

[0110] The processing system (control system) of the ophthalmic device 1 is centered around the control unit 100. The control unit 100 controls each part of the ophthalmic device 1.

[0111] The control unit 100 includes a main control unit 101 and a storage unit 102. The functions of the main control unit 101 are realized, for example, by a processor. The storage unit 102 stores in advance computer programs for controlling the ophthalmic device 1. These computer programs include programs for controlling the illumination optical system, the light-receiving optical system, the scanning disk, the image forming program, the data processing program, and the user interface program. The control unit 100 executes control processing by operating the main control unit 101 in accordance with such computer programs.

[0112] (Main control unit 101) The main control unit 101 controls the illumination optical system 10, the light-receiving optical system 20 including the image sensor 23, the moving mechanisms 15D and 22D, and the rotation mechanism 60D. Furthermore, the main control unit 101 controls the image forming unit 200, the data processing unit 300, and the user interface (UI) unit 110.

[0113] Control of the illumination optical system 10 includes control of the light source 11, among other things.

[0114] Control of the light source 11 includes turning the light source on and off, and adjusting the light intensity of the emitted light.

[0115] Control of the light-receiving optical system 20 includes control of the image sensor 23, among other things.

[0116] Control of the image sensor 23 includes setting the light-receiving area on the imaging surface and controlling the reading of the light-receiving result using a rolling shutter method (for example, setting the light-receiving size corresponding to the size of the illumination pattern (illumination area)). Control of the image sensor 23 also includes reset control, exposure control, charge transfer control, output control, etc.

[0117] The moving mechanism 15D moves the relay lens 15 in the direction of the optical axis O. The main control unit 101 outputs a control signal to the moving mechanism 15D, thereby moving the relay lens 15 by an amount and direction corresponding to the control signal. For example, the ophthalmic device 1 is provided with an actuator that generates a driving force to drive the moving mechanism 15D, and a transmission mechanism that transmits this driving force. The actuator is composed of, for example, a pulse motor. The transmission mechanism is composed of, for example, a combination of gears or a rack and pinion. The moving mechanism 15D receives the driving force generated by the actuator controlled by the main control unit 101 and moves the relay lens 15 in the direction of the optical axis O.

[0118] The moving mechanism 22D moves the relay lens 22 in the direction of the optical axis of the light-receiving optical system 20. The main control unit 101 outputs a control signal to the moving mechanism 22D, thereby moving the relay lens 22 by an amount and direction of movement corresponding to the control signal. For example, the ophthalmic device 1 is provided with an actuator that generates a driving force to drive the moving mechanism 22D, and a transmission mechanism that transmits this driving force. The actuator is composed of, for example, a pulse motor. The transmission mechanism is composed of, for example, a combination of gears or a rack and pinion. The moving mechanism 22D receives the driving force generated by the actuator controlled by the main control unit 101 and moves the relay lens 22 in the direction of the optical axis of the light-receiving optical system 20.

[0119] In some embodiments, the functions of the moving mechanisms 15D and 22D are realized by a single moving mechanism. In this case, the main control unit 101 can move the relay lenses 15 and 22 together by controlling the single moving mechanism.

[0120] In some embodiments, the moving mechanisms 15D and 22D are configured to work in conjunction with each other. In this case, the main control unit 101 can move the relay lenses 15 and 22 in conjunction (interlock) by controlling either of the moving mechanisms 15D or 22D.

[0121] The rotating mechanism 60D rotates the slit disc 60 around a rotation axis that passes through the center of rotation and is positioned in the direction of extension of the lens optical axis of the objective lens 31 (the optical axis of the objective optical system 30). The main control unit 101 outputs a control signal to the rotating mechanism 60D, thereby rotating the slit disc 60 by an amount and direction corresponding to the control signal. For example, the ophthalmic apparatus 1 is provided with an actuator that generates a driving force to drive the rotating mechanism 60D, and a transmission mechanism that transmits this driving force. The actuator is composed of, for example, a pulse motor. The transmission mechanism is composed of, for example, a combination of gears or a rack and pinion. The rotating mechanism 60D receives the driving force generated by the actuator controlled by the main control unit 101 and rotates the slit disc 60 around the rotation axis.

[0122] In some embodiments, the ophthalmic apparatus 1 may be provided with a sliding mechanism instead of a rotating mechanism 60D, which allows a slit plate having two or more slit openings to slide in the direction of intersection of the optical path of the illumination light and the optical path of the return light. In this case, the main control unit 101 controls the sliding mechanism so that the slit openings can cross the optical path of the illumination light and the optical path of the return light at a desired timing, similar to the slit openings formed on the slit disc 60.

[0123] In some embodiments, the ophthalmic apparatus 1 includes an optical system movement mechanism that moves the optical system relative to the eye E under examination. The optical system movement mechanism moves the optical system (apparatus optical system) shown in Figure 1 in three dimensions. The optical system shown in Figure 1 includes an illumination optical system 10, a light-receiving optical system 20, an objective optical system 30, a branching member 40, and a slit disc 60. For example, the optical system movement mechanism includes a first mechanism, a second mechanism, and a third mechanism. The first mechanism moves the optical system (a housing containing the optical system) in the horizontal direction (left-right direction). The second mechanism moves the optical system in the vertical direction (up-down direction). The third mechanism moves the optical system in the direction of the optical axis O of the illumination optical system 10 (depth direction, front-back direction, working distance direction). For example, the first mechanism includes a first stage that is movable in the horizontal direction and a first movement mechanism that moves the first stage. For example, the second mechanism includes a second stage that is movable in the vertical direction and a second movement mechanism that moves the second stage. For example, the third mechanism includes a third stage that is movable in the direction of the optical axis O, and a third moving mechanism that moves the third stage. Each moving mechanism includes a pulse motor as an actuator and operates under control from the main control unit 101.

[0124] Control over the optical system movement mechanism is used in alignment and tracking. Tracking involves moving the device's optical system in accordance with the eye movements of the subject being photographed. When tracking is performed, alignment and focus adjustments are carried out beforehand. Tracking is a function that maintains a suitable positional relationship of alignment and focus by making the position of the device's optical system follow the eye movements.

[0125] In manual alignment, the user operates the UI unit 110 to cancel out the displacement of the eye being photographed relative to the optical system, thereby moving the optical system and the eye E relative to the optical system. For example, the main control unit 101 controls the optical system movement mechanism by outputting control signals corresponding to the operation performed on the UI unit 110 to the first movement mechanism, the second movement mechanism, and the third movement mechanism, thereby moving the optical system relative to the eye E.

[0126] In the case of auto-alignment, the main control unit 101 controls the optical system movement mechanism so that the displacement of the eye being photographed relative to the optical system is canceled out, thereby moving the optical system relative to the eye E being photographed. For example, the ophthalmic device 1 includes two or more anterior segment cameras that photograph the anterior segment of the eye E being photographed from different directions. The main control unit 101 acquires the analysis results of two anterior segment images acquired by the two anterior segment cameras. Based on the acquired analysis results, the main control unit 101 determines the positional relationship between the two anterior segment cameras and the eye E being photographed, and based on the determined positional relationship, controls the optical system movement mechanism so that the positional relationship of the optical system relative to the eye E being photographed becomes a predetermined positional relationship.

[0127] Control of the image forming unit 200 includes image forming control, which forms an image of the eye E under examination from the light reception results obtained by the image sensor 23.

[0128] Control over the data processing unit 300 includes image processing control for the image formed by the image forming unit 200.

[0129] Control over the UI unit 110 includes control over the display device and control over the operation device (input device).

[0130] (Storage unit 102) The memory unit 102 stores various types of data. Examples of data stored in the memory unit 102 include light reception results obtained by the image sensor 23, image data of images formed by the image forming unit 200, processing results obtained by the data processing unit 300, and subject eye information. Subject eye information includes information about the subject, such as patient ID and name, and information about the subject eye, such as left / right eye identification information.

[0131] Furthermore, the memory unit 102 stores various programs and data necessary for operating the ophthalmic device 1.

[0132] (Image forming unit 200) The image forming unit 200 forms a light-receiving image based on the light-receiving result read from the image sensor 23 under control from the main control unit 101 (control unit 100). The image forming unit 200 sequentially forms light-receiving images corresponding to the (virtual) light-receiving area of ​​the image sensor 23, and from the multiple light-receiving images formed, it is possible to form a fundus image representing the morphology of the fundus Ef of the eye under examination. Various images (image data) formed by the image forming unit 200 are stored, for example, in the storage unit 102.

[0133] For example, the image forming unit 200 includes a processor and performs processing according to a program stored in a memory unit or the like to realize the above functions.

[0134] (Data processing unit 300) The data processing unit 300 performs various image processing operations on the light reception results acquired from the image sensor 23. Image processing operations include noise reduction processing on the light reception results and brightness correction processing to make it easier to identify predetermined areas depicted in the light reception image based on the light reception results.

[0135] The data processing unit 300 includes a processor and performs processing according to a program stored in a memory unit or the like to realize the above functions.

[0136] Figure 8 shows a block diagram of an example configuration of the data processing unit 300.

[0137] The data processing unit 300 includes an image correction unit 310. The image correction unit 310 performs black spot correction processing on the fundus image of the eye E formed by the image forming unit 200. The acquired fundus image of the eye E depicts two black spots corresponding to the openings 13a and 13b formed in the iris diaphragm 13, respectively. The black spot correction processing is performed on at least one of the multiple black spots depicted in the fundus image of the eye E.

[0138] Black spot shadow correction processing is a process that corrects the tonal information (luminance information, luminance distribution) of the black spot shadow area depicted in the image, thereby making the black spot shadow less noticeable compared to the surrounding area, or even making the black spot shadow disappear altogether.

[0139] One example of black spot shadow correction processing is a process that corrects the tonal values ​​(luminance values, luminance distribution) within a black spot shadow area based on the tonal values ​​(brightness) surrounding the black spot shadow area depicted in the fundus image. For example, the tonal values ​​within a black spot shadow area are corrected based on statistical values ​​of the luminance distribution of the area surrounding the black spot shadow area. Examples of statistical values ​​include median, mean, maximum, minimum, and mode.

[0140] As a second example of black spot shadow correction processing, an optical simulation is performed using the optical conditions of the ophthalmic device 1. Based on the areas of black spots identified in the simulation image obtained in advance, the areas to be corrected and the amount of correction are determined. For example, the image correction unit 310 corrects the areas of black spots by changing the brightness of a predetermined area in the fundus image obtained by the image forming unit 200 by a predetermined amount, using the areas to be corrected and the amount of correction determined in advance.

[0141] In some embodiments, the image correction unit 310 identifies areas of black spots in the fundus image by analyzing the fundus image of the eye E under examination. For example, areas of black spots are identified based on changes in the grayscale value of the contour of the area of ​​black spots, or based on a known shape of the area of ​​black spots. The image correction unit 310 can then perform the black spot correction process described above on the identified areas.

[0142] The light-receiving optical system 20 is an example of a "photography optical system" according to the embodiment. The slit disc 60 (and rotating mechanism 60D) is an example of a "scanning unit" according to the embodiment. The return light branching mirror 42 is an example of a "first branching mirror" according to the embodiment. The illumination light branching mirrors 41a and 41b are examples of "two or more second branching mirrors" according to the embodiment. The slit disc 60 is an example of an "optical chopper" or "Nipkow disc" according to the embodiment. The relay lens 15 is an example of a "first focusing lens disposed between one or more black spot plates and a slit disc and movable in the optical axis direction of the illumination optical system" according to the embodiment. The relay lens 22 is an example of a "second focusing lens disposed between a branching member and a slit disc and movable in the optical axis direction of the light-receiving optical system" according to the embodiment.

[0143] <Example of operation> Next, an example of the operation of the ophthalmic device 1 according to the first embodiment will be described.

[0144] Figure 9 shows an example of operation of the ophthalmic device 1 according to the first embodiment. Figure 9 is a flowchart of the operation example of the ophthalmic device 1 according to the first embodiment. The memory unit 102 stores a computer program for realizing the process shown in Figure 9. The main control unit 101 executes the process shown in Figure 9 by operating according to this computer program.

[0145] Prior to the process shown in Figure 9, the alignment of the optical system with respect to the eye E under examination is assumed to be completed, and the slit disc 60 is assumed to be pre-set to a predetermined rotation start angle.

[0146] (S1: Obtain diopter) First, the main control unit 101 acquires the diopter (refractive index) of the eye E being examined. For example, the main control unit 101 acquires the diopter of the eye E being examined from an external ophthalmic measuring device or electronic medical record. Alternatively, the main control unit 101 acquires the diopter specified by the user using the UI unit 110.

[0147] (S2: Focus control) Next, the main control unit 101 controls the movement mechanisms 15D and 22D based on the diopter of the eye E being examined, which was acquired in step S1. Specifically, the main control unit 101 determines the position of the relay lens 15 on the optical axis of the illumination optical system 10 and the position of the relay lens 22 on the optical axis of the light-receiving optical system 20, which correspond to the diopter of the eye E being examined. The main control unit 101 controls the movement mechanisms 15D and 22D so that the relay lenses 15 and 22 move to the determined positions, respectively.

[0148] In some embodiments, the main control unit 101 moves the relay lens 15 in the direction of the optical axis O by a movement direction and amount corresponding to the diopter of the eye E being examined, and also moves the relay lens 22 in the direction of the optical axis of the light-receiving optical system 20.

[0149] In some embodiments, the moving mechanisms 15D and 22D are configured to move the relay lenses 15 and 22 in conjunction with each other.

[0150] (S3: Light source turned on / Slit disk rotation started) Next, the main control unit 101 turns on the light source 11 to illuminate it. The main control unit 101 also controls the rotation mechanism 60D to start the rotation of the slit disk 60 around the rotation axis. The main control unit 101 starts the rotation of the slit disk 60 in a predetermined direction at a predetermined rotation speed.

[0151] As a result, as described above, the illumination optical system 10 starts scanning a predetermined imaging area in the fundus Ef using slit-shaped illumination light.

[0152] (S4: Light reception timing?) Next, the main control unit 101 determines whether or not it is the light-receiving timing when the reflected light from the retinal ef (Ef) is received on the imaging surface of the image sensor 23. The light-receiving timing corresponds to the timing when the slit opening of the slit disk 60 is positioned in the optical path of the reflected light in the light-receiving optical system 20.

[0153] For example, the main control unit 101 determines whether or not it is the light reception timing based on a predetermined rotation start angle, the rotation direction of the slit disc 60 set in step S3, and the rotation speed. When it is determined that it is the light reception timing (S4:Y), the operation of the ophthalmic device 1 proceeds to step S5. When it is determined that it is not the light reception timing (S4:N), the operation of the ophthalmic device 1 repeats the process of step S4.

[0154] (S5: Obtain light reception results) When it is determined in step S4 that it is time to receive light (S4:Y), the main control unit 101 controls the image sensor 23 and obtains the light reception results of pixels in the light-receiving area of ​​the imaging surface of the image sensor 23 that have received the reflected light of illumination from the illumination area of ​​the fundus Ef.

[0155] (S6: Next irradiation position?) Next, the main control unit 101 determines whether there is an illumination position to be illuminated with the illumination light next. The main control unit 101 can determine whether there is an illumination position to be illuminated with the illumination light next by determining whether the illumination range of the sequentially moving illumination light covers the predetermined imaging range of the fundus Ef.

[0156] Next, when it is determined that there is an irradiation area to be illuminated with the illumination light (S6:Y), the operation of the ophthalmic device 1 proceeds to step S4. Next, when it is determined that there is no irradiation area to be illuminated with the illumination light (S6:N), the operation of the ophthalmic device 1 proceeds to step S7.

[0157] (S7: End rotation of the slit disk / Turn off the light source) If it is determined in step S6 that there is no illumination position to be illuminated next with the illumination light (S6:N), the main control unit 101 controls the rotation mechanism 60D to stop the rotation of the slit disc 60. The main control unit 101 also sets the light source 11 to OFF and turns off the light source 11.

[0158] (S8: Forming an image) Next, the main control unit 101 causes the image forming unit 200 to form a fundus image of the eye E under examination from the light reception results obtained by repeating the process in step S5.

[0159] For example, the image forming unit 200 synthesizes multiple light-receiving results, each with a different illumination range, based on the order in which the illumination ranges move, for the number of times the process in step S5 is repeated. As a result, a fundus image for one frame of the fundus Ef of the eye under examination is formed.

[0160] In some embodiments, in step S5, illumination light is shone onto an illumination range that is set to have overlapping regions with adjacent illumination ranges. As a result, in step S8, a fundus image for one frame is formed by combining the light reception results so that the overlapping regions of each other overlap.

[0161] Figure 10A schematically shows the fundus image formed in step S8. In Figure 10A, the fundus image IMG0 formed in step S8 is assumed to be clipped to a circular shape, similar to fundus images acquired by conventional ophthalmic devices.

[0162] In the fundus image IMG0, black spots BS1 and BS2 are depicted, corresponding to the apertures 13a and 13b formed in the iris diaphragm 13, respectively. Here, black spot BS1 corresponds to aperture 13a, and black spot BS2 corresponds to aperture 13b.

[0163] The region of the black spot shadow BS1 formed in correspondence with aperture 13a contains fundus information (grayscale information) based on the amount of reflected light from the illumination light that passed through aperture 13b other than aperture 13a. The region of the black spot shadow BS2 formed in correspondence with aperture 13b contains fundus information (grayscale information) based on the amount of reflected light from the illumination light that passed through aperture 13a other than aperture 13b.

[0164] (S9: Corrects black spot shadows) Next, the main control unit 101 controls the image correction unit 310 to perform black spot shadow correction processing on the fundus image formed in step S8. The image correction unit 310 corrects the black spot shadows by changing the brightness of the black spot shadow areas BS1 and BS2 in the fundus image by a predetermined amount, based on the areas to be corrected and the amount of correction identified based on the simulation results performed in advance.

[0165] Figure 10B schematically shows the fundus image corrected in step S9. Figure 10B illustrates the fundus image after black spot shadow correction processing has been applied to the fundus image IMG0 shown in Figure 10A.

[0166] The image correction unit 310 applies black spot shadow correction processing to the fundus image IMG0 as described above, thereby generating a fundus image IMG1 that includes regions BS1a and BS2a in which the brightness of the regions of black spot shadows BS1 and BS2 has been corrected.

[0167] This concludes the operation of ophthalmic device 1 (end).

[0168] In Figure 9, steps S1 to S3, which have no technical relation to steps S4 to S5, do not necessarily have to be executed. Similarly, steps S4 to S5 have no technical relation to steps S8 to S9. Therefore, even if steps S8 to S9 are executed, steps S4 to S5 do not have to be executed, and even if steps S4 to S5 are executed, steps S8 to S9 do not have to be executed.

[0169] As described above, according to the first embodiment, the fundus image obtained by illuminating the fundus Ef of the eye E under examination with illumination light that has passed through two apertures 13a and 13b depicts two black spot shadows BS1 and BS2, corresponding to apertures 13a and 13b, respectively. Each black spot shadow contains gradation information obtained by illumination with illumination light that has passed through the other aperture excluding the corresponding aperture. As a result, neither the black spot shadows BS1 nor BS2 are completely blacked out, and each black spot shadow region contains gradation information (intraocular information, fundus information) corresponding to the amount of illumination light that has passed through the remaining aperture or the amount of reflected light that has passed through the remaining light-receiving aperture. Thus, by performing black spot shadow correction processing on the fundus image in which the above-described black spot shadows are depicted, it becomes possible to obtain a fundus image that is effective for diagnosis without losing fundus information.

[0170] Therefore, even when performing micro-pupil imaging by shortening the gap between the illumination aperture and the light-receiving aperture in the pupillary conjugate plane, it is possible to obtain fundus images that are effective for diagnosing micro-pupil eyes.

[0171] Furthermore, a slit disc that rotates around a rotation axis located on the extension of the optical axis of the objective lens 31 is used to generate slit-shaped illumination light, and the reflected light is received by the imaging surface of the image sensor 23. This makes it possible to match the optical path length (path length) and optical magnification of the illumination light from the slit aperture that generates the slit-shaped illumination light to the fundus Ef with the optical path length (path length) and optical magnification of the reflected light from the fundus Ef to the slit aperture that exposes the imaging surface of the image sensor 23. In other words, the illumination optical system 10 and the light-receiving optical system 20 are configured such that the optical path length and optical magnification of the illumination light from the branching member 40 to the slit aperture that crosses the optical path of the illumination light are approximately the same as the optical path length and optical magnification of the reflected light from the branching member 40 to the slit aperture that crosses the optical path of the reflected light. As a result, the same optical components can be used in the illumination optical system 10 and the light-receiving optical system 20, and the control of the optical system can be simplified, thus simplifying the optical design and configuration of the optical system.

[0172] In some embodiments, an optical member (optical path length correction member, path length correction member) is provided in at least one of the illumination optical system 10 and the light receiving optical system 20 to match the optical path length (path length) of the illumination light with that of the return light.

[0173] <Second Embodiment> The optical system configuration of the ophthalmic apparatus according to the embodiment is not limited to the optical system of the ophthalmic apparatus 1 according to the first embodiment. For example, the ophthalmic apparatus according to the embodiment may be provided with a perforated mirror instead of a branched mirror.

[0174] The following describes the ophthalmic device according to the second embodiment, focusing on the differences from the ophthalmic device 1 according to the first embodiment.

[0175] Figure 11 shows an example of the optical system configuration of an ophthalmic apparatus according to the second embodiment. In Figure 11, the same reference numerals are used for parts that are the same as those in Figure 1, and their descriptions are omitted as appropriate.

[0176] The optical system configuration of the ophthalmic device 1a according to the second embodiment differs from the optical system configuration of the ophthalmic device 1 according to the first embodiment shown in Figure 1, in that a branching member 40a is provided instead of the branching member 40. The branching member 40a includes a hole mirror 70 and a deflection mirror 71. The deflection mirror 71 is positioned between the hole mirror 70 and the deflection mirror 21 on the optical path of light passing through the hole formed in the hole mirror 70.

[0177] (hole mirror 70) The aperture mirror 70 (specifically, the hole portion described later) is positioned at or near the pupil conjugate position Q. The aperture mirror 70 has the function of a photographic aperture. The aperture mirror 70 is an optical path dividing member that spatially divides the optical path of the illumination light and the optical path of the return light from the fundus Ef to which the illumination light was irradiated.

[0178] The aperture mirror 70 has a hole (aperture) formed in the center of the base through which the optical axis passes, and a reflective member is provided around the periphery of the center to reflect light. In Figure 11, the aperture mirror 70 is positioned so that the optical axis of the objective optical system 30 passes through the hole, and the reflective member provided around the periphery is configured to reflect illumination light from the illumination optical system 10 and guide it to the objective optical system 30.

[0179] In some embodiments, the hole mirror 70, positioned so that the optical axis of the illumination optical system 10 passes through the hole, is configured with a reflective member provided on its periphery to guide the reflected light from the eye under examination E to the light-receiving optical system 20. In some embodiments, the hole mirror 70 has a hole formed on one side of the base through which the optical axis passes, and a reflective member that reflects light is provided on the other side of the base. In this case, the light that passes through the hole is guided to the light-receiving optical system 20, and the light reflected by the reflective member is guided to the eye under examination E. Alternatively, conversely, the light that passes through the hole is guided to the eye under examination E, and the light reflected by the reflective member is guided to the light-receiving optical system 20.

[0180] Illumination light from the illumination optical system 10 is reflected by the reflective material at the periphery of the hole formed in the hole mirror 70 and guided to the relay lens 32. The reflected light from the eye E under examination passes through the relay lens 32, through the hole formed in the hole mirror 70, is deflected by the deflection mirror 71, and guided to the light receiving optical system 20.

[0181] In some embodiments, a beam splitter, a half-mirror, a multifaceted mirror, or a dichroic mirror is used instead of the hole mirror 70.

[0182] The deflection mirror 71 makes it possible to match the optical path length (path length) and optical magnification of the illumination light from the slit aperture that generates the slit-shaped illumination light to the fundus Ef with the optical path length (path length) and optical magnification of the return light from the fundus Ef to the slit aperture that exposes the imaging surface of the image sensor 23. As a result, the same optical components can be used in the illumination optical system 10 and the light-receiving optical system 20, and the control of the optical system can be simplified, thereby simplifying the optical design and configuration of the optical system.

[0183] In some embodiments, an optical member (optical path length correction member, path length correction member) is further arranged in at least one of the illumination optical system 10 and the light receiving optical system 20 to match the optical path length (path length) of the illumination light with the optical path length (path length) of the return light.

[0184] In the second embodiment, one of the illumination optical system 10 and the light-receiving optical system 20 is positioned in the direction of reflection of the reflective member around the hole formed in the hole mirror 70, and the other of the illumination optical system 10 and the light-receiving optical system 20 is positioned in the direction of passage through the hole.

[0185] Furthermore, in the second embodiment as well, the illumination optical system 10 and the light receiving optical system 20 are configured such that the optical path length and optical magnification of the illumination light from the branching member 40a to the slit opening that crosses the optical path of the illumination light are substantially the same as the optical path length and optical magnification of the return light from the branching member 40a to the slit opening that crosses the optical path of the return light.

[0186] As described above, according to the second embodiment, similar to the first embodiment, by performing black spot correction processing on fundus images in which black spots are depicted, it becomes possible to obtain fundus images that are effective for diagnosis without losing fundus information. Therefore, even when performing micro-pupil imaging by shortening the gap, which is the distance between the illumination aperture and the light-receiving aperture in the pupillary conjugate plane, it is possible to obtain fundus images that are effective for diagnosing micro-pupil eyes.

[0187] Furthermore, the optical path length (path length) and optical magnification of the illumination light from the slit aperture that generates the slit-shaped illumination light to the fundus Ef can be matched with the optical path length (path length) and optical magnification of the return light from the fundus Ef to the slit aperture that exposes the imaging surface of the image sensor 23.

[0188] <Variation> The configuration of the ophthalmic apparatus according to the embodiment is not limited to the configuration of the ophthalmic apparatus according to the first embodiment or the second embodiment.

[0189] [First variation] The shape of the slit opening formed in the slit disc 60 according to this embodiment is not limited to the shape described in Figure 3. The shape of the slit opening formed in the slit disc 60 may be any shape.

[0190] Figure 12 shows an explanatory diagram of the slit disc 60 according to the first embodiment or the first modified example of the second embodiment. Similar to Figure 3, Figure 12 schematically shows an example of the configuration of the slit disc 60 as viewed from the direction of the rotation axis O1.

[0191] Each of the two or more slit openings formed in the slit disc 60 in this modified example has a shape that is rotated by 90 degrees from each of the slit openings 61-1 to 61-8 formed in the slit disc 60 shown in Figure 3. As a result, in this modified example, the irradiation area of ​​the illumination light irradiated onto the fundus Ef also has a shape that is rotated by 90 degrees from the irradiation area in the embodiment.

[0192] Figure 13 shows an explanatory diagram of the scanning of the fundus Ef using the slit disc 60 according to this modified example. In Figure 13, as in Figure 6, the illuminated regions IL1 to IL8 on the fundus Ef are shown as being illuminated by illumination light passing through the slit apertures 61-1 to 61-8, respectively.

[0193] As shown in Figure 13, when slit-shaped illumination light passing through the slit aperture 61-1 irradiates the illumination area IL1 on the fundus Ef, the reflected light from the illumination area IL1 is guided to the photodetector optical system 20. In the photodetector optical system 20, for example, the reflected light that has passed through the slit aperture 61-5, which is traversing the optical path of the reflected light, is received by the imaging surface of the image sensor 23.

[0194] Next, as the slit disc 60 rotates and the slit-shaped illumination light passing through the slit aperture 61-2 is irradiated onto the illumination area IL2 on the fundus Ef, the reflected light from the illumination area IL2 is guided to the light-receiving optical system 20. In the light-receiving optical system 20, for example, the reflected light that has passed through the slit aperture 61-6 as it crosses the optical path of the reflected light is received by the imaging surface of the image sensor 23.

[0195] Similarly, when the slit disc 60 rotates and the slit-shaped illumination light that has passed through the slit aperture 61-8 is irradiated onto the illumination area IL8 on the fundus Ef, the reflected light from the illumination area IL8 is guided to the light-receiving optical system 20. In the light-receiving optical system 20, for example, the reflected light that has passed through the slit aperture 61-4 as it traverses the optical path of the reflected light is received by the imaging surface of the image sensor 23.

[0196] As described above, according to this modified example, a predetermined imaging area IMR on the fundus Ef is sequentially illuminated with slit-shaped illumination light in a direction rotated by 90 degrees with respect to the scanning direction in the embodiment, and the reflected light from each illumination area is sequentially received.

[0197] [Second variation] The slit disc 60 according to this embodiment is not limited to the configuration described in Figure 3 or Figure 11.

[0198] In the first embodiment, the second embodiment, or the first modification thereof, a case was described in which two or more slit openings are formed in a single ring-shaped slit opening forming region having a predetermined radius with respect to the rotation center of the slit disc 60. In the slit disc 60 according to the embodiment, two or more slit openings may be formed in each of two or more ring-shaped slit opening forming regions having different radii with respect to the rotation center.

[0199] Figure 14 shows an explanatory diagram of the slit disc 60 according to the first embodiment or a second modified example of the second embodiment. Similar to Figure 3, Figure 14 schematically shows an example of the configuration of the slit disc 60 as viewed from the direction of the rotation axis O1.

[0200] In this modified example, the slit disc 60 has two or more slit openings formed in each of two slit opening forming regions having different radii. Specifically, slit openings 61-1 to 61-8 are formed in the ring-shaped slit opening forming region with a longer radius (outer diameter side slit opening forming region). Furthermore, slit openings 62-1 to 62-8 are formed in the ring-shaped slit opening forming region with a shorter radius (inner diameter side slit opening forming region).

[0201] For example, slit apertures 61-1 to 61-8 are configured to cross the optical path of illumination light in the illumination optical system 10, and slit apertures 62-1 to 62-8 are configured to cross the optical path of reflected light in the light-receiving optical system 20. Alternatively, for example, slit apertures 62-1 to 62-8 are configured to cross the optical path of illumination light in the illumination optical system 10, and slit apertures 61-1 to 61-8 are configured to cross the optical path of reflected light in the light-receiving optical system 20.

[0202] The configuration relating to any one of the first to second variations described above can be applied to the configuration relating to the remaining variations of the first to second variations.

[0203] [Effect] An ophthalmic device according to an embodiment will be described.

[0204] A first embodiment of the model includes an objective lens (31), an illumination optical system (10), a scanning unit (slit disc 60 and rotating mechanism 60D), a light-receiving optical system (20), and branching members (40, 40a). The illumination optical system includes an iris diaphragm (13). The iris diaphragm has two or more apertures (13a, 13b) positioned at a location substantially conjugate to the pupil (Eu) of the eye under examination (E). The illumination optical system generates slit-shaped illumination light from the illumination light emitted by irradiating the iris diaphragm with light from a light source (11), or generates slit-shaped illumination light by irradiating the iris diaphragm with slit-shaped light. The scanning unit moves the illumination area of ​​the illumination light in the imaging area (fundus Ef) of the eye under examination in a predetermined scanning direction. The light-receiving optical system is configured to guide the reflected light of the illumination light irradiated onto the eye under examination via the objective lens to an image sensor (23) positioned substantially conjugate to the imaging area. The branching member is positioned between the objective lens and the illumination optical system at a position approximately conjugate to the pupil optically, deflecting the illumination light from the illumination optical system and guiding it to the objective lens, while also deflecting the reflected light that has been guided through the objective lens toward the light-receiving optical system. The illumination optical system includes one or more black spot plates (50). The one or more black spot plates are positioned so that the illumination light is reflected by the objective lens and forms an image in the illumination optical system.

[0205] In this configuration, the image of the area of ​​the eye being examined obtained by the image sensor will show two or more black dots corresponding to two or more apertures formed in the iris diaphragm. Each of the two or more black dots contains intraocular information (grayscale information) obtained by illumination with light that has passed through the remaining apertures of the two or more apertures, excluding the corresponding aperture. As a result, each of the two or more black dots is not completely blacked out, and each black dot area contains intraocular information corresponding to the amount of light from the illumination that has passed through the remaining apertures.

[0206] Therefore, even if the eye being examined has a small pupil and it is necessary to shorten the gap between the illumination aperture and the light-receiving aperture in the pupillary conjugate plane, it is possible to acquire an image containing intraocular information of the eye being examined without completely losing intraocular information, and to make an appropriate diagnosis for images of eyes with small pupils.

[0207] In a second embodiment, in the first embodiment, the scanning unit includes a slit disk (60). The slit disk has two or more slit openings, including a first slit opening and a second slit opening, formed in the circumferential direction of a predetermined rotation center, and is rotatable about a rotation axis passing through the rotation center. The scanning unit is configured such that at least a portion of the second slit opening crosses the optical path of the return light in the light receiving optical system at a timing when at least a portion of the first slit opening crosses the optical path of the illumination light in the illumination optical system.

[0208] In this embodiment, the optical path length and optical magnification of the illumination light from the branching member to the first slit opening can be easily matched with the optical path length and optical magnification of the return light from the branching member to the second slit opening. As a result, the same optical components can be used in the illumination optical system and the light-receiving optical system, and the control of the optical system can be simplified, thereby simplifying the optical design and configuration of the optical system.

[0209] In a third embodiment, as in the second embodiment, each of the one or more black dot plates is positioned so that the illumination light is reflected by the objective lens with two or more apertures formed in the iris diaphragm as object points, thereby forming an image in the illumination optical system.

[0210] This configuration makes it possible to efficiently remove only the artifacts generated by the illumination light split by the branching member, while acquiring an image that includes intraocular information of the eye being examined without completely losing intraocular information.

[0211] In the fourth embodiment, as in the second embodiment, the direction in which the rotation axis extends substantially coincides with the direction in which the optical axis of the objective lens extends.

[0212] In this embodiment, the optical path length and optical magnification of the illumination light from the branching member to the first slit opening can be easily configured to perfectly match the optical path length and optical magnification of the return light from the branching member to the second slit opening. As a result, the same optical components can be used in the illumination optical system and the light-receiving optical system, and the control of the optical system can be simplified, thereby simplifying the optical design and configuration of the optical system.

[0213] In the fifth embodiment, as in the second embodiment, the imaging site is the fundus (Ef).

[0214] With this configuration, even if the eye under examination has a small pupil, a fundus image of the eye can be obtained without completely losing fundus information as intraocular information. Therefore, it becomes possible to make an appropriate diagnosis based on images of eyes with small pupils.

[0215] In the sixth embodiment, in any of the first to fifth embodiments, one or more black dot plates are positioned at at least one of the following locations: a position where an image is formed by the reflection of illumination light from the front surface of the objective lens, and a position where an image is formed by the reflection of illumination light from the rear surface of the objective lens.

[0216] According to this embodiment, it becomes possible to efficiently remove artifacts caused by at least one of the front and rear surfaces of the objective lens, while acquiring an image that includes intraocular information of the eye being examined without completely losing intraocular information.

[0217] In the seventh embodiment, in any of the first to fifth embodiments, the objective lens includes one or more cemented lenses formed by bonding two or more lenses together. One or more black dot plates are positioned in the illumination optical system at a location where illumination light is reflected from one or more cemented surfaces of the one or more cemented lenses to form an image.

[0218] This embodiment makes it possible to efficiently remove artifacts caused by one or more bonding surfaces of the objective lens while acquiring an image that includes intraocular information of the eye being examined without completely losing intraocular information.

[0219] In the eighth embodiment, in any of the second to fifth embodiments, the branching member includes a first branching mirror (return light branching mirror 42) and two or more second branching mirrors (illumination light branching mirrors 41a, 41b). The first branching mirror deflects the return light toward the light-receiving optical system. The two or more second branching mirrors are arranged near the first branching mirror and deflect the illumination light toward the objective lens.

[0220] According to this embodiment, it becomes possible to optically couple or separate the illumination optical system and the light-receiving optical system with a simple configuration.

[0221] In the ninth embodiment, in any of the second to fifth embodiments, the illumination optical system includes a first focusing lens (relay lens 15) positioned between one or more black spot plates and a slit disc, and movable in the optical axis direction of the illumination optical system. The light-receiving optical system includes a second focusing lens (relay lens 22) positioned between a branching member and a slit disc, and movable in the optical axis direction of the light-receiving optical system. The first focusing lens and the second focusing lens are configured to move integrally or in conjunction with each other.

[0222] According to this embodiment, the slit disk, image sensor, and imaging area can be positioned in a substantially conjugate optical location with a simple configuration and simple control.

[0223] In the tenth embodiment, in any of the second to fifth embodiments, the branching member includes a hole mirror (70) in which an opening is formed at a position substantially conjugate to the pupil optically, and a reflective member is provided around the opening. One of the illumination optical system and the light-receiving optical system is arranged in the direction of reflection of the reflective member, and the other of the illumination optical system and the light-receiving optical system is arranged in the direction of passage through the opening.

[0224] According to this embodiment, it becomes possible to optically couple or separate the illumination optical system and the light-receiving optical system with a simple configuration.

[0225] In the eleventh embodiment, as in the tenth embodiment, each of the one or more black dot plates is positioned so that the illumination light is reflected by the objective lens with an aperture formed in the hole mirror as the object point, thereby forming an image in the illumination optical system.

[0226] According to this embodiment, when using a follicular microscope, it becomes possible to efficiently remove artifacts caused by the objective lens while acquiring an image that includes intraocular information of the eye being examined without completely losing intraocular information.

[0227] In the twelfth embodiment, in the tenth embodiment, one or more black dot plates are positioned at at least one of the following locations: a position where illumination light is reflected from the front surface of the objective lens to form an image in the illumination optical system, and a position where illumination light is reflected from the rear surface of the objective lens to form an image in the illumination optical system.

[0228] According to this embodiment, when using a follicular microscope, it becomes possible to efficiently remove artifacts caused by at least one of the front and rear surfaces of the objective lens while acquiring an image containing intraocular information of the eye being examined without completely losing intraocular information.

[0229] In the thirteenth embodiment, in the tenth embodiment, the objective lens includes one or more cemented lenses formed by bonding two or more lenses together. One or more black dot plates are positioned in the illumination optical system at a location where illumination light is reflected by one or more cemented surfaces of the one or more cemented lenses to form an image.

[0230] According to this embodiment, when using a follicular microscope, it becomes possible to efficiently remove artifacts caused by one or more bonding surfaces of the objective lens while acquiring an image containing intraocular information of the eye being examined without completely losing intraocular information.

[0231] In the fourteenth embodiment, in the tenth embodiment, the illumination optical system and the light receiving optical system are configured such that the optical path length and optical magnification of the illumination light from the branching member to the first slit aperture are substantially the same as the optical path length and optical magnification of the return light from the branching member to the second slit aperture.

[0232] According to this embodiment, even when using a hole mirror, the optical path length and optical magnification of the illumination light from the branching member to the first slit opening can be easily configured to perfectly match the optical path length and optical magnification of the return light from the branching member to the second slit opening. As a result, the same optical components can be used in the illumination optical system and the light-receiving optical system, and the control of the optical system can be simplified, thereby simplifying the optical design and configuration of the optical system.

[0233] In the 15th embodiment, as in the 14th embodiment, the illumination optical system includes a first focusing lens (relay lens 15) positioned between one or more black spot plates and a slit disc, and movable in the optical axis direction of the illumination optical system. The light-receiving optical system includes a second focusing lens (relay lens 22) positioned between a branching member and a slit disc, and movable in the optical axis direction of the light-receiving optical system. The first focusing lens and the second focusing lens are configured to move integrally or in conjunction with each other.

[0234] According to this embodiment, even when using a hole mirror, the slit disk, image sensor, and imaging area can be positioned in a substantially conjugate optical location with a simple configuration and simple control.

[0235] A sixteenth embodiment includes an image correction unit (310) that corrects black spot shadows depicted in an image by applying brightness correction to an image of the eye under examination acquired based on the light reception result of the image sensor, in any of the first to fifth embodiments.

[0236] In this configuration, by correcting for two or more black spots depicted in the image of the eye under examination, it is possible to avoid a complete loss of intraocular information, and even if the eye under examination has a small pupil, it becomes possible to make an appropriate diagnosis based on the image of the small pupil.

[0237] In the 17th embodiment, in the 16th embodiment, the image correction unit applies brightness correction to at least one of two or more black spot shadows depicted in the image.

[0238] This approach avoids the complete loss of intraocular information and makes it possible to perform an appropriate diagnosis based on images of eyes with small pupils, even if the eye being examined has a small pupil.

[0239] In the 18th embodiment, in the 17th embodiment, the image correction unit corrects black spot shadows by changing the brightness of a predetermined area in the image by a predetermined amount.

[0240] In this configuration, by using the results of simulations performed in advance, it becomes possible to correct the black spot shadows depicted in the image of the eye being examined with simple processing.

[0241] <Other> The embodiments described above are merely examples of how to carry out this invention. Anyone intending to carry out this invention may make any modifications, omissions, additions, etc., within the scope of the gist of this invention. [Explanation of Symbols]

[0242] 1, 1a Ophthalmological equipment 10 Illumination optical system 13 Iris Diaphragm 15, 22 Relay Lens 20 Light receiving optical system 23 Image sensor 30 Objective Optical System 31 Objective lens 40, 40a Branching member 41a, 41b Illumination light splitting mirror 42 Reflection light splitting mirror 50 Black Dot Plates 60 Slit Disk 70 hole mirror 100 Control Unit 101 Main Control Unit 102 Storage section 200 Image forming unit 300 Data Processing Unit 310 Image Correction Unit E. Eye being examined Ef fundus Eu pupil P fundus conjugate position Q: Conjugate position of the pupil

Claims

1. The objective lens, An illumination optical system that includes an iris diaphragm positioned approximately conjugate to the pupil of the eye under examination and having two or more openings, and generates a slit-shaped illumination light from the illumination light emitted by irradiating the iris diaphragm with light from a light source, or generates a slit-shaped illumination light by irradiating the iris diaphragm with slit-shaped light, A scanning unit that moves the illumination area of ​​the illumination light in the imaging area of ​​the eye to be examined in a predetermined scanning direction, A light-receiving optical system configured to guide the reflected light of the illumination light irradiated onto the eye under examination via the objective lens to an image sensor positioned at a location substantially conjugate to the imaging area, A branching member is positioned between the objective lens and the illumination optical system at a position optically substantially conjugate to the pupil, which deflects the illumination light from the illumination optical system and guides it to the objective lens, and also deflects the reflected light guided through the objective lens toward the light-receiving optical system. Includes, An ophthalmic apparatus comprising an illumination optical system including one or more black dot plates positioned at a location where the illumination light is reflected by the objective lens and an image is formed in the illumination optical system.

2. The scanning unit includes a slit disk that is rotatable about a rotation axis passing through the rotation center, and has two or more slit openings formed in the circumferential direction of a predetermined rotation center, including a first slit opening and a second slit opening, and is configured such that at least a portion of the second slit opening crosses the optical path of the return light in the light receiving optical system at the timing when at least a portion of the first slit opening crosses the optical path of the illumination light in the illumination optical system. The ophthalmic device according to feature 1.

3. Each of the one or more black dot plates is positioned so that the illumination light is reflected by the objective lens with the two or more apertures formed in the iris diaphragm as object points, thereby forming an image in the illumination optical system. The ophthalmic device according to feature 2.

4. The direction in which the rotation axis extends substantially coincides with the direction in which the optical axis of the objective lens extends. The ophthalmic device according to feature 2.

5. The area being photographed is the fundus of the eye. The ophthalmic device according to feature 2.

6. The one or more black dot plates are positioned at at least one of the following locations: a position where the illumination light is reflected from the front surface of the objective lens to form an image, and a position where the illumination light is reflected from the rear surface of the objective lens to form an image. An ophthalmic device according to any one of claims 1 to 5, characterized by the features described herein.

7. The objective lens includes one or more cemented lenses formed by bonding two or more lenses together. The one or more black dot plates are positioned so that the illumination light is reflected by one or more bonding surfaces of the one or more cemented lenses, thereby forming an image in the illumination optical system. An ophthalmic device according to any one of claims 1 to 5, characterized by the features described herein.

8. The aforementioned branching member is A first branching mirror that deflects the reflected light toward the light-receiving optical system, Two or more second branch mirrors are positioned near the first branch mirror and deflect the illumination light toward the objective lens, including The ophthalmic apparatus according to any one of claims 2 to 5.

9. The illumination optical system includes a first focusing lens positioned between the one or more black spot plates and the slit disk, and movable in the optical axis direction of the illumination optical system. The light-receiving optical system includes a second focusing lens positioned between the branching member and the slit disc, and movable in the optical axis direction of the light-receiving optical system. The first focusing lens and the second focusing lens are configured to be movable integrally or in conjunction with each other. The ophthalmic apparatus according to any one of claims 2 to 5.

10. The branching member includes a hole mirror in which an opening is formed at a position that is optically substantially conjugate to the pupil, and a reflective member is provided around the opening. One of the illumination optical system and the light receiving optical system is positioned in the reflection direction of the reflective member. The illumination optical system and the other light-receiving optical system are positioned in the direction through which the aperture passes. The ophthalmic apparatus according to any one of claims 2 to 5.

11. Each of the one or more black dot plates is positioned so that the illumination light is reflected by the objective lens with the aperture formed in the hole mirror as the object point, thereby forming an image in the illumination optical system. The ophthalmic device according to feature 10.

12. The one or more black dot plates are positioned at at least one of the following locations: a position where the illumination light is reflected from the front surface of the objective lens and an image is formed in the illumination optical system; and a position where the illumination light is reflected from the rear surface of the objective lens and an image is formed in the illumination optical system. The ophthalmic device according to feature 10.

13. The objective lens includes one or more cemented lenses formed by bonding two or more lenses together. The one or more black dot plates are positioned so that the illumination light is reflected by one or more bonding surfaces of the one or more cemented lenses, thereby forming an image in the illumination optical system. The ophthalmic device according to feature 10.

14. The illumination optical system and the light receiving optical system are configured such that the optical path length and optical magnification of the illumination light from the branching member to the first slit opening are substantially the same as the optical path length and optical magnification of the return light from the branching member to the second slit opening. The ophthalmic device according to feature 10.

15. The illumination optical system includes a first focusing lens positioned between the one or more black spot plates and the slit disk, and movable in the optical axis direction of the illumination optical system. The light-receiving optical system includes a second focusing lens positioned between the branching member and the slit disc, and movable in the optical axis direction of the light-receiving optical system. The first focusing lens and the second focusing lens are configured to be movable integrally or in conjunction with each other. The ophthalmic device according to feature 14.

16. The image correction unit includes a unit that corrects black spots depicted in the image by applying brightness correction to the image of the eye under examination acquired based on the light reception results of the image sensor. An ophthalmic device according to any one of claims 1 to 5, characterized by the features described herein.

17. The image correction unit applies the brightness correction to at least one of the two or more black spot shadows depicted in the image. The ophthalmic device according to feature 16.

18. The image correction unit corrects the black spot shadows by changing the brightness of a predetermined area in the image by a predetermined amount. The ophthalmic device according to feature 17.

Images