Fundus observation device

Abstract

To provide a new technology to observe the ocular fundus of an eye to be examined with a wide angle at low costs and by a simple configuration.SOLUTION: An ocular fundus observation device includes an illumination optical system, a two-dimensional image sensor, a first light path dividing member, and an optical scanner. The illumination optical system illuminates the ocular fundus of an eye to be examined with slit-shaped illumination light. The two-dimensional image sensor receives return light from the eye to be examined in a movable virtual opening range at a position optically nearly conjugate to the ocular fundus. The first light path dividing member spatially divides a light path of the return light from the light path of the illumination light. The optical scanner is disposed between the first light path dividing member and the illumination optical system for scanning the ocular fundus with the illumination light by deflecting the illumination light in synchronization with the movement of the opening range.SELECTED DRAWING: Figure 10

Description

Technical Field

[0001] This invention relates to an ophthalmic fundus observation apparatus.

Background Art

[0002] For ophthalmic fundus observation apparatuses for screening and treating eye diseases, etc., there is a demand for apparatuses that can easily observe and photograph the fundus of the eye to be examined in a wide field of view. Specifically, there is a demand for an apparatus that can observe the fundus of the eye to be examined at a wide angle with a photographing angle of more than 80 degrees in a single photographing. As such an ophthalmic fundus observation apparatus, a Scanning Laser Ophthalmoscope (SLO) is known. The SLO is an apparatus that forms an image of the fundus by scanning the fundus with light and detecting the returned light with a light receiving device.

[0003] For example, Patent Document 1 discloses a scanning ophthalmoscope that can move two-dimensional parallel light scanning using a polyhedron mirror and a plane mirror to the eye to be examined by scanning movement means and scan the retina at a wide angle.

[0004] For example, Patent Document 2 discloses an ophthalmic fundus photographing apparatus that can combine line scanning and a rolling shutter to obtain a high-contrast image with a simple configuration.

[0005] In recent years, Optical Coherence Tomography (OCT), which measures or images the form of a measured object using a light beam from a laser light source or the like, has attracted attention. Since OCT has no invasiveness to the human body like X-ray CT (Computed Tomography), its application in the medical field and the biological field is particularly expected to expand. An apparatus using such OCT can obtain a high-definition image, and thus is applied to the diagnosis of various ophthalmic diseases.

[0006] For example, Patent Document 3 discloses an ophthalmic device that combines an imaging function using SLO and a measurement function using OCT. In particular, Patent Document 3 discloses a method for realizing both an imaging function using SLO and a measurement function using OCT by sharing an optical scanner. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Special Publication No. 2009-543585 [Patent Document 2] U.S. Patent No. 7831106 [Patent Document 3] Japanese Patent Publication No. 2018-108400 [Overview of the project] [Problems that the invention aims to solve]

[0008] The method disclosed in Patent Document 1 requires a high-speed scanner such as a polygon mirror, but high-speed scanners capable of wide-angle scanning are very expensive.

[0009] Furthermore, when performing wide-angle fundus imaging, it is desirable to connect the optical path of the illumination light and the optical path of the reflected light at a branching point located conjugate to the pupil of the eye being examined. In the method disclosed in Patent Document 2, it is difficult to separate the line scan optical system from the light source to the branching point, the observation optical system from the branching point to the image sensor, and the shared optical system for the illumination light and its reflected light from the pupil of the eye being examined to the branching point. In particular, when the field of view exceeds 80 degrees, it becomes extremely difficult in practice to keep the illumination beam in the line scan optical system and the shared beam in the shared optical system within 180 degrees.

[0010] Furthermore, in the method disclosed in Patent Document 3, the information acquisition time per point irradiated by the laser differs significantly, resulting in different imaging ranges that can be acquired within the same imaging time. Generally, the measurement range obtained in one OCT measurement (OCT imaging) is smaller than the imaging range obtained in one imaging by SLO. Therefore, when optically coupling an SLO optical system for SLO imaging and an OCT optical system for OCT measurement to observe over a wide-angle range, simply coupling these optical systems makes it impossible to perform SLO imaging and OCT measurement in parallel. In particular, when the optical scanner is shared between SLO imaging and OCT measurement, it becomes impossible to observe the fundus over a wide angle while measuring a desired area with OCT.

[0011] As described above, there is a need for a new technology that allows for wide-angle observation of the fundus of the eye being examined, with low cost and a simple configuration. In this case, it is desirable that OCT measurement be possible while observing the fundus of the eye being examined with a wide angle.

[0012] This invention was made in view of these circumstances, and one of its objectives is to provide a new technique for observing the fundus of the eye under examination at a wide angle, with low cost and a simple configuration. [Means for solving the problem]

[0013] One embodiment of the present invention is a fundus observation device comprising: an illumination optical system that illuminates the fundus of an eye under examination with slit-shaped illumination light; a two-dimensional image sensor that receives reflected light from the eye under examination within a virtually movable aperture range at a position substantially conjugate to the fundus; an optical path splitting unit that spatially divides the optical path of the illumination light and the optical path of the reflected light; and an optical scanner disposed between the optical path splitting unit and the illumination optical system, which deflects the illumination light in synchronization with the movement of the aperture range to scan the fundus with the illumination light. [Effects of the Invention]

[0014] According to the present invention, a new technique can be provided for observing the fundus of a subject's eye at a wide angle, at low cost and with a simple configuration.

Brief Description of Drawings

[0015] [Figure 1] It is a schematic diagram showing an example of the configuration of the optical system of the fundus observation device according to the first embodiment. [Figure 2] It is a schematic diagram showing an example of the configuration of the processing system of the fundus observation device according to the first embodiment. [Figure 3] It is a flowchart showing an example of the operation of the fundus observation device according to the first embodiment. [Figure 4] It is a schematic diagram showing an example of the configuration of the optical system of the fundus observation device according to the second embodiment. [Figure 5] It is a schematic diagram showing an example of the configuration of the optical system of the fundus observation device according to the second embodiment. [Figure 6] It is a schematic diagram showing an example of the configuration of the processing system of the fundus observation device according to the second embodiment. [Figure 7] It is a flowchart showing an example of the operation of the fundus observation device according to the second embodiment. [Figure 8] It is a schematic diagram for explaining the operation of the fundus observation device according to the second embodiment. [Figure 9] It is a schematic diagram showing an example of the configuration of the optical system of the fundus observation device according to the first modification of the embodiment. [Figure 10] It is a schematic diagram showing an example of the configuration of the optical system of the fundus observation device according to the second modification of the embodiment. [Figure 11] It is a schematic diagram showing an example of the configuration of the optical system of the fundus observation device according to the third modification of the embodiment. [Figure 12A] It is a schematic diagram showing an example of the configuration of the optical system of the fundus observation device according to the fourth modification of the embodiment. [Figure 12B] It is a schematic diagram showing an example of the configuration of the optical system of the fundus observation device according to the fourth modification of the embodiment. [Figure 13A] It is a schematic diagram showing an example of the configuration of the optical system of the fundus observation device according to the fifth modification of the embodiment. [Figure 13B] It is a schematic diagram showing an example of the configuration of the optical system of the fundus observation device according to the fifth modification of the embodiment. [Figure 14] This is a schematic diagram showing an example of the optical system configuration of a fundus observation device according to a sixth modified embodiment. [Figure 15] This is a schematic diagram showing an example of the optical system configuration of a fundus observation device according to a seventh modified embodiment. [Figure 16A] This is a schematic diagram showing an example of the optical system configuration of a fundus observation device according to the eighth modified embodiment. [Figure 16B] This is a schematic diagram showing an example of the optical system configuration of a fundus observation device according to the eighth modified embodiment. [Figure 16C] This is a schematic diagram showing an example of the optical system configuration of a fundus observation device according to the eighth modified embodiment. [Figure 17A] This is a schematic diagram showing an example of the optical system configuration of a fundus observation device according to the ninth modified embodiment. [Figure 17B] This is a schematic diagram showing an example of the optical system configuration of a fundus observation device according to the ninth modified embodiment. [Figure 17C] This is a schematic diagram showing an example of the optical system configuration of a fundus observation device according to the ninth modified embodiment. [Figure 18] This is a schematic diagram showing an example of the optical system configuration of a fundus observation device according to a 10th modified embodiment. [Figure 19] This is a schematic diagram showing an example of the optical system configuration of a fundus observation device according to the 11th modified embodiment. [Figure 20] This is a schematic diagram showing an example of the optical system configuration of a fundus observation device according to the 11th modified embodiment. [Figure 21A] This is a schematic diagram showing an example of the optical system configuration of a fundus observation device according to the 11th modified embodiment. [Figure 21B] This is a schematic diagram showing an example of the optical system configuration of a fundus observation device according to the 11th modified embodiment. [Figure 22] This is a schematic diagram showing an example of the optical system configuration of a fundus observation device according to the 11th modified embodiment. [Modes for carrying out the invention]

[0016] An example of an embodiment of the fundus observation device according to this invention will be described in detail with reference to the drawings. It is possible to apply the contents of the referenced documents and any prior art cited in this specification to the following embodiments.

[0017] In this specification, "processor" means, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), a programmable logic device (e.g., SPLD (Simple Programmable Logic Device), CPLD (Complex Programmable Logic Device), FPGA (Field Programmable Gate Array)), or other circuit. The processor realizes the functions according to the embodiment by, for example, reading and executing a program stored in a memory circuit or memory device.

[0018] The fundus observation device according to the embodiment illuminates the fundus of the eye under examination with illumination light having a linear cross-sectional beam shape, and receives the reflected light from the fundus with a two-dimensional image sensor on a movable focal plane at a position that is substantially conjugate to the fundus optically. At this time, the optical path of the illumination light and the optical path of the reflected light are coupled (separated) using a deflection member having a structure in which the reflected light passes through a first region (e.g., a region including the central part) and reflects the illumination light in a second region different from the first region (e.g., the peripheral part of the region including the central part (a region including the peripheral part)), and the fundus is scanned with the illumination light by deflecting the illumination light in synchronization with the movement of the focal plane. In some embodiments, the first region is the peripheral region of the region including the central part of the deflection member, and the second region is the region including the central part of the deflection member. The first region may be a region that does not overlap with the second region. In some embodiments, the optical path coupling portion of the deflecting member, where the optical path of the illumination light and the optical path of the return light meet, is positioned to be approximately conjugate to the pupil of the eye being examined. In some embodiments, the deflecting member is a perforated mirror.

[0019] This makes it possible to secure a shooting angle of view exceeding 80 degrees using only an optical system that scans in the width direction of the illumination light line, while easily arranging a shared optical system for the wide-angle illumination light path and the reflected light path.

[0020] Some embodiments include an optical scanner and an OCT optical system that performs an OCT scan by irradiating the eye under examination with measurement light deflected by the optical scanner and detecting interference light between the reflected measurement light and a reference light. In this case, an optical path coupling / separating member is placed between the deflection member and the two-dimensional image sensor to couple the optical path of the linear illumination light's reflected light with the optical path of the OCT optical system. That is, by optically coupling the OCT optical system on the transmission side of the deflection member (through the hole in the aperture mirror), the optical path of the illumination light's reflected light can be separated from the shared optical system at low cost. Furthermore, it becomes possible to perform OCT measurement (OCT imaging) at any position on the fundus being observed at a wide angle without sharing the optical scanner for OCT scanning and the optical scanner for deflecting the illumination light.

[0021] The following describes a case in which the fundus observation device according to the embodiment acquires an image of the fundus of the eye under examination mainly using an ellipsoidal mirror (or, in a broad sense, a concave mirror) as an aspherical mirror. Furthermore, the case in which the deflection member has a structure in which the reflected light passes through a region including the central part as a first region, and the illumination light is reflected in a peripheral region including the central part as a second region.

[0022] <First Embodiment> <Structure> Figure 1 shows an example of the optical system configuration of the fundus observation device according to the first embodiment. In Figure 1, the position that is approximately optically conjugate to the fundus Ef of the eye under examination E is shown as the fundus conjugate position P, and the position that is approximately optically conjugate to the pupil (iris) of the eye under examination E is shown as the pupil conjugate position (iris conjugate position) Q.

[0023] The fundus observation device 1 according to the first embodiment includes a slit projection optical system 10, a slit light receiving optical system 20, a hole mirror 30 as a deflection member having a scanning mechanism, a first ellipsoidal mirror 40, and a second ellipsoidal mirror 50.

[0024] (Slit projection optical system 10) The slit projection optical system 10 generates slit-shaped illumination light (illumination light with a line-shaped cross-sectional shape of the light beam) and projects the generated illumination light onto the hole mirror 30. The slit projection optical system 10 includes an illumination light source 11, an iris diaphragm 12, a slit 13, and a projection lens 14.

[0025] The illumination light source 11 includes a visible light source that generates light in the visible region. For example, the illumination light source 11 generates light having a central wavelength in the wavelength range of 420 nm to 700 nm. Such an illumination light source 11 includes, for example, an LED (Light Emitting Diode), an LD (Laser Diode), a halogen lamp, or a xenon lamp. In some embodiments, the illumination light source 11 includes a white light source or a light source capable of outputting light for each of the RGB color components. In some embodiments, the illumination light source 11 includes a light source capable of switching between outputting light in the infrared region or light in the visible region. The illumination light source 11 is positioned optically non-conjugate to the fundus Ef and pupil (iris) of the eye E under examination, respectively.

[0026] The iris diaphragm 12 (specifically, the opening described later) can be positioned at the pupillary conjugate position Q. The iris diaphragm 12 has one or more openings formed at positions away from the optical axis of the light path output from the illumination light source 11. The openings formed in the iris diaphragm 12 define the incident position (incidence shape) of the illumination light in the iris of the eye E under examination. For example, the iris diaphragm 12 has openings formed at point-symmetric positions with respect to the optical axis. This makes it possible to cause the illumination light to enter the eye from an eccentric position from the pupillary center (specifically, a point-symmetric position with respect to the pupillary center) when the pupillary center of the illumination light path is positioned on the optical axis of the light path.

[0027] Furthermore, by changing the relative position between the illumination light source 11 and the opening formed in the iris diaphragm 12, it is possible to change the light intensity distribution of the light passing through the opening formed in the iris diaphragm 12.

[0028] The slit 13 (specifically, the opening described later) can be positioned at the conjugate position P in the fundus. The opening formed in the slit 13 defines the shape of the illumination area (illumination pattern shape) of the illumination light in the fundus Ef of the eye under examination E.

[0029] The slit 13 is movable in the optical axis direction of the slit projection optical system 10 by a moving mechanism (not shown). The moving mechanism receives control from a control unit (described later) and moves the slit 13 in the optical axis direction. This allows the position of the slit 13 to be moved according to the condition of the eye E under examination (specifically, refractive power and shape of the fundus Ef).

[0030] In some embodiments, the slit 13 is configured to change at least one of the position and shape of the aperture without being moved in the optical axis direction, depending on the state of the eye E being examined. Such a function of the slit 13 is realized, for example, by a liquid crystal shutter.

[0031] Light from the illumination light source 11, passing through the opening formed in the iris diaphragm 12, passes through the opening formed in the slit 13, and is output as slit-shaped illumination light after passing through the projection lens 14. The slit-shaped illumination light output from the slit projection optical system 10 is guided to the hole mirror 30.

[0032] In some embodiments, the slit projection optical system 10 includes a projector equipped with a light source, which outputs slit-shaped illumination light. Examples of projectors include LCD (Liquid Crystal Display) projectors using transmissive liquid crystal panels, LCOS (Liquid Crystal On Silicon) projectors using reflective liquid crystal panels, and DLP (Digital Light Processing) (registered trademark) projectors using DMDs (Digital Mirror Devices).

[0033] (hole mirror 30) The hole mirror 30 (specifically, the deflection surface described later) can be positioned at the pupil conjugate position Q. The hole mirror 30 has a deflection surface whose orientation (deflection direction) can be changed, and functions as a uniaxial optical scanner that guides illumination light from the slit projection optical system 10 to the reflective surface of the first ellipsoidal mirror 40 described later. The deflection surface has a hole formed therein so that the optical axis of the slit light receiving optical system 20 described later passes through it. In other words, the hole mirror 30 has a structure through which the reflected light of the illumination light is transmitted (passed) through the center, and the illumination light is reflected at the periphery of the center.

[0034] The porcelain mirror 30 deflects the illumination light by changing the orientation of its deflection surface so that it moves sequentially in a direction perpendicular to the slit direction of the illumination area (the direction in which the slit extends, the longitudinal direction of the illumination area) at the illumination site of the eye E under examination. The porcelain mirror 30 is configured to change the direction of the illumination light deflection under control from the control unit described later.

[0035] The illumination light from the slit projection optical system 10 is deflected by the deflection plane around the hole and guided to the reflective surface of the first ellipsoidal mirror 40. The reflected light from the eye under examination E passes through the hole formed in the hole mirror 30 via the reflective surface of the first ellipsoidal mirror 40 and is guided to the slit light receiving optical system 20.

[0036] In some embodiments, the hole mirror 30 is configured to transmit the wavelength component (or polarization component) of the reflected light of the illumination light. In this case, the reflected light of the illumination light from the eye under examination E passes through the hole mirror 30 via the reflective surface of the first ellipsoidal mirror 40 and is guided to the slit light-receiving optical system 20.

[0037] (Slit light-receiving optical system 20) The slit light-receiving optical system 20 receives the reflected light from the illuminating eye E that has passed through the hole in the aperture mirror 30. The slit light-receiving optical system 20 includes an image sensor 21 and an imaging lens 22.

[0038] The image sensor 21 functions as a two-dimensional image sensor with pixelated light receivers. The light-receiving surface (detection surface, imaging surface) of the image sensor 21 can be positioned at the fundus conjugate position P. The image sensor 21 can set a movable aperture range (focal plane) at the fundus conjugate position P.

[0039] For example, the light reception results from the image sensor 21 are captured and read out using a rolling shutter method. In some embodiments, the control unit, described later, controls the readout of the light reception results by controlling the image sensor 21. In some embodiments, the image sensor 21 can automatically output light reception results for a predetermined line along with information indicating the light reception position.

[0040] Such an image sensor 21 includes, for example, a CMOS (Complementary Metal Oxide Semiconductor) image sensor. In this case, the image sensor 21 includes a plurality of pixels arranged in the column direction, with a plurality of pixel groups (photodetectors) arranged in the row direction. Specifically, the image sensor 21 includes a plurality of pixels arranged in two dimensions, a plurality of vertical signal lines, and a horizontal signal line. Each pixel includes a photodiode (photodetector) and a capacitor. The plurality of vertical signal lines are provided for each group of pixels in the column direction (vertical direction) orthogonal to the row direction (horizontal direction). Each vertical signal line is selectively electrically connected to a group of pixels where a charge corresponding to the light reception result has been accumulated. The horizontal signal line is selectively electrically connected to the plurality of vertical signal lines. Each pixel accumulates a charge corresponding to the light reception result of the reflected light, and the accumulated charge is read out sequentially, for example, for each group of pixels in the row direction. For example, for each line in the row direction, a voltage corresponding to the charge accumulated in each pixel is supplied to the vertical signal line. The vertical signal line is selectively electrically connected to the horizontal signal line. By sequentially performing the above row-direction line-by-line read operation in the vertical direction, it is possible to read the light reception results of multiple pixels arranged in a two-dimensional array.

[0041] By capturing (reading out) the reflected light reception result from such an image sensor 21 using a rolling shutter method, a light-receiving image corresponding to a desired virtual aperture shape extending in the low direction is obtained. Such control is disclosed, for example, in Patent Document 2 or U.S. Patent No. 8,237,835.

[0042] The imaging lens 22 causes the reflected light of the illumination light that has passed through the hole formed in the hole mirror 30 (or the reflected light of the illumination light that has passed through the hole mirror 30) to form an image on the light-receiving surface of the image sensor 21.

[0043] (First ellipsoidal mirror 40) The reflective surface (first reflective surface) of the first ellipsoidal mirror 40 is an ellipsoid. The first ellipsoidal mirror 40 is an example of a concave mirror.

[0044] The first ellipsoidal mirror 40 has two optically conjugate foci (first focal point F1, second focal point F2). The hole mirror 30 (the deflection surface of the hole mirror 30) is positioned at or near the first focal point F1 of the first ellipsoidal mirror 40. In some embodiments, the hole mirror 30 is positioned at or near a position optically conjugate to the first focal point F1 (the conjugate position of the first focal point F1).

[0045] (Second ellipsoidal mirror 50) The reflective surface (second reflective surface) of the second ellipsoidal mirror 50 is an ellipsoid. The second ellipsoidal mirror 50 is an example of a concave mirror.

[0046] The second ellipsoidal mirror 50 has two optically conjugate foci (first focal point F3, second focal point F4). The second ellipsoidal mirror 50 is positioned such that the first focal point F3 substantially coincides with the second focal point F2 of the first ellipsoidal mirror 40. In some embodiments, the second ellipsoidal mirror 50 is positioned such that the first focal point F3 substantially coincides with the position optically conjugate to the second focal point F2 of the first ellipsoidal mirror 40 (the conjugate position of the second focal point F2) or in its vicinity. The eye under examination E is positioned at the second focal point F4 of the second ellipsoidal mirror 50. That is, the second ellipsoidal mirror 50 is positioned such that the second focal point F4 substantially coincides with the position of the eye under examination E.

[0047] Thus, since there is no need to place a scanning optical element at the second focal point F2 (first focal point F3) between the first ellipsoidal mirror 40 and the second ellipsoidal mirror 50, the scanning range is not limited by a predetermined scanning direction (lateral direction, horizontal direction). For example, in the configuration described in Patent Document 1, a deflection member is provided to scan the illumination light in the lateral direction, so theoretically a shooting angle of view up to 180 degrees (actually up to about 150 degrees) can be secured. In contrast, according to this embodiment, a deflection member to scan in the lateral direction is unnecessary, so it becomes possible to shoot up to a shooting angle of view exceeding 180 degrees (because the cornea of ​​the human eye is positioned to protrude forward from the pupil, it is possible to observe a range exceeding 180 degrees with a fisheye lens-like effect).

[0048] The second ellipsoidal mirror 50 is positioned such that the angle between the line connecting the first focus F1 and the second focus F2 of the first ellipsoidal mirror 40 and the line connecting the first focus F3 and the second focus F4 of the second ellipsoidal mirror 50 is angle α. For example, angle α is 30 degrees. In some embodiments, the second ellipsoidal mirror 50 is configured to be relatively movable relative to the first ellipsoidal mirror 40 so as to change the angle α.

[0049] In this configuration, the illumination light deflected by the hole mirror 30 positioned at the first focal point F1 is reflected by the reflective surface of the first ellipsoidal mirror 40 and guided to the second focal point F2 of the first ellipsoidal mirror 40. The illumination light guided to the second focal point F2 is guided by the reflective surface of the second ellipsoidal mirror 50, reflected by this reflective surface, and guided to the eye under examination E positioned at the second focal point F4 of the second ellipsoidal mirror 50.

[0050] The illumination light guided into the eye E enters the eye through the pupil and irradiates the fundus Ef. The reflected illumination light from the fundus Ef exits the eye E through the pupil and travels in the reverse direction along the same path as the outward journey, guided to the first focal point F1 of the first ellipsoidal mirror 40. The reflected illumination light guided to the first focal point F1 passes through the hole formed in the hole mirror 30 (or passes through the hole mirror 30) as described above and is guided to the slit light-receiving optical system 20.

[0051] In some embodiments, at least one of the first ellipsoidal mirror 40 and the second ellipsoidal mirror 50 is a concave mirror whose reflective surface is formed in a concave shape. In some embodiments, the reflective surface of the concave mirror is formed to be a free-form surface.

[0052] In addition to the configuration shown in Figure 1, the fundus observation device 1 may be provided with an alignment optical system for aligning the eye under examination E with the optical system. Furthermore, the fundus observation device 1 may be provided with a focusing mechanism that involves moving a lens or moving a slit light-receiving optical system 20.

[0053] Furthermore, the fundus observation device 1 may be equipped with a configuration to provide functions associated with the examination. For example, the fundus observation device 1 may be provided with a fixation optical system for projecting a fixation target (fixation target) onto the fundus Ef of the eye E under examination. In addition, the fundus observation device 1 may be equipped with any elements or units such as members for supporting the face of the person being examined (chin rest, forehead rest, etc.).

[0054] Figure 2 shows an example of the configuration of the processing system of the fundus observation device 1 according to the first embodiment. In Figure 2, the same reference numerals are used for parts that are the same as in Figure 1, and their descriptions are omitted as appropriate.

[0055] The processing system of the fundus observation device 1 is centered around the control unit 60. The control unit 60 controls each part of the fundus observation device 1.

[0056] The control unit 60 includes a main control unit 61 and a storage unit 62. The functions of the main control unit 61 are realized, for example, by a processor. The storage unit 62 stores in advance computer programs for controlling the fundus observation device 1. These computer programs include a program for controlling the illumination light source, a program for controlling the image sensor, a program for controlling the follicular mirror, an image forming program, and a user interface program. The control unit 60 executes control processing by operating the main control unit 61 according to such computer programs.

[0057] (Main control unit 61) The main control unit 61 controls the slit projection optical system 10, the slit light receiving optical system 20, the hole mirror 30, the image forming unit 70, and the user interface (UI) unit 80.

[0058] Control of the slit projection optical system 10 includes control of the illumination light source 11. Control of the illumination light source 11 includes turning the light source on and off, adjusting the light intensity, and adjusting the aperture.

[0059] Control of the slit light-receiving optical system 20 includes control of the image sensor 21. Control of the image sensor 21 includes setting the movable aperture range (focal plane) at the fundus conjugate position P, and control for reading out the light-receiving result using a rolling shutter method (for example, setting the light-receiving size corresponding to the size of the illumination pattern). In addition, control of the image sensor 21 includes reset control, exposure control, charge transfer control, and output control.

[0060] Control of the hole mirror 30 includes controlling the angle of the deflection plane that deflects the illumination light. By controlling the angle of the deflection plane, it is possible to control the direction of deflection of the illumination light. By controlling the angular range of the deflection plane, it is possible to control the scan range (scan start position and scan end position). By controlling the rate at which the angle of the deflection plane changes, it is possible to control the scan speed.

[0061] Control of the image forming unit 70 includes image forming control, which forms an image of the eye E under examination from the light reception results obtained by the image sensor 21.

[0062] Control over the UI unit 80 includes control over the display device and control over the operation device (input device).

[0063] (Storage unit 62) The memory unit 62 stores various types of data. The data stored in the memory unit 62 includes, for example, light reception results obtained by the image sensor 21, image data of images formed by the image forming unit 70, and subject eye information. Subject eye information includes information about the subject, such as patient ID and name, and information about the subject eye, such as left / right eye identification information.

[0064] Furthermore, the memory unit 62 stores various programs and data necessary for operating the fundus observation device 1.

[0065] (Image forming unit 70) The image forming unit 70 can form a light-receiving image (fundus image) corresponding to an arbitrary aperture range (focal plane) based on the light-receiving result read from the image sensor 21 using a rolling shutter method. The image forming unit 70 can sequentially form light-receiving images corresponding to the aperture range and form an image of the eye under examination E from the multiple light-receiving images formed. Various images (image data) formed by the image forming unit 70 are stored, for example, in the storage unit 62.

[0066] For example, the image forming unit 70 includes a processor and performs processing according to a program stored in a memory unit or the like to realize the above functions.

[0067] (UI part 80) The UI unit 80 has functions for exchanging information between the user and the fundus observation device 1. The UI unit 80 includes a display device and an operating device. The display device may include a display unit or other display devices. The display device displays various types of information. The display device includes, for example, a liquid crystal display and receives control from the main control unit 61 to display the above information. The information displayed on the display device includes information corresponding to the control result by the control unit 60 and information (images) corresponding to the calculation result by the image forming unit 70. The operating device includes various hardware keys and / or software keys. The main control unit 61 receives the operation content of the operating device and can output control signals corresponding to the operation content to each unit. It is possible to configure at least a part of the operating device and at least a part of the display device as an integrated unit. A touch panel display is one example.

[0068] The slit projection optical system 10 is an example of an "illumination optical system" according to the embodiment. The image sensor 21 is an example of a "two-dimensional image sensor" according to the embodiment. The hole mirror 30 is an example of a "deflection member" according to the embodiment. The first ellipsoidal mirror 40 is an example of a "first concave mirror" according to the embodiment. The second ellipsoidal mirror 50 is an example of a "second concave mirror" according to the embodiment.

[0069] <Operation> Next, an example of the operation of the fundus observation device 1 according to the first embodiment will be described.

[0070] Figure 3 shows an example of operation of the fundus observation device 1 according to the first embodiment. Figure 3 is a flowchart of the operation example of the fundus observation device 1 according to the first embodiment. The memory unit 62 stores a computer program for realizing the processing shown in Figure 3. The main control unit 61 executes the processing shown in Figure 3 by operating according to this computer program.

[0071] In Figure 3, it is assumed that the eye E under examination is positioned at a predetermined eye position (the second focal point F4 of the second ellipsoidal mirror 50 in Figure 1).

[0072] (S1: Turn on the light source) The main control unit 61 controls the illumination light source 11 to turn it on.

[0073] Light emitted from the illumination light source 11 passes through the opening formed in the iris diaphragm 12, through the opening formed in the slit 13, through the projection lens 14, and is guided to the hole mirror 30 as slit-shaped illumination light.

[0074] (S2: Control of light deflection and setting of aperture range of the light-receiving surface) Next, the main control unit 61 controls the hole mirror 30 to set the orientation of the deflection surface in a predetermined deflection direction in order to illuminate a predetermined illumination range, and starts deflection control of the illumination light by sequentially changing the orientation of the deflection surface within a predetermined deflection angle range. In other words, the main control unit 61 starts scanning the fundus Ef with the illumination light.

[0075] In some embodiments, the main control unit 61 controls the aperture mirror 30 in synchronization with the movement of the aperture range, which can be set by a person, in the image sensor 21 to control the deflection of the illumination light.

[0076] In some embodiments, the main control unit 61 controls the image sensor 21 to set an aperture range that includes the range of reflected light received on the light-receiving surface corresponding to the illumination area of ​​the illuminating light in the fundus Ef. For example, the illumination area of ​​the illuminating light in the fundus Ef can be determined based on the deflection angle of the deflection surface of the fossa 30. The main control unit 61 can set the aperture range on the light-receiving surface of the image sensor 21 in accordance with the deflection direction of the deflection surface of the fossa 30, which is changed sequentially.

[0077] The illumination light guided to the hole mirror 30 is deflected by a deflection surface whose deflection direction has been changed and guided to the reflective surface of the first ellipsoidal mirror 40. This light is reflected by this reflective surface and, via the second focal point F2 of the first ellipsoidal mirror 40, is guided to the reflective surface of the second ellipsoidal mirror 50. The illumination light guided to the reflective surface of the second ellipsoidal mirror 50 is reflected by this reflective surface and enters the eye of the eye under examination E, which is positioned at the second focal point F4 of the second ellipsoidal mirror 50, and illuminates the fundus Ef. The return light of the illumination light from the fundus Ef travels in the reverse direction along the same path as the forward path, passes through the hole formed in the hole mirror 30, or passes through the hole mirror 30, and is received by the light-receiving surface of the image sensor 21 via the imaging lens 22. The aperture range of the light-receiving surface of the image sensor 21 is set to include the light-receiving range of the return light corresponding to the illumination range of the fundus Ef. Therefore, only the return light from the fundus Ef is received while suppressing the effects of unwanted scattered light.

[0078] (S3: End?) Next, the main control unit 61 determines whether or not to terminate the scan of the illumination light on the fundus Ef. For example, the main control unit 61 can determine whether or not to terminate the scan of the illumination light on the fundus Ef by determining whether or not the deflection angle of the deflection surface of the sequentially changed fossa 30 is within a predetermined deflection angle range.

[0079] When it is determined that the scan of the illumination light for the fundus Ef is complete (S3:Y), the operation of the fundus observation device 1 proceeds to step S4. When it is determined that the scan of the illumination light for the fundus Ef is not complete (S3:N), the operation of the fundus observation device 1 proceeds to step S2.

[0080] (S4: Acquire image) In step S3, when it is determined that the scanning of the illumination light for the fundus Ef is complete (S3:Y), the main control unit 61 controls the image forming unit 70 to form an image of the eye under examination E based on the light reception results read from the image sensor 21. In some embodiments, the image forming unit 70 sequentially forms light reception images based on the light reception results read from the image sensor 21 in step S2, and forms an image of the eye under examination E from the multiple light reception images formed.

[0081] This concludes the operation of the fundus observation device 1 (end).

[0082] As described above, according to the first embodiment, the optical path of the slit projection optical system 10 and the optical path of the slit light receiving optical system 20 are coupled using the hole mirror 30, and the illumination light is deflected using the hole mirror 30 and guided to the reflective surface of the first ellipsoidal mirror 40. As a result, it is possible to secure a shooting angle of view of more than 80 degrees with only an optical system that scans in the slit width direction (line width direction) perpendicular to the slit direction of the illumination light, in a low-cost and compact configuration, while easily arranging a shared optical system for the optical path of wide-angle illumination light and the optical path of the reflected light. Furthermore, since an optical system can also be arranged on the side through which the hole of the hole mirror 30 passes (transmits), a pupil relay system is not required, and the degree of freedom in arranging the optical system can be improved.

[0083] Furthermore, by using a perforated mirror 30 instead of a polygon mirror, it becomes possible to reduce noise while widening the deflection angle range. In addition, by making the scan length variable, the scan range of the illumination light can be set arbitrarily.

[0084] <Second Embodiment> The configuration of the fundus observation device according to the embodiment is not limited to the configuration of the fundus observation device 1 according to the first embodiment. For example, the fundus observation device 1 according to the first embodiment may further include an OCT optical system.

[0085] In the following embodiments, the case where a swept-source type OCT technique is used for measurement or imaging using OCT will be described in particular. However, it is also possible to apply the configuration according to the embodiment to fundus observation devices that use other types of OCT (e.g., spectral-domain type).

[0086] The following describes the fundus observation device according to the second embodiment, focusing on the differences from the fundus observation device 1 according to the first embodiment.

[0087] <Structure> Figure 4 shows an example of the optical system configuration of the fundus observation device according to the second embodiment. In Figure 4, the same reference numerals are used for parts that are the same as in Figure 1, and their descriptions are omitted as appropriate.

[0088] The difference between the optical system configuration of the fundus observation device 1a according to the second embodiment and the optical system configuration of the fundus observation device 1 according to the first embodiment is that an OCT optical system 100 is added to the optical system configuration of the fundus observation device 1. The optical path of the OCT optical system 100 is coupled with the optical path of the slit photodetector optical system 20 in the optical path between the slit photodetector optical system 20 and the hole mirror 30.

[0089] Specifically, a relay lens optical system including relay lenses 71 and 72 is arranged in the optical path between the slit light-receiving optical system 20 and the hole mirror 30. The optical path between relay lens 71 and relay lens 72 is converted into the optical path of a telecentric optical system, and a dichroic mirror 90 is arranged in the optical path of the telecentric optical system. In other words, the relay lens optical system converts at least a portion of the optical path in which the dichroic mirror 90 is arranged into the optical path of a telecentric optical system.

[0090] The dichroic mirror 90 is an optical path coupling and separation member that separates the optical path of the OCT optical system 100 from the optical path of the slit photodetector optical system 20 (combining the optical path of the slit photodetector optical system 20 and the optical path of the OCT optical system 100). The dichroic mirror 90 reflects the measurement light from the OCT optical system 100 and guides it to the relay lens 71, and also reflects the return light of the measurement light from the eye E under examination and guides it to the OCT optical system 100. In addition, the dichroic mirror 90 transmits the return light of the illumination light from the eye E under examination, which has been guided via the relay lens 71, and guides it to the relay lens 72.

[0091] (OCT optical system 100) Figure 5 shows an example configuration of the OCT optical system 100 shown in Figure 4. In Figure 5, the same parts as in Figure 4 are denoted by the same reference numerals, and explanations are omitted where appropriate.

[0092] The OCT optical system 100 is equipped with an optical system for performing OCT measurement (or OCT imaging) on ​​the eye E under examination. This optical system is an interference optical system that splits light from a wavelength-swept (wavelength scanning) light source into measurement light and reference light, interferes the return light of the measurement light from the eye E under examination with the reference light that has passed through the reference light path to generate interference light, and detects this interference light. The detection result (detection signal) of the interference light by the interference optical system is an interference signal that shows the spectrum of the interference light, and is sent to the image forming unit 70a and the data processing unit 75a, etc., described later.

[0093] The OCT light source 101, like a typical swept-source type fundus observation device, is configured to include a wavelength-swept (wavelength-scanning) light source capable of sweeping (scanning) the wavelength of the emitted light. The wavelength-swept light source is configured to include, for example, a resonator and a laser light source that emits light with a central wavelength of 1050 nm. The OCT light source 101 changes the output wavelength over time in the near-infrared wavelength band, which is invisible to the human eye.

[0094] The light L0 output from the OCT light source 101 is guided by the optical fiber 102 to the polarization controller 103, where its polarization state is adjusted. The polarization controller 103 adjusts the polarization state of the light L0 guided through the optical fiber 102 by, for example, applying external stress to the loop-shaped optical fiber 102.

[0095] The polarization state of the light L0, adjusted by the polarization controller 103, is guided through the optical fiber 104 to the fiber coupler 105, where it is split into the measurement light LS and the reference light LR.

[0096] The reference light LR is guided by the optical fiber 110 to the collimator 111, converted into a parallel beam, and then guided to the optical path length changing section 114 via the optical path length correction member 112 and the dispersion compensation member 113. The optical path length correction member 112 acts to match the optical path length of the reference light LR with that of the measurement light LS. The dispersion compensation member 113 acts to match the dispersion characteristics between the reference light LR and the measurement light LS.

[0097] The optical path length changing unit 114 is movable in the direction of the arrow shown in Figure 5, and changes the optical path length of the reference light LR. This movement changes the length of the optical path of the reference light LR. This change in optical path length is used to correct the optical path length according to the axial length of the eye under examination E, or to adjust the interference state. The optical path length changing unit 114 is composed of, for example, a corner cube and a moving mechanism that moves it. In this case, the corner cube of the optical path length changing unit 114 reverses the direction of propagation of the reference light LR, which has been made into a parallel beam by the collimator 111. The optical path of the reference light LR entering the corner cube and the optical path of the reference light LR exiting the corner cube are parallel.

[0098] The reference light LR, which has passed through the optical path length changing section 114, passes through the dispersion compensation member 113 and the optical path length correction member 112, is converted from a parallel beam to a focused beam by the collimator 116, and is incident on the optical fiber 117. The reference light LR incident on the optical fiber 117 is guided to the polarization controller 118 to adjust its polarization state, guided to the attenuator 120 by the optical fiber 119 to adjust the light intensity, and guided to the fiber coupler 122 by the optical fiber 121.

[0099] Meanwhile, the measurement light LS generated by the fiber coupler 105 is guided by the optical fiber 127 and made into a parallel beam by the collimator lens unit 140. The measurement light LS, now in a parallel beam, is deflected one-dimensionally or two-dimensionally by the optical scanner 150.

[0100] The collimator lens unit 140 includes a collimator lens positioned on the optical axis of the interference optical system included in the OCT optical system 100. The collimator lens makes the beam of measurement light emitted from the end of the optical fiber connected to the OCT optical system 100 and guiding the measurement light LS into a parallel beam. The end of the optical fiber is positioned, for example, at the fundus conjugate position P.

[0101] The optical scanner 150 (deflection plane) can be positioned at the pupil conjugate position Q. When deflecting illumination light in one dimension, the optical scanner 150 includes a galvanoscanner that deflects the measurement light LS within a predetermined deflection angle range with respect to a predetermined deflection direction. When deflecting illumination light in two dimensions, the optical scanner 150 includes a first galvanoscanner and a second galvanoscanner. The first galvanoscanner deflects the measurement light LS so that its illumination position moves in a horizontal direction (e.g., x-direction) perpendicular to the optical axis of the OCT optical system 100. The second galvanoscanner deflects the measurement light LS deflected by the first galvanoscanner so that its illumination position moves in a vertical direction (e.g., y-direction) perpendicular to the optical axis of the OCT optical system 100. Examples of scanning modes for moving the illumination position of the measurement light LS by the optical scanner 150 include horizontal scanning, vertical scanning, cross scanning, radial scanning, circular scanning, concentric scanning, and spiral scanning.

[0102] The measurement light LS, deflected by the optical scanner 150, passes through the focusing lens 151, is reflected by the dichroic mirror 90, passes through the hole in the hole mirror 30, is guided to the reflective surface of the first ellipsoidal mirror 40, and is guided to the eye under examination E via a path similar to that of the illumination light from the slit projection optical system 10. The focusing lens 151 is movable along the optical path of the measurement light LS (the optical axis of the OCT optical system 100). The focusing lens 151 is moved along the optical path of the measurement light LS by a movement mechanism (not shown) under control from a control unit described later.

[0103] The measurement light LS reflected by the reflective surface of the second ellipsoidal mirror 50 enters the eye through the pupil of the eye E at the second focal point F4 (the position of the eye being examined). The measurement light LS is scattered (including reflected) at various depth positions within the eye E. The return light of the measurement light LS, including this backscattered light, travels in the reverse direction along the same path as the forward path to the fiber coupler 105, and then reaches the fiber coupler 122 via the optical fiber 128.

[0104] The fiber coupler 122 generates interference light by combining (interfering with) the measurement light LS incident via the optical fiber 128 and the reference light LR incident via the optical fiber 121. The fiber coupler 122 generates a pair of interference light LC by splitting the interference light of the measurement light LS and the reference light LR at a predetermined splitting ratio (e.g., 1:1). The pair of interference light LC emitted from the fiber coupler 122 are led to the detector 125 by optical fibers 123 and 124, respectively.

[0105] Detector 125 is a balanced photodiode having, for example, a pair of photodetectors that detect a pair of interfering light LCs, and outputting the difference between the detection results. Detector 125 sends its detection result (interference signal) to DAQ (Data Acquisition System) 130. DAQ 130 is supplied with a clock KC from OCT light source 101. Clock KC is generated in the OCT light source 101 in synchronization with the output timing of each wavelength swept (scanned) within a predetermined wavelength range by a wavelength-swept light source. For example, OCT light source 101 optically delays one of two branched beams obtained by branching the light L0 of each output wavelength, and then generates clock KC based on the result of detecting the combined beam. Based on clock KC, DAQ 130 samples the detection result of detector 125. DAQ 130 sends the sampled detection result of detector 125 to image forming unit 70a and data processing unit 75a, etc. The image forming unit 70a (or data processing unit 75a) forms a reflectance intensity profile for each A line by, for example, applying a Fourier transform or the like to the spectral distribution based on the detection results obtained by the detector 125 for each series of wavelength scans (for each A line). Furthermore, the image forming unit 70a forms image data by imaging the reflectance intensity profiles of each A line.

[0106] In Figure 5, the difference in optical path length between the measurement light and the reference light is changed by changing the optical path length of the reference light, but the configuration according to this embodiment is not limited to this. For example, the configuration may be such that the difference in optical path length between the measurement light and the reference light is changed by changing the optical path length of the measurement light.

[0107] Figure 6 shows an example of the configuration of the processing system of the fundus observation device 1a according to the second embodiment. In Figure 6, the same reference numerals are used for parts that are the same as those in Figures 2, 4, or 5, and their descriptions are omitted as appropriate.

[0108] The differences between the processing system configuration of fundus observation device 1a and that of fundus observation device 1 are that a control unit 60a is provided instead of the control unit 60, an image forming unit 70a is provided instead of the image forming unit 70, and a data processing unit 75a and an OCT optical system 100 are added.

[0109] The control unit 60a includes a main control unit 61a and a storage unit 62a, and in addition to the controls that the control unit 60 can perform, it performs controls on the image forming unit 70a, the data processing unit 75a, and the OCT optical system 100. The functions of the main control unit 61a are realized by, for example, a processor, similar to the main control unit 61. The storage unit 62a, similar to the storage unit 62, stores a computer program for controlling the fundus observation device 1a. This computer program includes a program for controlling the illumination light source, an image sensor, a hole mirror, an image forming program, a data processing program, an OCT optical system control program, and a user interface program. The control unit 60a performs control processing by operating the main control unit 61a according to such a computer program.

[0110] The main control unit 61a controls the slit projection optical system 10, the slit light receiving optical system 20, the hole mirror 30, the image forming unit 70a, the data processing unit 75a, the OCT optical system 100, and the UI unit 80.

[0111] Control of the OCT optical system 100 includes control of the OCT light source 101, operation control of polarization controllers 103 and 118, movement control of the optical path length changing unit 114, operation control of the attenuator 120, control of the detector 125, control of the DAQ 130, control of the optical scanner 150, and control of the movement mechanism 151D.

[0112] Control of the OCT light source 101 includes turning the light source on and off, adjusting the light intensity, and adjusting the aperture. Control of the detector 125 includes adjusting the exposure of the detection element, adjusting the gain, and adjusting the detection rate. Control of the optical scanner 150 includes controlling the scan position, scan range, and scan speed of the optical scanner 150.

[0113] The moving mechanism 151D moves the focusing lens 151 in the direction of the optical axis of the OCT optical system 100. The main control unit 61a can change the focus position of the measurement light by controlling the moving mechanism 151D to move the focusing lens 151 in the direction of the optical axis of the OCT optical system 100. The focus position of the measurement light LS corresponds to the depth position (z position) of the beam waist of the measurement light LS.

[0114] Control over the image forming unit 70a includes image formation control, which forms an image of the eye E under examination from the light reception results obtained by the image sensor 21, as well as OCT image formation control, which is based on the detection results of interference light obtained by the OCT optical system 100.

[0115] Control over the data processing unit 75a includes controlling image processing on the image formed by the image forming unit 70a, and controlling image analysis processing.

[0116] Similar to the image forming unit 70, the image forming unit 70a is capable of forming a light-receiving image (fundus image) corresponding to an arbitrary aperture range based on the light-receiving result read from the image sensor 21. The image forming unit 70a can sequentially form light-receiving images corresponding to the aperture range and form an image of the eye under examination E from the multiple light-receiving images formed.

[0117] Furthermore, the image forming unit 70a forms OCT image (tomographic image) data based on the detection signal input from the DAQ 130 (detector 125) and the pixel position signal input from the control unit 60a. The OCT images formed by the image forming unit 70a include A-scan images and B-scan images. A B-scan image is formed, for example, by arranging A-scan images in the B-scan direction. This process includes noise reduction, filtering, variance compensation, and Fast Fourier Transform (FFT), similar to conventional swept-source type OCT. In the case of other types of OCT devices, the image forming unit 70a performs known processing according to that type. The various images (image data) formed by the image forming unit 70a are stored, for example, in the storage unit 62a.

[0118] The data processing unit 75a processes the image formed based on the light reception results obtained by the slit light receiving optical system 20, or the data acquired by OCT measurement on the eye E under examination. The data processing unit 75a can perform various image processing and analysis processes on the image formed by the image forming unit 70a. For example, the data processing unit 75a performs various correction processes such as brightness correction of the image.

[0119] The data processing unit 75a performs known image processing, such as interpolation to interpolate pixels between OCT images, to form image data of a three-dimensional image of the fundus Ef. Three-dimensional image data refers to image data in which the position of pixels is defined by a three-dimensional coordinate system. Three-dimensional image data can consist of voxels arranged in three dimensions. This image data is called volume data or voxel data. When displaying an image based on volume data, the data processing unit 75a performs rendering processing (such as volume rendering or MIP (Maximum Intensity Projection)) on this volume data to form pseudo-three-dimensional image data as viewed from a specific line of sight. This pseudo-three-dimensional image is displayed on the display device included in the UI unit 80.

[0120] Furthermore, it is possible to form stacked data of multiple tomographic images as 3D image data. Stacked data is image data obtained by arranging multiple tomographic images obtained along multiple scan lines in a 3D manner based on the positional relationship of the scan lines. In other words, stacked data is image data obtained by representing multiple tomographic images, which were originally defined by separate 2D coordinate systems, in a single 3D coordinate system (i.e., embedding them in a single 3D space).

[0121] The data processing unit 75a can perform various rendering operations on the acquired 3D dataset (volume data, stack data, etc.) to form B-mode images (longitudinal images, axial images), C-mode images (transverse images, horizontal images), projection images, shadowgrams, etc., in arbitrary cross-sections. Images of arbitrary cross-sections, such as B-mode and C-mode images, are formed by selecting pixels (voxels) on a specified cross-section from the 3D dataset. Projection images are formed by projecting the 3D dataset in predetermined directions (z-direction, depth direction, axial direction). Shadowgrams are formed by projecting a portion of the 3D dataset (for example, partial data corresponding to a specific layer) in predetermined directions. Images such as C-mode images, projection images, and shadowgrams, which are viewed from the front of the eye being examined, are called en-face images.

[0122] The data processing unit 75a can construct B-mode images and frontal images (vascular-enhanced images, angiograms) that highlight retinal and choroidal blood vessels based on data collected in time series by OCT (e.g., B-scan image data). For example, time-series OCT data can be collected by repeatedly scanning approximately the same area of ​​the eye E under examination.

[0123] In some embodiments, the data processing unit 75a compares time-series B-scan images obtained by B-scanning substantially the same area and constructs an enhanced image in which the changed portion is emphasized by converting the pixel values ​​of the portion with changing signal intensity to pixel values ​​corresponding to the change. Furthermore, the data processing unit 75a extracts a predetermined thickness of information from the multiple enhanced images constructed for a desired area and constructs it as an en-face image to form an OCTA image.

[0124] Images generated by the data processing unit 75a (e.g., 3D images, B-mode images, C-mode images, projection images, shadowgrams, OCTA images) are also included in the OCT image.

[0125] Furthermore, the data processing unit 75a performs predetermined analysis processing on the image formed based on the light reception results obtained by the slit light receiving optical system 20, the interference light detection results obtained by OCT measurement, or the OCT image formed based on said detection results. The predetermined analysis processing includes: identification of predetermined parts (tissues, lesions) in the eye E under examination; calculation of distance (interlayer distance), area, angle, ratio, and density between specified parts; calculation using a specified formula; identification of the shape of the predetermined parts; calculation of statistical values ​​for these; calculation of the distribution of measured values ​​and statistical values; and image processing based on these analysis processing results. Predetermined tissues include blood vessels, optic nerve head, fovea, macula, etc. Predetermined lesions include vitiligo, hemorrhage, etc.

[0126] The fundus observation device 1a may include a movement mechanism that moves the OCT optical system 100 in a one-dimensional or two-dimensional direction intersecting the optical axis of the OCT optical system 100. In this case, the main control unit 61a controls this movement mechanism to move the OCT optical system 100 relative to the dichroic mirror 90 in a one-dimensional or two-dimensional direction intersecting the optical axis of the OCT optical system 100. This moves the scan range using the optical scanner 150 of the OCT optical system 100, making it possible to scan a wide-angle scan range (for example, the SLO imaging range) in the fundus Ef.

[0127] The slit projection optical system 10 and the slit light receiving optical system 20 are examples of a "fundus observation optical system" according to the embodiment. The dichroic mirror 90 is an example of an "optical path coupling and separating member" according to the embodiment.

[0128] <Operation> Next, an example of the operation of the fundus observation device 1a according to the second embodiment will be described.

[0129] The fundus observation device 1a can perform OCT measurement using the OCT optical system 100 in parallel with the scan control of the fundus Ef using illumination light as shown in Figure 3. The control of OCT measurement that can be performed in parallel with the control shown in Figure 3 will be described below.

[0130] Figure 7 shows an example of operation of the fundus observation device 1a according to the second embodiment. Figure 7 is a flowchart of the operation example of the fundus observation device 1a according to the second embodiment. The memory unit 62a stores a computer program for realizing the processing shown in Figure 7. The main control unit 61a executes the processing shown in Figure 7 by operating according to this computer program.

[0131] In Figure 7, it is assumed that the eye E under examination is positioned at a predetermined eye position (the second focal point F4 of the second ellipsoidal mirror 50 in Figure 1).

[0132] (S11: Set scan range) First, the main control unit 61a sets the scan range of the optical scanner 150. Along with the scan range, the main control unit 61a can also set the scan start position, scan end position, scan speed (scan frequency), etc., for the optical scanner 150.

[0133] In some embodiments, the user can specify a scan mode or operation mode by operating an operating device in the UI unit 80. When a scan mode (e.g., horizontal scan, vertical scan) is specified by the user by operating an operating device, the main control unit 61a analyzes the operation information from the operating device to identify the specified scan mode. When an operation mode is specified by the user by operating an operating device, the main control unit 61a analyzes the operation information to identify a pre-specified scan mode (e.g., horizontal scan, vertical scan) in the specified operation mode (OCT measurement mode).

[0134] (S12: Turn on the OCT light source) Next, the main control unit 61a controls the OCT light source 101 to turn it on. In some embodiments, the main control unit 61a executes step S12 in synchronization with the lighting control of the illumination light source 11 in step S1 shown in Figure 3.

[0135] In some embodiments, the main control unit 61a performs focus adjustment control and polarization adjustment control. For example, the main control unit 61a controls the moving mechanism 151D to move the focusing lens by a predetermined distance, and then controls the OCT optical system 100 to perform OCT measurement. The main control unit 61a causes the data processing unit 75a to determine the focus state of the measurement light LS based on the detection result of interference light obtained by the OCT measurement. For example, the data processing unit 75a calculates a predetermined evaluation value for the image quality of the OCT image by analyzing the detection result of interference light acquired by the OCT measurement, and determines the focus state based on the calculated evaluation value. If the data processing unit 75a determines that the focus state of the measurement light LS is not appropriate based on the determination result, the main control unit 61a controls the moving mechanism 151D again and repeats until the focus state is determined to be appropriate.

[0136] Furthermore, for example, the main control unit 61a controls at least one of the polarization controllers 103 and 118 to change the polarization state of at least one of the optical light L0 and the measurement light LS by a predetermined amount, then controls the OCT optical system 100 to perform OCT measurement, and causes the image forming unit 70a to form an OCT image based on the detection results of the acquired interference light. The main control unit 61a causes the data processing unit 75a to determine the image quality of the OCT image obtained by the OCT measurement. If the polarization state of the measurement light LS is determined to be inappropriate based on the determination result by the data processing unit 75a, the main control unit 61a controls the polarization controllers 103 and 118 again and repeats until the polarization state is determined to be appropriate.

[0137] (S13: Perform OCT scan) Next, the main control unit 61a controls the optical scanner 150 to deflect the measurement light LS generated based on the light L0 emitted from the OCT light source 101, and scans a predetermined area of ​​the fundus Ef of the eye E being examined with the deflected measurement light LS. The detection results of the interference light acquired by the OCT measurement are sampled by the DAQ 130 and stored as an interference signal in the storage unit 62a or the like.

[0138] (S14: End?) Next, the main control unit 61a determines whether or not to terminate the OCT scan of the fundus Ef. For example, the main control unit 61a can determine whether or not to terminate the OCT scan of the fundus Ef by determining whether or not the deflection angle of the deflection plane of the optical scanner 150, which is changed sequentially, is within a predetermined deflection angle range.

[0139] When it is determined that the OCT scan of the fundus Ef is to be completed (S14:Y), the operation of the fundus observation device 1a proceeds to step S15. When it is determined that the OCT scan of the fundus Ef is not to be completed (S14:N), the operation of the fundus observation device 1a proceeds to step S13.

[0140] (S15: Forms an OCT image) In step S14, when it is determined that the OCT scan of the fundus Ef is complete (S14:Y), the main control unit 61a causes the image forming unit 70a to form multiple A scan images of the fundus Ef along the B scan direction based on the interference signal acquired in step S14. In some embodiments, the main control unit 61a controls the data processing unit 75a to form OCT images such as three-dimensional OCT images, B-mode images, C-mode images, projection images, shadowgrams, and OCTA images.

[0141] This concludes the operation of the fundus observation device 1a.

[0142] Figure 8 shows an explanatory diagram of the operation of the fundus observation device 1a according to the second embodiment.

[0143] As shown in Figure 8, the illumination light scan in the fundus Ef, achieved by deflecting the illumination light using the hole mirror 30, and the OCT scan in the fundus Ef, achieved by deflecting the measurement light LS using the optical scanner 150, are performed in parallel. This allows for the OCT scan to be performed on any scan range SC0 within the scan range SC1 (horizontal H0 × vertical V0) in the fundus Ef while the illumination light scan is being performed.

[0144] As a result, by scanning the illumination light across the SC1 scan range, it becomes possible to perform OCT measurements (OCT imaging) at any position in the fundus being observed with a wide angle.

[0145] As described above, according to the second embodiment, in addition to the effects obtained in the first embodiment, by optically coupling the OCT optical system 100 on the transmission side of the hole mirror 30 as a deflection member (through the hole in the hole mirror), the optical path of the wide-angle illumination light and the optical path of the reflected light can be separated at low cost. Furthermore, it becomes possible to perform OCT measurement (OCT imaging) at any position of the fundus being observed at a wide angle without sharing the optical scanner for OCT scanning and the optical scanner for deflecting the illumination light.

[0146] <Variation> <First variation> In the first and second embodiments, the case was described in which the second ellipsoidal mirror 50 is positioned such that the angle α between the line connecting the first focus F1 and the second focus F2 of the first ellipsoidal mirror 40 and the line connecting the first focus F3 and the second focus F4 of the second ellipsoidal mirror 50 is 30 degrees. However, the configuration according to the embodiments is not limited thereto. For example, the angle α between the line connecting the first focus F1 and the second focus F2 of the first ellipsoidal mirror 40 and the line connecting the first focus F3 and the second focus F4 of the second ellipsoidal mirror 50 may be approximately 0 degrees.

[0147] Figure 9 shows an example of the optical system configuration of a fundus observation device according to a first modified embodiment. In Figure 9, the same reference numerals are used for parts that are the same as in Figure 4, and their descriptions are omitted as appropriate.

[0148] The difference between the optical system configuration of the fundus observation device 1b according to the first modified example and the optical system configuration of the fundus observation device 1a according to the second embodiment is the arrangement of the second ellipsoidal mirror 50 relative to the first ellipsoidal mirror 40. In the fundus observation device 1b, the second ellipsoidal mirror 50 is arranged such that the angle α between the straight line connecting the first focal point F1 and the second focal point F2 of the first ellipsoidal mirror 40 and the straight line connecting the first focal point F3 and the second focal point F4 of the second ellipsoidal mirror 50 is 0.2 degrees (approximately 0 degrees).

[0149] In Figure 9, the fundus observation device 1b is equipped with an OCT optical system 100, but the fundus observation device 1b may also have a configuration in which the OCT optical system 100 is omitted, similar to Figure 1.

[0150] Depending on the angle α described above, the symmetry of the observation range with respect to the eye E under examination changes, along with the wide-angle range. According to the first modified example, compared to the second embodiment, it becomes possible to observe the fundus Ef within a wide-angle range that is symmetrical with respect to the eye E under examination.

[0151] <Second variation> In the first embodiment, a case in which illumination light is deflected using a hole mirror 30 was described, but the configuration of the embodiment is not limited thereto. In the first embodiment, for example, a reflective mirror may be placed at the first focal point F1 of the first ellipsoidal mirror 40, and a hole mirror may be placed at a position that is optically approximately conjugate to the pupil of the eye E being examined.

[0152] Figure 10 shows an example of the optical system configuration of a fundus observation device according to a second modified embodiment. In Figure 10, the same reference numerals are used for parts that are the same as in Figure 1, and their descriptions are omitted as appropriate.

[0153] The optical system configuration of the fundus observation device 1c according to the second modification differs from the optical system configuration of the fundus observation device 1 according to the first embodiment in that a reflective mirror 31 is placed in place of the hole mirror 30 at the first focal point F1 of the first ellipsoidal mirror 40, a hole mirror 32 is placed at the pupillary conjugate position Q, which is far from the first focal point F1, an optical scanner 17 is placed between the hole mirror 32 and the slit projection optical system 10, and relay lenses 33, 15, and 16 are added to relay the pupillary conjugate position Q.

[0154] The orientation of the deflection surface of the reflective mirror 31 is fixed. The relay lens 33 is positioned between the reflective mirror 31 and the hole mirror 32. The hole mirror 32 separates or combines the optical path of the slit projection optical system 10 and the optical path of the slit light receiving optical system 20. The orientation of the deflection surface of the hole mirror 32 is fixed. A relay lens 16, an optical scanner 17, and a relay lens 15 are positioned between the hole mirror 32 and the slit projection optical system 10. The optical scanner 17 is a uniaxial optical scanner that performs the same deflection operation of illumination light as the hole mirror 30.

[0155] In this case, the illumination light from the slit projection optical system 10 passes through the relay lens 15 and is deflected by the optical scanner 17. The illumination light deflected by the optical scanner 17 passes through the relay lens 16, is deflected in the peripheral region of the hole formed in the hole mirror 32, and is guided to the relay lens 33. The illumination light guided to the relay lens 33 is reflected by the reflection mirror 31 and guided to the reflection surface of the first ellipsoidal mirror 40. The reflected light from the fundus Ef of the eye under examination is deflected by the reflection mirror 31, passes through the relay lens 33, passes through the hole in the hole mirror 32, and is guided to the slit light receiving optical system 20.

[0156] The fundus observation device 1c may also have a configuration in which the reflective mirror 31 is omitted from the configuration shown in Figure 10. In this case, the illumination light that has passed through the relay lens 33 is directly guided to the reflective surface of the first ellipsoidal mirror 40, and the reflected light of the illumination light reflected from the reflective surface of the first ellipsoidal mirror 40 is directly guided to the relay lens 33.

[0157] According to the second modified example, compared to the first embodiment, even if there is not enough space to place the optical system near the first focal point F1 of the first ellipsoidal mirror 40, the degree of freedom in arranging the slit projection optical system 10 and the slit light-receiving optical system 20 can be improved by relaying the pupil conjugate position Q.

[0158] <Third variation> In the second embodiment, a case in which the illumination light is deflected using the hole mirror 30 was described, but the configuration of the embodiment is not limited thereto. In the second embodiment, similar to the second modification, for example, the reflective mirror of the first focal point F1 of the first ellipsoidal mirror 40 may be placed, and the hole mirror may be placed at a position that is optically approximately conjugate to the pupil of the eye E under examination.

[0159] Figure 11 shows an example of the optical system configuration of a fundus observation device according to a third modified embodiment. In Figure 11, the same reference numerals are used for parts that are the same as those in Figure 4 or Figure 10, and their descriptions are omitted as appropriate.

[0160] The optical system configuration of the fundus observation device 1d according to the third modified example differs from the optical system configuration of the fundus observation device 1a according to the second embodiment in that a reflective mirror 31 is placed in place of the hole mirror 30 at the first focal point F1 of the first ellipsoidal mirror 40, a hole mirror 32 is placed at the pupillary conjugate position Q, which is far from the first focal point F1, an optical scanner 17 is placed between the hole mirror 32 and the slit projection optical system 10, and relay lenses 15 and 16 are added to relay the pupillary conjugate position Q.

[0161] Similar to the second modification, the orientation of the deflection surfaces of the reflective mirror 31 and the hole mirror 32 is fixed. The pupil conjugate position Q is relayed by relay lenses 71 and 72. The hole mirror 32 separates or combines the optical path of the slit projection optical system 10 and the optical path of the slit light receiving optical system 20. Relay lenses 16, optical scanner 17, and relay lens 15 are positioned between the hole mirror 32 and the slit projection optical system 10. The optical scanner 17 is a uniaxial optical scanner that performs the same deflection operation of illumination light as the hole mirror 30.

[0162] In this case, the illumination light from the slit projection optical system 10 passes through the relay lens 15 and is deflected by the optical scanner 17. The illumination light deflected by the optical scanner 17 passes through the relay lens 16, is deflected in the peripheral region of the hole formed in the hole mirror 32, passes through the relay lens 72, the dichroic mirror 90, and the relay lens 71, is reflected by the reflection mirror 31, and is guided to the reflection surface of the first ellipsoidal mirror 40. The reflected light from the fundus Ef of the eye under examination is deflected by the reflection mirror 31, passes through the relay lens 71, the dichroic mirror 90, and the relay lens 72, passes through the hole in the hole mirror 32, and is guided to the slit light receiving optical system 20.

[0163] According to the third modified example, compared to the second embodiment, even if there is not enough space to place the optical system near the first focal point F1 of the first ellipsoidal mirror 40, the degree of freedom in arranging the slit projection optical system 10 and the slit light-receiving optical system 20 can be improved by relaying the pupil conjugate position Q.

[0164] <Fourth variation> In the above embodiment or its modified form, the hole mirror 30 that performs the deflection operation of the illumination light may have the following structure.

[0165] Figures 12A and 12B schematically show the structure of the hole mirror 30 according to the fourth modified embodiment. Figure 12A schematically shows the outline of the configuration of the hole mirror 30 according to this modified embodiment. Figure 12B schematically shows the cross-sectional shape when the hole mirror 30 in Figure 12A is cut by a cutting plane passing through the hole.

[0166] As shown in Figure 12A, the lens mirror 30 has a tapered hole portion 30a. For example, as shown in Figure 12B, the tapered hole portion 30a is formed such that the diameter widens from an opening of diameter h around the optical axis over an angular range r. For example, the diameter h is 3 to 4 mm and the angular range r is 120 degrees.

[0167] For example, the side with the larger diameter of the hole 30a is positioned to face the slit light-receiving optical system 20. That is, the hole mirror 30 is positioned such that the opening on the side facing the slit light-receiving optical system 20, which receives the reflected light from the illumination, is wider than the opening on the side facing the deflection surface of the illumination light. In other words, a tapered hole 30a is formed in the center of the hole mirror 30 so that the opening size on the side receiving the reflected light from the illumination is larger. As a result, even if the hole mirror 30 is tilted with respect to the optical axis, vignetting of the reflected light beam on the receiving side can be suppressed.

[0168] <Fifth variation> In the above embodiments or their modified forms, the perforated mirror 30 (or perforated mirror 32) is not limited to the structure relating to the fourth modified form.

[0169] Figures 13A and 13B schematically show the structure of the hole mirror 30 according to the fifth modified example of the embodiment. Figure 13A schematically shows the outline of the configuration of the hole mirror 30 according to this modified example. Figure 13B schematically shows the cross-sectional shape when the hole mirror 30 in Figure 13A is cut by a cutting plane passing through the hole.

[0170] As shown in Figure 13B, the hole mirror 30 includes a parallel plane plate 30d formed of a transmissive member that allows at least the reflected light of illumination to pass through, and a reflective film 30c provided on the surface of the parallel plane plate 30d. The reflective film 30c has an opening 30b formed in the center through which the optical axis passes. For example, the reflective film 30c is formed by depositing a metal film or a dielectric multilayer film onto the surface of the parallel plane plate 30d.

[0171] For example, the side without the reflective film 30c is positioned to face the slit light-receiving optical system 20. That is, the hole mirror 30 is positioned so that the illumination light is reflected by the reflective film 30c provided on the surface of the parallel flat plate 30d without passing through the transmitting member.

[0172] <Sixth variation> The configuration of the fundus observation device according to the embodiment is not limited to the above embodiment or its modified form. For example, in the configuration shown in Figure 1, three or more aspherical mirrors may be provided instead of the first ellipsoidal mirror 40 and the second ellipsoidal mirror. Examples of aspherical mirrors include, in addition to ellipsoidal mirrors, parabolic mirrors, hyperbolic mirrors, and mirrors whose reflective surface is represented by a higher-order polynomial. In some embodiments, the three or more aspherical mirrors include free-form mirrors.

[0173] In this modified example, the first ellipsoidal mirror 40 and the second ellipsoidal mirror are replaced with two concave mirrors (aspherical mirrors) and one convex mirror (aspherical mirror).

[0174] The following describes a fundus observation device according to a sixth modified embodiment, focusing on the differences from the fundus observation device 1 according to the first embodiment.

[0175] Figure 14 shows an example of the optical system configuration of a fundus observation device according to a sixth modified embodiment. In Figure 14, the same reference numerals are used for parts that are the same as in Figure 1, and their descriptions are omitted as appropriate.

[0176] The difference between the configuration of the fundus observation device 1e according to this modified example and the configuration of the fundus observation device 1 according to the embodiment is that, instead of the first ellipsoidal mirror 40 and the second ellipsoidal mirror 50, a reflective mirror 41 as a planar mirror, a hyperbolic mirror 42 as a concave mirror, a hyperbolic mirror 43 as a convex mirror, and an ellipsoidal mirror 51 as a concave mirror are provided.

[0177] The reflective mirror 41 reflects the illumination light reflected by the hole mirror 30 and guides it to the hyperbolic mirror 42. It also reflects the backlight of the illumination light reflected by the reflective surface of the hyperbolic mirror 42 and guides it to the hole mirror 30. In some embodiments, the fundus observation device 1e has a configuration in which the reflective mirror 41 is omitted.

[0178] By deflecting the optical axis with the reflective mirror 41, the size of the optical system of the fundus observation device 1e in the depth direction (z direction) can be reduced.

[0179] (Hyperboloid mirror 42) The hyperbolic mirror 42 has a concave reflective surface. The reflective surface of the hyperbolic mirror 42 is a hyperbolic surface. The hyperbolic mirror 42 is an example of a concave mirror.

[0180] One of the foci of the hyperbolic mirror 42 is the first focal spot F1. The hole mirror 30 (the deflection surface of the hole mirror 30) is positioned at or near the first focal spot F1 of the hyperbolic mirror 42. In some embodiments, the hole mirror 30 is positioned at or near a position optically conjugate to the first focal spot F1 (the conjugate position of the first focal spot F1).

[0181] (Hyperboloid mirror 43) The hyperbolic mirror 43 has a convex reflective surface. The reflective surface of the hyperbolic mirror 43 is a hyperbolic surface. The hyperbolic mirror 43 is an example of a convex mirror.

[0182] One of the foci of the hyperbolic mirror 43 is the second focus, F2.

[0183] (Ellipsoidal mirror 51) The reflective surface of the ellipsoidal mirror 51 is an ellipsoid. The second ellipsoidal mirror 50 is an example of a concave mirror.

[0184] The ellipsoidal mirror 51 has two optically conjugate foci (first focal point F3, second focal point F4). The ellipsoidal mirror 51 is positioned such that the first focal point F3 substantially coincides with the second focal point F2 of the hyperbolic mirror 43. In some embodiments, the ellipsoidal mirror 51 is positioned such that the first focal point F3 substantially coincides with the optically conjugate position of the second focal point F2 of the hyperbolic mirror 43 (the conjugate position of the second focal point F2) or in its vicinity. The eye under examination E is positioned at the second focal point F4 of the ellipsoidal mirror 51. That is, the ellipsoidal mirror 51 is positioned such that the second focal point F4 substantially coincides with the position of the eye under examination E.

[0185] In this configuration, the illumination light deflected by the hole mirror 30 positioned at the first focal point F1 is reflected by the reflective surface of the reflective mirror 41, reflected by the concave reflective surface of the hyperbolic mirror 42, reflected by the convex reflective surface of the hyperbolic mirror 43, reflected by the reflective surface of the ellipsoidal mirror 51, and guided to the eye under examination E positioned at the second focal point F4 of the ellipsoidal mirror 51.

[0186] The illumination light guided into the eye E enters the eye through the pupil and irradiates the fundus Ef. The reflected illumination light from the fundus Ef exits the eye E through the pupil and travels in the reverse direction along the same path as the outward journey, guided to the first focal point F1 of the hyperbolic mirror 42. The reflected illumination light guided to the first focal point F1 passes through the hole formed in the hole mirror 30 (or passes through the hole mirror 30) as described above and is guided to the slit light-receiving optical system 20.

[0187] In some embodiments, at least one of the hyperbolic mirrors 42, 43 is a parabolic mirror. In some embodiments, at least one of the hyperbolic mirrors 42, 43 and the ellipsoidal mirror 51 is formed such that its reflective surface is a free-form surface.

[0188] In addition, in the configuration shown in Figure 4 or Figure 9, three or more aspherical mirrors may be provided instead of the first ellipsoidal mirror 40 and the second ellipsoidal mirror 50, similar to this modified example.

[0189] <7th variation> The configuration of the fundus observation device according to the embodiment is not limited to the above embodiment or its modified form. For example, in the configuration shown in Figure 10, three or more aspherical mirrors may be provided instead of the first ellipsoidal mirror 40 and the second ellipsoidal mirror.

[0190] In this modified example, as in the sixth modified example, the first ellipsoidal mirror 40 and the second ellipsoidal mirror are replaced with two concave mirrors (aspherical mirrors) and one convex mirror (aspherical mirror).

[0191] The following describes the fundus observation device according to the seventh modification of the embodiment, focusing on the differences from the fundus observation device 1c according to the second modification.

[0192] Figure 15 shows an example of the optical system configuration of a fundus observation device according to a seventh modified embodiment. In Figure 15, the same reference numerals are used for parts that are the same as those in Figure 10 or Figure 14, and their descriptions are omitted as appropriate.

[0193] The difference between the configuration of the fundus observation device 1f according to this modified example and the configuration of the fundus observation device 1c according to the second modified example is that, instead of the first ellipsoidal mirror 40 and the second ellipsoidal mirror 50, a reflective mirror 41 as a planar mirror, a hyperbolic mirror 42 as a concave mirror, a hyperbolic mirror 43 as a convex mirror, and an ellipsoidal mirror 51 as a concave mirror are provided.

[0194] In this configuration, the illumination light deflected by the reflective mirror 31 positioned at the first focal point F1 is reflected by the reflective surface of the reflective mirror 41, reflected by the concave reflective surface of the hyperbolic mirror 42, reflected by the convex reflective surface of the hyperbolic mirror 43, reflected by the reflective surface of the ellipsoidal mirror 51, and guided to the eye under examination E positioned at the second focal point F4 of the ellipsoidal mirror 51.

[0195] The illumination light guided into the eye E enters the eye through the pupil and irradiates the fundus Ef. The reflected illumination light from the fundus Ef exits the eye E through the pupil and travels in the reverse direction along the same path as the outward journey, guided to the first focal point F1 of the hyperbolic mirror 42. The reflected illumination light guided to the first focal point F1 passes through the hole formed in the hole mirror 30 (or passes through the hole mirror 30) as described above and is guided to the slit light-receiving optical system 20.

[0196] In some embodiments, at least one of the hyperbolic mirrors 42, 43 is a parabolic mirror. In some embodiments, at least one of the hyperbolic mirrors 42, 43 and the ellipsoidal mirror 51 is formed such that its reflective surface is a free-form surface.

[0197] In the configuration shown in Figure 11, similar to this modified example, three or more aspherical mirrors may be provided instead of the first ellipsoidal mirror 40 and the second ellipsoidal mirror 50.

[0198] <8th variation> In the above embodiment or its modified form, the fundus observation device may have one or more aspherical refractive optical elements arranged in the optical path of the illumination light and the optical path of the return light of the illumination light.

[0199] Aspherical refractive optical elements can correct the aberration components inherent in mirrors whose reflective surfaces are quadratic surfaces, such as ellipsoidal mirrors, hyperbolic mirrors, and parabolic mirrors, by introducing an asymmetric aberration component in a predetermined direction (a direction intersecting the optical axis) with respect to the incident light. In other words, when aspherical mirrors such as ellipsoidal mirrors, hyperbolic mirrors, and parabolic mirrors are configured asymmetrically in a direction perpendicular (or, in a broad sense, intersecting) to the optical axis (for example, the optical path of illumination light or its return light), the aspherical refractive optical element can improve the imaging characteristics based on the incident light by correcting the aberration corresponding to the amount of deviation from the optical axis.

[0200] Examples of aspherical refractive optical elements include aspherical lenses such as anamorphic aspherical lenses.

[0201] It is desirable that each of the one or more aspherical refractive optical elements be positioned at the pupillary conjugate position Q. This allows for a reduction in the diameter of the aspherical refractive optical elements.

[0202] The following describes the fundus observation device according to the eighth modified embodiment, focusing on the differences from the fundus observation device 1 according to the first embodiment.

[0203] Figure 16A shows an example of the optical system configuration of a fundus observation device according to the eighth modified embodiment. In Figure 16A, the same reference numerals are used for parts that are the same as in Figure 1, and their descriptions are omitted as appropriate.

[0204] The difference between the configuration of the fundus observation device 1g according to this modified example and the configuration of the fundus observation device 1 according to the embodiment is that an aspherical refractive optical element 35 is arranged between the hole mirror 30 and the first ellipsoidal mirror 40. That is, the aspherical refractive optical element 35 is arranged in the optical path of the illumination light and the optical path of the reflected light of the illumination light.

[0205] In this modified example, if at least one of the first ellipsoidal mirror 40 and the second ellipsoidal mirror 50 is configured asymmetrically in the y-direction (first direction) with respect to the optical path (optical axis) of the illumination light or the reflected light, the aspherical refractive optical element 35 imparts an aberration component that is asymmetrical in the y-direction with respect to the incident light. This allows for correction of the aberration components of the first ellipsoidal mirror 40 and the second ellipsoidal mirror 50.

[0206] Figure 16B shows another example of the optical system configuration of the fundus observation device according to the eighth modified embodiment. In Figure 16B, the same reference numerals are used for parts that are the same as those in Figure 1 or Figure 16A, and their descriptions are omitted as appropriate.

[0207] The difference between the configuration of the fundus observation device 1h according to this modified example and the configuration of the fundus observation device 1 according to the embodiment is that an aspherical refractive optical element 35 is arranged between the first ellipsoidal mirror 40 and the second ellipsoidal mirror 50. That is, the aspherical refractive optical element 35 is arranged in the optical path of the illumination light and the optical path of the reflected light of the illumination light.

[0208] In this modified example, if at least one of the first ellipsoidal mirror 40 and the second ellipsoidal mirror 50 is configured asymmetrically in the y-direction with respect to the optical path (optical axis) of the illumination light or its reflected light, the aspherical refractive optical element 35 imparts an aberration component that is asymmetrical in the y-direction with respect to the incident light. This allows for correction of the aberration components of the first ellipsoidal mirror 40 and the second ellipsoidal mirror 50.

[0209] Figure 16C shows yet another configuration example of the optical system of the fundus observation device according to the eighth modified embodiment. In Figure 16C, the same reference numerals are used for parts that are the same as those in Figure 1 or Figure 16A, and their descriptions are omitted as appropriate.

[0210] The differences between the configuration of the fundus observation device 1j according to this modified example and the configuration of the fundus observation device 1 according to the embodiment are that an aspherical refractive optical element 35 is arranged in the optical path of the illumination light between the slit projection optical system 10 and the hole mirror 30, and an aspherical refractive optical element 35 is arranged in the optical path of the return light of the illumination light between the hole mirror 30 and the slit light receiving optical system 20. In other words, the two aspherical refractive optical elements 35 are arranged in the optical path of the illumination light and the optical path of the return light of the illumination light.

[0211] In this modified example, if at least one of the first ellipsoidal mirror 40 and the second ellipsoidal mirror 50 is configured asymmetrically in the y-direction with respect to the optical path (optical axis) of the illumination light or its reflected light, each of the two aspherical refractive optical elements 35 imparts an aberration component that is asymmetrical in the y-direction with respect to the incident light. This makes it possible to correct the aberration components of the first ellipsoidal mirror 40 and the second ellipsoidal mirror 50.

[0212] In addition, in the configurations shown in Figures 4, 9, or 14, one or more aspherical refractive optical elements 35 may be arranged in the optical path of the illumination light and the optical path of the reflected illumination light, similar to this modified example. In the configuration shown in Figure 14, if at least one of the hyperbolic mirrors 42, 43 and the ellipsoidal mirror 51 is configured asymmetrically in the y-direction with respect to the optical path (optical axis) of the illumination light or its reflected light, the aspherical refractive optical element 35 imparts an aberration component that is asymmetrical in the y-direction with respect to the incident light. This makes it possible to correct the aberration components of the hyperbolic mirrors 42, 43 and the ellipsoidal mirror 51.

[0213] Furthermore, in the configurations shown in Figures 4 and 9, an aspherical refractive optical element 35 may be placed between the dichroic mirror 90 and the OCT optical system 100. In some embodiments, the aspherical refractive optical element 35 is not placed in the optical path of the illumination light or the optical path of the return light of the illumination light, but is placed only between the dichroic mirror 90 and the OCT optical system 100.

[0214] This modified example describes the correction of aberrations in the y-direction, but it is also possible to correct aberrations in the x-direction. Furthermore, if the above-mentioned aspherical mirror is configured asymmetrically in the x-direction and y-direction, aberrations in both the x-direction and y-direction may be corrected.

[0215] <9th variation> For example, in the configuration shown in Figure 10, one or more aspherical refractive optical elements may be arranged in the optical path of the illumination light and the optical path of the return light of the illumination light, similar to the eighth modified example.

[0216] The following describes the fundus observation device according to the ninth modified embodiment, focusing on the differences from the fundus observation device 1c according to the second modified embodiment.

[0217] Figure 17A shows an example of the optical system configuration of a fundus observation device according to the ninth modified embodiment. In Figure 17A, the same reference numerals are used for parts that are the same as in Figure 10, and their descriptions are omitted as appropriate.

[0218] The difference between the configuration of the fundus observation device 1k according to this modified example and the configuration of the fundus observation device 1c according to the second modified example is that an aspherical refractive optical element 35 is placed between the reflective mirror 31 and the first ellipsoidal mirror 40. That is, the aspherical refractive optical element 35 is placed in the optical path of the illumination light and the optical path of the reflected light of the illumination light.

[0219] In this modified example, if at least one of the first ellipsoidal mirror 40 and the second ellipsoidal mirror 50 is configured asymmetrically in the y-direction with respect to the optical path (optical axis) of the illumination light or its reflected light, the aspherical refractive optical element 35 imparts an aberration component that is asymmetrical in the y-direction with respect to the incident light. This allows for correction of the aberration components of the first ellipsoidal mirror 40 and the second ellipsoidal mirror 50.

[0220] Figure 17B shows another example of the optical system configuration of the fundus observation device according to the ninth modified embodiment. In Figure 17B, the same reference numerals are used for parts that are the same as those in Figure 10 or Figure 17A, and their descriptions are omitted as appropriate.

[0221] The difference between the configuration of the fundus observation device 1m according to this modified example and the configuration of the fundus observation device 1c according to the second modified example is that an aspherical refractive optical element 35 is positioned between the first ellipsoidal mirror 40 and the second ellipsoidal mirror 50. That is, the aspherical refractive optical element 35 is positioned in the optical path of the illumination light and the optical path of the reflected light of the illumination light.

[0222] In this modified example, if at least one of the first ellipsoidal mirror 40 and the second ellipsoidal mirror 50 is configured asymmetrically in the y-direction with respect to the optical path (optical axis) of the illumination light or its reflected light, the aspherical refractive optical element 35 imparts an aberration component that is asymmetrical in the y-direction with respect to the incident light. This allows for correction of the aberration components of the first ellipsoidal mirror 40 and the second ellipsoidal mirror 50.

[0223] Figure 17C shows yet another configuration example of the optical system of the fundus observation device according to the ninth modified embodiment. In Figure 17C, the same reference numerals are used for parts that are the same as those in Figure 10 or Figure 17A, and their descriptions are omitted as appropriate.

[0224] The difference between the configuration of the fundus observation device 1n according to this modified example and the configuration of the fundus observation device 1c according to the second modified example is that an aspherical refractive optical element 35 is placed between the reflective mirror 31 and the relay lens 33. That is, the aspherical refractive optical element 35 is placed in the optical path of the illumination light and the optical path of the reflected light of the illumination light.

[0225] In this modified example, if at least one of the first ellipsoidal mirror 40 and the second ellipsoidal mirror 50 is configured asymmetrically in the y-direction with respect to the optical path (optical axis) of the illumination light or its reflected light, each of the two aspherical refractive optical elements 35 imparts an aberration component that is asymmetrical in the y-direction with respect to the incident light. This makes it possible to correct the aberration components of the first ellipsoidal mirror 40 and the second ellipsoidal mirror 50.

[0226] In the configurations shown in Figure 11 or Figure 15, one or more aspherical refractive optical elements 35 may be arranged in the optical path of the illumination light and the optical path of the reflected light, similar to this modified example. In the configuration shown in Figure 15, if at least one of the hyperbolic mirrors 42, 43 and the ellipsoidal mirror 51 is configured asymmetrically in the y-direction with respect to the optical path (optical axis) of the illumination light or its reflected light, the aspherical refractive optical element 35 imparts an aberration component that is asymmetrical in the y-direction with respect to the incident light. This makes it possible to correct the aberration components of the hyperbolic mirrors 42, 43 and the ellipsoidal mirror 51.

[0227] Furthermore, in the configuration shown in Figure 11, an aspherical refractive optical element 35 may be placed between the dichroic mirror 90 and the OCT optical system 100. In some embodiments, the aspherical refractive optical element 35 is not placed in the optical path of the illumination light or the optical path of the return light of the illumination light, but is placed only between the dichroic mirror 90 and the OCT optical system 100.

[0228] This modified example describes the correction of aberrations in the y-direction, but it is also possible to correct aberrations in the x-direction. Furthermore, if the above-mentioned aspherical mirror is configured asymmetrically in the x-direction and y-direction, aberrations in both the x-direction and y-direction may be corrected.

[0229] <10th variation> In the embodiments or modifications thereof described above, the case in which the aperture mirror 30 has an opening formed in a region including the central part through which the optical axis passes has been described, but the configurations of the embodiments are not limited thereto.

[0230] Figure 18 schematically shows the structure of the hole mirror 30 according to the tenth modified example of the embodiment. In Figure 18, the same reference numerals are used for parts that are the same as those in Figure 12A, and their descriptions are omitted as appropriate.

[0231] As shown in Figure 18, the perforated mirror 30 has a hole 30a formed at a position eccentric with respect to the optical axis. That is, the hole 30a is formed in the peripheral region of the area including the central region through which the optical axis passes. In this case, the illumination light reflected in the peripheral region of the perforated mirror 30 is guided to the eye under examination E, and the reflected illumination light from the eye under examination E passes through the hole 30a formed at a position eccentric with respect to the optical axis.

[0232] <11th variation> In the above embodiment or its modifications, the case described is one in which illumination light is reflected in the peripheral region of the region including the center of the hole mirror 30 as a deflection member, and the reflected light of the illumination light passes through the hole formed in the region including the center of the hole mirror 30. However, the configuration of the embodiment is not limited to this. For example, the illumination light may be reflected in the region including the center of the deflection member, and the reflected light of the illumination light may be transmitted (passed through) the peripheral region of the region including the center of the deflection member.

[0233] Figure 19 shows an example of the optical system configuration of a fundus observation device according to the 11th modified embodiment. In Figure 19, the same reference numerals are used for parts that are the same as in Figure 1, and their descriptions are omitted as appropriate.

[0234] The difference between the configuration of the fundus observation device 1p according to the 11th modified example and the configuration of the fundus observation device 1 according to the first embodiment is that a deflection mirror 37 is provided as a deflection member instead of the hole mirror 30.

[0235] The deflection mirror 37 (specifically, the deflection surface described later) can be positioned at the pupil conjugate position Q. Similar to the hole mirror 30, the deflection mirror 37 has a deflection surface whose orientation (deflection direction) can be changed, and functions as a uniaxial optical scanner that guides illumination light from the slit projection optical system 10 to the reflective surface of the first ellipsoidal mirror 40 described later.

[0236] Figure 20 schematically shows the configuration of the deflection mirror 37 according to the 11th modified example of the embodiment.

[0237] As shown in Figure 20, the deflection mirror 37 has a deflection surface on which a reflective member is provided. The deflection mirror 37 has a structure in which the illumination light is reflected by the deflection surface, and the reflected illumination light is transmitted (passed through) the peripheral part of the deflection surface. In this case, the illumination light is reflected in the region including the center of the deflection mirror 37, and the reflected illumination light passes through the peripheral region including the center of the deflection mirror 37.

[0238] The deflection mirror 37 deflects the illumination light by changing the orientation of its deflection surface so that it moves sequentially in a direction perpendicular to the slit direction of the illumination area (the direction in which the slit extends, the longitudinal direction of the illumination area) at the illumination site of the eye E under examination. The deflection mirror 37 is configured to change the direction of deflection of the illumination light under control from the control unit.

[0239] The illumination light from the slit projection optical system 10 is deflected by the deflection surface and guided to the reflective surface of the first ellipsoidal mirror 40. The reflected light from the eye under examination E passes through the reflective surface of the first ellipsoidal mirror 40, through the peripheral region of the deflection surface of the deflection mirror 37, and is guided to the slit light receiving optical system 20.

[0240] Figures 21A and 21B schematically show another example of the structure of the deflection mirror 37 according to the 11th modified embodiment. Figure 21A schematically shows the outline of the configuration of the deflection mirror 37 according to this modified embodiment. Figure 21B schematically shows the cross-sectional shape when the deflection mirror 37 in Figure 21A is cut by a cutting plane passing through the center.

[0241] As shown in Figures 21A and 21B, the deflection mirror 37 includes a parallel plane plate 37d formed of a transmissive member that allows at least the reflected light of illumination to pass through, and a reflective film 37b provided on the surface of the parallel plane plate 37d. The reflective film 37b is formed in the central part through which the optical axis passes. For example, the reflective film 37b is formed by depositing a metal film or a dielectric multilayer film onto the surface of the parallel plane plate 37d.

[0242] In some embodiments, similar to the eighth variant, the deflection mirror 37 is positioned eccentrically from the optical axis.

[0243] Figure 22 schematically shows another configuration example of the deflection mirror 37 according to the 11th modified example of the embodiment.

[0244] As shown in Figure 22, the deflection mirror 37 is positioned eccentrically from the optical axis. In this configuration, the illumination light reflected from the deflection surface of the deflection mirror 37 is guided to the eye under examination E, and the reflected illumination light from the eye under examination E passes through the peripheral region of the deflection surface.

[0245] [Effect] A fundus observation device according to an embodiment will be described.

[0246] Some embodiment of the fundus observation device (1, 1a, 1b, 1e, 1g, 1h, 1j, 1p) includes an illumination optical system (slit projection optical system 10), a two-dimensional image sensor (image sensor 21), and a deflection member (hole mirror 30, deflection mirror 37). The illumination optical system illuminates the fundus (Ef) of the eye under examination (E) with linear illumination light. The two-dimensional image sensor receives the reflected light from the fundus at a movable focal plane set at a position (fundus conjugate position P) that is optically approximately conjugate to the fundus. The deflection member connects the optical path of the illumination light and the optical path of the reflected light, and deflects the illumination light in synchronization with the movement of the focal plane, thereby scanning the fundus with the illumination light. The deflection member has a structure that allows the reflected light to pass through a first region and reflects the illumination light in a second region different from the first region.

[0247] The second region may be a region that does not overlap with the first region. With this configuration, the optical path of the illumination light and the optical path of the return light from the fundus are connected using a deflection member, and the illumination light is deflected using the deflection member to scan the fundus. As a result, a low-cost and compact configuration is achieved, and a wide-angle field of view can be secured using only an optical system that scans in the width direction of the illumination light line, while easily arranging a shared optical system for the wide-angle illumination light path and the return light path. Furthermore, since an optical system can be arranged on the transmitting side of the deflection member, a pupil relay system is not required, and the degree of freedom in arranging the optical system can be improved.

[0248] In some embodiments of fundus observation devices, the two-dimensional image sensor is a rolling shutter type image sensor.

[0249] This configuration allows for high-contrast observation of the fundus of the eye with a simple setup.

[0250] In some embodiment of the fundus observation device, the optical path coupling point between the optical path of the illumination light and the optical path of the return light is positioned at a location that is optically approximately conjugate to the pupil of the eye being examined (pupil-conjugate position Q).

[0251] This configuration allows for efficient illumination of the eye, enabling higher-contrast observation of the fundus.

[0252] In some embodiments of fundus observation devices, the field of view is 80 degrees or more.

[0253] This configuration allows for low-cost and simple setup, enabling wide-angle observation of the fundus with a field of view of 80 degrees or more.

[0254] Some embodiment of the fundus observation device includes an optical scanner (150), an OCT optical system (100) that irradiates the eye under examination with measurement light (LS) deflected by the optical scanner and performs an OCT scan by detecting interference light (LC) between the reflected measurement light and a reference light (LR), and an optical path coupling / separating member (dichroic mirror 90) positioned between the deflection member and a two-dimensional image sensor to couple the optical path of the reflected light and the optical path of the OCT optical system.

[0255] With this configuration, by optically coupling the OCT optical system on the transmission side of the deflection member, the optical path of the wide-angle illumination light and the optical path of the reflected light can be separated at low cost. Furthermore, it becomes possible to perform OCT measurements at any position on the fundus being observed at a wide angle without sharing the optical scanner for OCT scanning and the optical scanner for deflecting the illumination light.

[0256] In some embodiment of the fundus observation device, the illumination optical system includes a slit (13) that is illuminated by light from an illumination light source (11) and can be positioned at a location that is optically substantially conjugate to the fundus of the eye under examination.

[0257] With this configuration, it becomes possible to illuminate the fundus of the eye with illumination light having a linear cross-sectional shape, using a simple setup.

[0258] The fundus observation device (1b) according to some embodiments includes a fundus observation optical system (slit projection optical system 10 and slit light receiving optical system 20), an OCT optical system (100), and an optical path coupling / separating member (dichroic mirror 90). The fundus observation optical system illuminates the fundus (Ef) of the subject eye (E) with illumination light, and receives the return light of the illumination light from the fundus with a two-dimensional image sensor (image sensor 21). The OCT optical system includes an optical scanner (150), irradiates the subject eye with the measurement light (LS) deflected by the optical scanner, and performs an OCT scan to detect the interference light (LC) between the return light of the measurement light and the reference light (LR). The optical path coupling / separating member couples the optical path of the return light of the illumination light and the optical path of the OCT optical system. The fundus observation optical system has a structure in which the return light of the illumination light transmits through a first region and reflects the illumination light in a second region different from the first region, and includes a deflecting member (hole mirror 30, deflecting mirror 37) having a scan mechanism for scanning the fundus with the illumination light by deflecting the illumination light. The optical path coupling / separating member is disposed between the deflecting member and the two-dimensional image sensor.

[0259] The second region may be a region that does not overlap with the first region. According to such a configuration, the optical path of the illumination light and the optical path of the return light of the illumination light from the fundus are combined using the deflecting member, and the fundus is scanned by deflecting the illumination light using the deflecting member. Therefore, it is possible to easily arrange a shared optical system for a wide-angle illumination light optical path and a return light optical path while ensuring a wide-angle imaging angle with a low-cost and compact configuration. In addition, by optically coupling the OCT optical system on the transmission side of the deflecting member, the wide-angle illumination light optical path and its return light optical path can be separated at low cost. Further, it is possible to perform OCT measurement on an arbitrary position of the fundus being observed at a large wide angle without sharing the optical scanner for OCT scan and the optical scanner for deflecting the illumination light.

[0260] The fundus observation device according to some embodiments includes a first concave mirror (first elliptical mirror 40) having a concave first reflection surface and reflecting the illumination light deflected by a deflection member, and a second concave mirror (second elliptical mirror 50) having a concave second reflection surface and reflecting the illumination light reflected by the first reflection surface and guiding it to the eye to be examined. The deflection member guides the return light guided through the first concave mirror and the second concave mirror to a two-dimensional image sensor.

[0261] According to such a configuration, a wide-angle scan of the fundus using a concave mirror can be performed at low cost and with high precision. In particular, since there is no need for a deflection member that deflects the illumination light between the first concave mirror and the second concave mirror, it is possible to take a picture up to a shooting angle exceeding, for example, 180 degrees without being restricted by the scan range of the deflection member.

[0262] In the fundus observation device according to some embodiments, the first reflection surface is an elliptical surface, and the deflection member is disposed at or near the first focal point (F1) of the first concave mirror.

[0263] According to such a configuration, a wide-angle scan of the fundus using an elliptical mirror can be performed at low cost and with high precision.

[0264] In the fundus observation device according to some embodiments, the second reflection surface is an elliptical surface, and the eye to be examined is disposed at or near the first focal point (second focal point F4) of the second concave mirror.

[0265] According to such a configuration, a wide-angle scan of the fundus using an elliptical mirror can be performed at low cost and with high precision.

[0266] In the fundus observation device according to some embodiments, each of the first reflection surface and the second reflection surface is an elliptical surface, the deflection member is disposed at or near the first focal point (F1) of the first concave mirror, the second focal point (F2) of the first concave mirror is disposed so as to substantially coincide with the first focal point (F3) of the second concave mirror, and the eye to be examined is disposed at or near the second focal point (F4) of the second concave mirror.

[0267] This configuration enables low-cost, high-precision wide-angle fundus scanning using an ellipsoidal mirror.

[0268] In some embodiment of the fundus observation device, at least one of the first concave mirror and the second concave mirror is configured asymmetrically in a first direction (y-direction) that intersects the optical path of the illumination light. The fundus observation device includes an aspherical refractive optical element (35) positioned in at least one of the optical path of the illumination light and the optical path of the return light to correct aberration components in the first direction.

[0269] With this configuration, aberrations caused by the asymmetry of at least one of the configurations of the first concave mirror and the second concave mirror can be corrected.

[0270] Some embodiment of the fundus observation device includes a first concave mirror (hyperbolic mirror 42) having a concave first reflective surface that reflects illumination light deflected by a deflection member, a convex mirror (hyperbolic mirror 43) having a convex second reflective surface that reflects illumination light reflected by the first reflective surface, and a second concave mirror (ellipsoidal mirror 51) having a concave third reflective surface that reflects illumination light reflected by the second reflective surface and guides it to the eye under examination. The deflection member guides the reflected light that has been guided through the first concave mirror, the convex mirror, and the second concave mirror to a two-dimensional image sensor.

[0271] This configuration enables low-cost, high-precision wide-angle fundus scanning using a concave mirror. In particular, since a deflection member to deflect illumination light is not required between the convex mirror and the second concave mirror, it becomes possible to capture images with a field of view exceeding 180 degrees, for example, without being limited by the scanning range of such a deflection member.

[0272] In some embodiment of the fundus observation device, the first and second reflective surfaces are hyperbolic surfaces, and the third reflective surface is an ellipsoid.

[0273] This configuration enables low-cost, high-precision wide-angle fundus scanning using two hyperbolic mirrors and one cross-sectional mirror.

[0274] In the fundus observation device according to some embodiments, at least one of the first concave mirror, the convex mirror, and the second concave mirror is configured asymmetrically in a first direction (y direction) intersecting the optical path of the illumination light. The fundus observation device includes an aspherical refractive optical element (35) that is disposed on at least one of the optical path of the illumination light and the optical path of the return light, and corrects the aberration component in the first direction.

[0275] According to such a configuration, it is possible to correct the aberration caused by the asymmetry of the configuration of at least one of the first concave mirror, the convex mirror, and the second concave mirror.

[0276] In the fundus observation device according to some embodiments, a tapered hole is formed in the first region of the deflection member so that the opening size on the light receiving side of the return light of the illumination light becomes larger.

[0277] According to such a configuration, even when the deflection member is tilted, it is possible to suppress the occurrence of divergence of the light beam of the return light on the light receiving side.

[0278] In the fundus observation device according to some embodiments, the first region is a region including the central portion of the deflection member, and the second region is a peripheral region of the first region in the deflection member.

[0279] According to such a configuration, with a simple configuration, it is possible to combine the optical path of the illumination light and the optical path of the return light of the illumination light from the fundus, and deflect the illumination light to scan the fundus.

[0280] In the fundus observation device according to some embodiments, the first region is a peripheral region of a region including the central portion of the deflection member, and the second region is a region including the central portion of the deflection member.

[0281] According to such a configuration, with a simple configuration, it is possible to combine the optical path of the illumination light and the optical path of the return light of the illumination light from the fundus, and deflect the illumination light to scan the fundus.

[0282] <Others> The embodiments described above are merely examples of how to carry out this invention. Anyone intending to carry out this invention may make any modifications, omissions, additions, etc., within the scope of the gist of this invention.

[0283] In some embodiments, a program is provided for a processor (computer) to execute each step of the control method for the fundus observation device described above. Such a program can be stored on any non-temporary recording medium (storage medium) that is readable by the computer. Examples of such recording media include semiconductor memory, optical discs, magneto-optical discs (CD-ROM / DVD-RAM / DVD-ROM / MO, etc.), and magnetic storage media (hard disk / floppy disk / ZIP, etc.). It is also possible to send and receive this program via a network such as the Internet or a LAN. [Explanation of symbols]

[0284] 1, 1a, 1b, 1c, 1d, 1e, 1f, 1g, 1h, 1j, 1k, 1m, 1n, 1p Fundus observation device 10 Slit projection optical system 11 Lighting source 12 Iris Diaphragm 13 slits 14 Projection lens 15, 16, 33, 71, 72 Relay Lens 17,150 Optical Scanner 20 Slit light-receiving optical system 21 Image Sensor 22 Imaging lenses 30, 32 hole mirror 31, 41 Reflective mirrors 35 Aspherical refractive optical elements 37. Polarizing mirror 40 First ellipsoidal mirror 42, 43 Hyperboloid mirror 50. Second Ellipsoidal Mirror 51 Ellipsoidal mirror 60, 60a Control Unit 61, 61a Main control unit 62, 62a Storage section 70, 70a Image forming section 75a Data Processing Unit 80 UI section 90 Dichroic Mirror 100 OCT optics E. Eye being examined F1, F3 1st focal point F2, F4 2nd focal point P fundus conjugate position Q: Conjugate position of the pupil

Claims

1. An illumination optical system that illuminates the fundus of the eye under examination with a slit-shaped illumination light, A two-dimensional image sensor that receives reflected light from the eye under examination within a virtually movable aperture range at a position approximately conjugate to the fundus, An optical path splitting unit that spatially divides the optical path of the illumination light and the optical path of the return light, An optical scanner is positioned between the optical path splitting section and the illumination optical system, and deflects the illumination light in synchronization with the movement of the aperture range, thereby scanning the fundus with the illumination light. A first concave mirror having a concave first reflective surface that reflects the illumination light deflected by the optical scanner, A second concave mirror having a concave second reflective surface, which reflects the illumination light reflected by the first reflective surface and guides it to the eye under examination, An aspherical refractive optical element is disposed between the optical path splitting section and the first concave mirror, Includes, The second reflective surface is an ellipsoid, The eye under examination is positioned at or near the first focal point of the second concave mirror. At least one of the first concave mirror and the second concave mirror is configured asymmetrically in a first direction that intersects the optical path of the illumination light, The aspherical refractive optical element corrects the aberration component in the first direction in a fundus observation device.

2. The aforementioned two-dimensional image sensor is a rolling shutter type image sensor. The fundus observation device according to feature 1.

3. The optical path splitting section is positioned at a location that is approximately conjugate to the pupil of the eye being examined. The fundus observation device according to claim 1 or 2.

4. The field of view for shooting is 80 degrees or more. The fundus observation device according to any one of claims 1 to 3.

5. An OCT optical system includes an OCT optical scanner, which irradiates the eye under examination with measurement light deflected by the OCT optical scanner and performs an OCT scan by detecting interference light between the reflected light of the measurement light and a reference light. An optical path coupling and separating member is positioned between the optical path splitting section and the eye under examination, and connects the optical path of the return light and the optical path of the OCT optical system. including The fundus observation device according to any one of claims 1 to 4.

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