JP7430999B2 - Ophthalmological device and its control method - Google Patents

Description

The present invention relates to an ophthalmological apparatus and a control method thereof.

In recent years, ophthalmological examinations using ophthalmological equipment are performed during screening. Such an ophthalmological device is also expected to be applied to self-examination, and further miniaturization and weight reduction are desired.

For example, Patent Document 1 and Patent Document 2 disclose an ophthalmological apparatus configured to pattern-illuminate a subject's eye using slit light and detect the returned light with a CMOS (Complementary Metal Oxide Semiconductor) image sensor. ing. This ophthalmological apparatus can acquire an image of the eye to be examined with a simple configuration by adjusting the illumination pattern and the timing of light reception by the CMOS image sensor.

In such an ophthalmological apparatus, as in other ophthalmological apparatuses, by performing pattern illumination when the slit light is optimally focused, images with higher resolution can be obtained. Patent Document 1 and Patent Document 2 disclose a method of driving a focusing mechanism using the amount of reflected illumination light from an eye to be examined.

US Patent No. 7831106 US Patent No. 8237835

However, the amount of illumination light reflected from the eye to be examined changes depending on the condition of the eye to be examined or the irradiation position of the illumination light. Therefore, depending on the eye to be examined, the amount of reflected illumination light may be small, and it may be difficult to move the focal position of the slit light to an optimal position. That is, it is difficult to achieve an optimal focusing state with good reproducibility.

This invention was made to solve these problems, and its purpose is to provide a new technique for identifying the optimal focusing state with good reproducibility with a simple configuration. .

A first aspect of some embodiments includes a projection unit that projects pattern light having a projection shape extending in at least a first direction onto the subject's eye, and based on a detection result of return light of the pattern light from the subject's eye, an acquisition unit that acquires a received light image corresponding to an aperture shape extending at least in a second direction intersecting the first direction; and a identification unit that identifies a focused state of the patterned light based on a brightness distribution of the received light image. It is an ophthalmological device including.

A second aspect of some embodiments includes a projection unit that projects pattern light in a projection shape extending in at least the first direction onto the eye to be examined, and based on a detection result of return light of the pattern light from the eye to be examined, an acquisition unit that acquires a received light image corresponding to an aperture shape extending at least in the first direction; and a brightness distribution in a second direction intersecting the first direction in one or more received light images acquired by the acquisition unit. , and a specifying unit that specifies a focused state of the patterned light.

In a third aspect of some embodiments, in the first aspect or the second aspect, the specifying unit specifies the focus control content of the patterned light based on the luminance distribution in the second direction in the received light image. The image forming apparatus further includes a control section that performs focusing control of the patterned light based on the specified focusing control content.

In a fourth aspect of some embodiments, in the third aspect, the control unit performs the focusing control so that the bright part or the dark part moves to a predetermined position.

A fifth aspect of some embodiments, in the third aspect or fourth aspect, includes a focusing mechanism disposed in the optical path of the patterned light and the return light, and the control unit is configured to control the identified focusing mechanism. The focusing mechanism is controlled based on the control content.

In a sixth aspect of some embodiments, in any of the first to fifth aspects, the projection unit includes a projector that outputs patterned light whose projection shape can be changed.

In a seventh aspect of some embodiments, in the sixth aspect, the projection unit outputs patterned light having a first projection shape for specifying the focused state, and after controlling the focusing of the patterned light, A pattern light having a second projection shape different from the first projection shape is output, and the acquisition unit acquires a received light image based on a detection result of the return light of the pattern light having the second projection shape.

In an eighth aspect of some embodiments, in any of the first to seventh aspects, the acquisition unit includes an image sensor that detects the returned light, and acquires the received light image using a rolling shutter method.

A ninth aspect of some embodiments includes a projection step of projecting pattern light having a projection shape extending in at least a first direction onto the subject's eye, and based on the detection result of the return light of the pattern light from the subject's eye, an acquisition step of acquiring a received light image corresponding to an aperture shape extending at least in a second direction intersecting the first direction; and a specifying step of identifying a focused state of the patterned light based on a brightness distribution of the received light image. A method of controlling an ophthalmological apparatus includes the following steps.

A tenth aspect of some embodiments is based on a projection step of projecting pattern light having a projection shape extending in at least a first direction onto the subject's eye, and a detection result of the return light of the pattern light from the subject's eye. an acquisition step of acquiring a received light image corresponding to an aperture shape extending at least in the first direction; and a brightness distribution in a second direction intersecting the first direction in one or more received light images acquired in the acquisition step. , a specifying step of specifying a focused state of the patterned light.

In an eleventh aspect of some embodiments, in the ninth aspect or the tenth aspect, the identifying step specifies the focus control content of the patterned light based on the luminance distribution in the second direction in the received light image. The method further includes a control step of performing focusing control of the patterned light based on the specified focusing control content.

In a twelfth aspect of some embodiments, in any of the ninth to eleventh aspects, the projecting step includes a first projection that outputs patterned light having a first projection shape for specifying the focused state. and a second projection step of outputting pattern light of a second projection shape different from the first projection shape after focusing control of the pattern light, and the acquisition step includes the step of outputting the pattern light of a second projection shape different from the first projection shape, a first acquisition step of acquiring a received light image corresponding to the aperture shape based on a detection result of the returned light of the pattern light of the first projection shape; and a second projection shape projected in the second projection step. and a second acquisition step of acquiring a received light image based on the detection result of the returned light of the pattern light.

In a thirteenth aspect of some embodiments, in any of the ninth to twelfth aspects, the acquiring step acquires the received light image by a rolling shutter method based on the detection result of the returned light.

Note that it is possible to arbitrarily combine the configurations according to the plurality of aspects described above.

According to the present invention, it is possible to provide a new technique for specifying an optimal focusing state with good reproducibility with a simple configuration.

FIG. 1 is a schematic diagram showing a configuration example of an ophthalmologic apparatus according to an embodiment. FIG. 1 is a schematic diagram showing a configuration example of an ophthalmologic apparatus according to an embodiment. FIG. 1 is a schematic diagram showing a configuration example of an ophthalmologic apparatus according to an embodiment. FIG. 2 is an explanatory diagram of the operation of the ophthalmologic apparatus according to the embodiment. FIG. 2 is an explanatory diagram of the operation of the ophthalmologic apparatus according to the embodiment. FIG. 2 is an explanatory diagram of the operation of the ophthalmologic apparatus according to the embodiment. FIG. 2 is an explanatory diagram of the operation of the ophthalmologic apparatus according to the embodiment. It is a flow diagram of an example of operation of an ophthalmological device concerning an embodiment. It is a schematic diagram showing an example of composition of an ophthalmologic device concerning a modification of an embodiment. FIG. 7 is an explanatory diagram of the operation of the ophthalmologic apparatus according to a modification of the embodiment. FIG. 7 is an explanatory diagram of the operation of the ophthalmologic apparatus according to a modification of the embodiment. FIG. 7 is an explanatory diagram of the operation of the ophthalmologic apparatus according to a modification of the embodiment. FIG. 7 is an explanatory diagram of the operation of the ophthalmologic apparatus according to a modification of the embodiment. FIG. 7 is an explanatory diagram of the operation of the ophthalmologic apparatus according to a modification of the embodiment. It is a flowchart of the example of operation of the ophthalmologic apparatus concerning the modification of an embodiment.

An example of an embodiment of an ophthalmologic apparatus and a control method thereof according to the present invention will be described in detail with reference to the drawings. Note that the contents of the documents described in this specification can be appropriately cited as the contents of the following embodiments.

The ophthalmological apparatus according to the embodiment includes a projection system that projects pattern light onto the eye to be examined, and a light receiving system that receives the return light of the pattern light from the eye to be examined, and the ophthalmological apparatus includes It is possible to obtain an image of the fundus of the eye to be examined based on the following. In some embodiments, the ophthalmological device uses a configuration similar to that described above to obtain images of the anterior segment of the subject's eye.

For example, the projection system projects a slit-shaped (line-shaped) pattern of light extending in at least the first direction onto the subject's eye. The ophthalmological apparatus acquires a received light image corresponding to the aperture shape extending in at least the second direction from the result of receiving the returned light obtained by the light receiving system, and combines the patterned light based on the luminance distribution in the second direction in the received light image. Identify the state of focus. Here, the second direction is a direction intersecting the first direction. In some embodiments, the second direction is different from a direction perpendicular to the first direction.

In this specification, the "direction" of the pattern light, the "direction" of the aperture shape or the received light image, and the aperture direction do not mean the direction at each position in the absolute coordinate system, but rather It means a direction on a surface (for example, a light receiving surface in a light receiving system).

[Optical system configuration]
FIGS. 1 to 3 show block diagrams of exemplary configurations of ophthalmological apparatuses according to embodiments. FIGS. 1 and 2 are block diagrams of exemplary configurations of the optical system of the ophthalmologic apparatus 1 according to the embodiment. FIG. 3 shows a block diagram of a configuration example of a control system of the ophthalmologic apparatus 1. As shown in FIG. In FIGS. 1 to 3, similar parts are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

The ophthalmological apparatus 1 projects pattern light onto the eye E, receives the returned light, specifies the focused state of the pattern light, and performs focusing control based on the specified focused state. After the focus control, the ophthalmological apparatus 1 can obtain an image of the eye (fundus) of the eye E by projecting the pattern light onto the eye E again and receiving the returned light.

The ophthalmological apparatus 1 includes a projection system 10, a light receiving system 20, an image processing section 30, and an image output section 40.

The ophthalmologic apparatus 1 projects pattern light onto the eye E in a focus control mode for performing focus control and a photography mode for photographing, and acquires a received light image in each mode.

[Focus control mode]
The projection system 10 emits pattern light for focusing control, which has a projected shape extending at least in a direction (hereinafter referred to as an aperture crossing direction) intersecting the aperture direction (a direction corresponding to the aperture direction), to the subject's eye E. to project. The light receiving system 20 receives the returned light of the pattern light projected onto the eye E by the projection system 10. The image processing unit 30 acquires a received light image corresponding to the shape of the aperture extending at least in the aperture direction from the result of receiving the returned light by the light receiving system 20. The image processing unit 30 identifies the focused state (whether or not it is focused) of the pattern light based on the luminance distribution in the direction across the aperture in the received light image. The image processing unit 30 can specify control details for a focusing mechanism, which will be described later, based on the brightness distribution. A control unit, which will be described later, performs focusing control according to control details specified by the image processing unit 30 (that is, controls a focusing mechanism, which will be described later).

[Shooting mode]
After focusing control, the projection system 10 sequentially projects pattern light for imaging having a projection shape (for example, slit shape, line shape) extending in the aperture direction onto the eye E in a direction orthogonal to the aperture direction. In some embodiments, the projection shape in the focus control mode and the projection shape in the imaging mode are different from each other. The light receiving system 20 receives the returned light of the pattern light projected onto the eye E by the projection system 10. The image processing unit 30 sequentially acquires received light images corresponding to the aperture shape while shifting the aperture shape in a direction perpendicular to the aperture direction (or an aperture cross direction) from the result of the return light received by the light receiving system 20. , an image of the fundus of the eye E to be examined is acquired.

(Projection system 10)
Projection system 10 includes a pattern light generating section 11, a smoothing section 12, and an optical system 13.

(Pattern light generating section 11)
The pattern light generating section 11 is controlled by a control section, which will be described later, and generates pattern light in a projected shape extending at least in the direction crossing the aperture. The pattern light generating section 11 can selectively generate pattern light having two or more projection shapes, and can selectively project the pattern light onto two or more projection areas in the eye E (fundus).

As shown in FIG. 2, the pattern light generator 11 includes a light source 11A, an optical system 11B, and a spatial light modulator 11C. A projector is an example of the pattern light generating section 11 having such a configuration. That is, the pattern light generating section 11 includes a light source 11A, an optical system 11B, and a spatial light modulator 11C that correspond to the type of projector. The light source 11A can be placed at a position that is optically substantially conjugate with the imaging site of the eye E (for example, the fundus of the eye, the anterior segment of the eye).

In some embodiments, the light source 11A is a light source that can switch and output light in the infrared region or near-infrared region, and light in the visible region. For example, the light source 11A outputs light in the infrared region or near-infrared region when outputting a pattern light for focusing control (focus indicator) in the focus control mode, and in the imaging mode, the light source 11A outputs light in the infrared region or near-infrared region. When , it outputs light in the visible range.

In some embodiments, the pattern light generator 11 has the function of a DLP (Digital Light Processing (registered trademark)) projector using a digital micromirror device. In this case, in the first configuration example, a single digital micromirror device is used for light in the infrared region or near-infrared region. In the second configuration example, a digital micromirror device common to RGB color components is used for light from a white light source. In the third configuration example, a digital micromirror device is used for each RGB color component for light from a white light source.

In the first configuration example, the light source 11A includes, for example, an LED (Light Emitting Diode) light source that emits light in an infrared region or a near-infrared region. Further, the optical system 11B includes a relay optical system and an optical lens. Moreover, the spatial light modulator 11C includes a digital micromirror device in which a plurality of mirror elements are two-dimensionally arranged. Each of the plurality of mirror elements is independently controllable. Note that the spatial light modulator 11C can include a projection lens for projecting light spatially modulated by the digital micromirror device.

In the second configuration example, the light source 11A includes a white light source or a light source capable of outputting light of each color component of RGB. Further, the optical system 11B includes a color wheel, a relay optical system, and an optical lens for time-divisionally outputting light of each color component of RGB from the light from the light source 11A. Moreover, the spatial light modulator 11C includes a digital micromirror device in which a plurality of mirror elements are two-dimensionally arranged. Note that the spatial light modulator 11C can include a projection lens for projecting light spatially modulated by the digital micromirror device.

In the third configuration example, the light source 11A includes a white light source or a light source capable of outputting light of each RGB color component. Further, the optical system 11B includes a relay optical system and an optical lens. Moreover, the spatial light modulator 11C includes a plurality of digital micromirror devices provided for each RGB color component. Note that the spatial light modulator 11C can include a projection lens for projecting light spatially modulated by the digital micromirror device.

In some embodiments, the pattern light generator 11 has the function of a reflective liquid crystal projector using LCoS (Liquid Crystal on Silicon). In this case, the light source 11A includes a white light source. Further, the optical system 11B includes one or more reflective mirrors, one or more dichroic mirrors, and one or more polarizing beam splitters. In addition, the spatial light modulator 11C includes a reflective liquid crystal panel for each RGB color component, a cross dichroic prism for combining spatially modulated light for each color component, and a projector for projecting the combined light. and a projection lens for.

In some embodiments, the pattern light generator 11 has the function of a transmissive liquid crystal projector. In this case, the light source 11A includes a white light source. Further, the optical system 11B includes one or more reflective mirrors and one or more dichroic mirrors. In addition, the spatial light modulator 11C includes a transmissive liquid crystal panel for each RGB color component, a cross dichroic prism for combining spatially modulated light for each color component, and a cross dichroic prism for projecting the combined light. and a projection lens for.

In some embodiments, the pattern light generator 11 has the function of a known projector using MEMS (Micro Electro Mechanical Systems).

The projector as described above functions as a pixelated pattern light generator. Note that since the configuration of the projector as described above is well known, detailed explanation will be omitted. The pattern light generator 11 is capable of outputting pattern light (illumination light) corresponding to an illumination pattern whose shape and projection position can be arbitrarily changed.

The pattern light generating section 11 is controlled by a control section, which will be described later, and generates pattern light having an arbitrary projection shape. The projection shape can be set by the user using, for example, an operation unit described below. When the user uses the operation unit to specify a shape pattern, external shape, size, etc., the control unit specifies an illumination pattern based on the specified shape pattern, etc., and adjusts the spatial light modulator based on the specified illumination pattern. 11C.

(Smoothing unit 12)
The smoothing unit 12 smoothes the pattern light (light intensity distribution of the pattern light) generated by the pattern light generating unit 11 so that the light intensity distribution is diffused at least in the aperture direction (the light intensity distribution spreads at least in the aperture direction). do. That is, the smoothing unit 12 smoothes the pattern light so that the diffusion characteristics in the aperture direction and the diffusion characteristics in the cross-aperture direction are different. Specifically, the transmission angle θ1 of the transmitted light with respect to the predetermined incident angle θ0 for the aperture direction component of the pattern light is larger than the transmission angle θ2 of the transmitted light with respect to the predetermined incidence angle θ0 of the aperture cross direction component of the pattern light.

The smoothing unit 12 can be placed at a position that is optically approximately conjugate with the imaged region of the eye E to be examined (for example, the fundus of the eye, the anterior segment of the eye).

In some embodiments, the smoothing unit 12 includes a diffusion filter (optical low-pass filter). In some embodiments, the smoothing section 12 includes a birefringent plate having a birefringent index.

(Optical system 13)
The optical system 13 includes a relay optical system for relaying the pattern light smoothed by the smoothing section 12. In some embodiments, optical system 13 further includes a collimating lens and an optical scanner. In this case, the optical scanner can deflect the pattern light under control from a control section, which will be described later.

The pattern light that has passed through the optical system 13 is reflected by the optical multiplexer/demultiplexer 50 and guided to the optical system 51.

(Optical multiplexer/demultiplexer 50)
The optical multiplexer/demultiplexer 50 guides the light from the projection system 10 to the optical system 51 and guides the light from the optical system 51 to the light receiving system 20 . Such a function of the optical multiplexer/demultiplexer 50 can be realized by a beam splitter or a dichroic mirror.

(Optical system 51)
The optical system 51 is arranged between the optical multiplexer/demultiplexer 50 and the eye E to be examined. Optical system 51 includes a focusing mechanism 52. In some embodiments, the optical system 51 further includes an objective lens disposed between the focusing mechanism 52 and the eye E to be examined. In some embodiments, optical system 51 includes an anterior lens for moving the focal position of the patterned light closer to the anterior segment of the eye. In this case, the front lens is provided so that it can be inserted into and removed from the optical path of the pattern light.

Examples of the focusing mechanism 52 include a focusing lens movable along the optical axis direction (the direction of the optical path of patterned light), a liquid lens whose refractive index can be changed, a liquid crystal lens whose refractive index can be changed, and an optical axis direction. There is an objective lens that can be moved along.

The focusing lens or objective lens can be moved in the optical axis direction automatically or manually. For example, the ophthalmological apparatus 1 includes a moving mechanism that moves at least one of the focusing lens and the objective lens in the optical axis direction, and the control unit controls the moving mechanism to move at least one of the focusing lens and the objective lens along the optical axis. Focusing can be controlled by moving in the direction. Further, for example, the user can manually adjust the focusing state by moving at least one of the focusing lens and the objective lens in the optical axis direction by operating the moving mechanism.

Further, the control unit can perform focus control by changing the refractive index by controlling the liquid lens or liquid crystal lens.

The pattern light from the projection system 10 reflected by the optical multiplexer/demultiplexer 50 is projected onto the eye E via the optical system 51. The return light of the pattern light from the eye E to be examined passes through the optical system 51, is reflected by the optical multiplexer/demultiplexer 50, and is guided to the light receiving system 20.

(Light receiving system 20)
The light receiving system 20 includes an optical system 21 and an image sensor 22.

(Optical system 21)
The return light of the pattern light from the eye to be examined reflected by the optical multiplexer/demultiplexer 50 is incident on the optical system 21 . The optical system 21 includes an imaging lens that forms an image of the returned light on the detection surface of the image sensor 22. In some embodiments, optical system 21 further includes a relay optical system for relaying the return light.

(Image sensor 22)
The image sensor 22 functions as a pixelated light receiver. In this embodiment, image sensor 22 includes a CMOS image sensor. That is, the image sensor 22 includes a plurality of two-dimensionally arranged photodiodes, a plurality of vertical signal lines, and a horizontal signal line. A plurality of vertical signal lines are provided for each vertical photodiode group. Each vertical signal line is selectively electrically connected to a group of photodiodes in which charges corresponding to light reception results are accumulated. The horizontal signal line is selectively electrically connected to the plurality of vertical signal lines. Thereby, the photodiode provided for each pixel accumulates charges corresponding to the result of receiving the returned light, and the accumulated charges are sequentially read out for each photodiode group in the horizontal direction, for example. That is, a voltage corresponding to the charge accumulated in each photodiode is supplied to the vertical signal line for each horizontal line. The plurality of vertical signal lines are selectively electrically connected to the horizontal signal line. By sequentially performing the readout operation for each horizontal line in the vertical direction, the light reception results of the plurality of two-dimensionally arranged photodiodes are read out.

The detection surface of the image sensor 22 can be placed at a position that is optically substantially conjugate with the imaging site of the eye E to be examined (for example, the fundus of the eye, the anterior segment of the eye). That is, the detection surface of the image sensor 22 can be placed at a position that is optically substantially conjugate with the light source 11A.

Such readout control for the image sensor 22 can be executed under control from a control section, which will be described later.

Further, the control unit can read the result of receiving the returned light from the image sensor 22 using a so-called rolling shutter method. Thereby, by performing readout control corresponding to the desired aperture shape, a received light image corresponding to the aperture shape is acquired. Such control is disclosed in, for example, US Pat. No. 8,237,835.

Further, by controlling the pattern light generating section 11, the control section can sequentially generate slit-shaped (line-shaped) pattern light extending at least in the aperture direction in a direction perpendicular to the aperture direction. As disclosed in U.S. Pat. No. 8,237,835, etc., the control section reads the timing of pattern light generation by the pattern light generation section 11 and the reception result of the return light from the image sensor 22 in a rolling shutter method. Synchronize the timing. Thereby, it is possible to obtain an image of the eye to be examined with a simple configuration.

(Image processing unit 30)
The image processing unit 30 performs various image processing and analysis processing on the received light image obtained by the image sensor 22. Image processing includes noise removal processing for the received light image and brightness correction processing for making it easier to identify a predetermined region depicted in the received light image. The analysis processing includes processing for specifying a focus state, which will be described later, and processing for specifying control contents for performing focus control, which will be described later.

The image processing section 30 is capable of acquiring a received light image corresponding to an arbitrary aperture shape based on the received light results read out from the image sensor 22 using a rolling shutter method under the control of the control section. The image processing unit 30 acquires a light-receiving image of an aperture shape corresponding to the pattern light of the projection shape (first projection shape) for focusing control, and also acquires the light reception image of the aperture shape corresponding to the pattern light of the projection shape (second projection shape) for photographing. Obtain a light-receiving image of the corresponding aperture shape. As a result, the image processing unit 30 acquires a received light image corresponding to the aperture shape for focus control, and after the focus control acquires a received light image corresponding to the aperture shape (same or different from the aperture shape during focus control). can do.

In some embodiments, optical system 21 includes an aperture stop located between the imaging lens and image sensor 22. In this case, the returned light that has passed through the aperture stop is imaged on the detection surface of the image sensor 22. Therefore, the image processing section 30 acquires a received light image corresponding to the aperture shape of the aperture diaphragm, based on the received light results read out from the image sensor 22 using the global shutter method under the control of the control section. is possible.

Furthermore, the image processing unit 30 identifies the focused state of the pattern light based on the brightness distribution in the aperture direction (or aperture cross direction) in the acquired light reception image. In some embodiments, the focused state represents whether the focal position of the patterned light substantially corresponds to the desired illumination position.

The image processing unit 30 also specifies the amount and direction of movement of the focal position of the pattern light based on the luminance distribution in the direction across the aperture in the acquired light-receiving image.

The detailed operation of the image processing section 30 will be described later.

The image processing unit 30 includes a processor and implements the above functions by performing processing according to a program stored in a storage unit or the like.

In this specification, a "processor" refers to, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), a programmable logic device (for example, an S PLD (Simple Programmable Logic Device), CPLD (Complex It means a circuit such as a programmable logic device (programmable logic device) or FPGA (field programmable gate array). The processor realizes the functions according to the embodiment by, for example, reading and executing a program stored in a storage circuit or a storage device.

(Image output unit 40)
The image output unit 40 displays various information under the control of a control unit described below. For example, the image output unit 40 outputs the received light image obtained by the image processing unit 30. The light reception image obtained by the image processing unit 30 includes a light reception image acquired for focus control and a light reception image (photographed image) obtained by projecting pattern light again after focus control. .

The image output unit 40 includes a display device such as a flat panel display such as an LCD (Liquid Crystal Display).

(Other configurations)
In some embodiments, the ophthalmic device 1 further includes a fixation projection system. For example, the optical path of the fixation projection system is coupled to the optical path of the pattern light in the configuration of the optical system shown in FIG. The fixation projection system can present an internal fixation target or an external fixation target to the eye E to be examined. When presenting an internal fixation target to the eye E, the fixation projection system includes an LCD that displays the internal fixation target under the control of the control unit, and the fixation light flux output from the LCD is directed to the eye E. projected onto the fundus of the eye. The LCD is configured to be able to change the display position of the fixation target on the screen. By changing the display position of the fixation target on the LCD, it is possible to change the projected position of the fixation target on the fundus of the eye E to be examined. The display position of the fixation target on the LCD can be specified by the user using the operation unit.

In some embodiments, the fixation projection system includes, for example, a panel in which a plurality of LEDs are arranged instead of the LCD, and is configured to project the fixation target by lighting any of the LEDs. Ru.

Furthermore, since fixation can be induced by changing the projection position of the fixation target on the fundus of the eye E, it is also possible to change the observation direction.

In some embodiments, ophthalmic device 1 includes an alignment system. In some embodiments, the alignment system includes an XY alignment system and a Z alignment system. The XY alignment system is used to align the apparatus optical system and the subject's eye E in a direction intersecting the optical axis of the apparatus optical system (objective lens). The Z alignment system is used to align the apparatus optical system and the subject's eye E in the direction of the optical axis of the ophthalmological apparatus 1 (objective lens).

For example, the XY alignment system projects a bright spot in the infrared region or near-infrared region onto the eye E to be examined. The image processing unit 30 acquires the anterior segment image of the subject's eye E onto which the bright spot is projected, and determines the displacement between the bright spot image depicted in the acquired anterior eye segment image and the alignment reference position. A control unit, which will be described later, uses a moving mechanism (not shown) to relatively move the device optical system and the eye E in a direction intersecting the direction of the optical axis so that the determined displacement is canceled.

For example, the Z alignment system projects alignment light in the infrared region or near-infrared region from a position off the optical axis of the apparatus optical system, and receives the alignment light reflected from the anterior segment of the eye E to be examined. The image processing unit 30 identifies the distance of the eye E to be examined relative to the apparatus optical system from the light receiving position of the alignment light, which changes depending on the distance of the eye E to be examined relative to the apparatus optical system. A control unit, which will be described later, relatively moves the device optical system and the eye E in the direction of the optical axis using a moving mechanism (not shown) so that the specified distance becomes a desired working distance.

In some embodiments, the functionality of the alignment system is accomplished by two or more anterior segment cameras positioned off-axis of the device optics. For example, as disclosed in Japanese Unexamined Patent Publication No. 2013-248376, the image processing unit 30 analyzes anterior segment images of the subject's eye E obtained substantially simultaneously with two or more anterior segment cameras. , the three-dimensional position of the eye E to be examined is specified using known trigonometry. The control unit, which will be described later, moves the device optical system using a moving mechanism (not shown) so that the optical axis of the device optical system substantially coincides with the axis of the eye E and the distance of the device optical system to the eye E becomes a predetermined working distance. The system and the eye E to be examined are moved relative to each other in three dimensions.

[Control system configuration]
The control system of the ophthalmologic apparatus 1 will be described with reference to FIG. 3. As shown in FIG. 3, the control system of the ophthalmologic apparatus 1 is configured around a control section 100. Note that at least a part of the configuration of the control system may be included in the ophthalmologic apparatus 1.

(Control unit 100)
The control unit 100 controls each part of the ophthalmologic apparatus 1. Control unit 100 includes a main control unit 101 and a storage unit 102. The main control unit 101 includes a processor, and executes control processing for each unit of the ophthalmological apparatus 1 by executing processing according to a program stored in the storage unit 102.

(Main control unit 101)
The main control unit 101 controls the projection system 10 , the light receiving system 20 , the image processing unit 30 , the image output unit 40 , and the focusing mechanism 52 .

Control of the projection system 10 includes control of the pattern light generating section 11. Control of the pattern light generator 11 includes control of the light source 11A and control of the spatial light modulator 11C. Control of the light source 11A includes switching the light source on and off, and changing the amount of light from the light source. Control of the spatial light modulator 11C includes spatial amplitude control, phase control, and polarization control for the light from the light source 11A, and temporal amplitude control, phase control, and polarization control for the light from the light source 11A. .

When the projection system 10 includes an optical scanner, the main control unit 101 can control the optical scanner. Control of the optical scanner includes control of the scan range (scan start position and scan end position) and scan speed.

Control of the light receiving system 20 includes control of the image sensor 22. Control of the image sensor 22 includes control of changing at least one of exposure tying, sensitivity, and frame rate, and readout control using a rolling shutter method or a global shutter method.

The control of the image processing unit 30 includes execution control of the above-mentioned image processing and execution control of analysis processing. Control of the image output unit 40 includes display control of the various information described above.

Control of the focusing mechanism 52 includes control according to the mechanism for focusing the pattern light.

When the focusing mechanism 52 includes a focusing lens, the main control unit 101 specifies the focus control content corresponding to the amount and direction of movement of the focal position of the pattern light specified by the image processing unit 30. , controls a moving mechanism that moves the focusing lens in the optical axis direction based on the specified focusing control content.

When the focusing mechanism 52 includes an objective lens, the main control unit 101 specifies the focus control content corresponding to the amount and direction of movement of the focal position of the pattern light specified by the image processing unit 30, Based on the specified focusing control content, a moving mechanism that moves the apparatus main body or the objective lens in the optical axis direction is controlled.

When the focusing mechanism 52 includes a liquid lens or a liquid crystal lens, the main control unit 101 controls the focus control content corresponding to the amount and direction of movement of the focal position of the pattern light specified by the image processing unit 30. The liquid lens or liquid crystal lens is controlled based on the specified focusing control content.

As shown in FIG. 3, the storage unit 102 stores control information 102A. The control information 102A associates a plurality of focusing control contents (control amount, type of control signal) for the focusing mechanism 52 with a plurality of combinations of movement amounts and movement directions for moving the focal position of the pattern light. Contains corresponding information. The main control unit 101 refers to the correspondence information, specifies the focus control content for the focusing mechanism 52 from the movement amount and movement direction to move the focal position of the pattern light specified by the image processing unit 30, and specifies the It is possible to control the focusing mechanism 52 based on the focused focusing control contents.

(Storage unit 102)
The storage unit 102 stores various computer programs and data. The computer program includes a calculation program and a control program for controlling the ophthalmologic apparatus 1. Furthermore, the storage unit 102 stores the control information 102A as described above.

(Operation unit 110)
The operation unit 110 includes an operation device or an input device. The operation unit 110 includes buttons and switches (for example, an operation handle, an operation knob, etc.) provided on the ophthalmologic apparatus 1, and operation devices (such as a mouse, a keyboard, etc.). Further, the operation unit 110 may include any operation device or input device such as a trackball, an operation panel, a switch, a button, a dial, or the like.

In some embodiments, at least a portion of the image output section 40 and the operation section 110 are configured integrally. As a specific example, the functions of the image output section 40 and the operation section 110 are realized by a touch screen.

The projection system 10 is an example of a "projection section" according to the embodiment. The control unit 100 that controls the light receiving system 20 and the image sensor 22 is an example of the “acquisition unit” according to the embodiment. The image processing unit 30 is an example of a “specification unit” according to the embodiment.

[motion]
Next, the operation of the ophthalmologic apparatus 1 will be explained.

FIG. 4 shows an explanatory diagram of the focus state specifying process according to the embodiment. FIG. 4 shows the pattern light passing through the focusing lens or the objective lens, the returned light thereof, and the projected image PS of the pattern light superimposed on the received light image RS of the returned light. In FIG. 4, a projected image PS of pattern light is schematically superimposed on a received light image RS of returned light on the detection surface of the image sensor 22.

As described above, the projection system 10 is capable of projecting pattern light having an arbitrary projection shape onto the eye E to be examined. Further, the light receiving system 20 receives the return light of the pattern light at the image sensor 22, and the image processing unit 30 creates an arbitrary aperture shape using a rolling shutter method, for example, based on the detection result of the received return light. It is possible to obtain a corresponding light reception image.

For convenience of explanation, the patterned light PS is projected onto the eye E from above with respect to the optical axis of the ophthalmological apparatus 1 (objective lens or focusing lens), and the return light RF of the patterned light PS is projected from below with respect to the optical axis. It is assumed that light is received ((A) and (B) in FIG. 4). Note that the pattern light PS and the return light RF do not need to be symmetrical with respect to the optical axis. The optical path of either the pattern light PS or the return light RF may be arranged on the optical axis. For example, the optical path of the pattern light PS may be arranged on the optical axis, and the optical path of the return light RF may be arranged above or below the optical axis.

When the target object (for example, the fundus of the eye E to be examined) is located on the focal plane at the focal position FS, the position of the projected image PS of the pattern light and the position of the light-receiving side aperture match, and a bright light-receiving image RS with a clear outline is created. is obtained ((A) in FIG. 4).

On the other hand, when the object is located at the focal plane at a position FS1 distant from the focal position FS, the position of the projected image PS of the pattern light and the position of the light-receiving side aperture are far apart, resulting in a dark light-receiving image RS with a blurred outline. is obtained ((B) in FIG. 4).

Here, the pattern light generating section 11 moves the projection position of the pattern light on the object further upward or downward. At this time, even if the object is located on the focal plane at position FS1, the position of the projected image PS of the pattern light and the position of the light-receiving side aperture can be made to match. As a result, a bright light-receiving image RS as shown in FIG. 4(A) is obtained (FIG. 4(C)).

That is, by relatively moving the projection position or projection range of the pattern light and the light-receiving side aperture in the aperture cross direction, the brightness distribution of the light-receiving image changes. In this embodiment, the image processing unit 30 specifies the brightness distribution in the aperture direction of the acquired light-receiving image, and specifies the focused state of the pattern light based on the specified brightness distribution.

Furthermore, in FIGS. 4B and 4C, the projection position (projection range) of the pattern light is moved in a direction perpendicular to the aperture direction, so the brightness of the received light image changes. Although it is thereby possible to specify whether or not the focal position matches the imaging site, it is not possible to specify to what extent the focal position does not match the imaging site.

Therefore, by intersecting the projection position of the pattern light in a direction different from the direction perpendicular to the aperture direction (for example, at 45 degrees), the brightness distribution of the received light image can be changed according to the intersecting direction. This makes it possible to determine not only whether the focal position matches the imaging site but also the amount and direction of movement of the focal position if they do not match.

In this embodiment, patterned light whose projection system shape intersects with the aperture direction at approximately 45 degrees is used as follows. As a result, from the received light image obtained by projecting the pattern light once, it is possible to determine whether the focal position matches the imaging area, as well as the amount and direction of movement of the focal position if the focal position does not match. becomes possible.

5A to 5C schematically represent the relationship between the projected shape of the pattern light on the detection surface of the image sensor 22 and the aperture shape on the light receiving side, and the received light image. FIG. 5A mainly shows schematically the projected shape, the aperture shape, and the received light image at the time of focusing. FIG. 5B schematically represents the projected shape, aperture shape, and received light image when the focus position is on the front side. FIG. 5C schematically represents a projected shape, an aperture shape, and a received light image when the focus position is on the rear side. In FIGS. 5A to 5C, it is assumed that the projected shape of the pattern light PL intersects the aperture direction of the aperture shape AF at approximately 45 degrees.

As shown in FIG. 5A, upon focusing, a received light image Rm with a clear outline is obtained. In the received light image Rm, a bright portion Rp appears at the center of the patterned light PL rather than at the end. The bright area Rp is drawn at a position corresponding to the optical axis (on the detection surface of the image sensor 22). Therefore, the image processing unit 30 analyzes the received light image Rm, specifies the position of the bright area Rp in the brightness distribution in the aperture direction, and sets the position of the identified bright area Rp to a predetermined reference position (a position corresponding to the optical axis). ), it is possible to determine the in-focus state of the patterned light PL (that is, whether or not the focal position of the patterned light PL is the position of the imaging site). In some embodiments, the image processing unit 30 determines the in-focus state of the patterned light PL by analyzing the received light image Rm and determining whether a bright area Rp is identified in the brightness distribution in the aperture direction. can do. In this case, it is possible to determine whether the bright portion Rp has been identified by comparing the brightness level of the bright portion Rp with a predetermined threshold value.

As shown in FIG. 5B, when the focal position of the patterned light PL is on the front side, a received light image Rm with a blurred outline is obtained. In the received light image Rm, a bright portion Rp1 appears closer to the end than the center of the patterned light PL. For example, the bright area Rp1 is depicted on the left side with respect to the position corresponding to the optical axis (on the detection surface of the image sensor 22). Therefore, the image processing unit 30 analyzes the received light image Rm, identifies the position of the bright area Rp1 in the brightness distribution in the aperture direction, and determines the displacement of the position of the bright area Rp1 with respect to a predetermined reference position (position corresponding to the optical axis). Find (amount of deviation, direction of deviation). For example, the image processing unit 30 calculates the amount of movement of the focus position corresponding to the displacement of the bright area Rp1 with respect to the reference position using conversion information representing the amount of movement and direction of movement of the focus position corresponding to the displacement determined in advance. and the direction of movement. The main control unit 101 specifies focus control information from the specified movement amount and movement direction of the focus position, and controls the focusing mechanism 52 based on the specified focus control information.

As shown in FIG. 5C, when the focal position of the patterned light PL is on the rear side, a received light image Rm with a blurred outline is obtained. In the received light image Rm, a bright portion Rp2 appears closer to the end than the center of the patterned light PL. For example, the bright area Rp2 is depicted on the right side with respect to the position corresponding to the optical axis (on the detection surface of the image sensor 22). Therefore, the image processing unit 30 analyzes the received light image Rm, identifies the position of the bright area Rp2 in the brightness distribution in the aperture direction, and determines the displacement of the position of the bright area Rp2 with respect to a predetermined reference position (position corresponding to the optical axis). seek. For example, the image processing unit 30 calculates the amount of movement of the focus position corresponding to the displacement of the bright area Rp2 with respect to the reference position using conversion information representing the amount of movement and direction of movement of the focus position corresponding to the displacement determined in advance. and the direction of movement. The main control unit 101 specifies focus control information from the specified movement amount and movement direction of the focus position, and controls the focusing mechanism 52 based on the specified focus control information.

Note that in FIGS. 5A to 5C, the case where a bright portion appears during focusing has been described, but the same applies to the case where a dark portion appears during focusing.

As described above, the projection system 10 projects pattern light having a projection shape extending at least in the aperture cross direction (first direction) onto the eye E, and the image processing unit 30 processes the eye E detected by the light receiving system 20. A received light image corresponding to an aperture shape extending at least in the aperture direction (a second direction intersecting the first direction) is acquired based on the detection result of the return light of the pattern light from the aperture. The image processing unit 30 can identify the focused state of the pattern light based on the brightness distribution of the acquired light-receiving image. In some embodiments, the focus state includes information indicating whether or not the object is in focus, and control details for focusing when the object is out of focus.

FIG. 6 shows a flow diagram of an example of the operation of the ophthalmologic apparatus 1 according to the embodiment. The storage unit 102 stores a computer program for implementing the processing shown in FIG. The main control unit 101 executes the processing shown in FIG. 6 by operating according to this computer program.

Here, alignment of the apparatus optical system with respect to the eye E to be examined is completed by an alignment system (not shown), and a fixation target is set to the fundus of the eye E to be examined so as to guide the eye to a desired fixation position by a fixation projection system (not shown). is projected.

(S1: Project pattern light)
First, the main controller 101 controls the pattern light generator 11 to generate a projection-shaped pattern light for focusing control.

Specifically, the pattern light generator 11 generates pattern light that extends at least in a direction intersecting the opening direction of the aperture shape (aperture cross direction). The pattern light generated by the pattern light generation section 11 is projected onto the eye E through the smoothing section 12, the optical system 13, the optical multiplexer/demultiplexer 50, and the optical system 51.

(S2: Obtain a received light image)
Next, the main control unit 101 causes the image processing unit 30 to acquire a received light image.

Specifically, the pattern light projected onto the eye E by the projection system 10 is reflected by the eye E to be examined. The returned pattern light from the eye E passes through the optical system 51, the optical multiplexer/demultiplexer 50, and the optical system 21, and forms an image on the detection surface of the image sensor 22. The main control unit 101 reads out the result of the return light received by the image sensor 22 using a rolling shutter method corresponding to a predetermined aperture shape. The image processing unit 30 acquires a light reception image corresponding to the aperture shape based on the read light reception results.

(S3: Analysis)
Next, the main control unit 101 causes the image processing unit 30 to perform a predetermined analysis process on the received light image acquired in step S2.

Specifically, bright areas and dark areas appear in the acquired light-receiving image as described above. As described above, the image processing unit 30 identifies the brightness distribution in the aperture direction in the acquired light reception image.

(S4: Identify the focus state)
Next, the main control unit 101 causes the image processing unit 30 to specify the focused state of the pattern light.

Specifically, as shown in FIG. 5A, the image processing unit 30 identifies the position of the bright area (or dark area) from the luminance distribution identified in step S3, and determines the position of the identified bright area (or dark area). It is determined whether or not is at a predetermined reference position (a position corresponding to the optical axis). When it is determined that the position of the identified bright area (or dark area) is a predetermined reference position, it is determined that the focal position of the pattern light is the position of the imaging region.

When it is determined that the position of the identified bright part (or dark part) is not the predetermined reference position, the image processing unit 30 adjusts the brightness relative to the predetermined reference position in the luminance distribution, as shown in FIG. 5B or 5C. Find the displacement of the part (or dark part). Further, the image processing unit 30 specifies the amount and direction of movement of the focal position corresponding to the determined displacement.

In some embodiments, the main control unit 101 causes the image output unit 40 to output (display) information corresponding to the specified focus state or the movement amount and movement direction of the specified focal position. Information corresponding to the focus state includes information indicating whether the focus position of the pattern light is at the position of the desired imaging region (focus position), and information indicating whether the focus position of the pattern light is in front of the focus position. There is information such as whether it is located on the rear side or on the rear side. For example, the main control unit 101 displays information (or an image, text, mark, indicator) indicating whether the focal position of the pattern light is at the in-focus position in green, and Information indicating that the pattern light is located in front of the focal position is displayed in blue, and information indicating that the focal position of the pattern light is located in the rear of the focal position is displayed in red on the image output unit 40. In some embodiments, the main control unit 101 causes the image output unit 40 to display characters, images, and indicators indicating the focal position of the pattern light relative to the in-focus position.

(S5: Focus control)
Next, the main control unit 101 performs focusing control.

Specifically, when it is determined in step S4 that the focal position of the pattern light is the position of the imaging site, step S5 is skipped.

On the other hand, when it is determined in step S4 that the focal position of the pattern light is not the position of the imaging site, the main control unit 101 obtains focus control information from the movement amount and movement direction of the focal position specified in step S4. The focusing mechanism 52 is controlled based on the specified focusing control information.

(S6: Shooting)
Next, the main control section 101 controls the pattern light generation section 11 to generate a projection-shaped pattern light for photographing.

Specifically, the pattern light generating section 11 generates pattern light that extends in a direction (for example, the opening direction) substantially parallel to the opening direction of the opening shape, for example. The pattern light generated by the pattern light generation section 11 is projected onto the eye E through the smoothing section 12, the optical system 13, the optical multiplexer/demultiplexer 50, and the optical system 51. The pattern light projected onto the eye E to be examined is reflected by the eye E to be examined. The returned pattern light from the eye E passes through the optical system 51, the optical multiplexer/demultiplexer 50, and the optical system 21, and forms an image on the detection surface of the image sensor 22. The main control unit 101 reads out the result of the return light received by the image sensor 22 using a rolling shutter method corresponding to a predetermined aperture shape. The image processing unit 30 acquires a light reception image corresponding to the aperture shape based on the read light reception results.

Next, the main control unit 101 projects a pattern light having the same projection shape as described above at a projection position shifted in a direction perpendicular to the aperture direction, shifts the aperture position in the same manner as described above, and causes the image sensor 22 to Controls the reading of the return light reception results. A fundus image of the eye E to be examined is obtained by repeating such control a plurality of times to obtain a received light image for one frame.

This is the end of the operation of the ophthalmologic apparatus 1 (END).

<Modified example>
The configuration and control of the ophthalmological apparatus according to the embodiments are not limited to the above aspects. Modifications of the embodiment will be described below, focusing on the differences from the embodiment.

(First modification)
In the embodiment, a case has been described in which the pattern light generation unit 11 generates pattern light by spatially modulating the light from the light source using a light source and a non-light emitting device, but the configuration according to the embodiment is not limited to this. In this modification, the pattern light generating section includes a self-emitting device.

FIG. 7 shows a block diagram of a configuration example of a patterned light generation section according to a modification of the embodiment. The ophthalmologic apparatus according to this modification includes a pattern light generation section 11a shown in FIG. 7 instead of the pattern light generation section 11.

The patterned light generating section 11a according to this modification includes a self-emitting device 120 and an optical system 121. The self-emissive device 120 realizes a function as a pixelated pattern light generator by generating light that is modulated for each pixel. Examples of the self-luminous device 120 include a cathode-ray tube (CRT), a plasma display panel (PDP), an organic EL (OEL), an LED, and an inorganic EL. electro-luminescence:IEL ), vacuum fluorescent display (VFD), and field emission display (FED).

The self-luminous device 120 can be placed at a position that is optically approximately conjugate with the imaging site of the eye E to be examined (for example, the fundus of the eye, the anterior segment of the eye). Optical system 121 includes a projection lens for projecting light spatially modulated by self-emissive device 120.

The operation of the ophthalmologic apparatus according to this modification is the same as that in the embodiment, so detailed explanation will be omitted.

(Second modification)
In the embodiment or its modification, a case has been described in which the projected shape of the pattern light is a linear shape (rectangular shape) intersecting the aperture direction, but the configuration according to the embodiment is not limited to this. In this modification, the projected shape of the pattern light is curved. Furthermore, in this modification, the projected shape of the pattern light is a shape that intersects the opening direction multiple times.

FIG. 8 schematically shows a projected shape of pattern light according to a modification of the embodiment. FIG. 8 schematically represents the relationship between the projected shape of the pattern light on the detection surface of the image sensor 22 and the aperture shape on the light receiving side when in focus, when the focal position is on the front side, and when the focal position is on the rear side. .

As shown in FIG. 8, upon focusing, a received light image with a clear outline is obtained. In the received light image, since the pattern light PL1 intersects the aperture shape AF multiple times, bright parts and dark parts appear alternately. Therefore, the image processing unit 30 analyzes the received light image to specify the positions of bright parts and dark parts that appear alternately in the brightness distribution in the aperture direction, and the position of any one of the plurality of identified bright parts is determined to be a predetermined position. By determining whether the reference position (position corresponding to the optical axis) of can be determined.

Furthermore, in this modification, by determining whether or not the positions of the plurality of bright portions are at predetermined reference positions, it becomes possible to determine the focused state of the patterned light PL1 with higher accuracy.

Similarly, when the focal position of patterned light PL2 is on the front side or when the focal position of patterned light PL3 is on the rear side, a received light image with a blurred outline is acquired. In the received light image, since the pattern lights PL2 and PL3 cross the aperture shape AF multiple times, bright areas and dark areas appear alternately. Therefore, the image processing unit 30 analyzes the received light image, identifies the positions of bright parts and the positions of dark parts that appear alternately in the brightness distribution in the aperture direction, and identifies the positions of bright parts and dark parts that appear alternately in the brightness distribution in the aperture direction, and Find the displacement (amount of displacement, direction of displacement) at any position of the bright part of . For example, similar to the above, the image processing unit 30 can use predetermined conversion information to specify the amount and direction of movement of the focal position corresponding to the displacement of the position of the bright area with respect to the reference position. be. The main control unit 101 specifies focus control information from the specified movement amount and movement direction of the focus position, and controls the focusing mechanism 52 based on the specified focus control information.

In addition, in this modification, the displacements of the positions of multiple bright areas with respect to a predetermined reference position are determined, and the amount and direction of movement of the focal position corresponding to the determined displacements are specified, thereby achieving higher accuracy. It becomes possible to adjust the focal position of pattern lights PL2 and PL3.

Although FIG. 8 describes the case where a bright portion appears during focusing, the same applies to the case where a dark portion appears during focusing.

(Third modification)
In the second modification, a case has been described in which the projected shape of the pattern light is a shape that intersects the aperture direction multiple times, but the configuration according to the embodiment is not limited to this. For example, the projected shape of the pattern light may be a shape that is highly sensitive to determination of the in-focus state. An example of a shape that is highly sensitive for determining the in-focus state is a shape that has a portion substantially parallel to the aperture direction at a position corresponding to the optical axis.

FIG. 9 schematically shows a projected shape of pattern light according to a modification of the embodiment. FIG. 9 schematically represents the relationship between the projected shape of the pattern light on the detection surface of the image sensor 22 and the aperture shape on the light receiving side when in focus, when the focal position is on the front side, and when the focal position is on the rear side. .

As shown in FIG. 9, at the time of focusing, a received light image with a clear outline is obtained. At a position corresponding to the optical axis on the detection surface of the image sensor 22 (a reference position during focus control), pattern light PL11 having a shape having a portion approximately parallel to the aperture direction of the aperture shape AF is projected, so that in the received light image, A brighter area appears at the center than at the edges. Therefore, the image processing unit 30 analyzes the received light image, identifies the position of the bright part in the brightness distribution in the aperture direction, and determines that the position of the identified bright part is a predetermined reference position (position corresponding to the optical axis). By determining whether this is the case, it is possible to determine whether the patterned light PL11 is in focus (that is, whether the focal position of the patterned light PL1 is at the position of the imaging site).

Similarly, when the focal position of patterned light PL12 is on the front side or when the focal position of patterned light PL13 is on the rear side, a received light image with a blurred outline is acquired. In the received light image, dark areas tend to appear overall. Therefore, the image processing unit 30 analyzes the received light image, identifies the position of the bright part in the brightness distribution in the aperture direction, and determines the displacement (displacement amount) of the position of the bright part with respect to a predetermined reference position (position corresponding to the optical axis). , direction of deviation). For example, similar to the above, the image processing unit 30 can use predetermined conversion information to specify the amount and direction of movement of the focal position corresponding to the displacement of the position of the bright area with respect to the reference position. be. The main control unit 101 specifies focus control information from the specified movement amount and movement direction of the focus position, and controls the focusing mechanism 52 based on the specified focus control information.

Although FIG. 9 describes the case where a bright portion appears during focusing, the same applies to the case where a dark portion appears during focusing.

(Fourth modification)
In the embodiment or its modified example, a case has been described in which the projected shape of the pattern light intersects with the aperture shape on the light receiving side, but the configuration according to the embodiment is not limited to this. For example, the projected shape of the pattern light may be a shape extending in a direction substantially parallel to the aperture direction.

10A to 10C schematically represent the relationship between the projected shape of the pattern light on the detection surface of the image sensor 22 and the shape of the aperture on the light receiving side according to a modification of the embodiment. FIG. 10A mainly shows schematically the projected shape and the aperture shape at the time of focusing. FIG. 10B schematically represents the projected shape and aperture shape when the focal position is on the front side. FIG. 10C schematically represents the projected shape and aperture shape when the focal position is on the rear side. In FIGS. 10A to 10C, it is assumed that the projected shape of pattern light PL is parallel to the aperture direction of aperture shape AF.

As shown in FIG. 10A, upon focusing, a received light image with a clear outline is obtained. In the received light image, it becomes brighter overall. Therefore, the image processing unit 30 analyzes the received light image and determines whether a bright area is identified in the brightness distribution in the aperture direction, thereby determining the in-focus state of the patterned light PL (i.e., the focal position of the patterned light PL). is the position of the imaging site). In this case, it is possible to determine whether or not the bright portion has been identified by comparing the brightness level of the bright portion with a predetermined threshold.

As shown in FIG. 10B or 10C, when the focal position of the patterned light PL is on the front side or the rear side, a received light image with a blurred outline and a dark overall light is obtained. Therefore, the image processing unit 30 analyzes the received light image and determines whether a bright area is identified in the brightness distribution in the aperture direction, thereby determining the in-focus state of the patterned light PL (i.e., the focal position of the patterned light PL). is the position of the imaging site).

When a bright portion is not specified, the main control unit 101 relatively moves the projection position of the pattern light and the position of the aperture shape in a direction perpendicular to the aperture direction. Specifically, the main control unit 101 controls the pattern light generation unit 11 (11a) to generate pattern light so that the projection position on the imaging site is shifted. Alternatively, the main control unit 101 changes the aperture position by controlling the read timing of the light reception result of the return light of the pattern light by the image sensor 22, and sends the received light image corresponding to the changed aperture position to the image processing unit 30. Let them get it.

The image processing unit 30 specifies the brightness level in the brightness distribution of two or more received light images obtained by relatively moving the projection position of the pattern light and the position of the aperture shape, and calculates the difference from a predetermined threshold level. demand. For example, the image processing unit 30 may specify the amount of movement and the direction of movement of the focus position corresponding to the difference, using conversion information representing the amount of movement and direction of movement of the focus position corresponding to the difference determined in advance. It is possible. The main control unit 101 specifies focus control information from the specified movement amount and movement direction of the focus position, and controls the focusing mechanism 52 based on the specified focus control information.

Note that in FIGS. 10A to 10C, the case where a bright portion appears during focusing has been described, but the same applies to the case where a dark portion appears during focusing.

Furthermore, in FIGS. 10A to 10C, the received light images may be acquired using a global shutter method. In this case, there is no need to project the pattern light onto the eye to be examined multiple times.

FIG. 11 shows a flowchart of an operation example of the ophthalmologic apparatus 1 according to a modification of the embodiment. A computer program for realizing the processing shown in FIG. 11 is stored in the storage unit 102. The main control unit 101 executes the processing shown in FIG. 11 by operating according to this computer program.

Here, alignment of the apparatus optical system with respect to the eye E to be examined is completed by an alignment system (not shown), and a fixation target is set to the fundus of the eye E to be examined so as to guide the eye to a desired fixation position by a fixation projection system (not shown). is projected.

(S11: Project pattern light)
First, the main controller 101 controls the pattern light generator 11 to generate a projection-shaped pattern light for focusing control.

Specifically, the pattern light generating section 11 generates pattern light extending in a direction substantially parallel to the opening direction of the aperture shape. The pattern light generated by the pattern light generation section 11 is projected onto the eye E through the smoothing section 12, the optical system 13, the optical multiplexer/demultiplexer 50, and the optical system 51.

(S12: Obtain a received light image)
Next, the main control unit 101 causes the image processing unit 30 to acquire a received light image, similarly to step S2.

(S13: Analysis)
Next, the main control unit 101 causes the image processing unit 30 to perform a predetermined analysis process on the received light image acquired in step S12, similarly to step S3.

(S14: Identify the focus state)
Next, the main control unit 101 causes the image processing unit 30 to specify the focused state of the pattern light.

Specifically, as shown in FIG. 10A, the image processing unit 30 specifies the brightness level from the brightness distribution specified in step S13, and compares the specified brightness level with a predetermined threshold value to determine the received light image. Determine whether or not it is bright.

(S15: Next?)
In step S14, when it is determined that the received light image is bright, it is determined that the focal position of the pattern light is the position of the imaging site (S15:N), and the operation of the ophthalmological apparatus 1 moves to step S16.

When it is determined that the received light image is not bright, it is determined that the focal position of the pattern light is not the position of the photographed region (S15: Y), and the operation of the ophthalmologic apparatus 1 moves to step S11. In step S11, the main control unit 101 controls the pattern light generation unit 11 (11a) to generate pattern light so that the projection position on the imaging site is shifted. Alternatively, in step S12 following step S11, the main control unit 101 changes the aperture position by controlling the readout timing of the reception result of the return light of the pattern light by the image sensor 22, and corresponds to the changed aperture position. The image processing unit 30 is caused to acquire the received light image.

(S16: Focus control)
Next, the main control unit 101 performs focusing control.

Specifically, when it is determined in step S14 that the focal position of the pattern light is the position of the imaging site, step S16 is skipped.

On the other hand, when it is determined in step S14 that the focal position of the pattern light is not the position of the imaging site, the main control unit 101 relatively changes the projection position of the pattern light and the position of the aperture shape, as described above. The brightness level in the brightness distribution of two or more received light images obtained by the movement is specified, and the difference from a predetermined threshold level is determined. The image processing unit 30 uses, for example, predetermined conversion information to specify the amount and direction of movement of the focal position corresponding to the calculated difference. The main control unit 101 specifies focus control information from the specified movement amount and movement direction of the focus position, and controls the focusing mechanism 52 based on the specified focus control information.

(S17: Shooting)
Next, as in step S6, the main control unit 101 controls the pattern light generation unit 11 to generate a projection-shaped pattern light for photographing, and acquires an image of the fundus of the eye E to be examined.

This is the end of the operation of the ophthalmologic apparatus 1 (END).

In this modification, a case has been described in which the projected shape of the pattern light is a shape extending in a direction substantially parallel to the aperture direction in step S11, but the shape is not limited to the projected shape of the pattern light. For example, the projected shape of the pattern light may be a square shape, a circular shape, or a bright spot. That is, by analyzing images of the eye E obtained while sequentially changing the projection shape of the pattern light (projection position, projection range on the eye E), the focused state (or focus) of the pattern light can be determined. It is possible to specify the amount and direction of movement to be made to the focal position.

As described above, the projection system 10 projects pattern light having a projection shape extending at least in the aperture direction onto the eye E, and the image processing unit 30 returns the pattern light from the eye E detected by the light receiving system 20. Based on the light detection results, a received light image corresponding to an aperture shape extending in a predetermined aperture direction is acquired. The image processing unit 30 can identify the focused state of the pattern light based on the luminance distribution of one or more acquired light-receiving images. In some embodiments, the image processing unit 30 specifies the control content for focusing based on the brightness distribution of two or more received light images obtained by shifting the projection position or aperture position of the pattern light. do.

[Action/Effect]
The functions and effects of the ophthalmologic apparatus and the control method thereof according to the embodiment will be described.

An ophthalmological apparatus (1) according to some embodiments includes a projection section (projection system 10), an acquisition section (light receiving system 20 and a control section 100 that controls the image sensor 22), and a specific section (image processing section 30). ). The projection unit projects pattern light having a projection shape extending in at least the first direction onto the eye (E). The acquisition unit acquires a received light image corresponding to an aperture shape extending at least in a second direction intersecting the first direction, based on a detection result of the return light of the pattern light from the eye to be examined. The identifying unit identifies the focused state of the pattern light based on the brightness distribution of the received light image.

According to such a configuration, a received light image corresponding to the aperture shape extending in at least the second direction intersecting the first direction is obtained based on the reception result of the return light of the pattern light in the projection shape extending in at least the first direction. be done. This makes it possible to obtain a received light image in which the brightness distribution changes depending on the focused state of the pattern light. Therefore, with a simple configuration, it becomes possible to identify the optimal focusing state with good reproducibility.

An ophthalmological apparatus (1) according to some embodiments includes a projection section (projection system 10), an acquisition section (light receiving system 20 and a control section 100 that controls the image sensor 22), and a specific section (image processing section 30). ). The projection unit projects pattern light having a projection shape extending in at least the first direction onto the eye (E). The acquisition unit acquires a received light image corresponding to an aperture shape extending in at least the first direction based on a detection result of the return light of the pattern light from the eye to be examined. The identification unit identifies the focused state of the pattern light based on the luminance distribution in a second direction intersecting the first direction in the one or more received light images acquired by the acquisition unit.

According to such a configuration, a received light image corresponding to the aperture shape extending at least in the first direction is acquired based on the reception result of the return light of the pattern light having a projection shape extending in at least the first direction, and the acquired one The focused state of the pattern light is specified based on the luminance distribution in the second direction intersecting the first direction in the above-mentioned received light image. This makes it possible to identify the optimal focusing state with good reproducibility with a simple configuration.

In some embodiments, the identifying unit identifies the focus control details of the pattern light based on the luminance distribution in the second direction in the received light image, and determines the focus control details of the pattern light based on the identified focus control details. It includes a control section (110) that performs focus control.

According to such a configuration, it becomes possible to perform focusing control of pattern light with a simple configuration.

In some embodiments, the control unit performs focusing control so that the bright portion or the dark portion moves to a predetermined position (a position corresponding to the optical axis on the detection surface of the image sensor 22).

According to such a configuration, focus control can be performed based on bright areas or dark areas appearing in the received light image, so it is possible to perform focus control of pattern light with a simple configuration.

Some embodiments include a focusing mechanism (52) disposed in the optical path of the pattern light and the return light, and the control unit controls the focusing mechanism based on the specified focusing control content.

According to such a configuration, it becomes possible to perform focusing control of pattern light with a simple configuration.

In some embodiments, the projection unit includes a projector that outputs patterned light whose projection shape can be changed.

According to such a configuration, it is possible to easily change the projection shape and output pattern light, so it is possible to provide an ophthalmological device that can identify the optimal focusing state with good reproducibility with a simple configuration. It becomes like this.

In some embodiments, the projection unit outputs a pattern of light with a first projection shape for identifying the focused state, and after controlling the focus of the pattern light, outputs a pattern of light with a second projection shape different from the first projection shape. The acquisition unit outputs the light and acquires a received light image based on the detection result of the return light of the pattern light of the second projection shape.

According to such a configuration, with a simple configuration, the optimum focusing state is identified with good reproducibility, the pattern light is controlled to focus, and after the focus control, a new pattern light is output to focus on the subject's eye. It becomes possible to provide an ophthalmological device that can acquire images.

In some embodiments, the acquisition unit includes an image sensor (22) that detects returned light, and acquires a received light image using a rolling shutter method.

According to such a configuration, it is possible to provide an ophthalmologic apparatus that can identify an optimal focusing state with good reproducibility with a simple configuration.

A method for controlling an ophthalmologic apparatus (1) according to some embodiments includes a projection step of projecting pattern light in a projection shape extending in at least a first direction onto an eye to be examined (E), and a step of projecting the pattern light back from the eye to be examined. an acquisition step of acquiring a received light image corresponding to an aperture shape extending in at least a second direction intersecting the first direction based on the detection results of and a specific step of doing so.

According to such a method, a received light image corresponding to the aperture shape extending in at least the second direction intersecting the first direction is obtained based on the result of receiving the return light of the pattern light in the projection shape extending in at least the first direction. be done. This makes it possible to obtain a received light image in which the brightness distribution changes depending on the focused state of the pattern light. Therefore, with a simple configuration, it becomes possible to identify the optimal focusing state with good reproducibility.

A method for controlling an ophthalmologic apparatus (1) according to some embodiments includes a projection step of projecting pattern light in a projection shape extending in at least a first direction onto an eye to be examined (E), and a step of projecting a pattern light that returns from the eye to be examined. an acquisition step of acquiring a received light image corresponding to the aperture shape extending at least in the first direction based on the detection result; and a brightness in a second direction intersecting the first direction in the one or more received light images acquired in the acquisition step. The method includes a step of specifying a focused state of the patterned light based on the distribution.

According to such a method, a received light image corresponding to an aperture shape extending at least in the first direction is acquired based on the reception result of the return light of the pattern light having a projection shape extending at least in the first direction, and the acquired 1 The focused state of the pattern light is specified based on the luminance distribution in the second direction intersecting the first direction in the above-mentioned received light image. This makes it possible to identify the optimal focusing state with good reproducibility with a simple configuration.

In some embodiments, the identifying step includes identifying the focus control content of the pattern light based on the luminance distribution in the second direction in the received light image, and determining the focus control content of the pattern light based on the identified focus control content. A control step for performing focus control is included.

According to such a method, it becomes possible to perform focusing control of pattern light with a simple configuration.

In some embodiments, the projecting step includes a first projecting step of outputting a pattern of light having a first projection shape for identifying the focused state, and a first projection step of outputting a pattern of light having a first projection shape different from the first projection shape after controlling the focus of the pattern light. a second projection step of outputting pattern light of two projection shapes, and the acquisition step corresponds to the aperture shape based on the detection result of the return light of the pattern light of the first projection shape projected in the first projection step. a first acquisition step of acquiring a received light image; and a second acquisition step of acquiring a received light image based on the detection result of the return light of the pattern light of the second projection shape projected in the second projection step.

According to this method, with a simple configuration, the optimal focusing state is identified with good reproducibility, the pattern light is focused, and after the focus control, a new pattern light is output to focus on the subject's eye. You will be able to obtain images.

In some embodiments, the acquiring step acquires a received light image using a rolling shutter method based on the detection result of the returned light.

According to such a method, it becomes possible to specify the optimal focusing state with good reproducibility with a simple configuration.

The embodiment shown above or its modification example is only an example for implementing the present invention. Those who wish to implement this invention can make arbitrary modifications, omissions, additions, etc. within the scope of the gist of this invention.

In the above embodiments or variations thereof, the ophthalmological apparatus is used in the ophthalmological field, for example, with an axial length measurement function, an intraocular pressure measurement function, a fundus imaging function, an optical coherence tomography (OCT) function, an ultrasound examination function, etc. It may have any possible functionality. Note that the axial length measurement function is realized by an optical coherence tomography device or the like. In addition, the axial length measurement function projects light onto the eye to be examined and detects the return light from the fundus while adjusting the position of the optical system in the Z direction (anterior-posterior direction) with respect to the eye to be examined. The axial length of the eye may be measured. The intraocular pressure measurement function is realized by a tonometer or the like. The fundus photographing function is realized by a fundus camera, a scanning ophthalmoscope (SLO), or the like. The OCT function is realized by optical coherence tomography or the like. The ultrasonic testing function is realized by an ultrasonic diagnostic device or the like. Further, the present invention can also be applied to a device (multifunction device) that has two or more of these functions.

In some embodiments, a program is provided for causing a computer to execute the method for controlling an ophthalmological apparatus described above. Such a program can be stored in any computer-readable recording medium. Examples of this recording medium include semiconductor memory, optical disks, magneto-optical disks (CD-ROM/DVD-RAM/DVD-ROM/MO, etc.), magnetic storage media (hard disks/floppy (registered trademark) disks/ZIP, etc.), etc. It is possible to use It is also possible to send and receive this program via a network such as the Internet or LAN.

1 Ophthalmological apparatus 10 Projection system 11, 11a Pattern light generating section 11A Light source 11C Spatial light modulator 12 Smoothing section 11B, 13, 21, 51, 121 Optical system 20 Light receiving system 22 Image sensor 30 Image processing section 40 Image output section 50 Optical multiplexer/demultiplexer 52 Focusing mechanism 100 Control section 101 Main control section 102 Storage section 102A Control information 110 Operation section 120 Self-luminous device E Subject's eye

Claims (4)

A pattern light having a projection shape corresponding to the shape of the aperture on the light receiving side is projected onto the eye to be examined, and the pattern light corresponds to the shape of the aperture on the detection surface of an image sensor that receives the return light of the pattern light from the eye to be examined. An ophthalmological apparatus that reads out a reception result of the return light from the image sensor using a rolling shutter method,
a projection unit that includes a projector that outputs pattern light whose projection shape can be changed, and projects the pattern light having a projection shape extending in a first direction onto the subject's eye;
an acquisition unit that acquires a received light image corresponding to a shape of the aperture extending in a second direction intersecting the first direction, based on a detection result of the returned light;
a specifying unit that specifies a focused state of the patterned light based on the luminance distribution of the received light image;
including;
The projection unit projects the pattern light on the detection surface so as to intersect the aperture in a crossing direction different from a direction orthogonal to the second direction,
The identifying unit identifies the focused state based on the brightness distribution that changes depending on the projection position of the pattern light with respect to the aperture on the detection surface,
The specifying unit specifies the focus control content of the patterned light based on the luminance distribution in the second direction in the received light image,
The ophthalmologic apparatus includes a control unit that performs focus control of the patterned light based on the specified focus control content,
The projection unit outputs pattern light having a first projection shape for identifying the focused state, and after controlling the focus of the pattern light, outputs pattern light having a second projection shape different from the first projection shape. death,
The acquisition unit is an ophthalmological apparatus that acquires a received light image based on a detection result of return light of the pattern light having the second projection shape . The ophthalmologic apparatus according to claim 1 , wherein the control unit performs the focusing control so that a bright area or a dark area moves to a predetermined position. including a focusing mechanism disposed in the optical path of the pattern light and the return light,
The ophthalmologic apparatus according to claim 1 or 2 , wherein the control unit controls the focusing mechanism based on the specified focusing control content. Projecting pattern light having a projection shape corresponding to the shape of the aperture on the light receiving side onto the eye to be examined using a projector that outputs pattern light whose projection shape can be changed , and receiving return light of the pattern light from the eye to be examined. A control method for an ophthalmological apparatus that reads out the reception result of the return light from the image sensor using a rolling shutter method in accordance with the shape of the aperture on the detection surface of the image sensor, the method comprising:
a projection step of projecting the pattern light having a projection shape extending in a first direction onto the eye to be examined;
an acquisition step of acquiring a received light image corresponding to a shape of the aperture extending in a second direction intersecting the first direction, based on the detection result of the return light;
a specifying step of specifying a focused state of the patterned light based on the luminance distribution of the received light image;
including;
The projection step projects the pattern light so as to intersect the aperture in a cross direction different from a direction perpendicular to the second direction on the detection surface,
The identifying step identifies the focused state based on the brightness distribution that changes depending on the projection position of the pattern light with respect to the aperture on the detection surface,
The specifying step specifies the focus control content of the pattern light based on the luminance distribution in the second direction in the received light image,
The method for controlling the ophthalmological apparatus includes a control step of controlling the focus of the patterned light based on the specified focus control content,
The projection step includes:
a first projection step of outputting pattern light having a first projection shape for specifying the focused state;
After controlling the focus of the patterned light, a second projection step of outputting patterned light having a second projection shape different from the first projection shape;
including;
The acquisition step includes:
a first acquisition step of acquiring a received light image corresponding to the shape of the aperture based on a detection result of the return light of the pattern light of the first projection shape projected in the first projection step;
a second acquisition step of acquiring a received light image based on a detection result of the return light of the pattern light of the second projection shape projected in the second projection step;
A method of controlling an ophthalmological device , including :

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