JP2014108213A - Imaging device, imaging method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging device that enables a reduction in the number of components for an optical unit and miniaturization of the device and that facilitates adjustment of the optical unit.SOLUTION: An imaging device, which makes light from a light source scan a test object and which takes an image of the test object by return light from the test object, includes a wave aberration correction unit that corrects wave aberration, and an inclination drive unit that periodically inclines the wave aberration correction unit so as to make the test object scanned in a predetermined direction by light reflected from a reflection surface of the wave aberration correction unit.

Description

  The present invention relates to an imaging apparatus, an imaging method, and a program for acquiring an image of an object to be inspected.

  Aberration correction technology that detects the reflected light of the light projected on the fundus with a wavefront sensor located at a conjugate position with the pupil of the eye and controls the aberration correction device to correct the detected aberration to correct the aberration of the eye to be examined. Are known. Using this aberration correction technique, a minute part of the fundus is imaged with high resolution, and it is used for analysis of the shape of photoreceptor cells, blood flow analysis using visualization of blood cell flow, and the like.

  A fundus imaging apparatus that acquires a fundus image by correcting aberration of the eye to be examined is disclosed in Patent Document 1. The fundus imaging apparatus includes a scanning unit that scans light and a wavefront aberration correction unit for correcting wavefront aberration. Further, in order to arrange the scanning unit and the wavefront aberration correction unit in a conjugate manner with respect to the eye to be examined, it is necessary to guide light to the scanning unit and the wavefront aberration correction unit using an optical element such as a lens.

JP 2007-330582 A

  Here, in the configuration of the fundus imaging apparatus, there are problems that the number of parts constituting the optical unit increases, the apparatus becomes larger, and the adjustment of the optical unit becomes complicated.

  It is an object of the present invention to provide an imaging apparatus that can reduce the number of parts of an optical unit, reduce the size of the apparatus, and easily adjust the optical unit.

An image pickup apparatus according to one aspect of the present invention that achieves the above object scans an object to be inspected with light from a light source and picks up an image of the object to be inspected with return light from the object to be inspected. A device,
Wavefront aberration correcting means for correcting the wavefront aberration;
Inclination driving means for periodically tilting the wavefront aberration correction means so as to scan light reflected by the reflection surface of the wavefront aberration correction means in a predetermined direction with respect to the inspection object. And

  According to the present invention, the functions of the scanning unit and the wavefront aberration correction unit are integrated, and the wavefront aberration correction unit is periodically tilted so that the light reflected by the reflection surface of the wavefront aberration correction unit is scanned in one direction. can do. As a result, the number of parts of the optical unit can be reduced, the apparatus can be reduced in size, and an imaging apparatus that can easily adjust the optical unit can be provided.

1 is a diagram illustrating a configuration of an imaging apparatus according to an embodiment. FIG. 3 is a diagram illustrating a configuration of a scanning stage of the imaging apparatus according to the embodiment. 6 is a flowchart for describing an imaging procedure performed by the imaging apparatus according to the embodiment.

[Embodiment: Configuration in which the wavefront aberration correction device 12 is periodically tilted by the scanning stage 13 so that the light reflected by the reflection surface of the wavefront aberration correction device 12 is scanned in one direction.
Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the constituent elements described in the embodiments are merely examples, and the technical scope of the present invention is determined by the claims, and is not limited by the following individual embodiments. . What can be imaged by the imaging apparatus of the present embodiment is, for example, a human fundus, an anterior eye part, a human body, a blood vessel, a blood cell, or the like as a test object.

(Device configuration)
An imaging apparatus according to the present embodiment will be described with reference to FIG. The light source 1 is a laser for forming spot light for wavefront measurement on an inspection object (for example, the fundus). The light source 1 includes, for example, a light source such as an LD (Laser Diode), an LED (Light Emitting Diode), or an SLD (Super Luminescent Diode), and the wavelength may be in the near infrared region. In the present embodiment, an SLD (Super Luminescent Diode) light source having a wavelength of 760 nm is used as the light source 1. The collimator lens 2 changes the light from the light source 1 into parallel light.

  The dichroic mirror 3 has a characteristic of reflecting visible light and transmitting light in the 760 nm band emitted from the light source 1. The focus lens 4 and the focus lens 5 are arranged so as to be movable on the optical axis. The dichroic half mirror 6 reflects 50% of the light (wavefront aberration measurement light) from the light source 1 and transmits 50%, reflects the visible light from the fixation lamp display device 26, and images the inspection object. It has a characteristic of transmitting light (imaging light) having a wavelength of 840 nm from the light source 19. The light source 1 to the dichroic half mirror 6 constitute an aberration measuring light projection optical unit.

  The lens 7 is disposed such that the front focal position substantially coincides with the object to be inspected (for example, the eye pupil Ep to be examined). The focus lens 8 includes a concave lens 8a and a convex lens 8b that share a substantially focal point. The concave lens 8a and the convex lens 8b are connected to the linear motion stage 10 so that the position on the optical axis can be changed. The movement of the linear motion stage 10 is controlled by the control circuit 50. For example, the control circuit 50 controls the linear motion stage 10 to move the concave lens 8a and the convex lens 8b, and the distance between the concave lens 8a and the convex lens 8b so that the imaging magnification of the focus lens 8 becomes a predetermined magnification. Can be changed.

  Reference numeral 9 denotes a lens. The main scanning device 11 scans light in a main scanning direction (first direction: a direction perpendicular to the paper surface) that intersects the irradiation direction from the light source to the eye to be examined. The main scanning device 11 includes, for example, a resonance mirror, a galvanometer mirror, a polygon mirror, and the like. The wavefront aberration correction device 12 changes the shape of the reflecting surface so as to cancel the wavefront aberration. As the wavefront aberration correction device 12, for example, a deformable mirror (DM), a liquid crystal spatial light modulator (LCOS) using liquid crystal (LCOS), or the like can be used. The wavefront aberration correction device 12 is arranged at a conjugate position with respect to the object to be inspected (for example, the eye pupil Ep to be examined), that is, in the vicinity of the focal plane of the lens 9. The wavefront aberration correction device 12 is disposed on the scanning stage 13, and the scanning stage 13 corrects the wavefront aberration in the optical axis direction and the main scanning direction (sub-scanning direction (second direction) intersecting the first direction). The device 12 is periodically scanned and driven at a predetermined scanning angle, and the wavefront aberration correction device 12 is provided closer to the light source 19 (light source side) than the position of the scanning stage 13.

  The wavefront aberration correction device 12 is periodically scanned and driven at a predetermined scanning angle by the scanning stage 13, so that the light reflected by the reflection surface of the wavefront aberration correction device 12 is sub-scanned by the scanning drive of the scanning stage 13. Scanned in (second direction).

  The wavefront aberration correction device 12 and the main scanning device 11 scan light synchronously, so that the main scanning device 11 and the wavefront aberration correction device 12 constitute a two-dimensional scanning unit. Note that the gist of the present invention is not limited to a configuration that performs two-dimensional scanning. For example, the present invention can be applied to an LSLO (Line Scanning Laser Ophthalmoscope, hereinafter referred to as LSLO) that irradiates a test object with a linear laser and scans the linear laser in one direction. In this case, for example, the main scanning device 11 in FIG. 1 can be omitted.

  The dichroic mirror 14 has a characteristic of reflecting wavefront aberration measurement light (light from the light source 1) in the vicinity of a wavelength of 760 nm and transmitting imaging light (light from the light source 19). A lens 15, an aperture stop 16 that is disposed at a conjugate position with the object to be inspected, and removes unnecessary light, and a lens 17 form an image of the object to be inspected on a wavefront aberration detection device 18 (HS) in a telecentric manner. The wavefront aberration detection device 18 includes a microlens array and an image pickup device such as a CCD placed on the focal plane thereof, and the microlens array is disposed at a conjugate position with an object to be inspected (for example, an eye pupil Ep to be examined). The microlens array collects the light returned from the object to be examined (for example, the eye pupil Ep to be examined).

  The light source 19 is a light source such as a laser, an LD (Laser Diode), an LED (Light Emitting Diode), or an SLD (Super Luminescent Diode). In this embodiment, an example using an SLD light source that can reduce the influence of speckle because of its high luminance and wide wavelength width will be described, but the gist of the present invention is not limited to the use of the SLD light source. The optical fiber 20 (single mode) guides light from the light source 19. The collimator lens 21 is disposed on the optical path so that the focal position coincides with the fiber exit end of the optical fiber 20. The half mirror 22 on which the dielectric multilayer film is vacuum-deposited has a characteristic of reflecting 90% light and transmitting 10% light. The confocal stop 24 is disposed at the focal position of the lens 23 and is conjugated with the fundus. The light transmitted through the confocal stop 24 is received by a photoelectric conversion device 25 (light receiving element) such as an APD (avalanche photodiode) or a PMT (Photomultiplier Tube) and converted into an electric signal. In the present embodiment, an APD (avalanche photodiode) is used as the photoelectric conversion device 25.

  The fixation lamp display device 26 is, for example, a device such as an organic EL display, a liquid crystal display, or an LED matrix, and 27 is a lens. The focus lens 4 and the focus lens 5 are arranged so as to be movable on the optical axis. The fixation lamp display device 26, the lens 27, the focus lens 4, and the focus lens 5 constitute a fixation lamp display optical unit. In the present embodiment, the focus lenses 4 and 5 are shared by the fixation lamp display optical unit and the aberration measurement light projection optical unit.

  The control circuit 50 includes an A / D conversion unit 50a, a CPU 50b, and a memory (MEM) 50c. The electrical signal converted by the photoelectric conversion device 25 (light receiving element: APD) is input to the control circuit 50, and the A / D converter 50a of the control circuit 50 converts the electrical signal into digital data. The digital data converted by the A / D conversion unit 50a is stored in the memory 50c (MEM). At this time, image data indicating an object to be inspected (for example, the fundus of the eye E to be examined) is generated under the control of the CPU 50 b, and the generated image data is displayed on the display unit 52. The operation panel 51 (operation unit) receives an operation input of the fundus imaging apparatus and inputs it to the control circuit 50. The display unit 52 displays a fundus image. These processing operations will be described later.

(Procedure for imaging with an imaging device)
(Aberration correction)
FIG. 3 is a flowchart for describing an imaging procedure by the imaging apparatus of the present embodiment. First, in step S301, an imaging region of the inspection object is selected. The operator operates the fixation lamp position operation switch 51f to select an imaging region.

  In step S302, focus adjustment is performed. The operator operates the focus switches 51d and 51e to perform focus adjustment. By operating the focus adjustment switches 51d and 51e, the focus lens 8 (concave lens 8a and convex lens 8b) on the linear motion stage 10 is moved to adjust the focus in the depth of focus direction.

  In step S <b> 303, when the operator operates the aberration correction switch 51 a (Comp) of the operation panel 51 (operation unit), this operation input is input to the control circuit 50. The CPU 50b of the control circuit 50 performs control so that the main scanning device 11 and the scanning stage 13 are aligned (fixed) at the reference position. In this state, the main scanning device 11 and the scanning stage 13 hold (fix) the position in a stopped state without being driven to scan at the reference position.

  In step S304, the fixation lamp display device 26 presents a fixation target under the control of the CPU 50b. In step S305, the light source 1 is turned on under the control of the CPU 50b, and the light with a wavelength of 760 nm emitted from the light source 1 is converted into parallel light by the collimator lens 2, transmitted through the dichroic mirror 3, and parallel by the focus lens 4 and the focus lens 5. Projected as light. Approximately half of the light reflected by the dichroic half mirror 6 enters the object to be inspected (for example, the pupil Ep of the eye to be inspected) and forms spot light inside the object to be inspected (for example, the fundus Er). This spot light is reflected inside the inspection object (for example, fundus Er). Light reflected from the object to be inspected (including return light) passes through the dichroic half mirror 6, passes through the lens 7, the focus lens 8, and the lens 9, and is reflected by the main scanning device 11 and the wavefront aberration correction device 12. The light reflected by the main scanning device 11 and the wavefront aberration correction device 12 is reflected by the dichroic mirror 14, collected by the lens 15 at the aperture of the diaphragm 16, and imaged on the wavefront aberration detection device 18 by the lens 17.

  The wavefront aberration detection device 18 is a Hartmann Shack sensor that includes a microlens array and an image pickup device such as a CCD placed on the focal plane thereof. Is arranged. This microlens array forms a plurality of spot images on a CCD surface by dividing light from an object to be inspected (for example, a pupil Ep of an eye to be inspected) for each region. Then, the wavefront aberration detection device 18 outputs the position of the spot as image information and inputs it to the control circuit 50.

  The CPU 50b calculates the wavefront aberration from the image information, obtains the wavefront shape (correction data) of the wavefront aberration correction device 12 that cancels the wavefront aberration, and instructs the wavefront aberration correction device 12 to change the shape of the reflection surface. The wavefront aberration correction device 12 is driven according to the correction data to change the shape of the reflection surface. The spot position on the wavefront aberration detection device 18 is corrected by the deformation of the reflection surface of the wavefront aberration correction device 12, and the CPU 50b calculates the wavefront aberration again. This feedback control ends when the RMS (Root Mean Square) of the wavefront aberration converges to 0.05λ or less. When the RMS of the wavefront aberration is about 0.05λ or less, the CPU 50b ends the feedback control and displays on the display unit 52 that the aberration correction is completed to the photographer.

(Adaptive Optics (AO imaging))
When the correction of the wavefront aberration is completed, AO-SLO imaging (high resolution imaging) for imaging a minute area with high resolution is performed.

  In step S <b> 306, when the operator operates the AO imaging switch 51 b (AO) of the operation panel 51, this operation input is input to the control circuit 50. The CPU 50b of the control circuit 50 that has detected the input from the AO imaging switch 51b (AO) turns off the light source 1 and turns on the light source 19. In step S307, the CPU 50b controls the main scanning device 11 and the scanning stage 13 that supports the wavefront aberration correction device 12, and the main scanning device 11 and the scanning stage 13 scan angles corresponding to the angle of view for high-resolution imaging. Start scanning.

  In step S308, high-resolution imaging is executed. The light emitted from the light source 19 is guided to the focal position of the collimator lens 21 by the optical fiber 20, collimated by the collimator lens 21, and 10% of the light is transmitted by the half mirror 22. The light transmitted through the half mirror 22 passes through the dichroic mirror 14 and is scanned (reflected) by the wavefront aberration correction device 12 and the main scanning device 11. At this time, the wavefront aberration that cancels the aberration of the object to be inspected (for example, the eye to be examined) is added to the light reflected by the reflection surface of the wavefront aberration correction device 12 by the wavefront aberration correction in the previous step S305. The light reflected by the wavefront aberration correction device 12 and the reflection surface of the main scanning device 11 is transmitted through the lens 9, the focus lens 8, the lens 7, and the dichroic half mirror 6, and from the inspection object (for example, the pupil Ep of the eye to be inspected). Reaches the fundus Er). The main scanning device 11, the wavefront aberration correction device 12, and the scanning stage 13 scan, for example, a minute region of about 0.3 mm × 0.3 mm inside the inspection object (for example, on the fundus Er).

  Since the wavefront aberration that corrects the wavefront aberration of the inspection object is added to the light reaching the inspection object by the wavefront aberration correction device 12, there is an aberration inside the inspection object (for example, the fundus Er of the eye to be inspected). A light spot is formed in the absence of the light. For example, when the beam diameter of light incident on the pupil Ep of the eye to be examined is 4 mm in diameter, the beam diameter (spot diameter) of light on the fundus oculi Ep is reduced to about 5 μm.

  Reflected light (including return light) from the object to be inspected follows the incident optical path. The reflected light is reversely scanned (descanned) by the wavefront aberration correction device 12 disposed on the dichroic half mirror 6, the lens 7, the focus lens 8, the lens 9, the main scanning device 11, and the scanning stage 13. The light reflected by the wavefront aberration correction device 12 is canceled by reverse scanning (descanning), passes through the dichroic mirror 14, and 90% of the light is reflected by the half mirror 22. The light reflected by the half mirror 22 is condensed on the opening of the confocal stop 24 by the lens 23, and the light transmitted through the opening of the confocal stop 24 is received by the photoelectric conversion device 25 and converted into an electrical signal. This electrical signal is input to the control circuit 50. The electric signal input to the control circuit 50 is converted into digital data by the A / D conversion unit 50a (A / D) and recorded in the memory 50c (MEM), and the CPU 50b also converts the A / D conversion unit 50a (A / D) to convert the digital data converted into image data.

  In step S309, the display unit 52 displays the image converted by the CPU 50b. When the operator observes a high-resolution image drawn up to the photoreceptor cell level displayed on the display unit 52 and finely adjusts the imaging part (S310-Yes), the operator operates the fixation lamp position operation switch 51f. Then, the imaging region is finely adjusted to perform high resolution imaging (S308). If fine adjustment of the imaging region is unnecessary (S310-No), the process proceeds to step S311. On the other hand, when finely adjusting the focus of the image displayed on the display unit 52 (S311-Yes), the focus switches 51d and 51e are operated to perform fine adjustment of the focus to perform high-resolution imaging (S308). By operating the focus adjustment switches 51d and 51e, the focus lens 8 (concave lens 8a and convex lens 8b) on the linear motion stage 10 is moved to perform fine adjustment of the focus. When fine adjustment of the focus is unnecessary (S311-No), when the operator operates the recording switch 51c (rec) in step S312, the image data with the file name added is recorded in the memory 50c, and the image is picked up by the image pickup apparatus. Ends.

(Configuration of wavefront aberration correction device and scanning stage)
FIG. 2 shows the configuration of the scanning stage 13. The wavefront aberration correction device 12 disposed on the scanning stage 13 is composed of a deformable mirror (DM) capable of deforming the surface shape. The deformable mirror includes a mirror surface, a piezoelectric element that deforms the mirror surface, and an electrode that applies a voltage to the piezoelectric element. The mirror surface can be changed to an arbitrary shape by the expansion and contraction of the piezoelectric element by the voltage applied to the electrode.

  The scanning stage 13 is configured to freely tilt (rotate) the hinge 30 about the rotation axis (rotation center). The rotation center of the scanning stage 13 is provided on the reflection surface of the wavefront aberration correction device 12.

  Vibrating elements 31 and 32 are provided at both ends of the scanning stage 13, and the CPU 50b performs control for generating vibrations in which the vibrating elements 31 and 32 periodically repeat plus (+) displacement and minus (−) displacement. Signals 210 and 220 are generated. The vibration elements 31 and 32 are composed of, for example, a piezoelectric element, a voice coil motor, and the like, and vibration is controlled according to control signals 210 and 220 generated by the CPU 50b. By applying control signals 210 and 220 in which the plus (+) displacement and the minus (−) displacement are in opposite phases to the vibrating elements 31 and 32, the vibrating elements 31 and 32 vibrate in opposite phases, respectively.

  For example, in a state where the vibration element 31 is displaced to a plus (+) and the vibration element 32 is displaced to a minus (−), the right end side of the scanning stage 13 is raised by the plus (+) displacement of the vibration element 31. Further, the left end side of the scanning stage 13 is lowered by the minus (−) displacement of the vibration element 32. Conversely, in a state where the vibration element 32 is displaced to plus (+) and the vibration element 31 is displaced to minus (−), the left end side of the scanning stage 13 is raised by the plus (+) displacement of the vibration element 32. Further, the right end side of the scanning stage 13 is lowered due to the minus (−) displacement of the vibration element 31. The scanning stage 13 periodically repeats the inclination of a predetermined inclination angle (± α) about the hinge 30 as a rotation axis by the vibration that periodically repeats plus (+) displacement and minus (−) displacement of the vibration elements 31 and 32. Perform reciprocating motion (tilt drive).

  The control circuit 50 controls the tilt angle (± α) of the scanning stage 13 according to the light scanning angle. When the distance from the hinge 30 that is the center of rotation to the vibration elements 31 and 32 is L, and the displacement (plus (+) displacement or minus (−) displacement) of the vibration elements 31 and 32 is ST, sin α = ST / L. Can be represented. The control circuit 50 inputs the control signal for changing the displacement (ST) of the vibration elements 31 and 32 so as to have a predetermined inclination angle to the vibration elements 31 and 32, thereby changing the inclination angle of the scanning stage 13 to the light scanning angle. Can be controlled to match.

  When the scanning stage 13 performs periodic reciprocating motion (tilt driving) with an inclination angle (± α) around a predetermined rotation axis, the wavefront aberration correction device 12 disposed on the scanning stage 13 also has an inclination angle (± Perform periodic reciprocating motion (tilt drive) by α). By changing the inclination of the surface of the wavefront aberration correction device 12 by periodic reciprocation, light can be scanned in a predetermined direction on the reflection surface of the wavefront aberration correction device 12.

  The main scanning device 11 described above scans light in the main scanning direction (perpendicular to the paper surface). If the scanning stage 13 is arranged with the rotation axis (rotation center) of the hinge 30 of the scanning stage 13 aligned with the main scanning direction, the wavefront aberration correction device 12 on the scanning stage 13 transmits light incident on the reflecting surface in the main scanning direction. Will be scanned in the direction that intersects. The wavefront aberration correction device 12 on the scanning stage 13 intersects the light incident on the reflecting surface with respect to the main scanning direction by the periodic reciprocating motion (tilt driving) of the scanning stage 13 synchronized with the scanning of the main scanning device 11. Scan in the direction to do.

  The wavefront aberration correction device 12 and the scanning stage 13 scan the light incident on the reflection surface of the wavefront aberration correction device 12 in the sub-scanning direction (second direction) intersecting the main scanning direction (first direction). Functions as a sub-scanning device. The inspection object can be scanned two-dimensionally by combining the main scanning by the main scanning device 11 and the sub-scanning by the wavefront aberration correction device 12 and the scanning stage 13.

(Scanning angle of sub-scanning stage)
When the scanning range of the inspection object is, for example, 0.3 mm × 0.3 mm (S mode) and the focal length of the inspection object is 17 mm, the scanning angle of the inspection object (for example, the pupil Ep of the inspection eye) is ± 0. .5 °. When the imaging magnification between the object to be inspected (for example, the pupil of the eye to be examined) and the wavefront aberration correction device 12 is set to 1, the swing angle of the reflection surface of the wavefront aberration correction device 12 is a scanning angle (± 0.5 °). The inclination angle of the scanning stage 13 is ± 0.25 °. If the distance from the hinge 30 that is the center of rotation is L = 10 mm, the moving strokes (ST) of the vibration elements 31 and 32 are ± 43 μm. What is necessary is just to drive with the frequency from which the image of a desired frame number is obtained with this stroke. For example, in order to capture 30 frames per second of an image of an object to be inspected (for example, the fundus), it may be driven at 30 Hz.

  When the scanning range is wider than 0.3 mm × 0.3 mm (S mode), for example, 1.0 mm × 1.0 mm (M mode), the moving strokes (ST) of the vibration elements 31 and 32 are ±. 86 μm. Further, the moving strokes (ST) of the vibrating elements 31 and 32 when scanning a scanning range of 1.5 mm × 1.5 mm (L mode) is ± 129 μm.

  The CPU 50 b of the control circuit 50 can change the scanning range by changing the control signal input to the vibration elements 31 and 32 in synchronization with the scanning range of the main scanning device 11. Here, “scanning” is synonymous with “imaging”.

  Note that tilting the wavefront aberration correction device 12 with the scanning stage 13 may shift the reflection point of light, which may degrade the wavefront correction performance. However, when the diameter of the light incident on the wavefront aberration correction device 12 is 4 mm and the incident angle is 25 °, the change in the reflection point of the light at an inclination angle of ± 0.25 ° due to sub-scanning is 10 μm or less. Usually, since the alignment accuracy between the object to be inspected (for example, the eye to be inspected) and the apparatus is about ± 0.1 mm, the change in the reflection point of light is sufficiently small compared to this amount, so the wavefront correction performance does not deteriorate.

In the preceding example, the scanning stage 13 is disposed so as to perform periodic tilt driving in the sub-scanning direction, and the wavefront aberration correction device 12 is disposed on the scanning stage 13 at a conjugate position with respect to the object to be inspected. The example in which the main scanning device 11 is arranged on the eye side to be examined from the position has been described.
If the scanning stage 13 is arranged at a conjugate position with respect to the object to be inspected, the influence of the deviation of the reflection point of the wavefront aberration correction device 12 by periodic tilt driving is small as described above. For this reason, the direction of periodic tilt driving of the scanning stage 13 is not limited to the sub-scanning direction, and may be the main scanning direction. For example, the scanning stage 13 is disposed so as to be periodically tilted in the main scanning direction, and the wavefront aberration correction device 12 is disposed on the scanning stage 13 so as to be conjugate with the object to be inspected. A sub-scanning device may be arranged on the optometry side.

  When the scanning stage 13 is arranged at the position of the main scanning device 11 in FIG. 1, the displacement of the reflection point on the reflection surface of the wavefront aberration correction device 12 becomes large. That is, when light is scanned by the main scanning device 11 at a scanning angle of ± 0.5 °, if the distance between the main scanning device 11 and the wavefront aberration correction device 12 is 10 mm, the reflection point is about ± 0.1 mm. Displacement will occur. When the imaging range is the L mode, the displacement of the reflection point is further increased to ± 0.3 mm, and the correction accuracy of the wavefront aberration by the wavefront aberration correction device 12 is lowered.

  Therefore, in order not to reduce the correction accuracy of the wavefront aberration, the wavefront aberration correction device 12 and the scanning stage 13 are arranged closer to the light source 19 than the position of the main scanning device 11 at a position conjugate with the inspection object. good.

  Further, in the present embodiment, the example in which the vibration elements 31 and 32 are arranged at positions symmetrical with respect to the rotation center as the actuator in order to more stably realize the tilt driving of the scanning stage 13 has been described. The configuration of the scanning stage 13 is not limited to this example. For example, the vibration element is disposed on one side of the scanning stage 13 and an elastic member is disposed on the other side of the scanning stage 13 instead of the vibration element. It is also possible to configure the scanning stage 13. According to this configuration, the elastic force (restoring force) generated in the elastic member according to the compression displacement or the tensile displacement applied to the elastic member due to the displacement of one vibration element can be used for driving the scanning stage 13. As in the case of using two vibration elements as shown in FIG. 2, the periodic reciprocation of the scanning stage 13 can be stably performed. Further, a digital galvano scanner can be connected to the wavefront aberration correction device 12 as the scanning stage 13 and driven to tilt.

  As described above, the wavefront aberration correction device 12 is arranged on the scanning stage 13 and is configured to be capable of two-dimensional scanning in synchronization with the main scanning device 11, thereby reducing the number of parts without impairing aberration correction accuracy and reducing the size. Can be realized.

  By adopting a configuration in which the wavefront aberration correction device 12 is periodically tilted so that the light reflected by the reflection surface of the wavefront aberration correction device 12 is scanned in one direction by the scanning stage 13, the number of components can be reduced. Miniaturization and easy adjustment are possible.

  In the above-described embodiment, the case where the object to be imaged by the imaging apparatus is an eye has been described as an example. However, the gist of the present invention is not limited to this example, and the inside of the human body is imaged. It is possible to apply to an endoscope apparatus. In this case, the endoscope apparatus may have a light source, an imaging device, and an insertion unit for inserting the imaging device into the body (inside the body cavity).

(Other embodiments)
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 (10)

An imaging device that scans the inspection object with light from a light source and captures an image of the inspection object with return light from the inspection object,
Wavefront aberration correcting means for correcting the wavefront aberration;
An inclination driving means for periodically inclining the wavefront aberration correction means so as to scan the light reflected by the reflection surface of the wavefront aberration correction means in a predetermined direction with respect to the inspection object;
An imaging apparatus comprising:   Light that is disposed on the optical path between the object to be inspected and the wavefront aberration correction unit and that is scanned in the predetermined direction on the reflection surface of the wavefront aberration correction unit intersects the predetermined direction. The imaging apparatus according to claim 1, further comprising scanning means for scanning in a direction.   The imaging apparatus according to claim 2, wherein the wavefront aberration correction unit is provided on the light source side with respect to a position of the scanning unit. The predetermined direction is a sub-scanning direction;
The imaging apparatus according to claim 2, wherein the intersecting direction is a main scanning direction.   The tilt driving means periodically tilts the wavefront aberration correcting means so as to scan a linear laser beam in the predetermined direction with respect to the object to be inspected. The imaging apparatus of Claim 1. According to a scanning range in which the light from the light source is scanned with respect to the object to be inspected, the apparatus further comprises changing means for changing an inclination angle for inclining the wavefront aberration correcting means by the inclination driving means,
6. The imaging apparatus according to claim 1, wherein the tilt driving unit periodically tilts the wavefront aberration correcting unit according to the tilt angle changed by the changing unit. The object to be examined is an eye to be examined;
The imaging apparatus according to claim 1, wherein the wavefront aberration correcting unit is disposed at a conjugate position with respect to the anterior eye portion of the eye to be examined. An imaging method of scanning an object to be inspected with light from a light source and capturing an image of the object to be inspected with return light from the object to be inspected,
A tilting step of periodically tilting the wavefront aberration correcting means so that the light reflected by the reflection surface of the wavefront aberration correcting means for correcting the wavefront aberration is scanned in a predetermined direction with respect to the inspection object; A characteristic imaging method. According to a scanning range in which the light from the light source is scanned with respect to the object to be inspected, the method further includes a changing step of changing an inclination angle for periodically tilting the wavefront aberration correcting unit,
9. The imaging method according to claim 8, wherein, in the tilting step, the wavefront aberration correcting unit is periodically tilted by the tilt angle changed in the changing step.   The program for functioning a computer as each means of the imaging device of any one of Claims 1 thru | or 7.

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