JP2016168192A - Image capturing apparatus and control method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the following problem: if a confocal image is captured by reflecting all of the light in a center part of return light from a fundus oculus by a mirror disposed in an image formation plane and a non-confocal image is captured with return light transmitted through peripheral parts of the mirror, the resolution of the non-confocal image is deteriorated.SOLUTION: An image capturing apparatus according to the present invention comprises: first branching means for branching a part of the light in a center part of the return light obtained by irradiating a subject with measurement light from the light source to a confocal imaging unit and the other part of the light in the center part and the light in peripherals of the center part to a non-confocal imaging unit; first light receiving means for measuring the intensity of the light branched to the confocal imaging unit; second light receiving means for measuring the intensity of the light branched to the non-confocal imaging unit; and a first generation means for generating an image from signals corresponding to the intensities of the light received by the first and second light receiving means.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an image pickup apparatus and a control method thereof, and more particularly to an image pickup apparatus used for ophthalmic medical treatment and a control method thereof.

  As an ophthalmologic apparatus used for ocular examination, there is a scanning laser opthalmoscope (SLO: Scanning Laser Ophthalmoscope) using the principle of a confocal laser microscope. The scanning laser ophthalmoscope is a device (hereinafter referred to as an SLO device) that performs a raster scan on the fundus of the laser as measurement light and obtains a planar image from the intensity of the return light (hereinafter referred to as an SLO device). Is obtained.

  In recent years, it has become possible to acquire a planar image of the fundus with improved resolution by increasing the beam diameter of the measurement light in an SLO device so that the measurement light becomes a minute spot on the fundus. . However, as the beam diameter of the measurement light increases, the S / N ratio and resolution of the planar image due to the aberration of the measurement light and its return light generated in the eye to be examined in acquiring a planar image of the fundus oculi are reduced.

  This reduction in resolution is dealt with by measuring the aberration of the eye to be examined in real time with a wavefront sensor and correcting the aberration of the measurement light generated in the eye to be examined and its return light with a wavefront correction device. An adaptive optics SLO apparatus (hereinafter referred to as an AO-SLO apparatus) having an adaptive optical system such as a wavefront correction device has been developed to enable acquisition of a high-resolution planar image.

  When acquiring a high-resolution planar image with the AO-SLO apparatus, the beam diameter of the measurement light is increased in accordance with the confocal optical system as described above. However, the S / N ratio of a planar image is improved by introducing a non-confocal optical system into a part of the fundus region / tissue for acquiring an image.

  In Non-Patent Document 1, return light from the fundus is divided into a central part and a peripheral part on the image plane, and the peripheral part is further divided and made incident on each optical sensor. Then, an AO-SLO device that calculates (differences) the signals of the respective optical sensors to image the retina has been proposed, and attempts have been made to improve the SN ratio of the acquired planar image.

IOVS, Vol. 55, NO. 7, 4244-4251 (2014)

  The above-described AO-SLO apparatus can acquire a high-resolution and high-SNR planar image using an adaptive optics system.

  However, the non-patent document 1 has a configuration in which all the light at the center of the return light from the fundus is reflected by a mirror installed on the imaging surface. Therefore, the non-confocal image obtained by dividing the peripheral light around the center of the return light, making them incident on each optical sensor, and calculating the signal of each optical sensor has a low resolution. This leaves room for improvement.

  In view of the above problems, an object of the present invention is to provide an image pickup apparatus that can obtain a non-confocal image with high resolution.

  An image pickup apparatus according to the present invention is an optical image pickup apparatus that irradiates a test object with measurement light and picks up a confocal image and a non-confocal image of the test object. A part of the light at the center of the return light obtained by irradiating the object is branched to the confocal imaging unit, and the other light at the center and the light around the center are branched to the non-confocal imaging unit A first branching unit; a first light receiving unit that measures the intensity of light branched to the confocal imaging unit; a second light receiving unit that measures the intensity of light branched to the non-confocal imaging unit; First generation means for generating an image from a signal corresponding to the intensity of light received by each of the first and second means.

  According to the present invention, a high-resolution non-confocal image can be obtained.

It is a figure explaining the structure of the optical system of the SLO apparatus in Embodiment 1 of this invention. It is a figure explaining the structure of the optical system of the light-receiving part in Embodiment 1 of this invention. It is a figure explaining the structure of the isolation | separation part in Embodiment 1 of this invention. It is a figure explaining the wavelength distribution of the measurement light of the SLO apparatus in Embodiment 1 of this invention. It is a flowchart explaining the imaging procedure by the SLO apparatus in Embodiment 1 of this invention. It is a figure explaining the structure of the control software screen of the SLO apparatus in Embodiment 1 of this invention. It is a figure explaining the structure of the light-receiving part in Embodiment 2 of this invention. It is a figure explaining the division part in Embodiment 2 of this invention. It is a figure explaining the non-confocal image by which the outline emphasis in Embodiment 2 of the present invention was carried out. It is a figure explaining another form of the division part in Embodiment 2 of this invention. It is a figure explaining the structure of the isolation | separation part in Embodiment 3 of this invention. It is a figure explaining the structure of the control software screen of the SLO apparatus in Embodiment 3 of this invention.

  The form for implementing this invention is demonstrated by the following embodiment. However, the following embodiments do not limit the present invention related to the claims, and all combinations of features described in the present embodiments are not necessarily essential to the solution means of the present invention. Absent.

[Embodiment 1]
In the first embodiment, an AO-SLO device to which the present invention is applied will be described as an optical imaging device. The AO-SLO apparatus is an apparatus that includes an adaptive optics system and captures a planar image (AO-SLO image) of the fundus with high resolution and high image quality (high SN ratio). In addition, for the purpose of assisting the acquisition of an AO-SLO image, a WF-SLO device that captures a wide-angle planar image (WF-SLO image), and an anterior ocular segment observation device for grasping the incident position of measurement light And a fixation lamp display device for guiding the line of sight in order to adjust the imaging location.

  In the present embodiment, an AO-SLO apparatus that acquires a planar image by correcting optical aberration due to the eye to be inspected using a spatial light modulator is configured, and the diopter of the eye to be examined and optical aberration due to the eye to be examined Regardless of this, a good planar image can be obtained.

  Here, the compensation optical system is provided to capture a high-resolution planar image, but the compensation optical system may not be provided as long as the configuration is an optical system capable of realizing high resolution.

<Configuration of SLO device>
FIG. 1 is a diagram illustrating the configuration of the optical system of the SLO apparatus according to Embodiment 1 of the present invention. The SLO apparatus includes an AO-SLO unit 140, a WF-SLO unit 141, a fixation lamp unit, an anterior ocular segment observation unit, and a control PC 109. The structure of each part is demonstrated using FIG.

<The whole AO-SLO part>
First, the AO-SLO unit 140 in the present embodiment will be specifically described.

  In FIG. 1, the light emitted from the light source 101-1 is divided into the reference light 105 and the measurement light 106-1 by the optical coupler 131. The measurement light 106-1 is guided to the eye 107 to be observed through the single mode fiber 130-4, the spatial light modulator 159, the AO-SLO XY scanner 118-1, the dichroic mirror 170-1, and the like. Reference numeral 156 denotes a fixation lamp, and a light beam 157 from the fixation lamp 156 has a role of promoting fixation of the eye 107 to be examined.

  The measurement light 106-1 is reflected or scattered by the eye 107 to be returned to return light 108-1, and travels back along the optical path, and is reflected by the beam splitter 158-3, to the detectors 204-1 and 20-2 constituting the light receiving unit 200. Incident. The detector 204-1 corresponds to the first light receiving means in the present embodiment, and the detector 204-2 corresponds to the second light receiving means in the present embodiment.

  The detectors 204-1 and 204-2 convert the light intensity of the return light 108-1 into a voltage, and a planar image of the eye 107 to be examined is generated using the output signal. In this embodiment, the entire optical system is mainly configured using a refractive optical system using a lens, but may be configured by a reflective optical system using a spherical mirror instead of the lens.

  In this embodiment, a reflective spatial light modulator is used as the aberration correction device. However, a transmissive spatial light modulator or a deformable mirror may be used.

<Light source of AO-SLO section>
Next, the periphery of the light source 101-1 will be described. The light source 101-1 is an SLD (Super Luminescent Diode) which is a typical low coherent light source. The wavelength is 840 nm and the bandwidth is 50 nm. A low coherent light source is selected to obtain a planar image with little speckle noise. In addition, although SLD is selected as the type of light source, ASE (Amplified Spontaneous Emission) or the like may be used as long as low-coherent light can be emitted.

  In consideration of measuring the eye, near infrared light is suitable for the wavelength. Furthermore, since the wavelength affects the resolution in the horizontal direction of the obtained planar image, it is desirable that the wavelength be as short as possible, here 840 nm. Other wavelengths may be selected depending on the measurement site to be observed. In the present embodiment, a light source for fundus imaging and wavefront measurement is shared, but a different light source may be used and combined in the middle of the optical path.

  The light emitted from the light source 101-1 is split into the reference light 105 and the measurement light 106-1 at a ratio of 90:10 via the single mode fiber 130-1 and the optical coupler 131. Reference numerals 153-2 and 153-4 denote polarization controllers, which respectively control the polarization states of the reference light 105 and the measurement light 160-1.

<Reference optical path of AO-SLO section>
Next, the optical path of the reference beam 105 will be described.

  The reference light 105 divided by the optical coupler 131 is incident on the light quantity measuring device 164 via the optical fiber 130-2. The light quantity measuring device 164 monitors the light quantity of the measurement light 106-1 by measuring the light quantity of the reference light 105.

<Measurement optical path of AO-SLO section>
Next, the optical path of the measuring beam 106-1 will be described.

  The measurement light 106-1 split by the optical coupler 131 is guided to the lens 135-1 through the single mode fiber 130-4, adjusted to become parallel light having a beam diameter of 4 mm, and guided to the compensation optical system. The The adaptive optics system includes a beam splitter 158-1, a wavefront sensor 155 for measuring aberration, a spatial light modulator 159, a pinhole 198-1, and a measurement beam 106-1 and a return beam 108-1 to them. It comprises lenses 135-5 to 10 for emitting light.

  The measurement light 106-1 adjusted to become parallel light having a beam diameter of 4 mm passes through the beam splitters 158-1 and 158-3 and enters the spatial light modulator 159. Here, the cornea 126 of the eye 107 to be examined, the AO-SLO XY scanner 118-1, the wavefront sensor 155, and the spatial light modulator 159 are arranged with lenses 135-5 to 10 and the like so as to be optically conjugate. .

  Next, the measuring light 106-1 is modulated by the spatial light modulator 159, passes through the lenses 135-7 to 135-8, and enters the mirror of the AO-SLO unit XY scanner 118-1. Here, for the sake of simplicity, the AO-SLO XY scanner 118-1 is described as a single mirror, but in reality, two mirrors, an X scanner and a Y scanner, are arranged close to each other so that the top of the fundus 127 is covered. Raster scanning is performed in a direction perpendicular to the optical axis.

  Further, the center of the measuring beam 106-1 is adjusted so as to coincide with the rotation center of each mirror of the AO-SLO XY scanner 118-1.

  Here, the AO-SLO part X scanner is a scanner that scans the measuring beam 106-1 in a direction parallel to the paper surface, and uses a resonance type scanner, and its drive frequency is about 7.9 kHz. The AO-SLO unit Y scanner is a scanner that scans the measuring beam 106-1 in a direction perpendicular to the paper surface. A galvano scanner is used, the drive waveform is a sawtooth wave, the frequency is 32 Hz, and the duty ratio is 84%. It is. The driving frequency of the AO-SLO unit Y scanner is an important parameter that determines the frame rate for capturing an AO-SLO image. The AO-SLO unit XY scanner 118-1 is controlled from the control PC 109 via the optical scanner driving driver 182 in the driver unit 181.

  The lenses 135-9 to 10 are optical systems necessary for scanning the fundus 127, and are used to scan the fundus 127 using the measurement light 106-1 as the fulcrum center of the pupil of the eye 107 to be examined.

  Here, although the beam diameter of the measurement light 106-1 is 4 mm, the beam diameter may be larger in order to obtain a higher resolution AO-SLO image.

  Reference numeral 117-1 denotes an electric stage which can move in the direction indicated by the arrow, and can adjust the focus by moving the position of the associated lens 135-10. By adjusting the position of the lens 135-10, the measurement light 106-1 can be focused on a predetermined layer of the fundus 127 of the eye 107 to be imaged. In addition, the case where the eye 107 to be examined has a refractive error can be dealt with.

  Here, the electric stage 117-1 is controlled from the control PC 109 via the electric stage driving driver 183 in the driver unit 181.

  The measuring light 106-1 through the lenses 135-9 to 10-10 passes through the dichroic mirror 170-1 and is guided to the eye 107 to be examined. When the measurement light 106-1 is incident on the eye 107 to be examined, it becomes return light 108-1 due to reflection and scattering from the fundus 127. The return light 108-1 passes through the same optical path, is partially reflected by the beam splitter 158-1, is incident on the wavefront sensor 155 via the pinhole 198-1, and the return light 108-1 generated by the eye 107 to be inspected. Aberration is measured.

  Here, the pinhole 198-1 is installed for the purpose of shielding unnecessary light other than the return light 108-1. The return light 108-1 transmitted through the beam splitter 158-1 is reflected by the beam splitter 158-3 and enters the light receiving unit 200. The incident return light 108-1 is split by the branching unit and reaches the detectors 204-1 and 204-1, respectively. As the detectors 204-1 and 204, for example, an APD (Avalanche Photo Diode) or a PMT (Photomultiplier Tube) which is a high-speed and high-sensitivity optical sensor is used.

<Light receiver>
Next, a schematic configuration of the light receiving unit 200 will be described with reference to FIG.

  The return light 108-1 is incident on the separation unit 211 disposed on the imaging plane, and part of the light is reflected and incident on the detector 204-1. Further, the other part of the light incident on the separation unit 211 is transmitted and incident on the detector 204-2. The separation unit 211 corresponds to the first branching unit in this embodiment. Here, as shown in FIG. 3, the separation unit 211 is configured by a partially reflective partially transmissive region 314 at the center, a transmissive region 312 that is the periphery thereof, and a light shielding region 313 that shields light from other regions. Yes.

  The partially reflective partially transmissive region 314 used in this embodiment is configured by a partially reflective partially transmissive film formed by vapor-depositing chromium on a glass substrate. Furthermore, the absorption of about 10% is subtracted at the wavelength of the light source unit 101-1, the reflectance is about 65%, and the transmittance is about 25%. Of course, the present invention is not limited to this reflectance and transmittance.

  The center of the partially reflective partially transmissive region 314 is located at the center of the optical axis of the return light 108-1, and is disposed obliquely with respect to the optical axis so that the detector 204-1 receives the reflected light. When the separating unit 211 is disposed obliquely with respect to the optical axis of the return light 108-1, an ellipse in which the shapes of the partially reflective partially transmissive region 314 and the transmissive region 312 are circular when viewed from the optical axis direction. It has a shape.

  The reflected light 208 reflected by the partially reflective partially transmissive region 314 enters the detector 204-1 via the lens 210. The lens 210 and the detector 204-1 correspond to a confocal imaging unit in the present embodiment.

  The transmitted light 209 of the return light 108-1 transmitted through the partially reflected partially transmissive region 314 and the transmissive region 312 is incident on the detector 204-2 via the lens 212. The lens 212 and the detector 204-2 correspond to a non-confocal imaging unit in this embodiment.

<Whole WF-SLO part>
Next, the WF-SLO unit 141 will be described.

  The WF-SLO unit 141 has basically the same configuration as the AO-SLO unit 140. Description of similar components is omitted.

  In FIG. 1, measurement light 106-2 emitted from a light source 101-2 passes through a lens 135-2, lenses 135-11 to 14, a WF-SLO section XY scanner 118-2, dichroic mirrors 170-1 to 170-3, and the like. Then, it is guided to the eye 107 to be examined. The light source 101-2 is an SLD like the AO-SLO part, and the wavelength thereof is 920 nm and the bandwidth is 20 nm.

<Measurement optical path of WF-SLO section>
Next, the optical path of the measuring beam 106-2 will be described.

  In FIG. 1, measurement light 106-2 emitted from a light source 101-2 passes through a lens 135-2, lenses 135-11 to 14, a WF-SLO section XY scanner 118-2, dichroic mirrors 170-1 to 170-3, and the like. Then, it is guided to the eye 107 to be examined.

  Here, the WF-SLO unit X scanner, which is a constituent element of the WF-SLO unit XY scanner 118-2, is a scanner that scans the measuring beam 106-2 in a direction parallel to the paper surface. The driving frequency is about 3.9 kHz. The WF-SLO unit Y scanner is a scanner that scans the measuring beam 106-2 in a direction perpendicular to the paper surface, and uses a galvano scanner. The drive waveform is a sawtooth wave, the frequency is 15 Hz, and the duty ratio is 84. %. The driving frequency of the WF-SLO unit Y scanner is an important parameter that determines the frame rate of the WF-SLO image.

  Here, the beam diameter of the measuring beam 106-2 is 1 mm, but the beam diameter may be increased in order to obtain a higher-resolution WF-SLO image.

  When the measurement light 106-2 is incident on the eye 107 to be examined, the measurement light 106-2 becomes return light 108-2 due to reflection and scattering from the fundus 127. The return beam 108-2 is detected by the detector 138 via the dichroic mirrors 170-1 to 170, the lenses 135-13 to 14, the lenses 135-2 to 4, the WF-SLO XY scanner 119-2, the beam splitter 158-2, and the like. -2.

<Configuration of the fixation lamp>
In FIG. 1, a fixation lamp 156 is composed of a light emitting display module and has a display surface (□ 27 mm, 128 × 128 pixels) on the XY plane. Here, a liquid crystal, an organic EL, an LED array, or the like can be used. The eye 107 to be examined gazes at the light beam 157 from the fixation lamp 156, whereby the fixation of the eye 107 to be examined is guided. For example, as shown in FIG. 1B, the display surface of the fixation lamp 156 is displayed by flashing a cross pattern at an arbitrary lighting position 165.

  The luminous flux from the fixation lamp 156 is guided to the fundus 127 via the lenses 135-17 to 18 and the dichroic mirrors 170-1 to 170-3. The lenses 135-17 to 135-18 are arranged so that the display surface of the fixation lamp 156 and the fundus 127 are optically conjugate. The fixation lamp 156 is controlled from the control PC 109 via the fixation lamp driving driver 184 in the driver unit 181.

<Anterior segment observation unit>
Next, the anterior ocular segment observation unit will be described.

  In FIG. 1, the light emitted from the anterior segment illumination light source 101-3 irradiates the subject's eye 107, and the reflected light thereof passes through the dichroic mirrors 107-1 and 107-2 and the lenses 135-19 and 20 and the CCD camera 160. Is incident on. Then, by imaging the output signal from the CCD camera 160, the anterior segment can be observed. The anterior segment illumination light source 101-3 is an LED having a center wavelength of 740 nm.

<Focus, shutter, astigmatism correction>
The above-described AO-SLO unit, WF-SLO unit, and fixation lamp unit each have electric stages 117-1 to 117-3 individually, and adjust the focus by moving the three electric stages in conjunction with each other. However, if it is desired to individually adjust the focus position, it can be adjusted by moving the electric stage individually.

  Each of the AO-SLO unit and the WF-SLO unit includes a shutter (not shown), and can control whether or not measurement light is individually incident on the eye 107 by opening and closing the shutter.

  Although the shutter is used here, it can be controlled by directly turning on and off the light sources 101-1 and 101-2. Similarly, the anterior ocular segment observation unit and the fixation lamp unit can also be controlled by turning on / off the light source 101-3 and the fixation lamp 156.

  Further, the lens 135-10 can be replaced, and a spherical lens or a cylindrical lens can be used in accordance with the aberration (refractive abnormality) of the eye 107 to be examined. In addition to a single lens, a plurality of lenses may be installed in combination.

<Wavefront correction>
Next, wavefront correction using the wavefront sensor 155 and the spatial light modulator 159 will be described.

  The wavefront sensor 155 and the spatial light modulator 159 are electrically connected to the control PC 109. The wavefront sensor 155 measures the wavefront of the beam, uses a Shack-Hartmann sensor, and has a measurement range of −10D to + 5D. The obtained aberration is expressed using a Zernike polynomial, which indicates the aberration of the eye 107 to be examined. The Zernike polynomial is composed of a tilt (tilt) term, a defocus term, an astigma (astigmatism) term, a coma term, a trifoil term, and the like. The control PC 109 calculates a modulation amount (correction amount) for correcting to a wavefront having no aberration based on the obtained aberration of the eye 107 to be inspected, and commands the spatial light modulator 159 to perform the modulation. In this embodiment, a reflective liquid crystal spatial phase modulator having 600 × 600 pixels is used as the spatial light modulator 159.

<Wavelength>
FIG. 4 shows the wavelength distribution of the light sources used in the AO-SLO unit 140, the WF-SLO unit 141, the fixation lamp unit, and the anterior ocular segment observation unit. The wavelength of the light beam 157 from the fixation lamp 156 is 720 nm or less, and the light source 101-3 of the anterior ocular segment observation unit has a center wavelength of 740 nm. The wavelength of the light source 101-1 of the AO-SLO unit 140 is 840 nm and the bandwidth is 50 nm, and the wavelength of the light source 101-2 of the WF-SLO unit 141 is 920 nm and the bandwidth is 20 nm. In order to divide each light by the dichroic mirrors 170-1 to 170-3, different wavelength bands are used. FIG. 4 shows the difference in wavelength of each light source, and does not define the intensity and spectrum shape.

<Imaging>
Next, a method for generating a captured image will be described.

  The light incident on the detectors 204-1 and 20-2 is converted into a voltage by the intensity of the light. The voltage signals obtained by the detectors 204-1 and 204-2 are converted into digital values by the AD board 176-1 in the control PC 109. Next, the control PC 109 performs data processing synchronized with the operation and drive frequency of the AO-SLO unit XY scanner 118-1, and forms an AO-SLO image. Here, the capturing speed of the AD board 176-1 is 15 MHz. The control PC 109 corresponds to first generation means in this embodiment. Similarly, the voltage signal obtained by the detector 138-2 is converted into a digital value by the AD board 176-2 in the control PC 106, and a WF-SLO image is formed.

<Control software screen>
A control software screen displayed on the display unit of the PC 109 will be described with reference to FIG.

In FIG. 6, each symbol corresponds as follows.
Reference numeral 601 denotes an execution button 602 for instructing the start of imaging, STOP button 603 for instructing the end of imaging, and a chin rest adjustment button 604 for instructing fine adjustment of a chin rest portion (not shown). The focus adjustment button 605 for adjusting the WF-SLO image button 607 for instructing the start of image capturing of the WF-SLO image, the AO-SLO image capturing button 611 for instructing start of image capturing of the AO-SLO image, The aberration correction monitor 612 in which the value of the aberration amount is displayed, the anterior eye monitor 613 in which the anterior eye image is displayed, the fixation lamp position monitor 614 for indicating the lighting position of the fixation lamp 156, the wavefront The wavefront sensor monitor 615 on which the Hartmann image detected by the sensor 155 is displayed is the WF-SLO monitor 616 on which the WF-SLO image is displayed. The WF-SLO intensity monitor 617 for displaying the intensity of the output signal of the tractor 138-2 displays the AO-SLO confocal image for the WF-SLO recording button 618 for instructing recording of the WF-SLO image. The AO-SLO confocal monitor 619 displays the intensity of the output signal of the detector 204-1. The AO-SLO intensity monitor 620 displays an AO-SLO recording button 621 for instructing recording of an AO-SLO image. An auto focus button 622 for instructing auto focus, an aberration correction button 623 for instructing aberration correction, and an imaging condition setting button 624 for instructing change of set imaging conditions are AO- The depth adjustment button 625 for instructing the adjustment of the depth of the SLO image displays an AO-SLO non-confocal image. O-SLO non-confocal monitor <imaging procedure>
Next, an imaging procedure in the SLO device of this embodiment will be described with reference to FIGS.

  FIG. 5 shows an imaging procedure. Below, each process is described in detail.

(Step 1) Start imaging When the examiner inputs imaging start via the execution button 601 on the control software screen, the control PC 109 lights the pattern of the fixation lamp 156 at a predetermined standard position. In this embodiment, a pattern is lit at the center of the visual field.

(Step 2) Acquiring an anterior segment image The control PC 109 displays the anterior segment image captured by the CCD camera 160 on the anterior segment monitor 612. The examiner adjusts the positional relationship between the eye to be examined and the SLO device while viewing the anterior segment image displayed on the anterior segment monitor 612. A chin rest adjusting button 603 may be used to instruct fine adjustment of a chin rest not shown. Details are omitted because they are general.

(Step 3) Acquiring a WF-SLO Image When the position adjustment is completed and the examiner inputs the start of imaging of the WF-SLO image via the WF-SLO imaging button 605, the control PC 109 captures the WF-SLO image. The WF-SLO unit 141 is instructed to display the captured WF-SLO image on the WF-SLO monitor 615. The angle of view is 9 mm long × 12 mm wide, and the frame rate is 16 Hz. If necessary, the examiner instructs adjustment using the focus adjustment button 604 so that the WF-SLO intensity of the WF-SLO intensity monitor 616 increases. On the WF-SLO intensity monitor 616, the signal intensity detected by the WF-SLO unit 141 is displayed in time series in the horizontal axis time and the vertical axis signal intensity. Here, when the focus adjustment button 604 is adjusted by the examiner, the control PC 109 simultaneously adjusts the positions of the lenses 135-10, 14, and 18 in accordance with the input adjustment amount.

  When the examiner inputs WF-SLO recording via the WF-SLO recording button 617, the control PC 109 stores the WF-SLO data in a recording unit (not shown).

(Step 4) Displaying the AO-SLO image When the examiner inputs the AO-SLO imaging start via the AO-SLO imaging button 607, the control PC 109 opens the shutter of the AO-SLO measuring light, and the AO-SLO image is displayed. Measurement light 106-1 which is measurement light is irradiated to the eye 107 to be examined. An AO-SLO confocal image is displayed on the AO-SLO confocal monitor 618, and an AO-SLO non-confocal image is displayed on the AO-SLO non-confocal monitor 625. The imaging angle of view is set to 0.8 mm in length × 0.8 mm in width, and the frame rate is set to 32 Hz as an initial value. Similarly to the WF-SLO intensity monitor 616, the signal intensity detected by the AO-SLO unit is displayed in time series on the AO-SLO intensity monitor 619 and adjusted based on the examiner's instruction.

(Step 5) Determine AO-SLO image acquisition position The examiner designates a position where an AO-SLO image is to be acquired. The control PC 109 changes the lighting position of the pattern of the fixation lamp 156 according to the designated position.

  There are two means for designating the position for acquiring the AO-SLO image. One is a method for indicating the position of the fixation lamp 156 on the fixation lamp position monitor 613, and the other is a method for indicating a desired position on the WF-SLO monitor 615 using a pointing device (not shown). It is a click method. The control PC 109 associates the pixel on the WF-SLO monitor 615 with the position of the fixation lamp 156, and changes the lighting position of the pattern of the fixation lamp 156 according to the designated position. By changing the lighting position of the pattern of the fixation lamp 156, the line of sight can be guided to a desired position, and an AO-SLO image at the designated position can be taken.

(Step 6) Aberration Correction The control PC 109 displays the Hartmann image detected by the wavefront sensor 155 on the wavefront sensor monitor 614. The aberration component calculated from the Hartmann image is displayed on the aberration correction monitor 611. Aberrations are displayed separately for a defocus component (μm unit) and all aberration amounts (μm RMS unit). Here, since the position of the lens 135-10 which is the focus lens of the AO-SLO measurement light is adjusted in the step 3, aberration measurement in this step is possible. Specifically, the return light 108-1 passes through the pinhole 198-1 without being kicked, and reaches the wavefront sensor 155.

  When the examiner inputs auto-focus start via the auto-focus button 621, the positions of the lenses 135-10, 14, and 18 are adjusted so that the defocus value becomes small.

  Next, when the examiner inputs an aberration correction start via the aberration correction button 622, the spatial light modulator 159 is adjusted in a direction in which the aberration amount decreases, and the value of the aberration amount is sent to the aberration correction monitor 611 in real time. indicate. The images displayed on the AO-SLO confocal monitor 618 and the AO-SLO non-confocal monitor 625 are also updated to images with corrected aberrations in real time.

(Step 7) Acquire an AO-SLO image When the examiner inputs setting change via the imaging condition setting button 623, the control PC 109 determines the imaging field angle, frame rate, Change the imaging time.

  When the examiner inputs depth adjustment via the depth adjustment button 624, the lens 135-10 is moved to adjust the imaging range in the depth direction of the eye 107 to be examined. By this adjustment, specifically, an AO-SLO image of a desired layer such as a photoreceptor layer, a nerve fiber layer, or a pigment epithelium layer can be acquired.

  When the aberration amount becomes a sufficiently low value and the AO-SLO image is clearly displayed, the examiner presses the AO-SLO recording button 620. When there is an input of AO-SLO recording via the AO-SLO recording button 620, the control PC 109 saves the AO-SLO image in the recording unit.

(Step 8) Change of imaging position If there is an input from the examiner to change the imaging position of the AO-SLO image, the process returns to step 4. If not, proceed to the next step.

(Step 9) Left / Right Eye Switching When there is an input of left / right eye switching of the imaging target eye from the examiner, the process returns to Step 2. If not, proceed to the next step.

(Step 10) End When the examiner inputs the end of imaging via the STOP button 602, the control PC 109 stops the control software.

  As described above, according to the present embodiment, a non-confocal image and a confocal image with high resolution are picked up by receiving the return light through the separation unit having a partially reflective partially transmissive region. Can do.

[Embodiment 2]
As Embodiment 2, an SLO device to which the present invention is applied will be described with reference to FIG.

  In this embodiment, the basic configuration is almost the same as that of the first embodiment. The light receiving unit 200 is different from the first embodiment in that the transmitted light 209 transmitted through the separating unit 211 is further branched by the dividing unit 701 disposed on the imaging plane and received by two detectors.

<Light receiver>
In FIG. 7, the transmitted light 209 that has passed through the separation unit 211 is further divided into two by the division unit 701 disposed on the imaging plane, and is incident on the detectors 702-1 and 702-2, respectively. The dividing unit 701 corresponds to the second branching unit in this embodiment. The dividing portion 701 in the present embodiment is a knife edge prism having a triangular prism shape as shown in FIG. The detector 702-1 corresponds to the third light receiving means in the present embodiment, and the detector 702-2 corresponds to the fourth light receiving means in the present embodiment.

  Each of the detectors 702-1 and 702-2 is arranged coaxially with the scanning direction of the AO-SLO X scanner. The voltage signal obtained by each detector is converted into a digital value by the AD board 176-1 in the control PC 109 and input to the control PC 109. The control PC 109 corresponds to the second generation unit in this embodiment.

Assuming that digital values obtained from light at a certain time incident on the detectors 702-1 and 702 are Ia and Ib, respectively, a differential value I ′ in the X direction can be obtained from the following equation.
I ′ = (Ia−Ib) / (Ia + Ib)
An image is generated by I ′, and a non-confocal image with edge enhancement as shown in FIG. 9 can be acquired.

  In the present embodiment, a knife edge prism is used as the dividing unit 701. However, as shown in FIG.

  In this embodiment, the detectors 702-1 and 702-2 are arranged coaxially with the scanning direction of the AO-SLO section X scanner, but may be arranged coaxially with the scanning direction of the AO-SLO section Y scanner. It may be arranged on a shaft with an angle.

In this embodiment, the differential value I ′ is I ′ = (Ia−Ib) / (Ia + Ib)
But
I ′ = (Ib−Ia) / (Ia + Ib)
It is also possible to adopt a configuration in which which of the above two formulas is used can be selected.

  As described above, according to the present embodiment, the return light is further divided through the separation part having the partially reflective partially transmissive region, received by the two detectors, and calculated, whereby the contour with high resolution is obtained. It is possible to capture a non-confocal image and a confocal image in which is emphasized.

[Embodiment 3]
As Embodiment 3, an SLO device to which the present invention is applied will be described with reference to FIG.

  In this embodiment, the basic configuration is almost the same as in Embodiments 1 and 2, but the light receiving unit 200 can change the transmittance of the partially reflective partially transmissive region 314 of the separating unit 211. Is different from the first and second embodiments.

<Light receiver>
In the present embodiment, as shown in FIG. 11, the separation unit 211 has a circular pattern in which the central part of the partial reflection partial transmission region 314, the peripheral transmission region 312, and the light shielding region 313 for shielding light are set as one set. The configuration is arranged in a plurality. Each partially reflective partially transmissive region 314 has a different transmittance, and under the control of the control PC 109, the separation unit 211 is mechanically rotated by a transmittance selection control unit (not shown) and selectively patterned. The transmittance can be changed by switching. The separation unit 211 corresponds to a changing unit in this embodiment. If a pattern with high transmittance is selected, the resolution of the non-confocal image increases, but the amount of light incident on the confocal imaging system is reduced, and the image quality of the confocal image is degraded. Conversely, when a pattern with low transmittance is selected, the resolution of the non-confocal image is reduced, but more light is incident on the confocal imaging system, and the image quality of the confocal image is improved. For this reason, it is desirable to select an appropriate transmittance (corresponding to changing the branching ratio) according to the inspection object or while viewing the displayed non-confocal image and confocal image. This is an effective means for obtaining an image.

<Imaging procedure>
Next, an imaging procedure in the SLO device of this embodiment will be described with reference to FIGS.

  The imaging procedure other than step 7 is the same as the imaging procedure of the first embodiment. Therefore, in the present embodiment, only the imaging procedure of step 7 in FIG. 5 will be described.

(Step 7) Acquire an AO-SLO image When the examiner inputs setting change via the imaging condition setting button 623, the control PC 109 determines the imaging field angle, frame rate, Change the imaging time.

  When the examiner inputs depth adjustment via the depth adjustment button 624, the lens 135-10 is moved to adjust the imaging range in the depth direction of the eye 107 to be examined. By this adjustment, specifically, an image of a desired layer such as a photoreceptor layer, a nerve fiber layer, or a pigment epithelium layer can be acquired.

  Further, when there is an input of transmittance adjustment (branch ratio change) via the transmittance adjustment button 1201, a transmittance selection control unit (not shown) mechanically rotates the separation unit 211 according to the input, and the transmittance is adjusted. By changing the resolution, the resolution of the non-confocal image is adjusted. The transmittance adjustment button 1201 corresponds to a designation unit in the present embodiment.

  When the aberration amount becomes a sufficiently low value and the AO-SLO image is clearly displayed, the examiner presses the AO-SLO recording button 620. When there is an input of AO-SLO recording via the AO-SLO recording button 620, the control PC 109 saves the AO-SLO image in the recording unit.

  In this embodiment, the transmittance is changed by mechanically rotating a pattern arranged in a circle. However, even if the transmittance is changed by mechanically sliding patterns arranged in a row. Good. Alternatively, the transmittance may be changed using a dimming mirror, and the method for changing the transmittance is not limited to that described here.

  As described above, according to the present embodiment, a part of the center of the return light from the fundus can be incident on the non-confocal imaging unit, and a high-resolution non-confocal image and a confocal image can be obtained. Can be obtained.

140 AO-SLO part 141 WF-SLO part 200 Light receiving part 204 Detector 211 Separating part

Claims (5)

An image imaging device that irradiates an inspection object with measurement light and captures a confocal image and a non-confocal image of the inspection object,
Light from the central part of the return light obtained by irradiating the inspection light with the measurement light from the light source to the confocal imaging part, the other light in the central part and the light around the central part First branching means for branching to a non-confocal imaging unit;
First light receiving means for measuring the intensity of light branched to the confocal imaging unit;
Second light receiving means for measuring the intensity of light branched to the non-confocal imaging unit;
First generation means for generating an image from a signal corresponding to the intensity of light received by each of the first and second means;
An image pickup apparatus comprising: A second branching unit that branches the return light branched to the non-confocal imaging unit into two;
Third and fourth light receiving means for measuring the intensity of the light branched by the second branching means respectively;
Second generation means for generating an image by calculation using a signal corresponding to the intensity of light received by each of the third and fourth light receiving means;
The image capturing apparatus according to claim 1, further comprising: A changing unit for changing a branching ratio of the first branching unit;
The image capturing apparatus according to claim 1, wherein the image capturing apparatus is an image capturing apparatus. Designating means for designating a branching ratio of the first branching means;
The image capturing apparatus according to claim 3, wherein the changing unit changes the branching ratio based on a designated branching ratio. Light from the central part of the return light obtained by irradiating the inspection light with the measurement light from the light source to the confocal imaging part, the other light in the central part and the light around the central part First branching means for branching to a non-confocal imaging unit;
Changing means for changing the branching ratio of the first branching means;
First light receiving means for measuring the intensity of light branched to the confocal imaging unit;
Second light receiving means for measuring the intensity of light branched to the non-confocal imaging unit;
A method for controlling an image pickup apparatus having
Reading a specified branching ratio of the branching means;
Changing the branching ratio based on the read branching ratio;
Generating an image from a signal corresponding to the intensity of light received by each of the first and second light receiving means;
A control method for an image pickup apparatus, comprising:

Images