JP7325272B2 - Ophthalmic device and its control method - Google Patents

Description

The present invention relates to an ophthalmic apparatus and its control method.

In recent years, an ophthalmologic examination using an ophthalmologic apparatus is performed in screening. Such an ophthalmologic apparatus is expected to be applied to self-examination, and further miniaturization and weight reduction are desired.

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

In such an ophthalmologic apparatus, if an image of the eye to be inspected and a measurement result of the refractive power of the eye to be inspected can be obtained, information useful for screening and self-examination may be provided.

For example, Patent Literature 3 discloses an ophthalmologic apparatus having a refractive power measurement optical system for measuring the refractive power of an eye to be inspected in addition to an imaging optical system for acquiring an image of the eye to be inspected.

U.S. Pat. No. 7,831,106 U.S. Pat. No. 8,237,835 Japanese Patent No. 4523338

However, simply adding a conventional refractive power measurement optical system to the imaging optical system results in an increase in the size of the apparatus. Therefore, a new technique is desired for easily adding an optical system for measuring the refractive power of an eye to be examined to an imaging optical system.

The present invention was made to solve such problems, and its object is to provide a new technique for measuring the refractive power of an eye to be examined with a simple configuration.

A first aspect of some embodiments includes a projection unit that projects pattern light of a deformable projection shape onto an eye to be inspected, receives return light of the pattern light from the eye to be inspected, and obtains a reception result of the return light. an acquisition unit for acquiring an image of the eye to be inspected based on; and controlling the projection unit to project pattern light of a first projection shape onto the eye to be inspected, and causing the acquisition unit to acquire the first image of the eye to be inspected. and an eye refractive power value calculator that calculates the eye refractive power value of the subject's eye based on the image based on the returned light rendered in the first image.

In a second aspect of some embodiments, in the first aspect, the control unit causes the projection unit to project pattern light in a first projection shape, thereby causing the obtaining unit to project the first projection shape of the eye to be inspected. In addition to acquiring one image, the acquiring unit acquires a second image of the subject's eye by causing the projecting unit to project pattern light of a second projection shape onto the projecting unit.

In a third aspect of some embodiments, in the second aspect, the acquisition unit acquires the second image by a rolling shutter method.

In a fourth aspect of some embodiments, in any one of the first to third aspects, the acquisition section acquires the first image by a global shutter method.

A fifth aspect of some embodiments is any one of the first to fourth aspects, further comprising a focusing mechanism arranged in the optical paths of the pattern light and the return light, wherein the controller controls the eye refraction. The focusing mechanism is controlled based on the force value.

According to a sixth aspect of some embodiments, in any one of the first to fifth aspects, a correcting optical system is arranged in the optical paths of the pattern light and the return light, and the controller controls the eye refraction. The correction optical system is controlled based on the force value.

In a seventh aspect of some embodiments, in the sixth aspect, the correction optical system includes a variable cross cylinder lens.

An eighth aspect of some embodiments is any one of the first to seventh aspects, wherein a pupil region in the anterior segment image of the subject's eye is specified, and the size of the pupil region is equal to or less than a predetermined threshold. and the control unit, when the pupil determination unit determines that the size of the pupil region is equal to or less than a predetermined threshold value, corresponds to the size as the first projection shape. The projecting unit projects a ring-shaped projection shape pattern light having a diameter of .

In a ninth aspect of some embodiments, in any one of the first to eighth aspects, the projection unit includes a light source and a spatial light modulator that spatially modulates light from the light source. .

A tenth aspect of some embodiments is a control method for an ophthalmologic apparatus that projects pattern light of a deformable projection shape onto an eye to be examined. A control method for an ophthalmologic apparatus includes a first projection step of projecting a first pattern light having a first projection shape onto the eye to be examined, receiving a first return light of the first pattern light from the eye to be examined, a first acquisition step of acquiring a first image of the eye to be inspected based on the result of receiving one returned light; a second projection step of projecting a second pattern light of a second projection shape onto the eye to be inspected; a second acquisition step of receiving a second return light of the second pattern light from the second return light and acquiring a second image of the eye to be inspected based on the result of receiving the second return light; and a calculating step of calculating an eye refractive power value of the subject's eye based on the image based on the first returned light.

In an eleventh aspect of some embodiments, in the tenth aspect, the second acquisition step acquires the second image by a rolling shutter method.

In a twelfth aspect of some embodiments, in the tenth aspect or the eleventh aspect, the first acquisition step acquires the first image by a global shutter method.

A thirteenth aspect of some embodiments is any one of the tenth to twelfth aspects, wherein the focal position of the second pattern light is changed based on the eye refractive power value before the second projection step including a focusing step to

A fourteenth aspect of some embodiments is any one of the tenth to thirteenth aspects, wherein, before the second projection step, the optical path of the second pattern light is arranged based on the eye refractive power value. and a correction step for correcting the refractive properties of the optical element.

According to a fifteenth aspect of some embodiments, in any one of the tenth to fourteenth aspects, a pupillary region in the anterior segment image of the subject's eye is specified, and the size of the pupillary region is equal to or less than a predetermined threshold. wherein the first projection step corresponds to the size as the first projection shape when it is determined in the determination step that the size of the pupil region is equal to or less than a predetermined threshold A pattern light having a ring-shaped projected shape with a diameter of .

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 measuring the refractive power of an eye to be examined with a simple configuration.

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. 1 is a schematic diagram showing a configuration example of an ophthalmologic apparatus according to an embodiment; FIG. FIG. 4 is a flow diagram of an operation example of the ophthalmologic apparatus according to the embodiment; FIG. 4 is a flow diagram of an operation example of the ophthalmologic apparatus according to the embodiment; FIG. 4 is a flow diagram of an operation example of the ophthalmologic apparatus according to the embodiment; It is a schematic diagram showing a configuration example of an ophthalmologic apparatus according to a modification of the embodiment. It is a schematic diagram showing a configuration example of an ophthalmologic apparatus according to a modification of the 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. In addition, it is possible to appropriately incorporate the contents of the literature described in this specification as the contents of the following embodiments.

An ophthalmologic apparatus according to an embodiment includes a projection system that projects pattern light of a deformable projection shape onto an eye to be inspected, and a light receiving system that receives return light of the pattern light from the eye to be inspected. It is possible to acquire an image of a predetermined photographing site (fundus, anterior segment) of the subject's eye based on the result of receiving the returned light. Here, changing the projection shape of the pattern light means changing the projection position and projection range (including the shape) of the pattern light on the eye to be inspected.

For example, the projection system can project ring-shaped pattern light for refractive power measurement onto the subject's eye by changing the projection shape. The ophthalmologic apparatus obtains a ring-shaped received light image (ring image) from the result of receiving the returned light obtained by the light receiving system, and obtains the eye refractive power value of the subject's eye by analyzing the obtained received received light image.

Furthermore, the projection system can project a slit-like pattern light for photographing substantially parallel to the opening direction on the light receiving side onto the subject's eye by changing the projection shape. The ophthalmologic apparatus obtains a received light image corresponding to the shape of the aperture from the result of receiving the returned light obtained by the light receiving system. The ophthalmologic apparatus obtains one frame of an image of the subject's eye from the light reception result of the return light obtained by sequentially projecting slit-shaped pattern light onto the subject's eye in a direction perpendicular to the opening direction using a projection system.

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, and the predetermined optical A direction on a plane (for example, a light-receiving surface in a light-receiving system) is meant.

<Configuration of optical system>
First, the configuration of the optical system of the ophthalmologic apparatus according to the embodiment will be mainly described.

1 to 4 show block diagrams of configuration examples of an ophthalmologic apparatus according to an embodiment. 1 and 2 are block diagrams of configuration examples of an optical system of an ophthalmologic apparatus 1 according to an embodiment. FIG. 3 shows a block diagram of a configuration example of the data processing unit 30 of FIG. FIG. 4 shows a block diagram of a configuration example of the control system of the ophthalmologic apparatus 1. As shown in FIG. In FIGS. 1 to 4, the same parts are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

The ophthalmologic apparatus 1 acquires an image of the eye E by projecting deformable pattern light onto the eye E and receiving the return light. In this embodiment, the ophthalmologic apparatus 1 projects pattern light for refractive power measurement onto the subject's eye E, receives the return light, acquires an image of the subject's eye E, and draws the image in the acquired image. An image based on the returned light is analyzed, and an eye refractive power value of the eye E to be examined is calculated. Further, the ophthalmologic apparatus 1 projects pattern light for imaging onto a desired imaging region (fundus, anterior segment of the eye) of the eye E to be inspected, and receives the return light to obtain an image of the imaging region of the eye E to be inspected. do. In some embodiments, the focusing control of the pattern light is performed based on the eye refractive power value of the eye E to be examined. In some embodiments, astigmatism correction (correction of an astigmatic condition) is performed based on the ocular power value of the eye E to be examined.

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

The ophthalmologic apparatus 1 projects pattern light onto the subject's eye E in a refractive power measurement mode for performing refractive power measurement and an imaging mode for performing imaging, and acquires a received light image in each mode.

[Refractive power measurement mode]
The projection system 10 projects, for example, a ring-shaped projection-shaped pattern light for refractive power measurement onto the eye E to be examined. The light receiving system 20 receives the return light of the pattern light projected onto the eye E by the projection system 10 . The data processing unit 30 acquires a received light image from the result of receiving the return light by the light receiving system 20 . In some embodiments, the data processing section 30 acquires the received light image by a global shutter method. The data processing unit 30 analyzes the ring image based on the return light drawn in the received light image, and calculates the eye refractive power value of the eye E to be examined.

[Shooting mode]
After focus control, the projection system 10 sequentially projects pattern light for photographing having a projection shape (for example, a slit shape or a line shape) extending in the aperture direction onto the subject's eye E in a direction perpendicular to the aperture direction. The light receiving system 20 receives the return light of the pattern light projected onto the eye E by the projection system 10 . In some embodiments, the data processing section 30 acquires the received light image by a rolling shutter method. For example, the data processing unit 30 sequentially acquires received light images corresponding to the aperture shape while shifting the aperture shape in a direction orthogonal to the aperture direction (or the aperture crossing direction) from the result of receiving the returned light by the light receiving system 20. , an image of the fundus of the subject's eye E is obtained by synthesizing the obtained received light images.

(Projection system 10)
The projection system 10 includes a pattern light generator 11 and an optical system 12 .

(Pattern light generator 11)
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. Thereby, the projection position and projection range of the pattern light on the eye E to be examined are changed. The pattern light generator 11 can selectively generate pattern light of two or more projection shapes, and selectively project the pattern light onto two or more projection regions of 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 generator 11 having such a configuration. That is, the pattern light generator 11 includes a light source 11A, an optical system 11B, and a spatial light modulator 11C corresponding to the type of projector. The light source 11A can be arranged at a position substantially optically conjugate with the part of the subject's eye E to be imaged (for example, the fundus, the anterior segment).

In some embodiments, the light source 11A is a light source capable of outputting by switching between light in the infrared region or the 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 during refractive power measurement, and outputs light in the visible region during imaging of a desired imaging region.

In some embodiments, the pattern light generator 11 has the function of a DLP (Digital Light Processing (registered trademark)) type 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 of the RGB color components for the light from the 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 the infrared region or the near-infrared region. Also, the optical system 11B includes a relay optical system and an optical lens. The spatial light modulator 11C also includes a digital micromirror device in which a plurality of mirror elements are arranged two-dimensionally. Each of the multiple mirror elements is independently controllable. Note that the spatial light modulator 11C can include a projection lens for projecting the 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. The optical system 11B includes a color wheel for outputting light of each color component of RGB in a time division manner from the light from the light source 11A, a relay optical system, and an optical lens. The spatial light modulator 11C also includes a digital micromirror device in which a plurality of mirror elements are arranged two-dimensionally. Note that the spatial light modulator 11C can include a projection lens for projecting the 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 color component of RGB. Also, the optical system 11B includes a relay optical system and an optical lens. The spatial light modulator 11C also includes a plurality of digital micromirror devices provided for each of the RGB color components. Note that the spatial light modulator 11C can include a projection lens for projecting the 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, light source 11A includes a white light source. Also, the optical system 11B includes one or more reflecting mirrors, one or more dichroic mirrors, and one or more polarizing beam splitters. The spatial light modulator 11C includes a reflective liquid crystal panel for each RGB color component, a cross dichroic prism for synthesizing the light spatially modulated for each color component, and projects the synthesized light. including a projection lens for

In some embodiments, the pattern light generator 11 has the function of a transmissive liquid crystal projector. In this case, light source 11A includes a white light source. Also, the optical system 11B includes one or more reflecting mirrors and one or more dichroic mirrors. The spatial light modulator 11C includes a transmissive liquid crystal panel for each RGB color component, a cross dichroic prism for synthesizing the light spatially modulated for each color component, and projects the synthesized light. including 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).

Such a projector functions as a pixelated pattern light generator. Since the configuration of the projector as described above is publicly known, detailed description thereof will be omitted. The pattern light generator 11 can output 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, for example, using an operation unit, which will be described later. When the user specifies the shape pattern, outline, size, etc. using the operation unit, the control unit specifies the illumination pattern based on the specified shape pattern, etc., and the spatial light modulator 11C can be controlled.

(Optical system 12)
The optical system 12 includes a relay optical system for relaying the pattern light generated by the pattern light generator 11 . In some embodiments, optical system 12 further includes a collimating lens and an optical scanner. In this case, the optical scanner can deflect the pattern light under the control of a control unit, which will be described later.

The pattern light that has passed through the optical system 12 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 functions 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 and a correction optical system 53 . In some embodiments, optical system 51 further includes an objective lens positioned between focusing mechanism 52 and eye E to be examined. In some embodiments, optical system 51 includes an anterior lens for moving the focal position of the pattern light to the vicinity of the anterior segment of the eye. In this case, the front lens is provided so as to be insertable and removable with respect to the optical path of the pattern light.

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

A focusing lens or an objective lens can be moved in the direction of the optical axis automatically or manually. For example, the ophthalmologic apparatus 1 includes a moving mechanism for moving at least one of the focusing lens and the objective lens in the optical axis direction, and the controller controls the moving mechanism to move at least one of the focusing lens and the objective lens to the optical axis. Focus control can be performed by moving in the direction. Further, for example, the user can manually adjust the focused state by operating the moving mechanism to move at least one of the focusing lens and the objective lens in the optical axis direction.

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

An example of the correction optical system 53 is a variable cross cylinder lens. The variable cross cylinder lens is used to correct the astigmatism power and astigmatism axis angle of the subject's eye E, as disclosed in JP-A-2015-223518, for example. A control unit, which will be described later, can control the variable cross cylinder lens based on the astigmatism of the subject's eye E (cylinder power, astigmatism axis angle) so that the astigmatism is corrected. For example, the variable cross cylinder lens includes two cylinder lenses arranged in series on the optical axis and configured to be independently rotatable around the optical axis. The astigmatism power can be changed by independently rotating the two cylinder lenses in opposite directions. The astigmatic axis angle can be changed by rotating the two cylinder lenses by the same angle in the same direction.

The pattern light from the projection system 10 reflected by the optical multiplexer/demultiplexer 50 is projected onto the subject's eye E via the optical system 51 . Return light of the pattern light from the subject's eye E 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)
Light receiving system 20 includes an optical system 21 and an image sensor 22 .

(Optical system 21)
Return light of the pattern light from the subject's eye E 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 relay optics for relaying the returned light.

(Image sensor 22)
Image sensor 22 implements the function of a pixelated light receiver. For example, image sensor 22 includes a CMOS image sensor.

When the image sensor 22 includes a CMOS image sensor, the image sensor 22 includes a plurality of photodiodes arranged two-dimensionally, a plurality of vertical signal lines, and a horizontal signal line. A plurality of vertical signal lines are provided for each photodiode group in the vertical direction. Each vertical signal line is selectively electrically connected to a photodiode group in which electric charge corresponding to the result of light reception is accumulated. A horizontal signal line is selectively electrically connected to a plurality of vertical signal lines. As a result, the photodiode provided for each pixel accumulates electric charges corresponding to the result of receiving the returned light, and the accumulated electric 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. A plurality of vertical signal lines are selectively electrically connected to the horizontal signal lines. By sequentially performing the horizontal line-by-line readout operation in the vertical direction, the light reception results of the plurality of photodiodes arranged two-dimensionally are read out.

When the image sensor 22 includes a CMOS image sensor, an image corresponding to the result of receiving the returned light is acquired by the rolling shutter method. Accordingly, by performing readout control corresponding to a desired aperture shape, a received light image corresponding to the aperture shape is acquired. Such control is disclosed, for example, in US Pat. No. 8,237,835.

Furthermore, by controlling the pattern light generator 11, the controller can sequentially generate slit-shaped (line-shaped) pattern light extending at least in the aperture direction in a direction orthogonal to the aperture direction. As disclosed in U.S. Pat. No. 8,237,835, the control unit reads the pattern light generation timing by the pattern light generation unit 11 and the reception result of the return light from the image sensor 22 in the rolling shutter method. Synchronize with timing. Accordingly, it is possible to obtain an image of the subject's eye with a simple configuration.

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

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

In some embodiments, image sensor 22 includes a CCD (Charge-Coupled Device) image sensor.

When the image sensor 22 includes a CCD image sensor, the image sensor 22 includes a plurality of two-dimensionally arranged photodiodes, two or more vertical transfer registers, and a horizontal transfer register. Two or more vertical transfer registers are provided for each vertical photodiode group. A horizontal transfer register is selectively electrically connected to two or more vertical transfer registers. As a result, the photodiode provided for each pixel accumulates charges corresponding to the result of receiving the returned light, and the accumulated charges are read out to, for example, the vertical transfer register. A plurality of vertical transfer registers are selectively electrically connected to the horizontal transfer registers. For example, a signal corresponding to charges read out to one vertical transfer register is transferred to a horizontal transfer register, and the transferred signals are sequentially read out from the horizontal transfer register. By repeating this for a plurality of vertical transfer registers, the light reception results of a plurality of two-dimensionally arranged photodiodes are read out. When the image sensor 22 includes a CCD image sensor, an image corresponding to the result of receiving the returned light is acquired by a global shutter method or a rolling shutter method.

(Data processing unit 30)
The data processing unit 30 performs various types of 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 portion depicted in the received light image. The analysis processing includes small pupil processing and eye refractive power value calculation processing.

Small pupil processing is performed on the anterior segment image of the eye E to be examined. In some embodiments, the anterior segment image of the subject's eye E is obtained by projecting the pattern light generated by the pattern light generator 11 onto the anterior segment and receiving the return light by the image sensor 22. is obtained. In some embodiments, it is acquired using an anterior eye camera (not shown) that is separate from the optical system shown in FIG. The small pupil processing includes processing for specifying the pupil region and processing for determining the size of the pupil region.

The data processing unit 30 can acquire a received light image based on the light receiving result read out from the image sensor 22 by the global shutter method under the control of the control unit. Further, the data processing unit 30 can obtain a received light image corresponding to an arbitrary aperture shape based on the light receiving result read out from the image sensor 22 by the rolling shutter method under the control of the control unit. be.

The data processing unit 30 acquires a received light image (fundus image) corresponding to the return light of the ring-shaped (first projection shape) pattern light for refractive power measurement, and obtains a projection shape (second projection shape) for photographing. A received light image of the aperture shape corresponding to the pattern light of . As a result, the data processing unit 30 can obtain a received light image for refractive power measurement and can generate a received light image corresponding to the shape of the aperture for photographing.

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

As shown in FIG. 3 , the data processing section 30 includes an analysis section 31 and an eye refractive power value calculation section 32 .

(analysis unit 31)
The analysis unit 31 includes a pupil area identification unit 31A and a pupil determination unit 31B.

The pupil region specifying unit 31A performs pupil region specifying processing on the anterior segment image of the subject's eye E acquired using the image sensor 22 or the anterior segment camera (not shown) as described above.

For example, the pupil region identifying unit 31A identifies an image region (pupil region) corresponding to the pupil of the subject's eye E based on the distribution of pixel values (such as luminance values) of the acquired anterior segment image. Since the pupil is generally expressed with lower brightness than other parts, the pupil region can be specified by searching for the low-luminance image region. At this time, the pupil region may be specified in consideration of the shape of the pupil. In other words, the pupil region can be identified by searching for a substantially circular low-brightness image region.

The pupil determination unit 31B determines whether or not the subject's eye E has a small pupil based on the pupil region specified by the pupil region specification unit 31A.

For example, the pupil determination unit 31B identifies the contour of the identified pupil region, obtains an approximate circle of the identified contour, and determines the diameter (or radius) of the obtained approximate circle as the diameter (or radius) of the pupil region ( In a broad sense, size).

In some embodiments, the pupil determining unit 31B obtains the radius of curvature of each of the two or more sections different from each other in the contour of the identified pupil region, and uses the statistical values of the obtained two or more curvature radii to determine the pupil Find the diameter (or radius) of the region. Statistics include mean, median, mode, maximum, and minimum values.

In some embodiments, the pupil determination unit 31B obtains the center of curvature of each of two or more sections different from each other in the contour of the pupil region, and determines the center position or the center of gravity of the two or more obtained centers of curvature as the pupil region. Set as center position. The pupil determination unit 31B can obtain the diameter (or radius) of the pupil region using the statistical value of the distance (radius) from the set center position to the contour. Again, the statistical values include mean, median, mode, maximum, and minimum values.

The pupil determination unit 31B compares the obtained diameter (or radius) of the pupil region with a predetermined threshold. The predetermined threshold is a threshold for determining that the pupil of the subject's eye is a small pupil. An example of a predetermined threshold is 2 mm (diameter).

The analysis unit 31 determines that the subject's eye E has a small pupil when the pupil determination unit 31B determines that the diameter (or radius) of the pupil region is equal to or less than a predetermined threshold. On the other hand, when the pupil determination unit 31B determines that the diameter (or radius) of the pupil region is not equal to or less than the predetermined threshold value, the analysis unit 31 determines that the subject's eye E does not have a small pupil.

When it is determined that the subject's eye E has a small pupil, the control section, which will be described later, controls the pattern light generating section 11 to emit ring-shaped pattern light having a diameter (or radius) for a small pupil to the subject's eye E. project it. In some embodiments, the diameter for small pupils corresponds to the diameter (or radius) of the pupil region of the subject's eye E determined by the pupil determination unit 31B. For example, the control unit projects onto the eye E the pattern light having a ring diameter corresponding to the diameter (or radius) of the pupil region of the eye E determined by the pupil determination unit 31B. The ring diameter corresponding to the diameter of the pupil region of the eye E to be inspected includes a value obtained by subtracting a predetermined constant from the diameter of the pupil region, a value obtained by multiplying the diameter of the pupil region by a predetermined ratio smaller than 1, and a value obtained by multiplying the diameter of the pupil region by a predetermined ratio smaller than 1. There is a predetermined function value with diameter as a variable, and the like.

(Eye refractive power value calculator 32)
The eye refractive power value calculator 32 analyzes a ring image (pattern image) based on return light of the pattern light depicted in the fundus image of the eye E to be examined, which is acquired based on the light reception result of the image sensor 22 .

For example, the eye refractive power value calculator 32 obtains the luminance distribution of the acquired received light image (fundus image), and obtains the centroid position of the ring image from the obtained luminance distribution. Further, the eye refractive power value calculator 32 obtains luminance distributions along a plurality of scanning directions radially extending from the calculated barycentric position, and identifies the ring image from the luminance distributions. Subsequently, the eye refractive power value calculation unit 32 obtains an approximate ellipse of the identified ring image, and substitutes the major axis and minor axis of the approximate ellipse into a known formula to obtain the spherical power S, the cylinder power C, and the cylinder axis. Find the angle A. In some embodiments, the equivalent spherical power SE (=S+C/2) is calculated as the eye refractive power value.

In some embodiments, the eye refractive power value calculator 32 obtains the spherical power S, the cylinder power C, and the cylinder axis angle A, or the equivalent spherical power SE, based on the deformation and displacement of the ring image with respect to the reference pattern.

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

In this specification, the "processor" includes, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), a programmable logic device (e.g., SPLD (Simple Programmable Logic Device e), CPLD (Complex Programmable Logic Device), FPGA (Field Programmable Gate Array)) or the like. The processor implements the functions according to the embodiment by, for example, reading and executing a program stored in a storage circuit or storage device.

(Image output unit 40)
The image output unit 40 displays various information under the control of a control unit, which will be described later. For example, the image output section 40 outputs the received light image obtained by the data processing section 30 . The received light image obtained by the data processing unit 30 includes a received light image obtained for refractive power measurement and a received light image (captured image) obtained for photographing.

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 combined with the optical path of the pattern light in the configuration of the optical system shown in FIG. The fixation projection system can present the eye E to be examined with an internal fixation target, an external fixation target, or a target for refractive power measurement. When presenting the internal fixation target or the visual target to the subject's eye E, the fixation projection system includes an LCD that displays the internal fixation target or the visual target under the control of the control unit, and the luminous flux output from the LCD is projected onto the fundus of the eye E to be examined. The LCD is configured so that the display position of the fixation target on its screen can be changed. By changing the display position of the fixation target on the LCD, it is possible to change the projection 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 turning on any of the LEDs. be.

In addition, since fixation can be induced by changing the projection position of the fixation target on the fundus of the subject's 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 ophthalmologic apparatus 1 (objective lens).

For example, the XY alignment system projects a bright spot onto the eye E to be examined. The data processing unit 30 acquires the anterior segment image of the subject's eye E on which the bright spots are projected, and obtains the displacement between the bright spot image depicted in the acquired anterior segment image and the alignment reference position. A control unit, which will be described later, relatively moves the device optical system and the subject's eye E in a direction intersecting the optical axis direction by a moving mechanism (not shown) so that the obtained displacement is cancelled.

For example, the Z alignment system projects alignment light from a position off the optical axis of the apparatus optical system, and receives the alignment light reflected by the anterior segment of the eye E to be examined. The data processing unit 30 identifies the distance of the subject's eye E to the device optical system from the light receiving position of the alignment light that changes according to the distance of the subject's eye E to the device optical system. A control unit, which will be described later, relatively moves the device optical system and the subject's eye E in the direction of the optical axis by a moving mechanism (not shown) so that the specified distance becomes a desired working distance.

In some embodiments, the function of the alignment system is realized by two or more anterior cameras positioned off the optical axis of the system optics. For example, as disclosed in Japanese Unexamined Patent Application Publication No. 2013-248376, the data processing unit 30 analyzes the anterior segment images of the subject's eye E obtained substantially simultaneously by two or more anterior segment cameras. , the three-dimensional position of the subject's eye E is identified using known trigonometry. A control unit (to be described later) moves the apparatus optical system by a moving mechanism (not shown) so that the optical axis of the apparatus optical system substantially coincides with the axis of the eye E to be examined and the distance of the apparatus optical system from the eye E to be examined is a predetermined working distance. The system and the subject's eye E are relatively moved three-dimensionally.

<Configuration of control system>
Next, a control system of the ophthalmologic apparatus 1 according to the embodiment will be described.

A control system of the ophthalmologic apparatus 1 will be described with reference to FIG. As shown in FIG. 4 , the control system of the ophthalmologic apparatus 1 is configured around a control section 100 . Note that at least 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 unit of the ophthalmologic apparatus 1 . Control unit 100 includes main control unit 101 and storage unit 102 . The main control unit 101 includes a processor and executes processing according to a program stored in the storage unit 102 to control each unit of the ophthalmologic apparatus 1 .

(Main control unit 101)
A main control unit 101 controls the projection system 10 , the light receiving system 20 , the data processing unit 30 , the image output unit 40 , and the optical system 51 . Control of the optical system 51 includes control of the focusing mechanism 52 and control of the correction optical system 53 .

Control of the projection system 10 includes control of the pattern light generator 11 . Control of the pattern light generator 11 includes control of the light source 11A and control of the spatial light modulator 11C. The control of the light source 11A includes switching between lighting and extinguishing of the light source, and change control of the light amount of 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. .

If the projection system 10 includes an optical scanner, the main controller 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 timing, sensitivity, and frame rate, and readout control by rolling shutter method or global shutter method.

The control of the data processing unit 30 includes execution control of the image processing and execution control of the analysis processing. The 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. For example, the focusing mechanism 52 is controlled based on the spherical power S or the equivalent spherical power SE among the eye refractive power values calculated by the eye refractive power value calculator 32 .

When the focusing mechanism 52 includes a focusing lens, the main control unit 101 identifies the focus control content corresponding to the spherical power S (eye refractive power value) calculated by the eye refractive power value calculator 32, A moving mechanism for moving the focusing lens in the optical axis direction is controlled based on the content of the focusing control thus obtained.

When the focusing mechanism 52 includes an objective lens, the main control unit 101 identifies the focus control content corresponding to the spherical power S calculated by the eye refractive power value calculation unit 32, and applies the identified focus control content. Based on this, a moving mechanism for moving 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 specifies the focusing control content corresponding to the spherical power S calculated by the eye refractive power value calculating unit 32, and the specified focusing A liquid lens or a liquid crystal lens is controlled based on the content of control.

The control of the correction optical system 53 includes control according to a mechanism for correcting the astigmatic state of the subject's eye. For example, the correction optical system 53 is controlled based on the astigmatism degree C and the astigmatism axis angle A among the eye refractive power values calculated by the eye refractive power value calculator 32 .

For example, the main control unit 101 specifies the content of astigmatism correction control corresponding to the astigmatism power C calculated by the eye refractive power value calculation unit 32, and the astigmatism power is corrected based on the specified content of the astigmatism correction control. The correction optical system 53 is controlled as follows. Further, for example, the main control unit 101 identifies the astigmatism correction control content corresponding to the astigmatism axis angle A calculated by the eye refractive power value calculation unit 32, and based on the identified astigmatism correction control content, the astigmatism axis angle The correction optical system 53 is controlled so that the is corrected.

When the correction optical system 53 includes a variable cross cylinder lens, the main control unit 101 rotates the two cylinder lenses independently in opposite directions based on the astigmatism correction control content corresponding to the astigmatism power C, thereby correcting the astigmatism power. to correct. Further, the main control unit 101 corrects the astigmatism axis angle by rotating the two cylinder lenses by the same angle in the same direction based on the astigmatism correction control contents corresponding to the astigmatism axis angle A.

For example, control information is stored in advance in the storage unit 102 shown in FIG. The control information includes correspondence information that associates the refractive power with the focusing control details (control amount, type of control signal) for the focusing mechanism 52 for changing the focal position of the pattern light. The main control unit 101 refers to the correspondence information, specifies the focus control content for the focusing mechanism 52 from the spherical power S obtained by the eye refractive power value calculation unit 32, and based on the specified focus control content. can be used to control the focusing mechanism 52 .

Further, for example, the control information is a combination of astigmatic power C and astigmatic axis angle A in astigmatism correction control details (control amount, type of control signal) for the correction optical system 53 for changing the refraction characteristics in the optical path of the pattern light. contains correspondence information associated with . The main control unit 101 refers to the correspondence information, specifies the content of astigmatism correction control for the correction optical system 53 from the astigmatism power C and the astigmatism axis angle A obtained by the eye refractive power value calculation unit 32, and It is possible to control the correction optical system 53 based on the contents of the correction control.

(storage unit 102)
The storage unit 102 stores various computer programs and data. The computer program includes an arithmetic program and a control program for controlling the ophthalmologic apparatus 1 . Further, the storage unit 102 stores control information 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 in the ophthalmologic apparatus 1, and operation devices (a mouse, a keyboard, etc.). Further, the operation unit 110 may include arbitrary operation devices and input devices such as trackballs, operation panels, switches, buttons, and dials.

In some embodiments, at least part of the image output section 40 and the operation section 110 are integrally configured. As a specific example, the functions of the image output unit 40 and the operation unit 110 are implemented 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.

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

5 to 7 show flow charts of an operation example of the ophthalmologic apparatus 1 according to the embodiment. The storage unit 102 stores computer programs for realizing the processes shown in FIGS. The main control unit 101 executes the processes shown in FIGS. 5 to 7 by operating according to this computer program.

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

(S1: eye refractive power measurement)
First, the main control unit 101 performs refractive power measurement.

That is, the main control unit 101 causes the projection system 10 to project a ring-shaped pattern light with a predetermined diameter for refractive power measurement onto the subject's eye E, and based on the result of receiving the return light, the fundus image of the subject's eye E ( received light image) is acquired by the data processing unit 30 . After that, the main control unit 101 causes the eye refractive power value calculation unit 32 to calculate the eye refractive power value of the subject's eye E based on the ring image depicted in the acquired fundus image.

Details of step S1 will be described later.

(S2: focus control)
Next, the main control unit 101 controls the focusing mechanism 52 based on the spherical power S among the eye refractive power values calculated in step S1, thereby arranging the focal position of the pattern light near the desired imaging site. Let

Specifically, the main control unit 101 identifies, in the control information stored in the storage unit 102, the focus control content associated with the spherical power S among the eye refractive power values calculated in step S1, The focusing mechanism 52 is controlled based on the identified focus control details. As a result, the focal position of the pattern light is arranged in the vicinity of the desired imaging site according to the spherical power S of the eye E to be examined.

(S3: astigmatism correction)
Subsequently, the main control unit 101 corrects the astigmatic state of the subject's eye E by controlling the correction optical system 53 based on the astigmatism degree C and the astigmatism axis angle A among the eye refractive power values calculated in step S1. .

Specifically, in the control information stored in the storage unit 102, the main control unit 101 performs astigmatism correction control associated with the astigmatism power C and the astigmatism axis angle A among the eye refractive power values calculated in step S1. The content is specified, and the correction optical system 53 is controlled based on the specified astigmatism correction control content. As a result, the astigmatic state of the eye E to be examined is forced according to the astigmatism degree C and the astigmatic axis angle A of the eye E to be examined.

(S4: Shooting)
Next, the main control unit 101 causes the fundus of the subject's eye E to be photographed.

That is, the main control unit 101 causes the projection system 10 to project slit-shaped pattern light substantially parallel to the opening direction for imaging onto the subject's eye E, and based on the result of receiving the return light, the fundus image of the subject's eye E ( received light image) is acquired by the data processing unit 30 .

Details of step S4 will be described later.

With this, the operation of the ophthalmologic apparatus 1 is completed (end).

FIG. 6 shows a flow diagram of an example of the operation of step S1 in FIG.

(S11: Acquire an anterior segment image)
First, the main control unit 101 acquires an anterior segment image including an image area corresponding to the pupil of the eye E to be examined.

For example, when the image sensor 22 includes a CCD image sensor, the main controller 101 causes the pattern light generator 11 to generate projected pattern light for imaging the anterior eye, and directs the generated pattern light to the anterior eye. An image of the anterior segment is acquired by projecting and receiving the return light by the image sensor 22 . The pattern light generator 11 generates pattern light extending in a direction (for example, opening direction) substantially parallel to the opening direction of the opening shape, for example. The pattern light generated by the pattern light generator 11 is projected onto the subject's eye E via the optical system 12 , the optical multiplexer/demultiplexer 50 , and the optical system 51 . The pattern light projected onto the eye E to be inspected is reflected by the eye E to be inspected. Return light of the pattern light from the subject's 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 the result of receiving the return light by the image sensor 22 by the global shutter method.

For example, if the image sensor 22 includes a CMOS image sensor (or a CCD image sensor), the projection shape for imaging the anterior segment may be the same as the projection shape for imaging in step S4 of FIG. In this case, the main control unit 101 reads out the result of the return light received by the image sensor 22 by a rolling shutter method corresponding to a predetermined aperture shape. The data processing unit 30 acquires a received light image corresponding to the shape of the aperture based on the read result of received light. Subsequently, for example, the main control unit 101 projects pattern light having a projection shape similar to that described above to a projection position shifted in a direction orthogonal to the opening direction, shifts the opening position in the same manner as described above, and uses the image sensor 22 to Readout control of the light reception result of the returned light is performed. The anterior segment image of the subject's eye E is acquired by repeating such control a plurality of times and acquiring a received light image for one frame.

In some embodiments, for example, the main control unit 101 may photograph the anterior segment using an anterior segment camera (not shown) provided separately from the optical system shown in FIG. Thereby, an anterior segment image of the subject's eye E is acquired.

In some embodiments, the anterior segment image is obtained by externally receiving image data of the anterior segment image.

(S12: Identify pupil area)
Next, the main control unit 101 causes the pupil region specifying unit 31A to specify an image region corresponding to the pupil as the pupil region in the anterior segment image acquired in step S11.

The pupil region identifying unit 31A identifies the pupil region in the anterior segment image as described above.

(S13: Predetermined pupil size or less?)
Subsequently, the main control unit 101 causes the pupil determination unit 31B to determine whether or not the pupil of the subject's eye E is a small pupil from the pupil region identified in step S12.

Specifically, the pupil determination unit 31B identifies the contour of the pupil region identified in step S12, obtains the diameter (or radius) of the pupil region based on the identified contour, (or radius) and a predetermined threshold. The predetermined threshold corresponds to a predetermined pupil size. The pupil determination unit 31B determines that the pupil of the subject eye E is a small pupil when the diameter (or radius) of the pupil region is equal to or less than a predetermined threshold, and the diameter (or radius) of the pupil region exceeds the predetermined threshold. Then, it is determined that the pupil of the subject's eye E is not a small pupil.

In step S13, when it is determined that the pupil of the subject's eye E is a small pupil from the pupil region specified in step S12 (S13: Y), the operation of the ophthalmologic apparatus 1 proceeds to step S15. On the other hand, when it is determined in step S13 that the pupil of the subject's eye E is not a small pupil from the pupil region specified in step S12 (S13: N), the operation of the ophthalmologic apparatus 1 proceeds to step S14.

(S14: change projection shape)
In step S13, when it is determined that the pupil of the subject's eye E is a small pupil from the specified pupil region (S13: Y), the main control unit 101 controls the pattern light generation unit 11 to perform refraction measurement. Change the projected shape of the pattern light to change the predetermined diameter of the ring for .

(S15: Project pattern light)
Following step S14, or when it is determined in step S13 that the pupil of the subject's eye E is not a small pupil (S13: N), the main control unit 101 changes the ring-shaped pattern light for refractive power measurement to pattern light. Generated by the generator 11 .

When the projection shape of the pattern light is changed in step S14, the pattern light generator 11 generates ring-shaped pattern light having a diameter for measuring the refractive power of the small pupil. In some embodiments, the patterned light generator 11 generates a ring-shaped patterned light having a predetermined small pupil refractive power measurement diameter. In some embodiments, the pattern light generator 11 generates ring-shaped pattern light with a diameter corresponding to the diameter of the pupil region identified in step S13.

When it is determined in step S13 that the pupil of the subject's eye E is not a small pupil (S13: N), the pattern light generator 11 generates ring-shaped pattern light with a predetermined diameter for refractive power measurement. .

The pattern light generated by the pattern light generator 11 is projected onto the subject's eye E via the optical system 12 , the optical multiplexer/demultiplexer 50 , and the optical system 51 .

(S16: Acquisition of received light image)
Next, the main control section 101 causes the data processing section 30 to acquire the received light image.

Specifically, the pattern light projected onto the eye E to be examined by the projection system 10 is reflected by the eye E to be examined. Return light of the pattern light from the subject's 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 .

When the image sensor 22 includes a CCD image sensor, the main control unit 101 reads the result of receiving the return light by the image sensor 22 by, for example, a global shutter method, and outputs the received light image (fundus image) of the eye E to be examined to the data processing unit 30. to get

When the image sensor 22 includes a CMOS image sensor, the main control unit 101 reads the result of receiving the return light by the image sensor 22 by, for example, a rolling shutter method, and outputs the received light image (fundus image) of the eye E to be examined to the data processing unit 30. to get

(S17: Calculate eye refractive power value)
Subsequently, the main control unit 101 causes the analysis unit 31 to analyze the ring image drawn in the received light image acquired in step S16, and causes the eye refractive power value calculation unit 32 to calculate the eye refractive power value.

For example, the main control unit 101 causes the analysis unit 31 to determine whether or not the ring image based on the returned light has been obtained. The analysis unit 31 detects the edge positions (pixels) of the ring image based on the returned light, and determines whether or not the width of the ring image (the difference between the outer diameter and the inner diameter) is equal to or greater than a predetermined value. Alternatively, the analysis unit 31 may determine whether or not a ring image has been obtained by determining whether or not a ring can be formed based on points (images) having a predetermined height (ring diameter) or more. good.

When it is determined that the ring image has been acquired, the eye refractive power value calculation unit 32 analyzes the ring image depicted in the acquired received light image by a known method, and calculates the spherical power S, the cylinder power C, and the cylinder axis Find the angle A.

When it is determined that the ring image cannot be acquired, the main control unit 101 takes into account the possibility of the eye having a strong refractive error, and controls the focusing mechanism 52 to move to the minus power side (for example, −10D), and moves the focal position of the pattern light to the plus power side (for example, +10D). The main control unit 101 again projects the pattern light onto the subject's eye E and detects the ring image at each position. If it is still determined that the ring image cannot be acquired, the main control unit 101 executes predetermined measurement error processing. At this time, the operation of the ophthalmologic apparatus 1 may proceed to the next step. In the control unit 100, information indicating that the refractive power measurement result was not obtained is stored in the storage unit 102. FIG.

In some embodiments, the main measurement obtains the refractive power measurement after the provisional measurement is completed.

Also in this case, the main control unit 101 first causes the analysis unit 31 to determine whether or not the ring image based on the return light has been acquired. When it is determined that the ring image has been acquired, the eye refractive power value calculator 32 analyzes the ring image based on the return light by a known method, and obtains the temporary spherical power S and the temporary cylindrical power C. The main control unit 101 controls the focusing mechanism 52 based on the obtained temporary spherical power S and cylindrical power C to obtain a position corresponding to the equivalent spherical power (S+C/2) (corresponding to the temporary far point). position) to move the focal position of the pattern light.

Next, the main controller 101 executes fog control.

Specifically, the main control unit 101 arranges an optotype chart (not shown) for a predetermined diopter (for example, 1.5 diopters) from the position of the calculated equivalent spherical power at a position where the subject's eye E is fogged. . After that, the main control unit 101 projects the ring-shaped pattern light for refractive power measurement onto the subject's eye E as the main measurement, and acquires the ring image again. The main control unit 101 causes the eye refractive power value calculation unit 32 to calculate the spherical power, the cylindrical power, and the cylindrical axis angle from the analysis result of the ring image obtained in the same manner as described above and the control details of the focusing mechanism 52 .

Thus, the operation of step S1 in FIG. 5 is completed (end).

FIG. 7 shows a flow diagram of an operation example of step S4 in FIG.

(S21: Project pattern light)
In step S4, first, the main controller 101 controls the pattern light generator 11 to generate pattern light having a projection shape for photographing.

Specifically, the patterned light generator 11 generates patterned light extending in a direction substantially parallel to the aperture direction of the aperture shape (for example, the aperture direction). The pattern light generated by the pattern light generator 11 is projected onto the subject's eye E via the optical system 12 , the optical multiplexer/demultiplexer 50 , and the optical system 51 .

(S22: Acquire received light image)
Next, the main control section 101 causes the data processing section 30 to acquire the received light image.

The pattern light projected onto the eye E to be inspected is reflected by the eye E to be inspected. Return light of the pattern light from the subject's 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 .

When the image sensor 22 includes a CCD image sensor, the main control unit 101 reads the result of receiving the return light by the image sensor 22 by the global shutter method. The data processing unit 30 acquires a light reception image based on the read light reception result.

When the image sensor 22 includes a CMOS image sensor, the main control unit 101 reads the result of receiving the return light by the image sensor 22 by a rolling shutter method corresponding to a predetermined aperture shape. The data processing unit 30 acquires a received light image corresponding to the shape of the aperture based on the read result of received light. Subsequently, for example, the main control unit 101 projects pattern light having a projection shape similar to that described above to a projection position shifted in a direction orthogonal to the opening direction, shifts the opening position in the same manner as described above, and uses the image sensor 22 to Readout control of the light reception result of the returned light is performed. The fundus image of the subject's eye E is acquired by repeating such control a plurality of times to acquire a received light image for one frame.

Thus, the operation of step S4 in FIG. 5 is completed (end).

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

(First modification)
In the embodiment, the pattern light generator 11 uses a light source and a non-light-emitting device to spatially modulate the light from the light source to generate pattern light. is not limited to this. In this modification, the pattern light generator includes a self-luminous device.

FIG. 8 shows a block diagram of a configuration example of a patterned light generator according to a modification of the embodiment. The ophthalmologic apparatus according to this modification includes a pattern light generator 11a shown in FIG. 8 instead of the pattern light generator 11. In FIG.

The pattern light generator 11 a according to this modification includes a self-luminous device 120 and an optical system 121 . The self-luminous device 120 functions as a pixelated pattern light generator by generating modulated light for each pixel. Examples of the self-luminous device 120 include a cathode-ray tube (CRT), a plasma display panel (PDP), an organic EL (Organic Electro-Luminescence: OEL), an LED, and an inorganic EL (Inorganic Electro-Luminescence: IEL). ), vacuum fluorescent display (VFD), field emission display (FED), and the like.

The self-luminous device 120 can be arranged at a position substantially optically conjugate with the part of the subject's eye E to be imaged (for example, the fundus, the anterior segment). Optical system 121 includes a projection lens for projecting the light spatially modulated by self-luminous device 120 .

Since the operation of the ophthalmologic apparatus according to this modification is the same as that of the embodiment, detailed description thereof will be omitted.

(Second modification)
In the embodiment or its modification, the case where the image sensor 22 includes either one of the CMOS image sensor and the CCD image sensor has been described, but the configuration according to the embodiment is not limited to this. Here, the CMOS image sensor is an example of an image sensor capable of reading out the light receiving result of the return light of the pattern light by the rolling shutter method. A CCD image sensor is an example of an image sensor capable of reading out the result of receiving the return light of the pattern light by the global shutter method. In this modification, the image sensor includes a CCD image sensor and a CMOS image sensor.

FIG. 9 shows a block diagram of a configuration example of an ophthalmologic apparatus according to a modification of the embodiment. In FIG. 9, the same parts as in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

The configuration of the ophthalmologic apparatus 1a according to this modification differs from the configuration of the ophthalmologic apparatus 1 according to the embodiment in that a light receiving system 20a is provided instead of the light receiving system 20. FIG. The configuration of the light receiving system 20a differs from the configuration of the light receiving system 20 in that an image sensor 22a is provided instead of the image sensor 22. FIG.

The image sensor 22a includes an optical demultiplexer 22A, a CCD image sensor 22B, and a CMOS image sensor 22C.

The optical splitter 22A divides the return light from the optical system 21A into two return lights, and guides the two divided return lights to the CCD image sensor 22B and the CMOS image sensor 22C. Such a function of the optical demultiplexer 22A can be realized by a beam splitter. Beam splitters include half mirrors, dichroic mirrors, polarizing beam splitters, cold mirrors, hot mirrors, and the like.

For example, the optical demultiplexer 22A guides the return light of the pattern light for refractive power measurement to the CCD image sensor 22B, and guides the return light of the pattern light for photographing of the desired photographing unit to the CMOS image sensor 22C.

In this modification, the main control unit 101 can cause the data processing unit 30 to acquire a received light image by reading out the result of receiving the returned light by the CCD image sensor 22B by the global shutter method. Further, the main control unit 101 can cause the data processing unit 30 to acquire a received light image by reading out the result of receiving the returned light by the CMOS image sensor 22C by the rolling shutter method.

Other operations of the ophthalmologic apparatus 1a according to this modified example are the same as those of the embodiment, and detailed description thereof will be omitted.

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

An ophthalmologic apparatus (1, 1a) according to some embodiments includes a projection unit (projection system 10), an acquisition unit (a light receiving system 20 and a control unit 100 that controls an image sensor 22), and a control unit (100). and an eye refractive power value calculator (32). The projection unit projects pattern light of a deformable projection shape onto the subject's eye (E). The acquisition unit receives return light of the pattern light from the eye to be inspected, and acquires an image of the eye to be inspected based on the result of receiving the return light. The control unit causes the projection unit to project the pattern light of the first projection shape onto the subject's eye, and causes the acquisition unit to acquire the first image of the subject's eye. The eye refractive power value calculator calculates the eye refractive power value of the subject's eye based on the image based on the return light depicted in the first image.

According to such a configuration, the refractive power of the eye to be inspected is measured by changing the projection shape of the pattern light projected onto the eye to be inspected, so the refractive power of the eye to be inspected can be measured with a simple configuration. It becomes possible to provide an ophthalmologic apparatus that is

In the ophthalmologic apparatus according to some embodiments, the control unit causes the acquisition unit to acquire the first image of the subject's eye by causing the projection unit to project the pattern light of the first projection shape onto the projection unit, and causes the projection unit to acquire the first image of the subject's eye. The acquisition unit acquires a second image of the subject's eye by causing the projection unit to project the pattern light of the second projection shape.

According to such a configuration, an image for refractive power measurement is obtained by projecting the pattern light of the first projection shape onto the eye to be inspected, and photographing is performed by projecting the pattern light of the second projection shape onto the eye to be inspected. images can be acquired. Therefore, it is possible to provide an ophthalmologic apparatus capable of measuring the refractive power of an eye to be inspected and acquiring a photographed image with a simple configuration.

In the ophthalmologic apparatus according to some embodiments, the acquisition unit acquires the second image using a rolling shutter method.

With such a configuration, for example, it is possible to acquire the second image using a CMOS image sensor, so the ophthalmologic apparatus capable of measuring the refractive power of the subject's eye and acquiring an image with a simple configuration. will be able to provide

In the ophthalmologic apparatus according to some embodiments, the acquisition unit acquires the first image using a global shutter method.

With such a configuration, for example, it is possible to acquire the first image using a CCD image sensor, so the ophthalmologic apparatus capable of measuring the refractive power of the subject's eye and acquiring an image with a simple configuration. will be able to provide

The ophthalmic apparatus according to some embodiments includes a focusing mechanism (52) positioned in the optical paths of the pattern light and return light, and the controller controls the focusing mechanism based on the eye refractive power value.

According to such a configuration, it is possible to provide an ophthalmologic apparatus capable of measuring the refractive power of an eye to be examined with high accuracy according to the eye refractive power value of the eye to be examined.

An ophthalmologic apparatus according to some embodiments includes a correction optical system (53) arranged in the optical paths of the pattern light and the return light, and the controller controls the correction optical system based on the eye refractive power value.

According to such a configuration, it is possible to provide an ophthalmologic apparatus capable of measuring the refractive power of the subject's eye with high accuracy according to the astigmatic state of the subject's eye.

In some embodiments of the ophthalmic apparatus, the correction optics include a variable cross-cylinder lens.

According to such a configuration, it is possible to provide an ophthalmologic apparatus capable of measuring the refractive power of the subject's eye with high accuracy with a simple configuration.

An ophthalmologic apparatus according to some embodiments includes a pupil determination unit (31B) that identifies a pupil region in an anterior segment image of an eye to be examined and determines whether the size of the pupil region is equal to or less than a predetermined threshold. When the pupil determination unit determines that the size of the pupil region is equal to or less than the predetermined threshold value, the control unit causes the projection unit to project pattern light in a ring-shaped projection shape having a diameter corresponding to the size as the first projection shape. projected onto

According to such a configuration, even when the pupil of the eye to be inspected is a small pupil, the ring-shaped pattern light can be projected onto the fundus of the eye to be inspected. Accordingly, it is possible to provide an ophthalmologic apparatus capable of measuring the refractive power of an eye to be inspected with a simple configuration regardless of the size of the pupil of the eye to be inspected.

In the ophthalmic apparatus according to some embodiments, the projection unit includes a light source (11A) and a spatial light modulator (11B) that spatially modulates light from the light source.

According to such a configuration, the spatial light modulator is used to spatially modulate the light from the light source to output the pattern light whose projection shape can be changed, so that the configuration can be simplified. can.

A control method for an ophthalmologic apparatus (1, 1a) according to some embodiments is a control method for an ophthalmologic apparatus that projects pattern light having a deformable projection shape onto an eye to be examined (E). A method for controlling an ophthalmologic apparatus includes a first projection step, a first acquisition step, a second projection step, a second acquisition step, and a calculation step. The first projection step projects the first pattern light of the first projection shape onto the subject's eye. The first acquisition step receives a first return light of the first pattern light from the eye to be inspected, and acquires a first image of the eye to be inspected based on the reception result of the first return light. The second projecting step projects the second pattern light of the second projection shape onto the subject's eye. The second acquisition step receives second return light of the second pattern light from the eye to be inspected, and acquires a second image of the eye to be inspected based on the result of receiving the second return light. The calculating step calculates an eye refractive power value of the subject's eye based on the image based on the first returned light rendered in the first image.

According to this method, the refractive power of the eye to be examined is measured by changing the projection shape of the pattern light projected onto the eye to be examined, so that the refractive power of the eye to be examined can be measured with a simple configuration. will be able to

In the ophthalmologic apparatus control method according to some embodiments, the second acquisition step acquires the second image by a rolling shutter method.

According to such a method, it is possible to obtain the second image using, for example, a CMOS image sensor, so that it is possible to measure the refractive power of the subject's eye and obtain an image with a simple configuration.

In the ophthalmologic apparatus control method according to some embodiments, the first acquisition step acquires the first image by a global shutter method.

According to such a method, it is possible to acquire the first image using, for example, a CCD image sensor, so that it is possible to measure the refractive power of the subject's eye and acquire the image with a simple configuration.

A method of controlling an ophthalmic apparatus according to some embodiments includes a focusing step of changing a focal position of the second pattern light based on an eye refractive power value before the second projecting step.

According to such a method, it is possible to measure the refractive power of the subject's eye with high accuracy according to the eye refractive power value of the subject's eye.

A method for controlling an ophthalmologic apparatus according to some embodiments includes, before the second projection step, a correction step of correcting the refractive characteristics of an optical element arranged in the optical path of the second pattern light based on the eye refractive power value. include.

According to such a method, it is possible to measure the refractive power of the subject's eye with high accuracy according to the astigmatic state of the subject's eye.

A method for controlling an ophthalmologic apparatus according to some embodiments includes a determination step of determining whether a pupil region in an anterior segment image of an eye to be inspected is specified, and whether the size of the pupil region is equal to or less than a predetermined threshold; In the first projection step, when it is determined in the determination step that the size of the pupil region is equal to or less than a predetermined threshold value, the pattern light is projected in a ring-shaped projection shape having a diameter corresponding to the size as the first projection shape. .

According to such a method, even when the pupil of the eye to be inspected is small, the ring-shaped pattern light can be projected onto the fundus of the eye to be inspected. As a result, regardless of the size of the pupil of the eye to be inspected, it is possible to measure the refractive power of the eye to be inspected with a simple configuration.

The embodiment shown above or its modification is merely an example for carrying out the present invention. A person who intends 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 modifications thereof, the ophthalmologic apparatus is used in the field of ophthalmology, for example, for axial length measurement, intraocular pressure measurement, fundus imaging, optical coherence tomography (OCT), and ultrasonography. It may have any function possible. The axial length measurement function is realized by an optical coherence tomography or the like. In addition, the eye axial length measurement function projects light onto the eye to be inspected, and detects the return light from the fundus while adjusting the position of the optical system in the Z direction (back and forth direction) with respect to the eye to be inspected. The axial length of the eye may be measured. The intraocular pressure measurement function is realized by a tonometer or the like. The fundus imaging function is realized by a fundus camera, a scanning ophthalmoscope (SLO), or the like. The OCT function is realized by an optical coherence tomography or the like. The ultrasonic examination function is realized by an ultrasonic diagnostic apparatus or the like. Moreover, it is also possible to apply the present invention to a device (complex machine) having two or more of such functions.

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

1 ophthalmic apparatus 10 projection systems 11, 11a pattern light generator 11A light sources 11B, 12, 21, 51, 121 optical system 11C spatial light modulators 20, 20a light receiving systems 22, 22a image sensor 22A optical demultiplexer 22B CCD image sensor 22C CMOS image sensor 30 Data processing unit 31 Analysis unit 31A Pupil region identification unit 31B Pupil determination unit 32 Eye refractive power value calculation unit 40 Image output unit 50 Optical multiplexer/demultiplexer 52 Focusing mechanism 53 Correction optical system 100 Control unit 101 Main Control unit 102 Storage unit 110 Operation unit 120 Self-luminous device E Eye to be examined

Claims (15)

a projection unit that includes a spatial light modulator that spatially modulates light from a light source and that projects pattern light having a deformable projection shape onto an eye to be inspected;
an acquisition unit that receives return light of the pattern light from the eye to be inspected and acquires an image of the eye to be inspected based on a result of receiving the return light;
a control unit that causes the projection unit to project pattern light of a first projection shape onto the eye to be inspected, and causes the acquisition unit to acquire a first image of the eye to be inspected;
an eye refractive power value calculation unit that calculates an eye refractive power value of the subject's eye based on an image based on the returned light depicted in the first image;
including
The control unit causes the projection unit to project pattern light having a first projection shape by controlling the spatial light modulator, causes the acquisition unit to acquire a first image of the subject's eye, and controls the spatial light modulator. A second image of the subject's eye is acquired by the acquisition unit by controlling the device to sequentially project the pattern light of a second projection shape extending in a predetermined aperture direction onto the projection unit in a direction orthogonal to the aperture direction. ophthalmic equipment. The ophthalmologic apparatus according to claim 1 , wherein the acquisition unit acquires the second image by a rolling shutter method. 3. The ophthalmologic apparatus according to claim 1, wherein the acquisition unit acquires the first image by a global shutter method. including a focusing mechanism arranged in the optical path of the pattern light and the return light;
The ophthalmologic apparatus according to any one of claims 1 to 3, wherein the controller controls the focusing mechanism based on the eye refractive power value. including a correction optical system arranged in the optical paths of the pattern light and the return light;
The ophthalmologic apparatus according to any one of claims 1 to 4, wherein the control unit controls the correction optical system based on the eye refractive power value. The ophthalmologic apparatus according to claim 5 , wherein the correction optical system includes a variable cross cylinder lens. A pupil determination unit that identifies a pupil region in the anterior segment image of the eye to be inspected and determines whether the size of the pupil region is equal to or less than a predetermined threshold,
When the pupil determination unit determines that the size of the pupil region is equal to or less than a predetermined threshold value, the control unit outputs pattern light having a ring-shaped projection shape having a diameter corresponding to the size as the first projection shape. The ophthalmologic apparatus according to any one of claims 1 to 6 , wherein the projection unit projects. The spatial light modulator includes a digital micromirror device in which a plurality of mirror elements are two-dimensionally arranged.
The ophthalmologic apparatus according to any one of claims 1 to 7, characterized by: A control method for an ophthalmologic apparatus that includes a spatial light modulator that spatially modulates light from a light source and that projects pattern light in a deformable projection shape onto an eye to be examined,
a first projection step of projecting a first pattern light having a first projection shape onto the subject's eye by controlling the spatial light modulator ;
a first acquisition step of receiving a first return light of the first pattern light from the eye to be inspected and acquiring a first image of the eye to be inspected based on a result of receiving the first return light;
a second projection step of sequentially projecting a second pattern of light having a second projection shape extending in a predetermined aperture direction onto the subject eye in a direction orthogonal to the aperture direction by controlling the spatial light modulator;
a second acquisition step of receiving a second return light of the second pattern light from the eye to be inspected and acquiring a second image of the eye to be inspected based on a result of receiving the second return light;
a calculation step of calculating an eye refractive power value of the eye to be inspected based on an image based on the first returned light rendered in the first image;
A method of controlling an ophthalmic device comprising: 10. The method of controlling an ophthalmologic apparatus according to claim 9 , wherein said second acquisition step acquires said second image by a rolling shutter method. 11. The method of controlling an ophthalmologic apparatus according to claim 9 , wherein the first acquisition step acquires the first image by a global shutter method. 12. The method according to any one of claims 9 to 11, further comprising, prior to the second projection step, a focusing step of changing a focal position of the second pattern light based on the eye refractive power value. Control method of the ophthalmologic apparatus according to. Claims 9 to 9 , characterized by comprising, prior to the second projection step, a correction step of correcting a refractive characteristic of an optical element arranged in the optical path of the second pattern light based on the eye refractive power value. 13. A control method for an ophthalmologic apparatus according to any one of items 12 to 13 . identifying a pupillary region in the anterior segment image of the eye to be inspected, and determining whether the size of the pupillary region is equal to or less than a predetermined threshold;
In the first projecting step, when it is determined in the determining step that the size of the pupil region is equal to or less than a predetermined threshold value, the first projection shape is a ring-shaped projection shape pattern light having a diameter corresponding to the size. 14. The method of controlling an ophthalmologic apparatus according to any one of claims 9 to 13, characterized by projecting . The spatial light modulator includes a digital micromirror device in which a plurality of mirror elements are two-dimensionally arranged.
The method for controlling an ophthalmologic apparatus according to any one of claims 9 to 14, characterized in that:

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