Fundus observation device

Abstract

This fundus observation device includes an optical system, two concave mirrors, and a holding member. The optical system projects light from a light source onto the fundus of an eye being examined, and receives return light from the fundus. The two concave mirrors each have a concave reflective surface, and guide light from the optical system to the fundus and guide the return light to the optical system. The holding member holds the two concave mirrors. At least one of the two concave mirrors has a flange having one of a fixing part or a fixed part formed thereon. The other of a fixing part or a fixed part is formed on the holding member. The fundus observation device is configured so that the flange is held by the holding member in a state in which the fixed part is fixed by the fixing part.

Description

[Technical Field]

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

[0002] Fundus observation devices used for screening and treating eye diseases are required to be able to easily observe and photograph the fundus of a subject's eye over a wide field of view. Specifically, there is a need for devices that can observe the fundus of a subject's eye over a wide angle of view exceeding 80 degrees in a single image. A known example of such a fundus observation device is the scanning laser ophthalmoscope (SLO). The SLO is a device that scans the fundus with light and forms an image of the fundus by detecting the light returning from the fundus with a light-receiving device.

[0003] Various techniques relating to such fundus observation devices have been proposed.

[0004] For example, Patent Document 1 discloses a scanning ophthalmoscope that is capable of scanning the retina at a wide angle by moving a two-dimensional parallel light scan using two ellipsoidal mirrors and a plane mirror using a scanning movement means. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 2009-543585 Summary of the Invention [Problem to be solved by the invention]

[0006] When observing (photographing) the fundus at a wide angle, it is necessary to direct light deflected over a wide range of deflection angles into the eye through the pupil, which means that the precision of the optical system, such as the ellipsoidal mirror, has a greater impact on the precision of fundus observation.

[0007] However, with conventional techniques, even if the optical members themselves, such as ellipsoidal mirrors, are highly accurate, the accuracy of fundus observation may be reduced due to the accuracy of adjustments such as alignment of the optical members, or the adjustment work such as alignment of the optical members may become complicated. Therefore, a new technique for easily adjusting optical members with high accuracy is desired.

[0008] The present invention has been made in view of the above circumstances, and one of its objects is to provide a new technique for easily adjusting optical members with high precision. [Means for solving the problem]

[0009] One aspect of the embodiment includes an optical system that projects light from a light source onto the fundus of the eye to be examined and receives returning light from the fundus; two concave mirrors, each having a concave reflecting surface, that guide the light from the optical system to the fundus and guide the returning light to the optical system; and a holding member that holds the two concave mirrors, wherein at least one of the two concave mirrors has a flange on which one of a fixing portion and a fixed portion is formed, and the other of the fixing portion and the fixed portion is formed on the holding member, and the flange is held by the holding member in a state where the fixed portion is fixed by the fixing portion. The two concave mirrors include a first concave mirror having a first flange formed on its periphery and a concave first reflecting surface that reflects the light, and a second concave mirror having a second flange formed on its periphery and a concave second reflecting surface that guides the light reflected by the first concave mirror to the fundus, and the holding member holds the first flange and the second flange. It is a fundus observation device. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a new technique for easily adjusting an optical member with high precision. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic diagram showing an example of the configuration of an optical system of a fundus oculi observation device according to a first embodiment. [Figure 2A] 2 is a schematic diagram illustrating an example of the configuration of a first ellipsoidal mirror according to the first embodiment. FIG. [Figure 2B] 2 is a schematic diagram illustrating an example of the configuration of a first ellipsoidal mirror according to the first embodiment. FIG. [Figure 2C]2 is a schematic diagram illustrating an example of the configuration of a first ellipsoidal mirror according to the first embodiment. FIG. [Figure 2D] 2 is a schematic diagram illustrating an example of the configuration of a first ellipsoidal mirror according to the first embodiment. FIG. [Figure 2E] 2 is a schematic diagram illustrating an example of the configuration of a first ellipsoidal mirror according to the first embodiment. FIG. [Figure 3A] 4 is a schematic diagram illustrating an example of the configuration of a second ellipsoidal mirror according to the first embodiment. FIG. [Figure 3B] 4 is a schematic diagram illustrating an example of the configuration of a second ellipsoidal mirror according to the first embodiment. FIG. [Figure 3C] 4 is a schematic diagram illustrating an example of the configuration of a second ellipsoidal mirror according to the first embodiment. FIG. [Figure 3D] 4 is a schematic diagram illustrating an example of the configuration of a second ellipsoidal mirror according to the first embodiment. FIG. [Figure 3E] 4 is a schematic diagram illustrating an example of the configuration of a second ellipsoidal mirror according to the first embodiment. FIG. [Figure 4A] 2 is a schematic diagram illustrating an example of the configuration of a first ellipsoidal mirror and a second ellipsoidal mirror according to the first embodiment. FIG. [Figure 4B] 2 is a schematic diagram illustrating an example of the configuration of a first ellipsoidal mirror and a second ellipsoidal mirror according to the first embodiment. FIG. [Figure 5A] 2 is a schematic diagram illustrating an example of the configuration of a first ellipsoidal mirror and a second ellipsoidal mirror according to the first embodiment. FIG. [Figure 5B] 2 is a schematic diagram illustrating an example of the configuration of a first ellipsoidal mirror and a second ellipsoidal mirror according to the first embodiment. FIG. [Figure 6] 2 is a schematic diagram illustrating an example of the configuration of a first ellipsoidal mirror and a second ellipsoidal mirror according to the first embodiment. FIG. [Figure 7A] 4 is a schematic diagram illustrating an example of the configuration of a first ellipsoidal mirror and a second ellipsoidal mirror according to a comparative example of the first embodiment. FIG. [Figure 7B] 4 is a schematic diagram illustrating an example of the configuration of a first ellipsoidal mirror and a second ellipsoidal mirror according to a comparative example of the first embodiment. FIG. [Figure 8A] 2 is a schematic diagram illustrating an example of the configuration of a first ellipsoidal mirror and a second ellipsoidal mirror according to the first embodiment. FIG. [Figure 8B]2 is a schematic diagram illustrating an example of the configuration of a first ellipsoidal mirror and a second ellipsoidal mirror according to the first embodiment. FIG. [Figure 9] FIG. 2 is a schematic diagram showing an example of the configuration of a processing system of the fundus oculi observation device according to the first embodiment. [Figure 10] 10 is a flowchart showing an example of the operation of the fundus oculi observation device according to the first embodiment. [Figure 11] FIG. 10 is a schematic diagram showing an example of the configuration of an optical system of a fundus oculi observation device according to a second embodiment. [Figure 12] FIG. 10 is a schematic diagram showing an example of the configuration of an optical system of a fundus oculi observation device according to a second embodiment. [Figure 13] FIG. 10 is a schematic diagram showing an example of the configuration of a processing system of a fundus oculi observation device according to a second embodiment. [Figure 14] 10 is a flowchart showing an example of the operation of the fundus observation device according to the second embodiment. [Figure 15] FIG. 10 is a schematic diagram for explaining the operation of the fundus oculi observation device according to the second embodiment. [Figure 16] FIG. 10 is a schematic diagram showing an example of the configuration of an optical system of a fundus oculi observation device according to a third embodiment. [Figure 17] FIG. 10 is a schematic diagram showing an example of the configuration of an optical system of a fundus oculi observation device according to a fourth embodiment. [Figure 18] FIG. 11 is a schematic diagram showing an example of the configuration of an optical system of a fundus oculi observation device according to a fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Examples of embodiments of the fundus observation device according to the present invention will be described in detail with reference to the drawings. Note that the contents of documents cited in this specification and any publicly known techniques can be used in the following embodiments.

[0013] In this specification, the term "processor" refers to a circuit such as a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), or a programmable logic device (e.g., an SPLD (Simple Programmable Logic Device), a CPLD (Complex Programmable Logic Device), or an FPGA (Field Programmable Gate Array)). The processor realizes the functions according to the embodiment by, for example, reading and executing a program stored in a memory circuit or a storage device.

[0014] A fundus observation device according to an embodiment includes an optical system and two concave mirrors having concave reflecting surfaces, and guides light from the optical system to the fundus of the eye to be examined and also guides light returned from the fundus to the optical system. The optical system projects light from a light source onto the fundus via the two concave mirrors and receives light returned from the fundus via the two concave mirrors. The fundus observation device includes a holding member that holds the two concave mirrors. At least one of the two concave mirrors has a flange on which one of a fixing portion and a fixing portion is formed, and the holding member is formed with the other of the fixing portion and the fixing portion. The fundus observation device is configured so that the flange is held by the holding member with the fixing portion fixed by the fixing portion.

[0015] This allows the holding member to hold the concave mirror in a state where the fixed portion is fixed by the fixing portion so that the positional relationship between the concave mirror and the holding member is a predetermined positional relationship.As a result, it is possible to easily achieve optical measurement conditions designed with high precision and improve the accuracy of fundus observation at low cost.In particular, by manufacturing optical members such as the concave mirror using high-precision processing technology, it is possible to suppress deterioration of optical measurement accuracy caused by alignment accuracy.

[0016] The optical system includes an imaging optical system, an optical coherence tomography (OCT) optical system, an SLO optical system, or an optical system that combines two or more of these. The imaging optical system forms a fundus image based on the light reception result obtained by illuminating the fundus with light from a light source and receiving the light returned from the fundus. The OCT optical system splits the light from the light source into measurement light and reference light, scans the fundus with the measurement light, and forms a fundus image (tomographic image, front image) based on the detection result of the interference light obtained by detecting the interference light between the measurement light returned from the fundus and the reference light. The SLO optical system scans the fundus with light from the light source and forms a fundus image based on the light reception result obtained by receiving the light returned from the fundus.

[0017] In some embodiments, the two concave mirrors are arranged with their reflective surfaces facing each other, and are configured so that light deflected by the deflecting member is reflected by one concave mirror and the reflected light is reflected by the other concave mirror and directed to the eye to be examined. In some embodiments, an optical scanner or a reflecting mirror is arranged between the two concave mirrors, and the light reflected by one concave mirror is deflected by the optical scanner or reflecting mirror and reflected by the other concave mirror and directed to the eye to be examined.

[0018] The concave mirror may be an ellipsoidal mirror whose reflective surface forms a part of an ellipsoid (ellipsoidal surface), a parabolic mirror whose reflective surface forms a part of a paraboloid, or a free-form mirror whose reflective surface forms a part of a free-form surface. The two concave mirrors may be a combination of the same type of concave mirrors described above, or a combination of different types of concave mirrors described above. In some embodiments, the two concave mirrors are two ellipsoidal mirrors. In some embodiments, the two concave mirrors are an ellipsoidal mirror and a free-form mirror.

[0019] The fixing part fixes its positional relationship with the fixed part by fitting, hooking, latching together, crimping, connecting, or the like. In some embodiments, one of the fixing part and the fixed part is a fitting member, and the other is a fitted member. In some embodiments, one of the fixing part and the fixed part is a locking member, and the other is a locked member. In some embodiments, the fixing part is a recess or a hole, and the fixed part is a protrusion (projection).

[0020] A fundus observation device configured as described above with a holding member holding two concave mirrors can, for example, illuminate the fundus of an eye to be examined with illumination light having a slit-shaped (line-shaped) cross-sectional light beam shape, and receive return light of the illumination light from the fundus with a two-dimensional image sensor in a movable light-receiving range (focal plane, virtual aperture range) at a position approximately optically conjugate with the fundus. In this case, a deflecting member having a structure that transmits (passes) the return light through a central portion and reflects the illumination light at a peripheral portion of the central portion can be used to combine (separate) the optical paths of the illumination light and the return light, and deflect the illumination light in synchronization with the movement of the light-receiving range (focal plane), thereby scanning the fundus with the illumination light. In some embodiments, the optical path combining portion of the deflecting member between the optical paths of the illumination light and the return light is positioned at a position approximately optically conjugate with the pupil of the eye to be examined. In some embodiments, the deflecting member is a hole mirror.

[0021] This makes it possible to easily and inexpensively avoid deterioration of optical measurement conditions due to the assembly (mounting) accuracy of optical components, ensure a shooting angle of view of more than 80 degrees using only an optical system that scans in the width direction of the illumination light line, and easily arrange a shared optical system for the optical path of the wide-angle illumination light and the optical path of the return light.

[0022] In some embodiments, the fundus observation device further includes an optical scanner and an OCT optical system that irradiates the test eye with measurement light deflected by the optical scanner and performs OCT scanning to detect interference light between the return light of the measurement light and the reference light. In this case, an optical path coupling / separation member disposed between the deflection member and the two-dimensional image sensor couples the optical path of the return light of the slit-shaped (line-shaped) illumination 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 return light of the illumination light can be separated from the shared optical system at low cost. In addition, OCT measurement (OCT photography) can be performed at any position on the fundus observed at a wide angle without sharing the optical scanner for OCT scanning and the optical scanner for deflecting the illumination light.

[0023] Hereinafter, a case will be described in which the fundus observation device according to the embodiment acquires an image of the fundus of the subject eye using two ellipsoidal mirrors (concave mirrors in a broad sense) arranged to share one focal position.

[0024] For ease of explanation, the scanning center direction of the light projected onto the fundus will be referred to as the z direction (the optical axis direction of the optical system), the up-down direction (vertical direction) perpendicular to the z direction will be referred to as the y direction, and the left-right direction (horizontal direction) perpendicular to the z direction will be referred to as the x direction.

[0025] First Embodiment <Configuration> Fig. 1 shows an example of the configuration of the optical system of the fundus observation device according to the first embodiment. In Fig. 1, a position that is approximately optically conjugate with the fundus Ef of the subject's eye E is illustrated as a fundus conjugate position P, and a position that is approximately optically conjugate with the pupil (iris) of the subject's eye E is illustrated as a pupil conjugate position (iris conjugate position) Q.

[0026] 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.

[0027] (Slit projection optical system 10) The slit projection optical system 10 generates slit-shaped illumination light (illumination light having a linear cross section) 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.

[0028] 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 center wavelength in the wavelength range of 420 nm to 700 nm. Such 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 that can output light of each color component of RGB. In some embodiments, the illumination light source 11 includes a light source that can switch between outputting light in the infrared region or light in the visible region. The illumination light source 11 is disposed in a position that is optically non-conjugate with the fundus Ef and the pupil (iris) of the subject's eye E.

[0029] The iris diaphragm 12 (specifically, an opening described below) can be positioned at the pupil conjugate position Q. The iris diaphragm 12 has one or more openings formed at a position away from the optical axis of the optical path of the light output from the illumination light source 11. The openings formed in the iris diaphragm 12 determine the incident position (incident shape) of the illumination light on the iris of the subject's eye E. For example, the iris diaphragm 12 has openings formed at positions that are point-symmetric with respect to the optical axis. This makes it possible for the illumination light to enter the eye from a position eccentric from the pupil center (specifically, a position that is point-symmetric with respect to the pupil center) when the pupil center of the subject's eye E is positioned on the optical axis of the optical path of the illumination light.

[0030] In addition, 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.

[0031] The slit 13 (specifically, the opening described below) can be arranged at a fundus conjugate position P. The opening formed in the slit 13 defines the shape of the illumination area (irradiation pattern shape) of the illumination light on the fundus Ef of the subject's eye E.

[0032] The slit 13 can be moved in the optical axis direction of the slit projection optical system 10 by a moving mechanism (not shown). The moving mechanism moves the slit 13 in the optical axis direction under the control of a control unit (described later). This allows the position of the slit 13 to be moved according to the condition of the subject's eye E (specifically, the refractive power and the shape of the fundus Ef).

[0033] In some embodiments, the slit 13 is configured to be able to change at least one of the position and shape of the opening without being moved in the optical axis direction according to the state of the subject's eye E. Such a function of the slit 13 is realized by, for example, a liquid crystal shutter.

[0034] Light from illumination light source 11 passes through an opening formed in iris diaphragm 12, passes through an opening formed in slit 13, and is output as slit-shaped illumination light after passing through projection lens 14. The slit-shaped illumination light output from slit projection optical system 10 is guided to hole mirror 30.

[0035] 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 a transmissive liquid crystal panel, LCOS (Liquid Crystal On Silicon) projectors using a reflective liquid crystal panel, and DLP (Digital Light Processing) (registered trademark) projectors using a DMD (Digital Mirror Device).

[0036] (hole mirror 30) The hole mirror 30 (specifically, the deflection surface described below) 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 directs illumination light from the slit projection optical system 10 to the reflecting surface of the first ellipsoidal mirror 40 described below. The deflection surface has a hole formed therein so that the optical axis of the slit light receiving optical system 20 described below can pass through it. In other words, the hole mirror 30 has a structure in which the returning light of the illumination light is transmitted (passes through) the center and the illumination light is reflected around the center.

[0037] The hole mirror 30 deflects the illumination light by changing the orientation of the deflection surface so that it moves sequentially in a direction (direction of the slit width, short direction of the illumination area) perpendicular to the slit direction of the illumination area (direction in which the slit extends, long direction of the illumination area) at the site irradiated with the illumination light on the subject's eye E. The hole mirror 30 is configured to be able to change the deflection direction of the illumination light under the control of a control unit described later.

[0038] The illumination light from the slit projection optical system 10 is deflected by the deflection surface around the hole and is guided to the reflecting surface of the first ellipsoidal mirror 40. The return light of the illumination light from the subject's eye E passes through the hole formed in the hole mirror 30 via the reflecting surface of the first ellipsoidal mirror 40 and is guided to the slit light-receiving optical system 20.

[0039] In some embodiments, the hole mirror 30 functions as a two-axis optical scanner that directs illumination light from the slit projection optical system 10 onto the reflective surface of the first ellipsoidal mirror 40 .

[0040] In some embodiments, the hole mirror 30 is configured to transmit wavelength components (or polarization components) of the returning light of the illumination light. In this case, the returning light of the illumination light from the subject's eye E passes through the hole mirror 30 via the reflecting surface of the first ellipsoidal mirror 40 and is guided to the slit light-receiving optical system 20.

[0041] (Slit light receiving optical system 20) The slit light-receiving optical system 20 receives the return light of the illumination light from the subject's eye E that has passed through the hole of the hole mirror 30. The slit light-receiving optical system 20 includes an image sensor 21 and an imaging lens 22.

[0042] The image sensor 21 functions as a two-dimensional image sensor as a pixelated light receiver. The light receiving surface (detection surface, imaging surface) of the image sensor 21 can be placed at a fundus conjugate position P. The image sensor 21 can set a movable light receiving range (virtual aperture range, focal plane) at the fundus conjugate position P.

[0043] For example, the light reception results by the image sensor 21 are captured and read out using a rolling shutter method. In some embodiments, a control unit, which will be described later, controls the reading of the light reception results by controlling the image sensor 21. In some embodiments, the image sensor 21 can automatically output the light reception results for a predetermined number of lines together with information indicating the light reception position.

[0044] 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 (light receiving elements) arranged in a row direction, each of which includes a plurality of pixels arranged in a column direction. Specifically, the image sensor 21 includes a plurality of pixels arranged two-dimensionally, a plurality of vertical signal lines, and a horizontal signal line. Each pixel includes a photodiode (light receiving element) and a capacitor. The plurality of vertical signal lines are provided for each pixel group in a column direction (vertical direction) perpendicular to the row direction (horizontal direction). Each vertical signal line is selectively electrically connected to a pixel group in which charge corresponding to the light reception result is accumulated. The horizontal signal line is selectively electrically connected to the plurality of vertical signal lines. Each pixel accumulates charge corresponding to the light reception result of the returned light, and the accumulated charge is sequentially read out, for example, for each pixel group in the row direction. For example, a voltage corresponding to the charge accumulated in each pixel is supplied to the vertical signal line for each line in the row direction. The plurality of vertical signal lines are selectively electrically connected to the horizontal signal line. By sequentially performing the readout operation for each line in the row direction in the vertical direction, it is possible to read out the light reception results of a plurality of pixels arranged two-dimensionally.

[0045] A received light image corresponding to a desired virtual aperture shape extending in the row direction is acquired by capturing (reading out) the result of receiving the returned light using a rolling shutter method for such an image sensor 21. Such control is disclosed, for example, in U.S. Patent No. 7,831,106 or U.S. Patent No. 8,237,835.

[0046] The imaging lens 22 forms an image on the light receiving surface of the image sensor 21 of the return light of the illumination light that has passed through the hole formed in the hole mirror 30 (or the return light of the illumination light that has transmitted through the hole mirror 30).

[0047] (First ellipsoidal mirror 40) The reflecting surface (first reflecting surface) of the first ellipsoidal mirror 40 is an ellipsoidal surface (more specifically, a part of an ellipsoidal surface). The first ellipsoidal mirror 40 is an example of a concave mirror.

[0048] The first ellipsoidal mirror 40 has two optically conjugate focal points (a first focal point F1 and a second focal point F2). The hole mirror 30 (the deflection surface of the hole mirror 30) is disposed at or near the first focal point F1 of the first ellipsoidal mirror 40. In some embodiments, the hole mirror 30 is disposed at or near a position optically conjugate to the first focal point F1 (a conjugate position of the first focal point F1).

[0049] (Second ellipsoidal mirror 50) The reflecting surface (second reflecting surface) of the second ellipsoidal mirror 50 is an ellipsoidal surface (more specifically, a part of an ellipsoidal surface). The second ellipsoidal mirror 50 is an example of a concave mirror.

[0050] The second ellipsoidal mirror 50 has two optically conjugate focal points (a first focal point F3 and a second focal point F4). The second ellipsoidal mirror 50 is disposed so 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 disposed so that the first focal point F3 substantially coincides with a position optically conjugate with the second focal point F2 of the first ellipsoidal mirror 40 (a conjugate position of the second focal point F2) or a position close to the position. The subject's eye E is disposed at the second focal point F4 of the second ellipsoidal mirror 50. That is, the second ellipsoidal mirror 50 is disposed so that the second focal point F4 substantially coincides with the position of the subject's eye where the subject's eye E is disposed.

[0051] In this way, since there is no need to place a scanning optical component at the second focal point F2 (first focal point F3) between the first ellipsoidal mirror 40 and the second ellipsoidal mirror 50, there is no limitation on the scanning range in a predetermined scanning direction (lateral direction, horizontal direction). For example, in the configuration described in Patent Document 1, a deflection component that scans the illumination light in the lateral direction is provided, so that a shooting angle of view of up to 180 degrees (in reality, up to about 150 degrees) can be secured. In contrast, according to the embodiment, since a deflection component that scans in the lateral direction is not required, it is possible to capture an image with a shooting angle of view exceeding 180 degrees (since the cornea of ​​the human eye is positioned forward of the pupil, a fisheye lens-like effect allows for an observation range of more than 180 degrees).

[0052] The first ellipsoidal mirror 40 and the second ellipsoidal mirror 50 are an example of the "two concave mirrors" according to the embodiment. By being held by a holding member as described below, the second ellipsoidal mirror 50 can be positioned simply and at low cost so that the first focal point F3 substantially coincides with the second focal point F2 of the first ellipsoidal mirror 40.

[0053] 2A to 2E schematically show an example of a holding structure for the first ellipsoidal mirror 40. In Figures 2A to 2E, the same parts as in Figure 1 are given the same reference numerals, and descriptions thereof will be omitted where appropriate.

[0054] The holding member of the embodiment includes a first holding member 41 (see Figures 2A to 2D) that holds the first ellipsoidal mirror 40 and a second holding member 51 (see Figures 3A to 3D) that holds the second ellipsoidal mirror 50, and is configured to be able to hold the second holding member 51 relative to the first holding member 41.

[0055] The first ellipsoidal mirror 40 is formed, for example, by electroforming. Electroforming is a technique for electrochemically depositing metal ions in an electrolyte onto the surface of a matrix, faithfully replicating the shape of the matrix at the nano-level. This makes it possible to form the first ellipsoidal mirror 40 with a highly accurate shape.

[0056] Both ends of the first ellipsoidal mirror 40 in the long axis direction (predetermined first direction) have a shape cut by a plane perpendicular to the long axis direction, which makes it possible to reduce the weight and size of the first ellipsoidal mirror 40 while ensuring the size of the reflecting surface of the first ellipsoidal mirror 40 necessary for wide-angle fundus observation.

[0057] 2A to 2C are schematic perspective views of a first holding member 41 that holds a first ellipsoidal mirror 40. FIG. 2A shows an example of how the first ellipsoidal mirror 40 is attached to the first holding member 41. FIG. 2B shows an example of the first ellipsoidal mirror 40 held by the first holding member 41 when viewed from the reflecting surface side. FIG. 2C shows an example of the first ellipsoidal mirror 40 held by the first holding member 41 when viewed from the opposite side of the reflecting surface.

[0058] As shown in FIGS. 2A to 2C, a flange (first flange) is formed on the periphery of the first ellipsoidal mirror 40 (reflecting surface). At least one protrusion is formed on the flange. The protrusion is an example of a convex portion. In this embodiment, protrusions 40A and 40B are formed on the flange at positions facing each other across the reflecting surface. For example, protrusions 40A and 40B are formed at positions that are line-symmetrical with respect to a projection line of the major axis of the reflecting surface (the axis connecting the two foci of the ellipsoidal surface) projected onto the flange surface. In other words, protrusions 40A and 40B are formed at a position where a straight line connecting protrusions 40A and 40B is perpendicular to the projection line. An opening is formed in first holding member 41 so that the reflecting surface of first ellipsoidal mirror 40 held on the holding surface is exposed on the surface opposite the holding surface, and light incident from the surface opposite the holding surface is reflected by the reflecting surface and exits from the surface opposite the holding surface.

[0059] Furthermore, holes 41A and 41B into which protrusions 40A and 40B of first ellipsoidal mirror 40 are inserted are formed in first holding member 41. Holes 41A and 41B are an example of recesses. By inserting protrusions 40A and 40B into holes 41A and 41B, the position of first ellipsoidal mirror 40 relative to first holding member 41 is determined.

[0060] FIG. 2D shows a schematic plan view of first holding member 41 that holds first ellipsoidal mirror 40 when viewed from the reflecting surface side.

[0061] When the protrusion 40A is inserted into the hole 41A, a side surface 40Aa on the lower side (second focal point side) of the protrusion 40A abuts against a side surface 41Aa on the lower side of the hole 41A, and a side surface 40Ab on the reflective surface side of the protrusion 40A that intersects with the side surface 40Aa abuts against a side surface 41Ab on the opening side of the hole 41A. At the same time, a side surface 40Ba on the lower side of the protrusion 40B abuts against a side surface 41Ba on the lower side of the hole 41B, and a side surface 40Bb on the reflective surface side of the protrusion 40B that intersects with the side surface 40Ba abuts against a side surface 41Bb on the opening side of the hole 41B.

[0062] This makes it possible to easily and uniquely determine the position of the first ellipsoidal mirror 40 in the major axis direction and the position of the minor axis direction relative to the first holding member 41.

[0063] In some embodiments, the upper side (first focal point side) 40Ac of the protrusion 40A is further configured to abut against the upper side 41Ac of the hole 41A, and the upper side 40Bc of the protrusion 40B is configured to abut against the upper side 41Bc of the hole 41B.

[0064] First holding member 41 is configured to hold the flange in a state in which protrusions 40A and 40B are inserted into holes 41A and 41B, respectively, for positioning, and protrusions 40A and 40B are fixed by holes 41A and 41B. For example, in a state in which protrusions 40A and 40B are inserted into holes 41A and 41B and fixed, the flange is fixed to first holding member 41 by screwing, pinning, crimping, welding, caulking, or the like.

[0065] Fig. 2E shows a schematic plan view and a side view of the first ellipsoidal mirror 40. For ease of explanation, the plan view in Fig. 2E shows the first ellipsoidal mirror 40 as seen from the reflecting surface side.

[0066] Both the first focal point F1 and the second focal point F2 of the first ellipsoidal mirror 40 are located at positions away from the concave reflecting surface and the flange surface. In Fig. 2E, the distance in the minor axis direction between the reflecting surface and the first focal point F1 and the distance in the minor axis direction between the reflecting surface and the second focal point F2 are both longer than the distance in the minor axis direction between the reflecting surface and the flange surface.

[0067] The protrusions 40A and 40B are disposed near the second focal point F2 of the two focal points of the first ellipsoidal mirror 40. Specifically, as shown in FIG. 2E, on the surface of the flange formed on the first ellipsoidal mirror 40, the protrusion 40A is formed at a position where a line connecting a first projected point of the second focal point F2 of the first ellipsoidal mirror 40 (a projected point of the second focal point F2 onto the surface of the flange) and a second projected point of the first focal point F1 (a projected point of the first focal point F1 onto the surface of the flange) intersects at right angles with a line connecting the first projected point and the protrusion 40A. Similarly, on the surface of the flange formed on the first ellipsoidal mirror 40, the protrusion 40B is formed at a position where a line connecting the first projected point of the second focal point F2 of the first ellipsoidal mirror 40 and a second projected point of the first focal point F1 intersects at right angles with a line connecting the first projected point and the protrusion 40B.

[0068] This makes it possible to easily and accurately set the position of the second focal point F2 of the first ellipsoidal mirror 40 held by the first holding member 41 (which is also the position of the first focal point F3 of the second ellipsoidal mirror 50).

[0069] 3A to 3E schematically show an example of a holding structure for the second ellipsoidal mirror 50. In Figures 3A to 3E, the same parts as in Figure 1 are given the same reference numerals, and descriptions thereof will be omitted where appropriate.

[0070] The second ellipsoidal mirror 50 is formed by, for example, electroforming, similarly to the first ellipsoidal mirror 40. This makes it possible to form the second ellipsoidal mirror 50 having a shape with extremely high precision.

[0071] Both ends of the second ellipsoidal mirror 50 in the long axis direction (predetermined first direction) have a shape cut by a plane intersecting the long axis direction. This makes it possible to reduce the weight and size of the second ellipsoidal mirror 50 while ensuring the size of the reflecting surface of the second ellipsoidal mirror 50 necessary for wide-angle fundus observation. In particular, cutting the lower side makes it possible to avoid interference between the second ellipsoidal mirror 50 and the mouth or chin of the subject being observed.

[0072] 3A to 3C are schematic perspective views of a second holding member 51 that holds a second ellipsoidal mirror 50. FIG. 3A shows an example of how the second ellipsoidal mirror 50 is attached to the second holding member 51. FIG. 3B shows an example of the second ellipsoidal mirror 50 held by the second holding member 51 when viewed from the reflecting surface side. FIG. 3C shows an example of the second ellipsoidal mirror 50 held by the second holding member 51 when viewed from the opposite side of the reflecting surface.

[0073] As shown in FIGS. 3A to 3C, a flange (second flange) is formed on the periphery of the second ellipsoidal mirror 50 (reflecting surface). At least one protrusion is formed on the flange. The protrusion is an example of a convex portion. In this embodiment, protrusions 50A and 50B are formed on the flange at positions facing each other across the reflecting surface. For example, protrusions 50A and 50B are formed at positions that are line-symmetrical with respect to a projection line of the major axis of the reflecting surface (the axis connecting the two foci of the ellipsoidal surface) projected onto the flange surface. In other words, protrusions 50A and 50B are formed at a position where a straight line connecting protrusions 50A and 50B is perpendicular to the projection line. An opening is formed in the second holding member 51 so that the reflecting surface of the second ellipsoidal mirror 50 held on the holding surface is exposed on the surface opposite the holding surface, and light incident from the surface opposite the holding surface is reflected by the reflecting surface and exits from the surface opposite the holding surface.

[0074] Furthermore, holes 51A and 51B are formed in the second holding member 51, into which the protrusions 50A and 50B of the second ellipsoidal mirror 50 are inserted. The holes 51A and 51B are an example of recesses. By inserting the protrusions 50A and 50B into the holes 51A and 51B, the position of the second ellipsoidal mirror 50 relative to the second holding member 51 is determined.

[0075] FIG. 3D is a schematic plan view of the second holding member 51 that holds the second ellipsoidal mirror 50 as viewed from the reflecting surface side.

[0076] When the protrusion 50A is inserted into the hole 51A, a side surface 50Aa on the lower side (second focal point side) of the protrusion 50A abuts against a side surface 51Aa on the lower side of the hole 51A, and a side surface 50Ab on the reflective surface side of the protrusion 50A that intersects with the side surface 50Aa abuts against a side surface 51Ab on the opening side of the hole 51A. At the same time, a side surface 50Ba on the lower side of the protrusion 50B abuts against a side surface 51Ba on the lower side of the hole 51B, and a side surface 50Bb on the reflective surface side of the protrusion 50B that intersects with the side surface 50Ba abuts against a side surface 51Bb on the opening side of the hole 51B.

[0077] This makes it possible to easily and uniquely determine the position of the second ellipsoidal mirror 50 in the major axis direction and the position of the minor axis direction relative to the second holding member 51.

[0078] In some embodiments, the upper side (first focal point side) of the protrusion 50A is further configured to abut against the upper side of the hole 51A, and the upper side of the protrusion 50B is configured to abut against the upper side of the hole 51B.

[0079] The second holding member 51 is configured to hold the flange in a state in which the protrusions 50A and 50B are inserted into the holes 51A and 51B, respectively, for positioning, and the protrusions 50A and 50B are fixed by the holes 51A and 51B. For example, in a state in which the protrusions 50A and 50B are inserted into the holes 51A and 51B and fixed, the flange is fixed to the second holding member 51 by screwing, pinning, crimping, welding, caulking, or the like.

[0080] Fig. 3E shows a schematic plan view and a side view of the second ellipsoidal mirror 50. For ease of explanation, the plan view in Fig. 3E shows the second ellipsoidal mirror 50 as seen from the reflecting surface side.

[0081] Both the first focal point F3 and the second focal point F4 of the second ellipsoidal mirror 50 are located at positions away from the concave reflecting surface and the flange surface. In Fig. 3E, the distance in the minor axis direction between the reflecting surface and the first focal point F3 and the distance in the minor axis direction between the reflecting surface and the second focal point F4 are both longer than the distance in the minor axis direction between the reflecting surface and the flange surface. Note that the flange (surface) formed on the second ellipsoidal mirror 50 is approximately parallel to the major axis connecting the first focal point F3 and the second focal point F4.

[0082] The protrusions 50A and 50B are disposed near a first focal point F3 of the two focal points of the second ellipsoidal mirror 50. Specifically, as shown in FIG. 3E, on the surface of the flange formed on the second ellipsoidal mirror 50, the protrusion 50A is formed at a position where a line connecting a first projected point of the first focal point F3 of the second ellipsoidal mirror 50 (a projected point of the first focal point F3 onto the surface of the flange) and a second projected point of the second focal point F4 (a projected point of the second focal point F4 onto the surface of the flange) intersects at right angles with a line connecting the first projected point and the protrusion 50A. Similarly, on the surface of the flange formed on the second ellipsoidal mirror 50, the protrusion 50B is formed at a position where a line connecting the first projected point of the first focal point F3 of the second ellipsoidal mirror 50 and a second projected point of the second focal point F4 intersects at right angles with a line connecting the first projected point and the protrusion 50B.

[0083] This makes it possible to easily align the first focal point F3 of the second ellipsoidal mirror 50 held by the second holding member 51 with high accuracy.

[0084] As shown in Figures 2E and 3E, when the second focal point F2 of the first ellipsoidal mirror 40 and the first focal point F3 of the second ellipsoidal mirror 50 are positioned so that they are approximately in the same position, the first ellipsoidal mirror 40 is held by the first holding member 41 by protrusions 40A and 40B formed near the second focal point F2, and the second ellipsoidal mirror 50 is held by the second holding member 51 by protrusions 50A and 50B formed near the first focal point F3.

[0085] As described above, the first holding member 41 that holds the first ellipsoidal mirror 40 is fixed (joined) to the second holding member 51 that holds the second ellipsoidal mirror 50 in a predetermined positional relationship.

[0086] 4A and 4B show schematic side views of the first holding member 41 fixed to the second holding member 51. In FIGS. 4A and 4B, the same parts as those in FIGS. 2A to 2E and 3A to 3E are denoted by the same reference numerals, and descriptions thereof will be omitted where appropriate.

[0087] Each of the first holding member 41 and the second holding member 51 is designed so that the second focal point F2 of the first ellipsoidal mirror 40 and the first focal point F3 of the second ellipsoidal mirror 50 coincide when the two members are fixed in a predetermined positional relationship. Therefore, by fixing the first holding member 41 to a predetermined holding position on the second holding member 51, the second focal point F2 of the first ellipsoidal mirror 40 and the first focal point F3 of the second ellipsoidal mirror 50 substantially coincide (FIGS. 4A and 4B).

[0088] In some embodiments, the relative position of the first holding member 41 in the x and y directions with respect to the second holding member 51 can be changed. For example, as shown in FIG. 4A , with the first holding member 41 held by the second holding member 51, light from a light source disposed at a first focal point F1 of the first ellipsoidal mirror 40 or at a position substantially optically conjugate thereto is received at a second focal point F4 of the second ellipsoidal mirror 50 or at a position substantially optically conjugate thereto. At this time, the relative position of the first holding member 41 in the x and y directions with respect to the second holding member 51 is determined so that the light from the light source is focused at the second focal point F2 of the first ellipsoidal mirror 40, the first focal point F3 of the second ellipsoidal mirror 50, and the second focal point F4 ( FIG. 4B ).

[0089] 5A and 5B are schematic perspective views of the first holding member 41 fixed to the second holding member 51. In FIGS. 5A and 5B, the same parts as those in FIGS. 2A to 2E, 3A to 3E, 4A, and 4B are denoted by the same reference numerals, and descriptions thereof will be omitted where appropriate.

[0090] As described above, when the first holding member 41 is held at a predetermined holding position relative to the second holding member 51, a hole portion for fixing the pin is formed in the first holding member 41, and a hole portion for inserting the pin is formed in the second holding member 51, and the first holding member 41 is fixed to the second holding member 51 by pinning using pins 55 and 56.

[0091] Alternatively, as described above, when the relative position of the first holding member 41 with respect to the second holding member 51 is determined and held in that position, the first holding member 41 is fixed to the second holding member 51 by pinning using pins 55 and 56.

[0092] 2A to 5B, the holding member according to the embodiment is configured by joining the first holding member 41 and the second holding member 51, but the configuration according to the embodiment is not limited to this. For example, the holding member according to the embodiment may be configured such that the first holding member 41 and the second holding member 51 are fixed together in advance and integrated.

[0093] Fig. 6 is a schematic side view of the first ellipsoidal mirror 40 and the second ellipsoidal mirror 50 held by the first holding member 41 and the second holding member 51. In Fig. 6, the same parts as those in Figs. 1 to 5B are denoted by the same reference numerals, and the description thereof will be omitted where appropriate.

[0094] As described above, the first holding member 41 is configured to hold the flange of the first ellipsoidal mirror 40, and the second holding member 51 is configured to hold the flange of the second ellipsoidal mirror 50. Here, the first holding member 41 and the second holding member 51 (i.e., the holding members according to the embodiment) fixed to each other as shown in Fig. 5B hold the flange (surface) of the first ellipsoidal mirror 40 and the flange (surface) of the second ellipsoidal mirror 50 so that they are approximately parallel (Fig. 6).

[0095] With this, in a state in which the distance dz in the z direction is kept constant by the first holding member 41 and the second holding member 51 and alignment in the z direction is performed with high precision, alignment in the x and y directions can be performed with high precision by the one or more protrusions and the one or more holes. As a result, it becomes possible to align the first ellipsoidal mirror 40 and the second ellipsoidal mirror 50 with high precision easily and at low cost.

[0096] Furthermore, as described above, both end portions of the second ellipsoidal mirror 50 according to the embodiment have a shape cut by a plane intersecting the long axis direction of the reflecting surface, which is part of the ellipsoid. By cutting both end portions, weight and size can be reduced, and cutting the lower end portion in particular makes it possible to reduce the burden on the subject being observed.

[0097] 7A and 7B are schematic diagrams showing the positional relationship between the first and second ellipsoidal mirrors and the subject to be observed according to a comparative example of the embodiment. Fig. 7A is a top view showing an outline of the positional relationship between the first and second ellipsoidal mirrors and the subject to be observed according to a comparative example of the embodiment. Fig. 7B is a side view showing an outline of the positional relationship between the first and second ellipsoidal mirrors and the subject to be observed according to a comparative example of the embodiment.

[0098] The fundus observation device according to the comparative example of the embodiment includes a first ellipsoidal mirror 40' and a second ellipsoidal mirror 50'. The first ellipsoidal mirror 40' may be similar to the first ellipsoidal mirror 40 according to the embodiment. In contrast, both ends of the second ellipsoidal mirror 50' are not cut by a plane intersecting the major axis of the reflecting surface, which is an ellipsoid (see FIG. 7B).

[0099] In this case, when the subject SU moves his / her face closer to the second ellipsoidal mirror 50' in an attempt to position the eye to be examined at the position of the eye to be examined (the position of the second focal point F4 of the second ellipsoidal mirror 50'), part of his / her face (mouth, chin) interferes with the lower part of the second ellipsoidal mirror 50', as shown in Fig. 7B. Therefore, the subject SU needs to position the eye to be examined at the position of the eye to be examined by turning his / her face obliquely relative to the reflecting surface of the second ellipsoidal mirror 50', as shown in Fig. 7A. This may make it difficult to fixate the eye to be examined or may put strain on the posture of the subject SU during observation.

[0100] 8A and 8B schematically show the positional relationship between the first ellipsoidal mirror 40 and the second ellipsoidal mirror 50 according to the embodiment and the subject to be observed. Fig. 8A is a top view showing an outline of the positional relationship between the first ellipsoidal mirror 40 and the second ellipsoidal mirror 50 according to the embodiment and the subject to be observed. Fig. 8B is a side view showing an outline of the positional relationship between the first ellipsoidal mirror 40 and the second ellipsoidal mirror 50 according to the embodiment and the subject to be observed.

[0101] As described above, both ends of the second ellipsoidal mirror 50 are cut by planes intersecting the major axis of the reflecting surface, which is an ellipsoid (see FIG. 8B). In this case, even if the subject SU moves his / her face closer to the second ellipsoidal mirror 50 in an attempt to position the eye to be examined at the position (the position of the second focal point F4 of the second ellipsoidal mirror 50), it is possible to prevent the face (mouth, chin) from interfering with the lower part of the second ellipsoidal mirror 50, as shown in FIG. 8B. Therefore, the subject SU can position the eye to be examined at the position of the eye to be examined, facing forward with respect to the reflecting surface of the second ellipsoidal mirror 50, as shown in FIG. 8A. This facilitates fixation of the eye to be examined and does not impose strain on the posture of the subject SU during observation.

[0102] 1, the second ellipsoidal mirror 50 is positioned so that the angle between a line connecting the first focal point F1 and the second focal point F2 of the first ellipsoidal mirror 40 and a line connecting the first focal point F3 and the second focal point F4 of the second ellipsoidal mirror 50 is angle α. For example, the angle α is 30 degrees. In some embodiments, the second ellipsoidal mirror 50 is configured to be movable relative to the first ellipsoidal mirror 40 so that the angle α can be changed.

[0103] In this configuration, the illumination light deflected by the hole mirror 30 disposed at the first focal point F1 is reflected by the reflecting surface of the first ellipsoidal mirror 40 and directed to the second focal point F2 of the first ellipsoidal mirror 40. The illumination light directed to the second focal point F2 is directed to the reflecting surface of the second ellipsoidal mirror 50, reflected by this reflecting surface, and directed to the subject's eye E disposed at the second focal point F4 of the second ellipsoidal mirror 50.

[0104] The illumination light guided to the subject's eye E enters the eye through the pupil and is irradiated onto the fundus Ef. The return light of the illumination light reflected at the fundus Ef is emitted to the outside of the subject's eye E through the pupil, travels along the same path as the outward path in the opposite direction, and is guided to the first focal point F1 of the first ellipsoidal mirror 40. As described above, the return light of the 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) and is guided to the slit light-receiving optical system 20.

[0105] In some embodiments, at least one of the first ellipsoidal mirror 40 and the second ellipsoidal mirror 50 is a concave mirror having a reflective surface formed in a concave shape. In some embodiments, the reflective surface of the concave mirror is formed to be a free-form surface.

[0106] 1, the fundus observation device 1 may be provided with an alignment optical system for aligning the subject's eye E with the optical system. Also, the fundus observation device 1 may be provided with a focusing mechanism that moves a lens or moves the slit light-receiving optical system 20.

[0107] The fundus observation device 1 may also be provided with a configuration for providing functions associated with the examination. For example, the fundus observation device 1 may be provided with a fixation optical system for projecting a target (fixation target) for fixating the subject's eye E onto the fundus Ef of the subject's eye E. Furthermore, the fundus observation device 1 may be provided with any element or unit such as a member for supporting the subject's face (chin rest, forehead rest, etc.).

[0108] Fig. 9 shows an example of the configuration of a processing system of the fundus oculi observation device 1 according to the first embodiment. In Fig. 9, the same parts as in Fig. 1 are given the same reference numerals, and the description will be omitted as appropriate.

[0109] The processing system of the fundus observation device 1 is configured mainly around the control unit 60. The control unit 60 controls each unit of the fundus observation device 1.

[0110] 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 by, for example, a processor. The storage unit 62 stores in advance a computer program for controlling the fundus observation device 1. This computer program includes an illumination light source control program, an image sensor control program, a hole mirror control program, an image formation program, and a user interface program. The main control unit 61 operates in accordance with such computer programs, causing the control unit 60 to execute control processing.

[0111] (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.

[0112] The control of the slit projection optical system 10 includes control of the illumination light source 11. The control of the illumination light source 11 includes turning the light source on and off, adjusting the light amount, adjusting the aperture, and so on.

[0113] Control of the slit light-receiving optical system 20 includes control of the image sensor 21. Control of the image sensor 21 includes setting control of a movable light-receiving range (virtual aperture range, focal plane) at the fundus conjugate position P, and control for reading out the light-receiving results using a rolling shutter method (for example, setting a light-receiving size corresponding to the size of the illumination pattern). Control of the image sensor 21 also includes reset control, exposure control, charge transfer control, output control, etc.

[0114] Control of the hole mirror 30 includes control of the angle of the deflection surface that deflects the illumination light. By controlling the angle of the deflection surface, it is possible to control the deflection direction of the illumination light. By controlling the angle range of the deflection surface, it is possible to control the scan range (scan start position and scan end position). By controlling the speed at which the angle of the deflection surface is changed, it is possible to control the scan speed.

[0115] The control of the image forming unit 70 includes image formation control for forming an image of the subject's eye E from the light reception result obtained by the image sensor 21, and the like.

[0116] The control over the UI unit 80 includes control over the display device, control over the operation device (input device), and the like.

[0117] (Storage unit 62) The storage unit 62 stores various types of data. Examples of the data stored in the storage unit 62 include the light reception results obtained by the image sensor 21, image data of the image formed by the image forming unit 70, and information about the subject's eye. The information about the subject's eye includes information about the subject, such as the patient ID and name, and information about the subject's eye, such as identification information for the left eye or right eye.

[0118] Moreover, the storage unit 62 stores various programs and data for operating the fundus observation device 1.

[0119] (Image forming unit 70) The image forming unit 70 can form a light-receiving image (fundus image) corresponding to any light-receiving range (virtual aperture range, focal plane) based on the light-receiving results read out from the image sensor 21 by the rolling shutter method. The image forming unit 70 can sequentially form light-receiving images corresponding to the light-receiving range (aperture range) and form an image of the subject's eye E from the formed plurality of light-receiving images. Various images (image data) formed by the image forming unit 70 are stored in the storage unit 62, for example.

[0120] For example, the image forming unit 70 includes a processor, and performs processing in accordance with a program stored in a storage unit or the like, thereby realizing the above functions.

[0121] (UI part 80) The UI unit 80 has a function for exchanging information between the user and the fundus observation device 1. The UI unit 80 includes a display device and an operation device. The display device may include a display unit, or may include other display devices. The display device displays various types of information. The display device includes, for example, a liquid crystal display, and displays the above information under control of the main control unit 61. The information displayed on the display device includes information corresponding to the control results by the control unit 60, information (images) corresponding to the calculation results by the image forming unit 70, and the like. The operation device includes various hardware keys and / or software keys. The main control unit 61 can receive operation contents for the operation device and output control signals corresponding to the operation contents to each unit. At least a part of the operation device and at least a part of the display device can be configured integrally. A touch panel display is one example.

[0122] 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. The first holding member 41 and the second holding member 51 are an example of a "holding member" according to the embodiment. The protrusions 40A, 40B, 50A, and 50B are an example of a "fixed portion" according to the embodiment. The holes 41A, 41B, 51A, and 51B are an example of a "fixed portion" according to the embodiment. The slit projection optical system 10 and the slit light-receiving optical system 20 are an example of an "optical system" according to the embodiment. The hole mirror 30 is an example of a "deflecting member" according to the embodiment.

[0123] <Operation> Next, an example of the operation of the fundus oculi observation device 1 according to the first embodiment will be described.

[0124] Fig. 10 shows an example of operation of the fundus observation device 1 according to the first embodiment. Fig. 10 shows a flowchart of the example of operation of the fundus observation device 1 according to the first embodiment. A computer program for realizing the processing shown in Fig. 10 is stored in the storage unit 62. The main control unit 61 operates according to this computer program to execute the processing shown in Fig. 10.

[0125] In FIG. 10, it is assumed that the eye E is placed at a predetermined position (the second focal point F4 of the second ellipsoidal mirror 50 in FIG. 1).

[0126] (S1: Turn on the illumination light source) The main control unit 61 controls the illumination light source 11 to turn it on.

[0127] Light output from the illumination light source 11 passes through an opening formed in the iris diaphragm 12, passes through an opening formed in the slit 13, passes through the projection lens 14, and is guided to the hole mirror 30 as slit-shaped illumination light.

[0128] (S2: Controls the deflection of the illumination light and sets the aperture range of the light receiving surface) Next, the main controller 61 controls the hole mirror 30 to set the orientation of the deflection surface in a predetermined deflection direction to illuminate a predetermined irradiation range, and starts deflection control of the illumination light to sequentially change the orientation of the deflection surface within a predetermined deflection angle range. That is, the main controller 61 starts scanning the illumination light over the fundus Ef.

[0129] In some embodiments, the main control unit 61 controls the hole mirror 30 to control the deflection of the illumination light in synchronization with the movement of a virtual aperture range (light-receiving range) that can be arbitrarily set in the image sensor 21.

[0130] In some embodiments, the main controller 61 controls the image sensor 21 to virtually set an aperture range (light-receivable range) including a light-receiving range of the returning light on the light-receiving surface corresponding to the illumination light irradiation area on the fundus oculi Ef. For example, the illumination light irradiation area on the fundus oculi Ef can be specified based on the deflection angle of the deflection surface of the hole mirror 30. The main controller 61 can virtually 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 hole mirror 30, which is sequentially changed.

[0131] The illumination light guided to the hole mirror 30 is deflected by the deflection surface whose deflection direction has been changed, and is guided to the reflecting surface of the first ellipsoidal mirror 40. The illumination light is reflected by this reflecting surface and guided to the reflecting surface of the second ellipsoidal mirror 50 via the second focal point F2 of the first ellipsoidal mirror 40. The illumination light guided to the reflecting surface of the second ellipsoidal mirror 50 is reflected by this reflecting surface and enters the eye E to be examined, which is positioned at the second focal point F4 of the second ellipsoidal mirror 50, and irradiates the fundus Ef. The illumination light returning from the fundus Ef travels in the opposite direction along the same path as the outward 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 light-receiving surface of the image sensor 21 has a virtual aperture range (light-receiving range) set to include a light-receiving range of the returned light corresponding to the illumination light irradiation range on the fundus Ef. Therefore, only the light returning from the fundus Ef is received while suppressing the influence of unnecessary scattered light.

[0132] (S3:End?) Next, the main controller 61 determines whether or not to end the scanning of the illumination light on the fundus Ef. For example, the main controller 61 can determine whether or not to end the scanning of the illumination light on the fundus Ef by determining whether or not the deflection angle of the deflecting surface of the hole mirror 30, which is sequentially changed, is within a predetermined deflection angle range.

[0133] When it is determined that the scanning of the illumination light on the fundus Ef is to be ended (S3: Y), the operation of the fundus observation device 1 proceeds to step S4. When it is determined that the scanning of the illumination light on the fundus Ef is not to be ended (S3: N), the operation of the fundus observation device 1 proceeds to step S2.

[0134] (S4: Acquire image) In step S3, when it is determined that the scanning of the illumination light on the fundus Ef is to be ended (S3: Y), the main controller 61 controls the image forming unit 70 to form an image of the subject's eye E based on the light reception results read out 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 out from the image sensor 21 in step S2, and forms an image of the subject's eye E from the formed multiple light reception images.

[0135] This is the end of the operation of the fundus oculi observation device 1 (end).

[0136] As described above, according to the first embodiment, the first ellipsoidal mirror 40 and the second ellipsoidal mirror 50 can be aligned easily, at low cost, and with high accuracy. Furthermore, in the fundus observation device 1 equipped with such a first ellipsoidal mirror 40 and a second ellipsoidal mirror 50, the hole mirror 30 is used to couple the optical path of the slit projection optical system 10 with the optical path of the slit light receiving optical system 20, and the hole mirror 30 is used to deflect the illumination light and direct it to the reflecting surface of the first ellipsoidal mirror 40. This allows for a low-cost, compact configuration, ensuring a photographing angle of view exceeding 80 degrees with just an optical system that scans in the slit width direction (line width direction) perpendicular to the slit direction of the illumination light, while easily arranging an optical system that shares the optical path of the wide-angle illumination light and the optical path of the return light. Furthermore, because an optical system can be arranged on the passing (transmitting) side of the hole mirror 30, a pupil relay system is not required, improving the flexibility of the optical system arrangement.

[0137] Furthermore, by using the hole mirror 30 instead of a polygon mirror, etc., it is possible to widen the deflection angle range while achieving quieter operation. Also, by making the length in the slit direction or the length in the scan direction variable, it becomes possible to arbitrarily set the scan range of the illumination light.

[0138] 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.

[0139] In the following embodiments, a case where a swept-source type OCT technique is used in measurement or photography using OCT will be particularly described. However, the configuration according to the embodiment can also be applied to a fundus observation device that uses another type of OCT (for example, a spectral domain type).

[0140] Hereinafter, the fundus observation device according to the second embodiment will be described, focusing on the differences from the fundus observation device 1 according to the first embodiment.

[0141] <Configuration> Fig. 11 shows an example of the configuration of the optical system of the fundus observation device according to the second embodiment. In Fig. 11, the same parts as in Fig. 1 are given the same reference numerals, and the description will be omitted as appropriate.

[0142] The configuration of the optical system of the fundus observation device 1a according to the second embodiment is different from the configuration of the optical system of the fundus observation device 1 according to the first embodiment in that an OCT optical system 100 is added to the configuration of the optical system of the fundus observation device 1. The optical path of the OCT optical system 100 is combined with the optical path of the slit light-receiving optical system 20 in the optical path between the slit light-receiving optical system 20 and the hole mirror 30.

[0143] Specifically, a relay lens optical system including relay lenses 71 and 72 is disposed on the optical path between the slit light-receiving optical system 20 and the hole mirror 30. The optical path between the relay lenses 71 and 72 is converted into the optical path of a telecentric optical system, and a dichroic mirror 90 is disposed on 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 where the dichroic mirror 90 is disposed into the optical path of the telecentric optical system.

[0144] The dichroic mirror 90 is an optical path coupling / separation member that separates the optical path of the OCT optical system 100 from the optical path of the slit light-receiving optical system 20 (combines the optical path of the slit light-receiving 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 subject's eye E and guides it to the OCT optical system 100. The dichroic mirror 90 also transmits the return light of the illumination light from the subject's eye E that has been guided via the relay lens 71 and guides it to the relay lens 72.

[0145] (OCT optical system 100) Fig. 12 shows an example of the configuration of the OCT optical system 100 of Fig. 11. In Fig. 12, the same parts as in Fig. 11 are given the same reference numerals, and the description will be omitted as appropriate.

[0146] The OCT optical system 100 is provided with an optical system for performing OCT measurement (or OCT imaging) on ​​the subject's eye E. This optical system is an interference optical system that splits light from a wavelength sweep type (wavelength scanning type) light source into measurement light and reference light, causes return light of the measurement light from the subject's eye E to interfere 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 indicating the spectrum of the interference light, and is sent to an image forming unit 70a, a data processing unit 75a, etc., which will be described later.

[0147] The OCT light source 101, like a general swept-source type fundus observation device, is configured to include a wavelength sweep type (wavelength scanning type) light source that can sweep (scan) the wavelength of emitted light. The wavelength sweep type light source includes, for example, a resonator and includes a laser light source that emits light with a center wavelength of 1050 nm. The OCT light source 101 changes the output wavelength over time in the near-infrared wavelength band that is invisible to the human eye.

[0148] Light L0 output from the OCT light source 101 is guided by an optical fiber 102 to a 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, for example, by applying stress from the outside to the looped optical fiber 102.

[0149] The light L0, whose polarization state has been adjusted by the polarization controller 103, is guided by an optical fiber 104 to a fiber coupler 105, where it is split into a measurement light LS and a reference light LR.

[0150] The reference light LR is guided by an optical fiber 110 to a collimator 111, where it is converted into a parallel beam, and is then guided to an optical path length changing unit 114 via an optical path length correction member 112 and a dispersion compensation member 113. The optical path length correction member 112 acts to match the optical path length of the reference light LR with the optical path length 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.

[0151] The optical path length changing unit 114 is movable in the direction of the arrow shown in FIG. 12 and changes the optical path length of the reference light LR. This movement changes the optical path length 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 subject's eye E, adjust the interference state, and so on. The optical path length changing unit 114 is configured to include, for example, a corner cube and a movement mechanism that moves it. In this case, the corner cube of the optical path length changing unit 114 reverses the traveling direction of the reference light LR, which has been converted 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.

[0152] The reference light LR that has passed through the optical path length changing unit 114 passes through a dispersion compensation member 113 and an optical path length correction member 112, is converted from a parallel beam into a convergent beam by a collimator 116, and is then incident on an optical fiber 117. The reference light LR that has passed through the optical fiber 117 is guided to a polarization controller 118 where its polarization state is adjusted, is guided by an optical fiber 119 to an attenuator 120 where the light amount is adjusted, and is then guided by an optical fiber 121 to a fiber coupler 122.

[0153] On the other hand, the measurement light LS generated by the fiber coupler 105 is guided by the optical fiber 127 and collimated into a parallel beam by the collimator lens unit 140. The parallel beam of the measurement light LS is deflected one-dimensionally or two-dimensionally by the optical scanner 150.

[0154] The collimator lens unit 140 includes a collimator lens arranged on the optical axis of the interference optical system included in the OCT optical system 100. The collimator lens collimates the measurement light beam emitted from the end of an optical fiber that is connected to the OCT optical system 100 and guides the measurement light LS. The end of the optical fiber is arranged, for example, at a fundus conjugate position P.

[0155] The optical scanner 150 (deflection surface) can be positioned at the pupil conjugate position Q. When deflecting the illumination light one-dimensionally, the optical scanner 150 includes a galvanometer scanner that deflects the measurement light LS within a predetermined deflection angle range based on a predetermined deflection direction. When deflecting the illumination light two-dimensionally, the optical scanner 150 includes a first galvanometer scanner and a second galvanometer scanner. The first galvanometer scanner deflects the measurement light LS so as to move the irradiation position in a horizontal direction (e.g., x direction) perpendicular to the optical axis of the OCT optical system 100. The second galvanometer scanner deflects the measurement light LS deflected by the first galvanometer scanner so as to move the irradiation position 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 irradiation 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.

[0156] 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 reflecting surface of the first ellipsoidal mirror 40, and is guided to the subject's eye E via the same path as 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 controlled by a control unit (described later) and is moved along the optical path of the measurement light LS by a moving mechanism (not shown).

[0157] The measurement light LS reflected by the reflecting surface of the second ellipsoidal mirror 50 enters the eye through the pupil of the subject's eye E at the second focal point F4 (position of the subject's eye). The measurement light LS is scattered (including reflected) at various depth positions in the subject's eye E. The return light of the measurement light LS, including such backscattered light, travels in the opposite direction along the same path as the outward path and is guided to the fiber coupler 105, and reaches the fiber coupler 122 via the optical fiber 128.

[0158] Fiber coupler 122 generates interference light by combining (causing interference between) measurement light LS incident via optical fiber 128 and reference light LR incident via optical fiber 121. Fiber coupler 122 splits the interference light between measurement light LS and reference light LR at a predetermined splitting ratio (for example, 1:1) to generate a pair of interference light LC. The pair of interference light LC emitted from fiber coupler 122 is guided to detector 125 by optical fibers 123 and 124, respectively.

[0159] The detector 125 is, for example, a balanced photodiode that has a pair of photodetectors that respectively detect a pair of interference light beams LC and outputs the difference between the detection results. The detector 125 sends the detection result (interference signal) to a DAQ (Data Acquisition System) 130. A clock KC is supplied to the DAQ 130 from the OCT light source 101. The clock KC is generated in synchronization with the output timing of each wavelength swept (scanned) within a predetermined wavelength range by the wavelength swept light source in the OCT light source 101. For example, the OCT light source 101 optically delays one of two branched beams obtained by branching light beam L0 of each output wavelength, and then generates the clock KC based on the result of detecting the combined light. The DAQ 130 samples the detection result of the detector 125 based on the clock KC. The DAQ 130 sends the sampled detection result of the detector 125 to the image forming unit 70a, data processing unit 75a, etc. The image forming unit 70a (or the data processing unit 75a) forms a reflection intensity profile for each A-line, for example, for each series of wavelength scans (for each A-line), by performing a Fourier transform or the like on the spectral distribution based on the detection results obtained by the detector 125. Furthermore, the image forming unit 70a forms image data by imaging the reflection intensity profile for each A-line.

[0160] 12, the optical path length difference 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 the embodiment is not limited to this. For example, the optical path length difference between the measurement light and the reference light may be changed by changing the optical path length of the measurement light.

[0161] Fig. 13 shows an example of the configuration of a processing system of a fundus oculi observation device 1a according to the second embodiment. In Fig. 13, the same parts as those in Fig. 9, 11 or 12 are given the same reference numerals, and the description thereof will be omitted as appropriate.

[0162] The configuration of the processing system of the fundus observation device 1a differs from the configuration of the processing system of the fundus observation device 1 in 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.

[0163] The control unit 60a includes a main control unit 61a and a storage unit 62a, and in addition to the control that the control unit 60 can perform, controls 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. Similar to the storage unit 62, the storage unit 62a stores in advance computer programs for controlling the fundus observation device 1a. These computer programs include an illumination light source control program, an image sensor control program, a hole mirror control program, an image forming program, a data processing program, an OCT optical system control program, and a user interface program. The main control unit 61a operates in accordance with these computer programs, and the control unit 60a performs control processing.

[0164] 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.

[0165] Control over the OCT optical system 100 includes control over the OCT light source 101, operation control over the polarization controllers 103 and 118, movement control over the optical path length change unit 114, operation control over the attenuator 120, control over the detector 125, control over the DAQ 130, control over the optical scanner 150, and control over the movement mechanism 151D.

[0166] Control of the OCT light source 101 includes turning the light source on and off, adjusting the light intensity, adjusting the aperture, etc. Control of the detector 125 includes adjusting the exposure, gain, and detection rate of the detection element, etc. Control of the optical scanner 150 includes controlling the scanning position, scanning range, and scanning speed of the optical scanner 150, etc.

[0167] The moving mechanism 151D moves the focusing lens 151 in the optical axis direction of the OCT optical system 100. The main controller 61a controls the moving mechanism 151D to move the focusing lens 151 in the optical axis direction of the OCT optical system 100, thereby changing the focusing position of the measurement light LS. The focusing position of the measurement light LS corresponds to the depth position (z position) of the beam waist of the measurement light LS.

[0168] Control over the image forming unit 70a includes image formation control for forming an image of the subject's eye E from the light reception results obtained by the image sensor 21, as well as control for forming an OCT image based on the detection results of interference light obtained by the OCT optical system 100.

[0169] The control of the data processing unit 75a includes control of image processing of the image formed by the image forming unit 70a, control of image analysis processing, and the like.

[0170] Similar to the image forming unit 70, the image forming unit 70a can form a light-receiving image (fundus image) corresponding to a virtually set arbitrary aperture range (light-receiving range) based on the light-receiving results read out from the image sensor 21. The image forming unit 70a can sequentially form light-receiving images corresponding to the virtual aperture range, and form an image of the subject's eye E from the formed plurality of light-receiving images.

[0171] The image forming unit 70a also forms image data of an OCT image (tomographic image) 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, B-scan images, and the like. A B-scan image is formed, for example, by arranging A-scan images in the B-scan direction. This processing includes noise removal (noise reduction), filtering, dispersion compensation, FFT (Fast Fourier Transform), and other processes, similar to those of conventional swept-source OCT. For other types of OCT devices, the image forming unit 70a performs known processing appropriate to the type. Various images (image data) formed by the image forming unit 70a are stored, for example, in the storage unit 62a.

[0172] The data processing unit 75a processes an image formed based on the light reception result obtained by the slit light receiving optical system 20, or data acquired by OCT measurement of the subject's eye E. The data processing unit 75a can perform various image processing and analysis processing on the image formed by the image forming unit 70a. For example, the data processing unit 75a executes various correction processing such as brightness correction of the image.

[0173] The data processing unit 75a performs known image processing, such as interpolation processing that interpolates pixels between OCT images, to form image data of a three-dimensional image of the fundus oculi Ef. Note that image data of a three-dimensional image refers to image data in which pixel positions are defined by a three-dimensional coordinate system. Image data of a three-dimensional image includes image data consisting of three-dimensionally arranged voxels. This image data is called volume data or voxel data. When displaying an image based on the volume data, the data processing unit 75a performs rendering processing (volume rendering, MIP (Maximum Intensity Projection), etc.) on the volume data to form image data of a pseudo three-dimensional image as viewed from a specific line of sight. This pseudo three-dimensional image is displayed on a display device included in the UI unit 80.

[0174] It is also possible to form stack data of multiple tomographic images as image data of a three-dimensional image. Stack data is image data obtained by arranging multiple tomographic images obtained along multiple scan lines in a three-dimensional manner based on the positional relationship of the scan lines. In other words, stack data is image data obtained by expressing multiple tomographic images that were originally defined using separate two-dimensional coordinate systems using a single three-dimensional coordinate system (i.e., embedding them in a single three-dimensional space).

[0175] The data processing unit 75a can perform various rendering operations on the acquired three-dimensional data set (volume data, stack data, etc.) to generate B-mode images (longitudinal and axial cross-sectional images) of any cross-section, C-mode images (transverse and horizontal cross-sectional images) of any cross-section, projection images, shadowgrams, and the like. Images of any cross-section, such as B-mode images and C-mode images, are generated by selecting pixels (voxels) on a specified cross-section from the three-dimensional data set. Projection images are generated by projecting the three-dimensional data set in a predetermined direction (z direction, depth direction, axial direction). Shadowgrams are generated by projecting a portion of the three-dimensional data set (e.g., partial data corresponding to a specific layer) in a predetermined direction. Images viewed from the front side of the subject's eye, such as C-mode images, projection images, and shadowgrams, are called en-face images.

[0176] The data processing unit 75a can construct a B-mode image or a front image (a blood vessel-enhanced image, angiogram) in which retinal blood vessels and choroidal blood vessels are emphasized based on data collected in time series by OCT (for example, B-scan image data). For example, time-series OCT data can be collected by repeatedly scanning approximately the same region of the subject's eye E.

[0177] In some embodiments, the data processor 75a compares time-series B-scan images obtained by B-scanning approximately the same region and converts pixel values ​​of portions of signal intensity that have changed into pixel values ​​corresponding to the changes to construct an enhanced image in which the changed portions are emphasized. Furthermore, the data processor 75a extracts information on a predetermined thickness of a desired region from the constructed multiple enhanced images and constructs the extracted information as an en-face image, thereby forming an OCTA image.

[0178] Images generated by the data processing unit 75a (for example, a three-dimensional image, a B-mode image, a C-mode image, a projection image, a shadowgram, and an OCTA image) are also included in the OCT image.

[0179] Furthermore, the data processing unit 75a performs predetermined analytical processing on an image formed based on the light reception results obtained by the slit light-receiving optical system 20, the detection results of interference light obtained by OCT measurement, or an OCT image formed based on the detection results. The predetermined analytical processing includes identifying predetermined regions (tissues, lesions) in the subject's eye E; calculating the distance (interlayer distance), area, angle, ratio, and density between specified regions; performing calculations using specified formulas; identifying the shape of the predetermined regions; calculating statistical values ​​of these; calculating the distribution of measured values ​​and statistical values; and performing image processing based on the results of these analytical processing. Predetermined tissues include blood vessels, the optic disc, the fovea, the macula, etc. Predetermined lesions include exudates, hemorrhage, etc.

[0180] The fundus observation device 1a may include a movement mechanism that moves the OCT optical system 100 in one-dimensional or two-dimensional directions that intersect with the optical axis of the OCT optical system 100. In this case, the main controller 61a controls this movement mechanism to move the OCT optical system 100 relative to the dichroic mirror 90 in one-dimensional or two-dimensional directions that intersect with the optical axis of the OCT optical system 100. This makes it possible to move the scan range using the optical scanner 150 of the OCT optical system 100 and scan a wide-angle scan range (for example, the imaging range of the SLO) of the fundus Ef.

[0181] The OCT optical system 100 is an example of a "projection optical system" and a "light receiving optical system" according to the embodiment.

[0182] <Operation> Next, an example of the operation of the fundus oculi observation device 1a according to the second embodiment will be described.

[0183] 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 with illumination light shown in Fig. 10. Hereinafter, control of OCT measurement that can be performed in parallel with the control shown in Fig. 10 will be described.

[0184] Fig. 14 shows an operation example of the fundus oculi observation device 1a according to the second embodiment. Fig. 14 shows a flowchart of the operation example of the fundus oculi observation device 1a according to the second embodiment. A computer program for realizing the processing shown in Fig. 14 is stored in the storage unit 62a. The main control unit 61a operates according to this computer program to execute the processing shown in Fig. 14.

[0185] In FIG. 14, it is assumed that the eye E is placed at a predetermined position (the second focal point F4 of the second ellipsoidal mirror 50 in FIG. 1).

[0186] (S11: Set the scan range) First, the main control unit 61a sets the scan range of the optical scanner 150. The main control unit 61a can set the scan start position, scan end position, scan speed (scan frequency), etc. of the optical scanner 150, along with the scan range.

[0187] In some embodiments, the user can specify a scan mode or an operation mode by operating an operation device on the UI unit 80. When the user specifies a scan mode (e.g., horizontal scan, vertical scan) by operating the operation device, the main control unit 61a analyzes operation information from the operation device to identify the specified scan mode. When the user specifies an operation mode by operating the operation device, the main control unit 61a analyzes the operation information to identify a scan mode (e.g., horizontal scan, vertical scan) that has been specified in advance in the specified operation mode (OCT measurement mode).

[0188] (S12: Turn on the OCT light source) Next, the main controller 61a controls the OCT light source 101 to turn on the OCT light source 101. In some embodiments, the main controller 61a executes step S12 in synchronization with the control of turning on the illumination light source 11 in step S1 shown in FIG.

[0189] In some embodiments, the main controller 61a performs focus adjustment control and polarization adjustment control. For example, the main controller 61a controls the moving mechanism 151D to move the focusing lens a predetermined distance, and then controls the OCT optical system 100 to perform OCT measurement. The main controller 61a causes the data processor 75a to determine the focus state of the measurement light LS based on the detection result of the interference light obtained by the OCT measurement. For example, the data processor 75a analyzes the detection result of the interference light obtained by the OCT measurement to calculate a predetermined evaluation value related to the image quality of the OCT image, and determines the focus state based on the calculated evaluation value. If the focus state of the measurement light LS is determined to be inappropriate based on the determination result by the data processor 75a, the main controller 61a controls the moving mechanism 151D again, and repeats this process until the focus state is determined to be appropriate.

[0190] 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 light L0 and the measurement light LS by a predetermined amount, and 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 result 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 data processing unit 75a determines that the polarization state of the measurement light LS is not appropriate based on the determination result, the main control unit 61a again controls the polarization controllers 103 and 118, and repeats this process until it determines that the polarization state is appropriate.

[0191] (S13: Perform OCT scan) Next, the main controller 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 causes the deflected measurement light LS to scan a predetermined portion of the fundus Ef of the subject's eye E. The detection result of the interference light acquired by the OCT measurement is sampled in the DAQ 130 and stored as an interference signal in the memory unit 62a or the like.

[0192] (S14:End?) Next, the main controller 61a determines whether or not to end the OCT scan of the fundus Ef. For example, the main controller 61a can determine whether or not to end the OCT scan of the fundus Ef by determining whether or not the deflection angle of the deflection surface of the optical scanner 150, which is sequentially changed, is within a predetermined deflection angle range.

[0193] When it is determined that the OCT scan of the fundus Ef is to be ended (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 ended (S14: N), the operation of the fundus observation device 1a proceeds to step S13.

[0194] (S15: Forming an OCT image) In step S14, when it is determined that the OCT scan of the fundus oculi Ef is to be ended (S14: Y), the main controller 61a causes the image forming unit 70a to form a plurality of A-scan images of the fundus oculi Ef along the B-scan direction based on the interference signal acquired in step S14. In some embodiments, the main controller 61a controls the data processing unit 75a to form OCT images such as a three-dimensional OCT image, a B-mode image, a C-mode image, a projection image, a shadowgram, and an OCTA image.

[0195] This is the end of the operation of the fundus oculi observation device 1a.

[0196] FIG. 15 shows an explanatory diagram of the operation of the fundus oculi observation device 1a according to the second embodiment.

[0197] 15, scanning of the fundus Ef with illumination light, which is achieved by deflecting the illumination light using a hole mirror 30, and OCT scanning of the fundus Ef, which is achieved by deflecting the measurement light LS using an optical scanner 150, are performed in parallel. As a result, while scanning of the fundus Ef with illumination light is being performed in a scanning range SC1 (horizontal direction H0 × vertical direction V0), an OCT scan can be performed on a scanning range SC0 at any position within the scanning range SC1.

[0198] As a result, it becomes possible to perform OCT measurement (OCT photography) at any position on the fundus observed at a very wide angle by scanning the illumination light over the scan range SC1.

[0199] As described above, according to the second embodiment, in addition to the effects obtained by the first embodiment, by optically coupling the OCT optical system 100 on the transmission side of the hole mirror 30 serving 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 its return light can be separated at low cost. Furthermore, it becomes possible to perform OCT measurement (OCT photography) at any position on the fundus observed at a very wide angle, without sharing an optical scanner for OCT scanning and an optical scanner for deflecting the illumination light.

[0200] <Third embodiment> In the first and second embodiments, the second ellipsoidal mirror 50 is disposed such that the angle α between the line connecting the first focal point F1 and the second focal point F2 of the first ellipsoidal mirror 40 and the line connecting the first focal point F3 and the second focal point F4 of the second ellipsoidal mirror 50 is 30 degrees. However, the configuration according to the embodiment is not limited to this. For example, the angle α between the line connecting the first focal point F1 and the second focal point F2 of the first ellipsoidal mirror 40 and the line connecting the first focal point F3 and the second focal point F4 of the second ellipsoidal mirror 50 may be approximately 0 degrees.

[0201] Fig. 16 shows an example of the configuration of the optical system of the fundus observation device according to the third embodiment. In Fig. 16, the same parts as in Fig. 11 are given the same reference numerals, and the description will be omitted as appropriate.

[0202] The configuration of the optical system of the fundus observation device 1b according to the third embodiment differs from the configuration of the optical system of the fundus observation device 1a according to the second embodiment in 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 so that the angle α between the line connecting the first focal point F1 and the second focal point F2 of the first ellipsoidal mirror 40 and the 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).

[0203] In FIG. 16, the fundus observation device 1b is provided with the OCT optical system 100, but the fundus observation device 1b may have a configuration in which the OCT optical system 100 is omitted, similar to FIG.

[0204] Depending on the angle α, the symmetry of the observation range with respect to the subject's eye E changes along with the wide-angle range. Compared to the second embodiment, the third embodiment makes it possible to observe the fundus Ef within a wide-angle range that is symmetric with respect to the subject's eye E.

[0205] <Fourth embodiment> In the first embodiment, the case where the illumination light is deflected using the hole mirror 30 has been described, but the configuration according to the embodiment is not limited to this. In the first embodiment, for example, a reflecting mirror may be placed at the first focal point F1 of the first ellipsoidal mirror 40, and the hole mirror may be placed at a position that is approximately optically conjugate with the pupil of the subject's eye E.

[0206] Fig. 17 shows an example of the configuration of the optical system of the fundus observation device according to the fourth embodiment. In Fig. 17, the same parts as in Fig. 1 are given the same reference numerals, and the description will be omitted as appropriate.

[0207] The configuration of the optical system of the fundus observation device 1c according to the fourth embodiment differs from the configuration of the optical system of the fundus observation device 1 according to the first embodiment in that a reflecting mirror 31 is arranged instead of the hole mirror 30 at the first focal point F1 of the first ellipsoidal mirror 40, that a hole mirror 32 is arranged at the pupil conjugate position Q away from the first focal point F1, that an optical scanner 17 is arranged between the hole mirror 32 and the slit projection optical system 10, and that relay lenses 33, 15, and 16 are added to relay the pupil conjugate position Q.

[0208] The orientation of the deflection surface of the reflecting mirror 31 is fixed. The relay lens 33 is arranged between the reflecting 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. The relay lens 16, the optical scanner 17, and the relay lens 15 are arranged 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 the illumination light as the hole mirror 30.

[0209] In this case, 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 reflecting mirror 31 and is guided to the reflecting surface of the first ellipsoidal mirror 40. Return light of the illumination light from the fundus Ef of the subject's eye E is deflected by the reflecting 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.

[0210] According to the fourth embodiment, compared to the first embodiment, even if there is not enough space to place an optical system near the first focal point F1 of the first ellipsoidal mirror 40, by relaying the pupil conjugate position Q, the degree of freedom in placing the slit projecting optical system 10 and the slit receiving optical system 20 can be improved.

[0211] Fifth Embodiment In the second embodiment, the case where the illumination light is deflected using the hole mirror 30 has been described, but the configuration of the embodiment is not limited to this. In the second embodiment, as in the fourth embodiment, for example, a reflecting mirror may be disposed at the first focal point F1 of the first ellipsoidal mirror 40, and the hole mirror may be disposed at a position that is optically approximately conjugate with the pupil of the subject's eye E.

[0212] Fig. 18 shows an example of the configuration of the optical system of the fundus observation device according to the fifth embodiment. In Fig. 18, the same parts as those in Fig. 11 or 17 are given the same reference numerals, and the description will be omitted as appropriate.

[0213] The configuration of the optical system of the fundus observation device 1d according to the fifth embodiment differs from the configuration of the optical system of the fundus observation device 1a according to the second embodiment in that a reflecting mirror 31 is arranged instead of the hole mirror 30 at the first focal point F1 of the first ellipsoidal mirror 40, that a hole mirror 32 is arranged at the pupil conjugate position Q away from the first focal point F1, that an optical scanner 17 is arranged between the hole mirror 32 and the slit projection optical system 10, and that relay lenses 15 and 16 are added to relay the pupil conjugate position Q.

[0214] As in the fourth embodiment, the orientations of the deflection surfaces of the reflecting mirror 31 and the hole mirror 32 are 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 lens 16, optical scanner 17, and relay lens 15 are arranged 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 the illumination light as the hole mirror 30.

[0215] In this case, 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 reflecting mirror 31, and is guided to the reflecting surface of the first ellipsoidal mirror 40. Return light of the illumination light from the fundus Ef of the subject's eye E is deflected by the reflecting 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.

[0216] According to the fifth embodiment, compared to the second embodiment, even if there is not enough space to place an optical system near the first focal point F1 of the first ellipsoidal mirror 40, by relaying the pupil conjugate position Q, the degree of freedom in placing the slit projecting optical system 10 and the slit receiving optical system 20 can be improved.

[0217] [Effect] A fundus observation device according to an embodiment will be described.

[0218] A first aspect of the embodiment is a fundus observation device (1, 1a, 1b, 1c, 1d) including an optical system (slit projection optical system 10 and slit light receiving optical system 20, OCT optical system 100) that projects light from a light source (illumination light source 11, OCT light source 101) onto the fundus (Ef) of the subject's eye (E) and receives returning light from the fundus, two concave mirrors (first ellipsoidal mirror 40, second ellipsoidal mirror) that each have a concave reflecting surface and guide the light from the optical system to the fundus and guide the returning light to the optical system, and holding members (first holding member 41 and second holding member 51) that hold the two concave mirrors. At least one of the two concave mirrors has a flange on which one of a fixing portion and a fixed portion is formed. The other of the fixing portion and the fixed portion is formed on the holding member. The fundus observation device is configured so that the flange is held by the holding member with the fixed portion fixed by the fixing portion.

[0219] According to this aspect, one of the fixing portion and the fixed portion is formed on the flange of at least one of the two concave mirrors, and the other of the fixing portion and the fixed portion is formed on the holding member, and the holding member is configured to hold the flange with the fixed portion fixed by the fixing portion, making it possible to easily and highly precisely adjust the position of the concave mirror as an optical element relative to the holding member.

[0220] In a second aspect of the embodiment, in the first aspect, the two concave mirrors include a first concave mirror (first ellipsoidal mirror 40) having a first flange formed on its periphery and a concave first reflecting surface that reflects light, and a second concave mirror (second ellipsoidal mirror 50) having a second flange formed on its periphery and a concave second reflecting surface that guides light reflected by the first concave mirror to the fundus. The holding member holds the first flange and the second flange.

[0221] According to this aspect, the holding member fixes the concave mirror using the fixing portion and the fixed portion while holding the flange formed on the peripheral edge of the concave mirror, making it possible to reliably hold a concave mirror that has been aligned simply and with high precision.

[0222] In a third aspect of the embodiment, in the second aspect, the holding member holds the first flange and the second flange so that they are substantially parallel to each other.

[0223] According to this aspect, the positional relationship between the concave mirror and the holding member can be adjusted while the positional relationship in a specific direction is uniquely determined by the holding member, making it possible to align the concave mirror with the holding member easily and with high precision.

[0224] In a fourth aspect of the embodiment, in any of the first to third aspects, both end portions of at least one of the two concave mirrors in a predetermined first direction (the long axis direction of the ellipsoidal mirror) have a shape cut by a plane that intersects the first direction.

[0225] According to this aspect, it is possible to reduce the weight and size of the fundus observation device while ensuring the size of the reflecting surface necessary for wide-angle fundus observation. In particular, it is possible to avoid a situation in which the subject's mouth or chin interferes with the concave mirror, and it becomes possible for the subject to observe the subject's eye while facing the reflecting surface.

[0226] In a fifth aspect of the embodiment, in any of the first to fourth aspects, at least one of the two concave mirrors is an ellipsoidal mirror (first ellipsoidal mirror 40, second ellipsoidal mirror 50).

[0227] According to this aspect, it is possible to provide a fundus observation device that can easily align the ellipsoidal mirror with high accuracy.

[0228] In a sixth aspect of the embodiment, in the fifth aspect, the ellipsoidal mirror has a flange on which one of a fixed portion and a fixed portion is formed, and on the surface of the flange, a straight line connecting a first projection point and a second projection point of the two foci of the ellipsoidal mirror is perpendicular to a straight line connecting the first projection point and one of the fixed portion and the fixed portion.

[0229] According to this aspect, the vicinity of the focal point of the ellipsoidal mirror can be fixed to the holding member by the fixing portion and the fixed portion, thereby enabling highly accurate alignment of the ellipsoidal mirror.

[0230] In a seventh aspect of the embodiment, in any of the first to sixth aspects, the fixed portions are convex portions (projections 40A, 40B, 50A, 50B), and the fixing portions are concave portions or holes (41A, 41B, 51A, 51B).

[0231] According to this aspect, the holding member holds the concave mirror by fitting the convex portion into the concave portion or by inserting the convex portion into the hole portion, making it possible to align the concave mirror with high precision easily and at low cost.

[0232] In an eighth aspect of the embodiment, in any of the fifth to seventh aspects, the two concave mirrors include a first ellipsoidal mirror (40) and a second ellipsoidal mirror (50), and one of the two foci of the first ellipsoidal mirror (second focus F2) is positioned at one of the two foci of the second ellipsoidal mirror (first focus F3), and guides light from the optical system to the other of the two foci of the second ellipsoidal mirror (second focus F4).

[0233] According to this aspect, in a fundus observation device using two ellipsoidal mirrors, it is possible to align the concave mirror with high precision simply and at low cost.

[0234] In a ninth aspect of the embodiment, in the eighth aspect, the optical system includes a projection optical system (slit projection optical system 10, OCT optical system 100) that projects light from the light source, a light receiving optical system (slit light receiving optical system 20, OCT optical system 100) that receives the returned light, and a deflection member (hole mirror 30) that is arranged at the other of the two focal points (first focal point F1) of the first ellipsoidal mirror, deflects the light from the light source, and guides the returned light to the light receiving optical system.

[0235] According to this aspect, it is possible to easily arrange a shared optical system for the optical path of wide-angle light and the optical path of return light, while ensuring a photographic angle of view of more than 80 degrees with just the optical system, with a low-cost and compact configuration.

[0236] In a tenth aspect of the embodiment, in the eighth aspect, the optical system includes a projection optical system (slit projection optical system 10) that includes a deflection member (optical scanner 17) and deflects and projects light from the light source, a light receiving optical system (slit light receiving optical system 20) that receives the returned light, an optical path combining member (hole mirror 32) that optically combines the optical path of the projection optical system and the optical path of the light receiving optical system, and a reflecting member (reflecting mirror 31) that is arranged at the other of the two focal points (first focal point F1) of the first ellipsoidal mirror and that guides light from the light source that has been guided along the optical path combined by the optical path combining member to the first ellipsoidal mirror.

[0237] According to this aspect, when there is not enough space to place the optical system near the second focal point of the first ellipsoidal mirror, the degree of freedom in placing the projection optical system and the light receiving optical system can be improved.

[0238] <Other> The embodiment described above is merely one example for carrying out the present invention, and those who wish to carry out the present invention may make any modifications, omissions, additions, etc. within the scope of the gist of the present invention.

[0239] In some embodiments, a program is provided that causes a processor (computer) to execute each step of the above-described control method for a fundus observation device. Such a program can be stored in any non-transitory recording medium (storage medium) that can be read by a computer. Examples of this recording medium include semiconductor memory, optical disks, magneto-optical disks (CD-ROM / DVD-RAM / DVD-ROM / MO, etc.), and magnetic storage media (hard disks / floppy disks / ZIP, etc.). This program can also be transmitted and received via a network such as the Internet or a LAN. [Explanation of symbols]

[0240] 1, 1a, 1b, 1c, 1d Fundus observation device 10 Slit projection optical system 17, 150 Optical scanner 20 Surito Light Receiving Optics Department 30 and 32 acupoint mirrors 31 reflection ミラー 40 No. 1 Yiyen Mask 40A, 40B, 50A, 50B protrusions 41 1st holding member Acupoints 41A, 41B, 51A, and 51B 50 No. 2 Yiyen Mask 51 2nd holding member 100 OCT Optics Department E quilt eyes F1, F3 First Focus F2, F4 Second Focus P Fundus co-operational location Q pupil common position

Claims

1. an optical system that projects light from a light source onto the fundus of the subject's eye and receives light returning from the fundus; two concave mirrors each having a concave reflecting surface, guiding the light from the optical system to the fundus and guiding the return light to the optical system; a holding member for holding the two concave mirrors; Including, At least one of the two concave mirrors has a flange on which one of a fixing portion and a fixed portion is formed, the holding member is formed with the other of the fixing portion and the fixed portion, The flange is configured to be held by the holding member in a state in which the fixed portion is fixed by the fixing portion, The two concave mirrors are a first concave mirror having a first flange formed on a peripheral edge thereof and a first concave reflecting surface that reflects the light; a second concave mirror having a second flange formed on a peripheral edge thereof and a second reflecting surface having a concave shape that guides the light reflected by the first concave mirror to the fundus; Including, The holding member holds the first flange and the second flange.

2. The holding member holds the first flange and the second flange so that they are substantially parallel to each other.

2. The fundus observation device according to claim 1.

3. An optical system that projects light from a light source onto the fundus of the subject's eye and receives return light from the fundus; two concave mirrors each having a concave reflecting surface, guiding the light from the optical system to the fundus and guiding the return light to the optical system; a holding member for holding the two concave mirrors; Including, At least one of the two concave mirrors has a flange on which one of a fixing portion and a fixed portion is formed, the holding member is formed with the other of the fixing portion and the fixed portion, The flange is configured to be held by the holding member in a state in which the fixed portion is fixed by the fixing portion, A fundus observation device, wherein both ends of at least one of the two concave mirrors in a predetermined first direction have a shape that is cut by a plane that intersects with the first direction.

4. At least one of the two concave mirrors is an ellipsoidal mirror.

2. The fundus observation device according to claim 1.

5. At least one of the two concave mirrors is an ellipsoidal mirror.

4. The fundus observation device according to claim 3.

6. the ellipsoidal mirror has a flange on which one of the fixing portion and the fixed portion is formed, On the surface of the flange, a straight line connecting a first projected point and a second projected point of the two foci of the ellipsoidal mirror is perpendicular to a straight line connecting the first projected point and one of the fixing portion and the fixed portion.

6. The fundus observation device according to claim 4 or 5.

7. the fixed portion is a protrusion, The fixing portion is a recess or a hole.

2. The fundus observation device according to claim 1.

8. The fixed portion is a convex portion, The fixing portion is a recess or a hole.

4. The fundus observation device according to claim 3.

9. the two concave mirrors include a first ellipsoidal mirror and a second ellipsoidal mirror; one of two focal points of the first ellipsoidal mirror is disposed at one of two focal points of the second ellipsoidal mirror; The light from the optical system is guided to the other of the two focal points of the second ellipsoidal mirror.

9. The fundus observation device according to claim 4, claim 5, claim 7, or claim 8.

10. The optical system comprises: a projection optical system that projects light from the light source; a light receiving optical system that receives the returned light; a deflection member disposed at the other of the two focal points of the first ellipsoidal mirror, which deflects the light from the light source and guides the returning light to the light-receiving optical system; Contains 10. The fundus observation device according to claim 9.

11. The optical system comprises: a projection optical system including a deflection member for deflecting and projecting the light from the light source; a light receiving optical system that receives the returned light; an optical path coupling member that optically couples the optical path of the projection optical system and the optical path of the light receiving optical system; a reflecting member that is disposed at the other of the two focal points of the first ellipsoidal mirror and that guides the light from the light source that has been guided along the optical path combined by the optical path combining member to the first ellipsoidal mirror; Contains 10. The fundus observation device according to claim 9.

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