JP2021183280A - Imaging device, and operation method and program of the imaging device - Google Patents

Abstract

To facilitate positioning, focusing, and quality determination of a captured image irrespective of a scanning pattern.SOLUTION: An imaging device includes: first scanning means and second scanning means for reciprocatively scanning measurement light separated from light source light in first and second directions in a predetermined range on an ocular fundus; scanning control means for controlling the scanning by the first scanning means and the second scanning means so as to be executed simultaneously; depth information acquisition means for acquiring information in a depth direction of the ocular fundus on the basis of interference light between return light from the ocular fundus of the measurement light and reference light separated from the light source light; image generation means for generating a tomographic image in a predetermined range by using output of the depth information acquisition means and a control signal of the scanning control means; and display means for displaying the generated image. A tomographic image along an arbitrary line in a predetermined range can be generated by using output of the depth information acquisition means, and the tomographic image along the arbitrary line is displayed repeatedly in the display means before the depth information is acquired by the simultaneous reciprocative scanning by the two scanning means.SELECTED DRAWING: Figure 8

Description

The present invention relates to an image pickup device that obtains an image of the test object by scanning light on the test object, a control method and a program of the image pickup device.

Currently, as a method for non-invasively observing the internal structure of the eye, an optical coherence tomography apparatus (hereinafter referred to as OCT apparatus) using an optical coherence tomography (hereinafter referred to as OCT) to which an optical interference phenomenon is applied is used. ) Is used. In the OCT apparatus, the light emitted from the low-infrared coherent light source is divided into the measurement light and the reference light. Then, by interfering the diffusely reflected light of the measurement light radiated to the eye with the reference light, high-resolution and high-sensitivity tomographic information is obtained in the depth direction (measurement optical axis direction).

Conventionally, as a scanning mode of the measurement light of the OCT device in the eye, particularly the fundus, a raster scan in which the scanning of the measurement light in the X direction is repeated while shifting in the Y direction perpendicular to the X direction has been used. On the other hand, there is a technique for three-dimensionally obtaining tomographic information of the object to be inspected by scanning the object to be inspected in a plane so that the measurement light draws a Lissajous figure (hereinafter referred to as Lissajous scan). (See Patent Document 1 and Non-Patent Document 1).

In the case of raster scan, there is a difference in the acquisition time of tomographic information between, for example, the first scan position and the last scan position in the Y direction of the measurement light. That is, there is a difference in the acquisition time of tomographic information depending on the part on the fundus. When the object to be inspected is the eye, the eye constantly makes a movement called fixation tremor, so in the case of raster scan, it is necessary to deal with the movement of the part on the fundus that may expand due to this time difference. Become. On the other hand, in the case of the Lissajous scan, since the measurement light is scanned so as to draw a loop with a certain width, the difference in the acquisition time of the tomographic information in this loop becomes small. In the Lissajous scan, the tomographic information from the plurality of loops thus obtained is combined to generate three-dimensional tomographic information. Therefore, it is not necessary to consider the influence of the time difference due to the difference in the site where the tomographic information is acquired, and it becomes easier to deal with the fixation tremor in the Lissajous scan as compared with the case of the raster scan.

Japanese Unexamined Patent Publication No. 2016-017915

Yiwei Chen, Young-Joo Hong, Shuichi Makita and Yoshiaki Yasuno "Correction of eye motion artifacts in three-dimensional optical coherence tomography imaging based on the Lissajous scanning pattern", Optical Society of America (2016)

When acquiring tomographic information using an OCT device, adjustment of imaging conditions such as positioning of the measurement light scanning position to the site where tomographic information is acquired, focusing conditions of the measurement light, and optical path length difference between the measurement optical path and the reference optical path. Is required. At that time, a two-dimensional tomographic image in the depth direction of the fundus that can be observed by the subject or the imaging conditions can be confirmed by signal processing is acquired, and these imaging conditions are adjusted based on the two-dimensional tomographic image. Is commonly done. Further, the two-dimensional tomographic image is required to be continuously acquired and displayed for a certain period of time so as to be stably displayed until such adjustment is completed.

As described above, in the Lissajous scan, the tomographic information from the fundus is acquired by continuously changing or moving the elliptical scanning locus drawn by the measurement light. In the case of such a scanning mode of measurement light, the part where tomographic information is acquired is constantly changing. Therefore, in order to acquire the tomographic information from the same site twice, the scanning of the series of measurement lights after the scanning of the site is completed and the order of the scanning loci from which the tomographic information of the site is acquired is turned again. It takes time. This time is longer than the time during which the subject can maintain the fixed vision state so that the site does not move, and as a result, it becomes difficult to acquire tomographic information from the same site. Therefore, in the case of a measurement light scanning mode such as a resage scan, in the above-mentioned display of the two-dimensional tomographic image, a series of measurement light scans are performed to acquire three-dimensional tomographic information, and these three-dimensional faults are displayed. It is necessary to generate a two-dimensional tomographic image for adjusting the imaging conditions described above from the information. That is, in such a scanning mode of measurement light, a series of three-dimensional tomographic information must be acquired once in order to obtain imaging conditions, and a two-dimensional tomographic image generated on the acquisition must be displayed. It takes more than a certain amount of time.

The present invention has been made in view of the above circumstances, and adjusts the conditions for acquiring information when scanning light to obtain information on an inspected object so as to draw a figure such as a Lissajous figure. It is an object of the present invention to provide an image pickup device, a control method of the image pickup device, and a program capable of stably providing an image for the purpose in a relatively short time.

In order to solve the above problems, the image pickup apparatus according to one aspect of the present invention is
An optical separation means that separates the light emitted from the light source into the measurement light and the reference light,
A first scanning means for reciprocating scanning the measurement light in a predetermined range on the object to be inspected, and a second scanning means for reciprocating the measurement light in a second direction different from the first direction. Scanning means and
A first scan composed of a straight line or a curve having an angle of a predetermined angle or more with respect to the first direction by simultaneously driving the first scanning means and the second scanning means. A scanning control means for controlling the first scanning means and the second scanning means by giving a first control signal so as to scan two-dimensionally and comprehensively with the measurement light on the locus.
A light receiving means that receives interference light between the return light and the reference light scanned by the measurement light using the first scanning means and the second scanning means.
Depth information acquisition means for obtaining information in the depth direction of the object to be inspected on the first scanning locus based on the output of the light receiving means.
An image generation means that generates a tomographic image of the object to be inspected in the predetermined range by using the output of the depth information acquisition means and the first control signal.
A display means capable of displaying at least the output of the image generation means is provided.
The image generation means can generate a tomographic image along an arbitrary line within the predetermined range by using the output of the depth information acquisition means.
The display means is characterized in that a tomographic image along the arbitrary line is repeatedly displayed before the depth information is acquired by the first scanning locus.

According to the present invention, when information on an object to be inspected is obtained by scanning light so as to draw a figure such as a Lissajous figure, an image for adjusting conditions for information acquisition is stable in a relatively short time. It will be possible to provide to.

It is a figure which shows the schematic structure of the OCT apparatus used in the Example of this invention. It is a figure which shows the drive voltage waveform applied to the scanner when scanning the measurement light so as to draw a Lissajous figure with the measurement light. It is a figure explaining the scanning mode of the measurement light at the time of performing the drawing of the Lissajous figure by the measurement light by a scanner. It is a figure which shows an example of the fundus plane image obtained by arranging the 3D tomographic information obtained by the Lissajous scan in the order of the information acquisition position on the fundus. It is a figure which shows an example of the fundus plane image obtained by rearranging the fundus plane image shown in FIG. 4 using scanning position information. It is a figure which shows an example of the display style which displays the acquisition range of the fault information. It is a figure which shows an example of the 2D tomographic image displayed for confirming the imaging condition. It is a flowchart which shows the process of the image display processing which displays the 2D tomographic image in Example 1 of this invention. It is a figure which shows the schematic structure of the modification of the OCT apparatus used in the Example of this invention. It is a figure which shows an example of the fundus plane image obtained by arranging the 3D tomographic information obtained by the resage scan in the order of the information acquisition position on the fundus in Example 2 of this invention. It is a figure which shows the display example of the display device which displays each image obtained in Example 2. FIG.

Examples of the present invention will be described in detail below with reference to the drawings. The shape described in the following examples, the relative positions of the components, and the like are arbitrary and can be changed according to the configuration of the device to which the present invention is applied or various conditions. Also, in the drawings, the same reference numerals are used between the drawings to indicate elements that are the same or functionally similar.

<Device configuration>
FIG. 1 shows the overall configuration of the optical tomography imaging apparatus used in this embodiment. The OCT device 100 according to this embodiment includes an OCT optical system, a control device 109, a control PC 111, and a display device 112. Further, the OCT optical system has a low coherence light source 101, a beam splitter 103, a scanning optical system 104, an eyepiece system 105, a reference mirror 107, and a detection unit 110 as main configurations. Although the control PC 111 can be configured by using an arbitrary general-purpose computer, it may be a computer dedicated to the OCT device. The display device 112 can be configured by any display. Further, although the control device 109, the control PC 111, and the display device 112 are shown individually, they may be integrated as appropriate. The control PC 111 is accompanied by an input device for inputting measurement parameters of the OCT device, selecting various modes for acquiring data, and reading and executing a measurement program stored in advance. The input device may be arranged on the display device 112 side.

The light emitted from the low coherence light source 101 passes through an optical fiber and becomes parallel light by the fiber collimator 102. This parallel light is split into measurement light and reference light by the beam splitter 103.

The measurement light is applied to the eye 120 to be inspected through the scanning optical system 104 and the eyepiece lens system 105, which are composed of two galvano mirrors controlled by the control device 109. The two galvano mirrors include an X galvano mirror that changes the irradiation position of the measurement light in the X direction and a Y galvano mirror that changes the irradiation position of the measurement light in the Y direction orthogonal to the X direction. By operating these two galvano mirrors, the scanning optical system 104 can change the irradiation position of the measured light on the fundus in two dimensions. Further, the eyepiece system 105 is on the electric stage and can move in the optical axis direction according to the control signal of the control device 109. By moving the eyepiece system 105 in the optical axis direction, the focal position of the measurement light can be changed. The return light reflected or scattered from the fundus passes back through the above path and is returned to the beam splitter 103 via the eyepiece system 105 and the scanning optical system 104. The path through these optical systems to which the measurement light is guided is called a measurement optical path.

On the other hand, the reference light is reflected from the reference mirror 107 through the dispersion compensating glass 106, and is returned to the beam splitter 103 through the same path in the opposite direction. The reference mirror 107 is installed on an electric stage that moves in the optical axis direction, and can move its position in the optical axis direction according to a control signal of the control device 109. By adjusting the position of the reference mirror 107, the reference optical path length, which is the optical path length of the reference light, can be adjusted. The dispersion compensating glass 106 has a configuration in which two dispersion prisms having the shape of a right triangle are arranged so that their hypotenuses face each other. The reference optical path length can also be adjusted by shifting the positions of these dispersion prisms. Normally, since the optical systems constituting the measurement optical path and the reference optical path are different, the amount of wavelength dispersion of each is different, which is not the optimum interference condition. By inserting the dispersion compensating glass 106 in the reference optical path in order to adjust the wavelength dispersion amount, the optimum interference condition is obtained.

The return light reflected or scattered from the fundus of the eye 120 to be inspected and the reference light reflected by the reference mirror 107 are combined by the beam splitter 103. When the optical path length of the measurement light and the optical path length of the reference light are the same length, this combined light becomes interference light showing interference fringes. Since each of these interference fringes corresponds to a layer or the like in the back of the fundus, information (tomographic information) in the depth direction of the fundus can be obtained by analyzing the interference fringes. The interference light is input to the optical fiber by the fiber collimator 108 and input to the detection unit 110. The detection unit 110 includes a diffraction grating that disperses the input interference light and a line sensor unit that detects the dispersed light, and the line sensor unit converts the dispersed light into a digital detection signal and the detection signal. Is sent to the control device 109.

The control device 109 sends a detection signal to the control PC 111. The control PC 111 has a processing unit (not shown) that executes image forming processing software that generates an image of the fundus. The processing unit operates as a module corresponding to various steps in the image generation process described later, and executes these steps using the input detection signal. By executing these steps, the OCT device generates tomographic information used to generate a tomographic image at a position on the fundus irradiated with the measurement light.

As the OCT device used in this embodiment, a Fourier domain type OCT (FD-OCT) device that acquires the depth information of the measurement target included in the detected light by replacing it with the frequency information is exemplified. Further, as the FD-OCT (Fourier Domain Optical Coherence Tomography) device, a spectral domain type OCT (SD-OCT) device is particularly exemplified. However, the OCT device to be used is not limited to this, and for example, a wavelength sweep type OCT (SS-OCT) device may be used as the FD-OCT device. It is also possible to use other known OCT devices.

<Scan method>
In this embodiment, when a three-dimensional tomographic image is imaged from the fundus of the eye using the above-mentioned OCT device, a two-dimensional tomographic image is acquired in advance and the two-dimensional tomographic image is displayed. Then, by observing the displayed two-dimensional tomographic image or the like, it is determined whether or not the imaging condition needs to be adjusted, and further the adjustment is performed. In the following description, the Lissajous scan for acquiring a three-dimensional tomographic image will be described first in this embodiment. As described above, in the Lissajous scan, the measurement light is scanned so as to draw a Lissajous figure on the fundus.

The drive waveform of the galvano mirror when drawing a Lissajous figure with the measurement light will be described with reference to FIGS. 2 and 1. For convenience of explanation, the galvano mirror that scans the measurement light in the X axis in an arbitrary direction on the bottom surface of the eye is referred to as the X galvano mirror, and similarly, the galvano mirror that scans the measurement light in the Y axis direction on the bottom surface of the eye is the Y galvano mirror. Make it a mirror. Although the X-axis and the Y-axis are generally orthogonal to each other, they do not necessarily have to be orthogonal to each other.

When drawing a Lissajous figure with the measurement light, the X galvano mirror and the Y galvano mirror are given cosine waves having _{different periods T x} and T _{y as voltage signals for driving.} In this case, since the period is different, when one of the sine waves reaches the period, the other sine wave is less than the period or has passed the period and is in a state of transitioning to the next period. ..

ただし、式１において、０≦ｔ_ｘ＜Ｔ_ｘ、０≦ｔ_ｙ＜Ｔ_ｙであり、ｔ＝（Ｌ_ｘ-１）Ｔ_ｘ+ｔ_ｘ＝（Ｌ_ｙ-１）Ｔ_ｙ+ｔ_ｙである。
ここで、ｆ（ｔ）はガルバノミラーの駆動開始からｔ秒経過した時点の、リサージュ軌跡の位置を示し、Ａ_ｘおよびＡ_ｙはＸガルバノミラーおよびＹガルバノミラーの駆動波形の振幅を示す。Ｌ_ｘおよびＬ_ｙは各々の駆動波形である余弦波において、時刻ｔの点が何周期目であるかを表すインデックスである。なお、図２の例では、Ａ_ｘ＝Ａ_ｙ＝４［Ｖ］、Ｔ_ｘ＝８［ｍｓ］、およびＴ_ｙ＝９［ｍｓ］の条件となる場合を例示している。 That is, as two cosine waves represented by the following equation 1, a drive waveform whose phase shifts with each cycle is applied to each galvano mirror to drive them.

However, in Equation 1, 0 ≦ t _x <T _x , 0 ≦ _ty <T _y , and t = (L _x -1) T _x + t _x = (L _y -1) T _y + _ty . be.
Here, f (t) indicates the position of the Lissajous orbit at the time when t seconds have elapsed from the start of driving the galvano mirror, and A _x and _Ay indicate the amplitudes of the driving waveforms of the X galvano mirror and the Y galvano mirror. L _x and _Ly are indexes indicating the cycle number of the point at time t in the cosine wave which is each drive waveform. In the example of FIG. 2, the case where the conditions are A _x = A _y = 4 [V], T _x = 8 [ms], and T _y = 9 [ms] is illustrated.

FIG. 3 shows the trajectory of the measured light when the galvano mirror is driven using the drive waveform shown in FIG. 2 and the fundus is scanned with the measured light. When the galvano mirror is driven by the drive waveform, the locus of the measurement light drawn on the fundus is plotted for each cycle of the Y galvano mirror. In this case, eight patterns of annular loci 301 are obtained, and the Lissajous figure 302 is obtained by assembling (synthesizing) these annular loci 301. Hereinafter, for convenience of explanation, this annular locus 301 obtained for each cycle of the Y galvanometer mirror will be referred to as a loop. Here, the loop may be a locus for each period of the X galvano mirror.

[Example 1]
As a specific embodiment of the present invention, a case where tomographic information is acquired from the human eye retina (fundus of the eye to be inspected 120) of the inspected object will be described. In this case, when driving both galvano mirrors, the drive waveform represented by the following equation 2 will be applied.

ここで、Ａ_ｘおよびＡ_ｙは、被検眼１２０の眼底上で６×６ｍｍの範囲でリサージュ図形を描画するように測定光で走査するよう、制御装置１０９により調整される。ｔ_ｉは、ｉ番目の断層情報を取得する際のサンプリング時刻を表す。ここで、１ループにおけるサンプリング数＃Ａ＝１０２４として、走査範囲全体からは#Ａ^２／２＝５２４，２８８点でのサンプリングを実行することになる。この場合、検出部１１０のラインセンサにおける断層情報の取得レートをｆ_Ａ＝７０ｋＨｚとすると、測定光にて上述した走査範囲を走査するために要する走査時間は約７．５秒となる。

Here, _Ax and _Ay are adjusted by the control device 109 to scan with the measurement light so as to draw a Lissajous figure in a range of 6 × 6 mm on the fundus of the eye to be inspected 120. t _i represents the sampling time when acquiring the i-th fault information. Here, as the sampling number # A = 1024 in one loop, and executes sampling at ^#A 2/2 = 524,288 points from the entire scan range. In this case, assuming that the acquisition rate of tomographic information in the line sensor of the detection unit 110 is f _A = 70 kHz, the scanning time required to scan the above-mentioned scanning range with the measurement light is about 7.5 seconds.

The interference signal based on the interference light from the sampling point acquired by such scanning is converted into a wavenumber function. Further Fourier transform processing is executed on the obtained wavenumber function, and the luminance value at the sampling point is obtained by extracting the amplitude value of the obtained complex number data. By Fourier transforming the data sequence on the wavenumber axis in this way, it is possible to obtain tomographic information at each sampling point in the fundus.

The tomographic information obtained by the above-mentioned processing is a data string of luminance values arranged in the depth direction. For one of such data strings, for example, by calculating the average value of the luminance values, a representative value at each sampling point on the fundus can be obtained. A fundus image can be obtained by converting a representative value of this luminance value into a logarithmic display and arranging the obtained value as a pixel value. FIG. 4 shows a fundus image 401 obtained by arranging the obtained representative values in chronological order for each loop.

In the figure, the horizontal axis corresponds to sampling time t _i, i is increased as the go right direction, corresponding to the representative values obtained after loop drawing. Further, 1024 points of representative values for one loop are arranged in one column, and each time the representative value column of each loop is displayed, the row is changed and arranged downward. That is, the vertical axis in FIG. 4 corresponds to the order of the loops drawn when drawing the Lissajous figure. Figure 5 is a fundus image 501 representative values displayed in a manner, corresponds to a time t _i obtained by relocating on the basis of the information of the imaging position determined by equation 2 shown in FIG. 4 ..

As shown in FIG. 4, when tomographic information is obtained by Lissajous scan, the imaging position is constantly changing when viewed in chronological order. Therefore, when trying to see a tomographic image by cutting out a part, in order to see the tomographic image at the same position as the tomographic image, one Lissajous figure is drawn from the loop corresponding to the tomographic image and the next When drawing a Lissajous figure, you need to wait until the loop is drawn. For example, when the focus position is adjusted by the eyepiece system 105 or the depth position (coherence gate position) is adjusted by the reference mirror 107, the tomographic images obtained from the same position are continuously displayed for a certain period of time. desirable. However, in the case of Lissajous scan, it is difficult to display such a tomographic image.

Therefore, in this embodiment, before starting the so-called main imaging in which tomographic information is acquired by the resage scan using the drive waveform shown in Equation 2, the top of the fundus is scanned with the measurement light by a specific scanning line. The obtained tomographic images are displayed continuously. Specifically, on the fundus image 501 obtained by the illustrated procedure, a linear scan along the scanning line 602 is performed at the position of the broken line shown in FIG. 6, and the tomographic image 701 as shown in FIG. 7 is obtained. Is displayed on the display device 112. Such linear scanning of the measurement light is repeated, and the obtained tomographic image 701 is updated in real time and continuously displayed. As a result, imaging conditions such as the acquisition position (imaging position) of 3D tomographic information on the fundus, the focus position of the focusing optical system when focusing the measurement light on the fundus, and the position of the coherence gate on the fundus, etc. Can be easily adjusted. After adjusting the imaging conditions, the control PC 111 gives an instruction to execute the so-called main imaging to acquire tomographic information by Lissajous scan, and the main imaging is started. The switching from the display of the tomographic image 701 to the execution of the main imaging may be performed by a switch or the like separately provided on the control PC 111.

The fundus image 601 shown in FIG. 6 is displayed for determining the imaging position, and it is preferable that the tomographic information acquisition range 603 is superimposed and displayed on the fundus image 601. In this embodiment, the fundus image 501 shown in FIG. 5 described above is obtained by a three-dimensional tomographic information acquisition operation called prescan in advance, but the method for acquiring the fundus image 501 is not limited to this. For example, a known fundus camera, a laser scanning ophthalmoscope (SLO), or the like is added to the above-mentioned OCT device 100, and a fundus image is obtained and displayed using these, and the acquisition range is displayed on the displayed fundus image. It may be superimposed and displayed.

A series of procedures of the imaging process from the adjustment of the imaging conditions described above to the acquisition of the tomographic information by the Lissajous scan and the display of the image generated from the tomographic information will be described below with reference to the flowchart shown in FIG.

When an instruction to acquire a fundus image or three-dimensional tomographic information is input to the control PC 111, the process shown in FIG. 8 is started. When the process is started, in step S801, the control PC 111 reads out the imaging conditions preset as initial values from the storage unit (not shown). At that time, the control PC 111 scans the measurement light along a preset scanning line (for example, in the initial setting, a straight scanning line 602 extending in the X direction in the center of the display screen). It controls the optical system 104. In the subsequent step S802, the control PC 111 acquires tomographic information under the read scanning conditions, and displays the tomographic image 701 generated from the obtained tomographic information on the display device 112.

In step S803, the control PC 111 refers to the tomographic image displayed on the display device 112 and determines whether or not the current imaging conditions are appropriate. The suitability of the imaging conditions is determined by the contrast, the image quality, and, for example, the shape of the macula in the obtained image. As a result of the determination, if the current imaging conditions are appropriate, the control PC 111 shifts the flow to step S804. If it is determined that the imaging conditions are not appropriate, the control PC 111 returns the flow to step S801.

In step S801, the control PC 111 refers to the determination result of step S803 and changes the imaging conditions. For example, if it is recognized that the focusing condition is not met, the control PC111 moves a focusing lens (not shown), and if the position of the coherence gate is inappropriate, the control PC111 is the optical path length of the reference light or the measurement light. Make adjustments. If the imaging position is found to be inappropriate, the OCT device 100 is moved by a drive system (not shown) attached to the OCT device 100, and the positional relationship between the eye subject 120 and the OCT device 100 is changed. Is done. After the adjustment of the imaging conditions is completed, the flow proceeds to step S802 again, and the control PC 111 performs acquisition of tomographic information and display of the tomographic image 701 under the adjusted imaging conditions. The processing loop performed in steps S801 to S803 is executed by the control PC 111 until appropriate imaging conditions are obtained.

In step S804, the control PC 111 acquires tomographic information from the fundus by Lissajous scan under the adjusted imaging conditions (main imaging). The obtained tomographic information is converted into three-dimensional luminance information by each of the above-mentioned processes, and the luminance information is selected so as to have a preset display mode. The tomographic image or the like obtained as a result is displayed on the display device 112 by the control PC 111. After displaying the tomographic image and the like, the imaging process ends. By displaying the tomographic image obtained by performing the linear scanning of the measurement light in this way for adjusting the imaging conditions before performing the main imaging by the Lissajous scan, the imaging conditions can be easily adjusted. In addition, it is possible to estimate the image quality of the image that will be obtained in advance for the three-dimensional tomographic information (image) obtained in this imaging.

In the imaging process shown in FIG. 8, the fundus image 601 for adjusting the imaging conditions shown in FIG. 6 is not particularly displayed, and the acquisition position of the tomographic information is estimated from the obtained tomographic image. However, as described above, the fundus image may be displayed on the display device 112 before the main imaging by the Lissajous scan is started. In this case, the fundus image 501 shown in FIG. 5 is generated by so-called raster scan, and as shown in FIG. It is preferable to display the scanning line 602 corresponding to. By performing such a display, it becomes easy to adjust the position of the OCT device (OCT optical system) with respect to the eye 120 to be inspected in the XY direction.

Here, a case where the measurement light is linearly scanned on the fundus in order to generate the tomographic image 701 shown in FIG. 7 is described. However, as described above, when the fundus image 501 is generated by the raster scan, three-dimensional tomographic information is obtained from the fundus. In this case, the tomographic image of the scanning line 602 shown by the broken line in FIG. 6 may be formed by using the three-dimensional tomographic information and displayed on the display device 112.

Further, instead of the raster scan, the three-dimensional tomographic information of the fundus may be acquired in advance by the resage scan, and the fundus image 501 or the like may be generated using the three-dimensional tomographic information. Here, when the fixation of the human eye is not stable, when the tomographic image 701 is viewed, it may be observed that the position is largely displaced or that the image is finely blurred. It is judged that this is because the imaging time of about 7.5 seconds specified in this embodiment is too long, and the fixation cannot be maintained for that time. It is conceivable to shorten the imaging time to deal with such subjects. Therefore, by setting the 512 half parameters #A, the number of sampling points and ^#A 2/2 = 131,072 points, when in the quarter to shorten the imaging time may. In this case, the imaging time can be shortened to about 1.9 seconds, and the fundus image 501 can be generated while reducing the influence of the instability of fixation.

Further, when the tomographic image 701 is continuously displayed by linear scanning of the measurement light, the tomographic image 701 is blurred or the displayed shape is changed many times, so that the subject is not stable in fixation. You can also confirm that. In this case, as one of the imaging conditions, by reducing the number of sampling points as described above, it is possible to acquire three-dimensional tomographic information in which the influence of the change in fixation is suppressed.

In the above-described embodiment, an example of adjusting the imaging conditions while displaying the tomographic image obtained by linear scanning of the measured light in advance is shown. However, the mode of the scanning line is not limited to a straight line, and may be a curved line, or a closed curve / figure such as a circle, an ellipse, or a parallelogram. That is, the same effect can be obtained if the same position on the fundus can be repeatedly scanned with the measurement light and the same tomographic image can be continuously displayed. That is, before the main imaging by the Lissajous scan of the measurement light, the tomographic image at an arbitrary position is continuously acquired and displayed in advance to confirm the suitability of the imaging conditions, or the imaging conditions are adjusted to perform the main imaging. It is possible to make the image quality of the image obtained in the above suitable in advance.

(Modification example)
In this embodiment, an example of a Lissajous scan in which a Lissajous figure is drawn with measurement light in this imaging is shown. However, the present invention does not lose its effect even when scanning on the fundus with the measurement light so as to draw a figure similar to the Lissajous figure. The effect of the present invention is not limited to a pure Lissajous figure, that is, a mode in which a figure is drawn with measurement light by a combination of scanning in which scanning in the X direction and scanning in the Y direction are described by strict simple vibration. No. That is, the same effect can be obtained by scanning the measurement light with a lisage-like figure or a group of figures obtained in a mode in which scanning of each of the two different directions is described as a reciprocating motion so as to cover the imaging range.

ただし、同式において、０≦ｔ_ｘ＜Ｔ_ｘ、０≦ｔ_ｙ＜Ｔ_ｙであり、ｔ＝（Ｌ_ｘ−１）Ｔ_ｘ＋ｔ_ｘ＝（Ｌ_ｙ−１）Ｔ_ｙ＋ｔ_ｙである。ｆ（ｔ）はガルバノスキャナの駆動開始からｔ秒が経過した時点の軌跡の位置を示し、Ａ_ｘおよびＡ_ｙは各々ＸガルバノスキャナおよびＹガルバノスキャナに印加される駆動波形の振幅を表す。また、Ｌ_ｘおよびＬ_ｙは、各々の駆動波形である三角波において、時刻ｔの点が何周期目であるかを表すインデックスである。 As an example of such a figure, there is one obtained by applying a voltage showing a drive waveform composed of different triangular waves represented by the following equation 3 to the X galvano scanner and the Y galvano scanner, respectively.

However, In the equation, a _{0 ≦ t x <T x,} 0 ≦ t y <T y, is _{t = (L x -1) T} x + t x = (L y -1) T y + t y. f (t) indicates the position of the locus when t seconds have elapsed from the start of driving the galvano scanner, and A _x and _Ay represent the amplitude of the driving waveform applied to the X galvano scanner and the Y galvano scanner, respectively. Further, L _x and _Ly are indexes indicating the cycle number of the point at time t in the triangular wave which is each drive waveform.

By making the drive waveform a triangular wave in this way, the galvano scanner scans the fundus with the measurement light at a constant speed. In the triangular wave, the rate of change in the drive waveform when the voltage increases and when the voltage decreases is the same. Further, in the drive waveform applied to each galvano scanner, the period in one drive waveform and the period in the other drive waveform are not in an integral multiple relationship as described above, and each cycle deviates from an integral multiple. Is set to. By applying such a drive waveform to the corresponding galvano scanner and scanning the measurement light on the fundus by two galvano scanners, the measurement light draws a square annular locus that changes its shape with time. That is, the two galvano scanners each scan the measurement light at a constant speed, so that the measurement light is scanned linearly on the fundus. At that time, the measurement light is drawn so that the opposite sides of the trajectories of the square ring are parallel to each other. Since the drawing start position of the square annular locus moves at regular intervals with the passage of time, the spacing between the parallel portions of these linearly drawn scanning lines is also constant.

Further, the drive waveform applied to each of the two galvano scanners is not limited to that composed of a single function such as the cos waveform as described above. Specifically, in the drive waveform represented by the above equation 3, a sine waveform or the like is synthesized so that the change in the waveform is not steep in the region where the voltage changes from an increase to a decrease or a decrease to an increase. It may be a thing.

Alternatively, instead of driving each galvano scanner in a different cycle, each galvano scanner is driven in the same cycle, and the phase is changed (delayed) at a predetermined timing repeatedly, which is similar to the Lissajous figure. The figure can be drawn with the measurement light. When both galvano scanners are driven in the same cycle, the same galvano scanner can be used because the scanning speed of the measurement light is the same, and the drive system and the like can be standardized. When two galvanos scanners are driven in such a drive mode, the measurement light is repeatedly drawn in the same loop until the phase is changed, and it is expected that the position accuracy will be maintained during repeated scanning.

Even in the measurement light scanning mode described above as a modified example, the scanning locus of the measurement light is sequentially switched, so that a tomographic image for adjusting the imaging conditions is displayed as in the case described in the first embodiment. Is desirable to be done in advance. That is, in this embodiment, the measurement light is repeatedly scanned along a specific scanning locus, and the tomographic image at the same position is continuously and repeatedly displayed to confirm or adjust the imaging conditions. The effect in this case can be obtained in all cases where a figure similar to the Lissajous figure described in the modification is drawn with measurement light to acquire three-dimensional tomographic information.

As described above, the measurement light is reciprocally scanned on the fundus in the X direction, and at the same time, the measurement light is reciprocally scanned on the fundus in the Y direction, and at that time, the cycles of the reciprocating scans in the X and Y directions are different. You can draw a Lissajous figure with. At that time, the drive waveform given to each of the galvano scanners that scan the measurement light in the X and Y directions is not limited to the one represented by a single function, but is represented by a combination of a plurality of functions. May be. Alternatively, a figure similar to the Lissajous figure can be drawn by setting the reciprocating scans in the X and Y directions to have the same period and giving a phase difference so that one of the reciprocating scans is delayed. That is, two galvano scanners may simultaneously scan the measurement light back and forth to acquire tomographic information so that the scanning locus continuously changes its position and shape. The Lissajous figure drawn by the measurement light and the figure similar to the Lissajous figure are collectively referred to as a Lissajous figure here. Further, scanning the measurement light so as to draw the Lissajous figure on the fundus is called a Lissajous scan.

Further, in the above-described embodiment, the case where the scanning optical system 104 is composed of two, an X galvano scanner and a Y galvano scanner, is described. However, as described above, if it is possible to scan the measurement light so as to draw a lisage-like figure on the fundus, one or both of the scanning optical systems may be constructed by a resonance scanner. However, in this case, it becomes difficult to repeat the scanning of the measurement light on the scanning line 602 shown by the broken line in FIG. 6, so that it is necessary to change the optical system in the OCT apparatus.

The configuration of the OCT device 900 in this case is shown in FIG. The same components as those of the OCT apparatus 100 shown in FIG. 1 will be shown using the same reference numerals, and the description thereof will be omitted here. The OCT apparatus 900 differs in that a third scanner 901 is arranged between the beam splitter 103 and the scanning optical system 104 in the OCT optical system. By canceling the scanning of the measurement light by one of the resonance scanners by the third scanner, the measurement light can be repeatedly scanned on the same scanning line as described above.

As described above, the image pickup apparatus according to the first embodiment uses the optical separation means, the first and second scanning means, the scanning control means for controlling the scanning means, and the interference light as the OCT apparatus. It includes a light receiving means for receiving light, a depth information acquiring means, an image generating means, and a display means. The beam splitter 103, which is an optical separation means, separates the light emitted from the light source 101 into the measurement light and the reference light. As the first scanning means, the X galvano scanner reciprocally scans the measurement light in the first (X) direction within a predetermined range on the fundus to be inspected. The Y galvano scanner reciprocally scans the measurement light in the second (Y) direction different from the first direction as the second scanning means. Both of these galvano scanners are controlled by the control device 109, which is a scanning control means.

These X galvano scanner and Y galvano scanner are driven at the same time. As a result, the predetermined range exemplified by the acquisition range 603 shown in FIG. 6 is a first scanning locus composed of a straight line or a curve having an angle equal to or more than a predetermined angle with respect to the X direction, and the measurement light 2 It will be scanned dimensionally and comprehensively. By controlling such scanning means performed by the control device 109, the measurement light draws a Lissajous figure in the acquisition range 603 on the fundus.

Further, the beam splitter 103 receives the interference light between the return light from the fundus and the reference light of the measurement light scanned by both galvano scanners by the detection unit 110 which is a light receiving means. The detection unit 110, together with the control PC 111, obtains information in the depth direction of the fundus on the first scanning locus (each scanning locus of the Lissajous-like scan) as a depth information acquisition means based on the output of the detection unit 110. Further, the control PC 111 generates a tomographic image in the measurement range of the fundus using the output of the depth information acquisition means and the first control signal (driving waveforms of both scanners) as the image generation means. Further, the display device 112 can display at least the output of the image generation means as the display means.

In the first embodiment, the image generation means can generate a tomographic image along an arbitrary line (scanning line 602) within a predetermined range by using the output of the depth information acquisition means. Further, the display device 112 repeatedly displays the tomographic image along the arbitrary line before acquiring the depth information by the Lissajous-like scan.

At that time, the control PC 111 gives the control device 109 a second scanning signal, and both galvano scanners continuously repeat the scanning of the measurement light along the scanning line 602. The display device 112 repeatedly displays the tomographic image repeatedly generated by using the depth information obtained by scanning the continuous measurement light. In this case, the control device 109 stops scanning of either one of the galvano scanners so that the measurement light is scanned along a scanning line that is a straight line parallel to either scanning direction. When the scanning line 602 is a curved line or when a so-called circle scan for drawing a circle is performed, both galvano scanners are repeatedly operated under specific conditions. Further, the scanner as the scanning means is not limited to the galvano scanner, and one of them may be a resonance scanner.

Further, in the above-mentioned Example 1, as a figure to be used for adjusting the imaging condition, an example is shown in which a representative value corresponding to each pixel on the fundus is calculated and used from the three-dimensional tomographic information. At that time, in the case of a subject whose fixation is uncertain, an example of shortening the measurement time by reducing the number of sampling points is described. In this case, since the measurement time can be shortened, a tomographic image along an arbitrary line (scanning line 602) may be generated from the acquired three-dimensional tomographic information and displayed. Further, in the case of a Lissajous scan, for example, even if the amount of deviation of the cycle of the Y galvano scanner with respect to the X galvano scanner is doubled or tripled, the time required for acquisition on the three-dimensional fault can be shortened. That is, it is possible to acquire three-dimensional tomographic information in a short time by lowering the scanning locus density than the scanning locus of the measured light at the time of the main imaging and performing a resage-like scan. Alternatively, the reciprocating scanning cycle of both scanners may be shortened. Such a scanning locus can be grasped as a second scanning locus similar to the first scanning locus when the original Lissajous-like scanning locus is used as the first scanning locus. In this case, the three-dimensional tomographic information may be used to generate and display a tomographic image of the arbitrary line.

Further, when a resonance scanner is used for both scanning means, it is stated that a third scanning means is arranged in the above-mentioned example and is driven by the third scanning means so as to cancel the scanning of one of the resonance scanners. However, in this case, the scanning of the measurement light by both scanning means may be stopped, and a plurality of linear scanning of the measurement light may be performed within a predetermined range only by the third scanning means.

Further, the above-mentioned imaging conditions include, for example, at least one of the state of condensing the measurement light on the fundus of the eye, the state of receiving the interference light by the detection unit 110, and the adjustment of the optical path length difference between the optical path of the measurement light and the optical path of the reference light. There is one etc. The control PC 111 operates the control device 109 as an adjusting means for adjusting these conditions, and moves each component in the OCT device 100 and the like. The control PC 111 also functions as an image pickup switching means for switching from a measurement preparation state in which the image pickup condition can be adjusted by such an adjustment means to a measurement state in which depth information is acquired by a Lissajous-like scan.

Further, when adjusting the imaging position on the fundus, which is one of the imaging conditions, it is preferable to generate or repeatedly generate a two-dimensional front image including a predetermined range in the fundus and display it on the display device 112. .. As such a two-dimensional image generation means, there are a fundus camera, an SLO, and the like as described above, and it is preferable that the OCT apparatus 100 has these. In this case, the display device 112 superimposes a mark (solid line frame in FIG. 6) indicating a predetermined range (acquisition range 603) on the two-dimensional front image, and superimposes the superposed two-dimensional front image (FIG. 6) and an arbitrary line. It is preferable to display the tomographic image (FIG. 7) along the line side by side.

Further, as described above, an image quality evaluation index such as a Q index may be presented for determining the imaging condition. In this case, the control PC 111 may be provided with a function as an image quality index calculation means for calculating an index representing the image quality of the tomographic image from the information in the depth direction for generating the tomographic image. As for the image quality evaluation method, a known method may be used, and a detailed description thereof is omitted here. Further, the obtained index may be displayed on the display device 112 together with a tomographic image along an arbitrary line.

Further, another aspect of the OCT apparatus 100 according to the first embodiment described above includes an image generation means, a first scanning means, a second scanning means, and a scanning control means. The control PC 111 as an image generation means was obtained from the interference light of the measurement light divided from the light from the light source 101 and applied to the fundus with the return light from the fundus and the reference light corresponding to the measurement light. A three-dimensional tomographic image is generated using the tomographic information. The X galvano scanner, which is the first scanning means, reciprocates the measurement light on the fundus in the first direction, and the Y galvano scanner, which is the second scanning means, scans the measurement light on the fundus in a direction different from the first direction. Scan back and forth in two directions. The control device 109, which is a scanning control means, simultaneously performs reciprocating scanning of the measurement light by the X galvano scanner and reciprocating scanning of the measurement light by the Y galvano scanner. Then, an annular scanning locus (a plurality of loops) that continuously changes its shape and position within a predetermined range on the fundus is continuously drawn with the measurement light. Then, the control PC 111 continuously generates a tomographic image along an arbitrary line (scanning line 602) defined within a predetermined range as an image generation means.

Further, in the OCT apparatus, the control PC 111 adjusts the acquisition condition of the tomographic image by using the tomographic images continuously generated as the adjusting means. In this case, the acquisition condition corresponds to the imaging condition. Further, the control device 109 causes both galvano scanners to perform a Lissajous-like scan in which the annular scanning locus is continuously drawn by the measurement light using the adjusted acquisition conditions. Further, in the OCT device, the control PC 111 also functions as an end detecting means for detecting the end of the adjustment by the above-mentioned adjusting means. The control device 109 starts a Lissajous-like scan, which is a continuous drawing by the measurement light of the annular scanning locus, in response to the end of the adjustment detected by the end detecting means.

In the embodiment described above, it can be understood that the control PC 111 has a first mode and a second mode when controlling both galvano scanners via the control device 109. In this case, the first mode is a mode for performing a Lissajous-like scan in which an annular scanning locus is continuously drawn with measurement light. The second mode is performed before the first mode and continuously and repeatedly scans the measurement light along an arbitrary line arranged within a predetermined range. At that time, the control PC 111 continuously generates a tomographic image by using the tomographic information repeatedly obtained by the second mode as an image generation means. The generated tomographic image is continuously updated and displayed on the display device 112.

[Example 2]
In Example 1 described above, for example, linear scanning of the measurement light is repeatedly performed within the imaging range (acquisition range of three-dimensional tomographic information) before the execution of the main imaging, and the tomographic image obtained from this scanning line is repeatedly and continuously. It is supposed to be displayed as a target. As a result, it is possible to adjust the imaging conditions at the time of the main imaging in advance with reference to the tomographic image, and it is possible to improve the image quality of the captured image obtained by the main imaging. However, even when the main imaging is performed under appropriate imaging conditions, it is possible that appropriate tomographic information cannot be acquired due to, for example, a blink of an eye at the time of the main imaging, and the image quality of the obtained captured image may deteriorate. .. In the second embodiment, an image is provided which can easily detect the occurrence of blinks during the main imaging and can easily determine the necessity of re-imaging or the like.

In this embodiment, a method of determining the quality of the captured image will be described. As a display method of an image obtained as a result of imaging the fundus by scanning with a Lissajous figure or a similar figure, there are a display based on the time series of FIG. 4 and a display after correction of the imaging position of FIG. As an example of such an image display format, FIG. 11 shows one aspect of the display screen of the display device 112.

The display screen 1100 of the display device 112 includes a fundus image display unit 1101, a tomographic image display unit 1102, an image quality index display unit 1103, a first main imaging result display unit 1104, and a second main imaging result display unit 1105. Is done. The fundus image display unit 1101 displays the fundus image 601 on which the acquisition range 603 of the three-dimensional tomographic information for which the main imaging is performed and the scanning line 602, which are shown in FIG. 6, are superimposed. The tomographic image display unit 1102 displays a tomographic image 701 for use in adjusting the imaging conditions shown in FIG. 7. On the image quality index display unit 1103, a general image quality evaluation index such as a so-called Q index obtained from the tomographic image 701 displayed on the tomographic image display unit 1102 is displayed by, for example, an indicator mode. The first image pickup result display unit 1104 displays, for example, a fundus surface image composed of spatial coordinates based on the three-dimensional tomographic information obtained by the Lissajous scan described in Example 1. Further, on the second main imaging result display unit 1105, the fundus image obtained in the manner of forming the fundus image on the time axis described in FIG. 4 is displayed.

The operator or the control PC 111 adjusts the position of the coherence gate, the in-focus state, and the like with reference to the tomographic image displayed on the tomographic image display unit 1102. Specifically, the coherence gate position is adjusted by changing the difference between the optical path length of the measured light and the optical path length of the reference light by moving the reference mirror 107, and focusing is performed by moving the position of the eyepiece lens system 105. Adjust the condition. Further, the image quality index obtained from the tomographic image and displayed on the image quality index display unit 1103 is referred to to further adjust the imaging conditions. As the image quality index, the maximum luminance value, the average luminance value, the number of pixels whose luminance exceeds a certain value, the SN ratio, the contrast ratio, and the like are used to determine the quality of the tomographic image.

Further, as the image quality index display unit 1103, a scale-like one shown in a style of filling a window showing a value of the image quality index is illustrated here. However, the display format is not limited to this, and a display format such as a numerical value itself, a difference in color density, a difference in saturation, a bar graph, or a pie chart can be used.

When there is a blink during the main imaging, a black line appears in a band shape on the fundus image as shown in FIG. 10 in the time-series display illustrated in FIG. 4, and it is easy to determine the presence or absence of the blink and the time. Therefore, in addition to the fundus image obtained by the normal main imaging displayed on the first main imaging result display unit 1104, the fundus image configured by this time axis can be displayed on the second main imaging result display unit 1105. desirable. By displaying the fundus image before such position correction, it is possible to easily determine the occurrence of blinks during the main imaging. The display by the second image pickup result display unit 1105 may be stopped by the software operation of the image forming process executed by the control PC 111. Further, it may be possible to switch the display together with the display by the first image pickup result display unit 1104.

As described above, when a specific position is not scanned with the same figure as in the case of Lissajous scan, even if images separated by a certain time interval are displayed, the imaging position and scanning direction change sequentially, so the positioning of the imaging location (Left / Right / Depth position) and focusing are difficult. On the other hand, in the present invention, when the measurement light is scanned to obtain information on the object to be inspected so as to draw a Lissajous-like figure, the image for adjusting the conditions for information acquisition is stabilized in a relatively short time. It becomes possible to provide the information. That is, even when three-dimensional tomographic information is acquired by using an OCT device using a complicated scanning pattern, the quality of the finally obtained image is judged in advance by accurately performing imaging positioning and focusing. Can be done.

In the second embodiment, the display device 112 has at least a space coordinate image using a space that is a scanning position of the measurement light on any of the vertical and horizontal axes, and a time axis image that uses the time axis that is the scanning time of the measurement light. Either can be displayed. The spatial coordinate image corresponds to the image displayed on the first main imaging result display unit 1104, and the time axis image corresponds to the image displayed on the second main imaging result display unit 1105. As a display control means, the control PC 111 causes the display device 112 to display these two-dimensional front images generated by the control PC 111 using the depth information obtained by the Lissajous-like scan. Further, as shown in FIG. 4, when there is a blink (blink), a band-shaped abnormal portion is observed in the image. The control PC 111 detects the presence of this band-shaped abnormal portion as the occurrence of blinking of the eye to be inspected by discontinuing the pixel values in the vertical direction as a blink detecting means. When such a blink is detected, it is preferable to display the time axis image on the display device 112 in order to notify the operator to that effect.

In the above-described embodiment, the fundus of the eye to be inspected 120 has been described as an example of the object to be inspected, but the object to be inspected is not limited to this. For example, the object to be inspected may be the anterior eye portion of the eye to be inspected 120, or the skin or organ of the subject to be inspected. In this case, the above-mentioned imaging device can be used not only as an ophthalmic device but also as an imaging device for a medical device such as an endoscope.

(Other examples)
The present invention supplies a program that realizes one or more functions of the above-described embodiment to a system or device via a network or 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 the processing to be performed. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

Although the present invention has been described above with reference to the examples, the present invention is not limited to the above-mentioned examples. The present invention also includes inventions modified to the extent not contrary to the gist of the present invention, and inventions equivalent to the present invention. In addition, the above-mentioned examples and modifications thereof can be appropriately combined as long as the gist of the present invention is not violated.

101 Light source 102, 108 Fiber collimator 103 Beam splitter (optical separation means)
104 Scanning optical system (first scanning means, second scanning means)
109 Control device (scanning control means)
110 Detection unit (light receiving means)
111 Control PC (depth direction information acquisition means, image generation means)
112 Display device (display means)
120 Eye to be inspected (object to be inspected)

The present invention relates to an image pickup device that scans light on an object to be inspected to obtain an image of the object to be inspected, an operation method and a program of the image pickup device.

The present invention has been made in view of the above circumstances, and adjusts the conditions for acquiring information when scanning light to obtain information on an inspected object so as to draw a figure such as a Lissajous figure. It is an object of the present invention to provide an image pickup device, an operation method of the image pickup device, and a program capable of stably providing an image for the purpose in a relatively short time.

In order to solve the above problems, the image pickup apparatus according to one aspect of the present invention is
Acquisition to acquire a three-dimensional OCT image of the predetermined range using the interference light obtained by interfering the return light of the measurement light obtained by resage scanning the predetermined range of the eye to be inspected with the reference light corresponding to the return light. Means and
An adjusting means for adjusting at least one of the light collection state of the measurement light in the eye to be inspected, the light receiving state of the interference light, and the optical path length difference between the optical path of the measurement light and the optical path of the reference light.
During adjustment by said adjustment means, characterized Rukoto and a display control means for sequentially displaying on the display means a tomographic image obtained by scanning repeatedly a scanning line included in the predetermined range in the measurement light And.

Claims (3)

An optical separation means that separates the light emitted from the light source into the measurement light and the reference light,
A first scanning means for reciprocating the measurement light in a first direction within a predetermined range on the object to be inspected, and a first scanning means.
A second scanning means for reciprocating the measurement light in a second direction different from the first direction,
A first scan composed of a straight line or a curve having an angle of a predetermined angle or more with respect to the first direction by simultaneously driving the first scanning means and the second scanning means. A scanning control means for controlling the first scanning means and the second scanning means by giving a first control signal so as to scan two-dimensionally and comprehensively with the measurement light on the locus.
A light receiving means that receives interference light between the return light and the reference light scanned by the measurement light using the first scanning means and the second scanning means.
Depth information acquisition means for obtaining information in the depth direction of the object to be inspected based on the output of the light receiving means, and
An image generation means that generates a tomographic image of the object to be inspected in the predetermined range by using the output of the depth information acquisition means and the first control signal.
A display means capable of displaying at least the output of the image generation means is provided.
The image generation means can generate a tomographic image along an arbitrary line within the predetermined range by using the output of the depth information acquisition means.
The display means is an image pickup apparatus characterized in that a tomographic image along an arbitrary line is repeatedly displayed before acquisition of the depth information by the first scanning locus. An optical separation means that separates the light emitted from the light source into the measurement light and the reference light,
A first scanning means for reciprocating the measurement light in a first direction within a predetermined range on the object to be inspected, and a first scanning means.
A second scanning means for reciprocating the measurement light in a second direction different from the first direction,
A first scan composed of a straight line or a curve having an angle of a predetermined angle or more with respect to the first direction by simultaneously driving the first scanning means and the second scanning means. A scanning control means for controlling the first scanning means and the second scanning means by giving a first control signal so as to scan two-dimensionally and comprehensively with the measurement light on the locus.
A light receiving means that receives interference light between the return light and the reference light scanned by the measurement light using the first scanning means and the second scanning means.
Depth information acquisition means for obtaining information in the depth direction of the object to be inspected based on the output of the light receiving means, and
An image generation means that generates a tomographic image of the object to be inspected in the predetermined range by using the output of the depth information acquisition means and the first control signal.
A control method for an image pickup apparatus including at least a display means capable of displaying the output of the image generation means.
The image generation means generates a tomographic image along an arbitrary line within the predetermined range by using the output of the depth information acquisition means.
A control method for an image pickup apparatus, characterized in that a tomographic image along an arbitrary line is repeatedly displayed by the display means before acquisition of the depth information by the first scanning locus. A program comprising causing a computer to execute each step of the control method of the image pickup apparatus according to claim 3.

Images