JP7195769B2 - Imaging device and its operating method - Google Patents

Description

TECHNICAL FIELD The present invention relates to an imaging apparatus for imaging an object to be measured using light from a light source, and an operating method thereof.

Optical coherence tomography (hereinafter referred to as “OCT”) has been put into practical use as a method for nondestructively and noninvasively acquiring a tomographic image of a measurement object such as a living body. In the field of ophthalmology, one of the major applications of OCT, tomographic images of the fundus are useful and essential for the accurate diagnosis of diseases such as glaucoma and retinal diseases. It's becoming

OCT splits the light from the light source into measurement light and reference light, then causes the return light of the measurement light from the object to be measured to interfere with the reference light reflected from the reference mirror, and analyzes the intensity of the interference light. Thus, a tomographic image of the object to be measured is obtained. As an optical coherence tomography apparatus using this OCT, a time domain OCT (TD-OCT) apparatus that obtains depth information of a measurement target by changing the position of a reference mirror, an interference light is dispersed, and a depth information is obtained. Spectral domain OCT (SD-OCT) device that acquires the information by replacing it with frequency information, wavelength sweeping type (wavelength scanning type (wavelength scanning type)) OCT (Swept Source) that disperses the wavelength first and outputs OCT: SS-OCT) devices and the like are known. SD-OCT and SS-OCT are also collectively called FD-OCT (Fourier Domain OCT).

In recent years, for example, there has been a demand for higher imaging speeds in ophthalmic OCT devices. Developments are being made to reduce the time.

In addition, as another method for realizing high-speed imaging with an OCT apparatus, the measurement light is irradiated to the measurement target in a two-dimensional area instead of a point, and the return light of the measurement light from the measurement target is received by a two-dimensional sensor. Full Field OCT (FF-OCT) is available. In this FF-OCT, since signals are acquired in parallel and at the same time, further speeding up is expected. In particular, SS-FF-OCT, which uses a two-dimensional sensor capable of high-speed imaging in combination with the above-described wavelength sweeping (wavelength scanning) method, is one of the preferred options for speeding up.

In this way, conventional techniques for irradiating a two-dimensional area of a measurement target with measurement light and receiving the return light of the measurement light from the measurement target with a two-dimensional sensor are described, for example, in Patent Document 1 and Non-Patent Document 1. technique is known.

Japanese Patent No. 4597744

"Common approach for compensation of axial motion artifacts in swept-source OCT and dispersion in Fourier-domain OCT", Dierck Hillmann et. al, Optics Express, Vol. 20, Issue 6 (2012) pp. 6761-6776

Specifically, Patent Document 1 describes a technique configured to receive polarized light by splitting and performing imaging based on beat signals of interference light. Since it is a time-domain system, it is difficult to speed up tomographic imaging.

In addition, Non-Patent Document 1 describes a wavelength sweeping (wavelength scanning) type FF-OCT (SS-FF-OCT) technology composed of a wavelength sweeping (wavelength scanning) light source and a two-dimensional sensor. ing. However, in the technique of Non-Patent Document 1, for example, the timing of starting the wavelength sweep of the light source and the timing of starting the exposure of the two-dimensional sensor are deviated, thereby impairing the acquisition efficiency of the image signal, resulting in poor image quality. In some cases, a tomographic image could not be acquired.

SUMMARY OF THE INVENTION The present invention has been made in view of such problems, and an object of the present invention is to provide a mechanism capable of obtaining a tomographic image of good image quality by high-speed imaging.

The imaging apparatus of the present invention includes a light source that outputs light swept stepwise by switching a single wavelength interval, a light branching unit that branches the light from the light source into measurement light and reference light, and the measurement light. irradiating means for irradiating a two-dimensional area of a measurement target, and light receiving elements arranged two-dimensionally, and obtained by causing the return light of the measurement light from the measurement target to interfere with the reference light. detecting means for detecting the interfering light at a predetermined exposure timing; and controlling the operation of the light source and the operation of the detecting means to be interlocked so that the predetermined exposure timing is within the single wavelength interval. and a control means.
The invention also includes a method of operating an imaging device as described above.

According to the present invention, it is possible to obtain a tomographic image with good image quality by high-speed imaging.

It is a block diagram showing an example of functional composition of an imaging device concerning an embodiment of the present invention. It is a figure showing an example of the appearance composition of the imaging device concerning the embodiment of the present invention. 2 is a diagram showing an example of the internal configuration of the optical system shown in FIG. 1; FIG. It is a figure which shows embodiment of this invention and shows an example of an interference image, an interference signal, and a tomographic signal. 3 is a diagram showing an embodiment of the present invention and showing an example of a display screen displayed on the display unit shown in FIG. 1; FIG. 4 is a flow chart showing an example of a processing procedure in a photographing method of the photographing device according to the embodiment of the present invention; FIG. 4 is a diagram showing an embodiment of the present invention and explaining a volume data acquisition method; 4 is a flow chart showing an example of a processing procedure in a method for generating a single three-dimensional tomographic image of the imaging device according to the embodiment of the present invention; 4 is a flow chart showing an example of a processing procedure in a method for generating a three-dimensional tomographic image of the imaging device according to the embodiment of the present invention; 4 is a timing chart showing the embodiment of the present invention and showing an example of the operation method of the light source and the two-dimensional sensor shown in FIG. 3. FIG.

EMBODIMENT OF THE INVENTION Below, the form (embodiment) for implementing this invention is demonstrated, referring drawings. It should be noted that the descriptions of the embodiments of the invention set forth below are merely illustrative and exemplary in nature and are not intended to limit the disclosure or its application or uses in any way. . Also, the relative configuration of components, steps, numerical expressions and numerical values shown in the embodiments of the invention described below are not intended to limit the scope of the disclosure unless specifically stated otherwise. . In addition, techniques, methods and devices that are well known by those skilled in the art do not require those skilled in the art to know these details, so detailed descriptions thereof are omitted in the embodiments of the present invention described below. may be

[Overall configuration of photographing device 10]
FIG. 1 is a block diagram showing an example of the functional configuration of an imaging device 10 according to an embodiment of the invention. As shown in FIG. 1, the photographing apparatus 10 includes an optical system 100, an input unit 200, an overall control unit 300, an image generation unit 400, a display control unit 500, a storage unit 600, and a display unit 700. It is configured with

The optical system 100 is a component that irradiates the measurement target T with measurement light and detects the return light of the measurement light from the measurement target T under the control of the overall control unit 300 . The input unit 200 is a component for inputting various information and the like to the general control unit 300 and the like. The input unit 200 is composed of, for example, a keyboard, a mouse, and the like with which the user can input operations. The overall control unit 300 is a component that controls the overall operation of the imaging device 10 based on, for example, information input from the input unit 200 . The image generator 400 is a component that processes the signal S output from the optical system 100 and generates an image IM under the control of the overall controller 300 . The display control unit 500 is a component that performs control for displaying, for example, an image IM generated by the image generation unit 400 and information input from the input unit 200 on the display unit 700 . Note that the example shown in FIG. 1 shows an example in which the display control unit 500 is provided separately from the overall control unit 300. The control unit 300 may be configured to perform display control on the display unit 700 . The storage unit 600 is a configuration unit that stores programs and various types of information necessary for the overall control unit 300, the image generation unit 400, and the display control unit 500 to perform various types of processing. Further, the storage unit 600 is a component that stores various kinds of information and the like acquired by various processes performed by the overall control unit 300, the image generation unit 400, and the display control unit 500. FIG. For example, the storage unit 600 stores information specifying the measurement target T together with the image IM generated by the image generation unit 400 . The display unit 700 is, for example, a component including a display device such as a liquid crystal display.

FIG. 2 is a diagram showing an example of the external configuration of the photographing device 10 according to the embodiment of the present invention. In FIG. 2, the same reference numerals are assigned to the same components as those shown in FIG. 1, and detailed description thereof will be omitted. As shown in FIG. 2, the photographing apparatus 10 includes an optical head 11, a stage section 12, a base section 13, a PC (personal computer) 14, a face support 15, an input section 200, and a display section 700. It is configured with FIG. 2 also shows an XYZ coordinate system for determining positions in a three-dimensional space. The example shown in FIG. 2 shows an example in which the subject's eye (eye to be examined) E is applied as the measurement target T shown in FIG. Become.

The optical head 11 is a housing containing the optical system 100 shown in FIG. The stage unit 12 is a component that moves the optical head 11 in the XYZ directions with respect to the base unit 13 by a motor or the like, based on the control of the general control unit 300 shown in FIG. 1, for example. The base portion 13 is a component that supports the optical head 11 via the stage portion 12 . Further, the base portion 13 is a component that also supports the face support 15 . The face support 15 is a component for fixing the face F of the subject.

The PC 14 is a computer including the overall control unit 300, the image generation unit 400, the display control unit 500, and the storage unit 600 shown in FIG. The PC 14 can realize, for example, the overall control unit 300, the image generation unit 400, and the display control unit 500 shown in FIG. 1 as software modules that can be realized by hardware such as a CPU. In the embodiment of the present invention described below, an example in which the CPU (not shown) of the PC 14 executes a program stored in the storage unit 600 to implement the software module will be described. is not limited to this form. For example, the image generation unit 400 may be realized by dedicated hardware such as ASIC, and the display control unit may be realized by a dedicated processor such as GPU different from the CPU. Further, a configuration in which the connection between the optical system 100 provided in the optical head 11 and the PC 14 is realized by a configuration via a network, for example, is also applicable to the present invention.

Next, details of each component shown in FIG. 1 will be described.

<Optical system 100>
First, the optical system 100 shown in FIG. 1 will be described.
FIG. 3 is a diagram showing an example of the internal configuration of the optical system 100 shown in FIG. Note that the example shown in FIG. 3 also shows an example in which the subject's eye E is applied as the measurement target T shown in FIG. 1, similarly to FIG.

The optical system 100 has a light source 101, optical fibers 102-1 to 102-3, a coupler 103, a collimator lens 104, a beam splitter 105, an aperture 107, an eyepiece optical system 140, a reference optical system 150, and a light receiving optical system 160. configured as follows. Although not shown in FIG. 3, the optical system 100 includes a wide-angle fundus photographing unit for confirming the photographing position of the fundus Er of the eye E to be examined, and an anterior eye observation unit for facilitating alignment. A fixation lamp optical system for presenting the eye E to be examined with a fixation position is also provided. The wide-field-angle fundus photographing unit, the anterior segment observation unit, and the fixation lamp optical system can use known configurations in the present embodiment, and are not core configurations of the present invention. , the description of which is omitted.

The light source 101 is a wavelength swept light source (wavelength scanning light source) that can change the wavelength of light to be output. The light source 101 can change parameters such as the wavelength and wavelength width at which scanning is started in one scan, and the scan speed, which is the number of scans per second, under the control of the overall control unit 300. is. In this embodiment, the standard scanning speed is 25 scans per second. Further, in this embodiment, light intensity data for each wavelength of the light source 101 (hereinafter referred to as “spectrum data”) is measured in advance and stored in the storage unit 600 .

Light emitted from the light source 101 enters the coupler 103 via the single-mode optical fiber 102-1. The coupler 103 is an optical splitter that splits the light from the light source into the measurement light 121 and the reference light 123 . The measurement light 121 split by the coupler 103 is guided to the collimator lens 104 via the single-mode optical fiber 102-2 and then guided to the beam splitter 105 via the aperture 107. FIG. Reference light 123 branched by coupler 103 is guided to reference optical system 150 via single-mode optical fiber 102-3.

Aperture 107 is provided to cut out a region where the intensity distribution of measurement light 121 is substantially uniform. In this embodiment, since the measurement light 121 has a Gaussian distribution, the aperture 107 is configured to pass through the area of the measurement light 121 where the peak intensity is about half or more. Furthermore, in the present embodiment, the aperture 107 is configured to have a variable aperture diameter, which makes it possible to change the irradiation area of the fundus Er. With this configuration, even when the subject's eye E is myopic or hyperopic, the overall control unit 300 can perform control so that the illumination region is the same as when the subject's eye E is emmetropic. Note that the control of the aperture 107 can be performed in conjunction with the focus adjustment mechanism 141 .

In this embodiment, the focal length of the collimator lens 104 is selected so that the intensity distribution of the measurement light 121 is approximately uniform under the condition that the aperture diameter of the aperture 107 is maximized. By using a higher output light source 101, the allowable decrease in intensity with respect to the peak intensity may be tightened, and a more uniform region may be selected and used.

The measurement light 121 is guided to the eyepiece optical system 140 after passing through the beam splitter 105 . Specifically, the measurement light 121 guided to the eyepiece optical system 140 is guided to the subject's eye E via a focus adjustment mechanism 141, a scanner 142, a relay optical system 143, a scanner 144, an eyepiece lens 145, and an aperture 146. , irradiate a two-dimensional area of the fundus Er. Here, in the present embodiment, the eyepiece optical system 140 is irradiation means for irradiating a two-dimensional region of the eye to be examined E (more specifically, the fundus Er of the eye to be examined E), which is the measurement target T, with the measurement light 121. be.

The measuring light 121 reflected by the fundus Er of the eye to be examined E follows the optical path followed by the measuring light 121 in reverse order as return light 122 of the measuring light. Specifically, the return light 122 of the measurement light enters the eyepiece optical system 140, passes through the aperture 146, the eyepiece lens 145, the scanner 144, the relay optical system 143, the scanner 142, and the focus adjustment mechanism 141, and passes through the beam splitter 105. led to. The return light 122 guided to the beam splitter 105 enters the light receiving optical system 160 via the beam splitter 105 . Note that FIG. 3 schematically shows that light reflected by a part of the two-dimensional area of the fundus Er irradiated with the measurement light 121 is imaged on the two-dimensional sensor 162 as the return light 122 . Actually, however, in this embodiment, all the return light 122 reflected by the two-dimensional region of the fundus Er irradiated with the measurement light 121 is formed as an image on the two-dimensional sensor 162 .

The focus adjustment mechanism 141 includes mirrors 141-1 and 141-2, a stage 141-3, and a prism 141-4. be. The measurement light 121 incident on the focus adjustment mechanism 141 from the light source 101 side is reflected by one surface of the prism 141-4, then sequentially reflected by the mirrors 141-1 and 141-2. Reflected on the other side. The mirrors 141-1 and 141-2 are arranged on a stage 141-3 as shown in FIG. For example, the overall control unit 300 can change the optical path length of the measurement light 121 by moving the stage 141-3 in the direction indicated by the arrow in FIG. ing.

The scanner 142 and the scanner 144 are, for example, galvanometer scanners with variable angles of reflecting surfaces that reflect light. The scanner 142 and the scanner 144 are controlled by the overall control unit 300 to move the irradiation position of the measurement light 121 on the fundus Er in two mutually orthogonal X-direction (horizontal) and Y-direction (vertical) directions. (steering). Further, the scanner 142 and the scanner 144 are arranged so as to have a conjugate relationship with the pupil P of the subject's eye E by means of a relay optical system 143 and an eyepiece lens 145 . With this configuration, the overall control unit 300 can control the measurement light 121 incident on the subject's eye E to pass through approximately the same region of the pupil P regardless of steering by the scanner 142 and the scanner 144 . In addition, this control prevents the measurement light 121 from being partially blocked by the subject's eye E, so that efficient steering can be performed.

The aperture 146 is arranged substantially near the condensing point of the measuring light 121 close to the subject's eye E, and is configured to suitably irradiate the fundus Er.

On the other hand, the reference light 123 emitted from the single-mode optical fiber 102-3 is guided to the reference optical system 150 as described above. Specifically, the reference light 123 incident on the reference optical system 150 is guided to the collimator lens 151 , the aperture 153 , the dispersion compensating glass 154 and the transfer optical element 155 . Reference beam 123 is then directed to beam splitter 105 via transfer optics 155 .

The dispersion compensating glass 154 is used to compensate for dispersion due to the eye E to be examined and the optical elements forming the optical system 100 . Also, as shown in FIG. 3, the exit end of the optical fiber 102-3 and the collimator lens 151 are arranged on a stage 152. FIG. For example, the overall control unit 300 drives the stage 152 in the optical axis direction based on the input from the input unit 200 and the like in accordance with the difference in the axial length of the subject's eye E to be examined. The position can be adjusted. Here, the coherence gate position represents a position where the difference in the optical path length of the reference light 123 with respect to the optical path lengths of the measurement light 121 and the return light 122 disappears. In this embodiment, the optical path length of the reference light 123 is changed, but the present invention is not limited to this embodiment. It suffices if the difference in optical path length can be changed.

Further, in this embodiment, the exit end of the optical fiber 102-3 and the collimator lens 151 are moved by moving the stage 152, but the present invention is not limited to this form. For example, an optometer may be arranged immediately before the aperture 153, and it is desirable to adopt a configuration in which a light weight element is mounted on the stage 152 in order to increase the operating speed of longitudinal tracking, which will be described later.

The beam splitter 105 is combining means for combining the return light 122 incident from the eyepiece optical system 140 and the reference light 123 incident from the reference optical system 150 to generate interference light 124 . Interference light 124 generated by beam splitter 105 is guided to light receiving optical system 160 .

The interference light 124 guided to the light receiving optical system 160 is received by the two-dimensional sensor 162 via the imaging optical system 161 . The two-dimensional sensor 162 is detection means for detecting the incident interference light 124 as an interference signal. Then, the two-dimensional sensor 162 accumulates the detected interference signal data in the internal memory 163 . Here, the two-dimensional sensor 162 includes a plurality of light-receiving elements arranged two-dimensionally (the light-receiving elements are hereinafter referred to as “pixels”). It converts the light 124 into an interference signal.

FIG. 4 shows an embodiment of the present invention, and is a diagram showing an example of an interference image, an interference signal, and a tomographic signal. Specifically, FIG. 4A shows an example of an interference image 810, FIG. 4B shows an example of an interference signal 820, and FIG. 4C shows an example of a tomographic signal 830. As shown in FIG.

As shown in FIG. 4A, the signal generated by one exposure of the two-dimensional sensor 162 becomes an interference image 810 in which interference fringes are superimposed on the front view of the fundus Er. Coordinates 812 of the interference image 810 shown in FIG. 4(a) correspond to each pixel of the two-dimensional sensor 162, and using indices i=1, 2, . ). Here, N is the total number of coordinates of the interference image 810, and the upper left of the interference image 810 is the reference coordinate 811 (X1, Y1).

The signal of one wavelength scan at the coordinates 812 (Xi, Yi) of the interference image 810, which is the fundus image shown in FIG. 4(a), becomes the interference signal 820 shown in FIG. 4(b). 4B, a tomographic signal 830 shown in FIG. 4C is obtained, and a tomographic image is generated from a plurality of tomographic signals 830. FIG. Here, the tomographic direction indicated by the horizontal axis in FIG. 4C is the direction corresponding to the depth direction (Z direction) of the subject's eye E (more specifically, in this embodiment, the fundus Er of the subject's eye E). be.

Since the human eye fluctuates due to involuntary eye movement or the like, it is difficult to photograph the subject's eye E in a completely stationary state. In order to obtain an image of good quality, it is desirable to set the shooting speed to be unaffected by the movement of the human eye such as involuntary eye movement. preferably.

Data of a partial area 813 of the interference image 810 shown in FIG. 4A is sent to the image generation unit 400 in real time and imaged based on user's designation in the preview area 922, which will be described later with reference to FIG. . This image is further displayed on the display unit 700 in real time. This configuration eliminates the need to transfer a large amount of data, and can present a preview image to the user in real time. Also, based on this preview image, the user can determine whether the coherence gate position or the like is appropriate in terms of focus, coherence gate position, or steering described above.

In this embodiment, by appropriately selecting the collimating lens 151 and the aperture 153, the reference light 123 is imaged in a wider area than the measurement light 121 on the two-dimensional sensor 162. there is With this configuration, the accuracy required for adjusting the optical system is relaxed, and more stable imaging can be performed.

<Overall Control Unit 300>
Next, the overall control unit 300 shown in FIG. 1 will be described.
In this embodiment, as described above, the overall control unit 300 is configured as a software module realized by the CPU of the PC 14, and controls each component of the optical system 100 shown in FIG. Furthermore, in the present embodiment, the overall control unit 300 controls the overall operation of the photographing apparatus 10 and also functions as means for performing various selection processes, various measurement processes, and various arithmetic processes. Also, the overall control unit 300 receives input from the user who operates the photographing device 10 via the input unit 200 . Specifically, for example, the overall control unit 300 receives, via the input unit 200, information such as a patient ID that identifies the eye E to be examined, parameters necessary for imaging, selection of a pattern for scanning the fundus Er, and the like. be. The overall control unit 300 controls each component of the photographing apparatus 10 based on various types of information input via the input unit 200, and stores data such as obtained signals and images in the storage unit 600. It has the function of saving to

<Image generator 400>
Next, the image generator 400 shown in FIG. 1 will be described.
The image generator 400 performs various processes on the signal S output from the optical system 100 to generate and output an image of the subject's eye E. FIG.

<Display control unit 500>
Next, the display control unit 500 shown in FIG. 1 will be described.
As described above, the display control unit 500 performs control to display the image acquired from the image generation unit 400 on the display unit 700 under the control of the overall control unit 300 .

FIG. 5 shows an embodiment of the present invention, and is a diagram showing an example of a display screen 900 displayed on the display unit 700 shown in FIG. Note that, apart from the display screen 900 shown in FIG. 5, an input screen for specific information of the subject's eye E such as the patient ID input by the overall control unit 300 can also be displayed on the display unit 700. This input screen is A known configuration can be used, and since it is not the core configuration of the present invention, the description thereof will be omitted.

A display screen 900 shown in FIG. 5 is provided with image display areas 910, 920, 930, 940 and 950, and user interfaces 901 to 908 that can be operated by the user. Specifically, as a user interface that can be operated by the user, a left/right eye switching button 901 , an alignment adjustment section 902 , a focus adjustment slider bar 903 , a coherence gate adjustment slider bar 904 , a coherence gate automatic adjustment button 905 , and a display mode pull-down menu 906 . , a scan mode pull-down menu 907, and a shooting button 908 are provided. Images displayed in the display areas 910 , 920 , 930 , 940 and 950 are generated by the image generator 400 .

An image of the anterior segment of the eye E to be examined is displayed in the display area 910 so that the alignment between the optical head 11 and the eye E to be examined can be confirmed. Further, the overall control unit 300 automatically detects scattered light from the cornea of the measurement light 121 and highlights it as a bright spot 911 on the anterior segment image of the display area 910, so that the measurement light 121 can The user can easily visually recognize the position in the pupil where E is incident. In addition, in the display area 910, a target circle 912 presenting the target position of the pupil of the subject's eye E is superimposed on the anterior segment image, allowing the user to easily determine whether the alignment is appropriate. ing. Furthermore, in the display area 910, a mark 913 is displayed superimposed on the anterior segment image, and by aligning the bright spot 911 so as to overlap the mark 913, a fundus image with little reflection of corneal reflection is obtained. It is possible to do so. Further, the distance from the center of the pupil of the subject's eye E may be superimposed on the anterior segment image in the display area 910 so that the user can easily grasp the incident position of the measurement light 121 . Note that the optical system 100 of the present embodiment appropriately selects the reflectance of a dichroic mirror (not shown) that separates the anterior segment observation part and the measurement light 121, and the reflected light from the cornea displayed in the display area 910 is is configured so that the luminance value of is not saturated.

A wide-area fundus plane image of the fundus Er of the subject's eye E is displayed in real time in the display area 920, and a tomographic image capturing area 921 and a preview area 922 are superimposed on the fundus plane image.

An imaging region 921 is a target region for imaging a tomographic image, specified by the user using the input unit 200 . Also, the preview area 922 designates the position for previewing the tomographic images in the directions indicated by the corresponding arrows in the display areas 930 and 940 , and is designated by the user using the input unit 200 .

A series of interference images acquired based on the area designated by the imaging area 921 is hereinafter referred to as volume data. A series of interference images obtained by one wavelength scan is called single volume data. At this time, volume data is generated from a plurality of single volumes. In the following description, acquisition of volume data will be referred to as imaging, and acquisition of single volume data will be referred to as single imaging.

The photographing area 921 and the preview area 922 can be moved together or independently, and can be switched between combined and independent operations by a switch (not shown). In addition, the size of the preview area 922 is automatically changed in conjunction with the area (two-dimensional area) where the measurement light 121 irradiates the fundus Er, and the user can easily determine the range in which data can be acquired in a single shot without steering. can be discriminated.

A display mode pull-down menu 906 allows selection of the type of tomographic image to be displayed in the display area 950 . For example, the display mode pull-down menu 906 allows selection of a three-dimensional tomographic image as well as horizontal and vertical tomographic images of the region specified by the imaging region 921 .

When a tomographic image is displayed in the display area 950, the position of the tomographic image to be displayed can be changed by moving the crosshairs superimposed and displayed on the fundus plane image in the display area 920. be. In this embodiment, a horizontal tomographic image calculated from single volume data is displayed in the display area 930 , and a vertical tomographic image is displayed in the display area 940 . Furthermore, an arrow is superimposed on the preview area 922 so that the direction of the acquired data of the tomographic image can be easily determined. Furthermore, in this embodiment, it is possible to move the tomographic image, enlarge/reduce the image, adjust the contrast, and the like.

Further, when a three-dimensional tomographic image is displayed in the display area 950, by operating the input unit 200, the three-dimensional tomographic image can be moved, rotated, enlarged/reduced, and contrast can be adjusted on the display area 950. Besides, it is also possible to display only a specific retinal layer in the fundus Er of the eye E to be examined.

Here, the case where the displayed image is changed according to an instruction from the user has been described. Pre-prioritized images may be displayed.

By using the display screen 900 shown in FIG. 5, each image generated by the image generation unit 400 can be efficiently presented to the user. In addition, the user can select the desired image with a simple operation. Furthermore, for example, the operation is further simplified by associating the name of the disease with the image to be displayed in advance.

[Method for controlling photographing device 10 (imaging method)]
FIG. 6 is a flow chart showing an example of the processing procedure in the imaging method of the imaging device 10 according to the embodiment of the present invention. Although not shown in FIG. 6, acquisition of a wide-angle fundus image of the fundus Er by the wide-angle fundus imaging unit was started prior to the processing of the flowchart shown in FIG. 6, and was acquired at a predetermined frame rate. A wide-angle fundus image is displayed in the display area 920 in real time.

<Step S101 (selection of left and right eyes)>
When the user presses the left/right eye switching button 901 while the subject's face F is fixed on the face support 15, the overall control unit 300 changes the subject to be photographed based on the operation of the left/right eye switching button 901. Right eye (R) or left eye (L) is selected as eye examination E. After that, the overall control unit 300 moves the optical head 11 using the data stored in advance in the storage unit 600 based on the selection of left and right eyes. At this time, the overall control unit 300 may calculate the amount of movement using the data acquired by the anterior segment observation unit and the like, and move the optical head 11 more accurately.

<Step S102 (selection of shooting mode)>
Subsequently, when the user specifies a shooting mode from the scan mode pull-down menu 907, the overall control unit 300 selects the shooting mode based on the specification. Here, the imaging modes include, for example, a standard imaging mode in which imaging is performed at a standard scanning speed, a high resolution mode in which the resolution in the tomographic direction of the retina Er is improved, and a standard scanning speed. It is possible to select a high-speed photographing mode (High Speed Mode) or the like in which photographing is performed as quickly as possible.

In the present embodiment, the user designates the imaging mode. However, by selecting a disease to be diagnosed from a menu (not shown) (selecting the name of the disease), the user can select parameter parameters that are prioritized in advance for the disease. You can shoot with .

<Step S103 (start of wavelength sweep of light source)>
Subsequently, the overall control unit 300 turns on the light source 101 and starts wavelength sweeping (wavelength scanning) of the light output from the light source 101 . Specifically, based on the imaging mode selected in step S102, the overall control unit 300 sets parameters such as the scanning speed of the light source 101 and the imaging region (ROI) of the two-dimensional sensor 162, which are stored in advance in the storage unit 600. is used to initiate a wavelength scan of the light output from the light source 101 .

Further, the overall control unit 300 acquires data of the partial area 813 based on the preview area 922 and causes the images generated by the image generation unit 400 to be displayed in the display areas 930 and 940 .

<Step S104 (alignment adjustment)>
Subsequently, when the user clicks the center of the pupil of the anterior segment image displayed in the display area 910 via the input unit 200, the overall control unit 300 appropriately aligns the center of the pupil based on the position of the click. The optical head 11 is moved as shown. At this time, the overall control unit 300 performs control so that the incident position of the measuring light 121 is shifted from the corneal vertex, and automatically prevents the reflected light of the measuring light 121 from the cornea of the eye to be examined E from reaching the two-dimensional sensor 162 . adjust.

Further, the user can perform fine alignment adjustment by clicking the button of the alignment adjustment section 902 via the input section 200 . Further, in the display area 910, as described above, the target circle 912 presenting the target position of the pupil is displayed superimposed on the anterior segment image so that the user can easily determine whether the alignment is appropriate. It's becoming Furthermore, in the display area 910, the mark 913 is superimposed on the anterior segment image as described above, and by aligning the bright spot 911 so as to overlap the mark 913, the corneal reflection is less reflected. A fundus image can be acquired. The mark 913 is displayed at a position based on the parameters stored in the storage unit 600, and can be switched between display and non-display with a switch (not shown).

<Step S105 (focus adjustment)>
Subsequently, when the user operates the focus adjustment slider bar 903 while referring to the wide-angle fundus image displayed in the display area 920, the overall control unit 300 controls the wide-angle fundus imaging unit based on the user's operation input value. adjust the focus of Furthermore, the overall control unit 300 drives the focus adjustment mechanism 141 in conjunction with the focus adjustment of the wide-angle fundus imaging unit.

Furthermore, the overall control unit 300 adjusts the aperture diameter of the aperture 107 in conjunction with the movement of the focus adjustment mechanism 141 . For example, when the subject's eye E is myopic, the irradiation area of the fundus Er is narrowed. In this case, the aperture diameter of the aperture 107 is adjusted to be large. In addition, the overall control unit 300 controls the light source 101 in conjunction with the aperture diameter of the aperture 107 so that the amount of light incident on the subject's eye E is approximately constant. In this embodiment, the interlocking between the focus adjustment mechanism 141 and the aperture 107 is performed based on parameters stored in advance in the storage unit 600 .

In the present embodiment, the aperture diameter of the aperture 107 can be manually adjusted, and the irradiation area of the fundus Er can be changed according to the conditions such as miosis of the eye E to be examined to improve the efficiency. It is possible to take pictures in real time.

Regardless of whether the aperture diameter of the aperture 107 is adjusted automatically or manually, the size of the preview area 922 is displayed in conjunction with the area where the measurement light 121 irradiates the fundus Er. It is possible to easily visually recognize the shooting range of .

Note that since the focus adjustment mechanism 141 changes the optical path length, adjustment is facilitated by adjusting the focus prior to the coherence gate adjustment performed in step S107, which will be described later. Also, if the focus is adjusted at a timing different from this step, it is desirable to adjust the coherence gate in conjunction with it.

<Step S106 (selection of shooting position)>
Subsequently, when the user designates a desired preview position via the input unit 200, the overall control unit 300 adjusts the position of the preview area 922 based on the designation.

<Step S107 (coherence gate adjustment)>
Subsequently, when the user presses the coherence gate automatic adjustment button 905 , the general control section 300 determines the coherence gate position based on the brightness value of the image and drives the stage 152 .

Furthermore, the user can finely adjust the coherence gate by sliding the coherence gate adjustment slider bar 904 using the input unit 200 .

<Step S108 (shooting area adjustment)>
Subsequently, while confirming the images displayed in the display areas 930 and 940, the user designates the position and size of the photographing area 921 and the position of the preview area 922 from the input unit 200 so that the desired photographing range is obtained. Then, the overall control unit 300 performs adjustment based on the designation.

<Step S109 (start of shooting)>
Subsequently, when the user presses an imaging button 908 , the overall control unit 300 starts imaging a tomographic image of the subject's eye E based on the imaging region 921 . If the imaging area 921 is specified to be narrower than the preview area 922, the overall control unit 300 steers so that the centers of the imaging area 921 and the preview area 922 are aligned, performs single imaging, and generates single volume data. get. Also, if the shooting area 921 is specified to be wider than the preview area 922, the overall control unit 300 automatically determines the shooting order so that the volume data in the shooting area 921 can be acquired.

FIG. 7 shows an embodiment of the present invention and is a diagram for explaining a volume data acquisition method. In FIG. 7, the same reference numerals are assigned to the same configurations as those shown in FIG.

After the start of imaging in step S109, the overall control unit 300 hides the preview area 922, for example, as shown in FIG. Take pictures alternately. Here, as described above, the steering is controlled by the overall control unit 300 so that the scanner 142 and the scanner 144 move the irradiation position of the measurement light 121 on the fundus Er in the X direction (horizontal direction) and the Y direction (vertical direction). ) in two directions. At this time, the overall control unit 300 sets the amount of steering movement and the amount of overlap between single volume data based on parameters stored in advance in the storage unit 600, and performs control so that the imaging region 921 is included. . Here, including means that the obtained volume data is wider than the area designated by the imaging area 921 . Therefore, it is possible to reliably photograph the area intended by the user. In this embodiment, the parameters such as the amount of steering for single imaging are stored in the storage unit 600 in association with the single volume data.

Furthermore, immediately after the imaging button 908 is pressed, the overall control unit 300 performs single imaging of the approximate center of the imaging region 921, and stores the tomographic image in the partial region 813 in the storage unit 600 as a reference tomographic image. In subsequent single imaging, the overall control unit 300 sequentially performs single imaging so as to be adjacent to the already captured single volume data. Also, based on the result of comparing the tomographic image of the partial region 813 with the reference tomographic image, the overall control unit 300 automatically adjusts the focus and coherence gate position before steering to the next adjacent imaging position. Further, the overall control unit 300 may be configured to adjust the focus or coherence gate position and perform re-shooting when determining that the focus or coherence gate position has shifted significantly. With this configuration, it is possible to always perform single imaging at the optimum focus and coherence gate positions.

Although FIG. 7A shows the case where the aperture shape of the aperture 107 is rectangular, for example, as shown in FIG. 7B, the aperture shape of the aperture 107 is also circular. is applicable. That is, the overall control unit 300 sets the amount of steering movement and the amount of overlap between single volume data based on parameters stored in advance in the storage unit 600, and controls to include the imaging region 921. FIG.

If the shape of the aperture shown in FIG. 7A is rectangular, it is possible to easily set the amount of movement of the steering wheel and the amount of overlap between the single volumes during photographing. On the other hand, when the aperture shape shown in FIG. 7B is circular, it is possible to effectively use the Gaussian beam emitted from the single-mode optical fiber 102-2.

In addition, in FIGS. 7A and 7B, the area for which the single imaging has been completed is shown as an imaging completed area 923 . This photographed area 923 is displayed, for example, in a translucent color in the display area 920 so that the user can easily determine whether or not it is a single photographed area.

In addition, in FIGS. 7A and 7B, an area in which single imaging is being performed is indicated as an area 924 during imaging. This shooting area 924 is displayed in a distinguishable manner in a color different from that of the shooting area 923, for example.

Furthermore, in FIGS. 7A and 7B, an area in which single imaging has not yet been performed is shown as an unimaging area 925 . The unphotographed area 925 is displayed in a distinguishable manner, for example, in a color different from that of the photographed area 923 and the photographed area 924 .

Furthermore, in the display area 920 in FIGS. 7A and 7B, a photographed area 923, a photographed area 924, and an unphotographed area 925 are displayed for areas where single-imaging failed and areas where re-imaging was performed. may be displayed in a distinguishable manner with a color different from that.

The display in the display area 920 shown in FIGS. 7A and 7B described above allows the user to easily grasp the progress of shooting. In this embodiment, an example of distinguishing each area by color display has been described, but a different display method, for example, a method of distinguishing each area by superimposing text, may be used.

After the start of imaging in step S109, the overall control unit 300 controls the movement of the subject's eye E based on the reference wide-angle fundus image stored in the storage unit 600 and the wide-angle fundus image acquired in real time. Detect and track to compensate for motion. For example, every time a part of the wide-angle fundus image is acquired, the overall control unit 300 calculates the amount of movement of the subject's eye E using the phase-only correlation method, and captures an image of approximately the same position of the fundus Er. Then, tracking for driving and controlling the scanners 142 and 144 is performed. This tracking corresponds to tracking in the X and Y directions and is called lateral tracking here. With this configuration, it is possible to realize horizontal tracking at a higher speed than the frame rate of the wide-angle fundus image.

Furthermore, the overall control unit 300 may automatically detect the coherence gate position based on the luminance value of the tomographic image and perform tracking to drive and control the stage 152 . This tracking corresponds to tracking in the Z direction and is called longitudinal tracking here.

<Step S110 (determination of photographing end)>
Subsequently, the overall control unit 300 determines whether or not to end the shooting according to whether or not the user has issued an instruction to end the shooting via the input unit 200 . As a result of this determination, if the photographing is not to be ended (S110/NO), the process returns to step S101, and the processes after step S101 are performed again. It should be noted that at this time, for example, if the selection of the left and right eyes (S101) or the selection of the shooting mode (S102) is set to be omitted, the process returns to step S103, and the processes after step S103 are performed again. may

As a result of the determination in step S110, if the photographing is to be ended (S110/YES), the processing of the flow chart of FIG.

[Method for Controlling Imaging Apparatus 10 (Method for Generating Three-Dimensional Tomographic Image)]
After the end of photographing in step S110 of FIG. Then, the image generator 400 generates a single three-dimensional tomographic image from the single volume data, and then aligns and stitches together a plurality of single three-dimensional tomographic images to generate a three-dimensional tomographic image. Generate.

First, a method for generating a single three-dimensional tomographic image will be described with reference to FIG.
FIG. 8 is a flow chart showing an example of a processing procedure in a method for generating a single three-dimensional tomographic image of the imaging device 10 according to the embodiment of the present invention.

<Step S201 (alignment)>
First, the image generator 400 aligns a series of interference images in a single volume data. At this time, the image generation unit 400 uses the interference image acquired at the wavelength with the highest intensity in the spectrum data of the light source 101 as a reference image, performs correlation calculation of the interference images, and aligns the interference images.

<Step S202 (Acquisition of interference signal at coordinates (Xi, Yi))>
Subsequently, the image generator 400 acquires an interference signal at coordinates 812 (Xi, Yi) shown in FIG. 4(a).

<Step S203 (spectrum processing)>
Subsequently, the image generator 400 performs spectral processing on the interference signal acquired in step S202. Specifically, the image generator 400 first multiplies the spectral data by an appropriate magnification and subtracts it from the interference signal. Further, in the present embodiment, since interference signals are acquired at equal wavelength intervals, the image generator 400 performs rescaling so that interference signals are obtained at equal wavenumber intervals. Furthermore, the image generation unit 400 performs dispersion correction of the interference signal based on parameters that are measured in advance and stored in the storage unit 600 .

<Step S204 (window function processing)>
Subsequently, the image generation unit 400 multiplies the interference signal, which has undergone spectral processing in step S203, by the Hanning function as a window function. Note that the window function used in the process of step S204 is not limited to the Hanning function exemplified here, and it is also possible to use, for example, a rectangular function, a Tukey function, or the like.

<Step S205 (FFT calculation)>
Subsequently, the image generation unit 400 performs FFT operation on the interference signal subjected to the window function processing in step S204 to obtain a tomographic signal. An example of the tomographic signal acquired in step S205 is the tomographic signal 830 shown in FIG. 4(c).

<Step S206 (storage)>
Subsequently, the image generation unit 400 stores the data of the tomographic signal acquired in step S205 in the storage unit 600. FIG.

<Step S207 (determination of necessity of calculation of next coordinates)>
Subsequently, for example, the image generation unit 400 (or the overall control unit 300) determines whether the index i is smaller than the total number N of coordinates.

<Step S208 (Set Next Coordinates)>
As a result of the determination in step S207, if the index i is smaller than the total number N of coordinates (S207/YES), it is determined that there are coordinates that have not yet been calculated, and the process proceeds to step S208. After proceeding to step S208, for example, the image generation unit 400 (or the overall control unit 300) sets the next index (i++). After that, the process returns to step S202, and the processes after step S202 are performed again.

On the other hand, as a result of the judgment in step S207, if the index i is not smaller than the total number N of coordinates (S207/NO), it is judged that calculation processing has been performed for all coordinates, and the processing of the flowchart of FIG. 8 ends. .

A single three-dimensional tomographic image can be generated by performing the processing of the flowchart of FIG.

Next, a method for generating a three-dimensional tomographic image will be described with reference to FIG.
FIG. 9 is a flow chart showing an example of a processing procedure in a method for generating a three-dimensional tomographic image of the imaging device 10 according to the embodiment of the present invention.

<Step S301 (alignment)>
First, the image generating unit 400 aligns a plurality of single three-dimensional tomographic images based on parameters such as the amount of steering and the amount of overlap stored in the storage unit 600 . Specifically, the image generator 400 identifies adjacent single three-dimensional tomographic images from the steering amount, performs correlation calculation based on the expected overlapping region, and determines the position of the single three-dimensional tomographic image.

<Step S302 (bonding)>
Subsequently, based on the position determined in step S301, the image generation unit 400 performs averaging processing on overlapping regions, and stitches together single three-dimensional tomographic images. After that, the processing of the flowchart of FIG. 9 ends.

A three-dimensional tomographic image can be generated by performing the processing of the flowchart of FIG. Then, the generated three-dimensional tomographic image is trimmed based on the size specified by the imaging region 921 under the control of the display control unit 500 and displayed on the display unit 700 .

[Operation of light source 101 and two-dimensional sensor 162]
Next, the operation method of the light source 101 and the two-dimensional sensor 162 shown in FIG. 3 will be described using the timing chart shown in FIG.
FIG. 10 shows the embodiment of the present invention and is a timing chart showing an example of the operation method of the light source 101 and the two-dimensional sensor 162 shown in FIG.

In the present embodiment, a plurality of single shots are taken of the same location on the fundus Er of the subject's eye E in order to improve the signal-to-noise ratio by multiple single shots by steering and superposition processing. It also includes the case of re-imaging after adjustment of the coherence gate position.

<First embodiment>
First, a first embodiment of the operating method of the light source 101 and the two-dimensional sensor 162 shown in FIG. 3 will be described.

FIGS. 10(1a) to 10(1c) are timing charts showing time-series operations of the operation method of the light source 101 and the two-dimensional sensor 162 in the first example of the present embodiment. Specifically, FIG. 10(1a) shows the timing of the trigger signal generated by the overall control unit 300, FIG. 10(1b) shows the timing of the wavelength scanning operation of the light source 101, and FIG. The timing of the exposure operation of the two-dimensional sensor 162 is shown.

In the first embodiment, the overall control unit 300 performs control to link (synchronize) the operation of the light source 101 and the operation of the two-dimensional sensor 162 using the trigger signal 1001 shown in FIG. 10(a) as a reference. Specifically, the overall control unit 300 interlocks the operation of changing the wavelength of the light output from the light source 101 shown in FIG. 10(1b) and the exposure operation of the two-dimensional sensor 162 shown in FIG. 10(1c). control. At this time, the overall control unit 300 controls the operation of changing the wavelength of the light output from the light source 101 in steps as shown in FIG. 10(1c).

The processing of the first embodiment will be described in detail below.
The general control section 300 detects the rise of the trigger signal 1001 shown in FIG. 10(1a). Then, based on the detection and preset parameters, the overall control unit 300 switches the single wavelength section 1011 from the scan start wavelength 1010 of the light source 101 to stepwise scan the light source 101 as shown in FIG. 10(1b). wavelength scan. By making the wavelength scan stepwise as shown in FIG. 10(1b), it is possible to obtain a signal with a single wavelength during the timing of the exposure operation of the two-dimensional sensor 162, thereby improving the resolution. is possible.

The two-dimensional sensor 162 operates with a global shutter and operates at intervals of the exposure section 1081 shown in FIG. 10(1c). Based on the trigger signal 1001 , the overall control unit 300 causes the two-dimensional sensor 162 to suspend the current exposure operation shown in the exposure interval 1080 and restart the exposure operation in the exposure interval 1081 . According to this control, data with insufficient exposure is removed from an image (such as a tomographic image) generated by the image generation unit 400, and it is possible to acquire a tomographic image or the like with good image quality.

The overall control unit 300 controls the light source 101 to return to the scan start wavelength 1010 after performing wavelength scanning with a predetermined number of wavelength steps. In FIGS. 10(1a) to 10(1c), section 1030 corresponds to one wavelength scan. A flyback section 1020 is an operation section in which a scanner (not shown) used inside the light source 101 for wavelength scanning returns to its initial position. In this flyback section 1020, the overall control unit 300 controls the light source 101 to be turned off. In this case, since the light source 101 is turned off, the flyback section 1020 becomes an exposure section 1083 in which the two-dimensional sensor 162 does not capture the fundus Er. According to this control, invalid data is removed from an image (such as a tomographic image) generated by the image generating unit 400, and it is possible to acquire a tomographic image or the like with good image quality.

Furthermore, overall control unit 300 performs control so that the above-described steering is performed in flyback section 1020 . According to this control, efficient high-speed imaging can be performed. In the flyback section 1020, the overall control unit 300 may adjust the coherence gate position based on the tomographic image of the partial region 813. In this case, more efficient high-speed imaging can be performed. be.

<Second embodiment>
Next, a second embodiment of the operation method of the light source 101 and the two-dimensional sensor 162 shown in FIG. 3 will be described. In the following description of the second embodiment, the description of matters common to the first embodiment will be omitted, and the differences from the first embodiment will be described.

FIGS. 10(2a) to 10(2c) are timing charts showing time-series operations of the operation method of the light source 101 and the two-dimensional sensor 162 in the second example of the present embodiment. Specifically, FIG. 10(2a) shows the timing of the exposure operation of the two-dimensional sensor 162, FIG. 10(2b) shows the exposure timing signal generated by the two-dimensional sensor 162, and FIG. The timing of the wavelength scanning operation of the light source 101 is shown.

In the first embodiment described above, the overall control unit 300 performs control to link the operation of the light source 101 and the operation of the two-dimensional sensor 162 based on the trigger signal 1001 generated by its own processing. . On the other hand, in the second embodiment, the operation of the light source 101 and the operation of the two-dimensional sensor 162 are controlled based on the exposure timing signal of the two-dimensional sensor 162 shown in FIG. 10(2b). be. In the second embodiment, the overall control unit 300 generates the trigger signal 1001 based on the exposure timing signal generated by the two-dimensional sensor 162 (that is, based on the exposure operation of the two-dimensional sensor 162). sell.

The processing of the second embodiment will be described in detail below.
The two-dimensional sensor 162 generates an exposure timing signal 1005 for each exposure that converts light into a signal. The overall control unit 300 causes the light source 101 to start wavelength scanning every predetermined number of exposure timing signals 1005 . Further, in the case of the second embodiment, the overall control unit 300 interlocks the operation of the light source 101 and the operation of the two-dimensional sensor 162 , so that the light source 101 is controlled during the standby interval 1021 separately from the flyback interval 1020 . are also driven to maintain the light-off state. With this control, the light source 101 performs wavelength scanning of the light source 101 stepwise from a single wavelength section 1012 (the same wavelength as the single wavelength section 1011) after the standby section 1021 has passed. By this control, the operation of the single wavelength section 1012 of the light source 101 is interlocked with the operation of the exposure section 1081 of the two-dimensional sensor 162 . According to this control, the exposure operation of the two-dimensional sensor 162 can be interlocked with the operation of the light source 101 without interruption.

<Third embodiment>
Next, a third embodiment of the operating method of the light source 101 and the two-dimensional sensor 162 shown in FIG. 3 will be described. In addition, in the description of the third embodiment described below, the description of matters common to the first and second embodiments described above will be omitted, and the matters different from those of the first and second embodiments described above will be omitted. I will explain about.

FIGS. 10(3a) and 10(3b) are timing charts showing time-series operations of the operation method of the light source 101 and the two-dimensional sensor 162 in the third example of the present embodiment. Specifically, FIG. 10(3a) shows the timing of the exposure operation of the two-dimensional sensor 162, and FIG. 10(3b) shows the timing of the wavelength scanning operation of the light source 101. As shown in FIG.

In the first and second embodiments described above, the trigger signal 1001 and the exposure timing signal 1005 are used to control the operation of the light source 101 and the operation of the two-dimensional sensor 162 in conjunction with each other. On the other hand, in the third embodiment, the operation of the light source 101 and the operation of the two-dimensional sensor 162 are interlocked without using the trigger signal 1001 and the exposure timing signal 1005 . In this third embodiment, the overall control unit 300 compares the luminance information of the interference image based on the interference signal obtained by the two-dimensional sensor 162 detecting the interference light 124 with the luminance information of the reference image. It controls the operation of changing the wavelength of the light output from the light source 101 .

The processing of the third embodiment will be described in detail below.
In the present embodiment, the interference image of the partial region 813 is sent from the image generation unit 400 to the overall control unit 300 in real time during imaging. At this time, the overall control unit 300 acquires luminance information of the interference image of the partial area 813 (hereinafter referred to as “partial luminance information”) from the received interference image of the partial area 813 . Here, in this embodiment, the average brightness of the interference image of the partial area 813 is used as the partial brightness information.

Then, the overall control unit 300 compares the acquired partial brightness information with the reference partial brightness information, and detects an exposure section 1085 with low partial brightness information shown in FIG. 10(3a). Here, the reference partial brightness information is the average brightness of the interference image (reference image) for each wavelength acquired in advance and stored in the storage unit 600 .

If the exposure timing is inappropriate, the exposure interval 1086 shown in FIG. 10(3a) becomes interference signals of a plurality of different wavelengths, resulting in reduced resolution. Therefore, the overall control section 300 sets the adjustment section 1022 based on the exposure section 1087 and the exposure section 1085 at the end of one wavelength scan. In the case of the third embodiment, in order to link the operation of the light source 101 and the operation of the two-dimensional sensor 162, the overall control unit 300 turns off the light source 101 during the adjustment interval 1022 in addition to the flyback interval 1020. drive to maintain the state of With this control, the light source 101 scans the wavelength of the light source 101 stepwise from a single wavelength section 1013 (the same wavelength as the single wavelength section 1011) after the adjustment section 1022 has passed. By this control, the operation of the single wavelength section 1013 of the light source 101 is linked to the operation of the exposure section 1088 of the two-dimensional sensor 162 . According to this control, the exposure operation of the two-dimensional sensor 162 can be interlocked with the operation of the light source 101 without interruption.

As described above, the imaging apparatus 10 according to the embodiment of the present invention includes the coupler 103 (light splitter) that splits the light from the light source 101 into the measurement light 121 and the reference light 123, and the measurement light 121 to the measurement target T. The ocular optical system 140 (irradiation means) for irradiating a two-dimensional area of the eye to be examined E (more specifically, the fundus Er of the eye to be examined E), and a light receiving element arranged two-dimensionally. A two-dimensional sensor 162 (detecting means) that detects interference light 124 obtained by causing interference between the return light 122 from the eye examination E and the reference light 123, and the operation of the light source 101 and the operation of the two-dimensional sensor 162 are interlocked. It is configured to have an overall control unit 300 (control means) that performs control.
According to such a configuration, it is possible to acquire a tomographic image with good image quality by high-speed imaging.

(Other embodiments)
In the embodiment of the present invention described above, an example in which the subject's eye E is applied as the measurement target T has been described, but the present invention is not limited to this subject's eye E. In the present invention, an object other than the subject's eye E can also be applied as the measurement object T as long as it is an object for which a tomographic image can be captured using the light source 101 . That is, in the present invention, the photographing device 10 is not limited to an ophthalmic photographing device.

The present invention supplies a program that implements one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and one or more processors in the computer of the system or device reads and executes the program. It can also be realized by processing to It can also be implemented by a circuit (for example, ASIC) that implements one or more functions.
This program and a computer-readable storage medium storing the program are included in the present invention.

10: Imaging Device, 100: Optical System, 101: Light Source 101, 102-1 to 102-3: Optical Fiber, 103: Coupler, 104: Collimating Lens, 105: Beam Splitter, 107: Aperture, 140: Eyepiece Optical System, 150 : reference optical system, 160: light receiving optical system, 200: input unit, 300: overall control unit, 400: image generation unit, 500: display control unit, 600: storage unit, 700: display unit, T: measurement target, E : eye to be examined, Er: fundus

Claims (8)

a light source that outputs stepwise swept light by switching a single wavelength interval;
an optical branching means for branching the light from the light source into measurement light and reference light;
irradiating means for irradiating a two-dimensional area of a measurement target with the measurement light;
a detecting means including light receiving elements arranged two-dimensionally, and detecting interference light obtained by causing the return light of the measurement light from the object to be measured to interfere with the reference light at a predetermined exposure timing ; ,
control means for performing control to interlock the operation of the light source and the operation of the detection means so that the predetermined exposure timing is within the single wavelength interval ;
A photographing device characterized by comprising: 2. The photographing apparatus according to claim 1, wherein said control means performs control for interlocking an operation of changing the wavelength of said light output from said light source and an exposure operation of said detection means. 3. The photographing apparatus according to claim 1, wherein the control means uses the generated trigger signal to perform control to interlock the operation of the light source and the operation of the detection means. 4. The photographing apparatus according to claim 3 , wherein the detection means interrupts the current operation and restarts the operation by the control using the trigger signal. 4. A photographing apparatus according to claim 3 , wherein said control means generates said trigger signal based on the operation of said detection means. The control means controls the intensity of the light output from the light source based on a result of comparing luminance information of an interference image based on an interference signal obtained by detecting the interference light by the detection means with luminance information of a reference image. 3. The imaging apparatus according to claim 2, wherein said control of the operation of changing the wavelength is performed. The apparatus further comprises generating means for generating a tomographic image of the measurement object using an interference signal obtained by detecting the interference light in the detecting means whose operation is controlled by the control means. Item 7. The imaging device according to any one of Items 1 to 6 . A light source that outputs light that is swept stepwise by switching a single wavelength interval, an optical splitter that splits the light from the light source into measurement light and reference light, and a two-dimensional area to be measured from the measurement light. and light receiving elements arranged two-dimensionally, wherein interference light obtained by causing the return light of the measurement light from the object to be measured to interfere with the reference light for a predetermined exposure A method of operating an imaging device comprising a detection means for detecting at timing,
A method of operating a photographing device, characterized in that the photographing device controls the operation of the light source and the operation of the detecting means to be interlocked so that the predetermined exposure timing is within the single wavelength interval. .

Images