Ophthalmologic device, method for controlling ophthalmologic device, ophthalmologic imaging method, program, and recording medium

Abstract

An imaging unit of an ophthalmic apparatus according to an embodiment performs imaging using a rolling shutter imaging device while moving a projection position of slit light on a fundus of an eye to be examined. The focus adjustment unit has a structure for performing focus adjustment of the imaging unit. The processor performs a slit light projection control, a condition determination process, and a focus adjustment control. In the fissure light projection control, the processor controls the imaging unit in order to project fissure light to the fundus of the subject eye. In the condition determination process, the processor determines a focus adjustment condition on the basis of an output from the imaging device that detects return light of the slit light projected onto the fundus. In the focus adjustment control, the processor controls the focus adjustment unit based on the focus adjustment condition.

Description

Technical Field

[0001] The present invention relates to an ophthalmologic apparatus, a control method for an ophthalmologic apparatus, an ophthalmologic imaging method, a program, and a recording medium. Background Art

[0002] Fundus cameras and scanning laser ophthalmoscopy (SLO) are known as ophthalmic devices for imaging the fundus of an eye under examination. Patent Document 1 discloses an ophthalmic device that illuminates the fundus with slit light and detects the return light with a rolling shutter imaging device (CMOS), thereby generating a fundus image. This ophthalmic device synchronously repeats the movement of the projection position of the slit light on the fundus and the detection (imaging) of the return light by the imaging device, thereby acquiring fundus images with a simple structure.

[0003] Patent Document 1: U.S. Patent No. 7,831,106 Summary of the Invention

[0004] In known ophthalmic devices such as the one disclosed in Patent Document 1, since dedicated hardware elements are provided for focus adjustment, there are concerns about various problems such as increased size of the device, complicated device structure, and increased manufacturing costs.

[0005] An object of the present invention is to provide a new technology that enables focus adjustment without providing a dedicated hardware element for focus that is included in conventional ophthalmic devices of the same type.

[0006] One embodiment is an ophthalmic device, comprising: a shooting unit that moves the projection position of slit light on the fundus of an eye to be examined while shooting using a camera device; a focus adjustment unit that performs focus adjustment of the shooting unit; and a processor that executes: slit light projection control that controls the shooting unit in order to project slit light onto the fundus; condition determination processing that determines a focus adjustment condition based on the output of the camera device that detects the return light of the slit light projected by the slit light projection control; and focus adjustment control that controls the focus adjustment unit based on the focus adjustment condition determined by the condition determination processing.

[0007] Another embodiment is a method for controlling an ophthalmic device, the ophthalmic control including: a shooting unit for moving the projection position of the slit light on the fundus of the eye to be examined while shooting with a camera device; a focus adjustment unit for performing focus adjustment of the shooting unit; a processor; and a memory, the method causing the processor to execute: a first control step for controlling the shooting unit in order to project the slit light onto the fundus; a condition determination step for determining a focus adjustment condition based on the output of the camera device that detects the return light of the slit light projected by the first control step; and a second control step for controlling the focus adjustment unit based on the focus adjustment condition determined by the condition determination step.

[0008] Another embodiment is a method for photographing an eye using a camera while moving the projection position of slit light on the fundus of the eye being examined, the method comprising: a step of projecting slit light onto the fundus, and detecting return light of the slit light projected onto the fundus using the camera; a step of determining a focus adjustment condition based on an output from the camera that detects the return light; a step of performing focus adjustment based on the focus adjustment condition; and a step of photographing an eye using the camera while moving the projection position of the slit light on the fundus after performing the focus adjustment.

[0009] Yet another embodiment is a program for causing an ophthalmic device to execute, the ophthalmic device including a shooting unit, a focus adjustment unit, a processor, and a memory, the shooting unit moving the projection position of the slit light on the fundus of the eye to be examined while shooting using a camera device, the focus adjustment unit being used to perform focus adjustment of the shooting unit, the program causing the processor to execute: a first control step of controlling the shooting unit in order to project the slit light onto the fundus; a condition determination step of determining a focus adjustment condition based on the output of the camera device that detects the return light of the slit light projected through the first control step; and a second control step of controlling the focus adjustment unit based on the focus adjustment condition determined by the condition determination step.

[0010] Another embodiment is a program for causing a computer to execute processing, the computer including a processor and a memory, the processing being processing for moving the projection position of slit light on the fundus of the eye to be examined while photographing using a camera device, the program causing the processor to execute: a step of controlling the projecting of slit light onto the fundus and detecting return light of the slit light projected onto the fundus using the camera device; a step of determining a focus adjustment condition based on an output from the camera device that detects the return light; a step of executing focus adjustment based on the focus adjustment condition; and a step of controlling the projecting position of the slit light on the fundus while photographing using the camera device after executing the focus adjustment.

[0011] Still another aspect of the embodiment is a computer-readable non-transitory recording medium storing the program according to any aspect.

[0012] According to the present invention, focus adjustment can be performed without providing hardware elements dedicated to focus as in conventional ophthalmic apparatuses of the same type. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a schematic diagram for explaining a non-limiting example of the structure of the ophthalmologic apparatus according to the embodiment.

[0014] Figure 2 This is a schematic diagram for explaining a non-limiting example of the structure of the ophthalmologic apparatus according to the embodiment.

[0015] Figure 3 This is a schematic diagram for explaining a non-limiting example of the structure of the ophthalmologic apparatus according to the embodiment.

[0016] Figure 4 This is a schematic diagram for explaining a non-limiting example of the structure of the ophthalmologic apparatus according to the embodiment.

[0017] Figure 5 This is a schematic diagram for explaining a non-limiting example of the operation of the ophthalmologic apparatus according to the embodiment.

[0018] Figure 6 This is a schematic diagram for explaining a non-limiting example of the structure of the ophthalmologic apparatus according to the embodiment.

[0019] Figure 7 This is a schematic diagram for explaining a non-limiting example of an optical path formed by the ophthalmologic apparatus according to the embodiment.

[0020] Figure 8 This is a schematic diagram for explaining a non-limiting example of focus adjustment performed by the ophthalmologic apparatus according to the embodiment.

[0021] Figure 9 This is a schematic diagram for explaining a non-limiting example of focus adjustment performed by the ophthalmologic apparatus according to the embodiment.

[0022] Figure 10 This is a schematic diagram for explaining a non-limiting example of focus adjustment performed by the ophthalmologic apparatus according to the embodiment.

[0023] Figure 11 This is a schematic diagram for explaining a non-limiting example of focus adjustment performed by the ophthalmologic apparatus according to the embodiment.

[0024] Figure 12A This is a schematic diagram for explaining a non-limiting example of focus adjustment performed by the ophthalmologic apparatus according to the embodiment.

[0025] Figure 12B This is a schematic diagram for explaining a non-limiting example of focus adjustment performed by the ophthalmologic apparatus according to the embodiment.

[0026] Figure 12C This is a schematic diagram for explaining a non-limiting example of focus adjustment performed by the ophthalmologic apparatus according to the embodiment.

[0027] Figure 12D This is a schematic diagram for explaining a non-limiting example of focus adjustment performed by the ophthalmologic apparatus according to the embodiment.

[0028] Figure 13A This is a schematic diagram for explaining a non-limiting example of focus adjustment performed by the ophthalmologic apparatus according to the embodiment.

[0029] Figure 13B This is a schematic diagram for explaining a non-limiting example of focus adjustment performed by the ophthalmologic apparatus according to the embodiment.

[0030] Figure 14 This is a flowchart for explaining a non-limiting example of the operation executed by the ophthalmologic apparatus according to the embodiment.

[0031] Figure 15 This is a schematic diagram for explaining a non-limiting example of the operation performed by the ophthalmologic apparatus according to the embodiment.

[0032] Figure 16 This is a schematic diagram for explaining a non-limiting example of the operation performed by the ophthalmologic apparatus according to the embodiment.

[0033] Figure 17 This is a schematic diagram for explaining a non-limiting example of the operation performed by the ophthalmologic apparatus according to the embodiment.

[0034] Figure 18 This is a flowchart for explaining a non-limiting example of the operation executed by the ophthalmologic apparatus according to the embodiment.

[0035] Figure 19 This is a schematic diagram for explaining a non-limiting example of the operation performed by the ophthalmologic apparatus according to the embodiment.

[0036] Figure 20 This is a flowchart for explaining a non-limiting example of the operation executed by the ophthalmologic apparatus according to the embodiment.

[0037] Figure 21 This is a schematic diagram for explaining a non-limiting example of the structure of the ophthalmologic apparatus according to the embodiment.

[0038] Figure 22 This is a schematic diagram for explaining a non-limiting example of the operation performed by the ophthalmologic apparatus according to the embodiment.

[0039] Figure 23A This is a schematic diagram for explaining a non-limiting example of the operation performed by the ophthalmologic apparatus according to the embodiment.

[0040] Figure 23B This is a schematic diagram for explaining a non-limiting example of the operation performed by the ophthalmologic apparatus according to the embodiment.

[0041] Figure 23C This is a schematic diagram for explaining a non-limiting example of the operation performed by the ophthalmologic apparatus according to the embodiment.

[0042] Figure 24 This is a schematic diagram for explaining a non-limiting example of the structure of the ophthalmologic apparatus according to the embodiment.

[0043] Figure 25 This is a schematic diagram for explaining a non-limiting example of the structure of the ophthalmologic apparatus according to the embodiment.

[0044] Figure 26 This is a schematic diagram for explaining a non-limiting example of the structure of the ophthalmologic apparatus according to the embodiment.

[0045] Figure 27 This is a schematic diagram for explaining a non-limiting example of display information provided by the ophthalmologic apparatus according to the embodiment.

[0046] Figure 28 This is a schematic diagram for explaining a non-limiting example of display information provided by the ophthalmologic apparatus according to the embodiment. DETAILED DESCRIPTION

[0047] Some non-limiting aspects of the embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0048] Any method of the present disclosure may be combined with any known technology. For example, any matter disclosed in the documents cited in this specification may be combined with any method of the present disclosure. In addition, any known technology in the technical field related to the present disclosure may be combined with any method of the present disclosure. For example, any technical matter disclosed by the applicant of the present application (matters disclosed in patent applications, papers, etc.) related to the present disclosure or technology applicable to the technology may be combined with any method of the present disclosure.

[0049] Any two or more of the various aspects described in this disclosure may be combined at least partially.

[0050] At least a portion of the functionality of the elements described in this disclosure is implemented using circuitry or processing circuitry. Circuitry or processing circuitry includes general-purpose processors, special-purpose processors, integrated circuits, CPUs (Central Processing Units), GPUs (Graphics Processing Units), ASICs (Application Specific Integrated Circuits), programmable logic devices (e.g., SPLDs (Simple Programmable Logic Devices), CPLDs (Complex Programmable Logic Devices), FPGAs (Field Programmable Gate Arrays), and the like) configured and / or programmed to perform at least a portion of the functionality disclosed. Array: Field Programmable Gate Array), any of the previous circuit structures and any combination thereof. The processor is regarded as a processing circuit structure or circuit structure including transistors and / or other circuit structures. In the present disclosure, the circuit structure, unit, component or similar terms are hardware that performs at least part of the functions disclosed, or hardware that is programmed to perform at least part of the functions disclosed. The hardware may be the hardware disclosed in this specification, or known hardware that is programmed and / or configured to perform at least part of the functions described. When the hardware is a processor that can be regarded as a certain type of circuit structure, the circuit structure, unit, component or similar terms are a combination of hardware and software, and the software is used to constitute the hardware and / or processor.

[0051] An ophthalmic device in some embodiments includes a photographing unit, a focus adjustment unit, and a processor. The photographing unit is configured to move the projection position of the slit light on the fundus of the eye to be examined while photographing using a camera. The camera may be a rolling shutter camera or a camera having the same function. As an example of the latter, there is a camera that combines a global shutter image sensor and a mechanical slit aperture. The same is true for the camera of another embodiment. The photographing performed by the ophthalmic device of the present disclosure is sometimes referred to as slit scanning. The focus adjustment unit is configured to perform focus adjustment of the photographing unit. The processor is configured to perform slit light projection control, condition determination processing, and focus adjustment control. In the slit light projection control, the processor controls the photographing unit so that the slit light is projected onto the fundus of the eye to be examined. In the condition determination processing, the processor determines the focus adjustment condition based on the output from the camera that detects the return light of the slit light projected onto the fundus of the eye to be examined by the slit light projection control. In the focus adjustment control, the processor controls the focus adjustment unit based on the focus adjustment condition determined by the condition determination process.

[0052] In some embodiments of the ophthalmic apparatus, the processor may include a condition determination unit configured to execute a condition determination process. The condition determination unit is configured to determine the focus adjustment condition based on a position of a slit light image in an image generated by an imaging device of the imaging unit.

[0053] In some forms of such an embodiment, the condition determination unit can be configured to determine the position of the slit light image in the image generated by the camera device of the shooting unit based on the brightness distribution of at least a portion of the image area of the slit light image along a first direction, wherein the first direction corresponds to the moving direction of the projection position of the slit light formed by the shooting unit.

[0054] Furthermore, in some embodiments, the condition determination unit may be configured to generate the brightness distribution by adding the brightness of a pixel group constituting the image area of the slit light image in a second direction orthogonal to the first direction.

[0055] In some embodiments of the ophthalmic device, the imaging unit may include a first optical system and a second optical system. The first optical system is configured to project slit light toward the fundus of the eye to be examined. The second optical system is configured to guide return light of the slit light from the fundus of the eye to be examined to the imaging device. In this case, the focus adjustment unit may include a first focus adjustment unit for adjusting the focal position of the first optical system and a second focus adjustment unit for adjusting the focal position of the second optical system, and the condition determination unit may be configured to determine a first focus adjustment condition for controlling the first focus adjustment unit and a second focus adjustment condition for controlling the second focus adjustment unit as the focus adjustment condition.

[0056] In some aspects of such an embodiment, the first optical system may be configured to include a light source and a slit aperture for generating slit light from light emitted from the light source, and project the slit light generated by the slit aperture onto the fundus of the eye to be examined. Furthermore, the second optical system may include a focusing lens. Furthermore, the first focus adjustment unit may include a first moving mechanism for moving the slit aperture in a direction along the optical axis of the first optical system, and the second focus adjustment unit may include a second moving mechanism for moving the focusing lens in a direction along the optical axis of the second optical system. Furthermore, the condition determination unit may be configured to determine a first movement control condition for controlling the first moving mechanism as the first focus adjustment condition, and determine a second movement control condition for controlling the second moving mechanism as the second focus adjustment condition.

[0057] Furthermore, in some embodiments, the first movement control condition may include information indicating the movement direction and movement distance of the slit aperture, and the second movement control condition may include information indicating the movement direction and movement distance of the focus lens.

[0058] In some other embodiments in which the imaging unit includes a first optical system and a second optical system, the focus adjustment unit includes a first focus adjustment unit and a second focus adjustment unit, and the condition determination unit determines the first focus adjustment condition and the second focus adjustment condition, the first optical system may include: a light source; an iris diaphragm disposed at a position substantially optically conjugate with the iris of the eye to be examined, the iris diaphragm having an opening for transmitting light emitted from the light source; a lens for refracting light transmitted through the opening of the iris diaphragm; and a slit diaphragm for generating slit light from the light refracted by the lens and projecting the slit light generated by the slit diaphragm onto the fundus. Furthermore, the second optical system may include a focusing lens. Furthermore, the first focus adjustment unit may include a third movement mechanism for integrally moving the light source, iris diaphragm, lens, and slit diaphragm in a direction along the optical axis of the first optical system, and the second focus adjustment unit may include a fourth movement mechanism for moving the focus lens in a direction along the optical axis of the second optical system. Furthermore, the condition determination unit determines a third movement control condition for controlling the third movement mechanism as the first focus adjustment condition, and determines a fourth movement control condition for controlling the fourth movement mechanism as the second focus adjustment condition.

[0059] Furthermore, in some embodiments, the third movement control condition may include information indicating the movement direction and movement distance for the integrated movement of the light source, iris aperture, lens and slit aperture, and the fourth movement control condition may include information indicating the movement direction and movement distance of the focusing lens.

[0060] In some embodiments of the ophthalmologic apparatus, the processor is configured to control the imaging unit during slit light projection control so that the slit light projected toward the fundus of the eye to be examined is emitted from a position separated by a predetermined distance from the optical axis of the imaging unit. In this case, the condition determination unit is configured to determine the focus adjustment condition based on the predetermined distance, the position of the slit light image in an image generated by the imaging device of the imaging unit, and the focal length of the imaging unit.

[0061] In some embodiments of the ophthalmologic apparatus, the imaging unit includes an optical scanner that deflects slit light directed toward the eye to be examined, thereby moving the projection position of the slit light onto the fundus of the eye to be examined. In this case, the processor includes a projection control unit that controls slit light projection. The projection control unit is configured to control the imaging unit so that the slit light is projected onto the fundus while the deflection direction of the slit light generated by the optical scanner is fixed. Furthermore, the condition determination unit is configured to determine the focus adjustment condition based on the position of a slit light image corresponding to the slit light projected onto the fundus of the eye to be examined while the deflection direction of the slit light generated by the optical scanner is fixed.

[0062] In some embodiments of the ophthalmic apparatus, the processor includes a projection control unit that controls slit light projection, the projection control unit being configured to control the imaging unit so as to output a first slit light and a second slit light projected at different positions on the fundus of the eye under examination. In this case, the condition determination unit is configured to determine the focus adjustment condition based on the relative positions of a first slit light image corresponding to the first slit light and a second slit light image corresponding to the second slit light.

[0063] In some embodiments of an ophthalmic device, the imaging unit is configured to repeatedly perform a series of imaging operations by the imaging device while repeatedly moving the projection position of the slit light onto the fundus of the eye under examination, thereby acquiring time-series images. In this case, the processor is configured to perform first imaging control, second imaging control, and focus information generation processing in addition to executing slit light projection control, condition determination processing, and focus adjustment control. During the first imaging control, the processor controls the imaging unit to acquire time-series images of the fundus of the eye under examination. During the second imaging control, the processor controls the imaging unit to perform imaging operations for detecting the imaging unit's focus state on the fundus of the eye under examination. During the focus information generation processing, the processor generates focus information indicating the imaging unit's focus state on the fundus of the eye under examination based on the images acquired by the imaging unit during the imaging operations performed under the second imaging control. In some aspects of such embodiments, the processor may be configured to alternately execute the first imaging control and the second imaging control. Furthermore, in some aspects, the processor may be configured to further execute display control for causing the display device to display display information based on the focus information in parallel with the first imaging control, the second imaging control, and the focus information generation process.

[0064] Some embodiments of an ophthalmic device include a photographing unit and a processor. The photographing unit can repeat a series of movements of the projection position of the slit light on the fundus of the eye under examination while repeating a series of photographing operations performed by the imaging device, thereby acquiring time-series images. The processor is configured to execute a first photographing control, a second photographing control, a focus information generation process, and a display control. In the first photographing control, the processor controls the photographing unit so as to acquire time-series images of the fundus of the eye under examination. In the second photographing control, the processor controls the photographing unit so as to execute photographing operations for detecting the focus state of the photographing unit on the fundus of the eye under examination. In the focus information generation process, the processor generates focus information indicating the focus state of the photographing unit on the fundus of the eye under examination based on the images acquired by the photographing unit during the photographing executed by the second photographing control. In the display control, the processor causes the display device to display display information based on the focus information generated by the focus information generation process.

[0065] The method of some embodiments is a method for controlling an ophthalmic device. The ophthalmic device includes a shooting unit, a focus adjustment unit, a processor, and a memory. The shooting unit is configured to move the projection position of the slit light on the fundus of the eye to be examined while using a camera device to shoot. The focus adjustment unit is configured to perform focus adjustment of the shooting unit. The method of this embodiment is configured to cause the processor to perform the following steps: a first control step of controlling the shooting unit in order to project the slit light onto the fundus of the eye to be examined; a condition determination step of determining the focus adjustment condition based on the output from the camera device, which detects the return light of the slit light projected onto the fundus of the eye to be examined by the first control step; and a second control step of controlling the focus adjustment unit based on the focus adjustment condition determined by the condition determination step.

[0066] The method of some embodiments is a method for controlling an ophthalmic device. The ophthalmic device includes a shooting unit, a processor, and a memory. The shooting unit is configured to move the projection position of the slit light on the fundus of the eye to be examined while shooting with a camera. The method of this embodiment is configured to cause the processor to execute the following steps in parallel: a first shooting control step, controlling the shooting unit so that a series of movements of the projection position of the slit light on the fundus are repeated while a series of shootings performed by the camera are repeated, thereby acquiring time-series images; a second shooting control step, causing the shooting unit to execute shooting for detecting the focusing state of the shooting unit with respect to the fundus of the eye to be examined; a focusing information generating step, generating focusing information indicating the focusing state of the shooting unit with respect to the fundus of the eye to be examined based on the image acquired in the shooting performed by the second shooting control step; and a display control step, causing the display device to display display information based on the focusing information generated by the focusing information generating step.

[0067] Some embodiments of the method are methods for capturing images using an imaging device while moving the projection position of slit light onto the fundus of an eye under examination. The method of this embodiment is configured to execute the following steps: projecting slit light onto the fundus of the eye under examination and detecting return light of the slit light projected onto the fundus using an imaging device; determining a focus adjustment condition based on an output from an imaging device that detects return light of the slit light from the fundus of the eye under examination; performing focus adjustment based on the focus adjustment condition; and after performing the focus adjustment, capturing images using the imaging device while moving the projection position of the slit light onto the fundus of the eye under examination.

[0068] Some embodiments of the method involve capturing images of the fundus of an eye under examination using an imaging device while moving the projection position of slit light onto the fundus of the eye under examination. The method of this embodiment concurrently performs the following steps: acquiring time-series images by repeatedly performing a series of movements of the projection position of slit light onto the fundus of the eye under examination and a series of images captured by the imaging device; acquiring images by capturing images for detecting a focus state relative to the fundus of the eye under examination; generating focus information indicating a focus state based on the images captured by the capturing for detecting the focus state; and displaying display information based on the focus information.

[0069] The program of some embodiments is a program for causing an ophthalmic device to execute. The ophthalmic device includes: a shooting unit that moves the projection position of the slit light on the fundus of the eye to be examined while using a camera device to shoot; a focus adjustment unit that performs focus adjustment of the shooting unit; a processor; and a memory. The program of this embodiment is configured to cause the processor to execute the following steps: a first control step of controlling the shooting unit in order to project the slit light onto the fundus of the eye to be examined; a condition determination step of determining a focus adjustment condition based on an output from the camera device that detects the return light of the slit light projected onto the fundus of the eye to be examined by the first control step; and a second control step of controlling the focus adjustment unit based on the focus adjustment condition determined by the condition determination step. The recording medium of some embodiments is a computer-readable non-transitory recording medium on which the program of this embodiment is recorded.

[0070] A program in some embodiments is a program for causing an ophthalmic device to execute. The ophthalmic device includes: an imaging unit that moves the projection position of a slit light onto the fundus of an eye under examination while performing imaging with an imaging device; a processor; and a memory. The program in this embodiment is configured to cause the processor to execute the following steps in parallel: a first imaging control step that controls the imaging unit so that a series of movements of the projection position of the slit light onto the fundus of the eye under examination are repeated while a series of imaging with the imaging device is repeated, thereby acquiring time-series images; a second imaging control step that causes the imaging unit to perform imaging for detecting the imaging unit's focus state on the fundus of the eye under examination; a focus information generation step that generates focus information indicating the focus state based on the image acquired during the imaging performed by the second imaging control step; and a display control step that causes a display device to display display information based on the focus information generated by the focus information generation step. The recording medium in some embodiments is a computer-readable, non-transitory recording medium having the program in this embodiment recorded thereon.

[0071] In some embodiments, a program causes a computer including a processor and a memory to execute processing for moving the projection position of slit light onto the fundus of an eye under examination while capturing an image using an imaging device. The program of this embodiment is configured to cause the processor to execute the following steps: a step of controlling the projection of slit light onto the fundus of the eye under examination and detecting return light of the slit light projected onto the fundus of the eye under examination using an imaging device; a step of determining focus adjustment conditions based on an output from an imaging device that detects return light of the slit light projected onto the fundus of the eye under examination; a step of performing focus adjustment based on the focus adjustment conditions; and a step of controlling the projection position of the slit light onto the fundus of the eye under examination while capturing an image using the imaging device after the focus adjustment has been performed. In some embodiments, a recording medium is a computer-readable non-transitory recording medium having the program of this embodiment recorded thereon.

[0072] In some embodiments, a program causes a computer including a processor and a memory to execute processing for capturing images of the fundus of an eye under examination using an imaging device while moving the projection position of a slit light onto the fundus of the eye under examination. The program of this embodiment is configured to cause the processor to execute the following steps in parallel: a step of acquiring time-series images by repeating a series of movements of the projection position of the slit light onto the fundus of the eye under examination and a series of images captured by the imaging device; a step of acquiring images by capturing images for detecting a focus state relative to the fundus of the eye under examination; a step of generating focus information indicating a focus state based on the images captured during the capturing for detecting the focus state; and a step of displaying display information based on the focus information. In some embodiments, a recording medium is a computer-readable, non-transitory recording medium on which the program of this embodiment is recorded.

[0073] <First embodiment>

[0074] exist Figure 1 A non-limiting example of the structure of an ophthalmic device according to the first embodiment is shown in FIG. The ophthalmic device 1 of this embodiment has an ophthalmic imaging function for imaging the fundus of a living eye using a slit-scanning modality. The ophthalmic device 1 includes an imaging unit 2, a focus adjustment unit 3, a processor 4, a memory 5, and a user interface 6. Unless otherwise specified, the hardware elements included in the ophthalmic device 1 may be the same as those of existing slit-scanning ophthalmic imaging devices.

[0075] The photographing unit 2 is configured to move the projection position of the slit light on the fundus of the eye to be examined while photographing using a rolling shutter type image sensor (camera device), thereby performing a slit scan. In other words, the photographing unit 2 is configured to illuminate the fundus of the eye to be examined while moving the irradiation position (irradiation range) of the slit-shaped illumination light (slit light), and receive the return light from the fundus using an image sensor having light receiving elements arranged one-dimensionally or two-dimensionally. Under the control of the processor 4, the light receiving result of the return light is synchronized with the movement timing of the irradiation position of the slit light, and a signal (data) is read from the light receiving element at the light receiving position of the return light corresponding to the irradiation position of the slit light. The signal is read from the image sensor in a rolling shutter manner. A non-limiting example of the specific structure of the photographing unit 2 will be described later.

[0076] As described above, an imaging unit (imaging device) composed of a global shutter image sensor and a slit aperture can be used instead of a rolling shutter image sensor to perform the same imaging operation as that of a rolling shutter image sensor.

[0077] The focus adjustment unit 3 includes a structure for performing focus adjustment (focusing) on the imaging unit 2. The focus adjustment of the first embodiment can be performed using existing focus adjustment techniques. For example, focus adjustment can be performed by changing the focal length (focus position) of a lens disposed between the subject (the fundus of the eye to be examined) and the image sensor, and / or by changing the distance between the lens and the image sensor.

[0078] The processor 4 executes processing according to the program stored in the memory 5 and / or other storage devices, thereby realizing the functions of the first embodiment.

[0079] The memory 5 stores various computer programs and data. For example, the memory 5 stores control programs and / or control data for causing the ophthalmic device 1 to perform predetermined operations, and calculation programs and / or calculation data for causing the ophthalmic device 1 to perform predetermined calculations. The programs and data stored in the memory 5 are not limited to these. Furthermore, the memory 5 stores data acquired by the ophthalmic device 1. For example, data generated by the ophthalmic device 1 and data acquired externally by the ophthalmic device 1 are stored in the memory 5. In a typical embodiment, the memory 5 includes non-volatile memory and volatile memory.

[0080] The user interface 6 is an element (hardware element, software element, protocol) used to exchange information between the ophthalmic device 1 and its user. The user interface 6 includes, for example, an input unit (operation unit) for providing information from the user to the ophthalmic device 1, and an output unit for providing information from the ophthalmic device 1 to the user. Non-limiting examples of hardware elements of the input unit include an operation panel, a mouse, a keyboard, a trackball, switches, buttons, a dial, a scanner, an optical character recognition (OCR) device, a microphone, a camera (camcorder), and the like. Non-limiting examples of hardware elements of the output unit include a display, a printer, a speaker, and the like. The user interface 6 may include a device that integrates input and output functions, such as a touch screen.

[0081] Although not shown in the figure, the ophthalmic device 1 has elements for aligning (positioning) the imaging unit 2 relative to the inspected eye E, similar to existing ophthalmic devices of the same type. The alignment method performed by the ophthalmic device 1 may be arbitrary, for example, it may be a stereo alignment in which the position of the inspected eye E is determined using two or more anterior segment cameras described in Japanese Patent Application Laid-Open No. 2013-248376, or a method in which the position of the inspected eye E is determined by analyzing a frontal image of the inspected eye E (for example, an observation image of the anterior segment Ea), or a method in which the position of the inspected eye E is determined by projecting an alignment index onto the anterior segment Ea (cornea). The ophthalmic device 1 has hardware elements and software elements corresponding to the alignment method. Although not shown in the figure, the ophthalmic device 1 has a moving mechanism for moving the imaging unit 2 in three dimensions, similar to existing ophthalmic devices of the same type.

[0082] exist Figure 2 Detailed description of the non-limiting example of the structure of the imaging unit 2 is given in FIG. Figure 2 is a side view. Figure 2 In the embodiment, the direction along the optical axis of the optical system (the optical axis of the objective lens 46) is set as the Z direction (front-back direction, movement distance direction), a direction perpendicular to the Z direction (in this example, the left-right direction, the horizontal direction) is set as the X direction, and a direction perpendicular to both the Z direction and the Y direction (in this example, the up-down direction, the vertical direction) is set as the Y direction.

[0083] The imaging unit 2 of this example includes a light source 10, an illumination optical system 20, a light scanner 30, a imaging optical system 40, and an imaging device 50. The illumination optical system 20 generates slit light from the light emitted from the light source 10 and projects it toward the fundus Ef of the eye to be examined E. The light source 10 can be regarded as an element of the illumination optical system 20. The light scanner 30 moves the position (projection position) of the slit light projected by the illumination optical system 20 toward the fundus Ef. The light scanner 30 can be regarded as an element of the illumination optical system 20. The imaging optical system 40 guides the return light of the slit light projected by the illumination optical system 20 toward the fundus Ef to the imaging device 50. The imaging device 50 can be regarded as an element of the imaging optical system 40.

[0084] The light source 10 may include a visible light source that generates light in the visible region (for example, a white light source that generates white light). The light source 10 may include an infrared light source (near-infrared light source) that generates light in the infrared region (near-infrared region). The light source 10 can switch to output light of different wavelength bands. The light source 10 may include any type of light source, for example, it may include one or more of a light emitting diode (LED), a laser diode (LD), a halogen lamp, and a xenon lamp. When the shooting unit 2 is properly aligned with the eye E to be examined, the light source 10 is configured at a position that is optically non-conjugate with the fundus Ef and the iris, respectively. In some embodiments, under the control of the processor 4, the light source 10 outputs visible light for slit scanning and outputs near-infrared light or visible light for focus adjustment.

[0085] The illumination optical system 20 generates slit-shaped illumination light (slit light) from the light emitted from the light source 10 and projects it toward the fundus Ef of the eye to be examined E. In this example, the illumination optical system 20 includes an iris diaphragm 21, a slit aperture diaphragm (slit) 22, a relay lens 23, an optical scanner 30, a relay lens 31, a Hall mirror 45, and an objective lens 46. The relay lens 23 includes one or more lenses, the relay lens 31 includes one or more lenses, and the objective lens 46 includes one or more lenses.

[0086] The imaging optical system 40 guides the return light of the illumination light (slit light) projected onto the fundus Ef of the eye E to be examined by the illumination optical system 20 (and the optical scanner 30) to the imaging device 50. In this example, the imaging optical system 40 includes an objective lens 46, a Hall mirror 45, a focusing lens 47, and an imaging lens 48. The focusing lens 47 includes one or more lenses, and the imaging lens 48 includes one or more lenses.

[0087] Light output from the light source 10 (specifically, a portion of the light) passes through an opening formed in the iris diaphragm 21 , an opening formed in the slit aperture diaphragm 22 , and the relay lens 23 and is guided to the through-light scanner 30 .

[0088] When the imaging unit 2 is properly aligned with the eye E, the iris diaphragm 21 (specifically, the opening formed in the iris diaphragm 21 ) is arranged at a position substantially optically conjugate with the iris (pupil) of the eye E.

[0089] One or more openings are formed on the iris diaphragm 21 at positions separated from the optical axis of the illumination optical system 20. Figure 3 The illustrated, non-limiting iris diaphragm 21 is formed with two openings 21A and 21B having predetermined dimensions (predetermined length and predetermined width) along a circumferential direction centered on the optical axis O of the illumination optical system 20 .

[0090] The opening of the iris diaphragm 21 determines the incident state (incident position, incident shape) of the illumination light into the pupil of the eye to be examined E. For example, when using the iris diaphragm 21 formed with the openings 21A and 21B, when the optical axis O of the illumination optical system 20 (the optical axis of the objective lens 46) is arranged to be substantially aligned with the center of the pupil of the eye to be examined E (i.e., when properly aligned), the illumination light (slit light) can be guided to the fundus Ef by passing through positions decentered from the pupil center (specifically, two positions arranged symmetrically with respect to the pupil center point).

[0091] In some embodiments, by providing an optical element between the light source 10 and the iris diaphragm 21 to deflect the light from the light source 10, the light intensity distribution in the direction connecting the opening of the iris diaphragm 21 and the opening (slit) of the slit aperture 22 can be optimized. Furthermore, by configuring the light source 10 and the opening of the iris diaphragm 21 to be adjustable relative to each other, the light intensity distribution of the light passing through the opening of the iris diaphragm 21 can be varied.

[0092] When the imaging unit 2 is properly aligned with the eye E to be examined, the slit aperture 22 (specifically, the opening (slit) formed in the slit aperture 22 ) is arranged at a position substantially optically conjugate with the fundus Ef of the eye E to be examined.

[0093] The slit aperture 22 is formed with an opening (slit) having a longitudinal direction corresponding to a line direction (row direction) in which signals are read out from an image sensor 51 described later in a rolling shutter method. Figure 4 The slit aperture stop 22 , which is exemplified and not limited to this example, has an opening (slit) 22A having a predetermined size (predetermined length and predetermined width) formed in a region including the optical axis O of the illumination optical system 20 .

[0094] The opening (slit) formed in the slit aperture 22 defines the shape of the image projected by the slit light on the fundus Ef of the eye under examination E. The long side direction of the slit formed in the slit aperture 22 is sometimes referred to as the slit length direction. Furthermore, the short side direction of the slit formed in the slit aperture 22 is sometimes referred to as the slit width direction.

[0095] The slit aperture 22 can be moved in a direction along the optical axis of the illumination optical system 20 by a moving mechanism 22M. The moving mechanism 22M operates under the control of the processor 4. The processor 4 can be configured to control the moving mechanism 22M based on the state of the eye E to be examined (e.g., refractive power (diopter, visual acuity), fundus shape, etc.).

[0096] Light passing through the aperture of the iris diaphragm 21 is converted into slit-shaped illumination light (slit light) by passing through the aperture of the slit aperture diaphragm 22. The slit light is guided to the optical scanner 30 via the relay lens 23, deflected by the optical scanner 30, and guided to the Hall mirror 45 via the relay lens 31.

[0097] The Hall mirror 45 is an optical component used in conventional fundus cameras and the like, and functions as an optical path coupling component that couples the optical path of the illumination optical system 20 with the optical path of the imaging optical system 40. An opening (or light-transmitting portion) is formed at the center of the Hall mirror 45. For example, the outer edge of the opening is circular. The optical axes of the illumination optical system 20 and the imaging optical system 40 intersect at the opening of the Hall mirror 45. A reflecting portion (mirror portion) is formed around the opening of the Hall mirror 45.

[0098] The slit light guided to the Hall mirror 45 via the relay lens 31 is reflected by the reflecting portion, refracted by the objective lens 46 , and enters the inspected eye E. The slit light entering the inspected eye E is projected onto the fundus Ef.

[0099] In some embodiments, the projection image (projection area) of the slit light on the fundus Ef is generally slit-shaped, with the longitudinal direction of the projection image substantially aligned with the X direction. In this case, the optical scanner 30 deflects the slit light generated by the iris diaphragm 21 and the slit aperture diaphragm 22 to move the projection image of the slit light on the fundus Ef in the Y direction. Furthermore, the longitudinal direction of the projection image of the slit light on the fundus Er is not limited to the X direction, and the direction of movement of the projection image by the optical scanner 30 is not limited to the Y direction.

[0100] When the imaging unit 2 is properly aligned with the eye E, the optical scanner 30 is positioned substantially optically conjugate with the iris of the eye E. This allows the slit light to be deflected in the Y direction using the position within the pupil of the eye E (or a position near the pupil) as a pivot (scanning axis, deflection center axis), and the slit light can be sequentially projected onto a plurality of slit-shaped partial regions formed by imaginary divisions of the predetermined scanning range of the fundus Ef. In other words, slit scanning of the fundus Ef can be performed.

[0101] The reflected light of the slit light projected onto the fundus Ef is emitted from the eye E to be examined through the pupil of the eye Ef and enters the imaging unit 2. The light (return light) incident on the imaging unit 2 from the eye E to be examined is guided by the objective lens 46 to the Hall mirror 45. The return light passes through the opening of the Hall mirror 45 (or, is transmitted through the light-transmitting portion), is guided by the focusing lens 47 and the imaging lens 48 to the imaging device 50, and is detected.

[0102] The optical scanner 30 can, for example, deflect the slit light one-dimensionally or two-dimensionally. The optical scanner 30 for one-dimensional deflection deflects the slit light within a predetermined deflection angle range based on a predetermined direction. This deflection angle range is defined in a direction corresponding to the direction of movement of the slit light on the fundus Ef (e.g., the Y direction). The optical scanner 30 for two-dimensional deflection is, for example, a scanner composed of two optical scanners that provide different deflection directions. The optical scanner 30 can use any type of optical deflection device, such as a galvanostatic scanner.

[0103] The focus lens 47 can be moved in a direction along the optical axis of the photographing optical system 40 by a moving mechanism 47M. The moving mechanism 47M operates under the control of the processor 4. The processor 4 can be configured to control the moving mechanism 47M according to the state of the eye E to be examined (e.g., refractive power, fundus shape, etc.).

[0104] The imaging device 50 includes an image sensor 51 that detects the return light guided by the photographing optical system 40. The imaging device 50 can read out a signal from the image sensor 51 that detects the return light under the control of the processor 4.

[0105] The image sensor 51 functions as a pixelated light receiver. When the imaging unit 2 is properly aligned with the eye E, the light-receiving surface (detection surface, imaging surface) of the image sensor 51 is positioned substantially optically conjugate with the fundus Ef of the eye E. Under the control of the processor 4, the signal generated by the photoelectric conversion of the image sensor 51 is read out using a rolling shutter method.

[0106] In some embodiments, the image sensor 51 includes a CMOS (Complementary Metal-Oxide-Semiconductor Transistor) image sensor. In this case, the image sensor 51 includes a plurality of pixel groups arranged in the row direction, and the plurality of pixel groups are arranged in the column direction. More specifically, the image sensor 51 includes a plurality of pixels arranged in two dimensions, a plurality of vertical signal lines, and a horizontal signal line. Each pixel includes a photodiode and a capacitor. A vertical signal line is provided for each pixel group arranged in the column direction (vertical direction) orthogonal to the row direction (horizontal direction). Each vertical signal line is selectively electrically connected to a pixel group that accumulates a charge corresponding to the detection result of the return light. The horizontal signal line is selectively electrically connected to a plurality of vertical signal lines. Each pixel accumulates a charge corresponding to the detection result of the return light, and the accumulated charge is read out sequentially, for example, for each pixel group in the row direction. For example, for each line in the row direction, a voltage corresponding to the charge accumulated by each pixel is supplied to the vertical signal line. The plurality of vertical signal lines are selectively electrically connected to the horizontal signal lines. By sequentially performing the above-described readout operation for each line in the row direction in the vertical direction, detection results can be read out from a plurality of pixels arranged two-dimensionally.

[0107] By reading detection results from such an image sensor 51 using a rolling shutter method, a light-receiving image corresponding to a desired virtual aperture shape extending in the row direction is acquired. This control is well known and is disclosed in, for example, US Patent No. 7,831,106.

[0108] Slit scanning performed by the ophthalmologic apparatus 1 will be described. Figure 5 Schematically shows the position (projection range) IP of the projection image of the slit light on the fundus oculi Ef and the virtual opening range OP on the light receiving surface SR of the image sensor 51 .

[0109] The ophthalmic apparatus 1 deflects the slit light using the optical scanner 30 , thereby moving the projection range IP of the slit light on the fundus Ef in a direction (e.g., Y direction, column direction, vertical direction) perpendicular to the slit length direction (e.g., X direction, row direction, horizontal direction).

[0110] During the signal readout process from the image sensor 51 by the processor 4, the pixel groups targeted for signal readout are sequentially switched on a line-by-line basis, thereby sequentially setting the virtual aperture range OP. The aperture range OP is set, for example, to coincide with the range IP' of the slit light's return light projected onto the light-receiving surface SR, or to a range larger than this range IP'. The processor 4 executes the control for shifting the slit light's projection range IP and the control for shifting the aperture range OP in parallel. For example, the processor 4 executes these controls synchronously. This slit scanning allows for the acquisition of high-quality, high-contrast fundus images with a simple configuration, without being affected by unwanted scattered light.

[0111] In some embodiments, a black spot for removing harmful reflected light is provided between the optical scanner 30 and the Hall mirror 45. The black spot is arranged at a position substantially optically conjugate to the position of the central ghost image caused by the slit light reflected by the objective lens 46.

[0112] In conventional ophthalmic devices of the same type, a focus index projection optical system is provided between the optical scanner and the Hall effect mirror to generate a focus adjustment index (splitting index) projected onto the fundus Ef. A mechanism for moving the focus index projection optical system is also provided. In conventional ophthalmic devices of the same type, light output from the focus index optical system (focus index light) is projected onto the fundus Ef. The imaging optical system and the imaging device detect the light reflected from the fundus Ef. The position of the splitting index in the acquired image is determined using the Schlieren method. Based on the determined splitting index position, the focusing lenses of the focus index projection optical system and the imaging optical system are moved along their respective optical axes to perform focus adjustment. Thus, the focus index projection optical system and the movement mechanism are dedicated hardware elements for focus adjustment, provided in conventional ophthalmic devices of the same type.

[0113] In contrast, the ophthalmic device 1 of the first embodiment does not include the focus index projection optical system and its movement mechanism, as dedicated hardware elements for focusing, found in existing ophthalmic devices of the same type. Instead, the ophthalmic device 1 performs focus adjustment using a new technology described below. This new technology utilizes hardware elements found in existing ophthalmic devices of the same type in a novel way. In some aspects of the new technology, dedicated focus hardware elements are not required, while in other aspects, complex and large-scale dedicated focus hardware elements, such as a focus index projection optical system and its movement mechanism, are not required.

[0114] The processor 4 is configured to execute various control processes and various computational processes. For example, the processor 4 is configured to execute at least slit light projection control, condition determination processing, and focus adjustment control. These slit light projection control, condition determination processing, and focus adjustment control are part of a series of processes for focus adjustment (particularly autofocus). The ophthalmic apparatus 1 is configured to execute this series of processes (i.e., employing a structure with novel software elements), enabling focus adjustment without the use of dedicated focus hardware elements, or without the use of complex and large-scale dedicated focus hardware elements.

[0115] exist Figure 6 2 shows a non-limiting example of the configuration of the processor 4. The processor 4 in this example includes a projection control unit 401, a condition determination unit 402, and a focus adjustment control unit 403.

[0116] Slit light projection control is a control process of the imaging unit 2 executed to project slit light for focus adjustment onto the fundus Ef of the eye E to be examined, and is executed by the projection control unit 401. The slit light projection control may be performed in any manner, and some non-limiting examples thereof will be described below.

[0117] Condition determination processing is a computational process performed by the condition determination unit 402 to determine focus adjustment conditions based on the output from the imaging device 50, which detects return light from the slit light projected onto the fundus Ef by slit light projection control. The condition determination processing can be performed in any manner, and some non-limiting examples will be described below.

[0118] Focus adjustment control is a control process performed by the focus adjustment unit 3 to adjust the focus state of the imaging unit 2 based on the focus adjustment conditions determined by the condition determination process. This process is performed by the focus adjustment control unit 403. The focus adjustment control method may be arbitrary, and some non-limiting examples thereof will be described below.

[0119] exist Figure 2 In the illustrated example, the focus adjustment unit 3 includes a moving mechanism 22M for moving the slit aperture 22 and a moving mechanism 47M for moving the focus lens 47 , among the elements of the imaging unit 2 .

[0120] At this time, condition determination processing is performed to determine the control conditions for the moving mechanism 22M used for focusing the illumination optical system 20 (i.e., for adjusting the focal position of the illumination optical system 20) and the moving mechanism 47M used for focusing the imaging optical system 40 (i.e., for adjusting the focal position of the imaging optical system 40). The control conditions for the moving mechanism 22M include information indicating the direction and amount (distance) of movement of the slit aperture 22. The control conditions for the moving mechanism 47M include information indicating the direction and amount (distance) of movement of the focus lens 47. These control conditions may also include other information corresponding to the direction and amount of movement of the target element, for example, information indicating the content of the control signal sent to the moving mechanism 22M (moving mechanism 47M) (e.g., the number of control pulses).

[0121] Furthermore, focus adjustment control is performed so that the moving mechanism 22M is controlled based on the control condition of the moving mechanism 22M determined by the condition determination process, and the moving mechanism 47M is controlled based on the control condition of the moving mechanism 47M.

[0122] In some embodiments, the focus adjustment of the photographing optical system 40 is performed by moving the focus lens 47 as described herein, but in other embodiments, the focus adjustment of the photographing optical system 40 can be performed by moving the imaging device 50 (image sensor 51). In the latter embodiment, a movement mechanism for moving the imaging device 50 (image sensor 51) is provided, and a condition determination process determines a control condition for the movement mechanism. In focus adjustment control, the movement mechanism is controlled based on the control condition to move the imaging device 50 (image sensor 51).

[0123] In some embodiments, the projection control unit 401 first fixes the deflection direction of the slit light of the optical scanner 30 to a predetermined direction. That is, the projection control unit 401 fixes the orientation of the reflective surface (mirror) of the optical scanner 30 to a predetermined orientation.

[0124] With the optical scanner 30 in operation (operation to change the orientation of the mirror) stopped, the projection control unit 401 controls the imaging unit 2 to project slit light onto the fundus Ef. The imaging unit 2 detects the slit light projected onto the fundus Ef with the optical scanner 30 in operation stopped, using the imaging optical system 40 and the imaging device 50. The image input condition determination unit 402 receives the resulting image.

[0125] The condition determination unit 402 analyzes the image to determine the focus adjustment conditions. More specifically, the condition determination unit 402 analyzes the image acquired while the optical scanner 30 is in a stopped state to determine the position of the image of the slit light projected onto the fundus Ef while the optical scanner 30 is in a stopped state (i.e., the slit light image corresponding to the slit light) and to determine the focus adjustment conditions based on the determined position of the slit light image. Non-limiting examples of these processes performed by the condition determination unit 402 will be described below.

[0126] In some embodiments, the projection control unit 401 controls the imaging unit 2 to output at least two slit lights projected onto different positions of the fundus Ef of the eye under examination E. Here, the case of using two slit lights (a first slit light and a second slit light) is described, but those skilled in the art will readily appreciate that the same principles can be employed when using three or more slit lights. The first and second slit lights may be output, for example, sequentially or simultaneously.

[0127] The method of generating the first slit light and the second slit light with different projection positions on the fundus Ef of the eye to be examined E is arbitrary. In some embodiments, it is possible to use Figure 3 The iris diaphragm 21 shown has two openings 21A and 21B (referred to as the first opening 21A and the second opening 21B). Furthermore, these methods are performed, for example, in a state where the deflection direction of the slit light generated by the optical scanner 30 is fixed to a predetermined direction (i.e., the orientation of the mirror surface of the optical scanner 30 is fixed to a predetermined direction).

[0128] For example, the slit light generated based on the light passing through the first opening 21A is used as the first slit light, and the slit light generated based on the light passing through the second opening 21B is used as the second slit light, thereby generating the first slit light and the second slit light with different projection positions on the fundus Ef of the examined eye E.

[0129] Therefore, in one possible configuration example, a first shutter for blocking and opening the first opening 21A and a second shutter for blocking and opening the second opening 21B are provided. By alternately blocking and opening the first and second openings 21A and 21B under the control of the projection control unit 401, the first and second slit lights can be sequentially generated at different projection positions on the fundus Ef of the eye under examination E. For example, by opening the first opening 21A and closing the second opening 21B, the first slit light can be selectively generated, while by closing the first opening 21A and opening the second opening 21B, the second slit light can be selectively generated. Alternatively, by opening both the openings 21A and 21B, the first and second slit lights can be generated simultaneously.

[0130] The first shutter and the second shutter used in this embodiment are extremely simple and small-scale devices compared to the focus-dedicated hardware elements (focus index projection optical system and its moving mechanism) provided in conventional ophthalmic apparatuses of the same type.

[0131] In another configuration example, the light source 10 includes a first light source that emits light that passes only through the first opening 21A and a second light source that emits light that passes only through the second opening 21B. By alternately activating the first and second light sources under the control of the projection control unit 401, the first and second slit lights can be sequentially generated, projected at different locations on the fundus Ef of the eye under examination E. For example, by activating the first light source and deactivating the second light source, the first slit light can be selectively generated, while by deactivating the first light source and activating the second light source, the second slit light can be selectively generated. Furthermore, by activating both the first and second light sources, the first and second slit lights can be generated simultaneously.

[0132] The first light source and the second light source used in this embodiment are extremely simple and small-scale devices compared to the focusing-dedicated hardware elements (focus index projection optical system and its moving mechanism) provided in conventional ophthalmic apparatuses of the same type.

[0133] In other methods for generating the first and second slit lights, the optical scanner 30 can be utilized. In this method, the projection control unit 401 generates the first slit light by aligning the mirror of the optical scanner 30 in a first orientation and in a second orientation to generate the second slit light. This allows the first and second slit lights to be projected at different positions on the fundus Ef of the eye under examination E. In this method, the first and second slit lights can be generated without adding any hardware components.

[0134] According to any of the above-described methods or other methods, the projection control section 401 causes the imaging unit 2 to output the first slit light and the second slit light to be projected to different positions of the fundus Ef of the eye to be examined.

[0135] The imaging unit 2 acquires, through the imaging optical system 40 and the imaging device 50, a first image depicting a projection image of the first slit light onto the fundus Ef of the subject's eye E (first slit light image), and a second image depicting a projection image of the second slit light onto the fundus Ef of the subject's eye E (second slit light image). When the first slit light and the second slit light are generated sequentially, that is, when the first slit light projection and the second slit light projection are respectively performed onto the fundus Ef of the subject's eye E, the first image and the second image are different images. Furthermore, when the first slit light and the second slit light are generated simultaneously, that is, when the first slit light projection and the second slit light projection are performed simultaneously onto the fundus Ef of the subject's eye E, the first image and the second image are the same image.

[0136] The condition determination unit 402 detects a first slit light image from the first image and obtains first position information indicating the position of the first slit light image on the first image. Similarly, the condition determination unit 402 detects a second slit light image from the second image and obtains second position information indicating the position of the second slit light image on the second image. For example, the first position information may be one or more coordinates expressed in a coordinate system defined in the first image (e.g., a coordinate system representing pixel positions), and the second position information may be one or more coordinates expressed in a coordinate system defined in the second image (e.g., a coordinate system representing pixel positions).

[0137] The condition determination unit 402 determines the focus adjustment condition based on the relative positions of the first slit light image and the second slit light image. More specifically, the condition determination unit 402 may determine the difference between the coordinates of the first slit light image indicated by the first position information (the first coordinate) and the coordinates of the second slit light image indicated by the second position information (the second coordinate), and determine the focus adjustment condition based on the difference in the coordinates.

[0138] Next, the principle of focus adjustment according to the first embodiment and some non-limiting specific examples will be described.

[0139] To this end, first, the optical path of the illumination optical system 20 that projects slit light used for focus adjustment toward the fundus Ef of the eye E to be examined will be described. Figure 7 Shown by Figures 2 to 4 The optical system shown forms a non-limiting example of a light path. Figure 7 The upper layer is the top view, and the lower layer is the side view. Figure 7 The optical paths are optical paths when the two openings 21A and 21B of the iris diaphragm 21 are positioned as object points.

[0140] Light output from the light source 10 illuminates the iris diaphragm 21. A portion of the light (first light) passing through the first opening 21A of the iris diaphragm 21 passes through the slit 22A of the slit aperture diaphragm 22, thereby generating first slit light. Similarly, a portion of the light (second light) passing through the second opening 21B of the iris diaphragm 21 passes through the slit 22A of the slit aperture diaphragm 22, thereby generating second slit light.

[0141] Here, the first light passing through the first opening 21A may be, for example, light that passes through the first opening 21A when the first shutter is open, or light emitted from the first light source and passes through the first opening 21A. Similarly, the second light passing through the second opening 21B may be, for example, light that passes through the second opening 21B when the second shutter is open, or light emitted from the second light source and passes through the second opening 21B.

[0142] In the illumination optical system 20, the iris diaphragm 21 (first opening 21A and second opening 21B), the optical scanner 30, and the Hall mirror 45 are arranged in a substantially optically conjugate positional relationship with each other. When properly aligned, these elements of the illumination optical system 20 are arranged in a substantially optically conjugate position with the anterior ocular segment Ea (e.g., the pupil).

[0143] The first slit light generated by the iris diaphragm 21 and the slit aperture diaphragm 22 is relayed by the relay lens 23 and formed on the mirror surface of the optical scanner 30, and is deflected by the mirror surface. The first slit light deflected by the optical scanner 30 is relayed by the relay lens 31 and formed on the reflective portion (mirror portion) of the Hall mirror 45, and is deflected by the reflective portion. The first slit light deflected by the Hall mirror 45 is converted into converging light by the objective lens 46 and enters the eye E to be examined, temporarily forming an image on the anterior ocular segment Ea (for example, the pupil) and projected onto the fundus Ef. While the first slit light is projected onto the fundus Ef, photography is performed using the photographing optical system 40 and the camera device 50, thereby obtaining an image (the aforementioned first image) depicting the first slit light image corresponding to the first slit light.

[0144] Similarly, when the second slit light generated by the iris aperture 21 and the slit opening aperture 22 is projected onto the fundus Ef, shooting is performed using the shooting optical system 40 and the camera device 50, thereby obtaining an image depicting a second slit light image corresponding to the second slit light (the aforementioned second image).

[0145] When the focus of the illumination optical system 20 coincides with the fundus Ef, as shown in FIG. Figure 8 As shown, the first slit light L1 and the second slit light L2 are projected onto substantially the same position on the fundus Ef. In other words, when the focus of the illumination optical system 20 coincides with the fundus Ef, the intersection position C of the first slit light L1 and the second slit light L2 is located on the fundus Ef.

[0146] On the other hand, when the focus of the illumination optical system 20 does not coincide with the fundus Ef, as shown in FIG. Figure 9 As shown, the position on the fundus Ef projected by the first slit light L1 is different from the position on the fundus Ef projected by the second slit light L2. In other words, when the focus of the illumination optical system 20 does not coincide with the fundus Ef, the intersection position C of the first slit light L1 and the second slit light L2 is located at a position separated from the fundus Ef.

[0147] also, Figure 9The upper diagram shows a state where the intersection position C of the first slit light L1 and the second slit light L2 is arranged on the front side (on the anterior segment Ea side) relative to the fundus Ef, that is, a state in which the fundus Ef is so-called "front focus". The lower diagram shows a state where the intersection position C of the first slit light L1 and the second slit light L2 is arranged on the rear side relative to the fundus Ef, that is, a state in which the fundus Ef is so-called "back focus".

[0148] like Figure 8 As shown in FIG, when the focus of the illumination optical system 20 coincides with the fundus Ef, the first slit light L1 and the second slit light L2 are projected onto substantially the same position of the fundus Ef. Figure 10 An example of the fundus image acquired at this time is shown. Figure 10 In the fundus image, the first slit light image G1 , which is a fundus projection image of the first slit light L1 , and the second slit light image G2 , which is a fundus projection image of the second slit light L2 , are drawn at substantially the same position.

[0149] On the other hand, Figure 9 As shown, when the focus of the illumination optical system 20 does not coincide with the fundus Ef, the first slit light L1 and the second slit light L2 are projected onto mutually different positions of the fundus Ef. Figure 11 An example of the fundus image acquired at this time is shown in .

[0150] Figure 11 The fundus image on the left is Figure 9 This is an image obtained when the image is in "front focus" as in the upper layer. In this fundus image, the first slit light image G1 (the fundus projection image of the first slit light L1) and the second slit light image G2 (the fundus projection image of the second slit light L2) are depicted at different positions. More specifically, the first slit light image G1 is depicted below the center position in the vertical direction of the fundus image frame, and the second slit light image G2 is depicted above it.

[0151] in addition, Figure 11 The fundus image on the right is Figure 9 The image is obtained when the lens is in "back focus" as in the lower layer of the image. In this fundus image, the first slit light image G1 (the fundus projection image of the first slit light L1) and the second slit light image G2 (the fundus projection image of the second slit light L2) are depicted at different positions. More specifically, the first slit light image G1 is depicted above the center position in the vertical direction of the frame of the fundus image, and the second slit light image G2 is depicted below.

[0152] Thus, according to the first embodiment, instead of using the (complex and large-scale) focusing-dedicated hardware elements of the existing ophthalmic devices of the same type, the hardware elements possessed by the existing slit scanning fundus imaging modality are utilized to determine whether the focus of the imaging unit 2 is consistent with the fundus Ef of the eye under examination E.

[0153] Furthermore, according to the first embodiment, the direction in which the focus of the imaging unit 2 deviates with respect to the fundus Ef can be determined (that is, whether the focus state is front focus or back focus can be determined).

[0154] Furthermore, although details will be described later, according to the first embodiment, it is also possible to determine the amount by which the focus of the imaging unit 2 is deviated from the fundus oculi Ef.

[0155] According to the first embodiment, instead of using the (complex and large-scale) dedicated focusing hardware elements of the existing ophthalmic devices of the same type, the hardware elements possessed by the existing slit scanning fundus imaging modality are utilized, so that the imaging unit 2 can automatically focus on the fundus Ef of the inspected eye E.

[0156] The details will be described later, but in some methods, by projecting the first slit light L1 and the second slit light onto the fundus Ef respectively, a first image depicting the first slit light image G1 and a second image depicting the second slit light image G2 are obtained. By comparing the above two images, parameters related to the focusing state (for example, the direction and / or amount of deviation of the focus) can be determined.

[0157] In other embodiments, a single image is acquired by simultaneously projecting a first slit light L1 and a second slit light L2 having different characteristics (e.g., wavelength, intensity (light amount)) onto the fundus Ef. Based on the relative positions of the first slit light image G1 and the second slit light image G2 in the image, parameters related to the focus state (e.g., the direction and / or amount of focus deviation) can be determined. Furthermore, when the first slit light L1 and the second slit light L2 are projected separately onto the fundus Ef, the first slit light L1 and the second slit light L2 having different characteristics can be projected onto the fundus Ef.

[0158] The condition determination unit 402 refers to Figures 8 to 11 The focus adjustment condition is determined based on the principle described above. The condition determination unit 402 is configured to determine the focus adjustment condition based on the output (e.g., the first image, the second image) from the imaging device 50 that detects the return light of the slit light (e.g., the first slit light L1, the second slit light L2) projected onto the fundus Ef of the eye E under the slit light projection control.

[0159] In some embodiments, the condition determination unit 402 is configured to determine the focus adjustment condition based on the position of the slit light image (e.g., the first slit light image G1, the second slit light image G2) in the image (e.g., the first image, the second image) generated by the camera device 50, which detects the return light of the slit light (e.g., the first slit light L1, the second slit light L2) projected onto the fundus Ef of the inspected eye E through the slit light projection control.

[0160] The method for determining the position of the slit light image in the fundus image is arbitrary. In some embodiments, the condition determination unit 402 determines the position of the slit light image based on the brightness distribution of at least a portion of the image region of the slit light image along a first direction corresponding to the direction of movement of the projection position of the slit light generated by the imaging unit 2.

[0161] In some embodiments, the slit length direction of the slit 22A of the slit aperture 22 corresponds to the X direction, and the direction of movement (scanning direction) of the projection position of the slit light corresponds to the Y direction. In the fundus image acquired by the imaging unit 2, the direction corresponding to the X direction is also referred to as the X direction, and the direction corresponding to the Y direction is also referred to as the Y direction. The long side direction of the slit light image depicted in the fundus image is the X direction.

[0162] The condition determination unit 402 first generates a brightness distribution for the slit light image. This brightness distribution can be defined for the entire slit light image or for a portion of the image region. Furthermore, as a preparation for generating the brightness distribution, the condition determination unit 402 can apply segmentation to at least a portion of the fundus image to identify the slit light image within the fundus image and thereby determine the range within which the brightness distribution generation process is applied. The brightness distribution generated by the condition determination unit 402 represents the distribution of brightness in a first direction (the Y direction in the fundus image) corresponding to the scanning direction (the Y direction in real space).

[0163] Generate according to Figure 12A The brightness distribution of the slit light image G depicted in the fundus image shown in FIG. Figure 12A In the figure, the X direction (+X direction) is the right direction, and the Y direction (+Y direction) is the downward direction.

[0164] The condition determination unit 402 first sets an analysis area H (see FIG. Figure 12B As described above, the analysis region H may be set by segmentation or may be set at a predetermined position.

[0165] In the exemplary analysis region H, multiple pixels are arranged in the X and Y directions (i.e., two-dimensionally). In other words, the analysis region H includes multiple columns of pixels along the Y direction, and these multiple columns of pixels are arranged in the X direction. The condition determination unit 402 generates a brightness distribution along the Y direction by summing the brightness values of the multiple pixels two-dimensionally arranged in the analysis region H in the X direction.

[0166] In other approaches, a linear analysis region (one-dimensional analysis region) along the Y direction can be set to generate a brightness distribution for this one-dimensional analysis region. This method has the advantage of simplicity, but has the disadvantage that if noise enters the one-dimensional analysis region, its impact is directly reflected in the brightness distribution. Therefore, the method using a two-dimensional analysis region (H) has the advantage of reducing the impact of noise. Furthermore, the method using a two-dimensional analysis region (H) can emphasize the difference in brightness between the slit light image G and other image regions (generally, the former is greater and the latter is less), thereby improving the quality of the brightness distribution (e.g., precision, accuracy, and reproducibility).

[0167] exist Figure 12C An example of the brightness distribution of the slit light image G is shown in FIG. In some embodiments, the condition determination unit 402 finds the maximum value (MAX) and the minimum value (MIN) of the brightness distribution P, and finds their middle (center) value TH: TH = (MAX-MIN) / 2. The condition determination unit 402 finds the intersection of the brightness distribution P and the straight line "brightness = TH". There are two such intersections. Let the Y coordinates of the two intersections be Y1 and Y2. The condition determination unit 402 finds the middle (center) value Y(G) of the Y coordinates Y1 and Y2 of the two determined intersections: Y(G) = abs(Y1-Y2) / 2. Here, abs(α) represents the absolute value of the value α. In this embodiment, the value Y(G) thus obtained is used as the position (representative position, center of gravity position) of the slit light image G (refer to Figure 12D ).

[0168] The method for determining the position of the slit light image is not limited to the above method. For example, in the above method, the median value TH between the maximum value (MAX) and the minimum value (MIN) of the brightness distribution is determined (TH = (MAX - MIN) / 2). However, more generally, the equation "TH = (MAX - MIN) / R" can be used. Here, R can be a predetermined real number or a real number set based on the brightness distribution (or equivalent information).

[0169] In some embodiments, the position of the slit light image can be determined by considering the area under the curve (AUC) of the luminance distribution. For example, assuming the area under the curve of the overall luminance distribution is A, the Y coordinate that divides the area under the curve A into a predetermined ratio can be determined, and this Y coordinate can be used as the position (representative position, center of gravity) of the slit light image. As a specific example, the Y coordinate that divides the area under the curve A into a 1:1 ratio can be determined as the slit light image.

[0170] In other embodiments, the value TH may be a fixed value. The method for determining the fixed value TH is arbitrary. For example, the fixed value TH may be obtained by applying statistical calculations to a plurality of clinically collected data, or may be obtained based on data obtained through measurements using a model eye, or may be obtained through simulations such as ray tracing, or may be obtained by any combination of the above methods, or may be obtained using other methods.

[0171] The condition determination unit 402 determines the focus adjustment condition based on the position information of the slit light image acquired in this manner.

[0172] First, further reference Figure 13A and Figure 13B , explaining the principle of the processing performed to determine the focus adjustment conditions (position adjustment amount of the slit opening aperture 22, position adjustment amount of the focusing lens 47) based on the position (Y coordinate) of the slit light image.

[0173] Figure 13A The figure shows the path of light projected by the illumination optical system onto the fundus Ef of the eye E to be examined. Reference numeral 100 denotes a predetermined target 100 on the optical axis E0 of the eye to be examined E. Reference numeral 110 denotes an optical system located between the target 100 and the eye to be examined E. The focal length of the optical system 110 is denoted by F. The axial length of the eye to be examined E is denoted by L, and the refractive power is denoted by D.

[0174] Consider a case where light (parallel light) 120 emitted from a target 100 is projected onto the eye E to be examined via an optical system 110. Let h be the height (distance from the optical axis E0) of the light 120 incident on the eye E. Light 120 incident on the eye E is refracted by the ocular optical system (cornea, lens, etc.) and projected onto position 130 of the fundus Ef.

[0175] Here, in Figures 2 to 4 In the optical system shown, the height h of the light 120 is half the distance between the two openings 21A and 21B of the iris diaphragm 21 arranged substantially optically conjugate with the pupil of the eye E to be examined.

[0176] When the eye E under examination is emmetropic (0 diopter), the projection position 130 of the light 120 on the fundus Ef is located at the center of the fundus Ef (i.e., on the optical axis E0). In contrast, when the eye E under examination is not emmetropic, the projection position 130 of the light 120 on the fundus Ef is offset by a distance Δ from the optical axis E0 (offset Δ>0).

[0177] The reference numeral 140 denotes the conjugate point of the fundus Ef corresponding to the refractive power D of the eye E to be examined. The distance from the eye E to the conjugate point 140 is represented by L'. Here, L' = 1000 / D. Thus, according to Figure 13A It can be seen that Δ / L = h / L', and therefore Δ = L × h / L'. As previously described, the height h of the light 120 is a fixed value determined by the iris diaphragm 21. Therefore, the amount Δ by which the projection position 130 of the light 120 on the fundus Ef is offset from the optical axis E0 of the eye E varies depending on the refractive power D of the eye E (i.e., the distance L' between the eye E and the conjugate point 140) and the axial length L of the eye E. Furthermore, when the target 100 is annular or arcuate, the amount by which the projection position 130 of the light 120 on the fundus Ef is offset from the optical axis E0 of the eye E is represented by Δ.

[0178] Figure 13B The following shows the path of light when an image is captured using an imaging optical system that arranges a target image (projection image of target 100) coaxially with the optical axis E0, wherein the target image (projection image of target 100) is projected onto the fundus Ef at a position offset by Δ from the optical axis E0 of the eye to be examined E. Reference numeral 160 denotes an imaging plane (imaging plane of the imaging device 50), and reference numeral 150 denotes an optical system located between the eye to be examined E and the imaging plane 160. The focal length of the optical system 150 is the same as Figure 13A The focal length of the optical system 110 is the same, set to F.

[0179] When the eye E under examination is emmetropic, light 170 emitted from projection position 130 on the fundus Ef passes through optical system 150 and forms an image at a position where imaging plane 160 intersects optical axis E0. In contrast, when the eye E under examination is not emmetropic, the image position of light 170 on imaging plane 160 is offset by a distance Δ′ from optical axis E0 (offset Δ′>0). In this case, the image position along optical axis E0 (Z direction) is also offset.

[0180] according to Figure 13B It can be seen that Δ / L = Δ' / F, so Δ' = F × Δ / L. As mentioned above, Δ = L × h / L', so Δ' = F × h / L'. Furthermore, L' = 1000 / D, so Δ' = F × h × D / 1000.

[0181] Therefore, the refractive power D of the eye E on a specific meridian is expressed by the following formula: D = (1000 × Δ′) / (F × h). Here, F is the focal length of the imaging optical system, and h is half the distance between the two openings 21A and 21B of the iris diaphragm 21, both of which are known. Therefore, by determining the deviation Δ′ of the light 170 on the imaging plane 160, the refractive power D of the eye E on the specific meridian is obtained.

[0182] In an existing ophthalmic device of the same type as the ophthalmic device 1 of the first embodiment, information is pre-provided that indicates the relationship between the refractive power of the eye to be examined and the adjustment amount (movement distance) of the optical element for focus adjustment (the aforementioned focus index projection optical system and focusing lens), and focus adjustment corresponding to the refractive power of the eye to be examined is performed by referring to this information.

[0183] Similarly, some forms of the ophthalmologic apparatus 1 have in advance an optical element for indicating the refractive power of the eye to be examined and for adjusting the focus (in Figures 2 to 4 The optical system shown in FIG. 1 shows information regarding the relationship between the adjustment amounts (movement distances) of the slit aperture 22 and the focus lens 47. The ophthalmic apparatus 1 refers to this information to determine focus adjustment conditions based on the position of the slit light image in the image generated by the imaging device 50. The focus adjustment conditions include the movement direction and amount (or information corresponding thereto) of the slit aperture 22 and the movement direction and amount (or information corresponding thereto) of the focus lens 47.

[0184] In other embodiments, the ophthalmic apparatus 1 pre-stores information indicating the relationship between the relative positions (the interval in the Y direction) of the two slit light images and the adjustment amount of the focus adjustment optical element. In this case, the ophthalmic apparatus 1 can determine the focus adjustment conditions based on the positions of the slit light images in the image generated by the imaging device 50 by referring to this information.

[0185] More generally, the ophthalmologic apparatus 1 of the first embodiment may be configured to determine the focus adjustment condition based on arbitrary information that can be obtained from information (typically, an image) generated by imaging the fundus Ef onto which the slit light is projected.

[0186] The focus adjustment control unit 403 controls the focus adjustment unit 3 (focus adjustment control) based on the focus adjustment conditions determined by the condition determination unit 402 according to any of the above-mentioned methods. The focus adjustment control in this example includes: controlling the moving mechanism 22M based on the movement direction and movement amount of the slit aperture 22 (or information corresponding thereto) included in the focus adjustment conditions; and controlling the moving mechanism 47M based on the movement direction and movement amount of the focus lens 47 (or information corresponding thereto) included in the focus adjustment conditions.

[0187] In some embodiments, the slit aperture 22 and the focus lens 47 may be driven by a single moving mechanism. In this case, the condition determination unit 402 may determine a focus adjustment condition, and the focus adjustment control unit 403 may control the single moving mechanism based on the single focus adjustment condition.

[0188] In the above-mentioned example, the ophthalmic device 1 controls the imaging unit 2 in the slit light projection control so that slit light projected toward the fundus Ef of the eye E to be examined is emitted from a position (opening 21A or 21B of the iris aperture 21) separated by a predetermined distance (height h) relative to the optical axis of the imaging unit 2 (when properly aligned, the optical axis O of the imaging unit 2 is substantially consistent with the optical axis E0 of the eye E to be examined).

[0189] Furthermore, in the condition determination processing, the ophthalmic device 1 determines the focus adjustment conditions (the moving direction and amount of the slit opening aperture 22 or information corresponding to these, and the moving direction and amount of the focusing lens 47 included in the focus adjustment conditions or information corresponding to these) based on the predetermined distance (height h), the position of the slit light image in the image generated by the camera device 50 of the shooting unit 2 (offset Δ′) and the focal distance (F) of the shooting unit 2.

[0190] Then, the ophthalmologic apparatus 1 controls the focus adjustment unit 3 (the moving mechanism 22M and the moving mechanism 47M) based on the focus adjustment condition obtained by the condition determination process.

[0191] Regarding the operations performed by the ophthalmologic apparatus 1 according to the first embodiment, some non-limiting examples will be described. Figure 14 2 shows an example of an operation for autofocusing performed by the ophthalmologic apparatus 1 .

[0192] Before the autofocus operation, the ophthalmologic apparatus 1 aligns the imaging unit 2 with respect to the fundus Ef of the eye E to be examined (S1). After the alignment is completed, the ophthalmologic apparatus 1 begins autofocusing (S2). Furthermore, tracking may be performed to maintain the proper alignment achieved in step S1. Tracking refers to the process of moving the apparatus optical system in accordance with the movement of the eye E to maintain the proper positional relationship (proper alignment) between the eye E and the imaging unit 2.

[0193] In the autofocusing of this working example, the projection control unit 401 first positions the mirror surface of the optical scanner 30 at a predetermined neutral position (0-degree position) (S3). The 0-degree position is, for example, the center position of the movable range of the mirror surface of the optical scanner 30. The autofocusing of this working example is performed with the orientation of the mirror surface of the optical scanner 30 fixed, that is, with the operation of the optical scanner 30 stopped.

[0194] Next, the projection control unit 401 controls the light source 10 and / or the illumination optical system 20 so that illumination light is output from only one of the two openings 21A and 21B of the iris diaphragm 21 (for example, the first opening 21A). A portion of the illumination light emitted from the first opening 21A is converted into slit light (first slit light) by the slit 22A of the slit aperture diaphragm 22. The first slit light is relayed by the relay lens 23, deflected by the stopped optical scanner 30, relayed by the relay lens 31, deflected by the mirror portion of the Hall mirror 45, and refracted by the objective lens 46. The light enters the eye E to be examined and is projected onto the fundus Ef. The imaging optical system 40 and the imaging device 50 capture the fundus Ef projected with the first slit light, generating an image (first imaging: S4).

[0195] The image obtained by the first shooting in step S4 is referred to as the first image. Figure 15 Two examples of the first image are shown. Figure 15 The fundus image 200A on the left side is an example of an image obtained when the focus state is the front focus, and a slit light image G1 (first slit light image G1) is depicted below the center position in the Y direction of the fundus image 200A. Figure 15 The fundus image 200B on the right side is an example of an image obtained when the focus state is back focus, and a slit light image G1 (first slit light image G1 ) is depicted above the center position in the Y direction of the fundus image 200B.

[0196] Next, the projection control unit 401 controls the light source 10 and / or the illumination optical system 20 so that illumination light is output only from one of the two openings 21A and 21B of the iris diaphragm 21 (e.g., the second opening 21B). A portion of the illumination light emitted from the second opening 21B is converted into slit light (second slit light) by the slit 22A of the slit aperture diaphragm 22. The second slit light travels the same path as the first slit light and is projected onto the fundus Ef. The imaging optical system 40 and the imaging device 50 capture an image of the fundus Ef projected with the second slit light (second imaging: S5).

[0197] The image obtained by the second shooting in step S5 is referred to as the second image. Figure 16 Two examples of the second image are shown in . Figure 16 The fundus image 210A on the left side is an example of an image obtained when the focus state is the front focus, and a slit light image G2 (second slit light image G2) is depicted above the center position in the Y direction of the fundus image 210A. Figure 16The fundus image 210B on the right side is an example of an image obtained when the focus state is back focus, and a slit light image G2 (second slit light image G2) is depicted below the center position in the Y direction of the fundus image 210B.

[0198] In this working example, the second shot is performed after the first shot, but in other working examples, the first shot may be performed after the second shot. Furthermore, the number of shots performed for autofocus is not limited to two (the first shot and the second shot) and may be three or more. Those skilled in the art will appreciate that even when three or more shots are performed, autofocus may be performed using the same process as in this working example. Furthermore, as described later, the number of shots performed for autofocus may be only one.

[0199] The first image acquired in step S4 and the second image acquired in step S5 are input to the condition determination unit 402 .

[0200] As an optional process, the condition determination unit 402 can perform registration (alignment) between the first image and the second image. This registration includes, for example, the process of detecting feature points in the first image, the process of detecting feature points in the second image, the process of calculating the positional deviation between the first image and the second image based on the feature points in the first image and the feature points in the second image, and the process of adjusting the relative position between the first image and the second image to offset the positional deviation. The feature points used as the basis for registration are predetermined landmarks of the fundus oculi Ef, such as tissues such as the optic disc, macula, blood vessels, or lesions, treatment scars, etc. The condition determination process can be applied to the first image and the second image that have undergone such registration. In addition, a process of calculating the positional deviation between the first image and the second image can be performed, and this positional deviation can be reflected in the condition determination process.

[0201] Hereinafter, a case where the focus state is front focus will be described as a specific example of the process executed by the condition determination unit 402. The same process can be executed also when the focus state is back focus.

[0202] Further references Figure 17 . Figure 17 The left fundus image 200A is an example of an image acquired by the first shooting in step S4 when the focus state is the front focus, and the left fundus image 210A is an example of an image acquired by the second shooting in step S5 when the focus state is the front focus.

[0203] The condition determination unit 402 analyzes the fundus image 200A acquired through the first imaging step S4 to detect the first slit light image G1 and calculates the position (Y(G1)) of the detected first slit light image G1 (S6). Similarly, the condition determination unit 402 analyzes the fundus image 210A acquired through the second imaging step S5 to detect the second slit light image G2 and calculates the position (Y(G2)) of the detected second slit light image G2 (S7).

[0204] Next, the condition determination unit 402 estimates the refractive power of the eye E based on the relative position between the first slit light image G1 obtained in step S6 and the second slit light image G2 obtained in step S7 ( S8 ).

[0205] Next, the condition determination unit 402 determines the movement conditions (movement direction and movement amount) of the slit aperture 22 and the movement conditions (movement direction and movement amount) of the focusing lens 47 based on the estimated value of the refractive power of the examined eye E obtained in step S8 (S9).

[0206] The movement direction included in the movement condition determined in step S9 is determined based on the positional relationship between the first slit light image G1 and the second slit light image G2. In this example, the first slit light image G1 is located below the second slit light image G2, so it is determined that the focus is located in front of the fundus Ef (on the side of the anterior ocular segment Ea) (i.e., it is the front focus). On the other hand, when the first slit light image G1 is located above the second slit light image G2, it is determined that the focus is located in the back of the fundus Ef (i.e., it is the back focus). In addition, as mentioned above, the relationship between the positional relationship of the two slit light images and the direction of focus deviation is known information determined by the structure of the optical system of the imaging unit 2.

[0207] The movement amount included in the movement conditions determined in step S9 is determined based on information recording the relationship between the eye's refractive power (vision) and the movement amount of the focus adjustment optical elements (in this working example, the slit aperture 22 and the focusing lens 47). This information is pre-generated and stored in, for example, the memory 5.

[0208] The focus adjustment conditions determined by the condition determination unit 402 (in this operation example, the movement conditions of the slit aperture 22 and the movement conditions of the focus lens 47 determined in step S9 ) are sent to the focus adjustment control unit 403 .

[0209] The focus adjustment control unit 403 controls the focus adjustment unit 3 based on the focus adjustment condition determined in step S9 (S10). In this operation example, the focus adjustment control unit 403 controls the moving mechanism 22M based on the movement condition of the slit aperture diaphragm 22 determined in step S9, thereby moving the slit aperture diaphragm 22 in the movement direction indicated by the movement condition and by the movement amount indicated by the movement condition. The focus adjustment control unit 403 also controls the moving mechanism 47M based on the movement condition of the focus lens 47, thereby moving the focus lens 47 in the movement direction indicated by the movement condition and by the movement amount indicated by the movement condition.

[0210] Through the above-described steps, automatic focus adjustment of the imaging unit 2 (illumination optical system 20 and imaging optical system 40) is achieved according to the refractive power of the eye E to be examined. Specifically, the focal points of the illumination optical system 20 and the imaging optical system 40 are automatically positioned on (or near) the fundus Ef of the eye E to be examined. Once this automatic focus is completed (S11), the ophthalmologic apparatus 1 can begin imaging the fundus Ef (slit scanning).

[0211] exist Figure 18 2 shows another example of the operation for autofocusing executed by the ophthalmologic apparatus 1 according to the first embodiment.

[0212] exist Figure 14 In the working example, the focus adjustment conditions are determined based on the relative positions of the two slit light images. However, a situation in which one of the two slit light images cannot be detected is assumed. For example, if the eye E under examination has a small pupil, it is conceivable that one of the first and second slit light images is vignetted by the iris and does not form a slit light image. In addition, if the eye E under examination has a cataract, one of the first and second slit light images may be blocked by a cloudy portion of the lens and not form a slit light image, or may be weakened (attenuated) by the cloudy portion of the lens and the slit light image may become unclear. This working example provides automatic focusing that can be applied when such a problem occurs.

[0213] Steps S21 to S27 are respectively Figure 14 The steps S1 to S7 are performed in the same manner as in the above. In addition, in the steps S26 and S27 of this working example, not only the case where the position of the slit light image is detected but also the case where no slit light image is detected is assumed.

[0214] If the position of the first slit light image is not detected in step S26, or if the position of the second slit light image is not detected in step S27 (S28: No), the process proceeds to step S29. Specifically, if the position of the first slit light image fails to be detected in step S26 but the position of the second slit light image is successfully detected in step S27, the process proceeds to step S29. Alternatively, if the position of the first slit light image is successfully detected in step S26 but the position of the second slit light image is unsuccessful in step S27, the process proceeds to step S29.

[0215] On the other hand, when the detection of the position of the first slit light image is successful in step S26 and the detection of the position of the second slit light image is also successful in step S27 ( S28 : YES), the process proceeds to step S30 .

[0216] Although not shown in the figure, if the detection of the position of the first slit light image fails in step S26 and the detection of the position of the second slit light image also fails in step S27, the ophthalmic apparatus 1 may output an error message or a warning message, for example, through the user interface 6. In this case, the ophthalmic apparatus 1 may restart the focus adjustment (and the alignment process as a previous step) from the beginning (i.e., the process may return to step S21 or S23). Alternatively, the ophthalmic apparatus 1 may switch from the automatic focus mode to the manual focus mode. In the manual focus mode, the user manually performs the focus adjustment using the user interface 6 while referring to the observation image of the fundus Ef.

[0217] When only one of the position detection of the first slit light image and the position detection of the second slit light image is successful (S28: No), the condition determination unit 402 estimates the refractive power of the examined eye E based on the relative position between the detected position of the slit light image and the predetermined reference position (S29).

[0218] The method for determining the reference position referenced in step S29 is arbitrary. For example, the reference position can be determined based on data obtained through measurement using a model eye, or can be determined using simulations such as ray tracing, or can be determined based on data obtained through measurement of a healthy eye (one that does not have conditions such as small pupils or cataracts that could hinder the autofocusing of this embodiment), or can be determined using any combination of these methods, or other methods can be used. In the method using a model eye, for example, by performing steps S23 to S27 to determine the position where the two slit light images coincide, this position can be used as the reference position. The reference position can also be determined using the same principles for other methods.

[0219] For example, when detecting Figure 15 When the slit light image G1 of the fundus image 200A on the left side is Figure 19 The position (Y(G1)) of the slit light image G1 is determined as shown, and the refractive power of the examined eye E is estimated based on the relative position (ΔY) of the determined position (Y(G1)) of the slit light image G1 with respect to the reference position (Y0).

[0220] When both the position detection of the first slit light image and the position detection of the second slit light image are successful (S28: No), the condition determination unit 402 determines the position of the first slit light image and the position of the second slit light image. Figure 14 The refractive power of the eye E to be examined is estimated in the same manner as in step S8 (S30).

[0221] Next, the condition determination unit 402 determines the movement conditions (movement direction and movement amount) of the slit aperture 22 and the movement conditions (movement direction and movement amount) of the focusing lens 47 based on the estimated value of the refractive power of the eye E obtained in step S29 or S30 (S31). The movement direction is determined based on the positional relationship between the slit light image and the reference position. The method for determining the movement amount can be the same as that of Figure 14 The same is true for step S9.

[0222] Next, the focus adjustment control unit 403 controls the focus adjustment unit 3 based on the focus adjustment condition determined in step S31 (S32). Figure 14 The same procedure as step S10 is performed. The above completes the automatic focusing (S33) of this working example.

[0223] exist Figure 14 Examples of work and Figure 18 In the working example, two shots (first shot and second shot) are performed for autofocusing, but Figure 18 In a variation of the working example, automatic focusing can be performed by a single shot. In this variation, the ophthalmologic apparatus 1 outputs illumination light from only one of the two openings 21A and 21B of the iris diaphragm 21 to perform shooting, finds the position of the slit light image depicted in the fundus image acquired by the shooting, finds the estimated value of the refractive power of the eye under examination based on the relative position of the position of the slit light image and a predetermined reference position, determines the focus adjustment condition based on the estimated value, and controls the focus adjustment unit 3 based on the focus adjustment condition. The reference position used in this variation can be the same as Figure 18 The reference position is the same as in the working example.

[0224] exist Figure 20 2 shows another example of the operation for automatic focusing performed by the ophthalmologic apparatus 1 according to the first embodiment.

[0225] exist Figure 14 Examples of work and Figure 18 In the working example, focus adjustment is performed so that the focal point coincides with a predetermined position (fundus center, image frame center) of the fundus Ef of the examined eye E. In contrast, in this working example, focus adjustment can be performed so that the focal point coincides with an arbitrary position of the fundus Ef. This allows for the acquisition of an image clearly depicting the area of interest of the fundus Ef. Examples of the area of interest include tissues such as the optic nerve head, macula, and blood vessels, as well as lesions and treatment scars.

[0226] In this working example, the ophthalmologic apparatus 1 first begins generating and displaying observation images (real-time dynamic images, real-time video, or time-series images) of the subject's eye E (S41). Generation of the observation images can be performed using any method, such as by alignment components (e.g., two anterior ocular cameras for stereoscopic alignment, a camera for generating frontal images), or by repeated slit scanning. The observation images are displayed using the user interface 6 (display). The ophthalmologic apparatus 1 performs alignment based on the observation images acquired in step S41 (S42).

[0227] In some embodiments, after completing the alignment in step S42, the user uses the user interface 6 (input unit) to specify a desired location (the location of the region of interest, the location of interest) in the displayed observation image (S43). For example, the user touches the desired location in the observation image displayed on a touch screen. Alternatively, the user uses a pointing device to specify the desired location in the observation image displayed on the display.

[0228] In other embodiments, the processor 4 may analyze the observed image to determine the position of interest. In yet other embodiments, the user or the processor 4 may specify the position of interest in a previously acquired image of the fundus Ef, and the processor 4 may perform registration between that image and the observed image to determine the position in the observed image corresponding to the position of interest. In this case, the determined position in the observed image serves as the position of interest in step S43. In yet another embodiment, the user or the processor 4 may specify the position of interest in an observed image generated before alignment, and the processor 4 may perform alignment based on the specified position of interest.

[0229] The ophthalmologic apparatus 1 starts automatic focusing with respect to the position of interest of the fundus Ef specified in step S43 ( S44 ).

[0230] In the automatic focusing of this working example, first, the projection control unit 401 controls the optical scanner 30 so that the mirror surface is oriented in the direction corresponding to the focus position of the fundus Ef specified in step S43 (S45). The direction of the mirror surface of the optical scanner 30 is fixed to this direction. Figure 5 As can be seen from the figures (e.g., ), there is a known relationship between the position (Y coordinate) in the image acquired by the imaging unit 2 and the orientation of the mirror surface of the optical scanner 30. The process of step S45 is executed with reference to this relationship.

[0231] With the mirror surface of the optical scanner 30 fixed in an orientation corresponding to the target position of the fundus Ef specified in step S43 , the projection control section 401 controls the imaging unit 2 to execute the first imaging and the second imaging ( S46 , S47 ).

[0232] The processing of steps S48 to S53 in this working example is respectively carried out in accordance with Figure 14The same method is used to process steps S6 to S11 of the working example. In addition, in some embodiments, it is possible to execute Figure 18 The processing of steps S26 to S33 of the working example is performed instead of the processing of steps S48 to S53.

[0233] Some features and effects of the ophthalmologic apparatus 1 according to the first embodiment will be described.

[0234] An ophthalmologic apparatus 1 includes an imaging unit 2, a focus adjustment unit 3, and a processor 4. The imaging unit 2 is configured to perform imaging using a rolling shutter imaging device 50 (or an imaging device having the same function as a rolling shutter imaging device, such as an imaging unit that combines a global shutter image sensor with a slit aperture) while moving the projection position of slit light onto the fundus Ef of the eye being examined. The focus adjustment unit 3 has a structure for performing focus adjustment of the imaging unit 2. The processor 4 is configured to execute slit light projection control, condition determination processing, and focus adjustment control. In slit light projection control, the processor 4 controls the imaging unit 2 so that slit light is projected onto the fundus Ef. In condition determination processing, the processor 4 determines focus adjustment conditions based on output from the imaging device 50, which detects return light from the slit light projected onto the fundus Ef by the slit light projection control. In focus adjustment control, the processor 4 controls the focus adjustment unit 3 based on the focus adjustment conditions determined by the condition determination processing.

[0235] According to the ophthalmic device 1 of the first embodiment thus constructed, slit light can be projected onto the fundus Ef using the imaging unit 2 that performs slit scanning (a mode that combines movement of the projection position of the slit light with repeated imaging using a rolling shutter camera 50), and focusing conditions can be set using information obtained by imaging the fundus Ef projected with the slit light, thereby performing automatic focusing. Therefore, according to the ophthalmic device 1, focus adjustment can be performed without providing dedicated focus hardware elements, as is the case with existing ophthalmic devices of the same type. At least, according to the ophthalmic device 1, focus adjustment can be performed without providing complex and large-scale dedicated focus hardware elements, as is the case with existing ophthalmic devices of the same type. This can achieve miniaturization of the ophthalmic device, simplification of the structure of the ophthalmic device, and reduction in the manufacturing cost of the ophthalmic device.

[0236] The following describes some features that can be employed in implementing the ophthalmic device 1 of the first embodiment. These features are non-limiting examples. Two or more of these features may be at least partially combined. Furthermore, one or more of these features may be at least partially combined with other matters (such as matters disclosed in this disclosure or publicly known matters).

[0237] In some embodiments, the processor 4 may include a condition determination unit 402 that performs condition determination processing. The condition determination unit 402 may be configured to determine the focus adjustment condition based on the position of the slit light image in the image generated by the imaging device 50 that detects return light of the slit light projected onto the fundus Ef by the slit light projection control.

[0238] In some embodiments, the condition determination unit 402 can also be configured to perform: a process of generating a brightness distribution, which is a brightness distribution of an image area of at least a portion of the slit light image in an image generated by the camera device 50, wherein the camera device 50 detects the return light of the slit light projected to the fundus Ef by the slit light projection control, and the brightness distribution is along a first direction (scanning direction, Y direction, slit width direction) corresponding to the moving direction of the projection position of the slit light in the slit scan; and a process of determining the position of the slit light image based on the brightness distribution.

[0239] In some embodiments, the condition determination unit 402 can also be configured to generate a brightness distribution by adding the brightness of a pixel group of at least a portion of an image area of the slit light image in an image generated by the camera device 50 in a second direction (X direction, slit length direction) orthogonal to the above-mentioned first direction, and the camera device 50 detects the return light of the slit light projected onto the fundus Ef by slit light projection control.

[0240] In some embodiments, the imaging unit 2 may include an illumination optical system 20 (first optical system) that projects slit light toward the fundus Ef of the eye to be examined E, and a photographing optical system 40 (second optical system) that guides return light from the slit light from the fundus Ef to the imaging device 50. Furthermore, the focus adjustment unit 3 may include a first focus adjustment unit for adjusting the focal position of the illumination optical system 20 and a second focus adjustment unit for adjusting the focal position of the photographing optical system 40. In this case, the condition determination unit 402 may be configured to determine a condition for controlling the first focus adjustment unit (first focus adjustment condition) and a condition for controlling the second focus adjustment unit (second focus adjustment condition) as the focus adjustment condition.

[0241] In some embodiments, the illumination optical system 20 may be configured to include a light source 10 and a slit aperture 22 (slit aperture) for generating slit light from light emitted from the light source 10, and project the slit light generated by the slit aperture 22 onto the fundus Ef of the eye to be examined E. Furthermore, the imaging optical system 40 may further include a focus lens 47 (focus lens). Furthermore, the first focus adjustment unit may include a moving mechanism 22M (first moving mechanism) for moving the slit aperture 22 along the optical axis of the illumination optical system 20, and the second focus adjustment unit may include a moving mechanism 47M (second moving mechanism) for moving the focus lens 47 along the optical axis of the imaging optical system 40. In this case, the condition determination unit 402 may be configured to determine a condition for controlling the moving mechanism 22M (first movement control condition) as the first focus adjustment condition and a condition for controlling the moving mechanism 47M (second movement control condition) as the second focus adjustment condition.

[0242] In some embodiments, the first movement control condition for controlling the movement mechanism 22M may include information indicating the movement direction and movement distance of the slit aperture 22, and the second movement control condition for controlling the movement mechanism 47M may include information indicating the movement direction and movement distance of the focus lens 47. The information indicating the movement direction may be any information equivalent to the movement direction, for example, the content of a control signal corresponding to the movement direction (e.g., the positive / negative value of a control pulse). Similarly, the information indicating the movement distance may be any information equivalent to the movement distance, for example, the content of a control signal corresponding to the movement distance (e.g., the number of control pulses).

[0243] In some embodiments, the processor 4 (projection control unit 401) may be configured to control the imaging unit 2 during slit light projection control so that the slit light projected toward the fundus Ef of the subject's eye E is emitted from a position separated by a predetermined distance (height h) from the optical axis of the imaging unit 2. In this case, the condition determination unit 402 may determine the focus adjustment condition based on the position (distance Δ′) of the slit light image in the image generated by the imaging device 50 that detects return light of the slit light projected onto the fundus Ef by the slit light projection control, the focal length (F) of the imaging unit 2, and the height h.

[0244] In some embodiments, the imaging unit 2 may include an optical scanner 30 (optical scanner) that moves the projection position of the slit light on the fundus Ef by deflecting the slit light guided to the eye to be examined E. Furthermore, the processor 4 may include a projection control unit 401 (projection control unit) that performs slit light projection control. The projection control unit 401 may be configured to control the imaging unit 2 so that the slit light is projected onto the fundus Ef in a state where the deflection direction of the slit light generated by the optical scanner 30 is fixed. Furthermore, the condition determination unit 402 may include the projection control unit 401 that performs slit light projection control. Furthermore, the projection control unit 401 may be configured to determine the focus adjustment condition based on the position of the slit light image corresponding to the slit light projected onto the fundus Ef in a state where the deflection direction generated by the optical scanner 30 is fixed.

[0245] In some embodiments, the processor 4 may include a projection control unit 401 (projection control unit) that controls slit light projection. The projection control unit 401 may be configured to control the imaging unit so as to output a first slit light and a second slit light projected at different positions on the fundus Ef of the eye under examination E. The projection of the first slit light and the projection of the second slit light may be performed sequentially or simultaneously, for example. Furthermore, the condition determination unit 402 may be configured to determine the focus adjustment condition based on the relative positions of the first slit light image corresponding to the first slit light and the second slit light image corresponding to the second slit light.

[0246] <Second embodiment>

[0247] The ophthalmic device of the second embodiment will be described. Similar to the ophthalmic device 1 of the first embodiment, the ophthalmic device of the second embodiment has an ophthalmic imaging function for imaging the fundus of a living eye using a slit scanning modality. The device includes an imaging unit 2, a focus adjustment unit 3, a processor 4, a memory 5, and a user interface 6. Any aspects of the first embodiment can be applied to the ophthalmic device of the second embodiment. The second embodiment will be described below, with appropriate reference to aspects of the first embodiment.

[0248] The ophthalmologic apparatus of the second embodiment has Figure 21 The processor 4A shown here replaces Figure 6 The processor 4 shown, processor 4A, is a non-limiting example and includes a first processing module 400A and a second processing module 400B.

[0249] The first processing module 400A performs processing for focus adjustment (particularly, autofocus) and includes a projection control unit 401, a condition determination unit 402, and a focus adjustment control unit 403. The projection control unit 401, the condition determination unit 402, and the focus adjustment control unit 403 each have the same configuration as their counterparts in the first embodiment, and details regarding these components (such as configuration, function, and operation) refer to the first embodiment.

[0250] The second processing module 400B performs processing for monitoring the focus state when acquiring observation images (real-time dynamic images, real-time video, time-series images) of the fundus Ef of the subject's eye E using slit scanning. The second processing module 400B includes an imaging control unit 404 and a focus information generation unit 405 .

[0251] The imaging control unit 404 concurrently executes control for causing the imaging unit 2 to acquire an observation image of the fundus Ef (first imaging control) and control for detecting the focus state of the imaging unit 2 (second imaging control). The first imaging control and the second imaging control may be executed in parallel in any manner, for example, simultaneously, synchronously, alternately, or in a switching manner.

[0252] In the first imaging control, the imaging control unit 404 controls the imaging unit 2 so that a series of imaging by the imaging device 50 is repeated while a series of movements of the projection position of the slit light on the fundus Ef of the eye to be examined are repeated, thereby acquiring time-series images. The first imaging control, for example, repeats Figure 5 Thus, a plurality of images (time-sequential images) corresponding to the repetition of the slit scan are acquired, and the time-sequential images are displayed in real time on the display of the user interface 6, thereby providing an observation image of the fundus oculi Ef.

[0253] Reference Figure 22 A non-limiting example of the first shooting control is described. Figure 22 In the embodiment shown, the second shooting control described later is not combined, and only the first shooting control is shown. Figure 22 The method shown is an example of conventional technology for fundus observation using slit scanning. The processing of the second embodiment will be described later.

[0254] Figure 22 The first shooting control shown includes synchronously and repeatedly controlling the operation of the optical scanner 30 and the output of the slit light (the first slit light and the second slit light). Although not shown in the figure, the repetition of the control of reading out the signal from the camera device 50 (image sensor 51) in a rolling shutter manner and the repetition of the control of displaying the images (time-series images) sequentially acquired by the camera device 50 in real time are also related to the first shooting control. Figure 22 The controls shown are performed synchronously.

[0255] In the first imaging control of this example, the imaging control unit 404 moves the direction of the mirror surface of the optical scanner 30 within a predetermined angular range during the first period T1. Figure 22 In the diagram, the top edge of the sawtooth pulse (triangular pulse) representing the operation of the optical scanner 30 is the scan start angle, and the bottom edge is the scan end angle. The scan start angle is the initial angle (initial direction) of the mirror's orientation during a single slit scan, and the scan end angle is the final angle (final direction) of the mirror's orientation during a single slit scan. In other words, the angular range defined by the scan start angle and scan end angle is the angular range within which the mirror's orientation changes during a single slit scan.

[0256] During the first period T1, the shooting control unit 404 performs control for causing the light source 10 to output light (infrared light, near-infrared light) in synchronization with the control of the light scanner 30 for changing the direction of the mirror from the scan start angle to the scan end angle. More specifically, the shooting control unit 404 performs synchronous control of the light scanner 30 and the light source 10, so that light output from the light source 10 starts at the timing when the mirror of the light scanner 30 starts to change from the scan start angle, and stops at the timing when the mirror of the light scanner 30 reaches the scan end angle. Thus, a slit scan using the first slit light and the second slit light is performed (see Figure 5 ). By performing one slit scan in the first period T1, one image K1 corresponding to the first period T1 is generated.

[0257] Once the slit scan during the first period T1 is complete, the imaging control unit 404 prepares for the slit scan during the second period T2. Specifically, the imaging control unit 404 controls the optical scanner 30 so that the mirror, which was facing the scan end angle, returns to the scan start angle at the end of the first period T1. Once the mirror has moved to the scan start angle, the imaging control unit 404 controls the imaging unit 2 to perform the slit scan during the second period T2. This control is performed using the same principles as for the slit scan during the first period T1. Consequently, a single image K2 corresponding to the second period T2 is generated.

[0258] By executing this control during each period Tn (n is a positive integer less than or equal to N), N images K1 to KN corresponding to the N periods T1 to TN are obtained. This group of images K1 to KN is a time-series image. As previously described, this time-series image is displayed in real time on the display of the user interface 6. That is, at the timing when the processor 4A generates image Kn for each period Tn, it displays this image Kn on the display instead of the previous image K(n-1). Thus, the sequentially acquired time-series images (images K1 to KN) are presented to the user as real-time images (observation images). This concludes the description of the first imaging control.

[0259] Next, the second imaging control will be described. In the second imaging control, the imaging control unit 404 controls the imaging unit 2 so as to perform imaging for detecting the focusing state of the imaging unit 2 with respect to the fundus Ef of the eye to be examined E. The second imaging control performs a different control from the first imaging control and is a new control not installed in existing ophthalmic devices of the same type. Of course, it is also novel to combine the first imaging control and the second imaging control.

[0260] Figure 23A 、 Figure 23B and Figure 23C This is a non-limiting example of a combination of the first shooting control and the second shooting control. In this example, one first shooting control and one second shooting control are performed alternately. Generally speaking, more than one first shooting control and more than one second shooting control may be performed alternately. Figure 23A This shows the case where the focus of the imaging unit 2 coincides with the fundus Ef. Figure 23B The focus state of the imaging unit 2 is shown as the back focus. Figure 23C The case where the focus state of the imaging unit 2 is the front focus is shown.

[0261] The imaging control unit 404 executes the Figure 22 The slit scan is performed once during the first period T1 (ie, the first imaging control is performed once). As a result, an image K1 corresponding to the period U1 is acquired.

[0262] After the slit scan in period U1 is completed, the imaging control unit 404 moves the orientation of the mirror of the optical scanner 30 from the scanning end angle to the neutral position (0 degree position) and begins the second imaging control. In this second imaging control, the imaging control unit 404 causes the imaging unit 2 to perform imaging using the first slit light during period V11 and to perform imaging using the second slit light during period V12. Imaging using the first slit light and imaging using the second slit light are performed in the same manner as in the first embodiment.

[0263] Figure 23A The image M11(1) shown, Figure 23B The image M11(2) and Figure 23C Image M11(3) shown shows three examples of images acquired by imaging using the first slit light during period V11: an image obtained in a focused state, an image obtained in a later focused state, and an image obtained in a previous focused state. The slit light images depicted in these images are indicated by dotted lines.

[0264] Likewise, Figure 23A The image M12(1) shown, Figure 23B The image M12(2) and Figure 23CThe image M12(3) shown shows three examples of images acquired by imaging using the second slit light during period V12: an image obtained in a focused state, an image obtained in a later focused state, and an image obtained in a previous focused state. The slit light images depicted in these images are indicated by dotted lines.

[0265] exist Figure 23A In the image M11(1), the slit light image is depicted at the approximately center position in the Y direction, and in the image M12(1), the slit light image is also depicted at the approximately center position in the Y direction. As described in the first embodiment, Figure 23A The positional relationship between the two slit light images of the two images M11 ( 1 ) and M12 ( 1 ) indicates that the focus of the imaging unit 2 is substantially consistent with the fundus Ef.

[0266] In contrast, Figure 23B The positional relationship between the two slit light images of the two images M11(2) and M12(2) indicates that the focus of the imaging unit 2 is inconsistent with the fundus Ef. More specifically, it indicates that the focus state of the imaging unit 2 is rear focus relative to the fundus Ef. Figure 23C The positional relationship between the two slit light images of the two images M11 (3) and M12 (3) indicates that the focus of the imaging unit 2 is inconsistent with the fundus Ef. More specifically, it indicates that the focus state of the imaging unit 2 is the front focus relative to the fundus Ef.

[0267] The focus information generating unit 405 can generate information (focus information) indicating the focus state of the imaging unit 2 during the two periods V11 and V12 based on the two images acquired during the two periods V11 and V12. The focus information may include, for example, information indicating whether the focus of the imaging unit 2 coincides with the fundus Ef, information indicating the direction of focus deviation of the imaging unit 2 (i.e., information indicating whether the focus state of the imaging unit 2 is rear focus or front focus relative to the fundus Ef), information indicating the amount of focus deviation of the imaging unit 2, and the like.

[0268] The processor 4A may display information based on the generated focus information on the display of the user interface 6 .

[0269] When the slit scan of period V12 is completed, the imaging control unit 404 moves the direction of the mirror of the optical scanner 30 from the neutral position (0 degree position) to the scanning start angle and starts the second first imaging control (slit scan). This generates an image K2 corresponding to period U2.

[0270] When the crack scanning of period U2 is completed, the imaging control unit 404 moves the direction of the mirror of the optical scanner 30 from the scanning end angle to the neutral position (0 degree position) and starts the second second imaging control. Through this second imaging control, two images corresponding to the two periods V21 and V22 are obtained. For example, Figure 23A The two images M21(1) and M22(1) Figure 23B The two images M21(2) and M22(2) or Figure 23C The two images M21(3) and image M22(3).

[0271] The focus information generating unit 405 can generate information (focus information) indicating the focus state of the imaging unit 2 during the two periods V21 and V22 based on the two images acquired during the two periods V21 and V22. The processor 4A can display information based on the generated focus information on the display of the user interface 6.

[0272] The ophthalmologic apparatus of the second embodiment alternately executes the first imaging control and the second imaging control in the manner described above. This allows monitoring of the focus state of the imaging unit 2 with respect to the fundus Ef in parallel with the generation of observation images (time-sequential images K1, K2, K3, ...) of the fundus Ef using slit scanning.

[0273] Some features and effects of the ophthalmologic apparatus according to the second embodiment will be described.

[0274] The imaging unit 2 of the ophthalmologic apparatus of the second embodiment can acquire time-series images by repeatedly performing a series of image captures by the imaging device 50 while repeatedly shifting the projection position of the slit light onto the fundus Ef of the eye under examination. In other words, the imaging unit 2 can repeatedly perform slit scanning to generate time-series images (observation images). The processor 4A of the second embodiment not only includes a structure for executing the slit light projection control, condition determination processing, and focus adjustment control performed by the ophthalmologic apparatus 1 of the first embodiment, but also includes a structure for concurrently executing first imaging control, second imaging control, and focus information generation processing. In the first imaging control, the processor 4A controls the imaging unit 2 to acquire time-series images of the fundus Ef. In the second imaging control, the processor 4A causes the imaging unit 2 to perform imaging to detect the focus state of the imaging unit 2 with respect to the fundus Ef. In the focus information generation processing, the processor 4A generates focus information indicating the focus state of the imaging unit 2 based on the images acquired through the imaging performed by the second imaging control.

[0275] According to the ophthalmic device of the second embodiment thus constructed, the ophthalmic device can be miniaturized, the structure of the ophthalmic device can be simplified, the manufacturing cost of the ophthalmic device can be reduced, etc., similar to the first embodiment, and the focusing state of the shooting unit can be monitored in parallel with the observation image generation using slit scanning.

[0276] In some aspects, the processor 4A may be configured to alternately execute one or more first imaging controls and one or more second imaging controls.

[0277] In some embodiments, the processor 4A can be configured to also execute display control in parallel with the first imaging control, the second imaging control, and the focus information generation process. During display control, the processor 4A causes the display (display device) of the user interface 6 to display information based on the focus information. This not only enables the ophthalmic device to be miniaturized, its structure simplified, and its manufacturing cost reduced, but also allows the focus status of the imaging unit to be monitored and provided to the user in real time in conjunction with the generation of observation images using slit scanning. Furthermore, a non-limiting example of display control is described in the fifth embodiment.

[0278] <Third embodiment>

[0279] The ophthalmic device of the third embodiment will be described. Similar to the ophthalmic device 1 of the first embodiment and the ophthalmic device of the second embodiment, the ophthalmic device of the third embodiment has an ophthalmic imaging function for imaging the fundus of a living eye using a slit scanning modality. The device includes an imaging unit 2, a focus adjustment unit 3, a processor 4, a memory 5, and a user interface 6. Any of the matters of the first embodiment and any of the matters of the second embodiment can be applied to the ophthalmic device of the third embodiment. The third embodiment will be described below, with appropriate reference to matters of the first embodiment and the second embodiment.

[0280] The ophthalmologic apparatus of the third embodiment has Figure 24 The processor 4B shown here replaces Figure 6 The processor 4 shown is a non-limiting example. The processor 4B includes an imaging control unit 404 and a focus information generation unit 405, similar to the second processing module 400B of the processor 4A of the second embodiment. Specifically, the ophthalmic apparatus of the third embodiment has the first processing module 400A removed from the processor 4A of the second embodiment.

[0281] According to the ophthalmologic apparatus of the third embodiment thus configured, the focus state of the imaging unit can be monitored in parallel with the generation of observation images using slit scanning, similarly to the second embodiment.

[0282] <Fourth embodiment>

[0283] Similar to the ophthalmic devices of the first to third embodiments, the ophthalmic device of the fourth embodiment has an ophthalmic imaging function for imaging the fundus of a living eye using a slit scanning modality, and includes an imaging unit 2, a focus adjustment unit 3, a processor 4, a memory 5, and a user interface 6. Any of the items of the first embodiment, the second embodiment, and the third embodiment can be applied to the ophthalmic device of the fourth embodiment. The fourth embodiment will be described below, with appropriate reference to items of the first to third embodiments.

[0284] The ophthalmologic apparatus according to the fourth embodiment has Figure 25 The shooting unit 2A shown here replaces Figure 2 The imaging unit 2 shown is a non-limiting example. The imaging unit 2A is configured to perform slit scanning by capturing images using a rolling shutter image sensor (imaging device) while moving the projection position of the slit light onto the fundus Ef of the eye under examination E. Alternatively, an imaging unit (imaging device) combining a global shutter image sensor and a slit aperture may be used instead of a rolling shutter image sensor.

[0285] The imaging unit 2A of this embodiment includes a light source 10, an illumination optical system 20A, a light scanner 30, an imaging optical system 40, and an imaging device 50. The light source 10, the light scanner 30, the imaging optical system 40, and the imaging device 50 can be the same as the corresponding elements of the imaging unit 2 of the first embodiment. The light source 10 and / or the light scanner 30 can be considered as elements of the illumination optical system 20A, and the imaging device 50 can be considered as an element of the imaging optical system 40.

[0286] An illumination optical system 20A of this embodiment is provided instead of the illumination optical system 20 of the first embodiment. Figure 25 In the illustrated example, the illumination optical system 20A includes, in addition to the iris diaphragm 21 , the slit aperture diaphragm 22 , and the relay lens 23 similar to those of the first embodiment, a lens 24 disposed between the iris diaphragm 21 and the slit aperture diaphragm 22 .

[0287] Furthermore, the imaging unit 2A of this embodiment includes a moving mechanism 25M. The moving mechanism 25M moves the movable unit 25, which includes the light source 10, the iris diaphragm 21, the lens 24, and the slit aperture diaphragm 22, in a direction along the optical axis of the illumination optical system 20. The moving mechanism 25M operates under the control of the processor 4. The processor 4 can be configured to control the moving mechanism 25M based on the state of the eye E to be examined (e.g., refractive power (diopter, visual acuity), fundus shape, etc.).

[0288] The processor 4 of this embodiment, like the processor 4 of the first embodiment, includes a projection control unit 401, a condition determination unit 402, and a focus adjustment control unit 403 (see FIG. 4 ). Figure 6 The condition determination unit 402 of this embodiment performs the same condition determination processing as the first embodiment. Specifically, the condition determination unit 402 performs arithmetic processing for determining focus adjustment conditions based on the output of the imaging device 50, which detects the return light of the slit light projected onto the fundus Ef by the slit light projection control executed by the projection control unit 401. The condition determination processing of this embodiment can be performed in the same manner as the first embodiment.

[0289] In this embodiment, the illumination optical system 20A (first optical system) includes: a light source 10 (light source); an iris diaphragm 21 (iris diaphragm) disposed at a position substantially optically conjugate with the iris of the eye E to be examined, forming an opening for light emitted from the light source 10 to pass through; a lens 24 (lens) that refracts light that has passed through the opening of the iris diaphragm 21; and a slit aperture diaphragm 22 (slit aperture) for generating slit light from the light refracted by the lens 24. The illumination optical system 20A (first optical system) is configured to project the slit light generated by the slit aperture diaphragm 22 onto the fundus Ef of the eye E to be examined. Furthermore, the imaging optical system 40 (second optical system) includes a focusing lens 47 (focusing lens). Furthermore, the first focus adjustment unit for adjusting the focal position of the illumination optical system 20A includes a moving mechanism 25M (third moving mechanism) for moving the movable unit 25 in a direction along the optical axis of the illumination optical system 20A. Specifically, the first focus adjustment unit includes a moving mechanism 25M that integrally moves the light source 10, iris diaphragm 21, lens 24, and slit aperture diaphragm 22 along the optical axis of the illumination optical system 20A. Furthermore, the second focus adjustment unit, which adjusts the focal position of the imaging optical system 40, includes a moving mechanism 47M (a fourth moving mechanism) that moves the focus lens 47 along the optical axis of the imaging optical system 40. Furthermore, the condition determination unit 402 determines the conditions for controlling the moving mechanism 25M (the third movement control condition, the first focus adjustment condition) and the conditions for controlling the moving mechanism 47M (the fourth movement control condition, the second focus adjustment condition).

[0290] According to the ophthalmic device of the fourth embodiment thus constructed, similar to the first embodiment, the ophthalmic device can be miniaturized, the structure of the ophthalmic device can be simplified, the manufacturing cost of the ophthalmic device can be reduced, and an alternative to the ophthalmic device of the first embodiment can be provided.

[0291] <Fifth embodiment>

[0292] Similar to the ophthalmic devices of the first to fourth embodiments, the ophthalmic device of the fifth embodiment has an ophthalmic imaging function for imaging the fundus of a living eye using a slit scanning modality, and includes an imaging unit 2, a focus adjustment unit 3, a processor 4, a memory 5, and a user interface 6. Any of the items of the first embodiment, the second embodiment, the third embodiment, and the fourth embodiment can be applied to the ophthalmic device of the fifth embodiment. The fifth embodiment will be described below, with appropriate reference to items of the first to fourth embodiments.

[0293] The ophthalmologic apparatus of the fifth embodiment has Figure 26 The processor 4C shown here replaces Figure 6 The processor 4 shown, processor 4C, is a non-limiting example and includes a first processing module 400A and a second processing module 400C.

[0294] The first processing module 400A performs processing for focus adjustment (especially auto focus), which is different from the first processing module 400A ( Figure 21 ) Similarly, it includes a projection control unit 401, a condition determination unit 402 and a focus adjustment control unit 403.

[0295] The second processing module 400C is used to monitor the focus state when obtaining observation images (real-time dynamic images, real-time images, time-series images) of the fundus Ef of the subject's eye E using slit scanning, including the second processing module 400B ( Figure 21 ) The same shooting control unit 404 and focus information generating unit 405 also include a display control unit 406.

[0296] The display control unit 406 controls the display of the user interface 6 to display information based on the focus information (information indicating the focus state of the imaging unit 2) generated by the focus information generation unit 405. The display information may be any information generated based on at least the focus information, and may include, for example, information indicating whether the focus of the imaging unit 2 coincides with the fundus Ef, information indicating the direction of focus deviation of the imaging unit 2 (i.e., information indicating whether the focus state of the imaging unit 2 is back-focused or front-focused relative to the fundus Ef), and information indicating the amount of focus deviation of the imaging unit 2. The information may be displayed in any format, including any geometric or visual representation, such as medical images, schemas, diagrams, computer graphics, character strings, charts, and diagrams.

[0297] exist Figure 27 and Figure 28 Non-limiting examples of displayed information are shown in FIG. Figure 27 The display screen 500 shown is displayed by the display control unit 406 on the display of the user interface 6. The display screen 500 is provided with an image display unit 510 that displays an image of the fundus oculi Ef generated by the imaging unit 2. The image displayed on the image display unit 510 is, for example, an observed image acquired by the imaging unit 2 under the first imaging control executed by the imaging control unit 404. The first imaging control is a control for causing the imaging unit 2 to acquire an observed image of the fundus oculi Ef, and details thereof are referred to in the second embodiment.

[0298] Furthermore, the display screen 500 includes a focus adjustment operation unit 520 as a graphical user interface (GUI) for performing focus adjustment operations and a focus state indicator 530 as a graphical user interface for indicating a direction and amount of focus deviation of the imaging unit 2 .

[0299] The focus adjustment operation unit 520 is provided with a scale (diagonal mark) indicating the range of the diopter value of the imaging unit 2 (illumination optical system 20 , imaging optical system 40 ) and a pointer indicating the current diopter value on the scale.

[0300] Figure 27 The scale shown as a non-limiting example is a numerical axis representing a range from -20 diopters to +20 diopters, with values shown every 5 diopters on the numerical axis.

[0301] Figure 27 The pointer of the non-limiting example shown is a small inverted triangular (wedge-shaped) widget, whose downward-pointing apex indicates a point on the scale. The point indicated by the pointer corresponds to the current diopter value of the camera unit 2.

[0302] The user can move the pointer along the scale using, for example, a pointing device or a touch operation. When the user moves the pointer, the processor 4C (e.g., the focus adjustment control unit 403 or the imaging control unit 404) controls the focus adjustment unit 3 (e.g., the moving mechanism 22M or the moving mechanism 25M, and the moving mechanism 47M) based on the diopter value (target value) indicated by the moved pointer, thereby changing the diopter value of the imaging unit 2 to the target value.

[0303] The method of focusing the adjustment operation part (scale, pointer, etc.) is not limited to the above examples, and can be any. For example, in addition to the prompt Figure 27In addition to the scale and pointer, information (movement support information) indicating the direction (and amount) in which the pointer should be moved to align the focus of the imaging unit 2 with the fundus Ef can also be displayed. This movement support information is generated, for example, based on the focus information generated by the focus information generation unit 405. As previously described, the focus information is generated based on images captured by the imaging unit 2 under the second imaging control executed by the imaging control unit 404. The second imaging control is used to detect the focus state of the imaging unit 2. For details, see the second embodiment.

[0304] In another example, the focus adjustment operation unit may include a window widget indicating the current diopter value of the imaging unit 2 and a widget operated to change the diopter value indicated in the window widget.

[0305] The focus status indicator 530 indicates the direction and amount of focus deviation of the imaging unit 2. The display control unit 406 controls the display of the focus status indicator 530 based on the focus information generated by the focus information generation unit 405 from the image acquired by the imaging unit 2 under the second imaging control executed by the imaging control unit 404.

[0306] like Figure 28 As shown, the focus status indicator 530 includes a reference line 531 positioned vertically in the center and a small moving widget 532 whose display position changes vertically. Reference line 531 indicates the vertical position corresponding to the focus state of the imaging unit 2. Positions above reference line 531 correspond to "front focus," while positions below reference line 531 correspond to "back focus." Furthermore, the distance from reference line 531 indicates the amount of focus deviation; the greater the distance from reference line 531, the greater the amount of focus deviation.

[0307] The display control unit 406 performs a focus evaluation of the imaging unit 2 based on the focus information generated by the focus information generation unit 405, and determines the display position of the moving widget 532 based on the evaluation result. The content of the focus evaluation of the imaging unit 2 may be arbitrary, and may include, for example, determining whether the focus of the imaging unit 2 coincides with the fundus Ef, determining the direction of focus deviation from the fundus Ef (front focus or back focus), estimating the amount of focus deviation from the fundus Ef, and the like.

[0308] When it is determined that the focus of the imaging unit 2 coincides with the fundus oculi Ef, the display control unit 406 displays the moving widget 532 on the reference line 531 (see FIG. 5 ). Figure 28 (B)).

[0309] When it is determined that the focus of the imaging unit 2 is the front focus at a distance corresponding to the first diopter value relative to the fundus Ef, the display control unit 406 causes the moving widget 532 to be displayed at a position above the reference line 531 and at a distance corresponding to the first diopter value from the reference line 531 (see FIG. Figure 28 (A)).

[0310] When it is determined that the focus of the imaging unit 2 is the back focus at a distance corresponding to the second diopter value relative to the fundus Ef, the display control unit 406 causes the moving widget 532 to be displayed at a position below the reference line 531 and at a distance corresponding to the second diopter value from the reference line 531 (see FIG. Figure 28 (C)).

[0311] like Figure 28 As shown, the display method of the moving widget 532 can be changed depending on whether the focus of the imaging unit 2 is aligned with the fundus Ef. For example, the display control unit 406 displays the moving widget 532 in a first color (e.g., blue) when the focus of the imaging unit 2 is aligned with the fundus Ef, and in a second color (e.g., red) when the focus of the imaging unit 2 is not aligned with the fundus Ef. In another example, the display control unit 406 can display the moving widget 532 in a color corresponding to the direction of focus deviation (front focus or back focus) of the imaging unit 2. In yet another embodiment, the display control unit 406 can display the moving widget 532 in a color corresponding to the amount of focus deviation of the imaging unit 2. The display method of the moving widget 532 that changes according to the focus state of the imaging unit 2 is not limited to color and can be any method, such as shape, brightness, pattern, or on / off mode. In addition, the display control unit 406 can display information corresponding to the focus state of the imaging unit 2 (such as text string information or image information) separately from the moving widget 532. By configuring the display mode of the focus state indicator 530 (for example, the moving widget 532 ) to be changed according to the focus state of the imaging unit 2 , the user can easily grasp the focus state of the imaging unit 2 .

[0312] The display control unit 406 can synchronize the display mode of the moving widget 532 with the display mode of the focus adjustment operation unit 520. For example, Figure 27 As shown, the display color of the moving widget 532 and the display color of the pointer of the focus adjustment operation unit 520 can be made consistent. Figure 27 This shows that the focal point coincides with the fundus Ef when the focus state of the imaging unit 2 is -3 diopters (-3D). Synchronized display methods are not limited to color and can be any method, such as shape, brightness, pattern, or on / off mode. Synchronizing the display methods of two or more objects is not limited to displaying those objects in the same manner.

[0313] According to an ophthalmic device that can display such a display screen 500, the user can observe the fundus Ef through the image displayed by the image display unit 510, while using the focus status indicator 530 to grasp the focus status of the shooting unit 2 in real time, and can use the focus adjustment operation unit 520 to adjust the focus of the shooting unit 2.

[0314] <Other embodiments>

[0315] While some non-limiting embodiments of ophthalmic devices have been described above, the types of embodiments disclosed herein are not limited to ophthalmic devices. Examples of embodiments other than ophthalmic devices include methods for controlling ophthalmic devices, methods for photographing the fundus, programs, and recording media. Those skilled in the art will appreciate that these types of embodiments can be implemented using the aforementioned ophthalmic device embodiments.

[0316] According to these types of embodiments, similar to the embodiments of the ophthalmic device, the following effects can be achieved, namely, focusing adjustment can be performed without providing the same focusing-dedicated hardware elements as those in existing ophthalmic devices of the same type (i.e., an ophthalmic device having an ophthalmic imaging function that images the fundus of a living eye using a slit scanning modality); focusing adjustment can be performed without providing the same complex and large-scale focusing-dedicated hardware elements as those in existing ophthalmic devices of the same type; and focusing status of the imaging unit can be monitored in parallel with the generation of observation images using slit scanning.

[0317] Some non-limiting embodiments of these categories are described below. Any of these embodiments may combine any of the matters described in this disclosure regarding the ophthalmic device and any known technology.

[0318] Some embodiments of a method for controlling an ophthalmic device provide a new method for controlling an ophthalmic device including a photographing unit, a focus adjustment unit, a processor, and a memory. The photographing unit is configured to move the projection position of slit light on the fundus of the eye to be examined while photographing using a rolling shutter camera device (or a camera device having the same function as a rolling shutter camera device, such as a photographing unit that combines a global shutter image sensor and a slit aperture). Furthermore, the focus adjustment unit has a structure for performing focus adjustment of the photographing unit. The method of this embodiment causes the processor to execute a first control step, a condition determination step, and a second control step. In the first control step, the processor executes control of the photographing unit for projecting slit light onto the fundus of the eye to be examined. In the condition determination step, the processor determines a focus adjustment condition based on an output from the camera device that detects return light of the slit light projected onto the fundus of the eye to be examined by the first control step. In the second control step, the processor executes control of the focus adjustment unit based on the focus adjustment condition determined by the condition determination step.

[0319] Other embodiments of a method for controlling an ophthalmic device provide a novel method for controlling an ophthalmic device including a camera unit, a processor, and a memory. The camera unit is configured to capture images using a rolling shutter camera (or, for example, a camera unit that combines a global shutter image sensor and a slit aperture, which has the same functionality as a rolling shutter camera) while moving the projection position of slit light onto the fundus of the eye under examination. The method of this embodiment causes the processor to concurrently execute a first capture control step, a second capture control step, a focus information generation step, and a display control step. In the first capture control step, the processor controls the camera unit so that a series of captures by the camera are repeated while a series of movements of the projection position of slit light onto the fundus of the eye under examination are repeated, thereby acquiring time-series images. In the second control step, the processor causes the camera unit to execute capture to detect the focus state of the camera unit on the fundus of the eye under examination. In the focus information generation step, the processor generates focus information indicating the focus state based on the images acquired during the capture performed in the second capture control step. In the display control step, the processor causes the display device to display display information based on the focus information generated in the focus information generation step.

[0320] Some embodiments provide a method for photographing the fundus of an eye, providing a novel method for photographing the fundus of an eye under examination using a rolling shutter imaging device (or an imaging device having the same function as a rolling shutter imaging device, such as an imaging unit comprising a global shutter image sensor and a slit aperture) while moving the projection position of slit light onto the fundus of the eye under examination. This method includes the following steps: projecting slit light onto the fundus of the eye under examination and detecting return light from the slit light projected onto the fundus using the imaging device; determining a focus adjustment condition based on an output from the imaging device that detected the return light; performing focus adjustment based on the focus adjustment condition; and, after performing the focus adjustment, photographing the fundus of the eye under examination using the imaging device while moving the projection position of the slit light onto the fundus of the eye under examination.

[0321] Other embodiments of methods for photographing the fundus provide novel methods for photographing the fundus of an eye under examination using a rolling shutter imaging device (or an imaging device having the same function as a rolling shutter imaging device, such as an imaging unit that combines a global shutter image sensor and a slit aperture) while moving the projection position of slit light onto the fundus of the eye under examination. This method includes the following steps performed in parallel: a step of acquiring time-series images by repeating a series of movements of the projection position of slit light onto the fundus of the eye under examination and a series of photographing operations by the imaging device; a step of acquiring images by photographing for detecting the focus state relative to the fundus of the eye under examination; a step of generating focus information indicating the focus state based on the images acquired by photographing for detecting the focus state; and a step of displaying display information based on the focus information.

[0322] The program of some embodiments is a new program for causing an ophthalmic device to execute. The ophthalmic device includes a shooting unit, a focus adjustment unit, a processor, and a memory. The shooting unit is configured to move the projection position of the slit light on the fundus of the eye to be examined while using a rolling shutter camera device (or a camera device having the same function as a rolling shutter camera device, such as a shooting unit composed of a global shutter image sensor and a slit aperture). The focus adjustment unit has a structure for performing focus adjustment of the shooting unit. The program of this embodiment causes the processor of the ophthalmic device to execute a first control step, a condition determination step, and a second control step. In the first control step, the processor, under the program of this embodiment, executes control of the shooting unit for projecting slit light onto the fundus of the eye to be examined. In the condition determination step, the processor, under the program of this embodiment, determines the focus adjustment condition based on the output from the camera device, which detects the return light of the slit light projected onto the fundus of the eye to be examined by the first control step. In the second control step, the processor controls the focus adjustment unit based on the focus adjustment condition determined in the condition determination step under the program of this embodiment.

[0323] The program of some other embodiments is a new program for causing an ophthalmic device to execute. The ophthalmic device includes a photographing unit, a processor, and a memory. The photographing unit is configured to move the projection position of the slit light on the fundus of the eye to be examined while photographing using a rolling shutter camera device (or a camera device having the same function as a rolling shutter camera device, such as a photographing unit composed of a global shutter image sensor and a slit aperture). The program of this embodiment causes the processor of the ophthalmic device to execute a first photographing control step, a second photographing control step, a focus information generation step, and a display control step in parallel. In the first photographing control step, the processor executes control of the photographing unit under the program of this embodiment so that a series of movements of the projection position of the slit light on the fundus of the eye to be examined are repeated while a series of photographs performed by the camera device are repeated. In the second photographing control step, the processor causes the photographing unit to execute photographing for detecting the focusing state of the photographing unit on the fundus of the eye to be examined under the program of this embodiment. In the focus information generation step, the processor, under the program of this embodiment, generates focus information indicating a focus state based on an image acquired during imaging performed in the second imaging control step. In the display control step, the processor, under the program of this embodiment, causes a display device to display display information based on the focus information generated in the focus information generation step.

[0324] In yet other embodiments, the program is a novel program for causing a computer including a processor and a memory to execute the following processing: performing imaging using a rolling shutter imaging device (or an imaging device having the same function as a rolling shutter imaging device, such as an imaging unit that combines a global shutter image sensor and a slit aperture) while moving the projection position of slit light onto the fundus of the eye under examination. The program of this embodiment causes the computer processor to execute the following steps: performing control to project slit light onto the fundus of the eye under examination and detecting return light of the slit light projected onto the fundus using the imaging device; determining a focus adjustment condition based on an output from the imaging device that detects the return light; performing focus adjustment based on the focus adjustment condition; and, after performing the focus adjustment, performing control to image the fundus of the eye under examination while moving the projection position of the slit light onto the fundus of the eye under examination using the imaging device.

[0325] In yet other embodiments, a program is configured to cause a computer including a processor and a memory to execute the following processing: a process of capturing images using a rolling shutter imaging device (or an imaging device having the same function as a rolling shutter imaging device, such as an imaging unit that combines a global shutter image sensor and a slit aperture) while moving the projection position of slit light onto the fundus of an eye under examination. The program of this embodiment causes the computer processor to execute the following steps in parallel: a step of acquiring time-series images by repeatedly performing a series of movements of the projection position of slit light onto the fundus of the eye under examination and a series of imaging by the imaging device; a step of acquiring images by performing imaging for detecting a focus state relative to the fundus of the eye under examination; a step of generating focus information indicating a focus state based on the images captured by the imaging for detecting the focus state; and a step of displaying display information based on the focus information.

[0326] The recording medium of some embodiments is a computer-readable non-transitory recording medium having recorded thereon the program of any embodiment. The computer-readable non-transitory recording medium that can be used as the recording medium of the embodiments may be any type of recording medium, for example, a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory.

[0327] The present disclosure provides some embodiments and some illustrative methods thereof. These embodiments and methods are merely illustrative of the present invention. Therefore, any modification (omission, substitution, addition, etc.) within the scope of the subject matter of the present invention may be applied to the embodiments or methods provided in this disclosure.

[0328] (Explanation of Reference Numerals)

[0329] 1 Ophthalmic devices

[0330] 2 shooting units

[0331] 3 Focus adjustment unit

[0332] 4, 4A, 4B, 4C processors

[0333] 5 Memory

[0334] 6 User Interface

[0335] 10 Light Source

[0336] 20 Illumination Optical System

[0337] 21 Iris

[0338] 22 slit aperture

[0339] 22M mobile mechanism

[0340] 30 optical scanners

[0341] 47 Focusing lens

[0342] 47M mobile mechanism

[0343] 50 Camera

[0344] 401 Projection Control Department

[0345] 402 Conditional Decision Department

[0346] 403 Focus adjustment control unit

[0347] 404 Shooting Control Unit

[0348] 405 Focus Information Generation Department

[0349] 406 Display Control Unit

[0350] 500 display screen

[0351] 520: focus adjustment operation unit; 530: focus state indicator.

Claims

1. An ophthalmic device comprising: an imaging unit that uses an imaging device to capture images while moving a projection position of the slit light on the fundus of the eye to be examined; A focus adjustment unit, used to adjust the focus of the shooting unit; as well as processor, The processor performs: Slit light projection control, controlling the photographing unit in order to project slit light toward the fundus; a condition determination process of determining a focus adjustment condition based on an output of the imaging device that detects return light of the slit light projected by the slit light projection control; as well as The focus adjustment control controls the focus adjustment unit based on the focus adjustment condition determined by the condition determination process.

2. The ophthalmic device according to claim 1, wherein The processor includes a condition determination unit that executes the condition determination process. The condition determination unit determines the focus adjustment condition based on a position of a slit light image in an image generated by the imaging device.

3. The ophthalmic device according to claim 2, wherein: The condition determination unit determines the position of the slit light image based on a brightness distribution, which is a brightness distribution of at least a portion of an image area of the slit light image and is along a first direction corresponding to a moving direction of a projection position of the slit light generated by the imaging unit.

4. The ophthalmic device according to claim 3, wherein The condition determination unit generates the brightness distribution by adding the brightness of the pixel groups constituting the image area in a second direction orthogonal to the first direction.

5. The ophthalmic device according to claim 2, wherein The shooting unit includes: a first optical system that projects the slit light toward the fundus of the eye to be examined; and a second optical system for guiding the return light of the slit light from the fundus of the eye to be examined to the imaging device; The focus adjustment unit includes: a first focus adjustment unit, configured to adjust the focus position of the first optical system; and A second focus adjustment unit is used to adjust the focus position of the second optical system, The condition determination section determines, as the focus adjustment conditions, a first focus adjustment condition for controlling the first focus adjustment unit and a second focus adjustment condition for controlling the second focus adjustment unit.

6. The ophthalmic device according to claim 5, wherein The first optical system comprises: light source; and a slit aperture for generating slit light from light emitted from the light source, The first optical system projects the slit light generated by the slit aperture toward the fundus. The second optical system includes a focusing lens, The first focus adjustment unit includes a first moving mechanism for moving the slit aperture in a direction along the optical axis of the first optical system. The second focus adjustment unit includes a second moving mechanism for moving the focus lens in a direction along the optical axis of the second optical system. The condition determination unit determines a first movement control condition for controlling the first movement mechanism as the first focus adjustment condition, and determines a second movement control condition for controlling the second movement mechanism as the second focus adjustment condition.

7. The ophthalmic device according to claim 6, wherein: The first movement control condition includes information indicating the movement direction and movement distance of the slit aperture. The second movement control condition includes information indicating a movement direction and a movement distance of the focus lens.

8. The ophthalmic device according to claim 5, wherein The first optical system comprises: light source; an iris diaphragm disposed at a position substantially optically conjugate with the iris of the eye to be examined and having an opening portion for passing the light emitted from the light source; a lens configured to refract the light passing through the opening of the iris diaphragm; and a slit aperture for generating slit light from the light refracted by the lens, The first optical system projects the slit light generated by the slit aperture toward the fundus. The second optical system includes a focusing lens, The first focus adjustment unit includes a third moving mechanism for integrally moving the light source, the iris diaphragm, the lens, and the slit diaphragm in a direction along the optical axis of the first optical system. The second focus adjustment unit includes a fourth moving mechanism for moving the focus lens in a direction along the optical axis of the second optical system. The condition determination unit determines a third movement control condition for controlling the third movement mechanism as the first focus adjustment condition, and determines a fourth movement control condition for controlling the fourth movement mechanism as the second focus adjustment condition.

9. The ophthalmic device according to claim 8, wherein The third movement control condition includes information indicating the movement direction and movement distance of the light source, the iris diaphragm, the lens, and the slit diaphragm. The fourth movement control condition includes information indicating a movement direction and a movement distance of the focus lens.

10. The ophthalmic device according to claim 2, wherein: the processor controls the imaging unit in the slit light projection control so that the slit light projected toward the fundus is emitted from a position separated by a predetermined distance from an optical axis of the imaging unit, The condition determination unit determines the focus adjustment condition based on the position of the slit light image, a focal length of the imaging unit, and the predetermined distance.

11. The ophthalmic device according to claim 2, wherein: The photographing unit includes an optical scanner that moves a projection position of the slit light on the fundus by deflecting the slit light directed toward the eye to be examined, The processor includes a projection control unit that performs the slit light projection control, The projection control unit controls the imaging unit so that the slit light generated by the optical scanner is projected toward the fundus in a state where the deflection direction of the slit light is fixed. The condition determination unit determines the focus adjustment condition based on a position of a slit light image corresponding to the slit light projected onto the fundus in a state in which the deflection direction is fixed.

12. The ophthalmic device according to claim 2, wherein: The processor includes a projection control unit that performs the slit light projection control. The projection control unit controls the imaging unit so as to output the first slit light and the second slit light having different projection positions on the fundus. The condition determination unit determines the focus adjustment condition based on a relative position of a first slit light image corresponding to the first slit light and a second slit light image corresponding to the second slit light.

13. The ophthalmic device according to claim 1, wherein The imaging unit repeatedly moves the projection position of the slit light on the fundus and repeatedly performs a series of imaging by the imaging device, thereby acquiring time-series images. The processor also executes in parallel: A first shooting control, configured to enable the shooting unit to acquire the time-series images; a second photographing control for causing the photographing unit to perform photographing for detecting a focus state of the photographing unit on the fundus; and The focus information generation process generates focus information indicating the focus state based on the image acquired in the imaging performed by the second imaging control.

14. The ophthalmic device according to claim 13, wherein: The processor alternately performs the first photographing control and the second photographing control.

15. The ophthalmic device according to claim 13, wherein The processor further performs display control in parallel with the first imaging control, the second imaging control, and the focus information generation process to cause a display device to display display information based on the focus information.

16. A method of controlling an ophthalmic device, the controlling comprising: an imaging unit for imaging the fundus of the eye under examination by moving the projection position of the slit light on the fundus of the eye under examination; a focus adjustment unit for adjusting the focus of the imaging unit; a processor; and a memory. The method causes the processor to execute: A first control step is to control the photographing unit to project slit light toward the fundus; a condition determination step of determining a focus adjustment condition based on an output of the imaging device that detects return light of the slit light projected by the first control step; as well as The second control step is to control the focus adjustment unit based on the focus adjustment condition determined in the condition determination step.

17. A method for photographing a fundus of an eye to be examined using an imaging device while moving a projection position of slit light on the fundus of the eye to be examined, the method comprising: Projecting slit light onto the fundus, and detecting return light of the slit light projected onto the fundus using the imaging device; a step of determining a focus adjustment condition based on an output from the imaging device that detects the return light; a step of performing focus adjustment based on the focus adjustment condition; as well as After the focus adjustment is performed, the step of performing imaging using the imaging device while moving the projection position of the slit light on the fundus.

18. A program for causing an ophthalmologic apparatus to execute, the ophthalmologic apparatus comprising an imaging unit, a focus adjustment unit, a processor, and a memory, wherein the imaging unit uses an imaging device to capture images while moving the projection position of slit light on the fundus of an eye to be examined, and the focus adjustment unit is configured to adjust the focus of the imaging unit. The program causes the processor to execute: A first control step is to control the photographing unit to project slit light toward the fundus; a condition determination step of determining a focus adjustment condition based on an output of the imaging device that detects return light of the slit light projected by the first control step; and The second control step is to control the focus adjustment unit based on the focus adjustment condition determined in the condition determination step.

19. A program for causing a computer including a processor and a memory to execute processing for photographing a fundus of an eye to be examined by using an imaging device while moving the projection position of slit light on the fundus of the eye to be examined. The program causes the processor to execute: a step of performing control for projecting slit light onto the fundus and detecting return light of the slit light projected onto the fundus using the imaging device; a step of determining a focus adjustment condition based on an output from the imaging device that detects the return light; a step of performing focus adjustment based on the focus adjustment condition; as well as After the focus adjustment is performed, a control step is performed for performing imaging by the imaging device while moving the projection position of the slit light on the fundus.

20. A computer-readable non-transitory recording medium having the program according to claim 18 or 19 recorded thereon.

Images