JP2018166634A - Ophthalmologic device - Google Patents

Abstract

To provide a novel procedure of alignment for an ophthalmologic apparatus.SOLUTION: An ophthalmologic apparatus includes a data acquisition optical system, a projection unit, two or more imaging units, a cornea shape information acquisition unit, and a position determination unit. The data acquisition optical system has a configuration for acquiring data on an eye to be examined. The projection unit projects an index including at least one of a predetermined continuous pattern and a predetermined discrete pattern on the anterior eye part of the eye to be examined. The two or more imaging units image the anterior eye part onto which the index is projected from different directions. The cornea shape information acquisition unit acquires cornea shape information on the eye to be examined based on at least one of two or more first captured images acquired by the two or more imaging units. The position determination unit determines a movement target position of the data acquisition optical system based on two or more second captured images acquired by the two or more imaging units and the cornea shape information.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an ophthalmologic apparatus for acquiring data of an eye to be examined.

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

  As an example of an ophthalmologic photographing apparatus, an optical coherence tomography (Optical Coherence Tomography, OCT) is used to obtain a tomographic image, a fundus camera for photographing a fundus, a fundus image obtained by laser scanning using a confocal optical system. There is a scanning laser opthalmoscope (SLO).

  Examples of ophthalmic measuring devices include an ocular refraction examination device (refractometer, keratometer) that measures the refractive characteristics of the eye to be examined, a tonometer, a specular microscope that obtains corneal properties (corneal thickness, cell distribution, etc.), Hartmann There is a wave front analyzer that obtains aberration information of the eye to be examined using a shack sensor.

  In ophthalmic examination, alignment between the apparatus optical system and the eye to be examined is extremely important from the viewpoint of accuracy and accuracy of examination. This alignment is called alignment. The alignment includes an operation for aligning the optical axis of the apparatus optical system with the axis of the eye to be examined (XY alignment) and an operation for adjusting the distance between the eye to be examined and the apparatus optical system (Z alignment).

  There are various methods for alignment. As a typical technique, a technique is known in which light is projected onto the cornea and a reflected image (Purkinje image) is detected for alignment (see, for example, Patent Document 1).

  Further, as a technique realized in recent years, two or more photographed images obtained by photographing the anterior segment from different directions are analyzed to identify the three-dimensional position of the eye to be examined, and XY alignment is performed based on the three-dimensional position. There is a method for performing both of the Z alignment and the Z alignment (see, for example, Patent Document 2).

Japanese Patent Laid-Open No. 10-024019 JP 2013-248376 A

  Thus, when the conventional alignment method is used, the following problems may occur.

  The Purkinje image generated when a parallel light beam is irradiated is formed at a position displaced in the axial direction (Z direction) from the apex of the cornea by a distance that is a half of the radius of curvature of the cornea. When the Purkinje image is used for Z alignment, the Z position of the Purkinje image is estimated using a standard value (for example, 8 mm) of the corneal curvature radius.

  However, considering that there are individual differences in the corneal curvature radius and the range extends from about 6 mm to about 9 mm, it is difficult to say that it is preferable to perform Z alignment using a standard value. In particular, it is difficult to apply this conventional method to an ophthalmologic apparatus that requires high-precision alignment, such as a tonometer or a specular microscope.

  An object of the present invention is to provide a new method of alignment for an ophthalmic apparatus.

  An ophthalmologic apparatus according to a first aspect of an embodiment includes a data acquisition optical system for acquiring data of an eye to be examined, and an index including at least one of a predetermined continuous pattern and a predetermined discrete pattern. A projection unit that projects onto the anterior eye part, two or more photographing parts that photograph the anterior eye part on which the index is projected from different directions, and two or more first photographings acquired by the two or more photographing parts. Based on the corneal shape information acquisition unit for obtaining corneal shape information of the eye to be examined based on at least one of the images, on the basis of the two or more second captured images acquired by the two or more imaging units and the corneal shape information And a position determining unit that determines a movement target position of the data acquisition optical system.

  In the ophthalmologic apparatus according to the second aspect of the embodiment, the projection unit projects a ring pattern or a concentric pattern index onto the anterior eye part as the continuous pattern index.

  In the ophthalmologic apparatus according to the third aspect of the embodiment, the projection unit projects the ring pattern index and a central bright spot located at the center of the ring pattern onto the anterior segment.

  In the ophthalmologic apparatus according to the fourth aspect of the embodiment, the projection unit projects the index of the concentric circle pattern and a central bright spot located at the center of the concentric circle pattern onto the anterior ocular segment.

  In the ophthalmologic apparatus according to the fifth aspect of the embodiment, the projection unit uses, as the discrete pattern index, three or more bright spots arranged on a circle and a central bright spot located at the center of the circle. , And project onto the anterior segment.

  In the ophthalmologic apparatus according to the sixth aspect of the embodiment, the projection unit projects five or more bright spots arranged on a circle onto the anterior segment as an index of the discrete pattern.

  In the ophthalmologic apparatus according to the seventh aspect of the embodiment, the projection unit projects the central luminescent spot onto the anterior segment by projecting a light beam through the optical path of the data acquisition optical system.

  In the ophthalmologic apparatus according to the eighth aspect of the embodiment, the projection unit includes a non-parallel light projection unit that projects non-parallel light onto the anterior eye unit, and the corneal shape information acquisition unit includes at least the first captured image. The corneal shape information is obtained based on the projected image of the non-parallel light depicted in FIG.

  In the ophthalmologic apparatus according to the ninth aspect of the embodiment, the projection unit includes a parallel light projection unit that projects parallel light onto the anterior eye unit, and the position determination unit renders the two or more second captured images. A provisional position determination unit for obtaining a provisional movement target position of the data acquisition optical system based on the projected image of the parallel light, and the movement target position by correcting the provisional movement target position based on the corneal shape information. And a position correction unit for determining.

  An ophthalmologic apparatus according to a tenth aspect of the embodiment includes a drive unit that moves the data acquisition optical system and a control unit, and the control unit moves the data acquisition optical system to the provisional movement target position. Therefore, the first control of the drive unit is executed, and the corneal shape information acquisition unit is configured to perform the cornea based on the two or more first captured images acquired by the two or more imaging units after the first control. Shape information is obtained, the position correction unit determines the movement target position based on the cornea shape information, and the control unit moves the data acquisition optical system from the temporary movement target position to the movement target position. The second control of the drive unit is executed to move the motor.

  In the ophthalmologic apparatus according to the eleventh aspect of the embodiment, the provisional position determination unit analyzes the two or more second captured images to search for a projection image of the parallel light, and when the projection image is detected, When the provisional movement target position is obtained and the projection image is not detected, two or more third captured images acquired by the two or more imaging units are analyzed to search for a pupil image, and the pupil image is A pupil position acquisition unit for obtaining a three-dimensional position of the pupil of the eye to be examined when detected, wherein the control unit is configured to move the data acquisition optical system to a position corresponding to the three-dimensional position. And the provisional position determination unit analyzes the two or more captured images acquired by the two or more imaging units after the third control and searches again for the projection image of the parallel light. .

  An ophthalmologic apparatus according to a twelfth aspect of the embodiment includes an observation image acquisition unit that acquires an observation image of the anterior segment and an operation unit, and when the pupil image is not detected, the control unit The observation image is displayed on the display means, and the driving unit is controlled in accordance with an operation performed using the operation unit, and the temporary position determination unit is acquired by the two or more imaging units after the operation. The two or more captured images are analyzed to search again for the projection image of the parallel light.

  An ophthalmologic apparatus according to a thirteenth aspect of the embodiment has a projection unit that projects an index including at least one of a predetermined continuous pattern and a predetermined discrete pattern onto the anterior eye part of the eye to be examined, and the index is projected One or more captured images acquired by two or more photographing units that photograph the anterior eye part from different directions and one or more photographing parts that photograph the anterior eye part from an oblique direction among the two or more photographing units. A corneal shape information acquisition unit for obtaining corneal shape information of the eye to be examined based on

  According to the embodiment, it is possible to provide a new method of alignment for an ophthalmologic apparatus.

It is a schematic diagram showing an example of composition of an ophthalmology device concerning an embodiment. It is a schematic diagram showing an example of composition of an ophthalmology device concerning an embodiment. It is a schematic diagram showing an example of composition of an ophthalmology device concerning an embodiment. It is a schematic diagram showing an example of composition of an ophthalmology device concerning an embodiment. It is a schematic diagram showing an example of composition of an ophthalmology device concerning an embodiment. It is a schematic diagram showing an example of composition of an ophthalmology device concerning an embodiment. It is the schematic for demonstrating an example of the process which the ophthalmologic apparatus which concerns on embodiment performs. It is the schematic for demonstrating an example of the process which the ophthalmologic apparatus which concerns on embodiment performs. It is the schematic for demonstrating an example of the process which the ophthalmologic apparatus which concerns on embodiment performs. It is the schematic for demonstrating an example of the process which the ophthalmologic apparatus which concerns on embodiment performs. It is a flowchart showing an example of operation | movement of the ophthalmologic apparatus which concerns on embodiment. It is a flowchart showing an example of operation | movement of the ophthalmologic apparatus which concerns on embodiment.

  An example of an embodiment of an ophthalmologic apparatus according to the present invention will be described in detail with reference to the drawings. The ophthalmologic apparatus according to the embodiment is used for optical examination of an eye to be examined. Such an ophthalmologic apparatus includes, for example, at least one of an ophthalmologic photographing apparatus and an ophthalmologic measurement apparatus. Examples of ophthalmic imaging apparatuses include an optical coherence tomometer, a fundus camera, and a scanning laser ophthalmoscope. Examples of the ophthalmologic measurement apparatus include an eye refraction inspection apparatus, a tonometer, a specular microscope, and a wave front analyzer. Any known technique, including techniques disclosed in the documents cited in this specification, can be combined with the embodiments.

<Constitution>
A configuration example of an ophthalmologic apparatus is shown in FIGS. The ophthalmologic apparatus 1 has a function of acquiring data of the eye E to be examined. That is, the ophthalmologic apparatus 1 has one or both of a function of photographing the eye E and a function of measuring the characteristics of the eye E.

  The ophthalmologic apparatus 1 includes a control unit 11, a data processing unit 12, an optical unit 20, a face support unit 70, a first drive unit 80A, a second drive unit 80B, and a user interface (UI) 90. . Note that a configuration in which only one of the first drive unit 80A and the second drive unit 80B is provided may be employed. Typically, the ophthalmologic apparatus 1 may include only the first drive unit 80A.

  Each of the control unit 11 and the data processing unit 12 includes a processor. 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, SPLD (Simple Programmable LD). (Field Programmable Gate Array)).

  For example, the processor implements the functions according to the embodiment by reading and executing a program stored in a storage circuit or a storage device. At least a part of the memory circuit or the memory device may be included in the processor. Further, at least a part of the memory circuit or the memory device may be provided outside the processor 10. Processing that can be executed by the processor will be described later.

  The storage device or the like stores various data. Data stored in the storage device or the like includes data (measurement data, imaging data, etc.) acquired by the data acquisition optical system 30, information on the subject and the eye to be examined, and the like. The storage device or the like may store various computer programs and data for operating the ophthalmologic apparatus 1. The storage device or the like stores various types of data that are used and referred to in processing that will be described later.

(Control unit 11)
The control unit 11 executes control of each unit of the ophthalmologic apparatus 1. In particular, the control unit 11 controls the data processing unit 12, the optical unit 20, the first drive unit 80A, the second drive unit 80B, and the user interface 90. The control unit 11 includes an alignment control unit 111 and a UI control unit 112.

(Alignment control unit 111)
The alignment control unit 111 executes control related to alignment. The ophthalmologic apparatus 1 can execute alignment (index alignment mode) based on the index projected on the anterior segment Ea. Although details will be described later, in the index alignment mode, correction based on the corneal shape information of the eye E can be performed.

  The corneal shape information includes, for example, an arbitrary parameter value representing the shape of the cornea that can be measured using a known ophthalmic apparatus. Typically, the corneal shape information includes the radius of curvature (curvature), the direction of the strong main meridian, the radius of curvature along the strong main meridian (frequency), the direction of the weak main meridian, the radius of curvature (frequency) along the weak main meridian, Any of ellipticity, eccentricity, flatness, topography including irregular astigmatism, aberration information using Zernike polynomials, and the like may be included.

  Furthermore, the alignment control unit 111 may be capable of executing alignment based on the characteristic part of the eye E (pupil alignment mode) and alignment (manual alignment) manually performed by the examiner. The alignment control unit 111 executes processing for selecting an alignment mode and control of each unit in the selected alignment mode. A specific example of processing executed by the alignment control unit 111 will be described later.

(UI control unit 112)
The UI control unit 112 performs control related to the user interface 90. In other words, the UI control unit 112 performs control related to the exchange of information between the ophthalmologic apparatus 1 and the user. Typically, the UI control unit 112 executes control for displaying information on the display unit 91 and control according to an operation performed using the operation unit 92. The information output mode by the ophthalmologic apparatus 1 is not limited to display output, and may include sound output, print output, lighting of a light emitting diode, and the like. A specific example of the process executed by the UI control unit 112 will be described later.

(Data processing unit 12)
The data processing unit 12 executes various data processing. For example, the data processing unit 12 analyzes an image acquired by the anterior eye camera 60. The analysis result of the image is used for alignment or the like. Details of the data processing unit 12 will be described later (see FIG. 2).

(Optical unit 20)
The optical unit 20 stores a configuration for measuring and / or photographing the eye E and a configuration for preparing the same. The former includes the data acquisition optical system 30, and the latter includes the alignment optical system and the anterior eye camera 60. The alignment optical system is used in alignment, and includes a first light projection unit 41 and a second light projection unit 42 in this embodiment.

  In a typical example, the data acquisition optical system 30 and the first light projection unit 41 are stored inside the optical unit 20. Moreover, the 2nd light projection part 42 is installed in the housing | casing surface of the optical unit 20, or one part is exposed to the housing | casing surface. Similarly, the anterior eye camera 60 is installed on the surface of the housing of the optical unit 20, or a part of the anterior eye camera 60 is exposed on the surface of the housing.

  The first light projection unit 41 includes an optical system disposed inside the optical unit 20. The optical path formed by the optical system of the first light projection unit 41 is combined with the optical path of the data acquisition optical system 30 by the beam splitter 50. Although not shown, various optical members such as an objective lens are provided between the beam splitter 50 and the eye E to be examined.

  In addition to the configuration shown in FIG. 1, the optical unit 20 may be provided with an optical system (illumination optical system, observation optical system, photographing optical system, etc.) for photographing the eye E from the front. Furthermore, a configuration for performing focusing of the data acquisition optical system 30 may be provided. In a typical embodiment, an optical system for photographing the subject eye E from the front is not provided, and both the alignment and anterior eye photographing for acquiring corneal shape information are performed by the anterior eye camera. 60 is configured to be performed. However, the embodiment is not limited to such a configuration.

(Data acquisition optical system 30)
The data acquisition optical system 30 includes a configuration for measuring the characteristics of the eye E and / or a configuration for photographing the eye E. The data acquisition optical system 30 is configured according to the functions (measurement function, imaging function, etc.) provided by the ophthalmologic apparatus 1. The data acquisition optical system 30 includes, for example, a light source, an optical element (an 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 data acquisition optical system 30 may be the same as that of a conventional ophthalmic apparatus. At least a part of the data acquisition optical system 30 may be disposed outside the optical path combined with the optical path of the first light projection unit 41.

  The data acquisition optical system 30 may include a configuration for providing a function associated with the inspection. For example, a fixation optical system for projecting a target (fixation target) for fixing the eye E on the fundus of the eye E may be provided.

(Detection of the position of the data acquisition optical system 30)
The ophthalmologic apparatus 1 has a function of detecting the position of the data acquisition optical system 30. For example, the control unit 11 can record the content of the control for the first drive unit 80A and / or the second drive unit 80B, and can determine the position of the data acquisition optical system 30 from this record (control history). In another example, the ophthalmologic apparatus 1 includes a position sensor that detects the position of the data acquisition optical system 30.

  Based on the position of the data acquisition optical system 30 and the movement target position determined by the data processing unit 12, the control unit 11 (alignment control unit 111 or the like) is based on the first drive unit 80 </ b> A and / or the second drive unit 80 </ b> B. Can be controlled. Thereby, the data acquisition optical system 30 can be moved to the movement target position. Specifically, the control unit 11 obtains a difference between the position of the data acquisition optical system 30 and the movement target position. This difference is, for example, a vector value starting from the detected position of the data acquisition optical system 30 and ending at the movement target position. This vector value is, for example, a three-dimensional vector value expressed in an XYZ coordinate system.

(First light projection unit 41)
The first light projection unit 41 includes, for example, a light source and a collimator lens, and projects light onto the anterior eye part Ea. In this embodiment, the 1st light projection part 41 projects substantially parallel light (parallel light) on the anterior eye part Ea. Thereby, an index for alignment is projected onto the anterior segment Ea. This index is detected as a Purkinje image. The alignment using the index includes, for example, one or both of Z alignment and XY alignment. Z alignment is alignment in the optical axis direction (Z direction) of the data acquisition optical system 30. XY alignment is alignment in the X direction (horizontal direction) and Y direction (vertical direction) orthogonal to the Z direction.

  The Z alignment is executed by analyzing two or more captured images obtained substantially simultaneously by two or more anterior eye cameras 60, for example. The XY alignment is executed, for example, by analyzing two or more captured images obtained substantially simultaneously by two or more anterior segment cameras 60.

  The XY alignment of the anterior segment Ea is executed based on the position in the XY direction of the Purkinje image (index image) drawn on the image of the anterior segment Ea acquired by any one or more of the two or more anterior segment cameras 60. Is done. For example, the XY alignment based on the image of the anterior segment Ea is executed by manually or automatically moving the optical unit 20 so as to guide the index image within an allowable range of alignment deviation (alignment mark).

  Further, an image of the anterior segment Ea acquired by one of the two or more anterior segment cameras 60 (in other words, acquired by the anterior segment camera 60 disposed at a position off the optical path of the data acquisition optical system 30). It is possible to apply image processing for converting an image obtained by photographing the anterior eye portion Ea from an oblique direction into an image viewed from the front. This processing is, for example, viewpoint conversion based on the expected angle of the anterior eye camera 60 (the position of the anterior eye camera 60). XY alignment can be performed using the front image formed through such image processing.

  In the case of manual alignment, the UI control unit 112 displays the image of the anterior segment Ea and the alignment mark on the display unit 91, and the user operates the operation unit 92 so that the above condition is satisfied. In manual alignment, the UI control unit 112 can cause the display unit 91 to display information for assisting the user's operation. For example, information indicating the alignment shift direction and / or the shift amount can be displayed, and the direction and / or amount in which the optical unit 20 should be moved can be displayed.

  In the case of auto alignment, the data processing unit 12 calculates the displacement of the index image with respect to the alignment mark, and the alignment control unit 111 moves the optical unit 20 in the XY directions so as to cancel this displacement.

(Second light projection unit 42)
The second light projection unit 42 is disposed on the front surface of the optical unit 20 (the surface facing the eye E). The second light projection unit 42 projects, for example, one or both of a predetermined continuous pattern index and a predetermined discrete pattern index onto the anterior segment Ea.

  The continuous pattern is, for example, a ring pattern or a concentric pattern. When the ring pattern index is applied, the central bright spot located at the center of the ring pattern can be further projected onto the anterior eye portion Ea. Similarly, when the index of the concentric circle pattern is applied, the central luminescent spot located at the center of the concentric circle pattern can be further projected onto the anterior segment Ea. The central bright spot is formed by the first light projection unit 41, for example.

  The index of the continuous pattern is not limited to these. For example, an ellipse pattern, an arbitrary curve pattern, an arbitrary straight line pattern, and the like can be applied. The continuous pattern may not be a closed curve. For example, the continuous pattern may be a part of a circle, a part of a concentric circle, a part of an ellipse, or the like. The continuous pattern may be a planar pattern having a two-dimensional extension.

  The index of the discrete pattern may include an arbitrary number of bright spots (point-shaped index). In addition, the discrete pattern index may include an arbitrary number of bright lines (line segment-shaped index), an arbitrary number of planar patterns, and the like. For example, the discrete pattern index may include three or more bright spots arranged on a circle and a central bright spot located at the center of the circle. The central bright spot is formed by the first light projection unit 41, for example. As another example, the discrete pattern index may include five or more bright spots arranged on a circle.

  The second light projection unit 42 includes an arbitrary light source. The light source may be a light emitting device or a combination of a light emitting device and an optical element. A typical example of a light emitting device is a light emitting diode (LED). The light emitting device may have a shape corresponding to the index pattern. The second light projection unit 42 may include a plurality of light emitting devices arranged according to the index pattern. A typical example of an optical element combined with a light emitting device is a diffusion plate. In addition, an optical element having an opening or a light-transmitting portion having a shape corresponding to the index pattern can be combined with the light-emitting device.

  In this embodiment, the 2nd light projection part 42 projects light (non-parallel light) on the anterior eye part Ea from a finite distance. The projection image is used to acquire corneal shape information of the eye E. Both the projection image (index) formed by the first light projection unit 41 and the projection image (index) formed by the second light projection unit 42 are used for acquiring corneal shape information of the eye E to be examined. can do. For example, when the number of discrete pattern projection images formed by the second light projection unit 42 is relatively small, or when the second light projection unit 42 forms a continuous pattern projection image, The projection image formed by the first light projection unit 41 can be used.

  The 2nd light projection part 42 can be utilized as anterior ocular segment illumination. Anterior segment illumination is used when observing the anterior segment Ea.

  Specific examples of the first light projection unit 41 and the second light projection unit 42 will be described later.

(Anterior eye camera 60)
Two or more anterior eye cameras 60 are provided at different positions. Each anterior eye camera 60 is, for example, a video camera that performs moving image shooting at a predetermined frame rate. The two or more anterior segment cameras 60 photograph the anterior segment substantially simultaneously from different directions.

  In the example illustrated in FIG. 1, the data acquisition optical system 30 is provided at a position off the optical path, but is not limited thereto. For example, when an image sensor is provided in the data acquisition optical system 30, one of the two or more anterior segment cameras may be the image sensor.

  In this embodiment, for example, as shown in FIG. 3, two anterior eye cameras 60A and 60B are provided. 3 is a top view, and the + Y direction indicates a vertically upward direction, and the + Z direction indicates an optical axis direction of the data acquisition optical system 30 and a direction from the data acquisition optical system 30 toward the eye E. FIG. The anterior eye cameras 60 </ b> A and 60 </ b> B are provided at positions off the optical path of the data acquisition optical system 30. Hereinafter, the two anterior eye cameras 60 </ b> A and 60 </ b> B may be collectively represented by the symbol “60”.

  The number of the anterior segment camera may be an arbitrary number of 2 or more as long as the anterior segment can be photographed substantially simultaneously from two different directions. One anterior eye camera may be arranged coaxially with the data acquisition optical system 30.

  “Substantially simultaneously” indicates that, for example, in photographing with two or more anterior segment cameras, a deviation in photographing timing that allows negligible eye movement is allowed. Thereby, an image when the eye E is substantially at the same position (orientation) can be acquired by two or more anterior segment cameras.

  In addition, although shooting with two or more anterior eye cameras may be moving image shooting or still image shooting, in this embodiment, a case where moving image shooting is performed will be described in detail. In the case of moving image shooting, the above-described substantially simultaneous anterior ocular shooting can be realized by controlling the shooting start timing to match or by controlling the frame rate and shooting timing of each frame. On the other hand, in the case of still image shooting, this can be realized by controlling to match the shooting timing.

  Examples of the configuration of the front surface of the housing of the optical unit 20 are shown in FIGS. 4A to 4C. Reference numeral “51” denotes an objective lens. The objective lens 51 is disposed in front of the beam splitter 50 (the eye E to be examined). The objective lens 51 is disposed at the forefront position (position closest to the eye E) of the member group forming the optical path of the data acquisition optical system 30 and connects the first light projection unit 41 and the eye E. It is arrange | positioned in the forefront position of the member group which forms.

  A configuration in which an optical element or the like can be arranged in front of the objective lens 50 can also be applied. For example, when the ophthalmologic apparatus 1 includes an optical coherence tomography for fundus photographing, an anterior lens photographing attachment lens can be arranged in front of the objective lens 51.

  The member disposed at the forefront position of the data acquisition optical system 30 is not limited to the objective lens 51. For example, when the ophthalmologic apparatus 1 includes a tonometer, a nozzle for blowing an air flow on the corneal surface is disposed at the foremost position.

  The example shown in FIG. 4A will be described. In this example, the objective lens 51 is disposed slightly above the center position of the housing of the optical unit 20. At the time of inspection, the objective lens 51 is disposed so as to face the anterior segment Ea.

  In this example, an anterior eye camera 60A is disposed on the left side of the objective lens 50, and an anterior eye camera 60B is disposed on the right side. In this example, the height position of the objective lens 50 (position in the Y direction) and the height positions of the anterior eye cameras 60A and 60B are designed to be equal, but the present invention is not limited to this. For example, the anterior eye cameras 60 </ b> A and 60 </ b> B can be arranged below the lens center of the objective lens 50 (−Y direction). Thereby, it is possible to reduce the possibility that the subject's eyelashes or eyelashes appear in the captured images acquired by the anterior eye cameras 60A and 60B. Moreover, even if the subject has a deep eye depression (orbit), anterior segment imaging can be suitably performed. As another example, it can be designed such that the height position of the anterior eye camera 60A and the height position of the anterior eye camera 60B are different.

  The second light projection unit 42A of this example includes one or more light sources having a continuous shape (a light emitting device or a combination of a light emitting device and an optical element). The second light projection unit 42A is, for example, a ring light source (kerato ring light source) or a concentric light source (platid ring light source) used in an ophthalmologic apparatus (keratometer, corneal topographer, etc.) for measuring a corneal shape. The kerato ring light source outputs a light beam having a ring-shaped cross section for projecting a ring pattern index onto the anterior segment Ea. The placido ring light source outputs a light beam having a concentric cross section for projecting a concentric pattern index onto the anterior segment Ea.

  In the example shown in FIG. 4A, the second light projection unit 42A is a placido ring light source in which three ring light sources are arranged concentrically. The number of ring-shaped light sources constituting the placido ring light source may be arbitrary.

  The example shown in FIG. 4B will be described. In this example, the configuration and arrangement of the objective lens 51, the anterior eye camera 60A, and the anterior eye camera 60B are the same as the example shown in FIG. 4A. Other configurations and / or arrangements may be applied.

  The second light projection unit 42B of this example includes three point light sources (a light emitting device or a combination of a light emitting device and an optical element). The three point light sources 42 </ b> B are arranged at the vertices of an equilateral triangle having the optical axis position of the objective lens 51 as the center of gravity. The arrangement of the three point light sources is not limited to this, and may be arbitrary.

  The example shown in FIG. 4C will be described. In this example, the configuration and arrangement of the objective lens 51, the anterior eye camera 60A, and the anterior eye camera 60B are the same as the example shown in FIG. 4A. Other configurations and / or arrangements may be applied.

  The second light projection unit 42C of the present example includes five point light sources (a light emitting device or a combination of a light emitting device and an optical element). The five point light sources 42B are arranged at the apexes of a regular pentagon with the optical axis position of the objective lens 51 as the center of gravity. In addition, arrangement | positioning of five point light sources is not limited to this, You may be arbitrary.

  In the example shown in FIGS. 4A to 4C, the relative position among the objective lens 51, the anterior eye cameras 60A and 60B, and the second light projection unit 42 is fixed. In another example, at least one of these members can be configured to be movable. For example, a mechanism for moving the anterior eye camera 60A and / or 60B may be provided. In addition, a mechanism for moving the light source included in the second light projection unit 42 may be provided. In that case, a function of detecting the position of the movable member is provided.

  Moreover, when the 2nd light projection part 42 contains the light source of a continuous shape, the mechanism for changing the shape of this light source can be provided.

(Face support part 70)
The face support unit 70 includes a member for supporting the subject's face. For example, the face support unit 70 includes a forehead pad on which the subject's forehead abuts and a chin rest on which the subject's chin is placed. The face support unit 70 may include only one of the forehead support and the chin rest, or may include other members.

(First driving unit 80A and second driving unit 80B)
The first drive unit 80A moves the optical unit 20 under the control of the control unit 11 (alignment control unit 111 or the like). The first drive unit 80A can move the optical unit 20 three-dimensionally. The first drive unit 80A includes, for example, a mechanism for moving the optical unit 20 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. The first drive unit 80A may include a rotation mechanism that rotates the optical unit 20 within a plane (horizontal plane, vertical plane, etc.) including the optical axis of the optical unit 20.

  The second drive unit 80B moves the face support unit 70 under the control of the control unit 11 (alignment control unit 111 or the like). The second drive unit 80B can move the face support unit 70 three-dimensionally. The second drive unit 80B includes, for example, a mechanism for moving the face support unit 70 in the X direction, a mechanism for moving in the Y direction, and a mechanism for moving in the Z direction. The second drive unit 80B may include a rotation mechanism for changing the orientation of the face support unit 70 (or a member included therein). When a plurality of members are provided in the face support unit 70, the second drive unit 80B may be configured to move these members individually. For example, the second drive unit 80B may be configured to move the forehead rest and the chin rest individually.

(User interface 90)
The user interface 90 provides functions for exchanging information between the ophthalmologic apparatus 1 and the user, such as information display, information input, and operation instruction input. The user interface 90 provides an output function and an input function. The user interface 90 is controlled by the UI control unit 112.

  A display unit 91 is a typical example of a configuration that provides an output function. The display unit 91 includes a display device such as a flat panel display. Other examples of the configuration related to the output function include an audio output device and a light emitting diode.

  A typical example of a configuration that provides an input function is an operation unit 92. The operation unit 92 includes operation devices such as a lever, a button, a key, and a pointing device. Other examples of the configuration related to the input function include a microphone and a data writer.

  The user interface 90 may include a device in which an output function and an input function such as a touch panel display are integrated. The user interface 90 may include a graphical user interface (GUI) for inputting and outputting information.

(Details of the data processing unit 12)
Details of the data processing unit 12 will be described. As shown in FIG. 2, the data processing unit 12 includes an image correction unit 120, a corneal shape information acquisition unit 130, a position determination unit 140, and a pupil position acquisition unit 150. These function for alignment.

(Image correction unit 120)
The image correction unit 120 corrects the distortion of the captured image obtained by the anterior eye camera 60 based on predetermined aberration information. This process is executed by, for example, a known image processing technique based on a correction coefficient for correcting distortion. It should be noted that the image correction unit 120 is not required when the distortion aberration given to the captured image by the optical system of the anterior eye camera 60 is sufficiently small.

  The aberration information is stored in advance in a storage device or the like provided in the ophthalmologic apparatus 1, for example. Alternatively, the ophthalmologic apparatus 1 can be configured to refer to aberration information stored in advance in an external device. In the aberration information, information on distortion aberration generated in the captured image due to the influence of the optical system mounted on each anterior eye camera 60 is recorded. Here, the optical system mounted on the anterior eye camera 60 includes an optical element that generates distortion, such as a lens. The aberration information can be said to be a parameter obtained by quantifying the distortion that these optical elements give to the photographed image.

  An example of a method for generating aberration information will be described. Taking the instrumental difference (difference in distortion) of the anterior segment camera 60 into consideration, the following measurement is performed for each anterior segment camera 60. The operator prepares a predetermined reference point. The reference point is an imaging target used for detecting distortion. The operator performs shooting a plurality of times while changing the relative position between the reference point and the anterior eye camera 60. Thereby, a plurality of captured images of the reference point captured from different directions are obtained. The operator generates aberration information for the anterior eye camera 60 by analyzing a plurality of acquired images with a computer.

The analysis process for generating aberration information includes, for example, the following steps.
An extraction process for extracting an image area corresponding to a reference point from each captured image. A distribution state calculation process for calculating a distribution state (coordinates) of an image area corresponding to the reference point in each captured image. Based on the obtained distribution state A distortion aberration calculating step for calculating a parameter representing distortion aberration and a correction coefficient calculating step for calculating a coefficient for correcting the distortion aberration based on the obtained parameter

  Parameters relating to distortion aberration given to an image by the optical system include principal point distance, principal point position (vertical direction, horizontal direction), lens distortion (radiation direction, tangential direction), and the like. The aberration information is configured as information (for example, table information) in which the identification information of each anterior eye camera 60 is associated with the correction coefficient corresponding thereto. The image correction unit 120 performs aberration correction on the captured image acquired by the anterior eye camera 60A or 60B by referring to the aberration information generated in this way. Such aberration correction is called calibration or the like.

  The captured image corrected by the image correction unit 120 is sent to at least one of the cornea shape information acquisition unit 130, the position determination unit 140, and the pupil position acquisition unit 150. In a typical example, the control unit 11 (alignment control unit 111 or the like) is configured to switch the transmission destination of the captured image corrected by the image correction unit 120 according to the operation mode or the processing phase.

(Cornea shape information acquisition unit 130)
The corneal shape information acquisition unit 130 obtains corneal shape information of the eye E based on the two captured images (first captured images) acquired by the anterior segment cameras 60A and 60B. The corneal shape information includes any of the parameter values described above.

  The corneal shape information acquisition unit 130 is configured to obtain corneal shape information based on at least the index formed by the second light projection unit 42. Further, the corneal shape information acquisition unit 130 is configured to obtain corneal shape information based on the index formed by the first light projection unit 41 and the index formed by the second light projection unit 42.

  When the second light projection unit 42A shown in FIG. 4A is applied, the corneal shape information acquisition unit 130 obtains corneal shape information based on, for example, an index of a concentric pattern formed by the second light projection unit 42A. Composed. In another example, the corneal shape information acquisition unit 130 is based on the index (bright spot) formed by the first light projection unit 41 and the concentric pattern index formed by the second light projection unit 42A. Configured to ask for.

  When the second light projection unit 42B shown in FIG. 4B is applied, the corneal shape information acquisition unit 130 is formed by, for example, an index (bright spot) formed by the first light projection unit 41 and the second light projection unit 42B. The corneal shape information is obtained based on four indices including the three indices (bright spots).

  When the second light projection unit 42C illustrated in FIG. 4C is applied, the corneal shape information acquisition unit 130 obtains corneal shape information based on, for example, five indices (bright spots) formed by the second light projection unit 42C. Configured to seek. In another example, the corneal shape information acquisition unit 130 includes an index (bright spot) formed by the first light projection unit 41 and five indices (bright spots) formed by the second light projection unit 42C. The corneal shape information is determined based on one index.

  An example of processing executed by the cornea shape information acquisition unit 130 will be described. Hereinafter, the case where the light projection units 42A to 42C illustrated in FIG. 4A to FIG. 4C are applied will be exemplarily described, but the same processing is applied even when the second light projection unit 42 of another form is applied. can do.

  A case where the second light projection unit 42A illustrated in FIG. 4A is applied will be described. An example of two captured images (anterior segment images) acquired substantially simultaneously by the anterior segment cameras 60A and 60B is shown in FIG. 5A. The captured image 200A is an anterior segment image acquired by the anterior segment camera 60A, and the captured image 200B is an anterior segment image acquired by the anterior segment camera 60B. Here, the captured images 200 </ b> A and 200 </ b> B may be anterior eye image corrected by the image correcting unit 120.

  The photographed image 200A is an image obtained by photographing the anterior segment Ea from an oblique direction. The captured image 200A is formed by a pupil image 201A corresponding to the pupil Ep of the eye E, a bright spot image (Purkinje image) 202A formed by the first light projection unit 41, and a second light projection unit 42A. A concentric pattern index 203A is depicted.

  Similarly, the photographed image 200B is an image obtained by photographing the anterior segment Ea from an oblique direction different from that of the photographed image 200A. The captured image 200B is formed by a pupil image 201B corresponding to the pupil Ep of the eye E, a bright spot image (Purkinje image) 202B formed by the first light projection unit 41, and a second light projection unit 42A. A concentric pattern index 203B is depicted.

  In this example, the captured images 200A and 200B are acquired by shooting from a direction different from the optical axis of the objective lens 51 (that is, the optical axis of the data acquisition optical system 30 and the optical axis of the first light projection unit 41). It is an image. When the XY alignment is substantially matched, the Purkinje images 202A and 202B are formed on the optical axis of the objective lens 51.

  The expected angle of the anterior eye camera 60A (the angle with respect to the optical axis of the objective lens 51) and the expected angle of the anterior eye camera 60B are each known. Furthermore, the photographing magnification is also known. Therefore, based on the rendering position of an arbitrary object in the captured image 200A and the rendering position of the object in the captured image 200B, the relative position (in real space) of the object with respect to the ophthalmologic apparatus 1 (anterior eye camera 60A and 60B). 3D position) can be obtained (see the description of the position determination unit 140 described later).

  Further, since the anterior eye cameras 60A and 60B are arranged at positions deviating from the optical axis of the objective lens 51, the concentric pattern indices 203A and 203B drawn in the captured images 200A and 200B are detected as ellipses. Is done. In this specification, the index of the concentric circle pattern includes the index (typical actual projection image) of the concentric ellipse pattern. Similarly, the ring pattern index includes an elliptic pattern index (typical actual projection image).

  In this example, the corneal shape information acquisition unit 130 first searches the concentric pattern index 203A by analyzing the captured image 200A. This process includes, for example, a threshold process related to the pixel value of the photographed image 200A for searching for a pixel corresponding to the index 203A (a pixel having higher brightness than the surroundings). Thereby, the index 203A is specified. Depending on the alignment state or the like, there are cases in which not all ring pattern indexes corresponding to a plurality of ring-shaped light sources included in the second light projection unit 42A are specified.

  Once the concentric pattern index 203A is specified, the corneal shape information acquisition unit 130 analyzes the ring pattern index by analyzing at least one of the ring pattern indices included in the index 203A, as in the case of the conventional keratometer and corneal topographer. The diameter (radius, diameter) of the index of is obtained. At this time, the diameter can be obtained for a plurality of directions.

  Further, the cornea shape information acquisition unit 130 obtains an approximate ellipse of the index of the ring pattern, and based on the approximate ellipse, the direction of the strong main meridian, the radius of curvature in the strong main meridian direction, the direction of the weak main meridian, the weak main meridian The radius of curvature in the direction can be obtained. The approximate ellipse is obtained, for example, by fitting a plurality of points on the ring pattern index to a standard ellipse formula using the least square method.

  Another example will be described. Since the expected angles of the anterior eye cameras 60A and 60B are known, the distance between the eye to be examined and the anterior eye cameras 60A and 60B is known, and the corneal curvature radius of the eye to be examined is a predetermined reference value ( Assuming that it is equal to, for example, a standard value), the amount of ellipse (the direction of the strong main meridian, the direction of the weak main meridian, the ellipticity, the eccentricity, the flatness of the indices 203A and 203B projected onto the standard eye to be examined) Parameter values representing the shape of the ellipse, such as the rate) can be obtained in advance.

  The corneal shape information acquisition unit 130 can use the standard elliptical amount acquired in advance in this way. For example, the corneal shape information acquisition unit 130 calculates the amount of ellipse from the concentric pattern index 203A obtained by actually photographing the anterior segment Ea of the eye E, and the difference between the amount of ellipse and the standard amount of ellipse It is possible to obtain corneal shape information of the eye E based on this difference.

  When performing an operation on the ellipse, the center of the ellipse can be obtained from the concentric pattern index 203A, but the bright spot image (Purkinje image) 202A formed by the first light projection unit 41 can also be used as the center of the ellipse. .

  The above processing is an example in the case of obtaining corneal shape information based only on the captured image 200A. By similar processing, corneal shape information can be obtained from the captured image 200B. It is also possible to obtain corneal shape information based on (provisional) corneal shape information based on the captured image 200A and (provisional) corneal shape information based on the captured image 200B. For example, a statistical value (average value or the like) of two provisional corneal shape information may be calculated.

In this example to which the second light projection unit 42A shown in FIG. 4A is applied, the following known ellipse equation can be used: [{(x−x ₀ ) sin θ + (y−y ₀ ) cos θ}. ² / a ² ] + [{(x−x ₀ ) cos θ + (y−y ₀ ) sin θ} ² / b ² ] = 1. This equation represents an ellipse whose axial angle and center position are indefinite, (x ₀ , y ₀ ) being the central coordinates, θ being the axial angle, a being the major axis, and b being the minor axis. When this equation is used, an ellipse can be determined from the coordinates of at least five points on the circumference of the ellipse.

  A case where the second light projection unit 42B illustrated in FIG. 4B is applied will be described. An example of two captured images (anterior segment images) acquired substantially simultaneously by the anterior segment cameras 60A and 60B is shown in FIG. 5B. The captured image 300A is an anterior segment image acquired by the anterior segment camera 60A, and the captured image 300B is an anterior segment image acquired by the anterior segment camera 60B. Here, the captured images 300 </ b> A and 300 </ b> B may be anterior eye image corrected by the image correction unit 120.

  The photographed image 300A is an image obtained by photographing the anterior segment Ea from an oblique direction. The captured image 300A includes a pupil image 301A corresponding to the pupil Ep of the eye E, a bright spot image 302A formed by the first light projection unit 41, and three bright spots formed by the second light projection unit 42B. An image 303A is depicted.

  Similarly, the photographed image 300B is an image obtained by photographing the anterior segment Ea from an oblique direction different from that of the photographed image 300A. The captured image 300B includes a pupil image 301B corresponding to the pupil Ep of the eye E, a bright spot image 302B formed by the first light projection unit 41, and three bright spots formed by the second light projection unit 42B. An image 303B is depicted.

  In this example, the captured images 300A and 300B are acquired by photographing from a direction different from the optical axis of the objective lens 51 (that is, the optical axis of the data acquisition optical system 30 and the optical axis of the first light projection unit 41). It is an image. Further, when the XY alignment is substantially matched, the bright spot images 302A and 302B are formed on the optical axis of the objective lens 51.

  The expected angle of the anterior eye camera 60A, the expected angle of the anterior eye camera 60B, and the imaging magnification are known. Therefore, based on the rendering position of an arbitrary target in the captured image 300A and the rendering position of the target in the captured image 300B, the relative position (in real space) of the target with respect to the ophthalmologic apparatus 1 (anterior eye camera 60A and 60B). 3D position) can be obtained (see the description of the position determination unit 140 described later).

  In this example, the cornea shape information acquisition unit 130 first searches the bright image 302A and the three bright images 303A by analyzing the captured image 300A. This process includes, for example, a threshold process related to the pixel value of the captured image 300A for searching for a pixel corresponding to the bright spot image (a pixel having higher brightness than the surroundings). Thereby, the bright spot image 302A and the three bright spot images 303A are specified.

  The cornea shape information acquisition unit 130 executes a labeling process for the four specified bright spot images 302A and 303A. The labeling process is a process for specifying which of the four light spot images 302A and 303A corresponds to which light source included in the first light projection unit 41 and the second light projection unit 42B. An example of a labeling processing method will be described below. Note that the labeling method is not limited to these examples.

  In the first example of the labeling process, the cornea shape information acquisition unit 130 can give identification information to the bright spot image based on the relative position of the bright spot image with respect to a predetermined position of the image frame of the captured image 300A. . Examples of the predetermined position serving as a reference for this processing include the center, upper end, lower end, left end, and right end of the image frame.

  In the second example of the labeling process, the cornea shape information acquisition unit 130 gives identification information to the bright spot image based on the relative position of the bright spot image with respect to a predetermined part of the eye E to be examined depicted in the captured image 300A. can do. Examples of the predetermined part that becomes the reference of this process include the pupil center (pupil centroid), iris center (iris centroid), and diseased part.

  The third example of the labeling process is applicable when a plurality of bright spot images are drawn on the captured image 300A. The cornea shape information acquisition unit 130 can give identification information to each of the bright spot images based on the positional relationship between the bright spot images drawn in the captured image 300A.

  In the fourth example of the labeling process, the configuration and / or control of the first light projection unit 41 and / or the second light projection unit 42B is used to discriminate different bright spot images. For example, a plurality of different light sources are configured to output light having different characteristics (light quantity, wavelength, etc.). Alternatively, it is configured or controlled so that a plurality of different light sources modulate the intensity (flashing, etc.) at different frequencies.

  When the labeling process is completed, the cornea shape information acquisition unit 130 obtains the cornea shape information of the eye E based on the positions of the four bright spot images 302A and 303A.

In this example to which the second light projection unit 42B shown in FIG. 4B is applied, the following well-known ellipse equation can be used: {(xsin θ + y cos θ) ² / a ² } + {(x cos θ + ysin θ) ² / b ² } = 1. This expression represents an ellipse whose center position is known, where (x ₀ , y ₀ ) = (0, 0) is the center coordinate, θ is the axis angle, a is the major axis, and b is the minor axis. Thus, when the center of the ellipse is specified from the bright spot image 302A, the ellipse can be determined by obtaining three unknowns a, b, and θ from the coordinates of at least three points on the circumference of the ellipse.

  The above processing is an example in the case of obtaining corneal shape information based only on the captured image 300A. Through similar processing, corneal shape information can be obtained from the captured image 300B.

  On the other hand, it is also possible to obtain corneal shape information based on both the captured images 300A and 300B. In that case, for example, for each of the luminescent spot images 302A and 303A, the corneal shape information acquisition unit 130 displays the luminescent spot image in the captured image 300A, the luminescent spot image in the captured image 300B, and the anterior eye The relative position (three-dimensional position in real space) of the bright spot image with respect to the ophthalmologic apparatus 1 can be obtained based on the expected angle of the front camera 60A, the expected angle of the anterior eye camera 60B, and the imaging magnification.

  If any of the four bright spot images 302A and 303A is not detected from the photographed image 300A, after the alignment control unit 111 performs alignment adjustment, the corneal shape information acquisition unit 130 searches the bright spot image again. It can be carried out.

  In this embodiment, parallel light is projected coaxially with the data acquisition optical system 30 and non-parallel light is projected non-coaxially with the data acquisition optical system 30, but the present invention is not limited to this. For example, non-parallel light can be projected coaxially with the data acquisition optical system 30 and parallel light can be projected non-coaxial with the data acquisition optical system 30. Alternatively, both parallel light and non-parallel light can be projected non-coaxially with the data acquisition optical system 30.

  In another embodiment, all the light beams for measuring the corneal shape may be parallel light beams. In this case, since the influence of alignment (particularly Z alignment) on corneal shape measurement is reduced, it is not necessary to correct the corneal shape according to the alignment state.

  A case where the second light projection unit 42C illustrated in FIG. 4C is applied will be described. An example of two captured images (anterior segment images) acquired substantially simultaneously by the anterior segment cameras 60A and 60B is shown in FIG. 5C. The captured image 400A is an anterior segment image acquired by the anterior segment camera 60A, and the captured image 400B is an anterior segment image acquired by the anterior segment camera 60B. Here, the captured images 400 </ b> A and 400 </ b> B may be anterior eye image corrected by the image correction unit 120.

  The photographed image 400A is an image obtained by photographing the anterior segment Ea from an oblique direction. In the captured image 400A, a pupil image 401A corresponding to the pupil Ep of the eye E and five bright spot images 403A formed by the second light projection unit 42C are depicted. In this example, the bright spot image formed by the first light projection unit 41 is not drawn. However, in another example, a bright spot image formed by the first light projection unit 41 can be used.

  Similarly, the captured image 400B is an image obtained by capturing the anterior segment Ea from an oblique direction different from that of the captured image 400A. In the captured image 400B, a pupil image 401B corresponding to the pupil Ep of the eye E and five bright spot images 403B formed by the second light projection unit 42 are depicted.

  In this example, the captured images 400A and 400B are images acquired by photographing from a direction different from the optical axis of the objective lens 51 (that is, the optical axis of the data acquisition optical system 30).

  Since the expected angle of the anterior eye camera 60A, the expected angle of the anterior eye camera 60B, and the imaging magnification are known, the rendering position of an arbitrary target in the captured image 400A and the rendering position of the target in the captured image 400B Based on this, it is possible to obtain the relative position (three-dimensional position in the real space) of the target with respect to the ophthalmologic apparatus 1 (anterior eye camera 60A and 60B) (see the description of the position determination unit 140 described later).

  In this example, the cornea shape information acquisition unit 130 first searches the five bright spot images 403A by analyzing the captured image 400A. This process includes, for example, a threshold process related to the pixel value of the captured image 400A for searching for a pixel corresponding to the bright spot image 403A (a pixel having higher brightness than the surroundings). Thereby, five bright spot images 403A are specified.

  The cornea shape information acquisition unit 130 executes a labeling process for the identified five bright spot images 403A. The labeling process is a process for specifying which light source included in the second light projection unit 42C corresponds to each of the five bright spot images 403A. The labeling process is executed, for example, as described above.

  When the labeling process is completed, the cornea shape information acquisition unit 130 obtains the cornea shape information of the eye E based on the positions of the five bright spot images 403A.

In this example to which the second light projection unit 42C shown in FIG. 4C is applied, the following known ellipse formula is used as in the above example to which the second light projection unit 42A shown in FIG. 4A is applied. Can be: [{(x−x ₀ ) sin θ + (y−y ₀ ) cos θ} ² / a ² ] + [{(x−x ₀ ) cos θ + (y−y ₀ ) sin θ} ² / b ² ] = 1. Thus, when the center of the ellipse cannot be specified from the index, the ellipse can be determined by obtaining five unknowns x ₀ , y ₀ , a, b, θ from the coordinates of at least five points on the circumference of the ellipse.

  The above processing is an example in the case of obtaining corneal shape information based only on the captured image 400A. By similar processing, corneal shape information can be obtained from the captured image 400B. It is also possible to obtain corneal shape information based on both the captured images 400A and 400B. This process is executed, for example, in the same manner as in the above example to which the second light projection unit 42B illustrated in FIG. 4B is applied.

(Position determining unit 140)
The position determination unit 140 is based on the two captured images acquired by the anterior eye cameras 60A and 60B and the corneal shape information obtained by the corneal shape information acquisition unit 130, and the movement target position of the data acquisition optical system 30 To decide. The movement target position is a position representing the movement destination of the data acquisition optical system 30 in the alignment.

  The position determination unit 140 of this embodiment includes a provisional position determination unit 141 and a position correction unit 142.

(Temporary position determination unit 141)
Projected images (Purkinje image, bright spot image) of parallel light formed by the first light projection unit 41 are drawn on the captured images acquired by the anterior eye cameras 60A and 60B. The provisional position determination unit 141 provisionally determines the data acquisition optical system 30 based on the two Purkinje images by the first light projection unit 41 depicted in the two captured images acquired by the anterior eye cameras 60A and 60B. Find the target position.

  The temporary movement target position is a movement target position supplied to the position correction unit 142. In other words, the temporary movement target position is a movement target position at a stage before the final movement target position is obtained by the position correction unit 142.

  The provisional position determination unit 141 analyzes the captured image acquired by the anterior eye camera 60 </ b> A and searches for the Purkinje image by the first light projection unit 41. Similarly, the provisional position determination unit 141 analyzes the captured image acquired by the anterior eye camera 60 </ b> B and searches for the Purkinje image by the first light projection unit 41. When the Purkinje image by the first light projection unit 41 is detected from both captured images, the temporary position determination unit 141 obtains a temporary movement target position based on these Purkinje images. Hereinafter, an example of a series of processes for determining the provisional movement target position will be described.

  The alignment control unit 111 controls the first light projecting unit 41 to project parallel light onto the anterior segment Ea. As a result, a Purkinje image is formed on the optical axis of the data acquisition optical system 30. This Purkinje image is formed at a position displaced in the axial direction (Z direction) from the apex of the cornea by a distance that is a half of the radius of curvature of the cornea. In a standard living eye, the corneal curvature radius is about 7.8 to 8.0 millimeters, and the Purkinje image is formed at a position displaced about 3.9 to 4.0 millimeters from the apex of the cornea to the retinal side. The provisional position determination unit 141 obtains a provisional movement target position with reference to standard corneal shape information. In this example, the standard value of the corneal curvature radius is 8 mm, which is referred to.

  The anterior segment Ea on which the parallel light is projected is photographed substantially simultaneously by the two anterior segment cameras 60A and 60B. Two captured images acquired substantially simultaneously by the two anterior eye cameras 60 </ b> A and 60 </ b> B are corrected by the image correction unit 120 as necessary and input to the provisional position determination unit 141.

  The provisional position determination unit 141 searches for a Purkinje image by the first light projection unit 41 by analyzing each of the two captured images. This search processing includes threshold processing related to pixel values for detecting pixels (high luminance pixels) corresponding to Purkinje images, for example, as in the prior art.

  The provisional position determination unit 141 can obtain the position of the representative point in the image area detected as the Purkinje image. The representative point may be, for example, the center point or barycentric point of the image area. In this case, the temporary position determination unit 141 is configured to execute, for example, a process for obtaining an approximate circle or an ellipse around the periphery of the image area and a process for obtaining the center of the approximate circle or the approximate ellipse. Alternatively, the provisional position determination unit 141 determines a pixel having a pixel value (brightness value) exceeding a threshold from the pixels in the image area, and obtains the center of gravity position of the specified one or more pixels. Processing may be performed.

  When the position of the Purkinje image in each of the two captured images acquired by the anterior eye cameras 60A and 60B is specified, the provisional position determination unit 141 obtains a provisional movement target position based on the positions of these Purkinje images. . The provisional movement target position includes, for example, a position in the X direction (X coordinate value), a position in the Y direction (Y coordinate value), and a position in the Z direction (Z coordinate value). The temporary movement target position may include any one or more of the X coordinate value, the Y coordinate value, and the Z coordinate value. Further, the temporary movement target position may be defined using a coordinate system other than the three-dimensional orthogonal coordinate system (XYZ coordinate system).

  As described above, the provisional position determination unit 141 identifies the Purkinje image from each of the two captured images acquired substantially simultaneously. Examples of these captured images (anterior segment image) are shown in FIGS. 5A to 5C. For example, the captured image 200A illustrated in FIG. 5A is an anterior segment image acquired by the anterior segment camera 60A. The provisional position determination unit 141 analyzes the captured image 200A and identifies the Purkinje image 202A. Similarly, the photographed image 200B is an anterior segment image acquired by the anterior segment camera 60B. The provisional position determination unit 141 analyzes the captured image 200B and identifies the Purkinje image 202B.

  As described above, the expected angles of the anterior eye cameras 60A and 60B are known, and the imaging magnification is also known. The provisional position determination unit 141 is configured so that the Purkinje image is relative to the ophthalmologic apparatus 1 (anterior eye cameras 60A and 60B) based on the position of the Purkinje image 202A in the photographed image 200A and the position of the Purkinje image 202B in the photographed image 200B. A position (a three-dimensional position in real space) can be obtained. This process will be described with reference to FIG.

  The distance (base line length) between the two anterior eye cameras 60A and 60B is represented by “B”. A distance (photographing distance) between the base line connecting the two anterior eye cameras 60A and 60B and the Purkinje image P formed on the anterior eye part Ea is represented by “H”. Further, the distance (screen distance) between the anterior eye camera 60A and the screen plane is represented by “f”. Similarly, the distance between the anterior eye camera 60B and its screen plane is also represented by “f”.

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

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

  The provisional position determination unit 141 has an arrangement relationship (probability) shown in FIG. 3 with respect to the positions (known) of the two anterior eye cameras 60A and 60B and the position corresponding to the Purkinje image P in the two captured images. The three-dimensional position of the Purkinje image P is calculated by applying a known trigonometric method that takes into account corners and the like.

(Position correction unit 142)
The position correction unit 142 corrects the temporary movement target position obtained by the temporary position determination unit 141 based on the cornea shape information acquired by the cornea shape information acquisition unit 130. Thereby, the movement target position which is a processing result of the position determination part 140 is obtained.

An example of processing executed by the position correction unit 142 will be described with reference to FIG. FIG. 6 shows three cases (1) to (3). Here, the corneal curvature radius included in the corneal shape information acquired by the corneal shape information acquisition unit 130 is represented by r, and the standard value (for example, 8 mm) of the corneal curvature radius is represented by “r ₀ ”. Further, the optical axis of the data acquisition optical system 30 is denoted by reference numeral “30a”. Reference numeral “51” denotes an objective lens.

  The standard value does not have to be a single value, and may be a section (that is, a range) of values of the corneal curvature radius. This section is, for example, a connected section, and is a closed section or an open section.

Case (1) is a case where the corneal curvature radius r = r _{1 of the} eye E is smaller than the standard value r ₀ . Alternatively, Case (1) is a case where the corneal curvature radius r = r _{1 of the} eye E is smaller than an arbitrary value included in the standard section. Case (2) is a case corneal curvature radius r of the eye E is equal to the standard value r _0. Alternatively, Case (2) is a case where the cornea curvature radius r of the eye E is included in the standard section. Case (3) is a case where the corneal curvature radius r = r _{2 of the} eye E is larger than the standard value r ₀ . Alternatively, Case (3) is a case where the corneal curvature radius r = r _{2 of the} eye E is larger than an arbitrary value included in the standard section. Hereinafter, although the case where the standard value r ₀ is a single value will be described, the same processing can be executed when the standard interval is applied.

First, the standard case (2) will be described. As described above, Case (2) is a case where the corneal curvature radius r of the eye E is equal to the standard value r ₀ (r = r ₀ ). The Purkinje image formed in this case is indicated by “P ₀ ”.

In the conventional alignment, the objective lens 51 is arranged at a position deviated by a predetermined working distance WD in the −Z direction from the corneal apex position L of the eye E based on the Purkinje image P ₀ . At this time, under the assumption that the first distance (r _0/2) by the corneal apex from Purkinje image P ₀ in a position offset in the -Z direction of the half of the corneal curvature radius r = r ₀ is located The position displaced from the corneal apex position L by the working distance WD in the −Z direction is set as the movement target position. In this embodiment, the distance a position offset from the "r _0/2 + WD" only Purkinje image P ₀ in the -Z direction is set to the provisional movement target position.

Next, the case (1) will be described. As described above, the case (1) is a case where the corneal curvature radius r = r _{1 of the} eye E is smaller than the standard value r ₀ (r = r ₁ <r ₀ ). The Purkinje image formed in this case is indicated by “P ₁ ”.

The conventional alignment, it does not take into account the individual differences in corneal shape, the distance "r _0/2 + WD" only from the Purkinje image P ₁ and offset in the -Z direction position is set to the moving target position. Therefore, the distance between the corneal apex position L and the objective lens 51, only [Delta] Z ₁ is longer than the working distance WD. Here, ΔZ ₁ is substantially equal to “(r ₀ −r ₁ ) / 2”. In this embodiment, the distance "r _0/2 + WD" only from the Purkinje image P ₁ and offset in the -Z direction position is set to the interim movement target position.

Next, the case (3) will be described. As described above, the case (3) is a case where the corneal curvature radius r = r _{2 of the} eye E is larger than the standard value r ₀ (r = r ₂ > r ₀ ). The Purkinje image formed in this case is indicated by “P ₂ ”.

The conventional alignment, it does not take into account the individual differences in corneal shape, the distance "r _0/2 + WD" only from the Purkinje image P ₂ has been displaced in the -Z direction position is set to the moving target position. Therefore, the distance between the corneal apex position L and the objective lens 51, only [Delta] Z ₂ is shorter than the working distance WD. Here, ΔZ ₂ is substantially equal to “(r ₂ −r ₀ ) / 2”. In this embodiment, the distance "r _0/2 + WD" only from the Purkinje image P ₂ has been displaced in the -Z direction position is set to the interim movement target position.

Position correcting unit 142 compares corneal shape information corneal shape information acquired by the acquisition section 130 and (corneal radius of curvature r) and the standard value r _0.

When it is determined that the corneal curvature radius r is equal to the standard value r ₀ (that is, in the case (2)), the position correction unit 142 determines the temporary movement target position (determined by the temporary position determination unit 141 ( no correction for distance _"r 0/2 + WD" just offset from the Purkinje image _{P 0} in the -Z direction position). That is, when the corneal curvature radius r is determined to be equal to the standard value r _0, provisional movement target position is set as the movement target position. It is possible to correct the temporary movement target position according to conditions different from the corneal shape information.

When it is determined that the corneal curvature radius r is smaller than the standard value r ₀ (that is, in the case (1)), the position correction unit 142 determines the temporary movement target position obtained by the temporary position determination unit 141. (distance _"r 0/2 + WD" only from the Purkinje image _{P 1} and offset in the -Z direction position) corrected. Specifically, the position correction unit 142 sets a position displaced by ΔZ ₁ (= (r ₀ −r ₁ ) / 2) in the + Z direction from the provisional movement target position as the movement target position. Thereby, a position substantially separated from the corneal apex position L by the working distance WD is set as the movement target position.

When it is determined that the corneal curvature radius r is larger than the standard value r ₀ (that is, in the case (3)), the position correction unit 142 determines the provisional movement target position obtained by the provisional position determination unit 141. (distance _"r 0/2 + WD" only from the Purkinje image _{P 2} has been displaced in the -Z direction position) corrected. Specifically, the position correction unit 142 sets a position displaced by ΔZ ₂ (= (r ₂ −r ₀ ) / 2) in the + Z direction from the temporary movement target position as the movement target position. Thereby, a position substantially separated from the corneal apex position L by the working distance WD is set as the movement target position.

  As described above, in the conventional alignment, an error occurs in the movement target position (particularly, the Z alignment movement target position) due to individual differences in the corneal shape. However, according to the correction processing of this embodiment, the individual differences in corneal shape are affected. Instead, the data acquisition optical system 30 can be arranged at a position away from the corneal apex position L of the eye E by a working distance WD.

(Pupil position acquisition unit 150)
The pupil position acquisition unit 150 analyzes each of the two captured images acquired by the anterior eye cameras 60A and 60B and searches for a pupil image. When a pupil image is detected from both captured images, the pupil position acquisition unit 150 obtains the three-dimensional position of the pupil Ep of the eye E.

  The pupil position acquisition unit 150 includes a pupil image detection unit 151 and a pupil position calculation unit 152.

(Pupil image detection unit 151)
The pupil image detection unit 151 detects an image region (pupil image) in the captured image corresponding to the pupil Ep of the eye E by analyzing the captured image (the distortion of which has been corrected by the image correcting unit 120). To do.

  First, the pupil image detection unit 151 specifies a pupil image based on the distribution of pixel values (such as luminance values) of the captured image. In general, since the pupil is expressed with a lower luminance than other parts, the pupil image can be specified by searching for a low luminance image region. At this time, the pupil image may be specified in consideration of the shape of the pupil. For example, a pupil image can be detected by searching for a substantially circular and low-brightness image region.

(Pupil position calculator 152)
The pupil position calculation unit 152 obtains the three-dimensional position of the pupil Ep of the eye E based on the pupil image detected by the pupil image detection unit 151. In this example, the three-dimensional position of the pupil center of the eye E is obtained as the three-dimensional position of the eye E. Note that the definition of the three-dimensional position of the eye E is not limited to this. For example, the three-dimensional position of the eye E can be defined by the positions of arbitrary feature points such as the pupil center of gravity, iris center, iris center of gravity, and diseased part.

  The pupil position calculation unit 152 specifies the center position of the pupil image detected by the pupil image detection unit 151. Since the pupil is substantially circular as described above, the contour of the pupil image can be detected, the center position of the approximate ellipse of this contour can be specified, and this can be set as the pupil center. Further, the center of gravity of the pupil image may be obtained, and the position of the center of gravity may be used as the center of the pupil.

  Even when other feature points are applied, the position of the feature points can be specified based on the distribution of pixel values of the captured image as described above.

  Further, the pupil position calculation unit 152 is based on the positions (expected angles) of the two anterior eye cameras 60A and 60B, the imaging magnification, and the positions of the two pupil centers detected from the two captured images. The three-dimensional position of the pupil center of the optometry E is obtained. This process can be executed in the same manner as the specification of the three-dimensional position of the Purkinje image (see FIG. 3).

  The data processing unit 12 includes, for example, a processor, a RAM, a ROM, a hard disk drive, and the like. A storage device such as a hard disk drive stores in advance a computer program that causes the processor to execute the above-described processing.

<Operation>
The operation of the ophthalmologic apparatus 1 will be described. An operation example of the ophthalmologic apparatus 1 is shown in FIGS. 7A and 7B. In addition, input of patient information (patient ID, patient name, etc.) of the subject, selection of examination type (examination mode), and the like are performed in advance. Hereinafter, operations related to alignment will be mainly described.

(S1: Start projection of parallel light)
The alignment control unit 111 controls the first light projection unit 41 to output parallel light. Thereby, parallel light is projected onto the anterior segment Ea.

  Further, at this stage, the alignment control unit 111 may control the second light projection unit 42 to output non-parallel light. Thereby, non-parallel light is projected on the anterior segment Ea.

(S2: Start photographing with the anterior segment camera)
The alignment controller 111 controls the anterior eye cameras 60A and 60B to start photographing the anterior eye part Ea.

  Each of the anterior eye cameras 60 </ b> A and 60 </ b> B repeats image acquisition at predetermined time intervals, and sequentially sends the acquired captured images to the control unit 11. The alignment control unit 111 sequentially sends a pair of captured images (anterior segment images) acquired substantially simultaneously by the anterior segment cameras 60 </ b> A and 60 </ b> B to the data processing unit 12.

  The data processing unit 12 sequentially applies the following processing to a pair of anterior segment images that are sequentially input. Although optional, the image correction unit 120 can correct distortion of the anterior segment image based on the aberration information.

(S3: Purkinje image is detected)
The provisional position determination unit 141 analyzes the anterior segment image (corrected for distortion) in order to identify the Purkinje image based on the first light projection unit 41.

  If projection of non-parallel light has not been started by this stage, the Purkinje image based on the first light projection unit 41 is detected as a single bright spot in the anterior segment image.

  On the other hand, when projection of non-parallel light is started by this stage, the Purkinje image based on the first light projection unit 41 is detected as a bright spot located at or near the center position of the anterior segment image. . At this time, for example, based on the positional relationship of the plurality of indices in the anterior segment image, the relative position with respect to the predetermined position of the image frame, or the relative position with respect to the image of the predetermined part of the eye E, among the plurality of indices. A Purkinje image may be selected.

(S4: Was the Purkinje image detected successfully?)
When the Purkinje image based on the first light projection unit 41 is detected from the anterior segment image (for example, when the Purkinje image is detected from both of the pair of anterior segment images) (S4: Yes), the process is step S5. Migrate to In this case, the provisional position determination unit 141 can specify a representative point in the Purkinje image based on the first light projection unit 41 and obtain the position.

  When the Purkinje image based on the first light projection unit 41 is not detected from the anterior segment image (for example, when the Purkinje image is not detected from at least one of the pair of anterior segment images) (S4: No), processing Moves to step S10.

(S5: A temporary movement target position is determined)
In step S4, when a Purkinje image based on the first light projection unit 41 is detected from the anterior eye image (S4: Yes), the temporary position determination unit 141 determines the temporary movement target position based on the detected Purkinje image. Ask for. In this example, the provisional position determination unit 141 is a three-dimensional Purkinje image based on the first light projection unit 41 formed on the anterior segment Ea based on the pair of Purkinje images detected from the pair of anterior segment images. The position (X coordinate value, Y coordinate value, Z coordinate value) can be obtained. The obtained X coordinate value and Y coordinate value are used as the temporary movement target position as they are.

Further, the provisional position determination unit 141 is based on the Z-coordinate value of the Purkinje image based on the first light projection unit 41, a predetermined working distance (WD), and a standard value (r ₀ ) of a predetermined corneal curvature radius. Then, the Z coordinate value of the temporary movement target position is obtained (see FIG. 6). Thereby, a three-dimensional coordinate value representing the provisional movement target position is obtained.

(S6: Move the optical system to the temporary movement target position)
The alignment control unit 111 moves the optical axis of the objective lens 51 (the optical axis of the data acquisition optical system 30) to the position represented by the X coordinate value and the Y coordinate value of the provisional movement target position obtained in step S5. In addition, the first drive unit 80A is controlled.

  Furthermore, the alignment control unit 111 sets the first driving unit 80A so that the objective lens 51 (data acquisition optical system 30) is arranged at the position represented by the Z coordinate value of the temporary movement target position obtained in step S5. Control.

(S7: Was provisional alignment completed?)
Steps S3 to S7 are repeatedly executed until the provisional alignment in step S6 is completed. This series of operations is repeated until, for example, the optical axis of the data acquisition optical system 30 falls within a predetermined allowable range.

  When the provisional alignment in step S6 is completed (S7: Yes), the process proceeds to step S20.

(S10: detect pupil image)
In step S4, when the Purkinje image based on the first light projection unit 41 is not detected from the anterior ocular segment image (S4: No), the pupil image detection unit 1511 detects (distortion is corrected) in order to detect the pupil image. Analyze the anterior segment image).

(S11: Has the pupil image been successfully detected?)
When a pupil image is detected from the anterior segment image (for example, when a pupil image is detected from both of the pair of anterior segment images) (S11: Yes), the process proceeds to step S12.

  On the other hand, when no pupil image is detected from the anterior segment image (for example, when no pupil image is detected from at least one of the pair of anterior segment images) (S11: No), the process proceeds to step S13. .

(S12: Perform pupil alignment)
When a pupil image is detected from the anterior eye image (S11: Yes), the pupil position calculation unit 152 obtains the position of the pupil Ep of the eye E based on the detected pupil image. In this example, the pupil position calculation unit 152, based on a pair of pupil images (a pair of pupil centers) detected from a pair of anterior eye image, a three-dimensional position (X coordinate value, Y coordinate value and Z coordinate value) are obtained.

The alignment control unit 111 controls the first drive unit 80A so that the optical axis of the objective lens 51 is arranged at a position corresponding to the X coordinate value and the Y coordinate value of the pupil center obtained by the pupil position calculation unit 152. To do. Furthermore, the alignment control unit 111 has the objective lens 51 (data acquisition optical system) at a position corresponding to the Z coordinate value of the pupil center, the predetermined working distance (WD), and the standard value of the predetermined corneal curvature radius (r ₀ ). 30A is controlled to control the first drive unit 80A. When such pupil alignment is completed, the process returns to step S3.

(S13: Perform manual alignment)
When no pupil image is detected from the anterior eye image (S11: No), the alignment mode is switched to the manual alignment mode.

  In the manual alignment mode, the alignment control unit 111 receives the anterior segment image acquired by the anterior segment camera 60A and / or 60B (or the observation image of the anterior segment Ea acquired by the data acquisition optical system 30 or the like). And displayed as a moving image in real time on the display unit 91.

  The user operates the operation unit 92 in order to move the data acquisition optical system 30. At this time, the alignment control unit 111 controls the first drive unit 80 </ b> A according to the operation signal input from the operation unit 92. When manual alignment is completed, the process returns to step S3.

(S20: An index is detected)
When the provisional alignment in step S6 is completed (S7: Yes), the cornea shape information acquisition unit 130 analyzes the pair of captured images acquired by the anterior eye cameras 60A and 60B after the provisional alignment is completed. Thus, an index based on the second light projection unit 42 is detected. At this time, an index based on the first light projection unit 41 may be further detected. Here, the captured image may have been corrected by the image correction unit 120.

  For example, when the captured image illustrated in FIG. 5A or 5B is obtained, both the index based on the first light projection unit 41 and the index based on the second light projection unit 42 can be detected. Further, when the captured image shown in FIG. 5A or 5C is obtained, only the index based on the second light projection unit 42 can be detected.

  In addition, when the output of the finite distance target light (non-parallel light) from the 2nd light projection part 42 is not started by this stage, the alignment control part 111 controls the 2nd light projection part 42, and is finite. The distance target light (non-parallel light) is output. Thereafter, a pair of captured images acquired by the anterior eye cameras 60A and 60B is provided to the corneal shape information acquisition unit 130, and an index based on the second light projection unit 42 is detected.

(S21: Find corneal shape information)
The corneal shape information acquisition unit 130 obtains corneal shape information of the eye E based on the index detected in step S20. In this example, the corneal shape information includes a corneal curvature radius r. However, parameters other than the corneal curvature radius r can be used in the following processing.

(S22: Is it necessary to correct the temporary movement target position?)
The position correction unit 142 determines whether or not the temporary movement target position needs to be corrected based on the corneal curvature radius r calculated in step S21.

For example, the position correction unit 142 compares the corneal curvature radius r of the eye E with the standard value r ₀ (or standard interval). When the corneal curvature radius r is equal to the standard value r ₀ (or, if the corneal radius of curvature r is included in the standard section), the position correcting unit 142, the correction is determined unnecessary (S22: No). This determination result corresponds to case (2) in FIG. If it is determined that correction is unnecessary, the process proceeds to step S25.

On the other hand, when the corneal curvature radius r is not equal to the standard value r ₀ (or, if the corneal radius of curvature r is not included in the standard section), the position correction unit 142 determines the necessary correction (S22: Yes). This determination result corresponds to case (1) or (3) in FIG. If it is determined that correction is necessary, the process proceeds to step S23.

(S23: Calculate the correction amount)
If it is determined that correction is necessary (S22: Yes), the position correction unit 142 corrects the position (temporary movement target position) of the data acquisition optical system 30 based on the corneal curvature radius calculated in step S21. . The correction amount is, for example, as shown in FIG. 6, in the case of the case (1) is "[Delta] Z _1", in the case of the case (3) is a "[Delta] Z _2". Thereby, the final movement target position is determined.

(S24: Correct the position of the optical system)
The alignment control unit 111 controls the first drive unit 80A so as to move the data acquisition optical system 30 by the correction amount calculated in step S23. Thereby, the data acquisition optical system 30 is arranged at a position away from the corneal apex position L of the eye E by the working distance WD.

(S25: Measurement / imaging of eye to be examined)
When the correction of the alignment position in step S24 is completed, the control unit 11 controls the data acquisition optical system 30 to execute the measurement of the characteristics of the eye E and / or the imaging of the eye E. The UI control unit 112 causes the display unit 91 to display measurement data and / or captured images acquired by the data acquisition optical system 30. Moreover, the control part 11 can memorize | store measurement data and / or a picked-up image in a memory | storage device. This is the end of the process related to the operation in this example.

  Note that, instead of moving the data acquisition optical system 30 in step S24, a correction corresponding to the movement amount may be applied to the measurement result (measured value of the characteristic of the eye E). Further, the movement of the data acquisition optical system 30 and the correction of the measurement result may be combined.

<Action and effect>
Several actions and effects of the ophthalmologic apparatus according to the embodiment will be described.

  The ophthalmologic apparatus according to the embodiment includes a data acquisition optical system, a projection unit, two or more imaging units, a corneal shape information acquisition unit, and a position determination unit.

  The data acquisition optical system has a configuration for acquiring data of the eye to be examined. In the exemplary ophthalmic apparatus 1, the data acquisition optical system 30 has the function.

  The projection unit has a configuration for projecting an index including at least one of a predetermined continuous pattern and a predetermined discrete pattern onto the anterior eye portion of the eye to be examined. In the exemplary ophthalmic apparatus 1, the first light projection unit 41 and the second light projection unit 42 have the function.

  The two or more photographing units have a configuration for photographing the anterior segment where the index is projected by the projection unit from different directions. In the exemplary ophthalmic apparatus 1, the anterior eye cameras 60 </ b> A and 60 </ b> B have the function.

  The corneal shape information acquisition unit has a configuration for obtaining corneal shape information of the eye to be inspected based on at least one of two or more first captured images acquired by two or more imaging units. In the exemplary ophthalmologic apparatus 1, the cornea shape information acquisition unit 130 has the function.

  The position determination unit has a configuration for determining a movement target position of the data acquisition optical system based on two or more second captured images and corneal shape information acquired by two or more imaging units. In the exemplary ophthalmic apparatus 1, the position determination unit 140 has the function. The second captured image may be the same image as the first captured image, or may be an image different from the first captured image.

  According to the embodiment configured as described above, the movement target position (alignment target position) of the data acquisition optical system can be determined in consideration of the shape of the cornea of the eye to be examined. Therefore, it is possible to perform alignment with high accuracy regardless of individual differences in corneal shape.

  Such an advantage seems to be particularly effective in an ophthalmic apparatus that requires high-precision alignment such as a tonometer or a specular microscope. This advantage is also effective in other types of ophthalmologic apparatuses.

  In the embodiment, the index pattern projected by the projection unit is arbitrary. For example, in the embodiment, the projection unit may be configured to project a ring pattern or a concentric pattern index onto the anterior eye part as a continuous pattern index. As an example, there is a concentric pattern index 203A shown in FIG. 5A.

  Furthermore, the projection unit may be configured to project a ring pattern index and a central bright spot located at the center of the ring pattern onto the anterior eye segment. The projection unit may be configured to project the concentric pattern index and the central bright spot located at the center of the concentric pattern onto the anterior segment. Examples thereof include a concentric pattern index 203A and a bright spot image (Purkinje image) 202A shown in FIG. 5A.

  In the embodiment, the projection unit is configured to project three or more bright spots arranged on a circle and a central bright spot located at the center of the circle onto the anterior eye portion as an index of a discrete pattern. May be. As an example, there are three bright spot images 303A and 302A shown in FIG. 5B.

  In the embodiment, the projection unit may be configured to project five or more bright spots arranged on a circle onto the anterior eye part as a discrete pattern index. As an example, there are five bright spot images 403A shown in FIG. 5C.

  In the embodiment, the projection unit may be configured to project the central bright spot onto the anterior segment by projecting a light beam through the optical path of the data acquisition optical system. As an example, there is a first light projection unit 41 that projects a light beam to the anterior eye part Ea through the optical path of the data acquisition optical system 30.

  In the embodiment, the projection unit may include a non-parallel light projection unit that projects non-parallel light to the anterior segment. In the exemplary ophthalmic apparatus 1, the second light projection unit 42 has the function.

  Furthermore, the corneal shape information acquisition unit may be configured to obtain corneal shape information based on at least a projection image of non-parallel light drawn in the first captured image. For example, the corneal shape information acquisition unit may be configured to obtain corneal shape information based only on the projection image of non-parallel light depicted in the first captured image. Alternatively, the corneal shape information acquisition unit may be configured to obtain corneal shape information based on the projection image of non-parallel light and the projection image of parallel light drawn in the first captured image.

  In the embodiment, the projection unit may include a parallel light projection unit that projects parallel light onto the anterior segment. In the exemplary ophthalmic apparatus 1, the first light projection unit 41 has the function.

  Further, the position determination unit may include a provisional position determination unit and a position correction unit.

  The provisional position determination unit has a configuration for obtaining a provisional movement target position of the data acquisition optical system based on projection images of parallel light depicted in two or more second captured images. In the exemplary ophthalmic apparatus 1, the provisional position determination unit 141 has the function.

  The position correction unit has a configuration for correcting the temporary movement target position determined by the temporary position determination unit based on the cornea shape information acquired by the cornea shape information acquisition unit. In the exemplary ophthalmic apparatus 1, the position correction unit 142 has the function.

  According to the embodiment configured as described above, alignment using a parallel light projection image (Purkinje image) projected by the parallel light projection unit is possible. In this alignment, the provisional movement target position obtained from the Purkinje image that is not affected by the alignment state in the Z direction can be corrected according to the corneal shape of the eye to be examined. Therefore, individual differences in corneal shape do not adversely affect alignment accuracy.

  The ophthalmologic apparatus according to the embodiment may include a drive unit that moves the data acquisition optical system and a control unit. Here, the drive unit may be configured to relatively move the eye to be examined and the data acquisition optical system. In the exemplary ophthalmologic apparatus 1, the first drive unit 80 </ b> A and / or the second drive unit 80 serves as a drive unit. In the exemplary ophthalmologic apparatus 1, the control unit 11 (particularly the alignment control unit 111) serves as a control unit.

  The control unit performs the first control of the drive unit to move the data acquisition optical system to the temporary movement target position determined by the temporary position determination unit.

  After the first control of the drive unit, an image of the anterior segment by two or more imaging units is obtained. The corneal shape information acquisition unit obtains corneal shape information based on two or more first captured images acquired by two or more imaging units after the first control of the driving unit.

  Based on the corneal shape information obtained from the two or more first captured images acquired after the first control of the drive unit, the position correction unit determines a movement target position of the data acquisition optical system.

  In order to move the data acquisition optical system from the temporary movement target position determined by the temporary position determination unit to the movement target position determined by the position correction unit, the control unit executes the second control of the driving unit.

  According to the embodiment configured as described above, the data acquisition optical system is moved to the provisional movement target position based on the Purkinje image based on the parallel light, and thereafter, two or more anterior segment images are acquired, and these The corneal shape information of the eye to be examined can be acquired based on the anterior segment image, and the position of the data acquisition optical system can be corrected based on the corneal shape information.

  According to such a series of processes, corneal shape information is obtained from two or more anterior segment images acquired after alignment based on a Purkinje image based on parallel light. Can be easily obtained.

  For example, when non-parallel light is projected onto the anterior eye part in order to acquire corneal shape information, the position and size of the projection image of the non-parallel light is relative to the subject eye and the imaging part (in other words, alignment It changes according to the state. For this reason, errors are likely to be mixed in the processing for obtaining corneal shape information from the projection image of non-parallel light.

  On the other hand, in this embodiment, after adjusting the positional relationship between the eye to be examined and the imaging unit, two or more anterior segment images are acquired, and corneal shape information is obtained based on them. Therefore, the possibility of errors being mixed can be reduced. In addition, since the influence of the uncertainty of the positional relationship between the eye to be examined and the imaging unit on the position of the projected image based on non-parallel light is reduced, simplification of the algorithm for calculating the corneal shape information and computation Processing time can be shortened.

  In the embodiment, the provisional position determination unit analyzes the two or more second captured images acquired by the two or more imaging units to search for a parallel light projection image, and when the parallel light projection image is detected, The provisional movement target position may be obtained.

  On the other hand, when a projection image is not detected, the pupil position acquisition unit can search for a pupil image by analyzing two or more third captured images acquired by two or more imaging units. When a pupil image is detected, the pupil position acquisition unit can determine the three-dimensional position of the pupil of the eye to be examined. In the exemplary ophthalmic apparatus 1, the pupil position acquisition unit 150 has the function.

  The control unit can execute the third control of the drive unit in order to move the data acquisition optical system to a position corresponding to the three-dimensional position of the pupil of the eye to be examined obtained by the pupil position acquisition unit.

  Furthermore, the temporary position determination unit can search again for the projection image of the parallel light by analyzing two or more captured images acquired by the two or more imaging units after the third control of the driving unit.

  According to the embodiment configured as described above, when the Purkinje image based on the parallel light is not detected, the alignment based on the pupil can be executed, and the Purkinje image based on the parallel light can be searched again. Therefore, alignment based on the Purkinje image based on parallel light can be performed more reliably.

  The ophthalmologic apparatus according to the embodiment may include an observation image acquisition unit that acquires an observation image of the anterior segment and an operation unit. In the exemplary ophthalmologic apparatus 1, at least one of the anterior eye cameras 60 </ b> A and 60 </ b> B functions as an observation image acquisition unit. Note that the observation image acquisition unit may be included in the data acquisition optical system 30 or provided coaxially with the data acquisition optical system 30. In the exemplary ophthalmologic apparatus 1, the operation unit 92 has the function of the operation unit.

  When the pupil image is not detected by the pupil position acquisition unit, the control unit can display the observation image acquired by the observation image acquisition unit on the display unit. Furthermore, the control unit can control the drive unit according to an operation performed by the user using the operation unit. That is, the user can arbitrarily move the data acquisition optical system.

  In the exemplary ophthalmic apparatus 1, the display unit 91 functions as a display unit. The display means may be included in the ophthalmologic apparatus or a peripheral device connected to the ophthalmologic apparatus.

  The provisional position determination unit can search again for the projected image of the parallel light by analyzing two or more captured images acquired by the two or more imaging units after the movement operation of the data acquisition optical system.

  According to the embodiment configured as described above, when the pupil image is not found, the user can manually perform alignment, and after that, the Purkinje image based on the parallel light can be searched again. Therefore, alignment based on the Purkinje image based on parallel light can be performed more reliably.

  The ophthalmologic apparatus according to the embodiment includes a projection unit, two or more imaging units, and a corneal shape information acquisition unit. The projection unit has a configuration for projecting an index including at least one of a predetermined continuous pattern and a predetermined discrete pattern onto the anterior eye portion of the eye to be examined. In the exemplary ophthalmic apparatus 1, the first light projection unit 41 and the second light projection unit 42 have the function. The two or more photographing units are configured to photograph the anterior segment where the index is projected by the projection system from different directions. In the exemplary ophthalmic apparatus 1, the anterior eye cameras 60 </ b> A and 60 </ b> B have the function. The corneal shape information acquisition unit obtains corneal shape information of the eye to be inspected based on one or more captured images acquired by one or more imaging units in which the anterior segment is imaged from an oblique direction among the two or more imaging units. It is configured. In the exemplary ophthalmologic apparatus 1, the cornea shape information acquisition unit 130 has the function. In the exemplary ophthalmologic apparatus 1, both the anterior eye cameras 60A and 60B are arranged at positions where the anterior eye part can be photographed from an oblique direction. It is not limited to. For example, one of the two or more photographing units is arranged at a position where the anterior eye part can be photographed from the front, and one or more other photographing parts are arranged at a position where the anterior eye part can be photographed from an oblique direction. May have been.

  According to the embodiment configured as described above, it is possible to perform anterior segment imaging for acquiring corneal shape information using at least one of two or more imaging units that can also be used for alignment or the like. it can. Therefore, there is no need to provide an optical system for photographing the anterior segment from the front as in the prior art. Therefore, the configuration of the ophthalmic apparatus can be simplified and the cost can be reduced.

  The computer program for realizing the processing according to the embodiment can be stored in any recording medium readable by the computer. Examples of the recording medium include a semiconductor memory, an optical disk, a magneto-optical disk (CD-ROM / DVD-RAM / DVD-ROM / MO, etc.), a magnetic storage medium (hard disk / floppy (registered trademark) disk / ZIP, etc.), and the like. Can be used.

  It is also possible to send and receive computer programs via a network such as the Internet or a LAN.

  The aspects described above are merely examples for carrying out the present invention. A person who intends to implement the present invention can make arbitrary modifications (omission, replacement, addition, etc.) within the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Ophthalmology apparatus 11 Control part 111 Alignment control part 12 Data processing part 130 Corneal shape information acquisition part 140 Position determination part 141 Provisional position determination part 142 Position correction part 150 Pupil position acquisition part 30 Data acquisition optical system 41 1st light projection part 42 , 42A, 42B, 42C Second light projection unit 60, 60A, 60B Anterior eye camera 80A First drive unit 91 Display unit 92 Operation unit E Eye Ea to be examined

Claims (13)

A data acquisition optical system for acquiring data of the eye to be examined;
A projection unit that projects an index including at least one of a predetermined continuous pattern and a predetermined discrete pattern onto the anterior segment of the eye;
Two or more imaging units that image the anterior segment on which the index is projected from different directions;
A corneal shape information acquisition unit that obtains corneal shape information of the eye based on at least one of the two or more first captured images acquired by the two or more imaging units;
An ophthalmologic apparatus comprising: a position determination unit that determines a movement target position of the data acquisition optical system based on two or more second captured images acquired by the two or more imaging units and the corneal shape information. The ophthalmic apparatus according to claim 1, wherein the projection unit projects a ring pattern or a concentric pattern index onto the anterior eye part as the continuous pattern index. The ophthalmologic apparatus according to claim 2, wherein the projection unit projects an index of the ring pattern and a central bright spot located at the center of the ring pattern onto the anterior segment. The ophthalmologic apparatus according to claim 2, wherein the projection unit projects an index of the concentric circle pattern and a central bright spot located at the center of the concentric circle pattern onto the anterior segment. The projection unit projects three or more bright spots arranged on a circle and a central bright spot located at the center of the circle onto the anterior eye segment as an index of the discrete pattern. The ophthalmic apparatus according to claim 1. The ophthalmologic apparatus according to claim 1, wherein the projection unit projects five or more bright spots arranged on a circle onto the anterior eye portion as an index of the discrete pattern. The ophthalmologic apparatus according to claim 3, wherein the projection unit projects the central luminescent spot onto the anterior segment by projecting a light beam through an optical path of the data acquisition optical system. . The projection unit includes a non-parallel light projection unit that projects non-parallel light to the anterior eye unit,
The corneal shape information acquisition unit obtains the corneal shape information based on at least a projection image of the non-parallel light depicted in the first photographed image. Ophthalmic equipment. The projection unit includes a parallel light projection unit that projects parallel light onto the anterior segment,
The position determination unit
A provisional position determination unit for obtaining a provisional movement target position of the data acquisition optical system based on a projection image of the parallel light depicted in the two or more second captured images;
An ophthalmologic apparatus according to claim 1, further comprising: a position correction unit that corrects the provisional movement target position based on the corneal shape information and determines the movement target position. A drive unit for moving the data acquisition optical system;
Including a control unit and
The control unit performs a first control of the driving unit to move the data acquisition optical system to the provisional movement target position;
The corneal shape information acquisition unit obtains the corneal shape information based on the two or more first captured images acquired by the two or more imaging units after the first control,
The position correction unit performs the determination of the movement target position based on the cornea shape information,
10. The ophthalmologic apparatus according to claim 9, wherein the control unit executes second control of the drive unit to move the data acquisition optical system from the temporary movement target position to the movement target position. . The provisional position determination unit analyzes the two or more second captured images to search for a projection image of the parallel light, and when the projection image is detected, obtains the provisional movement target position;
When the projection image is not detected, the pupil image is searched by analyzing two or more third captured images acquired by the two or more imaging units, and when the pupil image is detected, Including a pupil position acquisition unit for obtaining a three-dimensional position of the pupil;
The control unit executes a third control of the driving unit to move the data acquisition optical system to a position corresponding to the three-dimensional position;
The temporary position determination unit analyzes two or more photographed images acquired by the two or more photographing units after the third control and searches again for a projection image of the parallel light. An ophthalmic device according to claim 1. An observation image acquisition unit for acquiring an observation image of the anterior eye part;
Including the operation unit and
When the pupil image is not detected, the control unit displays the observation image on a display unit, and controls the driving unit according to an operation performed using the operation unit,
The temporary position determining unit analyzes two or more captured images acquired by the two or more capturing units after the operation and searches again for the projection image of the parallel light. Ophthalmic equipment. A projection unit that projects an index including at least one of a predetermined continuous pattern and a predetermined discrete pattern onto the anterior segment of the eye to be examined;
Two or more imaging units that image the anterior segment on which the index is projected from different directions;
A corneal shape information acquisition unit that obtains corneal shape information of the eye to be inspected based on one or more captured images acquired by one or more imaging units that captured the anterior eye portion from an oblique direction among the two or more imaging units; Ophthalmic device.

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