JP6930841B2 - Ophthalmic equipment - Google Patents

Description

The present invention relates to an ophthalmic apparatus for acquiring data of an eye to be inspected.

The ophthalmologic apparatus includes an ophthalmologic measuring apparatus for measuring the characteristics of the eye to be inspected and an ophthalmologic imaging apparatus for obtaining an image of the eye to be inspected.

Examples of ophthalmic measuring devices include ophthalmic refraction testing devices (refractometers, keratometers) that measure the refraction characteristics of the eye to be inspected, tonometers, specular microscopes that obtain corneal characteristics (corneal thickness, cell distribution, etc.), and so on. There is a wave front analyzer that obtains error information of the eye to be inspected using a Hartmann-Shack sensor.

Examples of ophthalmologic imaging devices include an optical coherence tomography that obtains a tomographic image using optical coherence tomography (OCT), a fundus camera that photographs the fundus, and laser scanning using a confocal optical system. There is a scanning laser optical coherence tomography (SLO) that obtains an image of the fundus.

In an ophthalmic examination using such an apparatus, it is important to align the optical system with the eye to be inspected from the viewpoint of the accuracy and accuracy of the examination. Alignment generally includes an operation of aligning the optical axis of the optical system with the axis of the eye to be inspected (XY alignment) and an operation of adjusting the distance between the eye to be inspected and the optical system to a predetermined working distance (Z alignment). be.

In particular, ophthalmic devices that require Z alignment are provided with a mechanism for avoiding contact between the measuring unit containing the optical system and the eye to be inspected, or avoiding contact between the measuring unit and the eye to be inspected. In some cases, the drive unit that moves the measurement unit or the like is controlled.

For example, Patent Document 1 discloses an ophthalmic apparatus provided with a safety stopper mechanism for avoiding contact between the gantry and the eye to be inspected.

For example, in Patent Document 2, an index light is projected onto an eye to be inspected, and an index image based on the reflected light is detected to detect the position of the main body of the device installed on the gantry, and the main body of the device is the eye to be inspected. A method of stopping the forward movement of the gantry when it is determined that the gantry is closer than a predetermined distance is disclosed.

For example, in Patent Document 3, an index light is projected onto an eye to be inspected, the reflected light is bent in two directions by a prism lens, and detected by a two-dimensional light receiving element. A method of calculating the relative position of the optometry unit and stopping the movement of the optometry unit when the distance between the optometry unit and the optometry object is closer than the appropriate operating distance is disclosed.

Japanese Unexamined Patent Publication No. 2013-220134 Japanese Unexamined Patent Publication No. 01-274737 Japanese Unexamined Patent Publication No. 08-126609

However, in the method disclosed in Patent Document 1, even if the subject fixes his / her face on the forehead, the position of the eyes varies from person to person, so it is necessary to set the position of the safety stopper for each subject. There is.

Further, in the method disclosed in Patent Document 2 and Patent Document 3, the alignment state of the optical system with respect to the eye to be inspected is specified by detecting the index image based on the reflected light of the index light projected on the eye to be inspected. Therefore, if the eye to be inspected blinks or the line of sight is changed during the alignment, the alignment state cannot be specified. As a result, in the case of auto-alignment, the driving of the optical system must be stopped and the index image must wait until the index image is detected again. On the other hand, in the case of manual alignment, the optical system can be advanced by the operation of a user such as an examiner. Therefore, it is conceivable to provide a safety stopper mechanism as disclosed in Patent Document 1 or to prevent the examiner from accepting the operation while the index image is not detected. However, the eye to be inspected blinks or the line of sight is changed. Every time, the movement stops, giving a sense of discomfort to the operation.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a new technique for performing highly accurate alignment between an optical system and an eye to be inspected while avoiding contact. It is in.

The first aspect of the ophthalmic apparatus according to the embodiment is an optical system for acquiring data of the eye to be inspected, and a driving unit for relatively moving the optical system and the eye to be inspected in the optical axis direction of the optical system. , The control conditions for the driving unit are sequentially updated and updated based on the distance specifying unit that repeatedly specifies the distance between the optical system and the eye to be inspected and the distance that is sequentially specified by the distance specifying unit. It includes a control unit that relatively moves the optical system and the eye to be inspected by controlling the drive unit based on the control conditions. The control conditions include the movable distance in the direction in which the optical system approaches the eye to be inspected. The control unit sequentially obtains the movable distance based on the sequentially specified distance, and controls the drive unit within the range of the movable distance in the above direction.
Further, in the second aspect of the ophthalmic apparatus according to the embodiment, in the first aspect, the control unit is the driving unit so that the optical system does not approach the eye to be inspected more than a predetermined distance based on the distance. May be controlled.
Further, the third state like an ophthalmologic apparatus according to an embodiment, the first state-like or second aspect, wherein the optical system includes an objective lens, wherein the control unit, the working distance of the objective lens from the distance The subtracted distance may be obtained as the movable distance.
The fourth state like an ophthalmologic apparatus according to the embodiment, in any of the first aspect to third states like, and two or more of the imaging unit for simultaneously photographing the anterior segment of the eye to be examined from different directions The distance specifying unit includes a position specifying unit that specifies a three-dimensional position of the eye to be inspected by analyzing two or more captured images simultaneously obtained by the two or more imaging units, and the distance specifying unit is the optical system. The distance between the three-dimensional position and the three-dimensional position may be specified.
Further, the fifth state like an ophthalmologic apparatus according to an embodiment, in any of the first aspect to fourth states like, comprising an operation unit, wherein the control unit, the drive in response to an operation using the operation unit The unit may be controlled to move the optical system and the eye to be inspected relative to each other.
In addition, it is possible to arbitrarily combine the configurations according to the above-mentioned plurality of aspects.

According to the present invention, it is possible to provide a new technique for performing highly accurate alignment between the optical system and the eye to be inspected while avoiding contact.

It is the schematic which shows an example of the structure of the ophthalmic apparatus which concerns on embodiment. It is the schematic for demonstrating the operation of the ophthalmic apparatus which concerns on embodiment. It is the schematic for demonstrating the operation of the ophthalmic apparatus which concerns on embodiment. It is the schematic for demonstrating the operation of the ophthalmic apparatus which concerns on embodiment. It is a flowchart which shows the operation example of the ophthalmic apparatus which concerns on embodiment. It is a flowchart which shows the operation example of the ophthalmic apparatus which concerns on embodiment.

An embodiment of the present invention will be described. The ophthalmologic apparatus according to the embodiment may be any ophthalmologic measuring apparatus, any ophthalmologic imaging apparatus, or any multifunction device in which the ophthalmologic measuring apparatus and the ophthalmologic imaging apparatus are combined. Examples of the ophthalmic measuring device include a reflex meter, a keratometer, a visual function test device, and a tonometer. Examples of ophthalmologic imaging devices include OCT devices, fundus cameras, SLOs, and the like.

<Structure>
FIG. 1 shows a configuration example of the ophthalmic apparatus according to the embodiment. The ophthalmic apparatus 1 according to the embodiment includes a function of acquiring data of the eye to be inspected E, that is, a function of photographing the eye to be inspected E and / or a function of measuring the characteristics of the eye to be inspected E.

The ophthalmic device 1 includes a processor 10, an optical unit 20, a face support unit 70, a first drive mechanism 80A, a second drive mechanism 80B, and a user interface (UI) unit 90. It should be noted that the configuration may be such that only one of the first drive mechanism 80A and the second drive mechanism 80B is provided.

The optical unit 20 is provided with a measurement optical system 30 and an anterior eye camera 60. The measurement optical system 30 includes an objective lens 40. Two or more front eye cameras 60 are provided at different positions.

(Processor 10)
The processor 10 executes various types of information processing. In the present specification, the term "processor" refers to, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), a programmable logic device (for example, a SPLD (Simple Program)), a programmable logic device (for example, a SPLD) It means a circuit such as Programmable Logical Device) and FPGA (Field Programmable Gate Array).

The processor 10 realizes the function according to the embodiment by reading and executing a program stored in a storage circuit or a storage device, for example. At least a part of the storage circuit and the storage device may be included in the processor 10. Further, at least a part of the storage circuit and the storage device may be provided outside the processor 10. The processing that can be executed by the processor 10 will be described later. The processor 10 includes a control unit 11, a storage unit 12, and a data processing unit 13.

(Control unit 11)
The control unit 11 controls each unit of the ophthalmic apparatus 1. In particular, the control unit 11 controls the optical unit 20, the first drive mechanism 80A, and the second drive mechanism 80B. In the case of manual alignment, the control unit 11 receives an operation on the user interface unit 90 by the user and controls at least one of the first drive mechanism 80A and the second drive mechanism 80B to control the optical unit 20 and the eye E to be inspected. Move relative to each other. In the case of auto-alignment, the control unit 11 relatively moves the optical unit 20 and the eye E to be inspected by controlling at least one of the first drive mechanism 80A and the second drive mechanism 80B based on the control conditions described later. The control that can be executed by the control unit 11 will be described later.

(Memory unit 12)
The storage unit 12 stores various types of data. The data stored in the storage unit 12 includes data (measurement data, imaging data, etc.) acquired by the measurement optical system 30, information on the subject and the eye to be inspected, and the like. Various computer programs and data for operating the ophthalmic apparatus 1 may be stored in the storage unit 12. Various data used / referenced in the processing described later are stored in the storage unit 12. The storage unit 12 includes the above-mentioned storage circuit and storage device.

(Data processing unit 13)
The data processing unit 13 executes various data processing. In particular, the data processing unit 13 analyzes the image acquired by the anterior eye camera 60. The data processing unit 13 is provided with a position specifying unit 131 and a distance specifying unit 132. These operations will be described later.

(Optical unit 20)
In addition to the configuration shown in FIG. 1, the optical unit 20 may be provided with an optical system (observation optical system, photographing optical system, etc.) or an alignment optical system for photographing the eye E to be examined from the front. Further, a configuration for focusing the measurement optical system 30 may be provided. Further, the optical unit 20 may include a light source (anterior eye portion illumination light source) for illuminating the anterior eye portion Ea of the eye E to be inspected.

(Measurement optical system 30)
The measurement optical system 30 includes a configuration for measuring the characteristics of the eye E to be inspected. The measurement optical system 30 has a configuration corresponding to the functions (measurement function, imaging function, etc.) provided by the ophthalmic apparatus 1. For example, the measurement optical system 30 is provided with a light source, an optical element (optical member, an optical device), an actuator, a mechanism, a circuit, a display device, a light receiving element, an image sensor, and the like. The configuration of the measurement optical system 30 may be similar to that of the conventional ophthalmic apparatus. At least a part of the measurement optical system 30 may be arranged outside the optical path. For example, when a keratometer function for measuring the curvature of the cornea is provided, a light source (keratling light source) for projecting a ring-shaped luminous flux or a concentric luminous flux onto the cornea is arranged at a position immediately before the eye E to be inspected. For example, when a function of an optical interference tomometer for acquiring a tomographic image of the eye E to be examined or an intraocular distance is provided, the objective lens 40 and the eye E to be examined are used to change the focal position of the interference optical system. A removable front lens is provided between them.

The measurement optical system 30 may have a configuration for providing a function associated with the inspection. For example, an fixation optical system for projecting an optotype (fixation target) for fixing the eye E to be inspected on the fundus of the eye E may be provided.

(Anterior eye camera 60)
The anterior segment camera 60 captures the anterior segment Ea of the eye E to be inspected. As described above, two or more front eye cameras 60 are provided at different positions. Each front eye camera 60 is, for example, a video camera that shoots a moving image at a predetermined frame rate. The two or more anterior segment cameras 60 capture the anterior segment from different directions substantially simultaneously.

In this embodiment, as shown in FIGS. 2 and 3, two front eye cameras 60A and 60B are provided. FIG. 2 is a top view showing the positional relationship between the eye E to be inspected and the anterior eye cameras 60A and 60B. The + Y direction indicates a vertically upward direction, and the + Z direction indicates an optical axis direction of the measurement optical system 30 and a direction from the measurement optical system 30 toward the eye E to be inspected. FIG. 3 is a side view showing the positional relationship between the eye E to be inspected and the anterior eye cameras 60A and 60B. The anterior segment cameras 60A and 60B are provided at positions outside the optical path of the measurement optical system 30, respectively. Hereinafter, the two front eye cameras 60A and 60B may be collectively represented by reference numeral 60.

The number of front eye cameras may be any number of 2 or more, but any number of front eye cameras may be used as long as the front eye can be photographed substantially simultaneously from two different directions. Further, one front eye camera may be arranged coaxially with the measurement optical system 30.

“Substantially at the same time” means that in shooting with two or more anterior eye cameras, it is permissible to shift the shooting timing to the extent that eye movements can be ignored. Thereby, the image when the eye E to be inspected is in the same position (orientation) can be acquired by two or more anterior eye cameras.

Further, the shooting with two or more front eye cameras may be a moving image shooting or a still image shooting, but in the present embodiment, a case where the moving image shooting is performed will be described in particular detail. In the case of moving image shooting, it is possible to realize substantially simultaneous front eye shooting as described above by controlling the shooting start timing to be adjusted, and controlling the frame rate and the shooting timing of each frame. On the other hand, in the case of still image shooting, this can be realized by controlling the shooting timing to be adjusted.

In the present embodiment, two or more captured images obtained substantially simultaneously by two or more anterior eye cameras 60 are used for alignment (alignment) between the optical unit 20 and the eye E to be inspected. The alignment includes Z alignment in the optical axis direction (Z direction) of the measurement optical system 30 and XY alignment in the X direction (horizontal direction) and the Y direction (vertical direction) orthogonal to the Z direction.

In the present embodiment, the feature positions corresponding to the feature sites of the eye E to be inspected (for example, the center of the pupil or the cornea (center of gravity)) are specified for each of the two or more captured images obtained by the anterior segment camera 60, and the anterior segment is identified. The three-dimensional position of the feature portion of the eye E to be inspected is obtained based on the position of the camera 60 and the feature positions in the specified two or more captured images. In the case of manual alignment, the optical unit 20 and the eye E to be inspected are relatively moved by the user operating the user interface unit 90 so that the displacement of the position of the characteristic portion of the eye E to be inspected with respect to the alignment reference position is cancelled. .. In the case of auto-alignment, the control unit 11 moves the optical unit 20 three-dimensionally so that the displacement of the position of the characteristic portion of the eye E to be inspected with respect to the alignment reference position is cancelled. The alignment reference position is a position where the optical axis of the measurement optical system 30 substantially coincides with the axis of the eye to be inspected E and the distance of the measurement optical system 30 to the eye to be inspected E is a predetermined operating distance. Here, the working distance is a default value also called the working distance of the objective lens 40, and means the distance between the eye E to be inspected and the measuring optical system 30 at the time of inspection using the measuring optical system 30.

In the following embodiments, the distance between the measurement optical system 30 for acquiring the data of the eye to be inspected E and the eye to be inspected E is the distance between the optical unit 20 accommodating the optical system 30 to be inspected and the eye to be inspected E. Alternatively, it can be equated with the distance between the objective lens 40 and the eye E to be inspected.

(Face support 70)
The face support portion 70 includes a member for supporting the face of the subject. For example, the face support portion 70 includes a forehead pad on which the forehead of the subject is abutted and a jaw holder on which the jaw of the subject is placed. The face support portion 70 may be provided with only one of a forehead pad and a jaw support, and may be provided with a member other than these.

(1st drive mechanism 80A, 2nd drive mechanism 80B)
The first drive mechanism 80A moves the optical unit 20 under the control of the control unit 11. The first drive mechanism 80A can move the optical unit 20 three-dimensionally. The first drive mechanism 80A includes, for example, a mechanism for moving the optical unit 20 in the X direction, a mechanism for moving the optical unit 20 in the Y direction, and a mechanism for moving the optical unit 20 in the Z direction, as in the conventional case. The first drive mechanism 80A includes a plurality of stepping motors (driving means) for driving a mechanism for moving in the X direction, the Y direction, and the Z direction. For example, the control unit 11 can move the optical unit 20 by a movement amount corresponding to the number of pulses by supplying a drive signal of a predetermined number of pulses to the stepping motor. Further, the first drive mechanism 80A may include a rotation mechanism for rotating the optical unit 20 in a plane (horizontal plane, vertical plane, etc.) including the optical axis of the optical unit 20.

The second drive mechanism 80B moves the face support unit 70 under the control of the control unit 11. The second drive mechanism 80B can move the face support portion 70 three-dimensionally. The second drive mechanism 80B includes, for example, a mechanism for moving the face support portion 70 in the X direction, a mechanism for moving the face support portion 70 in the Y direction, and a mechanism for moving the face support portion 70 in the Z direction. Like the first drive mechanism 80A, the second drive mechanism 80B includes a plurality of stepping motors (driving means) for driving a mechanism for moving the mechanism in the X direction, the Y direction, and the Z direction. For example, the control unit 11 can move the face support unit 70 by a movement amount corresponding to the number of pulses by supplying a drive signal of a predetermined number of pulses to the stepping motor. Further, the second drive mechanism 80B may include a rotation mechanism for changing the direction of the face support portion 70 (or a member included therein). When a plurality of members are provided on the face support portion 70, the second drive mechanism 80B may be configured to move these members individually. For example, the second drive mechanism 80B may be configured to move the forehead rest and the chin rest individually. As described above, in general, at least one of the first drive mechanism 80A and the second drive mechanism 80B is provided. Only the chin rest may be movable in the Y direction in order to correspond to the size of the subject's face.

(User interface unit 90)
The user interface unit 90 provides functions for exchanging information between the ophthalmic apparatus 1 and its user, such as displaying information, inputting information, and inputting operation instructions. The user interface unit 90 provides an output function and an input function. Examples of configurations that provide an output function include a display device such as a flat panel display, an audio output device, a print output device, and a data writer that writes to a recording medium. Examples of configurations that provide input functions include operating levers, buttons, keys, pointing devices, microphones, data writers, and the like. The user interface unit 90 may include a device such as a touch panel display in which an output function and an input function are integrated. In addition, the user interface unit 90 may include a graphical user interface (GUI) for inputting / outputting information.

(Details of data processing unit 13)
The details of the data processing unit 13 will be described. As described above, the data processing unit 13 is provided with a position specifying unit 131 and a distance specifying unit 132.

(Positioning unit 131)
The position specifying portion 131 is a region corresponding to a characteristic portion of the eye E to be inspected drawn in each captured image by analyzing two or more captured images obtained substantially simultaneously by the anterior eye camera 60A and 60B. Specify the position (three-dimensional position). When the anterior eye camera 60A and 60B shoot a moving image, the position specifying unit 131 identifies the position of the region from each frame. The position specifying unit 131 can specify the position of the region by analyzing the pixel value of the captured image. When the captured image is a luminance image, the position specifying unit 131 identifies an image region (pixel) corresponding to the feature portion based on the distribution of the luminance values in the captured image. For example, when the feature portion is the center of the pupil, the position specifying unit 131 identifies an image region (pupil region) corresponding to the pupil of the eye E to be inspected based on the distribution of pixel values (luminance values, etc.) of the captured image. .. Since the pupil is generally drawn with a lower brightness than other parts, the pupil region can be specified by searching the low-brightness image region. At this time, the pupil region may be specified in consideration of the shape of the pupil. That is, it can be configured to specify the pupil region by searching for a substantially circular and low-luminance image region. Next, the position specifying unit 131 specifies the central position of the specified pupil region. Since the pupil is substantially circular as described above, the contour of the pupil region can be specified, the center position of this contour (approximate circle or approximate ellipse) can be specified, and this can be used as the center of the pupil. Further, the center of gravity of the pupil region may be obtained, and the position of the center of gravity may be set as the center of the pupil. Even when the feature position corresponding to another feature portion is specified, the feature position can be specified based on the distribution of the pixel values of the captured image in the same manner as described above. The index light beam may be projected onto the cornea and the position of the reflected image based on the reflected light of the index light beam from the corneum may be specified as the feature position.

Further, the position specifying unit 131 can specify the feature position as a three-dimensional position as shown in FIGS. 2 and 3. In FIGS. 2 and 3, the distance (baseline length) between the two front eye cameras 60A and 60B in the XY direction is represented by “B”. The distance (index image distance) between the baselines of the two front eye cameras 60A and 60B and the pupil center P as a characteristic site of the eye E to be inspected is represented by "H". The distance (screen distance) between the front eye cameras 60A and 60B and the screen plane thereof is represented by "f".

In such an arrangement state, the resolution of the images captured by the anterior eye cameras 60A and 60B is expressed by the following equation. Here, Δp represents the pixel resolution.

Resolution in the XY direction: ΔXY = H × Δp / f
Resolution in the Z direction: ΔZ = H × H × Δp / (B × f)

The position specifying unit 131 considers the arrangement relationship shown in FIGS. 2 and 3 with respect to the positions (known) of the two front eye cameras 60A and 60B and the position of the pupil center P in the two captured images. The position of the center of the pupil P is specified by applying the known trigonometry described above. The position of the pupil center P is specified as the position (three-dimensional position) of the eye E to be inspected.

The position of the eye E to be inspected specified by the position specifying unit 131 is sent to the control unit 11. As described above, the control unit 11 aligns the optical axis of the measurement optical system 30 with the axis of the eye E to be inspected based on the determined position of the eye E to be inspected, and the control unit 11 is the measurement optical system 30 with respect to the eye E to be inspected. The first drive mechanism 80A and / or the second drive mechanism 80B is controlled so that the distance becomes a predetermined working distance.

(Distance specifying part 132)
The distance specifying unit 132 specifies the distance (optical system / eye distance to be inspected) between the position of the eye to be inspected E specified by the position specifying unit 131 and the measurement optical system 30 (objective lens 40). For example, the position specifying unit 131 specifies the position of the eye E to be inspected in the three-dimensional coordinate system based on the reference position of the optical unit 20 (the position of the objective lens 40 of the measurement optical system 30). In this case, the distance specifying unit 132 can specify the above-mentioned optical system / eye distance to be inspected by a known distance calculation process in the three-dimensional coordinate system. The distance specifying unit 132 sequentially obtains the optical system and the distance to be examined by using the positions of the eyes to be inspected E which are sequentially specified.

The control unit 11 controls at least one of the first drive mechanism 80A and the second drive mechanism 80B based on the optical system / eye distance to be inspected specified by the distance identification unit 132 to control the optical unit 20 and the eye to be inspected E. Move relative to each other. At this time, the control unit 11 sequentially updates the control conditions for at least one of the first drive mechanism 80A and the second drive mechanism 80B based on the optical system / eye distance to be inspected sequentially specified by the distance specifying unit 132. The control unit 11 can control at least one of the first drive mechanism 80A and the second drive mechanism 80B based on the updated control conditions.

The control unit 11 updates the control conditions as necessary, and the first drive mechanism 80A and the first drive mechanism 80A and the control unit 11 prevent the optical unit 20 from approaching the eye E to be inspected more than a predetermined distance based on the optical system and the eye distance to be inspected. Controls at least one of the second drive mechanisms 80B. Specifically, the control unit 11 sequentially obtains the movable distance in the direction in which the optical unit 20 approaches the eye E to be inspected from the optically / eye-inspected distance specified sequentially, and the movable distance in the direction is the movable distance. The optical unit 20 and the eye E to be inspected are relatively moved within the range. Finding the movable distance is equivalent to finding the movement limit position.

For example, the movable distance is stored in the storage unit 12 or the like as the number of movable pulses of the drive signal supplied to at least one of the first drive mechanism 80A and the second drive mechanism 80B. Each time the control unit 11 drives at least one of the first drive mechanism 80A and the second drive mechanism 80B, the control unit 11 subtracts the number of pulses corresponding to the movement amount from the number of movable pulses stored in the storage unit 12 and the like, and newly The number of movable pulses updated to is stored in the storage unit 12 or the like again. As a result, the remaining movement amount is recognized from the number of movable pulses stored in the storage unit 12 or the like.

FIG. 4 shows an explanatory diagram of the movable distance according to the embodiment. In FIG. 4, the same parts as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

When the optical system / eye distance L1 is obtained by the distance specifying unit 132, the control unit 11 obtains the distance MC1 obtained by subtracting the working distance WD of the known objective lens 40 from the optical system / eye distance L1 as the movable distance. .. When the optical system / eye distance L1 to be inspected is sequentially specified by the distance specifying unit 132, the control unit 11 sequentially obtains the distance MC1 which is a movable distance. When the position of the eye to be inspected E is changed during the execution of Z alignment, when the distance specifying unit 132 newly specifies the optical system / eye to be inspected distance L2, the control unit 11 starts the objective lens from the optical system / eye to be inspected distance L2. The distance MC2 obtained by subtracting the operating distance WD of 40 is obtained as a new movable distance. The control unit 11 can move the optical unit 20 and the eye E to be inspected relative to each other within the movable distance (MC2) in the Z direction. The movable distance may be set to be larger (far) or smaller (near) than the working distance WD. In equipment with a short working distance WD, it is desirable to set the movable distance larger than the working distance WD in order to further reduce the risk of contact.

The optical unit 20 or the measurement optical system 30 is an example of the "optical system" according to the embodiment. At least one of the first drive mechanism 80A and the second drive mechanism 80B is an example of the "drive unit" according to the embodiment. The user interface unit 90 is an example of the "operation unit" according to the embodiment. The anterior eye camera 60 is an example of the “photographing unit” according to the embodiment.

<Operation>
The operation of the ophthalmic apparatus 1 will be described.

5 and 6 show a flow chart of an operation example of the ophthalmic apparatus 1. 5 and 6 show an operation example of Z alignment of the ophthalmic apparatus 1 according to the embodiment. In addition, in FIG. 5 and FIG. 6, it is assumed that the XY alignment is completed.

(S1)
Corresponding to the instruction given by the user or the control unit 11 to start photographing the anterior eye portion Ea of the eye subject E, the control unit 11 controls the anterior eye portion camera 60 to control the anterior eye portion E. Acquisition of the moving image of the anterior segment Ea is started. The anterior eye cameras 60A and 60B form a captured image (frame) at a predetermined frame rate. The captured images are sequentially input to the data processing unit 13.

(S2)
The control unit 11 causes the position identification unit 131 to specify the position of the eye to be inspected E. As described above, the position specifying unit 131 analyzes the two or more captured images obtained substantially simultaneously by the anterior segment cameras 60A and 60B in S1 to obtain the eye E drawn on each captured image. The three-dimensional position of the region corresponding to the center of the pupil is specified as the position of the eye E to be examined.

(S3)
The control unit 11 determines whether or not the position of the eye E to be inspected has been specified in S2. For example, the control unit 11 determines that the position of the eye E to be inspected has not been specified by the position specifying unit 131 when the pupil region cannot be specified by the position specifying unit 131 due to the blinking of the eye to be inspected E or a change in the line of sight. When it is determined in S2 that the position of the eye E to be inspected has been specified (S3: Y), the operation of the ophthalmic apparatus 1 shifts to S4. When it is determined in S2 that the position of the eye to be inspected E has not been specified (S3: N), the operation of the ophthalmic apparatus 1 shifts to S9.

(S4)
When it is determined in S3 that the position of the eye E to be inspected has been specified (S3: Y), the control unit 11 determines the optical system / eye distance to be inspected, which is the distance between the optical unit 20 and the eye E to be inspected. Let 132 identify. Next, as described above, the control unit 11 obtains the movable distance (the number of movable pulses) in the direction in which the optical unit 20 approaches the eye E to be examined from the specified optical / eye examination distance. For example, the movable distance is updated from the initial value to the newly obtained movable distance.

(S5)
The control unit 11 receives an operation on the user interface unit 90 by the user, and determines the amount of movement of at least one of the first drive mechanism 80A and the second drive mechanism 80B according to the operation content. In the present embodiment, for example, the control unit 11 moves the optical unit 20 by controlling the first drive mechanism 80A according to the operation content of the user. The control unit 11 determines whether or not the position when the optical unit 20 is moved by the movement amount is within the range of the movable distance obtained in S4. Whether or not it is within the range of the movable distance may be determined based on the number of pulses included in the drive signal output to the first drive mechanism 80A. When it is determined that the distance is within the movable distance (S5: Y), the operation of the ophthalmic apparatus 1 shifts to S6. When it is determined that the movable distance is not within the range (S5: N), the operation of the ophthalmic apparatus 1 shifts to S12.

(S6)
When it is determined in S5 that the position of the optical unit 20 after movement is within the range of the movable distance obtained in S4 (S5: Y), the control unit 11 determines the movement amount of the optical unit in S5. Move 20. For example, the control unit 11 can move the optical unit 20 by the movement amount by supplying the drive signal of the number of pulses corresponding to the movement amount to the first drive mechanism 80A.

(S7)
The control unit 11 determines whether or not the Z alignment is completed based on the position of the optical unit 20 moved in S6 and the position of the eye E to be inspected. For example, the control unit 11 completes Z alignment when the difference between the Z-direction distance between the position of the optical unit 20 and the position of the eye E to be inspected and the operating distance of the objective lens 40 is equal to or less than a predetermined threshold value. Is determined. When it is determined that the Z alignment is completed (S7: Y), the operation of the ophthalmic apparatus 1 shifts to S8. When it is determined that the Z alignment is not completed (S7: N), the operation of the ophthalmic apparatus 1 shifts to S2.

(S8)
When it is determined in S7 that the Z alignment is completed (S7: Y), the control unit 11 controls the measurement optical system 30 according to the function provided in the measurement optical system 30 to execute the measurement for the eye to be inspected E. .. This completes the operation of the ophthalmic apparatus 1 (end).

(S9)
When it is determined in S3 that the position of the eye E to be inspected has not been specified (S3: N), the control unit 11 accepts an operation on the user interface unit 90 by the user, and the first drive mechanism 80A and the first drive mechanism 80A and the first according to the operation content. 2 Determines the amount of movement of at least one of the drive mechanism 80B. The control unit 11 determines whether or not the position when the optical unit 20 is moved by the movement amount is within the range of the already obtained movable distance (or the movable distance with the initial value). Whether or not it is within the range of the movable distance may be determined based on the number of pulses included in the drive signal output to the first drive mechanism 80A. When it is determined that the distance is within the range of the determination movable distance (S9: Y), the operation of the ophthalmic apparatus 1 shifts to S10. When it is determined that the distance is not within the movable distance (S9: N), the operation of the ophthalmic apparatus 1 shifts to S11.

(S10)
When it is determined in S9 that the position of the optical unit 20 after movement is within the range of the movable distance (S9: Y), the control unit 11 moves the optical unit 20 by the movement amount determined in S9. The operation of the ophthalmic apparatus 1 shifts to S2.

(S11)
When it is determined in S9 that the position of the optical unit 20 after movement is not within the range of the movable distance (S9: N), the control unit 11 at least moves the optical unit 20 in the direction of approaching the eye E to be inspected. Stop it. The operation of the ophthalmic apparatus 1 shifts to S2.

(S12)
When it is determined in S5 that the position of the optical unit 20 after movement is not within the range of the movable distance obtained in S4 (S5: N), the control unit 11 approaches the optical unit 20 to the eye E to be inspected. Notify that it cannot move in the direction. This notification may be information output to the user interface unit 90, sound output, lamp lighting, or the like.

The control unit 11 can change the display mode for the user interface unit 90 depending on whether or not it is within the range of the movable distance. As a result, the user can easily grasp the distance between the optical unit 20 and the eye E to be inspected.

Further, the control unit 11 may change the display mode for the user interface unit 90 according to the number of movable pulses. As a result, the user can easily grasp how much the optical unit 20 and the eye E to be inspected can be moved relative to each other.

(S13)
Subsequently, the control unit 11 determines whether or not to end the operation of the ophthalmic apparatus 1. For example, in response to an instruction to end the operation of the ophthalmic apparatus 1 by the user or the control unit 11, the control unit 11 determines whether or not to end the operation of the ophthalmic apparatus 1. When it is determined that the operation of the ophthalmic apparatus 1 is terminated (S13: Y), the operation of the ophthalmic apparatus 1 is terminated (end). When it is determined that the operation of the ophthalmic apparatus 1 is not completed (S13: N), the operation of the ophthalmic apparatus 1 shifts to S2.

As described above, according to the embodiment, the control conditions including the movable distance and the like can be sequentially updated each time an image of the anterior eye portion Ea of the eye E to be inspected is obtained. Then, when the position of the eye E to be inspected cannot be specified due to blinking of the eye E to be inspected, a change in the line of sight, or the like, the optical unit 20 is within the range of the movable distance updated immediately before (or the movable distance with the initial value). And the eye E to be inspected can be moved relative to each other.

<Action / effect>
The operation and effect of the ophthalmic apparatus according to the embodiment will be described.

The ophthalmic apparatus (1) according to the embodiment controls an optical system (measuring optical system 30), a driving unit (at least one of the first driving mechanism 80A and the second driving mechanism 80B), a distance specifying unit (132), and a distance specifying unit (132). Includes part (11). The optical system is used to acquire the data of the eye to be inspected (E). The drive unit relatively moves the optical system and the eye to be inspected in the optical axis direction (Z direction) of the optical system. The distance specifying unit repeatedly specifies the distance between the optical system and the eye to be inspected (optical system / eye to be inspected distance). The control unit sequentially updates the control conditions for the drive unit based on the distance sequentially specified by the distance specifying unit, and controls the drive unit based on the updated control conditions to control the optical system and the eye to be inspected. Move relative to each other.

In such a configuration, the distance between the optical system and the eye to be inspected is repeatedly specified, the control conditions for the drive unit are sequentially updated based on the specified distance, and the optical system and the optical system are updated based on the updated control conditions. Move relative to the eye to be inspected. As a result, the optical system and the eye to be inspected can be relatively moved based on the control conditions updated immediately before, even when the eye to be inspected blinks or the line of sight is changed. Therefore, even while the eye to be inspected is blinking or the line of sight is changed, the optical system and the eye to be inspected are relatively moved based on the control conditions updated immediately before, so that the optical system and the eye to be inspected are moved. Highly accurate alignment is possible without frequent stops during alignment.

Further, in the ophthalmic apparatus according to the embodiment, the control unit may control the drive unit so that the optical system does not approach the eye to be inspected more than a predetermined distance based on the above distance.

According to such a configuration, an ophthalmic apparatus capable of highly accurate alignment while avoiding contact between the optical system and the eye to be inspected without frequently stopping between the alignment of the optical system and the eye to be inspected. Will be able to provide.

Further, in the ophthalmic apparatus according to the embodiment, the control unit sequentially obtains the movable distance in the direction in which the optical system approaches the eye to be inspected based on the sequentially specified distance, and the range of the movable distance in the above direction. The drive unit may be controlled within.

According to such a configuration, if it is within the movable distance range, highly accurate alignment can be performed without stopping between the alignment between the optical system and the eye to be inspected.

Further, in the ophthalmic apparatus according to the embodiment, the optical system includes the objective lens (40), and the control unit may obtain the distance obtained by subtracting the operating distance of the objective lens from the above distance as the movable distance.

According to such a configuration, it is possible to perform highly accurate alignment while ensuring the working distance of the objective lens without stopping frequently during the alignment with the eye to be inspected.

Further, the ophthalmic apparatus according to the embodiment includes two or more imaging units (anterior eye camera 60, 60A, 60B) for simultaneously photographing the anterior eye portion (Ea) of the eye to be inspected from different directions, and two or more imaging units. The distance specifying unit includes a position specifying unit (131) that specifies the three-dimensional position of the eye to be inspected by analyzing two or more captured images simultaneously obtained by the unit, and the distance specifying unit includes the optical system and the three-dimensional position. The distance between them may be specified.

With such a configuration, it is possible to take an image of the eye to be inspected from a wide range, and even when the distance between the optical system and the eye to be inspected is long to some extent, contact with the optical system is avoided. It is possible to perform highly accurate alignment with the eye to be inspected.

Further, the ophthalmic apparatus according to the embodiment includes an operation unit (user interface unit 90), and the control unit controls the drive unit in response to an operation using the operation unit to move the optical system and the eye to be inspected relative to each other. You may.

According to such a configuration, the optical system and the eye to be inspected are relatively moved based on the control condition updated immediately before, even while the eye to be inspected is blinking or the line of sight is changed. Highly accurate alignment is possible without giving a sense of discomfort to the operation by.

<Modification example>
The embodiments described above are merely typical examples of the present invention. Therefore, any modification (omission, replacement, addition, etc.) within the scope of the gist of the present invention can be appropriately applied.

When a plurality of measurements (photographs) are performed in sequence, alignment can be performed immediately before each measurement. For example, when corneal curvature measurement (kerato measurement), ocular refractive force measurement (ref measurement), and subjective test (vision measurement) are performed in this order, before the kerato measurement, between the kerato measurement and the reflex measurement, and , It is possible to perform alignment between the reflex measurement and the subjective test, respectively. In addition, alignment may be performed immediately before a part of a plurality of measurements.

In the embodiment, Z alignment can be performed by the method of this embodiment, and XY alignment can be performed by another method. For XY alignment, for example, the technique disclosed in Japanese Patent Application Laid-Open No. 2013-248376 may be applied. That is, it is possible to perform XY alignment with reference to the pupil based on two or more captured images of the anterior eye portion acquired substantially at the same time. Alternatively, when an observation optical system for photographing the eye to be inspected from the front is provided, it is known based on the index image (bright spot image) in the front image of the anterior segment obtained by the observation optical system, the position of the center of the pupil, and the like. It is possible to perform XY alignment of.

The embodiment is not limited to the method of specifying the distance between the optical unit 20 and the eye E to be inspected. For example, the relative position between the optical unit 20 and the eye E to be inspected may be detected by a so-called optical teco method, and the distance between the optical unit 20 and the eye E to be inspected may be specified. Further, a sensor for detecting the position of the eye to be inspected E may be provided, and the distance between the optical unit 20 and the eye to be inspected E may be specified by using the detection result of the sensor.

1 Ophthalmology device 11 Control unit 12 Storage unit 13 Data processing unit 20 Optical unit 30 Measurement optical system 40 Objective lenses 60, 60A, 60B Front eye camera 70 Face support 80A First drive mechanism 80B Second drive mechanism 90 User interface unit 131 Positioning part 132 Distance specifying part E Eye to be inspected Ea Anterior eye part

Claims (5)

An optical system for acquiring data of the eye to be inspected,
A drive unit that relatively moves the optical system and the eye to be inspected in the optical axis direction of the optical system,
A distance specifying unit that repeatedly specifies the distance between the optical system and the eye to be inspected,
The control conditions for the drive unit are sequentially updated based on the distance sequentially specified by the distance specifying unit, and the drive unit is controlled based on the updated control conditions to control the optical system and the cover. and a control unit for relatively moving the eye seen including,
The control condition includes a movable distance in a direction in which the optical system approaches the eye to be inspected.
The control unit, on the basis of the specified distance determined the movable distance sequentially sequentially, controls the drive unit for the optical axis direction within the range of the moving distance, ophthalmology device. The ophthalmic apparatus according to claim 1, wherein the control unit controls the drive unit so that the optical system does not approach the eye to be inspected more than a predetermined distance based on the distance. The optical system includes an objective lens.
The ophthalmic apparatus according to claim 1 or 2, wherein the control unit obtains a distance obtained by subtracting the operating distance of the objective lens from the distance as the movable distance. Two or more imaging units for simultaneously photographing the anterior segment of the eye to be inspected from different directions, and
By analyzing two or more captured images simultaneously obtained by the two or more imaging units, a position specifying unit that specifies the three-dimensional position of the eye to be inspected and a position specifying unit.
Including
The ophthalmic apparatus according to any one of claims 1 to 3, wherein the distance specifying unit specifies a distance between the optical system and the three-dimensional position. Including the operation unit
Any one of claims 1 to 4, wherein the control unit controls the drive unit in response to an operation using the operation unit to relatively move the optical system and the eye to be inspected. The ophthalmic device described in the section.

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