JP5919175B2 - Optical image measuring device - Google Patents

Description

  The present invention relates to an optical image measurement device that acquires an image of an object to be measured by using optical coherence tomography (OCT).

  In recent years, OCT that forms an image representing the surface form or 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, 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 to which OCT is applied. In this device, the measuring arm scans an object with a rotary turning mirror (galvanomirror), a reference mirror is installed on the reference arm, and the intensity of the interference light of the light beam from the measuring arm and the reference arm is dispersed at the exit. An interferometer is provided for analysis by the instrument. Further, the reference arm is configured to change the phase of the reference light beam stepwise by a discontinuous value.

  The apparatus of Patent Document 1 uses a so-called “Fourier Domain OCT (Fourier Domain OCT)” technique. In other words, a low-coherence beam is irradiated onto the object to be measured, the reflected light and the reference light are superimposed to generate interference light, and the spectral intensity distribution of the interference light is acquired and subjected to Fourier transform. Thus, the form of the object to be measured in the depth direction (z direction) is imaged. Note that this technique is also called a spectral domain.

  Furthermore, the apparatus described in Patent Document 1 includes a galvanometer mirror that scans a light beam (signal light), thereby forming an image of a desired measurement target region of the object to be measured. This apparatus is configured to scan the light beam only in one direction (x direction) orthogonal to the z direction. 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.

  In Patent Document 2, a plurality of two-dimensional tomographic images in the horizontal direction are formed by scanning (scanning) the signal 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, for example, a method of displaying a plurality of tomographic images side by side in a vertical direction (referred to as stack data or the like), volume data (voxel data) based on the stack data is rendered, and a three-dimensional image is rendered. There is a method of forming.

  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. And an OCT apparatus for imaging the form of an object to be measured by performing Fourier transform on the obtained image. Such an OCT apparatus 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, or the like was used as an apparatus for observing the eye to be examined (see, for example, Patent Document 6 and Patent Document 7). 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.

  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.

  In order to obtain an accurate image using OCT, it is necessary to match the polarization states of the reference light and the signal light. Factors that change the polarization state include the environment (temperature, humidity, etc.) and displacement of the device structure due to transportation, and the polarization characteristics of the object to be measured itself (eye polarization characteristics in ophthalmology).

  In conventional devices, a fixed polarization adjuster (polarization controller) is provided in the optical path to adjust the polarization state and maintain the polarization state, or a wave plate is provided in the optical path as appropriate. The polarization state was adjusted by rotating.

JP 11-325849 A JP 2002-139421 A JP 2007-24677 A JP 2006-153838 A JP 2008-73099 A JP-A-9-276232 JP 2008-259544 A US Pat. No. 7,400,410

“Ultra High Speed Spatial / Fourier domain OCT ophtalmatic imaging at 70,000 to 312,500 axial scanning per second”, OPTICAL EXPRESS. 2008 September 15, Vol. 16, Issue 19, pp. 15149-15169 “In vivo high-resolution video rate Spectral domain optical coherence of the human retina and optical nerve”, OPTICAL EXPR. 2004 February 9, Vol. 12, Issue 3, pp. 367-376

  However, since the polarization state changes in various ways and varies from time to time, it is extremely difficult to always perfectly match the polarization states of the reference light and the signal light.

  In addition, the conventional polarization adjustment was performed so that the intensity of the interference light detection result (interference signal) was monitored and maximized, but there are other factors that change the intensity of the interference signal besides the polarization state. To do. For example, the intensity of the interference signal is also changed by the state of alignment, the amount of light used for measurement, the vignetting of light, and the change of the signal according to the depth position. Therefore, it is difficult to optimize the polarization state with reference to the intensity of the interference signal.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a technique capable of suitably performing polarization adjustment between reference light and signal light in OCT measurement. is there.

In order to achieve the above object, the invention described in claim 1 generates interference light by superimposing signal light passing through the object to be measured on reference light, and based on the detection result of the interference light, the object to be measured An optical image measurement device that forms an image of an object, the detection unit detecting a polarization state of each of the signal light and the reference light, and based on the detection result of the polarization state, the signal light and / or the Based on the detection result of the interference light obtained by superimposing the signal light and the reference light after adjusting the polarization state, an adjustment unit for adjusting the polarization state of the reference light, the image of the object to be measured And a forming portion for forming the.
The invention according to claim 2 is the optical image measurement device according to claim 1, wherein the adjustment unit includes a mechanism for changing a polarization state of the signal light and / or the reference light, The setting state of the mechanism is determined based on the detection result of the polarization state, and the polarization state is adjusted by controlling the mechanism based on the determination result.
The invention according to claim 3 is the optical image measurement device according to claim 2, wherein the adjustment unit determines the setting state of the mechanism so that the intensity of the interference light is maximized. It is characterized by.
The invention according to claim 4 is the optical image measurement device according to claim 2 or claim 3, wherein the signal light and / or the reference light is guided by an optical fiber, and the mechanism is The polarization adjuster changes the polarization state of the signal light and / or the reference light by applying an external force to the optical fiber.
The invention according to claim 5 is the optical image measurement device according to any one of claims 1 to 4, wherein the detection unit superimposes the signal light on the reference light. The signal detected by the detection element as the polarization state, including a polarizing plate provided at a subsequent stage of the member, a mechanism for rotating the polarizing plate, and a detection element for detecting light that has passed through the polarizing plate Each intensity of light and the reference light is detected in association with the rotational position of the polarizing plate.
The invention according to claim 6 is the optical image measurement device according to any one of claims 1 to 5, wherein an optical path of one of the signal light and the reference light is provided. It has a first blocking mechanism for blocking, and the detection unit detects the polarization state of the other light in a state where the optical path of the one light is blocked.
The invention according to claim 7 is the optical image measurement device according to claim 6, wherein the one light is the signal light, the other light is the reference light, and the first light is the first light. The blocking mechanism is a scanning unit that changes the irradiation position of the signal light on the object to be measured.
The invention according to claim 8 is the optical image measurement device according to claim 6, wherein the one light is the reference light, the other light is the signal light, and the first light is the first light. The blocking mechanism is an optical attenuator that reduces the intensity of the reference light.
The invention according to claim 9 is the optical image measurement device according to any one of claims 1 to 5, wherein an optical path of one of the signal light and the reference light is provided. A second blocking mechanism for blocking is provided, and the adjustment unit adjusts the polarization state of the other light in a state where the optical path of the one light is blocked.
The invention according to claim 10 is the optical image measurement device according to claim 9, wherein the one light is the reference light, the other light is the signal light, and the second light. The blocking mechanism is an optical attenuator that reduces the intensity of the reference light.
The invention according to claim 11 is the optical image measurement device according to claim 9, wherein the one light is the signal light, the other light is the reference light, and the second light. The blocking mechanism is a scanning unit that changes the irradiation position of the signal light on the object to be measured.
The invention according to claim 12 is the optical image measurement device according to any one of claims 1 to 11, wherein information relating to an image quality of an image formed by the forming unit is acquired. A determination unit that determines image quality is provided, and the detection unit and the adjustment unit operate based on the determination result of the image quality.
The invention according to claim 13 is the optical image measurement device according to any one of claims 1 to 11, wherein the optical system for generating the interference light and the object to be measured are used. An alignment unit that performs alignment of the optical system, and the detection unit and / or the adjustment unit operate when the alignment is performed.
The invention according to claim 14 is the optical image measurement device according to any one of claims 1 to 11, wherein an instruction for operating the detection unit and the adjustment unit is input. It has the operation part used.

  The present invention actually detects the polarization state of the signal light and the polarization state of the reference light, and adjusts the polarization state of the signal light and / or the reference light based on the detection results, that is, adjusts the intensity of the interference light. Is configured to do. Therefore, it is possible to optimize the intensity of the interference light by matching the polarization states of the reference light and the signal light at the present time. In addition, unlike the conventional technique for monitoring the intensity of interference light that is affected by various factors other than the polarization state, it is configured to monitor the intensity of the signal light and the reference light accompanying the change in the polarization state. The polarization state can be optimized. Therefore, according to the present invention, it is possible to suitably adjust the polarization between the reference light and the signal light in the OCT measurement.

It is a schematic diagram showing an example of composition of a fundus oculi observation device concerning an embodiment. It is a schematic diagram showing an example of composition of a fundus oculi observation device concerning an embodiment. It is a schematic block diagram showing an example of composition of a fundus oculi observation device concerning an embodiment. It is a flowchart showing the operation example of the fundus oculi observation device concerning an embodiment.

  An example of an embodiment of an optical image measurement device according to the present invention will be described in detail with reference to the drawings. The optical image measurement apparatus according to the present invention forms a tomographic image or a three-dimensional image of an object to be measured using OCT. In this specification, images acquired by OCT may be collectively referred to as OCT images. In addition, a measurement operation for forming an OCT image may be referred to as OCT measurement. In addition, it is possible to use suitably the description content of the literature described in this specification as the content of the following embodiment.

  In the following embodiments, a fundus oculi observation device that performs OCT measurement of the fundus by applying Fourier domain type OCT with the object to be measured (fundus) being measured will be described. In particular, the fundus oculi observation device according to the embodiment can acquire both the fundus OCT image and the fundus oculi image using the spectral domain OCT technique, similarly to the device disclosed in Patent Document 5. Note that the configuration according to the present invention can be applied to an optical image measurement apparatus using a type other than the spectral domain, for example, a swept source OCT technique. In this embodiment, an apparatus combining an OCT apparatus and a fundus camera will be described. However, this embodiment may be applied to a fundus imaging apparatus other than a fundus camera, for example, an SLO (Scanning Laser Ophthalmoscope), a slit lamp, an ophthalmic surgical microscope, and the like. It is also possible to combine an OCT apparatus having the configuration according to the above. In addition, the configuration according to this embodiment can be incorporated into a single OCT apparatus.

[Constitution]
As shown in FIGS. 1 and 2, the fundus oculi observation device 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 acquiring an OCT image of the fundus. 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 signal light from the OCT unit 100 to the fundus oculi Ef and guides the signal light passing through the fundus oculi Ef to the OCT unit 100.

  The observation light source 11 of the illumination optical system 10 is constituted by a halogen lamp, for example. 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. An LED (Light Emitting Diode) can also be used as the observation light source.

  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 40, 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 34. 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 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. 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 40, 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 is 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. As the fixation position of the eye E, for example, a position for acquiring an image centered on the macular portion of the fundus oculi Ef, or a position for acquiring an image centered on the optic disc as in the case of a conventional fundus camera And a position for acquiring an image centered on the fundus center between the macula and the optic disc. It is also possible to arbitrarily change the display position of the fixation target.

  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 fundus oculi Ef.

  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 aperture mirror 21, and reaches the dichroic mirror 46. And is projected onto the cornea of the eye E by the objective lens 22.

  The cornea-reflected 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, and is reflected by the mirror 32. 40 is reflected by the dichroic mirror 33 and projected onto the light-receiving surface of the CCD image sensor 35 by the condenser lens 34. 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 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 measurement from the optical path for fundus photography. The dichroic mirror 46 reflects light in a wavelength band used for OCT measurement and transmits light for fundus photographing. In this optical path for OCT measurement, a collimator lens unit 40, an optical path length changing unit 41, a galvano scanner 42, a focusing lens 43, a mirror 44, and a relay lens 45 are provided in this order from the OCT unit 100 side. It has been.

  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 measurement. 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 galvano scanner 42 changes the traveling direction of light (signal light LS) passing through the optical path for OCT measurement. Thereby, the fundus oculi Ef can be scanned with the signal light LS. The galvano scanner 42 includes, for example, a galvano mirror that scans the signal light LS in the x direction, a galvano mirror that scans in the y direction, and a mechanism that drives these independently. Thereby, the signal 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 will be described with reference to FIG. The OCT unit 100 is provided with an optical system for acquiring an OCT image of the fundus oculi Ef. This optical system has the same configuration as a conventional spectral domain type OCT apparatus. That is, this optical system divides low-coherence light into reference light and signal light, and generates interference light by causing interference between the signal light passing through the fundus oculi Ef and the reference light passing through the reference optical path. It is configured to detect spectral components. This detection result (detection signal) is sent to the arithmetic control unit 200.

  In the case of a swept source type OCT apparatus, a wavelength swept light source is provided instead of a light source that outputs a low coherence light source, and an optical member that spectrally decomposes interference light is not provided. In general, for the configuration of the OCT unit 100, a known technique according to the type of optical coherence tomography can be arbitrarily applied.

  The light source unit 101 outputs a broadband low-coherence light L0. The low coherence light L0 includes, for example, a near-infrared wavelength band (about 800 nm to 900 nm) and has a temporal coherence length of about several tens of micrometers. Note that near-infrared light having a wavelength band that cannot be visually recognized by the human eye, for example, a center wavelength of about 1040 to 1060 nm, may be used as the low-coherence light L0.

  The light source unit 101 includes a light output device such as a super luminescent diode (SLD), an LED, or an SOA (Semiconductor Optical Amplifier).

  The low-coherence light L0 output from the light source unit 101 is guided to the fiber coupler 103 by the optical fiber 102 and split into the signal light LS and the reference light LR.

  The reference light LR is guided by the optical fiber 104 and reaches the optical attenuator (attenuator) 105. The optical attenuator 105 automatically adjusts the amount of the reference light LR guided to the optical fiber 104 under the control of the arithmetic control unit 200 using a known technique. The reference light LR whose light amount has been adjusted by the optical attenuator 105 is guided by the optical fiber 104 and reaches the polarization adjuster (polarization controller) 106. The polarization adjuster 106 is, for example, a device that adjusts the polarization state of the reference light LR guided in the optical fiber 104 by applying a stress from the outside to the optical fiber 104 in a loop shape. The configuration of the polarization adjuster 106 is not limited to this, and any known technique can be used. The reference light LR whose polarization state is adjusted by the polarization adjuster 106 reaches the fiber coupler 109.

The signal light LS generated by the fiber coupler 103 is guided by the optical fiber 107 and converted into a parallel light beam by the collimator lens unit 105. Further, the signal light LS reaches the dichroic mirror 46 via the optical path length changing unit 41, the galvano scanner 42, the focusing lens 43, the mirror 44, and the relay lens 45. The signal light LS is reflected by the dichroic mirror 46, is refracted by the objective lens 22, and is applied to the fundus oculi Ef. The signal light LS is scattered (including reflection) at various depth positions of the fundus oculi Ef. The backscattered light of the signal light LS from the fundus oculi Ef travels in the same direction as the forward path in the reverse direction, is guided to the fiber coupler 103, and reaches the fiber coupler 109 via the optical fiber 108.

The fiber coupler 109 causes the backscattered light of the signal light LS to interfere with the reference light LR that has passed through the fiber coupler 104. The interference light LC generated thereby is guided by the optical fiber 110 and emitted from the emission end 111. Further, the interference light LC is converted into a parallel light beam by the collimator lens 112, dispersed (spectral decomposition) by the diffraction grating 113, condensed by the condenser lens 114, and projected onto the light receiving surface of the CCD image sensor 115. Incidentally, the diffraction grating 11 3 shown in FIG. 2 is a transmission type, such as a reflective diffraction grating, it is also possible to use a spectral element of other forms.

  The CCD image sensor 115 is a line sensor, for example, and detects each spectral component of the split interference light LC and converts it into electric charges. The CCD image sensor 115 accumulates this electric charge, generates a detection signal, and sends it to the arithmetic control unit 200.

  In this embodiment, a Michelson type interferometer is employed, but any type of interferometer such as a Mach-Zehnder type can be appropriately employed. Further, in place of the CCD image sensor, another form of image sensor such as a CMOS (Complementary Metal Oxide Semiconductor) image sensor can be used.

  The OCT unit 100 is further provided with an optical fiber 120, a polarizing plate 122, and a detection element 123. One end of the optical fiber 120 is connected to the fiber coupler 109. The polarizing plate 122 is provided at the subsequent stage of the emission end 121 at the other end of the optical fiber 120. The polarizing plate 122 is a polarizer that transmits only light polarized in a specific direction. The polarizing plate 122 rotates upon receiving a driving force from the actuator 122A. Thereby, the polarization direction of the transmitted light changes. The detection element 123 detects light transmitted through the polarizing plate 122.

[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 CCD image sensor 115 and forms an OCT image of the fundus oculi Ef. The arithmetic processing for this is the same as that of a conventional spectral domain 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 fundus oculi Ef on the display device 3.

  As the control of the fundus camera unit 2, the arithmetic control unit 200 controls the operation of the observation light source 11, the imaging light source 15 and the LEDs 51 and 61, the operation control of the LCD 39, the movement control of the focusing lenses 31 and 43, and the reflector 67. Movement control, movement control of the focus optical system 60, movement control of the optical path length changing unit 41, operation control of the galvano scanner 42, and the like are performed.

  As the control of the OCT unit 100, the arithmetic control unit 200 controls the operation of the light source unit 101, the operation control of the optical attenuator 105, the operation control of the polarization adjuster 106, the operation control of the CCD image sensor 115, and the polarizing plate 122. Operation control of the (actuator 122A) is performed.

  The arithmetic control unit 200 includes, for example, a microprocessor, a RAM, a ROM, a hard disk drive, a communication interface, etc., as in a conventional computer. A computer program for controlling the fundus oculi observation device 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.

  The fundus camera unit 2, the display device 3, the OCT unit 100, and the calculation control unit 200 may be configured integrally (that is, in a single housing) or separated into two or more housings. It may be.

[Control system]
The configuration of the control system of the fundus oculi observation device 1 will be described with reference to FIG.

(Control part)
The control system of the fundus oculi observation device 1 is configured around the control unit 210. The control unit 210 includes, for example, the aforementioned 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, the main control unit 211 controls the focusing drive unit 31A, the optical path length changing unit 41, and the galvano scanner 42 of the fundus camera unit 2, and further the light source unit 101, the optical attenuator 105, and the polarization adjuster 106 of the OCT unit 100. To do.

  The focusing drive 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 also move an optical system provided in the fundus camera unit 2 in a three-dimensional manner by controlling an optical system drive unit (not shown). This control is used in alignment and tracking. Tracking is to move the apparatus optical system in accordance with the eye movement of the eye E. When tracking is performed, alignment and focusing are performed in advance. Tracking is a function of maintaining a suitable positional relationship in which the alignment and focus are achieved by causing the position of the apparatus optical system to follow the eye movement.

  Further, the main control unit 211 performs processing for writing data into the storage unit 212 and processing for reading data from the storage unit 212.

(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 fundus oculi observation device 1.

(Image forming part)
The image forming unit 220 forms tomographic image data of the fundus oculi Ef based on the detection signal from the CCD image sensor 115. This process includes processes such as noise removal (noise reduction), filter processing, FFT (Fast Fourier Transform), and the like, as in the conventional spectral domain type optical coherence tomography. In the case of another type of OCT apparatus, the image forming unit 220 executes a known process corresponding to the type. The image forming unit 220 functions as an example of a “forming unit”.

  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.

(Image processing unit)
The image processing unit 230 performs various types of image processing and analysis processing on the image formed by the image forming unit 220. For example, the image processing unit 230 executes various correction processes such as image brightness correction and dispersion correction. The image 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 image processing unit 230 executes known image processing such as interpolation processing for interpolating pixels between tomographic images to form image data of a three-dimensional image of the fundus oculi Ef. Note that the image data of a three-dimensional image means image data in which pixel positions are defined by a three-dimensional coordinate system. As image data of a three-dimensional image, there is image data composed of voxels arranged three-dimensionally. This image data is called volume data or voxel data. When displaying an image based on volume data, the image processing unit 230 performs rendering processing (volume rendering, MIP (Maximum Intensity Projection), etc.) on the volume data, and views the image from a specific gaze direction. Image data of a pseudo three-dimensional image is formed. This pseudo three-dimensional image is displayed on a display device such as the display unit 240A.

  It is also possible to form stack data of a plurality of tomographic images as image data of a three-dimensional image. The stack data is image data obtained by three-dimensionally arranging a plurality of tomographic images obtained along a plurality of scanning lines based on the positional relationship of the scanning lines. That is, stack data is image data obtained by expressing a plurality of tomographic images originally defined by individual two-dimensional coordinate systems by one three-dimensional coordinate system (that is, by embedding them in one three-dimensional space). is there.

  The image processing unit 230 that functions as described above includes, for example, the aforementioned microprocessor, RAM, ROM, hard disk drive, circuit board, and the like. In a storage device such as a hard disk drive, a computer program for causing the microprocessor to execute the above functions is stored in advance.

(User interface)
The user interface 240 includes a display unit 240A and an operation unit 240B. The display unit 240A includes the display device of the arithmetic control unit 200 and the display device 3 described above. The operation unit 240B includes the operation device of the arithmetic control unit 200 described above. The operation unit 240B may include various buttons and keys provided on the housing of the fundus oculi observation device 1 or outside. For example, when the fundus camera unit 2 has a housing similar to that of a conventional fundus camera, the operation unit 240B may include a joystick, an operation panel, or the like provided on the housing. The display unit 240 </ b> A may include various display devices such as a touch panel monitor provided in the housing of the fundus camera unit 2.

  The display unit 240A and the operation unit 240B 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 monitor, can be used. In that case, the operation unit 240B includes the touch panel display and a computer program. The operation content for the operation unit 240B is input to the control unit 210 as an electrical signal. Further, operations and information input may be performed using a graphic user interface (GUI) displayed on the display unit 240A and the operation unit 240B.

[Scanning signal light and OCT images]
Here, the scanning of the signal light LS and the OCT image will be described.

  Examples of scanning modes of the signal light LS by the fundus oculi observation device 1 include horizontal scanning, vertical scanning, cross scanning, radiation scanning, circular scanning, concentric scanning, and spiral (vortex) scanning. These scanning modes are selectively used as appropriate in consideration of the observation site of the fundus, the analysis target (such as retinal thickness), the time required for scanning, the precision of scanning, and the like.

  The horizontal scan scans the signal light LS in the horizontal direction (x direction). The horizontal scan also includes an aspect in which the signal light LS is scanned along a plurality of horizontal scanning lines arranged in the vertical direction (y direction). In this aspect, it is possible to arbitrarily set the scanning line interval. Further, the above-described three-dimensional image can be formed by sufficiently narrowing the interval between adjacent scanning lines (three-dimensional scanning). The same applies to the vertical scan.

  In the cross scan, the signal light LS is scanned along a cross-shaped trajectory composed of two linear trajectories (straight trajectories) orthogonal to each other. In the radiation scan, the signal light LS is scanned along a radial trajectory composed of a plurality of linear trajectories arranged at a predetermined angle. The cross scan is an example of a radiation scan.

  In the circle scan, the signal light LS is scanned along a circular locus. In the concentric scan, the signal light LS is scanned along a plurality of circular trajectories arranged concentrically around a predetermined center position. A circle scan is an example of a concentric scan. In the spiral scan, the signal light LS is scanned along a spiral (spiral) locus while the radius of rotation is gradually reduced (or increased).

  Since the galvano scanner 42 is configured to scan the signal light LS in directions orthogonal to each other, the signal light LS can be scanned independently in the x direction and the y direction, respectively. Further, by simultaneously controlling the directions of the two galvanometer mirrors included in the galvano scanner 42, the signal light LS can be scanned along an arbitrary locus on the xy plane. Thereby, various scanning modes as described above can be realized.

  By scanning the signal light LS in the above-described manner, a tomographic image on a plane stretched by the direction along the scanning line (scanning trajectory) and the fundus depth direction (z direction) can be acquired. In addition, the above-described three-dimensional image can be acquired particularly when the scanning line interval is narrow.

  A region on the fundus oculi Ef to be scanned with the signal light LS as described above, that is, a region on the fundus oculi Ef to be subjected to OCT measurement is referred to as a scanning region. The scanning area in the three-dimensional scan is a rectangular area in which a plurality of horizontal scans are arranged. The scanning area in the concentric scan is a disk-shaped area surrounded by the locus of the circular scan with the maximum diameter. In addition, the scanning area in the radial scan is a disk-shaped (or polygonal) area connecting both end positions of each scan line.

[Operation]
The operation of the fundus oculi observation device 1 will be described. FIG. 4 shows an example of the operation of the fundus oculi observation device 1.

(S1: Alignment / Focus)
First, a near-infrared moving image of the fundus oculi Ef is acquired 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. Further, the control unit 210 projects the alignment index by the alignment optical system 50 and the split index by the focus optical system 60 onto the eye E. The control unit 210 or the user performs alignment using the alignment index, and further performs focusing using the split index.

(S2: The polarization state adjustment process is started)
Upon completion of alignment and focusing, the control unit 210 causes the fundus oculi observation device 1 to start polarization state adjustment processing.

(S3: block the signal light path)
In the adjustment process of the polarization state, first, the control unit 210 controls the galvano scanner 42 to block the optical path (signal optical path) of the signal light LS. Blocking the signal light path means preventing the signal light LS (its backscattered light) from reaching the detection element 123. In this embodiment, the signal light path between the eye E and the fiber coupler 109 may be blocked. As an example of a method for blocking the signal optical path, there is a method in which the orientation of at least one of the two galvanometer mirrors constituting the galvano scanner 42 is largely changed from the neutral position. It is also possible to block the signal light path by providing a shutter in the signal light path.

(S4: Output light for OCT measurement)
Next, the control unit 210 controls the light source unit 101 to output the low coherence light L0. Since the signal light path is blocked, the detection element 123 detects the reference light LR that has passed through the optical fiber 104.

(S5: The polarization state of the reference light is detected)
The controller 210 changes the polarization state of the reference light LR that passes through the polarizing plate 122 by controlling the actuator 122A to rotate the polarizing plate 122. The detection element 123 detects the reference light LR in a polarization state corresponding to the rotation position of the polarizing plate 122. Accordingly, the detection element 123 detects the reference light LR in the polarization state with respect to each of the plurality of rotation positions of the polarizing plate 122. The detection result corresponding to each rotational position is sent to the control unit 210 as an electrical signal. The control unit 210 obtains the detection intensity of the reference light LR based on each detection result. This detected intensity is, for example, the signal intensity of the electrical signal.

  On the other hand, since the control unit 210 rotates the polarizing plate 122, it recognizes the rotational position of the polarizing plate 122 at each detection timing by the detection element 123. The controller 210 associates the detected intensity of the reference light LR with the rotational position of the polarizing plate 122. The rotation position of the polarizing plate 122 is, for example, a rotation angle with respect to a reference position in rotation. The control unit 210 stores the associated detected intensity and rotational position in the storage unit 212.

  Here, the detection of the intensity of the reference light LR at a plurality of rotation positions may be performed while continuously rotating the polarizing plate 122 or may be performed while rotating it intermittently.

(S6: Specify the polarization state of the reference light)
The controller 210 selects a predetermined one from the detected intensities of the reference light LR acquired in step 5. The selection target includes the maximum value of these detection intensities. This maximum value corresponds to the polarization state of the reference light LR. Note that instead of the maximum value (or together with the maximum value), another value of the detection intensity may be selected. Another example is a minimum value. Even when a value other than the maximum value is selected, it is possible to adjust the polarization state in the same manner as described later for the maximum value.

(S7: Release the blocking of the signal light path)
Next, the control unit 210 releases the blocking of the signal light path. When using the galvano scanner 42, for example, the control unit 210 returns the galvano mirror whose direction has been changed in step 3 to the neutral position. When using a shutter, the control unit 210 switches the shutter from the closed state to the open state.

(S8: The reference light path is blocked and the polarization state of the signal light is detected)
Subsequently, the control unit 210 blocks the optical path (reference optical path) of the reference light LR. In this embodiment, the optical path is blocked at any position of the optical fiber 104. As an example, the control unit 210 controls the optical attenuator 105 so that the intensity of the reference light LR passing therethrough becomes zero. Thereby, only the signal light LS (its backscattered light) is projected onto the detection element 123. As in the case of the reference light LR, the control unit 210 obtains a predetermined value (maximum value, minimum value, etc.) of the detected intensity of the signal light LS and the rotational position of the polarizing plate 122. This information corresponds to the polarization state of the signal light LS.

(S9: Adjust polarization state)
Next, the control unit 210 adjusts the polarization state of the reference light LR based on the polarization state of the reference light LR identified in Step 6 and the polarization state of the signal light LS identified in Step 8. This process includes a process of determining the setting state of the polarization adjuster 106 and a process of controlling the polarization adjuster 106 based on the determination result.

  In the former process, for example, the setting state of the polarization adjuster 106 that realizes the polarization state of the reference light LR that maximizes the intensity of the interference light LC is obtained. In order to maximize the intensity of the interference light LC, the polarization states of the reference light LR and the signal light LS may be matched. The coincidence of the polarization states includes matching the polarization directions (polarization angles) of both lights. In addition to this, it is desirable to obtain the matching deflection direction so that the intensities of both lights are as large as possible. At this time, not only the polarization state selected from a plurality of options in Steps 6 and 10, but also these options (that is, distribution information of detected intensity according to the rotational position of the polarizing plate 122) may be considered. Further, related information relating the rotation position of the polarizing plate 122 and the setting state of the polarization adjuster 106 is acquired in advance and stored in the storage unit 212, and the setting state associated with the desired rotation angle is related. It is desirable to be configured to obtain from information.

  When the setting state of the polarization adjuster 106 is determined, the control unit 210 sets the polarization adjuster 106 to this setting state. In this embodiment, since the polarization state is adjusted by shielding the reference optical path, the polarization state of the reference light LR is not immediately changed by this adjustment. The “adjustment of” includes such a case (for example, a case where the polarization state of the reference light LR passing through the reference optical path is changed after the blocking state is released).

(S10: Release the blocking of the reference optical path and perform OCT measurement)
Subsequently, the control unit 210 releases the blocking of the reference optical path. As a result, both the backscattered light of the signal light LS from the fundus oculi Ef and the reference light LR reach the fiber coupler 109 to generate interference light LC, and the CCD image sensor 115 detects the spectral component. The control unit 210 controls the galvano scanner 42 to scan the fundus oculi Ef with the signal light LS. The CCD image sensor 115 detects the spectral component of the interference light LC corresponding to each scan position. Based on these detection results, the image forming unit 220 forms a tomographic image of the fundus oculi Ef corresponding to this scan pattern.

[effect]
The effect of the fundus oculi observation device 1 will be described.

  The fundus oculi observation device 1 generates interference light LC by superimposing the signal light LS passing through the object to be measured (fundus Ef) on the reference light LR, and forms an image of the fundus oculi Ef based on the detection result of the interference light. It functions as an optical image measurement device. The fundus oculi observation device 1 includes a detection unit, an adjustment unit, and a formation unit.

  The detection unit detects the polarization state of the reference light LR and the polarization state of the signal light LS. The detection unit includes a polarizing plate 122, an actuator 122 </ b> A, a detection element 123, and a control unit 210. The polarizing plate 122 is provided after the fiber coupler 109 (superimposing member) that superimposes the signal light LS on the reference light LR. The actuator 122A is an example of a “mechanism for rotating a polarizing plate”. The detection element 123 detects light that has passed through the polarizing plate. The controller 210 associates the intensity of the reference light LR detected by the detection element 123 with the rotational position of the polarizing plate 122.

  The adjustment unit adjusts the polarization state of the reference light LR based on the detection result of the polarization state of the reference light LR. The adjustment unit includes the control unit 210 and the polarization adjuster 106. The polarization adjuster 106 is an example of a “mechanism for changing the polarization state”. Based on the detection results of the polarization states of the reference light LR and the signal light LS, the control unit 210 determines the setting state of the polarization adjuster 106 that maximizes the intensity of the reference light LR. By controlling the adjuster 106, the polarization state of the reference light LR is adjusted.

  The forming unit forms an image of the fundus oculi Ef based on the detection result of the interference light LC obtained by superimposing the reference light LR and the signal light LS after the polarization state of the reference light LR is adjusted.

  According to such a fundus oculi observation device 1, the polarization states of the reference light LR and the signal light LS can be actually detected, and the intensity of the interference light LC can be adjusted based on the detection result. Accordingly, it is possible to match the polarization states of the reference light LR and the signal light LS at the present time.

  Further, unlike the conventional technique for monitoring the intensity of interference light that is affected by various factors other than the polarization state, the intensity of the reference light LR and the signal light LS accompanying the change in the polarization state is monitored, and the intensity of the interference light LC Is optimized, that is, the polarization states of the reference light LR and the signal light LS are matched, so that the polarization state can be optimized.

  Thus, according to the fundus oculi observation device 1, the polarization adjustment between the reference light LR and the signal light LS in OCT measurement can be suitably performed.

  In addition, the fundus oculi observation device 1 includes a first blocking mechanism (galvano scanner 42) that blocks the signal light path. The detection unit detects the polarization state of the reference light LR in a state where the signal light path is blocked. The galvano scanner 42 is an example of a “scanning unit”. With such a configuration, it is possible to realize the detection of the polarization state of the reference light LR without adding new hardware in an optical image measurement device of a type that scans an object to be measured with the signal light LS. . Note that the detection of the polarization state of the reference light LR may be realized using a first blocking mechanism of another form, such as the shutter described above.

  In addition, the fundus oculi observation device 1 includes a second blocking mechanism (light attenuator 105) that blocks the reference optical path. The adjustment unit adjusts the polarization state in a state where the reference optical path is blocked. With such a configuration, in the type of optical image measurement device having the optical attenuator 105, it is possible to suitably adjust the polarization state of the reference light LR without adding new hardware. In addition, you may use the 2nd interruption | blocking mechanism which consists of other forms like a shutter.

[Modification]
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.

(Modification 1)
In the above embodiment, the polarization state of the reference light is adjusted, but the polarization state of the signal light may be adjusted. In the fundus oculi observation device (optical image measurement device) configured as described above,
The adjustment unit adjusts the polarization state of the signal light by performing the same processing as in the above embodiment based on the detection results of the polarization states of the signal light and the reference light. The adjustment unit includes, for example, a control unit and a polarization adjuster provided in the signal optical path. The polarization adjuster is an example of a “mechanism for changing the polarization state”. The control unit determines a setting state of the polarization adjuster that maximizes the intensity of the interference light based on the detection result of the polarization state of the signal light and the reference light, and controls the polarization adjuster based on the determination result. As a result, the polarization state of the signal light is adjusted.

  The forming unit forms an image of the fundus based on the detection result of the interference light obtained by superimposing the signal light and the reference light after the polarization state of the signal light is adjusted.

  According to such a fundus oculi observation device, the polarization states of the signal light and the reference light are actually measured, and the intensity of the interference light is adjusted based on the measurement results (that is, the polarization states of the signal light and the reference light are matched). )It can be performed. Therefore, it is possible to match the polarization states of the reference light and the signal light at the present time.

  In addition, unlike the conventional technique for monitoring the intensity of interference light that is affected by various factors other than the polarization state, it is configured to monitor the intensity of the signal light and the reference light accompanying the change in the polarization state. It is possible to optimize the polarization state.

  According to such a fundus oculi observation device, it is possible to suitably perform polarization adjustment between reference light and signal light in OCT measurement.

  Further, the fundus oculi observation device has a first blocking mechanism (for example, an optical attenuator, which may be a shutter or the like) that blocks the reference optical path. The detection unit detects the polarization state of the signal light in a state where the reference optical path is blocked. By using an optical attenuator as the first blocking mechanism, it is possible to detect the polarization state of the signal light without adding new hardware in an optical image measurement device of the type having an optical attenuator. It is.

  The fundus oculi observation device also has a second blocking mechanism (for example, a galvano scanner, which may be a shutter or the like) that blocks the signal light path. The adjustment unit adjusts the polarization state in a state where the signal optical path is blocked. With such a configuration, it is possible to suitably adjust the polarization state of signal light without adding new hardware in an optical image measurement device of a type having a scanning unit (galvano scanner).

  Instead of adjusting the polarization state of one of the signal light and the reference light as described above, it is also possible to adjust both polarization states. That is, the adjustment of the polarization state only needs to be performed so that the polarization states of the signal light and the reference light coincide with each other. Therefore, this may be realized while changing the polarization states of both lights. The adjustment process in this case is the same as that of the above modification in the above embodiment.

(Modification 2)
In Modifications 2 to 4, an example in which the polarization state is detected and adjusted in response to a predetermined trigger will be described.

  The fundus oculi observation device (optical image measurement device) according to this modification has a determination unit in addition to the configuration of the above embodiment, for example. The determination unit acquires information related to the image quality of the image formed by the forming unit and determines the image quality. In the above embodiment (FIG. 3), the determination unit is provided in the control unit 210 or the image processing unit 230. “Information relating to image quality” means arbitrary information that affects image quality, and is appropriately determined according to the image quality determination method.

  The image quality determination process is performed using any known technique. As an example, there is a method of obtaining the image quality by analyzing the image itself formed by the forming unit. It is also possible to detect signal light and / or interference light, acquire the intensity of the detected signal as “information on image quality”, and determine the image quality by performing threshold processing on the signal intensity. . Note that the image quality determination processing is not limited to these.

  The detection unit and the adjustment unit according to this modification operate based on the image quality determination result. In particular, the detection unit and the adjustment unit are configured to operate only when a determination result that the image quality is bad is obtained.

  According to such a modification, it is possible to execute this at a timing that requires adjustment of the polarization state.

(Modification 3)
In the above embodiment, the polarization state is detected and adjusted after completion of alignment and focusing. However, the polarization state may be detected and / or adjusted in parallel with the alignment. This timing control is performed by the control unit 210. According to this modification, the inspection time can be shortened.

  The “alignment unit” includes the alignment optical system 50. When alignment is performed automatically, the alignment unit includes the alignment optical system 50 and the control unit 210. Moreover, when performing alignment manually, the alignment part is comprised including the alignment optical system 50, the control part 210, and the user interface 240. FIG.

(Modification 4)
In the above embodiment, the detection unit and the adjustment unit are configured to operate in response to a predetermined operation (inputting an instruction for operating the detection unit and the adjustment unit) using the operation unit 240B. It is also possible. That is, it can be configured to detect and adjust the polarization state in response to a user instruction. According to this modification, the user can adjust the polarization state at a desired timing.

(Other variations)
In the above embodiment, the optical path length difference between the optical path of the signal light LS and the optical path of the reference light LR is changed by changing the position of the optical path length changing unit 41, but this optical path length difference is changed. The method is not limited to this. For example, it is possible to change the optical path length difference by disposing a reflection mirror (reference mirror) in the optical path of the reference light and moving the reference mirror in the traveling direction of the reference light to change the optical path length of the reference light. Is possible. Further, the optical path length difference may be changed by moving the fundus camera unit 2 or the OCT unit 100 with respect to the eye E to change the optical path length of the signal light LS. In particular, when the measured object is not a living body part, the optical path length difference can be changed by moving the measured object in the depth direction (z direction).

  A computer program for realizing the above embodiment can be stored in any recording medium readable by a computer. Examples of the recording medium include a semiconductor memory, an optical disk, a magneto-optical disk (CD-ROM / DVD-RAM / DVD-ROM / MO, etc.), a magnetic storage medium (hard disk / floppy (registered trademark) disk / ZIP, etc.), and the like. Can be used.

  It is also possible to transmit / receive this program through a network such as the Internet or a LAN.

1 Fundus observation device (optical image measurement device)
2 fundus camera unit 10 illumination optical system 30 photographing optical system 31 focusing lens 31A focusing drive unit 41 optical path length changing unit 42 galvano scanner 50 alignment optical system 60 focusing optical system 100 OCT unit 101 light source unit 105 optical attenuator 106 polarization Adjuster 115 CCD image sensor 122 Polarizing plate 122A Actuator 123 Detection element 200 Arithmetic control unit 210 Control unit 211 Main control unit 212 Storage unit 220 Image forming unit 230 Image processing unit 240A Display unit 240B Operation unit E Eye to be examined Ef Fundus LS Signal light LR Reference light LC Interference light

Claims (14)

An optical image measurement device that generates interference light by superimposing signal light passed through a measured object on reference light, and forms an image of the measured object based on a detection result of the interference light,
A detection unit for detecting the polarization state of each of the signal light and the reference light;
An adjustment unit that adjusts the polarization state of the signal light and / or the reference light based on the detection result of the polarization state;
An optical image measuring device comprising: a forming unit that forms an image of the object to be measured based on a detection result of interference light obtained by superimposing the signal light and the reference light after the polarization state is adjusted . The adjustment unit is
A mechanism for changing a polarization state of the signal light and / or the reference light,
2. The optical image according to claim 1, wherein a setting state of the mechanism is determined based on a detection result of the polarization state, and the polarization state is adjusted by controlling the mechanism based on the determination result. Measuring device. The optical image measurement device according to claim 2, wherein the adjustment unit determines a setting state of the mechanism so that the intensity of the interference light is maximized. The signal light and / or the reference light is guided by an optical fiber,
The said mechanism is a polarization controller which changes the polarization state of the said signal light and / or the said reference light by giving external force with respect to the said optical fiber. The Claim 2 or Claim 3 characterized by the above-mentioned. The optical image measuring device described. The detector is
A polarizing plate provided at a subsequent stage of a superimposing member that superimposes the signal light on the reference light;
A mechanism for rotating the polarizing plate;
A detection element that detects light that has passed through the polarizing plate, and
The intensity of each of the signal light and the reference light detected by the detection element and the rotation position of the polarizing plate are detected in association with each other as the polarization state. The optical image measuring device according to any one of the above. A first blocking mechanism that blocks an optical path of one of the signal light and the reference light;
The optical image measurement according to claim 1, wherein the detection unit detects a polarization state of the other light in a state where the optical path of the one light is blocked. apparatus. The one light is the signal light, and the other light is the reference light;
The optical image measurement apparatus according to claim 6, wherein the first blocking mechanism is a scanning unit that changes an irradiation position of the signal light with respect to the object to be measured. The one light is the reference light, the other light is the signal light,
The optical image measurement device according to claim 6, wherein the first blocking mechanism is an optical attenuator that reduces the intensity of the reference light. A second blocking mechanism that blocks an optical path of one of the signal light and the reference light;
The optical image measurement according to any one of claims 1 to 5, wherein the adjustment unit adjusts a polarization state of the other light in a state where the optical path of the one light is blocked. apparatus. The one light is the reference light, the other light is the signal light,
The optical image measurement device according to claim 9, wherein the second blocking mechanism is an optical attenuator that reduces the intensity of the reference light. The one light is the signal light, and the other light is the reference light;
The optical image measurement device according to claim 9, wherein the second blocking mechanism is a scanning unit that changes an irradiation position of the signal light with respect to the object to be measured. A determination unit that obtains information about the image quality of the image formed by the forming unit and determines the image quality;
The optical image measurement device according to any one of claims 1 to 11, wherein the detection unit and the adjustment unit operate based on the determination result of the image quality. An optical system for generating the interference light;
An alignment unit that performs alignment of the optical system with respect to the object to be measured,
The optical image measurement device according to any one of claims 1 to 11, wherein the detection unit and / or the adjustment unit operate when the alignment is performed. It has an operation part used for the input of the instruction | indication for operating the said detection part and the said adjustment part. The optical image measuring device as described in any one of Claims 1-11 characterized by the above-mentioned.

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