JP2018166631A - Ophthalmologic imaging apparatus - Google Patents

Abstract

To provide a new technology for simplifying constitution or control of an ophthalmologic imaging apparatus.SOLUTION: An ophthalmologic imaging apparatus includes an illumination optical system for radiating light from a first light source to a subject eye, an imaging optical system for guiding to a light field camera, light from an eyeground of the subject eye to which light from the first light source is radiated by the illumination optical system, and an image generation part for generating an eyeground image corresponding to a desired image surface position in the optical axis direction of the imaging optical system based on image data obtained by the light field camera.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an ophthalmologic photographing apparatus.

  The ophthalmologic photographing apparatus is an apparatus for acquiring an image of an eye to be examined. Examples of the ophthalmologic photographing apparatus include optical coherence tomography (OCT), a fundus camera, a scanning laser opthalmoscope (SLO), and the like.

  OCT can measure the surface form and internal form of an object to be measured using a light beam from a laser light source or the like. The fundus camera is an apparatus that can photograph and observe the state of the fundus of the subject's eye based on fundus reflected light of illumination light. The SLO is a device that obtains a fundus image by scanning laser light two-dimensionally with respect to the fundus using a confocal optical system and receiving the reflected light.

  The ophthalmologic photographing apparatus can photograph and measure the fundus of the eye to be examined. Such an ophthalmologic photographing apparatus needs to focus the photographing optical system on the photographing part. As a configuration for that purpose, for example, Patent Document 1 discloses a focus unit. The focus unit includes an indicator illumination member, a deflection prism, and a unit having an aperture and a split prism. Based on the focus information obtained by the focus unit, the in-focus state of the photographing optical system is controlled. Also, a diopter correction lens may be disposed in the optical path of the photographing optical system in order to correct diopter when the subject's eye is intense myopia or hyperopia.

JP 2006-116089 A

  In such an ophthalmologic photographing apparatus, if the focus position is not changed in accordance with the diopter of the eye to be examined, the acquired image becomes a so-called out-of-focus image, which may hinder diagnosis. For this reason, when photographing with the conventional ophthalmologic photographing apparatus, in addition to the alignment operation, a work for focusing is required, and the operation with respect to the ophthalmic photographing apparatus becomes complicated. In an ophthalmologic photographing apparatus that automatically changes the focus position, the above-described focus unit for focusing and a drive mechanism for changing the focus position of the photographing optical system are required. There is a problem of increasing complexity.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a new technique for simplifying the configuration and control of an ophthalmologic photographing apparatus.

The first aspect of the ophthalmologic photographing apparatus according to the embodiment includes an illumination optical system that irradiates the subject's eye with light from the first light source, and the eye to be examined that is irradiated with the light from the first light source by the illumination optical system. An imaging optical system that guides light from the fundus to a light field camera and a fundus image corresponding to a desired image plane position in the optical axis direction of the imaging optical system based on image data obtained by the light field camera An image generating unit.
In the second aspect of the ophthalmologic photographing apparatus according to the embodiment, in the first aspect, the illumination optical system has at least one of light from the first light source and a first wavelength range of light from the first light source. The light field camera switches between light from a second light source that emits light in a second wavelength range with different parts and irradiates the eye to be examined, and the light field camera includes at least a part of the first wavelength range and the second wavelength range. The image data may be acquired based on a light reception result of at least part of the light.
In the third aspect of the ophthalmologic photographing apparatus according to the embodiment, in the first aspect or the second aspect, the image generation unit includes a plurality of image plane positions corresponding to a plurality of image plane positions in the optical axis direction based on the image data. And an image extracting unit that extracts any one of the plurality of fundus images based on the image quality of each of the plurality of fundus images generated by the image generation unit.
According to a fourth aspect of the ophthalmologic photographing apparatus according to the embodiment, in the third aspect, an optical path combining member that combines the optical path of the illumination optical system and the optical path of the photographing optical system, and a combined optical path by the optical path combining member. And an arranged objective lens.
Further, in a fifth aspect of the ophthalmologic photographing apparatus according to the embodiment, in the fourth aspect, the optical path combining member is formed at a position where the hole is optically substantially conjugate with the pupil of the eye to be examined, from the illumination optical system. A hole mirror that deflects the light toward the objective lens may be included.
In the sixth aspect of the ophthalmologic photographing apparatus according to the embodiment, in the fourth aspect or the fifth aspect, the optical path combining member can be inserted into and removed from the optical path of the illumination optical system and the optical path of the photographing optical system. And the image generation unit obtains image data obtained by photographing the eye to be examined with the photographing optical system in a state where the optical path combining member is retracted from the optical path of the illumination optical system and the optical path of the photographing optical system. And generating a plurality of anterior ocular segment images corresponding to a plurality of image plane positions in the optical axis direction, and the image extracting unit generates the plurality of anterior ocular segments based on the image quality of the feature region in the anterior segment image. A shift amount specifying unit may be included that extracts any one of the partial images and specifies the shift amount in the optical axis direction based on the anterior segment image extracted by the image extraction unit.
According to a seventh aspect of the ophthalmologic photographing apparatus according to the embodiment, in the sixth aspect, the optical unit including the illumination optical system and the photographing optical system and the eye to be examined are relatively moved in the optical axis direction. A drive unit and a control unit that relatively moves the optical unit and the eye to be examined by controlling the drive unit based on the shift amount may be included.
Further, an eighth aspect of the ophthalmologic photographing apparatus according to the embodiment is the seventh aspect, in which the control unit relatively moves the optical unit and the eye to be examined based on the shift amount, and then performs the illumination. Based on the image data obtained by photographing the eye to be examined by the photographing optical system in a state where the optical path combining member is disposed in the optical path of the optical system and the optical path of the photographing optical system, An image may be generated.
Further, a ninth aspect of the ophthalmologic photographing apparatus according to the embodiment may include the light field camera in any one of the first to eighth aspects.
In addition, it is possible to combine arbitrarily the structure which concerns on the above-mentioned several aspect.

  According to the present invention, it is possible to provide a new technique for simplifying the configuration and control of an ophthalmologic photographing apparatus.

It is the schematic showing an example of a structure of the optical system of the ophthalmologic imaging device which concerns on 1st Embodiment. It is a schematic block diagram showing an example of the composition of the control system of the ophthalmology photographing instrument concerning a 1st embodiment. It is the schematic showing the flow of the operation example of the ophthalmologic imaging device which concerns on 1st Embodiment. It is the schematic showing an example of a structure of the optical system of the ophthalmologic imaging device which concerns on 2nd Embodiment. It is a schematic block diagram showing an example of the structure of the control system of the ophthalmologic imaging apparatus which concerns on 2nd Embodiment. It is the schematic showing the flow of the operation example of the ophthalmologic imaging device which concerns on 2nd Embodiment. It is the schematic showing the flow of the operation example of the ophthalmologic imaging device which concerns on 2nd Embodiment. It is a schematic block diagram showing an example of a structure of the optical system of the ophthalmologic imaging device which concerns on 3rd Embodiment. It is a schematic block diagram showing an example of a structure of the control system of the ophthalmologic imaging apparatus which concerns on 3rd Embodiment. It is the schematic showing the flow of the operation example of the ophthalmologic imaging device which concerns on 3rd Embodiment.

  An example of an embodiment of the present invention will be described in detail with reference to the drawings. The ophthalmologic photographing apparatus according to the embodiment is capable of acquiring an image at an arbitrary image plane position in the optical axis direction and irradiating light from the illumination optical system. A photographing optical system for photographing or observing the eye to be examined.

  Hereinafter, the ophthalmologic photographing apparatus according to the embodiment is a fundus photographing apparatus (fundus camera) for photographing the fundus of the subject's eye, but photographs any part of the subject's eye such as the anterior segment of the subject's eye. It is applicable to what to do. In addition, for example, an OCT apparatus, an SLO apparatus, a slit lamp, an ophthalmic surgical microscope, a photocoagulation apparatus, and the like can be combined with the configuration according to the following embodiment.

  The contents of the literature cited in this specification can be used as the contents of the following embodiments.

<First Embodiment>
[Constitution]
FIG. 1 shows a configuration example of an optical system of the ophthalmologic photographing apparatus 1 according to the first embodiment.

  The ophthalmologic photographing apparatus 1 includes an optical unit 2. The optical unit 2 includes an optical system for realizing the function of the fundus camera. Further, the ophthalmologic photographing apparatus 1 is provided with an arithmetic control unit and a user interface unit. The arithmetic control unit includes a computer that executes various arithmetic processes and control processes. The user interface unit is used to display an observation image and a captured image acquired using the optical unit 2 and to input an instruction to the ophthalmologic photographing apparatus 1.

[Optical unit]
The optical unit 2 is provided with an optical system for acquiring a two-dimensional image (fundus image) representing the surface form of the fundus oculi Ef of the eye E. The fundus image includes an observation image and a captured image. The observation image is, for example, a monochrome moving image formed at a predetermined frame rate using near infrared light. The captured image may be, for example, a color image obtained by flashing visible light, or a monochrome still image using near infrared light or visible light as illumination light. The optical unit 2 may be configured to be able to acquire images other than these, for example, a fluorescein fluorescent image, an indocyanine green fluorescent image, a spontaneous fluorescent image, and the like.

  The ophthalmologic photographing apparatus 1 is provided with a chin rest and a forehead support for supporting a subject's face. The optical unit 2 is provided with an illumination optical system 10 and a photographing optical system 20. The illumination optical system 10 irradiates illumination light to the fundus oculi Ef of the subject whose face is fixed to the chin rest and the forehead. The photographing optical system 20 guides the fundus reflection light of the illumination light to the light field camera 21 that is an imaging device.

  The illumination optical system 10 includes an observation light source 11, a photographing light source 12, a dichroic mirror 13, an iris diaphragm 14A, a lens diaphragm 14B, a relay lens 16, a black spot 14C, a mirror 18, a relay lens 19, and a cornea. An aperture 14D, a hole mirror 30, and an objective lens 31 are included. The iris diaphragm 14A is disposed at a position optically conjugate with the iris of the eye E. The lens diaphragm 14B is disposed at a position optically conjugate with the rear surface of the lens of the eye E to be examined. The black dots 14C are arranged at positions that are optically conjugate with holes to be described later formed in the hole mirror 30 when each surface of the objective lens 31 is a reflecting surface. The corneal stop 14D is disposed at a position optically substantially conjugate with the cornea of the eye E to be examined.

  The photographing optical system 20 includes a light field camera 21, a relay lens 22, a relay lens 24, a hole mirror 30, and an objective lens 31. The light field camera 21 may be provided outside the photographing optical system 20.

  The hole mirror 30 is an optical path combining member that combines the optical path of the illumination optical system 10 and the optical path of the photographing optical system 20. In the center region of the hole mirror 30, a hole through which the optical axis of the photographing optical system 20 passes is formed. The hole formed in the hole mirror 30 is disposed at a position that is optically conjugate with the pupil of the eye E to be examined. The peripheral part of the hole part formed in the hole mirror 30 (region around the hole part) reflects light from the illumination optical system 10 toward the objective lens 31. The objective lens 31 is disposed in the combined optical path of the optical path of the illumination optical system 10 combined by the hole mirror 30 and the optical path of the photographing optical system 20. The hole mirror 30 and the objective lens 31 are optical elements shared by the illumination optical system 10 and the photographing optical system 20.

  The observation light source 11 includes, for example, a halogen lamp or an LED (Light Emitting Diode). The observation light source 11 emits near infrared light as observation illumination light. The observation illumination light output from the observation light source 11 is reflected toward the eye E by the dichroic mirror 13, and is reflected by the mirror 18 via the iris diaphragm 14A, the lens diaphragm 14B, the relay lens 16, and the black point 14C. The observation illumination light reflected by the mirror 18 passes through the relay lens 19 and the corneal stop 14D, and is reflected by the peripheral portion of the hole portion (region around the hole portion) formed in the central region of the hole mirror 30, It is refracted by the objective lens 31 to illuminate the fundus oculi Ef.

  The fundus reflection light of the observation illumination light is refracted by the objective lens 31, passes through a hole formed in the central region of the hole mirror 30, and is guided to the light field camera 21 via the relay lenses 24 and 22. When the eye E is normal (0D), it is desirable that the fundus oculi Ef of the eye E and the microlens array surface described later in the light field camera 21 are optically substantially conjugate. The light field camera 21 detects fundus reflected light at a predetermined frame rate, for example. On the user interface unit, an image (observation image) at an arbitrary image plane position based on fundus reflection light detected by the light field camera 21 is displayed. When the display setting in the user interface unit is set to the anterior segment Ea, an observation image of the anterior segment of the eye E is displayed.

  The imaging light source 12 includes, for example, a xenon lamp or an LED. The imaging light source 12 emits visible light as imaging illumination light. The photographic illumination light output from the photographic light source 12 passes through the dichroic mirror 13 and irradiates the fundus oculi Ef through the same path as the observation illumination light.

  The fundus reflection light of the imaging illumination light is guided to the relay lens 22 through the same path as the fundus reflection light of the observation illumination light, and is guided to the light field camera 21 via the relay lens 22. The user interface unit displays an image (captured image) at an arbitrary image plane position based on fundus reflected light detected by the light field camera 21. Note that the user interface unit that displays the observation image and the user interface unit that displays the captured image may be the same or different. In addition, when similar imaging is performed by illuminating the eye E with infrared light, an infrared captured image is displayed.

  The light field camera 21 according to the embodiment is a photographing device that can obtain an image at an arbitrary image plane position in the optical axis direction of the photographing optical system 20 from a received signal by calculation. Thereby, it is possible to obtain an image at a desired image plane position in focus after shooting. Such a light field camera 21 has, for example, a microlens array type configuration. In this case, the light field camera 21 includes a microlens array and an image sensor. The microlens array is disposed between the eye E and the image sensor. The microlens array includes a plurality of microlenses arranged in a matrix on the focal plane. The plurality of microlenses are arranged such that the optical axis direction substantially coincides with the optical axis direction of the photographing optical system 20. The image sensor includes a plurality of pixels arranged in a matrix corresponding to the plurality of microlenses, and is disposed at a position separated by a predetermined distance with respect to the microlens array. The light refracted by each microlens enters a plurality of pixels corresponding to the microlens. Thereby, the plurality of pixels output detection results (image data) corresponding to the passing positions and directions of the light rays incident on the focal plane. In addition, a lens may be disposed between the relay lens 22 and the microlens array as necessary.

  As described above, the wavelength range of the observation illumination light from the observation light source 11 is different from the wavelength range of the imaging illumination light from the imaging light source 12. For this reason, in the normal optical system, both in-focus positions do not match due to the influence of the chromatic dispersion of the eye E or the optical system. However, the light field camera 21 receives the fundus reflection light of the imaging illumination light from the imaging light source 12 and the fundus reflection light of the observation illumination light from the observation light source 11 and acquires image data. In other words, the light field camera 21 according to the embodiment focuses on both an image using near infrared light as illumination light and an image using visible light as illumination light without changing the focusing means. Images can be acquired. That is, the light field camera 21 acquires image data based on the light reception results of at least a part of the wavelength range of the imaging illumination light from the imaging light source 12 and at least a part of the wavelength range of the observation illumination light from the observation light source 11. It is possible.

  The arithmetic and control unit performs a known deconvolution process (image restoration process) on the detection results (image data) output from the plurality of pixels of the light field camera 21, and thereby the image at the image plane position in focus. Can be generated.

  Such an ophthalmologic photographing apparatus 1 may be provided with a fixation optical system that projects a fixation light beam onto the eye E to be examined. For example, the optical path of the fixation optical system is combined with the optical path of the imaging optical system 20 between the hole mirror 30 and the light field camera 21 in the imaging optical system 20. That is, the fixation light flux is guided to the eye E through the optical path of the photographing optical system 20. The fixation light beam projected by the fixation optical system passes through the hole of the hole mirror 30, is refracted by the objective lens 31, and is projected onto the fundus oculi Ef through the pupil of the eye E to be examined. It is possible to change the fixation position of the eye E by changing the projection position of the fixation light flux on the fundus oculi Ef. The fixation optical system is used, for example, when photographing the fundus.

  Further, the ophthalmologic photographing apparatus 1 may be provided with an alignment optical system that projects alignment index light for performing alignment (alignment) between the optical unit 2 and the eye E to be examined. For example, the optical path of the alignment optical system is combined with the optical path of the imaging optical system 20 between the hole mirror 30 and the light field camera 21 in the imaging optical system 20. That is, the alignment index light from the alignment optical system passes through the hole of the hole mirror 30 through the optical path of the imaging optical system 20, is refracted by the objective lens 31, and is applied to the cornea of the eye E. The corneal reflection light of the alignment index light is imaged by the light field camera 21 via the objective lens 31 and the hole portion of the hole mirror 30. An image (alignment index image) at an arbitrary image plane position obtained by the light field camera 21 is displayed on the user interface unit together with the observation image. The user can perform alignment by performing the same operation as a conventional fundus camera (manual alignment function). An arithmetic control unit (not shown) may perform alignment by analyzing the position of the alignment index image and moving the optical unit 2 (auto alignment function). The alignment may be performed using an anterior segment camera that observes the anterior segment Ea from the outside of the photographing optical axis.

[Calculation control unit]
The configuration of the arithmetic control unit will be described. The arithmetic control unit controls each unit of the optical unit 2 and the user interface unit 400. For example, the arithmetic control unit displays a fundus image of the eye E on the user interface unit 400. The arithmetic control unit includes, for example, a microprocessor, a RAM (Random Access Memory), a ROM (Read Only Memory), a hard disk drive, a communication interface, and the like, as in a conventional computer. A computer program for controlling the ophthalmologic photographing apparatus 1 is stored in a storage device such as a hard disk drive. The arithmetic control unit may include an operation device (input device) such as a keyboard and a mouse, and a display device such as an LCD.

[Control system]
The configuration of the control system of the ophthalmologic photographing apparatus 1 will be described with reference to FIG. In FIG. 2, some components of the ophthalmologic photographing apparatus 1 are omitted, and components particularly necessary for describing this embodiment are selectively shown.

(Control part)
The control system of the ophthalmologic photographing apparatus 1 is configured around the control unit 100. The control unit 100 includes, for example, a microprocessor, RAM, ROM, hard disk drive, communication interface, and the like. The control unit 100 is provided with a main control unit 110 and a storage unit 120.

(Main control unit)
The main control unit 110 performs the various controls described above. For example, the main control unit 110 performs lighting control and extinguishing control of the observation light source 11 and the photographing light source 12, and photographing control of the light field camera 21. The main control unit 110 controls the optical system driving unit 2A, the data processing unit 300, the user interface unit 400, and the like.

  The optical system driving unit 2A drives a moving mechanism that three-dimensionally moves the optical unit 2 (device optical system) shown in FIG. The moving mechanism includes a holding member that holds the optical unit 2, an actuator that generates a driving force for moving the holding member, and a transmission mechanism that transmits the driving force. The actuator is constituted by, for example, a pulse motor. The transmission mechanism is configured by, for example, a combination of gears, a rack and pinion, or the like. The main control unit 110 can move the optical system provided in the ophthalmologic photographing apparatus 1 three-dimensionally by controlling the optical system driving unit 2A. This control is used in alignment and tracking. Tracking refers to moving the apparatus optical system in accordance with the movement of the eye E. Tracking is a function that maintains a suitable positional relationship in alignment by moving the apparatus optical system in real time according to the position and orientation of the eye E based on an image obtained by taking a moving image of the eye E. is there.

(Memory part)
The storage unit 120 stores various data. Examples of data stored in the storage unit 120 include image data of a fundus image and eye information to be examined. The eye information includes information about the subject such as the patient ID and name, information about the subject's disease name (such as glaucoma and cataract), and information about the eye such as left / right eye identification information. including. The storage unit 120 stores various programs and data for operating the ophthalmologic photographing apparatus 1.

(Data processing part)
The data processing unit 300 performs various data processing (image processing) and analysis processing on the image data obtained by the light field camera 21. For example, the data processing unit 300 performs image brightness correction. In addition, the data processing unit 300 performs various types of image processing and analysis processing on the image (fundus image, anterior eye image, etc.) obtained by the optical unit 2.

  The data processing unit 300 includes a deconvolution processing unit 310, an image quality evaluation unit 320, and a best image extraction unit 330.

  The deconvolution processing unit 310 performs a known deconvolution process on the image data obtained by the light field camera 21. For example, the deconvolution processing unit 310 performs the following processing. First, the deconvolution processing unit 310 performs ray tracing processing or the like on the image data according to the image plane position in the optical axis direction of the imaging optical system 20 specified by the main control unit 110 or the user, and performs a plurality of stereo operations. An image group is formed. The deconvolution processing unit 310 obtains parallax from the formed image group using a known algorithm, translates and superimposes the image group according to the obtained parallax, and averages the superimposed image group By performing the processing, an image (refocus image) corresponding to the image plane position is generated. The user can specify an image plane position to be observed using the user interface unit 400. The deconvolution processing unit 310 can generate an image corresponding to an arbitrary image plane position in the optical axis direction of the photographing optical system 20.

  The image quality evaluation unit 320 evaluates the image quality of an image at an arbitrary image plane position generated by the deconvolution processing unit 310. The image quality evaluation unit 320 can obtain an evaluation value representing the image quality of the generated image, and can evaluate the image quality of the image based on the obtained evaluation value. The evaluation value includes, for example, a value corresponding to contrast and luminance unevenness. In this embodiment, the image quality evaluation unit 320 evaluates the image quality of the image based on the contrast of the generated image. For example, the image quality evaluation unit 320 obtains the luminance difference in the luminance distribution of the entire image generated by the deconvolution processing unit 310 or the luminance difference in the luminance distribution of the feature region in the image as an evaluation value, and uses the obtained evaluation value. Based on this, the image quality of the image is evaluated. The characteristic region may be a region including a position corresponding to a characteristic part (boundary of the characteristic part) of the eye E. The feature area may be a predetermined area in the image.

  The image quality evaluation unit 320 is not limited to the one that directly evaluates the quality of the acquired image. The image quality evaluation unit 320 may indirectly evaluate the quality of the image by analyzing the image drawn on the acquired image. For example, when the relative position between the eye E and the optical unit 2 is a predetermined reference relative position, a light beam of near infrared light is projected onto the eye so that the size of the bright spot image is minimized, and the light beam is projected. An image at an arbitrary image plane position of the eye to be examined is acquired. The image quality evaluation unit 320 can evaluate the image quality based on the size and positional relationship of the bright spot image drawn on each of the images at a plurality of image plane positions generated by the deconvolution processing unit 310.

  The best image extraction unit 330 extracts the highest quality image from the images generated by the deconvolution processing unit 310 based on the evaluation result by the image quality evaluation unit 320. For example, the best image extraction unit 330 has the highest contrast as the highest image quality among the plurality of fundus images corresponding to the plurality of image plane positions in the optical axis direction of the imaging optical system 20 generated by the deconvolution processing unit 310. A good fundus image (a fundus image with the largest luminance difference) is extracted.

  The data processing unit 300 that functions as described above includes, for example, a microprocessor, a RAM, a ROM, a hard disk drive, a circuit board, and the like. In a storage device such as a hard disk drive, a computer program for causing the microprocessor to execute the above functions is stored in advance.

(User interface part)
The user interface unit 400 includes an operation unit 410 and a display unit 420. The operation unit 410 includes the operation device of the arithmetic control unit described above. The operation unit 410 may include various buttons and keys provided on the housing of the ophthalmologic photographing apparatus 1 or outside. The display unit 420 includes the display device of the arithmetic control unit described above. In addition, the display unit 420 may include various display devices such as a touch panel provided in the housing of the optical unit 2.

  Note that the operation unit 410 and the display unit 420 do not have to be configured as individual devices. For example, a device in which a display function and an operation function are integrated, such as a touch panel, can be used. In that case, the operation unit 410 includes the touch panel and a computer program. The operation content for the operation unit 410 is input to the control unit 100 as an electrical signal. Further, operations and information input may be performed using a graphical user interface (GUI) displayed on the display unit 420 and the operation unit 410.

  The imaging light source 12 is an example of a “first light source” according to the embodiment. The observation light source 11 is an example of a “second light source” according to the embodiment. The data processing unit 300 is an example of an “image generation unit” according to the embodiment. The best image extraction unit 330 is an example of an “image extraction unit” according to the embodiment. The hole mirror 30 is an example of an “optical path combining member” according to the embodiment. The optical system driving unit 2A is an example of the “driving unit” according to the embodiment.

[Operation example]
FIG. 3 shows an operation example of the ophthalmologic photographing apparatus 1 according to the first embodiment. FIG. 3 illustrates an example of an operation flow when photographing the fundus oculi Ef of the eye E. Here, it is assumed that alignment of the optical unit 2 with respect to the eye E to be examined (x direction, y direction, and z direction) is completed by a known method. For example, the main control unit 110 projects alignment index light onto the eye E by an alignment optical system (not shown) based on the user's operation content on the operation unit 410, and the corneal reflection light of the alignment index light together with the observation image of the eye E An alignment index image based on the above is displayed on the display unit 420. The user completes the alignment of the optical unit 2 with respect to the eye E by operating the operation unit 410 while viewing the image displayed on the display unit 420.

(S1)
The main control unit 110 controls the observation light source 11 to turn on the observation light source 11. The observation illumination light from the observation light source 11 is reflected by the dichroic mirror 13 as described above, reflected by the peripheral part of the hole formed in the central region of the hole mirror 30, and refracted by the objective lens 31. Illuminate Ef.

(S2)
The main control unit 110 controls the light field camera 21 to start photographing the fundus oculi Ef of the eye E illuminated with the observation illumination light, thereby causing the light field camera 21 to acquire image data.

(S3)
Subsequently, the main control unit 110 uses the image data obtained from the light field camera 21 in S2 to deconvolute processing units 310 for a plurality of fundus images at a plurality of image plane positions in the optical axis direction of the photographing optical system 20. To generate. The plurality of image plane positions may be determined in advance or may be designated by the user using the operation unit 410.

(S4)
The main control unit 110 causes the image quality evaluation unit 320 to evaluate the image quality for each of the plurality of fundus images generated in S3. The main control unit 110 causes the best image extraction unit 330 to extract the fundus image with the highest image quality based on the evaluation result by the image quality evaluation unit 320. The best image extraction unit 330 extracts the fundus image at the image plane position with the best contrast among the fundus images at the plurality of image plane positions generated in S3 as described above.

  When the interval between the image plane positions of the plurality of fundus images evaluated by the image quality evaluation unit 320 is rough and the evaluation value of the fundus image extracted by the best image extraction unit 330 is less than a predetermined threshold, the image quality evaluation unit 320 The image is acquired by reducing the interval between the image plane positions in the vicinity of the best image plane position of the extracted fundus image, the image quality of the acquired image is evaluated, and the best image extraction unit 330 is based on the evaluation result. Thus, it is possible to extract a fundus image at an image plane position with better contrast.

(S5)
The main control unit 110 displays the fundus image at the image plane position extracted in S4 on the display unit 420 as a moving image. The user can check the shooting position, the fixation position, and the like while viewing the fundus image displayed on the display unit 420.

(S6)
The main control unit 110 obtains a trigger for starting photographing and controls the observation light source 11 to turn off the observation light source 11.

(S7)
Subsequently, the main control unit 110 controls the photographing light source 12 to turn on the photographing light source 12. The photographing illumination light from the photographing light source 12 passes through the dichroic mirror 13 as described above, is reflected at the periphery of the hole formed in the central region of the hole mirror 30, and is refracted by the objective lens 31. Illuminate Ef.

(S8)
The main control unit 110 controls the light field camera 21 to start photographing the fundus oculi Ef of the subject eye E irradiated with photographing illumination light, thereby causing the light field camera 21 to acquire image data.

(S9)
Subsequently, the main control unit 110 generates a fundus image at a plurality of image plane positions in the optical axis direction of the photographing optical system 20 in the deconvolution processing unit 310 using the image data obtained from the light field camera 21 in S8. Let The plurality of image plane positions may be determined in advance as in S2, or may be designated by the user using the operation unit 410. The plurality of image plane positions in S9 may be set near the image plane position in S4.

(S10)
Similarly to S4, the main control unit 110 causes the image quality evaluation unit 320 to evaluate the image quality for each of the plurality of fundus images generated in S9. The main control unit 110 causes the best image extraction unit 330 to extract the fundus image with the highest image quality based on the evaluation result by the image quality evaluation unit 320. The best image extraction unit 330 extracts the fundus image having the highest contrast among the plurality of fundus images generated in S9 as the fundus image having the highest image quality.

  In S10, as in S4, the interval between the image plane positions of the plurality of fundus images evaluated by the image quality evaluation unit 320 is rough, and the evaluation value of the fundus image extracted by the best image extraction unit 330 is less than a predetermined threshold value. In some cases, the image quality evaluation unit 320 acquires an image by reducing the interval between the image plane positions in the vicinity of the best image plane position of the extracted fundus image, evaluates the image quality of the acquired image, and extracts the best image. The unit 330 can extract a fundus image at an image plane position with better contrast based on the evaluation result.

(S11)
The main control unit 110 causes the display unit 420 to display the fundus image extracted in S10. This is the end of the operation of the ophthalmologic photographing apparatus 1 (end).

  As described above, according to the first embodiment, since the light field camera 21 is provided in the photographing optical system 20, a plurality of images in the z direction can be obtained by performing a deconvolution process on the acquired image. An image at the surface position can be generated. As a result, it is possible to evaluate the image quality of the plurality of generated images and extract the most focused image. Therefore, an optical system and a control system for adjusting the focus of the photographing optical system 20 can be eliminated. Further, the infrared split light projection system provided for determining the focus of the image obtained by the photographing optical system 20 as in the prior art can be eliminated.

  In addition, according to the first embodiment, since photographing with infrared light and photographing with visible light are performed by a single light field camera, a focus error due to a wavelength difference between infrared light and visible light is performed. There is no need to provide an optical element (lens) for correcting the above.

  Further, conventionally, there may be a case where an image focused on the entire surface of the fundus oculi Ef cannot be obtained due to the shape of the fundus oculi Ef. Even in such a case, according to the first embodiment, an image that is in focus on the entire surface of the fundus oculi Ef can be acquired by extracting and synthesizing an image that is in focus for each portion of the fundus image. It becomes like this.

  In this embodiment, the fundus is focused for detecting the light of the split light projection system, and the fundus image is obtained by illuminating with infrared light to take an image for observation of the measurement site (optic nerve head, etc.). The optical system 20 may be provided with an imaging system using infrared light. In this case, a beam splitter may be disposed between the relay lens 22 and the relay lens 24 so that the optical path of the imaging system and the optical path of the imaging optical system 20 are combined.

Second Embodiment
In the first embodiment, a case has been described in which a fundus image at a plurality of image plane positions of the photographing optical system 20 is acquired using the light field camera 21, but the configuration of the ophthalmologic photographing apparatus according to the embodiment is limited to this. It is not a thing. For example, the ophthalmologic apparatus according to the embodiment may include a diopter correction lens that can be disposed in the optical path of the photographing optical system.

  Hereinafter, the ophthalmologic photographing apparatus according to the second embodiment will be described focusing on differences from the ophthalmic photographing apparatus 1 according to the first embodiment.

  FIG. 4 shows a configuration example of the optical system of the ophthalmologic photographing apparatus according to the second embodiment. 4, parts that are the same as those in FIG. 1 are given the same reference numerals, and descriptions thereof will be omitted as appropriate.

  The configuration of the optical system of the ophthalmic imaging apparatus 1a according to the second embodiment is different from the configuration of the optical system of the ophthalmic imaging apparatus 1 according to the first embodiment in that an optical unit 2a is provided instead of the optical unit 2. It is. The optical unit 2 a is different from the optical unit 2 in that a photographic optical system 20 a is provided instead of the photographic optical system 20. The photographic optical system 20a is different from the photographic optical system 20 in that a diopter correction lens 40 is detachably provided with respect to the optical path between the relay lens 22 and the relay lens 24.

  The diopter correction lens 40 includes a minus (−) lens for correcting high myopia and a plus (+) lens used for correcting high intensity hyperopia. As the minus lens, for example, a -10D (diopter) concave lens is used. For example, a + 10D convex lens is used as the plus lens.

  FIG. 5 shows a block diagram of a schematic configuration of a control system of the ophthalmologic photographing apparatus 1a according to the second embodiment. In FIG. 5, the same components as those in FIG.

  The optical unit 2a is provided with the lens driving unit 40A for inserting and removing the diopter correction lens 40 as described above.

  For example, a diopter correction lens 40 (a minus lens and a plus lens) is disposed along a circumferential direction on a turret plate that is rotatable about a rotation axis. Moreover, a hole is formed in the circumferential direction of the turret plate. The lens driving unit 40A rotates the turret plate around a rotation shaft provided at a position decentered from the optical axis of the photographing optical system 20a. By rotating the turret plate about the rotation axis by the lens driving unit 40A, a minus lens or a plus lens is disposed in the optical path of the photographing optical system 20a, or the diopter correction lens 40 is retracted from the optical path. be able to.

  Further, for example, a diopter correction lens 40 is disposed in a direction orthogonal to the optical path of the photographing optical system 20a, and a flat plate in which a hole is formed is slid in that direction to slide the optical path of the photographing optical system 20a. Alternatively, the diopter correction lens 40 may be inserted and removed. In this case, the lens driving unit 40A slides the plane plate in the direction. Thereby, the diopter correction lens 40 is disposed in the optical path of the photographing optical system 20a, or the diopter correction lens 40 is retracted from the optical path of the photographing optical system 20a.

  The configuration of the control system of the ophthalmic imaging apparatus 1a according to the second embodiment is different from the configuration of the control system of the ophthalmic imaging apparatus 1 according to the first embodiment in that a control unit 100a is provided instead of the control unit 100. It is. The control unit 100a includes a main control unit 110a and a storage unit 120a. The control content by the main control unit 110a is obtained by adding control to the lens driving unit 40A to the control content by the main control unit 110. The main control unit 110a performs the above control according to the program stored in the storage unit 120a.

  6A and 6B show an operation example of the ophthalmologic photographing apparatus 1a according to the second embodiment. 6A and 6B show an example of an operation flow in the case of photographing the fundus oculi Ef of the eye E while using the diopter correction lens 40 as necessary. Here, as in the first embodiment, it is assumed that the alignment (x direction, y direction, and z direction) of the optical unit 2a with respect to the eye E is completed by a known method.

(S21)
The main control unit 110a controls the observation light source 11 to turn on the observation light source 11. The observation illumination light from the observation light source 11 is reflected by the dichroic mirror 13 as described above, reflected by the peripheral part of the hole formed in the central region of the hole mirror 30, and refracted by the objective lens 31. Illuminate Ef.

(S22)
The main control unit 110a controls the light field camera 21 to start photographing the fundus oculi Ef of the eye E to which the observation illumination light is irradiated, thereby causing the light field camera 21 to acquire image data.

(S23)
Subsequently, the main control unit 110a uses the image data obtained from the light field camera 21 in S22 to deconvolute processing units 310 for a plurality of fundus images at a plurality of image plane positions in the optical axis direction of the photographing optical system 20a. To generate. The plurality of image plane positions may be determined in advance or may be designated by the user using the operation unit 410.

(S24)
The main control unit 110a causes the image quality evaluation unit 320 to evaluate the image quality for each of the plurality of fundus images generated in S23. The main control unit 110 causes the best image extraction unit 330 to extract the fundus image with the highest image quality based on the evaluation result by the image quality evaluation unit 320. The best image extraction unit 330 extracts the fundus image having the highest contrast among the plurality of fundus images generated in S23 as described above as the fundus image having the highest image quality. In S24, similarly to S4, a fundus image with good contrast may be extracted.

(S25)
The main control unit 110a determines whether or not sufficient image quality is obtained for the image quality of the fundus image extracted in S24. When the eye E is intensified myopia or intensity hyperopia, a fundus image with sufficient image quality may not be obtained within the changeable range of the image plane position in the optical axis direction of the imaging optical system 20 in some cases. Therefore, the main control unit 110a determines whether sufficient image quality is obtained for the fundus image extracted in S24 based on the evaluation result by the image quality evaluation unit 320. For example, the image quality evaluation unit 320 obtains the luminance difference of the portion corresponding to the boundary of the characteristic part of the eye E for each fundus image. The main control unit 110a causes the best image extraction unit 330 to extract the fundus image having the maximum luminance difference among the plurality of fundus images generated in S23. Then, the main control unit 110a determines that the fundus image has sufficient image quality when the luminance difference in the extracted fundus image is equal to or greater than a predetermined threshold, and is sufficient when the luminance difference is less than the predetermined threshold. It is determined that the fundus image is not image quality.

  When it is determined that the image quality of the fundus image extracted in S24 is sufficient (S25: Y), the operation of the ophthalmologic photographing apparatus 1a proceeds to S26. When it is determined that the image quality of the fundus image extracted in S24 is not sufficient (S25: N), the operation of the ophthalmologic photographing apparatus 1a proceeds to S27.

(S26)
When it is determined in S25 that the image quality of the fundus image is sufficient (S25: Y), the main control unit 110a causes the display unit 420 to display the fundus image extracted in S24. The user can check the shooting position, the fixation position, and the like while viewing the fundus image displayed on the display unit 420.

(S27)
When it is determined in S25 that the image quality of the fundus image is not sufficient (S25: N), the main control unit 110a determines whether or not to correct the diopter to the plus side. For example, the main control unit 110a determines the image quality of the fundus image at the plus side image plane position (luminance difference of the above portion) and the minus side with respect to the image plane position of the fundus image extracted in S24 among the plurality of fundus images. The image quality of the fundus image at the image plane position (luminance difference in the above portion) is compared. When it is determined that the image quality of the fundus image at the plus-side image plane position is higher than the image quality of the fundus image at the minus-side image plane position, the main control unit 110a determines to correct the diopter to the plus side. When it is determined that the image quality of the fundus image at the minus image plane position is higher than the image quality of the fundus image at the plus image plane position, the main control unit 110a determines to correct the diopter to the minus side.

  When it is determined that the diopter is corrected to the plus side (S27: Y), the operation of the ophthalmologic photographing apparatus 1a proceeds to S28. When it is determined not to correct the diopter to the plus side (S27: N), the operation of the ophthalmologic photographing apparatus 1a proceeds to S29.

(S28)
When it is determined in S27 that the diopter is corrected to the plus side (S27: Y), the main control unit 110a controls the lens driving unit 40A to add a plus lens (diopter correction lens 40 in the optical path of the photographing optical system 20). ). Subsequently, the operation of the ophthalmologic photographing apparatus 1a proceeds to S22.

(S29)
When it is determined in S27 that the diopter is not corrected to the plus side (S27: N), the main control unit 110a controls the lens driving unit 40A to add a minus lens (a diopter correction lens) in the optical path of the photographing optical system 20. 40). Subsequently, the operation of the ophthalmologic photographing apparatus 1a proceeds to S22.

(S30)
Subsequent to S26, the main control unit 110a controls the observation light source 11 to turn off the observation light source 11.

(S31)
Next, the main control unit 110a controls the photographing light source 12 to turn on the photographing light source 12. The photographing illumination light from the photographing light source 12 passes through the dichroic mirror 13 as described above, is reflected at the periphery of the hole formed in the central region of the hole mirror 30, and is refracted by the objective lens 31. Illuminate Ef.

(S32)
The main controller 110a controls the light field camera 21 to start photographing the fundus oculi Ef of the eye E to which the photographing illumination light is irradiated, thereby causing the light field camera 21 to acquire image data.

(S33)
The main control unit 110a uses the image data obtained from the light field camera 21 in S32 to generate a plurality of fundus images at each of a plurality of image plane positions in the optical axis direction of the photographing optical system 20 to the deconvolution processing unit 310. Let The plurality of image plane positions may be determined in advance as in S22, or may be designated by the user using the operation unit 410.

(S34)
The main control unit 110a causes the image quality evaluation unit 320 to evaluate the image quality for each of the plurality of fundus images generated in S33, as in S24. The main control unit 110 causes the best image extraction unit 330 to extract the fundus image with the highest image quality based on the evaluation result by the image quality evaluation unit 320. The best image extraction unit 330 extracts the fundus image having the highest contrast among the plurality of fundus images generated in S33 as the fundus image having the highest image quality.

(S35)
The main control unit 110 causes the display unit 420 to display the fundus image extracted in S34. This is the end of the operation of the ophthalmologic photographing apparatus 1a.

  As described above, according to the second embodiment, the following effects can be obtained in addition to the effects of the first embodiment. In other words, since a diopter correction lens for diopter correction is provided, adjustment of the focus position with a large correction amount due to intensity myopia or intensity hyperopia is realized by inserting and removing the diopter correction lens. Adjustment of the focus position with a small amount can be realized by the light field camera 21.

<Third Embodiment>
In the first embodiment or the second embodiment, the case where the light field camera 21 is used only for photographing has been described. However, the configuration of the ophthalmologic photographing apparatus according to the embodiment is not limited to this. For example, the light field camera 21 may be used for photographing and aligning the optical unit and the eye to be examined in the z direction (the optical axis direction of the photographing optical system 20).

  Hereinafter, an ophthalmologic photographing apparatus according to the third embodiment will be described focusing on differences from the ophthalmic photographing apparatus 1 according to the first embodiment.

  FIG. 7 shows a configuration example of an optical system of an ophthalmologic photographing apparatus according to the third embodiment. 7, parts that are the same as those in FIG. 1 are given the same reference numerals, and descriptions thereof will be omitted as appropriate.

  The configuration of the optical system of the ophthalmic imaging apparatus 1b according to the third embodiment is different from the configuration of the optical system of the ophthalmic imaging apparatus 1 according to the first embodiment in that an optical unit 2b is provided instead of the optical unit 2. It is. The configuration of the optical unit 2 b is different from the configuration of the optical unit 2 in that the anterior eye observation light source 70 is added and the hole mirror 30 is inserted into the optical path of the illumination optical system 10 and the optical path of the imaging optical system 20. It is a point that can be removed. The anterior segment observation light source 70 irradiates the anterior segment Ea of the eye E with light.

  In the same manner as in the first and second embodiments, the light field camera 21 moves the fundus oculi Ef of the eye E with the hole mirror 30 disposed in the optical path of the illumination optical system 10 and the optical path of the imaging optical system 20. Image data of the fundus oculi Ef can be acquired by photographing. The light field camera 21 captures the anterior segment Ea of the eye E by photographing the anterior segment Ea of the eye E with the hole mirror 30 retracted from the optical path of the illumination optical system 10 and the optical path of the imaging optical system 20. Image data can be acquired.

  In the photographing optical system 20, for example, an anterior segment focus lens may be detachably provided between the hole mirror 30 and the relay lens 24. In this case, when the anterior segment Ea is imaged by the light field camera 21 (that is, when the hole mirror 30 is retracted from the optical path of the illumination optical system 10 and the optical path of the imaging optical system 20), the optical path of the imaging optical system 20 is detected. An anterior segment focus lens is arranged. When the fundus oculi Ef is photographed by the light field camera 21 (that is, when the hole mirror 30 is disposed in the optical path of the illumination optical system 10 and the optical path of the photographing optical system 20), the anterior eye portion focus lens from the optical path of the photographing optical system 20 Is evacuated.

  The anterior ocular segment observation light source 70 irradiates light to the anterior ocular segment Ea of the eye E from outside the optical axis of the imaging optical system 20. Similar to the observation light source 11, the anterior ocular segment observation light source 70 includes, for example, a halogen lamp or an LED. Similar to the observation light source 11, the anterior segment observation light source 70 emits near infrared light as observation illumination light. In FIG. 7, a plurality of anterior ocular segment observation light sources 70 are provided around the optical axis of the photographing optical system 20. The anterior eye portion observation light source 70 is a light source for illuminating the anterior eye portion Ea of the eye E, while the observation light source 11 is a light source for illuminating the fundus oculi Ef of the eye E. Hereinafter, the observation light source 11 may be referred to as a fundus observation light source.

  FIG. 8 shows a block diagram of a schematic configuration of a control system of the ophthalmologic photographing apparatus 1b according to the third embodiment. 8, parts similar to those in FIG. 2 are given the same reference numerals, and description thereof will be omitted as appropriate.

  In addition to the anterior ocular segment observation light source 70 described above, the optical unit 2b is provided with a hole mirror drive unit 30A for inserting and removing the hole mirror 30.

  For example, the hole mirror driving unit 30A includes a holding member that holds the hole mirror 30, an actuator that generates a driving force for moving the holding member, and a transmission mechanism that transmits the driving force. The actuator is constituted by, for example, a pulse motor. The transmission mechanism is configured by, for example, a combination of gears, a rack and pinion, or the like. Thereby, the hole mirror drive unit 30A under the control of the control unit 100b moves the hole mirror 30 so that the hole mirror 30 is inserted into and removed from the optical path of the illumination optical system 10 and the optical path of the photographing optical system 20. be able to. The hole mirror driving unit 30A may be inserted into and removed from the optical path of the illumination optical system 10 and the optical path of the photographing optical system 20 by manual or user operation on the operation unit 410.

  The configuration of the control system of the ophthalmic imaging apparatus 1b according to the third embodiment is different from the configuration of the control system of the ophthalmic imaging apparatus 1 according to the first embodiment in that a control unit 100b is provided instead of the control unit 100. The data processing unit 300b is provided in place of the data processing unit 300. The control unit 100b includes a main control unit 110a and a storage unit 120a. The control content by the main control unit 110b is added to the control content by the main control unit 110 in that the control for the anterior ocular segment observation light source 70, the control for the hole mirror driving unit 30A, and the anterior ocular segment alignment control are added. . The anterior segment alignment control according to this embodiment is performed between the eye E and the optical unit 2b on the basis of the position of a characteristic part (for example, pupil region, pupil edge, iris pattern, etc.) in the anterior segment Ea of the subject eye E. This corresponds to alignment control for adjusting the distance to a predetermined distance. The main control unit 110b executes the above control according to a program stored in the storage unit 120b.

  The data processing unit 300b includes a deconvolution processing unit 310, an image quality evaluation unit 320, a best image extraction unit 330, a position specifying unit 340, and a deviation amount specifying unit 350.

  The deconvolution processing unit 310 performs a known deconvolution process on the image data of the fundus oculi Ef as in the above embodiment. Further, the deconvolution processing unit 310 can perform a known deconvolution process on the image data of the anterior segment Ea obtained by photographing the anterior segment Ea with the light field camera 21. The deconvolution processing unit 310 performs a deconvolution process on the image data of the anterior segment Ea obtained by the light field camera 21, thereby the anterior eye at an arbitrary image plane position in the optical axis direction of the photographing optical system 20. A partial image can be generated.

  The image quality evaluation unit 320 can evaluate the image quality of the anterior ocular segment image generated by the deconvolution processing unit 310 in addition to the image quality of the fundus image in the above embodiment.

  The position specifying unit 340 specifies the feature position in the anterior segment image of the eye E obtained by the light field camera 21. The position specifying unit 340 can specify a feature position for each of a plurality of anterior segment images generated by the deconvolution processing unit 310. The characteristic position may be a pupil center (center of gravity), a corneal center (center of gravity), a pupil edge, or a position where a predetermined iris pattern is present. For example, the position specifying unit 340 specifies an image region (pupil region) corresponding to the pupil of the eye E based on the distribution of the pixel values (such as luminance values) of the anterior segment image of the eye E. In general, since the pupil is drawn with lower brightness than other parts, the pupil area can be specified by searching the low brightness image area. At this time, the pupil region may be specified in consideration of the shape of the pupil. That is, the pupil region can be specified by searching for a substantially circular and low luminance image region. Next, the position specifying unit 340 specifies the center position of the specified pupil region. Since the pupil is substantially circular as described above, the contour of the pupil region can be specified, the center position of this contour (approximate circle or approximate ellipse) can be specified, and this can be used as the pupil center. Further, the center of gravity of the pupil region may be obtained, and the center of gravity position may be used as the center of the pupil. Even when the feature position corresponding to another feature part is specified, it is possible to specify the feature position based on the distribution of pixel values of the photographed image in the same manner as described above. Further, the position specifying unit 340 projects an index light beam on the cornea of the eye E, detects a reflected image (Purkinje image) based on the reflected light beam from the cornea, and specifies the position of the reflected image as the position of the eye E. It is also possible to do.

  The best image extraction unit 330 extracts the anterior segment image at the image plane position with the best contrast as in the above embodiment. The best image extraction unit 330 is identified by the position identification unit 340 among a plurality of anterior eye images corresponding to a plurality of image plane positions in the optical axis direction of the imaging optical system 20 generated by the deconvolution processing unit 310. It is possible to extract an anterior ocular segment image (an anterior ocular segment image having the best contrast) with the highest image quality at the feature position.

  The shift amount specifying unit 350 specifies the shift amount in the optical axis direction of the imaging optical system 20 between the image plane position corresponding to the anterior segment image extracted by the best image extracting unit 330 and the reference position. The reference position may be an arrangement position of the microlens array on the optical axis of the photographing optical system 20. The arrangement position is a position away from the objective lens 31 by a predetermined distance, and is a position optically conjugate with the light receiving surface of the camera in the conventional anterior ocular segment observation system. The deviation amount specifying unit 350 can specify the displacement from the image plane position corresponding to the anterior segment image extracted by the best image extracting unit 330 as the above-described deviation amount with reference to the known arrangement position in advance. It is.

  The main control unit 110b controls the optical system driving unit 2A so as to cancel the shift amount specified by the shift amount specifying unit 350 and relatively move the optical unit 2b and the eye E to be examined.

  FIG. 9 shows an operation example of the ophthalmologic photographing apparatus 1b according to the third embodiment. FIG. 9 shows the image of the fundus oculi Ef of the eye E while the optical unit 2 is completely aligned with the eye E in the x direction and the y direction, and the optical unit 2b is aligned with the eye E in the z direction. An example of the operation flow in the case of

(S41)
First, the main control unit 110b controls the hole mirror driving unit 30A to retract the hole mirror 30 from the optical path of the illumination optical system 10 and the optical path of the photographing optical system 20.

(S42)
Next, the main control unit 110b controls the anterior segment observation light source 70 to turn on the anterior segment observation light source 70.

  As described above, when the imaging optical system 20 is provided with the anterior segment focusing lens, the main control unit 110 b arranges the anterior segment focusing lens in the optical path of the imaging optical system 20.

(S43)
The main control unit 110b controls the light field camera 21 to start photographing the anterior segment Ea of the eye E to which the illumination light from the anterior segment observation light source 70 is irradiated. 21 is made to acquire image data.

(S44)
Subsequently, the main control unit 110b uses the image data obtained from the light field camera 21 in S43 to deconstruct the anterior ocular segment image at each of a plurality of image plane positions in the optical axis direction of the photographing optical system 20. 310. The plurality of image plane positions may be determined in advance or may be designated by the user using the operation unit 410.

(S45)
The main control unit 110b causes the position specifying unit 340 to specify the pupil region for each of the anterior segment images at the plurality of image plane positions generated in S44. Further, the main control unit 110b causes the image quality evaluation unit 320 to evaluate the image quality of the pupil region for each of the plurality of anterior segment images. Based on the evaluation result by the image quality evaluation unit 320, the main control unit 110b causes the best image extraction unit 330 to extract the highest image quality anterior segment image for the pupil region. The best image extraction unit 330 selects the anterior ocular segment image having the best contrast with respect to the edge of the pupil, the iris pattern, etc. among the multiple anterior ocular segment images generated in S44 as described above. Extract as

(S46)
The main control unit 110b causes the shift amount specifying unit 350 to specify the shift amount in the optical axis direction of the imaging optical system 20 between the image plane position corresponding to the anterior segment image extracted in S45 and the reference position.

(S47)
The main control unit 110b controls the optical system driving unit 2A based on the shift amount specified in S46 to move the optical unit 2b and the eye E to be relatively moved.

(S48)
The main control unit 110b determines whether the alignment of the photographing optical system 20 in the optical axis direction is completed. The main controller 110b can determine that the alignment is complete when the difference between the distance between the eye E and the optical unit 2 and the working distance of the objective lens 31 is within a predetermined threshold. For example, the main control unit 110b obtains the difference between the distance between the eye E and the optical unit 2 and the working distance of the objective lens 31 by using the control content for the optical system driving unit 2A. When it is determined that the alignment of the photographing optical system 20 in the optical axis direction is completed (S48: Y), the operation of the ophthalmologic photographing apparatus 1b proceeds to S49. When it is determined that the alignment in the optical axis direction of the photographing optical system 20 is not completed (S48: N), the operation of the ophthalmologic photographing apparatus 1b proceeds to S43.

(S49)
When it is determined in S48 that the alignment of the photographing optical system 20 in the optical axis direction is completed (S48: Y), the main control unit 110b controls the anterior segment observation light source 70 to control the anterior segment observation light source 70. Turn off the light.

(S50)
Subsequently, the main control unit 110b controls the hole mirror driving unit 30A to place the hole mirror 30 in the optical path of the illumination optical system 10 and the optical path of the photographing optical system 20.

  As described above, when the anterior ocular focusing lens is provided in the imaging optical system 20, the main control unit 110 b retracts the anterior ocular focusing lens from the optical path of the imaging optical system 20.

(S51)
The main controller 110b controls the photographing light source 12 to turn on the photographing light source 12. The photographing illumination light from the photographing light source 12 passes through the dichroic mirror 13 as described above, is reflected at the periphery of the hole formed in the central region of the hole mirror 30, and is refracted by the objective lens 31. Illuminate Ef.

(S52)
The main control unit 110b controls the light field camera 21 to start photographing the fundus oculi Ef of the eye E irradiated with photographing illumination light, thereby causing the light field camera 21 to acquire image data.

(S53)
The main control unit 110 causes the deconvolution processing unit 310 to generate a fundus image at each of a plurality of image plane positions in the optical axis direction of the imaging optical system 20 using the image data obtained from the light field camera 21 in S52. The plurality of image plane positions may be determined in advance as in S44, or may be designated by the user using the operation unit 410.

(S54)
Similarly to S4, the main control unit 110b causes the image quality evaluation unit 320 to evaluate the image quality for each of the plurality of fundus images generated in S53. The main control unit 110 causes the best image extraction unit 330 to extract the fundus image with the highest image quality based on the evaluation result by the image quality evaluation unit 320. The best image extraction unit 330 extracts the fundus image having the best contrast among the plurality of fundus images generated in S53 as the fundus image having the highest image quality.

(S55)
The main control unit 110b displays the fundus image extracted in S54 on the display unit 420. This is the end of the operation of the ophthalmologic photographing apparatus 1 (end).

  As described above, according to the third embodiment, the following effects can be obtained in addition to the effects of the first embodiment. That is, since the hole mirror 30 can be inserted into and removed from the optical path, a fundus image similar to the conventional one can be obtained by arranging the hole mirror 30 in the optical path, while the hole mirror 30 is retracted from the optical path. As a result, a wide range of the anterior segment can be observed with the light field camera 21 even at a position where the alignment matches. Thereby, the alignment accuracy can be improved while the light field camera 21 is used for both photographing and alignment.

  In addition to the light field camera 21 for photographing, an alignment light field camera may be provided in the optical system that does not pass through the hole mirror 30. In this case, it is not necessary to retract the hole mirror 30.

[effect]
The effect of the ophthalmologic apparatus according to the embodiment will be described.

  The ophthalmologic imaging apparatus (1, 1a, 1b) according to the embodiment includes an illumination optical system (10), imaging optical systems (20, 20a), and an image generation unit (data processing units 300, 300b). The illumination optical system irradiates the eye (E) with light (imaging illumination light) from the first light source (imaging light source 12). The photographing optical system guides light (fundus reflected light) from the fundus (Ef) of the subject's eye irradiated with light from the first light source to the light field camera (21) by the illumination optical system. The image generation unit generates a fundus image corresponding to a desired image plane position in the optical axis direction (z direction) of the photographing optical system based on image data obtained by the light field camera.

  According to such a configuration, light from the fundus is guided to the light field camera by the photographing optical system, and it corresponds to a desired image plane position in the optical axis direction of the photographing optical system based on the image data obtained by the light field camera. Since the generated fundus image is generated, an optical system and a control system for adjusting the focus of the photographing optical system can be eliminated. Further, as in the prior art, an infrared split light projection system provided for determining the focus of an image obtained by the photographing optical system can be eliminated.

  In the ophthalmologic photographing apparatus according to the embodiment, the illumination optical system includes a second light at least partially different from the first wavelength range (the visible wavelength range) of the light from the first light source and the light from the first light source. The light field camera switches between the light from the second light source (observation light source 11) that emits light in the wavelength range (wavelength range of infrared light) and irradiates the eye to be examined. Image data may be acquired based on the light reception result of at least part of light in the two wavelength range.

  According to such a configuration, since the eye to be examined is illuminated by the light from the first light source and the second light source by the light field camera, the light from the first light source and the light from the second light source are captured. It is not necessary to provide an optical element (lens) for correcting a focus error due to dispersion caused by the wavelength difference between the first and second lenses.

  In the ophthalmologic photographing apparatus according to the embodiment, the image generation unit generates a plurality of fundus images corresponding to a plurality of image plane positions in the optical axis direction based on the image data, and the plurality of fundus images generated by the image generation unit. An image extraction unit (best image extraction unit 330) that extracts any one of a plurality of fundus images based on the image quality of each fundus image may be included.

  According to such a configuration, since the fundus image having the highest image quality is extracted from the fundus images corresponding to a plurality of image plane positions, simple image processing is performed from image data obtained by the light field camera. It is possible to easily obtain a focused fundus image.

  The ophthalmic imaging apparatus according to the embodiment includes an optical path synthesis member (hole mirror 30) that synthesizes the optical path of the illumination optical system and the optical path of the imaging optical system, and an objective lens (31) arranged in the synthesis optical path by the optical path synthesis member. ).

  According to such a configuration, the configuration of the optical system of the ophthalmologic photographing apparatus can be simplified.

  In the ophthalmologic photographing apparatus according to the embodiment, the optical path synthesizing member is a hole mirror that deflects light from the illumination optical system toward the objective lens, the hole portion being formed at a position substantially optically conjugate with the pupil of the eye to be examined. (30) may be included.

  According to such a configuration, the optical path of the illumination optical system and the optical path of the photographing optical system can be combined with a simple configuration, and the optical system can be downsized.

  In the ophthalmologic photographing apparatus according to the embodiment, the optical path combining member can be inserted into and removed from the optical path of the illumination optical system and the optical path of the photographing optical system, and the image generation unit includes the optical path of the illumination optical system and the photographing optical system. A plurality of anterior segment images corresponding to a plurality of image plane positions in the optical axis direction based on image data obtained by photographing the eye to be examined by the photographing optical system in a state where the optical path combining member is retracted from the optical path of And generating an image extracting unit that extracts any one of a plurality of anterior ocular segment images based on the image quality of the characteristic region in the anterior ocular segment image, and generates light based on the anterior ocular segment image extracted by the image extracting unit. A shift amount specifying unit (350) that specifies the shift amount in the axial direction may be included.

  According to such a configuration, it is possible to obtain the relative position between the eye to be examined and the optical system in the optical axis direction of the imaging optical system while reducing the size of the optical system. Further, even in the vicinity of the alignment matching position, the anterior segment can be observed with a light field camera over a wide range.

  The ophthalmologic photographing apparatus according to the embodiment includes a driving unit (optical system driving) that relatively moves the optical unit (2, 2a, 2b) including the illumination optical system and the photographing optical system and the eye to be examined in the optical axis direction. 2A) and a control unit (100, 100a, 100b) that relatively moves the optical unit and the eye to be examined by controlling the drive unit based on the amount of deviation.

  According to such a configuration, it is possible to align the eye to be examined and the optical system in the optical axis direction of the photographing optical system while reducing the size of the optical system.

  In the ophthalmologic photographing apparatus according to the embodiment, the control unit relatively moves the optical unit and the eye to be inspected based on the shift amount, and then the optical path combining member is added to the optical path of the illumination optical system and the optical path of the photographing optical system. The fundus image may be generated by the image generation unit based on image data obtained by photographing the eye to be examined with the photographing optical system in a state where the eye is placed.

  According to such a configuration, the light field camera is used to align the eye to be examined and the optical system in the optical axis direction of the photographing optical system, and the fundus image in focus is acquired by the light field camera. It is possible to provide an ophthalmologic photographing apparatus capable of performing the above.

  The ophthalmologic photographing apparatus according to the embodiment may include the above light field camera.

  According to such a configuration, it is possible to provide an ophthalmologic photographing apparatus that is equipped with a light field camera and can eliminate the influence of the diopter of the eye to be examined without providing a conventional diopter adjustment mechanism. become.

(Modification)
The configurations described in the first to third embodiments can be arbitrarily combined.

  The configuration described above is merely an example for favorably implementing the present invention. Therefore, arbitrary modifications (omitted, replacement, addition, etc.) within the scope of the present invention can be made as appropriate. The configuration to be applied is selected according to the purpose, for example. In addition, depending on the configuration to be applied, a function and effect obvious to those skilled in the art and the function and effect described in this specification are obtained.

  In addition, said embodiment is not limited to the structure of a light field camera, or the processing content of a deconvolution process. In the above-described embodiment, by performing the deconvolution processing according to the configuration of the light field camera, it is possible to acquire an image that can be adjusted in focus after photographing at any of a plurality of image plane positions in the optical axis direction of the photographing optical system. Things can be applied.

DESCRIPTION OF SYMBOLS 1, 1a, 1b Ophthalmic imaging device 2, 2a, 2b Optical unit 2A Optical system drive part 10 Illumination optical system 11 Observation light source 12 Imaging light source 13 Dichroic mirror 14A Iris diaphragm 14B Crystal diaphragm 14C Black spot 14D Corneal diaphragm 16, 19, 22, 24 relay lens 18 mirror 20, 20a imaging optical system 21 light field camera 30 hole mirror 31 objective lens 40 diopter correction lens 40A lens driving unit 70 anterior ocular segment observation light source 100, 100a, 100b control unit 110, 110a, 110b main control Unit 120, 120a, 120b storage unit 300, 300b data processing unit 310 deconvolution processing unit 320 image quality evaluation unit 330 best image extraction unit 340 position specifying unit 350 deviation amount specifying unit E eye Ea anterior eye unit Ef fundus

Claims (9)

An illumination optical system for irradiating the eye to be examined with light from the first light source;
An imaging optical system that guides light from the fundus of the eye to be examined, which is irradiated with light from the first light source by the illumination optical system, to a light field camera;
An image generation unit that generates a fundus image corresponding to a desired image plane position in the optical axis direction of the imaging optical system based on image data obtained by the light field camera;
Ophthalmologic imaging device. The illumination optical system switches between light from the first light source and light from a second light source that emits light in a second wavelength range that is at least partially different from the first wavelength range of the light from the first light source. To irradiate the eye to be examined,
The said light field camera acquires the said image data based on the light reception result of at least one part of the said 1st wavelength range, and the light of at least a part of the said 2nd wavelength range. Ophthalmic photography device. The image generation unit generates a plurality of fundus images corresponding to a plurality of image plane positions in the optical axis direction based on the image data;
The image extracting unit for extracting any one of the plurality of fundus images based on the image quality of each of the plurality of fundus images generated by the image generating unit. Ophthalmic photography device. An optical path combining member that combines the optical path of the illumination optical system and the optical path of the imaging optical system;
An objective lens disposed in a combined optical path by the optical path combining member;
The ophthalmologic photographing apparatus according to claim 3, comprising: The optical path combining member includes a hole mirror in which a hole is formed at a position substantially optically conjugate with the pupil of the eye to be examined and deflects light from the illumination optical system toward the objective lens. The ophthalmologic imaging apparatus according to claim 4. The optical path combining member can be inserted into and removed from the optical path of the illumination optical system and the optical path of the photographing optical system.
The image generation unit is based on image data obtained by photographing the eye to be examined with the photographing optical system in a state where the optical path combining member is retracted from the optical path of the illumination optical system and the optical path of the photographing optical system. A plurality of anterior segment images corresponding to a plurality of image plane positions in the optical axis direction,
The image extraction unit extracts one of the plurality of anterior ocular segment images based on the image quality of the characteristic region in the anterior ocular segment image;
The ophthalmologic photographing apparatus according to claim 4, further comprising a shift amount specifying unit that specifies a shift amount in the optical axis direction based on the anterior segment image extracted by the image extracting unit. An optical unit including the illumination optical system and the photographing optical system, and a drive unit that relatively moves the eye to be examined in the optical axis direction;
A control unit that relatively moves the optical unit and the eye to be examined by controlling the driving unit based on the shift amount;
The ophthalmologic photographing apparatus according to claim 6, comprising: The control unit relatively moves the optical unit and the eye to be inspected based on the shift amount, and then the optical path combining member is disposed in the optical path of the illumination optical system and the optical path of the photographing optical system. The ophthalmologic photographing apparatus according to claim 7, wherein the fundus image is generated by the image generation unit based on the image data obtained by photographing the eye to be examined by the photographing optical system in a state. The ophthalmologic photographing apparatus according to any one of claims 1 to 8, comprising the light field camera.

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