Ophthalmic equipment and method of operating ophthalmic equipment

Abstract

The present invention provides an ophthalmic device and a method for operating the ophthalmic device that enable the examination of a subject's eye using an examination head (a pair of concave mirrors) without bringing the examination head close to the subject's nose. [Solution] The ophthalmic device (fundus camera 9) comprises an examination head 20, a pair of concave mirrors (concave mirror unit 50) that form an optical path for illumination light and return light between the examination head 20 and the eye E under examination, a displacement mechanism (each drive unit 14-17) that displaces the examination head 20, a plurality of cameras (stereo cameras 81L, 81R) provided on the examination head 20, a nose imaging control unit 91A that photographs the nose N of the subject H from multiple different directions using at least two or more cameras, an inclination angle determination unit 91C that determines the inclination angle θ of the inclination axis TA with respect to the reference axis VA, and a drive control unit 93 that drives the displacement mechanism to displace the examination head 20 along the inclination axis TA to the examination position of the eye E under examination.

Description

Technical Field

[0001] The present invention relates to an ophthalmic device including an inspection head provided with a pair of concave mirrors and a method of operating the ophthalmic device.

Background Art

[0002] In ophthalmology, ophthalmic examinations of an eye to be examined (acquisition of various eye characteristics such as the refractive power, intraocular pressure, and number of corneal endothelial cells of the eye to be examined, fundus photography, tomographic imaging, etc.) are performed using an ophthalmic device. As one type of such an ophthalmic device, a mirror-type fundus camera capable of wide-angle photography of the fundus is known (see Patent Document 1). A pair of concave mirrors is provided on the front surface of the inspection head of this fundus camera. This pair of concave mirrors forms an optical path of illumination light irradiated from the inspection head to the eye to be examined and an optical path of return light incident from the eye to be examined to the inspection head between the inspection head and the eye to be examined.

[0003] When performing fundus photography with the fundus camera described in Patent Document 1, alignment of the inspection head with respect to the eye to be examined, that is, alignment, is extremely important from the viewpoint of the image quality of the fundus image. Therefore, as described in Patent Documents 2 and 3, the anterior segment of the eye to be examined is photographed with a stereo camera, and alignment detection for detecting the relative position of the eye to be examined with respect to the inspection head based on the anterior segment image obtained by this photography is performed. Then, auto-alignment of the inspection head with respect to the eye to be examined is performed by moving the inspection head by an electric actuator based on the result of this alignment detection.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

[0005] When performing auto-alignment of the examination head for the eye under examination using the methods described in Patent Document 2 and Patent Document 3 in the fundus camera described in Patent Document 1, it is necessary to bring the examination head, particularly the pair of concave mirrors, close to the face of the subject, but in doing so, there is a risk that the pair of concave mirrors will come close to the nose of the subject.

[0006] This invention has been made in view of these circumstances, and aims to provide an ophthalmic device and a method for operating the ophthalmic device that can perform an examination of the subject's eye using an examination head (a pair of concave mirrors) without bringing the examination head close to the subject's nose. [Means for solving the problem]

[0007] An ophthalmic apparatus for achieving the object of the present invention comprises an examination head having an illumination optical system that emits illumination light to illuminate the eye under examination, and an imaging optical system that guides the reflected light from the eye irradiated with illumination light to an image sensor; a pair of concave mirrors provided on the examination head that form an optical path for illumination light and reflected light between the examination head and the eye under examination; a displacement mechanism that displaces the examination head relative to the eye under examination; a plurality of cameras provided on the examination head; a nose imaging control unit that causes at least two or more cameras to photograph the nose of the subject from multiple different directions; and images captured by each camera. The system comprises: a nose position detection unit that detects the relative position of the nose to the examination head based on an image of the nose; an inclination angle determination unit that determines the inclination angle of the inclination axis relative to the reference axis based on the detection result of the nose position detection unit, when the reference axis is parallel to the front-to-back direction which is the operating distance direction of the examination head and passes through the eye under examination, and the inclination axis is an axis tilted outward from the reference axis with the eye under examination as the center, away from the nose of the person under examination; and a drive control unit that drives a displacement mechanism to displace the examination head to the examination position of the eye under examination along the inclination axis with the inclination angle determined by the inclination angle determination unit.

[0008] This ophthalmic device allows the examination head (a pair of concave mirrors) to be moved to the examination position of the eye without having to bring it close to the patient's nose.

[0009] In another embodiment of the present invention, the nasal imaging control unit adjusts the position of the examination head using a displacement mechanism to a position where the nose can be photographed by all cameras, and then causes all cameras to simultaneously photograph the nose. This enables the nasal position detection unit to detect the relative position of the nose with high accuracy.

[0010] In another embodiment of the present invention, the nasal imaging control unit drives a displacement mechanism to move the examination head to a position where some cameras can image the nose, then performs a segmented imaging process in which some cameras image the nose, a position information acquisition process to acquire the imaging position information of the cameras that have imaged the nose in the segmented imaging process, and a repetitive process that repeatedly executes the segmented imaging process and the position information acquisition process until all cameras have completed imaging the nose. The nasal position detection unit then detects the relative position of the nose based on the images and imaging position information for each camera. This allows the nasal position detection unit to detect the relative position of the nose with high accuracy, even when it is not possible to image the nose simultaneously with all cameras.

[0011] In another aspect of the present invention, the tilt angle determination unit calculates the nasal distance, which is the distance between the examination head and the nose when the examination head is brought close to the eye under examination to a predetermined working distance, for each of a plurality of different tilt angles based on the detection result of the nasal position detection unit, and determines the tilt angle based on the calculation result of the nasal distance for each tilt angle. This makes it possible to determine a tilt angle at which the examination head can be displaced to the examination position of the eye under examination without bringing the examination head close to the patient's nose.

[0012] In another aspect of the present invention, an ophthalmic apparatus is provided in which multiple cameras capture images of the anterior segment of the eye under examination as the examination head is being displaced to the examination position by a displacement mechanism, and an alignment detection unit detects the relative position of the eye under examination with respect to the examination head based on the images of the anterior segment of the eye under examination captured by the multiple cameras. A drive control unit drives the displacement mechanism based on the detection result of the alignment detection unit to perform alignment of the examination head with respect to the eye under examination while maintaining the tilt angle determined by the tilt angle determination unit. This makes it possible to displace the examination head to the examination position of the eye under examination without bringing it close to the patient's nose.

[0013] In another aspect of the present invention, the ophthalmic apparatus includes a displacement mechanism that moves the examination head in the forward / backward, left / right, and up / down directions relative to the eye under examination, and a rotation mechanism that rotates the examination head about a predetermined axis of rotation. This allows the examination head to be arbitrarily displaced relative to the eye under examination.

[0014] In another aspect of the present invention, the axis of rotation is parallel to the vertical direction and the outward direction is parallel to the left-right direction.

[0015] In another aspect of the present invention, the ophthalmic apparatus is perpendicular to the vertical direction, and the outward direction is upward in the vertical direction.

[0016] In another aspect of the present invention, the ophthalmic apparatus comprises a pair of concave mirrors, a first concave mirror and a second concave mirror connected by a concave mirror bracket, wherein the first concave mirror has a first reflective surface facing the eye under examination, and the second concave mirror has a second reflective surface that partially faces the first reflective surface and reflects illumination light from the illumination optical system to the first reflective surface, and reflects the reflected light from the first reflective surface to the imaging optical system, and the pair of concave mirrors is equipped with a switching mechanism that allows switching between a first position in which the first reflective surface is positioned in front of the left eye and the second reflective surface is positioned on the left side of the face when the eye under examination is the left eye, and a second position in which the first reflective surface is positioned in front of the right eye and the second reflective surface is positioned on the right side of the face when the eye under examination is the right eye. This enables wide-angle imaging of the observed portion of the eye under examination.

[0017] A method for operating an ophthalmic device to achieve the object of the present invention comprises: an examination head having an illumination optical system that emits illumination light to illuminate the eye to be examined, and an imaging optical system that guides the reflected light from the eye irradiated with illumination light to an image sensor; a pair of concave mirrors provided on the examination head that form an optical path for illumination light and reflected light between the examination head and the eye to be examined; a displacement mechanism that displaces the examination head relative to the eye to be examined; and a plurality of cameras provided to be movable integrally with the examination head, wherein the method for operating an ophthalmic device comprises a nasal imaging control step that causes the nose of the patient to be photographed from multiple directions that are different from each other by at least two or more cameras, and The system includes: a nose position detection step that detects the relative position of the nose to the examination head based on the captured image of the nose taken for each examination; a tilt angle determination step that determines the tilt angle of the tilt axis relative to the reference axis based on the detection result of the nose position detection step, assuming that the reference axis is parallel to the front-to-back direction, which is the operating distance direction of the examination head, and passes through the eye under examination, and the tilt axis is an axis tilted outward from the reference axis with the eye under examination as the center, away from the nose under examination; and a drive control step that drives a displacement mechanism to displace the examination head to the examination position of the eye under examination along the tilt axis with the tilt angle determined in the tilt angle determination step. [Effects of the Invention]

[0018] The present invention makes it possible to perform an examination of the subject's eye using an examination head (a pair of concave mirrors) without bringing the examination head close to the subject's nose. [Brief explanation of the drawing]

[0019] [Figure 1] This is an external perspective view of the fundus camera of the first embodiment. [Figure 2] This is a side view of the fundus camera according to the first embodiment. [Figure 3] This is a front view of the fundus camera of the first embodiment, as seen from the subject's side. [Figure 4] This is a top view of the concave mirror unit rotated to the first position during fundus photography of the left eye. [Figure 5]Top view of the concave mirror unit rotated to the second position during fundus imaging of the right eye. [Figure 6] Top view of the imaging optical system of the examination head. [Figure 7] Side view of the illumination optical system of the examination head. [Figure 8] Front view of the illumination optical system and alignment optical system of the examination head. [Figure 9] Perspective view of the face support part seen from the subject side. [Figure 10] Functional block diagram of the control device. [Figure 11] Explanatory diagram for explaining the method of auto-alignment of the examination head. [Figure 12] Explanatory diagram for explaining the simultaneous imaging process of the subject's eyes (left eye, right eye) by the stereo camera. [Figure 13] Explanatory diagram for explaining an example of split imaging by the stereo camera during fundus imaging of the left eye. [Figure 14] Explanatory diagram for explaining an example of the method of determining the tilt angle by the tilt angle determination unit. [Figure 15] Explanatory diagram for explaining the first-1 example of auto-alignment of the examination head in the first embodiment. [Figure 16] Explanatory diagram for explaining the first-2 example of auto-alignment of the examination head in the first embodiment. [Figure 17] Explanatory diagram for explaining the first-3 example of auto-alignment of the examination head in the first embodiment. [Figure 18] Flowchart showing the flow of the examination process of the subject's eye by the fundus camera in the first embodiment. [Figure 19] Flowchart showing the flow of the tilt angle determination process. [Figure 20] Flowchart showing the flow of the auto-alignment process of the examination head. [Figure 21] Explanatory diagram for explaining the displacement of the examination head after the start of auto-alignment. [Figure 22] This is a flowchart showing a modified version of the auto-alignment process for the inspection head. [Figure 23] This is a side view of the main part of the fundus camera of the second embodiment. [Figure 24] This is an explanatory diagram illustrating a second-first example of auto-alignment of the inspection head in the second embodiment. [Figure 25] This is an explanatory diagram illustrating a second example of auto-alignment of the inspection head in the second embodiment. [Figure 26] This is a side view of the main part of the fundus camera of the third embodiment. [Figure 27] This is an explanatory diagram illustrating a third example of auto-alignment of the inspection head in the third embodiment. [Figure 28] This is an explanatory diagram illustrating a fourth example of auto-alignment of the inspection head in the fourth embodiment. [Modes for carrying out the invention]

[0020] [First Embodiment] <Overall configuration of the fundus camera> Figure 1 is an external perspective view of the fundus camera 9 of the first embodiment. Figure 2 is a side view of the fundus camera 9 of the first embodiment. Figure 3 is a front view of the fundus camera 9 of the first embodiment as seen from the subject H side. In the figures, the X-axis direction is the left-right direction with respect to the subject H, the Y-axis direction is the up-down direction, and the Z-axis direction is the front-back direction (also called the working distance direction) parallel to the forward direction towards the subject H (eye E) and the backward direction away from the subject H.

[0021] As shown in Figures 1 to 3, the fundus camera 9 corresponds to the ophthalmic device of the present invention and comprises a device stand 10, an examination head 20 (also called an optical head), a face support unit 30, a control panel 40, a concave mirror unit 50, an imaging optical system 60, an illumination optical system 70, an alignment optical system 80, and a control device 90.

[0022] The device stand 10 is a base member that is placed on an optical table T whose height can be adjusted in the Y-axis direction. A face support part 30 is fixed to the front end of the device stand 10 on the Z-axis forward side (subject H side), and a control panel 40 is attached to the rear end of the device stand 10 on the Z-axis rear side (examiner side). In addition, an examination head 20 is positioned in the central area of ​​the device stand 10, sandwiched between the face support part 30 and the control panel 40.

[0023] An X-axis movable frame 11, which is movable in the X-axis direction relative to the device frame 10, is positioned in the central region of the device frame 10. A Z-axis movable frame 12, which is movable in the Z-axis direction relative to the X-axis movable frame 11, is positioned on the X-axis movable frame 11. A Y-axis movable frame 13, which is movable in the Y-axis direction relative to the Z-axis movable frame 12, is positioned on the Z-axis movable frame 12. The device frame 10 has an X-axis drive unit 14 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 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 that moves the Y-axis movable frame 13 in the Y-axis direction. The X-axis drive unit 14, the Z-axis drive unit 15, and the Y-axis drive unit 16 constitute the movement mechanism of the present invention, and for example, a motor actuator is used.

[0024] The inspection head 20 is equipped with a concave mirror unit 50, an imaging optical system 60, an illumination optical system 70, and an alignment optical system 80. The inspection head 20 is mounted on a Y-axis movable frame 13. As a result, the inspection head 20 can move in the XYZ directions relative to the device stand 10 via the X-axis movable frame 11, the Z-axis movable frame 12, and the Y-axis movable frame 13.

[0025] The Y-axis movable frame 13 is provided with a swing rotation drive unit 17 and a rotation shaft 21. The swing rotation drive unit 17, together with the X-axis drive unit 14, Z-axis drive unit 15, and Y-axis drive unit 16 described above, constitute the displacement mechanism of the present invention.

[0026] The swing rotation drive unit 17 corresponds to the rotation mechanism of the present invention and rotates (swings) the inspection head 20 around a rotation axis 21 parallel to the Y-axis direction. This swing rotation drive unit 17 is composed of, for example, a motor, a worm gear, and a motor drive circuit. The rotation axis 21 is provided on the lower side of the inspection head 20 in the Y-axis direction and moves and rotates together with the inspection head 20 in the XYZ axis directions.

[0027] Thus, the inspection head 20 is movable in the XYZ directions by the X-axis drive unit 14, the Z-axis drive unit 15, and the Y-axis drive unit 16, and is also rotatable around the axis 21 centered by the swing rotation drive unit 17. This allows the inspection head 20 to be moved linearly in each axial direction, rotated around the rotation axis 21, or move in a trajectory that combines linear and rotational movement during auto-alignment and left / right eye switching.

[0028] The face support section 30 is provided at the front end of the device stand 10 and is located forward in the Z-axis direction from the concave mirror unit 50. The face support section 30 supports the forehead and chin of the subject H in order to stabilize the position and orientation of the eye E being examined. The face support section 30 includes a main body section 31, a forehead support frame 32 that contacts the forehead of the subject H, a chin support base 33 that contacts the chin of the subject H, a lifting rod 34 parallel to the Y-axis direction, and a chin support drive unit 35.

[0029] The jaw rest drive unit 35 is built into the main body 31 and drives the lifting rod 34 in the Y-axis direction. The jaw rest drive unit 35 is composed of, for example, a motor and a motor drive circuit. A jaw rest base 33 is provided at the upper end of the lifting rod 34, and the Y-axis position of the jaw rest base 33 can be adjusted by driving the lifting rod 34 in the Y-axis direction by the jaw rest drive unit 35.

[0030] The control panel 40 is located at the rear end of the device stand 10. This control panel 40 has a touch panel screen 41 that displays in color images of the fundus of the eye E taken by the imaging optical system 60 and images of the anterior segment of the eye E taken by the alignment optical system 80 (stereo cameras 81L, 81R shown in Figure 8 below).

[0031] The touch panel screen 41 receives touch input from the examiner on various images displayed on the screen (operation button images, anterior segment images, fundus images, etc.) and outputs operation signals to the control device 90. Therefore, the control panel 40 (touch panel screen 41) functions as an operation unit. A known tablet terminal may be used instead of the control panel 40. In addition, various known operation units and display units other than the control panel 40 may be used.

[0032] The control panel 40 is used for adjusting the position of the chin rest 33, moving the examination head 20 in the XYZ axis directions, rotating the examination head 20, switching between auto-alignment and manual alignment, starting the examination, and saving the examination results (fundus image).

[0033] The concave mirror unit 50 consists of a first concave mirror 51 and a second concave mirror 52, which correspond to the pair of concave mirrors of the present invention, and a concave mirror bracket 53 that connects the first concave mirror 51 and the second concave mirror 52. This concave mirror unit 50 is rotatably held at a position on the front side of the inspection head 20 by a unit rotation drive unit 55 provided on the inspection head 20, and faces the face support unit 30 (the face of the subject H).

[0034] The unit rotation drive unit 55 corresponds to the switching mechanism of the present invention and rotates the concave mirror unit 50 (concave mirror bracket 53) around a unit rotation axis 54 parallel to the Z-axis direction. The unit rotation drive unit 55 includes, for example, a motor, a timing belt stretched across two pulleys, and a motor drive circuit. When the eye E under examination is the left eye, the concave mirror unit 50 is switched by the unit rotation drive unit 55 to the first position described later (see Figure 4), and when the eye E under examination is the right eye, the unit rotation drive unit 55 is switched to the second position described later (see Figure 5).

[0035] The imaging optical system 60 is located on the upper side of the inspection head 20. The illumination optical system 70 is located on the lower side of the inspection head 20. The alignment optical systems 80 are located on the left and right sides of the lower front end of the inspection head 20.

[0036] The control device 90 controls various parts of the fundus camera 9 (face support unit 30, concave mirror unit 50, imaging optical system 60, illumination optical system 70, alignment optical system 80, etc.) based on input operations, including touch operations on the control panel 40 (touch panel screen 41). This control device 90 is installed on the examination head 20 and, for example, has a hardware configuration that includes a main board, a TRC (Time Ratio Control) control board, and a galvanometer driver board.

[0037] <Detailed configuration of the concave mirror unit> Figure 4 is a top view of the concave mirror unit 50 rotated to the first position during fundus photography of the left eye. Figure 5 is a top view of the concave mirror unit 50 rotated to the second position during fundus photography of the right eye. In the figures, the symbol CL represents the central axis of the examination head 20. This central axis CL coincides with (approximately coincides with, and the same applies hereafter) the unit rotation axis 54 when the examination head 20 is viewed from one direction in the Y-axis direction.

[0038] As shown in Figures 4 and 5, the concave mirror unit 50 is rotatably held by the unit rotation drive unit 55 at a position between the eye E under examination and the front surface of the examination head 20 (the dichroic mirrors 57L and 57R shown in Figure 6, which will be described later). The first concave mirror 51 and the second concave mirror 52, which constitute the concave mirror unit 50, form a reflected light path for illumination light from the illumination optical system 70 to the fundus of the eye E under examination, and a reflected light path for return light from the fundus of the eye E under examination to the imaging optical system 60.

[0039] The first concave mirror 51 has a first reflective surface 51a formed thereon, which has two optically conjugate focal points F1 and F2. The position of focal point F1 is the position where the pupil of the eye under examination E is positioned when observing and photographing the fundus of the eye under examination E.

[0040] The second concave mirror 52 has a second reflective surface 52a formed thereon, which has two optically conjugate foci F3 and F4. This second reflective surface 52a partially faces the first reflective surface 51a. The position of focal spot F3 is the same as the position of focal spot F2. The position of focal spot F4 is the position of the optical path branching point between the optical path of the imaging optical system 60 and the optical path of the illumination optical system 70.

[0041] The concave mirror bracket 53 connects the first concave mirror 51 and the second concave mirror 52 while maintaining the relative positions of the focal points F1 to F4. The unit rotation shaft 54 ​​of the unit rotation drive unit 55 is connected to this concave mirror bracket 53.

[0042] The concave mirror unit 50 is rotatable (swivelable) to a first position when the eye E being examined is the left eye (see Figure 4) and to a second position when the eye E being examined is the right eye (see Figure 5). By rotating this concave mirror unit 50 with the unit rotation drive unit 55, the concave mirror unit 50 is configured to be usable for both the left and right eyes.

[0043] The "first position" is a horizontal arrangement where the first concave mirror 51 is positioned in front of the left eye and the second concave mirror 52 is positioned on the left side of the face, as shown in Figure 4. The "second position" is a horizontal arrangement where the first concave mirror 51 is positioned in front of the right eye and the second concave mirror 52 is positioned on the right side of the face, as shown in Figure 5. In addition to the first and second positions, the concave mirror unit 50 also has a reference position, which is a vertical arrangement where the first concave mirror 51 is in the lower position and the second concave mirror 52 is in the upper position in the Y-axis direction, as shown in Figure 2 described above.

[0044] When performing fundus photography of the left eye, the examination head 20 is positioned towards the left end of the device stand 10 as viewed from the subject H side, and is tilted at an angle with respect to the central axis CL relative to the Z-axis, as shown in Figure 4. When performing fundus photography of the right eye, the examination head 20 is positioned towards the right end of the device stand 10 as viewed from the subject H side, and is tilted at an angle with respect to the central axis CL relative to the Z-axis, as shown in Figure 5.

[0045] Furthermore, the examination head 20 is positioned in its initial position before the start of fundus photography. This initial position is the central position of the device stand 10 in the X-axis direction (the central position of the movable range of the examination head 20 in the X-axis direction), and is a retracted position that is moved backward (separated) from the subject H in the Z-axis direction (see the symbol XVA in Figure 15).

[0046] Figure 6 is a top view of the imaging optical system 60 of the inspection head 20. Figure 7 is a side view of the illumination optical system 70 of the inspection head 20. Figure 8 is a front view of the illumination optical system 70 and alignment optical system 80 of the inspection head 20.

[0047] As shown in Figures 6 to 8, the imaging optical system 60 includes a left-eye imaging optical system 60L for left eye fundus imaging and a right-eye imaging optical system 60R for right eye fundus imaging (see Figure 6). The illumination optical system 70 is provided independently along the central axis CL of the examination head 20 (see Figure 7). The alignment optical system 80 includes a left-eye alignment optical system 80L used for auto-alignment before left eye fundus imaging and a right-eye alignment optical system 80R used for auto-alignment before right eye fundus imaging (see Figure 8).

[0048] The imaging optical system 60 and the illumination optical system 70 employ a separated illumination method in which the observation light beam and the illumination light beam are offset within the pupil circle of the eye E under examination. In addition, dichroic mirrors 57L and 57R are placed at the optical path branching points of each optical system to merge the observation light path, illumination light path, and alignment light path. If a coaxial illumination method is adopted instead of the separated illumination method in which the observation light beam and illumination light beam are aligned within the pupil circle as described above, a perforated mirror may be placed at the optical path branching point.

[0049] As shown in Figure 6, the imaging optical system 60 images the reflected light from the fundus of the eye E that has been incident via the concave mirror unit 50. This imaging optical system 60 comprises an imaging optical system 60L for the left eye and an imaging optical system 60R for the right eye, a slide plate 68, and a focusing drive unit 69.

[0050] The left-eye imaging optical system 60L and the right-eye imaging optical system 60R have a symmetrical structure with respect to the central axis CL on the upper surface of the examination head 20. Furthermore, the left-eye imaging optical system 60L and the right-eye imaging optical system 60R are eccentric optical systems with eccentric optical paths.

[0051] The left eye imaging optical system 60L includes a dichroic mirror 57L arranged along the optical path of the reflected light indicated by the arrow in the figure, an imaging aperture 600L, a first reflective mirror 61L, a first lens unit 62L, a second reflective mirror 63L, a second lens unit 64L, a focusing lens 65L, a third lens unit 66L, and an imaging unit 67L. The imaging aperture 600L is positioned conjugate to the pupil of the eye under examination E. In the imaging unit 67L, a fundus image sensor 671L (corresponding to the image sensor of the present invention) is positioned at an outward-facing inclination angle in a plan view, in accordance with the setting of the eccentric optical system. The fundus image sensor 671L is positioned conjugate to the fundus of the eye under examination E.

[0052] The imaging optical system 60R for the right eye includes a dichroic mirror 57R arranged along the optical path of the reflected light indicated by the arrow in the figure, an imaging aperture 600R, a first reflective mirror 61R, a first lens unit 62R, a second reflective mirror 63R, a second lens unit 64R, a focusing lens 65R, a third lens unit 66R, and an imaging unit 67R. The imaging aperture 600R is positioned conjugate to the pupil of the eye under examination E. In the imaging unit 67R, a fundus image sensor 671R (corresponding to the image sensor of the present invention) is positioned at an inclination angle that is outwardly open in a plan view, in accordance with the setting of the eccentric optical system. The fundus image sensor 671R is positioned conjugate to the fundus of the eye under examination E.

[0053] The slide plate 68 is provided on the upper surface of the inspection head 20 so as to be movable in a direction along the central axis CL (in the Z-axis direction in the figure). The upper surface of the slide plate 68 is provided with second lens units 64L, 64R, focusing lenses 65L, 65R, and third lens units 66L, 66R.

[0054] The focusing drive unit 69 is, for example, a motor actuator, and performs focusing control to adjust the focus of the imaging optical system 60 to the fundus of the eye E by displacing the slide plate 68 in a direction along the central axis CL when the fundus of the eye E is being photographed.

[0055] As shown in Figures 7 and 8, the illumination optical system 70 projects slit scan light, which is illumination light, onto the fundus of the eye E being examined via a concave mirror unit 50. This illumination optical system 70 includes a light source unit 71, a slit unit 72, a galvanometer scanner 73 (optical scanner), a first reflection mirror 741, a second reflection mirror 742, a left / right switching mirror 75, and dichroic mirrors 57L and 57R, all arranged along the illumination light path shown in the figures.

[0056] The optical path from the left / right switching mirror 75 to the dichroic mirror 57L includes the first lens unit 761L, the third reflective mirror 763L, and the second lens unit 762L shown in Figure 8, and the fourth reflective mirror 744L shown in Figure 7. Furthermore, the optical path from the left / right switching mirror 75 to the dichroic mirror 57R includes the first lens unit 761R, the third reflective mirror 763R, and the second lens unit 762R shown in Figure 8, and the fourth reflective mirror 744R shown in Figure 7.

[0057] The light source unit 71 emits illumination light toward the slit unit 72. This light source unit 71 has an iris diaphragm 71a located near the slit unit 72. The iris diaphragm 71a is positioned conjugate to the pupil of the eye E being examined.

[0058] The slit unit 72 includes a slit 72a and a projection lens 72b. The slit 72a is positioned conjugate to the fundus of the eye E being examined. This causes a slit-shaped illumination light (slit light) to be shone onto the fundus of the eye E being examined. The slit unit 72 is also provided with a slit drive unit 77. The slit drive unit 77 has a linear motion part that adjusts the focus of the slit 72a to match the eye E being examined.

[0059] The galvanoscanner 73 scans the illumination light (slit light) shining onto the fundus of the eye E being examined. The scanner drive unit 78 controls the drive of the galvanoscanner 73 (scan angle of the slit light).

[0060] The left / right switching mirror 75 is located on the lower side of the unit rotation axis 54 in the Y-axis direction and is rotatable around a mirror rotation axis 75a (see Figure 8) parallel to the Z-axis direction. A mirror rotation drive unit 79 is connected to the mirror rotation axis 75a. By rotating the mirror rotation axis 75a, the mirror rotation drive unit 79 can switch the tilt angle of the left / right switching mirror 75 between a first angle that reflects illumination light toward the first lens unit 761L and a second angle that reflects illumination light toward the first lens unit 761R.

[0061] Furthermore, the illumination optical system 70 may be provided with a fixation light projection system 770 (see Figure 10) that projects fixation light onto the fundus of the eye E to cause the eye E to fixate.

[0062] As shown in Figure 8, the alignment optical system 80 is provided at the left and right positions of the front end of the examination head 20. The alignment optical system 80 acquires an anterior segment image of the eye E when performing auto-alignment, which adjusts the position of the eye E to the position of the first focal point F1 of the first concave mirror 51. The alignment optical system 80 has a left-eye alignment optical system 80L used for auto-alignment of the left eye and a right-eye alignment optical system 80R used for auto-alignment of the right eye. The left-eye alignment optical system 80L (stereo camera 81L) functions as multiple cameras of the present invention when photographing the fundus of the left eye, and the right-eye alignment optical system 80R (stereo camera 81R) functions as multiple cameras of the present invention when photographing the fundus of the right eye. Furthermore, the number of cameras constituting the stereo cameras 81L and 81R is not particularly limited as long as there are two or more.

[0063] An alignment optical frame 22L is fixed to the lower Y-axis side of the dichroic mirror 57L in the examination head 20, and a left-eye alignment optical system 80L is provided in this alignment optical frame 22L. The left-eye alignment optical system 80L has a stereo camera 81L and an alignment illumination lamp 82L positioned on the lower Y-axis side of the dichroic mirror 57L. The alignment illumination lamp 82L illuminates the left eye, which is the eye under examination E, with illumination light via the dichroic mirror 57L. The stereo camera 81L has an anterior segment image sensor and stereographs the left eye, which is illuminated with illumination light via the dichroic mirror 57L, and outputs an anterior segment image of this left eye.

[0064] An alignment optical frame 22R is fixed to the lower Y-axis side of the dichroic mirror 57R in the examination head 20, and a right-eye alignment optical system 80R is provided in this alignment optical frame 22R. The right-eye alignment optical system 80R has a stereo camera 81R and an alignment illumination lamp 82R located on the lower Y-axis side of the dichroic mirror 57R. The alignment illumination lamp 82R illuminates the right eye, which is the eye under examination E, with illumination light via the dichroic mirror 57R. The stereo camera 81R has an anterior segment image sensor and stereographs the right eye, which is illuminated with illumination light via the dichroic mirror 57R, and outputs an anterior segment image of the right eye.

[0065] <Detailed configuration of the face support section> Figure 9 is a perspective view of the face support unit 30 from the subject H's side. As shown in Figure 9, the face support unit 30 supports the subject H's face in different positions and postures when taking fundus images of the left eye and when taking fundus images of the right eye (see Figures 4 and 5).

[0066] The forehead support frame 32 has a left-eye forehead support surface 32a that the subject H's forehead rests against during left-eye fundus photography, and a right-eye forehead support surface 32b that the subject H's forehead rests against during right-eye fundus photography. The left-eye forehead support surface 32a and the right-eye forehead support surface 32b are made of silicone rubber or the like.

[0067] The chin rest 33 has a left-eye chin rest surface 33a that supports the subject H's chin when the left eye is being photographed, and a right-eye chin rest surface 33b that supports the subject H's chin when the right eye is being photographed. The left-eye chin rest surface 33a and the right-eye chin rest surface 33b are each concave curved surfaces corresponding to the shape of the chin, and are formed on the chin rest 33 in such a way that they partially overlap each other.

[0068] <Control device detailed configuration> Figure 10 is a functional block diagram of the control device 90. As shown in Figure 10, in addition to the parts of the fundus camera 9 described above, the control device 90 is connected to an image forming unit 120, a data processing unit 130, and a storage unit 131.

[0069] The image forming unit 120 forms a fundus image of the eye under examination E based on the imaging signals output from the fundus image sensors 671L and 671R. The data processing unit 130 performs various image processing, such as brightness correction, on the fundus image of the eye under examination E formed by the image forming unit 120.

[0070] The memory unit 131 is a recording medium (storage medium) that stores the program executed by the control device 90, and various known storage devices are used. The memory unit 131 also stores the fundus image of the eye E under examination.

[0071] The control device 90 includes an arithmetic circuit composed of various processors and memory. These processors include CPUs (Central Processing Units), GPUs (Graphics Processing Units), ASICs (Application Specific Integrated Circuits), and programmable logic devices [e.g., SPLDs (Simple Programmable Logic Devices), CPLDs (Complex Programmable Logic Devices), and FPGAs (Field Programmable Gate Arrays)]. The various functions of the control device 90 may be implemented by a single processor, or by multiple processors of the same or different types.

[0072] The control device 90 functions as a nasal imaging control unit 91A, a nasal position detection unit 91B, a tilt angle determination unit 91C, an alignment detection unit 92, a drive control unit 93, a fixation control unit 94, a fundus imaging control unit 95, and a storage control unit 96 by executing a control program stored in the memory unit 131.

[0073] The nasal imaging control unit 91A, the nasal position detection unit 91B, and the tilt angle determination unit 91C operate before the auto-alignment of the examination head 20 begins to determine the tilt angle θ (see Figure 11) when the examination head 20 is viewed from above in the Y-axis direction and approaches the eye E under examination at an oblique angle during auto-alignment. In addition, the alignment detection unit 92, the drive control unit 93, and the fixation control unit 94 operate during auto-alignment, while the fundus imaging control unit 95 and the storage control unit 96 operate after auto-alignment is completed.

[0074] As described above, each component of the control device 90 functions before, during, and after the auto-alignment of the inspection head 20. Therefore, the method of auto-aligning the inspection head 20 will first be explained with reference to Figure 11. In Figure 11, the symbol "OS" indicates the left eye (Oculus Sinister), and the symbol "OD" indicates the right eye (Oculus Dexter). As shown by the symbol XIA in Figure 11, when the inspection head 20 is moved forward in the Z-axis direction from the frontal position of the eye E (in this case, the left eye OS) during auto-alignment of the inspection head 20, there is a risk that the inspection head 20 (first concave mirror 51) will come into close proximity to the nose N of the subject H.

[0075] Therefore, as shown by reference numeral XIB in Figure 11, in the fundus camera 9 of this embodiment, when the examination head 20 is auto-aligned, the examination head 20 is approached from an oblique direction when viewed from one direction in the Y-axis direction (for example, the upper side in the Y-axis direction).

[0076] Specifically, the reference axis VA is defined as an axis parallel to the Z-axis and passing through the eye under examination E (for example, its center). The outward direction X1 is defined as the direction away from the nose N with respect to the eye under examination E (in this case, the left eye OS) in the X-axis direction. The tilt axis TA is defined as the axis obtained by tilting the reference axis VA outward by an angle θ with respect to the eye under examination E as the center. The examination head 20 is then displaced along the tilt axis TA to an examination position (hereinafter simply referred to as the examination position) where fundus photography of the eye under examination E can be performed when viewed from above in the Y-axis direction. "Displacement" here includes movement and rotation of the examination head 20 in the XYZ axis directions.

[0077] The determination of the inclination angle θ of the tilt axis TA with respect to the reference axis VA when viewed from above in the Y-axis direction (in the XZ plane) is performed under the control of the nasal imaging control unit 91A, the nasal position detection unit 91B, and the inclination angle determination unit 91C. Specifically, the nasal imaging control unit 91A controls the imaging of the nose N using one of the stereo cameras 81L or 81R, and the nasal position detection unit 91B detects the position of the nose N, after which the inclination angle θ is determined by the inclination angle determination unit 91C. Here, "one of the stereo cameras 81L or 81R" refers to stereo camera 81L when imaging the fundus of the left eye OS, and stereo camera 81R when imaging the fundus of the right eye OD (the same applies hereafter).

[0078] Figure 12 is an explanatory diagram illustrating the simultaneous imaging process of the subject eye E (left eye OS, right eye OD) using stereo cameras 81L and 81R. Note that the stereo cameras 81L and 81R are shown in a simplified form in Figure 12.

[0079] As shown in Figure 12, the nasal imaging control unit 91A drives the X-axis drive unit 14, the Z-axis drive unit 15, and the Y-axis drive unit 16 to adjust the position of the examination head 20, for example, when the examination start operation for the eye E to be examined is performed on the control panel 40, before the auto-alignment of the examination head 20 begins.

[0080] Specifically, when performing fundus photography of the left eye OS, the nasal imaging control unit 91A moves the examination head 20 to a position where all cameras 81a constituting the stereo camera 81L can capture images of the nose N (see code XIIA in Figure 12). Also, when performing fundus photography of the right eye OD, the nasal imaging control unit 91A moves the examination head 20 to a position where all cameras 81a constituting the stereo camera 81R can capture images of the nose N (see code XIIB in Figure 12).

[0081] For example, the nasal imaging control unit 91A estimates the three-dimensional position coordinates of the subject H's nose N during fundus imaging of the left eye OS and the right eye OD, based on the XYZ position coordinates of each forehead support surface 32a, 32b and each chin support surface 33a, 33b. Alternatively, the nasal imaging control unit 91A causes one of the stereo cameras 81L, 81R to capture the subject H's face. The nasal imaging control unit 91A then estimates the three-dimensional position coordinates of the nose N by detecting the positions of the subject H's facial features (subject eye E, nose N, mouth, eyebrows, etc.) from the facial images captured by each camera 81a using a known method. Examples of methods for detecting the image of the nose N from the facial images include identifying the nose contour from the background of the facial image, identifying the cheek contour of the subject H from this background, or identifying the nostrils of the nose N from the facial image.

[0082] Next, the nose imaging control unit 91A detects a simultaneous imaging position (hereinafter simply referred to as the simultaneous imaging position) which is an imaging position in which the nose N can be imaged by all cameras 81a of one of the stereo cameras 81L and 81R, based on the estimated three-dimensional position coordinates of the nose N and the known imaging conditions of the stereo cameras 81L and 81R (imaging angle of view, direction of the imaging optical axis).

[0083] Then, if the nasal imaging control unit 91A can detect the simultaneous imaging position, it drives the X-axis drive unit 14, the Z-axis drive unit 15, and the Y-axis drive unit 16 to adjust the position of the examination head 20 to the simultaneous imaging position. Note that "position adjustment" here also includes not moving the examination head 20 if the initial position of the examination head 20 when the fundus camera 9 is powered on satisfies the conditions for the simultaneous imaging position. After the nasal imaging control unit 91A has finished adjusting the position of the examination head 20 to the simultaneous imaging position, it performs simultaneous imaging of the nose N using all cameras 81a of one of the stereo cameras 81L, 81R.

[0084] In this case, depending on the shape of the inspection head 20 including the concave mirror unit 50, the arrangement of each camera 81a in the stereo cameras 81L and 81R, and the shooting conditions of the stereo cameras 81L and 81R, the nasal imaging control unit 91A may not be able to detect the simultaneous shooting position, or it may be impossible to move the inspection head 20 to the simultaneous shooting position. In this case, it is not possible to simultaneously photograph the nose N with one of the cameras 81a of the stereo cameras 81L and 81R.

[0085] In such cases, the nasal imaging control unit 91A performs segmented imaging, which divides the imaging of the nose N by one of the stereo cameras 81L and 81R into multiple non-simultaneous shots.

[0086] Figure 13 is an explanatory diagram illustrating an example of segmented imaging by a stereo camera 81L during fundus imaging of the left eye OS. As shown by symbols XIIIA and XIIIB in Figure 13, the nasal imaging control unit 91A performs segmented imaging processing and position information acquisition processing for each camera 81a of the stereo camera 81L. If the stereo camera 81L consists of three or more cameras 81a, the segmented imaging processing and position information acquisition processing are performed for one or more cameras 81a.

[0087] The segmented imaging process involves the nasal imaging control unit 91A driving the X-axis drive unit 14, Z-axis drive unit 15, and Y-axis drive unit 16 to adjust the position of the inspection head 20 to a segmented imaging position (hereinafter referred to as the segmented imaging position), which is an imaging position where the nose N can be imaged with some (at least one) of the cameras 81a, and then causing the nose N to be imaged by these some cameras 81a. The position information acquisition process involves the nasal imaging control unit 91A acquiring the imaging position information (3D coordinates) of some of the cameras 81a that imaged the nose N in the segmented imaging process, based on the 3D position coordinates of the inspection head 20 at the time of execution of the segmented imaging process and the known position information of each camera 81a within the inspection head 20.

[0088] The nasal imaging control unit 91A then repeats the above-described segmented imaging process and position information acquisition process until imaging of the nose N by all cameras 81a is completed. This allows for obtaining images of the nose N for each camera 81a, as well as imaging position information for each camera 81a. Although not shown in the diagram, the segmented imaging process and position information acquisition process are similarly repeated for one or more cameras 81a when performing segmented imaging with the stereo camera 81R during fundus imaging of the right eye OD.

[0089] Returning to Figure 10, when the stereo cameras 81L and 81R simultaneously photograph the nose N, the nose position detection unit 91B detects relative position information (3D coordinates, etc.) indicating the relative position of the nose N (e.g., the tip of the nose) in the XYZ axis directions relative to the inspection head 20, based on the images of the nose N captured by each camera 81a. Note that the method for detecting the relative position of various objects using the stereo cameras 81L and 81R is a known technique (see, for example, Patent Document 2), so a detailed explanation is omitted here. The nose position detection unit 91B then outputs the relative position information of the nose N to the tilt angle determination unit 91C.

[0090] On the other hand, when the stereo cameras 81L and 81R capture images of the nose N in segments, the nose position detection unit 91B detects the relative position information of the nose N with respect to the inspection head 20 based on the captured image and shooting position information of the nose N for each camera 81a, and outputs this relative position information to the tilt angle determination unit 91C. In this case, the nose position detection unit 91B, for example, converts the captured images of the nose N for each camera 81a into images captured at the same shooting position based on the shooting position information for each camera 81a, and detects the relative position information of the nose N based on each of the converted captured images.

[0091] Figure 14 is an explanatory diagram illustrating an example of how the tilt angle determination unit 91C determines the tilt angle θ. As shown in Figure 14, the tilt angle determination unit 91C determines the tilt angle θ based on the relative position information of the nose N input from the nose position detection unit 91B.

[0092] For example, the tilt angle determination unit 91C calculates the nasal distance Nd, which is the distance (shortest distance) between the examination head 20 and the nose N when the examination head 20 is brought close to the eye E under examination to a predetermined working distance d, for each of several different tilt angles θ as shown by symbols XIVA to XIVC in Figure 14, based on the relative position information of the nose N. Then, based on the nasal distance Nd for each of the multiple tilt angles θ, the tilt angle determination unit 91C determines, for example, the smallest tilt angle θ among the tilt angles θ for which the nasal distance Nd is equal to or greater than a predetermined threshold, as the tilt angle θ during auto-alignment.

[0093] Returning to Figure 10, the alignment detection unit 92 detects the relative position of the eye E with respect to the inspection head 20 by determining the pupil center position of the eye E and calculating the three-dimensional coordinates of this pupil center position, based on the anterior segment image of the eye E taken stereoscopically by one of the cameras 81a of the stereo cameras 81L and 81R during the auto-alignment of the inspection head 20. Note that the method of alignment detection using stereo cameras 81L and 81R is a known technique (see Patent Document 2 above), so a detailed explanation is omitted here.

[0094] The drive control unit 93 controls the drive of each drive unit 14-17, 35, 55, 69, 77-79 of the fundus camera 9. The drive control unit 93 then drives the X-axis drive unit 14, the Z-axis drive unit 15, the Y-axis drive unit 16, and the swing rotation drive unit 17 to align the examination head 20 with the eye to be examined E, and to switch the eye to be examined (switching between left and right eyes). In addition, before the alignment of the examination head 20 is completed, the drive control unit 93 drives the unit rotation drive unit 55 to rotate the concave mirror unit 50 to the first position (when photographing the left eye OS) or the second position (when photographing the right eye OD).

[0095] Alignment of the inspection head 20 includes automatic alignment and manual alignment. Automatic alignment is performed by automatically driving the X-axis drive unit 14, Z-axis drive unit 15, Y-axis drive unit 16, and swing rotation drive unit 17. Manual alignment is performed by driving the X-axis drive unit 14, Z-axis drive unit 15, Y-axis drive unit 16, and swing rotation drive unit 17 in response to the inspector's input to the control panel 40. Switching between automatic and manual alignment is performed on the control panel 40.

[0096] During auto-alignment, the drive control unit 93 determines the tilt axis TA corresponding to the tilt angle θ initially determined by the tilt angle determination unit 91C.

[0097] For example, the drive control unit 93 first stereo-captures the face of the subject H (such as the eye E or nose N) using one of the stereo cameras 81L or 81R and determines the reference axis VA based on the captured image. Alternatively, the drive control unit 93 estimates the reference axis VA based on the Y-axis position of the chin rest 33 and known discrimination information for the left eye OS and right eye OD. Then, the drive control unit 93 determines the tilt axis TA as an axis tilted by an angle θ in the outward direction X1 of the reference axis VA, with the eye E as the center.

[0098] Next, the drive control unit 93 drives the X-axis drive unit 14, the Z-axis drive unit 15, the Y-axis drive unit 16, and the swing rotation drive unit 17 to start auto-alignment, which automatically displaces the inspection head 20 from the initial position when the fundus camera 9 is powered on to the inspection position.

[0099] Figure 15 is an explanatory diagram illustrating a first example of auto-alignment of the inspection head 20 in the first embodiment. As shown by the reference numeral XVA in Figure 15, in its initial position, the inspection head 20 is located at the center of its movable range in the X-axis direction (including the approximate center position or the position facing the face support portion 30) and at a retracted position in the Z-axis direction, moved backward in the Z-axis direction from the subject H. When the inspection head 20 is in its initial position, the central axis CL of the inspection head 20 coincides with the aforementioned center position when viewed from above in the Y-axis direction.

[0100] First, the drive control unit 93 drives the X-axis drive unit 14 to perform a first drive process that moves the inspection head 20 outward in the X1 direction from its initial position to the inclination axis TA when viewed from above in the Y-axis direction.

[0101] As shown by the symbol XVB in Figure 15, the drive control unit 93 drives the swing rotation drive unit 17 after the completion of the first drive process to perform a second drive process that rotates the inspection head 20 by an inclination angle θ around the rotation axis 21 (see arrow R). As a result, as shown by the symbol XVC in Figure 15, the central axis CL of the inspection head 20 becomes parallel to the inclination axis TA. Note that the second drive process may be performed before the first drive process.

[0102] Next, after the completion of the second drive process, the drive control unit 93 drives the X-axis drive unit 14 and the Z-axis drive unit 15 to start a third drive process that moves the inspection head 20 to the inspection position along the tilt axis TA when viewed from above in the Y-axis direction (see arrow XZ1). As a result, the inspection head 20 is moved toward the eye E to be examined while maintaining a constant tilt angle θ (including approximately constant, the same applies hereinafter).

[0103] During this auto-alignment process, the inspection head 20 is displaced to a position where the alignment detection unit 92 can identify the pupil center position of the left eye OS, i.e., a position where alignment can be detected, based on the stereo camera 81L capturing an anterior segment image of the left eye OS. As a result, the alignment detection result is input from the alignment detection unit 92 to the drive control unit 93. In addition, to enable alignment detection by the alignment detection unit 92, the Y-axis drive unit 16 may perform Y-axis position adjustment of the inspection head 20 before alignment detection (at any stage from the first to the third drive process).

[0104] As shown by the symbol XVD in Figure 15, the drive control unit 93 drives the X-axis drive unit 14, the Z-axis drive unit 15, and the Y-axis drive unit 16 based on the alignment detection result input from the alignment detection unit 92, and continues the third drive process until the inspection head 20 reaches the inspection position. In this third drive process performed based on the alignment detection result, the position of the inspection head 20 in the Y-axis direction is also adjusted.

[0105] Figure 16 is an explanatory diagram illustrating the first and second examples of auto-alignment of the inspection head 20 in the first embodiment. The drive control unit 93 drives the X-axis drive unit 14 and the Z-axis drive unit 15 to first move the inspection head 20 forward in the Z-axis direction (towards the subject H) by a predetermined distance, as shown by the symbol XVIA in Figure 16 (see arrow Z1), and then executes a first drive process to move the inspection head 20 outward in the inclination axis TA in the X1 direction, as shown by the symbol XVIB in Figure 16. The distance the inspection head 20 moves forward in the Z-axis direction is not particularly limited as long as a safe distance can be secured between the inspection head 20 (first concave mirror 51) and the nose N. For example, the distance in the Z-axis direction from the inspection head 20 to the nose N may be calculated based on the captured image obtained by stereo imaging of the nose N with the stereo camera 81L, and the movement distance may be determined based on this calculation result.

[0106] By first moving the inspection head 20 forward in the Z-axis direction and then moving it outward in the X1 direction to the tilt axis TA, the distance the inspection head 20 needs to travel outward in the X1 direction can be reduced compared to the example 1-1 shown in Figure 15 described above.

[0107] As shown by the symbol XVIC in Figure 16, the drive control unit 93 drives the swing rotation drive unit 17 after the completion of the first drive process and performs a second drive process similar to the first example described above (see symbol XVB in Figure 15), thereby making the central axis CL parallel to the tilt axis TA. In the first example as well, the second drive process may be performed before the first drive process.

[0108] As shown by the symbol XVID in Figure 16, after the completion of the second drive process, the drive control unit 93 drives the X-axis drive unit 14 and the Z-axis drive unit 15 to perform the third drive process in the same manner as in the previously described 1-1 example (see symbols XVC and XVD in Figure 15), thereby moving the inspection head 20 to the inspection position along the inclination axis TA when viewed from above in the Y-axis direction. Then, as shown by the symbol XVIE in Figure 16, the drive control unit 93 drives the X-axis drive unit 14, the Z-axis drive unit 15 and the Y-axis drive unit 16 based on the alignment detection result detected by the alignment detection unit 92 during the auto-alignment process, and continues the third drive process until the inspection head 20 reaches the inspection position.

[0109] Figure 17 is an explanatory diagram illustrating the first to third examples of auto-alignment of the inspection head 20 in the first embodiment. As shown by the labels XVIIA and XVIIB in Figure 17, the drive control unit 93 drives the X-axis drive unit 14, the Z-axis drive unit 15, the Y-axis drive unit 16, and the swing rotation drive unit 17 to perform a first drive process that simultaneously moves the inspection head 20 forward and outward in the Z-axis direction X1 and rotates the inspection head 20 by an inclination angle θ (see arrows XZ2 and R). This allows the inspection head 20 to be moved diagonally to the inclination axis TA when viewed from above in the Y-axis direction, and the central axis CL to be parallel to the inclination axis TA.

[0110] In the first drive process of the first to third examples, the inspection head 20 may be displaced along the tilt axis TA by the shortest distance to a position where the stereo camera 81L can capture images of the anterior segment of the left eye OS.

[0111] As shown by the symbol XVIIC in Figure 17, the drive control unit 93 drives the X-axis drive unit 14, the Z-axis drive unit 15, and the Y-axis drive unit 16 after the completion of the first drive process to execute the second drive process. The second drive process in the first to third examples is the same as the third drive process in the previously described "first to first example" and "first to second example," and moves the inspection head 20 to the inspection position along the inclination axis TA when viewed from above in the Y-axis direction. Then, as shown by the symbol XVIID in Figure 17, the drive control unit 93 drives the X-axis drive unit 14, the Z-axis drive unit 15, and the Y-axis drive unit 16 based on the alignment detection result detected by the alignment detection unit 92 during the auto-alignment, and continues the second drive process until the inspection head 20 reaches the inspection position.

[0112] Returning to Figure 10, once fundus photography of the eye E by the imaging optical system 60 is complete, the drive control unit 93 drives the Z-axis drive unit 15 to retract the examination head 20 by a predetermined distance to the rear (examiner side) in the Z-axis direction (see symbols XXID and XXIG in Figure 21, described later).

[0113] The fixation control unit 94 causes the fixation light projection system 770 to project fixation light onto the eye E by the subject eye E, at least from the start of auto-alignment of the examination head 20 until fundus photography of the eye E by the examination head 20 is completed. This allows the subject H's line of sight to be guided and fixed in the direction of the fixation light while the examination head 20 is moved from the initial position through the tilt axis TA to the examination position during auto-alignment. For example, when the examination head 20 is moved from the initial position to the tilt axis TA, the eye E can be rotated to follow this movement. As a result, the line of sight of the eye E can always be fixed to the examination head 20.

[0114] After the auto-alignment of the examination head 20 is completed, the fundus imaging control unit 95 controls the fundus imaging of the eye E under examination using the fundus camera 9. For example, the fundus imaging control unit 95 drives the focusing drive unit 69 in a known manner to focus the imaging optical system 60 (left eye imaging optical system 60L or right eye imaging optical system 60R) on the fundus of the eye E under examination, and also drives the slit drive unit 77 in a known manner to perform focusing control to focus the illumination light (slit light) on the fundus of the eye E under examination.

[0115] Next, the fundus imaging control unit 95 controls the scanner drive unit 78 and the imaging optical system 60 (left eye imaging optical system 60L or right eye imaging optical system 60R) in a known manner to perform slit scan imaging of the fundus, which includes scanning of the slit light on the fundus by the galvanoscanner 37 and fundus imaging at each scanning position of the slit light by the imaging optical system 60. As a result, the image forming unit 120 forms a fundus image of the eye under examination E based on the imaging signal output from one of the fundus image sensors 671L or 671R during the slit scan imaging, and the data processing unit 130 performs various image processing on this fundus image.

[0116] The storage control unit 96 displays the fundus image of the eye E after image processing by the data processing unit 130 on the control panel 40. Furthermore, if the examiner inputs an image saving operation to the control panel 40, the storage control unit 96 saves the fundus image of the eye E to the storage unit 131.

[0117] [Operation of the ophthalmic device of the first embodiment] Figure 18 is a flowchart showing the flow of the examination process of the eye E being examined using the fundus camera 9 of the first embodiment of the above configuration. As shown in Figure 18, with the subject H already resting their chin on the chin rest 33 and their forehead against the forehead support frame 32, the examiner operates the control panel 40 to adjust the height position (Y-axis position) of the chin rest 33 to match the subject H. The examiner also operates the control panel 40 to select the auto-alignment mode as the alignment mode for the examination head 20. Furthermore, the fixation control unit 94 starts projecting fixation light onto the eye E being examined using the fixation light projection system 770. This allows the gaze direction of the eye E being examined to be guided and fixed.

[0118] Furthermore, the examiner operates the control panel 40 to select, for example, the left eye OS (or right eye OD) as the eye to be examined E. In response to this selection, the drive control unit 93 drives the unit rotation drive unit 55 to rotate the concave mirror unit 50 to the first position corresponding to the left eye OS (see Figure 4) (step S1). Note that this step S1 may be performed simultaneously with the auto-alignment of the examination head 20 (step S3).

[0119] When the examiner inputs an operation to start the examination to the control panel 40, the nasal imaging control unit 91A, the nasal position detection unit 91B, and the tilt angle determination unit 91C are activated first, and the process of determining the tilt angle θ begins (step S2).

[0120] Figure 19 is a flowchart showing the process for determining the tilt angle θ in relation to the operation method of the ophthalmic device of the present invention. As shown in Figure 19, the nasal imaging control unit 91A drives the X-axis drive unit 14, the Z-axis drive unit 15, and the Y-axis drive unit 16 to adjust the position of the examination head 20 (step S2A).

[0121] At this time, the nasal imaging control unit 91A estimates the three-dimensional position coordinates of the nose N of the subject H based on the Y-axis positions of the chin rest 33 and each forehead rest surface 32a, 32b, or by analyzing the captured images obtained by capturing the subject H's face with the stereo camera 81L. Next, the nasal imaging control unit 91A performs simultaneous shooting position detection based on the estimated three-dimensional position coordinates of the nose N and the known shooting conditions of each camera 81a.

[0122] Next, if the nasal imaging control unit 91A detects a simultaneous imaging position in which the examination head 20 can be moved, it adjusts the position of the examination head 20 to the simultaneous imaging position using the X-axis drive unit 14, Z-axis drive unit 15, and Y-axis drive unit 16 (YES in step S2B). Then, the nasal imaging control unit 91A causes all cameras 81a of the stereo camera 81L to simultaneously image the nose N and outputs the image of the nose N from each camera 81a to the nasal position detection unit 91B (step S2C, corresponding to the nasal imaging control step of the present invention).

[0123] On the other hand, if the nasal imaging control unit 91A cannot detect a simultaneous imaging position in which the examination head 20 can be moved (NO in step S2B), it drives the X-axis drive unit 14, the Z-axis drive unit 15, and the Y-axis drive unit 16 to adjust the position of the examination head 20 to the segmented imaging position, and then performs segmented imaging processing to image the nose N with some of the cameras 81a (step S2D). At the same time, the nasal imaging control unit 91A also performs position information acquisition processing to acquire the imaging position information of some of the cameras 81a that have imaged the nose N in the segmented imaging processing (step S2D).

[0124] The nose imaging control unit 91A then repeats the above-described segmented imaging process and position information acquisition process until imaging of the nose N by all cameras 81a is completed (YES in step S2E, corresponding to step S2D, the nose imaging control step of the present invention). As a result, imaging of the nose N by all cameras 81a is performed in multiple stages, and the image of the nose N captured by each camera 81a and the position information of the captured image are output to the nose position detection unit 91B (NO in step S2E).

[0125] When the nose N is simultaneously photographed by the stereo camera 81L, the nose position detection unit 91B detects the relative position information of the nose N with respect to the inspection head 20 based on the images of the nose N taken by each camera 81a and outputs this relative position information to the tilt angle determination unit 91C (step S2F). Furthermore, when the nose N is photographed in segments by the stereo camera 81L, the nose position detection unit 91B detects the relative position information of the nose N based on the images of the nose N taken by each camera 81a and the position information of the images taken by each camera 81a and outputs this relative position information to the tilt angle determination unit 91C (step S2F). Note that step S2F corresponds to the nose position detection step of the present invention.

[0126] Next, the tilt angle determination unit 91C calculates the nasal distance Nd for each of several different tilt angles θ based on the relative position information of the nose N, as shown in Figure 14 (step S2G). Then, based on the calculation results of the nasal distance Nd for each of the multiple tilt angles θ, the tilt angle determination unit 91C determines the tilt angle θ for auto-alignment by selecting the smallest tilt angle θ among the tilt angles θ for which the nasal distance Nd is greater than or equal to a predetermined threshold (step S2H, corresponding to the tilt angle determination step of the present invention). This prevents the inspection head 20 from approaching the nose N during auto-alignment while minimizing the amount of movement of the inspection head 20.

[0127] Returning to Figure 18, once the tilt angle determination unit 91C has completed determining the tilt angle θ, the auto-alignment of the examination head 20 with respect to the eye E under examination is performed (step S3).

[0128] Figure 20 is a flowchart showing the flow of the auto-alignment process of the examination head 20 related to the operation method (drive control step) of the ophthalmic device of the present invention. Figure 21 is an explanatory diagram for explaining the displacement of the examination head 20 after the start of auto-alignment. Here, the eye under examination E is the left eye OS, and the explanation will be given using the case where the auto-alignment described in "Example 1-1" in Figure 15 above is performed as an example.

[0129] As shown in Figures 20 and 21, the drive control unit 93 determines the tilt axis TA based on the tilt angle θ determined by the tilt angle determination unit 91C, and then starts the auto-alignment of the inspection head 20.

[0130] First, the drive control unit 93 drives the X-axis drive unit 14 to perform a first drive process that moves the inspection head 20 outward in the direction X1 from its initial position to the tilt axis TA when viewed from above in the Y-axis direction (step S3A). At the same time, the alignment detection unit 92 starts stereo imaging with the stereo camera 81L and continuously performs the acquisition of images from the stereo camera 81L and the analysis of each captured image (step S3B).

[0131] Next, the drive control unit 93 drives the swing rotation drive unit 17 to rotate the inspection head 20 around the rotation axis 21 by an inclination angle θ, performing a second drive process (step S3C) to make the central axis CL of the inspection head 20 parallel to the inclination axis TA. As a result, the inspection head 20 is displaced from the initial position shown by the symbol XXIA in Figure 21 to the inclination axis TA as shown by the symbol XXIB, and the central axis CL becomes parallel to the inclination axis TA. Furthermore, by projecting fixation light by the fixation light projection system 770, the line of sight direction of the eye under examination E (left eye OS) can also be made to follow the displacement of the inspection head 20.

[0132] Then, the drive control unit 93 drives the X-axis drive unit 14 and the Z-axis drive unit 15 to start a third drive process (step S3D) which moves the inspection head 20 to the inspection position along the inclination axis TA when viewed from above in the Y-axis direction, as shown by the numeral XXIC in Figure 21.

[0133] While the first to third drive processes are being executed, the alignment detection unit 92 waits for alignment detection until the pupil center position of the left eye OS can be determined from the captured image acquired from the stereo camera 81L (NO in step S3E). Then, during auto-alignment, the stereo camera 81L captures the anterior segment of the left eye OS, and this anterior segment image of the left eye OS is input to the alignment detection unit 92 as an captured image from the stereo camera 81L. As a result, the alignment detection unit 92 can determine the pupil center position of the left eye OS based on the anterior segment image input from the stereo camera 81L (YES in step S3E).

[0134] Next, the alignment detection unit 92 performs alignment detection by converting the pupil center position of the left eye OS into three-dimensional coordinates, thereby detecting the relative position of the left eye OS with respect to the inspection head 20 (step S3F). The alignment detection unit 92 then outputs the detection result of the alignment detection to the drive control unit 93.

[0135] The drive control unit 93 drives the X-axis drive unit 14, Z-axis drive unit 15, and Y-axis drive unit 16 based on the alignment detection result input from the alignment detection unit 92, and continues the third drive process until the inspection head 20 reaches the inspection position. Specifically, the drive control unit 93 calculates the difference between the 3D coordinates of the inspection position (target coordinates) determined based on the alignment detection result and the current 3D coordinates of the inspection head 20 (current coordinates), and continues the third drive process until this difference falls below a threshold (steps S3G, S3H, and S3I). As a result, the inspection head 20 is moved to the inspection position while maintaining the tilt angle θ.

[0136] The drive control unit 93 stops driving the X-axis drive unit 14, Z-axis drive unit 15, and Y-axis drive unit 16 and terminates auto-alignment when the difference between the target coordinates and the current coordinates falls below a threshold (YES in step S3H). By displacing the inspection head 20 along the tilt axis TA to the inspection position during auto-alignment in this way, the inspection head 20 (first concave mirror 51) is prevented from coming too close to the nose N.

[0137] Figure 22 is a flowchart showing a modified version of the auto-alignment process of the inspection head 20. In Figure 20, alignment detection is performed by the alignment detection unit 92 during the auto-alignment process. However, even when the inspection head 20 reaches an area where alignment detection is possible, the alignment detection unit 92 may be unable to detect the alignment.

[0138] As shown in Figure 22, the drive control unit 93 determines that alignment is undetectable if the alignment detection unit 92 cannot identify the pupil center position of the left eye OS while the inspection head 20 is moving for a predetermined period of time or distance from the start of auto-alignment or the start of the third drive process (NO in step S3E, YES in step S3J). In this case, the drive control unit 93 switches the alignment mode of the inspection head 20 from auto-alignment mode to manual alignment mode and displays this fact on the control panel 40 (step S3K). This allows the examiner to operate the control panel 40 to perform manual alignment of the inspection head 20. By making it possible to switch to manual alignment in the middle of auto-alignment in this way, the inspection head 20 is prevented from approaching the face of the subject H while alignment is undetectable.

[0139] Returning to Figures 18 and 21, once auto-alignment is complete, the fundus imaging control unit 95 drives the focus drive unit 69 and the slit drive unit 77 in a known manner to perform focus control to adjust the focus of the imaging optical system 60 (in this case, the left eye imaging optical system 60L) and the illumination light (slit light) to the fundus of the left eye OS (step S4). Next, the fundus imaging control unit 95 controls the scanner drive unit 78 and the left eye imaging optical system 60L in a known manner to perform slit scan imaging of the fundus of the left eye OS (step S5).

[0140] Then, the image forming unit 120 forms a fundus image of the left eye OS based on the imaging signal output from the fundus image sensor 671L during slit scan imaging, and the data processing unit 130 performs various image processing on the fundus image of the left eye OS. This fundus image of the left eye OS is output from the data processing unit 130 to the storage control unit 96.

[0141] Meanwhile, once fundus imaging of the left eye OS is complete, the drive control unit 93 drives the Z-axis drive unit 15 to retract the inspection head 20 to the rear in the Z-axis direction, as shown by the symbol XXID in Figure 21 (step S6).

[0142] If fundus photography of the right eye OD is to be performed next, the processes from step S1 to step S7 are repeated (YES in step S8). In this case, under the control of the drive control unit 93, the concave mirror unit 50 is rotated to a second position corresponding to the right eye OD (see Figure 5). The examination head 20 is also displaced to the tilt axis TA corresponding to the right eye OD (see code XXIE in Figure 21), and then moved along the tilt axis TA to the examination position of the right eye OD (see code XXIF in Figure 21). Once fundus photography of the right eye OD is completed, under the control of the drive control unit 93, the examination head 20 is retracted to the rearward side in the Z-axis direction (see code XXIG in Figure 21), and then displaced back to the initial position (see code XXIH in Figure 21).

[0143] As described above, in the fundus camera 9 of the first embodiment, the tilt angle θ is determined based on the image captured by one of the stereo cameras 81L, 81R, which captures the nose N, and during auto-alignment, the examination head 20 can be moved along the tilt axis TA tilted by the tilt angle θ to the examination position of the eye E under examination. This makes it possible to always ensure a sufficient distance between the examination head 20 and the nose N compared to when the examination head 20 is moved from the frontal position of the eye E under examination to the examination position on the Z-axis forward side (see reference numeral XIA in Figure 11). As a result, the examination of the eye E under examination can be performed with the examination head 20 without bringing the examination head 20 (first concave mirror 51) close to the nose N.

[0144] [Second Embodiment] Figure 23 is a side view of the main part of the fundus camera 9 of the second embodiment. In the fundus camera 9 of the first embodiment described above, the inspection head 20 is rotated (swinged) by a swing rotation drive unit 17 around a rotation axis 21 provided on the lower side of the inspection head 20 in the Y-axis direction. However, as shown in Figure 23, the position of the rotation axis 21 is different in the fundus camera 9 of the second embodiment compared to the first embodiment.

[0145] The fundus camera 9 of the second embodiment has basically the same configuration as the fundus camera 9 of the first embodiment, except that the position of the rotation axis 21 is different. For this reason, parts that are functionally or structurally identical to those of the fundus camera 9 of the first embodiment are denoted by the same reference numerals and their descriptions are omitted.

[0146] In the second embodiment, the swing rotation drive unit 17 and the rotation axis 21 are located closer to the eye under examination E than the examination head 20, that is, on the Z-axis forward side of the examination head 20. This allows the rotation axis 21 and the eye under examination E (center of rotation) to be aligned when viewed from above in the Y-axis direction by adjusting the XZ position of the swing rotation drive unit 17 using the X-axis drive unit 14 and the Z-axis drive unit 15. In this case, the swing rotation drive unit 17 rotates (swings) the examination head 20 around the center of rotation of the eye under examination E.

[0147] The control device 90 of the second embodiment is basically the same as the control device 90 of the first embodiment, except that the method of auto-aligning the inspection head 20 by the drive control unit 93 is different from that of the first embodiment.

[0148] In the second embodiment, the drive control unit 93, similar to the first embodiment, determines the tilt axis TA based on the tilt angle θ determined by the tilt angle determination unit 91C, and then drives the X-axis drive unit 14, Z-axis drive unit 15, Y-axis drive unit 16 and swing rotation drive unit 17 to perform auto-alignment of the inspection head 20.

[0149] Figure 24 is an explanatory diagram illustrating a second-first example of auto-alignment of the inspection head 20 in the second embodiment. As indicated by reference numeral XXIVA in Figure 24, the inspection head 20 is initially positioned in the same initial position as in the first embodiment.

[0150] Next, as shown by the symbols XXIVA and XXIVB in Figure 24, the drive control unit 93 drives the X-axis drive unit 14 and the Z-axis drive unit 15 to perform a first drive process that moves the inspection head 20 (swing rotation drive unit 17 and rotation axis 21) from its initial position in the XZ axis direction (see arrow XZ2). Specifically, the inspection head 20 is moved in the XZ axis direction until the rotation axis 21 coincides with the rotation center of the eye E being examined when viewed from above in the Y axis direction.

[0151] After the completion of the first drive process, the drive control unit 93 drives the swing rotation drive unit 17 to perform a second drive process that rotates the examination head 20 by an inclination angle θ around the rotation axis 21 (the rotation center of the eye under examination E), as shown by the symbol XXIVB in Figure 24 (see arrow R). As a result, as shown by the symbol XXIVC in Figure 24, the examination head 20 moves to the inclination axis TA and the central axis CL becomes parallel to the inclination axis TA.

[0152] Next, after the completion of the second drive process, the drive control unit 93 drives the X-axis drive unit 14 and the Z-axis drive unit 15 to start a third drive process that moves the inspection head 20 to the inspection position along the inclination axis TA when viewed from above in the Y-axis direction, similar to the first embodiment (see arrow XZ1). As a result, the inspection head 20 is moved toward the eye to be examined E while maintaining a constant inclination angle θ.

[0153] Then, as shown by the symbol XXIVD in Figure 24, the drive control unit 93 drives the X-axis drive unit 14, the Z-axis drive unit 15, and the Y-axis drive unit 16 based on the alignment detection result detected by the alignment detection unit 92 during auto-alignment, and continues the third drive process until the inspection head 20 reaches the inspection position.

[0154] As explained in Figure 22 above, if the alignment detection unit 92 is unable to perform alignment detection while the inspection head 20 is moving for a predetermined period of time or distance from the start of auto-alignment or the start of the third drive process, the drive control unit 93 switches the alignment mode of the inspection head 20 to manual alignment mode.

[0155] Figure 25 is an explanatory diagram illustrating a second-second example of auto-alignment of the inspection head 20 in the second embodiment. As shown by the reference numerals XXVA and XXVB in Figure 25, the drive control unit 93 simultaneously drives the X-axis drive unit 14, the Z-axis drive unit 15, the Y-axis drive unit 16, and the swing rotation drive unit 17 to perform a first drive process that simultaneously moves the inspection head 20 in the XZ axis direction (see arrow XZ2) and rotates the inspection head 20 by an inclination angle θ (see arrow R). Note that the first drive process in the second-second example is a process that simultaneously performs the first and second drive processes of the "second-first example" described in Figure 24. As a result, the inspection head 20 is moved to the inclination axis TA, and the central axis CL of the inspection head 20 becomes parallel to the inclination axis TA.

[0156] In the first drive process, the inspection head 20 may be displaced along the tilt axis TA by the shortest distance to a position where one of the stereo cameras 81L or 81R can capture the anterior segment of the eye E (in this case, the left eye OS).

[0157] Then, after the completion of the first drive process, the drive control unit 93 drives the X-axis drive unit 14, the Z-axis drive unit 15, and the Y-axis drive unit 16 to perform a second drive process similar to the third drive process in the previously described "Example 2-1," thereby moving the inspection head 20 to the inspection position along the inclination axis TA when viewed from above in the Y-axis direction (see arrow XZ1). Then, as shown by the reference numeral XXVC in Figure 25, the drive control unit 93 drives the X-axis drive unit 14, the Z-axis drive unit 15, and the Y-axis drive unit 16 based on the alignment detection result detected by the alignment detection unit 92 during the auto-alignment process, and continues the second drive process until the inspection head 20 reaches the inspection position.

[0158] As described above, in the fundus camera 9 of the second embodiment, the same effect as in the first embodiment can be obtained as well, by moving the inspection head 20 along the tilt axis TA from an oblique direction to the inspection position of the eye E under examination during auto-alignment.

[0159] [Third Embodiment] Figure 26 is a side view of the main part of the fundus camera 9 of the third embodiment. In the fundus camera 9 of the first embodiment, the examination head 20 is brought close to the eye under examination E along the tilt axis TA, which is tilted in the X-axis direction (outward direction X1) when the reference axis VA is tilted during the auto-alignment of the examination head 20. In contrast, in the fundus camera 9 of the third embodiment, the examination head 20 is brought close to the eye under examination E along the tilt axis TA, which is tilted in a direction different from the X-axis direction when the reference axis VA is tilted during the auto-alignment of the examination head 20.

[0160] As shown in Figure 26, the fundus camera 9 of the third embodiment has basically the same configuration as the fundus camera 9 of the first embodiment, except that the examination head 20 is rotatable around the axis of rotation shafts 21,140, ​​it is equipped with a tilt rotation drive unit 141, and it performs auto-alignment of the examination head 20, which is different from that of the first embodiment. For this reason, components that are functionally or structurally identical to those of the fundus camera 9 of the first embodiment are denoted by the same reference numerals and their descriptions are omitted.

[0161] The rotating shaft 140 is provided between the bottom surface of the inspection head 20 and the tip of the rotating shaft 21. The rotating shaft 140 is perpendicular to the Y-axis direction and holds the inspection head 20 so that it can rotate freely around the axis perpendicular to the Y-axis direction. This allows the inspection head 20 to rotate (tilt: see arrow TL) around the rotating shaft 140 and to rotate (swing: see arrow SW) around the rotating shaft 21. The configuration of the rotating shafts 21 and 140 is not particularly limited as long as the inspection head 20 can swing and tilt.

[0162] The tilt rotation drive unit 141 corresponds to the rotation mechanism of the present invention. Furthermore, the tilt rotation drive unit 141, together with the X-axis drive unit 14, Z-axis drive unit 15, Y-axis drive unit 16 and swing rotation drive unit 17 described above, constitute the displacement mechanism of the present invention. The tilt rotation drive unit 141 has, for example, a motor, a worm gear, and a motor drive circuit, and rotates (tilts) the inspection head 20 around the rotation axis 140.

[0163] Thus, in the third embodiment, the inspection head 20 can be rotated (swing and tilt) on two axes by the swing rotation drive unit 17 and the tilt rotation drive unit 141. For this reason, in the third embodiment, a direction other than the outward direction X1 of the first embodiment (a direction perpendicular to the Z axis and away from the nose N), for example, upward in the Y axis direction, is defined as "outward direction Y1 (see Figure 27)," and the axis tilted with the reference axis VA tilted in the "outward direction Y1" with the eye E under examination as the center is defined as the tilt axis TA.

[0164] The control device 90 of the third embodiment is basically the same as the control device 90 of the first embodiment, except that the tilt direction of the tilt axis TA is different from that of the first embodiment.

[0165] In the third embodiment, the nasal imaging control unit 91A, the nasal position detection unit 91B, and the tilt angle determination unit 91C determine the tilt angle θ of the tilt axis TA in the outward direction Y1 (see Figure 27) relative to the reference axis VA when viewed from one direction in the X-axis direction, that is, the tilt angle θ of the tilt axis TA relative to the reference axis VA in the YZ plane. The specific method for determining the tilt angle θ is the same as the method for determining the tilt angle θ in the first embodiment, except that the tilt direction of the tilt axis TA is different, so a detailed explanation is omitted here.

[0166] In the third embodiment, the drive control unit 93 determines the tilt axis TA based on the tilt angle θ determined by the tilt angle determination unit 91C, and then drives the X-axis drive unit 14, Z-axis drive unit 15, Y-axis drive unit 16, swing rotation drive unit 17, and tilt rotation drive unit 141 to perform auto-alignment of the inspection head 20.

[0167] Figure 27 is an explanatory diagram illustrating a third example of auto-alignment of the inspection head 20 in the third embodiment. This third example is basically the same as the 1-1 example (see Figure 15) described in the first embodiment, except that the inclination direction of the tilt axis TA is different.

[0168] As shown by reference numeral XXVIIA in Figure 27, the inspection head 20 is initially positioned in the same initial position as in the first embodiment. The drive control unit 93 of the third embodiment drives the X-axis drive unit 14, the Z-axis drive unit 15, and the Y-axis drive unit 16 to perform a first drive process that moves the inspection head 20 outward Y1 (upward in the Y-axis direction) from the initial position to the inclination axis TA when viewed from one side in the X-axis direction.

[0169] As shown by the symbol XXVIIB in Figure 27, the drive control unit 93 drives the tilt rotation drive unit 141 after the completion of the first drive process to perform a second drive process that rotates the inspection head 20 by an inclination angle θ around the rotation axis 140 (see arrow R). As a result, as shown by the symbol XXVIIC in Figure 27, the central axis CL of the inspection head 20 becomes parallel to the inclination axis TA. Note that the second drive process may be performed before the first drive process.

[0170] Next, after the completion of the second drive process, the drive control unit 93 drives the X-axis drive unit 14, the Z-axis drive unit 15, and the Y-axis drive unit 16 to start a third drive process that moves the inspection head 20 to the inspection position along the tilt axis TA when viewed from one direction in the X-axis direction (see arrow YZ1). As a result, the inspection head 20 is moved toward the eye to be examined E while maintaining a constant tilt angle θ.

[0171] Then, as shown by the symbol XXVIID in Figure 27, the drive control unit 93 drives the X-axis drive unit 14, the Z-axis drive unit 15, and the Y-axis drive unit 16 based on the alignment detection result detected by the alignment detection unit 92 during auto-alignment, and continues the third drive process until the inspection head 20 reaches the inspection position.

[0172] In this case, if the alignment detection unit 92 is unable to perform alignment detection while the inspection head 20 is moving for a predetermined period of time or distance from the start of auto-alignment or the start of the third drive process, the drive control unit 93 switches the alignment mode of the inspection head 20 to manual alignment mode (see Figure 22).

[0173] In addition, similar to the first two examples of auto-alignment of the inspection head 20 in the first embodiment (see Figure 16), the inspection head 20 may first be moved a predetermined distance forward in the Z-axis direction (towards the eye E being examined) before starting the first drive process described above. Furthermore, similar to the first three examples of auto-alignment of the inspection head 20 in the first embodiment (see Figure 17), the first drive process may be performed to simultaneously move the inspection head 20 forward in the Z-axis direction and outward in the Y1 direction, and rotate the inspection head 20 by an inclination angle θ.

[0174] As described above, in the fundus camera 9 of the third embodiment, the examination head 20 can be moved along the tilt axis TA from an oblique direction (obliquely upward) to the examination position of the eye E under examination during auto-alignment, thus preventing the examination head 20 (first concave mirror 51) from coming into close proximity to the nose N. As a result, the same effects as in the first embodiment can be obtained.

[0175] In the third embodiment described above, during auto-alignment of the examination head 20, the examination head 20 is brought closer to the eye E by following the tilt axis TA, which is tilted outward Y1 (upward in the Y-axis direction) with the reference axis VA centered on the eye E. However, the tilt direction of this tilt axis TA is not particularly limited as long as it is perpendicular to the Z-axis direction and away from the nose N. Furthermore, the direction and configuration of the rotation axes 21 and 140 can be appropriately changed according to this tilt direction.

[0176] Furthermore, in the fundus camera 9 of the third embodiment described above, if the tilt direction of the tilt axis TA is fixed to the outward direction Y1, the swing rotation drive unit 17 may be omitted.

[0177] [Fourth Embodiment] Next, the fundus camera 9 of the fourth embodiment of the present invention will be described. In the fundus camera 9 of the second embodiment (see Figure 23), during auto-alignment of the examination head 20, the examination head 20 is brought close to the eye E by following the inclination axis TA, which is tilted in the X-axis direction (outward X1) with the reference axis VA as the center of the eye E being examined. In contrast, in the fundus camera 9 of the fourth embodiment, the examination head 20 is brought close to the eye E by following the inclination axis TA, which is tilted in the outward Y1 direction (upward in the Y-axis direction) with the reference axis VA as the center of the eye E being examined, similar to the fundus camera 9 of the third embodiment (see Figures 26 and 27).

[0178] The fundus camera 9 of the fourth embodiment, although not shown in the figures, has basically the same configuration as the fundus camera 9 of the second embodiment, except that the examination head 20 can be rotated (swing and tilted) on two axes, a rotation axis 21 and a rotation axis 140, similar to the fundus camera 9 of the third embodiment (see Figure 26). For this reason, components that are functionally or structurally identical to those of the fundus camera 9 of each of the above embodiments are given the same reference numerals and their descriptions are omitted. The specific configuration of the tilt mechanism (rotation axis 140 and tilt rotation drive unit 141) used in the fundus camera 9 of the fourth embodiment is known technology (see, for example, Japanese Patent Application Publication No. 2022-112637), so a specific description is omitted here.

[0179] The control device 90 of the fourth embodiment is basically the same as the control device 90 of the second embodiment, except that the tilt direction of the tilt axis TA is different from that of the second embodiment. In addition, the nasal imaging control unit 91A, nasal position detection unit 91B, and tilt angle determination unit 91C of the fourth embodiment determine the tilt angle θ of the tilt axis TA in the outward direction Y1 with respect to the reference axis VA, similar to the third embodiment. Furthermore, the drive control unit 93 of the fourth embodiment drives the X-axis drive unit 14, Z-axis drive unit 15, Y-axis drive unit 16, swing rotation drive unit 17, and tilt rotation drive unit 141 to perform auto-alignment of the inspection head 20.

[0180] Figure 28 is an explanatory diagram illustrating a fourth example of auto-alignment of the inspection head 20 in the fourth embodiment. This fourth example is basically the same as the 2-1 example (see Figure 24) described in the second embodiment, except that the inclination direction of the tilt axis TA is different. As indicated by reference numeral XXVIIIA in Figure 28, the inspection head 20 is initially positioned in the same initial position as in the first embodiment.

[0181] Next, as shown by the reference numerals XXVIIIA and XXVIIIB in Figure 28, the drive control unit 93 drives the X-axis drive unit 14, the Z-axis drive unit 15, and the Y-axis drive unit 16 to perform a first drive process that moves the examination head 20 in the XYZ directions until the rotation axis 21 and the rotation axis 140 coincide with the rotation center of the eye under examination E.

[0182] After the completion of the first drive process, the drive control unit 93 drives the tilt rotation drive unit 141 to perform a second drive process that rotates the inspection head 20 outward by an angle θ around the rotation axis 140 (the rotation center of the eye being examined E) in the direction Y1 (see arrow R). As a result, as shown by the symbol XXVIIIC in Figure 28, the inspection head 20 moves to the tilt axis TA and the central axis CL becomes parallel to the tilt axis TA.

[0183] Next, after the completion of the second drive process, the drive control unit 93 drives the X-axis drive unit 14, the Z-axis drive unit 15, and the Y-axis drive unit 16 to start a third drive process that moves the inspection head 20 to the inspection position along the tilt axis TA when viewed from one direction in the X-axis direction (see arrow YZ1). As a result, the inspection head 20 is moved toward the eye to be examined E while maintaining a constant tilt angle θ.

[0184] Then, as shown by reference numeral XXVIIID in Figure 28, the drive control unit 93 drives the X-axis drive unit 14, the Z-axis drive unit 15, and the Y-axis drive unit 16 based on the alignment detection result detected by the alignment detection unit 92 during auto-alignment, and continues the third drive process until the inspection head 20 reaches the inspection position.

[0185] In this case, if the alignment detection unit 92 is unable to perform alignment detection while the inspection head 20 is moving for a predetermined period of time or distance from the start of auto-alignment or the start of the third drive process, the drive control unit 93 switches the alignment mode of the inspection head 20 to manual alignment mode (see Figure 22).

[0186] In addition, the first drive process and the second drive process may be executed simultaneously, similar to the second example of auto-alignment of the inspection head 20 in the second embodiment described above (see Figure 25).

[0187] As described above, in the fundus camera 9 of the fourth embodiment, the examination head 20 can be moved along the tilt axis TA from an oblique direction (obliquely upward) to the examination position of the eye E under examination during auto-alignment, thus preventing the examination head 20 (first concave mirror 51) from coming into close proximity to the nose N. As a result, the same effects as in the second embodiment can be obtained.

[0188] In the fourth embodiment described above, during auto-alignment of the examination head 20, the examination head 20 is brought closer to the eye E by following the tilt axis TA, which is tilted outward Y1 (upward in the Y-axis direction) with the reference axis VA centered on the eye E. However, the tilt direction of the tilt axis TA is not particularly limited as long as it is perpendicular to the Z-axis direction and away from the nose N. Furthermore, the direction and configuration of the rotation axes 21 and 140 can be appropriately changed according to this tilt direction.

[0189] Furthermore, in the fundus camera 9 of the fourth embodiment described above, if the tilt direction of the tilt axis TA is fixed to the outward direction Y1, the swing rotation drive unit 17 may be omitted.

[0190] [others] In each of the above embodiments, the stereo cameras 81L and 81R are used to photograph and detect the position of the nose N, and to perform alignment detection. However, instead of the stereo cameras 81L and 81R, the inspection head 20 may be equipped with multiple cameras capable of photographing the eye E under examination from multiple directions. In this case, the multiple cameras are used to photograph and detect the position of the nose N, and to perform alignment detection. Alternatively, the stereo cameras 81L and 81R for alignment detection and the multiple cameras for photographing and detecting the position of the nose N may be individually provided on the inspection head 20. These multiple cameras may be provided at both ends in the X-axis direction and the lower end in the Y-axis direction on the front surface of the inspection head 20 to prevent each camera from approaching the nose N during the alignment of the inspection head 20.

[0191] In each of the above embodiments, the nose N is photographed by all cameras 81a constituting the stereo cameras 81L and 81R. However, the nose position detection unit 91B can detect the position of the nose N by photographing the nose N with just two cameras 81a. Therefore, if the total number of cameras 81a is three or more, it is not necessary to photograph the nose N with all cameras 81a, and in this case, the nose N may be photographed with at least two or more cameras 81a.

[0192] In each of the above embodiments, the inspection head 20 is moved from an oblique direction along the tilt axis TA to the inspection position of the eye E being examined during auto-alignment. However, the inspection head 20 may also be moved from an oblique direction along the tilt axis TA to the inspection position of the eye E being examined during manual alignment.

[0193] In the embodiments described above, the displacement mechanism for displacing the examination head 20 relative to the eye E under examination was described using an X-axis drive unit 14, a Z-axis drive unit 15, a Y-axis drive unit 16, and a swing rotation drive unit 17, and also using a tilt rotation drive unit 141 as an example. However, the configuration and type of this displacement mechanism are not particularly limited. For example, a robot arm (articulated arm) may be used as the displacement mechanism of the present invention.

[0194] In the embodiments described above, a fundus camera 9 was used as an example of the ophthalmic device of the present invention. However, the present invention is not limited thereto, and can be applied to various ophthalmic devices that perform examinations (measurement of ocular characteristics, photography, observation, etc.) of various parts of the eye E to be examined via a pair of concave mirrors.

[0195] 9… Fundus camera 10… Equipment stand 11…X-axis movable frame 12...Z-axis movable frame 13…Y-axis movable frame 14…X-axis drive unit 15…Z-axis drive unit 16…Y-axis drive unit 17...Swing rotation drive unit 20... Inspection head 21…Rotation axis 22L, 22R... Alignment Optical Frame 30…Face support part 31...Main body 32... Picture frame support 32a... Forehead support surface for the left eye 32b...Forehead surface for right eye 33... Chin rest 33a... Chin rest surface for the left eye 33b…Right eye chin rest surface 34…Lifting rod 35...Jaw support drive unit 37... Galvanometer Scanner 40... Control Panel 41…Touchscreen 50…Concave mirror unit 51...1st concave mirror 51a...first reflective surface 52…Second concave mirror 52a…Second reflective surface 53…Concave mirror bracket 54...Unit rotation axis 55...Unit Rotation Drive Unit 57L…Dichroic mirror 57R... Dichroic mirror 60…Photography Optical System 60L…Left eye imaging optical system 60R…Photography optical system for right eye 61L, 61R... First Reflecting Mirror 62L, 62R…First lens unit 63L, 63R... Second reflective mirror 64L, 64R…Second lens unit 65L, 65R… Focusing lenses 66L, 66R…Third lens unit 67L, 67R... Imaging Unit 68... Slide plate 69... Focusing drive unit 70...Illumination optical system 71...Light source section 71a... Iris Diameter 72... Slit Unit 72a... Slit 72b…Projection lens 73... Galvanometer Scanner 75…Left / Right Switching Mirror 75a... Mirror rotation axis 77... Slit drive unit 78... Scanner drive unit 79...Mirror rotation drive unit 80… Alignment Optics 80L… Alignment optics for the left eye 80R… Right eye alignment optics 81L, 81R… Stereo Camera 81a...Camera 82L, 82R… Alignment lighting lamps 90...Control device 91A... Nasal imaging control unit 91B...Nose position detection unit 91C... Inclination angle determination unit 92... Alignment detection unit 93... Drive control unit 94…Fixation control unit 95... Fundus imaging control unit 96...Storage Control Unit 120...Image forming unit 130...Data Processing Unit 131...Storage section 140... Rotation axis 141...Tilt rotation drive unit 600L, 600R... Shooting aperture 671L, 671R... Fundus image sensor 741...First Reflecting Mirror 742...Second Reflecting Mirror 744L, 744R… Fourth reflective mirror 761L, 761R…First lens unit 762L, 762R…Second lens unit 763L, 763R... Third Reflecting Mirror 770…Fixation light projection system CL…Central axis E...Eye being examined F1…1st focal point F2…Second focal point F3…Third focal point F4…4th focal point H... Subject N…Nose OD…Right eye OS…Left eye T... Optical Table TA... Inclined axis VA…Reference axis X1…outward direction Y1…outward direction θ...angle of inclination

Claims

1. An examination head comprising: an illumination optical system that emits illumination light to illuminate the eye under examination; and an imaging optical system that guides the reflected light from the eye irradiated with the illumination light to an image sensor; A pair of concave mirrors are provided on the inspection head, which form an optical path between the inspection head and the eye under examination for the illumination light and the reflected light, A displacement mechanism for displacing the examination head relative to the eye being examined, Multiple cameras are provided on the inspection head, A nose imaging control unit that uses at least two cameras to photograph the subject's nose from multiple directions that are different from each other, A nose position detection unit detects the relative position of the nose with respect to the inspection head based on the images of the nose captured by each of the cameras, A reference axis is defined as an axis parallel to the front-to-back direction, which is the operating distance direction of the inspection head, and passing through the eye to be examined. An inclination axis is defined as an axis tilted outward from the reference axis, with the eye to be examined as the center, and the inclination angle determination unit determines the inclination angle of the inclination axis with respect to the reference axis based on the detection result of the nose position detection unit. A drive control unit drives the displacement mechanism to displace the inspection head along the inclination axis of the inclination angle determined by the inclination angle determination unit to the inspection position of the eye under examination, An ophthalmic device equipped with the following features.

2. The ophthalmic apparatus according to claim 1, wherein the nasal imaging control unit adjusts the position of the examination head by the displacement mechanism to a position where the nose can be photographed by all the cameras, and then causes all the cameras to simultaneously photograph the nose.

3. The nasal imaging control unit, After driving the displacement mechanism to move the inspection head to a position where some of the cameras can photograph the nose, a segmented imaging process is performed to photograph the nose with some of the cameras. A position information acquisition process that acquires the shooting position information of the camera that captured the nose in the aforementioned segmented shooting process, A repetitive process that repeatedly executes the segmented shooting process and the position information acquisition process until all cameras have finished capturing the nose, Execute, The ophthalmic apparatus according to claim 1, wherein the nose position detection unit detects the relative position of the nose based on the captured image and the captured position information for each of the cameras.

4. The ophthalmic apparatus according to claim 1, wherein the tilt angle determination unit calculates the nasal distance, which is the distance between the examination head and the nose when the examination head is brought close to the eye under examination to a predetermined working distance, based on the detection result of the nasal position detection unit, for each of the plurality of different tilt angles, and determines the tilt angle based on the calculation result of the nasal distance for each tilt angle.

5. Multiple cameras photograph the anterior portion of the eye under examination while the inspection head is being displaced to the inspection position by the displacement mechanism. The system includes an alignment detection unit that detects the relative position of the eye to the examination head based on anterior segment images of the eye captured by multiple cameras, The ophthalmic apparatus according to claim 1, wherein the drive control unit drives the displacement mechanism based on the detection result of the alignment detection unit to perform alignment of the examination head with respect to the eye under examination while maintaining the tilt angle determined by the tilt angle determination unit.

6. The aforementioned displacement mechanism, A movement mechanism for moving the examination head in the forward / backward, left / right, and up / down directions relative to the eye being examined, A rotation mechanism that rotates the inspection head around a predetermined axis of rotation, An ophthalmic device according to any one of claims 1 to 5, including the following:

7. The rotation axis is parallel to the vertical direction, The ophthalmic apparatus according to claim 6, wherein the outward direction is parallel to the left-right direction.

8. The rotation axis is perpendicular to the vertical direction, The ophthalmic apparatus according to claim 6, wherein the outward direction is upward in the vertical direction.

9. The pair of concave mirrors are a first concave mirror and a second concave mirror connected by a concave mirror bracket. The first concave mirror has a first reflective surface facing the eye being examined, The second concave mirror has a second reflective surface that partially faces the first reflective surface and reflects the illumination light from the illumination optical system to the first reflective surface and the reflected light from the first reflective surface to the imaging optical system. The ophthalmic apparatus according to any one of claims 1 to 5, comprising a switching mechanism that allows the pair of concave mirrors to be switched between a first position in which the first reflective surface is positioned in front of the left eye and the second reflective surface is positioned on the left side of the face when the eye being examined is the left eye, and a second position in which the first reflective surface is positioned in front of the right eye and the second reflective surface is positioned on the right side of the face when the eye being examined is the right eye.

10. An examination head comprising: an illumination optical system that emits illumination light to illuminate the eye under examination; and an imaging optical system that guides the reflected light from the eye irradiated with the illumination light to an image sensor; A pair of concave mirrors are provided on the inspection head, which form an optical path between the inspection head and the eye under examination for the illumination light and the reflected light, A displacement mechanism for displacing the examination head relative to the eye being examined, Multiple cameras are provided to be movable integrally with the inspection head, In a method for operating an ophthalmic device equipped with the following features, A nose imaging control step involves using at least two of the cameras to photograph the subject's nose from multiple directions that are different from each other, A nose position detection step in which the relative position of the nose with respect to the inspection head is detected based on the image of the nose captured by each of the cameras, A reference axis is defined as an axis parallel to the front-to-back direction, which is the operating distance direction of the inspection head, and passing through the eye to be examined. An inclination axis is defined as an axis tilted outward from the reference axis, with the eye to be examined as the center, and the inclination angle determination step determines the inclination angle of the inclination axis with respect to the reference axis based on the detection result of the nose position detection step. A drive control step that drives the displacement mechanism to displace the inspection head along the inclination axis of the inclination angle determined in the inclination angle determination step to the inspection position of the eye under examination, A method for operating an ophthalmic device having a specific feature.

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