JP6431400B2 - Ophthalmic imaging apparatus and ophthalmic apparatus - Google Patents

Description

  The present invention relates to an ophthalmologic photographing apparatus and an ophthalmologic apparatus.

  In recent years, OCT (Optical Coherence Tomography), which forms an image representing the surface form and internal form of an object to be measured using a light beam from a laser light source or the like, has attracted attention. Since OCT has no invasiveness to the human body like X-ray CT (Computed Tomography), it is expected to be applied particularly in the medical field and the biological field. For example, in the field of ophthalmology, an apparatus for forming an image of the fundus oculi or cornea has been put into practical use.

  Patent Document 1 discloses an apparatus using a so-called Fourier domain OCT (Fourier Domain OCT) technique. That is, this apparatus irradiates the object to be measured with a beam of low coherence light, superimposes the reflected light and the reference light to generate interference light, acquires the spectral intensity distribution of the interference light, and performs Fourier transform. By performing the conversion, the form of the object to be measured in the depth direction (z direction) is imaged. Further, this apparatus includes a galvanometer mirror that scans a light beam (measurement light) in one direction (x direction) orthogonal to the z direction, thereby forming an image of a desired measurement target region of the object to be measured. It has become. An image formed by this apparatus is a two-dimensional tomographic image in the depth direction (z direction) along the scanning direction (x direction) of the light beam. Note that this technique is also called a spectral domain.

  In Patent Document 2, a plurality of two-dimensional tomographic images in the horizontal direction are formed by scanning (scanning) the measurement light in the horizontal direction (x direction) and the vertical direction (y direction), and based on the plurality of tomographic images. A technique for acquiring and imaging three-dimensional tomographic information of a measurement range is disclosed. As this three-dimensional imaging technology, for example, a method of displaying a plurality of tomographic images side by side (called stack data), volume data (voxel data) is generated based on the stack data, and rendering processing is performed on the volume data. And a method for forming a three-dimensional image.

  Patent Documents 3 and 4 disclose other types of OCT apparatuses. In Patent Document 3, the wavelength of light irradiated to a measured object is scanned (wavelength sweep), and interference intensity obtained by superimposing reflected light of each wavelength and reference light is detected to detect spectral intensity distribution. Is obtained, and an apparatus for imaging the form of the object to be measured by performing Fourier transform on the obtained image is described. Such a device is called a swept source type. The swept source type is a kind of Fourier domain type.

  In Patent Document 4, the traveling direction of light is obtained by irradiating the object to be measured with light having a predetermined beam diameter, and analyzing the component of interference light obtained by superimposing the reflected light and the reference light. An OCT apparatus for forming an image of an object to be measured in a cross-section orthogonal to is described. Such an OCT apparatus is called a full-field type or an en-face type.

  Patent Document 5 discloses a configuration in which OCT is applied to the ophthalmic field. Prior to the application of OCT, a fundus camera, a slit lamp, an SLO, or the like was used as an apparatus for observing the eye to be examined. A fundus camera is a device that shoots the fundus by illuminating the subject's eye with illumination light and receiving the fundus reflection light. A slit lamp is a device that acquires an image of a cross-section of the cornea by cutting off a light section of the cornea using slit light. The SLO is an apparatus that images the fundus surface by scanning the fundus with laser light and detecting the reflected light with a highly sensitive element such as a photomultiplier tube.

  An apparatus using OCT has an advantage over a fundus camera or the like in that a high-definition image can be acquired, and further, a tomographic image or a three-dimensional image can be acquired.

  As described above, an apparatus using OCT can be applied to observation of various parts of an eye to be examined, and can acquire high-definition images, and thus has been applied to diagnosis of various ophthalmic diseases.

JP 11-325849 A JP 2002-139421 A JP 2007-24677 A JP 2006-153838 A JP 2008-73099 A

  In order to improve the image quality of an image acquired by an ophthalmologic imaging apparatus using OCT, it is required to increase the intensity of interference light. In order to increase the intensity of the interference light, it is necessary to increase the intensity of the light from the light source and the measurement light. However, considering the safety of the eye to be examined, the amount of measurement light that can enter the eye to be examined is limited. For example, simply splitting the measurement light using an optical member such as a fiber coupler for the purpose of monitoring the amount of measurement light incident on the subject's eye reduces the amount of measurement light incident on the subject's eye, The image quality is degraded. As described above, in the conventional ophthalmologic photographing apparatus, there is a trade-off relationship between the safety of the eye to be examined and the improvement of the image quality of the image, and it has been difficult to achieve both.

  The present invention has been made to solve such a problem, and an object thereof is to provide a technique capable of improving the image quality while ensuring the safety of the eye to be examined.

  The ophthalmologic photographing apparatus according to the embodiment divides light from a light source into measurement light and reference light, makes the measurement light incident on the subject's eye, and detects interference light between the return light of the measurement light from the subject's eye and the reference light An interference optical system, and an image forming unit that forms an image of the eye to be inspected based on the detection result of the interference light by the interference optical system. The interference optical system receives light from the light source or measurement light as an image forming unit. Including a wavelength division member for dividing the measurement light in the first wavelength band to be subjected to the image forming process by the light and the measurement light in the second wavelength band other than the first wavelength band, and including only the first wavelength band Includes a monitoring unit that causes measurement light having a predetermined value or less to enter the eye to be examined and monitors the amount of measurement light in the second wavelength band.

  According to the present invention, it is possible to provide an ophthalmologic photographing apparatus capable of improving the image quality while ensuring the safety of the eye to be examined.

It is a schematic diagram showing an example of composition of an ophthalmology photographing instrument concerning an embodiment. It is a schematic diagram showing an example of composition of an ophthalmology photographing instrument concerning an embodiment. It is a schematic diagram showing an example of composition of an ophthalmology photographing instrument concerning an embodiment. It is a schematic diagram showing an example of composition of an ophthalmology photographing instrument concerning an embodiment. It is the schematic for demonstrating operation | movement of the ophthalmologic imaging device which concerns on embodiment. It is a schematic diagram showing an example of composition of an ophthalmology photographing instrument concerning an embodiment. It is the schematic for demonstrating operation | movement of the ophthalmologic imaging device which concerns on embodiment. It is the schematic showing an example of the structure of the ophthalmologic imaging device which concerns on the modification of embodiment.

  An example of an embodiment of the present invention will be described in detail with reference to the drawings. The ophthalmologic imaging apparatus according to the present invention has a function of an optical coherence tomography, and executes optical coherence tomography (hereinafter referred to as OCT) of an eye to be examined. This OCT is performed on any part of the eye to be examined, such as the fundus or the anterior eye segment.

  In this specification, images acquired by OCT may be collectively referred to as OCT images. Moreover, it is possible to use the description content of the literature referred in this specification as the content of the following embodiment.

  In the following embodiment, an ophthalmologic imaging apparatus capable of executing Fourier domain type OCT will be described. In particular, the ophthalmologic photographing apparatus according to the embodiment can apply a swept source type OCT technique. Note that the configuration according to the present invention can also be applied to an ophthalmologic photographing apparatus capable of executing a type other than the swept source type, for example, a spectral domain type OCT. Further, in the following embodiment, an apparatus that combines an OCT apparatus and a fundus camera will be described. However, in modalities other than the fundus camera, for example, SLO (Scanning Laser Ophthalmoscope), slit lamp, ophthalmic surgical microscope, photocoagulation apparatus, etc. It is also possible to combine the OCT apparatus having the configuration according to the embodiment. In addition, the configuration according to the embodiment can be incorporated into a single OCT apparatus.

[Constitution]
As shown in FIG. 1, the ophthalmologic photographing apparatus 1 includes a fundus camera unit 2, an OCT unit 100, and an arithmetic control unit 200. The retinal camera unit 2 has almost the same optical system as a conventional retinal camera. The OCT unit 100 is provided with an optical system for executing OCT. The arithmetic control unit 200 includes a computer that executes various arithmetic processes and control processes.

[Fundus camera unit]
The fundus camera unit 2 shown in FIG. 1 is provided with an optical system for obtaining a two-dimensional image (fundus image) representing the surface form of the fundus oculi Ef of the eye E to be examined. 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 fundus camera unit 2 may be configured to be able to acquire images other than these, such as a fluorescein fluorescent image, an indocyanine green fluorescent image, a spontaneous fluorescent image, and the like.

  The retinal camera unit 2 is provided with a chin rest and a forehead support for supporting the subject's face. Further, the fundus camera unit 2 is provided with an illumination optical system 10 and a photographing optical system 30. The illumination optical system 10 irradiates the fundus oculi Ef with illumination light. The photographing optical system 30 guides the fundus reflection light of the illumination light to an imaging device (CCD image sensor (sometimes simply referred to as a CCD) 35, 38). The imaging optical system 30 guides the measurement light from the OCT unit 100 to the eye E and guides the measurement light passing through the eye E to the OCT unit 100.

  The observation light source 11 of the illumination optical system 10 is configured by, for example, a halogen lamp or an LED (Light Emitting Diode). The light (observation illumination light) output from the observation light source 11 is reflected by the reflection mirror 12 having a curved reflection surface, passes through the condensing lens 13, passes through the visible cut filter 14, and is converted into near infrared light. Become. Further, the observation illumination light is once converged in the vicinity of the photographing light source 15, reflected by the mirror 16, and passes through the relay lenses 17 and 18, the diaphragm 19 and the relay lens 20. Then, the observation illumination light is reflected at the peripheral portion (region around the hole portion) of the aperture mirror 21, passes through the dichroic mirror 46, and is refracted by the objective lens 22 to illuminate the fundus oculi Ef.

  The fundus reflection light of the observation illumination light is refracted by the objective lens 22, passes through the dichroic mirror 46, passes through the hole formed in the central region of the perforated mirror 21, passes through the dichroic mirror 55, and is a focusing lens. It is reflected by the mirror 32 via 31. Further, the fundus reflection light passes through the half mirror 33A, is reflected by the dichroic mirror 33, and forms an image on the light receiving surface of the CCD image sensor 35 by the condenser lens. The CCD image sensor 35 detects fundus reflected light at a predetermined frame rate, for example. On the display device 3, an image (observation image) based on fundus reflection light detected by the CCD image sensor 35 is displayed. When the photographing optical system 30 is focused on the anterior segment, an observation image of the anterior segment of the eye E is displayed.

  The imaging light source 15 is constituted by, for example, a xenon lamp or an LED. The light (imaging illumination light) output from the imaging light source 15 is applied to 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 dichroic mirror 33 through the same path as that of the observation illumination light, passes through the dichroic mirror 33, is reflected by the mirror 36, and is reflected by the condenser lens 37 of the CCD image sensor 38. An image is formed on the light receiving surface. On the display device 3, an image (captured image) based on fundus reflection light detected by the CCD image sensor 38 is displayed. Note that the display device 3 that displays the observation image and the display device 3 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. It is also possible to use an LED as a photographing light source.

  An LCD (Liquid Crystal Display) 39 displays a fixation target and an eyesight measurement index. The fixation target is an index for fixing the eye E to be examined, and is used at the time of fundus photographing or OCT measurement.

  A part of the light output from the LCD 39 is reflected by the half mirror 33A, reflected by the mirror 32, passes through the focusing lens 31 and the dichroic mirror 55, passes through the hole of the perforated mirror 21, and then reaches the dichroic. The light passes through the mirror 46, is refracted by the objective lens 22, and is projected onto the fundus oculi Ef. By changing the display position of the fixation target on the screen of the LCD 39, the fixation position of the eye E can be changed.

  Further, the fundus camera unit 2 is provided with an alignment optical system 50 and a focus optical system 60 as in a conventional fundus camera. The alignment optical system 50 generates an index (alignment index) for performing alignment (alignment) of the apparatus optical system with respect to the eye E. The focus optical system 60 generates an index (split index) for focusing on the eye E to be examined.

  The light (alignment light) output from the LED 51 of the alignment optical system 50 is reflected by the dichroic mirror 55 via the apertures 52 and 53 and the relay lens 54, passes through the hole of the perforated mirror 21, and reaches the dichroic mirror 46. And is projected onto the cornea of the eye E by the objective lens 22.

  The corneal reflection light of the alignment light passes through the objective lens 22, the dichroic mirror 46 and the hole, part of which passes through the dichroic mirror 55, passes through the focusing lens 31, is reflected by the mirror 32, and is half mirror The light passes through 33A, is reflected by the dichroic mirror 33, and is projected onto the light receiving surface of the CCD image sensor 35 by the condenser lens. The light reception image (alignment index) by the CCD image sensor 35 is displayed on the display device 3 together with the observation image. The user performs alignment by performing the same operation as that of a conventional fundus camera. Further, the arithmetic control unit 200 may perform alignment by analyzing the position of the alignment index and moving the optical system (auto-alignment function).

  When performing the focus adjustment, the reflecting surface of the reflecting rod 67 is obliquely provided on the optical path of the illumination optical system 10. The light (focus light) output from the LED 61 of the focus optical system 60 passes through the relay lens 62, is separated into two light beams by the split indicator plate 63, passes through the two-hole aperture 64, and is reflected by the mirror 65, The light is focused on the reflecting surface of the reflecting bar 67 by the condenser lens 66 and reflected. Further, the focus light passes through the relay lens 20, is reflected by the perforated mirror 21, passes through the dichroic mirror 46, is refracted by the objective lens 22, and is projected onto the fundus oculi Ef.

  The fundus reflection light of the focus light is detected by the CCD image sensor 35 through the same path as the cornea reflection light of the alignment light. A light reception image (split index) by the CCD image sensor 35 is displayed on the display device 3 together with the observation image. The arithmetic and control unit 200 analyzes the position of the split index and moves the focusing lens 31 and the focus optical system 60 to perform focusing as in the conventional case (autofocus function). Alternatively, focusing may be performed manually while visually checking the split indicator.

  The dichroic mirror 46 branches the optical path for OCT from the optical path for fundus imaging. The dichroic mirror 46 reflects light in a wavelength band used for OCT and transmits light for fundus photographing. In this OCT optical path, in order from the OCT unit 100 side, a collimator lens unit 40, a wavelength division member 47, an optical path length changing unit 41, an optical scanner 42, a focusing lens 43, a mirror 44, and a relay A lens 45 is provided. The wavelength division member 47 branches the optical path for monitoring from the optical path for OCT. A detector 48 is provided in the optical path for monitoring.

  The wavelength division member 47 is arranged in the optical path of the measurement light, and among the measurement light generated in the OCT unit 100, a first wavelength band used for an image forming process by an image forming unit 220 described later, and a first wavelength band And the measurement light in the first wavelength band is transmitted. The first wavelength band or the second wavelength band can include one or more wavelength ranges. In the following, one wavelength range used for the image forming process in the wavelength band of the measurement light is defined as the first wavelength band, and two wavelength ranges on both sides of the first wavelength band in the wavelength band of the measurement light are defined as the second wavelength. This will be explained as a belt. In this embodiment, the wavelength division member 47 is disposed at the pupil position on the optical path of the measurement light between the collimator lens unit 40 and the optical scanner 42. Such a wavelength division member 47 can be composed of one or more wavelength selection members. The wavelength dividing member 47 is disposed in the optical path of light from the light source included in the light source unit 101 described later, and divides the light from the light source into the first wavelength band and the second wavelength band as described above. May be.

  The detection unit 48 is disposed in the optical path for monitoring divided by the wavelength division member 47 and detects the amount of measurement light in the second wavelength band divided by the wavelength division member 47. That is, the detection unit 48 detects the amount of measurement light in a wavelength band that is not subjected to image formation processing. Such a detection unit 48 can be configured by one or more photodetectors.

  In FIG. 2, the structural example of the wavelength division member 47 and the detection part 48 is shown. In FIG. 2, the collimator lens unit 40 and the optical path length changing unit 41 are illustrated in addition to the wavelength division member 47 and the detection unit 48. In FIG. 2, the same parts as those in FIG.

  The wavelength division member 47 includes, for example, a first wavelength selection member 471 and a second wavelength selection member 472. The detection unit 48 includes, for example, a first photodetector 481 and a second photodetector 482. The detection unit 48 may be configured with only one of the first photodetector 481 and the second photodetector 482. In this case, one of the first wavelength selection member 471 and the second wavelength selection member 472 constituting the wavelength division member 47 may be a high pass filter or a low pass filter. In addition, one of the first photodetector 481 and the second photodetector 482 may be used for detecting a physical quantity (for example, a polarization state) other than the light amount.

When the wavelength range of the first wavelength band is λ ₁ to λ ₂ (λ ₁ <λ ₂ ), the first wavelength selection member 471 reflects measurement light in the wavelength range of the wavelength λ ₁ or more, and other wavelengths. range measuring light (wavelength range of less than the wavelength lambda ₁₎ is transmitted. The second wavelength selection member 472 reflects measurement light in the wavelength range of wavelength λ ₂ or less and transmits measurement light in the other wavelength range (wavelength range exceeding wavelength λ ₂ ). Examples of the first wavelength selection member 471 and the second wavelength selection member 472 include a dichroic mirror.

  The first photodetector 481 detects the amount of measurement light transmitted through the first wavelength selection member 471. The second photodetector 482 detects the amount of measurement light transmitted through the second wavelength selection member 472. Examples of the first photodetector 481 and the second photodetector 482 include a photodiode.

The measurement light generated by the OCT unit 100 is converted into parallel light by the collimator lens unit 40. The parallel measurement light is split by the first wavelength selection member 471 into measurement light having a wavelength range of wavelength λ ₁ or more and measurement light having a wavelength range of less than wavelength λ ₁ . Measurement light in the wavelength range of wavelength λ ₁ or more is reflected by the first wavelength selection member 471, and measurement light in the wavelength range of less than wavelength λ ₁ is transmitted through the first wavelength selection member 471. The measurement light having a wavelength range of less than the wavelength λ ₁ transmitted through the first wavelength selection member 471 is guided to the first photodetector 481. The first optical detector 481 detects the light intensity of the measuring light in the wavelength range of less than the wavelength lambda _1. Measurement light in the wavelength range of wavelength λ ₁ or more is guided to the second wavelength selection member 472.

The measurement light in the wavelength range of wavelength λ ₁ or more is split by the second wavelength selection member 472 into measurement light in the wavelength range exceeding wavelength λ ₂ and measurement light in the wavelength range of wavelength λ ₂ or less. Measurement light in the wavelength range of wavelength λ ₂ or less is reflected by the second wavelength selection member 472, and measurement light in the wavelength range exceeding the wavelength λ ₂ is transmitted through the second wavelength selection member 472. Measurement light having a wavelength range exceeding the wavelength λ ₂ that has passed through the second wavelength selection member 472 is guided to the second photodetector 482. The second optical detector 482 detects the measurement light quantity of the wavelength range of more than the wavelength lambda _2. Measuring light having a wavelength lambda ₂ or less in the wavelength range is guided to the optical path length changing unit 41 as a measurement light in the first wavelength band is a wavelength range of the wavelength lambda ₂ or less in the wavelength lambda ₁ or more.

  The optical path length changing unit 41 is movable in the direction of the arrow shown in FIG. 1, and changes the optical path length of the optical path for OCT. This change in the optical path length is used for correcting the optical path length according to the axial length of the eye E or adjusting the interference state. The optical path length changing unit 41 includes, for example, a corner cube and a mechanism for moving the corner cube.

  The optical scanner 42 is disposed at a position optically conjugate with the pupil of the eye E. The optical scanner 42 changes the traveling direction of the light (measurement light LS) passing through the optical path for OCT. Thereby, the eye E can be scanned with the measurement light LS. The optical scanner 42 includes, for example, a galvanometer mirror that scans the measurement light LS in the x direction, a galvanometer mirror that scans in the y direction, and a mechanism that drives these independently. Thereby, the measurement light LS can be scanned in an arbitrary direction on the xy plane.

[OCT unit]
An example of the configuration of the OCT unit 100 is shown in FIG. The OCT unit 100 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 and is sent to the arithmetic control unit 200.

  The light source unit 101 is configured to include a wavelength sweep type (wavelength scanning type) light source capable of sweeping (scanning) the wavelength of emitted light, as in a general swept source type OCT apparatus. The wavelength sweep type light source includes a laser light source including a resonator. The light source unit 101 temporally changes the output wavelength in the near-infrared wavelength band that cannot be visually recognized by the human eye.

  The light L0 output from the light source unit 101 is guided to the polarization controller 103 by the optical fiber 102 and its polarization state is adjusted. The polarization controller 103 adjusts the polarization state of the light L0 guided through the optical fiber 102, for example, by applying stress from the outside to the looped optical fiber 102.

  The light L0 whose polarization state is adjusted by the polarization controller 103 is guided to the fiber coupler 105 by the optical fiber 104, and is divided into the measurement light LS and the reference light LR.

  The reference light LR is guided to the collimator 111 by the optical fiber 110 and becomes a parallel light beam. The reference light LR that has become a parallel light beam is guided to the corner cube 114 via the optical path length correction member 112 and the dispersion compensation member 113. The optical path length correction member 112 functions as a delay unit for matching the optical path length (optical distance) of the reference light LR and the optical path length of the measurement light LS. The dispersion compensation member 113 functions as a dispersion compensation means for matching the dispersion characteristics between the reference light LR and the measurement light LS.

  The corner cube 114 folds the traveling direction of the reference light LR that has become a parallel light beam by the collimator 111 in the reverse direction. The optical path of the reference light LR incident on the corner cube 114 and the optical path of the reference light LR emitted from the corner cube 114 are parallel. The corner cube 114 is movable in a direction along the incident optical path and the outgoing optical path of the reference light LR. By this movement, the length of the optical path of the reference light LR is changed.

  1 and 3, the optical path length changing unit 41 for changing the length of the optical path (measurement optical path, measurement arm) of the measurement light LS and the optical path (reference optical path, reference) of the reference light LR. Both corner cubes 114 for changing the length of the arm) are provided, but either one of them may be provided. It is also possible to change the difference between the measurement optical path length and the reference optical path length using optical members other than these.

  The reference light LR that has passed through the corner cube 114 passes through the dispersion compensation member 113 and the optical path length correction member 112, is converted from a parallel light beam to a focused light beam by the collimator 116, enters the optical fiber 117, and is guided to the polarization controller 118. Accordingly, the polarization state of the reference light LR is adjusted.

  For example, the polarization controller 118 has the same configuration as the polarization controller 103. The reference light LR whose polarization state is adjusted by the polarization controller 118 is guided to the attenuator 120 by the optical fiber 119, and the light quantity is adjusted under the control of the arithmetic control unit 200. The reference light LR whose light amount has been adjusted by the attenuator 120 is guided to the fiber coupler 122 by the optical fiber 121.

  On the other hand, the measurement light LS generated by the fiber coupler 105 is guided by the optical fiber 127 and converted into a parallel light beam by the collimator lens unit 40. The measurement light LS converted into a parallel light beam reaches the dichroic mirror 46 via the wavelength division member 47, the optical path length changing unit 41, the optical scanner 42, the focusing lens 43, the mirror 44, and the relay lens 45. Then, the measurement light LS is reflected by the dichroic mirror 46, refracted by the objective lens 22, and irradiated to 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 105, and reaches the fiber coupler 122 via the optical fiber 128.

  The fiber coupler 122 combines (interferes) the measurement light LS incident through the optical fiber 128 and the reference light LR incident through the optical fiber 121 to generate interference light. The fiber coupler 122 branches the interference light between the measurement light LS and the reference light LR at a predetermined branching ratio (for example, 1: 1), thereby generating a pair of interference lights LC. The pair of interference lights LC emitted from the fiber coupler 122 are guided to the detector 125 by optical fibers 123 and 124, respectively.

  The detector 125 is, for example, a balanced photodiode that includes a pair of photodetectors that respectively detect a pair of interference lights LC and outputs a difference between detection results obtained by the pair of photodetectors. The detector 125 sends the detection result (detection signal) to a DAQ (Data Acquisition System) 130. The clock 130 is supplied from the light source unit 101 to the DAQ 130. The clock KC 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 light source unit 101. For example, the light source unit 101 optically delays one of the two branched lights obtained by branching the light L0 of each output wavelength, and then generates the clock KC based on the result of detecting these combined lights. Generate. The DAQ 130 samples the detection result of the detector 125 based on the clock KC. The DAQ 130 sends the sampled detection result of the detector 125 to the arithmetic control unit 200. The arithmetic control unit 200 performs, for example, Fourier transform or the like on the spectrum distribution based on the detection result obtained by the detector 125 for each series of wavelength scans (for each A line), thereby obtaining the reflection intensity profile in each A line. Form. Furthermore, the arithmetic control unit 200 forms image data by imaging the reflection intensity profile of each A line.

[Calculation control unit]
The configuration of the arithmetic control unit 200 will be described. The arithmetic control unit 200 analyzes the detection signal input from the detector 125 and forms an OCT image of the eye E. The arithmetic processing for this is the same as that of a conventional swept source type OCT apparatus.

  The arithmetic control unit 200 controls each part of the fundus camera unit 2, the display device 3, and the OCT unit 100. For example, the arithmetic control unit 200 displays an OCT image of the eye E on the display device 3.

  The arithmetic and control unit 200 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 200 may include various circuit boards, for example, a circuit board for forming an OCT image. The arithmetic control unit 200 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. 4, some components of the ophthalmologic photographing apparatus 1 are omitted, and components particularly necessary for explaining this embodiment are selectively shown.

(Control part)
The control system of the ophthalmologic photographing apparatus 1 is configured around the control unit 210. The controller 210 includes, for example, a microprocessor, RAM, ROM, hard disk drive, communication interface, and the like. The control unit 210 is provided with a main control unit 211 and a storage unit 212.

(Main control unit)
The main control unit 211 performs the various controls described above. In particular, as shown in FIG. 4, the main control unit 211 includes the imaging focus drive unit 31A, the CCD image sensors 35 and 38, the LCD 39, the optical path length changing unit 41, the optical scanner 42, and the OCT focus drive of the fundus camera unit 2. The unit 43A, the detection unit 48, the light source unit 101 of the OCT unit 100, the reference drive unit 114A, the detector 125, the DAQ 130, and the like are controlled.

  The photographing focus driving unit 31A moves the focusing lens 31 in the optical axis direction. Thereby, the focus position of the photographic optical system 30 is changed. The main control unit 211 can control an optical system drive unit (not shown) to move the optical system provided in the fundus camera unit 2 three-dimensionally. 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. When tracking is performed, alignment and focusing are performed in advance. Tracking maintains a suitable positional relationship in which alignment and focus are achieved 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. It is a function.

  The OCT focusing drive unit 43A moves the focusing lens 43 along the optical axis of the measurement optical path. Thereby, the focus position of the measurement light LS is changed. The focus position of the measurement light LS corresponds to the depth position (z position) of the beam waist of the measurement light LS.

  The reference driving unit 114A moves the corner cube 114 provided in the reference optical path. Thereby, the length of the reference optical path is changed. As described above, the optical path length changing unit 41 and only one of the corner cube 114 and the reference driving unit 114A may be provided.

  As illustrated in FIG. 4, the main control unit 211 includes a monitoring unit 2111.

(Monitoring Department)
The monitoring unit 2111 monitors the amount of measurement light in the second wavelength band divided by the wavelength dividing member 47 based on the detection result by the detection unit 48. Specifically, the monitoring unit 2111 monitors the light quantity of the measurement light in the wavelength range less than the wavelength λ ₁ and the light quantity of the measurement light in the wavelength range that exceeds the wavelength λ ₂ divided by the wavelength division member 47. Since the amount of measurement light in the entire wavelength band generated in the OCT unit 100 can be a known amount, the amount of measurement light in the first wavelength band can be detected by detecting the amount of measurement light in the second wavelength band. It is possible to accurately estimate the amount of light. Therefore, by monitoring the light amount of the measurement light in the second wavelength band by the monitoring unit 2111, the light amount of the measurement light in the first wavelength band can be monitored.

For example, the monitoring unit 2111 measures the amount of measurement light in the wavelength range less than the wavelength λ ₁ detected by the first photodetector 481 and the measurement light in the wavelength range that exceeds the wavelength λ ₂ detected by the second photodetector 482. It is possible to obtain the light amount of the measurement light in the second wavelength band by adding the light amount. The monitoring unit 2111 compares the obtained amount of measurement light in the second wavelength band with a predetermined threshold value, and generates a comparison result. The main control unit 211 determines that the amount of measurement light incident on the eye E is large when it is determined that the amount of measurement light in the second wavelength band is equal to or greater than the above threshold based on the comparison result by the monitoring unit 2111. Then, it is possible to cause the notification unit 250 described later to output notification information or to stop the measurement light from entering the eye E. When stopping the incidence of the measurement light, the light source unit 101 includes a shutter member that can be inserted into the optical path of the light from the wavelength sweeping light source, and the main control unit 211 outputs (monitors) the monitoring unit 2111. It is possible to stop the incidence of the measurement light by inserting the shutter member into the optical path of the light based on the result. Further, the main control unit 211 may control the wavelength sweeping type light source of the light source unit 101 based on the output from the monitoring unit 2111. In this case, the main control unit 211 can adjust (reduce) the amount of light from the wavelength sweep type light source based on the output from the monitoring unit 2111, for example.

The monitoring unit 2111 measures the amount of measurement light in the wavelength range less than the wavelength λ ₁ detected by the first photodetector 481 and the measurement light in the wavelength range that exceeds the wavelength λ ₂ detected by the second photodetector 482. The amount of light obtained by weighting the amount of light may be obtained as the amount of measurement light in the second wavelength band.

The monitoring unit 2111, the measurement light quantity of the wavelength range of less than the wavelength lambda ₁ provided with the first threshold value, may be the second threshold value provided for measuring light quantity of the wavelength range of more than the wavelength lambda _2. For example, the monitoring unit 2111 compares the amount of measurement light in the wavelength range less than the wavelength λ ₁ with the first threshold value, compares the amount of measurement light in the wavelength range greater than the wavelength λ ₂ with the second threshold value, and Based on both or one of the two comparison results, it may be determined whether or not the amount of measurement light incident on the eye E is large. Alternatively, either the light amount of the measurement light in the wavelength range less than the wavelength λ ₁ or the light amount of the measurement light in the wavelength range greater than the wavelength λ ₂ is compared with the second threshold, and based on the comparison result of both, It may be determined whether or not the amount of incident measurement light is large. Alternatively, the monitoring unit 2111 enters the eye E based on a comparison result between one of the light amount of the measurement light in the wavelength range less than the wavelength λ ₁ or the light amount of the measurement light in the wavelength range greater than the wavelength λ ₂ and the threshold value. It may be determined whether the amount of measurement light is large.

(Memory part)
The storage unit 212 stores various data. Examples of the data stored in the storage unit 212 include OCT image image data, fundus image data, and examined eye information. The eye information includes information about the subject such as patient ID and name, and information about the eye such as left / right eye identification information. The storage unit 212 stores various programs and data for operating the ophthalmologic photographing apparatus 1.

(Image forming part)
The image forming unit 220 forms image data of a cross-sectional image of the fundus oculi Ef based on the detection signal from the detector 125 (DAQ 130). That is, the image forming unit 220 forms image data of the eye E based on the detection result of the interference light LC by the interference optical system. This process includes processes such as noise removal (noise reduction), filter processing, and FFT (Fast Fourier Transform), as in the case of the conventional swept source type OCT. The image data acquired in this way is a data set including a group of image data formed by imaging reflection intensity profiles in a plurality of A lines (paths of the measurement light LS in the eye E). is there.

  In order to improve the image quality, it is possible to superimpose (addition average) a plurality of data sets acquired by repeating scanning with the same pattern a plurality of times.

  The image forming unit 220 includes, for example, the circuit board described above. In this specification, “image data” and “image” based thereon may be identified. Moreover, the part of the eye E to be examined and the image thereof may be identified.

(Data processing part)
The data processing unit 230 performs various types of data processing (image processing) and analysis processing on the OCT image formed by the image forming unit 220. For example, the data processing unit 230 executes correction processing such as image brightness correction and dispersion correction. Further, the data processing unit 230 performs various types of image processing and analysis processing on the image (fundus image, anterior eye image, etc.) obtained by the fundus camera unit 2.

  The data processing unit 230 can form volume data (voxel data) of the eye E by performing known image processing such as interpolation processing for interpolating pixels between cross-sectional images. When displaying an image based on volume data, the data processing unit 230 performs a rendering process on the volume data to form a pseudo three-dimensional image when viewed from a specific viewing direction.

  The data processing unit 230 can perform alignment between the fundus image and the OCT image. When the fundus image and the OCT image are acquired in parallel, since both optical systems are coaxial, the optical axis of the imaging optical system 30 is used to (substantially) simultaneously acquire the fundus image and the OCT image. Can be aligned with reference to. Regardless of the acquisition timing of the fundus image and the OCT image, the front image obtained by projecting at least a part of the image area corresponding to the fundus oculi Ef of the OCT image onto the xy plane is aligned with the fundus image. By doing so, it is possible to align the OCT image and the fundus image. This alignment method is applicable even when the fundus image acquisition optical system and the OCT optical system are not coaxial. Even if both optical systems are not coaxial, if the relative positional relationship between both optical systems is known, the same alignment as in the coaxial case is executed with reference to this relative positional relationship. It is possible.

  The data processing unit 230 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.

(Notification part)
The notification unit 250 receives control from the control unit 210 (main control unit 211) and outputs notification information. Specifically, the notification unit 250 performs notification based on the output from the monitoring unit 2111 (outputs notification information). The notification unit 250 includes an audio output unit. In this case, the notification unit 250 can output auditory information (warning message, warning sound, etc.) as the notification information. Further, the function of the notification unit 250 may be realized by the display unit 241. In this case, the notification unit 250 (display unit 241) can output visual information (character string information, image information, etc.) as the notification information.

(User interface)
The user interface 240 includes a display unit 241 and an operation unit 242. The display unit 241 includes the display device of the arithmetic control unit 200 and the display device 3 described above. The operation unit 242 includes the operation device of the arithmetic control unit 200 described above. The operation unit 242 may include various buttons and keys provided on the housing of the ophthalmologic photographing apparatus 1 or outside. Further, the display unit 241 may include various display devices such as a touch panel provided in the housing of the fundus camera unit 2.

  The display unit 241 and the operation unit 242 do not need 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 242 includes the touch panel and a computer program. The operation content for the operation unit 242 is input to the control unit 210 as an electrical signal. Further, operations and information input may be performed using the graphical user interface (GUI) displayed on the display unit 241 and the operation unit 242.

  The OCT unit 100, the collimator lens unit 40, the wavelength division member 47, the detection unit 48, the optical path length changing unit 41, the optical scanner 42, the focusing lens 43, the mirror 44, and the relay lens 45 are related to “interference optics” according to this embodiment. It is an example of “system”.

(Wavelength division member)
The wavelength division member 47 includes the measurement light in the first wavelength band that is used for the image forming process among the measurement light LS obtained by branching the light L0 output from the light source unit 101, and a wavelength other than the first wavelength band. The light is divided into measurement light in the second wavelength band.

FIG. 5 schematically shows the light amount of the light L0 output from the wavelength sweep type light source of the light source unit 101. In FIG. 5, the horizontal axis represents time, and the vertical axis represents light quantity. The swept wavelength light source outputs light L0 whose output wavelength changes over time in a wavelength band WL0 in a wavelength range of predetermined wavelengths λ _{0 to} λ _N. As described above, since the light source unit 101 optically generates the clock KC based on the light L0 output from the wavelength sweep type light source, the wavelengths λ ₁ to λ ₂ (λ in which the frequency of the clock KC is stabilized in the wavelength band WL0. The measurement light in the wavelength band WL1 (that is, the first wavelength band) in the wavelength range of ₀ <λ ₁ <λ ₂ <λ _N ) is used for image forming processing by the image forming unit 220. In this embodiment, the wavelength band WL1 is set in advance based on the sampling range for the spectral distribution based on the detection result of the interference light LC. Wavelength division member 47, the configuration of FIG. 2, the measurement light LS from the collimator lens unit 40, a measurement light having a wavelength band WL1 in the wavelength range of the wavelength lambda ₁ to [lambda] ₂ (first wavelength band), the wavelength lambda ₁ It is divided into the measuring light below wavelength range exceeding waveband WL2 and the wavelength lambda ₂ in the wavelength range of the wavelength band WL3 (second wavelength band). The ophthalmologic imaging apparatus 1 performs OCT measurement using measurement light in the wavelength band WL1. The measurement light (the amount of light corresponding to the areas R1 and R2 in FIG. 5) in the wavelength bands WL2 and WL3 (that is, the second wavelength band) other than the wavelength band WL1 divided by the wavelength dividing member 47 is subjected to image forming processing. Without being detected by the detection unit 48.

  The ophthalmologic photographing apparatus 1 makes the measurement light in the wavelength band WL <b> 1 used for the image forming process performed by the image forming unit 220 incident on the eye E to be examined with a predetermined light amount or less. The predetermined value is determined in advance in consideration of optical members constituting the ophthalmologic photographing apparatus 1, control contents, safety of the eye to be examined, and the like. Further, the ophthalmologic photographing apparatus 1 can monitor the light amount of the measurement light in the wavelength bands WL2 and WL3 other than the wavelength band WL1 used for the image forming process, and can make a notification based on the monitoring result. Thus, while ensuring the safety of the eye to be inspected, the light L0 having the light amount increased by the light amount corresponding to the areas R1 and R2 in FIG. 4 is output from the light source unit 101, thereby corresponding to the area R3 in FIG. The amount of measurement light can be increased by the amount of light to be emitted. In this way, by utilizing the amount of light not subjected to the image forming process, it is possible to improve the image quality of the image acquired by the ophthalmologic photographing apparatus 1 while ensuring the safety of the eye to be examined.

  Such a wavelength division member 47 is desirably arranged at the following position.

  FIG. 6 schematically illustrates an arrangement position of the wavelength division member 47 in this embodiment. In FIG. 6, illustration of some optical members is omitted. Further, in FIG. 6, the same parts as those in FIG. 1 or FIG.

  In this embodiment, the wavelength division member 47 is, for example, an integer multiple or a half integer multiple of the resonator length of the resonator of the laser light source included in the wavelength sweep type light source from the division position of the measurement light LS and the reference light LR. It is arranged at a position on the optical path of the measurement light different from the optically separated position. The division position of the measurement light LS and the reference light LR is, for example, the position of the emission end from which the measurement light LS is emitted from the fiber coupler 105.

  More specifically, the optical distance from the division position of the measurement light LS and the reference light LR to the front surface of the wavelength division member 47 (the surface on the light source unit 101 side) is L, and the measurement light LS and the reference light LR The optical distance from the division position to the rear surface of the wavelength division member 47 (the surface on the optical scanner 42 side) is L ′, the resonator length of the resonator of the laser light source included in the wavelength sweep type light source is CL, and 1 When the above integer is n, the wavelength division member 47 is disposed at a position on the optical path of the measurement light that satisfies the expressions (1) and (2).

  By arranging the wavelength dividing member 47 at a position on the optical path of the measurement light that satisfies the expressions (1) and (2), the coherence revival phenomenon is avoided, and the image quality of the image acquired by the ophthalmologic photographing apparatus 1 is deteriorated. Can be suppressed.

  Further, as shown in FIG. 1, the wavelength division member 47 is disposed on the light source unit 101 side from the optical scanner 42. By doing so, it is not necessary to select the wavelength of the measurement light within the scan range by the optical scanner 42, and the size of the wavelength division member 47 can be reduced.

  As shown in FIG. 1, the wavelength division member 47 is disposed at a position on the optical path where light is guided as parallel light by the interference optical system. Further, the position can be a pupil position determined by an optical element such as the objective lens 22. By doing so, it is possible to minimize optical aberrations at the imaging position.

  Further, the wavelength division member 47 is disposed at a position different from the optically conjugate position with the pupil of the eye E on the optical path of the measurement light. By doing so, it becomes possible to reduce the noise of the return light.

  Further, at least one of the first wavelength band and the second wavelength band of the measurement light divided by the wavelength division member 47 may be configured to be changeable. For example, the wavelength division member 47 includes a plurality of wavelength division members having mutually different wavelength division characteristics, and is configured to be able to selectively insert the plurality of wavelength division members into the optical path of the measurement light. The main control unit 211 changes at least one of the first wavelength band and the second wavelength band of the measurement light divided by the wavelength division member 47 by inserting any one of the plurality of wavelength division members into the optical path of the measurement light. can do.

  As described above, by configuring at least one of the first wavelength band and the second wavelength band of the measurement light divided by the wavelength division member 47, even when there is an error in the output wavelength of the wavelength sweep type light source. Thus, it is possible to ensure the safety of the eye to be examined and improve the image quality by increasing the amount of measurement light.

[Operation example]
The operation of the ophthalmologic photographing apparatus 1 will be described.

  FIG. 7 shows a flowchart of an operation example of the ophthalmologic photographing apparatus 1. This operation example includes a process for aligning the eye E to be examined and the apparatus optical system based on an image, and a process for setting a scanning region based on the image. The alignment processing includes alignment for OCT measurement (auto alignment), focusing (auto focus), and tracking (auto tracking).

(S1)
First, acquisition of a near-infrared moving image of the fundus oculi Ef is started by continuously illuminating the fundus oculi Ef with illumination light from the observation light source 11 (which becomes near-infrared light by the visible cut filter 14). This near-infrared moving image is obtained in real time until the continuous illumination ends. The image of each frame composing the moving image is temporarily stored in the frame memory (storage unit 212) and sequentially sent to the data processing unit 230.

  Note that an alignment index by the alignment optical system 50 and a split index by the focus optical system 60 are projected onto the eye E to be examined. Therefore, the alignment index and the split index are depicted in the near-infrared moving image. These indices can be used for alignment and focusing. A fixation target by the LCD 39 is also projected onto the eye E. The subject is instructed to stare at the fixation target.

(S2)
The data processing unit 230 sequentially analyzes frames obtained by taking a moving image of the eye E with the optical system, obtains the position of the alignment target, and calculates the movement amount of the optical system. The control unit 210 performs auto alignment by controlling an optical system driving unit (not shown) based on the movement amount of the optical system calculated by the data processing unit 230.

(S3)
The data processing unit 230 sequentially analyzes frames obtained by taking a moving image of the eye E with the optical system, determines the position of the split target, and calculates the amount of movement of the focusing lens 31. The control unit 210 performs autofocus by controlling the photographing focus driving unit 31A based on the movement amount of the focusing lens 31 calculated by the data processing unit 230.

(S4)
Subsequently, the control unit 210 starts auto-tracking. Specifically, the data processing unit 230 analyzes in real time frames obtained sequentially by taking a moving image of the eye E with the optical system, and monitors the movement (position change) of the eye E. The control unit 210 controls an optical system driving unit (not shown) so as to move the optical system in accordance with the position of the eye E to be sequentially acquired. As a result, the optical system can follow the movement of the eye E in real time, and it is possible to maintain a suitable positional relationship in which the alignment is in focus.

(S5)
The control unit 210 displays the near-infrared moving image on the display unit 241 in real time. The user uses the operation unit 242 to set a scanning area on the near-infrared moving image. The scanning area to be set may be a one-dimensional area or a two-dimensional area.

  When the scanning mode of the measurement light LS and the region of interest (optic nerve head, macula, lesion, etc.) are set in advance, the control unit 210 sets the scanning region based on these settings. It is also possible to configure. Specifically, the region of interest is identified by image analysis by the data processing unit 230, and the control unit 210 defines a region of a predetermined pattern so as to include the region of interest (for example, the region of interest is located at the center). Set.

  Further, when setting the same scanning region as the OCT measurement performed in the past (so-called follow-up), the control unit 210 can reproduce and set the past scanning region on the real-time near-infrared moving image. . As a specific example, the control unit 210 includes information (scanning mode or the like) indicating a scanning area set in a past examination, and a near-infrared fundus image (a still image, for example, a frame) in which the scanning area is set. Are associated with each other and stored in the storage unit 212 (practically associated with a patient ID and left and right eye information). The control unit 210 aligns the past near-infrared fundus image and the frame of the current near-infrared moving image, and in the current near-infrared moving image corresponding to the scanning region in the past near-infrared fundus image. Specify the image area. Thereby, the scanning area applied in the past examination is set for the current near-infrared moving image.

(S6)
The detector 48 detects the amount of measurement light in the second wavelength band divided by the wavelength division member 47. The monitoring unit 2111 compares the light amount of the measurement light in the second wavelength band detected by the detection unit 48 with a predetermined threshold value.

(S7)
When the monitoring unit 2111 determines that the amount of measurement light in the second wavelength band is less than the predetermined threshold (S7: Y), the operation of the ophthalmologic photographing apparatus 1 proceeds to S8. When the monitoring unit 2111 determines that the amount of measurement light in the second wavelength band is equal to or greater than the predetermined threshold (S7: N), the operation of the ophthalmologic photographing apparatus 1 proceeds to S9.

(S8)
When the monitoring unit 2111 determines that the amount of measurement light in the second wavelength band is less than a predetermined threshold (S7: Y), the control unit 210 controls the light source unit 101 and the optical path length changing unit 41, and The OCT measurement of the fundus oculi Ef is performed by controlling the optical scanner 42 based on the scanning region set in S5.

  The image forming unit 220 forms a tomographic image (image) of the A line based on the collected data obtained by sampling the detection signal obtained by the detector 150 based on the clock KC as described above. To do. When the scanning mode is a three-dimensional scan, the data processing unit 230 forms a three-dimensional image of the fundus oculi Ef based on a plurality of tomographic images formed by the image forming unit 220. This is the end of this operation example (end).

(S9)
When the monitoring unit 2111 determines that the amount of measurement light in the second wavelength band is equal to or greater than a predetermined threshold (S7: N), the control unit 210 (main control unit 211) outputs notification information to the notification unit 250. And at least one of stopping the incidence of the measurement light to the eye E. Thereafter, the operation of the ophthalmologic photographing apparatus 1 ends (END).

  In addition, control of the control part 210 based on the monitoring result of the monitoring part 2111 shown to S6, S7, and S9 may be performed in either S1-S5.

  Further, the order of S4 and S5 may be changed. Moreover, in said S4 and S5, a near-infrared moving image is displayed and the scanning area | region is set on this near-infrared moving image, However, The setting aspect of a scanning area | region is not limited to this. For example, an image of one frame (referred to as a reference image) in the near-infrared moving image is displayed, and auto tracking is executed in the background. When the scanning area is set on the reference image, the control unit 210 performs alignment between the reference image and the image currently used for auto-tracking, thereby setting the scanning area set on the reference image. An image region in the real-time near-infrared moving image corresponding to is specified. This process can also set the scanning area in the real-time near-infrared moving image as in S4 and S5. Further, according to this method, since the scanning area can be set on the still image, the work can be facilitated and ensured as compared with the case of setting on the moving image that is actually auto-tracked.

  Note that the above embodiment is not limited to an ophthalmologic photographing apparatus, and can be applied to an ophthalmologic apparatus. In this case, the monitoring unit may monitor the amount of light from the light source, the polarization state, and the like. That is, the ophthalmologic apparatus makes light from a light source incident on the subject's eye, detects the return light from the subject's eye, and information about the eye to be examined (for example, an image) based on the detection result of the return light by the optical system It is possible to include the information generation part which produces | generates. This optical system divides light from a light source into light in a first wavelength band used for information generation processing by an information generation unit and light in a second wavelength band other than the first wavelength band. The light including the member and including only the first wavelength band is incident on the eye to be examined. The ophthalmologic apparatus includes a monitoring unit that monitors light in the second wavelength band.

[Action / Effect]
Several actions and effects of the ophthalmologic photographing apparatus according to this embodiment will be described.

  The ophthalmologic photographing apparatus according to the embodiment includes an interference optical system (for example, an OCT unit 100, a collimator lens unit 40, a wavelength division member 47, a detection unit 48, an optical path length changing unit 41, an optical scanner 42, a focusing lens 43, a mirror 44, And a relay lens 45) and an image forming unit (for example, the image forming unit 220). The interference optical system divides light (for example, light L0) from a light source (for example, the wavelength sweep type light source of the light source unit 101) into measurement light (for example, measurement light LS) and reference light (for example, reference light LR). Then, the measurement light is incident on the eye to be examined (for example, eye E to be examined), and interference light (for example, interference light LC) between the return light of the measurement light from the eye to be examined and the reference light is detected. The image forming unit forms an image of the eye to be examined based on the detection result of the interference light by the interference optical system. The interference optical system includes a wavelength division member (for example, wavelength division member 47). The wavelength division member uses the light from the light source or the measurement light, the measurement light in the first wavelength band (for example, the wavelength band WL1) used for the image forming process by the image forming unit, and the second wavelength other than the first wavelength band. It is used to divide the measurement light into bands (for example, wavelength bands WL2 and WL3). The ophthalmologic photographing apparatus includes a monitoring unit (for example, a monitoring unit 2111) that causes measurement light including only the first wavelength band to enter the eye to be examined and monitors the amount of measurement light in the second wavelength band.

  According to such a configuration, the measurement light is divided into measurement light in the first wavelength band used for image forming processing by the image forming unit and measurement light in the second wavelength band other than that, By monitoring the light quantity of the measurement light and making the measurement light in the first wavelength band enter the eye to be examined, the light quantity of the measurement light incident on the eye to be examined is used for image forming processing while ensuring the safety of the eye to be examined. It is possible to increase the amount of measurement light in a wavelength band that is not used. Thereby, it is possible to improve the image quality of the image acquired by the ophthalmologic photographing apparatus while ensuring the safety of the eye to be examined.

  Moreover, you may include the alerting | reporting part (for example, alerting | reporting part 250) which alert | reports based on the output from a monitoring part.

  According to such a configuration, it is possible to notify the subject of safety based on the amount of measurement light incident on the subject's eye, and to ensure the safety of the subject's eye.

  Further, a control unit (for example, the control unit 210 or the main control unit 211) that stops the measurement light from entering the eye to be inspected based on the output from the monitoring unit may be included.

  According to such a configuration, it is possible to ensure the safety of the eye to be examined.

  Moreover, you may include the control part which controls a light source based on the output from a monitoring part.

  According to such a configuration, by controlling the light source, it is possible to stop the incidence of the measurement light on the eye to be examined or to adjust the light quantity of the measurement light. It becomes possible to improve the image quality of the image acquired by the photographing apparatus.

  Moreover, the ophthalmologic apparatus (for example, ophthalmologic imaging apparatus 1) of embodiment contains an optical system and an information generation part. The optical system (for example, the OCT unit 100, the collimator lens unit 40, the wavelength division member 47, the detection unit 48, the optical path length changing unit 41, the optical scanner 42, the focusing lens 43, the mirror 44, and the relay lens 45) is a light source ( For example, light (for example, measurement light) from the wavelength sweep type light source of the light source unit 101 is incident on the eye to be examined (for example, eye E to be examined), and return light from the eye to be examined is detected. The information generation unit (for example, the image forming unit 220) generates information (for example, an image) related to the eye to be examined based on the detection result of the return light by the optical system. The optical system converts light from the light source into light in a first wavelength band (for example, wavelength band WL1) that is used for information generation processing (for example, image formation processing) by the information generation unit, and in light other than the first wavelength band. A wavelength division member (for example, wavelength division member 47) for dividing light into two wavelength bands (for example, wavelength bands WL2 and WL3) is included, and light including only the first wavelength band is incident on the eye to be examined. The ophthalmologic apparatus includes a monitoring unit (for example, a monitoring unit 2111) that monitors light in the second wavelength band.

  According to such a configuration, the light from the light source is divided into light in the first wavelength band that is used for information generation processing by the information generation unit and light in the second wavelength band other than that, and the light in the second wavelength band is divided. A wavelength band in which the amount of light incident on the subject's eye is not subjected to information generation processing while ensuring the safety of the subject's eye by monitoring the amount of light and making light in the first wavelength band incident on the subject's eye It is possible to increase by the amount of light. As a result, it is possible to improve the quality of information generated in the ophthalmologic apparatus while ensuring the safety of the eye to be examined.

(Modification)
When the ophthalmologic photographing apparatus 1 has a plurality of operation modes and performs OCT measurement by making measurement light in a wavelength band corresponding to the operation modes incident on the eye E, the first wavelength band divided by the wavelength dividing member 47 The second wavelength band may be changeable according to the operation mode.

  The configuration and operation of the ophthalmic imaging apparatus according to this modification are substantially the same as the configuration and operation of the ophthalmic imaging apparatus 1 according to this embodiment. Hereinafter, an ophthalmologic photographing apparatus according to this modification will be described focusing on differences from the present embodiment.

  FIG. 8 shows an example of a block diagram of a control system of the ophthalmologic photographing apparatus according to this modification. 8, parts similar to those in FIG. 4 are given the same reference numerals, and description thereof will be omitted as appropriate. The main difference between the configuration of the control system of the ophthalmologic imaging apparatus according to this modification and the configuration of the control system of the ophthalmic imaging apparatus 1 according to this embodiment is that the mode switching unit 2112 is provided in the main control unit 211. is there.

  The ophthalmologic imaging apparatus according to this modification performs OCT measurement in any of a plurality of operation modes in which at least one of the operation contents of the OCT unit 100 (interference optical system) and the image forming unit 220 is different, and in the switched operation mode. It is possible to acquire an image of the eye E by the OCT measurement performed. The mode switching unit 2112 switches a plurality of operation modes in response to a user operation on the operation unit 242. The plurality of operation modes include an imaging mode according to the imaging region, an examination mode according to the lesion, an imaging mode according to the scan pattern, an operation mode according to the analysis content for the acquired image, and an OCT measurement. There are operation modes according to the output mode of the obtained results.

  The ophthalmologic imaging apparatus according to the present modification switches, for example, either an anterior ocular segment imaging mode for imaging the anterior ocular segment or a fundus imaging mode for imaging the fundus as an imaging mode according to the imaging region. Shall be able to. In the anterior segment imaging mode, OCT measurement is performed using measurement light in the anterior segment imaging wavelength band of the center wavelength λa, and in the fundus imaging mode, OCT is performed using measurement light in the fundus imaging wavelength band of the center wavelength λb (λa> λb). Measurement is performed. In addition, the number of sampling points and the sampling interval of data within the oscillation wavelength band are changed according to the imaging mode, and the tomographic image display area is changed.

  The main control unit 211 changes at least one of the first wavelength band and the second wavelength band of the measurement light divided by the wavelength division member 47 according to the operation mode switched by the mode switching unit 2112. Specifically, when the mode switching unit 2112 switches to the anterior segment imaging mode, the main control unit 211 sets the first wavelength band and the second wavelength so that the first wavelength band becomes the anterior segment imaging wavelength band. The wavelength division member 47 is controlled so that the band is changed. When the mode switching unit 2112 switches to the fundus imaging mode, the main control unit 211 changes the first wavelength band and the second wavelength band so that the first wavelength band becomes the fundus imaging wavelength band. The wavelength division member 47 is controlled. As described above, the wavelength division member 47 can change the first wavelength band and the second wavelength band.

  The light source unit 101 includes one or more light sources (wavelength sweep type light sources) capable of emitting light in the first wavelength band and the second wavelength band, and the main control unit 211 is divided into first wavelengths divided by the wavelength dividing member 47. You may make it change the output wavelength band of the light source of the light source unit 101 according to the change of a wavelength band (or 2nd wavelength band). In this case, the main control unit 211 may change the wavelength band of light emitted from one wavelength sweep type light source, or may switch a plurality of wavelength sweep type light sources having different output wavelength bands. Good.

(Other variations)
The wavelength division member 47 in the embodiment is not limited to the configuration shown in FIG. 2 and may have other configurations.

  In addition, when one end of the wavelength sweep wavelength range (corresponding to the wavelength band WL0 in FIG. 5) and one end of the wavelength range used for image forming processing (corresponding to the wavelength band WL1 in FIG. 5) substantially match. The wavelength division member 47 according to the embodiment may be configured by a high-pass filter, a low-pass filter, or a single dichroic mirror. The wavelength division member 47 is specific if it can achieve the function of dividing the measurement light in the first wavelength band used for the image forming process into the measurement light in the second wavelength band other than the first wavelength band. Regardless of configuration.

  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 can be obtained.

DESCRIPTION OF SYMBOLS 1 Ophthalmologic imaging apparatus 2 Fundus camera unit 42 Optical scanner 47 Wavelength division member 471 First wavelength selection member 472 Second wavelength selection member 48 Detector 481 First photodetector 482 Second photodetector 100 OCT unit 200 Arithmetic control unit 210 Control unit 211 Main control unit 2111 Monitoring unit 2112 Mode switching unit 212 Storage unit 220 Image forming unit 230 Data processing unit 240 User interface 241 Display unit 242 Operation unit 250 Notification unit E Eye to be examined

Claims (5)

An interference optical system that splits light from a light source into measurement light and reference light, causes the measurement light to enter the eye to be examined, and detects interference light between the return light of the measurement light from the eye to be examined and the reference light When,
An image forming unit that forms an image of the eye to be inspected based on a detection result of the interference light by the interference optical system;
Including
The interference optical system uses light from the light source or measurement light in a first wavelength band that is used for image forming processing by the image forming unit and a second wavelength band other than the first wavelength band. Including a wavelength dividing member for dividing into measurement light, and allowing the measurement light including only the first wavelength band to enter the eye to be examined;
An ophthalmologic photographing apparatus including a monitoring unit that monitors the amount of measurement light in the second wavelength band. The ophthalmologic photographing apparatus according to claim 1, further comprising a notification unit that performs notification based on an output from the monitoring unit. The ophthalmologic imaging apparatus according to claim 1, further comprising a control unit that stops incidence of the measurement light on the eye to be examined based on an output from the monitoring unit. The ophthalmologic photographing apparatus according to claim 1, further comprising a control unit that controls the light source based on an output from the monitoring unit. An optical system that makes light from a light source incident on an eye to be examined and detects return light from the eye to be examined;
An information generating unit that generates information about the eye to be examined based on a detection result of the return light by the optical system;
Including
The optical system divides light from the light source into light in a first wavelength band used for information generation processing by the information generation unit and light in a second wavelength band other than the first wavelength band. The light including only the first wavelength band is incident on the eye to be examined,
An ophthalmologic apparatus including a monitoring unit that monitors light in the second wavelength band.

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