ophthalmic devices

Abstract

To observe the inside of the eye to be examined in a wide range.SOLUTION: An ophthalmologic apparatus includes: a first optical system for acquiring an image of a prescribed area of an eye to be examined; and a second optical system including a catadioptric optical unit and acquiring an image of a peripheral part of the prescribed area.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The disclosed technology relates to ophthalmic devices. [Background technology]

[0002] Various ophthalmic imaging devices have been developed that enable observation of the inside of a subject's eye (hereinafter referred to as the "examined eye"), particularly the fundus of the examined eye, for the purpose of diagnosing the eye and performing surgical procedures on the eye in ophthalmology. For example, technology relating to an observation device that creates a real image of the fundus of the examined eye is known (see Patent Document 1). In this specification, "ophthalmology" refers to the branch of medicine that deals with the eye.

[0003] In the technology described in Patent Document 1, a lens element having a concave surface shaped to match the curvature of the cornea is brought into close contact with the eye under examination (cornea), and an optical system is configured to form a real image of the fundus of the eye under examination, including the contacted lens element. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Special Publication No. 2000-504251 [Overview of the project] [Problems that the invention aims to solve]

[0005] The disclosed technology provides an ophthalmic device that allows for wide-area observation of the inside of an eye while reducing the burden on the subject with the eye, compared to observing the inside of an eye by making the lens element in close contact with the eye. [Means for solving the problem]

[0006] A first aspect of the disclosed technology is an ophthalmic device comprising: a first acquisition unit that acquires a first fundus image, which is a circular image taken with a shooting angle of view from 0 degrees to a first shooting angle centered on the visual axis of the eye under examination; a second acquisition unit that acquires a second fundus image, which is an annular image taken with a shooting angle of view of at least a second shooting angle that is smaller than the first shooting angle of view and greater than 0 degrees, and within a third shooting angle that is greater than the first shooting angle of view, centered on the visual axis; and a generation unit that combines the first fundus image and the second fundus image to generate a composite image of the eye under examination, wherein the generation unit superimposes and combines the blood vessels in the circular peripheral part of the first fundus image and the blood vessels in the inner peripheral part of the second fundus image to generate the composite image. [Brief explanation of the drawing]

[0007] [Figure 1] This is a block diagram showing an example of the overall configuration of an ophthalmic imaging device according to the first embodiment. [Figure 2] This image shows an example of the irradiation angle of the ophthalmic imaging device to the eye under examination according to the first embodiment. [Figure 3] This is an illustrative diagram showing an example of the area of ​​the fundus that can be photographed by the ophthalmic imaging device according to the first embodiment. [Figure 4] This is a schematic diagram showing an example of a scanning device included in the ophthalmic imaging device according to the first embodiment. [Figure 5] This is an illustrative diagram showing an example of a two-dimensional image obtained by the fundus imaging device according to the first embodiment. [Figure 6] This is a schematic diagram of the optical system in the common optical system included in the ophthalmic imaging apparatus according to the first embodiment. [Figure 7] This is a diagram showing an example of the lens configuration of the optical system according to the first embodiment. [Figure 8] This is a lateral aberration diagram of the optical system according to the first embodiment. [Figure 9] This is a diagram showing an example of the lens configuration of the optical system according to the second embodiment. [Figure 10] This is a lateral aberration diagram of the optical system according to the second embodiment. [Figure 11]It is a configuration diagram showing an example of the lens configuration of the optical system according to the third embodiment. [Figure 12] It is a lateral aberration diagram of the optical system according to the third embodiment. [Figure 13] It is the lens configuration of the optical system according to the fourth embodiment, and is a configuration diagram showing an example of the second embodiment. [Figure 14] It is a lateral aberration diagram of the optical system according to the fourth embodiment. [Figure 15] It is the lens configuration of the optical system according to the fifth embodiment, and is a configuration diagram showing an example of the second embodiment. [Figure 16] It is a lateral aberration diagram of the optical system according to the fifth embodiment. [Figure 17] It is a block diagram showing an example of the overall configuration of the image system according to the third embodiment. [Figure 18] It is a block diagram showing an example of the configuration of the ophthalmic imaging device according to the third embodiment. [Figure 19] It is a block diagram showing an example of the configuration of the image display terminal according to the third embodiment. [Figure 20] It is a flowchart showing an example of the flow of processing executed by the image display terminal according to the third embodiment. [Figure 21] It is an image diagram showing an example of the display screen of the display according to the third embodiment. [Figure 22] It is an image diagram showing an example of the display screen of the display according to the third embodiment. [Figure 23] It is an image diagram showing an example of the display screen of the display according to the third embodiment.

Embodiments for Carrying Out the Invention

[0008] Hereinafter, embodiments will be described with reference to the drawings.

[0009] 〔First Embodiment〕 FIG. 1 shows an example of the configuration of the ophthalmic imaging device 10 according to the present embodiment. As shown in Figure 1, the ophthalmic imaging device 10 includes a device body 14 and a control device 16 for imaging the fundus of the eye under examination. In the following description, "imaging" refers to the process by which a user uses the ophthalmic imaging device 10 to acquire an image of a subject, and may be referred to as "image acquisition." The device body 14 operates under the control of the control device 16. The device body 14 includes an SLO unit 18, a scanning device 19, and an OCT unit 20.

[0010] In the following explanation, when the ophthalmic imaging device 10 is placed on a horizontal plane, the horizontal direction will be referred to as the "X direction," the direction perpendicular to the horizontal plane as the "Y direction," and the direction from the anterior segment of the eye under examination 12 through the center O of the eyeball toward the fundus as the "Z direction." Therefore, the direction perpendicular to both the Y direction and the Z direction is the "X direction."

[0011] The ophthalmic imaging device 10 according to this embodiment has two functions as an example of the main functions that can be realized by the ophthalmic imaging device 10. The first function is to operate the ophthalmic imaging device 10 as a scanning laser ophthalmoscope (hereinafter referred to as "SLO") and perform imaging using SLO (hereinafter referred to as the SLO imaging system function). The second function is to operate the ophthalmic imaging device 10 as an optical coherence tomography (hereinafter referred to as "OCT") and perform imaging using OCT (hereinafter referred to as the OCT imaging system function).

[0012] The SLO imaging system function is implemented by a scanning device 19, which includes a control device 16, an SLO unit 18, and a first optical scanner 22, as part of the ophthalmic imaging device 10. The SLO unit 18 includes a light source and a detection element, etc., and is capable of imaging the fundus of the eye under examination 12. In other words, when the ophthalmic imaging device 10 operates as an SLO imaging system, the fundus of the eye under examination 12 (e.g., the imageable area 12A) is imaged as the subject. Specifically, light from the SLO unit 18 (hereinafter referred to as "SLO light") is scanned by the scanning device 19 through the pupil of the eye under examination 12 in the Y direction (vertical direction) by the first scanner 22 and in the X direction (horizontal direction) by the third scanner 29, and the image from the reflected light is acquired by the SLO unit 18. Note that the SLO imaging system function is a well-known function, so a detailed explanation will be omitted.

[0013] The OCT imaging system function is realized by a scanning device 19 including a control device 16, an OCT unit 20, and a second optical scanner 24. The OCT unit 20 includes a light source, a spectrometer, a sensor, and a reference optical system, and is capable of imaging multiple tomographic regions in the thickness direction of the fundus. In other words, when the ophthalmic imaging device 10 operates as an OCT imaging system, tomographic regions, which are regions in the thickness direction of the fundus (e.g., the scanable region 12A), are imaged. Specifically, light from the OCT unit 20 (hereinafter referred to as "measurement light") is scanned by the scanning device 19 through the pupil of the eye 12 under examination in the scanable region 12A, in the Y direction (vertical direction) by the second scanner 24 and in the X direction (horizontal direction) by the third scanner 29, and interference light is generated by interfering the reflected light of the measurement light with the reference light. The OCT unit 20 detects each spectral component of the interference light, and the control device 16 uses the detection results to acquire a physical quantity (e.g., a tomographic image) that indicates the tomographic region. Since the OCT imaging function is a well-known feature, a detailed explanation will be omitted.

[0014] In the following explanation, since both SLO light and measurement light are light that is scanned two-dimensionally in the X and Y directions, when it is not necessary to distinguish between SLO light and measurement light, SLO light and measurement light will be collectively referred to as "scanning light".

[0015] In this embodiment, an example of an ophthalmic imaging device 10 that includes a function using scanning light is described, but it is not limited to ophthalmic imaging devices that include a function using scanning light, and is sufficient as long as it has a function that allows observation of the eye under examination 12. For example, it is applicable to ophthalmic imaging devices that include a function that allows observation of the fundus of the eye under examination 12 by irradiating light toward the fundus of the eye under examination 12, not limited to the irradiation of scanning light. In other words, it is not limited to using the reflected light from the eye under examination 12 when scanning light is scanned, but includes a function that simply irradiates light to observe the eye under examination 12. Furthermore, it is not limited to irradiating light onto the eye under examination 12. For example, it includes a function that allows observation of the eye under examination 12 using light such as fluorescence generated in the eye under examination 12. For this reason, in the following description, the light used when observing the eye under examination 12 will be referred to as "light from the eye under examination 12," including the concept of reflected light from the fundus and light emission from the fundus.

[0016] Here, we will describe the irradiation angle of the light beam to the eye 12 under examination in the ophthalmic imaging device 10 according to this embodiment. Figure 2 shows an example of the irradiation angle of the ophthalmic imaging device 10 according to this embodiment relative to the eye under examination. Figure 3 shows an example of the area in which the fundus can be imaged. When observing the fundus of the eye under examination 12, a wider field of view (FOV) of the fundus can be observed by increasing the field of view of the observer. To observe this fundus area, the ophthalmic imaging device 10 according to this embodiment scans the fundus of the eye under examination 12 with scanning light and photographs the fundus of the eye under examination 12. Therefore, the field of view of the fundus corresponds to the irradiation angle of the scanning light. In other words, it is necessary to express how much of the fundus area can be photographed by providing a certain amount of light to the eye under examination 12. The scanning light to the fundus is directed toward the center of the pupil of the eye under examination 12. Due to refraction at the cornea of ​​the eye under examination, the light emitted from the ophthalmic device illuminates the fundus at a slightly narrower angle inside the eye. Figure 2 schematically shows the state in which the light emitted from the ophthalmic device is refracted at the center of the pupil. Furthermore, the external irradiation angle A, which is the angle of illumination within the eye being examined by the ophthalmic device, and the internal irradiation angle B, which is the angle of illumination within the eye being examined, must be distinguished and expressed accordingly.

[0017] External illumination angle A is the angle of light illumination from the ophthalmic imaging device 10, that is, from outside the eye under examination 12. In other words, external illumination angle A is the angle at which the illumination light is directed toward the pupil center point 27 of the eye under examination 12 (i.e., the center point of the pupil in orthogonal view) relative to the fundus of the eye under examination 12. This external illumination angle A is also equal to the angle of light that reflects from the fundus, exits the eye under examination 12 from the pupil center point 27, and is directed toward the ophthalmic imaging device 10. On the other hand, internal illumination angle B represents the angle at which the fundus of the eye under examination 12 is illuminated by scanning light and is effectively photographed, with the center O of the eyeball of the eye under examination 12 as the reference position. External illumination angle A and internal illumination angle B are in a corresponding relationship, but in the following explanation, since it is an explanation of an ophthalmic device, external illumination angle A is used as the illumination angle corresponding to the field of view of the fundus. Note that in the following explanation, the internal illumination angle may also be mentioned, but this is for reference only.

[0018] Therefore, as shown in Figure 3, the ophthalmic imaging device 10 images the reproducible area 12A, which is the fundus region of the eye under examination 12, using an external illumination angle A. This reproducible area 12A is, for example, the maximum area that can be scanned by the scanning light of the scanning device 19. An example of the reproducible area 12A is the range that provides a field of view of approximately 120 degrees at an external illumination angle A. In this case, the internal illumination angle corresponds to approximately 160 degrees.

[0019] For example, the imaging area 12A can be broadly divided into a first imaging area 12A1 and a second imaging area 12A2. The first imaging area 12A1 is the field of view near the visual axis CL passing through the pupil center point 27 and center O of the eye under examination 12, with an external illumination angle Aa. The second imaging area 12A2 is the peripheral area of ​​the first imaging area 12A1, which is the peripheral field of view away from the visual axis CL. An example of an external illumination angle Aa corresponding to the first imaging area 12A1 is approximately 30 degrees (corresponding to an internal illumination angle B of approximately 45 degrees), and an example of an external illumination angle A corresponding to the second imaging area 12A2 is approximately 120 degrees (corresponding to an internal illumination angle of approximately 160 degrees).

[0020] The scanning device 19 includes a common optical system 28 comprising a first optical scanner 22, a second optical scanner 24, a dichroic mirror 26, and a third optical scanner 29. The first optical scanner 22, the second optical scanner 24, and the dichroic mirror 26 are arranged such that the optical path length between the first optical scanner 22 and the dichroic mirror 26 matches the optical path length between the second optical scanner 24 and the dichroic mirror 26. The common optical system 28 is used in common for SLO light and illumination light. The common optical system 28 includes the third optical scanner 29. These first optical scanner 22, second optical scanner 24, and third optical scanner 29 are positioned conjugate to the center of the pupil of the eye under examination 12. Note that the dichroic mirror 26 is shared by both scanners and can therefore be considered as being included in the common optical system.

[0021] In this embodiment, a polygon mirror can be used as an example of the first optical scanner 22. Also, in this embodiment, a galvanometer mirror can be used as an example of the second optical scanner 24. The first optical scanner 22 and the second optical scanner 24 can be any optical elements that can deflect a light beam in a predetermined direction.

[0022] Figure 4 shows an example of a scanning device 19 including the main components of the common optical system 28. As shown in Figure 4, the common optical system 28 includes an optical system 28A and a third optical scanner 29.

[0023] The first optical scanner 22 sends SLO light from the SLO unit 18 to the dichroic mirror 26. The first optical scanner 22 also scans the SLO light in the Y direction. Scanning of the SLO light in the Y direction is achieved by operating an optical deflection element such as a polygon mirror. The dichroic mirror 26 transmits the SLO light sent from the first optical scanner 22 and guides it to the common optical system 28. In the common optical system 28, SLO light from the third optical scanner 29 is emitted to the optical system 28A. The third optical scanner 29 also scans the SLO light in the X direction. Scanning of the SLO light in the X direction is achieved by operating an optical deflection element such as a galvanometer mirror.

[0024] In the common optical system 28, SLO light from the third optical scanner 29 is incident on the pupil of the eye under examination 12 via the optical system 28A. When the SLO light is reflected in the imaging area 12A, the reflected SLO light travels in the reverse direction along the same optical path as the original SLO light to reach the SLO unit 18.

[0025] The second optical scanner 24 sends the measurement light from the OCT unit 20 to the dichroic mirror 26. The second optical scanner 22 scans the measurement light in the Y direction. The scanning of the measurement light in the Y direction is achieved by operating an optical deflection element such as a galvanometer mirror. The dichroic mirror 26 reflects the measurement light sent from the second optical scanner 24 and guides it to the common optical system 28. In the common optical system 28, the measurement light from the third optical scanner 29 is emitted into the optical system 28A. The third optical scanner 29 scans the measurement light in the X direction.

[0026] In the common optical system 28, measurement light from the third optical scanner 29 is incident on the pupil of the eye under examination 12 via the optical system 28A. When the measurement light is incident on the imaging area 12A, it is scattered and reflected at different positions in the film thickness direction of the imaging area 12A. The resulting measured reflected light travels in the reverse direction along the same optical path as the measurement light to reach the OCT unit 20.

[0027] As shown in Figure 1, the control device 16 controls the operation of the device body 14 by exchanging various information with the device body 14. The control device 16 can be implemented by a computer including a CPU (Central Processing Unit), ROM, and RAM (Random Access Memory). Furthermore, the control device 16 is not limited to a configuration including a computer and may be implemented by other hardware configurations. Based on the signal from the SLO unit 18, the control device 16 generates a two-dimensional image 12G showing the reproducible area 12A. The two-dimensional image 12G is a planar image showing the reproducible area 12A in a planar view. The control device 16 also generates a tomographic image of the fundus of the eye under examination 12, that is, a tomographic image within the reproducible area 12A, based on the signal from the OCT unit 20.

[0028] Figure 5 shows an example of a two-dimensional image 12G representing the image-capable area 12A generated by the control device 16. As shown in Figure 5, the X-direction scanning angle range is the range of the scanning angle of the scanning light in the X direction. Figure 5 illustrates the X-direction scanning angle range as a range of θ0 degrees to θn degrees. Similarly, the Y-direction scanning angle range is the scanning angle of the scanning light in the Y direction. Figure 5 illustrates the Y-direction scanning angle range as a range of φ0 degrees to φn degrees.

[0029] As shown in Figure 5, the two-dimensional image 12G is broadly divided into a circular first fundus image region 12G1 corresponding to the first imageable region 12A1 (see Figure 3) and an annular-shaped second fundus image region 12G2 corresponding to the second imageable region 12A2 (see Figure 3). However, obtaining images of both the first fundus image region 12G1 and the second fundus image region 12G2 with high precision using the same scanning method was not easy.

[0030] In other words, the ophthalmic imaging device 10 is required to image a wide area within the imageable region 12A of the fundus of the eye under examination 12. However, when the optical system 28A is constructed using only lenses, it is difficult to make the external illumination angle A of the eye under examination 12 ultra-wide and obtain a wider field of view. This is because it is required to solve multiple problems, such as ensuring the working distance WD (working distance) between the eye under examination 12 and the optical system surface closest to the eye under examination 12, improving aberration performance to obtain high-resolution images, suppressing flare and ghosting, reducing the size and weight of the device body, and reducing the difficulty and cost of manufacturing. These problems sometimes conflicted as the goal was to obtain a wider field of view.

[0031] Therefore, in this embodiment, we focus on the fact that a reflective-refractive optical system combining a reflective surface and a lens can suppress the occurrence of chromatic aberration as a whole optical system and can also be miniaturized, enabling wider-angle observation corresponding to the periphery of the central part of the fundus. In other words, in this embodiment, a ring-shaped second fundus image area 12G2 corresponding to the second imageable area 12A2 (see Figure 3) is captured, enabling peripheral observation of the central part of the fundus with a wider-angle external illumination angle A. In the following description, we will mainly describe a fundus imaging device that photographs the fundus of the eye under examination 12, but with the above optical configuration, by appropriately selecting the positional relationship with the eye under examination 12, it is also effective when observing not only the fundus but also the anterior segment of the eye under examination.

[0032] Figure 6 schematically shows the optical system 28A in the common optical system 28 that enables a wider field of view. As shown in Figure 6, the optical system 28A includes a first optical unit 280 and a second optical unit 282. However, in the optical system 28A, it is not easy to increase the working distance WD between the eye under examination 12 and the optical system using only lenses. In contrast, this embodiment uses a reflective surface with a donut-shaped annular effective reflection region having a transmitted aperture at the center of the reflective surface, and lenses, making it possible to form a wide annular peripheral field of view. Moreover, it is possible to create a compact optical system with a small number of constituent lenses that produces images in the ultra-wide angle region with sufficient aberration performance and minimizes the occurrence of flare and ghosting.

[0033] Next, the optical system 28A will be described in detail with reference to Figure 7, which is an example of an embodiment. In the first optical unit 280, which is positioned on the side of the eye being examined, as light enters from the pupil Pp side of the eye being examined 12, the light from the eye being examined 12 is reflected and converged toward the eye being examined by a first reflective surface (annular concave reflector) having a central aperture, after the spread of the light beam is suppressed by a first refractive surface with a concave surface facing the eye being examined. Next, the light is reflected in the opposite direction toward the eye being examined by a second reflective surface (annular convex reflector) and passes through the central aperture of the first reflective surface. The light from the eye being examined that is emitted from the first optical unit 280 is reflected by a second optical unit 282, which is made of a lens, and an image of the pupil conjugate Pcj is formed in the space opposite to the eye being examined, away from the second optical unit, at a position conjugate to the pupil Pp position of the eye being examined 12. In this optical configuration, the overall optical system can be miniaturized by making the first reflecting surface concave and the second reflecting surface convex. Furthermore, the first refractive surface with its concave side facing the eye under examination ensures a sufficient working distance (WD), allowing for miniaturization of the first reflecting surface, and enabling light beam separation by allowing light to pass through the apertures of the second and first reflecting surfaces. In this optical system configuration, a group of lenses with positive refractive power is positioned between the position of the fundus-conjugate image Fcj, which is conjugate to the fundus of the eye under examination, and the position of the pupil-conjugate image Pcj, which is conjugate to the pupil of the eye under examination. It is effective for aberration correction to include at least one surface with negative refractive power within the lens group.

[0034] Furthermore, by employing a back surface reflective surface that forms an integrated structure on both sides of a medium with a refractive index greater than 1, the first reflective surface with a central aperture and the second reflective surface with a central aperture can be made to achieve both a longer working distance WD and a smaller mirror.

[0035] In this case, by configuring the optical system 28A to satisfy the condition shown in equation (1) below, a larger field of view can be obtained with a smaller optical system while having a longer working distance WD. 0.1 <D·tan(A / 2) / S<1.0 ···(1) However, D is the distance from the pupil Pp position of the eye under examination 12 to the first refractive surface, S is the maximum effective diameter of the refractive surface in the optical system, and A is the external illumination angle as the external illumination angle to the pupil position. Furthermore, it is more preferable that equation (1) has an upper limit of 0.9 and a lower limit of 0.2.

[0036] Furthermore, the ophthalmic imaging device 10 according to this embodiment has SLO imaging system function and OCT imaging system function, and each of these functions requires high-speed scanning imaging with sufficient resolution. This requirement can be achieved by forming the optical system 28A so as to satisfy the condition shown in equation (2) below. 1 < |β| < 10 ···(2) However, β is the imaging magnification between the pupil position of the eye under examination 12 and the position of the pupil's conjugate, which is conjugate to the pupil position. In equation (2) above, it is preferable to make the lower limit greater than 2.

[0037] Furthermore, the pupillary coma aberration between the pupil Pp and pupillary conjugate Pcj of the eye under examination 12 results in a difference in the angle of view of the fundus image at the image position of pupillary conjugate Pcj, leading to a change in resolution at the fundus position. To correct this pupillary coma aberration, it is preferable to arrange a lens group having a positive refractive power overall between the fundus conjugate Fcj position and the pupillary conjugate Pcj position of the eye under examination 12, and to configure at least one surface with negative refractive power within the lens group. More preferably, the imaging magnification β in equation (2) is expressed by equation (3) shown below, and the distortion rate M of the maximum field of view when an aberration-free ideal lens is placed at the pupillary conjugate Pcj position can be taken into account. In this case, the upper limit is 17.0 and the lower limit is 9.0. |β| / (1-M)···(3)

[0038] (First embodiment) Figure 7 shows an example of the lens configuration of the optical system 28A in the ophthalmic imaging device 10 according to the first embodiment. The optical system 28A includes a first optical unit 280 in which lens components are arranged in order from the pupil Pp side of the eye under examination 12, including a positive meniscus lens L01 with a concave surface facing the pupil Pp, a negative meniscus lens L02 with an aspherical shape and a concave surface facing the pupil Pp, and a positive meniscus lens L03 with a convex surface facing the pupil Pp and a negative meniscus lens L04 bonded together. The light-emitting side of the first optical unit 280 also includes a second optical unit 282 in which a convex lens L05 and a meniscus lens L06 with a concave surface facing the pupil Pp are arranged in order from the pupil Pp side of the eye under examination 12.

[0039] Furthermore, all optical elements constituting the optical system 28A, namely the optical elements included in the first optical unit 280 (lenses L01, L02, L03, L04) and the optical elements included in the second optical unit 282 (lenses L05, L06), are arranged along a single optical axis AX.

[0040] Then, the parallel light beam emitted from the eye under examination 12 from the first optical unit 280 becomes slightly divergent light and enters the subsequent second optical unit 282. The second optical unit 282 has two lenses and converts the weak divergent light from the first optical unit 280 into a parallel light beam, and together with the first optical unit 280, it forms a conjugate image of the pupil Pp of the eye under examination 12 in the space opposite the eye under examination 12.

[0041] In this configuration, the light beam shown in FIG. 7 indicates a state in which a parallel light beam emitted from the pupil position Pp of the eye to be examined 12 forms a pupil conjugate point Pcj in the space on the opposite side of the eye to be examined 12 by the optical system 28A. Here, it is assumed that light from the fundus of the eye is emitted from the eye to be examined 12 as a parallel light beam. In this case, the conjugate point with the fundus of the eye to be examined 12 is the position indicated by the point Fcj in FIG. 7, and it shows that a primary space image of the fundus is formed between the annular concave reflecting surface Mr01 and the annular convex reflecting surface Mr02. Needless to say, in the above-described SLO unit 18 and OCT unit 20, the irradiation beams (laser light) from each unit enter the eye to be examined 12 at various angles (i.e., external irradiation angles) as parallel light beams centered on the pupil position Pp of the eye to be examined 12. The same applies to each of the embodiments described later.

[0042] Also, the imaging performance can be improved by making each surface an aspherical shape as appropriate. These aspherical surfaces have a height in the direction perpendicular to the optical axis as r, the distance along the optical axis from the tangent plane at the vertex of the aspherical surface to the position on the aspherical surface at height r (sag amount) as z, the reciprocal of the vertex curvature radius as c, the conic coefficient as k, and the aspherical coefficients of the nth order as A, B, C, D, and E. When they are represented by the following formula (4):

[0043] z=(c·r 2 ) / [1 + {1 - (1 + k)·r 2 ·c 2}] 1 / 2 +A·r 4 +B·r 6 +C·r 8 +D·r 10 +E·r 12 ···(4)

[0044] Table 1 below shows the values of the specifications of the optical system 28A in the first embodiment. Table 1 shows the case where the effective field of view (external illumination angle A from the pupil) is 100-132 degrees (50-66 degrees: first plane incidence angle), and the working distance WD is 18 mm. It also shows the case where the total length (distance L2 from the pupil Pp position to the conjugate pupil Pcj position of eye 12) is 520.88 mm, and the pupil imaging magnification β from the pupil Pp position to the conjugate pupil Pcj position is 4.9x. Furthermore, it shows the case where the distortion M1 (distortion of the maximum field of view at the conjugate pupil Pcj when an aberration-free ideal lens is placed at the conjugate pupil Pcj position) is 0.574.

[0045] [Table 1]

[0046] The aspheric coefficient for the seventh surface of lens L02, which indicates an aspheric surface, is: A:+0.398342E-06 B:-0.976217E-10 C:-0.544603E-13 That is the case.

[0047] Figure 8 shows the lateral aberration diagram of the optical system 28A configured according to the specifications in Table 1. This lateral aberration diagram is an aberration diagram of the fundus image when an aberration-free ideal lens is conveniently placed at the pupil conjugate Pcj position in order to evaluate the optical performance of this embodiment. In each embodiment described later, aberration calculations are performed with an aberration-free ideal lens in place in a similar manner. In the aberration diagram shown in Figure 8, the vertical axis represents image height, the solid line represents the central wavelength of 587.5620 nm, the dashed line represents 656.2790 nm, the dashed line represents 486.1330 nm, and the dashed line represents 435.8350 nm.

[0048] As is clear from the aberration diagram shown in Figure 8, the optical system 28A of the first embodiment also shows good correction and suppression of aberration variations for light in the visible light wavelength range. Furthermore, the optical system 28A shows good correction even when the effective field of view (i.e., external illumination angle A) is near 100 to 132 degrees (50 to 66 degrees: first plane incidence angle). This corresponds to an internal illumination angle of approximately 130 to 165 degrees. Although not shown in the figures, it has been confirmed that various aberrations such as spherical aberration, astigmatism, and distortion are also well corrected.

[0049] (Second example) The second embodiment is a modification of the first embodiment, with an expanded effective field of view (i.e., external illumination angle A). Since the second embodiment has the same configuration as the first embodiment, the same parts are denoted by the same reference numerals and detailed descriptions are omitted. The different optical system 28A will be described below.

[0050] Figure 9 shows the lens configuration of the optical system 28A in the ophthalmic imaging device 10 according to the second embodiment. The optical system 28A according to the second embodiment includes a first optical unit 280 in which lens components are arranged in order from the pupil Pp side of the eye 12 to the pupil Pp side, including a positive meniscus lens L01 with an aspherical shape having a concave surface facing the pupil Pp side, a negative meniscus lens L02 with an aspherical shape having the concave surface facing the pupil Pp side bonded to the light-emitting side surface of the positive meniscus lens L01, and a positive meniscus lens L03 with a convex surface facing the pupil Pp side bonded together with a negative meniscus lens L04. The light-emitting side of the first optical unit 280 has a second optical unit with a lens configuration similar to the second optical unit 282 shown in Figure 7.

[0051] Similar to the first embodiment, all optical elements constituting the optical system 28A (lenses L01, L02, L03, L04, lenses L05, L06) are arranged along a single optical axis AX.

[0052] Table 2 shows the specifications of the optical system 28A in the second embodiment. Table 2 shows the case where the effective field of view (external illumination angle A from the pupil) is 110 to 140 degrees (55 to 70 degrees: first plane incidence angle) and the working distance WD is 18 mm. It also shows the case where the total length (distance L2 from the pupil Pp position to the conjugate pupil Pcj position of eye 12) is 565 mm and the pupil imaging magnification β from the pupil Pp position to the conjugate pupil Pcj position is 3.92x. Furthermore, it shows the case where the distortion M2 (distortion of the maximum field of view at the conjugate pupil Pcj when an aberration-free ideal lens is placed at the conjugate pupil Pcj position) is 0.720.

[0053] [Table 2]

[0054] The aspheric coefficients for the third and fifth surfaces of lens L01 are common. A:-0.902137E-07 B:+0.794263E-11 C:-0.318956E-15 That is the case. Furthermore, the aspheric coefficient indicating the seventh aspheric surface in lens L02 is: A:+0.585897E-06 B:-0.983043E-10 C:+0.117076E-12 D:-0.125282E-16 That is the case.

[0055] Figure 10 shows the lateral aberration diagram of the optical system 28A configured according to the specifications in Table 2. In the aberration diagram shown in Figure 10, similar to the first embodiment, the vertical axis represents image height, the solid line represents the central wavelength of 587.5620 nm, the dashed line represents 656.2790 nm, the dashed line represents 486.1330 nm, and the dashed line represents 435.8350 nm.

[0056] As is clear from the aberration diagram shown in Figure 10, similar to the optical system 28A of the second embodiment, the variation in aberrations for light in the visible light wavelength range is suppressed and well corrected. Furthermore, it can be seen that the optical system 28A is well corrected even when the effective field of view is near 140 degrees (70 degrees: first plane incidence angle). This corresponds to an internal illumination angle of approximately 180 degrees. Although not shown in the figures, it has been confirmed that various aberrations such as spherical aberration, astigmatism, and distortion are also well corrected.

[0057] (Third embodiment) The third embodiment is a modification of the first embodiment. Since the third embodiment has the same configuration as the first embodiment, the same parts are denoted by the same reference numerals and detailed descriptions are omitted.

[0058] Figure 11 shows the lens configuration of the optical system 28A in the ophthalmic imaging device 10 according to the third embodiment. The optical system 28A according to the third embodiment includes a first optical unit 280 in which, starting from the pupil Pp side of the eye under examination 12, a positive meniscus lens L01 with a concave surface facing the pupil Pp side, a negative meniscus lens L02 including an aspherical shape with a concave surface facing the pupil Pp side, and a lens formed by bonding a positive meniscus lens L03 with a convex surface facing the pupil Pp side and a negative meniscus lens L04. The optical system on the light emission side of the first optical unit 280 also includes a second optical unit 282 in which, starting from the pupil Pp side of the eye under examination 12, a convex lens L05 and a meniscus lens L06 with a concave surface facing the pupil surface D side are arranged in order.

[0059] Furthermore, all optical elements constituting the optical system 28A, namely the optical elements included in the first optical unit 280 (lenses L01, L02, L03, L04) and the optical elements included in the second optical unit 282 (lenses L05, L06), are arranged along a single optical axis AX.

[0060] Table 3 shows the specifications of the optical system 28A in the third embodiment. Table 3 shows the case where the effective field of view (external illumination angle A from the pupil) is 100 to 130 degrees (50 to 65 degrees: first plane incidence angle) and the working distance WD is 18 mm. It also shows the case where the total length (distance L2 from the pupil Pp position to the conjugate pupil Pcj position of eye 12) is 549.19 mm and the pupil imaging magnification β from the pupil Pp position to the conjugate pupil Pcj position is 5.64x. Furthermore, it shows the case where the distortion M2 (distortion of the maximum field of view at the conjugate pupil Pcj when an aberration-free ideal lens is placed at the conjugate pupil Pcj position) is 0.517.

[0061] [Table 3]

[0062] The aspheric coefficient for the seventh surface of lens L02, which indicates an aspheric surface, is: A:+0.505045E-06 B:-0.185139E-09 C:+0.118203E-12 D:-0.133097E-16 That is the case.

[0063] Figure 12 shows the lateral aberration diagram of the optical system 28A configured according to the specifications in Table 3. In the aberration diagram shown in Figure 12, similar to the first embodiment, the vertical axis represents image height, the solid line represents the central wavelength of 587.5620 nm, the dashed line represents 656.2790 nm, the dashed line represents 486.1330 nm, and the dashed line represents 435.8350 nm.

[0064] As is clear from the aberration diagram shown in Figure 12, in the optical system 28A of the third embodiment, the variation in aberrations is suppressed for light in the visible light wavelength range, and it can be seen that the aberrations are well corrected even when the effective field of view is near 130 degrees (65 degrees: first plane incidence angle). This corresponds to an internal illumination angle of approximately 165 degrees. In addition, although not shown in the figure, it has been confirmed that various aberrations such as spherical aberration, astigmatism, and distortion are also well corrected.

[0065] [Second Embodiment] In the second embodiment, components similar to those in the first embodiment are denoted by the same reference numerals, and detailed descriptions are omitted.

[0066] In the second embodiment, when considering both reducing the aperture of the lens element and reducing the aperture of the reflective surface, the common optical system 28 is formed with a dominant emphasis on reducing the aperture of the lens element. Specifically, the focus is on reducing the aperture of the lens element, while allowing for a certain degree of enlargement of the reflective surface. The first optical unit 280 has, in order from the pupil Pp side of the eye under examination 12, a lens with positive refractive power with a concave surface facing the eye under examination 12, a first reflective surface as an annular concave reflective surface with a central aperture that is a surface reflective surface where the incident side is gas, a second reflective surface as an annular convex reflective surface that is a surface reflective surface where the incident side is gas, a lens with negative refractive power, and a lens with positive refractive power. In this case, it is preferable to place the lens with negative refractive power between the first reflective surface and the second reflective surface. The parallel light beam from the eye under examination 12 emitted from the first optical unit 280 becomes slightly divergent light and is incident on the subsequent second optical unit 282. The second optical unit 282 has two lenses and converts the weak divergent light from the first optical unit 280 into a parallel beam of light. Together with the first optical unit 280, it forms a conjugate image of the pupil Pp of the eye under examination 12 in the space opposite to the eye under examination 12.

[0067] (Fourth embodiment) Next, a fourth embodiment according to the second embodiment will be described. In the fourth embodiment, components similar to those in the first to third embodiments are denoted by the same reference numerals, and detailed descriptions are omitted.

[0068] Figure 13 shows the lens configuration of the optical system 28A in the ophthalmic imaging device 10 according to the fourth embodiment. The optical system 28A according to the fourth embodiment includes a first optical unit 280 in which a positive meniscus lens L01 with a concave surface facing the pupil Pp side, a ring-shaped first reflective surface Mr01 with a concave surface facing the pupil Pp side, a second reflective surface Mr02 provided at the center of the convex surface of the positive meniscus lens L01, a negative meniscus lens L02 with a concave surface facing the pupil Pp side, and a positive meniscus lens L03 with a concave surface facing the pupil Pp side are arranged in that order from the pupil Pp side of the eye to be examined 12. Furthermore, the light emission side of the first optical unit 280 includes a second optical unit 282 in which a meniscus lens L05 with a convex surface facing the pupil Pp side and a positive lens L06 are arranged in that order from the pupil Pp side of the eye to be examined 12.

[0069] Furthermore, all optical elements constituting the optical system 28A, namely the optical elements included in the first optical unit 280 (lenses L01, L02, L03) and the optical elements included in the second optical unit 282 (lenses L05, L06), are arranged along a single optical axis AX.

[0070] Table 4 shows the specifications of the optical system 28A in the fourth embodiment. Table 4 shows the case where the effective field of view (external illumination angle A from the pupil) is 80 to 130 degrees (40 to 65 degrees: first plane incidence angle) and the working distance WD is 39.1089 mm. It also shows the case where the total length (distance L2 from the pupil Pp position to the conjugate pupil Pcj position of eye 12) is 565 mm and the pupil imaging magnification β from the pupil Pp position to the conjugate pupil Pcj position is 6.4x. Furthermore, it shows the case where the distortion M2 (distortion of the maximum field of view at the conjugate pupil Pcj when an aberration-free ideal lens is placed at the conjugate pupil Pcj position) is 0.518.

[0071] [Table 4]

[0072] Figure 14 shows the lateral aberration diagram of the optical system 28A configured according to the specifications in Table 4. In the aberration diagram shown in Figure 14, similar to the first embodiment, the vertical axis represents image height, the solid line represents the central wavelength of 587.5620 nm, the dashed line represents 656.2790 nm, the dashed line represents 486.1330 nm, and the dashed line represents 435.8350 nm.

[0073] As is clear from the aberration diagram shown in Figure 14, in the optical system 28A of the fourth embodiment, the variation in aberrations for light in the visible light wavelength range is suppressed, and the effective field of view is well corrected around 100 degrees (50 degrees: first plane incidence angle). This corresponds to an internal illumination angle of approximately 135 degrees. In addition, although not shown in the figure, it has been confirmed that various aberrations such as spherical aberration, astigmatism, and distortion are also well corrected.

[0074] (Fifth example) The fifth embodiment is a modification of the fourth embodiment. Specifically, in the first optical unit 280, in the fourth embodiment, the second reflective surface Mr02 was provided at the center of the convex surface of the positive meniscus lens L01, but in the fifth embodiment, the second reflective surface Mr02 is provided as an element independent of the positive meniscus lens L01.

[0075] Since the fifth embodiment has the same configuration as the fourth embodiment, the same parts are denoted by the same reference numerals and detailed descriptions are omitted.

[0076] Figure 15 shows an example of the lens configuration of the optical system 28A according to the fifth embodiment. The optical system 28A according to the fifth embodiment includes a first optical unit 280 in which a positive meniscus lens L01 with a concave surface facing the pupil Pp side of the eye under examination 12, an annular first reflective surface Mr01 including an aspherical shape with a concave surface facing the pupil Pp side, a second reflective surface Mr02 including an aspherical shape provided at the center of the convex surface opposite to the pupil Pp, a negative lens L02 with a concave surface facing the pupil Pp side, and a positive meniscus lens L03 with a concave surface facing the pupil Pp side are arranged in order from the pupil Pp side of the eye under examination 12. The light output side of the first optical unit 280 also includes a second optical unit 282 in which a meniscus lens L05 with a convex surface facing the pupil Pp side and a positive lens L06 are arranged in order from the pupil Pp side of the eye under examination 12.

[0077] Furthermore, all optical elements constituting the optical system 28A (lenses L01, L02, L03, lenses L05, L06) are arranged along a single optical axis AX.

[0078] Table 5 shows the specifications of the optical system 28A in the fifth embodiment. Table 5 shows the case where the effective field of view (external illumination angle A from the pupil) is 70 to 130 degrees (35 to 65 degrees: first plane incidence angle) and the working distance WD is 34.448 mm. It also shows the case where the total length (distance L2 from the pupil Pp position to the conjugate pupil Pcj position of eye 12) is 620 mm and the pupil imaging magnification β from the pupil Pp position to the conjugate pupil Pcj position is 7.6x. Furthermore, it shows the case where the distortion M2 (distortion of the maximum field of view at the conjugate pupil Pcj when an aberration-free ideal lens is placed at the conjugate pupil Pcj position) is 0.450. It also shows the case where the maximum diameter of the reflective surface is 230 mm and the maximum effective diameter of the refractive surface is 106.3 mm.

[0079] [Table 5]

[0080] The aspheric coefficient indicating the aspheric surface of the fifth face is: A:-0.119695E-08 B:+0.639162E-12 C:+0.383380E-16 D:-0.483487E-20 E:+0.121159E-24 That is the case. Furthermore, the aspheric coefficient indicating the aspheric surface of the sixth face is, A:-0.449100E-06 B:+0.253492E-08 C:-0.308466E-11 D:+0.171588E-14 E:-0.458747E-18 That is the case.

[0081] Figure 16 shows the lateral aberration diagram of the optical system 28A configured according to the specifications in Table 5. In the aberration diagram shown in Figure 16, similar to the first embodiment, the vertical axis represents image height, the solid line represents the central wavelength of 587.5620 nm, the dashed line represents 656.2790 nm, the dashed line represents 486.1330 nm, and the dashed line represents 435.8350 nm.

[0082] As is clear from the aberration diagram shown in Figure 16, the optical system 28A of the fifth embodiment suppresses and effectively corrects aberrations for light in the visible light wavelength range. It can be seen that the correction is good even when the effective field of view is near 130 degrees (65 degrees: first plane incidence angle). This corresponds to an internal illumination angle of approximately 165 degrees. Furthermore, although not shown in the diagram, it has been confirmed that various aberrations such as spherical aberration, astigmatism, and distortion are also well corrected.

[0083] Table 6 shows the corresponding values ​​for each of the aforementioned conditional expressions in each configuration of the first to fifth embodiments described above.

[0084] [Table 6]

[0085] [Third Embodiment] In the third embodiment, components similar to those in the first and second embodiments are denoted by the same reference numerals, and detailed descriptions are omitted.

[0086] The third embodiment is an imaging system capable of providing images of the entire image-capable region 12A based on the field of view (FOV), which is the external illumination angle A. In other words, in the first and second embodiments, it is possible to obtain images of the periphery of the central part of the fundus according to the visual axis CL, i.e., the second fundus image region 12G2 (see Figure 3) corresponding to the annular-shaped second image-capable region 12A2. Therefore, in the third embodiment, it is possible to obtain images of the first fundus image region 12G1 (see Figure 3) corresponding to the central part of the fundus according to the visual axis CL, i.e., the first image-capable region 12A1, and then synthesize the images of the fundus center and the periphery of the central part of the fundus to obtain a two-dimensional image 12G of the entire image-capable region 12A.

[0087] Figure 17 shows an image system 100 as an example of an image system capable of providing all images of the imageable area 12A according to the third embodiment. The image system 100 comprises a first ophthalmic imaging device (fundus imaging device) 110, a second ophthalmic imaging device (fundus imaging device) 120, a network 130 such as the Internet and a local area network, an image server 140, and an image display terminal 150. The imaging system 100 includes a first ophthalmic imaging device 110 that obtains an image of the central part of the fundus using the visual axis CL. The imaging system 100 also includes a second ophthalmic imaging device 120 that captures the area around the central part of the fundus using the visual axis CL, using either the first or second embodiment of the imaging system 10, which includes each embodiment, to obtain a peripheral image. These first and second ophthalmic imaging devices 110 and 120 are connected to a network 130. The image server 140 and the image display terminal 150 are also connected to the network 130.

[0088] The first ophthalmic imaging device 110 is assumed to have a fundus region with a field of view of 0 to 305 degrees centered on the visual axis CL, i.e., an external illumination angle of 30 degrees. By using the SLO unit of this first ophthalmic imaging device 110, a fundus image of a circular region with a field of view of 15 degrees centered on the visual axis CL can be obtained. Furthermore, by using the OCT unit, OCT-3D volume data of a circular region with a field of view (i.e., external illumination angle) of 30 degrees centered on the visual axis CL can be obtained, enabling 3D data analysis and the creation of various maps. In addition, retinal tomographic images can also be obtained using the OCT unit. Furthermore, the second ophthalmic imaging device 120 is assumed to cover a fundus region with a field of view of 30 to 100 degrees centered on the visual axis CL, i.e., an external illumination angle of 30 to 100 degrees. By using the SLO unit of this second ophthalmic imaging device 120, a fundus image of a donut-shaped annular region surrounding a circular region can be obtained centered on the visual axis CL. In addition, by using the OCT unit, OCT-3D volume data of the annular region can be obtained, enabling 3D data analysis and the creation of various maps. Moreover, by using the OCT unit, retinal tomographic images within the annular region can also be obtained.

[0089] Figure 18 schematically shows an example in which the control device 16 is configured by a computer for either the first or second embodiment of the ophthalmic imaging device 10, which includes each embodiment that functions as a second ophthalmic imaging device 120.

[0090] The control device 16 is configured as a computer, with a CPU 16A, RAM 16B, ROM 16C, and input / output interface (I / O) 16H connected via bus 16J to exchange commands and data. The I / O 16H is also connected to a non-volatile memory 16D where various initial data is pre-stored, an operation unit 16E, a display 16F, and a communication unit 16G for data communication with external devices or a network 130. In this embodiment, the communication unit 16G communicates image data with an image server 140 or an image display terminal 150 via the network 130. Furthermore, the I / O 16H is connected to an SLO unit 18, a scanning device 19, and an OCT unit 20.

[0091] The display 16F is configured to include a device for displaying images and various information, and the operation unit 16E is configured to include input devices such as a keyboard and mouse for inputting data and commands used by the control device 16. The operation unit 16E and the display 16F may also be combined into hardware such as display buttons for receiving operation instructions and a touch panel display for displaying various information.

[0092] ROM 16C stores a fundus photography control program 16P that causes the control device 16 to perform fundus photography control. The fundus photography control program 16P has a processing function that captures the area around the central position of the fundus using the visual axis CL and obtains the peripheral image. In other words, the CPU 16A reads the fundus photography control program 16P from ROM 16C, loads it into RAM 16B, and executes the fundus photography control processing by the fundus photography control program 16P. By executing the fundus photography control processing, the ophthalmic imaging device 10 controlled by the control device 16 operates as the first ophthalmic imaging device 110. The fundus photography control program 16P may also be provided on a recording medium such as a CD-ROM.

[0093] The first ophthalmic imaging device 110 has the same configuration as the second ophthalmic imaging device 120, except for its function of capturing the central position of the fundus using the visual axis CL and obtaining the image; therefore, a detailed explanation will be omitted. When distinguishing between the first ophthalmic imaging device 110 and the second ophthalmic imaging device 120, the control device of the first ophthalmic imaging device 110 will be referred to as the control device 15. Furthermore, in this embodiment, to simplify the following explanation, it is assumed that the image of the central position of the fundus using the visual axis CL captured by the first ophthalmic imaging device 110 is acquired in advance, and that the acquired image is stored in the image server 140 in association with a patient ID indicating the patient of the eye being examined 12.

[0094] Although not shown in the diagram, the image server 140 includes a storage device for storing captured images associated with the patient ID, and has the function of storing captured images and outputting captured images that are retrieved using the patient ID as an identifier. The image server 140 also stores patient-related information such as the patient's name and the date of their visit, associated with the patient ID. In other words, the image server 140 is configured to be connectable to the first ophthalmic imaging device 110, the second ophthalmic imaging device 120, and the image display terminal 150, and is a server that has the function of exchanging data between the devices. The image server 140 is also a server that has the function of recording images taken by the first ophthalmic imaging device 110 and the second ophthalmic imaging device 120, shooting conditions, and patient data such as patient ID and name, as well as information related to the examination and diagnosis results.

[0095] The image display terminal 150 is a terminal on which image viewer software is installed to display patient information and images such as fundus images and retinal images of the patient, based on information from the image server 140. This image viewer also has an electronic medical record function. The electronic medical record function includes functions for inputting the doctor's diagnosis results, scheduling appointments, and outputting imaging instructions to the ophthalmic imaging equipment technician. Figure 19 schematically shows an example of an image display terminal 150 configured using a computer.

[0096] The image display terminal 150 is configured as a computer, with a CPU 151, RAM 152, ROM 153, and input / output interface (I / O) 158 connected via a bus 159 to exchange commands and data. The I / O 158 is also connected to a non-volatile memory 154 where various initial data is pre-stored, an operation unit 155, a display 156, and a communication unit 157 that communicates data with external devices or a network 130. In this embodiment, the communication unit 157 communicates image data with the image server 140 or the image display terminal 150 via the network 130.

[0097] The display 156 is configured to include a device for displaying images and various information, and the operation unit 155 is configured to include input devices such as a keyboard 155K and a mouse 155M for inputting data and commands used by the control device 16 (see Figure 17). The operation unit 155 and the display 156 may also be combined into hardware such as display buttons for receiving operation instructions and a touch panel display for displaying various information.

[0098] ROM 153 stores an image display program 153P that controls the image display terminal 150 to display fundus images. The image display program 153P has a processing function that combines the captured image of the first fundus image region 12G1 in the central part of the fundus and the captured image of the second fundus image region 12G2 surrounding the central part of the fundus to display a two-dimensional image 12G (details will be described later). The CPU 151 reads the image display program 153P from ROM 153, loads it into RAM 152, and executes the image display processing by the image display program 153P. As the CPU 151 executes the image display processing, the image display terminal 150 operates as a device that displays all two-dimensional images 12G of the captureable area 12A. The image display program 153P may also be provided on a recording medium such as a CD-ROM.

[0099] In this embodiment, the case in which the image display terminal 150 for displaying fundus images is configured independently of the first ophthalmic imaging device 110 and the second ophthalmic imaging device 120 is described. However, the image display terminal 150 may also be configured to serve as both the first ophthalmic imaging device 110 and the second ophthalmic imaging device 120.

[0100] Next, the operation of this embodiment will be explained. Figure 20 shows the processing flow of the image display program 153P executed on the image display terminal 150. The image display program 153P is executed by the CPU 151, for example, when the image display terminal 150 is powered on.

[0101] Figure 21 shows an example of a display screen that appears on the display 156 when the image display terminal 150 is powered on: the electronic medical record screen 200. The electronic medical record screen 200 includes a display area 201 for displaying patient information for the eye under examination 12, a display area 202 for displaying images of the first fundus image area 12G1 in the central part of the fundus, and a display area 204 for displaying images of the second fundus image area 12G2 surrounding the central part of the fundus. Adjacent to display area 202 is a display area 202A for displaying information indicating the model name of the first ophthalmic imaging device 110 that captures the first fundus image area 12G1, and an instruction button 203 for acquiring images by the first ophthalmic imaging device 110 is provided within display area 202. Adjacent to display area 204 is a display area 204A for displaying information indicating the model name of the second ophthalmic imaging device 120 that captures the second fundus image area 12G2, and an instruction button 205 for acquiring images by the second ophthalmic imaging device 120 is provided within display area 204. The electronic medical record screen 200 includes an instruction button 206 for fundus photography using the OCT function, an instruction button 207 for performing a diagnosis using artificial intelligence based on the image, and an instruction button 208 for various settings on screen 200.

[0102] First, in step S100 shown in Figure 20, the process of acquiring patient information is executed, and the acquired patient information is displayed on the display 156. Specifically, when the CPU 151 receives input of a patient ID from the user via the operation unit 155, it requests patient information associated with the patient ID from the image server 140, acquires the response information from the image server 140, and displays that patient information in the display area 201. Figure 21 shows an example of patient information in which the patient ID, patient name, and the date of the patient's last visit are acquired and displayed.

[0103] In the next step S102, the fundus images of the patient that have already been photographed are acquired and displayed on the electronic medical record in the next step S104. Specifically, when the CPU 151 receives input from the operation unit 155 to press the instruction button 203 for acquiring images taken by the first ophthalmic imaging device 110, it requests the image server 140 to retrieve the images taken by the first ophthalmic imaging device 110 associated with the patient ID, and retrieves the images in response from the image server 140 and displays them in the display area 202.

[0104] Figure 22 shows an example of an electronic medical record screen 210 in which an image 203G captured by the first ophthalmic imaging device 110 is displayed in the display area 202.

[0105] Next, in step S106 shown in Figure 20, the process of instructing the acquisition of an image of the second fundus image region 12G2, which is the periphery of the central part of the fundus, is executed, and a negative determination is made in step S108 until the acquisition is completed. If a positive determination is made in step S108, in step S110, an image of the fundus around the central part of the eye 12 of patient ID is acquired. In other words, when the CPU 151 receives input from the operation unit 155 to press the instruction button 205 for acquiring an image by the second ophthalmic imaging device 120, it outputs an instruction to the second ophthalmic imaging device 120 to photograph the fundus around the central part of the eye 12 of patient ID. The second ophthalmic imaging device 120 receives the instruction from the image display terminal 150, photographs the fundus around the central part of the eye 12 of patient ID, and outputs the captured image to the image display terminal 150. Furthermore, fundus photography of the central region of the eye under examination 12 and the output of the captured images may be processed via the image server 140.

[0106] Next, in step S112, image processing is performed to combine the image taken by the first ophthalmic imaging device 110 acquired in step S102 with the image taken by the second ophthalmic imaging device 120 acquired in step S110. In the next step S114, the image combined by the image processing is displayed in the display area 204 as all 2D images 12G of the captureable area 12A.

[0107] The synthesis process of the image 203G captured by the first ophthalmic imaging device 110 and the image 205G captured by the second ophthalmic imaging device 120 includes, for example, generating a three-dimensional image, cross-sectional image, and surface image of the retina using 3D data or scan data obtained from the OCT unit 20, and performing segmentation processing. Alternatively, fundus images may be generated using data obtained from each of the SLO units 18.

[0108] For example, when combining these images, image processing such as rotating or scaling the images can be performed so that the blood vessel patterns of each image overlap. The combined image will be a wide-angle image, as if it were taken with an ophthalmic device designed for wide-angle imaging with a field of view of 100 degrees. Needless to say, the image processing for combining the images is not limited to the method described above, and any known method may be used. The combined image is then stored in the image server 140.

[0109] Figure 23 shows an example of an electronic medical record screen 220 in which a two-dimensional image 12G is displayed in the display area 204, which is a composite of an image 203G taken by the first ophthalmic imaging device 110 and an image 205G taken by the second ophthalmic imaging device 120.

[0110] As described above, in the third embodiment, by combining the image of the center of the fundus and the image of the area surrounding the central part of the fundus, and obtaining a complete two-dimensional image 12G of the captureable region 12A, it is possible to obtain a wide-angle image, as if it were taken with an ophthalmic device for wide-angle image capture with a shooting angle of view of, for example, 100 degrees.

[0111] The image system 100 according to the third embodiment functions suitably when an ophthalmologist observes and diagnoses the fundus of a subject eye 12. That is, a diagnosis is made based on the fundus image synthesized by the image system 100 according to the third embodiment, and the diagnosis results are entered using the electronic medical record function of the image viewer. Furthermore, when performing AI diagnosis on the fundus image C, the system switches to AI diagnosis mode by pressing / clicking button V14 via an interface not shown. Also, if an OCT image is required for diagnosis, the system switches to OCT mode by pressing / clicking button V13. Ophthalmologists can accurately diagnose the central part of the fundus, including the optic nerve head and macula, using high-resolution central fundus images with a 30-degree field of view, and can also accurately determine whether or not there are lesions in the peripheral retina using a composite fundus image C equivalent to a 100-degree field of view. On the other hand, ophthalmologists often possess ophthalmic equipment for diagnosing using high-resolution images of the fundus and retina. However, this high-resolution ophthalmic equipment has a field of view in the range of 10 to 30 degrees, making it difficult to photograph the peripheral areas of the fundus and retina beyond this range. Therefore, ophthalmologists need to purchase wide-angle and ultra-wide-angle fundus equipment separately for the peripheral areas of the fundus and retina. In contrast, by using the image system 100 according to the third embodiment, it is possible to effectively utilize existing high-resolution ophthalmic equipment without purchasing new wide-angle and ultra-wide-angle fundus equipment, and to diagnose the central area of ​​the fundus and retina using high-resolution images. Furthermore, the peripheral areas of the fundus and retina can be diagnosed using the combined fundus image with a wide field of view exceeding 100 degrees.

[0112] In the above explanation, the field of view α of ophthalmic device 1 (first ophthalmic imaging device 110) was assumed to be 30 degrees and the field of view β of peripheral imaging ophthalmic device 2 (second ophthalmic imaging device 120) was assumed to be 30 to 100 degrees. However, the field of view of peripheral imaging ophthalmic device 2 can be set to suit the field of view of ophthalmic device 1, not limited to this. For example, Ophthalmic equipment: 45-degree field of view. Peripheral imaging ophthalmic equipment 2: 45-100 degrees field of view. Ophthalmic equipment field of view: 55 degrees; Peripheral imaging ophthalmic equipment 2 field of view: 55-120 degrees The field of view of the peripheral imaging ophthalmic device 2 can be designed using such combinations. While the maximum field of view of the peripheral imaging ophthalmic device 2 is set at 120 degrees, it is possible to adjust the optical system to achieve a field of view greater than 120 degrees. The design can be modified to accommodate various field of view to meet the needs of ophthalmologists. Also, considering the image processing process, The field of view for the ophthalmic equipment is 30 degrees, and the field of view for the peripheral imaging ophthalmic equipment 2 is 25-80 degrees. The field of view for the ophthalmic equipment is 45 degrees, and the field of view for the peripheral imaging ophthalmic equipment 2 is 40-100 degrees. The field of view for the ophthalmic equipment is 55 degrees, and the field of view for the peripheral imaging ophthalmic equipment 2 is 45-120 degrees. In such a combination, the outer periphery of the circular imaging area by ophthalmic device 1 and the inner periphery of the annular imaging area by peripheral imaging ophthalmic device 2 may be set to overlap.

[0113] In the embodiments described above, a polygon mirror or a galvanometer mirror was given as an example of the first optical scanner 22, the second optical scanner 24, and the third optical scanner 29, but the invention is not limited thereto. For example, other optical elements capable of scanning the scanning light in the Y direction may be used, such as a MEMS (Micro-electromechanical system) mirror, a rotating mirror, a prism, or a resonant mirror.

[0114] Furthermore, it goes without saying that the same scanning can be performed even if the X and Y directions are swapped in the scanning device described in each of the above embodiments.

[0115] Furthermore, in optical systems that enable ultra-wide-angle imaging in the peripheral region, stray light can be prevented by providing a light-shielding surface in the central region including the optical axis. By limiting the illumination area of ​​the scanning light from the SLO unit 18 and OCT unit 20 to the annular region of the imaging field, stray light can be reduced.

[0116] Furthermore, although the disclosed technology has been described using embodiments, the technical scope of the disclosed technology is not limited to the scope described in the embodiments above. Various modifications or improvements can be made to the embodiments above without departing from the gist of the disclosed technology, and such modified or improved forms are also included in the technical scope of the disclosed technology. In addition, all documents, patent applications and technical standards described herein are incorporated by reference to the same extent as if each individual document, patent application and technical standard were specifically and individually noted as being incorporated by reference. [Explanation of Symbols]

[0117] 10. Ophthalmic imaging equipment 12. Eye to be examined 12A Imaging area 12A1 First imaging area 12A2 Second imaging area 16 Control device 19 Scanning device 28 Common optical system 28A Optical System A External illumination angle

Claims

1. A scanning unit that scans light from a light source over the eye to be examined, The system comprises a first optical system and a second optical system, which are arranged sequentially on the same optical axis from the scanning unit toward the eye under examination, The first optical system and the second optical system are ophthalmic devices that form a pupil-conjugate position opposite to the eye under examination, which is conjugate to the position of the pupil of the eye under examination. The first optical system includes a first lens having positive refractive power and a second lens having negative refractive power, and forms an image of a predetermined area of ​​the eye under examination. The second optical system has a first aperture formed around the optical axis of the ophthalmic device and a first reflective surface that reflects light from the eye under examination, and a second aperture formed around the optical axis of the ophthalmic device and a second reflective surface that reflects the light reflected from the first reflective surface away from the eye under examination. The first optical system is an ophthalmic device that forms an image of the peripheral portion of the predetermined region by the light that passes through the second aperture, is reflected by the first reflective surface, is reflected by the second reflective surface and passes through the first aperture.

2. An ophthalmic device according to claim 1, The shape of the peripheral image is an annular shape centered on the optical axis of the ophthalmic device. Ophthalmology equipment.

3. An ophthalmic device according to claim 2, The image of a predetermined region including the optical axis obtained by the first optical system and the annular shape image of the peripheral part of the predetermined region obtained by the second optical system overlap, including their boundary. Ophthalmology equipment.

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