JP2017148241A - Ophthalmic photographing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ophthalmic photographing apparatus, even when an image has a wide filed angle, capable of suppressing appearance of ghost.SOLUTION: The ophthalmic photographing apparatus includes an optical system, a change part, and an image synthesis part. The optical system is used for photographing a fundus oculi of a subject's eye. The change part changes a direction of the subject's eye relative to the direction of an optical axis of the optical system. The image synthesis part generates a synthetic image formed by replacing a partial area of a first image that is obtained using the optical system when the subject's eye and the optical axis are set in a first relative direction, by an area corresponding to the partial area, in a second image that is obtained using the optical system when both are set in a second relative direction different from the first relative direction.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an ophthalmologic photographing apparatus.

  An ophthalmologic imaging apparatus for screening eye diseases and the like is required to be capable of easily imaging the fundus of the eye to be examined with a wide field of view. As such an ophthalmologic photographing apparatus, a scanning laser opthalmoscope (hereinafter referred to as SLO) is known. The SLO is an apparatus that forms an image of the fundus by scanning the fundus with light and detecting the return light with a light receiving device.

  For example, Patent Document 1 discloses an SLO that includes three optical scanners and controls them to perform a wide area scan and a scan that enlarges a part of the scan area.

Japanese Patent Laying-Open No. 2015-229023

  However, it is known that a ghost (noise) resulting from the surface reflection of the objective lens or the cornea of the eye to be examined is depicted at the center of an image acquired by an ophthalmologic photographing apparatus such as SLO. The size and light amount of the ghost increase as the angle of view increases. In many cases, a site of interest is arranged at the center of the acquired image, and if a ghost is depicted in the center, there may be a problem in diagnosis. It is desirable to suppress such a ghost not only in the center but also in what is depicted at an arbitrary position in the image.

  The present invention has been made in view of such circumstances, and an object thereof is to provide an ophthalmologic photographing apparatus capable of suppressing the ghost image even when the image has a wide angle of view.

  The ophthalmologic photographing apparatus according to the embodiment includes an optical system, a changing unit, and an image composition unit. The optical system is used for photographing the fundus of the eye to be examined. The changing unit relatively changes the direction of the eye to be examined and the direction of the optical axis of the optical system. The image composition unit converts a partial region of the first image acquired using the optical system when the eye to be examined and the optical axis are set in the first relative orientation to a second relative different from the first relative orientation. A composite image is generated by replacing the region corresponding to the partial region in the second image acquired using the optical system when the target direction is set.

  According to the present invention, it is possible to provide an ophthalmologic photographing apparatus capable of suppressing the ghost image even when the image has a wide angle of view.

It is a functional block diagram which shows schematic structure of the ophthalmologic imaging device which concerns on embodiment. It is the schematic which shows an example of a structure of the optical system of the ophthalmologic imaging device which concerns on embodiment. It is the schematic which shows an example of a structure of the optical system of the ophthalmologic imaging device which concerns on embodiment. It is the schematic which shows an example of a structure of the optical system of the ophthalmologic imaging device which concerns on embodiment. It is the schematic which shows an example of a structure of the processing system of the ophthalmologic imaging device which concerns on embodiment. It is operation | movement explanatory drawing of the ophthalmologic imaging device which concerns on embodiment. It is operation | movement explanatory drawing of the ophthalmologic imaging device which concerns on embodiment. It is a flowchart of the operation example of the ophthalmologic imaging device which concerns on embodiment. It is a functional block diagram which shows schematic structure of the ophthalmologic imaging device which concerns on the modification of embodiment.

  An example of an embodiment of an ophthalmologic photographing apparatus according to the present invention will be described in detail with reference to the drawings. In addition, it is possible to use the description content of the literature referred in this specification, and arbitrary well-known techniques for the following embodiment.

  The ophthalmologic imaging apparatus according to the embodiment moves the optical unit including a scanning optical system that deflects light from a light source with reference to the pupil of the eye to be examined, thereby transmitting light through the pupil to the posterior eye portion (fundus, glass) It is a device that can irradiate a wide range of body. Such a configuration can be applied to any ophthalmologic photographing apparatus capable of irradiating light to the posterior eye portion. An ophthalmologic imaging apparatus capable of irradiating light to the posterior eye part includes a laser treatment apparatus for irradiating a treatment site on the fundus with laser light, and a target while moving the target while keeping the eye fixed. It may be a perimeter for measuring the visual field based on the response of the examiner (patient). Further, the ophthalmologic photographing apparatus according to the embodiment may be a fundus oculi observation device (fundus camera) that does not include a scanning optical system.

  In addition, the ophthalmologic photographing apparatus according to the embodiment forms predetermined data distribution (image, layer thickness distribution, lesion distribution, etc.) in the posterior eye portion by receiving the return light from the posterior eye portion of the eye to be examined. Is possible. Such a configuration can be applied to any ophthalmic imaging apparatus that can acquire data by scanning the posterior eye segment with light. The ophthalmologic photographing apparatus capable of acquiring data by scanning the posterior eye portion with light includes SLO for obtaining a front image of the fundus by laser scanning using a confocal optical system, and optical coherence tomography (hereinafter referred to as optical coherence tomography: There are optical coherence tomographs that obtain a tomographic image of the fundus using OCT. Hereinafter, the ophthalmologic imaging apparatus according to the embodiment will be described as a multifunction machine that combines the function of the SLO and the function of the optical coherence tomography.

  In the following description, it is assumed that the horizontal direction when viewed from the subject is the X direction, the vertical direction is the Y direction, and the depth direction of the optical system is the Z direction when viewed from the subject.

[Constitution]
FIG. 1 shows a functional block diagram of a schematic configuration of the ophthalmologic photographing apparatus according to the embodiment.

  The ophthalmologic imaging apparatus 1 is an apparatus that scans the posterior segment of the eye E with a laser beam to acquire data, and forms a front image of the fundus oculi Ef based on the acquired data. The ophthalmologic photographing apparatus 1 includes a measurement unit 10 and a processing unit 70. The measurement unit 10 is used for optical observation of the fundus oculi Ef and optical measurement of the fundus oculi Ef. The processing unit 70 performs processing of data acquired by the measurement unit 10, control of each part of the apparatus, and the like.

(Measurement unit)
The measurement unit 10 includes an optical unit 20, a moving mechanism 30, a drive unit 30D, a light source 40, a fixation optical system 50, and an alignment system 60. The measurement unit 10 receives light from the light source 40 through the pupil of the eye E by the optical unit 20 configured to be movable with respect to the pupil position (pupil position) R (or a position near the pupil position R) of the eye E. Irradiate the posterior segment of the eye E. The pupil position R of the eye E or the vicinity thereof is a position separated from the objective lens included in the optical unit 20 by a predetermined distance along the optical axis of the optical unit 20. The predetermined distance corresponds to a distance obtained by adding the intercorneal pupil distance of the eye E to the working distance of the optical unit 20. The measurement unit 10 sends the data acquired by receiving the return light of the light applied to the posterior eye portion of the eye E to the processing unit 70.

  The optical unit 20 includes a scanning optical system 21, a projection system 22, and a light receiving system 23.

  The scanning optical system 21 deflects light from the light source 40 within a predetermined deflection angle range. In the embodiment, the scanning optical system 21 deflects light from the light source 40 two-dimensionally within a predetermined deflection angle range, but deflects light from the light source 40 one-dimensionally within a predetermined deflection angle range. It may be configured as follows. Such a scanning optical system 21 may include an optical scanner. The optical scanner uses a single axis or a biaxial deflecting member orthogonal to each other. Examples of the deflecting member include a galvanometer mirror, a resonant mirror, a polygon mirror, a rotating mirror, a dowel prism, a double dowel prism, a rotation prism, a MEMS (Micro Electro Mechanical System) scanner, and the like. There is.

  The projection system 22 is an optical system including an optical element for projecting light from the light source 40 deflected by the scanning optical system 21 onto the posterior eye portion (for example, the fundus oculi Ef) of the eye E. The projection system 22 may include a scanning optical system 21.

  The light receiving system 23 is an optical system including an optical element and a light receiving element for receiving the return light from the posterior eye portion of the eye E to the light projected by the projection system 22. As the light receiving element, one having sensitivity in the visible region or the infrared region is used according to the light output from the light source 40. The light receiving system 23 may include a scanning optical system 21.

  The optical unit 20 may include at least one of the light source 40 and the fixation optical system 50. At least one of the projection system 22 and the light receiving system 23 may be provided outside the optical unit 20.

  The moving mechanism 30 can move the optical unit 20 in the X direction, the Y direction, and the Z direction. Thereby, alignment with the to-be-tested eye E and the optical unit 20 can be performed.

  The moving mechanism 30 moves the optical unit 20 within a predetermined moving angle range with reference to the pupil position R of the eye E to be examined. When the optical axis of the optical unit 20 passes through the pupil position R from the front side of the eye E, the plane orthogonal to the optical axis is the XY plane (the X direction is the horizontal direction and the Y direction is the vertical direction), and the optical axis If the fundus direction parallel to the Z direction is the Z direction, the pupil position R includes not only the position actually corresponding to the pupil but also the X direction, the Y direction, and / or the pupil position R within a range that does not interfere with the scanning of the posterior eye portion. The position displaced in the Z direction (neighboring position) is also included. Hereinafter, in this specification, when the term “pupil position” is simply expressed except when “neighbor position” is specified, it means the pupil position or its vicinity.

  The movement mechanism 30 rotates the optical unit 20 within a predetermined movement angle range around the pupil position R of the eye E to be examined. Such a moving mechanism 30 includes, for example, one or more holding members that hold the optical unit 20 and one or more guide arms that are movably provided at any position within the above-described movement angle range. The The guide arm holds the holding member in a slidable state. Thereby, the direction of the eye E (the direction of the eyeball) and the direction of the optical axis of the optical unit 20 can be relatively changed. That is, light can be projected onto the posterior segment of the eye E from different directions, and the return light can be received.

  The drive unit 30D drives the movement mechanism 30 under the control of the control unit 200 of the processing unit 70 described later. The driving unit 30D includes an actuator that generates a driving force for moving the moving mechanism 30. An actuator that receives a control signal from the control unit 200 described later generates a driving force according to the control signal. This driving force is transmitted to the moving mechanism 30 via a driving force transmitting mechanism (not shown), and moves the moving mechanism 30 so as to be arranged at the position designated by the control signal. Thereby, the optical unit 20 can be moved to a desired position.

  The light source 40 outputs light (for example, laser light) for irradiating the posterior eye portion of the eye E to be examined. Examples of the light source 40 include a semiconductor laser light source (a wavelength sweep laser, a super luminescent diode, etc.), a solid-state laser, a gas laser, and a fiber laser. In addition, as the light source 40, it is also possible to apply one in which a plurality of light sources are combined and used by a multiplexer such as an optical fiber multiplexer or a dichroic mirror. In this embodiment, laser light is guided to the optical unit 20 by an optical fiber. For example, a means for reducing stress such as twisting or pulling due to movement of the optical unit 20 is provided in the joint portion of the optical fiber.

  The fixation optical system 50 includes a configuration for realizing at least one of internal fixation and external fixation. When realizing internal fixation, the fixation optical system 50 includes an optical system for projecting a fixation target onto the fundus oculi Ef of the eye E to be examined. The fixation target is a target for fixing the eye E to be examined. The fixation optical system 50 includes a fixation light source that outputs at least visible light. For example, the optical path formed by the fixation optical system 50 is coupled to the optical path formed by the projection system 22 or the light receiving system 23 in the optical unit 20. Thereby, the fixation optical system 50 can present a fixation target to the eye E through the optical path formed by the optical unit 20. The fixation optical system 50 may be included in the optical unit 20.

  When realizing external fixation, the fixation optical system 50 is provided in the housing of the optical unit 20, for example. The fixation optical system 50 has, for example, a configuration in which a light emitting unit such as an LED is provided at the other end of two or more arms that are fixed at one end to the optical unit 20 and connected to each other via a joint. When realizing external fixation, the fixation optical system 50 may be provided in the housing of the measurement unit 10 so as not to move with the optical unit 20.

  When the fixation optical system 50 realizes internal fixation, the control unit 200 can move the projection position (presentation position) of the fixation target as the optical unit 20 moves. When the fixation optical system 50 realizes both internal fixation and external fixation, the control unit 200 can link the internal fixation and the external fixation using the above configuration. As an example of linking internal fixation and external fixation, when the macula is included in the light scan area, the eye is fixed by the internal fixation and the macula is not included in the scan area Sometimes, the subject's eye is fixed by external fixation.

  The fixation optical system 50 may include a configuration (optical system) for realizing two or more internal fixations. When two internal fixations are realized, the fixation optical system 50 is provided inside the optical unit 20 to realize the first internal fixation, and a second internal provided outside the optical unit 20. And a configuration for realizing fixation. As an example of linking two internal fixations, when a macula is included in the light scanning region, the eye E is fixed by the first internal fixation (inside the optical unit 20), and the internal region of the scanning region is fixed. When the macular portion is not included, the eye E is fixed by the second internal fixation (outside the optical unit 20).

  The alignment system 60 includes, for example, an XY alignment detection light source, an XY alignment sensor, a Z alignment detection light source, and a Z alignment sensor. The XY alignment detection light from the XY alignment light source is guided to the cornea of the eye E as a parallel light beam. A bright spot image (virtual image) is formed on the cornea by reflecting the XY alignment detection light with the cornea. The XY alignment detection light reflected by the cornea is detected by an XY alignment sensor. A detection signal obtained by the XY alignment sensor is sent to the control unit 200. The control unit 200 identifies the position of the bright spot image formed on the cornea of the eye E from this detection signal, and detects a positional shift with respect to the optical unit 20 in the X direction and the Y direction.

  The Z alignment detection light from the Z alignment detection light source is projected onto the cornea of the eye E to be examined. A bright spot image (virtual image) is formed on the cornea by reflection of the Z alignment detection light into the cornea. The Z alignment detection light reflected by the cornea is detected by a Z alignment sensor. A detection signal obtained by the Z alignment sensor is sent to the control unit 200. The control unit 200 specifies the position of the bright spot image formed on the cornea of the eye E from this detection signal, and detects a positional shift with respect to the optical unit 20 in the Z direction.

  In addition, at least one of the above XY alignment and Z alignment may be performed using one or more cameras provided in the measurement unit 10. In this case, by obtaining the position of the eye E based on images taken by one or more cameras, at least one positional shift in the X direction, the Y direction, and the Z direction is detected. When two or more cameras are provided, the three-dimensional position of the eye E to be examined is obtained based on images taken substantially simultaneously from different directions, so that the X direction, the Y direction, and the Z direction can be obtained. At least one misregistration is detected.

  The control unit 200 performs alignment by moving the optical unit 20 by the moving mechanism 30 so as to cancel the detected positional deviation in the X direction, the Y direction, and the Z direction.

  The measurement unit 10 may include a focus optical system, and generate an index (split index) for focusing on the fundus oculi Ef. In this case, the light (focus light) output from the focus optical system is projected onto the fundus oculi Ef. The fundus reflection light of the light projected on the fundus oculi Ef is detected by a sensor (not shown). The control unit 200 can analyze the position of the split index from the detection signal obtained by this sensor, and can focus by moving, for example, a focusing lens and a focus optical system included in the optical unit 20 ( Auto focus function).

[Optical system]
Next, a configuration example of the optical unit 20 in FIG. 1 will be described assuming that the ophthalmologic photographing apparatus 1 according to the embodiment has an SLO function and an optical coherence tomography function. In the following, illustration of the fixation optical system 50 is omitted. Further, the function of the alignment system 60 in FIG. 1 is realized by the anterior ocular segment imaging system 120 and the like.

  The ophthalmologic photographing apparatus 1 can acquire an image of the eye E to be examined in a range corresponding to the photographing mode. The ophthalmologic photographing apparatus 1 can selectively arrange the objective lens unit corresponding to the photographing mode on the optical axis of the optical system.

  2 to 4 show configuration examples of the optical system included in the optical unit 20. The optical unit 20 includes an optical system 100. FIG. 2 illustrates a configuration example of the optical system 100 when the wide-angle (wide-angle) shooting mode is set. FIG. 3 shows a configuration example of the objective lens system according to the embodiment that can be switched according to the photographing mode. In FIG. 3, the same parts as those in FIG. FIG. 4 shows a configuration example of the optical system 100 when the high-magnification shooting mode is set. In FIG. 4, the same parts as those in FIG. 2 or FIG. 2 and 4, a position optically conjugate with the fundus oculi Ef of the eye E is shown as a fundus conjugate position P, and a position optically conjugate with the pupil of the eye E is shown as a pupil conjugate position Q. Yes.

  The optical system 100 includes a projection system that projects light onto the eye to be examined via the objective lens system 110, and a light receiving system that receives return light of the light projected onto the eye E via the objective lens system 110. The ophthalmologic photographing apparatus 1 forms an image based on the light reception result by the light receiving system. The ophthalmologic photographing apparatus 1 can form an SLO image and an OCT image. That is, the optical system 100 includes an SLO optical system 130 and an OCT optical system 140. The SLO optical system 130 includes an SLO projection system and an SLO light receiving system. The OCT optical system 140 includes an OCT projection system and an OCT light receiving system. The SLO projection system and the OCT projection system realize the function of the projection system 22 of FIG. The SLO light receiving system and the OCT light receiving system realize the function of the light receiving system 23 in FIG.

  The optical system 100 is provided with an anterior segment imaging system (anterior segment observation system) 120 for imaging the anterior segment of the eye to be examined. The optical system 100 can be moved in the X direction, the Y direction, and the Z direction by the moving mechanism 30 together with the objective lens system 110 and the anterior segment imaging system 120. The ophthalmologic photographing apparatus 1 moves the optical system 100 or the like by the moving mechanism based on the anterior eye portion image of the eye E to be examined obtained by the anterior eye photographing system 120, so that the optical system 100 is moved with respect to the eye E to be examined. It is possible to perform alignment for alignment. Hereinafter, the case where the optical system 100 includes the objective lens system 110 and the anterior ocular segment imaging system 120 will be described. However, the optical system 100 may be configured not to include these.

(Objective lens system)
The ophthalmologic photographing apparatus 1 can arrange an objective lens unit corresponding to the photographing mode on the optical axis O of the optical system 100. In this embodiment, the photographing mode includes a wide-angle photographing mode for photographing an image of the eye E in a first range (for example, an angle of view of 100 degrees) and a second range (for example, an angle of view of 50 degrees that is narrower than the first range). ) And a high magnification photographing mode for photographing an image of the eye E.

  The objective lens system 110 includes objective lens units 110A and 110B (see FIG. 3). For example, the objective lens units 110A and 110B can be manually arranged on the optical axis O manually by a known rotation mechanism or slide mechanism. In the wide-angle shooting mode, the optical axis of the objective lens unit 110A is arranged so as to coincide with the optical axis of the optical system 100 (FIG. 2). In the high magnification photographing mode, the optical axis of the objective lens unit 110B is arranged so as to coincide with the optical axis O (FIG. 4).

  The objective lens unit 110A includes two or more lenses. A dichroic mirror DM1A is provided between the two or more lenses. For example, the objective lens unit 110A may be a lens unit (Nagler type) including convex lenses 111A and 112A and a concave lens 113A. The convex lenses 111A and 112A and the concave lens 113A are arranged in this order from the eye E side. A dichroic mirror DM1A is disposed between the convex lens 112A and the concave lens 113A. The dichroic mirror DM1A is an optical path coupling member that couples the optical path of the anterior segment imaging system 120 to both the optical path of the SLO optical system 130 and the optical path of the OCT optical system 140 in the wide-angle imaging mode. Between the dichroic mirror DM1A and the concave lens 113A, a position (fundus conjugate position) P or its vicinity optically conjugate with the fundus (retina) is disposed. The objective lens unit 110A may include a dichroic mirror DM1A.

  The dichroic mirror DM1A receives light from the SLO optical system 130 (SLO light), return light from the eye E, light from the OCT optical system 140 (OCT light, measurement light), and return light from the eye E. Make it transparent. The dichroic mirror DM1A reflects the light from the anterior segment imaging system 120 toward the eye E, and reflects the return light from the eye E toward the anterior segment imaging system 120.

  The objective lens unit 110B includes at least one lens. A dichroic mirror DM1B is provided on the light source (SLO light source and OCT light source) side with respect to the at least one lens. For example, the objective lens unit 110B may include a convex lens 111B. The dichroic mirror DM1B is an optical path coupling member that couples the optical path of the anterior ocular segment imaging system 120 to both the optical path of the SLO optical system 130 and the optical path of the OCT optical system 140 in the high magnification imaging mode. The objective lens unit 110B may include a dichroic mirror DM1B.

  Similar to the dichroic mirror DM1A, the dichroic mirror DM1B includes light from the SLO optical system 130 (SLO light), return light from the eye E to be inspected, light from the OCT optical system 140 (OCT light, measurement light), and target light. The return light from the optometry E is transmitted. Further, the dichroic mirror DM1B reflects the light from the anterior eye imaging system 120 toward the eye E, and reflects the return light from the eye E toward the anterior eye imaging system 120. The position of the dichroic mirror DM1B on the optical axis O when the objective lens unit 110B is disposed on the optical axis O is the position of the dichroic mirror DM1A on the optical axis O when the objective lens unit 110A is disposed on the optical axis O. The position may be substantially the same. Thereby, when the shooting mode is changed, it is not necessary to adjust the position and orientation of the anterior segment imaging system 120.

  The objective lens unit 110A may include only the convex lenses 111A and 112A and the concave lens 113A, and the objective lens unit 110B may include only the convex lens 111B. Thereby, when the objective lens unit arranged on the optical axis O is switched, the dichroic mirrors DM1A and DM1B can be shared by one dichroic mirror.

  The objective lens system 110 can be moved along the optical axis O by a moving mechanism (not shown) (moving mechanism 110D described later). Thereby, the objective lens system 110 can be moved in the Z direction with respect to the optical system 100, and the focal positions of both the SLO optical system 130 and the OCT optical system 140 can be changed.

  Hereinafter, a case where the objective lens unit 110A is arranged on the optical axis O will be mainly described.

(Anterior segment imaging system)
The anterior segment imaging system 120 includes an anterior segment illumination light source 121, a collimator lens 122, an anterior segment imaging camera 123, an imaging lens 124, and a beam splitter BS1. The beam splitter BS1 is an optical path coupling member that couples the optical path of the return light to the optical path of the illumination light for illuminating the anterior segment of the eye E. For example, the light source 40 illustrated in FIG. 1 may include the anterior segment illumination light source 121.

  The anterior segment illumination light source 121 is a light source for illuminating the anterior segment of the eye E. The anterior segment imaging camera 123 includes an image sensor for detecting reflected light (return light) from the anterior segment of the eye E illuminated by the anterior segment illumination light source 121. As the anterior segment illumination light source 121, for example, an LED that emits light having a center wavelength of 950 nm is used. The light emitted from the anterior segment illumination light source 121 is converted into a parallel light beam by the collimator lens 122. The illumination light converted into a parallel light beam is reflected toward the dichroic mirror DM1A by the beam splitter BS1. The illumination light reflected by the beam splitter BS1 is deflected toward the eye E by the dichroic mirror DM1A. The return light of the illumination light from the eye E is reflected by the dichroic mirror DM1A and passes through the beam splitter BS1. The return light that has passed through the beam splitter BS1 is condensed on the detection surface of the image sensor in the anterior segment imaging camera 123 by the imaging lens 124. The detection surface of the image sensor is disposed at or near the pupil conjugate position (anterior eye conjugate position) Q. The image sensor is constituted by, for example, a CCD or a CMOS image sensor. The detection result of the return light from the anterior eye part of the eye E to be examined by the image sensor is used to form an image of the anterior eye part.

(SLO optical system)
The optical path of the SLO optical system 130 and the optical path of the OCT optical system 140 are coupled by a dichroic mirror DM2. At least a part of the SLO optical system 130 is formed as a telecentric optical system. Similarly, at least a part of the OCT optical system 140 is formed as a telecentric optical system. The dichroic mirror DM2 couples an optical path formed by the telecentric optical system of the SLO optical system 130 and an optical path formed by the telecentric optical system of the OCT optical system 140. Thereby, even when the focal position of the optical system 100 is changed by the movement of the objective lens system 110, the aberration of the pupil (for example, the exit pupil by the objective lens system 110) is reduced, and the adjustment of the in-focus state is facilitated.

  The dichroic mirrors DM1A (DM1B) and DM2 are desirably arranged on the optical axis O while maintaining the twisted relationship. The dichroic mirror DM1A (DM1B) is configured to transmit at least part of light guided through the optical path of the SLO optical system 130 and the optical path of the OCT optical system 140 (optical path of the optical system 100) and the light guided through the optical path of the anterior ocular photographing system 120. A first optical surface that reflects at least one of the light and transmits the other light is provided. The dichroic mirror DM2 reflects at least part of light guided through the optical path of the SLO optical system 130 and at least part of light guided through the optical path of the OCT optical system 140, and transmits the other light. A second optical surface is provided. The dichroic mirrors DM1A (DM1B) and DM2 include a plane including the normal line of the first optical surface and the optical axis of the SLO optical system 130, and a plane including the normal line of the second optical surface and the optical axis of the SLO optical system 130. Are arranged so as to be orthogonal or substantially orthogonal to each other. Accordingly, in the high magnification photographing mode shown in FIG. 4, since the concave lens 113A is not disposed between the dichroic mirror DM1B and the dichroic mirror DM2, astigmatism is removed by the dichroic mirror DM1B and the dichroic mirror DM2, or astigmatism. Can be made extremely small, so that deterioration of image quality can be suppressed. On the other hand, in the wide-angle shooting mode shown in FIG. 2, the roughness of the image is allowed as compared with the high-magnification shooting mode, so that the influence on the image quality due to the remaining astigmatism is small.

  The SLO optical system 130 includes an SLO light source 131, a collimating lens 132, a beam splitter BS2, a condenser lens 133, a confocal stop 134, a detector 135, an optical scanner 136, and a lens 137. The beam splitter BS2 is an optical path coupling member that couples the optical path of the return light to the optical path of the SLO light projected onto the eye E.

  As the SLO light source 131, for example, a light source that emits light having a center wavelength of 840 nm is used. Examples of the SLO light source 131 include a laser diode (hereinafter referred to as LD), a super luminescent diode (super luminescent diode: SLD), a laser driven light source (LDLS), and the like. The SLO light source 131 is disposed at or near a position (fundus conjugate position) P optically conjugate with the fundus (retina). For example, the light source 40 shown in FIG. 1 may include an SLO light source 131.

  The light emitted from the SLO light source 131 is converted into a parallel light beam by the collimator lens 132. The light converted into the parallel light flux passes through the beam splitter BS2. The light transmitted through the beam splitter BS2 is deflected by the optical scanner 136. The optical scanner 136 is used for scanning the fundus oculi Ef of the eye E with the light from the SLO light source 131. The optical scanner 136 includes an optical scanner 136X that deflects light in the X direction and an optical scanner 136Y that deflects light in the Y direction. The optical scanner 136X is a mirror capable of deflecting light by changing the tilt of the reflecting surface, and the tilt of the reflecting surface is controlled by the control unit 200 described later. The optical scanner 136X is used, for example, for horizontal scanning within the fundus. An optical scanner 136Y is disposed on the eye E side of the optical scanner 136X. The optical scanner 136Y is a mirror that can deflect light by changing the tilt of the reflecting surface, and the tilt of the reflecting surface is controlled by the control unit 200. The optical scanner 136Y is used, for example, for scanning in the vertical direction within the fundus oculi orthogonal to the horizontal direction. One of the optical scanner 136X and the optical scanner 136Y may be a low-speed scanner such as a galvanometer mirror, and the other may be a high-speed scanner such as a resonant mirror, a polygon mirror, or a MEMS (Micro Electro Mechanical Systems) mirror. The reflection surface of the optical scanner 136Y is disposed at a position (pupil conjugate position) Q that is optically conjugate with the pupil of the eye E or at the vicinity thereof. A lens 137 and a dichroic mirror DM2 are arranged on the eye E side of the optical scanner 136Y. The light from the SLO light source 131 deflected by the optical scanner 136 passes through the lens 137 and the dichroic mirror DM2, and is projected onto the eye E through the objective lens system 110. The optical scanner 136 realizes the function of the scanning optical system 21 in FIG.

  The return light of the light from the SLO light source 131 projected onto the eye E is reflected toward the detector 135 by the beam splitter BS2 via the same optical path. A condensing lens 133 and a confocal stop 134 are disposed between the beam splitter BS2 and the detector 135. The condensing lens 133 condenses the light reflected by the beam splitter BS2. The light condensed by the condensing lens 133 passes through the opening formed in the confocal stop 134 and enters the detection surface of the detector 135. The aperture formed in the confocal stop 134 is disposed at or near a position P (fundus conjugate position) optically conjugate with the fundus (retina). The detector 135 is composed of, for example, an avalanche photodiode (APD) or a photomultiplier tube (PMT).

(OCT optical system)
The OCT optical system 140 includes a focusing lens 141, an optical scanner 142, a collimating lens 143, and an interference optical system 150. The interference optical system 150 includes an OCT light source 151, fiber couplers 152 and 153, a prism 154, and a detector 155.

  The focusing lens 141 can be moved along the optical axis (optical path) of the OCT optical system 140 by a moving mechanism (not shown) (moving mechanism 141D described later). Thereby, the focal position of the OCT optical system 140 can be changed independently of the SLO optical system 130. Therefore, for example, after the focusing state of the SLO optical system 130 and the OCT optical system 140 is adjusted by the movement of the objective lens system 110, the focusing state of the OCT optical system 140 is finely adjusted by the movement of the focusing lens 141. Can do.

  The optical scanner 142 is used to scan the fundus oculi Ef of the eye E with measurement light based on the light from the OCT light source 151. The optical scanner 142 includes an optical scanner 142X that deflects light in the X direction and an optical scanner 142Y that deflects light in the Y direction. The optical scanner 142X is a mirror that can deflect light by changing the inclination of the reflection surface, and the control unit 200 controls the inclination of the reflection surface. The optical scanner 142 is used, for example, for scanning in the horizontal direction within the fundus. An optical scanner 142Y is arranged on the eye E side of the optical scanner 142X. The optical scanner 142Y is a mirror that can deflect light by changing the inclination of the reflection surface, and the control unit 200 controls the inclination of the reflection surface. The optical scanner 142Y is used, for example, for scanning in the vertical direction within the fundus oculi orthogonal to the horizontal direction. One of the optical scanner 142X and the optical scanner 142Y may be a low-speed scanner such as a low-speed galvanometer mirror, and the other may be a high-speed scanner such as a high-speed galvanometer mirror. An intermediate position between the optical scanners 142X and 142Y is disposed at a position (pupil conjugate position) Q that is optically conjugate with the pupil of the eye E or a vicinity thereof. A collimating lens 143 is disposed on the OCT light source 151 side of the optical scanner 142Y. The optical scanner 142 realizes the function of the scanning optical system 21 in FIG.

  The interference optical system 150 is provided with an optical system for acquiring an OCT image of the eye E. This optical system has the same configuration as a conventional swept source type OCT apparatus. That is, this optical system divides the light from the wavelength sweep type (wavelength scanning type) light source into the measurement light and the reference light, and returns the return light of the measurement light from the eye E and the reference light via the reference light path. An interference optical system that generates interference light by causing interference and detects the interference light. The detection result (detection signal) of the interference light by the interference optical system is a signal indicating the spectrum of the interference light. The interference optical system 150 may have a configuration similar to that of a conventional spectral domain type OCT apparatus, not a swept source type OCT apparatus.

  The OCT light source 151 is a wavelength sweep type (wavelength scanning type) light source capable of sweeping (scanning) the wavelength of OCT light (emitted light). As the wavelength sweep type light source, for example, a laser light source including a resonator and emitting light having a center wavelength of 1050 nm is used. The OCT light source 151 temporally changes the output wavelength in a near-infrared wavelength band that cannot be visually recognized by the human eye. For example, the light source 40 shown in FIG. 1 may include an OCT light source 151.

  The light L0 output from the OCT light source 151 is guided to the fiber coupler 152 by the optical fiber f1, and is divided into the measurement light LS and the reference light LR.

  The reference light LR is guided to the fiber exit end c1 by the optical fiber f2, and is irradiated to the collimator lens 156 from the fiber exit end c1. The reference light LR emitted from the fiber exit end c1 is converted into a parallel light beam by the collimator lens 156. The reference light LR converted into a parallel light beam is guided to the prism 154. The prism 154 folds the traveling direction of the reference light LR made into a parallel light beam by the collimating lens 156 in the reverse direction. The optical path of the reference light LR incident on the prism 154 and the optical path of the reference light LR emitted from the prism 154 are parallel. The prism 154 is movable in a direction along the incident optical path and the outgoing optical path of the reference light LR by a moving mechanism (not shown) (moving mechanism 154D described later). In this case, an actuator that generates a driving force for moving the moving mechanism and a transmission mechanism that transmits the driving force are provided. 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 length of the optical path of the reference light LR is changed.

  The reference light LR that has passed through the prism 154 is converted from a parallel light beam into a focused light beam by the collimator lens 157, enters the fiber incident end c2, and is guided to the fiber coupler 153 by the optical fiber f3. An optical path length correcting member or a dispersion compensating member may be disposed between the collimating lenses 156 and 157 and the prism 154. The optical path length correction member functions as a delay unit for matching the optical path length (optical distance) of the reference light LR with the optical path length of the measurement light LS. The dispersion compensation member functions as a dispersion compensation means for matching the dispersion characteristics between the reference light LR and the measurement light LS.

  On the other hand, the measurement light LS generated by the fiber coupler 152 is guided to the fiber end c3 by the optical fiber f4. The measurement light LS guided to the fiber end c3 is applied to the collimator lens 143. The measurement light LS emitted from the fiber end c3 is converted into a parallel light beam by the collimator lens 143. The measurement light LS converted into the parallel light beam reaches the dichroic mirror DM2 via the optical scanner 142 and the focusing lens 141. The measurement light LS is reflected by the dichroic mirror DM2, refracted by the objective lens system 110, and irradiated on the eye E. The measurement light LS is scattered (including reflection) at various depth positions of the eye E. The return light of the measurement light LS including such backscattered light travels in the reverse direction on the same path as the forward path, is guided to the fiber coupler 152, and reaches the fiber coupler 153 via the optical fiber f5.

  The fiber coupler 153 generates interference light by combining (interfering) the measurement light LS incident via the optical fiber f5 and the reference light LR incident via the optical fiber f3. The fiber coupler 153 generates a pair of interference light LC by branching the interference light between the measurement light LS and the reference light LR at a predetermined branching ratio (for example, 1: 1). The pair of interference lights LC emitted from the fiber coupler 153 is guided to the detector 155.

  The detector 155 is, for example, a balanced photodiode that includes a pair of photodetectors that detect a pair of interference lights LC and outputs a difference between detection results obtained by the pair of photodetectors. The detector 155 sends the detection result (detection signal) to a DAQ (Data Acquisition System) (not shown). A clock is supplied to the DAQ from the OCT light source 151. This clock is generated in synchronization with the output timing of each wavelength swept (scanned) within a predetermined wavelength range by the wavelength sweep type light source in the OCT light source 151. Based on this clock, the DAQ samples the detection result of the detector 155 and sends it to an image forming unit, which will be described later. The image forming unit forms a reflection intensity profile in each A line by performing Fourier transform or the like on the spectrum distribution based on the detection result obtained by the detector 155 for each series of wavelength scans (for each A line), for example. To do. Further, the image forming unit forms image data by imaging the reflection intensity profile of each A line.

  When the measurement unit 10 having the above configuration acquires an SLO image, the laser light output from the SLO light source 131 (light source 40) is two-dimensionally deflected by the optical unit 20 moved by the moving mechanism 30. The The two-dimensionally deflected laser light passes through the pupil of the eye E from the optical axis direction of the optical unit 20 and is projected onto the fundus oculi Ef.

  The return light of the laser light projected onto the fundus oculi Ef is light that returns to the optical unit 20 from the spot light formation position (and its vicinity). The return light includes scattered light (reflected light and backscattered light) of laser light from the fundus oculi Ef, fluorescence using the laser light as excitation light, and scattered light thereof. The return light passes through the pupil and exits from the eye E. The return light from the eye E travels in the opposite direction on the same path as the forward path and is guided to the detector 135. The return light guided to the detector 135 is detected by the light receiving element. The light receiving element photoelectrically converts the detected return light and outputs an electric signal (light receiving signal).

  The above process corresponds to measurement of one point of the fundus oculi Ef, and corresponds to measurement in an irradiation region of a single spot light with respect to the fundus oculi Ef. In this embodiment, the optical mechanism 20 is turned around the pupil position R (one-dimensionally, two-dimensionally, or three-dimensionally) by the moving mechanism 30, and spot light is scanned by the scanning optical system 21 in the optical unit 20. (One-dimensional or two-dimensional) deflection. Thereby, the irradiation area of the spot light on the fundus oculi Ef is moved. In other words, in this embodiment, scanning of the fundus oculi Ef for acquiring an SLO image is executed by combining the turning of the optical unit 20 by the moving mechanism 30 and the deflection by the scanning optical system 21.

  Similarly, when an OCT image is acquired in the measurement unit 10, the measurement light LS based on the light L 0 output from the OCT light source 151 (light source 40) is two-dimensionally generated by the optical unit 20 moved by the moving mechanism 30. Deflected. The measurement light LS that is two-dimensionally changed is projected from the optical axis direction of the optical unit 20 through the pupil of the eye E to the fundus oculi Ef. The measurement light LS that has entered the eye E is scattered by the anterior segment of the eye E. Further, part of the laser light incident on the eye E passes through the pupil and is imaged as spot light on the fundus oculi Ef.

  The return light of the measurement light LS projected on the fundus oculi Ef is scattered (including reflection) at various depth positions of the eye E. The return light of the measurement light LS including such backscattered light travels in the reverse direction on the same path as the forward path, and is combined with the reference light LR to become interference light LC, which is guided to the detector 155. The return light guided to the detector 155 is detected by the light receiving element. The light receiving element photoelectrically converts the detected return light and outputs an electric signal (light receiving signal).

  The above process corresponds to measurement of one point of the fundus oculi Ef, and corresponds to measurement in an irradiation region of a single spot light with respect to the fundus oculi Ef. As described above, the scanning mechanism 21 in the optical unit 20 deflects the spot light while turning the optical unit 20 around the pupil position R by the moving mechanism 30. Thereby, the irradiation area of the spot light on the fundus oculi Ef is moved. That is, by combining the turning of the optical unit 20 by the moving mechanism 30 and the deflection by the scanning optical system 21, scanning of the fundus oculi Ef for acquiring an OCT image is executed.

[Processing system]
FIG. 5 shows a configuration example of the processing unit 70 of the ophthalmologic photographing apparatus 1 according to the embodiment. In FIG. 5, the same parts as those in FIGS.

(Control part)
The processing unit 70 in FIG. 1 (the processing system of the ophthalmologic photographing apparatus 1) is configured around the control unit 200. The control unit 200 controls each unit of the ophthalmologic photographing apparatus 1. The control unit 200 includes a main control unit 201 and a storage unit 202. The function of the main control unit 201 is realized by a microprocessor, for example. The storage unit 202 stores in advance a computer program for controlling the ophthalmologic photographing apparatus. This computer program includes various light source control programs, optical scanner control programs, various detector control programs, image formation programs, data processing programs, user interface programs, and the like. When the main control unit 201 operates according to such a computer program, the control unit 200 executes control processing.

  Control for the objective lens system 110 includes control for a moving mechanism 110D that moves the objective lens system 110 along the optical axis O. For example, the moving mechanism 110D is provided with an actuator that generates a driving force for moving the moving mechanism 110D 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 201 controls the moving mechanism 110D by sending a control signal to the actuator.

  Controls for the SLO optical system 130 include control of the SLO light source 131, control of the optical scanner 136, control of the detector 135, and the like. Control of the SLO light source 131 includes turning on / off the light source, adjusting the light amount, adjusting the aperture, and the like. Control of the optical scanner 136 includes control of the scanning position and scanning range by the optical scanner 136X, control of the scanning position and scanning range by the optical scanner 136Y, and the like. The control of the detector 135 includes exposure adjustment of the detection element, gain adjustment, detection rate adjustment, and the like.

  Controls for the OCT optical system 140 include control of the OCT light source 151, control of the optical scanner 142, control of the moving mechanism 141D and the moving mechanism 154D, and control of the detector 155. Control of the OCT light source 151 includes turning on and off the light source, adjusting the light amount, adjusting the aperture, and the like. Control of the optical scanner 142 includes control of the scanning position and scanning range by the optical scanner 142X, control of the scanning position and scanning range by the optical scanner 142Y, and the like. The moving mechanism 141D moves the focusing lens 141 along the optical path of the OCT optical system 140. For example, the moving mechanism 141D is provided with an actuator that generates a driving force for moving the moving mechanism 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 201 controls the moving mechanism 141D by sending a control signal to the actuator. The moving mechanism 154D moves the prism 154 in a direction along the incident optical path and the outgoing optical path of the reference light LR. For example, the moving mechanism 154D is provided with an actuator that generates a driving force for moving the moving mechanism 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 201 controls the moving mechanism 154D by sending a control signal to the actuator. Control of the detector 155 includes exposure adjustment, gain adjustment, and detection rate adjustment of the detection element.

  Controls for the anterior segment imaging system 120 include control of the anterior segment illumination light source 121 and control of the anterior segment imaging camera 123. Control of the anterior segment illumination light source 121 includes turning on and off the light source, adjusting the light amount, adjusting the aperture, and the like. The control of the anterior eye photographing camera 123 includes exposure adjustment, gain adjustment, and photographing rate adjustment of the image sensor.

  As control for the optical system 100, control of the drive unit 30D that drives the moving mechanism 30 that moves the optical system 100 (including the dichroic mirrors DM1A and DM1B and the anterior segment imaging system 120) in the X direction, the Y direction, and the Z direction. There is. The main control unit 201 controls the drive unit 30D by sending a control signal to the actuator.

  The main control unit 201 includes an alignment control unit 201A, a tracking control unit 201B, a fixation target control unit 201C, and a display control unit 201D.

  The alignment control unit 201 </ b> A controls execution of alignment for aligning the optical system 100 with respect to the eye E. The alignment control unit 201A controls the position of the optical system 100 with respect to the eye E by controlling the driving unit 30D so that the amount of displacement detected based on the bright spot image obtained by the alignment system 60 is canceled. Perform alignment (XY direction, Z direction).

  The alignment control unit 201A can control the moving mechanism 30 (drive unit 30D) and the moving mechanism 110D based on the anterior eye image of the eye E obtained by the anterior eye imaging system 120. The alignment control unit 201A specifies, for example, a characteristic part in the anterior eye part image of the eye E obtained by the anterior eye photographing system 120, and a deviation amount between the position of the specified characteristic part and a predetermined target position The amount of movement of the optical system 100 or the like is obtained so that is canceled. The alignment control unit 201A aligns the optical system 100 with respect to the eye E by controlling the drive unit 30D based on the obtained movement amount (XY direction). The target position may be a predetermined position, or may be a position in the anterior ocular segment image specified using the UI unit 230.

  The alignment control unit 201A specifies, for example, the in-focus state (blurring condition) of the anterior eye image of the eye E obtained by the anterior eye imaging system 120, and the specified in-focus state is the desired in-focus state. It is possible to determine the amount of movement of the objective lens system 110 in the Z direction so that The alignment control unit 201A controls the movement mechanisms 100D and 110D based on the obtained movement amount, thereby aligning the optical system 100 and the objective lens system 110 with respect to the eye E (Z direction). In addition, the anterior eye part is imaged from two different directions using two or more cameras, the in-focus state is specified three-dimensionally from two or more images provided with parallax, and the specified in-focus state is desired. The amount of movement of the objective lens system 110 in the Z direction may be obtained so as to be in focus.

  The alignment control unit 201A may perform alignment (Z direction) of the objective lens system 110 with respect to the eye E by controlling the moving mechanism 110D based on the SLO image obtained by the SLO optical system 130. In this case, the alignment control unit 201A specifies the in-focus state (blurring degree) of the acquired SLO image, and the objective lens system 110 in the Z direction so that the specified in-focus state becomes a desired in-focus state. Find the amount of movement. The alignment control unit 201A controls the movement mechanism 110D based on the obtained movement amount.

  The tracking control unit 201 </ b> B controls tracking of the eye E to be examined obtained by the SLO optical system 130 with respect to the SLO image. For example, the tracking control unit 201B specifies a feature part in the SLO image at a predetermined timing, and when the position of the specified feature part changes, obtains a movement amount so that the shift amount of the position is canceled. The tracking control unit 201B controls tracking for the SLO image based on the obtained movement amount.

  Further, the tracking control unit 201B controls tracking of the eye E to be examined obtained by the OCT optical system 140 with respect to the OCT image based on the SLO image. For example, the tracking control unit 201B specifies a feature part in the SLO image at a predetermined timing, and when the position of the specified feature part changes, obtains a movement amount so that the shift amount of the position is canceled. The tracking control unit 201B controls tracking for the OCT image based on the obtained movement amount. The tracking control unit 201B may be provided in the data processing unit 220.

  The fixation target control unit 201C controls the fixation optical system 50. The fixation target control unit 201C controls turning on and off of the fixation light source (for internal fixation and external fixation), and moves the projection position (fixation position) of the fixation target on the fundus oculi Ef. It is possible. When the optical system 100 is turned around the pupil position R of the eye E by the moving mechanism 30, the fixation target control unit 201C is configured so that the direction of the eye E (eyeball) is stationary with respect to the optical axis O. The fixation target presentation position is moved in conjunction with the movement of 100. Alternatively, the fixation target control unit 201C may move the fixation target presentation position without causing the moving mechanism 30 to turn the optical system 100. Even in this case, the direction of the eye E and the direction of the optical axis O can be relatively changed.

  The display control unit 201D displays various information on the UI unit 230 described later. The information displayed on the UI unit 230 includes information generated by the control unit 200, an image formed by the image forming unit 210, information after data processing by the data processing unit 220, and the like.

(Image forming part)
Image forming unit 210 includes an SLO image forming unit 210A and an OCT image forming unit 210B. The SLO image forming unit 210 </ b> A forms image data of an SLO image based on the detection signal input from the detector 135 and the pixel position signal input from the control unit 200. The OCT image forming unit 210B forms image data of an OCT image (a tomographic image of the fundus oculi Ef) based on the detection signal input from the detector 155 and the pixel position signal input from the control unit 200. The image forming unit 210 forms an anterior ocular segment image based on the detection result of the reflected light from the anterior segment of the eye E to be examined by the imaging element of the anterior segment imaging camera 123. Various images (image data) formed by the image forming unit 210 are stored in the storage unit 202, for example.

(Data processing part)
The data processing unit 220 executes various data processing. As an example of data processing, there is processing for image data formed by the image forming unit 210 or another device. Examples of this processing include various types of image processing, image analysis processing, and diagnostic support processing such as image evaluation based on image data.

  The data processing unit 220 includes an image composition unit 220A. The image composition unit 220A obtains two or more images acquired using the SLO optical system 130 or the OCT optical system 140 in a state where the orientations of the eye E and the optical axis O of the optical system 100 are different from each other. A synthesized image in which ghost (noise) is suppressed is generated by synthesizing (SLO image or OCT image). Specifically, the image composition unit 220A corresponds to the partial area of the first image corresponding to the partial area in the second image with respect to the first image and the second image acquired in a state where the relative directions are different from each other. A composite image is generated by replacing the region. In this case, after the first image is acquired when the direction of the eye E and the direction of the optical axis O of the optical system 100 are in a predetermined relative state, the optical system 100 is acquired by the moving mechanism 30. Is rotated by a predetermined angle, and the second image is acquired when the relative orientation is different from the relative orientation when the first image is acquired. Further, after the first image is acquired in a state where the fixation target is presented at a predetermined position without turning the optical system 100 by the moving mechanism 30, the presentation position is different from when the first image is obtained. The second image may be acquired in a state where the fixation target is presented. Thereby, it is possible to acquire a composite image in which the ghost image depicted in one of the first image and the second image is suppressed using the other image.

  6A and 6B are explanatory diagrams illustrating an example of the operation of the image composition unit 220A. 6A and 6B show the operation contents when the image combining unit 220A combines two SLO images, the operation when combining two OCT images is the same.

  For example, the first SLO image IA and the second SLO image IB are acquired as shown in FIG. 6A by turning the optical system 100 by the moving mechanism 30 or changing the presentation position of the fixation target. The first SLO image IA is an SLO image having a predetermined angle of view f acquired using the SLO optical system 130 when the eye E and the optical axis O are set in the first relative orientation. The second SLO image IB is an SLO image having a predetermined angle of view f acquired by using the SLO optical system 130 when the second relative orientation different from the first relative orientation is set.

  Ghosts (noise) N1 and N2 resulting from the surface reflection of the cornea of the objective lens and the eye E are depicted in predetermined areas (center areas including the center) of the first SLO image IA and the second SLO image IB. Yes. The ghosts N1 and N2 are drawn in a predetermined shape at a predetermined position in the image determined by the arrangement relationship of the optical elements and the eye E to be examined.

  The image composition unit 220A generates a composite image IC in which the first partial region of the first SLO image IA is replaced with a region corresponding to the first partial region in the second SLO image IB. The image composition unit 220A further performs a process of replacing the second partial region of the second SLO image IB with a region corresponding to the second partial region in the first SLO image IA.

  Hereinafter, for convenience of explanation, a case where the turning direction is the X direction will be described. For example, in FIG. 6B, the horizontal direction represents the turning direction of the optical system 100 by the moving mechanism 30 (the difference direction between the first relative direction and the second relative direction). When the optical system 100 is turned by the angle α by the moving mechanism 30, the first SLO image IA is represented as an image with an angle of view 0 to an angle of view f as shown in FIG. 6B, and the second SLO image IB is displayed with the angle of view α It is expressed as an image having a view angle (f + α). The angle α (difference between the first relative direction and the second relative direction) is determined from the position and size in the image where the noises N1 and N2 are rendered.

  First, the image composition unit 220A divides each of the first SLO image IA and the second SLO image IB into three strip-shaped regions in the turning direction. Here, the area is divided into an area from an angle of view 0 to an angle of view α and two areas obtained by dividing the remaining area in the turning direction. Specifically, the first SLO image IA includes a region BR1a (IA (0 to α)) from an angle of view 0 to an angle of view α and a region BR1b (angle of view angle α to an angle of view ((f + α) / 2)). IA (α to (f + α) / 2)) and a region BR1c (IA ((f + α) / 2) to f) from the angle of view ((f + α) / 2) to the angle of view f. Noise N1 is included in region Br1b. Similarly, the second image SLO image IB includes a region BR2a (IB (α to (f + α) / 2)) from an angle of view α to an angle of view ((f + α) / 2) and an angle of view ((f + α) / 2. ) To field angle f, and is divided into area BR2b (IB ((f + α) / 2) to f) and field BR2c (IB (f to (f + α))) from field angle f to field angle (f + α). The Noise N2 is included in region BR2b. That is, the angle α is determined so that the noise N1 is included in the region BR1a and the noise N2 is included in the region BR2b. The region BR2a is a partial region corresponding to the region BR1b. The region BR1c is a partial region corresponding to the region BR2b. For example, when the widths W of the turning directions of the noises N1 and N2 are equal to each other, W <(f−α) / 2 may be set so that the noise is included in each of the region BR1b and the region BR2b. That is, α <(f−2W) may be satisfied. For example, α> W may be satisfied so that the noise N2 moved in the turning direction with respect to the noise N1 does not overlap the noise N1.

  Next, the image composition unit 220A performs a well-known registration process of the first SLO image IA and the second SLO image IB, and generates a composite image IC in which the images subjected to the alignment are combined. At this time, the area BR1b of the first SLO image is replaced with the area BR2a of the second SLO image IB. Further, the image composition unit 220A replaces the region BR2b of the second SLO image IB with the region BR1c of the first SLO image IA with the first SLO image IA. As a result, the composite image IC has a region BR1a from the field angle 0 to the field angle α, a region BR2a from the field angle α to the field angle ((f + α) / 2), and a field angle ((f + α) / 2) to the field angle. An image of the region BR1c is obtained up to f, and an image of the region BR2c is obtained from the view angle f to the view angle (f + α). As described above, the image composition unit 220A can generate the composite image IC based on the angle α. Thereby, in the generated composite image IC, a ghost image drawn in a known shape at a known position in at least one of the first SLO image IA and the second SLO image IB is suppressed. Further, the composite image IC is newly acquired as an image having a wider field angle than each of the first SLO image IA and the second SLO image IB.

  The image compositing unit 220A is not limited to the ghost image drawn in a known shape at a known position in at least one of the first image (first SLO image IA) and the second image (second SLO image IB). It is possible to generate a composite image in which a ghost image drawn in an arbitrary shape at an arbitrary position in the image is suppressed. In this case, the image composition unit 220A specifies the position and shape of the ghost that is drawn in common to both images based on the pixel values of the first image and the second image. The image composition unit 220A specifies a corresponding region in the second image corresponding to the region in which the ghost in the first image is rendered, and the image combining unit 220A in the first image corresponding to the region in which the ghost in the second image is rendered. Identify the corresponding area. The image composition unit 220A replaces the region in which the ghost in the first image is rendered with the corresponding region in the second image, and replaces the region in which the ghost in the second image is rendered with the corresponding region in the first image. Thus, a composite image is generated. Thereby, in the synthesized image, a ghost image drawn in an arbitrary shape at an arbitrary position in at least one of the first image and the second image is suppressed. In addition, the composite image is newly acquired as an image having a wider angle of view than each of the first image and the second image.

  In addition, the image composition unit 220A obtains the first partial region of the first OCT image acquired by using the OCT optical system 140 when the eye E and the optical axis O are set in the first relative orientation. When the two relative orientations are set, a composite image replaced with a region corresponding to the first partial region in the second OCT image acquired using the OCT optical system 140 may be generated. Also in this case, the image composition unit 220A may further perform a process of replacing the second partial region of the second OCT image with a region in the first OCT image corresponding to the second partial region.

(UI part)
A UI (User Interface) unit 230 has a function for exchanging information between the user and the ophthalmologic photographing apparatus. The UI unit 230 includes a display device and an operation device (input device). The display device may include a display unit and may include other display devices. The operation device includes various hardware keys and / or software keys. The control unit 200 can receive an operation content for the operation device and output a control signal corresponding to the operation content to each unit. It is possible to integrally configure at least a part of the operation device and at least a part of the display device. A touch panel display is an example.

  The moving mechanism 30, or the fixation optical system 50, the fixation target control unit 201C, and the control unit 200 are examples of the “change unit” according to the embodiment. The first SLO image IA is an example of a “first image” according to the embodiment, and the second SLO image IB is an example of a “second image” according to the embodiment.

[Operation]
An operation of the ophthalmologic photographing apparatus according to the embodiment will be described.

  FIG. 7 shows an example of the operation of the ophthalmologic photographing apparatus according to the embodiment. FIG. 7 is a flowchart illustrating an operation example when the ophthalmologic photographing apparatus according to the embodiment acquires an SLO image.

(S1)
First, the objective lens unit 110A for the wide-angle shooting mode is set on the optical axis O. For example, a user such as an examiner, a subject, a doctor, or a patient manually sets the objective lens unit 110A on the optical axis O. The ophthalmologic photographing apparatus can shift the operation to S <b> 2 based on an operation performed on the UI unit 230 by the user. The ophthalmic imaging apparatus detects the type of the objective lens unit arranged on the optical axis O, and when it is determined that the detected type is a type corresponding to the imaging mode registered in advance, the ophthalmic imaging apparatus. The operation may be shifted to S2.

(S2)
In a state in which the relative direction between the direction of the eye E to be examined and the direction of the optical axis O of the optical system 100 is set to a predetermined direction by the moving mechanism 30, the control unit 200 causes the eye E to be examined E by the anterior eye imaging system 120. An anterior ocular segment image is acquired by photographing the anterior ocular segment.

(S3)
The alignment control unit 201A controls the movement mechanism 30 (drive unit 30D) based on the anterior segment image acquired in S2 as described above, thereby positioning the optical system 100 and the objective lens system 110 with respect to the eye E. Matching is performed (X direction, Y direction, and Z direction). Alternatively, alignment may be performed using the alignment system 60.

(S4)
The control unit 200 moves the optical scanner 136 to a predetermined initial position.

(S5)
The control unit 200 turns on the SLO light source 131 and controls the optical scanner 136 to start scanning the fundus oculi Ef of the eye E with the light from the SLO light source 131. The SLO image forming unit 210A forms an SLO image of the fundus oculi Ef based on the detection result of the fundus reflected light by the detector 135. In S5, the tracking control unit 201B may start tracking control for the SLO image.

(S6)
The control unit 200 turns the optical system 100 by the specified angle α by controlling the drive unit 30D. The designated angle α may be an angle designated by the user using the UI unit 230 or may be a predetermined angle.

(S7)
The control unit 200 again controls the optical scanner 136 to start scanning the fundus oculi Ef of the eye E with the light from the SLO light source 131. The SLO image forming unit 210A forms an SLO image of the fundus oculi Ef based on the detection result of the fundus reflected light by the detector 135. Note that the anterior segment may be imaged in the same manner as S2 and S3 before the start of scanning, and alignment may be executed based on the obtained anterior segment image.

(S8)
Next, the control unit 200 causes the image composition unit 220A to perform composition processing using the SLO image obtained in S5 and the SLO image obtained in S7. The image composition unit 220A generates a composite image using two SLO images as shown in FIG. 6B.

(S9)
Next, the display control unit 201D displays the composite image generated in S8 on the display device included in the UI unit 230. This is the end of the operation of the ophthalmologic photographing apparatus.

<Modification>
In the above-described embodiment, two images are obtained in a state where the relative direction between the direction of the eye E and the direction of the optical axis O of the optical system 100 is different by turning the optical system 100 by the specified angle α by the moving mechanism 30. However, the configuration according to the embodiment is not limited to this.

  FIG. 8 is a functional block diagram of a schematic configuration of an ophthalmologic photographing apparatus according to a modification of the embodiment.

  The configuration of the ophthalmic imaging apparatus 1a according to the modification differs from the configuration of the ophthalmic imaging apparatus 1 according to the embodiment in that the angle detection unit 25 is provided in the measurement unit 10a and the processing unit 70a is based on the angle detection unit 25. The process is based on the detection result. The angle detection unit 25 detects the angle of the optical system 100 that is turned by the moving mechanism 30 with reference to the reference direction. The control unit 200a of the processing unit 70a obtains the difference between the angle detected by the angle detection unit 25 before the turn and the angle detected by the angle detection unit 25 after the turn, so that the angle at which the optical system 100 is turned is obtained. (Corresponding to the specified angle α) can be obtained. Thereby, since the obtained angle corresponds to the difference between the direction of the eye E and the first relative direction and the second relative direction of the optical axis O, as in the embodiment, the image composition unit 220A A composite image can be generated according to the turning angle of the optical system 100 obtained by the control unit 200a.

  Note that the angle detection unit 25 may detect a difference between angles before and after turning by the moving mechanism 30. The angle detection unit 25 and the control unit 200a, or the angle detection unit 25 is an example of a “detection unit” according to a modification of the embodiment.

  According to this modification, as in the embodiment, at least one of two images acquired by photographing in a state where the orientation of the eye E to be examined and the orientation of the optical axis O of the optical system 100 are different from each other. It is possible to obtain a composite image in which the ghost image drawn in the image is suppressed. This composite image is newly acquired as an image having a wider angle of view than each of the two images.

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

  The ophthalmologic photographing apparatus (ophthalmic photographing apparatus 1, 1a) according to the embodiment includes an optical system (optical system 100) and a changing unit (moving mechanism 30, or fixation optical system 50, fixation target control unit 201C and control unit). 200) and an image composition unit (image composition unit 220A). The optical system is used to photograph the fundus (fundus Ef) of the eye to be examined (eye E to be examined). The changing unit relatively changes the direction of the eye to be examined and the direction of the optical axis (optical axis O) of the optical system. The image composition unit obtains a partial region (region BR1b) of the first image (first SLO image IA) acquired using the optical system when the eye to be examined and the optical axis are set in the first relative orientation. Region (region BR2a) corresponding to the partial region in the second image (second SLO image IB) acquired using the optical system when the second relative orientation different from the first relative orientation is set. A composite image (composite image IC) replaced with is generated.

  According to such a configuration, the first image and the second image obtained in a state where the orientation of the eye to be examined and the relative orientation of the optical axis O of the optical system are different from each other are acquired, and the partial region of the first image is obtained. Since the composite image is generated by replacing the region corresponding to the partial region in the second image, it is possible to obtain a composite image from which ghost (noise) drawn in the partial region of the first image is removed. .

  In the ophthalmologic photographing apparatus according to the embodiment, the image composition unit further performs a process of replacing the partial region (region BR2b) of the second image with the region (region BR1c) in the first image corresponding to the partial region. Also good.

  According to such a configuration, since the composite image is generated by replacing the partial area of the second image with the area corresponding to the partial area in the first image, the partial area of the first image is rendered. It is possible to obtain a composite image from which not only a ghost to be displayed but also a ghost (noise) drawn in a partial region of the second image is removed.

  In the ophthalmologic photographing apparatus according to the embodiment, the partial region may be a central region including the central portion of the image.

  According to such a configuration, it is possible to obtain a composite image in which the ghost image caused by the surface reflection of the objective lens or the cornea of the eye to be examined is suppressed.

  In the ophthalmologic photographing apparatus according to the embodiment, the optical system includes an objective lens (objective lens system 110), and the changing unit is located at a position (pupil position R or its position) separated from the objective lens by a predetermined distance along the optical axis. A moving mechanism (moving mechanism 30) for turning the optical system around the (near position) may be included.

  According to such a configuration, the relative direction between the direction of the eye to be examined and the optical axis O of the optical system is changed by turning the optical system around a predetermined position. Ghost rendering is suppressed, and a wider-angle composite image can be acquired.

  In the ophthalmologic photographing apparatus according to the embodiment, the changing unit includes a fixation optical system (fixation optical system 50) that presents the fixation target to the eye to be examined through an optical path formed by the optical system, and presentation of the fixation target. And a control unit (control unit 200, fixation target control unit 201C) that changes the position.

  According to such a configuration, since the relative direction between the direction of the eye to be examined and the optical axis O of the optical system is changed by changing the position where the fixation target is presented, the apparatus can be reduced in size. The ghost image is suppressed, and a wider-angle composite image can be acquired.

  In the ophthalmologic photographing apparatus according to the embodiment, the partial region may be a region having a predetermined size and a predetermined shape including the center of the image acquired by the optical system.

  According to such a configuration, it is possible to acquire a composite image in which a ghost of a known shape is suppressed at a known position.

  In the ophthalmologic photographing apparatus according to the embodiment, the image composition unit may specify the partial region based on the pixel value of the image acquired by the optical system.

  According to such a configuration, it is possible to acquire a composite image in which a ghost having an arbitrary shape is suppressed at an arbitrary position.

  In the ophthalmologic photographing apparatus according to the embodiment, the image composition unit may determine the partial region based on the difference between the first relative orientation and the second relative orientation.

  According to such a configuration, since the partial region is determined according to the difference between the first relative orientation and the second relative orientation, the ghost rendered in the acquired image can be accurately depicted. It becomes possible to suppress.

  Further, the ophthalmologic photographing apparatus according to the embodiment may include a detection unit (the angle detection unit 25 and the control unit 200a or the angle detection unit 25) that detects a difference between the first relative direction and the second relative direction. Good.

  According to such a configuration, since the difference between the first relative orientation and the second relative orientation is detected by the detection unit, the relative orientation between the orientation of the eye to be examined and the orientation of the optical axis of the optical system Depending on the amount of change, the ghost rendered in the image can be accurately suppressed.

<Others>
The embodiment described above is merely an example for carrying out the present invention. A person who intends to implement the present invention can make arbitrary modifications, omissions, additions and the like within the scope of the present invention.

  In the above-described embodiment, the case where the configuration of the optical system 100 is the configuration illustrated in FIGS. 2 and 4 has been described. However, the configuration of the optical system according to the embodiment is not limited to this. The optical system according to the embodiment may include an optical system for irradiating a treatment site on the fundus with laser light, an optical system for moving a visual target in a state of being fixed to the eye to be examined, and the like.

  In the above-described embodiment, the case where the configuration of the objective lens system 110 is the configuration illustrated in FIGS. 2 to 4 has been described, but the configuration of the objective lens system according to the embodiment is not limited to this.

  In the above-described embodiment, the case where the image composition unit 220A generates a composite image as illustrated in FIGS. 6A and 6B has been described, but the embodiment is not limited to the processing content by the image composition unit 220A. For example, the image composition unit 220A may generate a composite image in which noise rendering is suppressed by performing addition / subtraction of two images having different relative orientations.

DESCRIPTION OF SYMBOLS 1, 1a Ophthalmic imaging device 10, 10a Measurement unit 20 Optical unit 21 Scanning optical system 22 Projection system 23 Light receiving system 25 Angle detection part 30 Movement mechanism 30D Drive part 40 Light source 50 Fixation optical system 60 Alignment system 70, 70a Processing unit 100 Optical system 200, 200a Control unit 210 Image forming unit 220 Data processing unit 220A Image composition unit 230 UI unit E Eye to be examined Ef Fundus

Claims (9)

An optical system for photographing the fundus of the eye to be examined;
A changing unit that relatively changes the direction of the eye to be examined and the direction of the optical axis of the optical system;
A partial region of the first image acquired using the optical system when the eye to be examined and the optical axis are set in a first relative orientation is a second relative different from the first relative orientation. An image compositing unit that generates a composite image replaced with a region corresponding to the partial region in the second image acquired using the optical system when the orientation is set;
Ophthalmologic imaging device. The ophthalmologic photographing apparatus according to claim 1, wherein the image composition unit further performs a process of replacing a partial area of the second image with an area in the first image corresponding to the partial area. The ophthalmologic photographing apparatus according to claim 1, wherein the partial region is a central region including a central portion of an image. The optical system includes an objective lens,
The change unit includes a moving mechanism for turning the optical system around a position separated from the objective lens by a predetermined distance along the optical axis. The ophthalmologic photographing apparatus according to Item. The changing unit is
A fixation optical system for presenting a fixation target to the eye to be examined through an optical path formed by the optical system;
A control unit for changing the presenting position of the fixation target;
The ophthalmologic photographing apparatus according to any one of claims 1 to 4, wherein: The ophthalmologic imaging according to any one of claims 1 to 5, wherein the partial region is a region having a predetermined size and a predetermined shape including a center of an image acquired by the optical system. apparatus. The ophthalmologic photographing apparatus according to any one of claims 1 to 6, wherein the image composition unit specifies the partial area based on a pixel value of an image acquired by the optical system. The said image synthetic | combination part determines the said partial area | region based on the difference of the said 1st relative direction and the said 2nd relative direction. The Claim 1 characterized by the above-mentioned. The ophthalmic imaging apparatus described. The ophthalmologic photographing apparatus according to claim 8, further comprising a detection unit that detects the difference between the first relative direction and the second relative direction.

Images