Ophthalmic device

Abstract

An ophthalmic apparatus includes an objective lens, an illumination optical system, an optical scanner, a light receiving optical system, and a pupil dividing member. The illumination optical system includes an illumination aperture in which one or more openings are formed at positions offset from an optical axis, and irradiates slit-shaped illumination light. The light scanner deflects the illumination light and directs the illumination light to the examined eye by means of the objective lens. The light receiving optical system guides return light of the illumination light from the subject eye through the objective lens to the image sensor. The pupil dividing member includes an imaging aperture in which one or more openings are formed at a position offset from the optical axis, and spatially separates an optical path of the illumination optical system from an optical path of the light receiving optical system.

Description

Technical Field

[0001] This disclosure relates to ophthalmic devices. Background Technology

[0002] In recent years, screening using ophthalmic devices has become increasingly common. These devices are also expected to be used for self-examination, with further miniaturization and weight reduction anticipated.

[0003] U.S. Patent Nos. 7,831,106 and 8,237,835 disclose an ophthalmic device configured to pattern illuminate the fundus of an examined eye using a slit-shaped illumination light and detect the reflected light using an image sensor. This ophthalmic device, by adjusting the illumination pattern and the timing of illumination based on the image sensor, can acquire clear fundus images with a simple structure.

[0004] In such an ophthalmic device, illumination light needs to pass through the pupil of the eye being examined and enter the eye, while reflected light from the fundus (return light, fundus reflected light) needs to pass through the pupil and exit. Therefore, in the ophthalmic device, at a position approximately optically conjugate to the pupil of the eye being examined, the image of the illumination opening through which the illumination light passes is separated from the image of the light-receiving opening (image capture opening) through which the reflected light passes.

[0005] International Publication No. 2021 / 205965 discloses an ophthalmic device that illuminates the fundus using slit-shaped illumination light passing through two illumination openings and receives reflected light from the fundus passing through a single light-receiving opening. In this ophthalmic device, slit-shaped illumination light is generated by irradiating the illumination light into a slit formed to suppress glare.

[0006] Japanese Patent Application Publication No. 2020-6172 discloses an ophthalmic device configured to offset the alignment reference position relative to the eye being examined according to the size of the pupil diameter, thereby housing the image of the illumination opening and the image of the light receiving opening within the pupil of the eye being examined. Summary of the Invention

[0007] One embodiment is an ophthalmic device comprising: an objective lens; an illumination optics system including an illumination aperture disposed at a position substantially optically conjugate to the pupil of the eye being examined and having one or more openings formed at a position offset from the optical axis, the illumination optics system illuminating slit-shaped illumination light; a light scanner disposed at a position substantially optically conjugate to the pupil and deflecting the illumination light to guide it to the eye being examined via the objective lens; a light-receiving optics system guiding the return light from the illumination light of the eye being examined through the objective lens to an image sensor disposed at a position substantially optically conjugate to the imaging portion of the eye being examined; and a pupil splitting component including an imaging aperture disposed at a position substantially optically conjugate to the pupil and having one or more openings formed at a position offset from the optical axis, the pupil splitting component spatially separating the optical paths of the illumination optics system from the optical paths of the light-receiving optics system. Attached Figure Description

[0008] Figure 1 This is a schematic diagram illustrating an example of the structure of the optical system of an ophthalmic device according to an embodiment.

[0009] Figure 2 This is a schematic diagram illustrating an example of the structure of the optical system of an ophthalmic device according to an embodiment.

[0010] Figure 3 This is a schematic diagram illustrating an example of the structure of the optical system of an ophthalmic device according to an embodiment.

[0011] Figure 4 This is a schematic diagram illustrating the structure of the optical system of the ophthalmic device used to explain the implementation method.

[0012] Figure 5 This is a diagram illustrating the operation of the ophthalmic device according to the implementation method.

[0013] Figure 6 This is a diagram illustrating the operation of the ophthalmic device according to the implementation method.

[0014] Figure 7 This is a diagram illustrating the operation of the ophthalmic device according to the implementation method.

[0015] Figure 8 This is a schematic diagram illustrating the structure of the optical system of the ophthalmic device used to explain the implementation method.

[0016] Figure 9 This is a schematic diagram illustrating the structure of the optical system of the ophthalmic device used to explain the implementation method.

[0017] Figure 10 This is a schematic diagram illustrating the structure of the optical system of the ophthalmic device used to explain the implementation method.

[0018] Figure 11This is a schematic diagram illustrating a structural example of the processing system of an ophthalmic device according to an embodiment.

[0019] Figure 12 This is a flowchart illustrating an example of the operation of an ophthalmic device according to an embodiment.

[0020] Figure 13A This is a diagram illustrating the operation of the ophthalmic device according to the implementation method.

[0021] Figure 13B This is a diagram illustrating the operation of the ophthalmic device according to the implementation method.

[0022] Figure 14A This is a schematic diagram illustrating the structure of an optical system of an ophthalmic device according to a first variation of the embodiment.

[0023] Figure 14B This is a schematic diagram illustrating the structure of the optical system of the ophthalmic device in the first modified embodiment of the implementation.

[0024] Figure 15 This is a schematic diagram illustrating the structure of an optical system of an ophthalmic device according to a second variation of the embodiment.

[0025] Figure 16 This is a schematic diagram illustrating the structure of the optical system of an ophthalmic device according to a third variation of the embodiment.

[0026] Figure 17A This is a schematic diagram used to illustrate conventional ophthalmic devices.

[0027] Figure 17B This is a schematic diagram used to illustrate conventional ophthalmic devices.

[0028] Figure 17C This is a schematic diagram used to illustrate conventional ophthalmic devices.

[0029] (Explanation of reference numerals in the attached diagram)

[0030] 1 Ophthalmic device

[0031] 10 Light Source

[0032] 20 Illumination Optical System

[0033] 21. Iris aperture

[0034] 22 Cracks

[0035] 30 light scanners

[0036] 35 Projection Optical System

[0037] 40. Camera optical system

[0038] 41, 43, 48 relay lenses

[0039] 42 Reflectors

[0040] 45 Pupil Segmentation Components

[0041] 46 Objective lens

[0042] 47 Focusing Lens

[0043] 49 Imaging Lenses

[0044] 50 camera devices

[0045] 51 Image Sensor

[0046] 100 Control Department

[0047] 101 Main Control Unit

[0048] 102 Storage Department

[0049] 200 Image forming unit

[0050] E. Examined eye

[0051] Ef fundus

[0052] Eu pupil. Detailed Implementation

[0053] In ophthalmic devices disclosed in U.S. Patent No. 7,831,106, U.S. Patent No. 8,237,835, and International Publication No. 2021 / 205965, there is a problem of central ghosting (objective lens glare) or black dot shadows caused by black dot plates configured to suppress central ghosting when photographing small pupil eyes with small pupil diameters.

[0054] exist Figures 17A-17C The diagram shows a schematic illustration of the process of taking a picture of the fundus of the examined eye using conventional ophthalmic equipment. Figure 17A This is a schematic diagram illustrating the illumination beam and imaging beam used when photographing the fundus of the examined eye. Figure 17B This is an example of a fundus image depicting the central ghostly figure as an artifact. Figure 17C This is an example of a fundus image depicting a black dot shadow as an artifact. Furthermore, Figure 17B and Figure 17C An example is shown where the fundus is illuminated using illumination light passing through two illumination openings, and the resulting fundus image is formed based on the illumination result of photographic light passing through a single light-receiving opening.

[0055] like Figure 17AAs shown, the illumination beam IL, which illuminates the fundus of the examined eye, passes through the objective lens OBJ positioned on the optical axis O, and is guided to the fundus through the pupil of the examined eye. The reflected beam of the illumination beam IL, which is the imaging beam SL, passes through the pupil and exits from inside the eye. It then passes through the objective lens OBJ and is guided to the light-receiving optical path (imaging optical path).

[0056] At a position roughly optically conjugate to the pupil of the examined eye, the illumination beam IL and the imaging beam SL are separated. However, when the examined eye has a small pupil, the illumination beam IL, passing through the pupil and entering the eye, is close to the imaging beam SL near the optical axis. As a result, reflected light from the lens surface SF (the lens surface near the lens apex) on the optical axis O of the objective lens OBJ easily enters the receiving light path, becoming the main cause of the central ghost image, which is an artifact. At this time, as... Figure 17B As shown, central ghost images CG1 and CG2 corresponding to the two illumination openings are depicted in the fundus image IMG10 of the examined eye. Each of the regions of central ghost images CG1 and CG2 is an area where fundus information is completely lost.

[0057] Therefore, in ophthalmic devices, a black dot plate is typically placed in the illumination path at a position approximately optically conjugate to the apex of the objective lens OBJ. This blocks reflected light from the lens surface SF of the objective lens OBJ, preventing the reflected light, which is the primary cause of the central ghost image, from being guided into the receiving light path. However, when the examined eye is highly myopic, sometimes the position optically conjugate to the fundus shifts, producing a black dot shadow as an artifact caused by the black dot plate. In this case, as... Figure 17C As shown, black dot shadows BS1 and BS2 corresponding to the two illumination openings are depicted in the fundus image IMG11 of the examined eye. Each of the regions of black dot shadows BS1 and BS2 is a region where black spots are formed and fundus information is completely lost.

[0058] On the other hand, the method disclosed in Japanese Patent Application Publication No. 2020-6172 allows for a structure that does not require a black dot plate. However, when the eye being examined has a small pupil, the alignment reference position needs to be changed, which complicates the control process.

[0059] As mentioned above, conventional methods suffer from the following problems: when the examined eye has a small pupil, the image quality of the fundus image is degraded due to the depiction of a central ghost image or black dot, resulting in the loss of at least a portion of the fundus information in the imaged area, or complicating the control process to avoid using a black dot plate. These problems exist not only when the imaged area is the fundus but also when the imaged area is inside the eye.

[0060] According to embodiments of the present invention, a new technique can be provided that avoids loss of intraocular information and properly achieves small pupil imaging without complicating control.

[0061] An example of an embodiment of the ophthalmic device of the present invention will be described in detail with reference to the accompanying drawings. Furthermore, the contents of the documents described in this specification may be appropriately referenced as part of the following embodiments.

[0062] The ophthalmic device of this embodiment includes an objective lens, an illumination optics system, a light scanner, a light-receiving optics system (imaging optics system), and a pupil segmentation component. The illumination optics system includes an illumination aperture positioned approximately optically conjugate to the pupil of the eye being examined, and is configured to illuminate a slit-shaped illumination beam. One or more openings (illumination openings) are formed in the illumination aperture at positions offset from the optical axis of the illumination optics system. The light scanner is configured to be positioned approximately optically conjugate to the pupil of the eye being examined, and deflects the illumination light emitted from the illumination optics system and guides it to the eye being examined via the objective lens. The light-receiving optics system is configured to guide the return light from the illumination light of the eye being examined, after passing through the objective lens, to an image sensor positioned approximately optically conjugate to the imaging site (e.g., fundus) of the eye being examined. The pupil segmentation component includes an imaging aperture positioned approximately optically conjugate to the pupil of the eye being examined, and spatially separates the optical paths of the illumination optics system and the light-receiving optics system. In the shooting aperture, one or more openings (light-receiving opening, shooting opening) are formed at a position deviating from the optical axis of the light-receiving optical system.

[0063] The reflected light from the imaging site is the scattered light (reflected light) of the illumination light from the imaging site that is illuminated by the illumination light incident on the eye being examined. In some embodiments, the reflected light from the imaging site includes the scattered light (reflected light) of the illumination light from the imaging site and the fluorescence and its scattered light that uses the illumination light incident on the imaging site as excitation light.

[0064] The shape of one or more openings formed in the illumination aperture can be arbitrary. The shape of one or more openings formed in the imaging aperture can be arbitrary. In some embodiments, the illumination optics system includes a light scanner. In some embodiments, the light-receiving optics system includes an image sensor.

[0065] With this structure, the illumination light and the return light (imaging light) can be spatially separated on the lens surface and inside the lens of the objective lens. As a result, reflected light from the lens surface of the objective lens, which is the main cause of central ghosting (objective lens glare), can be prevented from entering the optical path of the light-receiving optical system. Therefore, a black dot plate is not required, and images of the examined eye that do not produce black spots caused by black dot shadows (without loss of intraocular information such as fundus information) can be acquired. In addition, even when imaging small pupil eyes, intraocular images of the examined eye that can be appropriately diagnosed for small pupil eyes can be acquired without complicating control.

[0066] In some embodiments, the image sensor is configured to acquire the illumination result in a virtual opening area of ​​the illuminated surface in a rolling shutter manner, the virtual opening area of ​​the illuminated surface corresponding to the illumination area at the shooting location where the illumination light moves in a predetermined scanning direction by the light scanner.

[0067] Therefore, when photographing eyes with small pupils, it is possible to obtain clear intraocular images unaffected by unwanted scattered light without complicating the control process.

[0068] In some embodiments, to ensure that the pupil separation amount in the pupil conjugate plane at a position approximately optically conjugate to the pupil of the examined eye is greater than a predetermined central ghost image suppression threshold, one or more openings are formed in the illumination aperture and one or more openings in the imaging aperture. Here, the pupil separation amount is the shortest distance in the alignment direction (separation direction) between the images formed in the one or more openings of the illumination aperture and the images formed in the one or more openings of the imaging aperture. Furthermore, the alignment direction is the direction in which the distance between the ends of the images formed in the one or more openings of the illumination aperture and the ends of the images formed in the one or more openings of the imaging aperture in the pupil conjugate plane is the shortest distance.

[0069] Therefore, the illumination beam and the imaging beam can be reliably separated on the lens surface and inside the lens of the objective lens, and the generation of central ghost images can be reliably suppressed. As a result, diagnostic intraocular images can be acquired without the need for a black dot plate.

[0070] In some implementations, the illumination aperture and the shooting aperture are formed with the pupil separation amount being less than a predetermined small pupil shooting threshold.

[0071] Therefore, the generation of central ghost images can be reliably suppressed when photographing small pupil eyes. As a result, diagnostic intraocular images can be obtained without setting up a black dot plate when photographing small pupil eyes.

[0072] In some embodiments, the ophthalmic device illuminates a predetermined area of ​​the eye being examined while moving the illumination position (illumination area, illumination range) of a slit-shaped illumination light, and receives the reflected light from the predetermined area using an image sensor with one-dimensional or two-dimensionally arranged light-receiving elements. Synchronously with the movement of the illumination position, the light-receiving result of the reflected light is read from the light-receiving element at the light-receiving position corresponding to the illumination position. In some embodiments, the predetermined area is the anterior or posterior part of the eye. The anterior part includes the cornea, iris, lens, ciliary body, ciliary band, etc. The posterior part includes the vitreous body, fundus, or surrounding tissues (retina, choroid, sclera, etc.).

[0073] The control method of the ophthalmic device of the embodiment includes one or more steps performed in the control of the ophthalmic device of the embodiment. The program (computer program) / commands of the embodiment cause a computer (processor) to execute each step of the control method of the ophthalmic device of the embodiment. The computer program product of the embodiment includes a computer program / command. When the processor executes the computer program / command, the computer program product implements each step of the control method of the ophthalmic device of the embodiment. The recording medium of the embodiment is a computer-readable non-transitory storage medium (recording medium) that records (stores) the program of the embodiment. The computer-readable storage medium of the embodiment stores the computer program / command. When the processor executes the computer program / command, the computer-readable storage medium implements each step of the control method of the ophthalmic device of the embodiment.

[0074] In this specification, "processor" refers to circuits such as CPU (Central Processing Unit), GPU (Graphics Processing Unit), ASIC (Application Specific Integrated Circuit), and programmable logic devices (e.g., SPLD (Simple Programmable Logic Device), CPLD (Complex Programmable Logic Device), FPGA (Field Programmable Gate Array). A processor implements the functions of an embodiment, for example, by reading and executing a program stored in a storage circuit or storage device. The processor may include a storage circuit or storage device. Furthermore, the storage circuit or storage device may be located externally to the processor.

[0075] The following describes the case where the imaging site is the fundus of the eye. However, the following implementation method can also be applied when the imaging site is a site other than the fundus of the eye.

[0076] Furthermore, the following description addresses the case where both the illumination aperture and the shooting aperture have a single opening. However, the following implementation method can also be applied when at least one of the illumination aperture and the shooting aperture has two or more openings.

[0077] [Structure of an optical system]

[0078] exist Figures 1-3 A schematic diagram of the structure of the optical system of the ophthalmic device according to an embodiment is shown. Figure 1 An example of the structure of the optical system of the ophthalmic device according to an embodiment is shown. Figure 1 The diagram shows the optical conjugate position P of the fundus Ef of the examined eye E and the optical conjugate position Q of the pupil (iris) Eu of the examined eye E. Figure 2 The diagram schematically illustrates the view when viewed from the direction of optical axis O. Figure 1 Example of the structure of iris aperture 21. Figure 3 It is schematically shown by combining the side view viewed from a direction orthogonal to the optical axis O with the front view viewed from the direction of the optical axis O. Figure 1 The diagram shows the pupil segmentation component 45. Figures 1-3 In the accompanying drawings, the same reference numerals are used to label the same parts, and descriptions are omitted where appropriate.

[0079] The ophthalmic device 1 of the embodiments includes a light source 10, an illumination optics system 20, a light scanner 30, a projection optics system 35, an imaging optics system 40, and an imaging device 50. In some embodiments, the illumination optics system 20 includes at least one of the light source 10, the light scanner 30, and the projection optics system 35. In some embodiments, the imaging optics system 40 includes the imaging device 50. In some embodiments, the projection optics system 35 includes the light scanner 30.

[0080] (Light source 10)

[0081] Light source 10 includes a visible light source that generates light in the visible region. For example, light source 10 generates light with a center wavelength in the wavelength range of 420 nm to 700 nm. Such light source 10 includes, for example, an LED (Light Emitting Diode), an LD (Laser Diode), a halogen lamp, or a xenon lamp. In some embodiments, light source 10 includes a white light source or a light source capable of outputting light of each color component of RGB. In some embodiments, light source 10 includes a light source capable of switching between outputting light in the infrared region and light in the visible region. For example, light source 10 is positioned at a location that is not optically conjugate to either the retina (Ef) or the iris.

[0082] (Illumination Optical System 20)

[0083] The illumination optics system 20 uses light from the light source 10 to generate slit-shaped illumination light. The illumination optics system 20 guides the generated illumination light to the light scanner 30.

[0084] The illumination optical system 20 includes an iris aperture 21, a slit 22, and a relay lens 23. Light from the light source 10 passes through an opening (one or more openings) formed in the iris aperture 21, through an opening formed in the slit 22, and through the relay lens 23. The relay lens 23 includes one or more lenses. The light transmitted through the relay lens 23 is guided to the light scanner 30.

[0085] (Iris aperture 21)

[0086] The iris aperture 21 (specifically, the opening described later) can be configured as an illumination aperture at a position approximately optically conjugate to the iris (pupil) Eu of the examined eye E (pupil (iris) conjugate position Q or its vicinity). More than one opening (illumination opening) is formed in the iris aperture 21 at a position offset from the optical axis O. In this embodiment, a single opening is formed in the iris aperture 21 at a position offset from the optical axis O.

[0087] For example, such as Figure 2 As shown, a quadrilateral opening 21A is formed in the iris aperture 21 at a position offset from the optical axis O of the illumination optics system 20. The shape of the opening 21A can be rectangular or parallelogram. Alternatively, the shape of the opening 21A can be triangular, a polygon with more than one pentagon, elliptical, or circular. The opening formed in the iris aperture 21 defines the incident position (incident shape) of the illumination light in the iris (pupil) Eu of the examined eye E. For example, as... Figure 2 As shown, by forming an opening 21A, when the center of the pupil of the examined eye E is positioned on the optical axis O, the illumination light can enter the eye from a position offset from the center of the pupil.

[0088] Furthermore, by changing the relative position between the light source 10 and the opening formed in the iris aperture 21, the light intensity distribution passing through the opening formed in the iris aperture 21 can be altered. For example, the relative position between the light source 10 and the opening formed in the iris aperture 21 can be changed based on the refractive power of the examined eye E or image quality evaluation information of at least a portion of the fundus image obtained by the ophthalmic device 1.

[0089] (Crack 22)

[0090] The slit 22 (specifically, the opening described later) can be positioned approximately optically conjugate to the fundus Ef of the examined eye E (fundus conjugate position P or its vicinity). A single slit-shaped (linear) opening (slit opening) is formed in the slit 22. For example, the opening is formed in the slit 22 in a direction corresponding to the line direction (row direction) read from the image sensor 51 in a rolling shutter manner. For example, the opening is formed in the slit 22 such that the direction orthogonal to the direction of movement of the light-receiving range (virtual opening range) of the reflected light at the light-receiving surface of the image sensor 51 is the slit direction (long side direction of the slit). The opening formed in the slit 22 defines the illumination pattern of the illumination light in the fundus Ef of the examined eye E.

[0091] The slit 22 can be moved along the optical axis of the illumination optical system 20 via a moving mechanism (moving mechanism 22D described later). The moving mechanism is controlled by the control unit 100 described later to move the slit 22 along the optical axis. For example, the control unit 100 controls the moving mechanism according to the state of the examined eye E. Thus, the position of the slit 22 can be moved according to the state of the examined eye E (specifically, the refractive power and the shape of the fundus Ef).

[0092] In some embodiments, the slit 22 is configured to change at least one of its position and shape without moving in the optical axis direction, depending on the state of the examined eye E. Such a function of the slit 22 is achieved, for example, by a liquid crystal shutter.

[0093] Light from the light source 10, passing through the opening formed in the iris aperture 21, passes through the opening formed in the slit 22, thus outputting as slit-shaped illumination light. The slit-shaped illumination light is guided to the light scanner 30 through the relay lens 23.

[0094] (Optical Scanner 30)

[0095] The light scanner 30 (specifically, the deflecting surface) is positioned approximately optically conjugate to the pupil (iris) Eu of the examined eye E (pupil (iris) conjugate position Q or its vicinity). The light scanner 30 deflects the slit-shaped illumination light (slit-shaped light passing through the opening formed in the slit 22) that has passed through the relay lens 23. Specifically, the light scanner 30 uses the pupil (iris) Eu of the examined eye E or its vicinity as the scanning center position, and while changing the deflection angle within a predetermined deflection angle range, it deflects the slit-shaped illumination light and guides the deflected illumination light to the projection optical system 35. As a result, a predetermined illumination area in the fundus Ef is sequentially illuminated by the slit-shaped illumination light.

[0096] The optical scanner 30 can deflect the illumination light in one or two dimensions. In one-dimensional deflection, the optical scanner 30 includes a galvanometer scanner that deflects the illumination light within a predetermined deflection angle range, with a predetermined deflection reference direction as a reference. In two-dimensional deflection, the optical scanner 30 includes a first galvanometer scanner and a second galvanometer scanner. The first galvanometer scanner deflects the illumination light in a manner that moves the illumination position of the illumination light in a horizontal direction orthogonal to the optical axis of the illumination optical system 20. The second galvanometer scanner deflects the illumination light deflected by the first galvanometer scanner in a manner that moves the illumination position of the illumination light in a vertical direction orthogonal to the optical axis of the illumination optical system 20. Examples of scanning methods for moving the illumination position of the illumination light by the optical scanner 30 include horizontal scanning, vertical scanning, cross scanning, radial scanning, circular scanning, concentric circle scanning, and spiral scanning.

[0097] (Projection Optical System 35)

[0098] The projection optics system 35 guides the illumination light deflected by the light scanner 30 to the fundus Ef of the examined eye E. In this embodiment, the projection optics system 35 guides the illumination light deflected by the light scanner 30 to the fundus Ef via an optical path based on the optical path coupling between the pupil segmentation member 45 (described later) and the imaging optics system 40.

[0099] The projection optical system 35 includes a relay lens 41, a reflector 42, and a relay lens 43. Each of the relay lenses 41 and 43 includes more than one lens.

[0100] In the projection optical system 35, the illumination light deflected by the light scanner 30 passes through the relay lens 41, is reflected by the mirror 42, passes through the relay lens 43, and is guided to the pupil division component 45.

[0101] In some embodiments, the illumination optical system 20 is configured to include a light scanner 30 and a projection optical system 35.

[0102] (Filming optical system 40)

[0103] The imaging optical system 40 guides the illumination light from the projection optical system 35 to the fundus Ef of the examined eye E, and guides the return light from the illumination light from the fundus Ef to the imaging device 50.

[0104] In the imaging optical system 40, the optical path of the illumination light from the projection optical system 35 is coupled with the optical path of the return light of the illumination light from the fundus Ef. By using the pupil splitting member 45 as an optical path coupling member to couple these optical paths, the optical path of the illumination light and the optical path of its return light can be spatially split (pupil splitting) at the pupil conjugate surface at a position optically conjugate with the pupil Eu of the examined eye E.

[0105] The imaging optical system 40 includes a pupil divider 45, an objective lens 46, a focusing lens 47, a relay lens 48, and an imaging lens 49. The relay lens 48 includes one or more lenses.

[0106] (Pupil segmentation component 45)

[0107] The pupil splitting component 45 includes an imaging aperture that spatially separates the optical path of the illumination optics system 20 (the optical path of the illumination light from the projection optics system 35) from the optical path of the imaging optics system 40. In this embodiment, the pupil splitting component 45 is a mirror with an imaging aperture. The imaging aperture is positioned optically conjugate to the pupil Eu of the examined eye E (pupil conjugate position Q or nearby), and has one or more openings (light-receiving opening, imaging opening) at positions offset from the optical axis of the imaging optics system 40. In this embodiment, a single opening is formed in the imaging aperture. Furthermore, the pupil splitting component 45 includes a mirror that deflects the illumination light deflected by the light scanner 30 toward the examined eye E (specifically, the objective lens 46).

[0108] The pupil splitting component 45 couples the optical path of the illumination light from the projection optical system 35 (illumination optical system 20) to the optical path of the imaging optical system 40 in a substantially coaxial manner. Therefore, the optical axis of the common optical path of the illumination light and the return light in the imaging optical system 40 is substantially coincident with the optical axis O of the illumination optical system 20.

[0109] Or, for example Figure 3 As shown, the pupil segmentation component 45 includes a substrate 45a and a reflective component 45b. At this time, one or more openings (light-receiving opening, imaging opening) are formed in the substrate 45a, for example. Figure 3 In the structure shown, one or more openings formed in the substrate 45a function as an imaging aperture. In this embodiment, a single opening 45A is formed in the substrate 45a. The reflective component 45b deflects the illumination light from the projection optics system 35 toward the objective lens 46.

[0110] In some embodiments, the substrate 45a includes a shooting aperture with a single opening 45A.

[0111] exist Figure 3 In this system, a reflective element 45b is provided on the surface of the substrate 45a. An opening 45A is provided in both the substrate 45a and the reflective element 45b at a position offset from the optical axis O of the imaging optical system 40. For example, the pupil dividing member 45 may be a aperture lens in which the reflective element 45b is provided around the opening 45A formed as an imaging aperture. For example, the reflective element 45b may be provided in the pupil dividing member 45 around the opening 45A formed by the imaging aperture provided in the substrate 45a.

[0112] In some embodiments, a reflective element 45b is formed by depositing a reflective film onto the surface of the substrate 45a. The reflective film can be a metal film or a dielectric multilayer film. The reflective film is formed by depositing (mirror evaporation) a metal film onto the surface of the substrate 45a, or by depositing a multilayer dielectric film onto the surface of the substrate 45a.

[0113] In some embodiments, the substrate 45a may be a transparent component. In this case, it is sufficient that an opening 45A is formed in the reflective component 45b disposed on the surface of the substrate 45a.

[0114] When the optical system is aligned with the examined eye E, the pupil segmentation member 45 is positioned at a location corresponding to the optical axis O, approximately optically conjugate to the pupil Eu of the examined eye E. At this time, the illumination light from the projection optical system 35 is reflected by the reflecting member 45b and guided to the objective lens 46. The returned illumination light from the examined eye E passes through the opening 45A and is guided to the imaging optical system 40. In this embodiment, the pupil segmentation member 45, at a position approximately optically conjugate to the pupil of the examined eye E, spatially separates the illumination light from the returned light from the examined eye.

[0115] exist Figure 4 The diagram illustrates the pupil conjugate surface of the embodiment. Figure 4 This is a schematic diagram showing the image IPI of the illumination opening and the image SPI of the light-receiving opening in the pupil conjugate plane PL. Figure 4 In the middle, to and Figures 1-3 The same reference numerals are used for the same parts, and descriptions are omitted where appropriate.

[0116] Pupil segmentation is performed by the pupil segmentation component 45, thereby spatially separating the image of the opening of the iris aperture 21 (i.e., the illumination opening image IPI) and the image of the opening of the shooting aperture (pupil segmentation component 45) (i.e., the light-receiving opening image SPI) in the pupil conjugate plane PL. At this time, the illumination opening image IPI and the light-receiving opening image SPI are separated by a pupil separation amount GP, which is equivalent to the shortest distance between the illumination opening image IPI and the light-receiving opening image SPI in the alignment direction (separation direction).

[0117] By increasing the pupil separation amount GP, the overlap of the beam cross-sections of the illumination light and the return light in the lens surface or inside the objective lens 46 can be reliably avoided, and the generation of central ghosting can be suppressed without setting a black dot plate. Therefore, it is preferable to form an opening 21A (or more than one opening) in the iris aperture 21 and an opening 45A (or more than one opening) in the pupil separation member 45 (shooting aperture) in such a way that the pupil separation amount GP is greater than a predetermined central ghosting generation suppression threshold.

[0118] At this time, as Figure 3As shown, preferably, the pupil separation amount GP is kept approximately constant in a direction orthogonal to the alignment direction, with an opening 21A (or one or more openings) formed in the iris aperture 21 and an opening 45A (or one or more openings) formed in the pupil division member 45. The alignment direction is the alignment direction of the image formed in the pupil conjugate plane by the opening 21A (or one or more openings) in the iris aperture 21 and the image formed in the pupil division member 45 by the opening 45A (or one or more openings). Therefore, increasing the size of the openings 21A and 45A maximizes the pupil separation amount GP while ensuring sufficient light intake.

[0119] On the other hand, if the pupil separation amount GP is increased, the size of the pupil diameter that can be photographed becomes larger, and small pupil eyes cannot be photographed. Therefore, it is preferable to form an opening 21A (or more than one opening) in the iris aperture 21 and an opening 45A (or more than one opening) in the pupil separation member 45 (shooting aperture) in such a way that the pupil separation amount GP is less than a predetermined small pupil shooting threshold.

[0120] The suppression threshold for the central ghost image and the camera threshold for small pupils will be discussed later.

[0121] (Focusing lens 47)

[0122] The focusing lens 47 can be moved along the optical axis of the imaging optical system 40 via a moving mechanism (not shown). The moving mechanism is controlled by the control unit 100 (described later) to move the focusing lens 47 along the optical axis. As a result, the reflected light of the illumination light that has passed through the opening 45A formed in the pupil division member 45 can be imaged on the light-receiving surface of the image sensor 51 of the imaging device 50, according to the state of the eye being examined E.

[0123] In this imaging optical system 40, illumination light from the projection optical system 35 is reflected towards the objective lens 46 in the reflective component 45b. The illumination light reflected in the reflective component 45b is refracted by the objective lens 46, passes through the pupil of the examined eye E, and enters the eye to illuminate the fundus Ef of the examined eye E.

[0124] The reflected light from the illumination light from the fundus Ef is refracted by the objective lens 46, passes through the opening 45A formed in the pupil division member 45, passes through the focusing lens 47, passes through the relay lens 48, and is imaged on the light-receiving surface of the image sensor 51 of the imaging device 50 by the imaging lens 49.

[0125] (Camera device 50)

[0126] The imaging device 50 includes an image sensor 51 that receives the reflected light from the retina Ef of the examined eye E, which is guided through the imaging optical system 40. The imaging device 50 can be controlled by the control unit 100 (described later) to output the illumination result of the reflected light.

[0127] (Image sensor 51)

[0128] The image sensor 51 functions as a pixelated light receiver. The light-receiving surface (detection surface, imaging surface) of the image sensor 51 can be configured at a position approximately optically conjugate with the fundus Ef.

[0129] The light-receiving results from the image sensor 51 are acquired and read using a rolling shutter method. In some embodiments, the control unit 100, described later, controls the reading of the light-receiving results by controlling the image sensor 51. In some embodiments, the image sensor 51 can automatically output information indicating the light-receiving position and the light-receiving results of a predetermined row.

[0130] Such an image sensor 51 is a complementary metal-oxide-semiconductor (CMOS) image sensor. In this case, the image sensor 51 includes a plurality of pixels arranged in a two-dimensional pattern, a plurality of vertical signal lines, and horizontal signal lines. Each pixel includes a photodiode (light-receiving element) and a capacitor. The plurality of vertical signal lines are disposed in each pixel group in the column direction (vertical direction) orthogonal to the row direction (horizontal direction). Each vertical signal line is selectively electrically connected to a pixel group that has accumulated a charge corresponding to the light-receiving result. The horizontal signal lines are selectively electrically connected to the plurality of vertical signal lines. Each pixel accumulates a charge corresponding to the light-receiving result of the returned light, and the accumulated charge is sequentially read into, for example, each pixel group in the row direction. For example, in each line of the row direction, a voltage corresponding to the charge accumulated in each pixel is supplied to the vertical signal line. The plurality of vertical signal lines are selectively electrically connected to the horizontal signal lines. By sequentially performing the reading operation of each line in the row direction in the vertical direction, the light-receiving result of the plurality of pixels arranged in a two-dimensional pattern can be read.

[0131] By acquiring (reading) the light received by the returning light using a rolling shutter method to such an image sensor 51, a light-receiving image corresponding to a desired virtual opening shape extending in the row direction is obtained. Such control is disclosed, for example, in U.S. Patent No. 8,237,835.

[0132] exist Figure 5 The diagram illustrates the operation of the ophthalmic device 1 according to an embodiment. Figure 5The diagram schematically illustrates the illumination range IP of the slit-shaped illumination light illuminating the fundus Ef and the virtual opening range (light-receiving range) OP in the light-receiving surface SR of the image sensor 51.

[0133] For example, the control unit 100, described later, uses a light scanner 30 to deflect the slit-shaped illumination light formed by the illumination optics system 20. As a result, in the fundus Ef, the illumination range IP of the slit-shaped illumination light moves sequentially in a direction orthogonal to the slit direction (e.g., the row direction, the horizontal direction) (e.g., the vertical direction).

[0134] In the light-receiving surface SR of the image sensor 51, the control unit 100 (described later) changes the pixels of the acquisition object in lines, thereby setting a virtual aperture range OP. The aperture range OP is preferably the light-receiving range IP′ of the illumination light returning at the light-receiving surface SR, or a range larger than the light-receiving range IP′. For example, the control unit 100 (described later) performs movement control of the aperture range OP synchronously with the movement control of the illumination range IP. Thus, a high-quality image of the fundus Ef with strong contrast can be acquired with a simple structure without being affected by unwanted scattered light.

[0135] exist Figure 6 and Figure 7 The diagram illustrates an example of controlling the timing of the rolling shutter mode of the image sensor 51. Figure 6 An example of the timing of reading control of image sensor 51 is shown. Figure 7 It is to control the movement of the illumination range IP (light-receiving range IP′) at the same time as... Figure 6 The diagram shows the read control timings overlapping. Figure 6 and Figure 7 In the diagram, the horizontal axis represents the number of rows in the image sensor 51, and the vertical axis represents time.

[0136] In addition, Figure 6 and Figure 7 For ease of explanation, the example described uses an image sensor 51 with 1920 rows; however, the structure of the embodiment is not limited to the number of rows. Furthermore, in... Figure 7 For ease of explanation, the slit width (width in the row direction) of the slit-shaped illumination light is the width of 40 rows.

[0137] Horizontal readout control includes reset control, exposure control, charge transfer control, and output control. Reset control initializes the amount of charge accumulated in the pixels along the horizontal direction. Exposure control illuminates the photodiode, causing a charge corresponding to the amount of light received to accumulate in the capacitor. Charge transfer control transfers the charge accumulated in the pixel to the vertical signal line. Output control outputs the amount of charge accumulated in multiple vertical signal lines via the horizontal signal line. That is, as... Figure 6 As shown, the reading time T of the charge accumulated by the pixel in the row direction is the sum of the time Tr required for reset control, the time Te required for exposure control (exposure time), the time Tc required for charge transfer control, and the time Tout required for output control.

[0138] exist Figure 6 In this process, the start time of reading (acquisition) (the start time of time Tc) is offset by lines to obtain the light-receiving result (charge amount) accumulated by pixels within a desired range in the image sensor 51. For example, in Figure 6 When the pixel range shown is a frame of an image, the frame rate FR is uniquely determined.

[0139] In this embodiment, the illumination position of the illumination light with a slit width having multiple rows in the fundus Ef is shifted sequentially in the direction corresponding to the column direction of the fundus Ef.

[0140] For example, such as Figure 7 As shown, the illumination position of the illumination light in the fundus Ef is shifted row by row in the direction corresponding to the column direction every predetermined offset time Δt. The offset time Δt is obtained by dividing the exposure time Te of the pixels in the image sensor 51 by the slit width of the illumination light (e.g., the number of rows of the slit width = 40) (Δt = Te / 40). Synchronously with the movement of this illumination position, the start time of reading each row of pixels is delayed and started row by row in units of offset time Δt. Thus, a high-quality image of the fundus Ef with high contrast can be acquired in a short time with simple control.

[0141] In some implementations, the image sensor 51 is composed of one or more line sensors.

[0142] In the implementation, as described above, by making the pupil separation amount GP greater than the central ghost image generation suppression threshold and less than the small pupil imaging threshold, the generation of the central ghost image can be suppressed and small pupil imaging can be performed without setting a black dot plate.

[0143] The following describes the central ghost image generation suppression threshold and the small pupil capture threshold of the implementation method.

[0144] The central ghost image suppression threshold is determined by ensuring that the intersection of the illumination ray and the received ray (imaging ray) is not located on the lens surface or inside the lens of the objective lens 46. This central ghost image suppression threshold can be determined based on the working distance of the ophthalmic device 1, the diopter of the examineable eye E, the angle of the illumination light relative to the fundus Ef (imaging site), and the angle of the return light relative to the fundus Ef, as follows. The diopter is set to that of a highly myopic eye, thus enabling the suppression of central ghost image formation even if the examineable eye E is highly myopic, without the need for a black dot plate.

[0145] The threshold for small pupil imaging can be determined based on the predetermined pupil diameter for small pupil imaging, the pupil separation amount GP in the pupil conjugate surface PL, the width of the opening 21A (or one or more openings) in the alignment direction, and the width of the opening 45A (or one or more openings) in the alignment direction. The alignment direction refers to the orientation of the image formed by the opening 21A (or one or more openings) in the iris aperture 21 and the image formed by the opening 45A (or one or more openings) in the pupil separation component 45 within the pupil conjugate surface.

[0146] [Central ghost image generation suppression threshold]

[0147] exist Figure 8 The illumination light and the light received in the embodiment are schematically shown. Figure 8 A two-dimensional xy coordinate system is schematically shown for representing the intersection of the illumination ray and the received ray in x and y positions. Hereinafter, all distances are path lengths.

[0148] exist Figure 8 In the xy coordinate system shown, the direction of the optical axis O of the ophthalmic device 1, which extends from the center of the pupil C toward the fundus Ef, is set as the x direction, and the alignment direction of the image of the opening 21A at the pupil position and the opening 45A, which is orthogonal to the x direction, is set as the y direction.

[0149] Hereinafter, the focal distance of the lens of the examined eye E is defined as f, the origin is defined as the pupil center C of the examined eye E, and the distance in the x-direction from the pupil center C to the fundus Ef is defined as L. f (>0), let L be the distance in the x-direction from the pupil center C to the fundus conjugate position positioned in the direction facing the device. f ′(>0). Additionally, the x-direction from the pupil center C to the illumination ray W... IL With the received light W SL Let the distance between the intersection points be L0.

[0150] In the illumination light W IL With the received light W SLWhen the intersection point is located on the lens surface or inside the lens of objective lens 46, a central ghost image (objective lens glare) is generated. Therefore, when the intersection point is located outside the lens of objective lens 46, the generation of the central ghost image can be suppressed.

[0151] When solving for the intersection point, the lower edge of the image of the illumination opening (opening 21A of the iris aperture 21) in the pupil Eu and the lower edge of the opening (slit opening) formed by the slit 22 at the conjugate position of the fundus pass through.

[0152] In this context, the distance from the lower edge of the image of the illumination opening relative to the optical axis is defined as G, and the width of the opening formed in the slit 22 is defined as d. G Let β be the optical magnification from the fundus to the conjugate position of the fundus. The positions of the illumination rays at the lower edge of the image of the illumination opening (0, G) and the lower edge of the slit opening at the conjugate position of the fundus (L) are also considered. f ′,-β×d G / 2) can be expressed as in equation (1).

[0153] [Mathematical Expression 1]

[0154]

[0155] Similarly, when determining the intersection point, the upper edge of the image of the light-receiving opening in the pupil Eu and the upper edge of the exposure width at the light-receiving surface of the image sensor 51 at the conjugate position of the fundus pass through.

[0156] Specifically, H is defined as the distance from the upper edge of the image of the light-receiving opening relative to the optical axis, and d is defined as the exposure width at the light-receiving surface of the image sensor 51 at the conjugate position of the fundus. H The positions of the light-receiving rays at the upper edge (0, -H) of the image at the light-receiving opening and the upper edge (-L) of the exposure width at the light-receiving surface of the image sensor 51 at the conjugate position of the fundus are as follows. f ′,β×d H / 2) can be expressed as in equation (2).

[0157] [Mathematical Expression 2]

[0158]

[0159] The x-coordinate of the intersection of the above-mentioned lighting ray and the received ray can be expressed according to equations (1) and (2) as shown in equation (3).

[0160] [Mathematical Expression 3]

[0161]

[0162] Therefore, the distance L0 can be expressed according to equation (3) as in equation (4).

[0163] [Mathematical Expression 4]

[0164]

[0165] When the distance L0 between the intersection point and the pupil center C is equal to the working distance WD of the ophthalmic device 1, the pupil separation amount (G0+H0) is calculated when the intersection point of the illumination ray and the received ray is consistent with the lens surface of the objective lens 46 (refer to formula (5)).

[0166] [Mathematical Expression 5]

[0167]

[0168] In this setting, the visual acuity of the tested eye E is defined as D. When the tested eye E is highly myopic, D is a negative value. Additionally, L... f The relationship between ′ and D satisfies equation (6).

[0169] [Mathematical Expression 6]

[0170]

[0171] Furthermore, according to the paraxial imaging formula, L f The relationship between D and f satisfies equation (7).

[0172] [Mathematical Expression 7]

[0173]

[0174] The optical magnification β mentioned above is expressed as in equation (8).

[0175] [Mathematical Expression 8]

[0176]

[0177] If we substitute equations (6) to (8) into equation (5) for β and L f If ′, then the pupil separation quantity (G0+H0) of equation (5) is expressed as in equation (9).

[0178] [Mathematical Expression 9]

[0179]

[0180] in, Figure 8 d in G d H It can be represented using a perspective relative to the fundus Ef, which is the site of the photograph.

[0181] exist Figure 9The diagram illustrates the perspective of the implementation method. Figure 9 In the middle, to and Figure 8 The same reference numerals are used for the same parts, and descriptions are omitted where appropriate.

[0182] like Figure 9 As shown, if in relation to Figure 8 In the same xy coordinate system, if the angle of the illumination light relative to the fundus Ef is set as α, then the angle of the illumination light relative to the fundus Ef is expressed as in equation (10). Figure 8 d in G Similarly, if in the xy coordinate system, the angle of the returned light at the conjugate position (fundus position) relative to the fundus Ef is set as γ, then the angle of the returned light relative to the fundus Ef is expressed as in equation (11). Figure 8 d in H .

[0183] [Mathematical Expression 10]

[0184]

[0185] Therefore, equation (9) is transformed into equation (12) by substituting equations (10) and (11).

[0186] [Mathematical Expression 11]

[0187]

[0188] according to Figure 8 It can be seen that by increasing the pupil separation amount GP (=G+H), the intersection point position mentioned above moves towards the device side. Therefore, in order to suppress the generation of the central ghost image (objective lens glare), it is only necessary to make the intersection point position closer to the device side than the lens surface of the objective lens 46. At this time, the pupil separation amount GP (=G+H) only needs to be greater than the pupil separation amount (G0+H0) when the intersection point position coincides with the lens surface of the objective lens 46, as long as equation (13) is satisfied. That is, the pupil separation amount (G0+H0) is the threshold for suppressing the generation of the central ghost image.

[0189] [Mathematical Expression 12]

[0190]

[0191] [Small pupil detection threshold]

[0192] Furthermore, in order to perform small pupil imaging, the pupil separation amount (G+H) and the pupil diameter Φ used for small pupil imaging only need to satisfy the following relationship.

[0193] exist Figure 10 The image P1 of the illumination opening and the image P2 of the light-receiving opening in the pupil conjugate plane of the embodiment are schematically shown. Figure 10In the middle, to and Figure 4 The same reference numerals are used for the same parts, and descriptions are omitted where appropriate.

[0194] In order to perform small pupil imaging, in the arrangement direction of the image P1 of the illumination opening and the image P2 of the light-receiving opening, the sum of the pupil separation amount (G+H), the width g of the image P1 of the illumination opening in the arrangement direction and the width h of the image P2 of the light-receiving opening in the arrangement direction should be less than the pupil diameter Φ (Equation (15)) used for small pupil imaging.

[0195] Wherein, width g is equivalent to the width of opening 21A (or one or more openings) in the aforementioned arrangement direction. Width h is equivalent to the width of opening 45A (or one or more openings) in the aforementioned arrangement direction. That is, (Φ-(g+h)) is the small pupil capture threshold.

[0196] As described above, by setting the pupil separation amount to satisfy equations (14) and (15), even if the tested eye E is highly myopic, the generation of central ghost image can be suppressed and small pupil imaging can be performed without setting a black dot plate.

[0197] [Mathematical Expression 13]

[0198]

[0199] [Structure of the processing system]

[0200] like Figure 11 As shown, the processing system (control system) of the ophthalmic device 1 is configured with the control unit 100 as the center. In addition, at least a part of the structure of the processing system may also be included in the ophthalmic device 1.

[0201] (Control Unit 100)

[0202] The control unit 100 controls the various parts of the ophthalmic device 1. The control unit 100 includes a main control unit 101 and a storage unit 102. The main control unit 101 includes a processor that executes processing according to the program stored in the storage unit 102, thereby performing control processing on the various parts of the ophthalmic device 1.

[0203] (Main Control Unit 101)

[0204] The main control unit 101 controls the light source 10, the moving mechanism 10D, the illumination optical system 20, the light scanner 30, the imaging optical system 40, the imaging device 50, and the image forming unit 200. Furthermore, the main control unit 101 can control the operation unit 110 and the display unit 120. Based on the operation information input from the operation unit 110, the main control unit 101 can control each part of the ophthalmic device 1.

[0205] The control of the light source 10 includes turning the light source on and off (or switching the wavelength range of the light) and controlling the change in the amount of light from the light source.

[0206] The moving mechanism 10D changes at least one of the position and orientation of the light source 10 based on a known mechanism. The main control unit 101 can change at least one of the relative position and relative orientation of the light source 10 with respect to the iris aperture 21 and the slit 22.

[0207] The control of the illumination optical system 20 includes the control of the moving mechanism 22D. The moving mechanism 22D moves the slit 22 in the optical axis direction of the illumination optical system 20. The main control unit 101 controls the moving mechanism 22D according to the state of the examined eye E, thereby positioning the slit 22 at a position corresponding to the state of the examined eye E. The state of the examined eye E includes the shape of the fundus Ef, visual acuity (refractive power), axial length, etc. Visual acuity can be obtained, for example, from a known ocular refractive power measuring device disclosed in Japanese Patent Application Publication No. 61-293430 or Japanese Patent Application Publication No. 2010-259495. Axial length can be obtained from measurements taken using a known axial length measuring device or an optical coherence tomography scanner.

[0208] For example, the storage unit 102 stores first control information that pre-associates the position of the slit 22 in the optical axis of the illumination optical system 20 with the diopter. The main control unit 101 determines the position of the slit 22 corresponding to the diopter by referring to the first control information, and controls the moving mechanism 22D to position the slit 22 at the determined position.

[0209] The light intensity distribution passing through the opening formed in the slit 22 changes as the slit 22 moves. At this time, as described above, the main control unit 101 controls the moving mechanism 10D, thereby changing the position and orientation of the light source 10.

[0210] The control of the optical scanner 30 includes setting the deflection start angle and the deflection end angle of the deflection surface of the illumination light, and controlling the angle of the deflection surface. By controlling the angle range of the deflection surface, the scanning range (scanning start position and scanning end position) can be controlled. By controlling the rate at which the angle of the deflection surface changes, the scanning speed can be controlled.

[0211] The control of the imaging optical system 40 includes the control of the moving mechanism 47D. The moving mechanism 47D moves the focusing lens 47 along the optical axis of the imaging optical system 40. The main control unit 101 can control the moving mechanism 47D based on the analysis results of the image acquired using the image sensor 51. In addition, the main control unit 101 controls the moving mechanism 47D based on the user's operation content using the operation unit 110.

[0212] The control of the imaging device 50 includes the control of the image sensor 51. The control of the image sensor 51 includes control for reading the illumination result in a rolling shutter manner (e.g., setting the illumination size corresponding to the size of the illumination pattern). Additionally, the control of the image sensor 51 includes reset control, exposure control, charge transfer control, and output control. The time required for reset control (Tr), the time required for exposure control (exposure time) (Te), the time required for charge transfer control (Tc), and the time required for output control (Tout) can be changed.

[0213] The control of the image forming unit 200 includes various image processing, analysis processing, and image forming processing using the lighting results acquired from the image sensor 51. Image processing includes noise removal processing of the lighting results and brightness correction processing to make predetermined regions depicted in the lit image based on the lighting results easily identifiable. Analysis processing includes focusing state determination processing, etc.

[0214] The image forming unit 200 can form a light-receiving image (image) corresponding to any opening range based on the light-receiving results read from the image sensor 51 in a rolling shutter mode. The image forming unit 200 can sequentially form light-receiving images corresponding to the opening range, and form an image of the examined eye E based on the multiple light-receiving images formed.

[0215] The image forming unit 200 includes a processor, which processes the image according to a program stored in a storage unit, thereby achieving the functions described above.

[0216] In some embodiments, the light source 10 includes two or more light sources. For example, each of the two or more light sources is provided corresponding to two or more openings formed in the iris aperture 21. In this case, the main control unit 101 controls the moving mechanism provided corresponding to each of the two or more light sources, thereby changing at least one of the position and orientation (orientation of the direction with the largest light distribution) of each light source. For example, two or more light sources are provided corresponding to a single opening formed in the iris aperture 21. In this case, the main control unit 101 can make each of the two or more light sources independently change its light quantity, thereby adjusting the light quantity distribution of light passing through the iris aperture 21.

[0217] (Storage Department 102)

[0218] Storage unit 102 stores various computer programs and data. The computer programs include arithmetic programs and control programs for controlling the ophthalmic device 1.

[0219] (Operations Department 110)

[0220] The operation unit 110 includes an operating device or an input device. The operation unit 110 includes buttons, switches (e.g., operating handles, operating knobs, etc.), and operating devices (mouse, keyboard, etc.) disposed on the ophthalmic device 1. Alternatively, the operation unit 110 may include any operating device or input device such as a trackball, operation panel, switch, button, or dial.

[0221] (Display unit 120)

[0222] The display unit 120 displays an image of the examined eye E generated by the image forming unit 200. The display unit 120 is configured with a display device such as a flat panel display (LCD). In addition, the display unit 120 may include various display devices such as a touch panel disposed in the housing of the ophthalmic device 1.

[0223] Furthermore, the operation unit 110 and the display unit 120 do not need to be configured as separate devices. For example, a device integrating display and operation functions can be used, such as a touch panel. In this case, the operation unit 110 is configured to include the touch panel and a computer program. The operation content of the operation unit 110 is input to the control unit 100 as an electrical signal. Alternatively, a graphical user interface (GUI) displayed on the display unit 120 and the operation unit 110 can be used for operation and information input. In some embodiments, the functions of the display unit 120 and the operation unit 110 are implemented by a touch screen.

[0224] (Other structures)

[0225] In some embodiments, the ophthalmic device 1 also includes a fixation projection system. For example, in Figure 1 In the structure of the optical system shown, the optical path of the fixation projection system is coupled to the optical path of the imaging optical system 40. The fixation projection system can present an internal fixation target or an external fixation target to the eye being examined, E. When presenting an internal fixation target to the eye being examined, the fixation projection system includes an LCD that displays the internal fixation target under control from the control unit 100, and a fixation beam output from the LCD is projected onto the fundus of the eye being examined, E. The LCD is configured to change the display position of the fixation target on its screen. By changing the display position of the fixation target on the LCD, the projection position of the fixation target in the fundus of the eye being examined, E, can be changed. The display position of the fixation target on the LCD can be specified by the user using the operation unit 110.

[0226] In some embodiments, the ophthalmic device 1 includes an alignment system. In some embodiments, the alignment system includes an XY alignment system and a Z alignment system. The XY alignment system is used to align the device optics system with the examined eye E in a direction intersecting the optical axis of the device optics system (objective lens 46). The Z alignment system is used to align the device optics system with the examined eye E in the direction of the optical axis of the ophthalmic device 1 (objective lens 46).

[0227] For example, the XY alignment system projects a bright spot (in the infrared or near-infrared region) onto the eye being examined, E. The control unit 100 or the image forming unit 200 acquires an anterior eye image of the eye being examined, E, with the bright spot projected onto it, and calculates the displacement between the bright spot image depicted in the acquired anterior eye image and the alignment reference position. The control unit 100 moves the optical system of the device and the eye being examined, E, relative to each other in a direction intersecting the optical axis via a moving mechanism (not shown), to eliminate the calculated displacement.

[0228] For example, the Z-alignment system projects alignment light from an infrared or near-infrared region from a position offset from the optical axis of the device's optical system and receives the alignment light reflected in the anterior portion of the examined eye E. The control unit 100 or the image forming unit 200 determines the distance between the examined eye E and the device's optical system based on the position of the alignment light received, which varies according to the distance between the examined eye E and the device's optical system. The control unit 100 moves the device's optical system and the examined eye E relative to each other in the optical axis direction via a movement mechanism (not shown) to make the determined distance the desired working distance.

[0229] In some embodiments, the alignment system is implemented by two or more anterior eye cameras positioned off-axis from the optical axis of the device's optical system. For example, as disclosed in Japanese Patent Application Publication No. 2013-248376, the control unit 100 or the image forming unit 200 analyzes the anterior eye image of the subject eye E acquired substantially simultaneously by two or more anterior eye cameras, and determines the three-dimensional position of the subject eye E using a known triangulation method. The control unit 100 moves the device's optical system and the subject eye E three-dimensionally relative to each other via a movement mechanism (not shown), so that the optical axis of the device's optical system is substantially aligned with the axis of the subject eye E, and the distance between the device's optical system and the subject eye E becomes a predetermined working distance.

[0230] As described above, in the ophthalmic device 1, the slit 22 (opening), the imaging area (fundus Ef), and the image sensor 51 (light-receiving surface) are arranged in approximately optically conjugate positions. By moving the light-receiving area in the image sensor 51 in conjunction with the illumination position based on the illumination light, the ophthalmic device 1 can suppress the influence of unwanted scattered light and acquire a clear image of the imaging area.

[0231] The iris aperture 21 is an example of an "illumination aperture" in this embodiment. The opening 21A formed in the iris aperture 21 is an example of an "illumination opening" in this embodiment. The imaging optical system 40 is an example of a "light-receiving optical system" in this embodiment. The opening 45A formed in the pupil dividing member 45 or the imaging aperture included in the pupil dividing member 45 is an example of an "imaging aperture" in this embodiment. The opening 45A formed in the pupil dividing member 45 is an example of a "light-receiving opening" or "imaging opening" in this embodiment. The opening formed in the slit 22 is an example of a "slit opening" in this embodiment.

[0232] [Work]

[0233] Next, the operation of ophthalmic device 1 will be explained.

[0234] exist Figure 12 An example of the operation of the ophthalmic device 1 according to the embodiment is shown. Figure 12 A flowchart illustrating an example of the operation of the ophthalmic device 1 according to an embodiment is shown. The storage unit 102 stores information for implementing... Figure 12 The computer program for processing is shown. The main control unit 101 operates according to this computer program, thereby executing... Figure 12 The processing shown.

[0235] In addition, during Figure 12 Prior to the treatment shown, the eye E under examination is aligned with the optical system, and a fixation target is projected at a predetermined fixation position in the fundus Ef.

[0236] (S1: Obtain Viewpoint)

[0237] First, the main control unit 101 acquires the diopter. For example, the main control unit 101 moves the focusing lens 47 to determine the focusing state, and determines the diopter based on the position of the focusing lens 47 on the optical axis set to the focusing state (or the control result of the actuator driving the moving mechanism 47D). The main control unit 101 can acquire the diopter of the examined eye E from an external ophthalmic measurement device or an electronic medical record.

[0238] (S2: Change the location of the crack)

[0239] Next, the main control unit 101 changes the position of the slit 22 in the optical axis of the illumination optical system 20 according to the visual acuity of the examined eye E obtained in step S1.

[0240] Specifically, the main control unit 101 determines the position of the rift 22 corresponding to the viewing angle by referring to the first control information stored in the storage unit 102, and controls the moving mechanism 22D to position the rift 22 at the determined position.

[0241] (S3: Turn on the light source)

[0242] Next, the main control unit 101 controls the light source 10 to turn on, and the illumination optical system 20 generates slit-shaped illumination light. Then, the main control unit 101 controls the light scanner 30 to begin deflection control, thereby starting to illuminate the desired area of ​​the fundus Ef with illumination light. Once illumination begins, the slit-shaped illumination light sequentially illuminates the desired area as described above.

[0243] (S4: Obtain the light reception results)

[0244] The main control unit 101 acquires the light-receiving results of the pixels in the opening range of the image sensor 51 corresponding to the illumination range of the illumination light in the fundus Ef in step S3.

[0245] (S5: Next irradiation location?)

[0246] The main control unit 101 determines whether there is an illumination position that should be illuminated next. The main control unit 101 determines whether the illumination range of the sequentially moving illumination light covers the predetermined imaging range of the fundus Ef, thereby determining whether there is an illumination position that should be illuminated next.

[0247] If it is determined that there is an irradiation position that should be illuminated next (S5: Yes), the operation of ophthalmic device 1 proceeds to step S6. If it is determined that there is no irradiation position that should be illuminated next (S5: No), the operation of ophthalmic device 1 proceeds to step S7.

[0248] (S6: Change the deflection angle of the illumination light)

[0249] When it is determined in step S5 that there is an illumination position that should be illuminated by illumination light (S5: Yes), the main control unit 101 controls the light scanner 30 to change the deflection angle of the deflection surface of the light scanner 30 by a predetermined step amount.

[0250] Next, the operation of the ophthalmic device 1 proceeds to step S4. At this time, in step S4, the main control unit 101 acquires the illumination results of the pixels in the opening range of the image sensor 51 corresponding to the illumination range of the illumination light in the fundus Ef that was moved in step S6.

[0251] (S7: Turn off the light source)

[0252] If, in step S5, it is determined that there is no position to be illuminated by the light source next (S5: No), the main control unit 101 controls the light source 10 to turn off the light source 10. Furthermore, the main control unit 101 controls the light scanner 30 to stop its deflection operation.

[0253] (S8: Form an image)

[0254] Next, the main control unit 101 causes the image forming unit 200 to form a fundus image of the examined eye E based on the illumination results repeatedly acquired while changing the illumination range of the illumination light in steps S4 to S6.

[0255] For example, the image forming unit 200 combines multiple illumination results (the opening range in the light-receiving surface SR of the image sensor 51) that are different from each other in the illumination range of the illumination light corresponding to the number of repetitions of the processing in steps S4 to S6, based on the movement sequence of the illumination range. As a result, a single frame of fundus image Ef is formed.

[0256] In some embodiments, in step S6, illumination light is shone onto an illumination range defined in such a way that it includes overlapping regions with adjacent illumination ranges. Therefore, in step S8, a fundus image is synthesized by overlapping the overlapping regions, thereby forming a single frame of fundus image.

[0257] The operation of ophthalmic device 1 is now complete.

[0258] exist Figure 13A and Figure 13B The diagram shows a schematic illustration of the operation of taking a picture of the fundus Ef of the examined eye E in the ophthalmic device 1 of the embodiment. Figure 13A This is a schematic diagram illustrating the illumination beam and imaging beam when photographing the fundus Ef of the examined eye E in an embodiment. Figure 13B This is a diagram illustrating an example of a fundus image of the examined eye E obtained in an embodiment. Figure 13A In the middle, to and Figure 17A The same reference numerals are used for the same parts, and descriptions are omitted where appropriate.

[0259] As described above, the system is configured to illuminate the fundus Ef with light passing through an opening 21A formed on the iris aperture 21 at a position offset from the optical axis, and to receive reflected light from the fundus Ef passing through an opening 45A formed on the pupillary segment 45 at a position offset from the optical axis. Thus, as... Figure 13A As shown, the illumination beam IL and the imaging beam SL are spatially separated on the lens surface SF and inside the lens of objective lens 46. As a result, reflected light from the lens surface of the objective lens, which is the main cause of central ghosting (objective lens flare), can be prevented from entering the optical path of the imaging optical system 40.

[0260] Therefore, just like Figure 13B As shown, without the black dot plate, no black spots caused by black dot shadows are formed in the acquired fundus image IMG0 (fundus information is not lost). Therefore, fundus images of the examined eye that can be used for appropriate diagnosis can be acquired without complicating the control process.

[0261] At this time, pupil segmentation is performed such that the pupil separation amount in the pupil conjugate plane is greater than a predetermined central ghost image suppression threshold. Therefore, even if the examined eye E is highly myopic, the illumination light and the return light (imaging light) can be spatially separated on the lens surface of the objective lens 46. Furthermore, by performing pupil segmentation such that the pupil separation amount is less than a predetermined small pupil imaging threshold, even if the examined eye E is a small pupil eye, a fundus image of the examined eye suitable for appropriate diagnosis can be obtained. Therefore, when imaging a small pupil eye, a fundus image of the examined eye suitable for appropriate diagnosis of small pupil eyes can be obtained without complicating control.

[0262] [Variation Example]

[0263] The structure of the embodiment is not limited to the structure described above. The shapes of the illumination opening and the imaging opening in the embodiment can be arbitrary. In addition, the number of illumination openings and imaging openings in the embodiment can be two or more.

[0264] <First Variation>

[0265] The shape of the opening 21A formed in the iris aperture 21 in the embodiment is not limited to Figure 2 The shape shown. Hereinafter, a first variation of the embodiment will be described, focusing on the differences from the original embodiment.

[0266] exist Figure 14A The diagram shows a structural example of the iris aperture 21 of the first modified embodiment. Figure 14A This schematically illustrates the structural example of the iris aperture 21 in this modified example when viewed from the direction of the optical axis O. Figure 14A In the middle, to and Figure 2 The same reference numerals are used for the same parts, and descriptions are omitted where appropriate.

[0267] The structure of the iris aperture 21 in this variant is similar to... Figure 2 The difference in the structure of the iris aperture 21 shown lies in the shape of the opening 21A. In this modified example, the iris aperture 21 has an opening 21A of predetermined thickness formed along the circumferential direction centered on the optical axis O. For example, as... Figure 14A As shown, an opening 21A is formed, so that when the center of the pupil of the examined eye E is positioned on the optical axis O, the illumination light can enter the eye from a position deviating from the center of the pupil.

[0268] exist Figure 14B The diagram shows an explanatory diagram of the pupil conjugate surface in a first variation of the embodiment. Figure 14B This is a schematic diagram showing the image IPI1 of the illumination opening and the image SPI of the light-receiving opening in the pupil conjugate plane PL. Figure 14B In the middle, to and Figure 4The same reference numerals are used for the same parts, and descriptions are omitted where appropriate.

[0269] By performing pupil segmentation by the pupil segmentation component 45, in this modified example, the image IPI1 of the opening formed in the iris aperture 21 (i.e., the illumination opening) and the image SPI of the opening formed in the shooting aperture (pupil segmentation component 45) (i.e., the light-receiving opening) are spatially separated in the pupil conjugate plane PL. At this time, the image IPI1 of the illumination opening and the image SPI of the light-receiving opening are separated by a pupil separation amount GP, which is equivalent to the shortest distance in the alignment direction (separation direction) of the image IPI1 of the illumination opening and the image SPI of the light-receiving opening.

[0270] In this variation, the pupil separation GP in the pupil conjugate plane is... Figure 4 The pupil separation amount GP shown is the same. In this modified example, by increasing the pupil separation amount GP, the overlap of the beam cross-section of the illumination light and the return light in the lens surface or inside the objective lens 46 can be reliably avoided, and the generation of central ghost image can be suppressed without setting a black dot plate. Therefore, in this modified example, it is preferable to form an opening 21A (or more than one opening) in the iris aperture 21 and an opening 45A (or more than one opening) in the pupil separation member 45 in such a way that the pupil separation amount GP is greater than a predetermined central ghost image generation suppression threshold.

[0271] On the other hand, if the pupil separation amount GP is increased, the size of the pupil diameter that can be photographed becomes larger, and small pupil eyes cannot be photographed. Therefore, in this modified example, it is preferable to form an opening 21A (or more than one opening) in the iris aperture 21 and an opening 45A (or more than one opening) in the pupil segmentation member 45 in such a way that the pupil separation amount GP is less than a predetermined small pupil photographable threshold.

[0272] Furthermore, the opening 21A formed in the iris aperture 21 can be in the shape of a circular segment. The circular segment is the region enclosed by the minor arc of a circle or ellipse and the chord of that minor arc. The direction of the chord of the circular segment is approximately parallel to the direction corresponding to the direction of the slit formed in the opening of the slit 22.

[0273] <Second Variation>

[0274] The number of openings formed in the iris aperture 21 in this embodiment is not limited to one. Hereinafter, a second variation of the embodiment will be described, focusing on the differences from the previous embodiment.

[0275] exist Figure 15 The diagram shows a structural example of the iris aperture 21 in a second variation of the embodiment. Figure 15 This schematically illustrates the structural example of the iris aperture 21 in this modified example when viewed from the direction of the optical axis O. Figure 15 In the middle, to and Figure 2 The same reference numerals are used for the same parts, and descriptions are omitted where appropriate.

[0276] The structure of the iris aperture 21 in this variant is similar to... Figure 2 The structural difference of the iris aperture 21 shown lies in the number of openings. In this modified example, openings 21A and 21B are formed on the iris aperture 21 at positions offset from the optical axis O. For example, as... Figure 15 As shown, by forming openings 21A and 21B, when the center of the pupil of the examined eye E is positioned on the optical axis O, the illumination light can enter the eye from a position offset from the center of the pupil.

[0277] In this variation, the pupil separation GP in the pupil conjugate plane is... Figure 4 The pupil separation amount GP shown is the same. In this modified example, by increasing the pupil separation amount GP, the repetition of the beam cross sections of the illumination light and the return light in the lens surface or inside the objective lens 46 can be reliably avoided, and the generation of central ghost image can be suppressed without setting a black dot plate. Therefore, in this modified example, it is preferable to form openings 21A and 21B in the iris aperture 21 and opening 45A (or more than one opening) in the pupil separation member 45 in such a way that the pupil separation amount GP is greater than a predetermined central ghost image generation suppression threshold.

[0278] On the other hand, if the pupil separation amount GP is increased, the size of the pupil diameter that can be photographed becomes larger, and small pupil eyes cannot be photographed. Therefore, in this modified example, it is preferable to form openings 21A and 21B in the iris aperture 21 and opening 45A (or more than one opening) in the pupil segmentation member 45 in such a way that the pupil separation amount GP is less than a predetermined small pupil photographable threshold.

[0279] <Third Variation>

[0280] The number of openings formed in the pupil dividing member 45 in the embodiment is not limited to one. Hereinafter, a third variation of the embodiment will be described focusing on the differences from the embodiment.

[0281] exist Figure 16 The diagram shows a structural example of the pupil segmentation member 45 in a third variation of the embodiment. Figure 16 In this modified example, the pupil segmentation component 45 is schematically shown by combining a side view viewed from a direction orthogonal to the optical axis O with a front view viewed from the direction of the optical axis O. Figure 16 In the middle, to and Figure 3 The same reference numerals are used for the same parts, and descriptions are omitted where appropriate.

[0282] The structure of the pupil segmentation component 45 in this variant example is similar to... Figure 3The difference in the structure of the pupil dividing member 45 shown lies in the number of openings. In this modified example, openings 45A and 45B are formed at positions offset from the optical axis O. For example, as... Figure 16 As shown, by forming openings 45A and 45B, when the center of the pupil of the examined eye E is positioned on the optical axis O, the return light of the illumination light incident into the eye from a position offset from the center of the pupil can be guided to the image sensor 51.

[0283] In this variation, the pupil separation GP in the pupil conjugate plane is... Figure 4 The pupil separation amount GP shown is the same. In this modified example, by increasing the pupil separation amount GP, the overlap of the beam cross-section of the illumination light and the return light in the lens surface or inside the objective lens 46 can be reliably avoided, and the generation of central ghost image can be suppressed without setting a black dot plate. Therefore, in this modified example, it is preferable to form an opening 21A (or more than one opening) in the iris aperture 21 and openings 45A and 45B in the pupil separation member 45 in such a way that the pupil separation amount GP is greater than a predetermined central ghost image generation suppression threshold.

[0284] On the other hand, if the pupil separation amount GP is increased, the size of the pupil diameter that can be photographed becomes larger, making it impossible to photograph small pupil eyes. Therefore, in this modified example, it is preferable to form an opening 21A (or more than one opening) in the iris aperture 21 and openings 45A and 45B in the pupil separation member 45 in such a way that the pupil separation amount GP is less than a predetermined small pupil photographable threshold.

[0285] <Other variations>

[0286] The illumination optical system 20 includes a projector equipped with a light source, which can be configured to output slit-shaped illumination light. In this case, a projector is used instead of... Figure 1 The light source 10 and the slit 22. Projectors include LCD (Liquid Crystal Display) projectors using transmissive liquid crystal panels, LCOS (Liquid Crystal On Silicon) projectors using reflective liquid crystal panels, and DLP (Digital Light Processing) projectors using DMD (Digital Micromirror Device) (registered trademark), etc. For example, the illumination optical system 20 can be configured to illuminate the slit-shaped illumination light output from the projector onto the iris aperture 21.

[0287] [effect]

[0288] An ophthalmic device for describing an embodiment.

[0289] The ophthalmic device 1 of the first embodiment includes an objective lens 46, an illumination optics system 20, a light scanner 30, a light-receiving optics system (imaging optics system 40), and a pupil division component 45. The illumination optics system includes an illumination aperture (iris aperture 21) positioned approximately optically conjugate to the pupil Eu of the examined eye E and having one or more openings 21A, 21B formed at a position offset from the optical axis O. The illumination optics system illuminates slit-shaped illumination light. The light scanner is positioned approximately optically conjugate to the pupil and deflects the illumination light, guiding it to the examined eye via the objective lens. The light-receiving optics system guides the reflected illumination light from the examined eye through the objective lens to an image sensor 51 positioned approximately optically conjugate to the imaging site (fundus Ef) of the examined eye. The pupil splitting component includes a shooting aperture with one or more openings 45A, 45B, which is disposed at a position approximately optically conjugate to the pupil and formed at a position offset from the optical axis. The pupil splitting component spatially separates the optical path of the illumination optical system and the optical path of the receiving optical system.

[0290] In this manner, the illumination light and the return light can be spatially separated both on the lens surface and inside the lens of the objective lens. As a result, reflected light from the lens surface of the objective lens, a major cause of central ghosting (objective lens glare), can be prevented from entering the optical path of the receiving optical system. Therefore, without the need for a black dot plate, images of the examined eye that do not produce black spots (intraocular information such as fundus information is not lost) can be acquired. Furthermore, when photographing eyes with small pupils, intraocular images of the examined eye that allow for appropriate diagnosis of small pupils can be acquired without complicating control procedures.

[0291] In a second embodiment, according to the first embodiment, the illumination optical system includes a slit 22 disposed at a position substantially optically conjugate to the shooting location and having a slit-like opening, and is configured to illuminate the slit with light from a light source.

[0292] In this way, slit-shaped illumination light can be irradiated with a simple structure. Therefore, it is possible to acquire images of the examined eye with a simple structure, without producing black spots caused by black spot shadows (without loss of intraocular information such as fundus information), without setting up a black spot plate.

[0293] In a third embodiment, according to the first or second embodiment, the pupil segmentation component further includes a reflective component 45b that deflects the illumination light deflected by the light scanner toward the eye being examined.

[0294] In this way, the structure of the pupil segmentation component can be further simplified.

[0295] In a fourth embodiment, according to the first or second embodiment, the pupil splitting component is a aperture lens with a reflective component disposed around the opening formed in the shooting aperture.

[0296] In this way, the function of the pupil division component can be realized using a lens with a simple structure.

[0297] In the fifth embodiment, according to any one of the first to fourth embodiments, the image sensor is configured to acquire the light-receiving result in a virtual opening area of ​​a light-receiving surface in a rolling shutter manner. The virtual opening area of ​​the light-receiving surface corresponds to the illumination area at the shooting location where the illumination light moves in a predetermined scanning direction by the light scanner.

[0298] In this way, the effects of unwanted scattered light can be reliably eliminated, further improving the image quality of the examined eye.

[0299] In the sixth embodiment, according to any one of the first to fifth embodiments, the image sensor is a CMOS image sensor.

[0300] In this way, it is possible to prevent reflected light from the lens surface of the objective lens, which is the main cause of central ghosting (objective lens glare), from entering the optical path of the light-receiving optical system with a simple structure and low cost.

[0301] According to any one of the first to sixth embodiments, the ophthalmic device includes an image forming unit 200 that forms an image of the examined eye based on the light-receiving result at the light-receiving surface of the image sensor.

[0302] In this way, images of the examined eye that do not produce dark spots caused by black dot shadows can be acquired without setting a black dot plate. Furthermore, even when photographing eyes with small pupils, intraocular images of the examined eye that allow for an appropriate diagnosis of small pupils can be acquired without complicating control procedures.

[0303] In the eighth embodiment, the imaging site is the fundus Ef, according to any one of the first to seventh embodiments.

[0304] This method allows for the acquisition of fundus images of the examined eye that do not produce dark spots caused by black dot shadows, without the need for a black dot plate. Furthermore, when photographing eyes with small pupils, fundus images of the examined eye that allow for appropriate diagnosis of small pupils can be acquired without complicating the control process.

[0305] In the ninth embodiment, according to any one of the first to eighth embodiments, a single opening 21A is formed in the illumination aperture and a single opening 45A is formed in the shooting aperture.

[0306] In this way, based on a single illumination opening and a single imaging opening formed at a position offset from the optical axis, it is possible to prevent reflected light from the lens surface of the objective lens, which is the main cause of the central ghost image, from entering the optical path of the light-receiving optical system with a simple structure.

[0307] In the tenth embodiment, according to any one of the first to eighth embodiments, the pupil separation amount GP is greater than a predetermined central ghost image generation suppression threshold, and one or more openings are formed in the illumination aperture and one or more openings are formed in the shooting aperture. The pupil separation amount GP is the shortest distance in the alignment direction between the image formed in one or more openings of the illumination aperture and the image formed in one or more openings of the shooting aperture in the pupil conjugate surface PL at a position approximately optically conjugate with the pupil.

[0308] In this way, the generation of central ghost images can be reliably suppressed without setting up a black dot plate.

[0309] In the eleventh embodiment, according to the tenth embodiment, one or more openings are formed in the illumination aperture and one or more openings are formed in the imaging aperture, such that the pupil separation amount is approximately constant in a direction orthogonal to the arrangement direction. The arrangement direction is the direction in which the images formed in the one or more openings of the illumination aperture and the images formed in the one or more openings of the imaging aperture are arranged in the pupil conjugate plane.

[0310] In this way, the aperture size can be increased to ensure the amount of light and maximize the pupil separation.

[0311] In the twelfth embodiment, according to the tenth embodiment, the predetermined central ghost image generation suppression threshold is determined based on the working distance WD of the ophthalmic device, the visual acuity D of the examineable eye that can be photographed, the angle α of the illumination light relative to the photographed area, and the angle γ of the return light relative to the fundus Ef.

[0312] In this way, by determining the working distance of the ophthalmic device, the diopter of the eye to be photographed, the angle of illumination light relative to the photographed area, and the angle of return light relative to the fundus, the generation of central ghost images can be reliably suppressed without setting up a black dot plate.

[0313] In the thirteenth embodiment, according to the twelfth embodiment, the visual acuity is the visual acuity of a highly myopic eye.

[0314] In this way, even if the eye being examined is highly myopic, the generation of ghost images can be reliably suppressed without the use of a black dot plate.

[0315] In the fourteenth embodiment, according to the twelfth embodiment, the illumination aperture has one or more openings and the shooting aperture has one or more openings, such that the pupil separation amount is less than a predetermined small pupil shooting threshold.

[0316] In this way, even if the eye being examined has a small pupil, the generation of central ghost images can be reliably suppressed without setting up a black dot plate.

[0317] In the fifteenth embodiment, according to the fourteenth embodiment, the predetermined small pupil imaging threshold is determined based on the predetermined small pupil imaging pupil diameter, the width in the image arrangement direction of one or more openings of the illumination aperture, and the width in the image arrangement direction of one or more openings of the imaging aperture. The arrangement direction refers to the arrangement direction of the images formed in one or more openings of the illumination aperture and the images formed in one or more openings of the imaging aperture in the pupil conjugate plane.

[0318] By determining the diameter of the pupil for small pupil photography, the width of the image formed in the direction of the arrangement of one or more openings of the illumination aperture, and the width of the image formed in the direction of the arrangement of one or more openings of the shooting aperture, small pupil eyes can be reliably photographed.

[0319] The embodiments or variations thereof shown above are merely examples for implementing the present invention. Those wishing to implement the present invention may make any modifications, omissions, additions, etc., within the scope of the spirit of the present invention.

[0320] In the above embodiments, the ophthalmic device may have any function usable in the field of ophthalmology, such as axial length measurement, intraocular pressure measurement, optical coherence tomography (OCT), and ultrasound examination. Furthermore, the axial length measurement function is implemented by an optical coherence tomography scanner or the like. Additionally, the axial length measurement function projects light onto the examined eye, adjusts the position of the optical system relative to the examined eye in the Z-direction (anteroposterior direction), and detects the reflected light from the fundus to measure the axial length of the examined eye. The intraocular pressure measurement function is implemented by a tonometer or the like. The OCT function is implemented by an optical coherence tomography scanner or the like. The ultrasound examination function is implemented by an ultrasound diagnostic device or the like. Furthermore, the present invention can also be applied to devices (multifunction printers) possessing two or more of these functions.

Claims

1. An ophthalmic device comprising: Objective lens; An illumination optical system includes an illumination aperture that is positioned approximately optically conjugate to the pupil of the eye being examined and forms one or more openings at a position offset from the optical axis, the illumination optical system illuminating slit-shaped illumination light; A light scanner is positioned approximately optically conjugate to the pupil and deflects the illumination light, guiding it to the eye being examined via the objective lens. The light-receiving optical system guides the reflected light from the eye being examined through the objective lens to an image sensor positioned approximately optically conjugate with the imaging area of ​​the eye being examined. as well as A pupil splitting component includes a shooting aperture disposed at a position substantially optically conjugate to the pupil and forming one or more openings at a position offset from the optical axis, the pupil splitting component spatially separating the optical path of the illumination optical system from the optical path of the light-receiving optical system.

2. The ophthalmic device according to claim 1, characterized in that, The illumination optical system includes a slit located at a position substantially optically conjugate to the shooting location and having a slit-like opening, and is configured to illuminate the slit with light from a light source.

3. The ophthalmic device according to claim 1, characterized in that, The pupil segmentation component also includes a reflective component that deflects the illumination light, which has been deflected by the light scanner, toward the eye being examined.

4. The ophthalmic device according to claim 1, characterized in that, The pupil dividing component is a aperture lens with a reflective component disposed around the opening formed in the shooting aperture.

5. The ophthalmic device according to claim 1, characterized in that, The image sensor is configured to acquire the light-receiving result in a virtual opening area of ​​the light-receiving surface using a rolling shutter method. The virtual opening area of ​​the light-receiving surface corresponds to the illumination area at the shooting location where the illumination light moves through the light scanner in a predetermined scanning direction.

6. The ophthalmic device according to claim 5, characterized in that, The image sensor is a complementary metal-oxide-semiconductor image sensor.

7. The ophthalmic device according to claim 1, characterized in that, The ophthalmic device includes: The image forming unit forms an image of the examined eye based on the light-receiving result at the light-receiving surface of the image sensor.

8. The ophthalmic device according to claim 1, characterized in that, The area being photographed is the fundus of the eye.

9. The ophthalmic device according to any one of claims 1 to 8, characterized in that, A single opening is formed in the illumination aperture. The aperture used for shooting has a single opening.

10. The ophthalmic device according to any one of claims 1 to 8, characterized in that, In a manner that makes the pupil separation amount greater than a predetermined central ghost image suppression threshold, the illumination aperture has one or more openings and the shooting aperture has one or more openings, wherein the pupil separation amount is the shortest distance in the alignment direction between the image of the one or more openings formed in the illumination aperture and the image of the one or more openings formed in the shooting aperture in the pupil conjugate plane at a position approximately optically conjugate to the pupil.

11. The ophthalmic device according to claim 10, characterized in that, The illumination aperture and the shooting aperture are formed with the more than one opening in such a way that the pupil separation is approximately constant in a direction orthogonal to the arrangement direction.

12. The ophthalmic device according to claim 10, characterized in that, The predetermined central ghost image generation suppression threshold is determined based on the working distance of the ophthalmic device, the diopter of the subject eye that can be photographed, the angle of the illumination light relative to the photographed area, and the angle of the returned light relative to the fundus.

13. The ophthalmic device according to claim 12, characterized in that, The visual acuity mentioned refers to that of a person with high myopia.

14. The ophthalmic device according to claim 12, characterized in that, The illumination aperture has one or more openings and the shooting aperture has one or more openings, such that the pupil separation amount is less than a predetermined small pupil shooting threshold.

15. The ophthalmic device according to claim 14, characterized in that, The predetermined small pupil imaging threshold is determined based on the predetermined small pupil imaging pupil diameter, the width of the image formed in the one or more openings of the illumination aperture in the alignment direction, and the width of the image formed in the one or more openings of the imaging aperture in the alignment direction.

Images