JP2014111226A - Imaging apparatus and control method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce time required for feedback control until an appropriate aberration correction amount is obtained when the position of an object to be inspected is changed.
An imaging apparatus performs feedback control that repeats detection of wavefront aberration of an eye to be examined based on a detection signal from a wavefront sensor and control of a wavefront compensation device based on the result of the detection, and outputs the detection signal from the wavefront sensor. Based on this, the feedback control is temporarily stopped and the feedback control is resumed.
[Selection] Figure 5

Description

  The present invention relates to an imaging apparatus that images a measurement target such as an eye to be examined and a control method thereof.

  2. Description of the Related Art Recently, as an ophthalmologic imaging apparatus, SLO (Scanning Laser Ophthalmoscope) that irradiates a fundus of a laser beam two-dimensionally and receives reflected light, or imaging using interference of low-coherence light. Equipment has been developed.

This imaging device using low-coherence light interference is called OCT (Optical Coherence Tomography), and is used particularly for the purpose of obtaining a tomographic image of the fundus or its vicinity. .
Various types of OCT have been developed, including TD-OCT (Time Domain OCT: Time Domain Method) and SD-OCT (Spectral Domain OCT: Spectral Domain Method).

In particular, in such an ophthalmic imaging apparatus, in recent years, higher resolution has been promoted by increasing the NA of an irradiation laser.
However, when imaging the fundus, the image must be captured through the optical tissue of the eye such as the cornea or the crystalline lens.

  As the resolution increases, the influence of the aberration of the cornea and the crystalline lens has greatly influenced the image quality of the captured image.

  Therefore, research on AO-SLO and AO-OCT, in which AO (Adaptive Optics), which is an adaptive optical system that measures aberrations of the eye and corrects the aberrations, is incorporated in the optical system.

  For example, Non-Patent Document 1 shows an example of AO-OCT. These AO-SLO and AO-OCT generally measure the wavefront of the eye by the Shack-Hartmann wavefront sensor method.

  In the Shack-Hartmann wavefront sensor system, measurement light is incident on the eye and the reflected light is received by a CCD camera through a microlens array to measure the wavefront.

  AO-SLO and AO-OCT can be imaged with high resolution by driving a deformable mirror and a spatial phase modulator to correct the measured wavefront and imaging the fundus through them.

Y. Zhang et al, Optics Express, Vol. 14, no. 10, 15 May 2006

  In the image acquisition apparatus provided with the above-described conventional compensation optical system, the eye aberration is measured in order to correct the aberration, and the process of correcting the aberration based on the information is repeatedly performed to perform feedback control. .

  The feedback control is performed in order to cope with an error between the instruction value for the correction device and the actual correction amount, and for the eye to change the aberration depending on the state of tear fluid or refractive adjustment.

  Aberration correction control is also the same as general feedback control, and a certain amount of time is required from the start of processing until reaching an appropriate aberration correction state.

  In particular, since the response speed of the wavefront sensor or wavefront correction device used for correcting aberrations is slow, it takes several seconds to several tens of seconds to reach an appropriate correction state.

  In addition, in an optical tomographic imaging apparatus that images the fundus, such as OCT, it takes a relatively long time from the start of imaging to the completion of imaging of the eye. Often moves vertically.

  Since it is not a desired imaging position when the eye is moved, it is meaningless to take an image. Therefore, imaging is resumed after the eye returns to the original position.

  On the other hand, when the eye moves, the optical path through which the measurement light passes changes, and the measured aberration also changes greatly.

  The correction of the aberration by the feedback control changes from the original correction state to a greatly different state because the control is performed so as to correct the changed aberration.

  Therefore, in the conventional one, when the eye returns to a desired position next time, it takes more time to reach an appropriate correction state, and there is a problem that fundus images cannot be acquired immediately. .

  One of the objects of the present invention is to reduce the time required for feedback control required to obtain an appropriate aberration correction amount when the position of the inspection object to be measured changes in view of the above problems. That is.

One of the imaging devices according to the present invention is:
A fundus imaging optical system that receives reflected light from the eye to be imaged and images the fundus of the eye to be examined;
A wavefront compensation device that is disposed in the optical path of the fundus imaging optical system and that controls the wavefront of incident light to compensate for the wavefront aberration of the eye to be examined;
A wavefront aberration detection optical system for projecting measurement light toward the eye to be examined and detecting reflected light from the fundus by a wavefront sensor;
Perform feedback control that repeats detection of wavefront aberration of the eye based on the detection signal from the wavefront sensor and control of the wavefront compensation device based on the detection result, and feedback control based on the detection signal from the wavefront sensor Control means for temporarily stopping and resuming feedback control.

One of the imaging devices according to the present invention is
An aberration measurement means for measuring the aberration of the return light from the measurement object irradiated with the measurement light;
An aberration correction means for correcting at least one aberration of the measurement light and the return light;
Control means for starting imaging of the measurement object while feedback controlling the aberration correction means based on the measurement result of the aberration measurement means.

In addition, one of the control methods of the imaging apparatus according to the present invention is:
A wavefront compensation device that receives reflected light from the eye to be examined and is disposed in an optical path of a fundus imaging optical system that images the fundus of the eye to be examined, and controls a wavefront of incident light to compensate a wavefront aberration of the eye to be examined; A wavefront aberration detection optical system for projecting measurement light toward the eye to be examined and detecting reflected light from the fundus by a wavefront sensor,
A step of performing feedback control in which the imaging device repeats detection of wavefront aberration of the eye to be examined based on a detection signal from the wavefront sensor and control of the wavefront compensation device based on the detection result;
And a step of temporarily stopping feedback control and restarting feedback control based on a detection signal from the wavefront sensor.

In addition, one of the control methods of the imaging apparatus according to the present invention is:
A method for controlling an imaging apparatus, comprising: an aberration measuring unit that measures aberration of return light from a measurement object irradiated with measurement light; and an aberration correction unit that corrects at least one of the measurement light and the return light. Because
The imaging apparatus includes a step of starting imaging of the measurement target while feedback controlling the aberration correction unit based on a measurement result of the aberration measurement unit.

  According to the present invention, when the position of the inspection object to be measured is changed, it is possible to reduce the time required for the feedback control that is required until an appropriate aberration correction amount is obtained.

FIG. 3 is a schematic diagram for explaining a configuration example of an optical image capturing apparatus using an SLO including an adaptive optics system according to Embodiment 1 of the present invention. FIG. 6 is a schematic diagram for explaining a configuration example of an optical image pickup apparatus using OCT including an adaptive optics system according to a second embodiment of the present invention. The schematic diagram for demonstrating the wavefront correction device and wavefront sensor in Example 1 of this invention. (A) is a schematic diagram for demonstrating a deformable mirror. (B) is a schematic diagram of a reflective liquid crystal light modulator. (C-1), (c-2) is a schematic diagram which shows the structure of a Shack-Hartmann sensor. (D) is a schematic diagram which shows the state by which the light beam which measures a wave front was condensed on the CCD sensor. (E-1) and (e-2) are schematic diagrams when a wavefront having spherical aberration is measured. FIG. 3 is a diagram illustrating an aberration correction function by the adaptive optics system in Embodiment 1 of the present invention. The flowchart which shows an example of the control step in Example 1 of this invention. The flowchart which shows an example of the control step in Example 1 of this invention. FIG. 9 is a schematic diagram for explaining a configuration example of an optical image pickup apparatus using SLO including an adaptive optics system according to Embodiment 3 of the present invention.

  The mode for carrying out the present invention will be described with reference to the following examples. However, the present invention is not limited to the configurations of the following examples.

[Example 1]
As a first embodiment, a configuration example of an optical image capturing apparatus that captures an optical image of an object to be inspected by an SLO including an adaptive optical system to which the present invention is applied and an optical image capturing method will be described with reference to FIG.

  In the present embodiment, an example in which an object to be inspected is an eye to be inspected and an image of the fundus is imaged by an optical image imaging apparatus (fundus imaging optical system) using an SLO having an adaptive optical system will be described. The configuration of the eyepiece is the same in the OCT (optical coherence tomography apparatus).

  In FIG. 1, reference numeral 101 denotes a light source, and an SLD light source having a wavelength of 840 nm is used in this embodiment.

The wavelength of the light source 101 is not particularly limited, but particularly about 800 to 1500 nm is preferably used for fundus imaging in order to reduce glare and maintain resolution of the subject.
Although an SLD light source is used here, a laser or the like may be used in addition to this.
However, when a laser is used, in order to reduce speckle noise, a configuration for reducing the coherence such as passing a long-distance optical fiber is often added.
In the present embodiment, light sources for fundus imaging and wavefront measurement are shared, but it is also possible to use separate light sources and combine them in the middle.

The light emitted from the light source 101 passes through the single mode optical fiber 102 and is irradiated as a parallel light by the collimator 103.
The irradiated measurement light 105 is transmitted through a beam splitter 104 which is a light splitting means and guided to an adaptive optics system.

  This compensation optical system includes a beam splitter 106 that is a light splitting unit, a wavefront sensor (also referred to as a wavefront aberration detection optical system) 115 that is an example of an aberration measurement unit, and a wavefront correction device that is an example of an aberration correction unit (compensates for wavefront aberration). (Also referred to as a wavefront compensation device) 108 and reflecting mirrors 107-1 to 107-4 for guiding them.

  Here, the reflection mirror 107 is installed so that at least the pupil of the eye (anterior eye portion), the wavefront sensor 115, and the wavefront correction device 108 are optically conjugate.

In this embodiment, a deformable mirror is used as the wavefront correction device 108.
The deformable mirror can change the light reflection direction locally, and various types of mirrors have been put into practical use.

  For example, as the wavefront correction device 108, a device as shown in FIG.

  As shown in FIG. 3 (a), it is composed of a deformable film-like mirror surface 127 that reflects incident light, a base portion 126, and an actuator 128 that is sandwiched therebetween.

As an operation principle of the actuator 128, there is one using an electrostatic force, a magnetic force, and a piezoelectric effect, and the configuration of the actuator 128 differs depending on the operation principle.
A plurality of actuators 128 are two-dimensionally arranged on the base portion 126, and the mirror surface 127 can be freely deformed by selectively driving them.

As another configuration example of the wavefront correction device 108, there is a spatial phase modulator (reflection-type liquid crystal light modulator) using a liquid crystal element as shown in FIG.
This spatial phase modulator has a structure in which liquid crystal molecules 132 are enclosed in a space between a base portion 129 and a cover 130.

  The base portion 129 has a plurality of pixel electrodes 131, and the cover 130 has a transparent counter electrode (not shown).

  When no voltage is applied between the electrodes, the liquid crystal molecules are aligned as in 132-1. When a voltage is applied, the liquid crystal molecules transition to an aligned state as in 132-2, and the refractive index for incident light is Change.

  By controlling the voltage of each pixel electrode to change the refractive index of each pixel, spatial phase modulation becomes possible.

For example, when the incident light 133 is incident on the element, the light passing through the liquid crystal molecules 132-2 is delayed in phase from the light passing through the liquid crystal molecules 132-1, resulting in the formation of a wavefront as indicated by 134 in the figure.
However, since the liquid crystal element has polarization characteristics, the liquid crystal element often includes a polarizing plate for adjusting the polarization of incident light.

The light that has passed through the compensation optical system is scanned one-dimensionally or two-dimensionally by the scanning optical system 109.
In this embodiment, two galvano scanners are used for the scanning optical system 109 for main scanning (fundus horizontal direction) and sub-scanning (fundus vertical direction). A resonant scanner may be used on the main scanning side of the scanning optical system 109 for faster imaging.
Depending on the configuration, an optical system such as a mirror or a lens may be used between the scanners in order to bring each scanner in the scanning optical system 109 into an optically conjugate state.
Measurement light scanned by the scanning optical system 109 is applied to the eye 111 through the eyepieces 110-1 and 110-2.
The measurement light applied to the eye 111 is reflected or scattered by the fundus.
By adjusting the positions of the eyepieces 110-1 and 110-2, it is possible to perform optimal irradiation (projection) in accordance with the diopter of the eye 111.
Here, a lens is used for the eyepiece, but a spherical mirror or the like may be used.

  The light reflected and scattered from the retina of the eye 111 (reflected light) travels in the same direction as the incident light in the reverse direction, and is partially reflected by the wavefront sensor 115 by the beam splitter 106 to measure the wavefront of the light beam. Used for.

  In the present embodiment, as the wavefront sensor 115, a Shack-Hartmann sensor as shown in FIGS.

  In FIG. 3C-1, reference numeral 135 denotes a light beam for measuring the wavefront, which is condensed on the focal plane 138 on the CCD sensor 137 through the microlens array 136. FIG. 3C-2 is a diagram showing a cross-section at the position indicated by AA ′ in FIG. 3C-1, in which the microlens array 136 is composed of a plurality of microlenses 139. It is shown.

  Since the light ray 135 is condensed on the CCD sensor 137 through each microlens array 136, the light ray 135 is divided into spots corresponding to the number of the microlenses 139 and condensed.

FIG. 3D shows a state where the light beam for measuring the wavefront is collected on the CCD sensor 137.
The light beam that has passed through each microlens is collected at the spot 140.

Then, from the position of each spot 140, the wavefront of the incident light beam is calculated. For example, FIGS. 3 (e-1) and 3 (e-2) show schematic diagrams when a wavefront having spherical aberration is measured.
The light ray 135 has a wavefront as indicated by 141. The light beam 135 is collected by the microlens array 136 at a local position in the normal direction of the wavefront.

  The condensing state of the CCD sensor 137 in this case is shown in FIG.

  Since the light ray 135 has spherical aberration, the spot 140 is condensed in a state of being biased toward the center.

  By calculating this position, the wavefront of the ray 135 is known.

  A part of the reflected and scattered light transmitted through the beam splitter 106 is reflected by the beam splitter 104 and guided to the light intensity sensor 114 through the collimator 112 and the optical fiber 113. Light is converted into an electrical signal by the light intensity sensor 114, and the image processing unit 125 forms an image as a fundus image.

  In addition, the first embodiment includes an eye movement detection unit 148 that detects eye movement as position change detection means that detects a change in position of the object to be inspected by detecting a time change of the acquired image.

  The eye movement detection unit 148 is not limited to such a configuration, and may be configured to directly detect a change in the position of the eye, for example.

  The eye movement detection unit 148 is connected to the adaptive optics controller 116 that is a control unit that feedback-controls the wavefront correction device 108 in order to correct aberrations that occur in the eye.

  Then, the adaptive optics controller 116 determines interruption of the feedback control of the wavefront correction device 108 based on the information of the eye movement that is the detection result (measurement result) of the eye movement detection unit 148.

  Other configurations for detecting eye movement include eye movement using a method of detecting gaze by applying light to the cornea, a method of detecting movement by measuring a specific eye position using an interferometer, etc. It is also possible to use a detection device.

  In such a configuration, the optical system of the eyepiece is complicated, but image processing for position detection is not required, so the speed can be increased and the position detection accuracy is improved.

  The wavefront sensor 115 is connected to the adaptive optics controller 116 and transmits the wavefront of the received light beam to the adaptive optics controller 116.

  A wavefront correction device (variable shape mirror) 108 is also connected to the adaptive optics controller 116 and is deformed into a shape instructed by the adaptive optics controller 116.

  Based on the wavefront acquired from the wavefront sensor 115, the adaptive optics controller 116 calculates a shape that can be corrected to a wavefront having no aberration, and instructs the deformable mirror 108 to be deformed to that shape.

  The measurement of the wavefront by the wavefront sensor 115, the transmission of the wavefront to the compensation optical controller 116, and the instruction to the deformable mirror for correcting the aberration by the compensation optical controller 116 are repeatedly processed and are always optimal. Feedback control is performed so as to obtain a wavefront.

  At this time, in this embodiment, when the eye moves temporarily during imaging, that is, when the eye moves out of a predetermined range, the feedback control is temporarily stopped (temporarily stopped). At this time, the correction characteristic in the aberration correction means is maintained. Further, when the eye returns to the original position, that is, when the eye returns to a predetermined range, the fundus imaging can be performed without time loss with the following configuration so that the feedback control is resumed. It is said that.

  That is, when the eyeball temporarily moves during imaging, the eye movement detection unit 148 detects a change in the eyeball position and transmits it to the adaptive optics controller 116.

  Then, the adaptive optics controller 116 that has received this transmission maintains the correction state of the aberration at the time when the eye moves, temporarily stops the feedback control, and the correction maintained above when the eye returns to the original position. The feedback control is resumed from the state (a state in which the correction state of the aberration at the time when the eye moves) is reflected.

  Next, aberration correction by the adaptive optics system in the present embodiment will be described with reference to FIG.

  FIG. 4A shows a correction effect by a normal aberration correction function. The vertical axis represents the measured aberration amount, and the horizontal axis represents the time required for correcting the aberration by feedback control.

  At the correction start time, there is an aberration of about 3 μm as indicated by 142.

  By performing feedback control of the correction device based on the measured aberration, the aberration is gradually corrected and reaches a state of almost no aberration as indicated by 143, that is, a state where the amount of aberration is equal to or less than a threshold value.

  If fundus imaging is performed at this point, a high-resolution image can be acquired. Since the aberration is corrected by feedback control in this way, it takes several seconds to reduce the aberration amount that enables high-resolution imaging.

  In the middle of correcting the aberration by feedback control, since the amount of aberration is still large, high-resolution imaging is difficult.

  Next, with reference to FIG. 4B, a description will be given of the variation in aberration in the prior art when the eye to be inspected has moved.

  When the eye moves, the measured aberration changes greatly, and the entire aberration correction also controls the changed aberration.

  In the same manner as described above, the initial aberration as indicated by 142 is corrected to reach 143. Thereafter, when the eye moves around 144, the optical path passing through the eye changes and the amount of aberration also changes greatly.

  In the correction of aberration, the amount of aberration is reduced by performing feedback control to correct this aberration.

However, since it is not the original imaging position, imaging of the fundus at this point is meaningless, and imaging is not performed here.
Next, when the eye returns to the original position at the time indicated by 145, the amount of aberration increases again because the optical path to the eye returns.
Until feedback control is performed on this aberration and no aberration occurs, a time as indicated by 146 further elapses.

  Originally, the eye has returned to a desired position at the time of 145, so it is desired to resume the imaging. However, since the aberration remains, high-resolution imaging cannot be performed for a certain period of time.

  Here, the aberration correction flow in the present invention will be described with reference to FIG.

  First, aberration correction is started in step S101, and a reference position of the eye is set in step S102. Here, for example, a characteristic position such as a branching position of a blood vessel included in the fundus image or an optic disc is set as the reference position.

  Thereafter, the aberration is measured by the wavefront sensor 115 in step S103. In step S104, the eye movement detection unit 148 acquires eyeball position information.

  In step S <b> 105, the eye movement detection unit 148 determines whether the reference position of the eye has moved or whether the movement is small, and outputs the determination result to the adaptive optics controller 116. If the eye is not moving or there is little movement, the adaptive optics controller drives the correction device in step S106 based on the aberration information.

  If the eye moves and is not at the desired position, the process proceeds from step S105 to S107 without passing through S106, and the correction device maintains the previous state.

  In step S107, the completion request of the aberration correction process is confirmed. If there is no termination request, the process returns to S103, and if there is a termination request, the process ends in S108.

Further, another aberration correction flow in this embodiment will be described with reference to FIG.
In the same manner as described above, aberration correction is started in step S101.

  In step S102, the reference position of the eye is set. Thereafter, the aberration is measured by the wavefront sensor 115 in step S103, and the eye movement detection unit 148 acquires the eyeball position information in step S104.

  Next, in S105, it is determined from the reference position whether or not the eye has moved. If the eye has not moved, the correction device is driven in step S106 based on the aberration information.

  If the eye is moving, the process proceeds to step S109, and the elapsed time since the eye moved is confirmed.

  If the elapsed time has passed for an arbitrary time or longer (if it has continued for a predetermined time or more), it is determined that imaging at that position is necessary, and the reference position of the eye is determined based on the current position in step S110. Set.

  By setting a new position as the reference position, correction is performed in accordance with the measured aberration in the subsequent correction processing.

  Next, the process proceeds to step 107, where an end request is confirmed. If there is no end request, the process returns to S103, and if there is an end request, the process ends in S108.

  FIG. 4C shows the variation of the correction state in the present embodiment according to the above flow.

  In the same manner as described above, the initial aberration as indicated by 142 is corrected to reach the aberration amount indicated by 143.

  After that, when the eye moves around 144, the amount of aberration changes greatly because the optical path through the eye changes.

  At this time, the eye movement detection unit 148 detects that the eyeball position has changed, and the adaptive optics controller 116 maintains the state of the correction device. Since the state of the correction device does not change, the amount of aberration remains as indicated by 144. However, since no imaging is performed in this state, there is no problem.

  Next, when the eye returns to the original position as indicated by 145, the eye movement detection unit 148 detects this, and the adaptive optics controller 116 starts control of the correction device. At this point, the correction device almost matches the state of correcting the original aberration, so it can reach a state close to no aberration in a very short time, and high-resolution fundus imaging can be performed without time loss. Is possible.

[Example 2]
As Example 2, an optical imaging apparatus using OCT having an adaptive optics system to which the present invention is applied and an imaging method thereof will be described with reference to FIG.

  In FIG. 2, reference numeral 101 denotes a light source. In this embodiment, an SLD light source having a wavelength of 840 nm is used.

  The light source 101 only needs to have a low interference property, and an SLD having a wavelength width of 30 nm or more is preferably used.

  Further, an ultrashort pulse laser such as a titanium sapphire laser can be used as a light source.

  The light emitted from the light source 101 is guided to the fiber coupler 117 through the single mode optical fiber 102. The signal is branched into the signal light path 118 and the reference light path 119 by the fiber coupler 117.

  A fiber coupler having a branching ratio of 10:90 is used so that 10% of the input light quantity goes to the signal light path 118.

  The light that has passed through the signal light path 118 is irradiated as collimated light by the collimator 103.

  The collimator 103 and the subsequent steps are the same as those in the first embodiment, and the eye 111 is irradiated through the compensation optical system and the scanning optical system, and the reflected scattered light from the eye 111 is again guided to the signal light path (optical fiber) 118 through the same path. It reaches the fiber coupler 117 by being illuminated.

  On the other hand, the reference light (reference light corresponding to the measurement light) that has passed through the reference light path 119 is emitted from the collimator 120, reflected by the optical path length variable unit 121 including a stage and a mirror thereon, and then again the fiber coupler 117. Return to.

  The signal light and the reference light that have reached the fiber coupler 117 are combined and guided to the spectroscope 124 through the optical fiber 123. Based on the interference light information split by the spectroscope 124, a tomographic image of the fundus is formed by the OCT image processing unit 125a.

  The OCT image processing unit 125a can control the optical path length variable unit 121 and acquire an image at a desired depth position.

  The OCT image processing unit 125a is connected to the eye movement detection unit 148, and can detect the movement of the eye by detecting the time change of the acquired image.

  The eye movement detector 148 is connected to the adaptive optics controller 116, and the adaptive optics controller 116 controls aberration correction using the detected information of the eye movement.

  Since the present embodiment is OCT and the image acquired by the OCT image processing unit 125a is data having three dimensions, the eye movement to be detected can also detect three-dimensional movement.

  The adaptive optics controller 116 can acquire a high-resolution fundus tomographic image without time loss even when the eye moves by performing the same control as in the first embodiment.

[Example 3]
As a third embodiment, a configuration example of an optical image capturing apparatus and an optical image capturing method using an SLO having an adaptive optical system to which the present invention is applied will be described with reference to FIG.

  In this embodiment, the basic configuration is almost the same as that of the first embodiment, except that the eye movement detection unit 148 is connected to the adaptive optics controller 116 and is not connected to the image processing unit 125. Different from Example 1.

  In FIG. 7, the light emitted from the light source 101 is emitted as a parallel light beam by the collimator 103, and is irradiated to the eye 111 through the compensation optical system and the eyepiece optical system as in the first embodiment.

The reflected and scattered light from the eye 111 travels in the reverse direction on the same path as when it was incident, and part of the light is reflected by the wavefront sensor 115 by the beam splitter 106 and used to measure the wavefront of the light beam. A part of the reflected scattered light is reflected by the beam splitter 104.
Then, the light is guided to the light intensity sensor 114 through the collimator 112 and the optical fiber 113.

  Light is converted into an electrical signal by the light intensity sensor 114, and the image processing unit 125 forms an image as a fundus image.

  The wavefront sensor 115 is connected to the adaptive optics controller 116 and transmits the wavefront of the received light beam to the adaptive optics controller 116.

  The deformable mirror 108 is also connected to the adaptive optics controller 116 and is configured to be deformed into a shape designated by the adaptive optics controller 116.

  Based on the wavefront acquired from the wavefront sensor 115, the adaptive optics controller 116 calculates a shape that can be corrected to a wavefront having no aberration, and commands the deformable mirror 108 to be deformed to that shape.

  Wavefront measurement and instructions to the deformable mirror are repeatedly processed, and feedback control is performed so that an optimal wavefront is always obtained.

This embodiment is characterized in that the eye movement detection unit 148 detects eye movement based on information (detection signal) from the wavefront sensor 115 that is an aberration measuring means.
As described above, when the eye moves greatly, the wavefront measured by the wavefront sensor 115 changes greatly, so that the eye movement can be detected by monitoring this change.

  When eye movement is detected as in the first embodiment, the shape is maintained without driving the correction device.

  When the eye position returns to a substantially original position, the wavefront measured by the wavefront sensor 115 also returns to a state close to the previous value, so that the return of the eyeball position can be detected. When the eyeball position returns to the original position, the adaptive optics controller 116 starts control of the correction device. At this point, since the correction device almost matches the state of correcting the original aberration, the correction device can reach a state close to no aberration in a very short time, and high-resolution fundus imaging can be performed without time loss. It becomes possible.

  As described above, according to the present invention, various types of fundus imaging devices are configured by optical image imaging devices including SLO and OCT, so that high-quality imaging can be performed in a short time even for eyes with aberration. Can be done.

[Other Examples]
The present invention can also be realized by executing the following processing. That is, software (program) that realizes the functions of the above-described embodiments is supplied to a system or apparatus via a network or various storage media, and a computer (or CPU, MPU, or the like) of the system or apparatus reads the program. It is a process to be executed.

Claims (24)

A fundus imaging optical system that receives reflected light from the eye to be imaged and images the fundus of the eye to be examined;
A wavefront compensation device that is disposed in the optical path of the fundus imaging optical system and that controls the wavefront of incident light to compensate for the wavefront aberration of the eye to be examined;
A wavefront aberration detection optical system for projecting measurement light toward the eye to be examined and detecting reflected light from the fundus by a wavefront sensor;
Perform feedback control that repeats detection of wavefront aberration of the eye based on the detection signal from the wavefront sensor and control of the wavefront compensation device based on the detection result, and feedback control based on the detection signal from the wavefront sensor Control means for temporarily stopping and resuming feedback control;
An imaging device comprising:   The imaging apparatus according to claim 1, wherein the control unit temporarily stops feedback control and restarts feedback control based on information on a wavefront of reflected light detected by the wavefront sensor.   3. The imaging apparatus according to claim 1, wherein the control unit temporarily stops the feedback control and restarts the feedback control based on a change in the wavefront of the reflected light detected by the wavefront sensor. . Further comprising detection means for detecting movement information of the eye based on a detection signal from the wavefront sensor;
The control means temporarily stops feedback control when the motion information detected by the detection means is out of a predetermined range, and resumes feedback control when the motion information returns to the predetermined range. The imaging apparatus according to any one of claims 1 to 3, wherein   When the motion information returns to a predetermined range, the control means reflects information related to the control of the wavefront compensation device when the motion information is within the predetermined range to the wavefront compensation device. The imaging device according to claim 4. An aberration measurement means for measuring the aberration of the return light from the measurement object irradiated with the measurement light;
An aberration correction means for correcting at least one aberration of the measurement light and the return light;
Control means for starting imaging of the measurement object while feedback controlling the aberration correction means based on the measurement result of the aberration measurement means;
An imaging device comprising:   The imaging apparatus according to claim 6, wherein when the amount of aberration measured by the aberration measuring unit becomes equal to or less than a threshold, the control unit starts imaging of the measurement target while feedback controlling the aberration correcting unit.   The imaging device according to claim 6 or 7, wherein the control unit starts imaging of the measurement target by starting the configuration of the image of the measurement target.   The imaging device according to claim 6 or 7, wherein the control unit starts imaging of the measurement target by starting acquisition of an image of the measurement target. Further comprising an acquisition means for acquiring a tomographic image of the measurement object based on interference light in which the return light from the measurement object irradiated with the measurement light interferes with the reference light corresponding to the measurement light;
10. The control unit according to claim 6, wherein the control unit starts imaging of the measurement target by controlling the acquisition unit while feedback controlling the aberration correction unit based on a measurement result of the aberration measurement unit. The imaging device according to any one of the above. The measurement object is an eye to be examined;
The imaging apparatus according to claim 6, wherein the aberration correction unit is disposed at a position optically conjugate with the anterior eye portion of the eye to be examined.   The imaging apparatus according to claim 11, wherein the control unit maintains the correction characteristics of the aberration correction unit when the eye to be examined moves out of a predetermined range.   The control means corrects an aberration caused by the eye to be examined based on an aberration amount before the eye to be examined moves outside the predetermined range when the eye to be examined returns to the predetermined range. The imaging apparatus according to claim 12. The aberration measuring means is a Shack-Hartmann sensor;
The imaging apparatus according to claim 6, wherein the aberration correction unit is a deformable mirror or a spatial phase modulator. A wavefront compensation device that receives reflected light from the eye to be examined and is disposed in an optical path of a fundus imaging optical system that images the fundus of the eye to be examined, and controls a wavefront of incident light to compensate a wavefront aberration of the eye to be examined; A wavefront aberration detection optical system for projecting measurement light toward the eye to be examined and detecting reflected light from the fundus by a wavefront sensor,
A step of performing feedback control in which the imaging device repeats detection of wavefront aberration of the eye to be examined based on a detection signal from the wavefront sensor and control of the wavefront compensation device based on the detection result;
The imaging device temporarily stopping feedback control based on a detection signal from the wavefront sensor and resuming feedback control;
A method for controlling an imaging apparatus, comprising:   The step of stopping and resuming, wherein the imaging device temporarily stops feedback control and restarts feedback control based on information on a wavefront of reflected light detected by the wavefront sensor. Item 15. A method for controlling an imaging apparatus according to Item 15.   The step of stopping and restarting the image pickup apparatus temporarily stops feedback control and restarts feedback control based on a change in the wavefront of reflected light detected by the wavefront sensor. Item 17. A method for controlling an imaging apparatus according to Item 15 or 16. The imaging apparatus further includes a step of detecting movement information of the eye based on a detection signal from the wavefront sensor,
In the step of stopping and resuming, the imaging device temporarily stops feedback control when the detected motion information is out of a predetermined range, and when the motion information is returned to the predetermined range. 18. The method according to claim 15, wherein feedback control is resumed.   In the controlling step, when the motion information returns to a predetermined range, the imaging apparatus transmits information related to control of the wavefront compensation device to the wavefront compensation device when the motion information is within the predetermined range. The method of controlling an imaging apparatus according to claim 18, wherein the imaging apparatus is reflected. A method for controlling an imaging apparatus, comprising: an aberration measuring unit that measures aberration of return light from a measurement object irradiated with measurement light; and an aberration correction unit that corrects at least one of the measurement light and the return light. Because
A method of controlling an imaging apparatus, comprising: a step of starting imaging of the measurement target while the imaging apparatus feedback-controls the aberration correction unit based on a measurement result of the aberration measurement unit.   The step of starting imaging, wherein the imaging device starts imaging of the measurement object while feedback controlling the aberration correcting unit when the amount of aberration measured by the aberration measuring unit falls below a threshold value. Item 20. A method for controlling an imaging apparatus according to Item 20.   The imaging device according to claim 20 or 21, wherein, in the step of starting imaging, the imaging device starts imaging of the measurement target by starting the configuration of the image of the measurement target. Control method.   The imaging device according to claim 20 or 21, wherein in the step of starting imaging, the imaging device starts imaging of the measurement target by starting acquisition of an image of the measurement target. Control method.   24. A program for causing a computer to execute each step of the method for controlling an imaging apparatus according to claim 15.

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