Ophthalmic device, ophthalmic device control method, and program

Abstract

This ophthalmic device comprises an optical system, a movement mechanism, and a control unit. The optical system is configured to irradiate a subject's eye with light and receive return light from the subject's eye. The movement mechanism moves the subject's eye and the optical system relative to each other. The control unit controls the movement mechanism on the basis of an alignment completion position corresponding to the pupil diameter of the subject's eye.

Description

Ophthalmic apparatus, control method for ophthalmic apparatus, and program

[0001] The present disclosure relates to an ophthalmic apparatus, a control method for an ophthalmic apparatus, and a program.

[0002] There is a need for an ophthalmic apparatus for screening and treating eye diseases that can easily capture (observe) images of the fundus of an eye to be examined with a wide field of view. Specifically, there is a demand for an apparatus capable of capturing an image of the fundus of an eye to be examined at a wide angle with an imaging angle of view exceeding 80 degrees in a single imaging operation. A Scanning Laser Ophthalmoscope (SLO) is known as such an ophthalmic apparatus. SLO is an apparatus that forms an image of the fundus by scanning the fundus with light and detecting the returned light with a light receiving device.

[0003] Patent Document 1 discloses a scanning ophthalmoscope capable of scanning a retina at a wide angle by moving two-dimensional parallel light scanning using a polygonal mirror and a plane mirror to an eye to be examined by a scanning moving means.

[0004] Patent Documents 2 and 3 disclose a fundus imaging apparatus capable of acquiring a high-contrast image with a simple configuration by combining fundus scanning using slit-shaped illumination light and a rolling shutter method. In particular, Patent Document 3 discloses a method for acquiring a wide-angle fundus image of an eye to be examined by scanning the fundus of the eye with slit-shaped illumination light via two elliptical concave mirrors.

[0005] Such an ophthalmic apparatus uses a curved mirror such as an elliptical concave mirror, which leads to an increase in the size of the apparatus. Therefore, it is conceivable to reduce the size of the apparatus by reducing the curvature of the curved mirror. However, this requires shortening the distance between the curved mirror and the eye to be examined, and also requires highly accurate alignment of the eye to be examined with respect to the optical system of the apparatus.

[0006] Patent Documents 4, 5, and 6 disclose a method in which an ophthalmic apparatus is provided with two imaging units, a pupil region of an eye to be examined is specified from two captured images obtained by the two imaging units, and the eye to be examined and the optical system of the apparatus are aligned with a wide angle of view based on the specified pupil region.

[0007] Japanese Patent Publication No. 2009-543585, U.S. Patent No. 7,831,106, International Publication No. 2022 / 124170, Japanese Unexamined Patent Publication No. 2013-248376, Japanese Unexamined Patent Publication No. 2018-153543, Japanese Unexamined Patent Publication No. 2019-062981

[0008] In conventional methods, the subject's eyelashes and eyelids may be depicted in the two images obtained from the two imaging units. In such images, the accuracy of identifying the pupil region of the eye under examination decreases, making it difficult to precisely align the eye under examination with the device's optical system.

[0009] The above circumstances are not limited to devices that photograph the eye under examination at a wide angle, but also apply to devices that align the optical system of the device with respect to the eye under examination.

[0010] This invention has been made in view of the above circumstances, and one of its objectives is to provide a new technology for highly accurate alignment of the eye under examination and the apparatus optical system.

[0011] One aspect of several embodiments is an ophthalmic device comprising an optical system, a moving mechanism, and a control unit. The optical system is configured to illuminate the eye under examination with light and to receive reflected light from the eye. The moving mechanism moves the eye under examination relative to the optical system. The control unit controls the moving mechanism based on the alignment completion position corresponding to the pupil diameter of the eye under examination.

[0012] According to the present invention, a new technique can be provided for precisely aligning the eye under examination with the optical system of the device.

[0013] This is a schematic diagram showing an example of the configuration of the optical system of the ophthalmic device according to the embodiment. This is a schematic diagram for explaining showing an example of the configuration of the optical system of the ophthalmic device according to the embodiment. This is a schematic diagram showing an example of the configuration of the optical system of the ophthalmic device according to the embodiment. This is a schematic diagram showing an example of the configuration of the optical system of the ophthalmic device according to the embodiment. This is a schematic diagram for explaining the configuration of the optical system of the ophthalmic device according to the embodiment. This is a schematic diagram showing an example of the configuration of the optical system of the ophthalmic device according to the embodiment. This is a schematic diagram for explaining the configuration of the optical system of the ophthalmic device according to the embodiment. This is a schematic diagram for explaining the configuration of the optical system of the ophthalmic device according to the embodiment. This is a schematic diagram for explaining the operation of the ophthalmic device according to the embodiment. This is a schematic diagram for explaining the operation of the ophthalmic device according to the embodiment. This is a schematic diagram for explaining the operation of the ophthalmic device according to the embodiment. This is a schematic diagram for explaining the operation of the ophthalmic device according to the embodiment. This is a schematic diagram illustrating the operation of the ophthalmic device according to the embodiment. This is a schematic diagram illustrating the operation of the ophthalmic device according to the embodiment. This is a schematic diagram illustrating the operation of the ophthalmic device according to the embodiment. This is a schematic diagram illustrating the operation of the ophthalmic device according to the embodiment. This is a schematic diagram illustrating the operation of the ophthalmic device according to the embodiment. This is a schematic diagram showing an example of the configuration of the control system of the ophthalmic device according to the embodiment. This is a schematic diagram showing an example of the configuration of the control system of the ophthalmic device according to the embodiment. This is a flowchart showing an example of the operation of the ophthalmic device according to the embodiment. This is a flowchart showing an example of the operation of the ophthalmic device according to the embodiment. This is a flowchart showing an example of the operation of the ophthalmic device according to the embodiment. This is a schematic diagram illustrating the operation of the ophthalmic device according to the embodiment.

[0014] Examples of embodiments of the ophthalmic apparatus, control method for the ophthalmic apparatus, and program according to this invention will be described in detail with reference to the drawings. It is possible to apply the contents of the documents cited in this specification and any prior art to the following embodiments.

[0015] The ophthalmic apparatus according to the embodiment includes an optical system, a moving mechanism, and a control unit. The optical system is configured to irradiate the eye under examination with light and receive the reflected light from the eye under examination. The moving mechanism moves the eye under examination and the optical system relative to each other. The control unit controls the moving mechanism based on the alignment completion position corresponding to the pupil diameter of the eye under examination. The ophthalmic apparatus moves the optical system to the alignment completion position by moving the optical system relative to the eye under examination, and then uses the optical system to perform imaging, observation, or measurement of the eye under examination. The alignment completion position is a position that is shifted by an amount corresponding to the pupil diameter of the eye under examination from the alignment target position of the optical system relative to the eye under examination. For example, the alignment target position is a position where the position in a two-dimensional direction perpendicular to the optical axis of the optical system coincides with the reference position of the alignment target in the eye under examination, and the optical axis direction of the optical system is a predetermined working distance.

[0016] This allows for the determination of the alignment target position while minimizing the influence of the subject's eyelashes and eyelids, enabling highly accurate positioning of the device's optical system relative to the subject's eye.

[0017] In some embodiments, a larger pupil diameter results in a greater shift from the alignment target position to the alignment completion position. A larger pupil diameter also increases the amount of light entering the eye through the pupil. Therefore, the shift from the alignment target position to the alignment completion position can be increased, further reducing the influence of image reflections (photobomb) from the subject's eyelashes and eyelids.

[0018] In some embodiments, the alignment completion position is a position shifted from the alignment target position in the optical axis direction of the device optics so that the working distance is increased. This allows for reduced interference from the subject's eyelashes and eyelids in the image with simple control.

[0019] In some embodiments, the alignment completion position is a position shifted from the alignment target position in a direction intersecting the optical axis direction of the device's optical system (for example, a perpendicular direction). For example, by setting the alignment completion position below the alignment target position, the influence of the subject's upper eyelashes and upper eyelids in the image can be further reduced. For example, by setting the alignment completion position above the alignment target position, the influence of the subject's lower eyelashes and lower eyelids in the image can be further reduced. For example, by setting the alignment completion position to the side of the alignment target position, the influence of the subject's eyelashes and eyelids in the image can be further reduced.

[0020] In some embodiments, the ophthalmic device includes an alignment target position identification unit and an alignment completion position identification unit. The alignment target position identification unit is configured to identify the alignment target position of the device optical system relative to the eye under examination. The alignment completion position identification unit is configured to identify the alignment completion position, where the alignment target position is shifted by an amount corresponding to the pupil diameter of the patient.

[0021] In some embodiments, the alignment target position is determined based on two or more images obtained by two or more imaging units capable of substantially simultaneously imaging the eye (anterior segment) from different directions. Such methods for determining the alignment target position are disclosed, for example, in Patent Documents 4, 5, and 6.

[0022] In some embodiments, the alignment completion position identification unit identifies an alignment completion position that is shifted from the alignment target position by a shift amount corresponding to the pupil diameter of the subject, by referring to pre-stored alignment correction information. The alignment correction information may be table information in which multiple shift amounts are pre-associated with multiple pupil diameters.

[0023] The following describes a case in which the ophthalmic apparatus according to the embodiment includes an objective optical system having two or more curved mirrors, illuminates the fundus of the eye under examination using a slit-scan method, and captures the fundus at a wide angle by receiving the reflected light from the illumination light from the fundus. That is, the ophthalmic apparatus is configured to scan the fundus of the eye under examination with slit-shaped illumination light via two or more curved mirrors, and to receive the reflected light from the fundus via the two or more curved mirrors with an image sensor.

[0024] Furthermore, the embodiments are not limited to ophthalmic devices for photographing the fundus (fundus photography devices), but can be applied to ophthalmic devices for observing the fundus (fundus observation devices). The following embodiments can also be applied to ophthalmic devices for photographing or observing parts of the eye other than the fundus. Moreover, the following embodiments can also be applied to ophthalmic devices for measuring the fundus or other parts of the eye.

[0025] In some embodiments, each of the two or more curved mirrors has one or more focal points, and the two or more curved mirrors are arranged to share at least one focal point. For example, the two or more curved mirrors are arranged such that the two or more focal points of the two or more curved mirrors are located on substantially the same plane (common plane of focal points).

[0026] For example, an ophthalmic device illuminates the fundus with illumination light such that the longitudinal direction of the slit image projected onto the fundus and formed by the illumination light is approximately parallel to a plane containing two or more foci, and scans the fundus with the illumination light in a direction intersecting the longitudinal direction. Specifically, the ophthalmic device scans the fundus with illumination light in a direction perpendicular to the longitudinal direction of the slit image. Here, the slit image is the image of the aperture formed in the slit.

[0027] Examples of curved mirrors include ellipsoidal mirrors, parabolic mirrors, hyperbolic mirrors, freeform mirrors, and mirrors whose reflective surface is represented by a higher-order polynomial. The reflective surface of a curved mirror may be concave or convex. In this case, examples of curved mirrors include ellipsoidal concave mirrors, ellipsoidal convex mirrors, parabolic concave mirrors, parabolic convex mirrors, hyperbolic concave mirrors, hyperbolic convex mirrors, freeform mirrors with a concave reflective surface, freeform surfaces with a convex reflective surface, concave mirrors whose reflective surface is represented by a higher-order polynomial, and convex mirrors whose reflective surface is represented by a higher-order polynomial.

[0028] In this specification, the focal point may include not only a fixed point uniquely determined by the shape of a curved surface, but also a position where the degree of focus of light rays (light beams) reflected by a reflective surface is higher than at other positions. Furthermore, the position of the pupil and the iris of the eye under examination may be described as being substantially the same.

[0029] The focal plane is preferably a plane in which all the focal points of the two or more curved mirrors are located. However, the focal plane may also be a plane in which two or more focal points are located, excluding at least one of all the focal points of the two or more curved mirrors.

[0030] The control method for the ophthalmic apparatus according to the embodiment includes one or more steps for realizing processing performed by a processor (computer) in the ophthalmic apparatus according to the embodiment. The program according to the embodiment causes the processor 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 for 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 files, 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.

[0031] In this specification, "processor" means circuits such as a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), and a programmable logic device (e.g., an SPLD (Simple Programmable Logic Device), a CPLD (Complex Programmable Logic Device), or an FPGA (Field Programmable Gate Array)). The processor realizes the functions according to the embodiment by, for example, reading and executing a program stored in a memory circuit or storage device.

[0032] The following description will focus on the case where the ophthalmic apparatus according to the embodiment mainly comprises two elliptical concave mirrors as two curved mirrors. However, the following embodiments can also be applied to ophthalmic apparatuses that have three or more curved mirrors.

[0033] Furthermore, for the sake of clarity, in the following explanation, the depth direction (front-to-back direction) of the device will be referred to as the Z direction, the horizontal direction (left-to-right direction) perpendicular to the Z direction will be referred to as the X direction, and the vertical direction (up-down direction) perpendicular to the Z direction will be referred to as the Y direction. In some embodiments, the Z direction is the optical axis direction of the illumination light incident on the eye under examination. Here, the direction of the Z direction approaching the eye under examination may be referred to as the +Z direction, and the direction moving away from the eye under examination may be referred to as the -Z direction. Also, the direction of the X direction from the subject's left eye towards the right eye may be referred to as the +X direction, and the direction from the right eye towards the left eye may be referred to as the -X direction. In addition, the direction of the Y direction from the subject's eye towards the forehead (upward direction) may be referred to as the +Y direction, and the direction from the subject's forehead towards the eye (downward direction) may be referred to as the -Y direction.

[0034] Furthermore, in the following, the "longitudinal direction" of the slit image refers to the direction in which the longer side of the rectangle circumscribing the slit image extends (longitudinal direction), and the "short direction" of the slit image refers to the direction in which the shorter side of the rectangle circumscribing the slit image extends (short direction).

[0035] <Optical System> In the ophthalmic apparatus according to this embodiment, the two elliptic concave mirrors are positioned such that, during imaging, the major axes of both mirrors are approximately parallel to the alignment direction of the left eye (left eye under examination) and right eye (right eye under examination) of the subject being photographed. This makes it possible to photograph the eye under examination at a wide angle with the distance between the eye and the elliptic concave mirror close together without interfering with the subject's face. Such an ophthalmic apparatus is configured to sequentially photograph the fundus of the left and right eyes of the subject.

[0036] In this embodiment, when illumination light, which is deflected over a wide deflection angle range around the deflection reference angle direction, is incident on the eye under examination via two elliptic concave mirrors (curved mirrors), the deflection reference angle direction is made different for left eye and right eye imaging. Therefore, when switching the subject from the left eye to the right eye, or from the right eye to the left eye, it is desirable to change the orientation of the elliptic concave mirror facing the eye under examination. This makes it possible to minimize the range of motion of the optical system when changing the orientation of the elliptic concave mirror.

[0037] Therefore, the ophthalmic apparatus according to this embodiment is configured to have two elliptical concave mirrors as objective optical systems that can rotate around a predetermined axis of rotation, and includes an imaging optical system for the left eye and an imaging optical system for the right eye. Here, the illumination optical system may be common to both the left and right eyes, or it may include an illumination optical system for the left eye and an illumination optical system for the right eye. Furthermore, the ophthalmic apparatus includes a left-eye alignment optical system for aligning the apparatus optical system with respect to the left eye when imaging the left eye, and a right-eye alignment optical system for aligning the apparatus optical system with respect to the right eye when imaging the right eye.

[0038] In other words, the ophthalmic apparatus includes a single objective optical system common to both the left and right eyes, an illumination optical system, and an imaging optical system, wherein at least the imaging optical system includes an imaging optical system for the left eye and an imaging optical system for the right eye. Furthermore, the ophthalmic apparatus includes an alignment optical system for the left eye and an alignment optical system for the right eye.

[0039] The ophthalmic device according to this embodiment will be described in detail below.

[0040] Figures 1 to 13 show schematic diagrams illustrating examples of the optical system configuration of an ophthalmic apparatus according to the embodiment. Figure 1 is a block diagram of an example of the optical system configuration of an ophthalmic apparatus according to the embodiment. Figures 2 to 13 show examples of the configuration of the optical system 10 in Figure 1. In Figures 2 to 13, the same reference numerals are used for parts that are the same as in Figure 1, and explanations are omitted as appropriate.

[0041] The ophthalmologic apparatus 1 according to the embodiment includes an optical system 10 and a moving mechanism 10D. The optical system 10 scans the fundus of the subject's left eye EL or right eye ER with slit-shaped illumination light, and sequentially receives return light from the fundus. The moving mechanism 10D moves the optical system 10 relatively to the left eye EL or the right eye ER. The moving mechanism 10D moves the optical system 10 relatively to the left eye EL or the right eye ER by moving the optical system 10 three-dimensionally.

[0042] The ophthalmologic apparatus 1 is capable of switching imaging operations according to operation modes. In the left eye imaging mode, the ophthalmologic apparatus 1 aligns the optical system 10 with respect to the left eye EL by moving the optical system 10 relative to the left eye EL via the moving mechanism 10D. Thereafter, the ophthalmologic apparatus 1 scans the fundus of the left eye EL with the slit-shaped illumination light by means of the optical system 10, and sequentially receives return light from the fundus. In the right eye imaging mode, the ophthalmologic apparatus 1 aligns the optical system 10 with respect to the right eye ER by moving the optical system 10 relative to the right eye ER via the moving mechanism 10D. Thereafter, the ophthalmologic apparatus 1 scans the fundus of the right eye ER with the slit-shaped illumination light by means of the optical system 10, and sequentially receives return light from the fundus.

[0043] The optical system 10 includes an objective optical system 20, an illumination optical system 30, imaging optical systems 40L and 40R, optical path separating members 50L and 50R, fixation projection systems 60L and 60R, an optical path switching member 70, and anterior segment photography systems 80L and 80R serving as alignment optical systems. The anterior segment photography system 80L, which serves as an alignment optical system for the left eye, includes two anterior segment cameras 81LL and 81LR. The anterior segment photography system 80R, which serves as an alignment optical system for the right eye, includes two anterior segment cameras 81RL and 81RR. Furthermore, the optical system 10 includes dichroic mirrors 90L and 90R, and beam splitters BSL and BSR.

[0044] The anterior segment photography system 80L includes two anterior segment cameras 81LL and 81LR, and is configured to be capable of acquiring two anterior segment images, but may be configured to include three or more anterior segment cameras and be capable of acquiring three or more anterior segment images.

[0045] Similarly, the anterior ocular segment imaging system 80R includes two anterior ocular segment cameras 81RL and 81RR, and is configured to be capable of acquiring two anterior ocular segment images, but may include three or more anterior ocular segment cameras and be configured to be capable of acquiring three or more anterior ocular segment images.

[0046] The objective optical system 20 includes a catoptric optical system configured to optically relay a measurement position at which the pupil of the eye to be examined can be arranged. In the left eye imaging mode, the objective optical system 20 relays a left eye measurement position where the pupil (iris) of the left eye EL can be arranged to a left eye measurement conjugate position optically conjugate with the measurement position. In the right eye imaging mode, the objective optical system 20 relays a right eye measurement position where the pupil (iris) of the right eye ER can be arranged to a right eye measurement conjugate position optically conjugate with the measurement position.

[0047] The illumination optical system 30 is configured to sequentially irradiate the left eye EL and the right eye ER with slit-shaped illumination light via the objective optical system 20. Specifically, the illumination optical system 30 is configured to deflect the slit-shaped illumination light in the left eye imaging mode, and sequentially illuminate a predetermined irradiation region on the fundus of the left eye EL. Further, the illumination optical system 30 is configured to deflect the slit-shaped illumination light in the right eye imaging mode, and sequentially illuminate a predetermined irradiation region on the fundus of the right eye ER.

[0048] The imaging optical system 40L is configured to sequentially receive return light of the illumination light from a predetermined irradiation region on the fundus of the left eye EL in the left eye imaging mode. The imaging optical system 40R is configured to sequentially receive return light of the illumination light from a predetermined irradiation region on the fundus of the right eye ER in the right eye imaging mode.

[0049] The optical path separating member 50L is arranged at the aforementioned left eye measurement conjugate position, and separates the optical path of the illumination light from the illumination optical system 30 and the optical path of the return light of the illumination light from the fundus of the left eye EL. The optical path separating member 50R is arranged at the aforementioned right eye measurement conjugate position, and separates the optical path of the illumination light from the illumination optical system 30 and the optical path of the return light of the illumination light from the fundus of the right eye ER.

[0050] The fixation projection system 60L is configured to project the fixation beam onto the fundus of the left eye EL in left-eye imaging mode. The fixation projection system 60R is configured to project the fixation beam onto the fundus of the right eye ER in right-eye imaging mode.

[0051] The optical path switching member 70 is configured to guide the slit-shaped illumination light generated by the illumination optical system 30 and deflected by a deflection member (optical scanner) (not shown) to the optical path separation member 50L or the optical path separation member 50R. In the left eye imaging mode, the optical path switching member 70 guides the slit-shaped illumination light from the illumination optical system 30 to the optical path separation member 50L. In the right eye imaging mode, the optical path switching member 70 guides the slit-shaped illumination light from the illumination optical system 30 to the optical path separation member 50R.

[0052] In the anterior segment imaging system 80L, the two anterior segment cameras 81LL and 81LR are positioned to face the left eye measurement conjugate position described above, and in left eye imaging mode, they substantially simultaneously image the anterior segment of the left eye EL from a position away from the optical axis. In the anterior segment imaging system 80R, the two anterior segment cameras 81RL and 81RR are positioned to face the right eye measurement conjugate position described above, and in right eye imaging mode, they substantially simultaneously image the anterior segment of the right eye ER from a position away from the optical axis.

[0053] The dichroic mirror 90L is positioned between the objective optical system 20 and the optical path separation member 50L, and guides at least a portion of the light from the left eye EL to the anterior segment imaging system 80L. The light from the left eye EL may be the reflected light from the illumination light from the left eye EL, or the reflected light from the illumination light from the left eye EL illuminated by an anterior segment illumination light source (not shown). The dichroic mirror 90R is positioned between the objective optical system 20 and the optical path separation member 50R, and guides at least a portion of the light from the right eye ER to the anterior segment imaging system 80R. The light from the right eye ER may be the reflected light from the illumination light from the right eye ER, or the reflected light from the illumination light from the right eye ER illuminated by an anterior segment illumination light source (not shown).

[0054] The beam splitter BSL is positioned between the optical path separation member 50L and the imaging optical system 40L, and reflects the fixed light beam from the fixed projection system 60L toward the optical path separation member 50L. The beam splitter BSR is positioned between the optical path separation member 50R and the imaging optical system 40R, and reflects the fixed light beam from the fixed projection system 60R toward the optical path separation member 50R.

[0055] The following will provide a detailed explanation of each optical system that constitutes the optical system 10 shown in Figure 1.

[0056] (Objective Optical System 20) Figure 2 is an explanatory diagram of the configuration of the objective optical system 20 shown in Figure 1. In Figure 2, the state of the objective optical system 20 in left-eye imaging mode is schematically represented by a solid line, and the state of the objective optical system 20 in right-eye imaging mode is schematically represented by a dashed line. In Figure 2, the same reference numerals are used for parts that are the same as in Figure 1, and explanations are omitted as appropriate.

[0057] The objective optical system 20 includes a first elliptic concave mirror and a second elliptic concave mirror, and is configured to be rotatable about a predetermined pivot axis Ra by a rotation mechanism (not shown). The pivot axis Ra is an axis in the Z direction that passes through the center of gravity of the total mass of the first and second elliptic concave mirrors. This makes it possible to shorten the radius of rotation while considering weight balance. In some embodiments, the pivot axis Ra is positioned to pass through the midpoint between the left eye measurement position and the right eye measurement position. In this case, the sliding movement of the optical system 10, described later, associated with rotation can be eliminated. When the left eye measurement position and the right eye measurement position are at the same position, the pivot axis Ra is positioned to pass through both the left eye measurement position and the right eye measurement position.

[0058] In Figure 2, for the sake of clarity, the first and second elliptic concave mirrors will be referred to as the first elliptic concave mirror 21 and the second elliptic concave mirror 22 when in left-eye imaging mode, and as the first elliptic concave mirror 21' and the second elliptic concave mirror 22' when in right-eye imaging mode.

[0059] The reflective surface of the first elliptic concave mirror 21 (21') is a concave ellipsoid. The first elliptic concave mirror 21 (21') is an example of a curved mirror or a concave mirror. The first elliptic concave mirror 21 (21') has two optically conjugate foci (first focal point F1 and second focal point F2, or first focal point F1' and second focal point F2'). The first focal point F1 is the secondary pupillary conjugate point of the left eye EL (secondary left eye measurement conjugate position), and the first focal point F1' is the secondary pupillary conjugate point of the right eye ER (secondary right eye measurement conjugate position). The second focal point F2 is the primary pupillary conjugate point of the left eye EL (primary left eye measurement conjugate position), and the second focal point F2' is the primary pupillary conjugate point of the right eye ER (primary right eye measurement conjugate position).

[0060] The reflective surface of the second elliptic concave mirror 22 (22') is a concave ellipsoid. The second elliptic concave mirror 22 (22') is an example of a curved mirror or a concave mirror. The second elliptic concave mirror 22 (22') has two optically conjugate foci (first focal point F3 and second focal point F4, or first focal point F3' and second focal point F4'). The first focal point F3 is the primary pupillary conjugate point of the left eye EL (primary left eye measurement conjugate position), and the first focal point F3' is the primary pupillary conjugate point of the right eye ER (primary right eye measurement conjugate position).

[0061] The first elliptic concave mirror 21 (21') can be positioned such that its second focal spot F2 (F2') coincides with or near the first focal spot F3 (F3') of the second elliptic concave mirror 22 (22'). In some embodiments, the first elliptic concave mirror 21 (21') is positioned such that its second focal spot F2 (F2') coincides with or near the position optically conjugate to the first focal spot F3 (F3') of the second elliptic concave mirror 22 (22') (the conjugate position of the first focal spot F3 (F3')).

[0062] Figure 3A is a schematic diagram of the state of the objective optical system 20 in left-eye imaging mode when viewed from the front of the subject. Figure 3B is a schematic diagram of the state of the objective optical system 20 in left-eye imaging mode when viewed from above the subject.

[0063] In left-eye imaging mode, the first and second elliptic concave mirrors, rotated around the pivot axis Ra, enter a first rotation state. At this time, the two optically conjugate foci (first focal point F1, second focal point F2) of the first elliptic concave mirror 21 are arranged as shown in Figure 2. That is, the first elliptic concave mirror 21 and the second elliptic concave mirror 22 are configured to relay the left-eye measurement position (F4) to the left-eye measurement conjugate position (F1). An optical path separation member 50L is positioned at or near the first focal point F1 of the first elliptic concave mirror 21. The dichroic mirror 90L is configured to reflect at least a portion of the light from the left-eye EL reflected by the first elliptic concave mirror 21 in the -Y direction and guide it to the anterior segment imaging system 80L.

[0064] Figure 4A is a schematic diagram of the state of the objective optical system 20 in right-eye imaging mode when viewed from the front of the subject. Figure 4B is a schematic diagram of the state of the objective optical system 20 in right-eye imaging mode when viewed from above the subject.

[0065] In right-eye imaging mode, the first and second elliptic concave mirrors, rotated around the pivot axis Ra, enter a second rotation state. For example, the second rotation state is a state in which the first and second elliptic concave mirrors have been rotated 180 degrees around the pivot axis Ra from the first rotation state. At this time, the two optically conjugate foci (first focal point F1', second focal point F2') of the first elliptic concave mirror 21' are arranged as shown in Figure 2. That is, the first elliptic concave mirror 21' and the second elliptic concave mirror 22' are configured to relay the right-eye measurement position (F4') to the right-eye measurement conjugate position (F1'). An optical path separation member 50R is positioned at or near the first focal point F1' of the first elliptic concave mirror 21'. Furthermore, the dichroic mirror 90R is configured to reflect at least a portion of the light from the right eye ER, which is reflected by the first elliptic concave mirror 21', in the -Y direction and guide it to the anterior segment imaging system 80R.

[0066] The ophthalmic device 1 may be equipped with an objective system movement mechanism, which includes the rotation mechanism described above, in addition to a movement mechanism for aligning the device's optical system with respect to the eye under examination. The objective system movement mechanism includes a sliding mechanism that slides the optical system excluding the objective optical system 20 from the optical system 10 in conjunction with the rotation by the rotation mechanism described above.

[0067] Figure 5 shows an explanatory diagram of the sliding operation of the optical system 10 when switching between the left eye imaging mode and the right eye imaging mode, as viewed from above the subject.

[0068] The above-described sliding mechanism moves the optical system 10', excluding the objective optical system 20, in a direction intersecting the rotation axis Ra (see Figure 2) in conjunction with the rotation of the first elliptic concave mirror 21 and the second elliptic concave mirror 22 by the rotation mechanism. The optical system 10' moved by the sliding mechanism includes an illumination optical system 30, imaging optical systems 40L and 40R, optical path separation members 50L and 50R, fixation projection systems 60L and 60R, optical path switching members 70, anterior segment imaging systems 80L and 80R, dichroic mirrors 90L and 90R, and beam splitters BSL and BSR.

[0069] The slide mechanism according to the embodiment is capable of moving the optical system 10' along an arc-shaped path centered on a predetermined vertical (Y-direction) rotation axis. Examples of vertical rotation axes include a Y-direction rotation axis passing through the midpoint between the left eye measurement position and the right eye measurement position, a Y-direction rotation axis passing through the pupil of the left eye EL located at the left eye measurement position, and a Y-direction rotation axis passing through the pupil of the right eye ER located at the right eye measurement position. For example, when switching from left eye shooting mode to right eye shooting mode, the slide mechanism moves the optical system 10' along an arc-shaped path centered on a Y-direction rotation axis passing through the pupil of the left eye EL located at the left eye measurement position. For example, when switching from right eye shooting mode to left eye shooting mode, the slide mechanism moves the optical system 10' along an arc-shaped path centered on a Y-direction rotation axis passing through the pupil of the right eye ER located at the right eye measurement position.

[0070] In some embodiments, the sliding mechanism moves the optical system 10' in a linear direction intersecting the rotation axis Ra, in conjunction with the rotation of the first elliptic concave mirror 21 and the second elliptic concave mirror 22 by the rotation mechanism.

[0071] This sliding motion makes it possible to avoid contact between the first elliptic concave mirror 21 and the second elliptic concave mirror 22 and the subject's nose when switching from left-eye imaging mode to right-eye imaging mode, or from right-eye imaging mode to left-eye imaging mode.

[0072] (Optical systems other than the objective optical system 20) Figures 6A and 6B show examples of the configuration of the optical system 10 in Figure 1. Figure 6A shows an example of the configuration of the optical system 10 in left-eye imaging mode. Figure 6B shows an example of the configuration of the optical system 10 in right-eye imaging mode. In Figures 6A and 6B, the same reference numerals are used for parts that are the same as in Figure 1 or Figure 2, and explanations are omitted as appropriate.

[0073] <Illumination Optical System 30> The illumination optical system 30 includes a light source unit 31, an iris diaphragm 32, a relay lens 33, a slit 34, a relay lens 35, an optical scanner 95, and a relay lens 36.

[0074] The light source unit 31 outputs light in the visible or infrared wavelength range.

[0075] Figure 7 shows an example configuration of the light source unit 31 shown in Figure 6A or Figure 6B.

[0076] The light source unit 31 includes a projection lens 311, visible light sources 312R, 312G, and 312B, an infrared light source 312IR, and dichroic mirrors 313, 314, and 315. The visible light source 312R generates light in the wavelength range of the red (R) component. The visible light source 312G generates light in the wavelength range of the green (G) component. The visible light source 312B generates light in the wavelength range of the blue (B) component. The infrared light source 312IR generates light in the near-infrared wavelength range.

[0077] Each of these visible light sources 312R, 312G, 312B, and infrared light source 312IR is composed of, for example, an LED (Light Emitting Diode) or an LD (Laser Diode).

[0078] Dichroic mirrors 313, 314, and 315 are positioned between the projection lens 311 and the infrared light source 312IR.

[0079] The dichroic mirror 313 reflects light in the wavelength range emitted by the visible light source 312R toward the projection lens 311, and transmits light in the wavelength range emitted by the visible light sources 312G, 312B, and the infrared light source 312IR toward the projection lens 311.

[0080] The dichroic mirror 314 reflects light in the wavelength range emitted by the visible light source 312G toward the dichroic mirror 313, and transmits light in the wavelength range emitted by the visible light source 312B and the infrared light source 312IR toward the dichroic mirror 313.

[0081] The dichroic mirror 315 reflects light in the wavelength range emitted by the visible light source 312B toward the dichroic mirror 314, and transmits light in the wavelength range emitted by the infrared light source 312IR to the dichroic mirror 314.

[0082] By setting the visible light sources 312R, 312G, and 312B to ON and the infrared light source 312IR to OFF, the light source unit 31 can emit white light obtained by combining the light from the visible light sources 312R, 312G, and 312B. By setting the visible light sources 312R, 312G, and 312B to OFF and the infrared light source 312IR to ON, the light source unit 31 can emit infrared light from the infrared light source 312IR.

[0083] In some embodiments, with the infrared light source 312IR set to ON or OFF, at least one of the visible light sources 312R, 312G, and 312B is set to ON and at least one is set to OFF, allowing the light source unit 31 to emit combined light from the visible light sources 312R, 312G, and 312B. In this case, the amount of light emitted by the visible light source that is set to ON among the visible light sources 312R, 312G, and 312B can be arbitrarily changed.

[0084] The iris diaphragm 32 has one or more apertures formed at positions eccentric to the optical axis of the illumination optical system 30. In this embodiment, the iris diaphragm 32 is assumed to have a single aperture. The iris diaphragm 32 (specifically, the aperture) can be positioned at an iris (pupil) conjugate position, which is optically conjugate to or near the iris (pupil) of the eye being examined. That is, the iris diaphragm 32 can be positioned at the iris conjugate position of the left eye EL or the right eye ER. The iris diaphragm 32 functions as an illumination aperture. That is, the aperture formed in the iris diaphragm 32 defines the incident position (incidence shape) of the illumination light in the iris of the eye being examined.

[0085] In some embodiments, the relative position between the light source unit 31 and the aperture formed in the iris diaphragm 32 can be changed. This makes it possible to change the light intensity distribution of the light passing through the aperture formed in the iris diaphragm 32.

[0086] One or more openings are formed in the slit 34. In this embodiment, it is assumed that a single opening is formed in the slit 34. The opening formed in the slit 34 is formed such that its longitudinal direction coincides with the major axis direction of the first elliptic concave mirror 21 (the linear direction connecting the first focal point F1 and the second focal point F2). The slit 34 (specifically, the opening) can be positioned at a fundus conjugate position, which is optically conjugate to or near the fundus of the eye being photographed. That is, the slit 34 can be positioned at the fundus conjugate position of the left eye EL or the right eye ER. The opening formed in the slit 34 defines the shape of the illumination area (illumination pattern shape) in the fundus of the eye being photographed. The illumination light emitted from the light source unit 31 passes through the slit 34 and is projected onto the reflective surface of the first elliptic concave mirror 21 such that the longitudinal direction of the slit-shaped illumination light substantially coincides with the major axis direction of the first elliptic concave mirror 21, and is guided to the fundus of the eye being photographed as slit-shaped illumination light.

[0087] The slit 34 can be moved along the optical axis of the illumination optical system 30 by a moving mechanism (specifically, the moving mechanism 34D described later). This allows the position of the slit 34 to be moved according to the condition of the eye being examined (specifically, the diopter (refractive index) or the shape of the fundus (fundus curvature)).

[0088] For example, first control information, which pre-associates the position of the slit 34 on the optical axis of the illumination optical system 30 with each of several diopters, is stored in the storage unit 102, described later. The main control unit 101 refers to the first control information to identify the position of the slit 34 corresponding to the diopter and controls the moving mechanism 34D so that the slit 34 is positioned at the identified position.

[0089] Here, as the slit 34 moves, the light intensity distribution of the light passing through the opening formed in the slit 34 changes. At this time, the main control unit 101 can change the position and orientation of the light source included in the light source unit 31 by controlling a moving mechanism (not shown) that moves the light source unit 31.

[0090] In some embodiments, the slit 34 is configured to change at least one of the position and shape of the aperture without being moved in the optical axis direction, depending on the condition of the eye being photographed. Such a function of the slit 34 is realized, for example, by a liquid crystal shutter.

[0091] The slit 34 according to this embodiment is configured to be positioned on the optical axis of the illumination optical system 30 with different intersecting angles (tilting angles) with respect to the optical axis of the illumination optical system 30, depending on the eye being photographed (see Figures 6A and 6B).

[0092] Specifically, the slit 34 is positioned at an angle of intersection on the optical axis of the illumination optical system 30, corresponding to the direction of the line connecting the two focal points in the major axis direction of the first elliptic concave mirror 21 into which the slit-shaped illumination light is incident. For example, in left-eye imaging mode, the slit 34 is positioned on the optical axis of the illumination optical system 30 such that the exit surface of the slit 34 is optically approximately parallel to the major axis direction of the first elliptic concave mirror 21 shown in Figure 6A (the direction of the line connecting the first focal point F1 and the second focal point F2). Also, for example, in right-eye imaging mode, the slit 34 is positioned on the optical axis of the illumination optical system 30 such that the exit surface of the slit 34 is optically approximately parallel to the major axis direction of the first elliptic concave mirror 21 shown in Figure 6B (the direction of the line connecting the first focal point F1' and the second focal point F2'). Here, "optically approximately parallel" means not only that the optical axis (optical path) is approximately parallel in a straight line in real space, but also that it is substantially equivalent to a state where the optical axis is approximately parallel on a hypothetical optical axis obtained by removing the reflective material from the optical axis that is deflected by the reflective material.

[0093] The optical scanner 95 deflects the slit-shaped illumination light generated by irradiating the slit 34 with illumination light from the light source unit 31. The optical scanner 95 (specifically, the deflection surface) can be positioned at an iris-conjugate position, which is optically conjugate to or near the iris (pupil) of the eye being scanned. The optical scanner 95 is a uniaxial optical scanner that changes the orientation of the deflection surface around a predetermined deflection reference angle direction. The optical scanner 95 deflects the slit-shaped illumination light in one dimension. The optical scanner 95 deflects the illumination light in a direction that intersects the longitudinal direction of the slit image formed by the slit-shaped illumination light projected onto the fundus of the eye being scanned (specifically, in a perpendicular direction). As a result, the slit image moves in a direction that intersects the longitudinal direction of the slit image (scanning direction).

[0094] The optical scanner 95 includes, for example, a galvanometer scanner, a MEMS (Micro Electro Mechanical System) scanner, a polygon mirror, or a resonant scanner. For example, the optical scanner 95 includes a galvanometer scanner that deflects illumination light within a predetermined deflection angle range with respect to a predetermined deflection reference angle direction.

[0095] In some embodiments, the optical scanner 95 is a two-axis optical scanner that deflects slit-shaped illumination light in two dimensions. For example, the optical scanner 95 includes a first scanner and a second scanner. The first scanner deflects the illumination light so that the illumination area in the fundus of the eye being scanned moves in a horizontal direction perpendicular to the optical axis of the illumination optical system 30. The second scanner deflects the illumination light deflected by the first scanner so that the illumination area in the fundus moves in a vertical direction perpendicular to the optical axis of the illumination optical system 30.

[0096] In the optical system having the configuration described above, illumination light in the visible or infrared region emitted from the light source unit 31 is irradiated onto the iris diaphragm 32, passes through the opening formed in the iris diaphragm 32, passes through the relay lens 33, and is guided to the slit 34.

[0097] In left-eye imaging mode, the slit 34 is positioned such that the output surface of the slit 34 is optically approximately parallel to the major axis direction of the first elliptic concave mirror 21 (the direction of the line connecting the first focal point F1 and the second focal point F2), as shown in Figure 6A. In right-eye imaging mode, the slit 34 is positioned such that the output surface of the slit 34 is optically approximately parallel to the major axis direction of the first elliptic concave mirror 21 (the direction of the line connecting the first focal point F1' and the second focal point F2'), as shown in Figure 6B. The slit-shaped illumination light that passes through the opening formed in the slit 34 is transmitted through the relay lens 35, deflected by the optical scanner 95, transmitted through the relay lens 36, and guided to the optical path switching member 70.

[0098] In some embodiments, the illumination optical system 30 includes a projector equipped with a light source, and the projector outputs slit-shaped illumination light. In this case, a projector is provided instead of the light source unit 31, iris diaphragm 32, relay lens 33, and slit 34 shown in Figures 6A and 6B. Examples of projectors include LCD (Liquid Crystal Display) projectors using transmissive liquid crystal panels, LCOS (Liquid Crystal On Silicon) projectors using reflective liquid crystal panels, and DLP (Digital Light Processing) (registered trademark) projectors using DMD (Digital Mirror Device).

[0099] The optical path switching member 70 switches the optical path of the slit-shaped illumination light deflected by the optical scanner 95 according to the eye being examined. Specifically, the optical path switching member 70 guides the slit-shaped illumination light to the left eye measurement conjugate position (first focal point F1 in Figure 6A) or the right eye measurement conjugate position (first focal point F1' in Figure 6B) according to the shooting mode.

[0100] Between the optical path switching member 70 and the left eye measurement conjugate position where the optical path separating member 50L is located, a relay lens 37L, a reflective member 38L, and a relay lens 39L are arranged. Between the optical path switching member 70 and the right eye measurement conjugate position where the optical path separating member 50R is located, a relay lens 37R, a reflective member 38R, and a relay lens 39R are arranged.

[0101] In left-eye imaging mode, the optical path switching member 70 guides the slit-shaped illumination light that has passed through the relay lens 36 to the relay lens 37L. In right-eye imaging mode, the optical path switching member 70 guides the slit-shaped illumination light that has passed through the relay lens 36 to the relay lens 37R. Such a function of the optical path switching member 70 can be realized by a known optical path switching member, such as a flip mirror.

[0102] In some embodiments, the illumination optical system 30 further includes an optical path switching member 70, relay lenses 37L, 37R, reflective members 38L, 38R, and relay lenses 39L, 39R.

[0103] By adjusting the direction of the optical axis of the illumination optical system 30 using the optical path switching member 70 and the reflective members 38L and 38R, the size of the optical system 10 in the X and Y directions can be reduced. For example, by changing the direction of the optical axis in the +X direction using the reflective member 38L and changing the direction of the optical axis in the -X direction using the reflective member 38R, it is possible to reduce the size of the optical system 10 in the X direction.

[0104] <Imaging Optical System 40L, 40R> The imaging optical system 40L includes a relay lens 45L, an imaging lens 46L, and an image sensor 47L. The imaging optical system 40L is configured to be integrally movable in the optical axis direction. This allows the light-receiving surface of the image sensor 47L to be positioned at a fundus-conjugate position, which is optically conjugate to or near the fundus of the left eye EL. As a result, it is possible to adapt to the state of the left eye EL and image the reflected light from the left eye EL onto the light-receiving surface of the image sensor 47L. In some embodiments, the imaging optical system 40L includes a focusing lens, and the light-receiving surface of the image sensor 47L can be positioned at the above-mentioned fundus-conjugate position by moving the focusing lens in the optical axis direction.

[0105] The light reflected from the left eye EL is the scattered (reflected) light of the illumination light incident on the left eye EL. In some embodiments, the light reflected from the left eye EL includes the scattered (reflected) light of the illumination light incident on the left eye EL, and fluorescence and its scattered light, which are excited by the illumination light incident on the left eye EL.

[0106] The image sensor 47L realizes the function of a two-dimensional image sensor as a pixelated light receiver. The light-receiving surface (detection surface, imaging surface) of the image sensor 47L can be positioned at the above-mentioned fundus conjugate position. The image sensor 47L can set a virtually movable light-receiving region (light-receiving area) at the fundus conjugate position.

[0107] For example, the light reception result from the image sensor 47L is captured and read out using a rolling shutter method. In some embodiments, the light reception result from the image sensor 47L 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 47L. In some embodiments, the image sensor 47L can automatically output light reception results for a predetermined line along with information indicating the light reception position.

[0108] Such an image sensor 47L includes, for example, a CMOS (Complementary Metal Oxide Semiconductor) image sensor. In this case, the image sensor 47L includes a plurality of pixels (photodetectors) arranged in a row direction, and a plurality of pixels arranged in a column direction. Specifically, the image sensor 47L includes a plurality of pixels arranged in two dimensions, a plurality of vertical signal lines, and a horizontal signal line.

[0109] In some embodiments, the image sensor 47L includes, for example, a CCD (Charge Coupled Device) image sensor.

[0110] By capturing (reading out) the light reception results of the reflected light from such an image sensor 47L using a rolling shutter method, an image is obtained in a light-receiving region corresponding to a desired virtual aperture shape extending in the low direction. Such control is disclosed, for example, in Patent Document 2 or U.S. Patent No. 8,237,835.

[0111] Between the optical path separation member 50L and the imaging optical system 40L, a reflective member 41L, a relay lens 42L, a reflective member 43L, and a beam splitter BSL are arranged. In the reflection direction of the beam splitter BSL, a fixation projection system 60L, described later, is arranged. In some embodiments, the imaging optical system 40L includes a reflective member 41L, a relay lens 42L, a reflective member 43L, and a beam splitter BSL.

[0112] The reflected light from the left eye EL, separated by the optical path separation member 50L, is reflected by the reflective member 41L, passes through the relay lens 42L, is reflected by the reflective member 43L, passes through the beam splitter BSL, and is guided to the imaging optical system 40L. The reflected light guided to the imaging optical system 40L passes through the relay lens 45L and is imaged onto the light-receiving surface of the image sensor 47L by the imaging lens 46L.

[0113] On the other hand, the imaging optical system 40R has the same configuration as the imaging optical system 40L. That is, the imaging optical system 40R includes a relay lens 45R, an imaging lens 46R, and an image sensor 47R. The imaging optical system 40R is configured to be movable integrally in the optical axis direction. This allows the light-receiving surface of the image sensor 47R to be positioned at a fundus-conjugate position, which is optically conjugate to or near the fundus of the right eye ER. As a result, it is possible to adapt to the state of the right eye ER and image the reflected light from the right eye ER onto the light-receiving surface of the image sensor 47R. In some embodiments, the imaging optical system 40R includes a focusing lens, and the light-receiving surface of the image sensor 47R can be positioned at the above-mentioned fundus-conjugate position by moving the focusing lens in the optical axis direction.

[0114] The light reflected from the right eye ER is the scattered (reflected) light of the illumination light incident on the right eye ER. In some embodiments, the light reflected from the right eye ER includes the scattered (reflected) light of the illumination light incident on the right eye ER, and fluorescence and its scattered light, which are excited by the illumination light incident on the right eye ER.

[0115] Image sensor 47R, like image sensor 47L, realizes the function of a two-dimensional image sensor as a pixelated light receiver. The light-receiving surface (detection surface, imaging surface) of image sensor 47R can be positioned at the above-mentioned fundus conjugate position. Image sensor 47R can set a virtually movable light-receiving region (light-receiving area) at the fundus conjugate position.

[0116] The light reception results from the image sensor 47R are also captured and read out using a rolling shutter method, similar to the image sensor 47L. In some embodiments, the light reception results from the image sensor 47R are 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 results by controlling the image sensor 47R. In some embodiments, the image sensor 47R can automatically output light reception results for a predetermined line along with information indicating the light reception position.

[0117] Such an image sensor 47R, like the image sensor 47L, includes a CMOS image sensor. In some embodiments, the image sensor 47R includes, for example, a CCD image sensor.

[0118] By capturing (reading out) the light reception results of the reflected light from such an image sensor 47R using a rolling shutter method, an image is obtained in the light-receiving region corresponding to a desired virtual aperture shape extending in the low direction.

[0119] Between the optical path separation member 50R and the imaging optical system 40R, a reflective member 41R, a relay lens 42R, a reflective member 43R, and a beam splitter BSR are arranged. A fixation projection system 60R, described later, is arranged in the reflection direction of the beam splitter BSR. In some embodiments, the imaging optical system 40R includes a reflective member 41R, a relay lens 42R, a reflective member 43R, and a beam splitter BSR.

[0120] The reflected light from the right eye ER, separated by the optical path separation member 50R, is reflected by the reflective member 41R, passes through the relay lens 42R, is reflected by the reflective member 43R, passes through the beam splitter BSR, and is guided to the imaging optical system 40R. The reflected light guided to the imaging optical system 40R passes through the relay lens 45R and is imaged onto the light-receiving surface of the image sensor 47R by the imaging lens 46R.

[0121] By adjusting the orientation of the optical axes of the imaging optical systems 40L and 40R using the reflective members 41L, 43L, 41R, and 43R, it becomes possible to reduce the size of the optical system 10 in the X and Y directions. For example, by changing the orientation of the optical axis in the +X direction using the reflective members 41L and 43L, and changing the orientation of the optical axis in the -X direction using the reflective members 41R and 43R, it becomes possible to reduce the size of the imaging optical systems 40L and 40R in the X direction. For example, the orientation of the optical axis of the imaging optical system 40L can be adjusted using the reflective members 41L and 43L so as to coincide with the Z direction. For example, the orientation of the optical axis of the imaging optical system 40R can be adjusted using the reflective members 41R and 43R so as to coincide with the Z direction.

[0122] <Fixation Projection Systems 60L, 60R> When the left eye is in imaging mode, the fixation projection system 60L projects the fixation beam onto the fundus of the left eye EL. When the right eye is in imaging mode, the fixation projection system 60R projects the fixation beam onto the fundus of the right eye ER.

[0123] The fixation projection system 60L has the same configuration as the fixation projection system 60R.

[0124] Figure 8 shows an example configuration of the fixation projection system 60L in Figure 6A (fixation projection system 60R in Figure 6B).

[0125] The fixation projection system 60L includes a fixation light source 61L and a projection lens 62L. The fixation light source 61L can be positioned at a fundus-conjugate position, which is optically conjugate to or near the fundus of the left eye EL. The fixation beam emitted from the fixation light source 61L passes through the projection lens 62L, is reflected by the beam splitter BSL, and is guided through the reflecting member 43L, relay lens 42L, and reflecting member 41L to the optical path separation member 50L. The fixation beam guided to the optical path separation member 50L passes through the dichroic mirror 90L and is projected onto the fundus of the left eye EL via the first elliptic concave mirror 21 and the second elliptic concave mirror 22 (see Figure 6A).

[0126] The fixation projection system 60R includes a fixation light source 61R and a projection lens 62R. The fixation light source 61R can be positioned at a fundus-conjugate position, which is optically conjugate to or near the fundus of the right eye ER. The fixation beam emitted from the fixation light source 61R passes through the projection lens 62R, is reflected by the beam splitter BSR, and is guided through the reflecting member 43R, relay lens 42R, and reflecting member 41R to the optical path separation member 50R. The fixation beam guided to the optical path separation member 50R passes through the dichroic mirror 90R and is projected onto the fundus of the right eye ER via the first elliptic concave mirror 21 and the second elliptic concave mirror 22 (see Figure 6B).

[0127] <Optical path separation members 50L, 50R> The optical path separation member 50L is positioned at a left-eye measurement conjugate position, which is optically approximately conjugate to the left-eye measurement position, as described above. The optical path separation member 50R is positioned at a right-eye measurement conjugate position, which is optically approximately conjugate to the right-eye measurement position, as described above.

[0128] The optical path separation member 50L has the same configuration as the optical path separation member 50R.

[0129] Figure 9 schematically shows an example of the configuration of the optical path separation member 50L. Figure 9 schematically represents the cross-sectional structure of the optical path separation member 50L.

[0130] The optical path separation member 50L includes a reflective member 51L as a pupil-splitting mirror and a photographic aperture 52L. The photographic aperture 52L has an opening formed at a position eccentric from the optical axis O. The reflective member 51L is provided at a position eccentric from the optical axis O on the surface of the first elliptical concave mirror 21 of the photographic aperture 52L. That is, the reflective member 51L and the photographic aperture 52L are each positioned at the left eye measurement conjugate position.

[0131] Figure 10 schematically represents the conjugate plane at the left eye's measurement conjugate position.

[0132] The conjugate plane PL is a virtual plane perpendicular to the optical axis O at the left eye's measurement conjugate position on the optical axis O. In the conjugate plane PL, the image AP1 of the aperture formed in the iris diaphragm 32 and the image AP2 of the aperture formed in the imaging diaphragm 52L are arranged. At this time, the image of the aperture formed in the imaging diaphragm 52L and the image of the aperture formed in the iris diaphragm 32 are arranged so as not to overlap.

[0133] Therefore, in the optical path separation member 50L, the reflecting member 51L reflects the slit-shaped illumination light from the illumination optical system 30 and guides it to the objective optical system 20 (first elliptical concave mirror 21). The imaging aperture 52L guides the reflected light that has passed through its opening to the imaging optical system 40L.

[0134] Similarly, the optical path separation member 50R includes a reflective member 51R as a pupil-splitting mirror and a photographic aperture 52R. The photographic aperture 52R has an opening formed at a position eccentric from the optical axis. The reflective member 51R is provided at a position eccentric from the optical axis on the surface of the photographic aperture 52R that is on the reflective surface side of the first elliptical concave mirror 21. That is, the reflective member 51R and the photographic aperture 52R are each positioned at the right eye measurement conjugate position.

[0135] In other words, in the conjugate plane at the right eye measurement conjugate position, the image of the aperture formed in the iris diaphragm 32 and the image of the aperture formed in the imaging diaphragm 52R are arranged, similar to Figure 10. Therefore, in the optical path separation member 50R, the reflecting member 51R reflects the slit-shaped illumination light from the illumination optical system 30 and guides it to the objective optical system 20 (first elliptical concave mirror 21). The imaging diaphragm 52R guides the reflected light that has passed through its aperture to the imaging optical system 40R.

[0136] <Anterior segment imaging system 80L, 80R> Figure 11 schematically shows the positional relationship between the objective optical system 20 and the anterior segment imaging system 80L, 80R when viewed from the reflective surface side of the second elliptical concave mirror 22 (22'). In Figure 11, the same reference numerals are used for parts that are the same as in Figures 1, 2, 6A, and 6B, and explanations are omitted as appropriate.

[0137] As shown in Figure 11, the anterior segment imaging system 80L is positioned in the -Y direction, which is the reflection direction of the dichroic mirror 90L. The anterior segment imaging system 80R is positioned in the -Y direction, which is the reflection direction of the dichroic mirror 90R, as shown in Figure 11. This makes it possible to reduce the size of the optical system 10 in at least the X direction.

[0138] Figure 12 schematically shows an example configuration of the anterior segment imaging system 80L (80R). In Figure 12, the same reference numerals are used for parts that are the same as those in Figure 1 or Figure 11, and explanations are omitted as appropriate.

[0139] The anterior segment imaging system 80L includes two anterior segment cameras 81LL and 81LR, as well as an optical path deflection prism 82L and imaging lenses 82LL and 82LR.

[0140] The light-receiving surfaces (imaging surfaces) of the anterior segment cameras 81LL and 81LR can be positioned at a fundus-conjugate position, which is optically approximately conjugate to or near the fundus of the left eye EL. For example, the anterior segment cameras 81LL and 81LR are positioned such that the angle between the left eye measurement conjugate surface, which is perpendicular to the optical axis at the left eye measurement conjugate position, and the imaging optical axes Lref and Rref are the same, and they are arranged symmetrically with respect to the normal direction (optical axis direction) of the left eye measurement conjugate surface. In some embodiments, the light-receiving surfaces (imaging surfaces) are positioned at the fundus-conjugate position by moving the anterior segment cameras 81LL and 81LR in the optical axis direction. In some embodiments, two focusing lenses are provided between the dichroic mirror 90L and the imaging lenses 82LL and 82LR, respectively, and the light-receiving surfaces (imaging surfaces) are positioned at the fundus-conjugate position by moving each of the two focusing lenses in the optical axis direction.

[0141] For example, the reference optical axis Ref of the anterior segment imaging system 80L, which is deflected by the dichroic mirror 90L, passes through the midpoint of the baselines of the anterior segment cameras 81LL and 81LR, and is an optical axis perpendicular to said baseline. The imaging optical axis Lref of the anterior segment camera 81LL and the imaging optical axis Rref of the anterior segment camera 81LR are positioned to pass through a position optically equivalent to the left eye measurement conjugate position. That is, the anterior segment cameras 81LL and 81LR are positioned on imaging optical axes Lref and Rref, respectively, which intersect the reference optical axis Ref.

[0142] In some embodiments, a path deflection prism 82L is provided, as shown in Figure 12. The path deflection prism 82L is, for example, a triangular prism having a first deflection surface and a second deflection surface that intersect at a predetermined intersection angle and share a common edge. In this case, the reflected light from the dichroic mirror 90L is deflected toward the imaging lens 82LL by the first deflection surface of the path deflection prism 82L, and is imaged onto the light-receiving surface of the anterior eye-section camera 81LL by the imaging lens 82LL. The reflected light from the dichroic mirror 90L is also deflected toward the imaging lens 82LR by the second deflection surface of the path deflection prism 82L, and is imaged onto the light-receiving surface of the anterior eye-section camera 81LR by the imaging lens 82LR.

[0143] This allows the anterior segment cameras 81LL and 81LR to be positioned to optically capture the left eye's measurement conjugate position while avoiding physical interference between them.

[0144] Figure 13 schematically shows the imaging optical axes of the anterior segment cameras 81LL and 81LR in the objective optical system 20. In Figure 13, the same reference numerals are used for parts that are the same as those in Figures 1, 2, 11, and 12, and explanations are omitted as appropriate.

[0145] As shown in Figure 13, the anterior segment cameras 81LL and 81LR are positioned to face a left-eye measurement conjugate position (or a position optically conjugate to the left-eye measurement conjugate position) that is optically equivalent to the left-eye measurement position where the left-eye EL is located. In other words, the anterior segment cameras 81LL and 81LR can capture images of the left-eye EL from a position away from the optical axes of the illumination optical system 30 and the imaging optical system 40L.

[0146] Similarly, the anterior segment imaging system 80R includes two anterior segment cameras 81RL and 81RR, as well as an optical path deflection prism 82R and imaging lenses 82RL and 82RR (see Figure 12).

[0147] The light-receiving surfaces (imaging surfaces) of the anterior segment cameras 81RL and 81RR can be positioned at a fundus-conjugate position, which is optically approximately conjugate to or near the fundus of the right eye ER. For example, the anterior segment cameras 81RL and 81RR are positioned such that the angle between the right eye measurement conjugate surface, which is perpendicular to the optical axis, and the imaging optical axis is the same at the right eye measurement conjugate position, and are symmetrical with respect to the normal direction (optical axis direction) of the right eye measurement conjugate surface. In some embodiments, the light-receiving surfaces (imaging surfaces) are positioned at the fundus-conjugate position by moving the anterior segment cameras 81RL and 81RR in the optical axis direction. In some embodiments, two focusing lenses are provided between the dichroic mirror 90R and the imaging lenses 82RL and 82RR, respectively, and the light-receiving surfaces (imaging surfaces) are positioned at the fundus-conjugate position by moving each of the two focusing lenses in the optical axis direction.

[0148] For example, the reference optical axis Ref of the anterior segment imaging system 80R, which is deflected by the dichroic mirror 90R, passes through the midpoint of the baselines of the anterior segment cameras 81RL and 81RR, and is an optical axis perpendicular to those baselines. The imaging optical axis Lref of the anterior segment camera 81RL and the imaging optical axis Rref of the anterior segment camera 81RR are positioned to pass through a position optically equivalent to the right eye measurement conjugate position. That is, the anterior segment cameras 81RL and 81RR are positioned on imaging optical axes Lref and Rref, respectively, which intersect the reference optical axis Ref.

[0149] In some embodiments, a path deflection prism 82R is provided, as shown in Figure 12. The path deflection prism 82R is, for example, a triangular prism having a first deflection surface and a second deflection surface that intersect at a predetermined intersection angle and share a common edge. In this case, the reflected light from the dichroic mirror 90R is deflected toward the imaging lens 82RL by the first deflection surface of the path deflection prism 82R and is imaged onto the light-receiving surface of the anterior eye-section camera 81RL by the imaging lens 82RL. The reflected light from the dichroic mirror 90R is also deflected toward the imaging lens 82RR by the second deflection surface of the path deflection prism 82R and is imaged onto the light-receiving surface of the anterior eye-section camera 81RR by the imaging lens 82RR.

[0150] This allows the anterior segment cameras 81RL and 81RR to be positioned to optically capture the right eye's measurement conjugate position while avoiding physical interference between them.

[0151] Therefore, the anterior segment cameras 81RL and 81RR are positioned to face a right eye measurement conjugate position (or a position optically conjugate to the right eye measurement conjugate position) that is optically equivalent to the right eye measurement position where the right eye ER is located, similar to the anterior segment cameras 81LL and 81LR. In other words, the anterior segment cameras 81RL and 81RR can photograph the right eye ER from a position away from the optical axis of the illumination optical system 30 and the imaging optical system 40R.

[0152] In this embodiment, the anterior segment imaging system 80L is described as comprising two anterior segment cameras 81LL and 81LR, but it may also comprise three or more anterior segment cameras. Similarly, the anterior segment imaging system 80R is described as comprising two anterior segment cameras 81RL and 81RR, but it may also comprise three or more anterior segment cameras.

[0153] (Alignment target position and alignment completion position) With the above configuration, wide-angle light can be shone onto the left eye EL and the right eye ER, and the reflected light can be received. However, there is a high possibility that the subject's eyelashes or eyelids will be captured in the image during alignment, which may lead to a decrease in alignment accuracy due to the presence of these elements.

[0154] Specifically, in this embodiment, as described later, prior to fundus photography of the left eye EL, two or more images are acquired by photographing the anterior segment of the left eye EL using the anterior segment cameras 81LL and 81LR of the anterior segment imaging system 80L. In this case, the three-dimensional position of the pupil region of the left eye EL is identified as the alignment target position based on the positional relationship between the pupil region of the left eye EL depicted in the two or more images and the anterior segment cameras 81LL and 81LR. The same procedure applies to fundus photography of the right eye ER.

[0155] Figure 14A schematically shows the illumination beams IL1 and IL2 and the imaging beams RL1 and RL2 for anterior segment imaging when the optical system 10 is moved to the alignment target position relative to the left eye EL in left eye imaging mode.

[0156] As shown in Figure 14A, depending on the eye being examined, vignetting of the illumination beams IL1 and IL2 of the left eye EL may occur due to the eyelashes or eyelids. In this case, the eyelashes or eyelids will be visible in two or more images obtained by the anterior segment cameras 81LL and 81LR. This reduces the detection accuracy of the pupil region edge of the left eye EL, leading to failures in identifying the pupil region or a decrease in the accuracy of the pupil region position. As a result, the accuracy of the alignment of the optical system 10 with respect to the left eye EL decreases.

[0157] Therefore, in this embodiment, in the left eye imaging mode, the destination of the optical system 10 relative to the left eye EL is set not to the alignment target position, but to an alignment completion position which is shifted from the alignment target position by an amount corresponding to the pupil diameter of the left eye EL.

[0158] Figure 14B schematically shows the illumination beams IL1 and IL2 and the imaging beams RL1 and RL2 for anterior segment imaging when the optical system 10 is moved to the alignment completion position relative to the left eye EL in left eye imaging mode. In Figure 14B, the same reference numerals are used for parts that are the same as in Figure 14A, and explanations are omitted as appropriate.

[0159] As described above, by moving the device's optical system to the alignment completion position relative to the left eye EL, vignetting of the illumination beams IL1 and IL2 due to the left eye EL's eyelashes and eyelids is prevented. This suppresses the decrease in detection accuracy of the pupil region edge of the left eye EL and improves the accuracy of the alignment of the optical system 10 relative to the left eye EL.

[0160] When the optical system 10 is moved to the alignment completion position relative to the left eye EL, the light from the optical system 10 at the alignment completion position must reach the fundus Ef without vignetting caused by the eyelashes or eyelids of the left eye EL. On the other hand, as the distance between the left eye EL and the alignment target position increases, the amount of light reaching the fundus Ef decreases. Therefore, it is desirable to set the alignment completion position as close as possible to the left eye EL without causing vignetting caused by eyelashes or eyelids.

[0161] Figure 15 schematically shows the illumination beam and imaging beam incident on the fundus Ef of the left eye EL in the Y direction (vertical direction).

[0162] The illumination beams IL1Y and IL2Y, projected onto the left eye's EL, enter the eye through the pupil Ep (pupillary diameter PWY in the Y direction), are reflected at the fundus Ef, and the imaging beams RL1Y and RL2Y exit the eye.

[0163] Figures 16A and 16B schematically show the illumination beam entering the eye and the imaging beam exiting the eye at different pupil diameters. Figure 16A schematically represents the illumination beam and imaging beam when the pupil diameter φ is "PH1". Figure 16B schematically represents the illumination beam and imaging beam when the pupil diameter φ is "PH2 (>PH1)".

[0164] When the pupil diameter φ is "PH1", as shown in Figure 16A, illumination beams IL1Y and IL2Y enter within the pupil diameter PWY1 in the Y direction, and imaging beams RL1Y and RL2Y exit.

[0165] In contrast, when the pupil diameter φ is "PH2", as shown in Figure 16B, illumination beams IL1Y and IL2Y enter the pupil diameter PWY2 (>PWY1) in the Y direction, and imaging beams RL1Y and RL2Y exit. At this time, to prevent vignetting of eyelashes and eyelids, the optical system 10 is shifted by, for example, a shift amount Δshy in the -Z direction, so that illumination beams IL1Y and IL2Y enter the pupil diameter PWY2 in the Y direction, and imaging beams RL1Y and RL2Y exit.

[0166] Therefore, by performing ray tracing, it is possible to determine the amount of Y-direction shift that does not cause vignetting of eyelashes or eyelids, depending on the pupil diameter. In some embodiments, the amount of Y-direction shift that does not cause vignetting of eyelashes or eyelids, depending on the pupil diameter, can be determined experimentally.

[0167] Figure 17 schematically shows the illumination beam and imaging beam incident on the fundus Ef of the left eye EL in the X direction (left-right direction).

[0168] The illumination beams IL1X and IL2X irradiated onto the left eye's EL enter the eye through the pupil Ep (pupil diameter PWX in the X direction), are reflected at the fundus Ef, and the imaging beams RL1X and RL2X exit the eye.

[0169] Figures 18A and 18B schematically show the illumination beam entering the eye and the imaging beam exiting the eye at different pupil diameters. Figure 18A schematically represents the illumination beam and imaging beam when the pupil diameter φ is "PH1". Figure 18B schematically represents the illumination beam and imaging beam when the pupil diameter φ is "PH2 (>PH1)".

[0170] When the pupil diameter φ is "PH1", as shown in Figure 18A, illumination beams IL1X and IL2X enter within the pupil diameter PWX1 in the X direction, and imaging beams RL1X and RL2X are emitted.

[0171] In contrast, when the pupil diameter φ is "PH2", as shown in Figure 18B, illumination beams IL1X and IL2X enter the pupil diameter PWX2 (>PWX1) in the X direction, and imaging beams RL1X and RL2X exit. At this time, to prevent vignetting of eyelashes and eyelids, the optical system 10 is shifted by, for example, a shift amount Δshx in the -Z direction, so that illumination beams IL1X and IL2X enter the pupil diameter PWX2 in the X direction, and imaging beams RL1X and RL2X exit.

[0172] Therefore, by performing ray tracing, it is possible to determine the amount of shift in the X direction that does not cause vignetting of eyelashes or eyelids, depending on the pupil diameter. In some embodiments, the amount of shift in the X direction that does not cause vignetting of eyelashes or eyelids is experimentally determined depending on the pupil diameter.

[0173] Figure 19 schematically shows the relationship between pupil diameter, the amount of shift that causes vignetting in the X-direction illumination beam (photographic beam), and the amount of shift that causes vignetting in the Y-direction illumination beam (photographic beam). In Figure 19, the vertical axis represents pupil diameter, and the horizontal axis represents the amount of shift in the -Z direction that causes vignetting.

[0174] As shown in Figure 19, the relationship between the pupil diameter of the left eye EL and the amount of Z-direction shift that causes vignetting of the illumination beam in the X direction is represented by the characteristic line CX. That is, in the region above characteristic line CX, vignetting of the illumination beam in the X direction does not occur. Similarly, the relationship between the pupil diameter of the left eye EL and the amount of Z-direction shift that causes vignetting of the illumination beam in the Y direction is represented by the characteristic line CY. That is, in the region above characteristic line CY, vignetting of the illumination beam in the Y direction does not occur.

[0175] Therefore, by selecting a shift amount corresponding to the pupil diameter in region AR, which is the region above characteristic line CX and above characteristic line CY, vignetting of the illumination beam does not occur in either the X or Y direction.

[0176] For example, by selecting a shift amount according to the pupil diameter based on a predetermined characteristic line CC within the AR region, it is possible to set the alignment completion position so that it is as close as possible to the left eye EL without causing vignetting due to eyelashes or eyelids.

[0177] Although Figures 14A to 19 describe the left eye EL, the same applies to the right eye ER.

[0178] In some embodiments, at least one of the first elliptic concave mirror 21 and the second elliptic concave mirror 22 is a convex mirror (e.g., an elliptic convex mirror) whose reflective surface is formed in a convex shape. In some embodiments, at least one of the first elliptic concave mirror 21 and the second elliptic concave mirror 22 is a curved mirror whose reflective surface is a free-form surface.

[0179] Furthermore, the ophthalmic device 1 may be equipped with optional elements or units such as members for supporting the subject's face (chin rest, forehead rest, etc.).

[0180] <Control System> Figure 20 shows an example of the configuration of the control system of the ophthalmic device 1 according to the embodiment. In Figure 20, the same reference numerals are used for parts that are the same as those in Figures 1 to 13, and explanations are omitted as appropriate.

[0181] The control system (processing 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.

[0182] 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 computer programs for controlling the ophthalmic device 1 in advance. These computer programs include a program for controlling the illumination optical system, a program for controlling the imaging optical system, a program for controlling the optical scanner, a program for controlling the anterior segment imaging system, an image forming program, a data processing program, and a user interface program. The control unit 100 executes control processing by operating the main control unit 101 according to such computer programs.

[0183] (Main control unit 101) The main control unit 101 controls the objective optical system 20 (objective system movement mechanism 20D), illumination optical system 30, imaging optical system 40L, 40R, fixation projection system 60L, 60R, optical path switching member 70, anterior segment imaging system 80L, 80R, and movement mechanism 10D. Furthermore, the main control unit 101 controls the image forming unit 200, data processing unit 210, and user interface (UI) unit 220.

[0184] Control over the objective optical system 20 includes control over the objective system movement mechanism 20D, among other things.

[0185] The objective system moving mechanism 20D includes a rotation mechanism that rotates the first elliptic concave mirror 21 and the second elliptic concave mirror 22 around a predetermined rotation axis, and a sliding mechanism that, in conjunction with the rotation by the rotation mechanism, slides the optical system excluding the objective optical system 20 of the optical system 10 as shown in Figure 5. Each moving mechanism includes a pulse motor as an actuator and, under control from the main control unit 101, performs the rotation of the first elliptic concave mirror 21 and the second elliptic concave mirror 22 by the rotation mechanism and the sliding movement of the optical system by the sliding mechanism.

[0186] Control of the illumination optical system 30 includes control of the light source unit 31, control of the moving mechanism 34D, and control of the optical scanner 95.

[0187] Control of the light source unit 31 includes turning on, turning off, and adjusting the light intensity of each of the visible light sources 312R, 312G, 312B and the infrared light source 312IR.

[0188] The moving mechanism 34D moves the slit 34 in the direction of the optical axis of the illumination optical system 30. The main control unit 101 outputs a control signal to the moving mechanism 34D, thereby moving the slit 34 by an amount and direction corresponding to the control signal.

[0189] Furthermore, the moving mechanism 34D includes a rotation mechanism that changes the intersection angle of the exit surface of the slit 34 with respect to the optical axis of the illumination optical system 30. The rotation mechanism rotates the slit 34 around a rotation axis perpendicular to the optical axis of the illumination optical system 30. When in left-eye imaging mode, the moving mechanism 34D receives control from the main control unit 101 and rotates the slit 34 so that its longitudinal direction is optically approximately parallel to the major axis direction of the first elliptic concave mirror 21 in the first rotation state shown in Figure 6A. When in right-eye imaging mode, the moving mechanism 34D receives control from the main control unit 101 and rotates the slit 34 so that its longitudinal direction is optically approximately parallel to the major axis direction of the first elliptic concave mirror 21 in the second rotation state shown in Figure 6B.

[0190] In some embodiments, a first slit with a fixed intersection angle is provided for the left-eye imaging mode, and a second slit with a fixed intersection angle is provided for the right-eye imaging mode. In this case, the moving mechanism 34D is configured to receive control from the main control unit 101 and position either the first slit or the second slit on the optical axis of the illumination optical system 30.

[0191] For example, the ophthalmic device 1 is provided with an actuator that generates a driving force to drive the moving mechanism 34D, 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 34D receives the driving force generated by the actuator, which is controlled by the main control unit 101, from the transmission mechanism, and moves the slit 34 in the optical axis direction or rotates around the rotation axis.

[0192] Control of the optical scanner 95 includes controlling the angle of the deflection plane that deflects the illumination light. By controlling the angle of the deflection plane, it is possible to control the direction of deflection of the illumination light (scan direction). By controlling the angular range of the deflection plane, it is possible to control the scan range (scan start position and scan end position). By controlling the rate at which the angle of the deflection plane changes, it is possible to control the scan speed.

[0193] The optical path switching member 70 is controlled according to the shooting mode. When the left eye is in shooting mode, the optical path switching member 70 receives control from the main control unit 101 and guides the illumination light deflected by the optical scanner 95 to the optical path separation member 50L. When the right eye is in shooting mode, the optical path switching member 70 receives control from the main control unit 101 and guides the illumination light deflected by the optical scanner 95 to the optical path separation member 50R.

[0194] Control of the imaging optical system 40L includes control of the image sensor 47L and control of the focusing mechanism 40Ld. Control of the imaging optical system 40R includes control of the image sensor 47R and control of the focusing mechanism 40Rd.

[0195] Control of image sensors 47L and 47R includes setting the light-receiving area on the light-receiving surface and control for reading out the light-receiving result using a rolling shutter method (for example, setting the light-receiving size corresponding to the size of the illumination pattern). In addition, control of image sensors 47L and 47R includes reset control, exposure control, charge transfer control, output control, etc.

[0196] The focusing mechanism 40Ld moves the imaging optical system 40L in the direction of the optical axis. The focusing mechanism 40Rd moves the imaging optical system 40R in the direction of the optical axis. The main control unit 101 outputs control signals to the focusing mechanisms 40Ld and 40Rd, thereby moving the imaging optical systems 40L and 40R by an amount and direction of movement corresponding to the control signals. For example, the ophthalmic apparatus 1 is provided with actuators that generate driving force to drive the focusing mechanisms 40Ld and 40Rd, and a transmission mechanism that transmits this driving force. The actuators are composed of, for example, pulse motors. The transmission mechanism is composed of, for example, a combination of gears or a rack and pinion. The focusing mechanism 40Ld moves the imaging optical system 40L in the direction of the optical axis by receiving the driving force generated by the actuator controlled by the main control unit 101. The focusing mechanism 40Rd moves the imaging optical system 40R in the direction of the optical axis by receiving the driving force generated by the actuator controlled by the main control unit 101.

[0197] Control of the fixation projection systems 60L and 60R includes control of the fixation light sources 61L and 61R, among other things.

[0198] Control of the fixed light sources 61L and 61R includes turning the light sources on and off, and adjusting the light intensity.

[0199] Control for the anterior segment imaging systems 80L and 80R includes controlling the light-receiving surfaces of the anterior segment cameras 81LL and 81LR to be positioned at the conjugate location of the left eye EL in the fundus, and controlling the imaging of the anterior segment cameras 81LL and 81LR. Furthermore, control for the anterior segment imaging systems 80L and 80R includes controlling the light-receiving surfaces of the anterior segment cameras 81RL and 81RR to be positioned at the conjugate location of the right eye ER in the fundus, and controlling the imaging of the anterior segment cameras 81RL and 81RR.

[0200] Controlling the position of the light-receiving surfaces of the anterior segment cameras 81LL and 81LR at the conjugate position of the left eye EL involves either moving the anterior segment cameras 81LL and 81LR, or moving the focusing lens that transmits light from the left eye EL in the optical axis direction. Controlling the imaging of the anterior segment cameras 81LL and 81LR involves controlling the light-receiving sensitivity of each camera, controlling the frame rate (light-receiving timing), and synchronizing the two cameras.

[0201] Controlling the anterior segment cameras 81RL and 81RR to the conjugate position of the right eye ER involves either moving the light-receiving surfaces of the anterior segment cameras 81RL and 81RR, or moving the focusing lens that transmits light from the right eye ER in the optical axis direction. Controlling the imaging of the anterior segment cameras 81RL and 81RR involves controlling the light-receiving sensitivity of each camera, controlling the frame rate (light-receiving timing), and synchronizing the two cameras.

[0202] The moving mechanism 10D moves the optical system 10 (device optical system) of the ophthalmic device 1 in three dimensions. In a typical example, the moving mechanism 10D includes a mechanism for moving the optical system 10 (housing housing the optical system 10) in the X direction (left-right direction), a mechanism for moving it in the Y direction (up-down direction), and a mechanism for moving it in the Z direction (depth direction, front-back direction, working distance direction). The mechanism for moving in the X direction includes, for example, an X stage that can move in the X direction and an X moving mechanism that moves the X stage. The mechanism for moving in the Y direction includes, for example, a Y stage that can move in the Y direction and a Y moving mechanism that moves the Y stage. The mechanism for moving in the Z direction includes, for example, a Z stage that can move in the Z direction and a Z moving mechanism that moves the Z stage. Each moving mechanism includes a pulse motor as an actuator and operates under control from the main control unit 101.

[0203] Control of the movement mechanism 10D is used for alignment and tracking. Tracking is the process of moving the device's optical system in accordance with the eye movements of the subject's eye being photographed. When tracking is performed, alignment and focus adjustment are carried out in advance. 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.

[0204] In manual alignment, the user operates the UI unit 220 to cancel out the displacement of the eye being photographed relative to the optical system, thereby moving the optical system 10 and the eye being photographed relative to each other. For example, the main control unit 101 controls the movement mechanism 10D by outputting a control signal to the movement mechanism 10D corresponding to the operation performed on the UI unit 220, thereby moving the optical system relative to the eye being photographed.

[0205] In the case of auto-alignment, the main control unit 101 controls the movement mechanism 10D 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 being photographed. Specifically, as described in Patent Document 4, calculation processing is performed using trigonometry based on the positional relationship between the two anterior segment cameras of the anterior segment imaging system 80L or anterior segment imaging system 80R and the eye being photographed. The main control unit 101 controls the movement mechanism 10D so that the positional relationship of the eye being photographed relative to the optical system is a predetermined positional relationship.

[0206] Control of the image forming unit 200 includes image forming control, which forms an image of the left eye EL or the right eye ER from the light reception results obtained by the image sensor 47L or the image sensor 47R.

[0207] Control over the data processing unit 210 includes image processing control for images acquired by the imaging optical systems 40L and 40R, analysis processing control for images acquired by the anterior segment imaging systems 80L and 80R, and alignment control of the device optical system relative to the eye being examined.

[0208] Control over the UI unit 220 includes control over the display device and control over the operation device (input device).

[0209] (Storage Unit 102) The storage unit 102 stores various types of data. Examples of data stored in the storage unit 102 include light reception results obtained by the image sensors 47L and 47R, image data of images formed by the image forming unit 200, processing results obtained by the data processing unit 210, 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 eye / right eye identification information.

[0210] Furthermore, the memory unit 102 stores alignment correction information 102a. Alignment correction information 102a is information for shifting to the alignment completion position relative to the alignment target position. Alignment correction information 102a includes the shift direction and the shift amount. Alignment correction information 102a is table information in which multiple shift amounts are pre-associated with multiple pupil diameters. In this embodiment, alignment correction information 102a is table information in which multiple shift amounts are pre-associated with multiple pupil diameters along the characteristic line CC in the region AR shown in Figure 19. In some embodiments, alignment correction information 102a is stored in the data processing unit 210 (alignment completion position identification unit) described later.

[0211] In some embodiments, the alignment correction information 102a is common to both the left eye EL and the right eye ER. In some embodiments, the alignment correction information 102a includes alignment correction information for the left eye and alignment correction information for the right eye.

[0212] Furthermore, the memory unit 102 stores various programs and data necessary for operating the ophthalmic device 1.

[0213] (Image forming unit 200) The image forming unit 200, under control from the main control unit 101 (control unit 100), can form a light-receiving image corresponding to an arbitrary aperture range based on the light-receiving result read from the image sensor 47L or image sensor 47R using a rolling shutter method. The image forming unit 200 can sequentially form light-receiving images corresponding to (virtual) aperture ranges and form an image of the left eye EL or the right eye ER from the multiple light-receiving images formed. Various images (image data) formed by the image forming unit 200 are stored, for example, in the storage unit 102.

[0214] 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.

[0215] (Data Processing Unit 210) The data processing unit 210 performs various image processing, analysis processing, and alignment processing on the light reception results acquired from the image sensors 47L and 47R. Image processing includes noise reduction processing on the light reception results and brightness correction processing to make it easier to identify predetermined parts depicted in the light reception image based on the light reception results. Alignment processing includes processing to align the device optical system with respect to the eye under examination.

[0216] The data processing unit 210 includes a processor and performs processing according to a program stored in a memory unit or the like to realize the above functions.

[0217] Figure 21 shows a block diagram of an example configuration of the data processing unit 210 shown in Figure 20.

[0218] The data processing unit 210 includes a pupil region identification unit 211, a three-dimensional position identification unit 212, an alignment target position identification unit 213, and an alignment completion position identification unit 214.

[0219] The pupil region identification unit 211 acquires a pair of anterior segment images (captured images) of the left eye EL, which are obtained by capturing images substantially simultaneously using the anterior segment cameras 81LL and 81LR of the anterior segment imaging system 80L. By analyzing each of the acquired pair of anterior segment images, the pupil region identification unit 211 identifies the position (center position, centroid position) of the pupil region in the anterior segment image that corresponds to the pupil of the left eye EL.

[0220] First, the pupil region identification unit 211 identifies the image region (pupil region) corresponding to the pupil of the left eye EL based on the distribution of pixel values ​​(luminance values, etc.) in the anterior segment image. Generally, the pupil is drawn with lower luminance than other parts, so the pupil region can be identified by searching for low-luminance image regions. At this time, the pupil region may also be identified by considering the shape of the pupil. In other words, the system can be configured to identify the pupil region by searching for a roughly circular, low-luminance image region.

[0221] Next, the pupil region identification unit 211 identifies the central position of the identified pupil region. As described above, the pupil is approximately circular, so the outline of the pupil region can be identified, the central position of this outline (approximately a circle or ellipse) can be identified, and this can be set as the pupil center position. Alternatively, the centroid of the pupil region can be determined, and this centroid position can be identified as the pupil centroid position.

[0222] Similarly, the pupil region identification unit 211 acquires a pair of anterior segment images of the right eye ER obtained by substantially simultaneously capturing images with the anterior segment cameras 81RL and 81RR of the anterior segment imaging system 80R. By analyzing each of the acquired pair of anterior segment images, the pupil region identification unit 211 identifies the position of the pupil region in the anterior segment image that corresponds to the pupil of the right eye ER, similar to the pupil region of the left eye EL.

[0223] The pupil region identification unit 211 is capable of sequentially identifying the pupil region corresponding to the pupil in a pair of anterior segment images sequentially obtained by the anterior segment cameras 81LL, 81LR or 81RL, 81RR. Alternatively, the pupil region identification unit 211 may identify the pupil region at any number of frames (one or more) in a pair of anterior segment images sequentially obtained by the anterior segment cameras 81LL, 81LR or 81RL, 81RR.

[0224] The pupil region identification unit 211 includes a pupil diameter identification unit 211a. The pupil diameter identification unit 211a identifies the diameter (pupil diameter) of the pupil region identified by the pupil region identification unit 211. In some embodiments, the pupil diameter identification unit 211a identifies the distance between the edges of the pupil region in the diametrical direction passing through the pupil center position or pupil centroid position of the pupil region identified by the pupil region identification unit 211 as the pupil diameter. In some embodiments, the pupil diameter identification unit 211a identifies the distance between the edges of the pupil region in a predetermined diametrical direction (X direction or Y direction) passing through the pupil center position or pupil centroid position of the pupil region as the pupil diameter. In some embodiments, the pupil diameter identification unit 211a identifies the distance (maximum distance or minimum distance) between the edges in a predetermined direction (X direction or Y direction) of the pupil region identified by the pupil region identification unit 211 as the pupil diameter.

[0225] The pupil diameter identification unit 211a can identify the pupil diameter of the pupil region identified in each of the pair of anterior segment images obtained by the anterior segment cameras 81LL and 81LR, and identify the statistical value (mean, maximum, or minimum) of the two pupil diameters as the pupil diameter of the left eye EL. Similarly, the pupil diameter identification unit 211a can identify the pupil diameter of the pupil region identified in each of the pair of anterior segment images obtained by the anterior segment cameras 81RL and 81RR, and identify the statistical value (mean, maximum, or minimum) of the two pupil diameters as the pupil diameter of the right eye ER.

[0226] In some embodiments, the pupil diameter identification unit 211a identifies the pupil diameter of the eye under examination as the larger or smaller of the two pupil diameters of a pair of pupil regions identified for a pair of anterior segment images.

[0227] The 3D positioning unit 212 determines the 3D position of the pupil of the left eye EL based on the positions of the anterior segment cameras 81LL and 81LR and the pupil region (center position) determined by the pupil region determination unit 211. As disclosed in Patent Document 4, the 3D positioning unit 212 applies known trigonometry to the positions of the two anterior segment cameras 81LL and 81LR (which are known) and the position corresponding to the pupil region in a pair of anterior segment images. As a result, the 3D positioning unit 212 can calculate the 3D position of the pupil of the left eye EL as the 3D position of the left eye EL.

[0228] Furthermore, the 3D positioning unit 212 determines the 3D position of the pupil of the right eye ER based on the positions of the anterior segment cameras 81RL and 81RR and the pupil region (center position) determined by the pupil region determination unit 211. The 3D positioning unit 212 calculates the 3D position of the pupil of the right eye ER as the 3D position of the right eye ER by applying a known trigonometric method to the positions of the two anterior segment cameras 81RL and 81RR (which are known) and the position corresponding to the pupil region in the pair of anterior segment images.

[0229] The alignment target position identification unit 213 identifies the alignment target position (Xr, Yr, Zr). The alignment target position (Xr, Yr, Zr) is a three-dimensional position defined in a three-dimensional coordinate system with a predetermined reference position in the optical system of the ophthalmic device 1 as the origin. The X-direction coordinate position Xr and the Y-direction coordinate position Yr of the alignment target position are positions on the XY plane where the optical axis of the imaging optical system 40L substantially coincides with the axis of the left eye EL, or positions on the XY plane where the optical axis of the imaging optical system 40R substantially coincides with the axis of the right eye ER. The Z-direction coordinate position Zr of the alignment target position is a position on the optical axis of the imaging optical system 40L where the distance of the optical system 10 to the left eye EL is a predetermined working distance, or a position on the optical axis of the imaging optical system 40R where the distance of the optical system 10 to the right eye ER is a predetermined working distance. Here, the working distance is a predetermined value also called the working distance of the objective optical system 20, and corresponds to the original distance between the eye under examination and the optical system 10.

[0230] The alignment completion position identification unit 214 identifies the alignment completion position based on the alignment target position identified by the alignment target position identification unit 213. The alignment completion position is the position where the alignment control of the optical system 10 for the eye under examination (left eye EL or right eye ER) is completed. In this embodiment, the alignment completion position identification unit 214 identifies the alignment completion position by shifting the alignment target position in the -Z direction by a shift amount corresponding to the pupil diameter identified by the pupil diameter identification unit 211a. For example, the alignment completion position identification unit 214 refers to the alignment correction information 102a to identify the shift direction and shift amount corresponding to the pupil diameter identified by the pupil diameter identification unit 211a, and identifies the alignment completion position by shifting the alignment target position by the identified shift direction and shift amount.

[0231] The main control unit 101 controls the movement mechanism 10D so that the eye to be photographed is positioned at the alignment completion position identified by the alignment completion position identification unit 214.

[0232] (UI Unit 220) The UI unit 220 has functions for exchanging information between the user (examiner or subject) and the ophthalmic device 1. The UI unit 220 includes a display device and an operating device. The display device may include a display unit or other display devices. The display device displays various types of information. The display device includes, for example, a liquid crystal display, and receives control from the main control unit 101 to display the above information. The information displayed on the display device includes information corresponding to the control result by the control unit 100, and information (images) corresponding to the calculation result by the image forming unit 200 or the data processing unit 210. The operating device includes various hardware keys and / or software keys. The main control unit 101 can receive the operation content for the operating device and output control signals corresponding to the operation content to each unit. It is possible to configure at least a part of the operating device and at least a part of the display device as an integrated unit. A touch panel display is one example.

[0233] An anterior segment imaging system 80L or anterior segment imaging system 80R is an example of an "imaging unit" according to the embodiment. Anterior segment cameras 81LL, 81LR, or anterior segment cameras 81RL, 81RR are examples of "two or more imaging units" according to the embodiment. Optical path separation member 50L or optical path separation member 50R is an example of a "first optical path separation member" according to the embodiment. Dichroic mirror 90L or dichroic mirror 90R is an example of a "second optical path separation member" according to the embodiment. Iris diaphragm 32 is an example of an "illumination diaphragm" according to the embodiment. Anterior segment imaging system 80L is an example of an "imaging unit for the left eye" according to the embodiment. Anterior segment imaging system 80R is an example of an "imaging unit for the right eye" according to the embodiment. Imaging optical system 40L is an example of an "imaging optical system for the left eye" according to the embodiment. Imaging optical system 40R is an example of an "imaging optical system for the right eye" according to the embodiment. The first elliptic concave mirror 21 and the second elliptic concave mirror 22 are examples of "two or more curved mirrors" according to the embodiment. The optical path separation member 50L is an example of a "left eye optical path separation member" according to the embodiment. The optical path separation member 50R is an example of a "right eye optical path separation member" according to the embodiment. The alignment correction information 102a is an example of "table information" according to the embodiment.

[0234] <Example of Operation> Next, an example of the operation of the ophthalmic device 1 according to the embodiment will be described.

[0235] Figures 22 to 24 show examples of operation of the ophthalmic device 1 according to the embodiment. Figure 22 is a flowchart of an example of operation of the ophthalmic device 1 according to the embodiment. Figure 23 is a flowchart of an example of operation of steps S5 and S11 in Figure 22. Figure 24 is a flowchart of an example of operation of steps S6 and S12 in Figure 22. The storage unit 102 stores a computer program for realizing the processes shown in Figures 22 to 24. The main control unit 101 executes the processes shown in Figures 22 to 24 by operating according to this computer program.

[0236] (S1: Left eye shooting mode?) First, the main control unit 101 determines whether the shooting mode is left eye shooting mode or not. For example, the main control unit 101 determines the type of shooting mode based on the user's operation to the UI unit 220.

[0237] When it is determined that the shooting mode is left eye shooting mode (S1:Y), the operation of the ophthalmic device 1 proceeds to step S2, and slit imaging control is performed for the left eye EL in steps S2 to S6. When it is determined that the shooting mode is not left eye shooting mode (S1:N), the operation of the ophthalmic device 1 proceeds to step S7.

[0238] (S2: Switching the optical path of the illumination light) When it is determined in step S1 that the shooting mode is the left eye shooting mode (S1: Y), the main control unit 101 controls the optical path switching member 70 to switch the optical path so that the illumination light is guided to the optical path separating member 50L.

[0239] (S3: Changing the slit arrangement) Next, the main control unit 101 controls the moving mechanism 34D to change the intersection angle of the slit 34 with respect to the optical axis so that the exit surface of the slit 34 is optically approximately parallel to the major axis of the first elliptic concave mirror 21 shown in Figure 6A.

[0240] (S4: Start of illumination light irradiation) Next, the main control unit 101 controls the light source unit 31 to start the irradiation of illumination light. For example, the light source unit 31 starts irradiating with white light or infrared light as illumination light.

[0241] (S5: Alignment processing) Next, the main control unit 101 uses the anterior segment imaging system 80L to perform alignment processing of the optical system 10 with respect to the left eye EL. Details of step S5 will be described later.

[0242] (S6: Slit imaging) Next, the main control unit 101 performs imaging on the fundus of the left eye EL using a slit scan method. Details of step S6 will be described later.

[0243] (S7: Right eye shooting mode?) If it is determined in step S1 that it is not left eye shooting mode (S1: N), or following step S6, the main control unit 101 determines whether the shooting mode is right eye shooting mode. For example, the main control unit 101 determines the type of shooting mode based on the user's operation on the UI unit 220.

[0244] When it is determined that the shooting mode is the right eye shooting mode (S7:Y), the operation of the ophthalmic device 1 proceeds to step S8, and slit imaging control is performed on the right eye ER in steps S8 to S12. When it is determined that the shooting mode is not the right eye shooting mode (S7:N), the operation of the ophthalmic device 1 ends (end).

[0245] (S8: Switching the optical path of the illumination light) When it is determined in step S7 that the shooting mode is the right eye shooting mode (S7: Y), the main control unit 101 controls the optical path switching member 70 to switch the optical path so that the illumination light is guided to the optical path separating member 50R.

[0246] (S9: Changing the slit arrangement) Next, the main control unit 101 controls the moving mechanism 34D to change the intersection angle of the slit 34 with respect to the optical axis so that the exit surface of the slit 34 is optically approximately parallel to the major axis of the first elliptic concave mirror 21 shown in Figure 6B.

[0247] (S10: Start of illumination light irradiation) Next, the main control unit 101 controls the light source unit 31 in the same manner as in step S4 and starts the irradiation of illumination light.

[0248] (S11: Alignment processing) Next, the main control unit 101 performs alignment processing of the optical system 10 with respect to the right eye ER using the anterior segment imaging system 80R. Step S11 is the same as step S5, except that the anterior segment imaging system 80R is used instead of the anterior segment imaging system 80L.

[0249] (S12: Slit imaging) Next, the main control unit 101 performs imaging on the fundus of the right eye ER using a slit scan method. Step S12 is the same as step S6, except that the imaging optical system 40R is used instead of the imaging optical system 40L.

[0250] This concludes the operation of ophthalmic device 1 (end).

[0251] The process in step S5 or step S11 in Figure 22 is executed according to the flow shown in Figure 23. In Figure 23, the process in step S5 is explained for the left eye EL, but the process in step S11 is the same for the right eye ER, so a detailed explanation of the process in step S11 is omitted.

[0252] In Figure 23, it is assumed that, prior to step S21, the anterior segment cameras 81LL and 81LR of the anterior segment imaging system 80L are already positioned at the conjugate position of the left eye EL.

[0253] (S21: Imaging the anterior segment) In step S5, the main control unit 101 first controls the anterior segment cameras 81LL and 81LR of the anterior segment imaging system 80L to start imaging the anterior segment of the left eye EL from different directions and to start acquiring a pair of anterior segment images of the left eye EL that are acquired substantially simultaneously.

[0254] (S22: Identifying the pupil region) Next, the main control unit 101 controls the pupil region identification unit 211 to identify the pupil region for each of the pair of anterior segment images acquired in step S21.

[0255] (S23: Pupil diameter determination) Next, the main control unit 101 controls the pupil diameter determination unit 211a to determine the pupil diameter for each of the pupil regions in the pair of anterior segment images determined in step S22.

[0256] (S24: Calculation of the 3D position of the pupil region) Next, the main control unit 101 controls the 3D position identification unit 212 to calculate the 3D position of the pupil region of the left eye EL using the pupil region in the pair of anterior segment images identified in step S22, as described above.

[0257] (S25: Identifying the alignment target position) Next, the main control unit 101 controls the alignment target position identification unit 213 to identify the alignment target position based on the three-dimensional position of the pupil region calculated in step S24, as described above.

[0258] (S26: Identifying the alignment completion position) Next, the main control unit 101 controls the alignment completion position identification unit 214 to identify the alignment completion position from the alignment target position identified in step S25, as described above. The alignment completion position identification unit 214 identifies the alignment completion position which is shifted in the Z direction away from the eye under examination by a shift amount corresponding to the pupil diameter identified in step S23.

[0259] In left-eye shooting mode, the alignment completion position identification unit 214 identifies the shift direction and shift amount corresponding to the pupil diameter of the left eye EL identified in step S23 by referring to the alignment correction information 102a. Alternatively, the alignment completion position identification unit 214 identifies the shift direction and shift amount corresponding to the pupil diameter of the left eye EL identified in step S23 by referring to the alignment correction information for the left eye from the alignment correction information 102a. The alignment completion position identification unit 214 identifies the alignment completion position which is shifted by the specified shift direction and shift amount relative to the alignment target position identified in step S25.

[0260] Similarly, in right-eye imaging mode, the alignment completion position identification unit 214 identifies the shift direction and shift amount corresponding to the pupil diameter of the right eye ER identified in step S23 by referring to the alignment correction information 102a. Alternatively, the alignment completion position identification unit 214 identifies the shift direction and shift amount corresponding to the pupil diameter of the right eye ER identified in step S23 by referring to the alignment correction information for the right eye from the alignment correction information 102a. The alignment completion position identification unit 214 identifies an alignment completion position that is shifted by the specified shift direction and shift amount relative to the alignment target position identified in step S25.

[0261] (S27: Controlling the moving mechanism) Next, the main control unit 101 controls the moving mechanism 10D to move the optical system 10 relative to the left eye EL based on the alignment completion position identified in step S26.

[0262] This completes the process in step S5 (end).

[0263] The process in step S6 or step S12 in Figure 22 is performed according to the flow shown in Figure 24. In Figure 24, the process in step S6 is explained for the left eye EL, but the process in step S12 is the same for the right eye ER, so a detailed explanation of the process in step S12 is omitted.

[0264] (S31: Obtaining diopter) In step S6, first, the main control unit 101 obtains the diopter (refractive index). For example, the main control unit 101 obtains the diopter of the left eye EL from an external ophthalmic measuring device or electronic medical record. In some embodiments, the main control unit 101 controls the focusing mechanism 40Ld to determine the focus state and determines the diopter from the position on the optical axis of the imaging optical system 40L set to the focus state (or the control result of the actuator that drives the focusing mechanism 40Ld).

[0265] (S32: Moving the slit) Next, the main control unit 101 changes the position of the slit 34 in the optical axis of the illumination optical system 30 according to the diopter of the left eye EL acquired in step S31.

[0266] Specifically, the main control unit 101 refers to the first control information stored in the memory unit 102 to identify the position of the slit 34 corresponding to the diopter, and controls the moving mechanism 34D so that the slit 34 is positioned at the identified location.

[0267] (S33: Projection of fixation beam) Next, the main control unit 101 controls the fixation projection system 60L and starts projecting the fixation beam of the left eye EL onto the fundus of the eye.

[0268] (S34: Irradiation with illumination light) Next, the main control unit 101 starts deflection control of the optical scanner 95 with respect to the slit-shaped illumination light generated by the illumination optical system 30, thereby starting the irradiation of illumination light to the desired irradiation range in the fundus of the left eye EL. Once the irradiation of illumination light is started, the slit-shaped illumination light is sequentially irradiated within the desired irradiation range as described above.

[0269] (S35: Acquisition of light reception results) As described above, the main control unit 101 acquires the light reception results of pixels in the aperture range of the image sensor 47L corresponding to the illumination range of the fundus illumination light in step S34.

[0270] (S36: Next irradiation position?) The main control unit 101 determines whether there is an irradiation position to be irradiated with the illumination light next. The main control unit 101 can determine whether there is an irradiation position to be irradiated with the illumination light next by determining whether the irradiation range of the sequentially moving illumination light covers the predetermined shooting range of the fundus.

[0271] Next, when it is determined that there is an irradiation position to be irradiated with illumination light (S36: Y), the operation of the ophthalmic device 1 proceeds to step S37. Next, when it is determined that there is no irradiation position to be irradiated with illumination light (S36: N), the operation of the ophthalmic device 1 proceeds to step S38.

[0272] (S37: Changing the deflection angle of the illumination light) When it is determined in step S36 that there is an illumination position to be illuminated by the illumination light next (S36: Y), the main control unit 101 controls the optical scanner 95 to change the deflection angle of the deflection plane of the optical scanner 95 by a predetermined angle.

[0273] Following step S37, the process in step S6 proceeds to step S34.

[0274] (S38: Image formation) In step S36, if it is determined that there is no illumination position to be illuminated by the illumination light next (S36: N), the main control unit 101 causes the image forming unit 200 to form a fundus image of the left eye EL from the light reception results repeatedly acquired in steps S34 to S37 while changing the illumination range of the illumination light.

[0275] For example, the image forming unit 200 synthesizes multiple light-receiving results, each with a different illumination range (aperture range on the light-receiving surface of the image sensor 47L), based on the order in which the illumination ranges move, for the number of times the processing in steps S34 to S37 is repeated. As a result, a fundus image for one frame of the fundus of the left eye EL is formed.

[0276] In some embodiments, in step S34, illumination light is shone onto an illumination range that is set to have an overlapping region with an adjacent illumination range. As a result, in step S38, a fundus image for one frame is formed by combining fundus images so that their overlapping regions overlap.

[0277] This completes the process in step S6 of Figure 22 (end).

[0278] Figure 25 schematically shows the fundus of the eye being examined.

[0279] A slit image (an image of the aperture formed in the slit 34) SL0 is projected onto the fundus Ef of the left eye EL or right eye ER of the subject being photographed. In the image sensor 47L or image sensor 47R, the position of the virtual light-receiving area LA0 on the light-receiving surface is changed in synchronization with the movement of the slit image, which corresponds to the illumination area of ​​the illumination light in the fundus Ef.

[0280] Specifically, the light-receiving area LA0 of the image sensor 47L or image sensor 47R is set to include the range of the slit image SL0 in the fundus Ef. The slit image SL0 is scanned so that it moves in the short direction perpendicular to the longitudinal direction of the slit image SL0. In synchronization with the movement of the slit image SL0 in the fundus Ef, the image sensor 47L or image sensor 47R sequentially moves the light-receiving area LA0 on the light-receiving surface to include the range of the slit image SL0.

[0281] In the above embodiment, a case in which the objective optical system 20 is shared between the left-eye imaging mode and the right-eye imaging mode has been described, but the configuration according to the embodiment is not limited thereto. For example, an objective optical system for the left-eye imaging mode and an objective optical system for the right-eye imaging mode may be provided. In this case, two elliptic concave mirrors (for example, a first elliptic concave mirror 21 and a second elliptic concave mirror 22) are provided for imaging or measuring the left-eye EL, and two elliptic concave mirrors (for example, a first elliptic concave mirror 21' and a second elliptic concave mirror 22') are provided for imaging or measuring the right-eye ER.

[0282] In the above embodiment, the imaging optical systems 40L and 40R may be a single imaging optical system common to the left eye EL and the right eye ER. Also, the fixation projection systems 60L and 60R may be different; 40R may be a single fixation projection system common to the left eye EL and the right eye ER. The anterior segment imaging systems 80L and 80R may be a single anterior segment imaging system common to the left eye EL and the right eye ER.

[0283] Furthermore, in the above embodiment, the angle between the measurement conjugate plane and the imaging optical axis at a position that is optically substantially conjugate to the measurement position does not have to be the same for the two or more cameras in each anterior segment imaging system. Also, the two or more cameras may be arranged asymmetrically with respect to the normal direction of the measurement conjugate plane (so that the angle between the normal direction and the imaging optical axis is different).

[0284] Furthermore, although the above embodiment describes a case in which a dichroic mirror 90L or dichroic mirror 90R is arranged between the first elliptic concave mirror 21 and the optical path separating member 50L or optical path separating member 50R, the embodiment is not limited thereto. For example, in the left eye imaging mode, a dichroic mirror 90L may be arranged between the first elliptic concave mirror 21 and the second elliptic concave mirror 22 shown in Figure 6A. In this case, the anterior segment imaging system 80L can be positioned to look at the second focal point F2 (primary left eye measurement conjugate position) of the first elliptic concave mirror 21. Similarly, for example, in the right eye imaging mode, a dichroic mirror 90R may be arranged between the first elliptic concave mirror 21 and the second elliptic concave mirror 22 shown in Figure 6B. In this case, the anterior segment imaging system 80R can be positioned to look at the second focal point F2' (primary right eye measurement conjugate position) of the first elliptic concave mirror 21.

[0285] [Operation] An ophthalmic device, a control method for the ophthalmic device, and a program according to the embodiment will be described.

[0286] The first embodiment is an ophthalmic device (1) including an optical system (10), a moving mechanism (10D), and a control unit (100, main control unit 101). The optical system is configured to irradiate light onto the eye under examination (left eye EL, or right eye ER) and receive the reflected light from the eye under examination. The moving mechanism moves the eye under examination and the optical system relative to each other. The control unit controls the moving mechanism based on the alignment completion position corresponding to the pupil diameter of the eye under examination.

[0287] In this configuration, the eye under examination and the optical system are moved relative to each other based on the alignment completion position corresponding to the pupil diameter, so that the eyelashes and eyelids of the eye under examination can be avoided in the image while still allowing for imaging and measurement of the eye. This makes it possible to align the eye under examination and the optical system with high precision while still allowing for imaging and measurement of the eye under examination.

[0288] A second embodiment of the embodiment includes, in the first embodiment, an alignment target position identification unit (213) and an alignment completion position identification unit (214). The alignment target position identification unit identifies the alignment target position of the optical system with respect to the eye under examination. The alignment completion position identification unit identifies the alignment completion position in which the alignment target position is shifted by an amount corresponding to the pupil diameter.

[0289] In this configuration, the alignment target position is determined using the same method as in the conventional method, and the alignment completion position is identified from the determined alignment target position. Therefore, the alignment completion position can be identified with a simple process.

[0290] In the third embodiment, as in the second embodiment, the larger the pupil diameter, the greater the amount of shift from the alignment target position to the alignment completion position.

[0291] This configuration makes it possible to reliably avoid capturing images of the eye's eyelashes or eyelids while still allowing for the photographing and measurement of the eye under examination.

[0292] In a fourth embodiment, in the third embodiment, the alignment completion position is a position shifted from the alignment target position in the optical axis direction of the optical system such that the working distance is increased.

[0293] According to this configuration, a decrease in alignment accuracy caused by reflections of the eyelashes or eyelids of the eye under examination can be avoided with simple control, and the eye under examination and the optical system can be aligned with high precision.

[0294] In the fifth embodiment, in the third embodiment, the alignment completion position is a position shifted from the alignment target position in a direction intersecting the optical axis direction of the optical system.

[0295] According to this configuration, a decrease in alignment accuracy caused by reflections of the eyelashes or eyelids of the eye under examination can be avoided with simple control, and the eye under examination and the optical system can be aligned with high precision.

[0296] In the sixth embodiment, in any of the first to fifth embodiments, the control unit controls the movement mechanism based on the alignment completion position, which is determined by referring to table information (alignment correction information 102a) in which a plurality of shift amounts are pre-associated with a plurality of pupil diameters.

[0297] According to this configuration, the eye under examination and the optical system can be aligned with high precision, regardless of the pupil diameter of the eye under examination.

[0298] A seventh embodiment of the embodiment includes, in any of the second to fourth embodiments, two or more imaging units (anterior segment cameras 81LL, 81LR, or anterior segment cameras 81RL, 81RR) and a pupil region identification unit (211). The two or more imaging units are configured to substantially simultaneously image the anterior segment of the eye under examination from different directions. The pupil region identification unit identifies the pupil region in the eye under examination based on two or more images obtained by the two or more imaging units. The alignment target position identification unit identifies the alignment target position based on the pupil region.

[0299] This configuration allows for high-precision alignment between the eye under examination and the optical system over a wide field of view.

[0300] An eighth embodiment of the embodiment includes two or more curved mirrors (a first elliptic concave mirror 21 and a second elliptic concave mirror 22) in the seventh embodiment. The optical system is configured to irradiate the eye under examination with light through the two or more curved mirrors and to receive reflected light through the two or more curved mirrors.

[0301] In this embodiment, in an ophthalmic device that irradiates the eye under examination with light at a wide angle, it becomes possible to precisely align the eye under examination with the device's optical system.

[0302] A ninth aspect of the embodiment is a control method for an ophthalmic device (1) including an optical system (10) and a moving mechanism (10D). The optical system is configured to irradiate light onto the eye under examination (left eye EL, or right eye ER) and receive reflected light from the eye under examination. The moving mechanism moves the eye under examination and the optical system relative to each other. The control method for the ophthalmic device includes a pupil diameter identification step and a control step. The pupil diameter identification step identifies the pupil diameter of the eye under examination. The control step controls the moving mechanism based on the alignment completion position corresponding to the pupil diameter.

[0303] In this configuration, the eye under examination and the optical system are moved relative to each other based on the alignment completion position corresponding to the pupil diameter, so that the eyelashes and eyelids of the eye under examination can be avoided in the image while still allowing for imaging and measurement of the eye. This makes it possible to align the eye under examination and the optical system with high precision while still allowing for imaging and measurement of the eye under examination.

[0304] A tenth embodiment of the embodiment includes, in the ninth embodiment, an alignment target position identification step and an alignment completion position identification step. The alignment target position identification step identifies the alignment target position of the optical system with respect to the eye under examination. The alignment completion position identification step identifies the alignment completion position in which the alignment target position is shifted by an amount corresponding to the pupil diameter.

[0305] In this configuration, the alignment target position is determined using the same method as in the conventional method, and the alignment completion position is identified from the determined alignment target position. Therefore, the alignment completion position can be identified with a simple process.

[0306] In the eleventh embodiment, in the tenth embodiment, the larger the pupil diameter, the greater the amount of shift from the alignment target position to the alignment completion position.

[0307] This configuration makes it possible to reliably avoid capturing images of the eye's eyelashes or eyelids while still allowing for the photographing and measurement of the eye under examination.

[0308] In the twelfth embodiment, in the eleventh embodiment, the alignment completion position is a position shifted from the alignment target position in the optical axis direction of the optical system so that the working distance is increased.

[0309] According to this configuration, a decrease in alignment accuracy caused by reflections of the eyelashes or eyelids of the eye under examination can be avoided with simple control, and the eye under examination and the optical system can be aligned with high precision.

[0310] In the thirteenth embodiment, in the eleventh embodiment, the alignment completion position is a position shifted from the alignment target position in a direction intersecting the optical axis direction of the optical system.

[0311] According to this configuration, a decrease in alignment accuracy caused by reflections of the eyelashes or eyelids of the eye under examination can be avoided with simple control, and the eye under examination and the optical system can be aligned with high precision.

[0312] In the 14th embodiment, in any of the 9th to 13th embodiments, the control step controls the movement mechanism based on the alignment completion position, which is determined by referring to table information (alignment correction information 102a) in which a plurality of shift amounts are pre-associated with a plurality of pupil diameters.

[0313] According to this configuration, the eye under examination and the optical system can be aligned with high precision, regardless of the pupil diameter of the eye under examination.

[0314] A 15th embodiment of the embodiment is that, in any of the 10th to 12th embodiments, the ophthalmic device includes two or more imaging units (anterior segment cameras 81LL, 81LR, or anterior segment cameras 81RL, 81RR). The control method of the ophthalmic device includes a pupil region identification step. The pupil region identification step identifies the pupil region in the eye under examination based on two or more images obtained by the two or more imaging units. The alignment target position identification step identifies the alignment target position based on the pupil region.

[0315] This configuration allows for high-precision alignment between the eye under examination and the optical system over a wide field of view.

[0316] In the sixteenth embodiment, as in the fifteenth embodiment, the ophthalmic apparatus includes two or more curved mirrors (a first elliptic concave mirror 21 and a second elliptic concave mirror 22). The optical system is configured to irradiate the eye under examination with light through the two or more curved mirrors and to receive reflected light through the two or more curved mirrors.

[0317] In this embodiment, in an ophthalmic device that irradiates the eye under examination with light at a wide angle, it becomes possible to precisely align the eye under examination with the device's optical system.

[0318] The seventeenth embodiment is a program that causes a computer to execute each step of the control method for an ophthalmic device according to any of the ninth to thirteenth embodiments.

[0319] This embodiment makes it possible to provide a program that can accurately align the eye under examination with the optical system to the extent that the eye under examination can be photographed and measured.

[0320] <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.

[0321] 1 Ophthalmic device 10 Optical system 10D Moving mechanism 20 Objective optical system 21 First elliptic concave mirror 22 Second elliptic concave mirror 30 Illumination optical system 40L, 40R Imaging optical system 47L, 47R Image sensor 80L, 80R Anterior segment imaging system 81LL, 81LR, 81RL, 81RR Anterior segment camera 100 Control unit 101 Main control unit 102 Storage unit 102a Alignment correction information 200 Image forming unit 210 Data processing unit 211 Pupil region identification unit 211a Pupil diameter identification unit 212 3D position identification unit 213 Alignment target position identification unit 214 Alignment completion position identification unit EL Left eye ER Right eye F1, F3 First focus F2, F4 Second focus

Claims

1. An ophthalmic device comprising: an optical system configured to irradiate an eye under examination with light and receive reflected light from the eye under examination; a moving mechanism that moves the eye under examination and the optical system relative to each other; and a control unit that controls the moving mechanism based on an alignment completion position corresponding to the pupil diameter of the eye under examination.

2. The ophthalmic apparatus according to claim 1, comprising: an alignment target position identification unit for identifying the alignment target position of the optical system with respect to the eye under examination; and an alignment completion position identification unit for identifying the alignment completion position in which the alignment target position is shifted by a shift amount corresponding to the pupil diameter.

3. The ophthalmic device according to claim 2, characterized in that the larger the pupil diameter, the greater the amount of shift from the alignment target position to the alignment completion position.

4. The ophthalmic apparatus according to claim 3, characterized in that the alignment completion position is a position shifted from the alignment target position in the direction of the optical axis of the optical system so that the working distance is increased.

5. The ophthalmic apparatus according to claim 3, characterized in that the alignment completion position is a position shifted from the alignment target position in a direction intersecting the optical axis direction of the optical system.

6. The ophthalmic apparatus according to any one of claims 1 to 5, characterized in that the control unit controls the movement mechanism based on the alignment completion position, which is identified by referring to table information in which a plurality of shift amounts are pre-associated with a plurality of pupil diameters.

7. An ophthalmic device according to any one of claims 2 to 4, comprising: two or more imaging units configured to substantially simultaneously photograph the anterior segment of the eye under examination from different directions; and a pupil region identification unit that identifies the pupil region of the eye under examination based on two or more images obtained by the two or more imaging units, wherein the alignment target position identification unit identifies the alignment target position based on the pupil region.

8. The ophthalmic apparatus according to claim 7, comprising two or more curved mirrors, wherein the optical system is configured to irradiate the eye under examination with light via the two or more curved mirrors and to receive the reflected light via the two or more curved mirrors.

9. A method for controlling an ophthalmic device, comprising: an optical system configured to irradiate an eye under examination with light and receive reflected light from the eye under examination; and a moving mechanism that moves the eye under examination and the optical system relative to each other, the method comprising: a pupil diameter identification step of identifying the pupil diameter of the eye under examination; and a control step of controlling the moving mechanism based on an alignment completion position corresponding to the pupil diameter.

10. A control method for an ophthalmic device according to claim 9, comprising: an alignment target position identification step of identifying the alignment target position of the optical system with respect to the eye under examination; and an alignment completion position identification step of identifying the alignment completion position in which the alignment target position is shifted by a shift amount corresponding to the pupil diameter.

11. The control method for an ophthalmic device according to claim 10, characterized in that the larger the pupil diameter, the greater the amount of shift from the alignment target position to the alignment completion position.

12. The control method for an ophthalmic apparatus according to claim 11, characterized in that the alignment completion position is a position shifted from the alignment target position in the direction of the optical axis of the optical system so that the working distance is increased.

13. The control method for an ophthalmic apparatus according to claim 11, characterized in that the alignment completion position is a position shifted from the alignment target position in a direction intersecting the optical axis direction of the optical system.

14. The control step is characterized in that the movement mechanism is controlled based on the alignment completion position, which is identified by referring to table information in which a plurality of shift amounts are pre-associated with a plurality of pupil diameters, as described in any one of claims 9 to 13.

15. The ophthalmic device includes two or more imaging units configured to substantially simultaneously photograph the anterior segment of the eye under examination from different directions, and includes a pupil region identification step to identify the pupil region of the eye under examination based on two or more images obtained by the two or more imaging units, and the alignment target position identification step to identify the alignment target position based on the pupil region, characterized in that the ophthalmic device is controlled according to any one of claims 10 to 12.

16. The method for controlling an ophthalmic device according to 15, wherein the ophthalmic device includes two or more curved mirrors, and the optical system is configured to irradiate the eye under examination with light via the two or more curved mirrors and to receive the reflected light via the two or more curved mirrors.

17. A program characterized by causing a computer to execute each step of the control method for an ophthalmic device described in any one of claims 9 to 13.

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