Fundus observation device

Abstract

To provide a fundus observation device that enables the realization of a compact and economical actual machine while employing a mirror-based system that imposes less burden on a subject when widely observing the fundus of an eye to be examined.SOLUTION: A fundus observation device A includes an illumination optical system 70 that illuminates a fundus Ef of an eye E to be examined with slit-scan light, an observation optical system 60 that receives return light from the fundus Ef of the eye E to be examined, and a pair of concave mirrors disposed between the eye E to be examined and a light path branching part, and forming a reflection light path of the slit-scan light and a reflection light path of the return light, as components of an optical system. The pair of concave mirrors constitute 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. In the components of the optical system, at least part of the components including the concave mirror unit 50 is provided so as to be pivotable relative to a device base 10 so as to draw a swivel 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.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] A fundus observation device is a device for displaying and observing / photographing a fundus image of a subject's eye at 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 angular range of the slit projection direction of the slit light passing through the slit of the illumination optical system and the angular range of the scanning direction of the optical scanner. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-122620 Summary of the Invention [Problem to be solved by the invention]

[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 highly precisely mirror-finished to achieve good image quality with reduced corneal reflection flare. 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. [Means for solving the problem]

[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 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 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. The pair of concave mirrors is configured as a concave mirror unit in which a first concave mirror and a second concave mirror are connected by a concave mirror bracket. At least some of the optical system components, including the concave mirror unit, are provided rotatably with respect to an apparatus stand 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. [Effects of the Invention]

[0008] The fundus observation device of the present invention has at least some of the components, including the concave mirror unit, shared by both the left and right eyes, so that when observing the fundus of the subject's eye at a wide angle, a mirror system is used that places less strain on the subject, while still allowing for a compact and economical actual device to be realized. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is an overall perspective view of a fundus oculi observation device of Example 1, viewed obliquely from the front direction. FIG. [Figure 2] 1 is an overall perspective view of a fundus oculi observation device of Example 1, seen from an oblique rear direction. FIG. [Figure 3] 1 is a plan view showing a first position of the left eye photographing device and a second position when photographing the right eye. FIG. [Figure 4] FIG. 2 is a plan view showing a concave mirror unit, an optical head frame, and a Y-axis movable frame. [Figure 5] FIG. 2 is an explanatory diagram showing an optical system rotation angle α of an optical system component. [Figure 6] FIG. 10 is a position characteristic diagram showing the optical system rotation angle α, the X-axis movement amount, and the Z-axis movement amount. [Figure 7] FIG. 2 is a plan view showing the configuration of an observation optical system and an alignment optical system. [Figure 8] FIG. 2 is a plan view showing the configuration of an illumination optical system. [Figure 9] FIG. 2 is a block diagram showing the configuration of a control system in the fundus observation device of the first embodiment. [Figure 10] 10 is a flowchart showing the flow of an operation for photographing the left and right eyes of a subject. [Figure 11] 10A and 10B are diagrams illustrating the horizontal cross-sectional angle range of illumination light projected onto the fundus. [Figure 12] FIG. 10 is a diagram showing the vertical cross-sectional angular range of illumination light projected onto the fundus. [Figure 13] FIG. 10 is a plan view showing a comparative example of a mirror-based fundus observation device. DETAILED DESCRIPTION OF THE INVENTION

[0010] A mode for carrying out a fundus observation device of the present invention will be described below based on Example 1 shown in the drawings.

[0011] The fundus observation device applied in Example 1 is a device called a mydriatic fundus camera, which 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 axis (horizontal direction) when the subject faces the main body of the fundus observation device, the Y axis indicates the up-down axis (vertical direction), and the Z axis indicates the front-back axis (depth direction) perpendicular to the X and Y axes. [Example]

[0012] [Overall configuration of the device (Fig. 1 to 3)] The fundus observation device A comprises 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 rotatably mounted on a Y-axis movable frame 13, which is movable in three directions, the X-axis, the Y-axis, and the Z-axis, relative to the device stand 10. The Y-axis movable frame 13 has an optical system rotation drive unit 17 that drives and rotates the optical head frame 20 in the XY plane around an optical system rotation axis 21 set in the Z-axis direction. The optical system rotation drive unit 17 has a motor, a worm gear, and a motor drive circuit that drive and rotate the optical head frame 20. When switching between the left eye and the right eye to be observed, the optical head frame 20 rotates around the optical system rotation axis 21 relative to the Y-axis movable frame 13 so as to switch between a first position (upper position in FIG. 3 ) and a second position (lower position in FIG. 3 ).

[0016] The face support unit 30 is positioned closer to the device pedestal 10 than the concave mirror unit 50 in the Z-axis direction. It supports the forehead and chin of the subject H to stabilize the position and orientation of the subject's eye E when observing and 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 having a forehead rest surface 32a, a chin rest 33 having a chin rest surface 33a, 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 for driving the lifting rod 34 in the Y-axis direction. The face support unit 30 corresponds to a first position (upper position in FIG. 3 ) of the concave mirror unit 50 relative to the left eye and a second position (lower position in FIG. 3 ) of the concave mirror unit 50 relative to the right eye while the subject H maintains a face-supported state facing forward. In other words, 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 position for the left eye and a second position for the right eye when the subject H maintains a face support state facing forward relative to the face support section 30.

[0017] The control panel unit 40 is disposed at the rear position of the device stand 10, and is provided so that the screen angle can be adjusted relative to the Y-axis movable frame 13. This 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, an anterior segment image of the subject's eye E from the anterior segment stereo camera provided in the alignment optical system 80, etc. On the touch panel screen 41, the examiner's touch operation with his or 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 in the same space where the fundus observation device A is placed. In addition to the control panel unit 40, a remote operation 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 an examiner in a space distant from the fundus observation device A.

[0018] 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 the face support section 30 and the optical head frame 20, and is fixed to the optical head frame 20 via a fixing bracket 54. When switching between the left and right eyes as the observation target, the concave mirror unit 50 rotates together with the optical head frame 20, which rotates relative to the Y-axis movable frame 13, around the optical system rotation axis 21 so as to switch between a first position (upper position in FIG. 3) and a second position (lower position in FIG. 3). The detailed configuration of the concave mirror unit 50 will be described later.

[0019] As shown in the upper part of Fig. 3, the observation optical system 60 is provided by arranging components of the observation optical system 60 at a position on the frame surface of the optical head frame 20 along a folded optical path that suppresses protrusion in the X-axis direction. When switching between the left eye and the right eye to be observed, the observation optical system 60 rotates together with the optical head frame 20, which switches between a first position (upper position in Fig. 3) and a second position (lower position in Fig. 3). The detailed configuration of the observation optical system 60 will be described later.

[0020] As shown in the lower part of Fig. 3, the illumination optical system 70 is provided by arranging components of the illumination optical system 70 along a folded optical path that suppresses protrusion in the X-axis direction at a position on the rear surface of the optical head frame 20. When switching between the left eye and the right eye to be observed, the illumination optical system 70 rotates together with the optical head frame 20, which switches between a first position (upper position in Fig. 3) and a second position (lower position in Fig. 3). The detailed configuration of the illumination optical system 70 will be described later.

[0021] As shown in the upper part of Fig. 3, the alignment optical system 80 is provided by arranging the components of the alignment optical system 80 at the front end of the frame of the optical head frame 20. When switching between the left eye and the right eye to be observed, the alignment optical system 80 rotates together with the optical head frame 20, which switches between a first position (upper position in Fig. 3) and a second position (lower position in Fig. 3). The detailed configuration of the alignment optical system 80 will be described later.

[0022] The control unit 90 electronically controls each part of the fundus observation device A (optical head frame 20, face support unit 30, observation optical system 60, illumination optical system 70, alignment optical system 80, etc.) based on input operations including touch operations on the touch panel screen 41 of the control panel unit 40. As shown in Fig. 3, this control unit 90 is provided at a position above the observation optical system 60 of the optical head frame 20, and has a main board, a TRC control board, a galvano driver board, etc. as a hardware configuration. The detailed configuration of the control unit 90 will be described later.

[0023] When the fundus observation device A 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 covers the entire device stand 10, X-axis movable frame 11, and Z-axis movable frame 12, and is fixed to the device stand 10. A control panel hole is formed in this fixed cover to allow movement of the control panel unit 40, which moves together with the Y-axis movable frame 13. The movable cover covers the entire optical head frame 20, components of the optical system, and control unit 90, and is fixed to the optical head frame 20. A fundus observation hole is formed in this movable cover at a position facing the first elliptical concave surface of the first elliptical concave mirror 51 of the concave mirror unit 50. 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.

[0024] [Detailed structure of the concave mirror unit (Figs. 3 to 6)] The concave mirror unit 50 is disposed at a position between the subject's eye E and the optical path branching section, and forms a reflected optical path of the slit scan light from the illumination optical system 70 to the fundus, and a reflected optical path of the return light from the fundus to the observation optical system 60. The optical path branching section is a branching section where the optical path of the observation optical system 60 and the optical path of the illumination optical system 70 are separated, and a dichroic mirror 55 is disposed at the optical path branching position. As shown in FIG. 4 , 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. The second elliptical concave mirror 52 has a fixing bracket 54 that connects and fixes the concave mirror unit 50 to the optical head frame 20.

[0025] The first elliptical concave mirror 51 has a first elliptical concave surface 51a with 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 with 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 branching 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 respective focal points F1, F2, F3, and F4.

[0026] The concave mirror unit 50 is configured to be used for both the left and right eyes by rotating relative to the device base 10 along a rotation trajectory that switches between a first position (when photographing the left eye in FIG. 3) when the eye being observed is the left eye and a second position (when photographing the right eye in FIG. 3) when the eye being observed is the right eye. The "first position" refers to a horizontal arrangement state in which 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. 3. The "second position" refers to a horizontal arrangement state in which 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. 3. In addition, the concave mirror unit 50 has a reference position other than the first position and the second position, and this "reference position" refers to a vertical arrangement state in which the first elliptical concave mirror 51 is positioned at the upper position and the second elliptical concave mirror 52 is positioned at the lower position in the Y-axis direction, as shown in Figures 1 and 5.

[0027] When the concave mirror unit 50 is switched from the reference position to the first position, the first position is a position where the optical system rotation angle α about the optical system rotation axis 21 is rotated clockwise from α=0° at the reference position to α=+α° (for example, approximately +90°) as shown in Figures 5 and 6. When the concave mirror unit 50 is switched from the reference position to the second position, the second position is a position where the optical system rotation angle α about the optical system rotation axis 21 is rotated counterclockwise from α=0° at the reference position to α=-α° (for example, approximately -90°) as shown in Figures 5 and 6. Note that the optical system rotation angle α is also the rotation angle of the optical head frame 20 to which the concave mirror unit 50 is connected and fixed, and therefore can be said to be the rotation angle of the entire optical system including the concave mirror unit 50.

[0028] When the concave mirror unit 50 is in the first position, the Y-axis movable frame 13 is moved in the X-axis and Z-axis directions from the reference position shown by the imaginary lines to a position on the left side of the device pedestal 10, closer to the front end, as shown in the upper part of Figure 3. When the concave mirror unit 50 is in the second position, the Y-axis movable frame 13 is moved in the X-axis and Z-axis directions from the reference position shown by the imaginary lines to a position on the right side of the device pedestal 10, closer to the front end, as shown in the lower part of Figure 3. When the concave mirror unit 50 is in the reference position, the Y-axis movable frame 13 is in the center position of the device pedestal 10 in the X-axis direction, and is in a distant position farthest from the subject H in the Z-axis direction, as shown in the center part of Figure 3.

[0029] When the concave mirror unit 50 is switched from the reference position to the first position, the X-axis movable frame 11 is moved an amount of X-axis movement DX mm from the reference position of DX = 0 mm to DX = -DX mm (for example, about -50 mm) as shown in Figures 3 and 6. When the concave mirror unit 50 is switched from the reference position to the second position, the X-axis movable frame 11 is moved an amount of X-axis movement DX mm from the reference position of DX = 0 mm to DX = +DX mm (for example, about +50 mm) as shown in Figures 3 and 6.

[0030] When the Z-axis movable frame 12 switches the concave mirror unit 50 from the reference position to the first position, it moves closer in the Z-axis direction by an amount DZ mm from the reference position of DZ = 0 mm to DZ = +DZ mm (for example, about +150 mm), as shown in Fig. 3. When the Z-axis movable frame 12 switches the concave mirror unit 50 from the reference position to the second position, it moves closer in the Z-axis direction by an amount DZ mm from the reference position of DZ = 0 mm to DZ = +DZ mm (for example, about +150 mm), as shown in Fig. 3.

[0031] When the concave mirror unit 50 is switched from the reference position to the first position or the second position, the operation is a combination of YX plane rotational movement of the concave mirror unit 50 and the optical head frame 20, X-axis direction movement of the X-axis movable frame 11, and Z-axis direction movement of the Z-axis movable frame 12. Therefore, the concave mirror unit 50 is rotatable with respect to the device pedestal 10 so as to describe a rotational trajectory that switches between the first position when the eye to be observed is the left eye and the second position when the eye to be observed is the right eye. When the Y-axis movable frame 13 is switched from the reference position to the first position or from the reference position to the second position, 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 clearance distance from the face of the subject H.

[0032] [Detailed optical system configuration (Fig. 7, Fig. 8)] 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 other than the concave mirror unit 50. All optical systems, including the concave mirror unit 50, are configured as optical systems shared by both the left and right eyes. The observation optical system 60 and the illumination optical system 70 employ a separate illumination method in which the observation light beam and the illumination light beam are offset within the pupil circle. A dichroic mirror 55 is disposed at the optical path branching point, which merges 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 diaphragm 600 are disposed at positions conjugate with the pupil, and the slit 72a and the fundus image sensor 671 are disposed at positions conjugate with the fundus. If a coaxial illumination method 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 point between the observation light path and the illumination light path.

[0033] The observation optical system 60 has a fundus image sensor 671 and receives return light from the fundus of the subject's eye E via the concave mirror unit 50. The observation optical system 60 is configured by arranging components along a bent return light path that suppresses protrusion in the X-axis direction indicated by the arrow in FIG. 7 , starting from the dichroic mirror 55 located at the optical path branching section relative to the frame surface of the optical head frame 20. The observation optical system 60 includes a photographing aperture 600, a first reflecting mirror 61, a first lens unit 62, a second reflecting mirror 63, a second lens unit 64, a focusing lens 65, a third lens unit 66, and a fundus camera 67 as its components. The photographing aperture 600 is located at a position conjugate with the pupil of the subject's eye E. The fundus camera 67 has a built-in fundus image sensor 671. The fundus image sensor 671 is located at a position conjugate with the fundus of the subject's eye E.

[0034] The observation optical system 60 has a slide plate 68 that is slidable in the X-axis direction relative to the optical head frame 20, and a second lens unit 64, a focusing lens 65, and a third lens unit 66 are arranged on the upper surface of the slide plate 68. The slide plate 68 performs focusing by using a 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.

[0035] The illumination optical system 70 has a light source unit 71 and is an optical system that projects slit scan light onto the fundus of the subject's eye E via the concave mirror unit 50. This illumination optical system 70 is configured by arranging components along a folded return optical path that suppresses protrusion in the X-axis direction indicated by the arrow in Fig. 8, with the dichroic mirror 55 arranged at the optical path branching unit being the end component relative to the rear surface of the frame of the optical head frame 20. The illumination optical system 70 has, as components, the light source unit 71, a slit unit 72, a galvanometer scanner 73, a lens unit 74, a first reflecting mirror 75, and a second reflecting mirror 76.

[0036] The light source unit 71 is an output unit for illumination light, and has an iris diaphragm 71a located near the 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 slit unit 72 is equipped with a slit driver 77 that controls the slit light directed from the slit unit 72 toward the galvanometer scanner 73. The slit driver 77 has a linear motion unit that adjusts the focus of the slit 72a to match the subject's eye E. The galvanometer scanner 73 is equipped with a scanner driver 78 on the optical head frame 20 that controls the scan angle of the slit light by the galvanometer mirror 73a using a rotary encoder.

[0037] The alignment optical system 80 is provided at the front end of the frame surface of the optical head frame 20, and is an optical system that acquires an anterior eye image 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 focal point F1 of the first elliptical concave mirror 51. As shown in FIG. 7 , the alignment optical system 80 has, as its components, an anterior eye stereo camera 81 and an alignment illumination lamp 82. The anterior eye stereo camera 81 has a built-in anterior eye image sensor 811, and the camera lens optical axis is arranged facing the dichroic mirror 55. The alignment illumination lamp 82 is arranged so that the alignment illumination optical axis faces the dichroic mirror 55. The anterior eye image sensor 811 acquires an anterior eye image of the subject's eye E illuminated by the alignment illumination optical axis from the dichroic mirror 55 reflected by the concave mirror unit 50. The anterior segment images are two images captured from different positions so that alignment adjustment on a three-dimensional coordinate axis is possible.

[0038] [Control system configuration (Fig. 9)] 9, 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 and the like. 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.

[0039] 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 to the position of 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 91 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 an anterior segment image of the subject's eye E. The fine alignment control outputs drive commands from the alignment control unit 91 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 image of the subject's eye E acquired from the alignment optical system 80. In other words, the fine alignment control controls to align the three-dimensional coordinate position of the pupil with the three-dimensional coordinate position of the focal point F1 of the first elliptical concave mirror 51. Here, the alignment control unit 91 illuminates the anterior segment of the subject's eye E by turning on the alignment illumination lamp 82, and acquires an anterior segment image from the anterior segment image sensor 811 of the anterior segment stereo camera 81. 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 of the subject's eye E in the Y-axis direction has already been performed, such as when switching the subject's eye E from the left eye to the right eye.

[0040] The left / right eye switching control unit 92 performs the control necessary to switch the eye being observed between the left eye and the right eye. To switch to the left eye, the unit switches from the reference position to the first position to enter the fundus observation mode for the left eye, and returns to the reference position once observation / photography of the left eye is completed. To switch to the right eye, the unit switches from the reference position to the second position to enter the fundus observation mode for the right eye, and returns to the reference position once observation / photography of the right eye is completed. When switching between the left eye and the right eye being observed, the left / right eye switching control unit 92 controls the optical system rotation angle of the concave mirror unit 50 and the optical head frame 20, controls the left / right movement amount of the X-axis movable frame 11, and controls the front / back movement amount of the Z-axis movable frame 12.

[0041] The optical system rotation angle control of the concave mirror unit 50 and the optical head frame 20 uses an optical system rotation drive unit 17, which controls the optical system rotation angle α of the concave mirror unit 50 and the optical head frame 20. The left and right movement amount of the X-axis movable frame 11 is controlled using an X-axis drive unit 14, which controls the X-axis movement amount of the X-axis movable frame 11. The front and back movement amount of the Z-axis movable frame 12 is controlled using a Z-axis drive unit 15, which controls the Z-axis movement amount of the Z-axis movable frame 12.

[0042] When observing / taking a fundus image of the subject's eye E, the fundus image taking control unit 93 performs focusing control in the observation optical system 60, 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 in the observation optical system 60 uses a focusing drive unit 69 to control the amount of movement of the slide plate 68 in the X-axis direction. Slit control in the illumination optical system 70 uses a slit drive unit 77 to perform linear control of the slit unit 72. Scan control in the illumination optical system 70 uses a scanner drive unit 78 to drive and control the galvanometer scanner 73 at a fundus scan angle set in the scan direction.

[0043] The user interface unit 110 has a function for exchanging information between the user and the fundus observation device A, 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 sensor 671. 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.

[0044] [Fundus image observation / photography processing operation (Fig. 10)] The photographing processing operation of the fundus image executed in the control unit 90 will be described below with reference to the flowchart in Fig. 10. The photographing processing operation of the fundus image starts when the subject H is confirmed by the fundus observation device A 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 ophthalmic examination of the subject H, and can include age, sex, past examination information for follow-up, etc.

[0045] Step S1 is a step in which the left / right eye switching control unit 92 switches from the reference position to the first position to enable fundus observation of the left eye. The left / right eye switching control unit 92 controls switching from the reference position, where the first elliptical concave mirror 51 and the second elliptical concave mirror 52 are arranged vertically, to the first position, where 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 left eye, which is the eye to be observed. Note that, in controlling the switching from the reference position to the first position, the face of the subject H is placed on the face support unit 30 when the reference position is reached before the control is executed.

[0046] 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 eye image captured by the anterior eye image sensor 811 is 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 focal point F1 of the first elliptical concave mirror 51. The coarse alignment control may be omitted if it is confirmed in advance that the pupil height position of the left eye is appropriate.

[0047] Step S3 is a step in which the fundus image capturing control unit 93 performs focusing control to align the focus of the observation optical system 60 and the illumination optical system 70 with the position of the fundus of the left eye. The fundus image capturing control unit 93 controls the amount of movement of the slide plate 68 in the X-axis direction using the focusing drive unit 69 to align the focus of the observation optical system 60 with the position of the fundus of the left eye. The fundus image capturing control unit 93 performs linear control of the slit 72a using the slit drive unit 77 to align the focus of the illumination optical system 70 with the position of the fundus of the left eye.

[0048] In step S4, the fundus image capturing control unit 93 controls the left-eye observation optical system 60L to acquire a fundus image of the left eye 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 using the slit drive unit 77, and scan control based on the fundus scan angle in the scan direction 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 671 included in the observation optical system 60, based on the fundus slit projection angle in the slit projection direction and the fundus scan angle in the scan direction.

[0049] 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.

[0050] In step S6, the left / right eye switching control unit 92 switches from the first position to the reference position so that the subject's eye E and the concave mirror unit 50 are at their farthest apart. The left / right eye switching control unit 92 controls the switching from the first position, 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 reference position, in which the first elliptical concave mirror 51 and the second elliptical concave mirror 52 are arranged in a vertical row. Note that, once the switching from the first position to the reference position is completed, the control for switching from the first position to the reference position proceeds to the next step S7 with the subject's H's face still resting on the face support unit 30.

[0051] In step S7, the left / right eye switching control unit 92 switches from the reference position to the second position to enable fundus observation of the right eye. The left / right eye switching control unit 92 controls the switching from the reference position, where the first elliptical concave mirror 51 and the second elliptical concave mirror 52 are arranged vertically, to the second position, where 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.

[0052] 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. The alignment control unit 91, for example, 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 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.

[0053] Step S9 is a step in which the fundus image capturing control unit 93 performs focusing control to align the focus of the observation optical system 60 and the illumination optical system 70 with the position of the fundus of the right eye. The fundus image capturing control unit 93 controls the amount of movement of the slide plate 68 in the X-axis direction using the focusing drive unit 69, thereby aligning the focus of the observation optical system 60 with the position of the fundus of the right eye. The fundus image capturing control unit 93 performs linear control of the slit 72a using the slit drive unit 77, thereby aligning the focus of the illumination optical system 70 with the position of the fundus of the right eye.

[0054] In step S10, the fundus image capturing control unit 93 controls acquisition of a fundus image of the right eye by the observation optical system 60 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 for switching the fundus slit width in the slit projection direction using the slit drive unit 77, and scan control by the fundus scan angle in the scan direction 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 by the fundus slit projection angle in the slit projection direction and the fundus scan angle in the scan direction using the fundus image sensor 671 included in the observation optical system 60.

[0055] In step S11, the fundus image capturing control unit 93 determines whether or not capturing of a wide-angle fundus image of the right eye has been completed. If it is determined in step S11 that capturing of a wide-angle fundus image 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 capturing of a wide-angle fundus image of the right eye has been completed, the process proceeds to step S12.

[0056] Step S12 is a step in which the left / right eye switching control unit 92 switches from the second position to the reference position to place the subject's eye E and the concave mirror unit 50 at the furthest distance from each other. The left / right eye switching control unit 92 controls switching from the second position, 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 reference position, 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 reference position is completed.

[0057] [Wide-angle fundus observation / photography (Figures 11 and 12)] When the fundus image capturing process operation is started, the control unit 90 sequentially performs the processes in each step from step S1 to step S12 in Fig. 10, and proceeds to END when switching to the reference position is completed in step S12. The control unit 90 executes each process shown in Fig. 10 to observe / capture wide-angle fundus images for each of the left and right eyes. In step S4 in Fig. 10, the control unit 90 controls the illumination optical system 70 to form a slit scan light for the fundus of the left eye, while controlling the observation optical system 60 to acquire a fundus image of the left eye. In addition, in step S10 in Fig. 10, the control unit 90 controls the illumination optical system 70 to form a slit scan light for the fundus of the right eye, while controlling the observation optical system 60 to acquire a fundus image of the right eye.

[0058] Next, the reason why a wide-angle fundus image can be acquired by executing fundus image acquisition control in steps S4 and S10 of FIG. 10 will be explained. In the fundus observation device A, as shown in FIGS. 11 and 12, the pupil of the subject's eye E is positioned at the 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 XZ cross-sectional angle range δXZ (FIG. 11) in the slit projection direction by the slit unit 72 and the YZ cross-sectional angle range δYZ (FIG. 12) in the scanning direction by the galvano scanner 73. Here, the XZ cross-sectional angle range δXZ can be set to an angle range of 150° or more by the slit unit 72. Furthermore, the YZ cross-sectional angle range δYZ can be set to an angle range of 100° or more by the galvano scanner 73. Therefore, the observation optical system 60 can acquire the required wide-angle fundus image.

[0059] [Technology for commercializing a mirror-based fundus observation device (Figure 13)] 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-type 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-type 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.

[0060] 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, it has a configuration like that shown in the comparative example device in Fig. 17. The comparative example device has an illumination optical system, an observation optical system, and a pair of elliptical concave mirrors included in the optical system, independently for each of the left and right eyes.

[0061] However, among the components of the optical system, the elliptical concave mirror requires a large outer diameter to capture a wide-angle fundus image satisfying the required angle of view. Furthermore, the elliptical concave mirror requires a highly accurate mirror finish 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 for the left eye and one for the right eye. Therefore, a mirror-based fundus observation device would be large and expensive if it were to be realized as a real device for each of the left and right eyes of the subject. For example, if Wt in Figure 17 is the width of the optical table, the width Wd (>Wt) of the real device would exceed the width Wt of the optical table, resulting in a low product size rating. Furthermore, the need for four expensive elliptical concave mirrors in a mirror-based fundus observation device would result in a low product cost rating.

[0062] The mirror-based fundus observation device A focuses on the elliptical concave mirror, which is an expensive component of the optical system when it is 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, all components of the optical system, including the concave mirror unit 50, are configured to be rotatable relative to the device stand 10 so that they can be used when the eye being observed is the left eye or the right eye.

[0063] That is, the components of the optical system of Example 1 are made up of a concave mirror unit 50, an observation optical system 60, an illumination optical system 70, and an alignment optical system 80, all of which are mounted on an optical head frame 20. The optical head frame 20 is mounted rotatably along the YX plane relative to a Y-axis movable frame 13. The Y-axis movable frame 13 is mounted so as to be capable of combined linear motion in the X-axis direction and linear motion in the Z-axis direction relative to the device pedestal 10. Therefore, when switching between the left and right eyes to be observed, the concave mirror unit 50 rotates while tracing a three-dimensional rotational motion trajectory relative to the device pedestal 10, switching between a first position (upper position in FIG. 3 ) and a second position (lower position in FIG. 3 ).

[0064] Furthermore, the fundus observation device A does not have a pair of elliptical concave mirrors for each eye, as in the comparative example device, but is configured with a concave mirror unit 50 shared by both eyes, thereby reducing the number of expensive elliptical concave mirrors from four to two. Furthermore, the components of the fundus observation device A other than the concave mirror unit 50 are configured as a single component shared by both eyes, rather than as independent components for each eye, as in the comparative example device. This allows the number of components in the observation optical system 60, illumination optical system 70, and alignment optical system 80 to be reduced from two rows to one row. Furthermore, the optical head frame 20, on which all components are mounted, is rotatable relative to the device stand 10, tracing a three-dimensional rotational movement trajectory, allowing the observation target eye to be switched between the left and right eyes by rotation within a limited space. As a result, the fundus observation device A 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 eye E over a wide angle.

[0065] [Effects of Fundus Observation Device A] (1) The fundus observation device A includes, as components of the optical system, an illumination optical system 70 having a light source unit 71 and projecting slit scanning light onto the fundus Ef of the subject's eye E, an observation optical system 60 having an image sensor (fundus image sensor 671) and receiving returning light from the fundus Ef of the subject's eye E, and a pair of concave mirrors arranged at a position between the subject's eye E and the optical path branching unit and forming a reflected light path of the slit scanning light and a reflected light path of the returning light. The pair of concave mirrors is configured as 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. At least some of the components of the optical system, including the concave mirror unit 50, are 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, making it possible to realize a compact and economical actual device while using a mirror system that places less strain on the subject H when observing the fundus Ef of the subject's eye E at a wide angle.

[0066] (2) The pair of concave mirrors are a first elliptical concave mirror 51 and a second elliptical concave mirror 52, each having two optically conjugate focal points F1, F2 and F3, F4, with the first elliptical concave surface 51a and the second elliptical concave surface 52a partially opposing each other. The first position of the concave mirror unit 50 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 side of the face, and 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 side of the face. This invention uses a concave mirror unit 50 that uses a pair of elliptical concave mirrors whose combination can be easily determined by a focus criterion, and the first and second positions 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.

[0067] (3) At least some of the components of the optical system, including the concave mirror unit 50, are mounted on the optical head frame 20. The device stand 10 has a Y-axis movable frame 13 that is movable in three axes: the left-right axis (X-axis), the front-back axis (Z-axis), and the up-down axis (Y-axis). The optical head frame 20 is mounted rotatably around an optical system rotation axis 21 set in the front-back axis (Z-axis) relative to the movable frame (Y-axis movable frame 13). In this invention, when switching between the left eye and the right eye to be observed, the movable frame (Y-axis movable frame 13) on which the optical head frame 20 is mounted moves in three axial directions relative to the device stand 10, thereby increasing the degree of freedom in setting the rotation trajectory that the concave mirror unit 50 traces relative to the device stand 10.

[0068] (4) The optical head frame 20 is provided with all of the components of the optical system, including the concave mirror unit 50, the observation optical system 60, and the illumination optical system . In this invention, the optical system including the concave mirror unit 50, the observation optical system 60, and the illumination optical system 70 is shared by both the left and right eyes, and compared to when all of the optical system components are configured independently for the left and right eyes, the number of optical system parts is significantly reduced, resulting in a simple configuration that reduces product costs.

[0069] (5) The observation optical system 60 and the illumination optical system 70 are provided in the optical head frame 20 and are configured as optical systems for both the left and right eyes, with components arranged along a folded optical path that reduces protrusion in the left-right axis direction (X-axis direction). In this invention, when switching between the left and right eyes to be observed, the rotation diameter in the left-right axis direction (X-axis direction) due to the rotational movement of the optical head frame 20 is reduced compared to the rotation diameter when the components are arranged along a linear optical path, making it possible to realize a miniaturized fundus observation device A.

[0070] (6) 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. The drive unit 100 has an optical system rotation drive unit 17 in a movable frame (Y-axis movable frame 13) that drives and rotates the optical head frame 20 around an optical system rotation axis 21. The control unit 90 has a left / right eye switching control unit 92 that outputs a rotation drive command to the optical system rotation drive unit 17 to drive and rotate the optical head frame 20 when switching between the left eye and the right eye to be observed. In this invention, when switching between the left eye and the right eye to be observed, the optical head frame 20 equipped with the concave mirror unit 50 can be simply rotated relative to the movable frame (Y-axis movable frame 13) to switch 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.

[0071] (7) The drive unit 100 has a left-right axis drive unit (X-axis drive unit 14) and a front-back axis drive unit (Z-axis drive unit 15). When switching between the left eye and the right eye to be observed, the left-right eye switching control unit 92 outputs a movement command to the left-right axis drive unit (X-axis drive unit 14) and the front-back axis drive unit (Z-axis drive unit 15) to move the movable frame (Y-axis movable frame 13) in the left-right axis direction (X-axis direction) and the front-back axis direction (Z-axis direction) relative to the device base 10 so as to draw an arc trajectory that maintains the gap distance between the concave mirror unit 50 and the face of the subject H. In this invention, when the eye to be observed is switched between the left eye and the right eye, the concave mirror unit 50 moves along an arcuate trajectory that maintains a gap distance from the face of the subject H, thereby not only preventing the rotating concave mirror unit 50 from interfering with the face, but also preventing the discomfort caused by the unit getting too close to the face.

[0072] (8) The device stand 10 is provided with a face support unit 30 at a position in front of the concave mirror unit 50 in the front-to-back axis direction (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 up-down axis direction (Y-axis direction) for supporting the chin of the subject H. The concave mirror unit 50 is provided rotatably relative to the device stand 10 so as to trace a rotational trajectory that switches between a first position for the left eye and a second position for the right eye when the subject H is in a face-supported state facing forward relative to the face support unit 30. In this invention, when switching between the left eye and the right eye to be observed, the subject H can remain in a face support position facing forward, and there is no need to change the face support position of the subject H, thereby reducing the burden of changing the face support position on the subject H. In addition, in this invention, a face support unit with a well-known configuration that is adopted in various ophthalmologic devices can be used as the face support unit 30.

[0073] The fundus observation device A of Example 1 has 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 Example 1, and design changes and additions are permitted as long as they do not deviate from the gist of the invention according to each claim of the claims.

[0074] In the first embodiment, all components, including the concave mirror unit 50, are rotatably mounted relative to the device pedestal 10 along a rotation path that switches between a first position for the left eye and a second position for the right eye. However, the components of the optical system rotatably mounted relative to the device pedestal are not limited to all components, including the concave mirror unit. For example, the concave mirror unit may be rotatably mounted relative to the device pedestal, but the observation optical system, illumination optical system, alignment optical system, and other optical systems may only move relative to the device pedestal without rotating. Alternatively, the concave mirror unit and one or two of the observation optical system, illumination optical system, and alignment optical system may be rotatably mounted relative to the device pedestal, while the remaining optical systems may only move relative to the device pedestal without rotating. In other words, it is sufficient that at least some of the components of the optical system, including the concave mirror unit, are rotatably mounted relative to the device pedestal.

[0075] In Example 1, a configuration example was shown in which the concave mirror unit 50 includes a first elliptical concave mirror 51 and a second elliptical concave mirror 52 connected by a concave mirror bracket 53. However, the concave mirror unit is not limited to the configuration shown in Example 1. 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.

[0076] In the first embodiment, the left / right eye switching control unit 92 rotates the optical head frame 20 to which the concave mirror unit 50 is fixed between a reference position, a first position, and a second position when switching between the left eye and the right eye to be observed. However, the left / right eye switching control unit is not limited to this rotational drive control. For example, the left / right eye switching control unit may eliminate the reference position that is the starting point of the rotational drive, and perform left / right eye switching control by switching from the first position to the second position and from the second position to the first position.

[0077] In the first embodiment, an example was shown in which the optical head frame 20 is provided on the Y-axis movable frame 13 that performs a combination of linear motion in the X-axis direction and linear motion in the Z-axis direction. However, the optical head frame is not limited to the configuration shown in the first embodiment. For example, the optical head frame may be provided on a Y-axis movable frame that performs linear motion in the X-axis direction, linear motion in the Z-axis direction, and rotational motion around a rotation axis in the Y-axis direction.

[0078] In Example 1, an example was shown in which all the components of the optical system are rotated, and therefore the observation optical system 60, illumination optical system 70, and alignment optical system 80 are configured as optical systems shared by both the left and right eyes. However, the observation optical system, illumination optical system, and alignment optical system are not limited to the configurations shown in Example 1. The optical system components that are not rotated may be configured as optical systems independent of the left and right eyes. Furthermore, the specific configuration of the optical system may of course adopt any of the configurations of several examples proposed in Patent Document 1 (JP 2023-122620 A), in addition to the configuration shown in Example 1.

[0079] In Example 1, the face support unit 30 includes a forehead support frame 32 having a forehead support surface 32a and a chin rest 33 having a chin support surface 33a, and is configured to be used for both the left and right eyes of the subject H without changing the positions of the forehead and chin. However, the face support unit is not limited to the configuration shown in Example 1. The face support unit may also be configured to be used for both the left and right eyes by simply slightly changing the positions of the subject's forehead and chin, and includes a forehead support frame having two adjacent forehead support surfaces, one on the left and one on the right. Furthermore, the face support unit may also be configured independently for the left and right eyes, with a left-eye face support portion when the eye to be observed is the left eye and a right-eye face support portion when the eye to be observed is the right eye.

[0080] Example 1 has shown an optical system configuration including only a fundus camera as the optical system of the fundus observation device A. However, the optical system of the fundus observation device is not limited to the configuration shown in Example 1. The fundus observation device may be configured to additionally include, in addition to the fundus camera, an optical system for 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 takes a fundus image. In contrast, OCT is an optical coherence tomography that uses light interference to image a tomographic image of the retina present at the fundus of the subject's eye and take a fundus tomographic image. [Explanation of symbols]

[0081] A Fundus observation device 10. Device stand 20 Optical head frame 30 Face support 40 Control panel section 50 Concave mirror unit 60 Observation Optical System 70 Illumination optical system 80 Alignment Optical System 90 Control Unit E. Examined eye Ef fundus

Claims

1. an illumination optical system having a light source unit and projecting slit scanning light onto the fundus of the subject's eye; an observation optical system having an image sensor and receiving return light from the fundus of the subject's eye; a pair of concave mirrors that are arranged at a position between the eye to be examined and an optical path branching unit and form a reflected optical path of the slit scanning light and a reflected optical path of the return light; A fundus observation device including the above as a component of an optical system, 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, At least some of the components of the optical system, including the concave mirror unit, are provided rotatably with respect to the apparatus stand so as to trace a rotational locus that switches between a first position when the eye being observed is the left eye and a second position when the eye being observed is the right eye. A fundus observation device characterized by:

2. In the fundus observation device according to claim 1, 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 the first elliptical concave surface and the second elliptical concave surface partially facing each other; The concave mirror unit has a first position where the first elliptical concave mirror is disposed in front of the left eye and a second elliptical concave mirror is disposed on the side of the face, and a second position where the first elliptical concave mirror is disposed in front of the right eye and a second elliptical concave mirror is disposed on the side of the face. A fundus observation device characterized by:

3. In the fundus observation device according to claim 2, At least some of the components of the optical system, including the concave mirror unit, are provided on an optical head frame; the device stand has a movable frame that is movable in three axes, i.e., a left-right axis, a front-back axis, and a top-bottom axis, The optical head frame is provided to be rotatable about an optical system rotation axis set in the front-rear axis direction relative to the movable frame. A fundus observation device characterized by:

4. In the fundus observation device according to claim 3, The optical head frame is provided with all of the components of the optical system, including the concave mirror unit, the observation optical system, and the illumination optical system. A fundus observation device characterized by:

5. In the fundus observation device according to claim 4, The observation optical system and the illumination optical system are provided on the optical head frame, and are configured as an optical system for both the left and right eyes, with components arranged along a folded optical path that suppresses protrusion in the left-right axis direction. A fundus observation device characterized by:

6. In the fundus observation device according to any one of claims 1 to 5, the fundus observation device includes a control unit that controls each unit of the device by outputting a command to a drive unit, the drive unit has an optical system rotation drive unit in the movable frame that rotates and drives the optical head frame around an optical system rotation axis, The control unit has a left / right eye switching control unit that outputs a rotation drive command to the optical system rotation drive unit to rotate the optical head frame when switching between the left eye and the right eye to be observed. A fundus observation device characterized by the above.

7. 7. The fundus observation device according to claim 6, The drive unit has a left-right axis drive unit and a front-rear axis drive unit, When switching between the left and right eyes as the observation target eye, 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 axis direction and the front-back axis direction relative to the device base so as to draw an arc trajectory that maintains a gap distance between the concave mirror unit and the face of the subject. A fundus observation device characterized by the above.

8. In the fundus observation device according to any one of claims 1 to 5, the apparatus stand is provided with a face support unit at a position in front of the concave mirror unit in the front-to-back axis 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 axis direction and supports the chin of the subject; The concave mirror unit is provided rotatably with respect to the device base so as to trace a rotational locus that switches between a first position for the left eye and a second position for the right eye when the subject is in a face-supported state facing forward with respect to the face support part. A fundus observation device characterized by:

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