JP2022066325A - Ophthalmologic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ophthalmologic apparatus which can accurately obtain a physical relation between a subject eye and a measurement optical system.

SOLUTION: An ophthalmologic apparatus comprises: two optometry units (100L, 100R) which respectively correspond to right and left subject eyes of a subject; and drive units (20, 22) which relatively independently move the optometry units with respect to a face support unit (24). The optometry unit comprises: at least two imaging parts (108A, 108B) which substantially simultaneously image a feature portion on an anterior eye part of the subject eye from different directions; a measurement optical system (112); and an alignment optical system (106) which projects an alignment light flux along the optical axis of the measurement optical system to the anterior eye part. The ophthalmologic apparatus also comprises an analysis unit (132) which specifies a position of a corneal reflex light image of the alignment light flux as a feature portion by analyzing at least two photographed images captured by the imaging units for specifying the position of the subject eye.

SELECTED DRAWING: Figure 2

COPYRIGHT: (C)2022,JPO&INPIT

Description

The present invention relates to an ophthalmic apparatus and an optometry system, and more particularly to an ophthalmic apparatus for aligning an eye to be inspected with an optical system and acquiring data of the eye to be inspected, and an ophthalmologic examination system including the ophthalmic apparatus.

In Patent Document 1, the anterior segment of the eye to be inspected is photographed substantially simultaneously from different directions by two or more anterior segment cameras, and the position of the eye to be inspected is determined based on the two or more captured images. An ophthalmic apparatus that aligns with an optometric optical system is disclosed.

Japanese Unexamined Patent Publication No. 2013-248376

In the conventional ophthalmic apparatus, the anterior segment camera, the alignment optical system, the illumination optical system, the photographing optical system, the measuring optical system, etc. are arranged in front of the eye to be inspected (for example, FIGS. 1 and 4B of Patent Document 1 and the like). reference). For this reason, the conventional ophthalmic apparatus has a problem that the size in the depth direction with respect to the eye to be inspected becomes large.

Further, in the conventional ophthalmic apparatus, there is a problem that various optical systems arranged in front of the eye to be inspected obstruct the space in the depth direction with respect to the eye to be inspected. The conventional ophthalmic apparatus has a problem that, for example, an apparatus other than the optical system included in the ophthalmic apparatus cannot be arranged in a space in the depth direction with respect to the eye to be inspected to perform an optometry.

The present invention has been made in view of such circumstances, and is an ophthalmic apparatus and an optometry device capable of reducing the size in the depth direction with respect to the optometry and utilizing the space in the depth direction with respect to the optometry. The purpose is to provide a system.

In order to solve the above problems, the ophthalmic apparatus according to the first aspect of the present invention is provided corresponding to the face support portion that supports the subject's face and the left and right eyes of the subject, respectively. It is provided with two optometry sections and a drive section that moves the two optometry sections relatively independently of the face support section, and the two optometry sections are respectively arranged to face the eye to be inspected. At least two images of the deflection member and at least two imaging units arranged in the deflection direction by the deflection member, and the characteristic portion on the anterior eye portion of the eye to be inspected is photographed substantially simultaneously from different directions via the deflection member. Equipped with two shooting units.

According to the first aspect, by deflecting the optical path of the alignment optical system and two or more imaging units by using a deflection member, an ophthalmic apparatus having a compact structure in the depth direction with respect to the eye to be inspected and a wide range of alignment is realized. be able to.

In the first aspect, the ophthalmic apparatus according to the second aspect of the present invention analyzes at least two captured images taken by at least two imaging units to identify the position of a characteristic portion on the anterior eye portion. It further includes an analysis unit and a control unit that controls the drive unit based on the position of the feature portion specified by the analysis unit.

In the ophthalmic apparatus according to the third aspect of the present invention, in the first or second aspect, the characteristic site on the anterior segment of the eye is a pupil.

In the first or second aspect, the ophthalmic apparatus according to the fourth aspect of the present invention further includes an alignment optical system that projects an alignment luminous flux onto the anterior eye portion of the eye to be inspected, and features a feature portion on the anterior eye portion. Is the corneal reflected light image of the alignment luminous flux.

In the ophthalmic apparatus according to the fifth aspect of the present invention, in any one of the first to fourth aspects, the optometry unit presents an optometry target to the eye to be inspected via a deflection member, respectively. It is provided with a presentation section.

In the ophthalmic apparatus according to the sixth aspect of the present invention, in any one of the first to fifth aspects, the optometry unit uses an optical element that optically corrects the visual function of the eye to be inspected as a deflection member. It is provided with an optical element arranging portion to be arranged at a position between the eye to be inspected or at a position optically conjugate with this position.

The ophthalmic apparatus according to the seventh aspect of the present invention further includes an optometry window made of a translucent member arranged between the eye to be inspected and the deflection member in any one of the first to sixth aspects.

The optometry system according to the eighth aspect of the present invention is an optometry system including an ophthalmic apparatus according to any one of the first to seventh aspects and a subjective optometry target on which an examination target is formed. The ophthalmic apparatus is a housing for accommodating two optometry portions, further comprising a housing provided with two openings facing the optometry object, and the two openings can be opened and closed, respectively, and is deflected. The member is a half mirror that transmits light incident from the opening to the eye to be inspected, and the subjective optometry optotype is placed at a position that can be visually recognized by the eye to be inspected through the half mirror when the opening is opened. It is intended to be done.

According to the eighth aspect, by bending the optical path of the alignment optical system and the stereo camera by using the half mirror, it is possible to perform the optometry using the space in the depth direction (behind the half mirror) with respect to the optometry. Become.

According to the present invention, by deflecting the optical paths of two or more imaging sections using a deflection member, the size in the depth direction with respect to the eye to be inspected can be reduced, and a wide range of alignment is possible by the two imaging sections. It is possible to realize a variety of ophthalmic devices. Further, according to the present invention, when the distance between the pupils of the subject is narrow, even if the two eye examination parts are brought close to each other, the left and right eye examination parts do not interfere with each other due to the deflection of the optical path. Can be done.

FIG. 1 is an external view showing an ophthalmic apparatus according to the first embodiment of the present invention. FIG. 2 is a diagram showing an optical system of an eye examination unit according to the first embodiment of the present invention. FIG. 3 is a block diagram showing an ophthalmic apparatus according to the first embodiment of the present invention. FIG. 4 is a diagram showing a state in which a stereo camera is mirror-converted with respect to a mirror. FIG. 5 is a top view showing the positional relationship between the eye to be inspected and the stereo camera after the reflection conversion. FIG. 6 is a side view showing the positional relationship between the eye to be inspected and the stereo camera after the reflection conversion. FIG. 7 is an external view showing an ophthalmic apparatus according to the first embodiment of the present invention. FIG. 8 is a diagram showing an optical system of an eye examination unit according to a second embodiment of the present invention. FIG. 9 is a block diagram showing an ophthalmic apparatus according to a second embodiment of the present invention.

Hereinafter, embodiments of the ophthalmic apparatus and the optometry system according to the present invention will be described with reference to the accompanying drawings.

[First Embodiment]
FIG. 1 is an external view showing an ophthalmic apparatus according to the first embodiment of the present invention.

The ophthalmic apparatus 10 according to the present embodiment is an apparatus capable of performing both objective measurement of the subject's eye and subjective eye examination by the optometry unit 100 (100L and 100R).

As shown in FIG. 1, the ophthalmic apparatus 10 according to the present embodiment includes an optometry table 12, an optometry unit 100 (100L and 100R), and a user interface (UI) 200.

The optometry table 12 is a table whose height can be adjusted according to the body shape and the like of the subject.

A columnar support portion 14 is attached to the optometry table 12 substantially perpendicular to the surface of the optometry table 12. The support portion 14 is configured to be expandable and contractible. By expanding and contracting the support portion 14 according to the body shape and the like of the subject, it is possible to adjust the heights of the eye examination portions 100L and 100R.

An arm portion 16 is attached to the upper end portion of the support portion 14. The arm portion 16 is rotatable around the support portion 14. A hanging portion 18 is attached to the arm portion 16, and eye examination portions 100L and 100R are suspended from the hanging portion 18. The subject or an optometrist (for example, an ophthalmologist, a nurse, an orthoptist, etc.) covers the eye examination portions 100L and 100R by rotating the eye examination portions 100L and 100R with respect to the support portion 14. You can make the examiner face you.

The suspension unit 18 has a built-in first drive unit 20 (see FIG. 3) for moving the eye examination units 100L and 100R. The operator can move the eye examination units 100L and 100R by operating the first drive unit using the UI 200. The operator can adjust the angles and intervals of the eye examination units 100L and 100R according to the positions and intervals of the left and right eyes of the subject by the first drive unit.

The optometry unit 100 (100L and 100R) includes an optical system for inspecting the left and right eyes of the subject, respectively, and has a binocular simultaneous objective refraction measurement and a subjective eye examination function. When the subject supports the face on the face support portion 24 (see FIG. 3), the left and right eyes are faced directly to the optometry windows of the optometry portions 100L and 100R so that various measurements can be performed. It has become.

The UI 200 includes an operation unit for receiving an operation input from an operator and a display unit for displaying a measurement result by the ophthalmic apparatus 10. In the example shown in FIG. 1, the touch panel display 202 and the controller 204 are shown as the UI 200.

The touch panel display 202 includes a graphical user interface (GUI) for accepting operations, a display screen for displaying measurement results by the ophthalmic apparatus 10, and a touch panel for accepting operations by the operator on the surface of the display screen. It is provided. The touch panel may be any of a matrix switch, a resistance film method, a surface acoustic wave method, an infrared method, an electromagnetic induction method, and a capacitance method.

The controller 204 includes an operation member (operation button, switch, etc.) that accepts the operation of the operator.

The type of UI 200 is not limited to the touch panel display 202 and the controller 204. The UI 200 may include a pointing device such as a mouse, a keyboard for inputting characters, and the like in place of or in addition to these.

Next, the configurations of the eye examination units 100L and 100R according to the present embodiment will be described. Since the eye examination units 100L and 100R are symmetrical, the eye examination unit 100R for the right eye will be described below, and the description of the eye examination unit 100L for the left eye will be omitted.

FIG. 2 is a diagram showing an optical system of the eye examination unit 100R according to the present embodiment. In the following description, a three-dimensional orthogonal coordinate system is used in which the X direction is the horizontal direction (horizontal direction), the Y direction is the vertical direction (vertical direction), and the Z direction is the direction perpendicular to the XY direction. Here, the Z direction substantially coincides with the line-of-sight direction.

As shown in FIG. 2, the eye examination unit 100R includes a mirror (deflection member) 104, an alignment optical system 106, a stereo camera 108 (cameras (photographing units) 108A and 108B), an objective lens 110, and a measurement optical system 112. Each of these configurations is housed in the ophthalmoscope housing 102.

A substantially circular optometry window 102A is formed in the optometry portion housing 102. A plate-shaped member that transmits light (for example, a member having a relatively high transparency such as white plate glass) may be fitted in the optometry window 102A.

The mirror (deflection member) 104 is arranged on the back side (-Z side) with respect to the optometry window. The mirror 104 is arranged so as to be located in front of the subject when the subject E faces the optometry window 102A, and the right end (+ X side) is on the back side of the optometry window 102A. It is tilted so that it is on the (-Z side). In the present embodiment, the mirror 104 is used as the deflection member, but instead of the mirror 104, an optical member such as a prism capable of deflecting light may be used.

The alignment optical system 106 is arranged in the measurement optical system 112 and includes a light source (for example, a light emitting diode (LED)) and a light projecting lens. The light emitted from this light source is applied to the mirror 104 as parallel light through the objective lens 110. The light emitted to the mirror 104 is reflected by the mirror 104 and is applied to the eye E to be inspected. As a result, the alignment index image is projected on the eye E to be inspected.

The stereo camera 108 includes two or more cameras mounted at different locations in the eye examination unit 100R. The anterior segment of the eye E to be inspected is photographed from different directions substantially simultaneously. By analyzing the positions (feature sites) of the feature points in the two or more anterior eye portion images taken by the stereo camera 108, the positional relationship between the eye to be inspected E and the optometry portion 100R can be obtained. The eye examination unit 100R can be aligned with the eye to be inspected E.

Here, as the feature point on the anterior segment of the eye, a corneal reflex image (Pulkinje image) of the index luminous flux projected on the cornea of the anterior segment of the eye is used, but the present invention is not limited to this, and the center of the pupil or the like may be used.

In the example shown in FIG. 2, the stereo camera 108 is composed of two cameras 108A and 108B, but the number of cameras and the installation location are not limited to the example shown in FIG. One of the cameras 108A and 108B may be arranged in the measurement optical system 112. When the stereo camera 108 is composed of three or more cameras, a part of the stereo camera 108 may be arranged in the measurement optical system 112.

The measurement optical system 112 includes a configuration for measuring the characteristics of the eye E to be inspected. In addition to the alignment optical system 106, the measurement optical system 112 projects an optotype image onto the eye to be inspected E via the objective lens 110 and the mirror 104, or projects the optotype image onto the eye to be inspected E via the objective lens 110 and the mirror 104. It includes a projection optical system for projecting measurement light and a light receiving optical system 113 for receiving reflected light.

FIG. 3 is a block diagram showing an ophthalmic apparatus according to the present embodiment.

(Processor 120)
The processor 120 executes various types of information processing. In the present specification, the "processor" is, 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 Programmable Logic Device), a CPLD (Complex). It means a circuit such as Programmable Logic Device) and FPGA (Field Programmable Gate Array).

The processor 120 realizes the function according to the embodiment, for example, by reading and executing a program stored in a storage circuit or a storage device. At least a portion of the storage circuit or storage device may be included in the processor 120. Further, at least a part of the storage circuit and the storage device may be provided outside the processor 120. The processing that can be executed by the processor 120 will be described later. The processor 120 includes a control unit 122, a storage unit 124, and a data processing unit 126.

(Control unit 122)
The control unit 122 controls each unit of the ophthalmic apparatus 10. In particular, the control unit 122 controls the eye examination units 100L and 100R, the first drive unit 20, and the second drive unit 22. The control that can be executed by the control unit 122 will be described later.

(Storage unit 124)
The storage unit 124 stores various data. As the storage unit 124, for example, a device including a magnetic disk such as an HDD (Hard Disk Drive), a device including a flash memory such as an eMMC (embedded Multi Media Card), an SSD (Solid State Drive), or the like may be used. can. The data stored in the storage unit 124 includes data (measurement data, imaging data, etc.) acquired by the light receiving optical system of the measurement optical system 112, information on the subject and the eye E to be inspected, and the like. Various computer programs and data for operating the ophthalmologic apparatus 10 may be stored in the storage unit 124. Various data used and referred to in the processing described later are stored in the storage unit 124. The storage unit 124 includes the above-mentioned storage circuit and storage device.

(Data processing unit 126)
The data processing unit 126 executes various data processing. In particular, the data processing unit 126 includes an analysis unit 132 that analyzes the captured image acquired by the stereo camera 108.

(Eye examination unit 100)
The eye examination units 100L and 100 contain a configuration for measuring and photographing the eye to be inspected E and a configuration for preparing the measurement and imaging of the eye to be inspected E. The former includes measurement optical system and the latter includes alignment optical system. The eye examination units 100L and 100R may be provided with a configuration for focusing the measurement optical system 112. Further, the eye examination portions 100L and 100R may include a light source (anterior eye portion illumination light source) for illuminating the anterior eye portion of the eye to be inspected E.

(Measurement optical system 112)
The measurement optical system 112 includes a configuration for measuring the characteristics of the eye E to be inspected. The measurement optical system 112 has a configuration corresponding to the functions (measurement function, imaging function, etc.) provided by the ophthalmic apparatus 10. For example, in addition to the alignment optical system 106, the measurement optical system 112 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 112 may be similar to that of the conventional ophthalmic apparatus. The measurement optical system 112 projects an optotype image onto the eye to be inspected E through the objective lens 110 and the mirror 104, projects the measurement light onto the eye to be inspected E through the objective lens 110 and the mirror 104, and receives light. The optical system 113 makes it possible to receive the reflected light. When the measurement optical system 112 has a function of objectively measuring the refractive power of the eye to be inspected, for example, a known optical system of a reflex meter is arranged.

The measurement optical system 112 may be provided with a configuration for providing functions incidental to the inspection. For example, a fixative optical system may be provided that presents an optotype for fixing or fogging the eye E to be inspected.

(Alignment optical system 106)
The alignment optical system 106 includes a light source and a projection lens, and projects a light flux onto the eye E to be inspected. The light source included in the alignment optical system 106 is arranged in the measurement optical system 112 and projects a parallel light flux onto the cornea of the eye E to be inspected along the optical axis of the objective lens 110. As a result, an index for alignment is projected onto the cornea of the eye E to be inspected. This index is detected as a virtual image (Purkinje image) due to corneal surface reflection. The alignment using the index includes at least the optical axis alignment in the optical axis direction of the measurement optical system 112. Alignment using the index may include XY alignment in the X and Y directions.

In the present embodiment, the optical axis of the measurement optical system 112 is bent by the mirror 104, and the optical axis of the measurement optical system 112 substantially coincides with the Z axis at the position of the mirror image of the measurement optical system 112 with respect to the mirror 104. It is configured to do. Therefore, the alignment of the measurement optical system 112 in the optical axis direction corresponds to Z alignment. In the following description, the alignment of the measurement optical system 112 in the optical axis direction is referred to as Z alignment.

Z alignment is performed by analyzing two or more captured images obtained substantially simultaneously by the stereo camera 108. XY alignment is performed by analyzing two or more captured images obtained by the stereo camera 108.

XY alignment is performed based on the position of the Purkinje image (index image) drawn on two or more captured images in the XY direction. The XY alignment is performed by manually or automatically moving the eye examination unit 100R so as to guide the index image within the allowable range (alignment mark) of the alignment deviation.

In the case of manual alignment, the control unit 122 displays two or more captured images and an alignment mark on the UI 200 (touch panel display 202). The operator operates the UI 200 to move the eye examination unit 100R by the first drive unit 20, and moves the index image within the allowable range of alignment deviation (alignment mark).

In the case of auto-alignment, the data processing unit 126 calculates the displacement of the index image with respect to the alignment mark. The control unit 122 moves the eye examination unit 100R in the XY direction so as to cancel the displacement calculated by the data processing unit 126.

(Stereo camera 108)
The stereo camera 108 includes two or more cameras mounted at different locations in the eye examination unit 100R. Each camera of the stereo camera 108 is, for example, a video camera that shoots a moving image at a predetermined frame rate. Each camera receives the light reflected by the mirror 104 and photographs the anterior eye portion of the eye E to be inspected from different directions substantially simultaneously.

In the example shown in FIG. 2, the cameras 108A and 108B of 2 are provided. Further, the cameras 108A and 108B are arranged at positions deviating from the optical path of the measurement optical system 112, respectively.

The cameras 108A and 108B may be provided below (-Y side) the optical path of the measurement optical system 112. As a result, the reflected light of the luminous flux (index) projected on the anterior eye portion (for example, the cornea) of the eye E to be inspected is less likely to be eclipsed by the eyelashes and eyelids.

The number of cameras included in the stereo camera 108 may be any number of 2 or more, but any number of cameras may be used as long as the front eye portion of the eye to be inspected E can be photographed substantially simultaneously from two different directions. Further, one of the cameras included in the stereo camera 108 may be arranged coaxially with the measurement optical system 112.

Here, "substantially simultaneously" means that, in shooting with two or more cameras of the stereo camera 108, a deviation in shooting timing to the extent that eye movements can be ignored is allowed. By photographing the anterior segment of the eye E to be examined from different directions substantially simultaneously with two or more cameras of the stereo camera 108, two or more images taken when the eye E to be inspected is in the same position (orientation) are acquired. Will be possible.

Further, the shooting by the stereo camera 108 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 the case of moving image shooting, the anterior eye portion of the eye E to be inspected is photographed "substantially simultaneously" by each camera by controlling the shooting start timing to be adjusted and the frame rate and the shooting timing of each frame. can do. On the other hand, in the case of still image shooting, by controlling so as to match the shooting timing of each camera included in the stereo camera 108, it is possible to shoot the anterior eye portion of the eye E to be inspected "substantially simultaneously" by each camera. ..

(Optometry optotype display unit 114)
The optometry visual target presentation unit 114 visually presents the optometry visual target (for example, a Randolt ring, etc.) to the eye E to be inspected through the mirror 104 from the measurement optical system 112. As the optometry visual target presenting unit 114, for example, a liquid crystal display that displays various visual targets can be used.

In the optical system of the optometry optotype presentation unit 114, at least one of the optotype unit and the lens is configured to be movable along the optical axis of the optical system, and the optotype image is configured according to the diopter of the eye to be inspected and the optometry conditions. It is possible to change the presentation distance of. Further, an optical element for correcting astigmatism of the eye to be inspected may be arranged on the optical path. The optometry visual marker presentation 114 may be common to the fixative optical system.

(Optical element arrangement unit 116)
The optical element arranging unit 116 includes a plurality of types of corrective lenses 116A, and is an optical element (corrective lens 116A) for optically correcting the visual function of the eye to be inspected E between the eye to be inspected E and the mirror 104. To insert. The optical element arranging portion 116 may be provided at a predetermined position outside the optometry window 102A so that the optometrist or the like can manually replace the correction lens 116A. The optical element arranging unit 116 may be arranged at a position optically conjugate with the predetermined position inside the measurement optical system 112.

(Face support part 24)
The face support portion 24 includes a member for supporting the face of the subject. For example, the face support portion 24 includes a forehead pad on which the forehead of the subject is abutted and a chin rest on which the chin of the subject is placed. The face support portion 24 may be provided with only one of the forehead rest and the chin rest, and may be provided with a member other than these.

(1st drive unit 20 and 2nd drive unit 22)
The first drive unit 20 moves the eye examination units 100L and 100R under the control of the control unit 122. The first drive unit 20 can move the eye examination units 100L and 100R three-dimensionally, respectively. The first drive unit 20 includes, for example, a mechanism for moving the eye examination units 100L and 100R in the X direction, a mechanism for moving in the Y direction, and a mechanism for moving in the Z direction, as in the conventional case. including. Further, the first drive unit 20 may include a rotation mechanism for rotating the eye examination units 100L and 100R in a plane (horizontal plane, vertical surface, etc.) including the Z axis of the eye examination units 100L and 100R, respectively.

The second drive unit 22 moves the face support unit 24 under the control of the control unit 122. The second drive unit 22 can move the face support unit 24 three-dimensionally. The second drive unit 22 includes, for example, a mechanism for moving the face support portion 24 holding at least one of the subject's forehead and chin, and a mechanism for moving the face support portion 24 in the Y direction. , Includes a mechanism for moving in the Z direction. Further, the second drive unit 22 may include a rotation mechanism for changing the direction of the face support unit 24 (or a member included therein). When a plurality of members are provided on the face support portion 24, the second drive portion 22 may be configured to move these members individually. For example, the second drive unit 22 may be configured to move the forehead rest and the chin rest individually. The ophthalmology device 10 may include only one of the first drive unit 20 and the second drive unit 22, or may include both.

The user interface (UI200) provides functions for exchanging information between the ophthalmic appliance 10 and its user, such as information display, information input, and operation instruction input. The UI 200 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 UI 200 may also include a graphical user interface (GUI) for inputting and outputting information.

In the present embodiment, the UI 200 includes a touch panel display 202 in which an output function and an input function are integrated, and a controller 204.

(Details of data processing unit 126)
The details of the data processing unit 126 will be described. The data processing unit 126 includes an index image detecting unit 128 and a position specifying unit 130.

(Index image detection unit 128)
The index image detection unit 128 detects the index image drawn on each captured image by analyzing two or more captured images obtained substantially simultaneously by the stereo camera 108.

When the cameras 108A and 108B shoot a moving image, the index image detection unit 128 detects the index image from each frame. The index image detection unit 128 detects the index image by analyzing the pixel value of the captured image. When the captured image is a luminance image, the index image detection unit 128 identifies an image region (pixel) corresponding to the indicator image based on the distribution of the luminance values in the captured image. This process includes, for example, a process of selecting a pixel having a luminance value higher than a predetermined threshold value. When the captured image is a color image, the index image detection unit 128 includes, for example, a process of selecting a pixel having a luminance value higher than a predetermined threshold value, or a process of selecting a pixel representing a predetermined color.

(Positioning part 130)
The position specifying unit 130 identifies the position of the eye E to be inspected based on two or more index images detected from two or more captured images acquired substantially simultaneously by the stereo camera 108.

The position specifying unit 130 calculates at least the distance between the eye to be inspected E and the measurement optical system 112 in the Z direction. Z alignment is executed based on this calculation result. Further, the position specifying unit 130 may calculate the displacement between the eye to be inspected E and the measurement optical system 112 in the XY direction. XY alignment is executed based on this calculation result.

Next, the process executed by the position specifying unit 130 according to the present embodiment will be described with reference to FIGS. 4 to 6.

FIG. 4 shows a state in which the cameras 108A and 108B are mirror-converted with respect to the mirror 104, respectively. Hereinafter, the cameras 108A'and 108B' after the reflection conversion will be described.

FIG. 5 is a top view showing the positional relationship between the eye E to be inspected and the cameras 108A'and 108B' after the reflection conversion, and FIG. 6 is a side view.

The distance (baseline length) between the cameras 108A'and 108B' in the XY direction is represented by "B". The distance (index image distance) between the baselines of the cameras 108A'and 108B'and the index image P is represented by "H". The distance (screen distance) between each camera 108A'and 108B'and its screen plane is represented by "f". Generally, when the index luminous flux is projected as a parallel luminous flux with respect to the eye E to be inspected, the index image (Pulkiner image) P is located at a position displaced in the + Z direction from the corneal surface by half of the radius of curvature of the cornea of the eye E to be inspected. It is formed.

In such an arrangement state, the resolution of the images captured by the cameras 108A'and 108B' is expressed by the following equation. Here, Δp represents the pixel resolution.

Resolution in XY direction: ΔXY = H × Δp / f
Resolution in the Z direction: ΔZ = H × H × Δp / (B × f)
The position specifying unit 130 is a known trigonometry in which the arrangement relationship shown in FIGS. 5 and 6 is taken into consideration with respect to the positions (known) of the cameras 108A'and 108B' and the positions of the index images P in the two captured images. By applying, the position of the index image P, that is, the position of the eye to be inspected E is specified. The identified position includes at least a position in the Z direction and may further include a position in the XY direction.

The position of the eye E to be inspected specified by the position specifying unit 130 is sent to the control unit 122. The control unit 122 has the first drive unit 20 and the second drive unit 22 so as to match the distance between the eye to be inspected E and the measurement optical system 112 in the Z direction with the working distance based on the Z position of the eye to be inspected E. Control at least one of them. Further, the control unit 122 has at least one of the first drive unit 20 and the second drive unit 22 so as to align the optical axis of the measurement optical system 112 with the axis of the eye E to be inspected based on the XY position of the eye E to be inspected. To control. The working distance means a predetermined distance between the eye E to be inspected for measuring by the measuring optical system 112 and the measuring optical system 112.

As described above, the position specifying unit 130 can obtain the position of the index image P (Purkinje image) as the position of the eye to be inspected E (approximate position thereof). Further, the position specifying unit 132 can obtain the position of the cornea (vertex) of the eye E to be inspected based on the position of the specified index image P and the separately measured corneal radius of curvature. In the state where the XYZ alignment is correct, it is considered that the corneal apex is arranged at a position displaced in the −Z direction by half of the radius of curvature of the cornea from the index image P. Therefore, by subtracting the value of half of the radius of curvature of the cornea from the Z coordinate value of the index image P, the Z coordinate value of the corneal apex (XYZ coordinate value including it) can be obtained.

The radius of curvature of the cornea can be an average radius of curvature r8 mm, but an actual value can also be used as long as the radius of curvature of the cornea of the eye to be examined can be obtained.

The measurement of the radius of curvature of the cornea is performed using a keratometer or a corneal topographer. When the ophthalmic apparatus 10 does not have the function of measuring the radius of curvature of the cornea, the measured value of the radius of curvature of the cornea obtained in the past is input to the ophthalmic apparatus 10. The position specifying unit 130 obtains the position of the corneal apex using this measured value. On the other hand, when the ophthalmic apparatus 10 has a function of measuring the radius of curvature of the cornea, for example, the radius of curvature of the cornea can be measured after performing the alignment, and the alignment can be performed again using the obtained measured value. Further, even when the ophthalmic apparatus 10 has a function of measuring the radius of curvature of the cornea, it is possible to use the measured value of the radius of curvature of the cornea obtained in the past.

According to the present embodiment, by bending the optical path of the alignment optical system 106 and the stereo camera 108 using the mirror 104, an ophthalmic apparatus having a compact structure in the depth direction with respect to the eye to be inspected and a wide range of alignment is realized. be able to.

[Second Embodiment]
FIG. 7 is an external view showing an optometry system including an ophthalmic apparatus according to a second embodiment of the present invention. FIG. 8 is a diagram showing an optical system of an eye examination unit of the ophthalmic apparatus according to the present embodiment, and FIG. 9 is a block diagram showing the ophthalmic apparatus according to the present embodiment.

As shown in FIG. 7, in the optometry system 1 according to the present embodiment, the optometry indicator 50 is arranged at a position at an actual distance (for example, 5 m from the eye to be inspected) behind (-Z side) the ophthalmic apparatus 10. ing. An optotype for subjective optometry (for example, a Randolt ring or the like) is formed on the surface of the subjective optometry target 50. The subjective optometry marker 50 may be attached to the wall surface behind the ophthalmologic device 10 or may be attached to a movable panel (for example, a tsuitate with casters). The optometry target 50 may be a printed matter or the like on which an optometry target for optometry is formed, but the present invention is not limited to this. For example, a device for presenting a virtual image of an optotype for optometry may be provided at an examination distance (for example, 5 m from the eye to be inspected).

As shown in FIG. 8, an opening 102B is formed behind the half mirror 104A (-Z side), and the opening 102B can be opened and closed by the lid 102C.

As shown in FIG. 8, the eye examination unit 100R according to the present embodiment is provided with a half mirror 104A instead of the mirror 104. The half mirror 104A reflects a part of the light emitted from the alignment optical system 106 and the measurement optical system 112 toward the eye E to be inspected, and a part of the light incident from the opening 102B (-Z side). It can be transmitted to the E side (+ Z side) of the eye to be inspected. Here, the ratio of the light reflected by the half mirror 104A and the light transmitted through the half mirror 104A may be 50:50, or may be configured to increase either ratio.

Instead of the half mirror 104A, a dichroic mirror that reflects almost 100% of near-infrared light used for objective measurement and alignment and has an appropriate ratio of visible light transmittance and reflectance can also be used.

When the optotype in the measurement optical system 112 is turned off and the opening 102B is opened, the light incident from the opening 102B (-Z side) passes through the half mirror 104A and reaches the eye E side (+ Z side) to be inspected. .. The subject can visually recognize the subjective optometry target 50 by the optometry E. This enables optometry with the same visual chart for the left and right eyes, instead of the visual charts individually presented to the left and right eyes by the optometry visual marker presenting unit 114.

According to this embodiment, by using the half mirror 104A and bending the optical path of the alignment optical system 106 and the stereo camera 108, it is possible to perform optometry using the space behind the half mirror 104A (-Z side). become.

As shown in FIG. 9, a transmissive liquid crystal panel 134 may be arranged behind the half mirror 104A (-Z side). In this case, the control unit 122 can control the display of the liquid crystal panel 134 so that the subject can visually display various messages. The control unit 122 may display a frame on the liquid crystal panel 134, and the subject may move the frame according to the input from the UI 200 so as to match the contour of the subjective optometry target 50. Then, an image for instructing the Randolt ring of the subjective optometry target 50 is displayed on the liquid crystal panel 134, and the subject can determine whether or not the open direction of the Randolt ring can be visually recognized and the opening direction of the UI 200. It may be possible to input via. This makes it possible to instruct the visual acuity on the subjective optometry target 50 via the liquid crystal panel 134 and perform a visual acuity test.

It is also possible to display similar messages, frames, and other information on the optometry indicator presentation unit 114 instead of the liquid crystal panel 134, and to superimpose the information on the optometry indicator 50. In this case, since the presentation distance can be changed and astigmatism can be corrected according to the accommodation power of the eye to be inspected, the information can be presented in a state of good visibility.

In this embodiment, the half mirror 104A is used, but the mirror 104 is used with the mirror 104 and the actuator or motor for driving the mirror 104, and the mirror 104 is split into the eye examination window 102A and the opening 102B. It may be possible to evacuate from between.

Further, in the present embodiment, a transmissive liquid crystal display may be attached to the surface of the half mirror opposite to the surface facing the optometry window so that a message or the like to the subject can be displayed on the transmissive liquid crystal display. good.

10, 10A Ophthalmology equipment 20 1st drive unit 22 2nd drive unit 24 Face support unit 100, 100L, 100R Eye examination unit 104 Mirror (deflection member)
104A Half Mirror 106 Alignment Optical System 108A, 108B Camera 120 Processor

Claims (3)

A face support part that supports the subject's face,
Two optometry sections provided corresponding to the left and right eyes of the subject, and
It is provided with a drive unit that moves the two eye examination portions relatively independently of the face support portion.
The two eye examination sections are each
At least two imaging units that photograph the characteristic site on the anterior segment of the eye to be inspected from different directions substantially simultaneously.
A measurement optical system for measuring the characteristics of the eye to be inspected,
An alignment optical system that projects an alignment luminous flux along the optical axis of the measurement optical system is provided on the anterior eye portion of the eye to be inspected.
In order to identify the position of the eye to be inspected, at least two images taken by the at least two imaging units are analyzed, and the position of the corneal reflex image of the alignment light flux as a characteristic portion on the anterior eye portion. An ophthalmic device equipped with an analysis unit that identifies. The ophthalmic apparatus according to claim 1, wherein the alignment optical system is arranged in the measurement optical system. A control unit that controls the drive unit based on the position of the feature portion specified by the analysis unit, and a control unit.
The ophthalmic apparatus according to claim 1 or 2.

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