Ophthalmic device, method for controlling the ophthalmic device, program, and recording medium

Abstract

To improve the quality of an image obtained by ophthalmologic imaging.SOLUTION: An ophthalmologic apparatus according to one embodiment comprises: an imaging unit; a control unit; and an image processing unit. The imaging unit includes an optical system that satisfies a condition of a shine proof. The control unit is configured to control the imaging unit so as to apply two or more times of imaging with different imaging conditions to a subject eye. The image processing unit is configured to generate a high dynamic range image on the basis of two or more images of the subject eye acquired by the two or more times of imaging with different imaging conditions.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an ophthalmic device, a method for controlling the ophthalmic device, a program, and a recording medium.

Background Art

[0002] In the field of ophthalmology, image diagnosis occupies an important position. In ophthalmic image diagnosis, various ophthalmic devices are used. Examples of ophthalmic devices include a slit lamp microscope, a fundus camera, a scanning laser ophthalmoscope (SLO), and an optical coherence tomography (OCT). In addition, various inspection devices and measurement devices such as a refractometer, a keratometer, a tonometer, a specular microscope, a wavefront analyzer, and a microperimeter are also equipped with a function of photographing the anterior eye segment and the fundus.

[0003] One of the most widely and frequently used devices among these various ophthalmic devices is the slit lamp microscope, which is also called a stethoscope for ophthalmologists. A slit lamp microscope is an ophthalmic device that illuminates an eye to be examined with slit light and observes or photographs the illuminated cross-section from the side with a microscope (see, for example, Patent Documents 1 and 2). In addition, there is also known a slit lamp microscope that can scan a three-dimensional region of an eye to be examined at high speed by using an optical system configured to satisfy the conditions of shine-proof (see, for example, Patent Document 3). In addition to the slit lamp microscope, a rolling shutter camera or the like is known as an imaging method for scanning an object with slit light.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

[0005] One objective of this invention is to improve the quality of images obtained in ophthalmic imaging. [Means for solving the problem]

[0006] One exemplary embodiment of the embodiment is an ophthalmic device comprising: an imaging unit including an optical system that satisfies shineproof conditions; a control unit that controls the imaging unit to apply two or more imagings to the eye under different imaging conditions; and an image processing unit that generates a high dynamic range image based on two or more images of the eye acquired by the two or more imagings.

[0007] Another exemplary embodiment is a method for controlling an ophthalmic apparatus including an imaging unit having an optical system that satisfies shineproof conditions and a processor, wherein the processor functions as a control unit that controls the imaging unit to apply two or more imagings to the eye under examination under different imaging conditions, and as an image processing unit that generates a high dynamic range image based on two or more images of the eye under examination obtained by the two or more imagings.

[0008] A further exemplary embodiment of the embodiment is a program for operating an ophthalmic apparatus including an imaging unit having an optical system that satisfies shineproof conditions and a processor, wherein the program causes the processor to function as a control unit that controls the imaging unit to apply two or more imagings to the eye under examination under different imaging conditions, and as an image processing unit that generates a high dynamic range image based on two or more images of the eye under examination obtained by the two or more imagings.

[0009] A further exemplary embodiment of the embodiment is a computer-readable non-temporary recording medium on which a program for operating an ophthalmic apparatus including an imaging unit with an optical system satisfying shineproof conditions and a processor is recorded, wherein the program causes the processor to function as a control unit that controls the imaging unit to apply two or more imagings to the eye under examination under different imaging conditions, and as an image processing unit that generates a high dynamic range image based on two or more images of the eye under examination obtained by the two or more imagings. [Effects of the Invention]

[0010] According to this embodiment, it is possible to improve the quality of images obtained in ophthalmic imaging. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic diagram showing the configuration of an ophthalmic device according to an exemplary embodiment. [Figure 2] This is a flowchart illustrating the processes performed by an ophthalmic device according to an exemplary embodiment of the model. [Figure 3] This is a schematic diagram showing the configuration of an ophthalmic device according to an exemplary embodiment. [Figure 4] This is a flowchart illustrating the processes performed by an ophthalmic device according to an exemplary embodiment of the model. [Figure 5] This is a schematic diagram showing the configuration of an ophthalmic device according to an exemplary embodiment. [Figure 6] This is a flowchart illustrating the processes performed by an ophthalmic device according to an exemplary embodiment of the model. [Figure 7A] This is a timing chart showing the processes performed by an ophthalmic device according to an exemplary embodiment of the model. [Figure 7B] This is a timing chart showing the processes performed by an ophthalmic device according to an exemplary embodiment of the model. [Figure 7C] This is a timing chart of a conventional process shown for comparison with the process performed by an ophthalmic device according to an exemplary embodiment of the model. [Figure 8] It is a schematic diagram showing the configuration of an ophthalmic device according to an exemplary aspect of an embodiment. [Figure 9] It is a flowchart showing the processes executed by an ophthalmic device according to an exemplary aspect of an embodiment. [Figure 10A] It is a timing chart showing the processes executed by an ophthalmic device according to an exemplary aspect of an embodiment. [Figure 10B] It is a timing chart showing the processes executed by an ophthalmic device according to an exemplary aspect of an embodiment. [Figure 11] It is a flowchart showing the processes executed by an ophthalmic device according to an exemplary aspect of an embodiment. [Figure 12] It is a schematic diagram showing the configuration of an ophthalmic device according to an exemplary aspect of an embodiment. [Figure 13] It is a flowchart showing the processes executed by an ophthalmic device according to an exemplary aspect of an embodiment. [Figure 14] It is a schematic diagram showing the configuration of an ophthalmic device according to an exemplary aspect of an embodiment. [Figure 15] It is a flowchart showing the processes executed by an ophthalmic device according to an exemplary aspect of an embodiment. [Figure 16] It is a timing chart showing the processes executed by an ophthalmic device according to an exemplary aspect of an embodiment. [Figure 17] It is a schematic diagram showing the configuration of an ophthalmic device according to an exemplary aspect of an embodiment. [Figure 18] It is a schematic diagram showing the configuration of an ophthalmic device according to an exemplary aspect of an embodiment. [Figure 19A] It is a timing chart showing the processes executed by an ophthalmic device according to an exemplary aspect of an embodiment. [Figure 19B] It is a timing chart showing the processes executed by an ophthalmic device according to an exemplary aspect of an embodiment. [Figure 20] It is a timing chart showing the processes executed by an ophthalmic device according to an exemplary aspect of an embodiment. [Figure 21]This is a flowchart illustrating the processes performed by an ophthalmic device according to an exemplary embodiment of the model. [Figure 22A] This is a timing chart showing the process performed by an ophthalmic device according to an exemplary embodiment of the model, and a schematic diagram of the image obtained by said process. [Figure 22B] This is a timing chart showing the process performed by an ophthalmic device according to an exemplary embodiment of the model, and a schematic diagram of the image obtained by said process. [Figure 23] This is a schematic diagram illustrating the high dynamic range image generation performed by an ophthalmic device according to an exemplary embodiment of the model. [Figure 24A] This is a flowchart illustrating the processes performed by an ophthalmic device according to an exemplary embodiment of the model. [Figure 24B] This is a flowchart illustrating the processes performed by an ophthalmic device according to an exemplary embodiment of the model. [Figure 25] This is a timing chart showing the process performed by an ophthalmic device according to an exemplary embodiment of the model, and a schematic diagram of the image obtained by said process. [Figure 26] This is a schematic diagram showing the configuration of an ophthalmic device according to an exemplary embodiment. [Figure 27] This is a schematic diagram showing the configuration of an ophthalmic device according to an exemplary embodiment. [Modes for carrying out the invention]

[0012] Several non-limiting exemplary embodiments of the model will be described in detail with reference to the drawings.

[0013] Any prior art can be combined with any aspect of this disclosure. For example, any matter disclosed in the documents referenced herein can be combined with any aspect of this disclosure. Furthermore, any prior art in the art related to this disclosure can be combined with any aspect of this disclosure.

[0014] All contents disclosed in Patent Document 3 (Japanese Patent Publication No. 2019-213733) are incorporated herein by reference. Furthermore, any technical matters disclosed by the applicant of this application with respect to the technology related to this disclosure (matters disclosed in patent applications, papers, etc.) can be combined with any aspect relating to this disclosure.

[0015] It is possible to combine at least two or more of the various embodiments relating to this disclosure.

[0016] At least some of the functionality of the elements described in this disclosure is implemented using a circuitry or processing circuitry. The circuitry or processing circuitry is configured and / or programmed to perform at least some of the disclosed functionality and may include general-purpose processors, dedicated 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 Gates)). This includes any of the following: an array, a conventional circuit configuration, and any combination thereof. A processor is considered a processing circuit configuration or circuit configuration, including transistors and / or other circuit configurations. In this disclosure, a circuit configuration, unit, means, or similar terms means hardware that performs at least a portion of the disclosed functions, or hardware programmed to perform at least a portion of the disclosed functions. The hardware may be the hardware disclosed herein, or it may be known hardware programmed and / or configured to perform at least a portion of the described functions. If the hardware is a processor that can be considered a certain type of circuit configuration, then a circuit configuration, unit, means, or similar terms means a combination of hardware and software, the software being used to configure the hardware and / or processor.

[0017] The following embodiments describe various methods for handling monochrome images (using a monochrome camera), but those skilled in the art will understand that similar processing can be performed when handling color images (using a color camera). As a non-limiting example when handling color images, considering that a color camera generally generates three color component images (R component image, G component image, and B component image), it is possible to employ methods such as generating a high dynamic range image for each component image, generating a high dynamic range image using the luminance signal value (Y) generated from the three color component images, converting a color image to a monochrome image to generate a high dynamic range image, or generating a high dynamic range image from only selected color component images.

[0018] <Overview of Embodiments> The embodiments of this disclosure aim to improve ophthalmic imaging using an optical system that satisfies the conditions of Scheinproof. As an application thereto, some exemplary aspects of the embodiments of this disclosure aim to improve ophthalmic imaging by acquiring images while moving an optical system that satisfies the conditions of Scheinproof.

[0019] More specifically, embodiments of the present disclosure aim to improve the dynamic range of images obtained using an optical system that satisfies the Scheinproof conditions. As an application thereto, several exemplary aspects of embodiments of the present disclosure aim to improve the dynamic range of each of a series of images collected while moving an optical system that satisfies the Scheinproof conditions.

[0020] In general, improving dynamic range offers various advantages, and in ophthalmic imaging, which is the subject of this disclosure, these advantages include the following:

[0021] In ophthalmic imaging that utilizes light, it is sometimes necessary to represent two or more eye regions with significantly different light reflectivity in a single image. For example, in anterior segment imaging, images depicting both the cornea and the lens are often generated. However, the reflectivity of the cornea and the lens differs greatly; in fact, the reflectivity of the corneal surface is known to be approximately 62 times that of the lens surface. Therefore, the dynamic range of typical image sensors is insufficient to represent the cornea and the lens with appropriate brightness for each.

[0022] The embodiments of this disclosure can be used to solve such problems. Specifically, one objective of the embodiments of this disclosure is to suitably represent two or more eye regions with significantly different reflectivity in a single image. This makes it possible to improve the quality of images obtained in ophthalmic imaging.

[0023] The wide dynamic range images obtained from ophthalmic imaging according to this disclosure can be used in various ways. For example, by selectively extracting a portion (partial range) of the wide dynamic range of the image obtained from ophthalmic imaging according to this disclosure, it becomes possible to provide an image to any output device (such as a display device) that matches the characteristics of that output device (such as the dynamic range range).

[0024] To improve the dynamic range of images obtained in ophthalmic imaging, embodiments of the present disclosure are configured to apply two or more images of the eye under different shooting conditions using an optical system that satisfies the shineproof condition, and to generate a high dynamic range image based on two or more images of the eye obtained thereby.

[0025] Two or more images taken under different shooting conditions using an optical system that satisfies the conditions for a shineproof image may be taken in any manner. For example, the two or more images taken according to the embodiment may be two or more images taken sequentially, two or more images taken in parallel (simultaneously), or a combination thereof.

[0026] Furthermore, the number of cameras (image sensors, imaging devices) used for two or more shots according to the embodiment may be arbitrary. In some exemplary embodiments, two or more shots are taken sequentially using one camera. In some exemplary embodiments, two or more shots are taken in parallel using two or more cameras.

[0027] An optical system that satisfies the Scheinproof conditions may be, for example, the one disclosed in Patent Document 3 (Japanese Patent Application Publication No. 2019-213733), but is not limited thereto. By using an optical system that satisfies the Scheinproof conditions, it becomes possible to focus on and photograph a wide area of ​​the eye under examination. For example, in anterior segment imaging, it becomes possible to focus on and photograph an area defined by at least the anterior surface of the cornea and the posterior surface of the lens, making it possible to represent the entire main observation target of the anterior segment with high resolution.

[0028] Therefore, the high dynamic range image generated by the embodiment of this disclosure will have a wide area of ​​the eye under examination represented in high definition, and each depicted part will be represented with appropriate brightness.

[0029] Thus, the embodiments of this disclosure make it possible to provide novel eye images that achieve a wide shooting range, high resolution throughout the entire shooting range, and optimal brightness for each part. To this end, the embodiments include a novel configuration in which two or more shots with different shooting conditions are applied to the eye under examination using an optical system that satisfies shineproof conditions, and a high dynamic range image is generated based on two or more images of the eye under examination obtained thereby.

[0030] The shooting conditions may be any conditions set in a photograph using an optical system that satisfies the Scheinproof conditions. For example, the types of shooting conditions include conditions related to the optical system (optical system conditions), conditions related to the movement of the optical system (movement conditions), and other conditions.

[0031] Types of optical system conditions include conditions related to the illumination optical system for projecting illumination light onto the eye under examination (illumination conditions), and conditions related to the imaging optical system for photographing the eye under examination using an image sensor (exposure conditions).

[0032] Illumination conditions include conditions related to the intensity of the illumination light (illumination intensity conditions) and conditions related to the projection time of the illumination light (illumination time conditions). The projection time of the illumination light is the length of time (projection period) during which the illumination light is projected onto the eye under examination. In this disclosure, the projection time of the illumination light may be referred to as the illumination time.

[0033] Examples of illumination intensity conditions include conditions related to the light source that emits illumination light (e.g., the height of the light source control pulse), and conditions related to the light-reducing filters installed in the illumination optical system (e.g., conditions related to the selection of two or more light-reducing filters, conditions related to the control of a variable light-reducing filter).

[0034] Examples of illumination time conditions include conditions related to the light source that emits illumination light (e.g., the width of the light source control pulse) and conditions related to the shutter provided in the illumination optical system (e.g., the shutter opening time).

[0035] One type of exposure condition is the exposure time condition. Exposure time conditions include, for example, conditions related to the image sensor (e.g., exposure time of the image sensor) and conditions related to the shutter provided in the imaging optical system (e.g., shutter open time). Exposure time is the length of the period (exposure period) during which the image sensor can receive light.

[0036] When the imaging optical system has two or more image sensors, the exposure conditions (exposure time, exposure period, etc.) of these image sensors can be coordinated.

[0037] The types of movement conditions include the optical system's movement range (scan range, scan start position, scan end position), movement distance (scan distance), movement speed (scan speed), movement timing (scan start timing, scan end timing, etc.), and movement mode (continuous movement, intermittent movement, etc.).

[0038] Other conditions besides optical system conditions and movement conditions include conditions related to the coordination (synchronization) of two or more conditions, and conditions related to the eye being examined.

[0039] Examples of conditions relating to the linkage of two or more conditions include conditions relating to the linkage of two or more optical system conditions, conditions relating to the linkage of two or more movement conditions, and conditions relating to the linkage of one or more optical system conditions and one or more movement conditions.

[0040] Examples of conditions related to the eye being examined include conditions related to fixation, conditions related to the use of contrast agents, conditions related to the use of pupil-dilating agents, and conditions related to the characteristics of the eye. These characteristics of the eye may include parameters that affect the brightness of the eye image, or parameters that may affect the brightness of the eye image, such as pupil diameter and iris color.

[0041] In some exemplary embodiments, two or more imaging tests with different imaging conditions, performed using an optical system that satisfies the Scheinproof condition, are applied to substantially the same location on the eye under examination.

[0042] If the optical system moves continuously, for example, by controlling the system so that the time required for two or more shots is sufficiently short relative to the movement speed of the optical system, it is possible to acquire two or more images depicting approximately the same position on the eye being examined.

[0043] If the movement of the optical system is intermittent, for example, by controlling the system to alternate between taking two or more images of the same position on the eye under examination and moving the optical system, it is possible to obtain two or more images depicting approximately the same position on the eye under examination.

[0044] In contrast, in some other exemplary embodiments, two or more scans with different imaging conditions, performed using an optical system that satisfies the Scheinproof condition, may be applied to two or more different locations on the eye under examination. For example, two or more scans with different scanning directions can be applied to the three-dimensional region of the eye under examination as two or more scans with different imaging conditions. One specific example may be configured to perform a first scan under a first imaging condition by moving a slit beam with the longitudinal direction oriented horizontally in the vertical direction, and a second scan under a second imaging condition by moving a slit beam with the longitudinal direction oriented horizontally, and to generate a high dynamic range image based on a first three-dimensional image obtained from the first scan and a second three-dimensional image obtained from the second scan.

[0045] The process of generating a high dynamic range image from two or more images acquired using an optical system that satisfies the Scheinproof conditions may be a process that generates a high dynamic range image based on all of the two or more acquired images, or it may be a process that generates a high dynamic range image based on only a portion of the two or more acquired images.

[0046] The high dynamic range images of this disclosure are images having a wider dynamic range than the dynamic range of two or more images (original image group) acquired in two or more shooting sessions with different shooting conditions using an optical system that satisfies the Scheinproof condition. In other words, the high dynamic range images of this disclosure are images having an expanded (enlarged) dynamic range than the images included in the original image group.

[0047] The embodiments of this disclosure may be configured to perform control to achieve at least such functions. This control may include, as described above, control of the illumination optical system and / or control of the imaging optical system. The embodiments of this disclosure may also be configured to perform control to achieve other functions.

[0048] The control of the illumination optical system may be of any type, for example, electrical control such as control of the light source (on / off) or control of an electronic shutter, mechanical control such as control of a mechanical shutter or a rotary shutter, or a combination of electrical and mechanical control. These shutters are provided in the illumination optical system and function to switch between the passage and shielding of the illumination light output from the light source (i.e., to switch between the projection and non-projection of illumination light onto the eye under examination).

[0049] The control of the illumination optical system is not limited to controlling the switching between a state in which illumination light is projected onto the eye under examination (projection state) and a state in which it is not projected (non-projection state), but may also be used to modulate the intensity or amount of illumination light projected onto the eye under examination.

[0050] Switching between a projection state and a non-projection state is equivalent to switching the intensity of the illumination light projected onto the eye under examination between a positive value and zero. In contrast, intensity modulation is equivalent to switching the intensity of the illumination light projected onto the eye under examination between two different values, a first value and a second value. Here, both the first and second values ​​are non-negative, and either one or both of the first and second values ​​are positive. Therefore, switching between a projection state and a non-projection state can be considered an example of intensity modulation.

[0051] The control of the imaging optical system may be of any type, for example, it may be electrical control such as control of the image sensor or control of the electronic shutter, or mechanical control such as control of a mechanical shutter or control of a rotary shutter, or a combination of electrical and mechanical control.

[0052] Some exemplary embodiments of the embodiment may be a combination of a technique for generating a series of shine-proof images (a group of shine-proof images) corresponding to multiple positions (multiple cross-sections) of the eye under examination by moving an illumination optical system and a imaging optical system that satisfy shine-proof conditions (continuously or intermittently) and taking multiple images (a group of images), and a technique for generating a high dynamic range image based on the group of shine-proof images acquired by this group of images.

[0053] Several exemplary embodiments may be configured to acquire multiple sets of Scheinproof images corresponding to multiple shooting conditions by performing a parallel combination of optical system movement and image grouping multiple times while sequentially changing the shooting conditions, and further generate one or more high dynamic range images based on the acquired sets of Scheinproof images. In this embodiment, it is possible to generate two or more high dynamic range images corresponding to two or more target positions (two or more shooting positions, two or more target cross-sections) included in the image grouping. For example, according to this embodiment, it is possible to generate a high dynamic range image that represents the volume (three-dimensional region) of the scanned eye by a parallel combination of optical system movement and image grouping.

[0054] When both illumination and exposure conditions are variable, some exemplary embodiments may be configured to collect multiple sets of shineproof images by controlling only the illumination conditions, or by controlling only the exposure conditions, or by controlling both the illumination and exposure conditions.

[0055] More generally, in embodiments where two or more types of shooting conditions are variable, some exemplary embodiments may be configured to acquire multiple sets of Scheinproof images corresponding to multiple different shooting conditions by performing multiple parallel combinations of optical system movement and shooting groups while sequentially changing one or more types of shooting conditions selected from these two or more types of shooting conditions, and to generate one or more high dynamic range images from these sets of Scheinproof images.

[0056] The selection of imaging conditions may be made, for example, by the user or by a computer. Computer-based selection is performed based on predetermined information. For example, the computer may be configured to select imaging conditions based on imaging conditions applied in past imaging, medical information about the subject and / or the eye being examined (such as an electronic medical record), the disease being examined or screened for, the subject's attributes and condition, and the condition of the eye being examined.

[0057] When the lighting conditions are variable and the exposure conditions are fixed or preset, the embodiment is configured to collect multiple sets of shine-proof images by controlling the lighting conditions. When two or more types of lighting conditions are variable, the embodiment can change (select) the type of lighting condition that is controlled to collect multiple sets of shine-proof images.

[0058] Conversely, when the lighting conditions are fixed or preset and the exposure conditions are variable, the embodiment is configured to collect multiple shine-proof image sets by controlling the exposure conditions. When two or more types of exposure conditions are variable, the embodiment can change (select) the type of exposure condition that is controlled to collect multiple shine-proof image sets.

[0059] As mentioned above, the number of image sensors used in the embodiment may be arbitrary. In the embodiment using one image sensor, two or more images with different shooting conditions are applied sequentially to the eye under examination. On the other hand, in the embodiment using two or more image sensors, two or more images with different shooting conditions can be applied to the eye under examination in a partially parallel manner in time. In other words, in the embodiment using two or more image sensors, two or more images with different shooting conditions can be applied to the eye under examination such that their shooting times overlap at least partially. It should be noted that even in the embodiment using two or more image sensors, they may be applied to the eye under examination in a partially parallel manner in time, similar to the embodiment using one image sensor.

[0060] The embodiments outlined above will now be described in part

[0061] <Ophthalmological equipment> Several exemplary embodiments of an ophthalmic apparatus according to the present invention are provided.

[0062] Figure 1 shows the configuration of an ophthalmic device according to one embodiment of the invention. The ophthalmic device 1000 in this example includes an imaging unit 1010, a control unit 1020, and an image processing unit 1030.

[0063] The imaging unit 1010 includes an optical system 1011 that satisfies the Scheinproof conditions, and generates a digital image (Scheinproof image) by photographing the eye under examination using this optical system. The optical system 1011 includes an image sensor (not shown) for generating the digital image. Several non-exclusive specific examples of the imaging unit 1010, including the optical system 1011 that satisfies the Scheinproof conditions, will be described later.

[0064] The control unit 1020 controls the imaging unit 1010 to apply two or more imaging tests with different imaging conditions to the eye under examination. Under the control performed by the control unit 1020, the imaging unit 1010 generates two or more shine-proof images corresponding to two or more different imaging conditions. As described above, the two or more shine-proof images generated by the imaging unit 1010 under the control performed by the control unit 1020 are images taken of substantially the same position on the eye under examination.

[0065] The control unit 1020 includes hardware elements such as a processor and a memory device. The memory device stores computer programs such as control programs. The functions of the control unit 1020 are realized through the cooperation of software such as control programs and hardware such as the processor.

[0066] The shooting conditions in this embodiment may be any conditions (parameters) that affect the brightness of the generated image. Examples of shooting conditions in this embodiment include the aforementioned lighting conditions (e.g., lighting intensity, lighting time) and exposure conditions (e.g., exposure time, exposure period). Several non-exclusive specific examples of control for causing the shooting unit 1010 to perform two or more shots with different shooting conditions will be described later.

[0067] Thus, the two or more shineproof images generated by the imaging unit 1010 under the control performed by the control unit 1020 are two or more images with different brightness levels that depict substantially the same position on the eye being examined.

[0068] The image processing unit 1030 generates a high dynamic range image based on two or more shine-proof images generated by the imaging unit 1010 under control performed by the control unit 1020.

[0069] The image processing unit 1030 includes hardware elements such as a processor and a memory device. The memory device stores computer programs, such as image processing programs. The functions of the image processing unit 1030 are realized through the cooperation of software, such as image processing programs, and hardware, such as the processor.

[0070] As described above, the high dynamic range image in this embodiment is an image having a wider dynamic range than the dynamic range of two or more shineproof images (original image group) generated by the imaging unit 1010 under control performed by the control unit 1020.

[0071] The type of processing performed by the image processing unit 1030 to generate a high dynamic range image from the original image set can be arbitrary. Several examples of processing performed by the image processing unit 1030 are described below. Note that the processing performed by the image processing unit 1030 is not limited to these examples.

[0072] The first example of high dynamic range image generation is described below. While the following example describes a case where two original images are considered, those skilled in the art will understand that similar processing can be performed even when three or more original images are considered.

[0073] In this example, we consider two original images (the first original image and the second original image) included in the original image set. As mentioned above, the first original image and the second original image depict substantially the same position on the eye under examination, and the brightness of the first original image and the brightness of the second original image are different from each other.

[0074] First, the image processing unit 1030 identifies a first pixel from the first original image that satisfies a preset pixel value condition.

[0075] Furthermore, the image processing unit 1030 modifies the pixel value of the first pixel of the first original image based on the pixel value of the second pixel of the second original image that corresponds to the first pixel identified from the first original image.

[0076] In this way, the image processing unit 1030 performs a first process of identifying a first pixel from the first original image, a second process of identifying a second pixel in the second original image that corresponds to the first pixel, and a third process of changing the pixel value of the first pixel based on the pixel value of the second pixel.

[0077] Regarding the first process, the pixel value condition is a condition relating to the value of a pixel, and in this embodiment, it is a condition relating to the brightness of the image, that is, a condition relating to luminance. The pixel value condition may be, for example, a threshold value for the pixel value or a range of pixel values.

[0078] Furthermore, the pixel value conditions may or may not be the default values. In the latter case, for example, the image processing unit 1030 can determine them based on the brightness of the original image group (for example, the first original image and the second original image).

[0079] In the first process, the image processing unit 1030 identifies pixels in the first original image that satisfy the pixel value conditions by, for example, comparing each pixel of the first original image with the pixel value conditions. In this example, the set of pixels that satisfy the pixel value conditions is called a specific pixel group, and each pixel included in this specific pixel group is called a specific pixel.

[0080] The second process will now be explained. As mentioned above, the first original image and the second original image are images depicting essentially the same position on the eye being examined.

[0081] If it can be assumed that there is no substantial positional misalignment between the image of the eye under examination depicted in the first original image and the image of the eye under examination depicted in the second original image, or if it is determined that there is no substantial positional misalignment, then a natural correspondence can be defined between the pixel positions of the first original image and the pixel positions of the second original image.

[0082] One example of a case where we can assume there is no positional misalignment is when the time difference between the capture of the first original image and the capture of the second original image is sufficiently small (sufficiently small compared to the speed of eye movement or the movement speed of the optical system in the scan described later).

[0083] One example of a case where no positional misalignment is determined is when a positional misalignment evaluation (such as image registration or any other known process) is performed between the first original image and the second original image, and such a result is obtained.

[0084] In the natural correspondence described above, for any feature point of the eye under examination, the pixel position (coordinate) of that feature point in the first original image substantially coincides with the pixel position (coordinate) of that feature point in the second original image. In other words, when the first original image and the second original image are superimposed on each other, the image of the eye under examination in the first original image substantially overlaps with the image of the eye under examination in the second original image.

[0085] Once this natural correspondence is defined, the image processing unit 1030 can identify a pixel in the second original image that is located at the same coordinates as the first pixel (each pixel that satisfies the pixel value condition) identified in the first processing, and set this identified pixel as the second pixel.

[0086] In contrast, if there is a possibility of a substantial positional misalignment between the image of the eye under examination depicted in the first original image and the image of the eye under examination depicted in the second original image, or if it is determined that a substantial positional misalignment exists, the image processing unit 1030 can perform registration between the first original image and the second original image. This image registration is performed, for example, by identifying feature points in the first original image corresponding to a predetermined part of the eye under examination, identifying feature points in the second original image corresponding to the same part, and calculating the relative displacement between these feature points.

[0087] By determining the correspondence between the defining coordinate system of pixel positions in the first original image and the defining coordinate system of pixel positions in the second original image based on the relative displacement calculated in image registration, the image processing unit 1030 can identify the pixels in the second original image that correspond to the first pixels (each pixel that satisfies the pixel value conditions) identified from the first original image in the first processing, and set these identified pixels as the second pixels.

[0088] The third process involves changing the pixel value of the first pixel identified from the first original image in the first process, based on the pixel value of the second pixel (the pixel corresponding to the first pixel) identified from the second original image in the second process.

[0089] Some examples of processes performed in the third process include: replacing the pixel value of the first pixel with the pixel value of the second pixel; changing the pixel value of the second pixel and replacing the pixel value of the first pixel; determining the pixel value of the first pixel based on the pixel values ​​in the pixel group of the second original image that includes the second pixel; and determining the pixel value of the first pixel based on the pixel value of the first pixel and the pixel value of the second pixel.

[0090] Through these first to third processes, the pixel values ​​of each pixel in the first original image that satisfy predetermined pixel value conditions can be changed using the pixel values ​​of the corresponding pixels in the second original image, which have a different brightness from the first original image. This makes it possible to generate images with a dynamic range expanded beyond the dynamic range of these original images (high dynamic range images as referred to in this disclosure).

[0091] As described above, the first original image and the second original image are elements of a group of original images generated by the imaging unit 1010 under control performed by the control unit 1020. In some exemplary embodiments, the first original image is a relatively bright image among two or more original images that are elements of this group of original images, and the second original image is a relatively dark image. In this case, the image processing unit 1030 may be configured to perform the first to third processes described above as follows.

[0092] First, in the first process, the image processing unit 1030 identifies pixels with a brightness value equal to or greater than a preset first threshold from a relatively bright first original image as first pixels (specific pixels). This first threshold may be set to identify pixels with excessively high brightness values ​​(pixels that are too bright, pixels whose brightness is (almost) saturated, etc.).

[0093] Next, in the second process, the image processing unit 1030 identifies the second pixel of the second original image (a relatively dark image) that corresponds to the first pixel identified from the first original image in the first process.

[0094] Then, in the third process, the image processing unit 1030 changes the pixel value of the first pixel (the pixel in the first original image corresponding to this second pixel) that was identified from the first original image in the first process, based on the pixel value of the second pixel identified from the second original image in the second process.

[0095] In this configuration, the pixel values ​​of pixels with excessively high brightness in the relatively bright first original image can be changed based on the pixel values ​​of the corresponding pixels in the relatively dark second original image. This makes it possible to generate a high dynamic range image in which the exposure of the overly bright parts of the first original image is optimized.

[0096] Conversely, in some exemplary embodiments, the first original image is a relatively dark image among two or more original images that are elements of the original image group, and the second original image is a relatively bright image. In this case, the image processing unit 1030 may be configured to perform the first to third processes described above as follows.

[0097] First, in the first processing step, the image processing unit 1030 identifies pixels with a brightness value below a preset second threshold from the relatively dark first original image as the first pixels (specific pixels). This second threshold may be set to identify pixels with excessively low brightness values ​​(pixels that are too dark).

[0098] Next, in the second process, the image processing unit 1030 identifies a second pixel in the second original image (a relatively bright image) that corresponds to the first pixel identified from the first original image in the first process.

[0099] Then, in the third process, the image processing unit 1030 changes the pixel value of the first pixel (the pixel in the first original image corresponding to this second pixel) that was identified from the first original image in the first process, based on the pixel value of the second pixel identified from the second original image in the second process.

[0100] In this configuration, the pixel values ​​of pixels with excessively low brightness in the relatively dark first original image can be changed based on the pixel values ​​of the corresponding pixels in the relatively bright second original image. This makes it possible to generate a high dynamic range image in which the exposure of excessively dark areas of the first original image is optimized.

[0101] The process can be combined to correct the exposure of overly bright areas and to correct the exposure of overly dark areas of the original image. In this embodiment, at least three original images are selected from the original image group. The following specific example describes the case where three original images are considered, but those skilled in the art will understand that similar processing can be performed when four or more original images are considered.

[0102] If three original images are selected, they are referred to as the high-luminance original image, the medium-luminance original image, and the low-luminance original image, in order of brightness. Here, high-luminance, medium-luminance, and low-luminance refer to the relative brightness levels. In this case, the image processing unit 1030 may be configured to perform the first to third processes described above as follows.

[0103] First, in the first processing step, the image processing unit 1030 identifies from the medium-luminance original image pixels that have a luminance value equal to or greater than a preset first threshold (referred to as high-luminance pixels) and pixels that have a luminance value equal to or less than a preset second threshold (referred to as low-luminance pixels).

[0104] Next, in the second process, the image processing unit 1030 identifies pixels in the low-luminance original image that correspond to the high-luminance pixels identified in the medium-luminance original image in the first process. Furthermore, the image processing unit 1030 identifies pixels in the high-luminance original image that correspond to the low-luminance pixels identified in the medium-luminance original image in the first process.

[0105] Then, in the third process, the image processing unit 1030 changes the pixel values ​​of the high-luminance pixels identified from the medium-luminance original image in the first process based on the pixel values ​​of the pixels identified from the low-luminance original image in the second process. Furthermore, the image processing unit 1030 changes the pixel values ​​of the low-luminance pixels identified from the medium-luminance original image in the first process based on the pixel values ​​of the pixels identified from the high-luminance original image in the second process.

[0106] In this embodiment, the pixel values ​​of pixels with excessively high brightness (high-brightness pixels) in the medium-brightness original image can be changed based on the pixel values ​​of the corresponding pixels in the low-brightness original image, which is relatively darker than the medium-brightness original image. Conversely, the pixel values ​​of pixels with excessively low brightness (low-brightness pixels) in the medium-brightness original image can be changed based on the pixel values ​​of the corresponding pixels in the high-brightness original image, which is relatively brighter than the medium-brightness original image. As a result, it is possible to generate a high dynamic range image in which the exposure of both the overly bright and overly dark parts of the first original image is optimized. This concludes the explanation of the first example of high dynamic range image generation.

[0107] Next, we will explain a second example of high dynamic range image generation. This example focuses on the fact that in images of the eye, there are areas that are always depicted brightly and areas that are always depicted darkly; that is, certain areas are always depicted brightly and other areas are always depicted darkly. For example, in an image of the anterior segment of the eye, the cornea (especially the corneal apex and its vicinity) is depicted brightly, and the lens is depicted darkly. Similarly, in an image of the fundus, the optic nerve head is depicted brightly, and the macula is depicted darkly.

[0108] The following specific example describes the case where two original images are considered, but those skilled in the art will understand that the same process can be performed even when three or more original images are considered.

[0109] We consider two original images (the first original image and the second original image) included in the original image set. As mentioned above, the first original image and the second original image depict substantially the same position on the eye under examination, and the brightness of the first original image and the brightness of the second original image are different from each other.

[0110] First, the image processing unit 1030 identifies an image region (first image region) corresponding to a predetermined part of the eye being examined from the first original image. The image processing unit 1030 also identifies an image region (second image region) corresponding to the same part from the second original image. Furthermore, the image processing unit 1030 changes the pixel values ​​of the first image region in the first original image based on the pixel values ​​of the second image region in the second original image.

[0111] Let's explain a specific example. When each original image included in the original image group is an anterior segment image, the image processing unit 1030 identifies the image region corresponding to the cornea of ​​the eye under examination from the first original image and the second original image, respectively. The image region identified from the first original image is called the first corneal region, and the image region identified from the second original image is called the second corneal region.

[0112] Here, we assume that the first original image is a relatively bright image, and the second original image is a relatively dark image.

[0113] The image processing unit 1030 changes the pixel values ​​of the first corneal region in the first original image based on the pixel values ​​of the second corneal region in the second original image.

[0114] According to this specific example, the pixel values ​​of pixels included in the first corneal region, which is particularly brightly depicted in the relatively bright first original image, can be changed based on the pixel values ​​of pixels included in the second corneal region in the relatively dark second original image. This makes it possible to generate a high dynamic range image in which the exposure of the first corneal region in the first original image is optimized.

[0115] Let's explain another specific example. When each original image included in the original image group is an anterior segment image, the image processing unit 1030 identifies the image region corresponding to the lens of the eye under examination from the first original image and the second original image, respectively. The image region identified from the first original image is called the first lens region, and the image region identified from the second original image is called the second lens region.

[0116] Here, we assume that the first original image in this example is a relatively dark image, and the second original image is a relatively bright image.

[0117] The image processing unit 1030 changes the pixel values ​​of the first lens region in the first original image based on the pixel values ​​of the second lens region in the second original image.

[0118] According to this specific example, the pixel values ​​of pixels included in the first lens region, which is particularly dark in the relatively dark first original image, can be changed based on the pixel values ​​of pixels included in the second lens region in the relatively brighter second original image. Therefore, it is possible to generate a high dynamic range image in which the exposure of the first lens region in the first original image is optimized. This concludes the explanation of the second example of high dynamic range image generation.

[0119] Next, a third example of high dynamic range image generation will be described. In this example, the image processing unit 1030 is configured to generate a high dynamic range image by applying tone mapping processing to two or more original images included in the original image group.

[0120] Generally, tone mapping is a technique that transforms the pixel value distribution of an image with a certain dynamic range into a new pixel value distribution in order to output it on a medium with a narrower dynamic range (for example, displaying it on a display device or printing it on paper).

[0121] In this example, the image processing unit 1030 is configured to scale the luminance distribution of multiple images with different brightness levels acquired under different shooting conditions, thereby matching it to a luminance distribution that can be represented by an output device (e.g., a display device, a printing device, etc.). This generates an apparent (representational) high dynamic range image. This concludes the explanation of the third example of high dynamic range image generation.

[0122] Methods for generating high dynamic range (HDR) images are not limited to those described above. Several exemplary embodiments may be configured to perform HDR image generation using a machine learning model. This machine learning model may be constructed, for example, by applying training data to a neural network (e.g., a convolutional neural network) that includes multiple pairs of images obtained from two or more shooting sessions under different shooting conditions and HDR images generated from those images. This machine learning model functions to take two or more eye images as input and output a HDR image.

[0123] In another example, a machine learning model may be constructed by applying training data containing multiple pairs of single eye images and high dynamic range images generated from these eye images to a neural network (e.g., a convolutional neural network). This machine learning model would function to take a single eye image as input and output a high dynamic range image.

[0124] Figure 2 shows an example of the operation of the ophthalmic device 1000.

[0125] First, the ophthalmic device 1000 applies two or more imaging tests to the eye under examination by controlling the imaging unit 1010 with the control unit 1020 (S1). This results in a set of original images consisting of two or more shine-proof images corresponding to two or more imaging conditions.

[0126] Furthermore, the ophthalmic device 1000, using its image processing unit 1030, generates a high dynamic range image (S2) based on the original image set acquired in step S1, which has a dynamic range expanded from that of the original image.

[0127] The ophthalmic device 1000 outputs the high dynamic range image generated in step S2. For example, the ophthalmic device 1000 may be configured to perform one of the following output processes: providing the high dynamic range image to a display device, transmitting it to another computer, storing it in a storage device, recording it on a recording medium, or providing it to a printing device.

[0128] The images generated by such an ophthalmic device 1000 possess a unique and superior quality, having both high resolution over a wide range as a shine-proof image and appropriate overall brightness as a high dynamic range image. This concludes the description of the ophthalmic device 1000 according to this embodiment.

[0129] Figure 3 shows the configuration of an ophthalmic device according to one embodiment of the invention. Similar to the ophthalmic device 1000 described above, the ophthalmic device 1100 in this example includes an imaging unit 1010, a control unit 1020, and an image processing unit 1030, and furthermore, the imaging unit 1010 includes an optical system 1011.

[0130] The optical system 1011 of this embodiment includes an illumination optical system 1012. The illumination optical system 1012 is configured to project illumination light onto the eye under examination. The illumination optical system 1012 operates under the control of a control unit 1020 based on preset illumination conditions.

[0131] Similar to the control unit 1020 of the ophthalmic device 1000 described above, the control unit 1020 in this embodiment controls the imaging unit 1010 to apply two or more images with different imaging conditions to the eye under examination. The imaging conditions in this embodiment include at least conditions related to the illumination optical system 1012 (illumination conditions). Therefore, the control unit 1020 in this embodiment controls the imaging unit 1010 (at least the illumination optical system 1012) to apply two or more images with at least different illumination conditions to the eye under examination.

[0132] An example of the operation of the ophthalmic device 1100 is shown in Figure 4.

[0133] First, the ophthalmic device 1100 applies at least two imaging sessions to the eye under examination, each with at least two different lighting conditions, by controlling the imaging unit 1010 with the control unit 1020 (S11). This results in a set of original images consisting of two or more shine-proof images corresponding to two or more imaging conditions (including at least two or more lighting conditions).

[0134] Furthermore, the ophthalmic device 1100, using its image processing unit 1030, generates a high dynamic range image (S12) based on the original image set acquired in step S11, which has a dynamic range expanded from that of the original image. The image generated in step S12 possesses both high resolution over a wide range as a shine-proof image and appropriate overall brightness as a high dynamic range image.

[0135] In some exemplary embodiments, the illumination conditions may include illumination intensity conditions that define the intensity of the illumination light. In this case, the control unit 1020 may be configured to control the imaging unit 1010 (at least the illumination optical system 1012) to apply at least two imagings with different illumination intensity conditions to the eye under examination. Matters concerning illumination intensity conditions (types of illumination intensity conditions, configurations for changing illumination intensity conditions, etc.) have been described above. Exemplary embodiments in which illumination intensity conditions are used will be described later.

[0136] In some exemplary embodiments, the illumination conditions may include illumination time conditions that define the projection time of the illumination light. In this case, the control unit 1020 may be configured to control the imaging unit 1010 (at least the illumination optical system 1012) to apply at least two imagings with different illumination time conditions to the eye under examination. Matters concerning illumination time conditions (types of illumination time conditions, configurations for changing illumination time conditions, etc.) have been described above. Exemplary embodiments in which illumination time conditions are used will be described later. This concludes the description of the ophthalmic apparatus 1100 according to this embodiment.

[0137] Figure 5 shows the configuration of an ophthalmic device according to one embodiment. This embodiment is an example of an embodiment in which illumination intensity conditions are used. Similar to the ophthalmic device 1100 described above, the ophthalmic device 1200 in this example includes an imaging unit 1010, a control unit 1020, and an image processing unit 1030, the imaging unit 1010 includes an optical system 1011, and the optical system 1011 includes an illumination optical system 1012.

[0138] The imaging unit 1010 in this embodiment is equipped with a moving mechanism 1019. The moving mechanism 1019 is configured to move the optical system 1011. The moving mechanism 1019 may also include a mechanism that has the same function (same action as the movement of the optical system 1011) as the movement of the optical system 1011. Examples of such mechanisms include a mechanism that moves the illumination position by deflecting illumination light (slit light) (illumination scanner, movable illumination mirror), and a mechanism that moves the imaging position by deflecting light from the eye under examination toward the imaging unit 1010 (image sensor not shown) (imaging scanner, movable imaging mirror).

[0139] Similar to the control unit 1020 of the ophthalmic device 1000 described above, the control unit 1020 of this embodiment controls the imaging unit 1010 to apply two or more images with different imaging conditions to the eye under examination. The imaging conditions of this embodiment include at least illumination conditions, and furthermore, the illumination conditions of this embodiment include at least illumination intensity conditions. Therefore, the control unit 1020 of this embodiment controls the imaging unit 1010 (at least the illumination optical system 1012) to apply two or more images with at least different illumination intensity conditions to the eye under examination.

[0140] The illumination intensity conditions in this embodiment include two or more conditions. That is, the illumination intensity conditions in this embodiment include two or more conditions corresponding to multiple different illumination intensities. As a specific example of the two or more conditions included in the illumination intensity conditions, the control embodiments shown in Figures 7A and 7B, which will be described later, include a condition that shows a relatively high intensity (circle 1) and a condition that shows a relatively low intensity (circle 2).

[0141] The control unit 1020 in this embodiment is configured to repeatedly cause the imaging unit 1010 to acquire a group of images consisting of two or more images corresponding to two or more conditions included in the illumination intensity conditions, by combining the control of the illumination optical system 1012 for cyclically applying two or more conditions included in the illumination intensity conditions (referred to as illumination control) and the control of the movement mechanism 1019 for moving the optical system 1011 (referred to as movement control). That is, the control unit 1020 is configured to acquire multiple image groups by executing illumination control and movement control, and each of the multiple image groups contains two or more images corresponding to two or more conditions included in the illumination intensity conditions.

[0142] This section explains lighting control. The K conditions included in the lighting intensity conditions are denoted as the first condition, the second condition, ..., and the Kth condition. Here, K is an integer greater than or equal to 2. The first to Kth conditions are ordered in this order. Applying the first to Kth conditions in this order is called a series of condition applications. Lighting control is the control that causes the lighting optical system 1012 to repeatedly perform this series of condition applications.

[0143] As a concrete example of lighting control, the control modes shown in Figures 7A and 7B, described later, repeatedly apply a series of conditions consisting of a condition showing relatively high intensity (circle 1) and a condition showing relatively low intensity (circle 2). Note that when the lighting intensity condition includes two conditions, the lighting control (cyclic application) is the alternating application of these two conditions.

[0144] The application mode of the first to K conditions is not limited to cyclic application; the first to K conditions may be applied iteratively while changing their order. Furthermore, in the iterative application of the first to K conditions, it is not necessary to apply all K conditions in each iteration.

[0145] The movement control is described below. Movement control is a control mechanism for changing the position of the eye being photographed by the optical system 1011. Movement control enables the imaging unit 1010 to acquire images of the eye at multiple positions. Furthermore, movement control moves the optical system 1011 while maintaining that the optical system 1011 satisfies the shine-proof conditions. This makes it possible to collect multiple images that are in focus over a wide range.

[0146] Thus, in this embodiment, under the illumination control and movement control of the control unit 1020, the imaging unit 1010 scans the eye under examination (taking images at multiple positions) and collects multiple shine-proof images. In other words, the imaging unit 1010 in this embodiment collects a series of shine-proof images by cyclically changing the illumination intensity conditions according to the illumination control and changing the scan position (projection position of illumination light and shooting position) according to the movement control.

[0147] The image processing unit 1030 in this embodiment can generate multiple high dynamic range images based on multiple image groups acquired by a combination of illumination control and movement control. As mentioned above, the number of conditions included in the illumination intensity condition is assumed to be K (K is an integer of 2 or more). Each condition included in the illumination intensity condition is represented by C(k) (k=1, 2, ..., K). Also, the number of scan positions by movement control is assumed to be L (L is an integer of 2 or more). Each scan position is represented by P(l) (l=1, 2, ..., L).

[0148] In this embodiment, K images are obtained at each scan position P(l). The image corresponding to the scan position P(l) and the kth condition C(k) is represented by G(P(l), C(k)). The K images G(P(l), C(1)), G(P(l), C(2)), ..., G(P(l), C(K)) corresponding to the scan position P(l) are called the first condition image, the second condition image, ..., and the kth condition image, respectively.

[0149] The image processing unit 1030 generates a high dynamic range image H(P(l)) at each scan position P(l) based on K conditional images G(P(l), C(1)) to G(P(l), C(K)) corresponding to each scan position P(l). This results in L high dynamic range images H(P(1)) to H(P(L)) corresponding to L scan positions P(1) to P(L).

[0150] The image processing unit 1030 can generate a high dynamic range image representing the volume (3D region) of the eye under examination based on L high dynamic range images H(P(1)) to H(P(L)).

[0151] An example of the operation of the ophthalmic device 1200 is shown in Figure 6.

[0152] First, the imaging unit 1010 of the ophthalmic device 1200 starts scanning the eye under examination through illumination control and movement control by the control unit 1020 (S21). During the scanning of the eye under examination, imaging is first performed at the first scan position P(1) under K illumination intensity conditions (conditions 1 to K) (S22). This yields condition images G(P(1), C(1)) to G(P(1), C(K)) corresponding to the first scan position P(1). The ophthalmic device 1200 saves condition images G(P(1), C(1)) to G(P(1), C(K)) in association with the first scan position P(1) (S23). For example, the saving process of the condition images is performed by the control unit 1020, and the storage location of the condition images is the memory device (described above) within the control unit 1020.

[0153] Steps S22 and S23 are repeated until the scan is completed (S24). If the scan is not completed (S24: No), the system moves to the next scan position for imaging via movement control (S25). Once the scan is completed, the system proceeds to step S26 (S24: Yes).

[0154] As a result, steps S22 and S23 are performed at each of the L scan positions P(1) to P(L), and K conditional images G(P(l), C(1)) to G(P(l), C(K)) corresponding to each scan position P(l) are acquired and stored.

[0155] The image processing unit 1030 generates a high dynamic range image H(P(l)) at the scan position P(l) based on K conditional images G(P(l), C(1)) to G(P(l), C(K)) corresponding to each scan position P(l) (S26). This yields L high dynamic range images H(P(1)) to H(P(L)) corresponding to L scan positions P(1) to P(L).

[0156] Each image generated in step S26 possesses both the broad-range high resolution required for a shine-proof image and the overall brightness appropriateness required for a high dynamic range image. Furthermore, in this embodiment, such high-quality images can be obtained for multiple positions on the eye under examination.

[0157] In some exemplary embodiments, in addition to acquiring such high-quality images across the three-dimensional region of the eye under examination, it is also possible to generate high dynamic range images that represent the volume (three-dimensional region) of the eye under examination.

[0158] Figures 7A and 7B show two examples of scanning controlled by lighting and movement. Figure 7C shows a conventional scan for comparison with these examples.

[0159] The conventional scan shown in Figure 7C is achieved through coordinated control (synchronous control) of the light source's emission (output of illumination light, projection of illumination light onto the eye under examination), the camera's exposure (image capture), and the scan position (position of the moving optical system 1011).

[0160] More specifically, this conventional scan combines the continuous emission of illumination light, repeated exposure by a camera, and the continuous movement of the optical system 1011 from the scan start position to the scan end position. The repeated exposure by the camera is performed by alternating between exposure and charge transfer (and exposure standby).

[0161] In contrast, in the scan of this embodiment shown in Figure 7A, the camera exposure and movement of the scan position are performed in the same manner as in the conventional scan shown in Figure 7C. However, unlike the conventional scan shown in Figure 7C, which continuously emits illumination light, the light source emits illumination light intermittently (pulsed emission).

[0162] Furthermore, in the scan of this embodiment shown in Figure 7A, switching control of illumination intensity conditions is performed, which is not performed in the conventional scan shown in Figure 7C. Here, illumination intensity conditions "Circle 1" and "Circle 2" correspond to the conditions C(1) and C(2) described above, respectively. That is, in the example of Figure 7A, the illumination intensity conditions include two conditions C(1) and C(2), and these two conditions C(1) and C(2) are applied cyclically (i.e., alternately). Note that condition C(1) is an illumination intensity condition that shows a relatively high intensity, and condition C(2) is an illumination intensity condition that shows a relatively low intensity.

[0163] In the scan shown in Figure 7A, the sequence of illumination light emission (projection) (multiple flashes arranged in chronological order) and the camera exposure sequence (multiple exposures arranged in chronological order) are synchronized with each other. The duration of each flash in the illumination light sequence corresponds to the projection period, and its length corresponds to the projection time.

[0164] Similarly, each exposure period in the exposure sequence corresponds to the exposure period, and its length corresponds to the exposure time. The projection time may be constant or non-constant. The exposure time may be constant or non-constant.

[0165] In the scan of Figure 7A, for each exposure period in the exposure sequence, a portion of that exposure period coincides with one projection period. That is, for each exposure period in the exposure sequence, the length of the projection period (projection time) is shorter than the length of the exposure period (exposure time), and a portion of this exposure period overlaps with the entirety of this projection period.

[0166] As a result, in each exposure period of the exposure sequence, effective exposure (light reception and charge accumulation by the image sensor) occurs only during a projection period shorter than the exposure period itself. This reduces image blurring caused by movement of the scan position or eye movements during exposure compared to conventional ophthalmic imaging techniques. Therefore, it becomes possible to provide images of higher quality than conventional ophthalmic imaging techniques.

[0167] Furthermore, it becomes possible to perform image analysis (e.g., corneal detection, cell detection, etc.) with higher quality than conventional ophthalmic image analysis techniques. Moreover, since the time that illumination light is projected onto the eye under examination can be shortened, it is possible to reduce the burden on the patient compared to the case where illumination light is continuously projected as shown in Figure 7C.

[0168] Furthermore, in the scan shown in Figure 7A, the optical system 1011 moves continuously from the scan start position to the scan end position, and there are no repeated sudden starts and stops of the optical system 1011. As a result, vibrations caused by such movements do not occur during the scan, and therefore do not adversely affect the image quality.

[0169] On the other hand, in another scan of this embodiment shown in Figure 7B, the optical system 1011 is moved intermittently from the scan start position to the scan end position, except that it is the same as the scan in Figure 7A. Therefore, the scan in Figure 7B can be performed with the same effect as the scan in Figure 7A, except for the vibration problem caused by the sudden acceleration and deceleration of the optical system 1011. Furthermore, by improving the structure and mechanism of the ophthalmic device 1200, the vibration problem caused by the sudden acceleration and deceleration of the optical system 1011 can be reduced or eliminated.

[0170] Figure 8 shows the configuration of an ophthalmic device according to one embodiment. This embodiment is an example of an embodiment in which illumination time conditions are used. Similar to the ophthalmic device 1200 described above, the ophthalmic device 1300 in this example includes an imaging unit 1010, a control unit 1020, and an image processing unit 1030. The imaging unit 1010 includes an optical system 1011 and a moving mechanism 1019, and the optical system 1011 includes an illumination optical system 1012.

[0171] Similar to the control unit 1020 of the ophthalmic device 1000 described above, the control unit 1020 in this embodiment controls the imaging unit 1010 to apply two or more images with different imaging conditions to the eye under examination. The imaging conditions in this embodiment include at least illumination conditions, and furthermore, the illumination conditions in this embodiment include at least illumination time conditions. Therefore, the control unit 1020 in this embodiment controls the imaging unit 1010 (at least the illumination optical system 1012) to apply two or more images with at least different illumination time conditions to the eye under examination.

[0172] The illumination time conditions in this embodiment include two or more conditions. That is, the illumination time conditions in this embodiment include two or more conditions corresponding to multiple different illumination times. As a specific example of the two or more conditions included in the illumination time conditions, the control embodiments shown in Figures 10A and 10B, which will be described later, include a condition indicating a relatively short illumination time (circle 1) and a condition indicating a relatively long illumination time (circle 2).

[0173] The control unit 1020 in this embodiment is configured to repeatedly cause the imaging unit 1010 to acquire a group of images consisting of two or more images corresponding to two or more conditions included in the illumination time conditions, by combining the control of the illumination optical system 1012 for cyclically applying two or more conditions included in the illumination time conditions (referred to as illumination control) and the control of the movement mechanism 1019 for moving the optical system 1011 (referred to as movement control).

[0174] In other words, the control unit 1020 is configured to acquire multiple image groups by performing lighting control and movement control, and each of the multiple image groups contains two or more images corresponding to two or more conditions included in the lighting time conditions.

[0175] This section explains illumination control. The M conditions included in the illumination time conditions are denoted as the first condition, the second condition, ..., and the Mth condition. Here, M is an integer greater than or equal to 2. The first to Mth conditions are ordered in this order. Applying the first to Mth conditions in this order is called a series of condition applications. Illumination control is the control that causes the illumination optical system 1012 to repeatedly perform this series of condition applications.

[0176] As a concrete example of lighting control, the control modes shown in Figures 10A and 10B, described later, repeatedly apply a series of conditions consisting of a condition indicating a relatively short lighting time (circle 1) and a condition indicating a relatively long lighting time (circle 2). Note that when the lighting time condition includes two conditions, the lighting control (cyclic application) is the alternating application of these two conditions.

[0177] The application mode of the first to M conditions is not limited to cyclic application; the first to M conditions may be applied iteratively while changing their order. Furthermore, in the iterative application of the first to M conditions, it is not necessary to apply all M conditions in each iteration.

[0178] The movement control is described below. Movement control is a control mechanism for changing the position of the eye being photographed by the optical system 1011. Movement control enables the imaging unit 1010 to acquire images of the eye at multiple positions. Furthermore, movement control moves the optical system 1011 while maintaining that the optical system 1011 satisfies the shine-proof conditions. This makes it possible to collect multiple images that are in focus over a wide range.

[0179] Thus, in this embodiment, under the illumination control and movement control of the control unit 1020, the imaging unit 1010 scans the eye under examination (taking images at multiple positions) and collects multiple shine-proof images. In other words, the imaging unit 1010 in this embodiment collects a series of shine-proof images by cyclically changing the illumination time conditions according to the illumination control and changing the scan position (projection position of illumination light and shooting position) according to the movement control.

[0180] The image processing unit 1030 in this embodiment can generate multiple high dynamic range images based on a group of images acquired by a combination of lighting control and motion control.

[0181] As mentioned above, the number of conditions included in the illumination time condition is assumed to be M (where M is an integer greater than or equal to 2). Each condition included in the illumination time condition is represented by C(m) (m = 1, 2, ..., M). Also, the number of scan positions due to movement control is assumed to be N (where N is an integer greater than or equal to 2). Each scan position is represented by P(n) (n = 1, 2, ..., N).

[0182] In this embodiment, M images are obtained at each scan position P(n). The image corresponding to the scan position P(n) and the mth condition C(m) is represented by G(P(n), C(m)). The M images G(P(n), C(1)), G(P(n), C(2)), ..., G(P(n), C(M)) corresponding to the scan position P(n) are called the first condition image, the second condition image, ..., the Mth condition image, respectively.

[0183] The image processing unit 1030 generates a high dynamic range image H(P(n)) at each scan position P(n) based on M conditional images G(P(n), C(1)) to G(P(n), C(M)) corresponding to each scan position P(n). This results in N high dynamic range images H(P(1)) to H(P(N)) corresponding to N scan positions P(1) to P(N).

[0184] The image processing unit 1030 can generate a high dynamic range image representing the volume (3D region) of the eye under examination based on N high dynamic range images H(P(1)) to H(P(N)).

[0185] Figure 9 shows an example of the operation of the ophthalmic device 1300.

[0186] First, the imaging unit 1010 of the ophthalmic device 1300 starts scanning the eye under examination through illumination control and movement control by the control unit 1020 (S31).

[0187] In scanning the eye under examination, images are first captured at the first scan position P(1) under M conditions of illumination time (conditions 1 to M) (S32). This yields conditional images G(P(1), C(1)) to G(P(1), C(M)) corresponding to the first scan position P(1).

[0188] The ophthalmic device 1300 stores the first to M conditional images G(P(1), C(1)) to G(P(1), C(M)) in association with the first scan position P(1) (S33).

[0189] Steps S32 and S33 are repeated until the scan is completed (S34). If the scan is not completed (S34: No), the system moves to the next scan position for imaging via movement control (S35). Once the scan is completed, the system proceeds to step S36 (S34: Yes).

[0190] As a result, steps S32 and S33 are performed at each of the N scan positions P(1) to P(N), and M condition images G(P(n), C(1)) to G(P(n), C(K)) corresponding to each scan position P(n) are acquired and saved.

[0191] The image processing unit 1030 generates a high dynamic range image H(P(n)) at each scan position P(n) based on M conditional images G(P(n), C(1)) to G(P(n), C(M)) corresponding to each scan position P(n) (S36). This results in N high dynamic range images H(P(1)) to H(P(N)) corresponding to N scan positions P(1) to P(N).

[0192] Each image generated in step S36 possesses both the broad-range high resolution required for a shine-proof image and the overall appropriateness of brightness required for a high dynamic range image. Furthermore, in this embodiment, such high-quality images can be obtained for multiple positions on the eye under examination.

[0193] In some exemplary embodiments, in addition to acquiring such high-quality images across the three-dimensional region of the eye under examination, it is also possible to generate high dynamic range images that represent the volume (three-dimensional region) of the eye under examination.

[0194] Two examples of scanning using lighting control and movement control according to this embodiment are shown in Figures 10A and 10B.

[0195] In the scan of this embodiment shown in Figure 10A, the camera exposure and movement of the scan position are performed in the same manner as the conventional scan shown in Figure 7C, but unlike the conventional scan shown in Figure 7C, in terms of the emission of light from the light source, the illumination light is output intermittently (pulsed emission).

[0196] Furthermore, in the scan of this embodiment shown in Figure 10A, switching control of illumination time conditions is performed, which is not performed in the conventional scan shown in Figure 7C. Here, illumination time conditions "Circle 1" and "Circle 2" correspond to the conditions C(1) and C(2) described above, respectively. That is, in the example of Figure 10A, the illumination time conditions include two conditions C(1) and C(2), and these two conditions C(1) and C(2) are applied cyclically (i.e., alternately). Note that condition C(1) is an illumination time condition that indicates a relatively short duration, and condition C(2) is an illumination time condition that indicates a relatively long duration.

[0197] In the scan shown in Figure 10A, the sequence of illumination light emission (projection) (multiple flashes arranged in chronological order) and the camera exposure sequence (multiple exposures arranged in chronological order) are synchronized with each other. The duration of each flash in the illumination light sequence corresponds to the projection period, and its length corresponds to the projection time (illumination time).

[0198] Similarly, each exposure period in the exposure sequence corresponds to the exposure period, and its length corresponds to the exposure time. In this embodiment, the projection time (illumination time) is non-constant. The exposure time may be constant or non-constant.

[0199] In the scan shown in Figure 10A, for each exposure period in the exposure sequence, a portion of the exposure period coincides with one projection period. That is, for each exposure period in the exposure sequence, the projection period (projection time, illumination time) is shorter than the exposure period (exposure time), and a portion of this exposure period overlaps with the entire projection period. As a result, in each exposure period in the exposure sequence, exposure (light reception by the image sensor, charge accumulation) occurs only during the projection period which is shorter than the exposure period, thus reducing image blurring caused by movement of the scan position or eye movements during exposure compared to conventional ophthalmic imaging techniques. Therefore, it becomes possible to provide images of higher quality than conventional ophthalmic imaging techniques.

[0200] Furthermore, it becomes possible to perform image analysis (e.g., corneal detection, cell detection, etc.) with higher quality than conventional ophthalmic image analysis techniques. Moreover, since the time that illumination light is projected onto the eye under examination can be shortened, it is possible to reduce the burden on the patient compared to the case where illumination light is continuously projected as shown in Figure 7C.

[0201] Furthermore, in the scan shown in Figure 10A, the optical system 1011 moves continuously from the scan start position to the scan end position, and there are no repeated sudden starts and stops of the optical system 1011. As a result, vibrations caused by such movements do not occur during the scan, and therefore do not adversely affect the image quality.

[0202] On the other hand, in another scan of this embodiment shown in Figure 10B, the optical system 1011 is moved intermittently from the scan start position to the scan end position, except that it is the same as the scan in Figure 10A. Therefore, the scan in Figure 10B has the same effect as the scan in Figure 10A, except that it does not cause vibration problems due to the sudden acceleration and deceleration of the optical system 1011. Furthermore, by improving the structure and mechanism of the ophthalmic device 1300, the vibration problems caused by the sudden acceleration and deceleration of the optical system 1011 can be reduced or eliminated.

[0203] In some exemplary embodiments, the illumination conditions may include both illumination intensity conditions and illumination duration conditions. The ophthalmic apparatus of this embodiment is configured to apply two or more images to the eye under examination while switching between illumination conditions by combining illumination intensity conditions and illumination duration conditions. The configuration and operation of such an ophthalmic apparatus of this embodiment will be understandable to those skilled in the art from Figures 5 to 10B and the above description based on these drawings. The same applies when the illumination conditions include conditions other than those described above.

[0204] In the embodiments shown in Figures 5 to 7B and Figures 8 to 10B, two or more image groups corresponding to two or more conditions are collected in a single scan. That is, in the embodiments shown in Figures 5 to 7B and Figures 8 to 10B, two or more image groups corresponding to two or more conditions are collected while the optical system 1011 moves from the scan start position to the scan end position only once.

[0205] However, the mode of scanning for collecting two or more image sets corresponding to two or more conditions is not limited thereto. In the mode shown in Figure 11, which will be described next, two or more scans are performed to collect two or more image sets corresponding to two or more conditions.

[0206] Although the embodiment shown in Figure 11 employs a case where the illumination time conditions include two or more conditions, the same applies when the illumination intensity conditions include two or more conditions, when other types of illumination conditions include two or more conditions, or when other types of shooting conditions other than illumination conditions include two or more conditions.

[0207] The embodiment shown in Figure 11 will be described below. The terms and symbols used in the embodiments shown in Figures 8 to 10B will be applied as appropriate. First, the scanning of the eye under examination is started by illumination control and movement control (S41).

[0208] When scanning begins, the scan under the first condition C(1) of the M illumination time conditions (conditions 1 to M) is applied to the eye under examination (S42). This scan involves moving the optical system 1011 from the scan start position to the scan end position while fixing the illumination time condition to the first condition C(1), and taking multiple (N) images. As a result, for the first condition C(1), N images G(P(1), C(1)) to G(P(N), C(1)) corresponding to the N scan positions P(1) to P(N) are obtained. The N images G(P(1), C(1)) to G(P(N), C(1)) corresponding to the first condition C(1) are called the first image group.

[0209] Once the scan under the first condition C(1) is completed, the scan under the next condition C(2) is performed in the same manner as in step S42 (S43).

[0210] Such scans are performed for each of the M conditions C(1) to C(M) (S44). If a scan has not yet been performed for a certain condition (S44: No), the process moves on to scanning for the next condition (S45). Once the scans for all conditions are complete, the process moves on to step S46 (S44: Yes).

[0211] This yields M image sets corresponding to M conditions C(1) to C(M). The m-th image set corresponding to the m-th condition C(m) contains N images G(P(1), C(m)) to G(P(N), C(m)) corresponding to N scan positions P(1) to P(N).

[0212] Once scanning under all conditions is complete (S44: Yes), the image processing unit 1030 performs registration between the first to M image groups (S46). This registration aligns the M images G(P(n), C1)) to G(P(n), C(M)) that correspond to the same scan position P(n).

[0213] The method used for this registration may be arbitrary and may include, for example, the control details for each scan (such as the content of movement control, lighting control, and imaging control), images of the eye taken separately from the scan, and known registration methods.

[0214] In some exemplary embodiments, M volume data (3D images) may be generated from M image groups corresponding to M conditions C(1) to C(M), registration (3D registration) may be performed between these M volume data, and the results of this 3D registration may be used to align the M image groups.

[0215] The registration in step S46 aligns and associates M images G(P(n), C(1)) to G(P(n), C(M)) corresponding to each scan position P(n). The M images G(P(n), C(1)) to G(P(n), C(M)) obtained in this way correspond to the M conditional images G(P(n), C(1)) to G(P(n), C(M)) corresponding to the scan position P(n) mentioned above.

[0216] The image processing unit 1030 generates a high dynamic range image H(P(n)) at each scan position P(n) based on M conditional images G(P(n), C(1)) to G(P(n), C(M)) corresponding to each scan position P(n) (S47). This yields N high dynamic range images H(P(1)) to H(P(N)) corresponding to N scan positions P(1) to P(N).

[0217] Each image generated in step S47 possesses both the broad-range high resolution required for a shine-proof image and the overall brightness appropriateness required for a high dynamic range image. Furthermore, in this embodiment, such high-quality images can be obtained for multiple positions on the eye under examination.

[0218] In some exemplary embodiments, in addition to acquiring such high-quality images across the three-dimensional region of the eye under examination, it is also possible to generate high dynamic range images that represent the volume (three-dimensional region) of the eye under examination.

[0219] Figure 12 shows the configuration of an ophthalmic device according to one embodiment of the invention. Similar to the ophthalmic device 1000, the ophthalmic device 1400 in this example includes an imaging unit 1010, a control unit 1020, and an image processing unit 1030, and furthermore, the imaging unit 1010 includes an optical system 1011.

[0220] The optical system 1011 of this embodiment includes an illumination optical system 1012, similar to the ophthalmic apparatus 1200 described above, and further includes an imaging optical system 1013. The imaging optical system 1013 is configured to image the eye under examination, which is illuminated by the illumination optical system 1012. The imaging optical system 1013 operates under the control of a control unit 1020 based on preset exposure conditions.

[0221] Similar to the control unit 1020 of the ophthalmic device 1000, the control unit 1020 in this embodiment controls the imaging unit 1010 to apply two or more images with different imaging conditions to the eye under examination. The imaging conditions in this embodiment include at least conditions related to the imaging optical system 1013 (exposure conditions). Therefore, the control unit 1020 in this embodiment controls the imaging unit 1010 (at least the imaging optical system 1013) to apply two or more images with different exposure conditions to the eye under examination.

[0222] Figure 13 shows an example of the operation of the ophthalmic device 1400.

[0223] First, the ophthalmic device 1400 applies at least two different exposure conditions to the eye under examination by controlling the imaging unit 1010 with the control unit 1020 (S51). This results in a set of original images consisting of two or more shine-proof images corresponding to two or more imaging conditions (including at least two or more exposure conditions).

[0224] Furthermore, the ophthalmic device 1400, using the image processing unit 1030, generates a high dynamic range image (S52) based on the original image set acquired in step S51, which has a dynamic range expanded from that of the original image. The image generated in step S52 possesses both high resolution over a wide range as a shine-proof image and appropriate overall brightness as a high dynamic range image.

[0225] In some exemplary embodiments, the exposure conditions may include exposure time conditions that determine the exposure time by the imaging optical system 1013. In this case, the control unit 1020 may be configured to control the imaging unit 1010 (at least the imaging optical system 1013) to apply at least two imagings with different exposure time conditions to the eye under examination. Matters concerning exposure time conditions (types of exposure time conditions, configurations for changing exposure time conditions, etc.) have been described above. Exemplary embodiments in which exposure time conditions are used will be described later. This concludes the description of the ophthalmic apparatus 1400 according to this embodiment.

[0226] Figure 14 shows the configuration of an ophthalmic apparatus according to one embodiment of the invention. This embodiment is an example of an embodiment in which exposure time conditions are used. Similar to the ophthalmic apparatus 1400 described above, the ophthalmic apparatus 1500 in this example includes an imaging unit 1010, a control unit 1020, and an image processing unit 1030. The imaging unit 1010 includes an optical system 1011 and a moving mechanism 1019, and the optical system 1011 includes an illumination optical system 1012 and an imaging optical system 1013. In addition, the imaging optical system 1013 in this example includes an image sensor 1014 and an optical system (not shown) that guides light from the eye under examination to the image sensor 1014.

[0227] The illumination optical system 1012 and the imaging optical system 1013 are configured to satisfy the conditions for a Scheinproof camera and function as a Scheinproof camera. More specifically, the illumination optical system 1012 and the imaging optical system 1013 are configured such that the plane passing through the optical axis of the illumination optical system 1012 (a plane including the object surface), the main surface of the imaging optical system 1013, and the imaging surface of the image sensor 1014 intersect on the same straight line.

[0228] By using an illumination optical system 1012 and an imaging optical system 1013 that satisfy the conditions for a shineproof image, it is possible to take images with the imaging optical system 1013 in focus at all positions within the object plane (all positions in the direction along the optical axis of the illumination optical system 1012).

[0229] The exposure time conditions in this embodiment include two or more conditions. That is, the exposure time conditions in this embodiment include two or more conditions corresponding to multiple different exposure times. As a specific example of the two or more conditions included in the exposure time conditions, in the control embodiment shown in Figure 16, which will be described later, a condition indicating a relatively long exposure time (circle 1) and a condition indicating a relatively short exposure time (circle 2) are provided.

[0230] The control unit 1020 in this embodiment is configured to repeatedly cause the imaging unit 1010 to acquire a group of images consisting of two or more images corresponding to two or more conditions included in the exposure time conditions, by combining the control of the imaging optical system 1013 for cyclically applying two or more conditions included in the exposure time conditions (referred to as exposure control) and the control of the movement mechanism 1019 for moving the optical system 1011 (referred to as movement control).

[0231] In other words, the control unit 1020 is configured to acquire multiple image groups by performing exposure control and movement control, and each of the multiple image groups contains two or more images corresponding to two or more conditions included in the exposure time conditions.

[0232] Let's explain exposure control. The Q conditions included in the exposure time conditions are designated as the first condition, the second condition, ..., and the Qth condition. Here, Q is an integer greater than or equal to 2. The first to Qth conditions are ordered in this order. Applying the first to Qth conditions in this order is called a series of condition applications. Exposure control is the control that causes the imaging optical system 1013 to repeatedly perform this series of condition applications.

[0233] As a concrete example of exposure control, the control mode shown in Figure 106, described later, repeatedly applies a series of conditions consisting of a condition indicating a relatively long exposure time (circle 1) and a condition indicating a relatively short exposure time (circle 2). Note that when the exposure time condition includes two conditions, the exposure control (cyclic application) is the alternating application of these two conditions.

[0234] The application mode of conditions 1 through Q is not limited to cyclic application; conditions 1 through Q may be applied iteratively while changing their order. Furthermore, in the iterative application of conditions 1 through Q, it is not necessary to apply all Q conditions in each iteration.

[0235] The movement control is described below. Movement control is a control mechanism for changing the position of the eye being photographed by the optical system 1011. Movement control enables the imaging unit 1010 to acquire images of the eye at multiple positions. Furthermore, movement control moves the optical system 1011 while maintaining that the optical system 1011 satisfies the shine-proof conditions. This makes it possible to collect multiple images that are in focus over a wide range.

[0236] Thus, in this embodiment, under exposure control and movement control by the control unit 1020, the imaging unit 1010 scans the eye under examination (taking images at multiple positions) and collects multiple shine-proof images.

[0237] In other words, the imaging unit 1010 in this embodiment collects a series of shine-proof images by cyclically changing the exposure time conditions according to the exposure control and changing the scan position (projection position of illumination light and shooting position) according to the movement control.

[0238] The image processing unit 1030 in this embodiment can generate multiple high dynamic range images based on a group of images acquired by a combination of exposure control and movement control.

[0239] As mentioned above, the number of conditions included in the exposure time condition is Q (where Q is an integer greater than or equal to 2). Each condition included in the exposure time condition is represented by C(q) (q = 1, 2, ..., Q). Also, the number of scan positions due to movement control is R (where R is an integer greater than or equal to 2). Each scan position is represented by P(r) (r = 1, 2, ..., R).

[0240] In this embodiment, Q images are obtained at each scan position P(r). The image corresponding to the scan position P(r) and the qth condition C(q) is represented by G(P(r), C(q)). The Q images G(P(r), C(1)), G(P(r), C(2)), ..., G(P(r), C(Q)) corresponding to the scan position P(r) are called the first condition image, the second condition image, ..., and the Qth condition image, respectively.

[0241] The image processing unit 1030 generates a high dynamic range image H(P(r)) at each scan position P(r) based on Q conditional images G(P(r), C(1)) to G(P(r), C(Q)) corresponding to each scan position P(r). This results in R high dynamic range images H(P(1)) to H(P(R)) corresponding to R scan positions P(1) to P(R).

[0242] The image processing unit 1030 can generate a high dynamic range image representing the volume (3D region) of the eye under examination based on R high dynamic range images H(P(1)) to H(P(R)).

[0243] Figure 15 shows an example of the operation of the ophthalmic device 1500.

[0244] First, the imaging unit 1010 of the ophthalmic device 1500 starts scanning the eye under examination through exposure control and movement control by the control unit 1020 (S61).

[0245] In scanning the eye under examination, first, images are taken at the first scan position P(1) under Q exposure time conditions (conditions 1 to 1Q) (S62). This yields conditional images G(P(1), C(1)) to G(P(1), C(Q)) corresponding to the first scan position P(1).

[0246] The ophthalmic device 1500 stores the first to Q conditional images G(P(1), C(1)) to G(P(1), C(Q)) in association with the first scan position P(1) (S63).

[0247] Steps S62 and S63 are repeated until the scan is completed (S64). If the scan is not completed (S64: No), the system moves to the next scan position for imaging via movement control (S65). Once the scan is completed, the system proceeds to step S66 (S64: Yes).

[0248] As a result, steps S62 and S63 are performed at each of the R scan positions P(1) to P(R), and Q conditional images G(P(r), C(1)) to G(P(r), C(Q)) corresponding to each scan position P(r) are acquired and stored.

[0249] The image processing unit 1030 generates a high dynamic range image H(P(r)) at each scan position P(r) based on Q conditional images G(P(r), C(1)) to G(P(r), C(Q)) corresponding to each scan position P(r) (S66). This results in R high dynamic range images H(P(1)) to H(P(R)) corresponding to R scan positions P(1) to P(R).

[0250] Each image generated in step S66 possesses both the broad-range high resolution required for a shine-proof image and the overall brightness appropriateness required for a high dynamic range image. Furthermore, in this embodiment, such high-quality images can be obtained for multiple positions on the eye under examination.

[0251] In some exemplary embodiments, in addition to acquiring such high-quality images across the three-dimensional region of the eye under examination, it is also possible to generate high dynamic range images that represent the volume (three-dimensional region) of the eye under examination.

[0252] An example of scanning using the illumination control and movement control of this embodiment is shown in Figure 16. In the scan shown in Figure 16, the movement of the scan position is performed in the same manner as the conventional scan shown in Figure 7C above, but the light source emits illumination light intermittently (pulsed emission), and the exposure of the camera is controlled by switching the exposure time conditions.

[0253] In this example, exposure time conditions "Circle 1" and "Circle 2" correspond to the aforementioned conditions C(1) and C(2), respectively. That is, in the example in Figure 16, the exposure time conditions include two conditions C(1) and C(2), and these two conditions C(1) and C(2) are applied cyclically (i.e., alternately). Note that condition C(1) is an exposure time condition that represents a relatively long time, and condition C(2) is an exposure time condition that represents a relatively short time.

[0254] In this example, the illumination light output is intermittent, but the illumination light output may also be continuous. While continuous output does not achieve the effects attained by intermittent output, it offers advantages such as easier control of the light source and lower control processing load.

[0255] In the scan shown in Figure 16, the sequence of illumination light emission (projection) (multiple flashes arranged in chronological order) and the camera exposure sequence (multiple exposures arranged in chronological order) are synchronized with each other. The duration of each flash in the illumination light sequence corresponds to the projection period, and its length corresponds to the projection time (illumination time).

[0256] Similarly, each exposure period in the exposure sequence corresponds to the exposure period, and its length corresponds to the exposure time. In this example, the projection time (illumination time) may be constant or non-constant, but the exposure time is non-constant.

[0257] In the scan shown in Figure 16, for each exposure period in the exposure sequence, a portion of the exposure period coincides with one projection period. That is, for each exposure period in the exposure sequence, the projection period (projection time, illumination time) is shorter than the exposure period (exposure time), and a portion of this exposure period overlaps with the entire projection period. As a result, in each exposure period in the exposure sequence, exposure (light reception by the image sensor, charge accumulation) occurs only during the projection period which is shorter than the exposure period, thus reducing image blurring caused by movement of the scan position or eye movements during exposure compared to conventional ophthalmic imaging techniques. Therefore, it becomes possible to provide images of higher quality than conventional ophthalmic imaging techniques.

[0258] Furthermore, it becomes possible to perform image analysis (e.g., corneal detection, cell detection, etc.) with higher quality than conventional ophthalmic image analysis techniques. Moreover, because the time during which illumination light is projected onto the eye under examination can be shortened, the burden on the patient can be reduced compared to continuous projection of illumination light.

[0259] Furthermore, in the scan shown in Figure 16, the optical system 1011 moves continuously from the scan start position to the scan end position, and there are no repeated sudden starts and stops of the optical system 1011. As a result, vibrations caused by such movements do not occur during the scan, and therefore do not adversely affect the image quality.

[0260] In the scan shown in Figure 16, the optical system 1011 is moved continuously from the scan start position to the scan end position, but the optical system 1011 may also be moved intermittently, as described in Figures 7B and 10B above.

[0261] In some exemplary embodiments, both switching of illumination conditions and switching of exposure conditions may be possible, and two or more images may be applied to the eye under examination while combining the switching of two or more illumination conditions and the switching of two or more exposure conditions. The configuration and operation of such an ophthalmic device will be understood from this disclosure by those skilled in the art.

[0262] In the embodiments shown in Figures 12 to 16, two or more image groups corresponding to two or more exposure conditions are acquired in a single scan. However, as in the embodiment shown in Figure 11, two or more scans may be performed to acquire two or more image groups corresponding to two or more exposure conditions. The configuration and operation of such an ophthalmic device will be understandable to those skilled in the art from this disclosure.

[0263] Figure 17 shows the configuration of an ophthalmic device according to one embodiment of the model. The ophthalmic device 1600 of this embodiment includes an imaging unit 1010, a control unit 1020, and an image processing unit 1030, and the imaging unit 1010 includes an optical system 1011 and a moving mechanism 1019.

[0264] The optical system 1011 of this embodiment includes an illumination optical system 1012 and an imaging optical system 1013. The imaging optical system 1013 of this embodiment includes a first image sensor 1014A, a second image sensor 1014B, an optical system (not shown) that guides light from the eye under examination to the first image sensor 1014A, and an optical system (not shown) that guides light from the eye under examination to the second image sensor 1014B.

[0265] The illumination optical system 1012 and the imaging optical system 1013 are configured to satisfy the anti-glare condition and function as an anti-glare camera. More specifically, the plane passing through the optical axis of the illumination optical system 1012 (the plane including the object plane), the principal plane of the imaging optical system 1013, and the imaging plane of the first image sensor 1014A intersect on the same straight line, and the plane passing through the optical axis of the illumination optical system 1012 (the plane including the object plane), the principal plane of the imaging optical system 1013, and the imaging plane of the second image sensor 1014B intersect on the same straight line. Thus, the illumination optical system 1012 and the imaging optical system 1013 are configured. Thereby, both the first image sensor 1014A and the second image sensor 1014B can perform imaging with the imaging optical system 1013 in focus at all positions within the object plane (all positions in the direction along the optical axis of the illumination optical system 1012).

[0266] One example of the ophthalmic device 1600 of this aspect is shown in FIG. 18. The ophthalmic device 1700 in this example includes a first imaging optical system 1013A and a second imaging optical system 1013B as the imaging optical system 1300 of the ophthalmic device 1600.

[0267] Although not shown, the first imaging optical system 1013A includes the first image sensor 1014A of FIG. 17 and an optical system that guides light from the eye under examination to the first image sensor 1014A. Similarly, the second imaging optical system 1013B includes the second image sensor 1014B of FIG. 17 and an optical system that guides light from the eye under examination to the second image sensor 1014B.

[0268] In the ophthalmic device 1700 shown in FIG. 18, two independent imaging optical systems 1013A and 1013B are provided. Such an embodiment will be described later. The number of imaging optical systems provided in the ophthalmic device may be three or more.

[0269] Note that the ophthalmic device 1600 shown in FIG. 17 includes not only a configuration in which two or more imaging optical systems are provided as shown in FIG. 18, but also a configuration in which two or more imaging elements are provided in a single imaging optical system. Two or more imaging elements in a single imaging optical system are respectively arranged in two or more optical paths branched using a beam splitter such as a half mirror.

[0270] The imaging conditions of this embodiment include conditions (synchronization conditions) for performing synchronization control of the operation of the illumination optical system 1012, the operation of the first imaging optical system 1013A, and the operation of the second imaging optical system 1013B. Examples of this synchronization condition are shown in FIGS. 19A and 19B. FIG. 19B is an enlarged view of a part of FIG. 19A.

[0271] In FIGS. 19A and 19B, camera A corresponds to the first imaging element 1014A of the first imaging optical system 1013A, and camera B corresponds to the second imaging element 1014B of the second imaging optical system 1013B.

[0272] The control unit 1020 in this example performs synchronization control of the light emission timing (illumination period) of the illumination optical system 1012, the exposure timing (exposure period) of the first imaging element 1014A, and the exposure timing (exposure period) of the second imaging element 1014B so that the actual exposure time by the first imaging element 1014A and the actual exposure time by the second imaging element 1014B are different from each other. This synchronization control is for realizing two exposure time conditions of the exposure time of the first imaging element 1014A and the exposure time of the second imaging element 1014B.

[0273] In the example shown in FIGS. 19A and 19B, the length TA of the period (first exposure period) in which the illumination period and the exposure period of the first imaging element 1014A overlap is longer than the length TB of the period (second exposure period) in which the illumination period and the exposure period of the second imaging element 1014B overlap.

[0274] Here, the length of the first exposure period (first exposure time) TA is the actual exposure time by the first image sensor 1014A, and the length of the second exposure period (second exposure time) TB is the actual exposure time by the second image sensor 1014B. In this example, the first exposure time TA is set to approximately twice the second exposure time.

[0275] Thus, the control unit 1020 in this example controls the imaging unit 1010 so that at least a portion of the first exposure period by the first image sensor 1014A and at least a portion of the second exposure period by the second image sensor 1014B overlap, and also controls the imaging unit 1010 so that the first exposure time TA by the first image sensor 1014A and the second exposure time TB by the second image sensor 1014B are different. As a result, the control unit 1020 in this example controls the imaging unit 1010 so that two or more images with different imaging conditions are applied to the eye under examination using the two image sensors 1014A and 1014B.

[0276] Furthermore, as shown in Figure 19A, the scanning in this example is performed by synchronizing the emission control of a light source for intermittently outputting illumination light (pulsed emission) with the exposure control of two cameras (two image sensors 1014A and 1014B, and two imaging optical systems 1013A and 1013B).

[0277] In this example, as shown in Figure 19B, the length of one emission period of the light source (width of one pulse, illumination period, projection period) (illumination time, projection time) is equal to the first exposure time TA. In other words, in this example, the exposure time of camera A (the length of the top edge of one pulse in the sequence showing the exposure operation of camera A) is set to be longer than the illumination time TA, and the synchronization conditions are set so that the exposure period of camera A (the period shown by the top edge of one pulse in the sequence showing the exposure operation of camera A) overlaps with the entire illumination period, so that the actual exposure time of camera A (first exposure time TA) is equal to the illumination time TA.

[0278] On the other hand, the exposure time of camera B (the length of the top edge of one pulse in the sequence indicating the exposure operation of camera B) is set to be equal to the exposure time of camera A, and is longer than the illumination time TA. However, by shifting the exposure time of camera B in time with respect to the illumination period and the exposure time of camera A, the synchronization conditions are set so that the exposure time of camera B (the period indicated by the top edge of one pulse in the sequence indicating the exposure operation of camera B) overlaps with only a part of the illumination period (in this example, about half of the illumination period). As a result, the actual exposure time of camera B (the second exposure time TB) is about half of the illumination time TA, that is, about half of the first exposure time TA.

[0279] In the examples shown in Figures 19A and 19B, the illumination light is output intermittently, but the illumination light output may also be continuous. In the case of continuous output, the exposure period and the exposure period are equal, so the synchronization conditions are set so that the exposure period of camera A (first image sensor 1014A, first imaging optical system 1013A) and the exposure period of camera B (second image sensor 1014B, second imaging optical system 1013B) are different values.

[0280] Figure 20 shows one example of synchronization conditions for synchronously controlling the operation of the illumination optical system 1012, the operation of the first imaging optical system 1013A, and the operation of the second imaging optical system 1013B in the case of continuous output.

[0281] In the examples shown in Figure 19A, Figure 19B, and Figure 20, the optical system 1011 is moved continuously from the scan start position to the scan end position. However, the optical system 1011 may be moved intermittently, as described in Figures 7B and 10B above.

[0282] Thus, the control unit 1020 in this embodiment controls the imaging optical system 1013 (for example, two imaging optical systems 1013A and 1013B) for repeatedly applying two imaging conditions with different imaging conditions to the eye under examination using two image sensors 1014A and 1014B, and controls the movement mechanism 1019 for moving the optical system 1011, thereby causing the imaging unit 1010 to repeatedly acquire a group of images consisting of two images corresponding to two imaging conditions.

[0283] Furthermore, the image processing unit 1030 in this embodiment can generate multiple high dynamic range images based on multiple image groups acquired by the imaging unit 1010 under the control of the control unit 1020.

[0284] For example, the image processing unit 1030 may be configured to generate a single high dynamic range image based on a group of images including images acquired during the exposure period of camera A that overlap with one illumination period, and images acquired during the exposure period of camera B that overlap with the same illumination period. In other words, the image processing unit 1030 in this example is configured to generate a high dynamic range image for each illumination period.

[0285] In this example, a high dynamic range image can be generated from a group of images acquired simultaneously, which has the advantage of eliminating the need for registration between images included in the image group. Furthermore, it has the advantage of making the process of forming the image group used to generate the same high dynamic range image very easy.

[0286] In another example, the image processing unit 1030 may be configured to generate a single high dynamic range image based on a group of images including images acquired during the exposure period of camera A that overlaps with the first illumination period and images acquired during the exposure period of camera B that overlaps with the second illumination period, which has a small time difference with respect to the first illumination period. For example, it is possible to select the illumination period immediately before or immediately after the first illumination period as the second illumination period.

[0287] According to this example, since a high-dynamic range image can be generated from an image group acquired substantially simultaneously, there is an advantage that it is not necessary to perform registration between two images included in the image group. Further, there is also an advantage that the process of forming an image group provided for generating the same high-dynamic range image can be easily performed.

[0288] The processing executed by the image processing unit 1030 of this aspect is not limited to these examples. The image processing unit 1030 may be configured to generate a high-dynamic range image based on an image group consisting of two images corresponding to two freely selected illumination periods.

[0289] Although the case where two image pickup devices are used has been described above, those skilled in the art will be able to understand that the same configuration and processing can be applied even when three or more image pickup devices are used.

[0290] When two or more image pickup devices are used, the setting of shooting conditions other than the exposure conditions may be arbitrary. For example, the gains of two or more image pickup devices may be set equally.

[0291] Regarding the processing executed by one example of the ophthalmic device according to the embodiment (for example, any one of the ophthalmic devices 1000 to 1700, or at least a partial combination of any two or more of the ophthalmic devices 1000 to 1700), it will be described while further referring to FIGS. 21 to 23.

[0292] In this example, two shootings with different illumination conditions are applied to the subject eye, and a high-dynamic range image is generated based on the two images acquired thereby. Unless otherwise specified, the processing in this example may be the same as any aspect according to the present disclosure and / or any example according to the present disclosure.

[0293] As shown in the flowchart of Figure 21, in this example, alignment is performed first (S71). Alignment is the positioning of the optical system 1011 with respect to the eye under examination. Alignment is performed automatically and / or manually. In addition, preparatory operations other than alignment are also performed.

[0294] Next, the optical system 1011 is moved to the scan start position (S72). The movement of the optical system 1011 to the scan start position is performed automatically and / or manually.

[0295] Once the optical system 1011 is positioned at the scan start position, the imaging unit 1010 starts scanning the eye under the control of the control unit 1020 (S73). The scan in this step is performed by a combination of illumination control and movement control. The control unit 1020 causes the imaging unit 1010 to start scanning in response to a predetermined event. This event may be, for example, an instruction from the user or the completion of step S72.

[0296] Upon receiving the start of the scan, the control unit 1020 controls the image sensor 1014 of the optical system 1011 to start exposure (S74), controls the light source of the illumination optical system 1012 to oscillate high-power pulsed light (S75), and controls the image sensor 1014 to end the exposure (S76). The high-power pulsed light is pulsed light with a relatively higher output compared to the low-power pulsed light described later.

[0297] Furthermore, the control unit 1020 stores the image acquired by the image sensor 1014 in steps S74 to S76 in a storage device (not shown) (S77). This image is acquired using the high-power pulsed light in step S75 and is relatively brighter than the low-luminance image described later. In this example, this image is referred to as the high-luminance image.

[0298] Once a high-brightness image is acquired and saved, the control unit 1020 controls the image sensor 1014 of the optical system 1011 to start exposure (S78), controls the light source of the illumination optical system 1012 to oscillate low-power pulsed light (S79), and controls the image sensor 1014 to end exposure (S80). The low-power pulsed light is pulsed light with a relatively lower output compared to the high-power pulsed light mentioned above.

[0299] Furthermore, the control unit 1020 stores the image acquired by the image sensor 1014 in steps S78 to S80 in a storage device (not shown) (S81). This image is acquired using the low-power pulsed light in step S79 and is relatively darker than the aforementioned high-luminance image. In this example, this image is referred to as the low-luminance image.

[0300] Once the series of shooting operations shown in steps S74 to S81 are completed, the control unit 1020 determines whether a predetermined number of images have been acquired (S82). If the specified number of images have not yet been acquired (S82: No), the process returns to step S74. If the specified number of images have already been acquired (S82: Yes), the process proceeds to step S83, and the scan is completed (S83).

[0301] Note that the parameters for the determination in step S82 are not limited to the number of images, but may also be, for example, the number of iterations of steps S74 to S81, the elapsed time between iterations of steps S74 to S81, or the distance traveled by the optical system 1011.

[0302] In this manner, the control unit 1020 repeatedly executes steps S74 to S82 until a specified number of images are acquired. Let "U" be the total number of iterations of steps S74 to S82. Figure 22A shows the operation in the u-th iteration and the u+1-th iteration. Here, u is an integer between 1 and U-1.

[0303] At scan position P(u) corresponding to the u-th iteration, high-power pulsed light V(u, H) and low-power pulsed light V(u, L) are output from the light source, and the image sensor 1014 is exposed twice, W(u, H) and W(u, L).

[0304] Here, the exposure period W(u, H) corresponds to the projection period of high-power pulsed light V(u, H), and the exposure period W(u, L) corresponds to the projection period of low-power pulsed light V(u, L). The image G(u, H) acquired by the image sensor 1014 during exposure W(u, H) is a high-luminance image, and the image G(u, L) acquired during exposure W(u, L) is a low-luminance image.

[0305] The same applies to the operation at scan position P(u+1) corresponding to the (u+1)th iteration, and the resulting set of images. This collects U image sets (pairs of high-luminance and low-luminance images).

[0306] Figure 22B shows another example of scanning. In this example, a single pulse of light V(u) is output at scan position P(u) corresponding to the u-th iteration, and two exposures (first exposure and second exposure) are performed.

[0307] Only a portion of the first exposure period (for example, only half of the first exposure period) overlaps with the projection period of pulsed light V(u), and the entire second exposure period overlaps with the projection period of pulsed light V(u). The overlapping period between the first exposure period and the projection period of pulsed light V(u) is the actual exposure W(u, L) in the first exposure. This actual exposure W(u, L) will also be referred to as the first exposure. Similarly, the overlapping period between the second exposure period and the projection period of pulsed light V(u) is the actual exposure W(u, H) in the second exposure.

[0308] In this example, a low-luminance image G(u, L) is acquired by the first exposure W(u, L), and a high-luminance image G(u, H) is acquired by the second exposure W(u, H). The same applies to the operation at scan position P(u+1) corresponding to the (u+1)th iteration, and the resulting image set. This results in the collection of U image sets (pairs of high-luminance and low-luminance images).

[0309] The image processing unit 1030 generates U high dynamic range images based on the U image groups collected by the scan (S84). In this example, a high dynamic range image is generated based on each image group, that is, based on each pair of high-luminance image G(u, H) and low-luminance image G(u, L).

[0310] Let's explain one specific example of step S84. The image processing unit 1030 identifies pixels with brightness values ​​above a predetermined threshold (brightness-exceeding pixels) from the high-brightness image G(u, H), identifies pixels in the low-brightness image G(u, L) corresponding to the identified brightness-exceeding pixels (corresponding pixels), and replaces the pixel value of the brightness-exceeding pixels with a pixel value based on the pixel value of the corresponding pixels.

[0311] For example, the image processing unit 1030 multiplies the pixel value of the corresponding pixel by a predetermined value (for example, 2) and replaces the pixel value of the pixel with the product of these values. The value multiplied by the pixel value of the corresponding pixel may be a pre-set default value, a value determined based on a pair of high-luminance image G(u, H) and low-luminance image G(u, L), or a value determined by other means.

[0312] An example of step S84 is shown in Figure 23. The luminance-excess region g(u, H) of the high-luminance image G(u, H) is an image region consisting of luminance-excess pixels. Also, the region g(u, L) of the low-luminance image G(u, L) is an image region (corresponding region) that corresponds to the luminance-excess region g(u, H) of the high-luminance image G(u, H).

[0313] According to the process described in the specific example above, the brightness of the over-brightness region g(u, H) in the high-brightness image G(u, H) is optimized based on the corresponding region g(u, L) in the low-brightness image G(u, L). This results in the acquisition of the image (high dynamic range image) H(u). Region h(u) in the high dynamic range image H(u) represents the image region whose brightness has been optimized.

[0314] While Figure 23 illustrates the optimization of brightness in the corneal region, the same procedure can be used to optimize the brightness of image regions in other areas.

[0315] Step S84 yields a high dynamic range image in which various parts of the eye under examination (corneal epithelium, corneal endothelium, anterior surface of the lens, posterior surface of the lens, etc.) are represented with similar tones. Furthermore, a high dynamic range image representing the three-dimensional region (scanned region) of the eye under examination is obtained.

[0316] Next, the ophthalmic device 1000 (for example, the image processing unit 1030) applies gamma correction to the high dynamic range image generated in step S84 to generate an image of brightness and tristimulus values ​​corresponding to the output device (S85).

[0317] The ophthalmic device 1000 then provides the image generated after gamma correction in step S85 to a predetermined output device. For example, the ophthalmic device 1000 displays the image generated after gamma correction in step S85 on a display device (not shown) (S86). The ophthalmic device 1000 also saves one or more of the various images generated in this example to a storage device (not shown) (S86). This concludes the explanation of the processes performed in this embodiment.

[0318] The processes performed by one embodiment of the ophthalmic device according to the embodiment (for example, one of the ophthalmic devices 1000 to 1700, or at least a partial combination of two or more of the ophthalmic devices 1000 to 1700) will be described with further reference to Figures 24A to 25.

[0319] In this embodiment, two images are taken of the eye under examination using two image sensors, and a high dynamic range image is generated based on the two images obtained.

[0320] Unless otherwise specified, some of the processes in this embodiment may be performed in the same or similar manner as the processes described in any aspect of the present disclosure and / or any embodiment of the present disclosure.

[0321] As shown in the flowcharts of Figures 24A and 24B, in this example, alignment is first performed (S91), the optical system 1011 is moved to the scan start position (S92), and the scan of the eye under examination is started (S93). The scan in this step is performed by a combination of illumination control, exposure control, and movement control.

[0322] Refer to Figure 25. Upon receiving the start of the scan, the control unit 1020 controls the first image sensor 1014A to start exposure (S94), waits for a time Δa from step S94 (S95), and then controls the second image sensor 1014B to start exposure (S96).

[0323] Furthermore, the control unit 1020 controls the light source of the illumination optical system 1012 to start outputting pulsed light (S97), waits for a time Δb from step S97 (S98), controls the first image sensor 1014A to end the exposure (S99), and stores the image (first image) acquired by the first image sensor 1014A during the exposure period from steps S94 to S99 in a storage device (not shown) (S100).

[0324] The first image acquired in step S100 is a relatively dark image compared to the high-luminance image described later, as it was acquired with a relatively short exposure period compared to the exposure period of the second image sensor 1014B, which will be described later. In this example, this first image is referred to as the low-luminance image.

[0325] Furthermore, the control unit 1020 waits for a time Δc from step S99 (S101), controls the light source of the illumination optical system 1012 to stop the output of pulsed light (S102), controls the second image sensor 1014B to end the exposure (S103), and saves the image (second image) acquired by the second image sensor 1014B during the exposure period from steps S96 to S103 to a storage device (not shown) (S104).

[0326] The second image acquired in step S104 is a relatively bright image compared to the low-luminance image, acquired with a relatively longer exposure period compared to the exposure period of the first image sensor 1014A mentioned above. In this example, this second image is referred to as the high-luminance image.

[0327] Once the series of shooting operations shown in steps S94 to S104 are completed, the control unit 1020 determines whether a predetermined number of images have been acquired (S105). If the specified number of images have not yet been acquired (S105: No), the process returns to step S94. If the specified number of images have already been acquired (S105: Yes), the process proceeds to step S106, and the scan is completed (S106).

[0328] Note that the parameters for the determination in step S105 are not limited to the number of images, but may also be, for example, the number of iterations of steps S94 to S104, the elapsed time between iterations of steps S94 to S104, or the distance traveled by the optical system 1011.

[0329] In this manner, the control unit 1020 repeatedly executes steps S94 to S105 until a specified number of images are acquired. Let "U" be the total number of iterations of steps S94 to S105. Figure 25 shows the operation in the u-th iteration and the u+1-th iteration. Here, u is an integer between 1 and U-1.

[0330] At the scan position corresponding to the u-th iteration, the light source of the illumination optical system 1012 emits light once, the first image sensor 1014A is exposed, and the second image sensor 1014B is exposed. The relationship between the projection period of illumination light, the exposure period of the first image sensor 1014A, and the exposure period of the second image sensor 1014B is as shown in Figure 25 and in the above description.

[0331] Through the coordinated control of the illumination optical system 1012, the first image sensor 1014A, and the second image sensor 1014B, a pair of low-luminance image G(u, L) and high-luminance image G(u, H) corresponding to the scan position corresponding to the u-th iteration is obtained. The same applies to the scan position corresponding to the (u+1)th iteration. As a result, U image groups (pairs of high-luminance and low-luminance images) are collected.

[0332] The image processing unit 1030 generates U high dynamic range images based on the U image groups collected by the scan (S107). The processing performed in step S107 may be the same as, for example, step S84 in Figure 21, Figure 23, and the methods described therein.

[0333] Step S107 yields a high dynamic range image in which various parts of the eye under examination (corneal epithelium, corneal endothelium, anterior surface of the lens, posterior surface of the lens, etc.) are represented with similar tones. Additionally, a high dynamic range image representing the three-dimensional region (scanned region) of the eye under examination is obtained.

[0334] Next, the ophthalmic device 1000 (for example, the image processing unit 1030) applies gamma correction to the high dynamic range image generated in step S107 (S108) and displays it on the display device (S86). The ophthalmic device 1000 also saves one or more of the various images generated in this example to a storage device (S86). This concludes the explanation of the processes performed in this embodiment.

[0335] Figure 26 shows specific examples of the configurations of ophthalmic devices that can function as ophthalmic devices 1000 to 1700 according to some exemplary embodiments described above. Figure 26 is a top view.

[0336] The direction along the axis of the eye E being examined is defined as the Z direction, the direction perpendicular to this, which is left and right for the subject, is defined as the X direction, and the direction perpendicular to both the X and Z directions (up and down direction, along the body axis) is defined as the Y direction.

[0337] The ophthalmic apparatus in this example is a slit lamp microscope system 1 having a configuration similar to that disclosed in Patent Document 3 (Japanese Patent Application Publication No. 2019-213733), and includes an illumination optical system 2, an imaging optical system 3, a video recording optical system 4, an optical path coupling element 5, a movement mechanism 6, a control unit 7, a data processing unit 8, a communication unit 9, and a user interface 10.

[0338] The cornea of ​​the eye E under examination is indicated by the symbol C, and the lens by the symbol CL. The anterior chamber corresponds to the region between the cornea C and the lens CL (the region between the cornea C and the iris).

[0339] For details of each element of the slit lamp microscope system 1, please refer to Patent Document 3 (Japanese Patent Application Publication No. 2019-213733).

[0340] The combination of illumination optical system 2, imaging optical system 3, and moving mechanism 6 is an example of the imaging unit 1010 of the ophthalmic device 1000 (~1700). Illumination optical system 2 is an example of illumination optical system 1012, and imaging optical system 3 is an example of imaging optical system 1013.

[0341] The illumination optical system 2 projects slit light onto the anterior segment of the eye E under examination. Reference numeral 2a indicates the optical axis (illumination optical axis) of the illumination optical system 2.

[0342] The imaging optical system 3 images the anterior segment of the eye onto which slit light from the illumination optical system 2 is projected. Reference numeral 3a indicates the optical axis (imaging optical axis) of the imaging optical system 3. Optical system 3A guides the light from the anterior segment of the eye E onto which slit light is projected to the image sensor 3B. The image sensor 3B receives the light guided by optical system 3A on its imaging surface. The image sensor 3B includes an area sensor (CCD area sensor, CMOS area sensor, etc.) having a two-dimensional imaging area. Image sensor 3B is an example of the image sensor 1014 (1014A, 1014B) of the ophthalmic device 1000 (~1700).

[0343] The illumination optical system 2 and the imaging optical system 3 function as a Scheinproof camera, and are configured such that the object surface along the illumination optical axis 2a, the optical system 3A, and the imaging surface of the image sensor 3B satisfy the Scheinproof condition; that is, the YZ plane (including the object surface) passing through the illumination optical axis 2a, the main surface of the optical system 3A, and the imaging surface of the image sensor 3B intersect on the same straight line.

[0344] As a result, the illumination optical system 2 and the imaging optical system 3 can perform imaging with focus on at least the area from the posterior surface of the cornea C to the anterior surface of the lens CL (anterior chamber). Furthermore, the illumination optical system 2 and the imaging optical system 3 can perform imaging with focus on at least the area from the apex of the anterior surface of the cornea C (Z=Z1) to the apex of the posterior surface of the lens CL (Z=Z2). Note that coordinate Z=Z0 indicates the intersection of the illumination optical axis 2a and the imaging optical axis 3a.

[0345] The video recording optical system 4 is a video camera that records video of the anterior segment of the eye E in parallel with the illumination optical system 2 and the recording optical system 3. The optical path coupling element 5 couples the optical path of the illumination optical system 2 (illumination optical path) and the optical path of the video recording optical system 4 (video recording optical path).

[0346] Figure 27 shows a specific example of an optical system including an illumination optical system 2, an imaging optical system 3, a video recording optical system 4, and an optical path coupling element 5. The optical system shown in Figure 27 includes an illumination optical system 20, which is an example of an illumination optical system 2; a left imaging optical system 30L and a right imaging optical system 30R, which are examples of an imaging optical system 3 (the first imaging optical system 1013A and the second imaging optical system 1013B of the ophthalmic apparatus 1700 in Figure 18); a video recording optical system 40, which is an example of a video recording optical system 4; and a beam splitter 47, which is an example of an optical path coupling element 5.

[0347] The symbol 20a indicates the optical axis of the illumination optical system 20 (illumination optical axis), the symbol 30La indicates the optical axis of the left imaging optical system 30L (left imaging optical axis), and the symbol 30Ra indicates the optical axis of the right imaging optical system 30R (right imaging optical axis). The angle θL indicates the angle between the illumination optical axis 20a and the left imaging optical axis 30La, and the angle θR indicates the angle between the illumination optical axis 20a and the right imaging optical axis 30Ra. The coordinate Z=Z0 indicates the intersection of the illumination optical axis 20a, the left imaging optical axis 30La, and the right imaging optical axis 30Ra.

[0348] The movement mechanism 6 moves the illumination optical system 20, the left imaging optical system 30L, and the right imaging optical system 30R in the direction indicated by the arrow 49 (X direction).

[0349] The illumination light source 21 of the illumination optical system 20 outputs illumination light (e.g., visible light), and the positive lens 22 refracts the illumination light. The slit forming section 23 forms a slit, allowing a portion of the illumination light to pass through. The generated slit light is refracted by the objective lens groups 24 and 25, reflected by the beam splitter 47, and projected onto the anterior segment of the eye E under examination.

[0350] The reflector 31L and imaging lens 32L of the left imaging optical system 30L guide the light from the anterior segment (light traveling in the direction of the left imaging optical system 30L), onto which slit light is projected by the illumination optical system 20, to the image sensor 33L. The image sensor 33L receives the guided light on the imaging surface 34L.

[0351] The left imaging optical system 30L repeatedly takes images in parallel with the movement of the illumination optical system 20, the left imaging optical system 30L, and the right imaging optical system 30R by the movement mechanism 6. This allows for the acquisition of multiple anterior segment images (a series of Scheinproof images).

[0352] The object surface along the illumination optical axis 20a, the optical system including the reflector 31L and imaging lens 32L, and the imaging surface 34L satisfy the Scheinproof condition. The right imaging optical system 30R has a similar configuration and function.

[0353] The pair of image sensors 33L and 33R is an example of the pair of the first image sensor 1014A and the second image sensor 1014B.

[0354] The acquisition of Scheinproof images using the left imaging optical system 30L and the acquisition of Scheinproof images using the right imaging optical system 30R are performed in parallel.

[0355] The control unit 7 can synchronize repeated imaging by the left imaging optical system 30L and repeated imaging by the right imaging optical system 30R. This allows for a correspondence between a series of Scheinproof images obtained by the left imaging optical system 30L and a series of Scheinproof images obtained by the right imaging optical system 30R.

[0356] Furthermore, the control unit 7 or the data processing unit 8 may perform a process to determine the correspondence between multiple anterior segment images obtained by the left imaging optical system 30L and multiple anterior segment images obtained by the right imaging optical system 30R.

[0357] The video recording optical system 40 records video of the anterior segment of the eye E under examination from a fixed position, in parallel with the recording by the left recording optical system 30L and the right recording optical system 30R. Light that has passed through the beam splitter 47 is reflected by the reflector 48 and incident on the video recording optical system 40. The light incident on the video recording optical system 40 is refracted by the objective lens 41 and then imaged onto the imaging surface of the image sensor 43 (area sensor) by the imaging lens 42. The video recording optical system 40 is used for monitoring the movement of the eye E under examination, alignment, tracking, and processing the collected shine-proof images.

[0358] Returning to Figure 26, the movement mechanism 6 moves the illumination optical system 2 and the imaging optical system 3 together in the X direction.

[0359] The control unit 7 controls each part of the slit lamp microscope system 1. By controlling the illumination optical system 2, the imaging optical system 3, and the movement mechanism 6, and controlling the video recording optical system 4 in parallel, the control unit 7 can perform slit scanning (collection of a series of shine-proof images) and video recording (collection of a series of time-series images) by the imaging unit 1010 of the ophthalmic device 1000 (~1700) in parallel.

[0360] Furthermore, the control unit 7 synchronizes the control of the illumination optical system 2, the imaging optical system 3, and the movement mechanism 6 with the control of the video recording optical system 4, thereby synchronizing the slit scan and video recording.

[0361] If the imaging optical system 3 includes a left imaging optical system 30L and a right imaging optical system 30R, the control unit 7 can synchronize the repeated imaging by the left imaging optical system 30L (collection of Scheinproof image groups) and the repeated imaging by the right imaging optical system 30R (collection of Scheinproof image groups) with each other.

[0362] The control unit 7 includes a processor, a memory device, and the like. The memory device stores computer programs, such as various control programs. The functions of the control unit 7 are realized through the cooperation of software, such as control programs, and hardware, such as the processor. The control unit 7 controls the illumination optical system 2, the imaging optical system 3, and the movement mechanism 6 in order to scan the three-dimensional region of the eye E under examination with slit light. For details of this control, please refer to Patent Document 3 (Japanese Patent Application Publication No. 2019-213733).

[0363] The data processing unit 8 performs various data processing operations. The data processing unit 8 includes a processor, a memory device, and other components. The memory device stores computer programs, such as various data processing programs. The functions of the data processing unit 8 are realized through the cooperation of software, such as data processing programs, and hardware, such as the processor. The data processing unit 8 has the functions of the image processing unit 1030 of the ophthalmic device 1000 (~1700). However, the functions of the data processing unit 8 are not limited to this.

[0364] The communication unit 9 performs data communication between the slit lamp microscope system 1 and other devices. The user interface 10 includes any user interface devices such as a display device and an operating device.

[0365] The slit lamp microscope system 1 shown in Figures 26 and 27 is merely illustrative, and the configuration for implementing the ophthalmic apparatus 1000-1700 is not limited to the slit lamp microscope system 1.

[0366] Some non-limiting features of the ophthalmic apparatus according to this embodiment will be described.

[0367] A first embodiment of the ophthalmic apparatus according to the embodiment includes an imaging unit, a control unit, and an image processing unit. The imaging unit includes an optical system that satisfies the conditions of shineproof. The control unit is configured to control the imaging unit to apply two or more imagings to the eye under examination under different imaging conditions. The image processing unit is configured to generate a high dynamic range image based on two or more images of the eye under examination obtained by two or more imagings under different imaging conditions.

[0368] A second embodiment of the ophthalmic apparatus according to the embodiment has the following non-limiting features in addition to the non-limiting features of the first embodiment: The optical system includes an illumination optical system that projects illumination light onto the eye under examination based on preset illumination conditions. Furthermore, the control unit is configured to control the imaging unit to apply at least two or more images to the eye under examination under different illumination conditions.

[0369] A third embodiment of the ophthalmic apparatus according to the embodiment has the following non-limiting features in addition to the non-limiting features of the second embodiment: The illumination conditions include illumination intensity conditions that determine the intensity of the illumination light. Furthermore, the control unit is configured to control the imaging unit so as to apply at least two or more imagings with different illumination intensity conditions to the eye under examination.

[0370] A fourth embodiment of the ophthalmic apparatus according to the embodiment has the following non-limiting features in addition to the non-limiting features of the third embodiment: The imaging unit further includes a moving mechanism for moving the optical system. The illumination intensity conditions include two or more conditions. The control unit is configured to cause the imaging unit to repeatedly acquire a group of images consisting of two or more images corresponding to the two or more conditions included in the illumination intensity conditions by combining control of the illumination optical system for cyclically applying the two or more conditions included in the illumination intensity conditions and control of the moving mechanism for moving the optical system.

[0371] A fifth embodiment of the ophthalmic apparatus according to the embodiment has the following non-limiting features in addition to the non-limiting features of the fourth embodiment: The image processing unit is configured to generate a plurality of high dynamic range images based on a plurality of image groups acquired by the imaging unit under a combination of control of the illumination optical system and control of the movement mechanism.

[0372] A sixth embodiment of the ophthalmic apparatus according to the embodiment has the following non-limiting features in addition to the non-limiting features of any of the second to fifth embodiments: The illumination conditions include illumination time conditions that define the projection time of illumination light. The control unit is configured to control the imaging unit to apply at least two or more imagings with different illumination time conditions to the eye under examination.

[0373] A seventh embodiment of the ophthalmic apparatus according to the embodiment has the following non-limiting features in addition to the non-limiting features of the sixth embodiment: The imaging unit further includes a moving mechanism for moving the optical system. The illumination time conditions include two or more conditions. The control unit is configured to cause the imaging unit to repeatedly acquire a group of images consisting of two or more images corresponding to the two or more conditions included in the illumination time conditions by combining control of the illumination optical system for cyclically applying the two or more conditions included in the illumination time conditions and control of the moving mechanism for moving the optical system.

[0374] An eighth embodiment of the ophthalmic apparatus according to the embodiment has the following non-limiting features in addition to the non-limiting features of the seventh embodiment: The image processing unit is configured to generate a plurality of high dynamic range images based on a plurality of image groups acquired by the imaging unit under a combination of control of the illumination optical system and control of the movement mechanism.

[0375] A ninth embodiment of the ophthalmic apparatus according to the embodiment has the following non-limiting features in addition to the non-limiting features of any of the first to eighth embodiments: The optical system includes an imaging optical system that photographs the eye under examination based on preset exposure conditions. The control unit is configured to control the imaging unit to apply at least two or more photographs to the eye under examination with different exposure conditions.

[0376] A tenth embodiment of the ophthalmic apparatus according to the embodiment has the following non-limiting features in addition to the non-limiting features of the ninth embodiment: The imaging optical system includes an image sensor. The exposure conditions include exposure time conditions that determine the exposure time by the image sensor. The control unit is configured to control the imaging unit so as to apply at least two or more imagings with different exposure time conditions to the eye under examination.

[0377] An eleventh embodiment of the ophthalmic apparatus according to the embodiment has the following non-limiting features in addition to the non-limiting features of the tenth embodiment: The imaging unit further includes a moving mechanism for moving the optical system. The exposure time conditions include two or more conditions. The control unit is configured to cause the imaging unit to repeatedly acquire a group of images consisting of two or more images corresponding to the two or more conditions included in the exposure time conditions by combining control of the imaging optical system for cyclically applying the two or more conditions included in the exposure time conditions and control of the moving mechanism for moving the optical system.

[0378] A twelfth embodiment of the ophthalmic apparatus according to the embodiment has the following non-limiting features in addition to the non-limiting features of the eleventh embodiment: The image processing unit is configured to generate a plurality of high dynamic range images based on a plurality of image groups acquired by the imaging unit under a combination of control of the imaging optical system and control of the movement mechanism.

[0379] A thirteenth embodiment of the ophthalmic apparatus according to the embodiment has the following non-limiting features in addition to the non-limiting features of any of the ninth to twelfth embodiments: The imaging optical system includes two or more image sensors. The control unit is configured to control the imaging unit to perform two or more imaging sessions with different imaging conditions using two or more image sensors.

[0380] A 14th embodiment of the ophthalmic apparatus according to the embodiment has the following non-limiting features in addition to the non-limiting features of the 13th embodiment: Two or more image sensors included in the imaging optical system include a first image sensor and a second image sensor. The control unit is configured to control the imaging unit such that the first exposure time for the first image sensor and the second exposure time for the second image sensor are different.

[0381] A fifteenth embodiment of the ophthalmic apparatus according to the embodiment has the following non-limiting features in addition to the non-limiting features of the thirteenth or fourteenth embodiment: Two or more image sensors included in the imaging optical system include a first image sensor and a second image sensor. The control unit is configured to control the imaging unit such that at least a portion of the first exposure period by the first image sensor and at least a portion of the second exposure period by the second image sensor overlap.

[0382] A 16th embodiment of the ophthalmic apparatus according to the embodiment has the following non-limiting features in addition to the non-limiting features of any of the 13th to 15th embodiments: The imaging unit further includes a moving mechanism for moving the optical system. The control unit is configured to repeatedly cause the imaging unit to acquire a group of images consisting of two or more images corresponding to two or more imagings with different imaging conditions using two or more image sensors included in the imaging optical system, by combining control of the imaging optical system for repeatedly applying two or more imagings with different imaging conditions to the eye under examination using two or more image sensors included in the imaging optical system, and control of the moving mechanism for moving the optical system.

[0383] A 17th embodiment of the ophthalmic apparatus according to the embodiment has the following non-limiting features in addition to the non-limiting features of the 16th embodiment: The image processing unit is configured to generate a plurality of high dynamic range images based on a plurality of image groups acquired by the imaging unit under a combination of control of the imaging optical system and control of the movement mechanism.

[0384] An eighteenth embodiment of the ophthalmic apparatus according to the embodiment has the following non-limiting features in addition to the non-limiting features of the first embodiment. The optical system includes an illumination optical system that projects illumination light onto the eye under examination based on preset illumination conditions, and an imaging optical system that photographs the eye under examination based on preset exposure conditions. The imaging optical system includes a first image sensor and a second image sensor. The control unit controls the imaging unit to satisfy the following four conditions. The first condition is that the first exposure time by the first image sensor and the second exposure time by the second image sensor are different. The second condition is that at least a portion of the first exposure period by the first image sensor and at least a portion of the second exposure period by the second image sensor overlap. The third condition is that the first portion of the projection period of illumination light by the illumination optical system overlaps with the first exposure period by the first image sensor. The fourth condition is that the second portion of the projection period of illumination light overlaps with the second exposure period by the second image sensor.

[0385] A 19th embodiment of the ophthalmic apparatus according to the embodiment has the following non-limiting features in addition to the non-limiting features of the 18th embodiment: The imaging unit further includes a moving mechanism for moving the optical system. The control unit is configured to repeatedly cause the imaging unit to acquire a group of images including an image corresponding to a first imaging using the first image sensor and an image corresponding to a second imaging using the second image sensor, by combining control of the imaging optical system for repeatedly applying a first imaging using the first image sensor to the eye under examination and a second imaging using the second image sensor to the eye under examination, and control of the moving mechanism for moving the optical system.

[0386] A 20th embodiment of the ophthalmic apparatus according to the embodiment has the following non-limiting features in addition to the non-limiting features of the 19th embodiment: The image processing unit is configured to generate a plurality of high dynamic range images based on a plurality of image groups acquired by the imaging unit under a combination of control of the imaging optical system and control of the movement mechanism.

[0387] A 21st embodiment of the ophthalmic apparatus according to the embodiment has the following non-limiting features in addition to the non-limiting features of any of the 1st to 20th embodiments: Two or more images of the eye under examination obtained by applying two or more imagings to the eye under examination under different imaging conditions include a first image and a second image. The image processing unit is configured to perform the following processes: identify a first pixel from the first image that satisfies predetermined pixel value conditions, and change the pixel value of the first pixel in the first image based on the pixel value of the second pixel in the second image that corresponds to the first pixel identified from the first image.

[0388] A 22nd embodiment of the ophthalmic apparatus according to the embodiment has the following non-limiting features in addition to the non-limiting features of the 21st embodiment: A first image included in two or more images of the eye obtained by applying two or more exposures to the eye under different exposure conditions is a relatively bright image among the two or more images. A second image included in two or more images of the eye obtained by applying two or more exposures to the eye under different exposure conditions is a relatively dark image among the two or more images. The image processing unit is configured to identify a pixel having a brightness value equal to or greater than a predetermined first threshold from the relatively bright first image as a first pixel. Furthermore, the image processing unit is configured to change the pixel value of a first pixel that is equal to or greater than the first threshold in the relatively bright first image based on the pixel value of a second pixel in the relatively dark second image that corresponds to a first pixel having a pixel value equal to or greater than the first threshold in the relatively bright first image.

[0389] A 23rd embodiment of the ophthalmic apparatus according to the embodiment has the following non-limiting features in addition to the non-limiting features of the 21st embodiment: A first image included in two or more images of the eye obtained by applying two or more exposures to the eye under different exposure conditions is a relatively dark image among the two or more images. A second image included in two or more images of the eye obtained by applying two or more exposures to the eye under different exposure conditions is a relatively bright image among the two or more images. The image processing unit is configured to identify a pixel having a brightness value below a predetermined second threshold from the relatively dark first image as a first pixel. Furthermore, the image processing unit is configured to change the pixel value of a first pixel that is below the second threshold in the relatively dark first image based on the pixel value of a second pixel in the relatively bright second image that corresponds to a first pixel having a pixel value below the second threshold in the relatively dark first image.

[0390] A 24th embodiment of the ophthalmic apparatus according to the embodiment has the following non-limiting features in addition to the non-limiting features of any of the first to 23 embodiments: Two or more images of the eye under examination obtained by applying two or more imagings to the eye under examination under different imaging conditions include a first image and a second image. The image processing unit is configured to perform a process to identify a first image region corresponding to a predetermined part of the eye under examination from the first image, a process to identify a second image region corresponding to the same part of the eye under examination from the second image, and to change the pixel values ​​of the first image region in the first image based on the pixel values ​​of the second image region in the second image.

[0391] A 25th embodiment of the ophthalmic apparatus according to the embodiment has the following non-limiting features in addition to the non-limiting features of any of the 1st to 24th embodiments: The image processing unit is configured to apply tone mapping processing to two or more images of the eye under examination obtained by applying two or more images of the eye under examination under different shooting conditions.

[0392] A 26th embodiment of the ophthalmic apparatus according to the embodiment has the following non-limiting features in addition to the non-limiting features of any of the 1st to 25th embodiments: The optical system includes an illumination optical system for projecting illumination light onto the eye under examination and an imaging optical system for photographing the eye under examination. The imaging unit includes a moving mechanism for moving the illumination optical system and the imaging optical system. The control unit is configured to control at least one of the illumination optical system and the imaging optical system in order to control the imaging unit for two or more imaging sessions with different imaging conditions, such that the projection time of illumination light onto the eye under examination is shorter than the exposure time of the imaging optical system, and at least a portion of the projection period of illumination light onto the eye under examination and at least a portion of the exposure period of the imaging optical system overlap.

[0393] As described herein, ophthalmic devices having these non-limiting features make it possible to improve the quality of images obtained in ophthalmic imaging. In particular, it is possible to improve the quality of images obtained in ophthalmic imaging using an optical scanning method.

[0394] Furthermore, those skilled in the art will understand that by combining any of the matters described herein with an ophthalmic device having any of the non-limiting features, it is possible to further improve image quality in ophthalmic imaging and to provide a variety of applications for ophthalmic imaging.

[0395] <Other Embodiments> While embodiments of ophthalmic devices have been described so far, the embodiments relating to this disclosure are not limited to ophthalmic devices. Embodiments other than ophthalmic devices include control methods, programs, and recording media for ophthalmic devices. Similar to the embodiments of ophthalmic devices, these embodiments can also improve image quality in ophthalmic imaging.

[0396] One embodiment of the control method for an ophthalmic device is a method for controlling an ophthalmic device.

[0397] This ophthalmic device includes an imaging unit and a processor. The imaging unit includes an optical system that satisfies the Scheinproof requirements.

[0398] The method according to this embodiment is configured to make the processor included in the ophthalmic device function as a control unit and an image processing unit.

[0399] The processor, which functions as the control unit, controls the imaging unit to apply two or more images with different imaging conditions to the eye under examination.

[0400] The processor, which functions as an image processing unit, generates a high dynamic range image based on two or more images of the eye under examination, obtained through two or more imaging sessions with different shooting conditions.

[0401] Any of the matters described herein can be combined with the methods according to these embodiments.

[0402] One embodiment of the program is a program for operating an ophthalmic device.

[0403] This ophthalmic device includes an imaging unit and a processor. The imaging unit includes an optical system that satisfies the Scheinproof requirements.

[0404] The program according to this embodiment is configured to cause the processor included in the ophthalmic device to function as a control unit and an image processing unit.

[0405] According to the program of this embodiment, the processor, which functions as a control unit, controls the imaging unit to apply two or more images with different imaging conditions to the eye under examination.

[0406] The processor, which functions as an image processing unit according to the program of this embodiment, generates a high dynamic range image based on two or more images of the eye under examination obtained from two or more imaging sessions with different shooting conditions.

[0407] Any of the matters described in this disclosure can be combined with the program according to this embodiment.

[0408] One embodiment of the recording medium is a computer-readable, non-temporary recording medium on which a program for operating an ophthalmic device is recorded.

[0409] This ophthalmic device includes an imaging unit and a processor. The imaging unit includes an optical system that satisfies the Scheinproof requirements.

[0410] The program recorded on the recording medium according to this embodiment is configured to cause the processor included in the ophthalmic device to function as a control unit and an image processing unit.

[0411] The processor, which functions as a control unit according to the program recorded on the recording medium in this embodiment, controls the imaging unit to apply two or more images with different imaging conditions to the eye under examination.

[0412] A processor functioning as an image processing unit, based on a program recorded on the recording medium according to this embodiment, generates a high dynamic range image based on two or more images of the eye under examination obtained from two or more exposures under different shooting conditions.

[0413] Any of the matters described in this disclosure can be combined with the recording medium according to this embodiment.

[0414] The computer-readable non-temporary recording medium that can be used as a recording medium according to this embodiment may be any form of recording medium, for example, a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory.

[0415] Any aspect described in the embodiment of the ophthalmic device can be combined with embodiments other than the ophthalmic device.

[0416] For example, items arbitrarily selected from among the various items described as arbitrary embodiments of the ophthalmic device according to the embodiment can be combined with embodiments of the control method for the ophthalmic device, embodiments of the program, embodiments of the recording medium, and so on.

[0417] Furthermore, any of the matters described in this disclosure can be combined with embodiments of control methods for ophthalmic devices, embodiments of programs, embodiments of recording media, and so on.

[0418] This disclosure presents several embodiments and some exemplary aspects thereof. These embodiments and aspects are merely illustrative of the present invention. Therefore, any modifications (omissions, substitutions, additions, etc.) within the scope of the gist of the present invention can be applied to the embodiments and aspects presented in this disclosure. [Explanation of Symbols]

[0419] 1. Slit lamp microscope system (ophthalmic equipment) 2 Illumination optical system 3. Imaging optical system 3B image sensor 6 Moving mechanism 7 Control Unit 20 Illumination optical system 30L left-hand imaging optical system 30R Right-hand shooting optical system 33L, 33R image sensor 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700 Ophthalmic equipment 1010 Photography Department 1011 Optical system 1012 Illumination optical system 1013, 1013A, 1013B imaging optical system 1014, 1014A, 1014B image sensor 1019 Moving mechanism 1020 Control Unit 1030 Image Processing Unit

Claims

1. A photographic unit including an optical system that satisfies the requirements for shineproofing, A control unit that controls the imaging unit to apply two or more images to the eye under examination, each with different imaging conditions that affect the brightness of the generated image, An image processing unit generates a high dynamic range image having a wider dynamic range than the dynamic range of each of the two or more images based on two or more images of the subject's eye at different brightness levels obtained by the two or more aforementioned imaging operations. Includes, The optical system described above is An illumination optical system that projects illumination light onto the eye under examination based on pre-set illumination conditions, A photographic optical system that photographs the eye under examination based on pre-set exposure conditions, Includes, The imaging optical system includes a first image sensor and a second image sensor. The control unit, The first exposure time using the first image sensor and the second exposure time using the second image sensor are different. At least a portion of the first exposure period by the first image sensor and at least a portion of the second exposure period by the second image sensor overlap, and The first portion of the projection period of the illumination light by the illumination optical system overlaps with the first exposure period, and the second portion of the projection period overlaps with the second exposure period. The above control of the imaging unit is performed, The imaging unit further includes a moving mechanism for moving the optical system, The control unit, by combining control of the imaging optical system for repeatedly applying a first image using the first image sensor to the eye under examination and a second image using the second image sensor to the eye under examination, and control of the movement mechanism for moving the optical system, causes the imaging unit to repeatedly acquire an image group including an image corresponding to the first image and an image corresponding to the second image. The image processing unit generates multiple high dynamic range images based on a plurality of image groups acquired by the imaging unit. Ophthalmology equipment.

2. The illumination optical system projects illumination light onto the eye under examination based on preset illumination conditions. The control unit performs the control of the imaging unit so as to apply at least two or more images under different lighting conditions to the eye under examination. An ophthalmic apparatus according to claim 1.

3. The aforementioned lighting conditions include lighting intensity conditions that determine the intensity of the illuminating light, The control unit performs the control of the imaging unit so as to apply at least two or more images with different illumination intensity conditions to the eye under examination. The ophthalmic apparatus according to claim 2.

4. The illumination intensity conditions include two or more conditions, The control unit, by combining the control of the illumination optical system for cyclically applying the two or more conditions and the control of the movement mechanism for moving the optical system, causes the imaging unit to repeatedly acquire a group of images consisting of two or more images with different brightness levels corresponding to the two or more conditions. The ophthalmic apparatus according to claim 3.

5. The aforementioned lighting conditions include lighting time conditions that define the projection time of the illuminating light, The control unit performs the control of the imaging unit so as to apply at least two or more images with different illumination time conditions to the eye under examination. The ophthalmic apparatus according to claim 2.

6. The illumination time conditions include two or more conditions, The control unit, by combining the control of the illumination optical system for cyclically applying the two or more conditions and the control of the movement mechanism for moving the optical system, causes the imaging unit to repeatedly acquire a group of images consisting of two or more images with different brightness levels corresponding to the two or more conditions. The ophthalmic apparatus according to claim 5.

7. The aforementioned imaging optical system photographs the eye under examination based on preset exposure conditions. The control unit performs the control of the imaging unit so as to apply at least two or more images with different exposure conditions to the eye under examination. An ophthalmic apparatus according to claim 1.

8. The exposure conditions include exposure time conditions that determine the first exposure time and the second exposure time, The control unit performs the control of the imaging unit so as to apply at least two or more images with different exposure time conditions to the eye under examination. The ophthalmic apparatus according to claim 7.

9. The exposure time conditions include two or more conditions, The control unit, by combining the control of the imaging optical system for cyclically applying the two or more conditions and the control of the movement mechanism for moving the optical system, causes the imaging unit to repeatedly acquire a group of images consisting of two or more images with different brightness levels corresponding to the two or more conditions. The ophthalmic apparatus according to claim 8.

10. The imaging optical system includes two or more image sensors, including a first image sensor and a second image sensor. The control unit controls the imaging unit to perform two or more imaging operations using the two or more image sensors. The ophthalmic apparatus according to claim 7.

11. The control unit, by combining the control of the imaging optical system for repeatedly applying the two or more images taken using the two or more image sensors to the eye under examination, and the control of the movement mechanism for moving the optical system, causes the imaging unit to repeatedly acquire a group of images consisting of two or more images of different brightness levels corresponding to the two or more images taken using the two or more image sensors. An ophthalmic apparatus according to claim 10.

12. The two or more images include a first image and a second image, The aforementioned image processing unit, From the first image, a first pixel that satisfies predetermined pixel value conditions is identified, The pixel value of the first pixel is changed based on the pixel value of the second pixel of the second image that corresponds to the first pixel. An ophthalmic apparatus according to claim 1.

13. The first image is the relatively brighter image among the two or more images. The second image is the relatively darker image among the two or more images. The image processing unit identifies pixels having a brightness value equal to or greater than a first threshold from the first image as the first pixels. The ophthalmic apparatus according to claim 12.

14. The first image is the relatively darker image among the two or more images. The second image is the relatively brighter image among the two or more images. The image processing unit identifies pixels having a brightness value below a second threshold from the first image as the first pixels. The ophthalmic apparatus according to claim 12.

15. The two or more images include a first image and a second image, The aforementioned image processing unit, From the first image, a first image region corresponding to a predetermined part of the eye under examination is identified, From the second image, a second image region corresponding to the predetermined part is identified, The pixel values ​​of the first image region are changed based on the pixel values ​​of the second image region. An ophthalmic apparatus according to claim 1.

16. The control unit controls at least one of the illumination optical system and the imaging optical system in the control of the imaging unit for two or more imaging sessions such that the projection time of the illumination light onto the eye under examination is shorter than the exposure time of the imaging optical system, and at least a portion of the projection period of the illumination light onto the eye under examination and at least a portion of the exposure period of the imaging optical system overlap. An ophthalmic apparatus according to claim 1.

17. A method for controlling an ophthalmic apparatus including an imaging unit with an optical system that satisfies the conditions of shineproofing, and a processor, The aforementioned processor, A control unit that controls the imaging unit to apply two or more images to the eye under examination, each with different imaging conditions that affect the brightness of the generated image, and An image processing unit generates a high dynamic range image having a wider dynamic range than the dynamic range of each of the two or more images, based on two or more images of the subject's eye at different brightness levels obtained by the two or more aforementioned imaging sessions. To make it function as, The optical system described above is An illumination optical system that projects illumination light onto the eye under examination based on pre-set illumination conditions, A photographic optical system that photographs the eye under examination based on pre-set exposure conditions, Includes, The imaging optical system includes a first image sensor and a second image sensor. The processor, which functions as the control unit, The first exposure time using the first image sensor and the second exposure time using the second image sensor are different. At least a portion of the first exposure period by the first image sensor and at least a portion of the second exposure period by the second image sensor overlap, and The first portion of the projection period of the illumination light by the illumination optical system overlaps with the first exposure period, and the second portion of the projection period overlaps with the second exposure period. The above control of the imaging unit is performed, The imaging unit further includes a moving mechanism for moving the optical system, The processor, which functions as the control unit, repeatedly applies a first image using the first image sensor to the eye under examination and a second image using the second image sensor to the eye under examination, and by combining the control of the movement mechanism for moving the optical system, the processor causes the imaging unit to repeatedly acquire an image group including an image corresponding to the first image and an image corresponding to the second image. The processor, which functions as the image processing unit, generates a plurality of high dynamic range images based on a plurality of image groups acquired by the imaging unit. method.

18. A program for operating an ophthalmic device including an imaging unit with an optical system that satisfies the conditions of shineproofing, and a processor, The aforementioned processor, A control unit that controls the imaging unit to apply two or more images to the eye under examination, each with different imaging conditions that affect the brightness of the generated image, and An image processing unit generates a high dynamic range image having a wider dynamic range than the dynamic range of each of the two or more images, based on two or more images of the subject's eye at different brightness levels obtained by the two or more aforementioned imaging sessions. To make it function as, The optical system described above is An illumination optical system that projects illumination light onto the eye under examination based on pre-set illumination conditions, A photographic optical system that photographs the eye under examination based on pre-set exposure conditions, Includes, The imaging optical system includes a first image sensor and a second image sensor. The processor, which functions as the control unit, The first exposure time using the first image sensor and the second exposure time using the second image sensor are different. At least a portion of the first exposure period by the first image sensor and at least a portion of the second exposure period by the second image sensor overlap, and The first portion of the projection period of the illumination light by the illumination optical system overlaps with the first exposure period, and the second portion of the projection period overlaps with the second exposure period. The above control of the imaging unit is performed, The imaging unit further includes a moving mechanism for moving the optical system, The processor, which functions as the control unit, repeatedly applies a first image using the first image sensor to the eye under examination and a second image using the second image sensor to the eye under examination, and by combining the control of the movement mechanism for moving the optical system, the processor causes the imaging unit to repeatedly acquire an image group including an image corresponding to the first image and an image corresponding to the second image. The processor, which functions as the image processing unit, generates a plurality of high dynamic range images based on a plurality of image groups acquired by the imaging unit. program.

19. A computer-readable non-temporary recording medium on which a program for operating an ophthalmic device, including an imaging unit with an optical system that satisfies the conditions of shineproofing, and a processor, is recorded. The program causes the processor to A control unit that controls the imaging unit to apply two or more images to the eye under examination, each with different imaging conditions that affect the brightness of the generated image, and An image processing unit generates a high dynamic range image having a wider dynamic range than the dynamic range of each of the two or more images, based on two or more images of the subject's eye at different brightness levels obtained by the two or more aforementioned imaging sessions. To make it function as, The optical system described above is An illumination optical system that projects illumination light onto the eye under examination based on pre-set illumination conditions, A photographic optical system that photographs the eye under examination based on pre-set exposure conditions, Includes, The imaging optical system includes a first image sensor and a second image sensor. The processor, which functions as the control unit, The first exposure time using the first image sensor and the second exposure time using the second image sensor are different. At least a portion of the first exposure period by the first image sensor and at least a portion of the second exposure period by the second image sensor overlap, and The first portion of the projection period of the illumination light by the illumination optical system overlaps with the first exposure period, and the second portion of the projection period overlaps with the second exposure period. The above control of the imaging unit is performed, The imaging unit further includes a moving mechanism for moving the optical system, The processor, which functions as the control unit, repeatedly applies a first image using the first image sensor to the eye under examination and a second image using the second image sensor to the eye under examination, and by combining the control of the movement mechanism for moving the optical system, the processor causes the imaging unit to repeatedly acquire an image group including an image corresponding to the first image and an image corresponding to the second image. The processor, which functions as the image processing unit, generates a plurality of high dynamic range images based on a plurality of image groups acquired by the imaging unit. Recording medium.

Images