Fundus observation device

Abstract

The purpose of the present invention is to realize a compact and economical device that uses a mirror system that places less strain on an examinee when observing the fundus of an eye to be examined at a wide angle. A fundus observation device (A1) includes, as components of an optical system, an illumination optical system (70) that has a light source unit (71) and illuminates a fundus Ef of the eye E to be examined by slit scan light; an observation optical system (60) that has fundus image sensors (671L, 671R) and receives return light from the fundus Ef of the eye E to be examined; and a pair of concave mirrors that are disposed at positions between the eye E to be examined and an optical path branch unit and form a reflection optical path for the slit scan light and a reflection optical path for the return light. The pair of concave mirrors is configured by a concave mirror unit (50) in which a first elliptical concave mirror (51) and a second elliptical concave mirror (52) are connected by a concave mirror bracket (53). The concave mirror unit (50) can be turned with respect to a device stand (10) so as to trace a turning trajectory for switching between a first arrangement when the eye to be observed is the left eye and a second arrangement when the eye to be observed is the right eye.

Description

Fundus observation device

[0001] The present invention relates to a fundus observation device.

[0002] A fundus observation device is a device for displaying and observing / photographing a fundus image of a subject's eye with a wide angle of view. Patent Document 1 proposes a mirror-based optical system configuration, which creates a space in front of the subject's eye and reduces the burden on the subject, compared to a lens-based system in which an objective lens is placed close to the subject's eye. The device described in Patent Document 1 includes, as optical system components, an illumination optical system having a light source, a slit, and an optical scanner; an observation optical system having an image sensor; and a pair of elliptical concave mirrors. The pair of elliptical concave mirrors form a reflected optical path for projecting slit scanning light from the illumination optical system onto the fundus, and a reflected optical path for light returning from the fundus to the observation optical system. This fundus observation device acquires a wide-angle fundus image by positioning the subject's eye at the focal position of one of the elliptical concave mirrors, using the horizontal cross-sectional angular range in the slit projection direction of the slit light passing through the slit of the illumination optical system and the vertical cross-sectional angular range in the scanning direction of the optical scanner.

[0003] Japanese Patent Application Laid-Open No. 2023-122620

[0004] Incidentally, a mirror-type fundus observation device requires each component included in the optical system for each of the left and right eyes to be examined, and therefore, when the fundus observation device is realized as an actual device corresponding to the left and right eyes to be examined, it is configured to include an illumination optical system, an observation optical system, and a pair of elliptical concave mirrors included in the optical system, independently for the left and right eyes.

[0005] However, the elliptical concave mirror needs to have a large outer diameter to acquire a wide-angle fundus image that satisfies the required angle of view, and the elliptical concave surface needs to be finished with high precision to reduce corneal reflection flare and achieve good image quality. Furthermore, if the elliptical concave mirrors are configured independently to correspond to the left and right eyes of the subject, a total of four elliptical concave mirrors are required: a pair of elliptical concave mirrors for the left eye and a pair of elliptical concave mirrors for the right eye. Therefore, if a mirror-type fundus observation device is to be realized as an actual device corresponding to each of the left and right eyes of the subject, it will end up being a large and expensive device.

[0006] The present invention has been made with an eye on the above-mentioned problems, and aims to provide a fundus observation device that uses a mirror system that imposes less strain on the subject when observing the fundus of the subject's eye over a wide angle, while also being compact and economical to implement.

[0007] The fundus observation device of the present invention includes, as its optical system components, an illumination optical system having a light source unit that projects slit scan light onto the fundus of the eye to be examined, an observation optical system having an image sensor that receives return light from the fundus of the eye to be examined, and a pair of concave mirrors that are arranged between the eye to be examined and an optical path branching unit and form a reflected light path of the slit scan light and a reflected light path of the return light. The pair of concave mirrors are configured as a concave mirror unit in which a first concave mirror and a second concave mirror are connected by a concave mirror bracket. The concave mirror unit is provided rotatably with respect to an apparatus stand so as to describe a rotation locus that switches between a first position when the eye to be observed is the left eye and a second position when the eye to be observed is the right eye.

[0008] The fundus observation device according to the present invention uses a concave mirror unit that is shared by both the left and right eyes, and thus can realize a compact and economical actual device while using a mirror system that places less strain on the subject when observing the fundus of the subject's eye over a wide angle.

[0009] 1 is an overall perspective view of a fundus observation device of Example 1 as seen from a diagonal rear direction. FIG. 2 is an overall side view showing the fundus observation device of Example 1. FIG. 3 is an overall front view showing the fundus observation device of Example 1. FIG. 4 is a plan view showing a first arrangement of the concave mirror unit when photographing the left eye. FIG. 5 is a plan view showing a second arrangement of the concave mirror unit when photographing the right eye. FIG. 6 is an explanatory diagram showing a mirror rotation angle α of the concave mirror unit. FIG. 7 is an explanatory diagram showing a frame tilt rotation angle θ of the optical head frame and X-axis / Z-axis movement amount. FIG. 8 is a position characteristic diagram showing the mirror rotation angle, frame tilt rotation angle, and X-axis / Z-axis movement amount. FIG. 9 is a plan view showing the configuration of an observation optical system among the components of the optical system. FIG. 10 is a side view showing the configuration of an illumination optical system among the components of the optical system. FIG. 11 is a front view showing the configuration of an alignment optical system among the components of the optical system. FIG. 12 is a perspective view showing a face support unit provided in the fundus observation device. FIG. 13 is a block diagram showing the configuration of a control system in the fundus observation device of Example 1. FIG. 14 is a flowchart showing the flow of the photographing operation of the left eye and right eye of a subject. FIG. 15 is a diagram showing the horizontal cross-sectional angular range of illumination light projected onto the fundus. FIG. 16 is a diagram showing the vertical cross-sectional angular range of illumination light projected onto the fundus. 1 is a plan view showing a comparative example of a mirror-type fundus observation device. FIG. 2 is an overall perspective view of the fundus observation device of Example 2 seen from an oblique front direction. FIG. 3 is an overall perspective view of the fundus observation device of Example 2 seen from an oblique rear direction. FIG. 4 is an explanatory diagram showing right eye photographing and left eye photographing in plan view. FIG. 5 is a front view showing a first arrangement state of the concave mirror unit and a face support part in the fundus observation device of Example 3. FIG. 6 is an overall front view showing a second arrangement state of the concave mirror unit and a face support part in the fundus observation device of Example 3. FIG. 7 is a characteristic diagram comparing the position characteristics of the mirror rotation angle, the frame tilt rotation angle, and the X-axis / Z-axis movement amount in the fundus observation device of Example 3 with those in Example 1. FIG. 8 is a plan view showing the first arrangement of the concave mirror unit when photographing the left eye in the fundus observation device of Example 1. FIG. 9 is a plan view showing the first arrangement of the concave mirror unit when photographing the left eye in the fundus observation device of Example 3.

[0010] The embodiments for carrying out the fundus observation device of the present invention will be described below based on the first, second and third embodiments shown in the drawings.

[0011] The fundus observation device applied in Examples 1, 2, and 3 is a device called a mydriatic fundus camera that observes, photographs, and records fundus images of the subject's eye and provides them as electronic images for diagnosis. This fundus observation device acquires wide-angle fundus images that allow for thorough observation of the entire fundus from the macula to the periphery. Note that, in the drawings, X, Y, and Z indicate the left-right (horizontal) axis when the subject faces the main body of the fundus observation device, the Y axis indicates the up-down (vertical) axis, and the Z axis indicates the front-back axis (depth direction) perpendicular to the X and Y axes.

[0012] [Overall configuration of the device (Figures 1 to 3)] The fundus observation device A1 includes a device stand 10, an optical head frame 20, a face support unit 30, a control panel unit 40, a concave mirror unit 50, an observation optical system 60, an illumination optical system 70, an alignment optical system 80, and a control unit 90.

[0013] The device stand 10 is a base member placed on an optical table T whose height in the Y-axis direction is adjustable. The device stand 10 has an optical head frame 20, in which components of the optical system are provided, located in a central region sandwiched between a face support unit 30 and a control panel unit 40. The face support unit 30 is fixed to the front side of the device stand 10 facing the subject H, and the control panel unit 40 is attached to the back side facing the examiner.

[0014] The device pedestal 10 has an X-axis movable frame 11 disposed above a central region sandwiched between the face support unit 30 and the control panel unit 40, the X-axis movable frame 11 being movable in the X-axis direction relative to the device pedestal 10. A Z-axis movable frame 12 is disposed above the X-axis movable frame 11, the Z-axis movable frame 12 being movable in the Z-axis direction relative to the X-axis movable frame 11. A Y-axis movable frame 13 is disposed above the Z-axis movable frame 12, the Y-axis movable frame 13 being movable in the Y-axis direction relative to the Z-axis movable frame 12. The device pedestal 10 has an X-axis drive unit 14, such as a motor actuator, that moves the X-axis movable frame 11 in the X-axis direction. The X-axis movable frame 11 has a Z-axis drive unit 15, such as a motor actuator, that moves the Z-axis movable frame 12 in the Z-axis direction. The Z-axis movable frame 12 has a Y-axis drive unit 16, such as a motor actuator, that moves the Y-axis movable frame 13 in the Y-axis direction.

[0015] The optical head frame 20 is a frame member in which the optical system components, namely the concave mirror unit 50, the observation optical system 60, the illumination optical system 70, and the alignment optical system 80, are mounted. The optical head frame 20 is mounted on a Y-axis movable frame 13 that is movable in three directions, namely the X-axis, Y-axis, and Z-axis directions, relative to the device pedestal 10. The Y-axis movable frame 13 has a tilt rotation drive unit 17 that rotates the optical head frame 20 in the XZ plane around a frame rotation axis 21 set in the Y-axis direction. The tilt rotation drive unit 17 has a motor, worm gear, and motor drive circuit that rotate the optical head frame 20. In this way, the optical head frame 20 is mounted to be capable of complex motion relative to the device pedestal 10 so as to trace a combined motion trajectory of linear motion in the X-axis and Z-axis directions and rotational motion around the frame rotation axis 21 when switching between the left and right eyes being observed.

[0016] The face support unit 30 is disposed in front of the concave mirror unit 50 in the Z-axis direction of the device pedestal 10, and is a member that supports the forehead and chin of the subject H to stabilize the position and orientation of the subject's eye E when observing / photographing the fundus. The face support unit 30 is configured for both the left and right eyes and includes a chin rest support unit 31 fixed to the front end of the device pedestal 10, a forehead rest frame 32, a chin rest 33, a lifting rod 34, and a chin rest drive unit 35. The chin rest drive unit 35 is built into the chin rest support unit 31 and includes a motor and a motor drive circuit that drive the lifting rod 34 in the Y-axis direction.

[0017] The control panel unit 40 is disposed at the rear position of the device stand 10. The control panel unit 40 has a touch panel screen 41 that displays in color a fundus image of the subject's eye E from the fundus camera provided in the observation optical system 60 and an anterior segment image of the subject's eye E from the anterior segment stereo camera provided in the alignment optical system 80. The examiner's touch operation of the touch panel screen 41 with his / her finger on various button images, anterior segment images, fundus images, etc. displayed on the screen serves as an input operation to the control unit 90. The control panel unit 40 is used when acquiring a fundus image in a face-to-face examination in which the subject H and the examiner are both present at the location where the fundus observation device A1 is installed. In addition to the control panel unit 40, a remote control tablet (not shown) having a screen and input operation functions equivalent to those of the control panel unit 40 may be provided so that a fundus image can be acquired by remote operation by the examiner.

[0018] The concave mirror unit 50 is formed by connecting a pair of first and second elliptical concave mirrors 51 and 52 with a concave mirror bracket 53. The concave mirror unit 50 is disposed between the face support section 30 and the optical head frame 20 and is rotatable about a unit rotation axis 54 set in the Z-axis direction relative to the optical head frame 20. The optical head frame 20 has a unit rotation drive section 55 at the front end of the upper surface of the frame, which drives the concave mirror unit 50 to rotate about the unit rotation axis 54. The unit rotation drive section 55 includes a motor that drives the concave mirror unit 50 to rotate, a timing belt wound around two pulleys, and a motor drive circuit. When switching between the left and right eyes to be observed, the concave mirror unit 50 rotates about the unit rotation axis 54 relative to the optical head frame 20 to switch between a first position (solid line position in FIGS. 1 and 3 ) and a second position (phantom line position in FIG. 3 ). The detailed configuration of the concave mirror unit 50 will be described later.

[0019] The observation optical system 60 is provided by arranging observation optical components on the upper surface of the optical head frame 20. The illumination optical system 70 is provided by arranging illumination optical components on the lower surface of the optical head frame 20. The alignment optical system 80 is provided by arranging alignment optical components on the left and right positions below the front end of the optical head frame 20. The detailed configurations of the observation optical system 60, illumination optical system 70, and alignment optical system 80 will be described later.

[0020] The control unit 90 electronically controls each part of the fundus observation device A1 (such as the face support unit 30, concave mirror unit 50, observation optical system 60, illumination optical system 70, and alignment optical system 80) based on input operations including touch operations on the touch panel screen 41 of the control panel unit 40. This control unit 90 is provided on one side of the optical head frame 20 or on both sides of the optical head frame 20, and has a main board, a TRC control board, a galvano driver board, and the like as a hardware configuration. The detailed configuration of the control unit 90 will be described later.

[0021] When the fundus observation device A1 is commercialized as an actual device, a cover structure (not shown) that covers the outer periphery will be added. The cover structure is set up separately into a fixed cover and a movable cover. The fixed cover entirely covers the optical head frame 20, the observation optical system 60, the illumination optical system 70, the alignment optical system 80, and the control unit 90, and is fixed to the device stand 10. The movable cover is fixed to the concave mirror unit 50 and is provided rotatable together with the concave mirror unit 50 relative to the optical head frame 20. This movable cover covers most of the concave mirror unit 50, and a fundus observation hole is formed in a position facing the first elliptical concave surface of the first elliptical concave mirror 51. The opening area of ​​the fundus observation hole is set to an area corresponding to the combined area of ​​the subject's eye E and its surrounding area.

[0022] [Detailed Configuration of the Concave Mirror Unit (FIGS. 4 to 8)] The concave mirror unit 50 is disposed between the subject's eye E and the optical path branching section, and forms a reflected optical path for the slit scan light from the illumination optical system 70 to the fundus, and a reflected optical path for the return light from the fundus to the observation optical system 60. The optical path branching section branches the optical path of the observation optical system 60 from the optical path of the illumination optical system 70, and dichroic mirrors 57L and 57R are disposed at the optical path branching position. The concave mirror unit 50 is configured by connecting a first elliptical concave mirror 51 and a second elliptical concave mirror 52 with a concave mirror bracket 53, and has a stopper plate 56 (see FIGS. 2, 4, and 5) at the outer end position of the first elliptical concave mirror 51. The optical head frame 20 has limit switches 58 and 59 (see FIG. 13) on either side of the unit rotation axis 54. When the concave mirror unit 50 rotates to the first position, the stopper plate 56 comes into contact with a limit switch 58 to perform a switching operation, and when the concave mirror unit 50 rotates to the second position, the stopper plate 56 comes into contact with a limit switch 59 to perform a switching operation.

[0023] The first elliptical concave mirror 51 has a first elliptical concave surface 51a having two optically conjugate focal points F1 and F2. The position of the focal point F1 is the position where the pupil of the subject's eye E is positioned when observing / photographing the fundus. The second elliptical concave mirror 52 has a second elliptical concave surface 52a having two optically conjugate focal points F3 and F4, with a portion of the second elliptical concave surface 52a facing the first elliptical concave surface 51a. The position of the focal point F3 coincides with the position of the focal point F2. The position of the focal point F4 is the position of the optical path branch point between the optical path of the observation optical system 60 and the optical path of the illumination optical system 70. The concave mirror bracket 53 connects the first elliptical concave mirror 51 and the second elliptical concave mirror 52 while maintaining the positional relationship between the focal points F1, F2, F3, and F4, and is also connected to a unit rotation shaft 54 ​​from a unit rotation drive unit 55.

[0024] The concave mirror unit 50 is configured for both left and right eyes by rotating relative to the device stand 10 along a rotation path that switches between a first configuration (when photographing the left eye in FIG. 4 ) for the left eye being observed and a second configuration (when photographing the right eye in FIG. 5 ) for the right eye being observed. In the first configuration, the concave mirror unit 50 is configured such that the first elliptical concave mirror 51 is positioned in front of the left eye and the second elliptical concave mirror 52 is positioned on the left side of the face, as shown in FIG. 4 . In the second configuration, the concave mirror unit 50 is configured such that the first elliptical concave mirror 51 is positioned in front of the right eye and the second elliptical concave mirror 52 is positioned on the right side of the face, as shown in FIG. 5 . The concave mirror unit 50 also has a reference configuration in addition to the first and second configurations. The "first configuration" and "second configuration" refer to horizontal arrangement states. In contrast, the "standard arrangement" refers to a vertical arrangement state in which the first elliptical concave mirror 51 is positioned at the lower position and the second elliptical concave mirror 52 is positioned at the upper position in the Y-axis direction, as shown in Figures 6 and 7.

[0025] When the concave mirror unit 50 is switched from the standard configuration to the first configuration, the first configuration is a position where the mirror rotation angle α about the unit rotation axis 54 is rotated counterclockwise from α=0° in the standard configuration to α=−α° (for example, approximately −90°) as shown in Figures 6 and 8. When the concave mirror unit 50 is switched from the standard configuration to the second configuration, the second configuration is a position where the mirror rotation angle α about the unit rotation axis 54 is rotated clockwise from α=0° in the standard configuration to α=+α° (for example, approximately +90°) as shown in Figures 6 and 8.

[0026] When the concave mirror unit 50 is in the first position, the optical head frame 20 is positioned closer to the left end of the device pedestal 10, as shown in Fig. 4, with the frame central axis CL tilted at an angle relative to the line of sight of the subject's eye E (Z-axis direction) so that the concave mirror unit 50 faces the subject H. When the concave mirror unit 50 is in the second position, the optical head frame 20 is positioned closer to the right end of the device pedestal 10, as shown in Fig. 5, with the frame central axis CL tilted at an angle relative to the line of sight of the subject's eye E (Z-axis direction) so that the concave mirror unit 50 faces the subject H. When the concave mirror unit 50 is in the standard position, the optical head frame 20 is positioned at the center of the device pedestal 10, as shown in Fig. 7, with the optical head frame 20 moved in the depth direction of the Z-axis so that the optical head frame 20 is farthest from the subject H.

[0027] When the optical head frame 20 switches the concave mirror unit 50 from the reference arrangement to the first arrangement, the frame tilt rotation angle θ about the frame rotation axis 21 is rotated counterclockwise from θ=0° in the reference arrangement to θ=−θ° (for example, approximately −10°) as shown in Figures 7 and 8. When the optical head frame 20 switches the concave mirror unit 50 from the reference arrangement to the second arrangement, the frame tilt rotation angle θ about the frame rotation axis 21 is rotated clockwise from θ=0° in the reference arrangement to θ=+θ° (for example, approximately +10°) as shown in Figures 7 and 8.

[0028] When the concave mirror unit 50 is switched from the standard configuration to the first configuration, the X-axis movable frame 11 is moved an amount DX mm along the X axis from DX = 0 mm in the standard configuration to DX = -DX mm (for example, about -100 mm), which is the left end position, as shown in Figures 7 and 8. When the concave mirror unit 50 is switched from the standard configuration to the second configuration, the X-axis movable frame 11 is moved an amount DX mm along the X axis from DX = 0 mm in the standard configuration to DX = +DX mm (for example, about +100 mm), which is the right end position, as shown in Figures 7 and 8.

[0029] When the concave mirror unit 50 is switched from the standard configuration to the first configuration, the Z-axis movable frame 12 moves closer in the Z-axis direction by an amount DZ mm from DZ = 0 mm in the standard configuration to DZ = +DZ mm (for example, about +72 mm), as shown in Figures 7 and 8. When the concave mirror unit 50 is switched from the standard configuration to the second configuration, the Z-axis movable frame 12 moves closer in the Z-axis direction by an amount DZ mm from DZ = 0 mm in the standard configuration to DZ = +DZ mm (for example, about +72 mm), as shown in Figures 7 and 8.

[0030] When the concave mirror unit 50 is switched from the reference configuration to the first configuration or the second configuration, the operation is a combination of a YX plane rotational movement of the concave mirror unit 50, an XZ plane rotational movement of the optical head frame 20, an X-axis direction movement of the X-axis movable frame 11, and a Z-axis direction movement of the Z-axis movable frame 12. Therefore, the concave mirror unit 50 is provided rotatable with respect to the device pedestal 10 so as to describe a rotational trajectory that switches between the first configuration when the eye to be observed is the left eye and the second configuration when the eye to be observed is the right eye. When the optical head frame 20 is switched from the reference configuration to the first configuration or from the reference configuration to the second configuration, it rotates with respect to the device pedestal 10 and moves in the X-axis and Z-axis directions so as to describe an arc trajectory while maintaining a gap distance from the face of the subject H.

[0031] [Detailed Configuration of Optical System (FIGS. 9 to 11)] In addition to the concave mirror unit 50, the fundus observation device A includes an observation optical system 60 (photographing optical system), an illumination optical system 70, and an alignment optical system 80 as optical systems. As shown in FIG. 9, the observation optical system 60 is configured as independent optical systems for the left and right eyes, having an observation optical system 60L for the left eye when the eye to be observed is the left eye, and an observation optical system 60R for the right eye when the eye to be observed is the right eye. As shown in FIG. 10, the illumination optical system 70 is configured as an optical system shared by both the left and right eyes, independently provided along the frame center axis CL of the optical head frame 20. As shown in FIG. 11, the alignment optical system 80 is configured as independent optical systems for the left and right eyes, having an alignment optical system 80L for the left eye when the eye to be observed is the left eye, and an alignment optical system 80R for the right eye when the eye to be observed is the right eye. The observation optical system 60 and the illumination optical system 70 employ a separated illumination system in which the observation light beam and the illumination light beam are offset within the pupil circle. Dichroic mirrors 57L and 57R are disposed at the optical path branching section, which merge the observation light path, the illumination light path, and the alignment light path. The conjugate relationship of the optical systems is such that the iris diaphragm 71a and the photographing diaphragms 600L and 600R are disposed at positions conjugate with the pupil, and the slit 72a and the fundus image sensors 671L and 671R are disposed at positions conjugate with the fundus. If a coaxial illumination system is employed in which the observation light beam and the illumination light beam are aligned within the pupil circle, a perforated mirror may be disposed at the optical path branching section.

[0032] The observation optical system 60 has fundus image sensors 671L, 671R and is an optical system that receives return light from the fundus of the subject's eye E that has passed through the concave mirror unit 50. As shown in FIG. 9 , the observation optical system 60 is provided in the optical head frame 20 and includes a left-eye observation optical system 60L and a right-eye observation optical system 60R that are positioned at line symmetrical positions equidistant from each other about the frame center axis CL of the optical head frame 20 and have two optical path axes that are parallel to each other in a plan view. Each of the left-eye observation optical system 60L and the right-eye observation optical system 60R is configured as a decentered optical system with a decentered optical path. When a decentered optical system is used in the observation optical system 60, the tilt directions of the left and right fundus image sensors 671L, 671R are different, so the left-eye observation optical system 60L and the right-eye observation optical system 60R are configured independently for the left and right eyes.

[0033] The left-eye observation optical system 60L is configured by arranging components along the optical path of the returned light indicated by the arrow in FIG. 9 , starting from the dichroic mirror 57L located at the optical path branching section relative to the upper surface of the optical head frame 20. The left-eye observation optical system 60L includes a photographing aperture 600L, a first reflecting mirror 61L, a first lens unit 62L, a second reflecting mirror 63L, a second lens unit 64L, a focusing lens 65L, a third lens unit 66L, and a fundus camera 67L as components. The photographing aperture 600L is positioned conjugate with the pupil of the subject's eye E. The fundus camera 67L is provided with a fundus image sensor 671L positioned at an inclination angle facing outward in a plan view due to the decentered optical system setting. The fundus image sensor 671L is positioned conjugate with the fundus of the subject's eye E.

[0034] The right-eye observation optical system 60R is configured by arranging components along the optical path of the returned light indicated by the arrow in FIG. 9 , starting from the dichroic mirror 57R located at the optical path branching section on the upper surface of the optical head frame 20. The right-eye observation optical system 60R includes a photographing aperture 600R, a first reflecting mirror 61R, a first lens unit 62R, a second reflecting mirror 63R, a second lens unit 64R, a focusing lens 65R, a third lens unit 66R, and a fundus camera 67R. The photographing aperture 600R is positioned conjugate with the pupil of the subject's eye E. The fundus camera 67R is provided with a fundus image sensor 671R tilted outward in plan view due to the decentered optical system setting. The fundus image sensor 671R is positioned conjugate with the fundus of the subject's eye E.

[0035] The left-eye observation optical system 60L and the right-eye observation optical system 60R have, as a common component, a slide plate 68 that is slidable in the Z-axis direction relative to the optical head frame 20. A second lens unit 64L, a focusing lens 65L, a third lens unit 66L, a second lens unit 64R, a focusing lens 65R, and a third lens unit 66R are arranged on the upper surface of the slide plate 68. The slide plate 68 performs focusing by using a single focusing drive unit 69, such as a motor actuator, to adjust the focus of the observation optical system 60 to the fundus of the subject's eye E during fundus observation.

[0036] The illumination optical system 70 has a light source unit 71 and is an optical system that projects slit scanning light onto the fundus of the subject's eye E via the concave mirror unit 50. This illumination optical system 70 is provided on the optical head frame 20 and includes one light source unit 71, one slit unit 72 (slit), and one galvanometer scanner 73 (optical scanner). The illumination optical system 70 is configured as an optical system shared by both the left and right eyes, in which a left / right switching mirror 75 is arranged between the galvanometer scanner 73 and the concave mirror unit 50, in addition to the light source unit 71, the slit unit 72, and the galvanometer scanner 73.

[0037] The illumination optical system 70 is configured by arranging components along the optical path of illumination light indicated by the arrows in Fig. 10 , with the light source unit 71 as the starting component and the dichroic mirrors 57L and 56R arranged at the optical path branching unit as the ending component. The illumination optical system 70 includes the light source unit 71, a slit unit 72, a galvanometer scanner 73, a first reflecting mirror 741, a second reflecting mirror 742, and a left-right switching mirror 75. As shown in Fig. 11 , the optical path from the left-right switching mirror 75 (virtual line) toward the dichroic mirror 57L includes a first lens unit 761L, a third reflecting mirror 743L, a second lens unit 762L, and a fourth reflecting mirror 744L. As shown in FIG. 11, the optical path from the left / right switching mirror 75 (solid line) to the dichroic mirror 57R includes a first lens unit 761R, a third reflecting mirror 743R, a second lens unit 762R, and a fourth reflecting mirror 744R.

[0038] The light source unit 71 is an output unit for illumination light, and has an iris diaphragm 71a located near the input slit unit 72. The iris diaphragm 71a is arranged at a position conjugate with the pupil of the subject's eye E. The slit unit 72 has a slit 72a and a projection lens 72b. The slit 72a is arranged at a position conjugate with the fundus of the subject's eye E. The optical head frame 20 is equipped with a slit drive unit 77 that controls the slit light directed from the slit unit 72 toward the galvano scanner 73. The slit drive unit 77 has a linear motion unit that adjusts the focus of the slit 72a to match the subject's eye E.

[0039] The galvanometer scanner 73 is provided with a scanner driver 78 that controls the scan angle of the slit light by the galvanometer mirror using a rotary encoder, in the optical head frame 20. The left / right switching mirror 75 is provided with a mirror rotation driver 79 that switches and drives the mirror tilt angle around a mirror rotation axis 75a set in the Z-axis direction, in the optical head frame 20, as shown in Fig. 11 .

[0040] The alignment optical systems 80 are provided at the left and right positions of the front end of the optical head frame 20, and are optical systems that acquire images of the anterior segment of the subject's eye E used for alignment when performing alignment to adjust the position of the subject's eye E to the position of the first focal point F1 of the first elliptical concave mirror 51. As shown in Fig. 11, the alignment optical systems 80 are configured as independent optical systems for the left and right eyes, having an alignment optical system 80L for the left eye when the subject's eye is the left eye, and an alignment optical system 80R for the right eye when the subject's eye is the right eye.

[0041] As shown in FIG. 11 , the left eye alignment optical system 80L is provided in an alignment optical frame 22L fixed to the optical head frame 20. The left eye alignment optical system 80L includes an anterior eye stereo camera 81L, whose camera lens optical axis faces the dichroic mirror 57L, and an alignment illumination lamp 82L, whose alignment illumination optical axis faces the dichroic mirror 57L. The anterior eye stereo camera 81L incorporates an anterior eye image sensor 811L (see FIG. 13 ), and the camera lens optical axis and alignment illumination optical axis from the dichroic mirror 57L are reflected by the first elliptical concave mirror 51 to acquire an illuminated anterior eye image of the left eye. Two anterior eye images of the left eye are generated from different positions to enable three-dimensional alignment adjustment.

[0042] As shown in FIG. 11 , the right-eye alignment optical system 80R is provided in an alignment optical frame 22R fixed to the optical head frame 20. The right-eye alignment optical system 80R includes an anterior-segment stereo camera 81R, whose camera lens optical axis faces the dichroic mirror 57R, and an alignment illumination lamp 82R, whose alignment illumination optical axis faces the dichroic mirror 57R. The anterior-segment stereo camera 81R incorporates an anterior-segment image sensor 811R (see FIG. 13 ), and acquires an illuminated anterior-segment image of the right eye when the camera lens optical axis and alignment illumination optical axis from the dichroic mirror 57L are reflected by the first elliptical concave mirror 51. Two anterior-segment images of the right eye are generated from different positions to enable three-dimensional alignment adjustment.

[0043] [Detailed Configuration of Face Support Unit ( FIG. 12 )] The face support unit 30 includes a chin rest support unit 31 fixed to the front end of the device pedestal 10, a forehead rest frame 32 that supports the forehead of the subject H, a chin rest 33 that supports the chin of the subject H, an elevation rod 34 with the chin rest 33 attached to its upper end, and a chin rest drive unit 35. This face support unit 30 requires the subject's eye E to fixate to the side in order to avoid contact between the subject H's face and the device body. Furthermore, the face support unit 30 must accommodate the different facial positions and angles in order to change the line of sight during wide-angle left-eye observation / photography and right-eye observation / photography. The optical head frame 20 is tilted to partially accommodate the different facial positions and angles. Therefore, although the face position and angle differ, the degree of difference is small, so the face support part 30 is basically designed to be used for both the left and right eyes, and this is accommodated by slightly changing the positions of the forehead support surface and the chin support surface.

[0044] The forehead support frame 32 is configured to be used for both the left and right eyes, with a left eye support surface 32a and a right eye support surface 32b adjacent to each other. The left eye support surface 32a and the right eye support surface 32b are made of a material such as silicone rubber and are provided at positions corresponding to the forehead position on the face.

[0045] The chin rest 33 is configured to be used for both the left and right eyes, with a left eye chin rest surface 33a and a right eye chin rest surface 33b located adjacent to each other. The left eye chin rest surface 33a and the right eye chin rest surface 33b are provided at positions corresponding to the chins of the subject H when observing with the left eye and the right eye, respectively. The left eye chin rest surface 33a and the right eye chin rest surface 33b each have a concave curved shape that matches the shape of the jaw, and are formed in adjacent positions so that they partially overlap.

[0046] [Control system configuration (Fig. 13)] As shown in Fig. 13, the control system of the fundus observation device A includes a control unit 90 that controls each unit of the device by outputting commands to a drive unit 100 etc. The control system of the fundus observation device A includes a user interface unit 110, an image forming unit 120, and a data processing unit 130 in addition to the control unit 90 and the drive unit 100. The control unit 90 has an alignment control unit 91, a left / right eye switching control unit 92, a fundus image photographing control unit 93, and a storage unit 94. The storage unit 94 stores information required for alignment control, left / right eye switching control, fundus image photographing control, etc.

[0047] The alignment control unit 91 performs coarse alignment control to adjust the height position of the subject's eye E in the Y-axis direction to an appropriate height position, and fine alignment control to align the position of the pupil of the subject's eye E with the focal point F1 of the first elliptical concave mirror 51 in preparation for fundus observation / photography. The coarse alignment control outputs a drive command from the alignment control unit 61 to the chin rest drive unit 35 when adjusting the height in the Y-axis direction by manual operation or when adjusting the height in the Y-axis direction by automatic control based on anterior segment images of the subject's eye E acquired from the anterior segment image sensors 811L, 811R of the alignment optical system 80. The fine alignment control outputs drive commands from the alignment control unit 61 to the X-axis drive unit 14, the Y-axis drive unit 16, and the Z-axis drive unit 15 based on the anterior segment images of the subject's eye E acquired from the alignment optical system 80. Here, the alignment control unit 91 illuminates the anterior segment of the subject's eye E by turning on the alignment illumination lamps 82L, 82R, and acquires anterior segment images from the anterior segment image sensors 811L, 811R of the anterior segment stereo cameras 81L, 81R. Note that the coarse alignment control may be omitted and only the fine alignment control may be executed if it is confirmed that the height adjustment in the Y-axis direction of the subject's eye E has already been performed, such as when switching the subject's eye E from the left eye to the right eye.

[0048] The left / right eye switching control unit 92 performs the control necessary to switch the observation target eye between the left eye and the right eye. To switch to the left eye, the configuration is switched from the standard configuration to the first configuration to set up the fundus observation mode for the left eye, and the configuration is returned to the standard configuration once observation / photography of the left eye is completed. To switch to the right eye, the configuration is switched from the standard configuration to the second configuration to set up the fundus observation mode for the right eye, and the configuration is returned to the standard configuration once observation / photography of the right eye is completed. When switching the observation target eye between the left eye and the right eye, the left / right eye switching control unit 92 controls the mirror rotation angle of the concave mirror unit 50, the frame tilt rotation angle of the optical head frame 20, the amount of left / right movement of the X-axis movable frame 11, and the amount of front / rear movement of the Z-axis movable frame 12. The left / right eye switching control unit 92 controls the switching rotation of the left / right switching mirror 75 of the illumination optical system 70.

[0049] The mirror rotation angle control of the concave mirror unit 50 uses limit switches 58, 59 and a unit rotation drive unit 55 to control the mirror rotation angle α of the concave mirror unit 50. The frame tilt rotation angle control of the optical head frame 20 uses a tilt rotation drive unit 17 to control the frame tilt rotation angle θ of the optical head frame 20. The left and right movement amount control of the X-axis movable frame 11 uses an X-axis drive unit 14 to control the X-axis movement amount of the X-axis movable frame 11. The front and back movement amount control of the Z-axis movable frame 12 uses a Z-axis drive unit 15 to control the Z-axis movement amount of the Z-axis movable frame 12. The switching rotation control of the left and right switching mirror 75 uses a mirror rotation drive unit 79 to control the switching of the set angle of the left and right switching mirror 75.

[0050] When observing / capturing a fundus image of the subject's eye E, the fundus image capture control unit 93 performs focusing control for the left-eye observation optical system 60L and the right-eye observation optical system 60R, slit control for the slit unit 72 in the illumination optical system 70, and scan control for the galvanometer scanner 73 for each of the left and right eyes. Focusing control for the left-eye observation optical system 60L and the right-eye observation optical system 60R is performed by using a focusing drive unit 69 to control the amount of movement of the slide plate 68 in the Z-axis direction. Slit control in the illumination optical system 70 is performed by using a slit drive unit 77 to perform linear control of the slit unit 72. Scan control in the illumination optical system 70 is performed by using a scanner drive unit 78 to drive and control the galvanometer scanner 73 at a set vertical fundus scan angle.

[0051] The user interface unit 110 has a function for exchanging information between the user and the fundus observation device A1, and includes a display device and an operation device. The display device and the operation device are exemplified by the touch panel screen 41 of the control panel unit 40. The image forming unit 120 forms a fundus image of the subject's eye E from a plurality of received light images acquired from the fundus image sensors 671L and 671R. The data processing unit 130 performs various image data processing such as brightness correction processing on the fundus image of the subject's eye E formed by the image forming unit 120.

[0052] [Fundus image observation / photographing processing operation (FIG. 14)] The fundus image photographing processing operation executed in the control unit 90 will be described below with reference to the flowchart in FIG. 14. The fundus image photographing processing operation starts when the subject H is confirmed by the fundus observation device A1 with the power switch turned on, and the patient (= subject H) is registered by the name and patient ID that identify the patient. The "patient ID" is an identification number for managing personal information related to the ophthalmologic examination of the subject H, and can include age, sex, past examination information for follow-up, etc.

[0053] In step S1, the left / right eye switching control unit 92 switches from the standard arrangement to the first arrangement to enable fundus observation of the left eye. The left / right eye switching control unit 92 controls the switching from the standard arrangement, in which the first elliptical concave mirror 51 and the second elliptical concave mirror 52 are arranged vertically, to the first arrangement, in which the first elliptical concave mirror 51 and the second elliptical concave mirror 52 are arranged horizontally and the first elliptical concave mirror 51 is arranged immediately before the left eye, which is the eye to be observed. Note that, in the standard arrangement before the control for switching from the standard arrangement to the first arrangement is performed, the face of the subject H is placed on the face support unit 30 so that the left eye is the eye to be observed, and the left / right switching mirror 75 is switched so that the slit scan light is directed toward the left eye.

[0054] In step S2, the alignment control unit 91 performs alignment control to position the pupil of the left eye, which is the subject's eye E, at a position where the fundus of the left eye can be observed. The alignment control unit 91 performs, for example, coarse alignment control followed by fine alignment control. In the coarse alignment control, the chin rest drive unit 35 controls the left eye pupil height so that the anterior segment image of the left eye captured by the anterior segment image sensor 811L falls within the display range of the touch panel screen 41. In the fine alignment control, the X-axis drive unit 14, the Y-axis drive unit 16, and the Z-axis drive unit 15 control the three-dimensional position of the first elliptical concave mirror 51 so that the pupil position of the left eye coincides with the position of the first focal point F1 of the first elliptical concave mirror 51. Note that the coarse alignment control may be omitted if it is confirmed in advance that the pupil height position of the left eye is appropriate.

[0055] In step S3, the fundus imaging control unit 93 performs focusing control to align the focus of the left eye observation optical system 60L and the illumination optical system 70 with the position of the fundus of the left eye. The fundus imaging control unit 93 adjusts the focus of the left eye observation optical system 60L with the position of the fundus of the left eye by controlling the amount of movement of the slide plate 68 in the Z axis direction using the focusing drive unit 69. The fundus imaging control unit 93 adjusts the focus of the illumination optical system 70 with the position of the fundus of the left eye by controlling the linear movement of the slit 72a using the slit drive unit 77.

[0056] Step S4 is a step in which the fundus image capturing control unit 93 performs fundus image acquisition control to acquire a fundus image of the left eye using the left-eye observation optical system 60L while performing slit scan control on the fundus of the left eye in the illumination optical system 70. The fundus image capturing control unit 93 performs slit width switching control to switch the fundus slit width in the slit projection direction of the XZ cross section using the slit drive unit 77, and scan control based on the fundus scan angle in the scan direction of the YZ cross section using the scanner drive unit 78, in the illumination optical system 70. The fundus image capturing control unit 93 acquires a wide-angle fundus image of the left eye using the fundus image sensor 671L included in the left-eye observation optical system 60L, using the fundus slit projection angle based on the XZ cross section in the slit projection direction and the fundus scan angle based on the YZ cross section in the scan direction.

[0057] In step S5, the fundus image capturing control unit 93 determines whether or not wide-angle fundus image capturing of the left eye has been completed. If it is determined in step S5 that wide-angle fundus image capturing of the left eye has not been completed, the process returns to step S4 to continue fundus image acquisition control, and if it is determined that wide-angle fundus image capturing of the left eye has been completed, the process proceeds to step S6.

[0058] In step S6, the left / right eye switching control unit 92 switches from the first arrangement to the standard arrangement so that the subject's eye E and the concave mirror unit 50 are at the furthest distance from each other. The left / right eye switching control unit 92 controls the switching from the first arrangement, in which the first elliptical concave mirror 51 and the second elliptical concave mirror 52 are arranged in a horizontal row and the first elliptical concave mirror 51 is arranged immediately in front of the left eye, which is the eye to be observed, to the standard arrangement, in which the first elliptical concave mirror 51 and the second elliptical concave mirror 52 are arranged in a vertical row. Note that, when the switching to the standard arrangement is completed, the control for switching from the first arrangement to the standard arrangement involves changing the position of the subject H's face relative to the face support unit 30 so that the right eye becomes the eye to be observed, and controlling the switching rotation of the left / right switching mirror 75 so that the slit scan light is directed toward the right eye.

[0059] In step S7, the left / right eye switching control unit 92 switches from the standard arrangement to the second arrangement to enable fundus observation of the right eye. The left / right eye switching control unit 92 controls the switching from the standard arrangement, in which the first elliptical concave mirror 51 and the second elliptical concave mirror 52 are arranged vertically, to the second arrangement, in which the first elliptical concave mirror 51 and the second elliptical concave mirror 52 are arranged horizontally and the first elliptical concave mirror 51 is arranged immediately in front of the right eye, which is the eye to be observed.

[0060] In step S8, the alignment control unit 91 performs alignment control to position the pupil of the right eye, which is the subject's eye E, at a position where the fundus of the right eye can be observed. For example, the alignment control unit 91 omits the coarse alignment control and performs only the fine alignment control. The fine alignment control involves controlling the three-dimensional position of the first elliptical concave mirror 51 using the X-axis drive unit 14, the Y-axis drive unit 16, and the Z-axis drive unit 15 so that the pupil position of the right eye coincides with the position of the first focal point F1 of the first elliptical concave mirror 51. Note that the coarse alignment control is not omitted unless it is confirmed in advance that the pupil height position of the right eye is at an appropriate position.

[0061] In step S9, the fundus imaging control unit 93 performs focusing control to align the focus of the right-eye observation optical system 60R and the illumination optical system 70 with the position of the fundus of the right eye. The fundus imaging control unit 93 adjusts the focus of the right-eye observation optical system 60R to the position of the fundus of the right eye by controlling the amount of movement of the slide plate 68 in the Z-axis direction using the focusing drive unit 69. The fundus imaging control unit 93 adjusts the focus of the illumination optical system 70 to the position of the fundus of the right eye by controlling the linear movement of the slit 72a using the slit drive unit 77.

[0062] Step S10 is a step in which the fundus image capturing control unit 93 performs fundus image acquisition control to acquire a fundus image of the right eye using the right-eye observation optical system 60R while performing slit scan control on the fundus of the right eye in the illumination optical system 70. The fundus image capturing control unit 93 performs slit width switching control to switch the fundus slit width in the slit projection direction of the XZ cross section using the slit drive unit 77, and scan control based on the fundus scan angle in the scan direction of the YZ cross section using the scanner drive unit 78, in the illumination optical system 70. The fundus image capturing control unit 93 acquires a wide-angle fundus image of the right eye using the fundus image sensor 671R included in the right-eye observation optical system 60R, based on the fundus slit projection angle in the XZ cross section in the slit projection direction and the fundus scan angle in the YZ cross section in the scan direction.

[0063] In step S11, the fundus image capturing control unit 93 determines whether or not wide-angle fundus image capturing of the right eye has been completed. If it is determined in step S11 that wide-angle fundus image capturing of the right eye has not been completed, the process returns to step S10 to continue fundus image acquisition control, and if it is determined that wide-angle fundus image capturing of the right eye has been completed, the process proceeds to step S12.

[0064] Step S12 is a step in which the left / right eye switching control unit 92 switches from the second arrangement to the standard arrangement to achieve the configuration in which the subject's eye E and the concave mirror unit 50 are furthest apart. The left / right eye switching control unit 92 controls switching from the second arrangement, in which the first elliptical concave mirror 51 and the second elliptical concave mirror 52 are arranged in a horizontal row and the first elliptical concave mirror 51 is arranged immediately in front of the right eye, which is the eye to be observed, to the standard arrangement, in which the first elliptical concave mirror 51 and the second elliptical concave mirror 52 are arranged in a vertical row. Note that step S12 proceeds to END when switching to the standard arrangement is complete.

[0065] [Observing / Photographing Wide-Angle Fundus Images (FIGS. 15 and 16)] When the fundus image photographing process operation is started, the control unit 90 sequentially performs the processes in steps S1 to S12 of FIG. 14 , and proceeds to END when switching to the reference position is completed in step S12. The control unit 90 can observe / photograph wide-angle fundus images of each of the left and right eyes by executing the processes shown in FIG. 14 . Step S4 of FIG. 14 performs fundus image acquisition control to acquire a fundus image of the left eye using the left-eye observation optical system 60L while performing slit scan control on the fundus of the left eye in the illumination optical system 70. Furthermore, step S10 of FIG. 14 performs fundus image acquisition control to acquire a fundus image of the right eye using the right-eye observation optical system 60R while performing slit scan control on the fundus of the right eye in the illumination optical system 70.

[0066] Next, the reason why steps S4 and S10 for executing fundus image acquisition control can acquire wide-angle fundus images will be explained. In the fundus observation device A1, as shown in FIGS. 15 and 16 , the pupil of the subject's eye E is positioned at the first focal point F1 of the first elliptical concave mirror 51. Therefore, the range of the slit scanning light projected onto the fundus Ef is determined by the X-Z cross-sectional angular range δXZ ( FIG. 15 ) in the slit projection direction by the slit unit 72 and the Y-Z cross-sectional angular range δYZ ( FIG. 16 ) in the scanning direction by the galvano scanner 73. Here, the X-Z cross-sectional angular range δXZ can be set to an angular range of 150° or more by the slit unit 72. Furthermore, the Y-Z cross-sectional angular range δYZ can be set to an angular range of 100° or more by the galvano scanner 73. Therefore, the left-eye observation optical system 60L and the right-eye observation optical system 60R can acquire the required wide-angle fundus images.

[0067] [Regarding the practical technology for a mirror-based fundus observation device (FIG. 17)] A prior art fundus observation device is the device proposed in Patent Document 1 (JP 2023-122620 A). Patent Document 1 proposes the configuration of an optical system using a mirror-based fundus observation device that imposes less strain on the subject by forming a space in front of the subject's eye, compared to a lens-based fundus observation device in which an objective lens is placed close to the subject's eye. The fundus observation device described in Patent Document 1 includes, as optical system components, an illumination optical system having a light source unit, a slit, and an optical scanner, an observation optical system having an image sensor, and a pair of elliptical concave mirrors.

[0068] Incidentally, a mirror-type fundus observation device requires each component included in the optical system for each of the left and right eyes to be examined. Therefore, when the fundus observation device is realized as an actual device corresponding to the left and right eyes of the subject without changing the face support position of the subject, the configuration of the illumination optical system, observation optical system, and pair of elliptical concave mirrors included in the optical system is provided independently for each of the left and right eyes, as shown in the comparative example device in FIG.

[0069] However, among the components of the optical system, the elliptical concave mirror requires a large outer diameter to acquire a wide-angle fundus image satisfying the required angle of view, and the elliptical concave surface must be highly precisely polished to achieve good image quality with reduced corneal reflection flare. Furthermore, if the elliptical concave mirrors are configured independently for the left and right eyes of the subject, a total of four elliptical concave mirrors are required: one pair for the left eye and one pair for the right eye. Therefore, if a mirror-based fundus observation device were to be realized as an actual device corresponding to each of the left and right eyes of the subject, it would end up being a large and expensive device. For example, if Wt in FIG. 17 is the width of the optical table, the width Wd (>Wt) of the actual device would exceed the width Wt of the optical table, resulting in a low product size evaluation. Furthermore, the need for four expensive elliptical concave mirrors in an actual mirror-based fundus observation device would result in a low product cost evaluation.

[0070] The mirror-based fundus observation device A1 focuses on elliptical concave mirrors, which are expensive components of the optical system when put into practical use, and employs a pair of elliptical concave mirrors configured as a concave mirror unit 50 in which a first elliptical concave mirror 51 and a second elliptical concave mirror 52 are connected by a concave mirror bracket 53. Furthermore, the concave mirror unit 50 is configured to be rotatable relative to the device stand 10 so as to trace a rotational trajectory that switches between a first arrangement when the eye to be observed is the left eye and a second arrangement when the eye to be observed is the right eye, so as to be able to accommodate the left eye and the right eye.

[0071] That is, the concave mirror unit 50 is rotatably mounted on the optical head frame 20, and the optical head frame 20 is mounted so as to describe a compound motion locus that is a combination of linear motion in the X-axis and Z-axis directions and rotational motion around the frame rotation axis 21. Therefore, when the observation target eye is switched between the left eye and the right eye, the concave mirror unit 50 rotates while describing a three-dimensional rotational motion locus relative to the device stand 10 so as to switch between the first position (position in FIG. 4) and the second position (position in FIG. 5).

[0072] Furthermore, the fundus observation device A1 does not place a pair of elliptical concave mirrors for each of the left and right eyes as in the comparative example device, but is configured with a concave mirror unit 50 that is shared by both the left and right eyes, thereby reducing the number of expensive elliptical concave mirrors from four to two. Furthermore, by providing the concave mirror unit 50 rotatably with respect to the device stand 10, the eye to be observed can be switched between the left and right eyes by rotating it within a limited space. As a result, the fundus observation device A1 can be realized as a compact and economical actual device while using a mirror system that imposes little burden on the subject H when observing the fundus Ef of the subject's eye E at a wide angle.

[0073] [Effects of the Fundus Observation Device A1] (1) The fundus observation device A1 includes, as components of the optical system, an illumination optical system 70 having a light source unit 71 and projecting slit scan light onto the fundus Ef of the subject's eye E, an observation optical system 60 having image sensors (fundus image sensors 671L, 671R) and receiving return light from the fundus Ef of the subject's eye E, and a pair of concave mirrors that are arranged at a position between the subject's eye E and the optical path branching unit and form a reflected light path of the slit scan light and a reflected light path of the return light. The pair of concave mirrors is configured by a concave mirror unit 50 in which a first concave mirror (first elliptical concave mirror 51) and a second concave mirror (second elliptical concave mirror 52) are connected by a concave mirror bracket 53. The concave mirror unit 50 is provided rotatably with respect to the device stand 10 so as to describe a rotation locus that switches between a first position when the subject's eye is the left eye and a second position when the subject's eye is the right eye. This invention uses a concave mirror unit 50 that is shared by both the left and right eyes, and thus realizes a compact and economical actual device while using a mirror system that imposes less strain on the subject H when observing the fundus Ef of the subject's eye E at a wide angle.

[0074] (2) The pair of concave mirrors is a first elliptical concave mirror 51 and a second elliptical concave mirror 52, each having two optically conjugate foci F1, F2 and F3, F4, with the first elliptical concave surface 51a and the second elliptical concave surface 52a partially opposing each other. In the first arrangement, the concave mirror unit 50 has the first elliptical concave mirror 51 positioned in front of the left eye and the second elliptical concave mirror 52 positioned on the left side of the face, and in the second arrangement, the first elliptical concave mirror 51 positioned in front of the right eye and the second elliptical concave mirror 52 positioned on the right side of the face. This invention provides a concave mirror unit 50 using a pair of elliptical concave mirrors whose combination is easily determined by a focal reference, and the first and second arrangements can be defined by a horizontal arrangement in which the first elliptical concave mirror 51 and the second elliptical concave mirror 52 are interchanged left and right.

[0075] (3) Of the components of the optical system, the concave mirror unit 50 is provided rotatably around a unit rotation axis 54 set in the Z-axis direction relative to the optical head frame 20. Of the components of the optical system, the illumination optical system 70 and the observation optical system 60 are provided by arranging components along the optical path relative to the optical head frame 20. The optical head frame 20 is provided movably relative to the device pedestal 10. In this invention, when switching between the left eye and the right eye to be observed, the optical head frame 20 moves relative to the device pedestal 10, thereby increasing the degree of freedom in setting the rotation trajectory that the concave mirror unit 50 traces relative to the device pedestal 10.

[0076] (4) The fundus observation device A1 includes a control unit 90 that controls each unit of the device by outputting commands to a drive unit 100. The drive unit 100 has a unit rotation drive unit 55 in the optical head frame 20 that drives and rotates the concave mirror unit 50 around a unit rotation axis 54. The control unit 90 has an left / right eye switching control unit 92 that outputs a rotation drive command to the unit rotation drive unit 55 to drive and rotate the concave mirror unit 50 when switching between the left eye and the right eye. In this invention, when switching between the left eye and the right eye, simply by rotating the concave mirror unit 50 relative to the optical head frame 20, it is possible to switch between a first arrangement when the eye to be observed is the left eye and a second arrangement when the eye to be observed is the right eye.

[0077] (5) The optical head frame 20 is mounted on a Y-axis movable frame 13 that is movable in three axes, the X-axis, Y-axis, and Z-axis directions, relative to the device pedestal 10. The drive unit 100 has an X-axis drive unit 14 and a Z-axis drive unit 15. When switching between the left and right eyes to be observed, the left / right eye switching control unit 92 outputs movement commands to the X-axis drive unit 14 and the Z-axis drive unit 15 to move the Y-axis movable frame 13 in the X-axis and Z-axis directions relative to the device pedestal 10 so as to trace an arcuate trajectory that maintains the gap distance between the concave mirror unit 50 and the face of the subject H. In this invention, when switching between the left and right eyes to be observed, the movement of the optical head frame 20 tracing an arcuate trajectory in the X-axis and Z-axis directions prevents the rotating concave mirror unit 50 from approaching the subject H and prevents interference with the subject H's face.

[0078] (6) The drive unit 100 has a tilt rotation drive unit 17 in the Y-axis movable frame 13 that tilts and rotates the optical head frame 20 in a planar direction around a frame rotation axis 21 set in the Y-axis direction. When switching between the left and right eyes to be observed, the left / right eye switching control unit 92 outputs a command to the tilt rotation drive unit 17 to rotate the optical head frame 20 relative to the Y-axis movable frame 13 so that the optical head frame 20 is positioned facing the subject H in each of the first and second positions. When switching between the left and right eyes to be observed, this invention can prevent the position of the subject H's face from moving away in the X-axis direction compared to an optical head frame 20 that does not tilt and rotate, and can reduce the space required in the X-axis direction when the concave mirror unit 50 rotates.

[0079] (7) The illumination optical system 70 is provided in the optical head frame 20 and includes one light source unit 71, one slit (slit unit 72), and one optical scanner (galvano scanner 73), and is configured as an optical system shared by both left and right eyes, with a left-right switching mirror 75 that switches the illumination optical path between left and right between the optical scanner and the concave mirror unit 50. This invention has a simple optical system configuration for the illumination optical system 70 shared by both left and right eyes, while the left-right switching mirror 75 allows it to accommodate optical system configurations of independent left and right observation optical systems 60L and 60R for the left and right eyes.

[0080] (8) The observation optical system 60 is provided in the optical head frame 20 and has an independent optical system configuration with a left-eye observation optical system 60L and a right-eye observation optical system 60R that are arranged line-symmetrically with respect to the frame center axis CL of the optical head frame 20. In this invention, each of the independent left-eye observation optical system 60L and right-eye observation optical system 60R can be made into a decentered optical system, and as a result, the decentered optical system can absorb the distortion (asymmetry) of the first elliptical concave mirror 51 and the second elliptical concave mirror 52.

[0081] (9) The device stand 10 is provided with a face support unit 30 located in front of the concave mirror unit 50 in the X-axis direction. The face support unit 30 has a forehead support frame 32 that supports the forehead of the subject H, and a chin rest 33 that is movable in the Y-axis direction and supports the chin of the subject H. The forehead support frame 32 has a forehead support surface 32a for the left eye and a forehead support surface 32b for the right eye adjacent to each other. The chin rest 33 has a chin support surface 33a for the left eye and a chin support surface 33b for the right eye adjacent to each other. In this invention, the face support unit 30 can be configured to be shared by both the left and right eyes simply by changing the forehead support surface 32a for the left eye and the forehead support surface 32b for the right eye adjacent to each other and the chin support surface 33a for the left eye and the chin support surface 33b for the right eye adjacent to each other.

[0082] Example 2 is an example that differs from Example 1 in that both the observation optical system 60 and the illumination optical system 70 are configured as optical systems shared by both the left and right eyes, and in that the face support unit 30 is configured independently for each of the left and right eyes. Note that the device stand 10, optical head frame 20, concave mirror unit 50, and control unit 90 of Example 2 have the same configurations as those of Example 1.

[0083] [Overall configuration of the device (FIGS. 18 and 19)] The fundus oculi observation device A2 includes a device stand 10, an optical head frame 20, a face support section 30, a control panel section 40, a concave mirror unit 50, an observation optical system 60, an illumination optical system 70, and a control section 90. Note that the alignment optical system 80 is not shown and will not be described.

[0084] A face support unit for the left eye 30L and a face support unit for the right eye 30R, which are configured independently for the left and right eyes, are fixed to the left and right positions of the device pedestal 10 on the front side facing the subject H. As in Example 1, the optical head frame 20 is provided on a Y-axis movable frame (not shown) that is movable in three axes directions, namely the X-axis, Y-axis, and Z-axis, relative to the device pedestal 10, and is driven to rotate in the XZ plane direction. A control panel unit 40 is disposed at the rear of the optical head frame 20.

[0085] The left-eye face support section 30L is configured to include a chin rest support section 31L fixed to a position on the right side of the front end of the device pedestal 10, a forehead rest frame 32L, a chin rest 33L, a lifting rod 34L, and a chin rest drive section 35L. The right-eye face support section 30R is configured to include a chin rest support section 31R fixed to a position on the left side of the front end of the device pedestal 10, a forehead rest frame 32R, a chin rest 33R, a lifting rod 34R, and a chin rest drive section 35R. The left-eye face support section 30L has a forehead rest surface 32a for the left eye on the forehead rest frame 32L and a chin rest surface 33a for the left eye on the chin rest 33L. The right-eye face support section 30R has a forehead rest surface 32b for the right eye on the forehead rest frame 32R and a chin rest surface 33b for the right eye on the chin rest 33R.

[0086] The concave mirror unit 50 is constructed by connecting a pair of a first elliptical concave mirror 51 and a second elliptical concave mirror 52 with a concave mirror bracket 53. This concave mirror unit 50 is disposed at a position sandwiched between both face support parts 30L, 30R and the optical head frame 20, and is provided so as to be rotatable about a unit rotation axis 54 set in the Z-axis direction relative to the optical head frame 20.

[0087] The observation optical system 60 is configured to be shared by both the left and right eyes and is provided by arranging components on the upper surface of the frame of the optical head frame 20. The illumination optical system 70 is configured to be shared by both the left and right eyes and is provided by arranging components on the lower surface of the frame of the optical head frame 20. The control unit 90 is provided at one side position of the optical head frame 20 or at both side positions of the optical head frame 20. Note that other configurations of the fundus observation device A2 are the same as those of the fundus observation device A1, so illustrations and explanations will be omitted.

[0088] [Fundus observation / photography of left and right eyes (FIG. 20)] The fundus observation device A2 is placed on the top surface of the optical table T, as shown in FIG. 20. The concave mirror unit 50 is configured to be used for both left and right eyes by rotating with respect to the device stand 10 so as to trace a rotation trajectory that switches between a first position (when photographing the left eye in FIG. 20) when the eye to be observed is the left eye and a second position (when photographing the right eye in FIG. 20) when the eye to be observed is the right eye. The "first position" is a position where the first elliptical concave mirror 51 is placed in front of the left eye and the second elliptical concave mirror 52 is placed on the left side of the face, as shown in FIG. 20. The "second position" is a position where the first elliptical concave mirror 51 is placed in front of the right eye and the second elliptical concave mirror 52 is placed on the right side of the face, as shown in FIG. 5. Here, the concave mirror unit 50 has a reference arrangement in addition to the first arrangement and the second arrangement, and this "reference arrangement" is a state in which the first elliptical concave mirror 51 is positioned at the lower side and the second elliptical concave mirror 52 is positioned at the upper side in the Y-axis direction, as shown in Fig. 18. Note that other operations of the fundus observation device A2 are similar to those of the fundus observation device A1, and therefore illustrations and explanations thereof will be omitted.

[0089] [Effects of Fundus Observation Device A2] The fundus observation device A2 of Example 2 can obtain the following effects in addition to the effects (1) to (7) of Example 1.

[0090] (10) The illumination optical system 70 and the observation optical system 60 are configured as optical systems for both the left and right eyes, and are arranged on the optical head frame 20. This invention allows the illumination optical system 70 and the observation optical system 60 to have a simpler and more cost-effective optical system configuration than when at least one of the two optical systems, the illumination optical system 70 and the observation optical system 60, is configured as an independent optical system for each of the left and right eyes.

[0091] (11) The device pedestal 10 is provided with a left-eye face support portion 30L and a right-eye face support portion 30R, each of which is provided independently for the left and right eyes, at a position closer to the concave mirror unit 50 in the Z-axis direction. The left-eye face support portion 30L has forehead support frames 32L, 32R for supporting the forehead of the subject H, and chin rests 33L, 33R that are movable in the Y-axis direction and support the chin of the subject H. The left-eye face support portion 30L has a left-eye forehead support surface 32La in the forehead support frame 32L, and a left-eye chin support surface 33La in the chin rest 33L. The right-eye face support portion 30R has a right-eye forehead support surface 32Ra in the forehead support frame 32R, and a right-eye chin support surface 33Ra in the chin rest 33R. This invention allows for switching between the left eye and the right eye to be observed using the independent left-eye face support portion 30L and right-eye face support portion 30R.

[0092] Example 3 is an example that differs from Example 1 in the positional relationship between the first elliptical concave mirror 51 and the second elliptical concave mirror 52 with respect to the left eye EL and the right eye ER in the first arrangement and the second arrangement, and in that the face support unit 30 is a member that supports the face of the subject H while keeping it facing forward. Note that the configuration of the fundus observation device A3 of Example 3 is the same as that of Example 1 except for the configuration described based on Figs. 21 to 23 .

[0093] [Device configuration (Figs. 21 to 23)] The fundus oculi observation device A1 of Example 1 has the concave mirror unit 50 arranged as shown in Figs. 21 and 22. As shown in Fig. 21, the concave mirror unit 50 is configured so that, in the first arrangement, the first elliptical concave mirror 51 is arranged in front of the left eye EL and the second elliptical concave mirror 52 is arranged in front of the right eye ER. As shown in Fig. 22, the concave mirror unit 50 is configured so that, in the second arrangement, the first elliptical concave mirror 51 is arranged in front of the right eye ER and the second elliptical concave mirror 52 is arranged in front of the left eye EL. That is, in the first and second arrangements, the concave mirror unit 50 arranges the second elliptical concave mirror 52 in front of the eye that is not the eye to be examined.

[0094] 21 and 22 , the device stand 10 is provided with a face support section 30 located in front of the concave mirror unit 50 in the Z-axis direction, the face support section 30 having a forehead support frame 32 for supporting the forehead of the subject H, and a chin support 33 that is movable in the Y-axis direction and supports the chin of the subject H. The forehead support frame 32 has a common forehead support surface 32c that supports the face of the subject H while keeping it facing forward, regardless of whether the concave mirror unit 50 is in the first position or the second position. The chin support 33 has a common chin support surface 33c that supports the face of the subject H while keeping it facing forward, regardless of whether the concave mirror unit 50 is in the first position or the second position.

[0095] As in the first embodiment, the "reference arrangement" of the concave mirror unit 50 is a vertical arrangement in which the first elliptical concave mirror 51 is positioned at the lower position and the second elliptical concave mirror 52 is positioned at the upper position in the Y-axis direction (see FIG. 6 ). When switching from the reference arrangement to the first arrangement, the concave mirror unit 50 rotates clockwise around the unit rotation axis 54 until the mirror rotation angle α becomes +α° (e.g., approximately +90°) from α=0° in the reference arrangement, as shown in FIG. 23 . When switching from the reference arrangement to the second arrangement, the concave mirror unit 50 rotates counterclockwise around the unit rotation axis 54 until the mirror rotation angle α becomes −α° (e.g., approximately −90°) from α=0° in the reference arrangement, as shown in FIG. 23 . The concave mirror unit 50 of the third embodiment rotates in the opposite direction to that of the first embodiment (dashed line characteristics) when switching from the reference arrangement to the first arrangement or the second arrangement.

[0096] When the concave mirror unit 50 is switched from the reference configuration to the first configuration, the optical head frame 20 rotates counterclockwise around the frame rotation axis 21 until the frame tilt rotation angle θ becomes θ2 = -(θ1 + a)° from θ = 0° in the reference configuration, as shown in FIG. 25 . When the concave mirror unit 50 is switched from the reference configuration to the second configuration, the optical head frame 20 rotates clockwise around the frame rotation axis 21 until the frame tilt rotation angle θ2 becomes θ2 = +(θ1 + a)° from θ = 0° in the reference configuration. Note that, when the frame tilt rotation angle in Example 3 (solid line characteristics) is θ2 and the frame tilt rotation angle in Example 1 (dashed line characteristics) is θ1, the frame tilt rotation angles have a relationship of θ2 > θ1. In other words, when the optical head frame 20 in Example 3 is switched from the reference configuration to the first configuration or the second configuration, the frame tilt rotation angle θ2 is increased by a° compared to the frame tilt rotation angle θ1 in Example 1.

[0097] 24, in the fundus observation device A1 of Example 1, the first position is a position where the first elliptical concave mirror 51 is placed in front of the left eye EL and the second elliptical concave mirror 52 is placed on the left side of the face of the subject H. The second position is a position where the first elliptical concave mirror 51 is placed in front of the right eye ER and the second elliptical concave mirror 52 is placed on the right side of the face of the subject H (see FIG. 5).

[0098] In this way, in the fundus observation device A1 of Example 1, the second elliptical concave mirror 52 is positioned around to the side of the face of the subject H, so that the position of the unit rotation axis 54 in plan view is away from the center line BCL of the device stand, as shown in Figure 24.

[0099] In contrast, in the fundus observation device A3 of Example 3, the positional relationship between the first arrangement and the second arrangement of the concave mirror unit 50 is different from that of the fundus observation device A1 of Example 1. That is, in the concave mirror unit 50 of Example 3, as shown in Fig. 25, in the first arrangement, the first elliptical concave mirror 51 is arranged in front of the left eye EL and the second elliptical concave mirror 52 is arranged in front of the right eye ER. In the concave mirror unit 50, in the second arrangement, the first elliptical concave mirror 51 is arranged in front of the right eye ER and the second elliptical concave mirror 52 is arranged in front of the left eye EL (see Fig. 22).

[0100] In this way, in the fundus observation device A3 of Example 3, the second elliptical concave mirror 52 is disposed at a position in front of the eye of the subject H, and therefore, as shown in FIG. 25, the position of the unit rotation axis 54 in plan view becomes a position close to the device gantry center line BCL. As a result, the X-axis movement amount DX mm of the X-axis movable frame 11 decreases. More details will be explained with reference to FIG. 23. The X-axis movement amount DX mm of the fundus observation device A1 of Example 1 changes from DX = -DX mm to DX = +DX mm around the reference position, as shown by the dashed line. On the other hand, the X-axis movement amount DX mm of the fundus observation device A3 of Example 3 decreases by b according to the amount by which the position of the unit rotation axis 54 approaches the device gantry center line BCL, as shown by the solid line. Furthermore, the ophthalmologic apparatus A1 of Example 1 is configured so that the subject H and the second elliptical concave mirror 52 are aligned in the X-axis direction, but the fundus observation device A3 of Example 3 is configured so that the subject H and the second elliptical concave mirror 52 are aligned in the Y-axis direction. As a result, the fundus observation device A3 occupies less space in the X-axis direction on the subject H side compared to the ophthalmologic apparatus A1.

[0101] As described above, the fundus observation device A3 can reduce the X-axis movement amount DX mm and the space occupied by the subject H and the device in the X-axis direction in the space on the subject H side compared to the ophthalmologic device A1. This makes it possible to reduce the device stand width Wd in the actual device and the table width Wt of the optical table T in the actual device for the fundus observation device A3 of Example 3.

[0102] The fundus observation device A1 of Example 1 has a forehead support surface 32a for the left eye and a forehead support surface 32b for the right eye adjacent to the forehead support frame 32, and a chin support surface 33a for the left eye and a chin support surface 33b for the right eye adjacent to the chin support 33 (see Figure 12).

[0103] In this way, the fundus observation device A1 of Example 1 has separate receiving surfaces for the left eye and the right eye. Therefore, when switching the observation target eye between the left eye EL and the right eye ER, the subject H needs to change the direction of his or her face between facing right and left.

[0104] In contrast to this, the fundus oculi observation device A3 of Example 3 has a common forehead support surface 32c and a common chin support surface 33c on the forehead support frame 32 and the chin support 33, which support the face of the subject H while keeping it facing forward regardless of whether the concave mirror unit 50 is in the first position or the second position. Therefore, the eye to be observed can be switched while maintaining the face of the subject H facing forward, and the burden on the subject can be reduced.

[0105] [Effects of Fundus Observation Device A3] The fundus observation device A3 of Example 3 can obtain the following effects in addition to the effects (1), (3) to (8) of the fundus observation device A1 of Example 1.

[0106] (12) The pair of concave mirrors are a first elliptical concave mirror 51 and a second elliptical concave mirror 52, each having two optically conjugate foci F1, F2 and F3, F4, and each having a first elliptical concave surface 51a and a second elliptical concave surface 52a that partially face each other. In the first arrangement, the concave mirror unit 50 has the first elliptical concave mirror 51 positioned in front of the left eye EL and the second elliptical concave mirror 52 positioned in front of the right eye ER, and in the second arrangement, the first elliptical concave mirror 51 positioned in front of the right eye ER and the second elliptical concave mirror 52 positioned in front of the left eye EL. In this invention, the first arrangement and the second arrangement are defined by an arrangement in which the first elliptical concave mirror 51 and the second elliptical concave mirror 52 are interchanged in position in front of the left and right eyes EL, ER, and the device stand width Wd and table width Wt of the actual device can be reduced compared to the fundus observation device A1 of Example 1.

[0107] (13) The device stand 10 is provided with a face support unit 30 located in front of the concave mirror unit 50 in the Z-axis direction, the face support unit 30 having a forehead support frame 32 for supporting the forehead of the subject H and a chin support 33 that is movable in the Y-axis direction and supports the chin of the subject H. The forehead support frame 32 has a common forehead support surface 32c that supports the face of the subject H while keeping it facing forward, regardless of whether the concave mirror unit 50 is in the first or second position. The chin support 33 has a common chin support surface 33c that supports the face of the subject H while keeping it facing forward, regardless of whether the concave mirror unit 50 is in the first or second position. In this invention, when switching between the left and right eyes to be observed, the subject H can simply maintain their face facing forward.

[0108] The fundus observation device A1 of Example 1, the fundus observation device A2 of Example 2, and the fundus observation device A3 of Example 3 have been described above with reference to the drawings. However, the specific configuration of the fundus observation device of the present invention is not limited to Examples 1, 2, and 3, and design changes and additions are permitted as long as they do not deviate from the gist of the invention according to each claim in the scope of claims.

[0109] In Examples 1 to 3, the concave mirror unit 50 is shown as an example of a configuration in which a first elliptical concave mirror 51 and a second elliptical concave mirror 52 are connected by a concave mirror bracket 53. However, the concave mirror unit is not limited to the configuration shown in Examples 1 and 2. The concave mirror unit may also be configured to connect a pair of concave mirrors having curved shapes other than elliptical with a concave mirror bracket. Furthermore, the concave mirror unit may also be configured to combine a pair of concave mirrors with one or more plane mirrors and connect them with a concave mirror bracket.

[0110] In the first to third embodiments, the left / right eye switching control unit 92 rotates the concave mirror unit 50 between the reference arrangement, the first arrangement, and the second arrangement when switching between the left and right eyes. However, the left / right eye switching control unit is not limited to this rotational drive control. For example, the reference arrangement, which is the starting point of the rotational drive, may be eliminated, and left / right eye switching control may be performed by switching from the first arrangement to the second arrangement and from the second arrangement to the first arrangement.

[0111] In Examples 1 to 3, the optical head frame 20 is provided movably relative to the device pedestal 10 so as to trace a composite motion trajectory based on a combination of linear motion in the X-axis direction and Z-axis direction and rotational motion around a rotational axis in the Y-axis direction. However, the optical head frame is not limited to the configurations shown in Examples 1 and 2. The optical head frame may be provided movably relative to the device pedestal by performing either one of linear motion in the X-axis direction and Z-axis direction and rotational motion around a rotational axis in the Y-axis direction, or may be provided movably relative to the device pedestal by performing a combination of any two of these motions.

[0112] Example 1 illustrates an example in which the illumination optical system 70 is configured as an optical system shared by both the left and right eyes, and the observation optical system 60 is configured as an optical system independent of the left and right eyes. Example 2 illustrates an example in which the illumination optical system 70 and the observation optical system 60 are configured as an optical system shared by both the left and right eyes. However, the illumination optical system and the observation optical system are not limited to the configurations illustrated in Examples 1 and 2. The illumination optical system and the observation optical system may also be configured as an optical system independent of the left and right eyes. Furthermore, the specific configuration of the optical system may be any of the multiple examples proposed in Patent Document 1 (JP 2023-122620 A), in addition to the configurations illustrated in Examples 1 and 2.

[0113] In Example 1, the face support unit 30 includes a forehead support frame 32 having a forehead support surface 32a for the left eye and a forehead support surface 32b for the right eye adjacent to each other, and a chin rest 33 having a chin support surface 33a for the left eye and a chin rest surface 33b for the right eye adjacent to each other, and is configured to be shared by slightly changing the positions of the forehead and chin of the subject H. In Example 2, the face support unit 30 includes a face support unit 30L for the left eye and a face support unit 30R for the right eye, which are provided independently for the left and right eyes. In Example 3, the face support unit 30 includes a forehead support frame 32 having a common forehead support surface 32c and a chin rest 33 having a common chin support surface 33c, and is configured to be shared by the left and right eyes without changing the positions of the forehead and chin of the subject H. However, the configuration of the face support unit is not limited to the configurations shown in Examples 1 to 3.

[0114] In Examples 1 to 3, the optical system configuration of the fundus observation devices A1, A2, and A3 is shown to include only a fundus camera. However, the optical system of the fundus observation device is not limited to the configurations shown in Examples 1 to 3. The fundus observation device may be configured to include, in addition to the fundus camera, an OCT (abbreviation for "Optical Coherence Tomography") that acquires a tomographic image of the fundus of the subject's eye. The fundus camera is a camera that images the state of the fundus, such as the retina, optic nerve, and capillaries at the back of the subject's eye, and captures the fundus image. The OCT is an optical coherence tomography that uses light interference to image the tomographic layer of the retina present at the fundus of the subject's eye and captures the fundus tomographic image.

[0115] The fundus observation devices of Examples 1 to 3 may be combined as appropriate with other configurations as long as some of the configurations do not contradict each other. The fundus observation devices of Examples 1 to 3 can be described in part or in whole as in the following supplementary notes. However, the contents are not limited to the supplementary notes described below. [1] A fundus observation device including, as components of the optical system, an illumination optical system having a light source unit that projects slit scan light onto the fundus of the subject's eye, an observation optical system having an image sensor that receives return light from the fundus of the subject's eye, and a pair of concave mirrors that are arranged at a position between the subject's eye and an optical path branching unit and form a reflected light path of the slit scan light and a reflected light path of the return light, wherein the pair of concave mirrors are configured as a concave mirror unit in which a first concave mirror and a second concave mirror are connected by a concave mirror bracket, and the concave mirror unit is provided rotatably with respect to a device stand so as to describe a rotation locus that switches between a first arrangement when the subject's eye is the left eye and a second arrangement when the subject's eye is the right eye. [2] The fundus observation device described in [1], wherein the pair of concave mirrors are a first elliptical concave mirror and a second elliptical concave mirror, each having two optically conjugate focal points, and wherein a first elliptical concave surface and a second elliptical concave surface partially oppose each other, and wherein the concave mirror unit, in the first arrangement, places the first elliptical concave mirror in front of the left eye and places the second elliptical concave mirror in a position on the left side of the face, and in the second arrangement, places the first elliptical concave mirror in front of the right eye and places the second elliptical concave mirror in a position on the right side of the face. [3] The fundus observation device described in [2], wherein the concave mirror unit is provided rotatably about a unit rotation axis set in the front-rear axis direction with respect to an optical head frame, and the illumination optical system and the observation optical system, which are components of the optical system, are provided by arranging components along an optical path with respect to the optical head frame, and the optical head frame is provided movably with respect to the device stand.[4] In the fundus observation device described in any one of [1] to [3], the fundus observation device is provided with a control unit that controls each part of the device by outputting a command to a drive unit, the drive unit has a unit rotation drive unit in the optical head frame that drives the concave mirror unit to rotate around the unit rotation axis, and the control unit has a left / right eye switching control unit that outputs a rotation drive command to the unit rotation drive unit to drive the concave mirror unit to rotate when switching the observation target eye between the left eye and the right eye. [5] In the fundus observation device described in [4], the optical head frame is provided on a movable frame that is movable in three axial directions, i.e., in the left-right axial direction, the up-down axial direction, and the front-back axial direction, relative to the device stand, the drive unit has a left-right axis drive unit and a front-back axis drive unit, and the left-right eye switching control unit outputs a movement command to the left-right axis drive unit and the front-back axis drive unit to move the movable frame in the left-right axial direction and the front-back axial direction relative to the device stand so as to draw an arc trajectory that maintains the gap distance between the concave mirror unit and the face of the subject, when switching the observation target eye between the left eye and the right eye. [6] In the fundus observation device described in any one of [1] to [5], the drive unit has a tilt rotation drive unit in the movable frame that tilts and rotates the optical head frame in a planar direction around a frame rotation axis set in the up-down axis direction, and the left / right eye switching control unit outputs a command to the tilt rotation drive unit to rotate the optical head frame relative to the movable frame so that the optical head frame is positioned facing the subject in each of the first arrangement and the second arrangement when switching the observation target eye between the left eye and the right eye. [7] In the fundus observation device described in [6], the illumination optical system is provided in the optical head frame, and includes one light source unit, one slit, and one optical scanner, and is an optical system configuration shared by both the left and right eyes, in which a left / right switching mirror that switches the illumination optical path between the left and right eyes is arranged between the optical scanner and the concave mirror unit.[8] The fundus observation device described in any one of [1] to [7], characterized in that the observation optical system is provided in the optical head frame and has an observation optical system for the right eye and an observation optical system for the left eye that are arranged line-symmetrically with respect to the frame center axis of the optical head frame, forming an optical system configuration independent of the left and right eyes. [9] The fundus observation device described in [8], characterized in that the device stand has a face support unit, located in front of the concave mirror unit in the front-to-back axis direction, having a forehead support frame that supports the forehead of the subject and a chin rest that is movable in the up-down axis direction and supports the chin of the subject, the forehead support frame having forehead support surfaces for the left eye and forehead support surfaces for the right eye adjacent to each other, and the chin rest having chin support surfaces for the left eye and chin support surfaces for the right eye adjacent to each other.

[10] The fundus observation device described in any one of [1] to [7], characterized in that the illumination optical system and the observation optical system are arranged in the optical head frame and form an optical system configuration shared by the left and right eyes.

[11] In the fundus observation device described in

[10] , the device stand is provided with a face support part for the left eye and a face support part for the right eye, each of which has a forehead support frame for supporting the forehead of the subject and a chin support that is movable in the up-down direction and supports the chin of the subject, at a position closer to the concave mirror unit in the front-to-back axis direction, the face support part for the left eye has a forehead support surface for the left eye in the forehead support frame and a chin support surface for the left eye in the chin support, and the face support part for the right eye has a forehead support surface for the right eye in the forehead support frame and a chin support surface for the right eye in the chin support.

[12] In the fundus observation device described in [1] and [3] to [8], the pair of concave mirrors are a first elliptical concave mirror and a second elliptical concave mirror, each having two optically conjugate focal points, with the first elliptical concave surface and the second elliptical concave surface partially opposing each other, and the concave mirror unit is characterized in that, in the first arrangement, the first elliptical concave mirror is arranged in front of the left eye and the second elliptical concave mirror is arranged in front of the right eye, and in the second arrangement, the first elliptical concave mirror is arranged in front of the right eye and the second elliptical concave mirror is arranged in front of the left eye.

[13] In the fundus observation device described in

[12] , the device stand is provided with a face support unit at a position closer to the concave mirror unit in the front-to-back direction, the face support unit having a forehead support frame for supporting the forehead of the subject, and a chin support that is movable in the up-down direction and supports the subject's chin, the forehead support frame having a common forehead support surface that supports the face of the subject while keeping it facing forward regardless of whether the concave mirror unit is in the first position or the second position, and the chin support surface having a common chin support surface that supports the face of the subject while keeping it facing forward regardless of whether the concave mirror unit is in the first position or the second position. CROSS-REFERENCE TO RELATED APPLICATIONS

[0116] This application claims priority based on Japanese Patent Application No. 2024-052994, filed with the Japan Patent Office on March 28, 2024, the entire disclosure of which is incorporated herein by reference in its entirety.

Claims

1. A fundus observation device whose optical system components include an illumination optical system having a light source unit that projects slit scan light onto the fundus of the eye to be examined, an observation optical system having an image sensor that receives return light from the fundus of the eye to be examined, and a pair of concave mirrors that are positioned between the eye to be examined and an optical path branching unit and form a reflected light path of the slit scan light and a reflected light path of the return light, wherein the pair of concave mirrors are configured as a concave mirror unit in which a first concave mirror and a second concave mirror are connected by a concave mirror bracket, and the concave mirror unit is rotatable relative to the device stand so as to describe a rotational trajectory that switches between a first position when the eye to be observed is the left eye and a second position when the eye to be observed is the right eye.

2. A fundus observation device according to claim 1, wherein the pair of concave mirrors are a first elliptical concave mirror and a second elliptical concave mirror, each having two optically conjugate focal points, with the first elliptical concave surface and the second elliptical concave surface partially opposing each other, and the concave mirror unit is configured such that, in the first arrangement, the first elliptical concave mirror is positioned in front of the left eye and the second elliptical concave mirror is positioned on the left side of the face, and in the second arrangement, the first elliptical concave mirror is positioned in front of the right eye and the second elliptical concave mirror is positioned on the right side of the face.

3. A fundus observation device according to claim 2, characterized in that the concave mirror unit is rotatable about a unit rotation axis set in the front-to-back axial direction relative to the optical head frame, the illumination optical system and the observation optical system, which are components of the optical system, are arranged by arranging components along an optical path relative to the optical head frame, and the optical head frame is movably arranged relative to the device stand.

4. A fundus observation device according to claim 3, characterized in that the fundus observation device comprises a control unit that controls each part of the device by outputting commands to a drive unit, the drive unit having a unit rotation drive unit on the optical head frame that drives the concave mirror unit to rotate around the unit rotation axis, and the control unit has a left / right eye switching control unit that outputs a rotation drive command to the unit rotation drive unit to drive the concave mirror unit to rotate when switching between the left eye and the right eye to be observed.

5. A fundus observation device according to claim 4, wherein the optical head frame is provided on a movable frame that is movable in three axes, i.e., in the left-right, up-down and front-back directions, relative to the device stand; the drive unit has a left-right axis drive unit and a front-back axis drive unit; and the left-right eye switching control unit outputs movement commands to the left-right axis drive unit and the front-back axis drive unit to move the movable frame in the left-right and front-back directions relative to the device stand so as to trace an arcuate trajectory that maintains the gap distance between the concave mirror unit and the subject's face, when switching between the left eye and the right eye to be observed.

6. A fundus observation device according to claim 5, wherein the drive unit has a tilt rotation drive unit on the movable frame that tilts and rotates the optical head frame in a planar direction around a frame rotation axis set in the vertical axis direction, and the left / right eye switching control unit outputs a command to the tilt rotation drive unit to rotate the optical head frame relative to the movable frame so that the optical head frame is positioned facing the subject in each of the first and second positions when switching between the left and right eyes being observed.

7. A fundus observation device according to claim 6, characterized in that the illumination optical system is provided on the optical head frame, includes one light source unit, one slit, and one optical scanner, and has an optical system configuration for use by both the left and right eyes, with a left-right switching mirror being arranged between the optical scanner and the concave mirror unit to switch the illumination optical path between left and right.

8. A fundus observation device according to any one of claims 1 to 7, characterized in that the observation optical system is provided in the optical head frame, and has an independent optical system configuration for the right and left eyes, with an observation optical system for the right eye and an observation optical system for the left eye arranged in line symmetry with respect to the central axis of the optical head frame.

9. A fundus observation device according to claim 8, wherein the device stand is provided with a face support unit located in front of the concave mirror unit in the front-to-back direction, the face support unit having a forehead support frame for supporting the subject's forehead and a chin support that is movable in the up-down direction and supports the subject's chin, the forehead support frame having a forehead support surface for the left eye and a forehead support surface for the right eye in adjacent positions, and the chin support surface having a chin support surface for the left eye and a chin support surface for the right eye in adjacent positions.

10. A fundus observation device according to any one of claims 1 to 7, characterized in that the illumination optical system and the observation optical system are arranged in the optical head frame as an optical system for both the left and right eyes.

11. A fundus observation device according to claim 10, wherein the device stand is provided with a face support section for the left eye and a face support section for the right eye, each of which has a forehead support frame for supporting the subject's forehead and a chin support that is movable in the up-down direction and supports the subject's chin, located in front of the concave mirror unit in the front-to-back direction, the face support section for the left eye having a forehead support surface for the left eye in the forehead support frame and a chin support surface for the left eye in the chin support, and the face support section for the right eye having a forehead support surface for the right eye in the forehead support frame and a chin support surface for the right eye in the chin support.

12. A fundus observation device according to claim 1, wherein the pair of concave mirrors are a first elliptical concave mirror and a second elliptical concave mirror, each having two optically conjugate foci, with the first elliptical concave surface and the second elliptical concave surface partially opposing each other, and the concave mirror unit is configured such that, in the first arrangement, the first elliptical concave mirror is positioned in front of the left eye and the second elliptical concave mirror is positioned in front of the right eye, and in the second arrangement, the first elliptical concave mirror is positioned in front of the right eye and the second elliptical concave mirror is positioned in front of the left eye.

13. A fundus observation device according to claim 12, wherein the device stand is provided with a face support section at a position closer to the concave mirror unit in the front-to-back direction, the face support section having a forehead support frame for supporting the subject's forehead, and a chin support that is movable in the up-down direction and supports the subject's chin; the forehead support frame has a common forehead support surface that supports the subject's face while keeping it facing forward regardless of whether the concave mirror unit is in the first position or the second position; and the chin support surface has a common chin support surface that supports the subject's face while keeping it facing forward regardless of whether the concave mirror unit is in the first position or the second position.

Images