Fundus camera

Abstract

A fundus camera of non-limiting embodiments projects illumination light output from an illumination optical system including a light source and a light scanner to a fundus of an eye under examination by means of a first curved mirror and a second curved mirror. The first curved mirror and the second curved mirror have mutually different curvature distributions. Return light of the illumination light projected to the fundus is detected by a light receiving optical system by means of the second curved mirror and the first curved mirror. The first curved mirror and the second curved mirror each have one or more focal points, and the first curved mirror and the second curved mirror are configured to share one focal point. The light receiving optical system includes a first lens group, a second lens group configured eccentrically with respect to the first lens group, and an image sensor that detects return light that has passed through the first lens group and the second lens group.

Description

Technical Field

[0001] This disclosure relates to a fundus imaging device. Background Technology

[0002] Various imaging modalities are used in ophthalmic diagnosis and treatment. In recent years, devices that can easily and with a wide field of view capture the fundus of the examined eye have been used for screening and treatment of eye diseases. For example, scanning laser ophthalmoscopy (SLO) is known to capture images of a range of more than 80 degrees in a single shot. Patent document 1 discloses a fundus imaging device that can perform a wide-angle scan of the retina by moving a two-dimensional parallel light scanner using a multifaceted mirror and a plane mirror to the examined eye via a scanning movement unit.

[0003] In addition, Patent Document 2 discloses a fundus imaging device that achieves wide-angle fundus imaging by using an elliptical concave mirror or a wide-angle lens. When using this fundus imaging device, in order to position the eye being examined in a suitable imaging position, it is necessary to keep the face in close contact with the pads provided by the device.

[0004] Patent documents 3 and 4 disclose a fundus imaging device that combines fundus scanning using slit-shaped illumination light with a rolling shutter, enabling the generation of high-contrast images with a simple structure. In particular, in the fundus imaging device described in patent document 4, two elliptical concave mirrors are introduced into the optical system for fundus scanning using slit-shaped illumination light, enabling wide-angle imaging of the fundus.

[0005] Existing technical documents Patent documents Patent Document 1: Japanese Patent Publication No. 2009-543585 Patent Document 2: Japanese Patent Application Publication No. 2022-184520 Patent Document 3: U.S. Patent No. 7831106 Patent Document 4: International Publication No. 2022 / 124170 Summary of the Invention Typically, fundus imaging devices capable of wide-angle imaging are large devices due to the inclusion of multiple large elliptical concave mirrors (see, for example, Patent Document 2). Figure 3 A).

[0006] One object of this disclosure is to provide a technique for miniaturizing a fundus imaging device capable of wide-angle shooting.

[0007] An exemplary embodiment is a fundus imaging device for imaging the fundus of an eye being examined. The fundus imaging device includes: an illumination optical system including a light source generating illumination light and a light scanner deflecting the illumination light; a first curved mirror reflecting the illumination light from the illumination optical system; a second curved mirror having a different curvature distribution than the first curved mirror and reflecting and guiding the illumination light reflected by the first curved mirror to the eye being examined; and a light-receiving optical system detecting the reflected light from the illumination light projected onto the fundus of the eye being examined using the second curved mirror and the first curved mirror. The first and second curved mirrors each have more than one focal point, and the first and second curved mirrors share a common focal point. The light-receiving optical system includes: a first lens group; a second lens group offset relative to the first lens group; and an image sensor detecting the reflected light passing through the first and second lens groups.

[0008] According to the exemplary manner of the implementation, it is possible to miniaturize the fundus imaging device capable of wide-angle shooting. Attached Figure Description

[0009] Figure 1 This is a schematic diagram illustrating the structure of a fundus imaging device in a non-limiting manner according to an embodiment.

[0010] Figure 2 This is a schematic diagram illustrating the structure of a fundus imaging device in a non-limiting manner according to an embodiment.

[0011] Figure 3 This is a schematic diagram illustrating the structure of a fundus imaging device in a non-limiting manner for explaining the embodiments.

[0012] Figure 4 This is a schematic diagram illustrating the structure of a fundus imaging device in a non-limiting manner for explaining the embodiments.

[0013] Figure 5 This is a schematic diagram illustrating the structure of a fundus imaging device in a non-limiting manner for explaining the embodiments.

[0014] Figure 6 This is a schematic diagram illustrating the structure of a fundus imaging device in a non-limiting manner according to an embodiment.

[0015] Figure 7 This is a schematic diagram illustrating the structure of a fundus imaging device in a non-limiting manner according to an embodiment.

[0016] Figure 8 This is a schematic diagram illustrating the operation of a fundus imaging device in a non-limiting manner for explaining the implementation method.

[0017] Figure 9 This is a schematic diagram illustrating the operation of a fundus imaging device in a non-limiting manner for explaining the implementation method.

[0018] Figure 10 This is a schematic diagram illustrating the operation of a fundus imaging device in a non-limiting manner for explaining the implementation method.

[0019] Figure 11 This is a schematic diagram illustrating the operation of a fundus imaging device in a non-limiting manner for explaining the implementation method. Detailed Implementation

[0020] Non-limiting embodiments of this disclosure will be described.

[0021] The implementation method can be combined with any known technology. For example, any matter described in the documents cited in this disclosure can be combined with any embodiment. Moreover, at least one of any known document related to the technical field of this disclosure, any known technology in a technical field similar to the technical field of this disclosure, and any known technology in a technical field different from the technical field of this disclosure can be combined with any embodiment.

[0022] For example, matters disclosed in Patent Document 4 (International Publication No. 2022 / 124170) may be cited in this disclosure. More generally, any technical matters disclosed by the applicant of this application (matters disclosed in patent applications, papers, etc.) relating to the technology of this disclosure may be cited in this disclosure by reference.

[0023] Any two or more of the non-limiting methods of the implementation can be combined at least partially.

[0024] At least a portion of the functionality of any of the methods described in this disclosure is implemented using a circuitry or processing circuitry. The circuitry or processing circuitry includes general-purpose processors, special-purpose processors, integrated circuits, CPUs (Central Processing Units), GPUs (Graphics Processing Units), ASICs (Application Specific Integrated Circuits), programmable logic devices (e.g., SPLDs (Simple Programmable Logic Devices), CPLDs (Complex Programmable Logic Devices), FPGAs (Field Programmable Gate Arrays)), existing circuitry, and any combination thereof. A processor is considered as a processing circuitry or circuitry including transistors and / or other circuitry. In this disclosure, circuitry, unit, component, or similar terms refer to hardware that performs at least a portion of the disclosed functionality or hardware programmed to perform at least a portion of the disclosed functionality. Hardware may be the hardware disclosed in this specification, or it may be known hardware that is programmed and / or configured to perform at least a portion of the functions described herein. When hardware is a processor that can be considered as a type of circuit structure, circuit structure, unit, component, or similar terminology refers to a combination of hardware and software used to constitute the hardware and / or processor.

[0025] <Summary of Implementation Methods> One object of the embodiments of this disclosure is to miniaturize a fundus imaging device capable of wide-angle shooting. The effects of the embodiments of this disclosure are not limited to those achieved by accomplishing this object. In this disclosure, some non-limiting methods of implementation are described. Those skilled in the art will understand that each disclosed method has its own specific effects corresponding to its characteristics (structure, operation, function, use, etc.).

[0026] For example, in existing fundus imaging devices, the eye to be examined needs to be positioned appropriately for wide-angle imaging of the fundus. For this purpose, as described in paragraph 0030 of Patent Document 2 (Japanese Patent Application Publication No. 2022-184520), the face needs to be pressed firmly against a pad provided in the device. This causes discomfort and considerable burden for many subjects. This problem can be solved by some of the embodiments of this disclosure.

[0027] A first embodiment is a fundus imaging device for imaging the fundus of a subject eye, including an illumination optical system, a first curved mirror, a second curved mirror, and a light-receiving optical system. Some fundus imaging devices may also include other components. For example, some fundus imaging devices may include three or more curved mirrors.

[0028] The illumination optics system includes a light source that generates illumination light. Furthermore, the illumination optics system includes a light scanner that deflects the illumination light generated by the light source. A first curved mirror reflects the illumination light generated by the illumination optics system. A second curved mirror reflects the illumination light reflected by the first curved mirror and guides it to the eye being examined. With this structure, the fundus imaging device can project illumination light to various locations on the fundus of the eye being examined.

[0029] The shape of the first curved mirror (the reflecting surface of the illumination light (concave reflecting surface)) is different from that of the second curved mirror (the reflecting surface of the illumination light (concave reflecting surface)). In other words, the curvature distribution of the first curved mirror (the reflecting surface of the illumination light (concave reflecting surface)) is different from that of the second curved mirror (the reflecting surface of the illumination light (concave reflecting surface)).

[0030] The light-receiving optical system detects the reflected light from the illumination light generated by the illumination optical system and projected onto the fundus of the eye being examined using the first and second curved mirrors. Specifically, the reflected light from the illumination light of the eye being examined is reflected by the second curved mirror, further reflected by the first curved mirror, and guided to the light-receiving optical system for detection.

[0031] In this method, the first curved mirror (the reflecting surface (concave reflecting surface) that reflects the illumination light) has one or more focal points. Additionally, the second curved mirror (the reflecting surface (concave reflecting surface) that reflects the illumination light) also has one or more focal points.

[0032] Furthermore, the first and second curved mirrors share a common focal point. That is, a focal point of the first curved mirror and a focal point of the second curved mirror are located at the same position.

[0033] Furthermore, in this embodiment, the light-receiving optical system includes a first lens group and a second lens group. The second lens group is offset relative to the first lens group. That is, the optical axes of the first lens group and the second lens group are not on the same straight line, but are parallel to each other.

[0034] Furthermore, the light-receiving optical system of this method includes an image sensor that detects the return light of the illumination light that has passed through the first lens group and the second lens group. A fundus image can be constructed based on the output signal from the image sensor.

[0035] According to this method, by using an optical system including a first curved mirror and a second curved mirror to scan the structure of the fundus, a wide-angle fundus imaging can be performed. The first curved mirror and the second curved mirror have different curvature distributions but share a common focal point.

[0036] Furthermore, according to this method, by using a light-receiving optical system comprising a first lens group and a second lens group arranged off-center to detect the reflected light of the illumination light, a smaller first and second curved mirror can be used than before. The reasons for this will be explained in more detail. One of the reasons hindering the miniaturization of curved mirrors is the deterioration of the aberration performance of the optical system. That is, an optical system comprising two (or more) curved mirrors is not a coaxial optical system; therefore, miniaturization of the curved mirrors generates asymmetric aberrations (e.g., image plane tilt), deteriorating aberration performance. Consequently, the difficulty of aberration correction in the subsequent optical system increases. In the prior art, it is impossible to correct such asymmetric aberrations. In contrast, in this method, by using an off-center optical system as the light-receiving optical system, asymmetric aberrations caused by the miniaturization of the curved mirrors can be suppressed. Therefore, according to this method, a fundus imaging device equipped with a smaller curved mirror than before can be realized. Therefore, miniaturization of a fundus imaging device capable of wide-angle imaging can be achieved.

[0037] In a second embodiment, according to the fundus imaging device of the first embodiment, the image sensor of the light-receiving optical system is tilted relative to both the optical axis of the first lens group and the optical axis of the second lens group.

[0038] According to this method, by combining a first lens group and a second lens group arranged offset from each other with an image sensor arranged at an angle, it is possible to improve the suppression of asymmetric aberrations caused by the miniaturization of the curved mirror. Therefore, it is possible to miniaturize a fundus imaging device capable of wide-angle shooting. Furthermore, image quality can also be improved.

[0039] In a third embodiment, the fundus imaging device according to the first embodiment further includes a third lens group that is offset relative to both the first and second lens groups. Furthermore, the image sensor of the light-receiving optical system in this embodiment detects the return light of the illumination light that has passed through the first, second, and third lens groups.

[0040] According to this method, a structural example can be provided that uses a light-receiving optical system comprising three lens groups arranged in a mutually offset configuration to detect the reflected light of illumination light. Thus, a smaller first and second curved mirror can be used, enabling the miniaturization of a fundus imaging device capable of wide-angle imaging.

[0041] In the fourth embodiment, according to the third-party fundus imaging device, the image sensor of the light-receiving optical system is tilted relative to the optical axes of the first lens group, the second lens group, and the third lens group.

[0042] According to this method, by combining a first lens group, a second lens group, and a third lens group arranged offset from each other with an image sensor arranged at an angle, it is possible to improve the suppression of asymmetric aberrations caused by the miniaturization of the curved mirror. Therefore, it is possible to miniaturize a fundus imaging device capable of wide-angle shooting.

[0043] In a fifth embodiment, according to the fundus imaging device of the third or fourth embodiment, the reflected light from the illumination light of the examined eye passes sequentially through the first lens group, the second lens group, and the third lens group and is guided to the image sensor. Furthermore, the fundus imaging device of this embodiment includes a first focusing mechanism as a component for adjusting the focus of the light-receiving optical system. The first focusing mechanism moves the second lens group, the third lens group, and the image sensor as a single unit. The direction of movement is, for example, along the optical axis of the second lens group (or the third lens group).

[0044] According to this method, the focusing of the light-receiving optical system can be adjusted based on the refractive power of the eye being examined. This enables the miniaturization of a fundus imaging device capable of wide-angle shooting and improves image quality.

[0045] In a sixth embodiment, the fundus imaging device according to any one of the first to fifth embodiments uses a first elliptical concave mirror as a first curved mirror and a second elliptical concave mirror as a second curved mirror.

[0046] According to this method, a preferred structural example of a miniaturized fundus imaging device capable of wide-angle shooting can be provided.

[0047] In the seventh embodiment, examples of the dimensions of the first and second elliptical concave mirrors are provided according to the fundus imaging device of the sixth embodiment. In this embodiment, the major axis of both the first and second elliptical concave mirrors is within the range of 70 mm to 80 mm. Furthermore, the minor axis of both the first and second elliptical concave mirrors is within the range of 50 mm to 60 mm.

[0048] According to this method, a fundus imaging device equipped with a smaller-sized elliptical concave mirror and capable of wide-angle imaging can be provided. In fact, existing fundus imaging devices use elliptical concave mirrors with both major and minor axes exceeding 100 mm. In contrast, this method allows for the introduction of a much smaller elliptical concave mirror. In the inventor's design, an elliptical concave mirror approximately the size of a bowl can be used, large enough to partially cover the subject's eyes and nose, thus reducing the overall size of the device to about a quarter of its previous size.

[0049] In the eighth embodiment, the fundus imaging device according to the sixth or seventh embodiment provides a configuration example of a first elliptical concave mirror and a second elliptical concave mirror. In this embodiment, the first elliptical concave mirror and the second elliptical concave mirror are configured such that the plane containing the major axis of the first elliptical concave mirror and the plane containing the major axis of the second elliptical concave mirror are not parallel to each other.

[0050] For example, the first elliptical concave mirror can be configured such that its major axis is oriented in a direction parallel to the horizontal plane, and the second elliptical concave mirror can be configured such that its major axis is oriented in a direction parallel to a plane inclined relative to the horizontal plane.

[0051] According to this method, a preferred structural example of a miniaturized fundus imaging device capable of wide-angle imaging can be provided. Furthermore, according to this method, the possibility of the device (e.g., an elliptical concave mirror or its housing) touching the subject's head can be reduced.

[0052] In some configurations, the first and second elliptical concave mirrors can be arranged such that the plane containing the major axis of the first elliptical concave mirror is parallel to the plane containing the major axis of the second elliptical concave mirror. For example, two or more curved mirrors can be configured such that two or more focal points of the two or more curved mirrors (two or more elliptical concave mirrors) are located on substantially the same plane (common plane of focal points).

[0053] In the ninth embodiment, according to the fundus imaging device of the eighth embodiment, the first elliptical concave mirror and the second elliptical concave mirror are configured such that the major axis of the first elliptical concave mirror is perpendicular to the major axis of the second elliptical concave mirror.

[0054] For example, the first elliptical concave mirror can be configured such that its major axis is oriented in a direction parallel to the horizontal plane, and the second elliptical concave mirror can be configured such that its major axis is oriented in a direction perpendicular to the horizontal plane. In other words, the first elliptical concave mirror can be configured such that its major axis is oriented in a direction parallel to the horizontal plane, and the second elliptical concave mirror can be configured such that its major axis is oriented in a direction parallel to the vertical plane.

[0055] According to this method, a preferred structural example of a miniaturized fundus imaging device capable of wide-angle imaging can be provided. Furthermore, according to this method, the possibility of the device (e.g., an elliptical concave mirror or its housing) touching the subject's head can be reduced.

[0056] In a tenth embodiment, a structural example of an illumination optical system is provided for a fundus imaging apparatus according to any one of the first to ninth embodiments. The illumination optical system of this embodiment further includes a slit component having a slit opening. Illumination light generated by a light source is projected onto the slit component. A portion of the illumination light projected onto the slit component is guided to a light scanner through the slit opening. The light scanner deflects the illumination light that has passed through the slit opening. The light scanner can change the direction of the deflected illumination light. The illumination light deflected by the light scanner is projected onto the fundus of the examined eye by means of a first elliptical concave mirror and a second elliptical concave mirror.

[0057] According to this method, a preferred structural example of a miniaturized fundus imaging device capable of wide-angle imaging can be provided. More specifically, in the miniaturized fundus imaging device capable of wide-angle imaging, fundus scanning can be performed using slit-shaped illumination light (slit illumination light).

[0058] In this method, the image sensor can perform signal readout using a rolling shutter method. This method allows for simultaneous control of both the optical scanner used to deflect the slit illumination light and the image sensor that reads signals using a rolling shutter method. According to this method, in addition to enabling miniaturization of the fundus imaging device capable of wide-angle shooting, it is also possible to generate high-contrast images with a simple structure.

[0059] In the eleventh embodiment, according to the fundus imaging device of the tenth embodiment, the slit component is tilted relative to the optical axis of the illumination optical system.

[0060] According to this method, a preferred structural example of a miniaturized fundus imaging device capable of wide-angle shooting can be provided.

[0061] In the twelfth embodiment, the fundus imaging device according to the tenth or eleventh embodiment includes a second focusing mechanism as a component for focusing the illumination optical system. The second focusing mechanism moves the slit member. The direction of movement is, for example, along the optical axis of the illumination optical system (optical axis direction).

[0062] According to this method, the focusing of the illumination optical system can be adjusted based on the refractive power of the examined eye. This enables the miniaturization of a fundus imaging device capable of wide-angle shooting and improves image quality.

[0063] The following explains the various matters that can be arbitrarily adopted in some ways.

[0064] The fundus imaging device may include both a first focusing mechanism for adjusting the focus of the light-receiving optical system and a second focusing mechanism for adjusting the focus of the illumination optical system. In this manner, the control of the first focusing mechanism and the control of the second focusing mechanism can be performed simultaneously.

[0065] The fundus imaging device illuminates the fundus with slit illumination light in such a way that the long side of the slit image (the image of the slit illumination light passing through the slit opening) formed by illumination light projected onto the fundus of the examined eye is substantially parallel to a plane containing two or more focal points. The slit illumination light moves in a direction that intersects the long side of the slit image (e.g., a direction perpendicular to the long side).

[0066] Examples of curved mirrors include elliptical mirrors, parabolic mirrors, hyperboloid mirrors, freeform mirrors, and mirrors whose reflecting surfaces are represented by high-order polynomials. The reflecting surface of a curved mirror can be either concave or convex. Specifically, examples of curved mirrors include elliptical concave mirrors, elliptical convex mirrors, parabolic concave mirrors, parabolic convex mirrors, hyperboloid concave mirrors, hyperboloid convex mirrors, freeform mirrors with concave reflecting surfaces, freeform mirrors with convex reflecting surfaces, concave mirrors whose reflecting surfaces are represented by high-order polynomials, and convex mirrors whose reflecting surfaces are represented by high-order polynomials.

[0067] The focal point of a curved mirror refers not only to the position uniquely determined by the shape of the curved surface, but sometimes also to the position where the convergence of the light rays (beams) reflected by the reflecting surface is higher than other positions.

[0068] In the following embodiments, the fundus imaging device with two curved mirrors (two elliptical concave mirrors) will be mainly described, but the fundus imaging device is not limited to this and may also have three or more curved mirrors.

[0069] In the following embodiments, following ophthalmological convention, the direction along the axis of the examined eye E is defined as the Z direction (axial direction, Z-axis), and the plane perpendicular to the Z direction is defined as the XY plane. The Z direction (Z-axis) is also defined as the direction of the optical axis of the optical system that applies illumination light to the examined eye. The left-right direction (horizontal direction) of the examinee is defined as the X direction (X-axis), and the direction perpendicular to both the X and Z directions (vertical direction, vertical direction, body axis direction) is defined as the Y direction (Y-axis).

[0070] In addition, the direction of the long side of the slit image refers to, for example, the direction along the long side of the rectangle tangent to the slit image, and the direction of the short side of the slit image refers to, for example, the direction along the short side of the rectangle.

[0071] In this disclosure, various non-limiting embodiments, including the first to twelfth embodiments described above, are described. This disclosure primarily describes exemplary embodiments of fundus imaging devices. However, the categories of embodiments are not limited thereto. For example, those skilled in the art will understand that embodiments of this disclosure can provide various methods for controlling fundus imaging devices, various medical methods, various imaging methods, various data processing methods, various programs, various recording media, etc.

[0072] <Non-limiting embodiments> Some non-limiting aspects of the fundus imaging device described in the embodiments will be explained. Figure 1 An example of the structure of the optical system of the fundus imaging device according to an embodiment is shown. Figure 1 In the figure, the reference numeral P indicates the position approximately optically conjugate to the fundus Ef of the examined eye E (fundus conjugate position). Additionally, the reference numeral Q indicates the position approximately optically conjugate to the iris (pupil) of the examined eye E (iris conjugate position, pupil conjugate position).

[0073] The fundus imaging device 1 of this embodiment includes an illumination optical system 10, an imaging optical system 20, an aperture lens 30 as an optical path splitting component (optical path coupling component), and a relay optical system 50.

[0074] The illumination optical system 10 generates illumination light that is projected onto the fundus Ef of the examined eye E. In this embodiment, the illumination optical system 10 generates slit illumination light (the beam cross-section shape is approximately slit-shaped). The generated illumination light is projected onto the aperture lens 30.

[0075] The illumination optical system 10 includes an illumination source 11, an iris aperture 12, a relay lens 13, a slit component 14, a relay lens 15, a light scanner 16, and a relay lens 17. In some embodiments, the relay lens 13 is composed of more than one lens. The same applies to relay lenses 15 and 17.

[0076] The illumination source 11 generates light within a predetermined wavelength range. For example, the illumination source 11 includes a visible light source that generates light in the visible region. The visible light source of the illumination source 11, for example, generates light with a center wavelength in the wavelength range of 420 nm to 700 nm. Such an illumination source 11 includes, for example, any one of a light-emitting diode (LED), a laser diode (LD), a halogen lamp, and a xenon lamp. In some embodiments, the illumination source 11 includes a white light source and / or includes a light source capable of outputting light of each of the RGB color components. In some embodiments, the illumination source 11 includes an infrared light source that generates light in the infrared region. In some embodiments, the illumination source 11 includes a light source capable of selectively or simultaneously outputting infrared light and visible light.

[0077] An opening is formed in the iris aperture 12. The iris aperture 12 (opening) can be configured at the iris conjugate position Q, which is the position optically conjugate to or near the iris (pupil) of the examined eye E. More than one opening is formed on the iris aperture 12 at a position deviating from the optical axis of the light path output from the illumination source 11. The opening of the iris aperture 12 defines the incident position (incident shape) of the illumination light in the iris (pupil) of the examined eye E.

[0078] In some methods, the relative position between the illumination source 11 and the opening of the iris aperture 12 can be changed. This alters the light intensity distribution passing through the opening of the iris aperture 12.

[0079] In some embodiments, the illumination source 11 functions as an iris aperture 12. In this embodiment, the iris aperture component (the component that performs the function of the iris aperture 12) located in the illumination source 11 is positioned at the iris conjugate position Q.

[0080] An opening (slit opening) is formed in the slit component 14. The slit component 14 (slit opening) can be configured at a fundus conjugate position P, which is a position optically conjugate to or near the fundus Ef of the examined eye E. The slit opening of the slit component 14 defines the shape of the projection area of ​​the illumination light in the fundus Ef of the examined eye E (the slit image projected onto the fundus Ef). Illumination light emitted from the illumination source 11 is projected onto the slit component 14, a portion of which passes through the slit opening. Thus, a slit illumination light with a beam cross-sectional shape that is approximately slit-shaped is generated.

[0081] The slit component 14 can be moved in the direction along the optical axis of the illumination optical system 10 via a moving mechanism (not shown) (specifically, the moving mechanism 14D described later). As a result, the slit component 14 can be moved to a position corresponding to the state of the examined eye E (specifically, refractive power, axial length, shape of fundus Ef, etc.).

[0082] In some embodiments, the movable slit component 14 can be substituted, or, based on this, configured to change the position and / or shape of the slit opening. This function is achieved, for example, by a liquid crystal shutter.

[0083] The optical scanner 16 has a surface (deflection surface) that deflects the illumination light. The optical scanner 16 (deflection surface) can be configured at an iris conjugate position Q, which is the position optically conjugate to or near the iris (pupil) of the examined eye E. The optical scanner 16 is, for example, a single-axis optical scanner configured to change the orientation of the deflection surface in a predetermined direction. The optical scanner 16 deflects the slit illumination light generated by the slit member 14 in one dimension. For example, the optical scanner 16 deflects the slit illumination light such that the slit image projected onto the fundus Ef moves in a direction intersecting the long side direction of the slit image (typically, a direction perpendicular to the long side direction). The direction of movement of the slit image is called the scanning direction.

[0084] The optical scanner 16 can be any device capable of changing the direction of light travel, such as any of a current scanner, a MEMS (Micro Electro Mechanical System) scanner, a faceted mirror, and a resonant scanner. For example, the optical scanner 16 includes a current scanner that deflects the illumination light within a predetermined deflection angle range with a predetermined deflection direction as a reference.

[0085] In some embodiments, the optical scanner 16 may be a biaxial optical scanner capable of deflecting the slit illumination light in two dimensions. For example, the optical scanner 16 includes a first scanner and a second scanner. The first scanner deflects the slit illumination light in such a way that it moves the slit image on the fundus Ef in a horizontal direction (X direction) orthogonal to the optical axis of the illumination optics system 10. The second scanner deflects the slit illumination light in such a way that it moves the slit image on the fundus Ef in a vertical direction (Y direction) orthogonal to the optical axis of the illumination optics system 10. Either the first scanner or the second scanner may be configured on one side of the illumination source 11.

[0086] According to the illumination optical system 10 of this method, firstly, illumination light emitted by the illumination source 11 is projected onto the iris aperture 12. A portion of the illumination light passing through the opening of the iris aperture 12 is relayed by the relay lens 13 and projected onto the slit member 14. A portion of the illumination light passing through the slit opening of the slit member 14 is used as slit illumination light. The generated slit illumination light is relayed by the relay lens 15 and projected onto the polarization plane of the light scanner 16. The slit illumination light deflected by the light scanner 16 is relayed by the relay lens 17 and guided to the aperture lens 30.

[0087] In some embodiments, the illumination optics system 10 includes a projector with a light source that generates slit illumination light. In this embodiment, instead of Figure 1The illumination optical system 10 includes an illumination source 11, an iris aperture 12, a relay lens 13, and a slit component 14, and a projector is installed thereon. Projectors that can be used in the illumination optical system 10 include, for example, liquid crystal display (LCD) projectors using a transmissive liquid crystal panel, LCOS (Liquid Crystal On Silicon) projectors using a reflective liquid crystal panel, and DLP (Digital Light Processing) projectors using a digital micromirror device (DMD).

[0088] The aperture lens 30 has a light-reflecting surface and an opening (aperture) formed on the light-reflecting surface. The aperture lens 30 (aperture) can be positioned at the iris conjugate position Q. The aperture lens 30 functions as a light path segmentation component that spatially segments the light path of the illumination light and the light path of the returning light from the examined eye E, which transmits the illumination light. The aperture lens 30 can also be regarded as a light path coupling component that couples the light path of the illumination light with the light path of its returning light.

[0089] The aperture lens 30 has an aperture at the center of the substrate through which the optical axis passes, and a light-reflecting surface is provided around the center (peripheral portion). Figure 1 In the optical system, the aperture lens 30 is configured such that the optical axis of the imaging optical system 20 passes through the aperture. Additionally, in... Figure 1 In the optical system, the illumination light provided by the illumination optical system 10 is reflected by the light-reflecting surface of the periphery of the aperture lens 30 and guided to the relay optical system 50.

[0090] The structure of the optical system using aperture 30 is not limited to Figure 1 The structure is shown. In some embodiments, the aperture lens 30 is configured such that the optical axis of the illumination optics system 10 passes through the aperture in the center, and the reflected light from the illumination light of the examined eye E is reflected by the reflective surface in the peripheral portion and guided to the imaging optics system 20. Alternatively, in some embodiments, the aperture lens 30 has an aperture for the optical axis to pass through formed on one side of the substrate, and a light-reflecting surface is provided on the other side of the substrate. In this case, the light passing through the aperture is guided to the imaging optics system 20, and the light reflected by the light-reflecting surface is guided to the examined eye E. Conversely, the light passing through the aperture is guided to the examined eye E, and the light reflected by the light-reflecting surface is guided to the imaging optics system 20.

[0091] Illumination light from illumination optics 10 is reflected by a reflective surface formed around the aperture of aperture lens 30 and guided to relay optics 50. Return light from the examined eye E is guided by relay optics 50 to aperture lens 30, passes through the aperture of aperture lens 30, and is guided to imaging optics 20.

[0092] Optical elements that can be used as optical path splitting components to separate the optical path of the illuminating light from the optical path of its return light are not limited to aperture mirror 30. In some embodiments, any one of beam splitters, semi-reflective mirrors, polygonal mirrors, and dichroic mirrors can be used instead of aperture mirror 30.

[0093] The imaging optical system 20 functions as a light-receiving optical system, and with the help of the relay optical system 50, it detects the return light of the illumination light projected onto the fundus Ef of the examined eye E. Figure 1 The imaging optical system 20 detects the reflected light from the examined eye E passing through the aperture of the endoscope 30. The reflected light from the examined eye E includes reflected light from the illumination light incident on the examined eye E (particularly reflected light from the fundus Ef) and scattered light. In some embodiments, the reflected light from the examined eye E includes, in addition to reflected and scattered light from the illumination light incident on the examined eye E, fluorescence excited by the illumination light incident on the examined eye E and its scattered light.

[0094] The imaging optical system 20 includes an image sensor 21, a lens group 22, and a lens group 23. The lens group 22 consists of one lens or a combination of two or more lenses. Similarly, the lens group 23 consists of one lens or a combination of two or more lenses.

[0095] Lens group 22 and lens group 23 are arranged off-center from each other. That is, the optical axis of lens group 22 and the optical axis of lens group 23 are arranged parallel to each other, but not on the same straight line.

[0096] Image sensor 21 is a two-dimensional image sensor that functions as a pixelated light receiver. The light-receiving surface (light detection surface) of image sensor 21 can be configured at a conjugate position P on the fundus. The image sensor 21 can be configured with a virtually movable light-receiving area (light-receiving region) at the conjugate position P on the fundus.

[0097] For example, the illumination result of image sensor 21 is acquired and read using a rolling shutter method. In some embodiments, the illumination result of image sensor 21 is acquired and read using a global shutter method that allows for changing or moving the illuminated area. Control of image sensor 21 for reading illumination results is performed by control unit 60, described later. In some embodiments, image sensor 21 can automatically output a predetermined amount of illumination result along with information indicating the illumination location.

[0098] Such an image sensor 21 includes, for example, a CMOS (Complementary Metal Oxide Semiconductor) image sensor. In this case, the image sensor 21 has multiple groups of pixels (light-receiving elements) arranged in the row direction, and each pixel group includes multiple pixels arranged in the column direction. That is, such an image sensor 21 includes multiple pixels arranged in two dimensions, multiple vertical signal lines, and horizontal signal lines.

[0099] In some embodiments, the image sensor 21 includes, for example, a CCD (Charge Coupled Device) image sensor.

[0100] By acquiring (reading) the light-receiving result from the image sensor 21 using a rolling shutter method, an image in the light-receiving area corresponding to the desired virtual opening shape extending in the row direction can be obtained. Reading control using the rolling shutter method is well-known, and its details are described, for example, in Patent Document 3, U.S. Patent No. 8237835, etc.

[0101] The reflected light from the examined eye E passes through the aperture of the aperture lens 30 and is imaged onto the light-receiving surface of the image sensor 21 by the lens group 23 and the lens group 22. The examined eye E is illuminated by illumination light from the illumination optical system 10.

[0102] Image sensor 21 and lens group 22 can be moved integrally along the optical axis of imaging optical system 20 by means of a moving mechanism (not shown) (specifically, moving mechanism 20D described later). This moves image sensor 21 and lens group 22 to a position corresponding to the state of the examined eye E (specifically, refractive power, axial length, shape of fundus Ef, etc.), thereby allowing the reflected light from the examined eye E to be imaged onto the light-receiving surface of image sensor 21.

[0103] In some embodiments, the image sensor 21 is fixed in position, while the lens group 22 can be moved along the optical axis of the imaging optical system 20 by means of a moving mechanism. In other embodiments, the image sensor 21 and lens group 22 are fixed in position, while the lens group 23 can be moved along the optical axis of the imaging optical system 20 by means of a moving mechanism. In still other embodiments, the image sensor 21 is fixed in position, while the lens groups 22 and 23 can be moved along the optical axis of the imaging optical system 20 by means of a moving mechanism. According to any of these embodiments, return light suitable for the state of the examined eye E can be received.

[0104] In some configurations, one or more relay lenses may be configured between the aperture lens 30 and the lens group 23, between the lens group 23 and the lens group 22, and between the lens group 22 and the image sensor 21. Alternatively, one or more relay lenses may be configured between the aperture lens 30 and the relay optical system 50.

[0105] A relay optical system 50 is positioned between the aperture lens 30 and the examined eye E. The relay optical system 50 relays the slit image formed by the slit illumination light generated by the illumination optical system 10 to the fundus Ef of the examined eye E. The relay optical system 50 includes a reflective optical system with a viewing angle extension function. In this case, the relay optical system 50 may also include a refractive optical system such as an aberration-correcting lens. In some embodiments, the relay optical system 50 may not have a viewing angle extension function.

[0106] exist Figure 2 Show Figure 1 A specific example of the optical system shown. Figure 2 The diagram shows views viewed from above (XZ plan, top view) and views viewed from the side (YZ plan, side view). The XZ plan is the portion enclosed by a single-dotted line, and the YZ plan is the portion enclosed by a double-dotted line. Figure 2 In, with Figure 1 The same elements are labeled with the same reference numerals. Regarding... Figure 1 Unless otherwise specified, the description of the same requirements is omitted.

[0107] exist Figure 2 In the structural example, the illumination source 11 of the illumination optical system 10 includes three light sources, a lens group disposed on the optical path originating from each light source, two optical path combining components for combining the three optical paths originating from the three light sources respectively, and a lens group disposed on the combining optical path of these three optical paths. The three light sources generate illumination light with different characteristics.

[0108] Illumination light generated by each light source of illumination source 11 is guided to slit member 14 by means of a lens group, an iris aperture 12, and a relay lens 13 composed of the lens group, arranged in the synthesizing optical path. As shown in the XZ plan view, in this example, slit member 14 is inclined relative to the optical axis of illumination optical system 10. Illumination light passing through the slit opening of slit member 14 (slit illumination light) is guided to light scanner 16 by means of relay lens 15. Light scanner 16 can rotate the light deflection surface in the direction indicated by the double arrows in the YZ plan view. Slit illumination light deflected by light scanner 16 is guided to aperture lens 30 by means of relay lens 17. Slit illumination light is reflected by aperture lens 30 and incident on relay optical system 50. Alternatively, in another embodiment, slit illumination light passes through the aperture of aperture lens 30 and is incident on relay optical system 50.

[0109] As shown in the XZ plan view, the relay optical system 50 includes a first elliptical concave mirror 51 and a second elliptical concave mirror 52.

[0110] The light-reflecting surface of the first elliptical concave mirror 51 is a concave elliptical surface. The first elliptical concave mirror 51 is an example of a curved mirror or a concave mirror. The first elliptical concave mirror 51 has two optically conjugate focal points (first focal point F1, second focal point F2). The aperture portion of the aperture lens 30 is disposed at or near the first focal point F1, and as previously described, it can be disposed at the iris conjugate position (pupil conjugate position) Q.

[0111] The light-reflecting surface of the second elliptical concave mirror 52 is a concave elliptical surface. The second elliptical concave mirror 52 is an example of a curved mirror or a concave mirror. The second elliptical concave mirror 52 has two optically conjugate foci (first focal point F3, second focal point F4).

[0112] The first elliptical concave mirror 51 and the second elliptical concave mirror 52 share a common focal point. That is, the first focal point F3 of the second elliptical concave mirror 52 is located at the same position as or near the second focal point F2 of the first elliptical concave mirror 51. In some embodiments, the first focal point F3 of the second elliptical concave mirror 52 may be located at a position optically conjugate to the second focal point F2 of the first elliptical concave mirror 51 (the conjugate position of the second focal point F2) or near it.

[0113] When photographing the fundus Ef of the examined eye E, the examined eye E (iris and pupil) is positioned at or near the second focal point F4 of the second elliptical concave mirror 52.

[0114] In some embodiments, the first elliptical concave mirror 51 and the second elliptical concave mirror 52 may be configured such that the two focal points (first focal point F1 and second focal point F2) of the first elliptical concave mirror 51 and the two focal points (first focal point F3 and second focal point F4) of the second elliptical concave mirror 52 are located on the same plane (confocal plane).

[0115] For example, such as Figure 3 As shown, the first elliptical concave mirror 51 and the second elliptical concave mirror 52 are oriented such that the major axis 51a of both the first elliptical concave mirror 51 and the major axis 52a of the second elliptical concave mirror 52 are contained within the horizontal plane (XY plane). Reference numeral H indicates the subject's head. In this example, the second elliptical concave mirror 52, positioned directly in front of the subject's eye E, is sized to cover part of the subject's eye and nose. The first elliptical concave mirror 51 is also sized to the same extent.

[0116] In contrast, in some embodiments, the first elliptical concave mirror 51 and the second elliptical concave mirror 52 may also be configured such that the plane containing the major axis 51a of the first elliptical concave mirror 51 is not parallel to the plane containing the major axis 52a of the second elliptical concave mirror 52.

[0117] exist Figure 4 One example is shown below. In this example, the second elliptical concave mirror 52 is oriented such that its major axis 52a is contained within a horizontal plane (XY plane), and the first elliptical concave mirror 51 is oriented such that the X, Y, and Z components of the vector representing the orientation of its major axis 51a are all non-zero vectors. In this example, the second elliptical concave mirror 52, positioned directly in front of the examined eye E, is sized to cover part of the subject's eye and nose, and the first elliptical concave mirror 51 is sized to the same extent.

[0118] exist Figure 5 Another example is shown below. In this example, the second elliptical concave mirror 52 is oriented such that its major axis 52a is contained within the horizontal plane (XY plane), and the first elliptical concave mirror 51 is oriented such that its major axis 51a is contained within the vertical plane (YZ plane). In this example, the second elliptical concave mirror 52, positioned directly in front of the examined eye E, is sized to cover part of the subject's eye and nose, and the first elliptical concave mirror 51 is sized to the same extent.

[0119] In the above-described structure, slit illumination light from the illumination optical system 10 is incident on the relay optical system 50 via the aperture lens 30 disposed at the first focal point F1 of the first elliptical concave mirror 51. It is reflected by the reflective surface of the first elliptical concave mirror 51 and guided to the second focal point F2 of the first elliptical concave mirror 51. The second focal point F2 of the first elliptical concave mirror 51 is located at the same position as the first focal point F3 of the second elliptical concave mirror 52. The slit illumination light guided to the first focal point F3 of the second elliptical concave mirror 52 is reflected by the reflective surface of the second elliptical concave mirror 52 and guided to the examined eye E disposed at the second focal point F4 of the second elliptical concave mirror 52.

[0120] The slit illumination light, guided to the examined eye E, passes through the cornea, anterior chamber, pupil, lens, and vitreous humor and is projected onto the fundus Ef. The fundus reflection of the slit illumination light passes through the vitreous humor, lens, pupil, anterior chamber, and cornea before exiting the examined eye E. The return light from the examined eye E, including the fundus reflection of the slit illumination light, travels in the opposite direction along the same path as the slit illumination light, is guided to the first focal point F1 of the first elliptical concave mirror 51, passes through the aperture of the aperture lens 30 located at the first focal point F1, and is guided to the imaging optical system 20.

[0121] Figure 2 The imaging optical system 20 includes three lens groups 22a, 22b, and 23. The combination of two lens groups 22a and 22b is equivalent to... Figure 1Lens group 22. Return light incident on the imaging optical system 20 passes sequentially through lens group 23, lens group 22b, and lens group 22a, and is guided to the image sensor 21. Lens group 22b is off-center relative to lens group 23, and lens group 22a is off-center relative to lens group 22b. Here, lens group 22a is off-center relative to both lens group 22b and lens group 23.

[0122] exist Figure 2 In the structure, the eccentricity direction of lens group 22b relative to lens group 23 shown in the XZ plan view is the same as the eccentricity direction of lens group 22a relative to lens group 22b, and the eccentricity direction of lens group 22b relative to lens group 23 shown in the YZ plan view is the same as the eccentricity direction of lens group 22a relative to lens group 22b. That is, lens group 23, lens group 22b, and lens group 22a are arranged in a stepped eccentric configuration along the same direction.

[0123] exist Figure 2 In this structure, the image sensor 21 is tilted relative to the optical axes of the lens group 23, lens group 22b, and lens group 22a. The returned light is detected by the light-receiving surface of the image sensor 21, and the detection result of the returned light within the light-receiving area set on the light-receiving surface is obtained.

[0124] The fundus imaging device 1 may also include structures for providing functions associated with the examination. For example, the fundus imaging device 1 may be equipped with a fixation optical system for projecting a target (fixation target) onto the fundus Ef of the examined eye E, the target (fixation target) being used to fixate the examined eye E. Additionally, the fundus imaging device 1 may be equipped with an alignment optical system for aligning the examined eye E with the optical system. Furthermore, the fundus imaging device 1 may include any selectable elements or units, such as components for supporting or holding the subject's face (chin rest, forehead protector, etc.).

[0125] The fundus imaging device 1 can adjust the focus of the illumination optical system 10 by moving the slit member 14, and adjust the focus of the imaging optical system 20 by moving the lens group 22 and the image sensor 21 (or the lens group 22). The structure for adjusting the focus is not limited to these. In some embodiments, the fundus imaging device can be configured to adjust the focus by moving the optical system unit (including the illumination optical system 10, the imaging optical system 20, and the aperture lens 30, or including the illumination optical system 10, the imaging optical system 20, the aperture lens 30, the first elliptical concave mirror 51, and the second elliptical concave mirror 52) by a moving mechanism not shown.

[0126] Next, the processing system of the fundus imaging device 1 according to the embodiment will be described. Figure 6 An example of a processing system architecture is shown below. Figure 6 In, with Figure 1 and Figure 2 The same elements are labeled with the same reference numerals in the accompanying drawings. Regarding... Figure 1 and Figure 2 Unless otherwise specified, the description of the same requirements is omitted.

[0127] The processing system of the fundus imaging device 1 is centered around the control unit 60. The control unit 60 controls each part of the fundus imaging device 1.

[0128] The control unit 60 includes a main control unit 61 and a storage unit 62. The functions of the main control unit 61 are implemented, for example, by a processor. The storage unit 62 stores a computer program for controlling the fundus imaging device 1. This computer program includes programs for controlling the illumination source, image sensor, light scanner, image construction, user interface, and data communication. The main control unit 61 operates according to this computer program, thereby performing various control processes.

[0129] The main control unit 61 controls the illumination optical system 10, the imaging optical system 20, the image building unit 70, the user interface (UI) unit 80, and the communication unit 90 respectively.

[0130] The control of the lighting optical system 10 includes the control of the lighting source 11, the control of the moving mechanism 14D, and the control of the light scanner 16.

[0131] Control of the lighting source 11 includes turning the light source on and off, adjusting the light intensity, switching the wavelength, and adjusting the aperture.

[0132] The moving mechanism 14D moves the slit member 14 in a direction along the optical axis of the illumination optics system 10. The main control unit 61 outputs a control signal to the moving mechanism 14D, causing the slit member 14 to move by a corresponding amount (distance) in the direction corresponding to the control signal. For example, the moving mechanism 14D includes an actuator that generates a driving force for moving the slit member 14 and a transmission mechanism that transmits the driving force. The actuator may be, for example, a pulse motor. The transmission mechanism may be, for example, a combination of gears or a rack and pinion. The moving mechanism 14D transmits the driving force generated by the operation of the actuator, which is controlled by the main control unit 61, to the slit member 14 via the transmission mechanism, thereby moving the slit member 14.

[0133] Control of the optical scanner 16 includes controlling the orientation (angle) of the deflection surface on which the illumination light is projected. By changing the orientation of the deflection surface, the deflection direction (scanning direction) of the illumination light changes. By controlling the range of the change in the orientation of the deflection surface (angle range), the scanning range (scan start position and scan end position) is controlled. By controlling the speed at which the orientation of the deflection surface changes, the scanning speed is controlled.

[0134] Control of the shooting optical system 20 includes control of the image sensor 21 and control of the moving mechanism 20D.

[0135] Control of the image sensor 21 includes setting control of the light-receiving area on the light-receiving surface and controlling the reading of the light-receiving results in a rolling shutter manner (e.g., setting the light-receiving size corresponding to the size of the illumination pattern). Additionally, control of the image sensor 21 includes reset control, exposure control, charge transfer control, and output control.

[0136] The moving mechanism 20D moves at least a portion of the imaging optical system 20. For example, the moving mechanism 20D moves the image sensor 21 and lens group 22 (lens groups 22a and 22b) in a direction along the optical axis of the imaging optical system 20. In another example, the moving mechanism 20D moves the lens group 22 (lens groups 22a and 22b) in a direction along the optical axis of the imaging optical system 20. The main control unit 61 outputs a control signal to the moving mechanism 20D, causing the image sensor 21 and lens group 22 (or lens group 22) to move by a movement amount (movement distance) corresponding to the control signal in the movement direction corresponding to the control signal. The structure of the moving mechanism 20D can be the same as that of the moving mechanism 14D.

[0137] The control of the image construction unit 70 includes image construction control, which constructs an image of the examined eye E based on the light reception results obtained by the image sensor 21.

[0138] The control of the user interface unit 80 includes the control of the display device and the control of the operating device (input device).

[0139] The control of the communication unit 90 includes control for sending data to external devices, control for receiving data from external devices, control for encryption processing, and control for decryption processing.

[0140] The storage unit 62 stores various types of data. Data stored in the storage unit 62 includes, for example, the light reception results obtained by the image sensor 21, the image generated by the image construction unit 70, parameters related to image processing such as image distortion correction, and information about the eye being examined. The information about the eye being examined includes patient ID and name, as well as information related to the eye being examined, such as left and right eye identification information.

[0141] In addition, the storage unit 62 stores various programs and data for operating the fundus imaging device 1.

[0142] The image construction unit 70 can construct a light-receiving image (fundus image) corresponding to any light-receiving area based on the light-receiving results read from the image sensor 21 in a rolling shutter mode. The image construction unit 70 sequentially constructs light-receiving images corresponding to the light-receiving areas, and constructs an image of the examined eye E (fundus Ef) based on the multiple light-receiving images obtained therefrom. The image generated by the image construction unit 70 is stored in the storage unit 62 or other storage device.

[0143] The image construction unit 70 includes a processor that operates according to a program stored in the storage unit 62 or other storage device, thereby performing the image construction process described above.

[0144] The image construction unit 70 can also perform a process to correct the distortion of the generated image (image distortion correction). The image distortion correction uses at least one of a preset distortion correction parameter and a distortion correction parameter set based on the degree of distortion of the image to be corrected.

[0145] For example, the image construction unit 70 is configured to correct the pixel positions in each region by making one or more regions of a polygon in the original image into regions of a predetermined shape, thereby correcting the distortion of the original image. In some embodiments, the image construction unit 70 is configured to selectively apply image distortion correction only to predetermined correction regions.

[0146] The user interface unit 80 has the function of exchanging information and instructions between the user and the fundus imaging device 1. The user interface unit 80 includes a display device and an operating device. The user interface unit 80 may also include a device that integrates at least a portion of the functions of the display device and at least a portion of the functions of the operating device (e.g., a touch panel display).

[0147] The display device may include a display unit that is an essential component of the fundus imaging device 1, and may also include a display device that is a peripheral device of the fundus imaging device 1. The display device is controlled by the main control unit 61 to provide visual information. The display device may include, for example, a liquid crystal display (LCD).

[0148] The operating device includes one or more hardware keys and / or one or more software keys. The operating device may include an operating section that is an essential component of the fundus imaging device 1, and may also include operating devices that are peripheral devices of the fundus imaging device 1. The operating device generates an electrical signal corresponding to the content of the operation instruction performed using the operating device and sends it to the main control unit 61. The main control unit 61 receives the electrical signal from the operating device, generates a control signal corresponding to the content of the operation instruction, and sends it to the element that is the object of control.

[0149] The communication unit 90 performs data communication between the fundus imaging device 1 and other devices. That is, the communication unit 90 sends data to other devices and receives data sent from other devices. The method of data communication performed by the communication unit 90 is arbitrary. For example, the communication unit 90 may include one or more various communication interfaces, such as an Internet-compliant communication interface, a dedicated line-compliant communication interface, a LAN-compliant communication interface, a short-range communication interface, etc. Data communication can be wired or wireless.

[0150] The data sent or received by the communication unit 90 may be encrypted. In this case, the control unit 60 and / or the communication unit 90 may include an encryption processing unit for encrypting the data sent by the communication unit 90 and a decryption processing unit for decrypting the data received by the communication unit 90.

[0151] The following describes some of the functions of the fundus imaging device 1 according to the embodiment. In addition, some effects performed by the fundus imaging device 1 according to the embodiment will also be described.

[0152] The fundus imaging device 1 is a device for imaging the fundus Ef of the examined eye E, and includes an illumination optical system 10, an imaging optical system 20, and a relay optical system 50. The illumination optical system 10 includes an illumination source 11 that generates illumination light, a light scanner 16 that deflects the illumination light generated by the illumination source 11, etc.

[0153] The relay optical system 50 includes a first elliptical concave mirror 51 and a second elliptical concave mirror 52. The first elliptical concave mirror 51 is an example of a first curved mirror that reflects illumination light from the illumination optical system 10. The second elliptical concave mirror 52 is an example of a second curved mirror that reflects and guides the illumination light reflected by the first elliptical concave mirror 51 to the eye being examined, E.

[0154] The light-reflecting surface of the first elliptical concave mirror 51 is elliptical, therefore it has two focal points (first focal point F1 and second focal point F2). Similarly, the light-reflecting surface of the second elliptical concave mirror 52 is elliptical, therefore it has two focal points (first focal point F3 and second focal point F4). The first elliptical concave mirror 51 and the second elliptical concave mirror 52 share one focal point (second focal point F2 and first focal point F3). That is, the spatial position of the second focal point F2 is approximately the same as the spatial position of the first focal point F3.

[0155] The light-reflecting surface of the first elliptical concave mirror 51 is formed with a pre-designed curvature distribution, and the light-reflecting surface of the second elliptical concave mirror 52 is also formed with a pre-designed curvature distribution. The curvature distributions of the first elliptical concave mirror 51 and the second elliptical concave mirror 52 are different from each other.

[0156] For example, the light-reflecting surface of the first elliptical concave mirror 51 may be a portion of an elliptical surface with a major axis value in the range of 60 mm to 90 mm and a minor axis value in the range of 40 mm to 70 mm. Similarly, the light-reflecting surface of the second elliptical concave mirror 52 may be a portion of an elliptical surface with a major axis value in the range of 60 mm to 90 mm and a minor axis value in the range of 40 mm to 70 mm.

[0157] To further specify, the light-reflecting surface of the first elliptical concave mirror 51 may be a portion of an elliptical surface with a major axis value in the range of 70 mm to 80 mm and a minor axis value in the range of 50 mm to 60 mm. Similarly, the light-reflecting surface of the second elliptical concave mirror 52 may be a portion of an elliptical surface with a major axis value in the range of 70 mm to 80 mm and a minor axis value in the range of 50 mm to 60 mm.

[0158] In one embodiment embodied by the inventor, the light-reflecting surface of the first elliptical concave mirror 51 is designed as part of an ellipse with a major axis of 75 mm and a minor axis of 50 mm, and the light-reflecting surface of the second elliptical concave mirror 52 is designed as part of an ellipse with a major axis of 72 mm and a minor axis of 60 mm. In this example, the deflection angle of the illumination light incident on the relay optical system 50 (i.e., the deflection angle range at the first focal point F1 of the illumination light deflected by the light scanner 16) is 50 degrees, and the deflection angle of the illumination light exiting the relay optical system 50 (i.e., the deflection angle range at the second focal point F4) is 150 degrees. Therefore, the relay optical system 50 in this example amplifies the deflection angle of the illumination light by a factor of 3, enabling wide-angle (150 degrees) imaging of the fundus Ef of the examined eye E.

[0159] The imaging optical system 20 is configured to detect the reflected light from the illumination light projected onto the fundus Ef of the examined eye E using a second elliptical concave mirror 52 and a first elliptical concave mirror 51, and is an example of a receiving optical system. The imaging optical system 20 includes a lens group 23, a lens group 22, an image sensor 21, etc. The lens groups 23 and 22 are arranged off-center from each other. The image sensor 21 detects the reflected light passing through the lens groups 23 and 22. The lens group 23 is an example of a first lens group, and the lens group 22 is an example of a second lens group.

[0160] According to the fundus imaging device 1 configured in this way, the structure of the fundus Ef can be scanned using an optical system including a first elliptical concave mirror 51 and a second elliptical concave mirror 52, and fundus imaging can be performed with a wide angle.

[0161] Furthermore, according to the fundus imaging device 1, a structure is adopted that uses an imaging optical system 20 comprising lens groups 23 and 22 arranged offset from each other to detect the reflected light of the illumination light, enabling the use of a first elliptical concave mirror 51 and a second elliptical concave mirror 52 that are smaller than conventional ones. In other words, a fundus imaging device 1 equipped with smaller curved mirrors than conventional ones is realized. Therefore, according to the technology of this embodiment, a miniaturized fundus imaging device capable of wide-angle imaging can be achieved.

[0162] In the fundus imaging device 1 of the embodiment, the image sensor 21 (specifically, the light-receiving surface) of the imaging optical system 20 is configured in an inclined position relative to both the optical axis of the lens group 23 and the optical axis of the lens group 22. Furthermore, the orientation of the image sensor 21 can be determined using optical design techniques such as ray tracing.

[0163] Thus, by combining the mutually offset lens groups 23 and 22 with the tilted image sensor 21, asymmetric aberrations caused by miniaturization of the first elliptical concave mirror 51 and the second elliptical concave mirror 52 can be suppressed. Therefore, it is possible to miniaturize the fundus imaging device capable of wide-angle shooting and also improve image quality.

[0164] In a non-limiting embodiment of the fundus imaging device 1, the lens group 22 of the imaging optical system 20 includes two lens groups 22a and 22b. In this embodiment, the three lens groups 23, 22b, and 22a are arranged in a mutually offset state. Thus, the imaging optical system 20 of this embodiment includes a lens group 23 corresponding to a first lens group, a lens group 22b corresponding to a second lens group, a lens group 22a corresponding to a third lens group, and an image sensor 21. The image sensor 21 detects the reflected light that passes sequentially through the lens group 23, lens group 22b, and lens group 22a.

[0165] According to this method, an example of a structure for detecting the return light of illumination light using an imaging optical system 20 comprising three lens groups 23, 22b, and 22a arranged in a mutually offset configuration can be provided. Thus, a smaller first elliptical concave mirror 51 and a smaller second elliptical concave mirror 52 can be used, thereby enabling miniaturization of the fundus imaging device 1 capable of wide-angle imaging.

[0166] In a non-limiting embodiment of the fundus imaging device 1, the image sensor 21 is arranged with its orientation tilted relative to the optical axes of the lens group 23, the lens group 22b, and the lens group 22a.

[0167] According to this method, by combining three lens groups 23, 22b, and 22a, which are arranged eccentrically, with an image sensor 21 that is tilted, it is possible to suppress asymmetric aberrations caused by miniaturization of the first elliptical concave mirror 51 and the second elliptical concave mirror 52. Therefore, it is possible to miniaturize a fundus imaging device capable of wide-angle shooting and improve image quality.

[0168] In a non-limiting embodiment of the fundus imaging device 1, the return light of the illumination light applied to the examined eye E passes sequentially through lens group 23, lens group 22b, and lens group 22a and is guided to image sensor 21. Furthermore, the fundus imaging device 1 of this embodiment includes a moving mechanism 20D for adjusting the focus of the imaging optical system 20. The moving mechanism 20D moves at least a portion of the components of the imaging optical system 20 in the direction along the optical axis of the imaging optical system 20. For example, the moving mechanism 20D may have a structure that moves lens group 22b, lens group 22a, and image sensor 21 as a whole or individually; a structure that moves lens group 22b and lens group 22a as a whole or individually; a structure that moves lens group 22b; or a structure that moves lens group 22a. The moving mechanism 20D can function as an example of a first focusing mechanism.

[0169] According to this method, the focus of the imaging optical system 20 can be adjusted according to the refractive power of the examined eye E. This enables the miniaturization of the fundus imaging device 1 capable of wide-angle imaging and improves image quality.

[0170] In the fundus imaging device 1 of the embodiment, the relative arrangement of the first elliptical concave mirror 51 and the second elliptical concave mirror 52 can be arbitrarily designed. In some non-limiting embodiments, the first elliptical concave mirror 51 and the second elliptical concave mirror 52 are configured such that the plane containing the major axis 51a of the first elliptical concave mirror 51 is parallel to the plane containing the major axis 52a of the second elliptical concave mirror 52. For example, the first elliptical concave mirror 51 and the second elliptical concave mirror 52 are oriented such that the major axis 51a of the first elliptical concave mirror 51 and the major axis 52a of the second elliptical concave mirror 52 are both contained within a horizontal plane (XY plane) (see [link]). Figure 3 ).

[0171] Additionally, in some non-limiting embodiments, the first elliptical concave mirror 51 and the second elliptical concave mirror 52 are configured such that the plane containing the major axis 51a of the first elliptical concave mirror 51 is not parallel to the plane containing the major axis 52a of the second elliptical concave mirror 52. For example, the second elliptical concave mirror 52 is oriented such that its major axis 52a is contained within a horizontal plane (XY plane), and the first elliptical concave mirror 51 is oriented such that the X-direction component, Y-direction component, and Z-direction component of the vector representing the orientation of its major axis 51a are all non-zero vectors (see [reference]). Figure 4 ).

[0172] Additionally, in some non-limiting embodiments, the first elliptical concave mirror 51 and the second elliptical concave mirror 52 are configured such that the plane containing the major axis 51a of the first elliptical concave mirror 51 is perpendicular to the plane containing the major axis 52a of the second elliptical concave mirror 52. For example, the second elliptical concave mirror 52 is oriented such that its major axis 52a is contained in a horizontal plane (XY plane), and the first elliptical concave mirror 51 is oriented such that its major axis 51a is contained in a vertical plane (YZ plane) (see [reference]). Figure 5 ).

[0173] according to Figure 4 Examples Figure 5 Examples or similar examples can reduce the likelihood that an elliptical concave mirror (especially the first elliptical concave mirror 51) or its housing will come into contact with the head H of the person being examined.

[0174] In a non-limiting embodiment of the fundus imaging device 1, the illumination optical system 10 includes a slit member 14 having a slit opening. Illumination light generated by the illumination source 11 is projected onto the slit member 14. The light scanner 16 deflects the illumination light (slit illumination light) that passes through the slit opening.

[0175] According to this method, a miniaturized fundus imaging device capable of wide-angle imaging using slit illumination light can be provided. In this method, the image sensor 21 can read signals using a rolling shutter method. Therefore, in addition to miniaturizing the fundus imaging device capable of wide-angle imaging, it is also possible to generate high-contrast images with a simple structure.

[0176] In a non-limiting manner of the fundus imaging device 1 in the embodiment, the slit member 14 is arranged with an orientation tilted relative to the optical axis of the illumination optical system 10.

[0177] According to this method, a preferred structural example of a fundus imaging device capable of wide-angle shooting and miniaturization can be provided.

[0178] In a non-limiting embodiment of the fundus imaging device 1, a moving mechanism 14D is included for adjusting the focus of the illumination optical system 10. The moving mechanism 14D moves the slit member 14 in the direction (optical axis direction) along the optical axis of the illumination optical system 10. The moving mechanism 14D can function as an example of a second focusing mechanism.

[0179] According to this method, the focus of the illumination optical system 10 can be adjusted according to the refractive power of the eye being examined. This enables the miniaturization of the fundus imaging device 1 capable of wide-angle imaging and improves image quality.

[0180] In existing fundus imaging devices such as the invention described in Patent Document 2 (Japanese Patent Application Publication No. 2022-184520), the face is pressed tightly against the pads provided in the device, and the subject's eye is used to view the internal state of the device while taking the picture, which places a great burden on the subject. According to the fundus imaging device 1 of the embodiment, the design of the optical system (especially the first elliptical concave mirror 51 and the second elliptical concave mirror 52) has been thoroughly studied, and / or the techniques of the modified examples described later are applied, thereby at least partially eliminating this problem.

[0181] The following describes some non-limiting variations of the fundus imaging device 1 according to the embodiments.

[0182] Typically, fundus photography is applied to the left and right eyes of the subject, respectively. In a non-limiting manner, the fundus photography device 1 of the embodiment can be configured to switch between fundus photography of the left eye and fundus photography of the right eye by means of a moving illumination optical system 10, a shooting optical system 20, a aperture lens 30 and a relay optical system 50.

[0183] like Figure 7 As shown, the fundus imaging device 1 of this type includes: a measuring head 100, which is a unit housing an illumination optical system 10, an imaging optical system 20, an aperture lens 30, and a relay optical system 50; and a moving mechanism 100D for moving the measuring head 100. Figure 7 In, with Figure 1 , Figure 2 and Figure 6 The same elements are labeled with the same reference numerals in the accompanying drawings. Regarding... Figure 1 , Figure 2 and Figure 6 Unless otherwise specified, the description of the same requirements is omitted.

[0184] See Figure 8 and Figure 9 The method by which the moving mechanism 100D moves the measuring head 100 is explained.

[0185] like Figure 8As shown, the moving mechanism 100D is configured to rotate the measuring head 100 along a track T centered on the rotation center C. For example, the moving mechanism 100D includes an actuator that generates driving force and a transmission mechanism that transmits this driving force. The moving mechanism 100D transmits the driving force generated by the operation of the actuator, controlled by the main control unit 61, to the measuring head 100 via the transmission mechanism, thereby moving the measuring head 100. Thus, when photographing the subject's left eye EL, the measuring head 100 (second elliptical concave mirror 52) can be positioned directly in front of the left eye EL; similarly, when photographing the right eye ER, the measuring head 100 (second elliptical concave mirror 52) can be positioned directly in front of the right eye ER. The structure of the moving mechanism 100D is not limited to an electric mechanism. Some versions of the moving mechanism 100D can be manual mechanisms, possessing a transmission mechanism that transmits power supplied by the user's operation, but without an actuator.

[0186] Thus, in this method, by moving a single measuring head 100, both eyes can be photographed without the need for separate measuring heads for the left and right eyes. Therefore, the fundus imaging device 1 capable of wide-angle photography can be miniaturized. Furthermore, it should be noted that according to the embodiment, a curved mirror (e.g., an elliptical concave mirror) smaller than conventional mirrors can be used. Therefore, even when both left and right eye measuring heads are provided, the device can still be miniaturized compared to existing similar fundus imaging devices (i.e., existing fundus imaging devices with both left and right eye measuring heads).

[0187] The configuration of the optical system within the measuring head 100 of this method is described below. For example... Figure 9 As shown, the illumination optical system 10, the imaging optical system 20, the aperture lens 30, the first elliptical concave mirror 51, and the second elliptical concave mirror 52 are mounted on the substrate 101. The first elliptical concave mirror 51 and the second elliptical concave mirror 52 are disposed on the side of the eye being examined (left eye EL, right eye ER) relative to the substrate 101, while the illumination optical system 10, the imaging optical system 20, and the aperture lens 30 are disposed on the opposite side of the eye being examined relative to the substrate 101.

[0188] This optical system configuration enables miniaturization of the measuring head 100, as well as miniaturization and labor-saving of the moving mechanism 100D (reducing the driving force required to move the measuring head 100).

[0189] Furthermore, by conducting an in-depth study of the optical system configuration, the possibility of the measuring head 100 touching the subject's head H can be reduced. This in-depth study of the optical system configuration includes a detailed examination of the relative configuration of the first elliptical concave mirror 51 and the second elliptical concave mirror 52 (see, for example, [reference needed]). Figures 3-5In-depth research on the configuration of the illumination optical system 10, the imaging optical system 20, and the aperture lens 30, etc. Figure 9 In the example, by placing the illumination optics 10, the imaging optics 20, and the aperture lens 30 on the side of the substrate 101 opposite to the head H, these optical components are prevented from colliding with the subject's head H.

[0190] The following describes another variation of the fundus imaging apparatus 1 according to the embodiment. In the above embodiment, the imaging optical system 20 (light-receiving optical system) is configured as an off-center optical system to reduce asymmetric aberrations, achieving compactness of the curved mirror (e.g., an elliptical concave mirror). However, the method for reducing asymmetric aberrations is not limited to introducing an off-center optical system. For example, to reduce asymmetric aberrations, optical methods utilizing prisms or freeform surfaces (aspherical surfaces) and / or image processing methods applying aberration correction processing to the constructed image can be employed. In the image processing method, for example, software equipped with a predetermined aberration correction algorithm can be used, or a machine learning model that has undergone learning related to aberration correction can be used. Two or more methods for reducing asymmetric aberrations can be combined at least partially to improve the aberration reduction effect.

[0191] The following describes another variation of the fundus imaging device 1 according to the embodiment. In the above embodiment, a structure for collecting return light detection results using a rolling shutter method was described, but the embodiment is not limited to this. For example, some fundus imaging devices 1 include a movable slit constructed of hardware such as a focal plane shutter. This movable slit is positioned near the light-receiving surface of the image sensor 21 or at a position approximately optically conjugate to the light-receiving surface of the image sensor 21. According to this method, control for reading the detection results of the return light obtained by the image sensor 21 can be simplified.

[0192] The following describes another variation of the fundus imaging device 1 according to the embodiment. This example provides an example of switching between right eye fundus imaging and left eye fundus imaging. This example can be used instead of... Figure 8 and Figure 9 The movement of the measuring head 100 is shown. The structure of the fundus imaging device 1 in this example can be compared with... Figure 7 Same. See below. Figure 7 Also see Figure 10 and Figure 11 .

[0193] The moving mechanism 100D moves the first and second curved mirrors. As previously described, the moving mechanism 100D operates electrically or manually. The first and second curved mirrors can be any of the aforementioned configurations. In this example, the first and second curved mirrors are described as a first elliptical concave mirror 51 and a second elliptical concave mirror 52, respectively. However, the implementation is not limited to this.

[0194] The moving mechanism 100D in this example can be configured to move the measuring head 100, which houses the illumination optical system 10, the imaging optical system 20, the aperture lens 30, and the relay optical system 50. The elements to be moved by the moving mechanism 100D are not limited to those in this example, and at least include the first curved mirror and the second curved mirror. For example, the measuring head 100 can have a subunit including at least a first elliptical concave mirror 51 and a second elliptical concave mirror 52, and the moving mechanism 100D can be configured to move this subunit.

[0195] The moving mechanism 100D is configured to allow the first elliptical concave mirror 51 and the second elliptical concave mirror 52 to rotate integrally about an axis (rotation axis) perpendicular to the alignment direction of the subject's left and right eyes (i.e., the X direction). In other words, the moving mechanism 100D is configured to allow the first elliptical concave mirror 51 and the second elliptical concave mirror 52 to rotate integrally about a rotation axis parallel to the subject's anterior-posterior axis (dorsoventral axis). The first elliptical concave mirror 51 and the second elliptical concave mirror 52 move integrally in the XY plane by means of the moving mechanism 100D configured in this way. The rotation axis can be a shaft component included in the moving mechanism 100D or a virtual axis. The orientation of the rotation axis can be strictly parallel to the subject's anterior-posterior axis or not strictly parallel. For example, there can be an angular error between the orientation of the rotation axis and the subject's anterior-posterior axis that is permissible from the point of view of device design or use. Alternatively, an intentional angular difference based on the point of view of device design or use can be set between the orientation of the rotation axis and the subject's anterior-posterior axis. Furthermore, the rotation axis is positioned such that the positional correspondence between the first elliptical concave mirror 51 and the second elliptical concave mirror 52 relative to the subject's left and right eyes can be switched. For example, the rotation axis may be configured to pass between the left and right eyes. In some cases, the rotation axis may be configured to pass between the left and right eyes of the subject (midline). The rotation angle range of the first elliptical concave mirror 51 and the second elliptical concave mirror 52 via the moving mechanism 100D is 180 degrees or more.

[0196] The moving mechanism 100D can also be configured to move the first elliptical concave mirror 51 and the second elliptical concave mirror 52 in a direction along the front-back axis of the subject.

[0197] When the fundus imaging device 1 is not used for eye imaging, the first elliptical concave mirror 51 and the second elliptical concave mirror 52 can be positioned at predetermined reference positions. The reference positions can be as follows: Figure 10 The arrangement of the first elliptical concave mirror 51 and the second elliptical concave mirror 52 in the left-right direction (X direction) can also be arranged in the up-down direction (Y direction), or other configurations. Furthermore, the reference position can be a position farther from the eye being examined compared to the position when the image is taken (the image taking position).

[0198] The following example illustrates the switching between fundus photography of the right and left eyes. Figure 10 As shown in the left figure, when the examined eye is the right eye (ER), the second elliptical concave mirror 52 is positioned in front of the right eye (ER), and the first elliptical concave mirror 51 is positioned in front of the left eye (EL). Additionally, as... Figure 10 As shown in the right figure, when the eye being examined is the left eye (EL), the second elliptical concave mirror 52 is positioned in front of the left eye (EL), and the first elliptical concave mirror 51 is positioned in front of the right eye (ER). Thus, in this example, the positions of the first elliptical concave mirror 51 and the second elliptical concave mirror 52 relative to the right eye (ER) and left eye (EL) alternate depending on whether the eye being examined is the right eye (ER) or the left eye (EL). In this example, the moving mechanism 100D operates electrically or manually, causing the measuring head 100 to... Figure 10 The rotation center C1 shown is a 180-degree rotation, thereby switching between right and left eye fundus imaging. In other words, the moving mechanism 100D in this example operates electrically or manually, causing the measuring head 100 to rotate 180 degrees around an axis parallel to the subject's anterior-posterior axis and passing through the rotation center C1, thereby switching between right and left eye fundus imaging. The direction of rotation of the measuring head 100 is... Figure 10 The direction can be clockwise or counterclockwise.

[0199] The following example illustrates the steps for switching between fundus photography of the right eye and the left eye. Figure 11 The top left image is related to Figure 10 The top view corresponding to the left image (front view). Additionally, Figure 11 The top right image is related to Figure 10 The top view corresponding to the right-hand image (front view). This example uses the image from... Figure 11 The top left image shows the switching state for performing ER fundus photography on the right eye. Figure 11 The upper right image illustrates the state of the fundus photography performed on the left eye using EL (Elastic Eye Lens). Conversely, from... Figure 11 The image in the upper right corner shows the switching state for left eye EL fundus imaging. Figure 11The image in the upper left corner shows the state of fundus photography for right eye ER. Those skilled in the art should understand that the same steps can be followed.

[0200] Although not illustrated, the moving mechanism 100D, operated electrically or manually, changes the position of the first elliptical concave mirror 51 and the second elliptical concave mirror 52 from their respective reference positions. Figure 11 The configuration status is shown in the top left image. Figure 11 With the first elliptical concave mirror 51 and the second elliptical concave mirror 52 configured as shown in the upper left figure, the fundus imaging device 1 performs fundus imaging on the right eye ER.

[0201] After performing fundus photography of the right eye ER, the moving mechanism 100D, through electric or manual operation, moves the first elliptical concave mirror 51 and the second elliptical concave mirror 52 from... Figure 11 The configuration status shown in the top left image has changed to Figure 11 The configuration status is shown in the lower left image. Figure 11 The lower left figure shows the first moving action M1, which moves the second elliptical concave mirror 52, which is positioned in front of the right eye ER, and the first elliptical concave mirror 51, which is positioned in front of the left eye EL, together in a direction away from the subject's head H.

[0202] After performing the first moving operation M1, the moving mechanism 100D, through electric or manual operation, moves the first elliptical concave mirror 51 and the second elliptical concave mirror 52 from... Figure 11 The configuration state shown in the lower left image has been transitioned to... Figure 11 The configuration status is shown in the lower right image. Figure 11 The lower right figure illustrates the second movement operation M2. This second movement operation M2 involves rotating the second elliptical concave mirror 52, positioned in front of the right eye ER, and the first elliptical concave mirror 51, positioned in front of the left eye EL, by a combined rotation of 180 degrees. This positions the second elliptical concave mirror 52 in front of the left eye EL and the first elliptical concave mirror 51 in front of the right eye ER. The second movement operation M2 alternates the positional correspondence of the first elliptical concave mirror 51 and the second elliptical concave mirror 52 relative to the right eye ER and the left eye EL.

[0203] After performing the second moving operation M2, the moving mechanism 100D, through electric or manual operation, moves the first elliptical concave mirror 51 and the second elliptical concave mirror 52 from... Figure 11 The configuration status shown in the lower right image has changed to... Figure 11 The configuration status is shown in the upper right image. Figure 11The upper right figure shows the third moving operation M3, which involves moving the first elliptical concave mirror 51 and the second elliptical concave mirror 52 together towards the subject's head H, positioning the second elliptical concave mirror 52 in front of the left eye (EL) and the first elliptical concave mirror 51 in front of the right eye (ER). Figure 11 With the first elliptical concave mirror 51 and the second elliptical concave mirror 52 configured as shown in the upper right figure, the fundus imaging device 1 performs fundus imaging on the left eye EL.

[0204] According to this example, and Figure 8 and Figure 9 Compared to the shown method of switching the subject's eye, the moving distance of the first elliptical concave mirror 51 and the second elliptical concave mirror 52 can be shortened, thus enabling faster movement and a shorter movement time. Furthermore, according to this example, the subject's eye can be switched while maintaining the subject's head orientation, thus reducing the burden on the subject. Moreover, according to... Figure 11 As shown, the measuring head 100 is rotated while it is retracted from the subject's head H, thus preventing the measuring head 100 from contacting or colliding with the subject.

[0205] The embodiments and non-limiting methods described in this disclosure are merely examples for carrying out the invention. Practitioners of the invention may make any modifications, omissions, additions, etc., within the scope of the invention's spirit.

[0206] (Explanation of reference numerals in the attached image) 1: Fundus imaging device 10: Illumination Optical System 11: Light source 14: Cracked components 14D: Moving mechanism 16: Light Scanner 20: Imaging Optical System 20D: Mobile mechanism 21: Image Sensor 22, 22a, 22b, 23: Lens groups 50: Relay Optical System 51: First Elliptical Concave Mirror 52: Second elliptical concave mirror 100: Measuring head 100D: Mobile Mechanism

Claims

1. A fundus imaging device for imaging the fundus of a subject eye, the fundus imaging device comprising: An illumination optical system includes a light source that generates illumination light and a light scanner that deflects the illumination light; The first curved mirror reflects the illumination light from the illumination optical system; The second curved mirror has a different curvature distribution than the first curved mirror, and reflects and guides the illumination light reflected by the first curved mirror to the eye being examined. as well as The light-receiving optical system detects the reflected light of the illumination light projected onto the fundus of the examined eye using the second curved mirror and the first curved mirror. The first curved mirror and the second curved mirror each have more than one focal point. The first curved mirror and the second curved mirror share a common focal point. The light-receiving optical system includes: First lens group; The second lens group is offset relative to the first lens group; and An image sensor detects the reflected light that has passed through the first lens group and the second lens group.

2. The fundus imaging device according to claim 1, wherein, The image sensor is tilted relative to both the optical axis of the first lens group and the optical axis of the second lens group.

3. The fundus imaging device according to claim 1, wherein, The light-receiving optical system also includes: The third lens group is offset relative to both the first and second lens groups. The image sensor detects the returning light that has passed through the first lens group, the second lens group, and the third lens group.

4. The fundus imaging device according to claim 3, wherein, The image sensor is tilted relative to the optical axis of the first lens group, the optical axis of the second lens group, and the optical axis of the third lens group.

5. The fundus imaging device according to claim 3 or 4, wherein, The returned light passes sequentially through the first lens group, the second lens group, and the third lens group and is guided to the image sensor. The fundus imaging device also includes: The first focusing mechanism enables the second lens group, the third lens group, and the image sensor to move as a whole.

6. The fundus imaging device according to any one of claims 1 to 5, wherein, The first curved mirror and the second curved mirror are respectively a first elliptical concave mirror and a second elliptical concave mirror.

7. The fundus imaging device according to claim 6, wherein, The major axis of both the first and second elliptical concave mirrors is within the range of 70 mm to 80 mm. The minor axis of the first elliptical concave mirror and the minor axis of the second elliptical concave mirror are each within the range of 50 mm to 60 mm.

8. The fundus imaging device according to claim 6 or 7, wherein, The first elliptical concave mirror and the second elliptical concave mirror are configured such that the plane containing the major axis of the first elliptical concave mirror and the plane containing the major axis of the second elliptical concave mirror are not parallel to each other.

9. The fundus imaging device according to claim 8, wherein, The first elliptical concave mirror and the second elliptical concave mirror are configured such that the plane containing the major axis of the first elliptical concave mirror is perpendicular to the plane containing the major axis of the second elliptical concave mirror.

10. The fundus imaging device according to any one of claims 1 to 9, wherein, The illumination optical system also includes: Cracked component, having a crack opening, The illumination light generated by the light source is projected onto the slit component. The optical scanner deflects the illumination light that passes through the slit opening.

11. The fundus imaging device according to claim 10, wherein, The slit component is tilted relative to the optical axis of the illumination optics system.

12. The fundus imaging device according to claim 10 or 11, wherein, The fundus imaging device also includes: The second focusing mechanism moves the slit component along the optical axis of the illumination optics system.

13. The fundus imaging device according to any one of claims 1 to 12, wherein, The fundus imaging device also includes: The moving mechanism causes the first curved mirror and the second curved mirror to move. When the eye being examined is the right eye, the second curved mirror is positioned in front of the right eye, and the first curved mirror is positioned in front of the left eye. When the eye being examined is the left eye, the second curved mirror is positioned in front of the left eye, and the first curved mirror is positioned in front of the right eye.

14. The fundus imaging device according to claim 13, wherein, The moving mechanism causes the first curved mirror and the second curved mirror to rotate as a unit around an axis parallel to the front and rear axes of the subject.

15. The fundus imaging device according to claim 14, wherein, The moving mechanism also causes the first curved mirror and the second curved mirror to move in the direction along the front and rear axes. When the eye being examined is switched from the subject's first eye to the second eye, the moving mechanism causes the second curved mirror positioned in front of the first eye and the first curved mirror positioned in front of the second eye to move together away from the subject, causing the first curved mirror and the second curved mirror to rotate together around the axis, causing the first curved mirror and the second curved mirror to move together towards the subject, positioning the first curved mirror in front of the first eye and the second curved mirror in front of the second eye.

Images