JP2024014009A - Ophthalmological device, method for controlling ophthalmological device, program, and recording medium - Google Patents

Abstract

The present invention aims to improve the quality of images obtained in ophthalmological imaging. An ophthalmologic apparatus according to one embodiment includes an imaging section, a control section, and an image processing section. The photographing section includes an optical system that satisfies Scheimpflug conditions. The control unit is configured to control the imaging unit so that two or more imaging operations with different imaging conditions are applied to the subject's eye. The image processing unit is configured to generate a high dynamic range image based on two or more images of the eye to be examined acquired through two or more imaging operations under different imaging conditions. [Selection diagram] Figure 1

Description

The present invention relates to an ophthalmologic apparatus, a method for controlling an ophthalmologic apparatus, a program, and a recording medium.

Image diagnosis occupies an important position in the field of ophthalmology. Various ophthalmological devices are used in ophthalmological image diagnosis. Ophthalmological equipment includes slit lamp microscopes, fundus cameras, scanning laser ophthalmoscopes (SLO), and optical coherence tomography (OCT). In addition, various inspection and measurement devices such as refractometers, keratometers, tonometers, specular microscopes, wavefront analyzers, and microperimeters are also equipped with functions for photographing the anterior segment and fundus of the eye.

One of the most widely and frequently used of these various ophthalmic devices is the slit lamp microscope, also called the stethoscope for ophthalmologists. A slit lamp microscope is an ophthalmological device that illuminates a subject's eye 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). Additionally, a slit lamp microscope is known that can scan a three-dimensional area of the eye to be examined at high speed by using an optical system configured to satisfy Scheimpflug conditions (for example, see Patent Document 3). reference). In addition to the slit lamp microscope, a rolling shutter camera is also known as an imaging method that scans an object with slit light.

JP 2016-159073 Publication Japanese Patent Application Publication No. 2016-179004 JP2019-213733A

One objective of the present invention is to improve the quality of images obtained in ophthalmological imaging.

One exemplary aspect of the embodiment includes an imaging section including an optical system that satisfies Scheimpflug conditions, and controlling the imaging section so that two or more imagings with different imaging conditions are applied to the eye to be examined. The ophthalmologic apparatus includes a control unit and an image processing unit that generates a high dynamic range image based on two or more images of the subject's eye acquired by the two or more imaging operations.

Another exemplary aspect of the embodiment is a method of controlling an ophthalmologic apparatus including an imaging unit including an optical system that satisfies Scheimpflug conditions, and a processor, the method comprising controlling the processor twice under different imaging conditions. a control unit that controls the imaging unit so as to apply the above imaging to the eye to be examined, and a high dynamic range image based on two or more images of the eye to be examined acquired by the two or more imaging operations; This method functions as an image processing unit that generates an image.

Yet another exemplary aspect of the embodiment is a program for operating an ophthalmological apparatus including an imaging unit including an optical system that satisfies Scheimpflug conditions, and a processor, the program operating the processor under imaging conditions. a control unit that controls the imaging unit so as to apply two or more different imaging shots to the eye to be examined; This is a program that functions as an image processing unit that generates a range image.

Yet another exemplary aspect of the embodiment is a computer-readable non-transitory device on which a program for operating an ophthalmological apparatus including an imaging unit including an optical system that satisfies Scheimpflug conditions and a processor is recorded. The recording medium includes a control unit configured to control the imaging unit so as to cause the processor to apply two or more imagings with different imaging conditions to the eye to be examined; It is a recording medium that functions as an image processing unit that generates a high dynamic range image based on two or more acquired images of the subject's eye.

According to the embodiment, it is possible to improve the quality of images obtained by ophthalmological imaging.

FIG. 1 is a schematic diagram illustrating the configuration of an ophthalmologic apparatus according to an exemplary aspect of an embodiment. 3 is a flowchart illustrating processing performed by an ophthalmologic apparatus according to an exemplary aspect of an embodiment. FIG. 1 is a schematic diagram illustrating the configuration of an ophthalmologic apparatus according to an exemplary aspect of an embodiment. 3 is a flowchart illustrating processing performed by an ophthalmologic apparatus according to an exemplary aspect of an embodiment. FIG. 1 is a schematic diagram illustrating the configuration of an ophthalmologic apparatus according to an exemplary aspect of an embodiment. 3 is a flowchart illustrating processing performed by an ophthalmologic apparatus according to an exemplary aspect of an embodiment. 5 is a timing chart illustrating processing performed by an ophthalmologic apparatus according to an exemplary aspect of the embodiment. 5 is a timing chart illustrating processing performed by an ophthalmologic apparatus according to an exemplary aspect of the embodiment. 5 is a timing chart of conventional processing shown for comparison with processing performed by an ophthalmologic apparatus according to an exemplary aspect of the embodiment. FIG. 1 is a schematic diagram illustrating the configuration of an ophthalmologic apparatus according to an exemplary aspect of an embodiment. 3 is a flowchart illustrating processing performed by an ophthalmologic apparatus according to an exemplary aspect of an embodiment. 5 is a timing chart illustrating processing performed by an ophthalmologic apparatus according to an exemplary aspect of the embodiment. 5 is a timing chart illustrating processing performed by an ophthalmologic apparatus according to an exemplary aspect of the embodiment. 3 is a flowchart illustrating processing performed by an ophthalmologic apparatus according to an exemplary aspect of an embodiment. FIG. 1 is a schematic diagram illustrating the configuration of an ophthalmologic apparatus according to an exemplary aspect of an embodiment. 3 is a flowchart illustrating processing performed by an ophthalmologic apparatus according to an exemplary aspect of an embodiment. FIG. 1 is a schematic diagram illustrating the configuration of an ophthalmologic apparatus according to an exemplary aspect of an embodiment. 3 is a flowchart illustrating processing performed by an ophthalmologic apparatus according to an exemplary aspect of an embodiment. 5 is a timing chart illustrating processing performed by an ophthalmologic apparatus according to an exemplary aspect of the embodiment. FIG. 1 is a schematic diagram illustrating the configuration of an ophthalmologic apparatus according to an exemplary aspect of an embodiment. FIG. 1 is a schematic diagram illustrating the configuration of an ophthalmologic apparatus according to an exemplary aspect of an embodiment. 5 is a timing chart illustrating processing performed by an ophthalmologic apparatus according to an exemplary aspect of the embodiment. 5 is a timing chart illustrating processing performed by an ophthalmologic apparatus according to an exemplary aspect of the embodiment. 5 is a timing chart illustrating processing performed by an ophthalmologic apparatus according to an exemplary aspect of the embodiment. 3 is a flowchart illustrating processing performed by an ophthalmologic apparatus according to an exemplary aspect of an embodiment. FIG. 2 is a timing chart representing a process executed by an ophthalmologic apparatus according to an exemplary aspect of the embodiment, and a schematic diagram of an image obtained by the process. FIG. 2 is a timing chart representing a process executed by an ophthalmologic apparatus according to an exemplary aspect of the embodiment, and a schematic diagram of an image obtained by the process. 1 is a schematic diagram depicting high dynamic range image generation performed by an ophthalmological device according to an example aspect of an embodiment; FIG. 3 is a flowchart illustrating processing performed by an ophthalmologic apparatus according to an exemplary aspect of an embodiment. 3 is a flowchart illustrating processing performed by an ophthalmologic apparatus according to an exemplary aspect of an embodiment. FIG. 2 is a timing chart representing a process executed by an ophthalmologic apparatus according to an exemplary aspect of the embodiment, and a schematic diagram of an image obtained by the process. FIG. 1 is a schematic diagram illustrating the configuration of an ophthalmologic apparatus according to an exemplary aspect of an embodiment. FIG. 1 is a schematic diagram illustrating the configuration of an ophthalmologic apparatus according to an exemplary aspect of an embodiment.

Some non-limiting exemplary aspects of embodiments will now be described in detail with reference to the drawings.

Any known technology can be combined with any aspect of the present disclosure. For example, any matter disclosed in the documents cited herein can be combined with any aspect of the present disclosure. Furthermore, any known technology in the technical field related to the present disclosure can be combined with any aspect of the present disclosure.

All contents disclosed in Patent Document 3 (Japanese Unexamined Patent Publication No. 2019-213733) are incorporated into the present disclosure by reference. Furthermore, any technical matter disclosed by the applicant of the present application regarding technology related to the present disclosure (matters disclosed in patent applications, papers, etc.) can be combined with any aspect of the present disclosure.

It is possible to at least partially combine any two or more of the various aspects of the present disclosure.

At least some of the functionality of the elements described in this disclosure is implemented using circuitry or processing circuitry. The circuitry or processing circuitry may include a general purpose processor, a special purpose processor, an integrated circuit, a central processing unit (CPU), a graphics processing unit (GPU) configured and/or programmed to perform at least some of the disclosed functions. ), ASIC (Application Specific Integrated Circuit), programmable logic device (for example, SPLD (Simple Programmable Logic Device), CPLD (Complex Programmable Log) IC Device), FPGA (Field Programmable Gate Array), conventional circuit configurations, and any of these A processor is considered to be a processing circuitry or circuitry that includes transistors and/or other circuitry. In this disclosure, the term circuitry, unit, means, or similar terminology refers to the disclosure Hardware that performs at least some of the functions disclosed herein, or hardware that is programmed to perform at least some of the functions disclosed. or may be known hardware programmed and/or configured to perform at least some of the functions described.A processor where the hardware may be considered a type of circuitry. , the term circuitry, unit, means, or similar terms is a combination of hardware and software, the software being used to configure the hardware and/or the processor.

In the following embodiments, various aspects when handling monochrome images (when using a monochrome camera) will be explained, but it is also possible to perform similar processing when handling color images (when using a color camera). , will be understood by those skilled in the art. As a non-limiting example when dealing with color images, considering that a color camera generally generates three color component images (R component image, G component image, and B component image), component images A method to generate a high dynamic range image using luminance signal values (Y) generated from three color component images, a method to generate a high dynamic range image by converting a color image to a monochrome image, and a method to generate a high dynamic range image by converting a color image into a monochrome image It is possible to adopt a method of generating an image, a method of generating a high dynamic range image only from selected color component images, and the like.

<Overview of embodiment>
Embodiments according to the present disclosure aim to improve ophthalmological imaging using an optical system that satisfies Scheimpflug conditions. As an application, some exemplary aspects of embodiments of the present disclosure seek to improve ophthalmic imaging in which images are acquired while moving an optical system that satisfies Scheimpflug conditions.

More specifically, embodiments according to the present disclosure aim to improve the dynamic range of images obtained using an optical system that satisfies Scheimpflug conditions. As an application, some exemplary aspects of embodiments of the present disclosure seek to improve the dynamic range of each of a series of images collected while moving an optical system that satisfies Scheimpflug conditions. be.

In general, there are various advantages to improving the dynamic range, and in ophthalmic imaging, which this disclosure deals with, there are the following advantages.

In ophthalmological imaging using light, two or more eye regions with significantly different light reflectances may be represented in one image. For example, anterior segment imaging often generates images depicting the cornea and crystalline lens, but the reflectance of the cornea and crystalline lens is significantly different, and in fact, the reflectance at the corneal surface is It is known that the reflectance is about 62 times that of the surface of the crystalline lens. Therefore, the dynamic range of a typical image sensor cannot represent the cornea and crystalline lens with appropriate brightness.

Embodiments according to the present disclosure can be used to solve such problems. That is, one objective of the embodiments according to the present disclosure is to suitably represent two or more eye parts having significantly different reflectances in one image. This makes it possible to improve the quality of images obtained through ophthalmological imaging.

The wide dynamic range image obtained by the ophthalmological imaging according to the present disclosure can be used in various ways. For example, by selectively extracting a part (partial range) of a wide dynamic range of an image obtained by ophthalmological imaging according to the present disclosure, the characteristics (dynamic range range, etc.) of an arbitrary output device (such as a display device) It becomes possible to provide an image corresponding to the output device to the output device.

In order to improve the dynamic range of images obtained in ophthalmological imaging, embodiments according to the present disclosure apply two or more images to a subject's eye under different imaging conditions using an optical system that satisfies Scheimpflug conditions. , is configured to generate a high dynamic range image based on the two or more images of the subject's eye acquired thereby.

The two or more shootings performed under different shooting conditions using an optical system that satisfies the Scheimpflug condition may be performed in any shooting mode. For example, the two or more imaging operations according to the embodiment may be two or more imaging operations performed sequentially (sequentially), or two or more imaging operations that are performed in parallel (simultaneously). , or a combination thereof.

Further, the number of cameras (imaging elements, photographing devices) used for two or more photographing operations according to the embodiment may be arbitrary. In some example aspects, two or more shots are taken sequentially using one camera. Additionally, in some exemplary aspects, two or more images are taken in parallel using two or more cameras.

The optical system that satisfies the Scheimpflug condition may be, for example, the one disclosed in Patent Document 3 (Japanese Patent Laid-Open No. 2019-213733), but is not limited thereto. By using an optical system that satisfies Scheimpflug's conditions, it becomes possible to focus and photograph a wide range of the eye to be examined. For example, with anterior segment imaging, it is possible to focus on at least the area defined by the anterior surface of the cornea and the posterior surface of the crystalline lens, and the entire main observation target of the anterior segment can be expressed in high definition. becomes possible.

Therefore, in the high dynamic range image generated by the embodiment of the present disclosure, a wide range of the subject's eye is expressed in high definition, and each region depicted is expressed with suitable brightness. .

In this way, the embodiments of the present disclosure provide a novel eye image that achieves all of the following: a wide imaging range, high definition over the entire imaging range, and appropriate brightness for each region. For this purpose, two or more images of the eye to be examined under different imaging conditions are applied to the eye using an optical system that satisfies the Scheimpflug conditions, and two or more images of the eye to be examined are thus obtained. The system has a novel configuration in which a high dynamic range image is generated based on the image.

The photographing conditions may be any conditions set for photographing using an optical system that satisfies Scheimpflug conditions. For example, types of photographing conditions include conditions related to the optical system (optical system conditions), conditions related to movement of the optical system (movement conditions), and conditions other than these.

Types of optical system conditions include conditions related to the illumination optical system for projecting illumination light onto the eye to be examined (illumination conditions), conditions for the photographic optical system to photograph the eye to be examined using an image sensor (exposure conditions), etc. There is.

The types of illumination conditions include conditions regarding the intensity of illumination light (illumination intensity conditions), conditions regarding the projection time of illumination light (illumination time conditions), and the like. The projection time of the illumination light is the length of the period (projection period) during which the illumination light is projected onto the eye to be examined. In this disclosure, the projection time of illumination light may be referred to as illumination time.

Examples of illumination intensity conditions include conditions related to the light source that emits illumination light (for example, the height of the light source control pulse), conditions related to the neutral density filter provided in the illumination optical system (for example, conditions related to the selection of two or more neutral density filters) conditions, conditions related to variable neutral density filter control), etc.

Examples of illumination time conditions include conditions regarding a light source that emits illumination light (for example, width of a light source control pulse), conditions regarding a shutter provided in an illumination optical system (for example, shutter opening time), and the like.

There is an exposure time condition as a type of exposure condition. The exposure time conditions include, for example, conditions related to the image sensor (eg, exposure time of the image sensor), conditions related to the shutter provided in the photographic optical system (eg, shutter opening time), and the like. The exposure time is the length of a period (exposure period) during which the image sensor can receive light.

When the photographic optical system has two or more image sensors, the exposure conditions (exposure time, exposure period, etc.) of these image sensors can be linked.

Types of movement conditions include optical system 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.) ), movement modes (continuous movement, intermittent movement, etc.).

Conditions other than optical system conditions and movement conditions include conditions related to linkage (synchronization) of two or more conditions, conditions related to the eye to be examined, and the like.

Examples of conditions related to coordination of two or more conditions include conditions related to coordination of two or more optical system conditions, conditions related to coordination of two or more movement conditions, and conditions related to coordination of one or more optical system conditions and one or more movement conditions. There are conditions regarding cooperation with.

Examples of conditions related to the eye to be examined include conditions related to fixation, conditions related to use of a contrast medium, conditions related to use of a mydriatic agent, conditions related to eye characteristics, and the like. The eye characteristics may include parameters that affect or can affect the brightness of the eye image, such as pupil diameter, iris color, etc. be.

In some exemplary embodiments, two or more imagings performed under different imaging conditions using an optical system that satisfies Scheimpflug conditions are applied to substantially the same position of the eye to be examined.

When the movement of the optical system is continuous, for example, by controlling the time required for two or more images to be sufficiently short compared to the movement speed of the optical system, the eye to be examined can be Two or more images depicting approximately the same location can be acquired.

If the movement of the optical system is intermittent, for example, controlling the same position of the eye to be examined twice or more and moving the optical system may be performed alternately. Two or more images with the location depicted can be acquired.

In contrast, in some other exemplary embodiments, two or more images with different imaging conditions are performed using an optical system that satisfies the Scheimpflug condition at two or more different positions of the subject's eye. It may be applied to For example, two or more scans in different scanning directions can be applied to the three-dimensional region of the eye to be examined as two or more images with different imaging conditions. One specific example is to perform the first scan under the first imaging condition by moving the slit light whose longitudinal direction is the horizontal direction in the vertical direction, and to move the slit light whose longitudinal direction is the vertical direction in the horizontal direction. and execute a second scan under the second imaging condition, and perform a high dynamic range image based on the first three-dimensional image obtained in the first scan and the second three-dimensional image obtained in the second scan. The image may be configured to generate an image.

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

The high dynamic range image of the present disclosure is the dynamic range of two or more images (original image group) obtained through two or more shootings under different shooting conditions using an optical system that satisfies Scheimpflug conditions. This is an image with a wider dynamic range. In other words, the high dynamic range image of the present disclosure is an image that has a dynamic range that is expanded (enlarged) than the images included in the original image group.

Embodiments according to the present disclosure may be configured to perform control for realizing at least such a function. This control may include control of the illumination optical system and/or control of the photographing optical system, as described above. Note that embodiments according to the present disclosure may be configured to be able to execute control for realizing other functions.

Control of the illumination optical system may be any type of control, for example, electrical control such as light source control (on/off) or electronic shutter control, or mechanical shutter control or rotary shutter control. It may be mechanical control such as control, or it may be a combination of electrical control and mechanical control. Note that these shutters are provided in the illumination optical system, and are designed to switch between passing and blocking the illumination light output from the light source (that is, switching between projecting and not projecting the illumination light to the subject's eye). )Function.

Control of the illumination optical system is not limited to control for switching between a state in which illumination light is projected onto the eye to be examined (projection state) and a state in which it is not projected (non-projection state); Control may also be used to modulate the intensity or amount of illumination light.

Note that switching between the projection state and the non-projection state corresponds to switching the intensity of the illumination light projected onto the eye to be examined between a positive value and zero. In contrast, intensity modulation corresponds to switching the intensity of illumination light projected onto the eye to be examined between a first value and a second value that are different from each other. Here, both the first value and the second value are non-negative values, and either one or both of the first value and the second value is a positive value. Therefore, switching between the projection state and the non-projection state can be said to correspond to one example of intensity modulation.

The control of the photographing optical system may be any type of control, for example, electrical control such as control of an image sensor or control of an electronic shutter, or control of a mechanical shutter or control of a rotary shutter. It may be mechanical control or a combination of electrical control and mechanical control.

Some exemplary aspects of the embodiments include performing multiple shots (shooting group) while moving (continuously or intermittently) the illumination optical system and the shooting optical system that satisfy the Scheimpflug condition. technology that generates a series of Scheimpflug images (Scheimpflug image group) corresponding to multiple positions (multiple cross-sections) of the subject's eye, and high dynamic range based on the Scheimpflug image group acquired by this imaging group. The configuration may be a combination of technology for generating images.

Some exemplary embodiments produce multiple Scheimpflug image groups corresponding to multiple imaging conditions by performing parallel combinations of optical system movement and imaging groups multiple times while sequentially changing imaging conditions. The image forming apparatus may be configured to obtain a plurality of Scheimpflug images, and further generate one or more high dynamic range images based on the plurality of obtained Scheimpflug images. In this aspect, two or more high dynamic range images corresponding to two or more imaging target positions (two or more imaging positions, two or more target cross sections) included in the imaging group can be generated. For example, according to this aspect, it is possible to generate a high dynamic range image representing the volume (three-dimensional region) of the scanned eye by a parallel combination of the movement of the optical system and the imaging group.

In cases where both the illumination conditions and the exposure conditions are variable, some example embodiments may be configured to collect multiple Scheimpflug images by controlling only the illumination conditions and the exposure conditions. It may be configured to collect a plurality of Scheimpflug image groups by controlling only the conditions, or may be configured to collect a plurality of Scheimpflug image groups by controlling both illumination conditions and exposure conditions. It's okay.

More generally, in embodiments where two or more types of imaging conditions are variable, some exemplary aspects sequentially change one or more types of imaging conditions selected from the two or more types of imaging conditions. By performing the parallel combination of the movement of the optical system and the shooting group multiple times while changing the . The image forming apparatus may be configured to generate more than one high dynamic range image.

The type of imaging condition may be selected by, for example, a user or a computer. The selection by the computer is performed based on predetermined information. For example, the computer can store information such as the imaging conditions applied in past imaging, medical information (electronic medical records, etc.) regarding the subject and/or the subject's eye, the disease targeted for examination or screening, the subject's attributes and condition, the subject's It may be configured to select the type of imaging condition based on the state of optometry or the like.

Where the illumination conditions are variable and the exposure conditions are fixed or preset, embodiments are configured to collect multiple Scheimpflug images by controlling the illumination conditions. If more than one type of illumination condition is variable, embodiments can change (select) the type of illumination condition that is controlled to collect multiple Scheimpflug images.

Conversely, if the illumination conditions are fixed or preset and the exposure conditions are variable, embodiments are configured to collect multiple Scheimpflug images by controlling the exposure conditions. If more than one type of exposure condition is variable, embodiments can change (select) the type of exposure condition that is controlled to collect multiple Scheimpflug images.

As mentioned above, the number of image sensors used in the embodiments may be arbitrary. In a mode in which one image sensor is used, two or more images with different imaging conditions are sequentially applied to the eye to be examined. On the other hand, in an embodiment in which two or more image sensors are used, two or more images with different imaging conditions can be applied to the subject's eye partially in parallel in terms of time. In other words, in an embodiment in which two or more image sensors are used, two or more images with different imaging conditions can be applied to the subject's eye such that their imaging times at least partially overlap. In addition, even in the mode using two or more image sensors, similar to the mode using one image sensor, it may be applied to the subject's eye partially in parallel in terms of time.

Some exemplary aspects of the embodiments outlined above will now be described. Although the present disclosure mainly describes exemplary aspects of an ophthalmic device, exemplary aspects of a method for controlling an ophthalmic device, exemplary aspects of a program, and exemplary aspects of a recording medium, aspects of embodiments is not limited to these. For example, those skilled in the art will understand that the present disclosure provides various aspects of medical methods, various aspects of imaging methods, various aspects of data processing methods, and the like.

<Ophthalmological equipment>
Some exemplary aspects of ophthalmic devices according to embodiments are provided.

FIG. 1 shows the configuration of an ophthalmologic apparatus according to one aspect of the embodiment. The ophthalmological apparatus 1000 of this example includes an imaging section 1010, a control section 1020, and an image processing section 1030.

The photographing unit 1010 includes an optical system 1011 that satisfies Scheimpflug conditions, and generates a digital image (Scheimpflug image) by photographing the eye to be examined using this optical system. The optical system 1011 includes an image sensor (not shown) for generating a digital image. Some non-limiting specific examples of the imaging unit 1010 including the optical system 1011 that satisfies the Scheimpflug condition will be described later.

The control unit 1020 controls the imaging unit 1010 to apply two or more imagings under different imaging conditions to the subject's eye. Under the control executed by the control unit 1020, the imaging unit 1010 generates two or more Scheimpflug images each corresponding to two or more different imaging conditions. As described above, the two or more Scheimpflug images generated by the imaging unit 1010 under the control executed by the control unit 1020 are images taken at substantially the same position of the eye to be examined.

Control unit 1020 includes hardware elements such as a processor and a storage device. The storage device stores computer programs such as control programs. The functions of the control unit 1020 are realized by cooperation between software such as a control program and hardware such as a processor.

The photographing conditions in this aspect may be any conditions (parameters) that affect the brightness of the generated image. Note that the photographing conditions of this embodiment include, for example, the aforementioned illumination conditions (eg, illumination intensity, illumination time) and exposure conditions (eg, exposure time, exposure period). Some non-limiting specific examples of control for causing the imaging unit 1010 to perform two or more imaging operations under different imaging conditions will be described later.

In this way, the two or more Scheimpflug images generated by the imaging unit 1010 under the control executed by the control unit 1020 are two or more Scheimpflug images that depict substantially the same position of the subject's eye but have different brightness. These are the images above.

The image processing unit 1030 generates a high dynamic range image based on the two or more Scheimpflug images generated by the imaging unit 1010 under the control executed by the control unit 1020.

Image processing unit 1030 includes hardware elements such as a processor and a storage device. The storage device stores computer programs such as image processing programs. The functions of the image processing unit 1030 are realized through cooperation between software such as an image processing program and hardware such as a processor.

As described above, the high dynamic range image of this embodiment is wider than the dynamic range of two or more Scheimpflug images (original image group) generated by the imaging unit 1010 under the control executed by the control unit 1020. The image has a dynamic range.

The type of processing performed by the image processing unit 1030 to generate a high dynamic range image from the original image group may be arbitrary. Some examples of processing performed by the image processing unit 1030 will be described below. Note that the processing executed by the image processing unit 1030 is not limited to these examples.

A first example of high dynamic range image generation will be described. Although the following specific example describes a case where two original images are considered, those skilled in the art will understand that similar processing can be performed when three or more original images are considered. Will.

In this example, two original images (a first original image and a second original image) included in the original image group are considered. As mentioned above, the first original image and the second original image depict substantially the same position of the eye to be examined, and the brightness of the first original image and the brightness of the second original image are different. Sato are different from each other.

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

Furthermore, the image processing unit 1030 determines 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. Change the pixel value of a pixel.

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

Regarding the first process, the pixel value condition is a condition regarding the value of a pixel, and in this aspect, it is a condition regarding the brightness of an image, that is, a condition regarding luminance. The pixel value condition may be, for example, a pixel value threshold, a pixel value range, or the like.

Furthermore, the pixel value condition may or may not be a default value. In the latter case, for example, the image processing unit 1030 can make the determination based on the brightness of the original image group (for example, the first original image and the second original image).

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

The second process will be explained. As described above, the first original image and the second original image are images depicting substantially the same position of the eye to be examined.

If it can be assumed that there is no substantial positional deviation between the image of the eye to be examined depicted in the first original image and the image of the eye to be examined depicted in the second original image, or If it is determined that there is no significant positional shift, a natural correspondence can be defined between the pixel positions of the first original image and the pixel positions of the second original image.

An example of a case where it can be assumed that there is no positional shift is that the time difference between the capture to generate the first original image and the capture to generate the second original image is sufficiently small (due to eye movements). (in some cases, the speed is sufficiently small compared to the moving speed of the optical system in scanning, which will be described later).

As an example of a case where it is determined that there is no positional deviation, a positional deviation evaluation (for example, any known process such as image registration) between the first original image and the second original image is performed. There are cases where such a determination result is obtained.

In the above natural correspondence relationship, for any feature point of the eye to be examined, the pixel position (coordinates) of the feature point in the first original image and the pixel position (coordinates) of the feature point in the second original image substantially match. In other words, when the first original image and the second original image are superimposed on each other, the image of the eye to be examined in the first original image and the image of the eye to be examined in the second original image substantially overlap.

When this natural correspondence relationship is defined, the image processing unit 1030 processes this first pixel (each pixel that satisfies the pixel value condition) identified from the first original image in the first process. It is possible to specify a pixel of the second original image located at the same coordinates as the coordinates of the pixel of , and set this specified pixel as the second pixel.

On the other hand, if there is a possibility that there is a substantial positional shift between the image of the eye to be examined depicted in the first original image and the image of the eye to be examined depicted in the second original image, , or if it is determined that there is a substantial misalignment, the image processing unit 1030 may perform registration between the first original image and the second original image. This image registration involves, for example, identifying feature points in a first original image corresponding to a predetermined region of the subject's eye, identifying feature points in a second original image corresponding to the same region, and identifying these features. This is done by calculating the relative displacement between points.

By determining the correspondence between the coordinate system defining the pixel position in the first original image and the coordinate system defining the pixel position in the second original image, based on the relative displacement calculated in the image registration, The image processing unit 1030 identifies pixels of the second original image that correspond to the first pixels (each pixel that satisfies the pixel value condition) identified from the first original image in the first process, and The pixel can be set as the second pixel.

The third process is to convert the pixel value of the first pixel identified from the first original image in the first process to the pixel value of the second pixel (the pixel value) identified from the second original image in the second process. The pixel value is changed based on the pixel value of the pixel (pixel corresponding to pixel 1).

Some examples of operations performed in the third process include: replacing the pixel value of the first pixel with the pixel value of the second pixel; a process of changing and replacing the pixel value of the first pixel; a process of determining the pixel value of the first pixel based on the pixel value in a pixel group of the second original image including the second pixel; A process of determining a pixel value of a first pixel based on a pixel value of a pixel and a pixel value of a second pixel.

Through these first to third processes, the pixel value of each pixel that satisfies a predetermined pixel value condition in the first original image is changed to the pixel value of the second original image, which has a different brightness from the first original image. This can be changed using the pixel values of the corresponding pixels, and it is possible to generate an image (high dynamic range image as referred to in the present disclosure) having a dynamic range expanded from the dynamic range of these original images.

As described above, the first original image and the second original image are elements of the original image group generated by the imaging unit 1010 under the control executed by the control unit 1020. In some example aspects, the first original image is a relatively brighter image of the two or more original images that are members of the original image set, and the second original image is a relatively brighter image of the two or more original images that are members of the original image group. This is a dark image. In this case, the image processing unit 1030 may be configured to execute the first to third processes described above as follows.

First, in the first process, the image processing unit 1030 selects a pixel having a luminance value equal to or higher than a preset first threshold from a relatively bright first original image as a first pixel (specific pixel). Identify. This first threshold value may be set so as to be able to identify pixels whose brightness values are too high (pixels that are too bright, pixels whose brightness is (almost) saturated, etc.).

Next, in the second process, the image processing unit 1030 generates a second original image (relatively dark image) corresponding to the first pixel identified from the first original image in the first process. Identify the second pixel.

Then, in the third process, the image processing unit 1030 extracts the pixel 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. The pixel value of the identified first pixel (the pixel of the first original image corresponding to this second pixel) is changed.

According to this aspect, the pixel value of a pixel with too high luminance in the relatively bright first original image can be changed based on the pixel value of a corresponding pixel in the relatively dark second original image. Therefore, it is possible to generate a high dynamic range image in which the exposure of too bright parts of the first original image is optimized.

Conversely, in some example aspects, the first original image is a relatively darker image of the two or more original images that are members of the original image group, and the second original image is a relatively darker image of the two or more original images that are members of the original image group. This is a particularly bright image. In this case, the image processing unit 1030 may be configured to execute the first to third processes described above as follows.

First, in the first process, the image processing unit 1030 selects a pixel having a luminance value equal to or less than a preset second threshold from a relatively dark first original image as a first pixel (specific pixel). Identify. This second threshold value may be set so as to be able to identify pixels whose brightness values are too low (pixels that are too dark).

Next, in the second process, the image processing unit 1030 generates a second original image (relatively bright image) corresponding to the first pixel identified from the first original image in the first process. Identify the second pixel.

Then, in the third process, the image processing unit 1030 extracts the pixel 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. The pixel value of the identified first pixel (the pixel of the first original image corresponding to this second pixel) is changed.

According to this aspect, the pixel value of a pixel with too low luminance in the relatively dark first original image can be changed based on the pixel value of the corresponding pixel in the relatively bright second original image. Therefore, it is possible to generate a high dynamic range image in which the exposure of too dark parts of the first original image is optimized.

It is possible to combine the process of optimizing the exposure of too bright parts of the original image with the process of optimizing the exposure of too dark parts. In this aspect, at least three original images are selected from the original image group. Although the following specific example describes a case where three original images are considered, those skilled in the art will understand that similar processing can be performed when four or more original images are considered. Will.

When three original images are selected, they are called a high-brightness original image, a medium-brightness original image, and a low-brightness original image in descending order of brightness. Here, high brightness, medium brightness, and low brightness mean relative brightness levels. In this case, the image processing unit 1030 may be configured to execute the first to third processes described above as follows.

First, in the first process, the image processing unit 1030 extracts pixels (referred to as high-luminance pixels) having a luminance value equal to or higher than a preset first threshold value from a medium-luminance original image, and a preset second pixel. Pixels (referred to as low-luminance pixels) having a luminance value less than or equal to a threshold value are identified.

Next, in the second process, the image processing unit 1030 identifies pixels of the low-brightness original image that correspond to the high-brightness pixels identified from the medium-brightness original image in the first process. Furthermore, the image processing unit 1030 identifies pixels of the high-brightness original image that correspond to the low-brightness pixels identified from the medium-brightness original image in the first process.

Then, in the third process, the image processing unit 1030 processes the high-brightness image specified from the medium-brightness original image in the first process based on the pixel value of the pixel specified from the low-brightness original image in the second process. Change the pixel value of a pixel. Furthermore, the image processing unit 1030 changes the pixel value of the low-brightness pixel identified from the medium-brightness original image in the first process based on the pixel value of the pixel specified from the high-brightness original image in the second process. do.

According to this aspect, the pixel value of a pixel with too high brightness (high brightness pixel) in the medium brightness original image is changed to the pixel value of a corresponding pixel in the low brightness original image, which is relatively dark compared to the medium brightness original image. In addition, the pixel value of a pixel whose brightness is too low in the medium brightness original image (low brightness pixel) is changed based on the pixel value of the corresponding pixel in the high brightness original image, which is relatively bright compared to the medium brightness original image. Therefore, it is possible to generate a high dynamic range image in which the exposure of both too bright and too dark parts of the first original image is optimized. This concludes the description of the first example of high dynamic range image generation.

Next, a second example of high dynamic range image generation will be explained. This example is based on the fact that in an image of the eye, there are certain parts that are depicted brightly and parts that are darkly depicted, that is, one part is always depicted brightly and another part is always depicted darkly. It focuses on the fact that For example, in an image of the anterior segment of the eye, the cornea (particularly the corneal vertex and its vicinity) is depicted brightly, and the crystalline lens is depicted darkly. Furthermore, in an image of the fundus, the optic disc is depicted brightly, and the macula is depicted darkly.

Although the following specific example describes a case where two original images are considered, those skilled in the art will understand that similar processing can be performed when three or more original images are considered. Will.

Consider two original images (a first original image and a second original image) included in the original image group. As mentioned above, the first original image and the second original image depict substantially the same position of the eye to be examined, and the brightness of the first original image and the brightness of the second original image are different. Sato are different from each other.

First, the image processing unit 1030 identifies an image area (first image area) corresponding to a predetermined part of the eye to be examined from the first original image. Furthermore, the image processing unit 1030 identifies an image area (second image area) corresponding to the same part from the second original image. Furthermore, the image processing unit 1030 changes the pixel value of the first image area in the first original image based on the pixel value of the second image area in the second original image.

A specific example will be explained. When each original image included in the original image group is an anterior segment image, the image processing unit 1030 extracts an image region corresponding to the cornea of the eye to be examined from each of the first original image and the second original image. Identify. The image area identified from the first original image is referred to as a first corneal area, and the image area identified from the second original image is referred to as a second corneal area.

Here, it is assumed that the first original image is a relatively bright image, and the second original image is a relatively dark image.

The image processing unit 1030 changes the pixel value of the first corneal region in the first original image based on the pixel value of the second corneal region in the second original image.

According to this specific example, the pixel values of pixels included in the first corneal region that is particularly brightly depicted in the relatively bright first original image are changed to Since the change can be made based on the pixel values of pixels included in the corneal region, it is possible to generate a high dynamic range image in which the exposure of the first corneal region in the first original image is optimized.

Another specific example will be explained. When each original image included in the original image group is an anterior segment image, the image processing unit 1030 extracts an image area corresponding to the crystalline lens of the eye to be examined from each of the first original image and the second original image. Identify. The image area specified from the first original image is called a first lens area, and the image area specified from the second original image is called a second lens area.

Here, it is assumed that the first original image in this specific example is a relatively dark image, and the second original image is a relatively bright image.

The image processing unit 1030 changes the pixel value of the first lens region in the first original image based on the pixel value of the second lens region in the second original image.

According to this specific example, the pixel values of pixels included in the first crystalline lens region that is particularly darkly depicted in the relatively dark first original image are changed to Since it can be changed based on the pixel value of the pixel included in the crystalline lens region, 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 description of the second example of high dynamic range image generation.

Next, a third example of high dynamic range image generation will be explained. The image processing unit 1030 in this example 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.

In general, tone mapping is used to transform an image's pixel value distribution into new pixels in order to output an image with a certain dynamic range on media with a narrower dynamic range (e.g., to display it on a display device, print it on paper, etc.). This is a technology that converts it into a value distribution.

The image processing unit 1030 of this example scales the luminance distribution of each of a plurality of images of different brightness acquired under a plurality of different photographing conditions, so that the image can be expressed on an output device (for example, a display device, a printing device, etc.). It is configured to fit a possible brightness distribution. As a result, an apparent (expressive) high dynamic range image is generated. This concludes the description of the third example of high dynamic range image generation.

The method of high dynamic range image generation is not limited to what has been described above. Some example aspects may be configured to utilize machine learning models to perform high dynamic range image generation. This machine learning model uses, for example, a neural network (e.g., Convolutional neural networks). This machine learning model functions to receive input of two or more eye images and output a high dynamic range image.

In another example, the machine learning model includes applying training data containing multiple pairs of a single eye image and high dynamic range images generated from the eye image to a neural network (e.g., a convolutional neural network). may be constructed by This machine learning model functions to receive an input of one eye image and output a high dynamic range image.

FIG. 2 shows an example of the operation of the ophthalmologic apparatus 1000.

First, the ophthalmological apparatus 1000 controls the imaging unit 1010 by the control unit 1020 to apply two or more imagings under different imaging conditions to the subject's eye (S1). As a result, an original image group consisting of two or more Scheimpflug images each corresponding to two or more imaging conditions is obtained.

Furthermore, the ophthalmological apparatus 1000 causes the image processing unit 1030 to generate a high dynamic range image having a dynamic range expanded from the dynamic range of the original image based on the original image group acquired in step S1 (S2). .

The ophthalmologic apparatus 1000 outputs the high dynamic range image generated in step S2. For example, the ophthalmological apparatus 1000 can provide a high dynamic range image to a display device, transmit it to another computer, save it to a storage device, record it to a recording medium, and provide it to a printing device. It may be configured to execute output processing for any one of them.

The image generated by such an ophthalmological apparatus 1000 has the unique advantage of having both high definition over a wide range as a Scheimpflug image and appropriate overall brightness as a high dynamic range image. The image has a high quality. This concludes the description of the ophthalmologic apparatus 1000 according to this aspect.

FIG. 3 shows the configuration of an ophthalmologic apparatus according to one aspect of the embodiment. Similar to the ophthalmologic apparatus 1000 described above, the ophthalmologic apparatus 1100 of this example includes an imaging section 1010, a control section 1020, and an image processing section 1030, and the imaging section 1010 further includes an optical system 1011. .

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 to be examined. The illumination optical system 1012 operates under the control of a control unit 1020 based on preset illumination conditions.

Similar to the control unit 1020 of the ophthalmological apparatus 1000 described above, the control unit 1020 of this embodiment controls the imaging unit 1010 so as to apply two or more imagings under different imaging conditions to the subject's eye. The photographing conditions of this embodiment include at least conditions regarding the illumination optical system 1012 (illumination conditions). Therefore, the control unit 1020 of this embodiment controls the imaging unit 1010 (at least the illumination optical system 1012) so that at least two or more imaging operations with different illumination conditions are applied to the subject's eye.

FIG. 4 shows an example of the operation of the ophthalmological apparatus 1100.

First, the ophthalmologic apparatus 1100 controls the imaging unit 1010 using the control unit 1020 to perform at least two imaging operations on the subject's eye under different illumination conditions (S11). As a result, an original image group consisting of two or more Scheimpflug images each corresponding to two or more photographing conditions (including at least two or more illumination conditions) is obtained.

Furthermore, the ophthalmological apparatus 1100 uses the image processing unit 1030 to generate a high dynamic range image having a dynamic range expanded from the dynamic range of the original image based on the original image group acquired in step S11 (S12). . The image generated in step S12 has both a wide range of high definition as a Scheimpflug image and appropriate overall brightness as a high dynamic range image.

In some example aspects, the illumination conditions may include illumination intensity conditions that define the intensity of 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) so that at least two or more imaging operations with different illumination intensity conditions are applied to the subject's eye. Matters related to illumination intensity conditions (types of illumination intensity conditions, configuration for changing illumination intensity conditions, etc.) have been described above. Exemplary ways in which illumination intensity conditions are used are discussed below.

In some example aspects, the illumination conditions may include illumination time conditions that define the projection time of 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) so that at least two or more imagings with different illumination time conditions are applied to the subject's eye. Matters related to the illumination time conditions (types of illumination time conditions, configuration for changing the illumination time conditions, etc.) have been described above. Exemplary ways in which illumination time conditions are used are discussed below. This concludes the description of the ophthalmologic apparatus 1100 according to this aspect.

FIG. 5 shows the configuration of an ophthalmological apparatus according to one aspect of the embodiment. This aspect is an example of an aspect in which illumination intensity conditions are used. Similar to the ophthalmologic apparatus 1100 described above, the ophthalmologic apparatus 1200 of this example includes an imaging section 1010, a control section 1020, and an image processing section 1030, the imaging section 1010 includes an optical system 1011, and the optical system 1011 is an illumination optical system. Contains 1012.

The photographing unit 1010 of this embodiment includes a moving mechanism 1019. The moving mechanism 1019 is configured to move the optical system 1011. Note that the moving mechanism 1019 may include a mechanism having the same function as moving the optical system 1011 (same effect as moving the optical system 1011). Examples of such a mechanism include a mechanism (illumination scanner, movable illumination mirror) that moves the illumination position by deflecting illumination light (slit light), and a mechanism that moves the illumination position by deflecting illumination light (slit light); There are mechanisms (imaging scanners, movable imaging mirrors) that move the imaging position by deflecting the image.

Similar to the control unit 1020 of the ophthalmological apparatus 1000 described above, the control unit 1020 of this embodiment controls the imaging unit 1010 so as to apply two or more imagings under different imaging conditions to the subject's eye. The photographing conditions of this aspect include at least illumination conditions, and further, the illumination conditions of this aspect 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) so that at least two or more imaging operations with different illumination intensity conditions are applied to the eye to be examined.

The illumination intensity conditions of this aspect include two or more conditions. That is, the illumination intensity conditions of this aspect include two or more conditions corresponding to a plurality of different illumination intensities. As a specific example of two or more conditions included in the illumination intensity conditions, in the control mode shown in FIGS. 7A and 7B, which will be described later, there is a condition (circle 1) that indicates a relatively high intensity, and a condition that indicates a relatively low intensity. condition (mark 2) is provided.

The control unit 1020 of this embodiment controls the illumination optical system 1012 to cyclically apply two or more conditions included in the illumination intensity conditions (referred to as illumination control), and moves the optical system 1011. By combining the control of the mechanism 1019 (referred to as movement control), the photographing unit 1010 is caused to repeatedly acquire an image group consisting of two or more images each corresponding to two or more conditions included in the illumination intensity condition. It is configured. That is, the control unit 1020 is configured to acquire a plurality of image groups by executing illumination control and movement control, and each of the plurality of image groups is configured to acquire two or more image groups included in the illumination intensity condition. It includes two or more images each corresponding to a condition.

Lighting control will be explained. Let K conditions included in the illumination intensity conditions be a first condition, a second condition, . . . , and a K-th condition. Here, K is an integer of 2 or more. It is assumed that 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 application. Illumination control is control for causing the illumination optical system 1012 to repeatedly apply this series of conditions.

As a specific example of lighting control, in the control mode shown in FIGS. 7A and 7B, which will be described later, a series of conditions showing relatively high intensity (mark 1) and conditions showing relatively low intensity (mark 2) is used. The application of the conditions is repeated. Note that illumination control (cyclic application) when two conditions are included in the illumination intensity condition is alternate application of these two conditions.

The application mode of the first to Kth conditions is not limited to cyclic application, and the first to Kth conditions may be applied repeatedly while changing the order. Furthermore, in the iterative application of the first to Kth conditions, it is not necessary to apply all of the K conditions in each iteration.

Movement control will be explained. Movement control is control for changing the position of the eye to be imaged by the optical system 1011. The movement control allows the imaging unit 1010 to acquire images at multiple positions of the eye to be examined. Furthermore, the movement control moves the optical system 1011 while maintaining the state in which the optical system 1011 satisfies Scheimpflug conditions. This makes it possible to collect multiple images that are in focus over a wide range.

In this manner, in this embodiment, the imaging unit 1010 scans the eye to be examined (photographing multiple positions) and collects multiple Scheimpflug images under illumination control and movement control by the control unit 1020. In other words, the imaging unit 1010 of this embodiment captures a series of shine images by changing the scanning position (the illumination light projection position and the imaging position) according to the movement control while cyclically changing the illumination intensity condition according to the illumination control. Collect proof images.

The image processing unit 1030 of this embodiment can generate a plurality of high dynamic range images based on a plurality of image groups acquired by a combination of illumination control and movement control. As described above, it is assumed that the number of conditions included in the illumination intensity condition is K (K is an integer of 2 or more). Each condition included in the illumination intensity condition is expressed as C(k) (k=1, 2, . . . , K). Further, 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).

In this embodiment, K images are obtained at each scan position P(l). An image corresponding to the scan position P(l) and the k-th condition C(k) is represented by G(P(l), C(k)). Also, K images G(P(l), C(1)), G(P(l), C(2)), . . . , G(P(l)) corresponding to the scan position P(l) are ), C(K)) are called a first condition image, a second condition image, . . . , a K-th condition image, respectively.

The image processing unit 1030, based on the K condition images G(P(l), C(1)) to G(P(l), C(K)) corresponding to each scan position P(l), A high dynamic range image H(P(l)) at the scan position P(l) is generated. As a result, L high dynamic range images H(P(1)) to H(P(L)) corresponding to L scan positions P(1) to P(L) are obtained.

The image processing unit 1030 generates a high dynamic range image representing the volume (three-dimensional region) of the eye to be examined based on the L high dynamic range images H(P(1)) to H(P(L)). can do.

An example of the operation of the ophthalmologic apparatus 1200 is shown in FIG.

First, the imaging unit 1010 of the ophthalmological apparatus 1200 starts scanning the subject's eye under illumination control and movement control by the control unit 1020 (S21). In scanning the eye to be examined, first, imaging is performed under K illumination intensity conditions (first to Kth conditions) at a first scan position P(1) (S22). As a result, the first to Kth condition images G(P(1), C(1)) to G(P(1), C(K)) corresponding to the first scan position P(1) are obtained. It will be done. The ophthalmological apparatus 1200 corresponds to the first to Kth condition images G(P(1), C(1)) to G(P(1), C(K)) to the first scan position P(1). and save it (S23). For example, the storage process of the condition image is executed by the control unit 1020, and the storage destination of the condition image is the storage device (described above) within the control unit 1020.

Steps S22 and S23 are repeatedly executed until the scan is completed (S24). If the scan has not been completed (S24: No), the movement control moves to photographing at the next scan position (S25). When the scan is completed, the process moves to step S26 (S24: Yes).

As a result, steps S22 and S23 are executed at each of L scan positions P(1) to P(L), and K condition images G(P(l), C(1)) to G(P(l), C(K)) are obtained and stored.

The image processing unit 1030, based on the K condition images G(P(l), C(1)) to G(P(l), C(K)) corresponding to each scan position P(l), A high dynamic range image H(P(l)) at the scan position P(l) is generated (S26). As a result, L high dynamic range images H(P(1)) to H(P(L)) corresponding to L scan positions P(1) to P(L) are obtained.

Each image generated in step S26 has both high definition over a wide range as a Scheimpflug image and appropriate overall brightness as a high dynamic range image. Furthermore, in this aspect, such high-quality images can be acquired at multiple positions of the eye to be examined.

In some exemplary embodiments, in addition to being able to obtain such high quality images over a three-dimensional region of the subject's eye, a high dynamic range image is generated that represents the volume (three-dimensional region) of the subject's eye. It is also possible to do so.

Two examples of scanning with illumination control and movement control are shown in FIGS. 7A and 7B. FIG. 7C also shows a conventional scan for comparison with these examples.

The conventional scan shown in FIG. 7C consists of light emission from a light source (output of illumination light, projection of illumination light onto the subject's eye), exposure (photographing) of a camera, and scan position (position of optical system 1011 being moved). This is achieved through cooperative control (synchronous control).

More specifically, this conventional scanning involves continuous emission of illumination light, repeated photographing (exposure) by a camera, and continuous movement of the optical system 1011 from the scan start position to the scan end position. It is a combination of Repetitive camera exposure is achieved by alternating exposure and charge transfer (and exposure standby).

On the other hand, in the scan of this embodiment shown in FIG. 7A, the exposure of the camera and the movement of the scanning position are performed in the same manner as the conventional scan shown in FIG. 7C, but the illumination light from the light source is continuously emitted. Unlike the conventional scan shown in FIG. 7C in which light is emitted, illumination light is output intermittently (pulse light emission).

Furthermore, in the scan of this embodiment shown in FIG. 7A, switching control of illumination intensity conditions is performed, which is not performed in the conventional scan shown in FIG. 7C. Here, the illumination intensity conditions "circle 1" and "circle 2" correspond to the aforementioned conditions C(1) and C(2), respectively. That is, in the example of FIG. 7A, the illumination intensity condition includes two conditions C(1) and C(2), and these two conditions C(1) and C(2) are cyclically (that is, alternately) ) is applied. Note that condition C(1) is an illumination intensity condition that exhibits relatively high intensity, and condition C(2) is an illumination intensity condition that exhibits relatively low intensity.

In the scan of FIG. 7A, the illumination light emission (projection) sequence (multiple times of light emission arranged in chronological order) and the exposure sequence of the camera (multiple exposures arranged in chronological order) are synchronized with each other. . The period of each light emission in the sequence of illumination light corresponds to a projection period, and its length corresponds to a projection time.

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

In the scan of FIG. 7A, 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 length of the projection period (projection time) is shorter than the length of the exposure period (exposure time), and a part of this exposure period and this projection period overlaps with the whole.

As a result, in each exposure period in the exposure sequence, exposure (light reception by the image sensor, charge accumulation) is actually performed only during a projection period shorter than that exposure period, so movement of the scan position during exposure and eye movement Image blur caused by ophthalmological imaging can be reduced compared to conventional ophthalmic imaging techniques. Therefore, it becomes possible to provide images of higher quality than conventional ophthalmological imaging techniques.

Furthermore, it becomes possible to perform image analysis (for example, corneal detection, cell detection, etc.) with higher quality than conventional ophthalmological image analysis techniques. Moreover, since the time during which the illumination light is projected onto the eye to be examined can be shortened, the burden on the examinee can be reduced compared to the case where the illumination light is continuously projected as shown in FIG. 7C. becomes possible.

In addition, in the scan of FIG. 7A, the optical system 1011 is continuously moved from the scan start position to the scan end position, and the optical system 1011 does not repeatedly start and stop suddenly, so vibrations caused by this do not occur during the scan. This will not occur during the process, and will not adversely affect the quality of the image.

On the other hand, another scan of this embodiment shown in FIG. 7B is the same as the scan in FIG. 7A except that the optical system 1011 is intermittently moved from the scan start position to the scan end position. Therefore, according to the scan of FIG. 7B, the same effect as the scan of FIG. 7A can be obtained except for the problem of vibration caused by the sudden start and stop of the optical system 1011. Note that by devising the structure and mechanism of the ophthalmologic apparatus 1200, the problem of vibration caused by sudden start and stop of the optical system 1011 can be reduced or eliminated.

FIG. 8 shows the configuration of an ophthalmologic apparatus according to one aspect of the embodiment. This aspect is an example of an aspect in which illumination time conditions are used. Similar to the ophthalmologic apparatus 1200 described above, the ophthalmologic apparatus 1300 of this example includes an imaging section 1010, a control section 1020, and an image processing section 1030, and the imaging section 1010 includes an optical system 1011 and a moving mechanism 1019. 1011 includes an illumination optical system 1012.

Similar to the control unit 1020 of the ophthalmological apparatus 1000 described above, the control unit 1020 of this embodiment controls the imaging unit 1010 so as to apply two or more imagings under different imaging conditions to the subject's eye. The photographing conditions of this aspect include at least illumination conditions, and further, the illumination conditions of this aspect include at least illumination time conditions. Therefore, the control unit 1020 of this embodiment controls the imaging unit 1010 (at least the illumination optical system 1012) so that at least two or more imagings with different illumination time conditions are applied to the eye to be examined.

The illumination time conditions of this aspect include two or more conditions. That is, the illumination time conditions of this aspect include two or more conditions corresponding to a plurality of different illumination times. As a specific example of two or more conditions included in the illumination time condition, in the control mode shown in FIGS. 10A and 10B described later, a condition indicating a relatively short illumination time (mark 1) and a relatively long illumination time A condition (circle 2) indicating that is provided.

The control unit 1020 of this embodiment controls the illumination optical system 1012 to cyclically apply two or more conditions included in the illumination time condition (referred to as illumination control), and controls the illumination optical system 1012 to move the optical system 1011. By combining the control of the mechanism 1019 (referred to as movement control), the photographing unit 1010 is caused to repeatedly acquire an image group consisting of two or more images each corresponding to two or more conditions included in the illumination time condition. It is configured.

That is, the control unit 1020 is configured to acquire a plurality of image groups by executing illumination control and movement control, and each of the plurality of image groups is configured to acquire two or more image groups included in the illumination time condition. It includes two or more images each corresponding to a condition.

Lighting control will be explained. Let M conditions included in the illumination time conditions be a first condition, a second condition, . . . , and an M-th condition. Here, M is an integer of 2 or more. It is assumed that 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 application. Illumination control is control for causing the illumination optical system 1012 to repeatedly apply this series of conditions.

As a specific example of lighting control, in the control mode shown in FIGS. 10A and 10B, which will be described later, a condition indicating a relatively short illumination time (circle 1) and a condition indicating a relatively long illumination time (circle 2) are selected. A series of conditions are repeatedly applied. Note that illumination control (cyclic application) when two conditions are included in the illumination time condition is alternate application of these two conditions.

The application mode of the first to Mth conditions is not limited to cyclic application, and the first to Mth conditions may be applied repeatedly while changing the order. Furthermore, in the iterative application of the first to Mth conditions, it is not necessary to apply all M conditions in each iteration.

Movement control will be explained. Movement control is control for changing the position of the eye to be imaged by the optical system 1011. The movement control allows the imaging unit 1010 to acquire images at multiple positions of the eye to be examined. Furthermore, the movement control moves the optical system 1011 while maintaining the state in which the optical system 1011 satisfies Scheimpflug conditions. This makes it possible to collect multiple images that are in focus over a wide range.

In this manner, in this embodiment, the imaging unit 1010 scans the eye to be examined (photographing multiple positions) and collects multiple Scheimpflug images under illumination control and movement control by the control unit 1020. In other words, the imaging unit 1010 of this embodiment captures a series of shine images by changing the scanning position (the illumination light projection position and the imaging position) according to the movement control while cyclically changing the illumination time condition according to the illumination control. Collect proof images.

The image processing unit 1030 of this embodiment can generate a plurality of high dynamic range images based on a plurality of image groups acquired by a combination of illumination control and movement control.

As mentioned above, it is assumed that the number of conditions included in the illumination time condition is M (M is an integer of 2 or more). Each condition included in the illumination time condition is expressed as C(m) (m=1, 2, . . . , M). Further, the number of scan positions by movement control is set to N (N is an integer of 2 or more). Each scan position is represented by P(n) (n=1, 2, . . . , N).

In this aspect, M images are obtained at each scan position P(n). An image corresponding to the scan position P(n) and the m-th condition C(m) is represented by G(P(n), C(m)). Furthermore, M images G(P(n), C(1)), G(P(n), C(2)), . . . , G(P(n)) corresponding to the scan position P(n) are ), C(M)) are called a first condition image, a second condition image, . . . , an M-th condition image, respectively.

The image processing unit 1030, based on M condition images G(P(n), C(1)) to G(P(n), C(M)) corresponding to each scan position P(n), A high dynamic range image H(P(n)) at the scan position P(n) is generated. As a result, N high dynamic range images H(P(1)) to H(P(N)) corresponding to N scan positions P(1) to P(N) are obtained.

The image processing unit 1030 generates a high dynamic range image representing the volume (three-dimensional region) of the eye to be examined based on the N high dynamic range images H(P(1)) to H(P(N)). can do.

An example of the operation of the ophthalmologic apparatus 1300 is shown in FIG.

First, the imaging unit 1010 of the ophthalmological apparatus 1300 starts scanning the subject's eye under illumination control and movement control by the control unit 1020 (S31).

In scanning the eye to be examined, first, imaging is performed under M illumination time conditions (first to Mth conditions) at the first scan position P(1) (S32). As a result, the first to Mth condition images G(P(1), C(1)) to G(P(1), C(M)) corresponding to the first scan position P(1) are obtained. It will be done.

The ophthalmological apparatus 1300 corresponds to the first to Mth condition images G(P(1), C(1)) to G(P(1), C(M)) to the first scan position P(1). and save it (S33).

Steps S32 and S33 are repeatedly executed until the scan is completed (S34). If the scan has not been completed (S34: No), the movement control moves to photographing at the next scan position (S35). When the scan is completed, the process moves to step S36 (S34: Yes).

As a result, steps S32 and S33 are executed at each of N scan positions P(1) to P(N), and M condition images G(P(n), C(1)) to G(P(n), C(K)) are obtained and stored.

The image processing unit 1030, based on M condition images G(P(n), C(1)) to G(P(n), C(M)) corresponding to each scan position P(n), A high dynamic range image H(P(n)) at the scan position P(n) is generated (S36). As a result, N high dynamic range images H(P(1)) to H(P(N)) corresponding to N scan positions P(1) to P(N) are obtained.

Each image generated in step S36 has both high definition over a wide range as a Scheimpflug image and appropriate overall brightness as a high dynamic range image. Furthermore, in this aspect, such high-quality images can be acquired at multiple positions of the eye to be examined.

In some exemplary embodiments, in addition to being able to obtain such high quality images over a three-dimensional region of the subject's eye, a high dynamic range image is generated that represents the volume (three-dimensional region) of the subject's eye. It is also possible to do so.

Two examples of scanning using illumination control and movement control in this embodiment are shown in FIGS. 10A and 10B.

In the scan of this embodiment shown in FIG. 10A, the exposure of the camera and the movement of the scan position are performed in the same manner as the conventional scan shown in FIG. 7C, but the light source emits illumination light continuously. Unlike the conventional scan shown in FIG. 7C, illumination light is intermittently output (pulsed light emission).

Furthermore, in the scan of this embodiment shown in FIG. 10A, switching control of illumination time conditions is performed, which is not performed in the conventional scan shown in FIG. 7C. Here, the illumination time conditions "Round 1" and "Round 2" correspond to the aforementioned conditions C(1) and C(2), respectively. That is, in the example of FIG. 10A, the illumination time condition includes two conditions C(1) and C(2), and these two conditions C(1) and C(2) are cyclically (that is, alternately) ) is applied. Note that condition C(1) is an illumination time condition indicating a relatively short time, and condition C(2) is an illumination time condition indicating a relatively long time.

In the scan shown in FIG. 10A, the sequence of illumination light emission (projection) (multiple times of light emission arranged in chronological order) and the sequence of exposure of the camera (multiple exposures arranged in chronological order) are synchronized with each other. . Each light emission period in the illumination light sequence corresponds to a projection period, and its length corresponds to a projection time (illumination time).

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

In the scan of FIG. 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 length of the projection period (projection time, illumination time) is shorter than the length of the exposure period (exposure time), and This entire projection period overlaps. As a result, in each exposure period in the exposure sequence, exposure (light reception by the image sensor, charge accumulation) is actually performed only during a projection period shorter than that exposure period, so movement of the scan position during exposure and eye movement Image blur caused by ophthalmological imaging can be reduced compared to conventional ophthalmic imaging techniques. Therefore, it becomes possible to provide images of higher quality than conventional ophthalmological imaging techniques.

Furthermore, it becomes possible to perform image analysis (for example, corneal detection, cell detection, etc.) with higher quality than conventional ophthalmological image analysis techniques. Moreover, since the time during which the illumination light is projected onto the eye to be examined can be shortened, the burden on the examinee can be reduced compared to the case where the illumination light is continuously projected as shown in FIG. 7C. becomes possible.

In addition, in the scan of FIG. 10A, the optical system 1011 is continuously moved from the scan start position to the scan end position, and the optical system 1011 does not repeatedly start and stop suddenly, so vibrations caused by this do not occur during the scan. This will not occur during the process, and will not adversely affect the quality of the image.

On the other hand, another scan of this embodiment shown in FIG. 10B is the same as the scan in FIG. 10A except that the optical system 1011 is intermittently moved from the scan start position to the scan end position. Therefore, according to the scan of FIG. 10B, the same effect as the scan of FIG. 10A can be obtained except for the problem of vibration caused by the sudden start and stop of the optical system 1011. Note that by devising the structure and mechanism of the ophthalmologic apparatus 1300, it is possible to reduce or eliminate the problem of vibration caused by sudden start and stop of the optical system 1011.

In some example aspects, lighting conditions may include both lighting intensity conditions and lighting time conditions. The ophthalmological apparatus of this aspect is configured to perform two or more imaging operations on the subject's eye while switching the illumination conditions by combining illumination intensity conditions and illumination time conditions. Those skilled in the art will be able to understand the configuration and operation details of the ophthalmologic apparatus of this embodiment from FIGS. 5 to 10B and the above description based on these drawings. The same applies to cases where the illumination conditions include conditions other than these.

In the embodiments shown in FIGS. 5 to 7B and the embodiments shown in FIGS. 8 to 10B, two or more image groups corresponding to two or more conditions are collected in one scan. That is, in the embodiments shown in FIGS. 5 to 7B and the embodiments shown in FIGS. 8 to 10B, two or more conditions are met while the optical system 1011 is moved only once from the scan start position to the scan end position. We have collected two or more image groups corresponding to .

However, the mode of scanning for collecting two or more image groups corresponding to two or more conditions is not limited to this. In the embodiment shown in FIG. 11, which will be described next, two or more scans are performed to collect two or more image groups corresponding to two or more conditions.

Note that the embodiment shown in FIG. 11 adopts the case where the illumination time condition includes two or more conditions, but if the illumination intensity condition includes two or more conditions, two or more illumination conditions of another type are used. The same applies to the case where the condition includes a condition, or the case where two or more types of photographing conditions other than the illumination condition are included.

The aspect shown in FIG. 11 will be explained. The terms and symbols used in the embodiments shown in FIGS. 8 to 10B are applied as appropriate. First, scanning of the eye to be examined is started by illumination control and movement control (S41).

When the scan is started, the scan under the first condition C(1) among the M illumination time conditions (first to Mth conditions) is applied to the eye to be examined (S42). This scan is performed multiple times (N times) while moving the optical system 1011 from the scan start position to the scan end position with the illumination time condition fixed at the first condition C(1). As a result, for the first condition C(1), N images G(P(1), C(1)) to G(P (N), C(1)) are obtained. N images G(P(1), C(1)) to G(P(N), C(1)) corresponding to the first condition C(1) are referred to as a first image group.

When the scan under the first condition C(1) is completed, the next scan under the second condition C(2) is performed in the same manner as step S42 (S43).

Such a scan is performed for each of M conditions C(1) to C(M) (S44). If scanning under a certain condition has not been performed yet (S44: No), the process moves to scanning under the next condition (S45). When scanning under all conditions is completed, the process moves to step S46 (S44: Yes).

As a result, M image groups respectively corresponding to M conditions C(1) to C(M) are obtained. The m-th image group corresponding to the m-th condition C(m) consists of N images G(P(1), C(m )) to G(P(N), C(m)).

When scanning under all conditions is completed (S44: Yes), the image processing unit 1030 performs registration between the first to Mth image groups (S46). This registration aligns M images G(P(n), C1)) to G(P(n), C(M)) corresponding to the same scan position P(n). .

The method used for this registration may be arbitrary. For example, the control contents in each scan (movement control contents, lighting control contents, imaging control contents, etc.), the It may include images, known registration methods, and the like.

In some exemplary aspects, M volume data (three-dimensional images) are generated from M image groups corresponding to M conditions C(1) to C(M), and these M volumes are Registration (three-dimensional registration) between the data may be executed, and the results of this three-dimensional registration may be used to align the M image groups.

Through the registration in step S46, the M images G(P(n), C(1)) to G(P(n), C(M)) corresponding to each scan position P(n) are aligned. and are associated with each other. The M images G(P(n), C(1)) to G(P(n), C(M)) obtained in this way correspond to the scan position P(n) described above. This corresponds to M condition images G(P(n), C(1)) to G(P(n), C(M)).

The image processing unit 1030, based on M condition images G(P(n), C(1)) to G(P(n), C(M)) corresponding to each scan position P(n), A high dynamic range image H(P(n)) at the scan position P(n) is generated (S47). As a result, N high dynamic range images H(P(1)) to H(P(N)) corresponding to N scan positions P(1) to P(N) are obtained.

Each image generated in step S47 has both high definition over a wide range as a Scheimpflug image and appropriate overall brightness as a high dynamic range image. Furthermore, in this aspect, such high-quality images can be acquired at multiple positions of the eye to be examined.

In some exemplary embodiments, in addition to being able to obtain such high quality images over a three-dimensional region of the subject's eye, a high dynamic range image is generated that represents the volume (three-dimensional region) of the subject's eye. It is also possible to do so.

FIG. 12 shows the configuration of an ophthalmological apparatus according to one aspect of the embodiment. Like the ophthalmologic apparatus 1000, the ophthalmologic apparatus 1400 of this example includes an imaging section 1010, a control section 1020, and an image processing section 1030, and the imaging section 1010 further includes an optical system 1011.

The optical system 1011 of this embodiment includes an illumination optical system 1012 like the ophthalmological apparatus 1200 described above, and further includes a photographing optical system 1013. The photographing optical system 1013 is configured to photograph the subject's eye onto which illumination light is projected by the illumination optical system 1012. The photographing optical system 1013 operates under the control of a control unit 1020 based on preset exposure conditions.

Similar to the control unit 1020 of the ophthalmological apparatus 1000, the control unit 1020 of this embodiment controls the imaging unit 1010 so as to apply two or more imagings under different imaging conditions to the eye to be examined. The photographing conditions of this aspect include at least conditions regarding the photographing optical system 1013 (exposure conditions). Therefore, the control unit 1020 of this embodiment controls the imaging unit 1010 (at least the imaging optical system 1013) so that at least two or more imaging operations with different exposure conditions are applied to the subject's eye.

FIG. 13 shows an example of the operation of the ophthalmologic apparatus 1400.

First, the ophthalmologic apparatus 1400 controls the imaging unit 1010 using the control unit 1020 to apply at least two imaging operations to the subject's eye with different exposure conditions (S51). As a result, an original image group consisting of two or more Scheimpflug images each corresponding to two or more photographing conditions (including at least two or more exposure conditions) is obtained.

Further, the ophthalmological apparatus 1400 causes the image processing unit 1030 to generate a high dynamic range image having a dynamic range expanded from the dynamic range of the original image based on the original image group acquired in step S51 (S52). . The image generated in step S52 has both high definition over a wide range as a Scheimpflug image and appropriate overall brightness as a high dynamic range image.

In some exemplary aspects, the exposure conditions may include exposure time conditions that define 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) so that at least two or more imagings with different exposure time conditions are applied to the eye to be examined. Matters related to the exposure time conditions (types of exposure time conditions, configuration for changing the exposure time conditions, etc.) have been described above. Exemplary ways in which exposure time conditions are used are discussed below. This concludes the description of the ophthalmologic apparatus 1400 according to this aspect.

FIG. 14 shows the configuration of an ophthalmological apparatus according to one aspect of the embodiment. This embodiment is an example of an embodiment in which exposure time conditions are used. Similar to the ophthalmologic apparatus 1400 described above, the ophthalmologic apparatus 1500 of this example includes an imaging section 1010, a control section 1020, and an image processing section 1030, and the imaging section 1010 includes an optical system 1011 and a moving mechanism 1019. 1011 includes an illumination optical system 1012 and a photographing optical system 1013. In addition, the photographing optical system 1013 of this example includes an image sensor 1014 and an optical system (not shown) that guides light from the eye to the image sensor 1014.

The illumination optical system 1012 and the photographing optical system 1013 are configured to satisfy Scheimpflug conditions and function as a Scheimpflug camera. More specifically, a plane passing through the optical axis of the illumination optical system 1012 (a plane including the object plane), the principal plane of the photographing optical system 1013, and the imaging plane of the image sensor 1014 intersect on the same straight line. The illumination optical system 1012 and the photographing optical system 1013 are configured to do so.

By using the illumination optical system 1012 and the photographing optical system 1013 that satisfy the Scheimpflug condition, the photographing optical system 1013 can be positioned at all positions in the object plane (all positions in the direction along the optical axis of the illumination optical system 1012). You can take pictures with the camera in focus.

The exposure time conditions of this aspect include two or more conditions. That is, the exposure time conditions of this aspect include two or more conditions corresponding to a plurality of different exposure times. As a specific example of two or more conditions included in the exposure time condition, in the control mode shown in FIG. 16, which will be described later, there are a condition indicating a relatively long exposure time (marked 1) and a condition indicating a relatively short exposure time. (Circle 2) is provided.

The control unit 1020 of this aspect controls the photographing optical system 1013 to cyclically apply two or more conditions included in the exposure time condition (referred to as exposure control), and moves the optical system 1011 to move the optical system 1011. By combining the control of the mechanism 1019 (referred to as movement control), the photographing unit 1010 is caused to repeatedly acquire an image group consisting of two or more images each corresponding to two or more conditions included in the exposure time condition. It is configured.

That is, the control unit 1020 is configured to acquire a plurality of image groups by executing exposure control and movement control, and each of the plurality of image groups is configured to acquire two or more image groups included in the exposure time condition. It includes two or more images each corresponding to a condition.

Exposure control will be explained. Let Q conditions included in the exposure time conditions be a first condition, a second condition, . . . , and a Q-th condition. Here, Q is an integer of 2 or more. It is assumed that 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 application. Exposure control is control for causing the photographing optical system 1013 to repeatedly apply this series of conditions.

As a specific example of exposure control, in the control mode shown in FIG. 106, which will be described later, a series of conditions including a condition indicating a relatively long exposure time (mark 1) and a condition indicating a relatively short exposure time (mark 2) are used. Condition application is being executed repeatedly. Note that exposure control (cyclic application) when two conditions are included in the exposure time condition is alternate application of these two conditions.

The application mode of the first to Qth conditions is not limited to cyclic application, and the first to Qth conditions may be applied repeatedly while changing the order. Furthermore, in the iterative application of the first to Q-th conditions, it is not necessary to apply all of the Q conditions in each iteration.

Movement control will be explained. Movement control is control for changing the position of the eye to be imaged by the optical system 1011. The movement control allows the imaging unit 1010 to acquire images at multiple positions of the eye to be examined. Furthermore, the movement control moves the optical system 1011 while maintaining the state in which the optical system 1011 satisfies Scheimpflug conditions. This makes it possible to collect multiple images that are in focus over a wide range.

In this manner, under the exposure control and movement control by the control section 1020, the imaging section 1010 scans the eye to be examined (photographing at a plurality of positions) and collects a plurality of Scheimpflug images.

In other words, the imaging unit 1010 of this embodiment captures a series of shine images by changing the scan position (illumination light projection position and photographing position) according to the movement control while cyclically changing the exposure time condition according to the exposure control. Collect proof images.

The image processing unit 1030 of this embodiment can generate a plurality of high dynamic range images based on a plurality of image groups acquired by a combination of exposure control and movement control.

As mentioned above, it is assumed that the number of conditions included in the exposure time condition is Q (Q is an integer of 2 or more). Each condition included in the exposure time condition is represented by C(q) (q=1, 2, . . . , Q). Further, the number of scan positions by movement control is assumed to be R (R is an integer of 2 or more). Each scan position is represented by P(r) (r=1, 2, . . . , R).

In this embodiment, Q images are obtained at each scan position P(r). An image corresponding to the scan position P(r) and the q-th condition C(q) is represented by G(P(r), C(q)). Also, Q images G(P(r), C(1)), G(P(r), C(2)), . . . , G(P(r)) corresponding to the scan position P(r) are ), C(Q)) are called a first condition image, a second condition image, . . . , a Q-th condition image, respectively.

The image processing unit 1030, based on the Q condition images G(P(r), C(1)) to G(P(r), C(Q)) corresponding to each scan position P(r), A high dynamic range image H(P(r)) at the scan position P(r) is generated. As a result, R high dynamic range images H(P(1)) to H(P(R)) corresponding to R scan positions P(1) to P(R), respectively, are obtained.

The image processing unit 1030 generates a high dynamic range image representing the volume (three-dimensional region) of the eye to be examined based on the R high dynamic range images H(P(1)) to H(P(R)). can do.

An example of the operation of the ophthalmologic apparatus 1500 is shown in FIG.

First, the imaging unit 1010 of the ophthalmological apparatus 1500 starts scanning the subject's eye under exposure control and movement control by the control unit 1020 (S61).

In scanning the eye to be examined, first, imaging is performed under Q exposure time conditions (first to Q-th conditions) at the first scan position P(1) (S62). As a result, the first to Qth condition images G(P(1), C(1)) to G(P(1), C(Q)) corresponding to the first scan position P(1) are obtained. It will be done.

The ophthalmological apparatus 1500 corresponds to the first to Qth condition images G(P(1), C(1)) to G(P(1), C(Q)) to the first scan position P(1). and save it (S63).

Steps S62 and S63 are repeatedly executed until the scan is completed (S64). If the scan has not been completed (S64: No), the movement control moves to photographing at the next scan position (S65). When the scan is completed, the process moves to step S66 (S64: Yes).

As a result, steps S62 and S63 are executed at each of R scan positions P(1) to P(R), and Q condition images G(P(r), C(1)) to G(P(r), C(Q)) are obtained and stored.

The image processing unit 1030, based on the Q condition images G(P(r), C(1)) to G(P(r), C(Q)) corresponding to each scan position P(r), A high dynamic range image H(P(r)) at the scan position P(r) is generated (S66). As a result, R high dynamic range images H(P(1)) to H(P(R)) corresponding to R scan positions P(1) to P(R), respectively, are obtained.

Each image generated in step S66 has both high definition over a wide range as a Scheimpflug image and appropriate overall brightness as a high dynamic range image. Furthermore, in this aspect, such high-quality images can be acquired at multiple positions of the eye to be examined.

In some exemplary embodiments, in addition to being able to obtain such high quality images over a three-dimensional region of the subject's eye, a high dynamic range image is generated that represents the volume (three-dimensional region) of the subject's eye. It is also possible to do so.

FIG. 16 shows an example of scanning using illumination control and movement control in this embodiment. In the scan shown in FIG. 16, the scanning position is moved in the same manner as the conventional scan shown in FIG. 7C, but the light source outputs illumination light intermittently (pulse light emission). Furthermore, exposure time conditions for camera exposure are controlled to switch.

In this example, the exposure time conditions "Round 1" and "Round 2" correspond to the aforementioned conditions C(1) and C(2), respectively. That is, in the example of FIG. 16, the exposure time condition includes two conditions C(1) and C(2), and these two conditions C(1) and C(2) are cyclically (that is, alternately) ) is applied. Note that condition C(1) is an exposure time condition indicating a relatively long time, and condition C(2) is an exposure time condition indicating a relatively short time.

In this example, the illumination light is output intermittently, but the illumination light may be output continuously. In the case of continuous output, the effects achieved by intermittent output cannot be obtained, but there are advantages such as easy control of the light source and a small load on control processing.

In the scan shown in FIG. 16, the illumination light emission (projection) sequence (multiple times of light emission arranged in chronological order) and the camera exposure sequence (multiple exposures arranged in chronological order) are synchronized with each other. . Each light emission period in the illumination light sequence corresponds to a projection period, and its length corresponds to a projection time (illumination time).

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

In the scan of FIG. 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 length of the projection period (projection time, illumination time) is shorter than the length of the exposure period (exposure time), and This entire projection period overlaps. As a result, in each exposure period in the exposure sequence, exposure (light reception by the image sensor, charge accumulation) is actually performed only during a projection period shorter than that exposure period, so movement of the scan position during exposure and eye movement Image blur caused by ophthalmological imaging can be reduced compared to conventional ophthalmic imaging techniques. Therefore, it becomes possible to provide images of higher quality than conventional ophthalmological imaging techniques.

Furthermore, it becomes possible to perform image analysis (for example, corneal detection, cell detection, etc.) with higher quality than conventional ophthalmological image analysis techniques. Moreover, since the time during which the illumination light is projected onto the subject's eye can be shortened, the burden on the subject can be reduced compared to the case where the illumination light is continuously projected.

In addition, in the scan of FIG. 16, the optical system 1011 is continuously moved from the scan start position to the scan end position, and the optical system 1011 does not repeatedly start and stop suddenly, so vibrations caused by this do not occur during the scan. This will not occur during the process, and will not adversely affect the quality of the image.

In the scan of FIG. 16, the optical system 1011 is continuously moved from the scan start position to the scan end position, but the optical system 1011 may be moved intermittently as shown in FIGS. 7B and 10B described above.

Some example aspects may be capable of both switching illumination conditions and switching exposure conditions, and combining switching two or more illumination conditions and switching two or more exposure conditions. You may apply two or more imaging|photography to an eye to be examined while carrying out the imaging|photography. Those skilled in the art will be able to understand the configuration and operation of such an ophthalmological device from this disclosure.

In the embodiments shown in FIGS. 12 to 16, two or more image groups corresponding to two or more exposure conditions are collected in one scan, but as in the embodiment shown in FIG. Two or more scans may be performed to collect two or more image groups corresponding to the exposure conditions. Those skilled in the art will be able to understand the configuration and operation of such an ophthalmological device from this disclosure.

FIG. 17 shows the configuration of an ophthalmological apparatus according to one aspect of the embodiment. The ophthalmological apparatus 1600 of this embodiment includes an imaging section 1010, a control section 1020, and an image processing section 1030, and the imaging section 1010 includes an optical system 1011 and a moving mechanism 1019.

The optical system 1011 of this embodiment includes an illumination optical system 1012 and a photographing 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 to the first image sensor 1014A, and the eye to be examined. and an optical system (not shown) that guides light from the image sensor 1014B to the second image sensor 1014B.

The illumination optical system 1012 and the photographing optical system 1013 are configured to satisfy Scheimpflug conditions and function as a Scheimpflug camera. More specifically, the plane passing through the optical axis of the illumination optical system 1012 (the plane including the object plane), the main surface of the photographing optical system 1013, and the imaging surface of the first image sensor 1014A are on the same straight line. The plane passing through the optical axis of the illumination optical system 1012 (the plane including the object plane), the main surface of the photographing optical system 1013, and the imaging surface of the second image sensor 1014B are the same. An illumination optical system 1012 and a photographing optical system 1013 are configured to intersect on a straight line. As a result, both the first image sensor 1014A and the second image sensor 1014B focus the photographing optical system 1013 on all positions in the object plane (all positions in the direction along the optical axis of the illumination optical system 1012). You can take pictures with the camera in the correct position.

One example of an ophthalmologic apparatus 1600 according to this embodiment is shown in FIG. The ophthalmological apparatus 1700 of this example includes a first photographing optical system 1013A and a second photographing optical system 1013B as the photographing optical system 1300 of the ophthalmological apparatus 1600.

Although not shown, the first imaging optical system 1013A includes the first imaging device 1014A shown in FIG. 17 and an optical system that guides light from the eye to the first imaging device 1014A. Similarly, the second imaging optical system 1013B includes the second imaging device 1014B shown in FIG. 17 and an optical system that guides light from the subject's eye to the second imaging device 1014B.

An ophthalmological apparatus 1700 shown in FIG. 18 is provided with two mutually independent imaging optical systems 1013A and 1013B. Such embodiments are described below. The number of imaging optical systems provided in the ophthalmologic apparatus may be three or more.

Note that the ophthalmologic apparatus 1600 shown in FIG. 17 has 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 a single imaging optical system is provided with two or more imaging elements. It also includes configurations. Two or more image sensors in a single photographic optical system are arranged in two or more optical paths that are split using, for example, a beam splitter such as a half mirror.

The photographing conditions of this aspect include conditions (synchronization conditions) for performing synchronous control of the operation of the illumination optical system 1012, the operation of the first photographing optical system 1013A, and the operation of the second photographing optical system 1013B. . Examples of this synchronization condition are shown in FIGS. 19A and 19B. FIG. 19B is an enlarged view of a portion of FIG. 19A.

In FIGS. 19A and 19B, camera A corresponds to the first image sensor 1014A of the first photographing optical system 1013A, and camera B corresponds to the second image sensor 1014B of the second photographing optical system 1013B.

The control unit 1020 of this example controls the light emission timing (illumination period) of the illumination optical system 1012 so that the actual exposure time by the first image sensor 1014A and the actual exposure time by the second image sensor 1014B are different from each other. Then, synchronization control is performed between the exposure timing (exposure period) of the first image sensor 1014A and the exposure timing (exposure period) of the second image sensor 1014B. This synchronous control is for realizing two exposure time conditions: the exposure time of the first image sensor 1014A and the exposure time of the second image sensor 1014B.

In the examples 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 image sensor 1014A overlap is It is longer than the length TB of the period (second exposure period) overlapping with the exposure period 1014B.

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.

In this way, the control unit 1020 of the present example is configured such that at least part of the first exposure period by the first image sensor 1014A and at least part of the second exposure period by the second image sensor 1014B overlap. The image capturing unit 1010 is controlled so that the first exposure time TA of the first image sensor 1014A and the second exposure time TB of the second image sensor 1014B are different. It is for controlling. As a result, the control unit 1020 of this example controls the imaging unit 1010 to apply two or more imagings under different imaging conditions to the subject's eye using the two image sensors 1014A and 1014B.

In addition, as shown in FIG. 19A, the scan in this example involves light emission control of a light source for intermittently outputting illumination light (pulse light emission), and two cameras (two image sensors 1014A and 1014B, two imaging devices). This is performed by synchronizing the exposure control of the optical systems 1013A and 1013B).

In this example, as shown in FIG. 19B, the length (illumination time, projection time) of one light emission period (width of one pulse, illumination period, projection period) of the light source is equal to the first exposure time TA. equal. That is, in this example, the possible exposure time of camera A (the length of the upper side of one pulse in the sequence showing the exposure operation of camera A) is set longer than the illumination time TA, and the possible exposure period of camera A ( Since the synchronization conditions are set so that the period indicated by the upper side of one pulse in the sequence indicating the exposure operation of camera A overlaps with the entire illumination period, the actual exposure time of camera A (the period indicated by the upper side of one pulse) overlaps with the entire illumination period. TA) is equal to the illumination time TA.

On the other hand, the possible exposure time of camera B (the length of the upper side of one pulse in the sequence showing the exposure operation of camera B) is set equal to the possible exposure time of camera A, and is longer than the illumination time TA. However, by temporally shifting the exposure period of camera B with respect to the illumination period and the exposure period of camera A, the exposure period of camera B (the upper side of one pulse in the sequence indicating the exposure operation of camera B The synchronization conditions are set such that the period shown in FIG. As a result, the actual exposure time (second exposure time TB) of camera B is approximately half of the illumination time TA, that is, approximately half of the first exposure time TA.

In the examples shown in FIGS. 19A and 19B, the illumination light is output intermittently, but the illumination light may be output continuously. In the case of continuous output, the exposure period is equal to the exposure period, so the exposure period of camera A (first image sensor 1014A, first photographing optical system 1013A) and camera B (second image sensor 1014B, Synchronization conditions are set so that the exposure possible periods of the second photographing optical system 1013B) have different values.

FIG. 20 shows synchronization for performing synchronous control of the operation of the illumination optical system 1012, the operation of the first photographing optical system 1013A, and the operation of the second photographing optical system 1013B in the case of such continuous output. An example of a condition is shown.

In the example shown in FIG. 19A, the example shown in FIG. 19B, and the example shown in FIG. 20, the optical system 1011 is continuously moved from the scan start position to the scan end position. The optical system 1011 may be moved intermittently.

In this manner, the control unit 1020 of this embodiment controls the imaging optical system 1013 (for example, the imaging optical system 1013 (for example, the two imaging optical By combining the control of the systems 1013A and 1013B) and the control of the moving mechanism 1019 for moving the optical system 1011, the photographing unit 1010 is caused to repeatedly acquire an image group consisting of two images corresponding to two photographing conditions. .

Furthermore, the image processing unit 1030 of this embodiment can generate a plurality of high dynamic range images based on a plurality of image groups acquired by the imaging unit 1010 under the control of the control unit 1020.

For example, the image processing unit 1030 may perform processing based on an image group including an image acquired during an exposure period of camera A that overlaps with one illumination period, and an image acquired during an exposure period of camera B that overlaps with the same illumination period. may be configured to generate one high dynamic range image. That is, the image processing unit 1030 of this example is configured to generate a high dynamic range image for each illumination period.

According to this example, since a high dynamic range image can be generated from a group of images acquired simultaneously, there is an advantage that there is no need to perform registration between images included in the image group. Another advantage is that the process of forming a group of images to be provided to generate the same high dynamic range image can be performed very easily.

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

According to this example, since a high dynamic range image can be generated from a group of images acquired substantially simultaneously, there is an advantage that there is no need to perform registration between two images included in the image group. . Another advantage is that processing for forming a group of images to be provided to generate the same high dynamic range image can be easily performed.

The processing executed by the image processing unit 1030 of this embodiment 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.

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

In the case where two or more image sensors are used, settings for photographing conditions other than exposure conditions may be arbitrary. For example, the gains of two or more image sensors may be set equal.

Regarding the process performed by one example of the ophthalmologic apparatus according to the embodiment (for example, any one of the ophthalmologic apparatuses 1000 to 1700, or at least a partial combination of any two or more of the ophthalmologic apparatuses 1000 to 1700) , will be explained with further reference to FIGS. 21 to 23.

In this embodiment, two images are taken under different illumination conditions on the subject's eye, and a high dynamic range image is generated based on the two images thus obtained. Unless otherwise noted, the processing in this example may be the same as any aspect and/or any example of this disclosure.

As shown in the flowchart of FIG. 21, in the process of this example, alignment is first performed (S71). Alignment is positioning of the optical system 1011 with respect to the eye to be examined. Alignment is performed automatically and/or manually. Preparatory operations other than alignment are also performed.

Next, the optical system 1011 is moved to the scan start position (S72). Movement of the optical system 1011 to the scan start position is performed automatically and/or manually.

Once the optical system 1011 is placed at the scan start position, the imaging unit 1010 starts scanning the eye to be examined under the control of the control unit 1020 (S73). The scanning 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 completion of step S72.

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

Further, the control unit 1020 stores the images acquired by the image sensor 1014 in steps S74 to S76 in a storage device (not shown) (S77). This image is a relatively bright image compared to a low-luminance image, which will be described later, that was acquired using the high-output pulsed light in step S75. In this example, this image is called a high-brightness image.

After the 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), and 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 the exposure (S80). The low-power pulsed light is pulsed light with relatively low power compared to the above-mentioned high-power pulsed light.

Further, the control unit 1020 stores the images acquired by the image sensor 1014 in steps S78 to S80 in a storage device (not shown) (S81). This image is a relatively dark image compared to the above-mentioned high-intensity image obtained using the low-power pulsed light in step S79. In this example, this image is called a low-luminance image.

When the series of photographing operations shown in steps S74 to S81 are completed, the control unit 1020 determines whether a pre-specified 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 advances to step S83, and the scan ends (S83).

Note that the parameters for the determination in step S82 are not limited to the number of images, and may be, for example, the number of repetitions of steps S74 to S81, the elapsed time of repetition of steps S74 to S81, the moving distance of the optical system 1011, and the like.

In this way, the control unit 1020 repeatedly executes steps S74 to S82 until the specified number of images are acquired. Let the total number of repetitions of steps S74 to S82 be "U". FIG. 22A represents the operations at the u-th iteration and the u+1-th iteration. Here, u is an integer greater than or equal to 1 and less than or equal to U-1.

At scan position P(u) corresponding to the u-th repetition, 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 Two exposures W(u, H) and W(u, L) are performed.

Here, the period of exposure W (u, H) corresponds to the projection period of high-power pulsed light V (u, H), and the period of exposure W (u, L) corresponds to the projection period of low-power pulsed light V (u, L). It corresponds to the projection period of The image G (u, H) acquired by the image sensor 1014 through exposure W (u, H) is a high brightness image, and the image G (u, L) acquired through exposure W (u, L) is a low brightness image. be.

The same applies to the operation at the scan position P(u+1) corresponding to the u+1th repetition and the image group obtained thereby. As a result, U image groups (pairs of high-brightness images and low-brightness images) are collected.

FIG. 22B depicts another example of scanning. In this example, a single pulsed light V(u) is output at the scan position P(u) corresponding to the u-th repetition, and two exposures (first exposure and second exposure) are performed. is executed.

Only a part of the first exposure period (for example, only half of the first exposure period) overlaps with the projection period of the pulsed light V(u), and the entire second exposure period overlaps with the projection period of the pulsed light V(u). This overlaps with the projection period of pulsed light V(u). The overlapping period between the first exposure period and the pulsed light V(u) projection period 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 pulsed light V(u) projection period is the actual exposure W(u, H) in the second exposure.

In this example, a low brightness image G (u, L) is acquired by the first exposure W (u, L), and a high brightness image G (u, H) is acquired by the second exposure W (u, H). is obtained. The same applies to the operation at the scan position P(u+1) corresponding to the u+1th repetition and the image group obtained thereby. As a result, U image groups (pairs of high-brightness images and low-brightness images) are collected.

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

One specific example of step S84 will be explained. The image processing unit 1030 identifies pixels having a luminance value equal to or higher than a predetermined threshold (exceeding luminance pixels) from the high luminance image G(u, H), and generates a low luminance image G(u, H) corresponding to the identified excess luminance pixel. , L) (corresponding pixel), and replace the pixel value of the over-luminance pixel with a pixel value based on the pixel value of the corresponding pixel.

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 over-luminance pixel with the value of the product. The value by which the pixel value of the corresponding pixel is multiplied is a preset default value, a value determined based on the pair of high brightness image G (u, H) and low brightness image G (u, L), or , may be a value determined by other methods.

An example of step S84 is shown in FIG. The excess brightness area g(u,H) of the high brightness image G(u,H) is an image area made up of excessive brightness pixels. Furthermore, the area g(u,L) of the low-brightness image G(u,L) is an image area (corresponding area) corresponding to the excess brightness area g(u,H) of the high-brightness image G(u,H). be.

According to the process described in the above specific example, the brightness of the excess brightness area g(u, H) of the high brightness image G(u, H) is changed to the corresponding area g(u, , L). As a result, an image (high dynamic range image) H(u) is obtained. A region h(u) of the high dynamic range image H(u) indicates an image region whose brightness has been optimized.

Note that although the example in FIG. 23 describes optimization of the brightness of the corneal region, optimization of the brightness of image regions of other parts is performed in the same manner.

Through such step S84, a high dynamic range image is obtained in which various parts of the eye to be examined (corneal epithelium, corneal endothelium, anterior surface of the crystalline lens, posterior surface of the crystalline lens, etc.) are expressed in equal tones. Furthermore, a high dynamic range image representing a three-dimensional region (scanned region) of the eye to be examined is obtained.

Next, the ophthalmological apparatus 1000 (for example, the image processing unit 1030) generates an image with luminance and tristimulus values compatible with the output device by applying gamma correction to the high dynamic range image generated in step S84. (S85).

Then, the ophthalmologic apparatus 1000 provides the image generated by the gamma correction in step S85 to a predetermined output device. For example, the ophthalmologic apparatus 1000 displays the image generated by performing gamma correction in step S85 on a display device (not shown) (S86). Further, the ophthalmologic apparatus 1000 stores one or more of the various images generated in this example in a storage device (not shown) (S86). This concludes the explanation of the processing executed in this embodiment.

Regarding the process performed by one example of the ophthalmologic apparatus according to the embodiment (for example, any one of the ophthalmologic apparatuses 1000 to 1700, or at least a partial combination of any two or more of the ophthalmologic apparatuses 1000 to 1700) , will be explained with further reference to FIGS. 24A to 25.

In this embodiment, two images are taken using two imaging devices on the subject's eye, and a high dynamic range image is generated based on the two images thus obtained.

Unless otherwise noted, the processing in some steps of this embodiment is the same or similar to the processing described in any aspect of this disclosure and/or any embodiment of this disclosure. May be executed.

As shown in the flowcharts of FIGS. 24A and 24B, in the process of this example, alignment is first performed (S91), the optical system 1011 is moved to the scan start position (S92), and scanning of the subject's eye is started ( S93). The scanning in this step is performed by a combination of illumination control, exposure control, and movement control.

See FIG. 25. Upon starting 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 controls the second image sensor 1014B. Then, exposure is started (S96).

Further, 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), and controls the first image sensor 1014A. The exposure is ended (S99), and the image (first image) acquired by the first image sensor 1014A during the exposure period of steps S94 to S99 is stored in a storage device (not shown) (S100).

The first image acquired in step S100 is relatively high-intensity image, which will be described later, acquired in a relatively short exposure period compared to the exposure period of the second image sensor 1014B, which will be described later. This is a dark image. In this example, this first image is called a low-luminance image.

Further, 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 outputting the pulsed light (S102), and controls the second image sensor 1014B. The exposure is ended (S103), and the image (second image) acquired by the second image sensor 1014B during the exposure period of steps S96 to S103 is stored in a storage device (not shown) (S104).

The second image acquired in step S104 is relatively relatively long compared to the above-mentioned low-luminance image, which was acquired in a relatively long exposure period compared to the exposure period of the first image sensor 1014A. This is a bright image. In this example, this second image is called a high-brightness image.

When the series of photographing operations shown in steps S94 to S104 are completed, the control unit 1020 determines whether a pre-specified 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 advances to step S106, and the scan ends (S106).

Note that the parameters for the determination in step S105 are not limited to the number of images, and may be, for example, the number of repetitions of steps S94 to S104, the elapsed time of repetition of steps S94 to S104, the moving distance of the optical system 1011, etc.

In this way, the control unit 1020 repeatedly executes steps S94 to S105 until the specified number of images are acquired. Let the total number of repetitions of steps S94 to S105 be "U". FIG. 25 shows the operations at the u-th iteration and the u+1-th iteration. Here, u is an integer greater than or equal to 1 and less than or equal to U-1.

At the scan position corresponding to the u-th repetition, one light emission of the light source of the illumination optical system 1012, exposure of the first image sensor 1014A, and exposure of the second image sensor 1014B are performed. 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 FIG. 25 and the above description.

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

The image processing unit 1030 generates U high dynamic range images based on the U image groups collected by scanning (S107). The process executed in step S107 may be, for example, similar to step S84 in FIG. 21, FIG. 23, and the techniques described therein.

In step S107, a high dynamic range image is obtained in which various parts of the eye to be examined (corneal epithelium, corneal endothelium, anterior surface of the crystalline lens, posterior surface of the crystalline lens, etc.) are expressed in equal tones. Furthermore, a high dynamic range image representing a three-dimensional region (scanned region) of the eye to be examined is obtained.

Next, the ophthalmological apparatus 1000 (for example, the image processing unit 1030) applies gamma correction to the high dynamic range image generated in step S107 (S108), and displays the image on the display device (S86). Further, the ophthalmological apparatus 1000 stores one or more of the various images generated in this example in the storage device (S86). This concludes the explanation of the processing executed in this embodiment.

FIG. 26 shows an example of a specific configuration of an ophthalmologic device that can function as the ophthalmologic devices 1000 to 1700 according to some of the exemplary aspects described above. FIG. 26 is a top view.

The direction along the axis of the eye E to be examined is the Z direction, and among the directions perpendicular to this, the left and right directions for the examinee are the X direction, and the directions perpendicular to both the X direction and the Z direction (vertical direction, body axis direction) ) is the Y direction.

The ophthalmological apparatus of this example is a slit lamp microscope system 1 having a configuration similar to that disclosed in Patent Document 3 (Japanese Patent Laid-Open No. 2019-213733), and includes an illumination optical system 2 and a photographing optical system 3. , a moving image photographing optical system 4, an optical path coupling element 5, a moving mechanism 6, a control section 7, a data processing section 8, a communication section 9, and a user interface 10.

The cornea of the eye E to be examined is indicated by the symbol C, and the crystalline lens is indicated by the symbol CL. The anterior chamber corresponds to the area between the cornea C and the crystalline lens CL (the area between the cornea C and the iris).

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

The combination of the illumination optical system 2, the photographing optical system 3, and the moving mechanism 6 is an example of the photographing section 1010 of the ophthalmological apparatus 1000 (~1700). The illumination optical system 2 is an example of the illumination optical system 1012, and the photographing optical system 3 is an example of the photographing optical system 1013.

The illumination optical system 2 projects slit light onto the anterior segment of the eye E to be examined. Reference numeral 2a indicates the optical axis (illumination optical axis) of the illumination optical system 2.

The photographing optical system 3 photographs the anterior segment of the eye onto which the slit light from the illumination optical system 2 is projected. Reference numeral 3a indicates the optical axis (photographing optical axis) of the photographing optical system 3. The optical system 3A guides light from the anterior segment of the subject's eye E onto which the slit light is projected to the image sensor 3B. The image sensor 3B receives the light guided by the 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. The image sensor 3B is an example of the image sensor 1014 (1014A, 1014B) of the ophthalmological apparatus 1000 (-1700).

The illumination optical system 2 and the photographing optical system 3 function as a Scheimpflug camera, and are designed so that the object surface along the illumination optical axis 2a, the imaging surface of the optical system 3A and the image sensor 3B satisfy Scheimpflug conditions. In other words, the YZ plane (including the object plane) passing through the illumination optical axis 2a, the main surface of the optical system 3A, and the imaging surface of the image sensor 3B are configured to intersect on the same straight line.

Thereby, the illumination optical system 2 and the photographing optical system 3 can perform photographing in a state in which at least the range from the back surface of the cornea C to the front surface of the crystalline lens CL (anterior chamber) is in focus. In addition, the illumination optical system 2 and the photographing optical system 3 are in focus at least in the range from the vertex of the front surface of the cornea C (Z=Z1) to the vertex of the rear surface of the crystalline lens CL (Z=Z2). It can be performed. Note that the coordinate Z=Z0 indicates the intersection of the illumination optical axis 2a and the photographing optical axis 3a.

The moving image photographing optical system 4 is a video camera, and takes a moving image of the anterior segment of the eye E to be examined in parallel with the photographing of the eye to be examined by the illumination optical system 2 and the photographing 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 imaging optical system 4 (video imaging optical path).

A specific example of an optical system including the illumination optical system 2, the photographing optical system 3, the moving image photographing optical system 4, and the optical path coupling element 5 is shown in FIG. The optical system shown in FIG. 27 includes an illumination optical system 20 which is an example of the illumination optical system 2, and a photographing optical system 3 (first photographing optical system 1013A and second photographing optical system 1013B of the ophthalmological apparatus 1700 in FIG. 18). It includes a left photographing optical system 30L and a right photographing optical system 30R which are examples of the above, a video photographing optical system 40 which is an example of the video photographing optical system 4, and a beam splitter 47 which is an example of the optical path coupling element 5.

Reference numeral 20a indicates the optical axis (illumination optical axis) of the illumination optical system 20, reference numeral 30La indicates the optical axis (left imaging optical axis) of the left photographing optical system 30L, and reference numeral 30Ra indicates the optical axis (of the right photographing optical system 30R). right photographing optical axis). The angle θL indicates the angle between the illumination optical axis 20a and the left photographing optical axis 30La, and the angle θR indicates the angle between the illumination optical axis 20a and the right photographing optical axis 30Ra. Coordinate Z=Z0 indicates the intersection of the illumination optical axis 20a, the left photographing optical axis 30La, and the right photographing optical axis 30Ra.

The moving mechanism 6 moves the illumination optical system 20, the left photographing optical system 30L, and the right photographing optical system 30R in the direction shown by an arrow 49 (X direction).

The illumination light source 21 of the illumination optical system 20 outputs illumination light (for example, visible light), and the positive lens 22 refracts the illumination light. The slit forming section 23 forms a slit to allow part 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 to be examined.

The reflector 31L and the imaging lens 32L of the left photographing optical system 30L direct light from the anterior segment of the eye onto which the slit light is projected by the illumination optical system 20 (light traveling in the direction of the left photographing optical system 30L) to the imaging element. Leads to 33L. The image sensor 33L receives the guided light at an image pickup surface 34L.

The left photographing optical system 30L repeatedly performs photographing in parallel with the movement of the illumination optical system 20, the left photographing optical system 30L, and the right photographing optical system 30R by the moving mechanism 6. As a result, a plurality of anterior segment images (a series of Scheimpflug images) are obtained.

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

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

Scheimpflug image collection by the left photographing optical system 30L and Scheimpflug image collection by the right photographing optical system 30R are performed in parallel with each other.

The control unit 7 can synchronize repeated shooting by the left shooting optical system 30L and repeated shooting by the right shooting optical system 30R. Thereby, a correspondence relationship between the series of Scheimpflug images obtained by the left photographing optical system 30L and the series of Scheimpflug images obtained by the right photographing optical system 30R is obtained.

Note that the process of determining the correspondence between the plurality of anterior eye segment images obtained by the left photographing optical system 30L and the plurality of anterior eye segment images obtained by the right photographing optical system 30R is performed by the control unit 7 or the data. It may also be executed by the processing unit 8.

The video photographing optical system 40 photographs a video of the anterior segment of the eye E from a fixed position in parallel with the photographing by the left photographing optical system 30L and the photographing by the right photographing optical system 30R. The light that has passed through the beam splitter 47 is reflected by a reflector 48 and enters the moving image photographing optical system 40 . The light incident on the moving image photographing optical system 40 is refracted by an objective lens 41 and then imaged by an imaging lens 42 on an imaging surface of an image sensor 43 (area sensor). The moving image photographing optical system 40 is used for monitoring the movement of the eye E to be examined, alignment, tracking, processing of collected Scheimpflug images, and the like.

Referring back to FIG. 26. The moving mechanism 6 moves the illumination optical system 2 and the photographing optical system 3 integrally in the X direction.

The control unit 7 controls each part of the slit lamp microscope system 1. The control unit 7 controls the illumination optical system 2, the photographing optical system 3, and the moving mechanism 6, and controls the video photographing optical system 4 in parallel, thereby controlling the photographing of the ophthalmological apparatus 1000 (~1700). Slit scanning (collecting a series of Scheimpflug images) and video shooting (collecting a series of time-series images) by the unit 1010 can be performed in parallel.

Furthermore, the control unit 7 controls the illumination optical system 2, photographing optical system 3, and moving mechanism 6, and controls the video photographing optical system 4 in synchronization with each other, thereby performing slit scanning and video photographing. They can be synchronized with each other.

When the photographing optical system 3 includes a left photographing optical system 30L and a right photographing optical system 30R, the control unit 7 controls repeated photographing (collection of Scheimpflug image groups) by the left photographing optical system 30L and repetition by the right photographing optical system 30R. Photographing (collection of Scheimpflug image groups) can be synchronized with each other.

The control unit 7 includes a processor, a storage device, and the like. The storage device stores computer programs such as various control programs. The functions of the control unit 7 are realized by cooperation between software such as a control program and hardware such as a processor. The control unit 7 controls the illumination optical system 2, the photographing optical system 3, and the movement mechanism 6 in order to scan a three-dimensional region of the eye E to be examined with the slit light. For details of this control, please refer to Patent Document 3 (Japanese Unexamined Patent Publication No. 2019-213733).

The data processing unit 8 performs various data processing. The data processing unit 8 includes a processor, a storage device, and the like. The storage device stores computer programs such as various data processing programs. The functions of the data processing section 8 are realized by cooperation between software such as a data processing program and hardware such as a processor. The data processing section 8 has the function of the image processing section 1030 of the ophthalmological apparatus 1000 (~1700). The function of the data processing section 8 is not limited to this.

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 operation device.

The slit lamp microscope system 1 shown in FIGS. 26 and 27 is merely an example, and the configuration for implementing the ophthalmological apparatuses 1000 to 1700 is not limited to the slit lamp microscope system 1.

Some non-limiting features of ophthalmic devices according to embodiments will be described.

A first aspect of the ophthalmologic apparatus according to the embodiment includes an imaging section, a control section, and an image processing section. The photographing section includes an optical system that satisfies Scheimpflug conditions. The control unit is configured to control the imaging unit so that two or more imaging operations with different imaging conditions are applied to the subject's eye. The image processing unit is configured to generate a high dynamic range image based on two or more images of the eye to be examined acquired through two or more images taken under different imaging conditions.

The second aspect of the ophthalmological apparatus according to the embodiment includes the following non-limiting features in addition to the non-limiting features of the first aspect. The optical system includes an illumination optical system that projects illumination light onto the eye to be examined based on preset illumination conditions. Furthermore, the control unit is configured to control the imaging unit so that at least two or more imaging operations with different illumination conditions are applied to the eye to be examined.

The third aspect of the ophthalmological apparatus according to the embodiment includes the following non-limiting feature in addition to the non-limiting feature of the second aspect. The illumination conditions include an illumination intensity condition that determines the intensity of illumination light. Further, the control unit is configured to control the imaging unit so that at least two or more imaging operations with different illumination intensity conditions are applied to the eye to be examined.

The fourth aspect of the ophthalmic apparatus according to the embodiment includes the following non-limiting features in addition to the non-limiting features of the third aspect. The photographing section further includes a moving mechanism that moves the optical system. The illumination intensity condition includes two or more conditions. The control unit controls the illumination by combining the control of the illumination optical system for cyclically applying two or more conditions included in the illumination intensity conditions and the control of the movement mechanism for moving the optical system. The imaging unit is configured to repeatedly acquire an image group consisting of two or more images corresponding to two or more conditions included in the intensity condition.

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

The sixth aspect of the ophthalmological 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 aspects. The illumination conditions include illumination time conditions that determine the projection time of illumination light. The control unit is configured to control the imaging unit so that at least two or more imaging operations with different illumination time conditions are applied to the eye to be examined.

The seventh aspect of the ophthalmic apparatus according to the embodiment includes the following non-limiting features in addition to the non-limiting features of the sixth aspect. The photographing section further includes a moving mechanism that moves the optical system. The illumination time condition includes two or more conditions. The control unit controls the illumination by combining the control of the illumination optical system for cyclically applying two or more conditions included in the illumination time condition and the control of the movement mechanism for moving the optical system. The imaging unit is configured to repeatedly acquire an image group consisting of two or more images corresponding to two or more conditions included in the time condition.

The eighth aspect of the ophthalmic apparatus according to the embodiment includes the following non-limiting feature in addition to the non-limiting feature of the seventh aspect. The image processing section is configured to generate a plurality of high dynamic range images based on a plurality of image groups acquired by the photographing section under a combination of control of the illumination optical system and control of the movement mechanism.

The ninth aspect of the ophthalmological 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 aspects. The optical system includes a photographing optical system that photographs the eye to be examined based on preset exposure conditions. The control unit is configured to control the imaging unit so that at least two or more imaging operations with different exposure conditions are applied to the subject's eye.

The tenth aspect of the ophthalmological apparatus according to the embodiment includes the following non-limiting feature in addition to the non-limiting feature of the ninth aspect. The photographing optical system includes an image sensor. The exposure conditions include an exposure time condition that determines the exposure time by the image sensor. The control unit is configured to control the imaging unit so that at least two or more imaging operations with different exposure time conditions are applied to the subject's eye.

The eleventh aspect of the ophthalmological apparatus according to the embodiment includes the following non-limiting features in addition to the non-limiting features of the tenth aspect. The photographing section further includes a moving mechanism that moves the optical system. The exposure time condition includes two or more conditions. The control unit controls the exposure by combining the control of the photographing optical system for cyclically applying two or more conditions included in the exposure time condition and the control of the movement mechanism for moving the optical system. The imaging unit is configured to repeatedly acquire an image group consisting of two or more images corresponding to two or more conditions included in the time condition.

The twelfth aspect of the ophthalmological apparatus according to the embodiment includes the following non-limiting feature in addition to the non-limiting feature of the eleventh aspect. The image processing section is configured to generate a plurality of high dynamic range images based on a plurality of image groups acquired by the photographing section under a combination of control of the photographing optical system and control of the moving mechanism.

The thirteenth aspect of the ophthalmological apparatus according to the embodiment includes the following non-limiting features in addition to the non-limiting features of any of the ninth to twelfth aspects. The photographing optical system includes two or more image sensors. The control unit is configured to control the imaging unit to perform two or more imaging operations under different imaging conditions using two or more image sensors.

The fourteenth aspect of the ophthalmological apparatus according to the embodiment includes the following non-limiting features in addition to the non-limiting features of the thirteenth aspect. The two or more image sensors included in the photographic optical system include a first image sensor and a second image sensor. The control unit is configured to control the imaging unit so that a first exposure time by the first image sensor and a second exposure time by the second image sensor are different.

The fifteenth aspect of the ophthalmological apparatus according to the embodiment includes the following non-limiting features in addition to the non-limiting features of the thirteenth or fourteenth aspects. The two or more image sensors included in the photographic optical system include a first image sensor and a second image sensor. The control unit is configured to control the imaging unit so that at least a part of the first exposure period by the first image sensor and at least a part of the second exposure period by the second image sensor overlap. has been done.

The 16th aspect of the ophthalmological 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 aspects. The photographing section further includes a moving mechanism that moves the optical system. The control unit controls the photographing optical system to repeatedly apply two or more images to the subject's eye under different photographing conditions using two or more image sensors included in the photographing optical system, and moves the optical system. An image consisting of two or more images corresponding to two or more shootings under different shooting conditions using two or more image sensors included in the shooting optical system. The imaging unit is configured to repeatedly acquire the group.

The seventeenth aspect of the ophthalmological apparatus according to the embodiment includes the following non-limiting features in addition to the non-limiting features of the sixteenth aspect. The image processing section is configured to generate a plurality of high dynamic range images based on a plurality of image groups acquired by the photographing section under a combination of control of the photographing optical system and control of the moving mechanism.

The 18th aspect example of the ophthalmological apparatus according to the embodiment includes the following non-limiting feature in addition to the non-limiting feature of the first aspect example. The optical system includes an illumination optical system that projects illumination light onto the subject's eye based on preset illumination conditions, and a photographic optical system that photographs the subject's eye based on preset exposure conditions. The photographing optical system includes a first image sensor and a second image sensor. The control section controls the imaging section so that the following four conditions are satisfied. 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 part of the first exposure period by the first image sensor and at least part of the second exposure period by the second image sensor overlap. The third condition is that the first portion of the illumination light projection period by the illumination optical system overlaps the first exposure period by the first image sensor. The fourth condition is that the second portion of the illumination light projection period overlaps with the second exposure period by the second image sensor.

The nineteenth aspect of the ophthalmic apparatus according to the embodiment includes the following non-limiting features in addition to the non-limiting features of the eighteenth aspect. The photographing section further includes a moving mechanism that moves the optical system. The control unit controls the imaging optical system to repeatedly apply a first imaging using the first imaging device to the eye to be examined and a second imaging using the second imaging device to the eye to be examined. By combining this and the control of the movement mechanism for moving the optical system, an image corresponding to the first image capturing using the first image sensor and a second image capturing using the second image sensor are supported. The photographing unit is configured to repeatedly acquire a group of images including the images.

The 20th aspect of the ophthalmological apparatus according to the embodiment includes the following non-limiting features in addition to the non-limiting features of the 19th aspect. The image processing section is configured to generate a plurality of high dynamic range images based on a plurality of image groups acquired by the photographing section under a combination of control of the photographing optical system and control of the moving mechanism.

The twenty-first aspect of the ophthalmological apparatus according to the embodiment includes the following non-limiting features in addition to the non-limiting features of any of the first to twentieth aspects. The two or more images of the eye to be examined obtained by applying two or more times of imaging under different imaging conditions to the eye to be examined include a first image and a second image. The image processing unit performs a process of identifying a first pixel that satisfies a predetermined pixel value condition from the first image, and a process of identifying a first pixel of the second image that corresponds to the first pixel identified from the first image. The pixel value of the first pixel of the first image is changed based on the pixel value of the second pixel of the first image.

The 22nd aspect example of the ophthalmological apparatus according to the embodiment includes the following non-limiting feature in addition to the non-limiting feature of the 21st aspect example. The first image included in the two or more images of the eye to be examined obtained by applying two or more shots under different imaging conditions to the eye to be examined is the relatively smaller image of the two or more images. This is a bright image. The second image included in the two or more images of the eye to be examined obtained by applying two or more shots under different imaging conditions to the eye to be examined is the relatively smaller image of the two or more images. This is a dark image. The image processing unit is configured to identify, as a first pixel, a pixel having a luminance value equal to or greater than a predetermined first threshold from a relatively bright first image. Furthermore, the image processing unit is configured to calculate a pixel value of a second pixel in the relatively dark second image corresponding to a first pixel having a pixel value equal to or higher than the first threshold value in the relatively bright first image. Based on this, the pixel value of the first pixel that is equal to or greater than the first threshold value in the relatively bright first image is changed.

The 23rd aspect of the ophthalmological apparatus according to the embodiment includes the following non-limiting features in addition to the non-limiting features of the 21st aspect. The first image included in the two or more images of the eye to be examined obtained by applying two or more shots under different imaging conditions to the eye to be examined is the relatively smaller image of the two or more images. This is a dark image. The second image included in the two or more images of the eye to be examined obtained by applying two or more shots under different imaging conditions to the eye to be examined is the relatively smaller image of the two or more images. This is a bright image. The image processing unit is configured to identify, as a first pixel, a pixel having a luminance value equal to or less than a predetermined second threshold from the relatively dark first image. Furthermore, the image processing unit is configured to calculate a pixel value of a second pixel in a relatively bright second image corresponding to a first pixel having a pixel value equal to or less than a second threshold in the relatively dark first image. Based on this, the pixel value of the first pixel that is equal to or less than the second threshold value in the relatively dark first image is changed.

The twenty-fourth aspect of the ophthalmologic apparatus according to the embodiment includes the following non-limiting features in addition to the non-limiting features of any of the first to twenty-third aspects. The two or more images of the eye to be examined obtained by applying two or more times of imaging under different imaging conditions to the eye to be examined include a first image and a second image. The image processing unit performs a process of identifying a first image region corresponding to a predetermined region of the subject's eye from the first image, and a process of identifying a second image region corresponding to the same region of the subject's eye from the second image. The image processing apparatus is configured to perform a process of specifying an image area, and to change a pixel value of the first image area in the first image based on a pixel value of the second image area in the second image.

The twenty-fifth aspect of the ophthalmological apparatus according to the embodiment includes the following non-limiting features in addition to the non-limiting features of any of the first to twenty-fourth aspects. The image processing unit is configured to apply tone mapping processing to two or more images of the eye to be examined, which are obtained by applying two or more images of the eye under different imaging conditions to the eye to be examined.

The twenty-sixth aspect of the ophthalmologic apparatus according to the embodiment includes the following non-limiting features in addition to the non-limiting features of any of the first to twenty-fifth aspects. The optical system includes an illumination optical system that projects illumination light onto the eye to be examined, and a photographic optical system that photographs the eye to be examined. The photographing section includes a moving mechanism that moves the illumination optical system and the photographing optical system. In controlling the imaging unit for two or more images with different imaging conditions, the control unit controls the illumination light onto the eye to be examined so that the projection time of the illumination light to the eye to be examined is shorter than the exposure time of the imaging optical system. At least one of the illumination optical system and the photographing optical system is controlled so that at least a part of the light projection period and at least a part of the exposure period of the photographing optical system overlap.

As described in this disclosure, an ophthalmological device having these non-limiting features can improve the quality of images obtained in ophthalmological imaging. In particular, it is possible to improve the quality of images obtained by ophthalmological imaging using optical scanning.

Further, by combining any of the matters described in the present disclosure with an ophthalmological device having any non-limiting characteristics, it is possible to further improve images in ophthalmological imaging, and Those skilled in the art will appreciate that a variety of applications can be provided.

<Other embodiments>
Although embodiments of ophthalmological devices have been described so far, embodiments according to the present disclosure are not limited to ophthalmological devices. Embodiments other than ophthalmological devices include a method for controlling an ophthalmological device, a program, a recording medium, and the like. Similar to the embodiments of the ophthalmological device, these embodiments also allow for improved image quality in ophthalmological imaging.

A method for controlling an ophthalmologic apparatus according to one embodiment is a method for controlling an ophthalmologic apparatus.

This ophthalmological apparatus includes an imaging unit and a processor. The photographing section includes an optical system that satisfies Scheimpflug conditions.

The method according to the present embodiment is configured to cause a processor included in the ophthalmologic apparatus to function as a control unit and an image processing unit.

A processor functioning as a control unit controls the imaging unit so that two or more imaging operations with different imaging conditions are applied to the eye to be examined.

A processor functioning as an image processing unit generates a high dynamic range image based on two or more images of the subject's eye acquired by two or more images taken under different imaging conditions.

Any of the items described in this disclosure can be combined with the method according to this embodiment.

A program according to one embodiment is a program for operating an ophthalmologic apparatus.

This ophthalmological apparatus includes an imaging unit and a processor. The photographing section includes an optical system that satisfies Scheimpflug conditions.

The program according to this embodiment is configured to cause a processor included in an ophthalmological apparatus to function as a control unit and an image processing unit.

A processor functioning as a control unit according to the program according to the present embodiment controls the imaging unit so that two or more imagings with different imaging conditions are applied to the eye to be examined.

A processor functioning as an image processing unit according to the program according to the present embodiment generates a high dynamic range image based on two or more images of the eye to be examined acquired through two or more shootings under different shooting conditions.

Any items described in this disclosure can be combined with the program according to this embodiment.

The recording medium according to one embodiment is a computer-readable non-transitory recording medium in which a program for operating an ophthalmological apparatus is recorded.

This ophthalmological apparatus includes an imaging unit and a processor. The photographing section includes an optical system that satisfies Scheimpflug conditions.

The program recorded on the recording medium according to this embodiment is configured to cause a processor included in the ophthalmologic apparatus to function as a control section and an image processing section.

A processor functioning as a control unit according to a program recorded on the recording medium according to the present embodiment controls the imaging unit so that two or more imagings with different imaging conditions are applied to the eye to be examined.

The processor functioning as an image processing unit according to the program recorded on the recording medium according to the present embodiment generates a high dynamic range image based on two or more images of the eye to be examined acquired through two or more shootings under different shooting conditions. Generate an image.

Any items described in this disclosure can be combined with the recording medium according to this embodiment.

The computer-readable non-temporary recording medium that can be used as the recording medium according to this embodiment may be any type of recording medium, such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory. It may be.

Any of the items described in the ophthalmological device embodiments can be combined in non-ophthalmological device embodiments.

For example, items arbitrarily selected from various items described as arbitrary aspects of the ophthalmological apparatus according to the embodiments may be used as an embodiment of the ophthalmological apparatus control method, a program embodiment, and a recording medium embodiment. It can be combined with etc.

Furthermore, any of the matters described in the present disclosure can be combined into an embodiment of a method for controlling an ophthalmologic apparatus, an embodiment of a program, an embodiment of a recording medium, and the like.

This disclosure presents several embodiments and several exemplary aspects thereof. These embodiments and aspects are merely illustrative of the invention. Therefore, any modification (omission, substitution, addition, etc.) within the scope of the gist of the present invention can be applied to the embodiments and aspects presented in this disclosure.

1 Slit lamp microscope system (ophthalmological equipment)
2 Illumination optical system 3 Photography optical system 3B Image pickup device 6 Movement mechanism 7 Control unit 20 Illumination optical system 30L Left photography optical system 30R Right photography optical system 33L, 33R Image pickup devices 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700 Ophthalmological apparatus 1010 Photographing section 1011 Optical system 1012 Illumination optical system 1013, 1013A, 1013B Photographing optical system 1014, 1014A, 1014B Image sensor 1019 Movement mechanism 1020 Control section 1030 Image processing section

Claims (29)

an imaging section including an optical system that satisfies Scheimpflug conditions;
a control unit that controls the imaging unit so as to apply two or more imagings with different imaging conditions to the eye to be examined;
and an image processing unit that generates a high dynamic range image based on two or more images of the subject's eye acquired by the two or more imaging operations. The optical system includes an illumination optical system that projects illumination light onto the eye to be examined based on preset illumination conditions,
The control unit performs the control of the imaging unit so that at least two or more imagings with different illumination conditions are applied to the eye to be examined.
The ophthalmological device of claim 1. The illumination conditions include an illumination intensity condition that determines the intensity of illumination light,
The control unit performs the control of the imaging unit so that at least two or more imagings with different illumination intensity conditions are applied to the eye to be examined.
The ophthalmological device according to claim 2. The imaging unit further includes a moving mechanism that moves the optical system,
The illumination intensity condition includes two or more conditions,
The control unit controls the two or more conditions by combining control of the illumination optical system for cyclically applying the two or more conditions and control of the movement mechanism for moving the optical system. causing the photographing unit to repeatedly acquire an image group consisting of two or more images corresponding to the condition;
The ophthalmological device according to claim 3. The image processing unit generates a plurality of high dynamic range images based on the plurality of image groups acquired by the imaging unit.
The ophthalmological device according to claim 4. The illumination conditions include illumination time conditions that determine the projection time of illumination light,
The control unit controls the imaging unit so that at least two or more imagings with different illumination time conditions are applied to the eye to be examined.
The ophthalmological device according to claim 2. The imaging unit further includes a moving mechanism that moves the optical system,
The illumination time condition includes two or more conditions,
The control unit controls the two or more conditions by combining control of the illumination optical system for cyclically applying the two or more conditions and control of the movement mechanism for moving the optical system. causing the photographing unit to repeatedly acquire an image group consisting of two or more images corresponding to the condition;
The ophthalmological device according to claim 6. The image processing unit generates a plurality of high dynamic range images based on the plurality of image groups acquired by the imaging unit.
The ophthalmological device according to claim 7. The optical system includes a photographing optical system that photographs the eye to be examined based on preset exposure conditions,
The control unit performs the control of the imaging unit so that at least two or more imagings with different exposure conditions are applied to the eye to be examined.
The ophthalmological device of claim 1. The photographing optical system includes an image sensor,
The exposure conditions include an exposure time condition that determines the exposure time by the image sensor,
The control unit performs the control of the imaging unit so that at least two imagings with different exposure time conditions are applied to the eye to be examined.
The ophthalmological device according to claim 9. The imaging unit further includes a moving mechanism that moves the optical system,
The exposure time conditions include two or more conditions,
The control unit controls the two or more conditions by combining the control of the photographing optical system for cyclically applying the two or more conditions and the control of the moving mechanism for moving the optical system. causing the photographing unit to repeatedly acquire an image group consisting of two or more images corresponding to the condition;
The ophthalmological device of claim 10. The image processing unit generates a plurality of high dynamic range images based on the plurality of image groups acquired by the imaging unit.
The ophthalmological device of claim 11. The photographing optical system includes two or more image sensors,
The control unit controls the imaging unit to perform the imaging two or more times using the two or more imaging devices.
The ophthalmological device according to claim 9. The two or more image sensors include a first image sensor and a second image sensor,
The control unit performs the control of the imaging unit so that a first exposure time by the first image sensor and a second exposure time by the second image sensor are different.
The ophthalmological device of claim 13. The two or more image sensors include a first image sensor and a second image sensor,
The control unit controls the imaging unit so that at least a part of a first exposure period by the first image sensor and at least a part of a second exposure period by the second image sensor overlap. I do,
The ophthalmological device of claim 13. The imaging unit further includes a moving mechanism that moves the optical system,
The control unit controls the imaging optical system for repeatedly applying the two or more imaging operations using the two or more imaging devices to the eye to be examined, and the movement mechanism for moving the optical system. and causing the imaging unit to repeatedly acquire an image group consisting of two or more images corresponding to the two or more imagings using the two or more imaging devices.
The ophthalmological device of claim 13. The image processing unit generates a plurality of high dynamic range images based on the plurality of image groups acquired by the imaging unit.
17. The ophthalmological device of claim 16. The optical system is
an illumination optical system that projects illumination light onto the eye to be examined based on preset illumination conditions;
and a photographing optical system that photographs the eye to be examined based on preset exposure conditions,
The photographing optical system includes a first image sensor and a second image sensor,
The control unit includes:
A first exposure time by the first image sensor and a second exposure time by the second image sensor are different,
At least a part of the first exposure period by the first image sensor and at least a part of the second exposure period by the second image sensor overlap, and
a first portion of a period during which the illumination light is projected by the illumination optical system overlaps with the first exposure period, and a second portion of the projection period overlaps with the second exposure period;
performing the control of the imaging unit;
The ophthalmological device of claim 1. The imaging unit further includes a moving mechanism that moves the optical system,
The control unit is configured to repeatedly apply a first imaging using the first imaging device to the eye to be examined, and repeatedly apply a second imaging using the second imaging device to the eye to be examined. By combining the control of the photographing optical system and the control of the moving mechanism for moving the optical system, an image including an image corresponding to the first photographing and an image corresponding to the second photographing is obtained. causing the imaging unit to repeatedly acquire the group;
The ophthalmological device of claim 18. The image processing unit generates a plurality of high dynamic range images based on the plurality of image groups acquired by the imaging unit.
The ophthalmological device of claim 19. the two or more images include a first image and a second image,
The image processing unit includes:
identifying a first pixel that satisfies a predetermined pixel value condition from the first image;
changing the pixel value of the first pixel based on the pixel value of a second pixel of the second image corresponding to the first pixel;
The ophthalmological device of claim 1. The first image is a relatively bright image among the two or more images,
The second image is a relatively dark image among the two or more images,
The image processing unit identifies, from the first image, a pixel having a luminance value equal to or greater than a first threshold value as the first pixel.
The ophthalmological device of claim 21. The first image is a relatively dark image among the two or more images,
The second image is a relatively bright image among the two or more images,
The image processing unit identifies, from the first image, a pixel having a luminance value equal to or less than a second threshold value as the first pixel.
The ophthalmological device of claim 21. the two or more images include a first image and a second image,
The image processing unit includes:
identifying a first image area corresponding to a predetermined region of the eye to be examined from the first image;
identifying a second image area corresponding to the predetermined region from the second image;
changing the pixel value of the first image area based on the pixel value of the second image area;
The ophthalmological device of claim 1. The image processing unit applies tone mapping processing to the two or more images.
The ophthalmological device of claim 1. The optical system is
an illumination optical system that projects illumination light onto the eye to be examined;
and a photographing optical system for photographing the eye to be examined;
The photographing unit includes a moving mechanism that moves the illumination optical system and the photographing optical system,
In the control of the imaging unit for the two or more imaging operations, the control unit controls the illumination light so that the projection time of the illumination light onto the subject's eye is shorter than the exposure time of the imaging optical system; controlling at least one of the illumination optical system and the photographing optical system so that at least a part of the projection period of the illumination light to the eye to be examined overlaps with at least a part of the exposure period of the photographing optical system;
The ophthalmological device of claim 1. A method for controlling an ophthalmological apparatus including an imaging unit including an optical system that satisfies Scheimpflug conditions and a processor, the method comprising:
The processor,
a control unit that controls the imaging unit so as to apply two or more imagings under different imaging conditions to the eye to be examined; and
A method comprising: functioning as an image processing unit that generates a high dynamic range image based on two or more images of the eye to be examined acquired through the two or more imaging operations. A program for operating an ophthalmological apparatus including an imaging unit including an optical system that satisfies Scheimpflug conditions and a processor,
The processor,
a control unit that controls the imaging unit so as to apply two or more imagings under different imaging conditions to the eye to be examined; and
A program that functions as an image processing unit that generates a high dynamic range image based on two or more images of the eye to be examined acquired by the two or more imaging operations. A computer-readable non-transitory recording medium on which a program for operating an ophthalmological apparatus including an imaging unit including an optical system that satisfies Scheimpflug conditions and a processor is recorded,
The program causes the processor to
a control unit that controls the imaging unit so as to apply two or more imagings under different imaging conditions to the eye to be examined; and
A recording medium configured to function as an image processing unit that generates a high dynamic range image based on two or more images of the eye to be examined acquired through the two or more imaging operations.

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