WO2016067365A1 - Observation device, observation method, and computer program - Google Patents

Abstract

The present invention allows a test subject to favorably see an observed image acquired by capturing an image of an eye even when the position of the eye changes. An observation device (1) is provided with a projection means (110) capable of projecting on an eye of a test subject a first image to be projected on the corneal surface of the eye and a second image to be formed on the retina of the eye, and an image pickup means (140) for acquiring an observed image by capturing an image of the eye. The projection means uses the observed image as the second image and adjusts the projection position of the second image so that the light (L12) for forming the second image on the retina passes through the pupil of the eye.

Description

Observation apparatus, observation method, and computer program

The present invention relates to an observation apparatus, an observation method, and a computer program for observing the eye state of a subject (for example, the state of a tear film formed on the surface of the cornea).

As such an observation apparatus, an observation apparatus that presents an observation image obtained by imaging a subject's eye to the subject is known. For example, Patent Document 1 describes a fundus camera including a television monitor that displays a fundus image of a subject eye photographed with a television camera on the subject eye. Patent Document 2 describes an ophthalmologic examination apparatus including a liquid crystal display that presents an anterior segment image of a subject eye photographed by a television camera toward a subject. Patent Document 3 describes an ophthalmologic apparatus that includes a display that displays a video signal from a light receiving element on which an anterior ocular segment image is formed so that a subject can gaze at an image displayed on the display during measurement. Has been.

JP-A-63-59927 JP-A-6-245907 Patent No. 2960739

The observation devices described in Patent Literature 1 to Patent Literature 3 have difficulty in continuously presenting an observation image that can be viewed by the subject when the eye position of the subject (for example, the position of the anterior eye or pupil) changes. Or not easy. That is, it is difficult or not easy for the observation devices described in Patent Literature 1 to Patent Literature 3 to continue presenting an observation image that can be visually recognized when the subject moves his / her eyes.

For example, the observation apparatus described in Patent Document 1 can move the television monitor in a required range on a plane perpendicular to the optical axis when the eye of the subject turns around. However, since it is necessary to physically move the television monitor each time the subject's eyes turn around, it is difficult to keep presenting an observation image that can be visually recognized by the subject relatively easily.

For example, the observation devices described in Patent Documents 2 and 3 do not consider any change in the position of the eye of the subject. For this reason, there is a possibility that light for forming an observation image on the retina cannot pass through the pupil due to a change in the position of the eye of the subject. As a result, the subject may not be able to visually recognize the observation image.

Examples of problems to be solved by the present invention include the above. It is an object of the present invention to provide an observation apparatus, an observation method, and a computer program that enable a subject to appropriately view an observation image acquired by imaging an eye even when the position of the eye changes. To do.

In order to solve the above problems, an observation apparatus of the present invention is an observation apparatus for observing the state of a subject's eye, and is formed on a first image to be projected on the surface of the cornea of the eye and the retina of the eye. A projection unit capable of projecting a second image to be imaged onto the eye; and an imaging unit that acquires an observation image by imaging the eye, wherein the projection unit uses the observation image as the second image. In addition, the projection position of the second image is adjusted so that light that forms the second image on the retina passes through the pupil of the eye.

In order to solve the above-described problems, the observation method of the present invention can project a first image to be projected onto the cornea surface of a subject's eye and a second image to be imaged on the retina of the eye onto the eye. An observation method of observing the state of the eye using a projection unit and an imaging unit that acquires an observation image by imaging the eye, using the observation image as the second image, and the first image The projection position of the second image is adjusted so that light that forms two images on the retina passes through the pupil of the eye.

In order to solve the above problem, the computer program of the present invention can project a first image to be projected onto the cornea surface of a subject's eye and a second image to be imaged on the retina of the eye onto the eye. A computer program for operating an observation device that observes the state of the eye using a projection unit and an imaging unit that acquires an observation image by imaging the eye, and uses the observation image as the second image In addition, the observation apparatus is caused to perform an operation of adjusting the projection position of the second image so that the light that forms the second image on the retina passes through the pupil of the eye.

The operation and gain of the present invention will be clarified from the embodiments described below.

It is a block diagram which shows the structure of the observation apparatus of 1st Example. It is a flowchart which shows the flow of operation | movement of the observation apparatus of 1st Example. It is a top view which shows a test | inspection image. It is a top view which shows an observation image. It is a top view which shows the projection image obtained by synthesize | combining a test | inspection image and an observation image. It is a schematic diagram explaining the adjustment operation of the display position of an observation image. It is a schematic diagram explaining the adjustment operation of the display position of an observation image. It is a block diagram which shows the structure of the observation apparatus of 2nd Example. It is a block diagram which shows the structure of the observation apparatus of 3rd Example.

Hereinafter, as embodiments for carrying out the invention, embodiments of the observation apparatus, the observation method, and the computer program of the present invention will be described in order.

(Embodiment of observation apparatus)
<1>
The observation device of the present embodiment is an observation device that observes the state of the eye of a subject, and includes a first image to be projected on the surface of the cornea of the eye and a second image to be imaged on the retina of the eye. A projection unit capable of projecting onto the eye; and an imaging unit that acquires an observation image by imaging the eye, wherein the projection unit uses the observation image as the second image, and the second image. The projection position of the second image is adjusted so that the light that forms an image on the retina passes through the pupil of the eye.

According to the observation apparatus of the present embodiment, the eye state of the subject is observed. For example, the observation device is reflected in the eye (typically the surface of the eye, the surface of the cornea, the surface of the tear film formed on the surface of the cornea, the surface of the oil layer covering the tear film or the cornea). The state of the projection image) can be observed. The operation of “observing the eye state” mentioned here includes an arbitrary operation for directly or indirectly estimating the eye state. For example, the operation of “observing the state of the eye” is an operation of imaging the eye described later (typically imaging the surface of the eye, the surface of the cornea, or the tear film formed on the surface of the cornea). May be included. For example, the operation of “observing the eye state” may include an operation of analyzing an observation image acquired by imaging the eye. For example, the operation of “observing the eye state” may include an operation of directly or indirectly estimating the eye state based on the analysis result of the observation image. However, a part of the operation of “observing the eye state” may be performed by a user of the observation apparatus (for example, an ophthalmologist or a subject). For example, the user of the observation device may estimate the eye state directly or indirectly based on an observation image acquired by the observation device imaging the eye.

In order to observe the state of the eye, the observation apparatus includes a projecting unit and an imaging unit.

The projection means projects both the first image and the second image on the eyes of the subject. That is, the projecting unit projects a projection image including the first image and the second image or obtained by synthesizing the first image and the second image onto the eye of the subject. The “projecting the projected image onto the eye” referred to here corresponds to the projected image in a desired region on the eye surface regardless of whether or not the projected image is formed on the eye surface. It shall mean the whole operation | movement which guides or irradiates projection light or illumination light. Therefore, the operation of “projecting the projected image onto the eye” not only projects the projected image directly on the eye, but also projects the projected image onto a desired optical means (for example, a diffusion plate) and applies it to the optical means. An operation for realizing a state in which the projected image is reflected in the eye, an operation for illuminating the eye with a light / dark pattern corresponding to the projection image, and the like may be included.

The first image is an image projected on the surface of the cornea of the subject's eye. The first image may be an image formed on the surface of the cornea. The first image may not be an image formed on the surface of the cornea. The first image may not be an image formed on the retina of the subject's eye. On the other hand, the second image is an image different from the first image. The second image is an image formed on the retina of the subject's eye. Note that the retina is located behind the cornea when viewed from the projection means side (that is, the image formed on the retina is not imaged on the cornea but is also projected on the cornea). Considering it, it can be said that the second image is an image projected onto the surface of the cornea.

The first example of the projecting unit is a display unit (for example, a display element to be described later) for displaying the first image and the second image, light for projecting the first image on the cornea, and the second image are combined on the retina. A light guide means for guiding light for imaging to the eyes may be provided. The first example of the light guiding means is a diffusing means for diffusing light for projecting the first image onto the cornea (for example, a diffusing plate described later) and light for forming the second image on the retina. Optical means for guiding to the retina (for example, a Koehler illumination lens or an eyepiece lens described later) may be provided. The second example of the light guide means guides the light for projecting the first image onto the cornea to the cornea and the optical means for guiding the light for forming the second image on the retina to the retina (for example, described later). An objective lens or the like).

The second example of the projection means projects light (in other words, illuminates the eyes) with a light / dark pattern corresponding to the first image (for example, a platide plate described later), and a display for displaying the second image. Means (for example, a display element to be described later) and light guide means (for example, an eyepiece to be described later) for guiding light for forming a second image on the retina to the retina may be provided.

The imaging means acquires an observation image by imaging the eye. In particular, the imaging means acquires an observation image by imaging the surface of the eye (for example, the surface of the cornea). Moreover, it is preferable that an imaging means acquires an observation image by imaging the eye on which the first image is projected. However, the imaging unit may acquire an observation image by imaging an eye on which the first image is not projected.

Particularly in this embodiment, the projection unit uses the observation image acquired by the imaging unit as the second image. Therefore, the projecting unit projects the observation image acquired by the imaging unit onto the eyes of the subject so that the observation image is formed on the retina.

In this embodiment, the projection unit further adjusts the projection position of the second image (that is, the observation image). In particular, the projection unit adjusts the projection position of the second image so that light for forming the second image on the retina passes through the pupil of the eye of the subject. Therefore, even when the position of the subject's eye (for example, the position of the anterior eye or pupil) changes, the projection unit can adjust the projection position of the second image according to the position of the subject's eye. . As a result, the projecting unit can project the second image so that the light for forming the second image on the retina passes through the pupil (for example, the pupil whose position has changed).

The projection unit may adjust the projection position of the second image (that is, the observation image) under the control of the control unit. That is, the observation apparatus according to the present embodiment may include a control unit that controls the projection unit so as to adjust the projection position of the second image (that is, the observation image). In particular, the control means controls the projection means to adjust the projection position of the second image for the purpose of allowing the light for forming the second image on the retina to pass through the pupil of the eye of the subject. Also good.

The “projection position of the second image” referred to here is typically the projection position of the second image on the surface of the cornea (that is, the light for imaging the second image on the retina on the cornea surface). (Irradiation position). However, a virtual direction orthogonal to the optical axis of a light guide means (for example, a projection lens, a Koehler illumination lens, an eyepiece lens or an objective lens described later) that guides the light for forming the second image on the retina to the eye. Adjustment of the projection position of the second image on a smooth plane substantially leads to adjustment of the projection position of the second image on the surface of the cornea. Therefore, the “projection position of the second image” here refers to the second image on a virtual plane orthogonal to the optical axis of the light guiding means for guiding the light for forming the second image on the retina to the eye. It may mean the projection position of.

As described above, the observation device of the present embodiment adjusts the projection position of the observation image so that the light for forming the observation image used as the second image on the retina passes through the pupil of the subject's eye. be able to. For this reason, a test subject can visually recognize an observation image suitably. In particular, even when the position of the subject's eyes (for example, the position of the anterior eye or the pupil) changes, the subject can appropriately view the observation image.

<2>
In another aspect of the observation apparatus of the present embodiment, the observation device further includes a detection unit that detects the position of the pupil, and the projection unit converts the second image based on the position of the pupil detected by the detection unit. The projection position of the second image is adjusted so that light to be imaged on the retina passes through the pupil of the eye.

According to this aspect, the observation apparatus is based on the position of the pupil detected by the detection unit so that the light for forming the observation image used as the second image on the retina passes through the pupil of the subject's eye. Thus, the projection position of the observation image can be adjusted. For this reason, the observation apparatus can suitably adjust the projection position of the observation image so that the light for forming the observation image on the retina passes through the pupil of the eye of the subject.

<3>
In another aspect of the observation apparatus including the detection unit as described above, the projection unit projects the second image by an amount corresponding to the shift amount of the current position of the pupil detected by the detection unit from the pupil reference position. The projection position of the second image is adjusted so that the position deviates from the projection reference position.

According to this aspect, the observation apparatus is based on the position of the pupil detected by the detection unit so that the light for forming the observation image used as the second image on the retina passes through the pupil of the subject's eye. Thus, the projection position of the observation image can be adjusted.

For example, when the projection means projects an observation image at the projection reference position on the surface of the cornea in a situation where the pupil is located at the pupil reference position, the light for forming the observation image on the retina causes the pupil of the subject's eye to be formed. Assume a passing observation device. In such an observation device, when the current position of the pupil deviates from the pupil reference position, the observation image is formed on the retina even if the projection means projects the observation image onto the projection reference position on the surface of the cornea. There is a possibility that part or all of the light to be transmitted does not pass through the pupil of the eye of the subject. Therefore, in the observation apparatus of this aspect, when the current position of the pupil deviates from the pupil reference position, the observation image on the surface of the cornea is an amount corresponding to the deviation amount of the current position of the pupil from the pupil reference position. The projection position of the observation image is adjusted so that the projection position deviates from the projection reference position. As a result, if the current position of the pupil deviates from the pupil reference position, the projection means projects the observation image at a position deviated from the projection reference position on the surface of the cornea (typically the position where the pupil is present). Therefore, light for forming an observation image on the retina passes through the pupil of the subject's eye. As a result, even when the position of the eye of the subject (for example, the position of the anterior eye or the pupil) changes, the subject can appropriately view the observation image.

<4>
In another aspect of the observation apparatus including the detection unit as described above, the detection unit detects the position of the pupil based on the observation image.

According to this aspect, the detection unit can detect the position of the pupil relatively easily based on the observation image acquired by the imaging unit by imaging the eye. A specific method for detecting the position of the pupil by the detecting means is arbitrary. However, typically, the detection means detects the position of the pupil by analyzing the observation image.

<5>
In another aspect of the observation apparatus of the present embodiment, the projection unit adjusts the projection position of the first image so that light that projects the first image onto the surface of the cornea is projected around the pupil. To do.

According to this aspect, the subject preferably visually recognizes the observation image used as the second image, but does not visually recognize part or all of the first image that is relatively less necessary to be visually recognized. Therefore, the subject can appropriately view the observation image without being bothered by the first image projected onto the eye together with the observation image used as the second image.

<6>
In another aspect of the observation apparatus according to the present embodiment, the projection unit distributes the first image and the projection position of the first image around the projection position of the second image on the surface of the cornea. Projecting the second image.

According to this aspect, the projecting means can project the projected image in which the second image is located at the center portion and the first image is located at the outer edge portion on the eye. Here, considering that the pupil is likely to be located at the center of the eye (that is, the center of the surface of the eye, the surface of the anterior eye or the surface of the cornea), the center of the projection image projected by the projection means The light that forms the second image located on the retina easily passes through the pupil. Therefore, the projecting means can suitably project the second image so that the light that forms the second image on the retina passes through the pupil.

(Embodiment of observation method)
<7>
The observation method of the present embodiment includes a projection unit capable of projecting a first image to be projected onto the cornea surface of a subject's eye and a second image to be imaged on the retina of the eye, and the eye An observation method for observing the state of the eye using an imaging unit that acquires an observation image by imaging, wherein the observation image is used as the second image, and the second image is displayed on the retina. The projection position of the second image is adjusted so that the light to be imaged passes through the pupil of the eye.

According to the observation method of the present embodiment, it is possible to receive the same effects as the various effects that the observation apparatus of the present embodiment described above receives. Incidentally, in response to the various aspects of the observation apparatus of the present embodiment described above, the observation method of the present embodiment can also adopt various aspects.

(Embodiment of computer program)
<8>
The computer program according to the present embodiment includes a projection unit capable of projecting a first image to be projected on the cornea surface of a subject's eye and a second image to be imaged on the retina of the eye, and the eye. A computer program for operating an observation device that observes the state of the eye using an imaging unit that acquires an observation image by imaging, wherein the observation image is used as the second image, and the second image The observation apparatus is caused to perform an operation of adjusting the projection position of the second image so that light that forms an image on the retina passes through the pupil of the eye.

According to the computer program of the present embodiment, it is possible to receive the same effects as the various effects that the observation apparatus of the present embodiment described above receives. Incidentally, in response to the various aspects of the observation apparatus of the present embodiment described above, the computer program of the present embodiment can also adopt various aspects. Further, the computer program of the present embodiment may be recorded on a computer-readable recording medium.

Such an operation and other advantages of the present embodiment will be further clarified from examples described below.

As described above, the observation apparatus according to the present embodiment includes the projection unit and the imaging unit, and the observation image is displayed so that the light that forms the observation image used as the second image on the retina passes through the pupil of the eye. Adjust the projection position. In the observation method of the present embodiment, the projection position of the observation image is adjusted so that the light that forms the observation image used as the second image on the retina passes through the pupil of the eye. The computer program according to the present embodiment causes the observation apparatus to perform an operation of adjusting the projection position of the observation image so that the light that forms the observation image used as the second image on the retina passes through the pupil of the eye. Therefore, even when the position of the eye changes, the subject can preferably visually recognize the observation image acquired by imaging the eye.

Hereinafter, embodiments of the observation apparatus, the observation method, and the computer program of the present invention will be described with reference to the drawings. In the following, the observation apparatus, the observation method, and the computer program of the present invention are formed on the surface of the cornea by acquiring the observation image by imaging the surface of the subject's cornea and analyzing the acquired observation image. It is assumed that the present invention is applied to an observation apparatus that estimates (in other words, measures) the state of the tear film.

However, the observation apparatus, the observation method, and the computer program of the present invention may be applied to any observation apparatus that observes the eye state of the subject. For example, the observation apparatus, the observation method, and the computer program of the present invention acquire an observation image by imaging the surface of the subject's cornea and display the acquired observation image to a user (for example, an ophthalmologist) or the like. You may apply with respect to an observation apparatus. In this case, the user may estimate the eye state based on the observation image displayed by the observation device.

(1) First Example First, an observation apparatus 1 according to a first example will be described with reference to FIGS.

(1-1) Configuration of Observation Device 1 of First Example First, the configuration of the observation device 1 of the first example will be described with reference to FIG. FIG. 1 is a block diagram showing the configuration of the observation apparatus 1 of the first embodiment.

As shown in FIG. 1, the observation apparatus 1 of the first example includes a projection unit 110 that is a specific example of the “projection unit” in the above-described embodiment, and one of the “projection unit” in the above-described embodiment. The diffusion plate 120 as a specific example, the eyepiece lens 124 as a specific example of the “projection unit” in the above-described embodiment, and the Koehler illumination lens as a specific example of the “projection unit” in the above-described embodiment 131, a beam splitter 132, an imaging unit 140 that is a specific example of the “imaging unit” in the above-described embodiment, and a control unit 150 that is a specific example of the “control unit” in the above-described embodiment. Prepare. In FIG. 1, the projection unit 110, the diffusion plate 120, the eyepiece lens 124, the Koehler illumination lens 131, the beam splitter 132, and the imaging unit 140 respectively represent the projection unit 110, the eyepiece lens 124, the Koehler illumination lens 131, or the imaging. It is described using a cross-sectional view along the optical axis of the portion 140.

Projection unit 110 projects a desired projection image. The projection unit 110 projects the projection image so that at least a part of the projection image forms an image on a diffusion plate 120 described later. The projection unit 110 projects the projection image so that at least a part of the projection image forms an image on the retina. In order to project a projection image, the projection unit 110 includes a display element 111, a projection lens 112, and a projection diaphragm 113.

The display element 111 displays a projection image to be projected by the projection unit 110. The display element 111 is an arbitrary display device such as a liquid crystal display, for example.

The display element 111 includes a display surface 111a on which a projection image is displayed. In the first embodiment, the display surface 111a is a first display area for displaying an examination image (see FIGS. 3A to 3D described later) used for observing the state of the tear film. It is virtually divided into 111a1 and a second display area 111a2 for displaying an observation image (see FIG. 4 described later) that is an imaging result of the imaging unit 140.

The first display area 111a1 is distributed so as to surround the second display area 111a2. In other words, the first display area 111a1 is distributed around or outside the second display area 111a2. The second display area 111a2 is preferably closer to the center of the display surface 111a than the first display area 111a1.

The display element 111 displays an inspection image in the first display area 111a1. Further, the display element 111 displays an observation image in the second display area 111a2. In other words, in the first embodiment, the display element 111 is arranged so that the inspection image surrounds the observation image (in other words, the observation image is positioned at or near the center of the inspection image). A projected image obtained by combining the image is displayed. As a result, illumination light L11 for projecting the inspection image onto the eye (more specifically, projecting the inspection image onto the diffusion plate 120) is emitted from the first display region 111a1. From the second display area 111a2, illumination light L12 for projecting the observation image onto the eye (more specifically, forming the observation image on the retina) is emitted.

The projection lens 112 focuses the illumination light L11 on the diffusion plate 120. As a result, the inspection image projected by the projection unit 110 is formed on the diffusion plate 120. In addition, the projection lens 112 forms an image of the illumination light L12 on the retina together with the Koehler illumination lens 131 and the eyepiece lens. As a result, the observation image projected by the projection unit 110 forms an image on the retina.

The projection diaphragm 113 adjusts the light amounts of the illumination light L11 and the illumination light L12 emitted from the projection unit 110.

The diffusion plate 120 is a plate (in other words, a screen) that diffuses the illumination light L11 incident on the diffusion plate 120. Specifically, the diffusing plate 120 emits the illumination light L11 incident on the surface 121 of the diffusing plate 120 facing the projection unit 110 side, and the surface 122 of the diffusing plate 120 facing the subject side (corneal side). Is diffused as illumination light L21. At least a part of the illumination light L21 diffused by the diffusion plate 120 illuminates the cornea.

In the first embodiment, the cross section of the surface 122 of the diffusion plate 120 (specifically, the cross section along the optical axis) is preferably a saw-shaped cross section. That is, the surface 122 preferably has a shape like the surface of a Fresnel lens. In particular, the cross section of the surface 122 is a saw-shaped cross section that can diffuse more illumination light L11 toward the cornea as illumination light L21 as compared to the case where the cross section of the surface 122 is not a saw-like cross section. It is preferable to become. As a result, as shown in FIG. 1, the illumination light L11 is diffused by the diffusion plate 120 so that more illumination light L11 is directed to the cornea as illumination light L21.

In the first embodiment, an opening 123 is formed in the diffusion plate 120. The eye of the subject is located at a position where the cornea can face the opening 123. The opening 123 is an opening that penetrates the diffusion plate 120 from the surface 121 toward the surface 122.

The opening 123 is an opening through which the reflected light L31 that is the illumination light L21 reflected by the cornea passes. An eyepiece lens 124 that guides the reflected light L31 to the reflection surface of the beam splitter 132 is disposed in the opening 123.

The opening 123 is further an opening through which the illumination light L12 incident on the diffusion plate 120 after passing through the beam splitter 132 passes. The illumination light L12 passing through the opening 123 is guided to the retina by the eyepiece lens 124 disposed in the opening 123. As a result, the illumination light L12 forms an image on the retina. That is, the illumination light L12 emitted from the projection unit 110 is not diffused by the diffusion plate 120. However, at least a part of the illumination light L12 emitted from the projection unit 110 may be diffused by the diffusion plate 120.

In FIG. 1, the diffusion plate 120 is a transmission type diffusion plate. However, the diffusion plate 120 may be a reflection type diffusion plate. Further, the observation apparatus 1 may include an arbitrary optical element that can diffuse the illumination light L11 incident on the diffusion plate 120 in addition to or instead of the diffusion plate 120. For example, the observation apparatus 1 may include a Fresnel lens in addition to or instead of the diffusion plate 120. Further, the cross section of the surface 122 of the diffusion plate 120 may not be a saw-shaped cross section. For example, the surface 122 of the diffusion plate 120 may be a flat surface.

The Koehler illumination lens 131, together with the projection lens 112 and the eyepiece lens 124, forms an image of the illumination light L12 on the retina. Typically, an intermediate imaging plane on which the illumination light L12 forms an image is positioned between the Koehler illumination lens 131 and the eyepiece lens 124. For example, the illumination light L12 forms an image on an intermediate image plane that coincides with the front focal point of the eyepiece lens 124 positioned between the Koehler illumination lens 131 and the eyepiece lens 124. The illumination light L11 preferably does not pass through the Koehler illumination lens 131 (that is, does not pass through the lens surface of the Koehler illumination lens 131). However, at least a part of the illumination light L11 may pass through the Koehler illumination lens 131.

The beam splitter 132 transmits the illumination light L11 and the illumination light L12 emitted from the projection unit 110. On the other hand, the beam splitter 132 reflects the reflected light L31, which is the illumination light L21 reflected by the cornea, toward the imaging unit 140.

The imaging unit 140 is a corneal reflection image of the diffusion plate 120 on which the inspection image is projected (that is, an image formed by the reflected light L31 that is the illumination light L21 reflected by the cornea, and is substantially the diffusion plate 120. The surface 122) or the surface of the cornea. In order to capture a cornea reflection image or the surface of the cornea, the imaging unit 140 includes an imaging diaphragm 141, an imaging lens 142, and an imaging element 143.

The imaging diaphragm 141 adjusts the light amount of the reflected light L31 reflected by the beam splitter 130 (more specifically, the light amount of the reflected light L31 toward the image sensor 143).

The imaging lens 142 forms an image of the reflected light L31 on the imaging device 143 (more specifically, on the imaging surface of the imaging device 143). As a result, on the image sensor 143, a cornea reflection image of the diffusion plate 120 on which the inspection image is projected or an image showing the surface of the cornea is formed.

The image sensor 143 includes a CCD sensor or a CMOS sensor that converts the reflected light L31 incident on the image sensor 143 into an electric signal. As a result, the image sensor 143 acquires an observation image that is a cornea reflection image of the diffusion plate 120 on which the inspection image is projected or an image showing the surface of the cornea. The observation image acquired by the image sensor 143 is output to the control unit 150.

The control unit 150 controls the overall operation of the observation apparatus 1. For example, the control unit 150 may include a CPU (Central Processing Unit). The control unit 150 may include a memory such as a ROM (Read Only Memory) or a RAM (Random Access Memory), for example.

Particularly in the first embodiment, the control unit 150 estimates the state of the tear film formed on the surface of the cornea by analyzing the observation image acquired by the imaging unit 140. Furthermore, the control unit 150 controls the projection unit 110 so that the illumination light L12 for forming an observation image on the retina passes through the pupil of the subject. The control unit 150 includes an image analysis unit 151 and a state estimation unit 152 mainly for estimating the tear film state. Furthermore, the control unit 150 includes a pupil detection unit 153 and a display control unit 154 in order to control the projection unit 110 so that the illumination light L12 mainly passes through the pupil of the subject.

The control unit 150 may execute a computer program on the CPU for causing the CPU to execute the operations of the image analysis unit 151, the state estimation unit 152, the pupil detection unit 153, and the display control unit 154. The control unit 150 may read such a computer program from a recording medium such as a memory, or may download the computer program via a network. As a result, the image analysis unit 151, the state estimation unit 152, the pupil detection unit 153, and the display control unit 154 function on the CPU as logical processing blocks, for example. However, at least one of the image analysis unit 151, the state estimation unit 152, the pupil detection unit 153, and the display control unit 154 may be a circuit block physically realized in the control unit 150.

The image analysis unit 151 analyzes the observation image acquired by the imaging unit 140. For example, as will be described in detail later, when an all-white inspection image is projected onto the diffusion plate 120, the image analysis unit 151 may analyze the interference color that appears in the observation image. The interference color appearing in the observation image is the color exhibited by the interference light between the reflected light L31 reflected by the surface of the oil layer and the reflected light L31 reflected by the back surface of the oil layer (that is, the interface between the oil layer and the water layer). means. For example, as will be described in detail later, when an inspection image including a linear pattern is projected on the diffusion plate 120, the image analysis unit 151 changes the temporal change (temporal) of the linear pattern appearing in the observation image. May be analyzed.

The state estimation unit 152 estimates the state of the tear film based on the analysis result of the image analysis unit 151 (in other words, measures). For example, based on the “interference color appearing in the observation image” that is an example of the analysis result of the image analysis unit 151, the state estimation unit 152 configures an “oil layer (that is, a tear film) that is an example of the state of the tear film. It is also possible to estimate the “thickness of the oil layer)”. For example, the state estimation unit 152 uses “BUT (tear film Break Up Time), which is an example of a tear film state, based on an“ analysis of a linear pattern with time ”that is an example of an analysis result of the image analysis unit 151 : Tear film destruction time: the time from when the subject's eyes open until the surface of the tear film breaks)) may be estimated.

The pupil detection unit 153 detects the position of the subject's pupil that appears in the observation image acquired by the imaging unit 140. For example, the pupil detection unit 153 detects the position of the pupil appearing in the observation image by analyzing the observation image acquired by the imaging unit 140.

The display control unit 154 controls the display element 111 so as to display an examination image used for observing the state of the tear film. Further, the display control unit 154 controls the display element 111 so that the observation image acquired by the imaging unit 140 is displayed.

In the first embodiment, the display control unit 154 controls the display element 111 so as to display the inspection image in the first display area 111a1 surrounding the second display area 111a2. Further, the display control unit 154 controls the display element 111 so as to display the observation image in the second display area 111a2 surrounded by the first display area 111a1. Therefore, the display control unit 154 displays the projection image obtained by combining the observation image and the inspection image so that the observation image overlaps the center (or the vicinity of the center) of the inspection image. The element 111 is controlled. In other words, the display control unit 154 controls the display element 111 to display a projection image obtained by combining the observation image and the inspection image so that the inspection image surrounds the observation image.

The display control unit 154 further adjusts the display position of the observation image on the display surface 111a of the display element 111 based on the detection result of the pupil detection unit 153. That is, the display control unit 154 further controls the display element 111 so as to adjust the display position of the observation image based on the detection result of the pupil detection unit 153. Specifically, the display control unit 154 adjusts the display position of the observation image on the display surface 111a so that the illumination light L12 for forming the observation image on the retina passes through the pupil. That is, the display control unit 154 adjusts the position where the second display region 111a2 is distributed on the display surface 111a.

The display position of the observation image on the display surface 111a is adjusted by adjusting the surface of the cornea (or an optical member that guides the illumination light L12 from the projection unit 110 to the retina (for example, the Koehler illumination lens 131 or the eyepiece 124). This corresponds to adjustment of the projection position of the observation image on a virtual optical surface perpendicular to the optical axis. That is, the adjustment of the display position of the observation image on the display surface 111a corresponds to the adjustment of the irradiation position of the illumination light L12 on the surface of the cornea. Therefore, it can be said that the display control unit 154 substantially adjusts the projection position of the observation image (that is, the irradiation position of the illumination light L12).

(1-2) Operation of the Observation Device 1 of the First Example Next, the operation of the observation device 1 of the first example will be described with reference to FIG. FIG. 2 is a flowchart showing a flow of operations of the observation apparatus 1 of the first embodiment.

As shown in FIG. 2, the display control unit 154 controls the display element 111 so as to display the inspection image on the display surface 111 (step S101). At this time, the display control unit 154 may control the display element 111 so as to display the inspection image on the entire display surface 111. Alternatively, the display control unit 154 displays the inspection image on the first display area 111a1 (that is, the center of the display surface 111a or the area excluding the second display area 111a2) in the display surface 111a. May be controlled. As a result, the display element 111 displays an inspection image (step S101).

Here, the inspection image will be described with reference to FIGS. 3 (a) to 3 (d). FIG. 3A to FIG. 3D are plan views each showing an inspection image.

FIG. 3A shows an inspection image displayed when the observation apparatus 1 estimates the thickness of the oil layer, which is an example of the tear film state. As shown in FIG. 3A, when the observation apparatus 1 estimates the thickness of the oil layer, the display control unit 154 displays an inspection image that is an all-white image (that is, an image that is entirely white). The display element 111 is controlled to display.

FIG. 3B shows a first example of an inspection image displayed when the observation apparatus 1 estimates a BUT that is an example of a tear film state. As shown in FIG. 3B, when the observation apparatus 1 estimates the BUT, the display control unit 154 displays an examination image that is an image of a plurality of concentric rings (that is, a multiple ring pattern). Thus, the display element 111 is controlled.

FIG. 3C shows a second example of the inspection image displayed when the observation apparatus 1 estimates the BUT. As shown in FIG. 3C, when the observation apparatus 1 estimates the BUT, the display control unit 154 replaces the inspection image that is a multiple ring pattern shown in FIG. The display element 111 may be controlled so as to display an inspection image which is an image (that is, a stripe pattern) of a plurality of straight lines or line segments.

FIG. 3D shows a third example of the inspection image displayed when the observation apparatus 1 estimates the BUT. As shown in FIG. 3D, when the observation apparatus 1 estimates the BUT, the display control unit 154 displays the inspection image that is a multiple ring pattern shown in FIG. 3B and the inspection image shown in FIG. The display element 111 may be controlled so as to display an inspection image that is an image of a lattice (that is, a lattice pattern) instead of the inspection image that is a stripe pattern.

That is, when the observation apparatus 1 estimates the BUT, the display control unit 154 displays the inspection image that is an image (that is, a linear pattern) of a plurality of straight lines, line segments, or curves. To control.

Note that the inspection image shown in FIG. 3A is merely an example of the inspection image displayed when the observation apparatus 1 estimates the thickness of the oil layer. Therefore, when the observation apparatus 1 estimates the oil layer thickness, the display control unit 154 controls the display element 111 so as to display another inspection image different from the inspection image shown in FIG. May be.

Similarly, the inspection images shown in FIGS. 3B to 3D are only examples of inspection images displayed when the observation apparatus 1 estimates the BUT. Therefore, when the observation apparatus 1 estimates the BUT, the display control unit 154 displays the other inspection image different from the inspection images shown in FIGS. May be controlled.

In FIG. 2 again, when the display element 111 displays the inspection image, illumination light L11 for projecting the inspection image onto the diffusion plate 120 is emitted from the display surface 111a (or the first display region 111a1). The illumination light L11 enters the diffusion plate 120 via the projection lens 112 and the projection stop 113. As a result, an inspection image is formed on the diffusion plate 120. The diffusion plate 120 diffuses the illumination light L11 incident on the diffusion plate 120 as illumination light L21. As a result, the illumination light L21 enters the subject's cornea. Therefore, the diffusing plate 120 functions as an illuminating plate that illuminates the eyes with a light / dark pattern corresponding to the inspection image projected by the projection unit 110. At this time, the inspection image may be formed on the cornea. Alternatively, the inspection image may not be formed on the cornea.

After that, the imaging unit 140 captures the cornea reflection image of the diffuser plate 120 on which the inspection image is projected or the surface of the cornea (step S102). As a result, the imaging unit 140 acquires an observation image that is an image reflecting the surface state of the cornea (step S102).

Here, the observation image will be described with reference to FIG. FIG. 4 is a plan view showing an observation image.

FIG. 4 shows an observation image obtained by capturing a corneal reflection image of the diffusion plate 120 when the inspection image (multiple ring pattern) shown in FIG. 3B is projected on the diffusion plate 120. Yes. As shown in FIG. 4, in the observation image, not only the inspection image (that is, a multiple ring pattern) on the diffusion plate 120 reflected in the cornea (and the eye) of the subject, but also the anterior eye of the subject. Department is included. However, when the observation apparatus 1 estimates BUT as will be described later, it is preferable that the imaging lens 142 is focused on the diffusing plate 120 reflected in the cornea, so the anterior eye portion of the subject is slightly blurred. there is a possibility.

In FIG. 2 again, the display control unit 154 synthesizes the inspection image displayed on the display element 111 in step S101 and the observation image acquired by the imaging unit 140 in step S102 (step S103). As a result, the display control unit 154 generates a projection image obtained by synthesizing the inspection image and the observation image (step S103).

Here, a projection image obtained by synthesizing the inspection image and the observation image will be described with reference to FIG. FIG. 5 is a plan view showing a projection image obtained by synthesizing the inspection image and the observation image.

As shown in FIG. 5, in the projection image, the inspection image that is a multiple ring pattern surrounds the observation image. In the projection image, the observation image is arranged at the center of the inspection image or in the vicinity of the center. For this reason, the display control unit 154 combines the inspection image and the observation image so that the inspection image surrounds the observation image (for example, the observation image is located at or near the center of the inspection image). To do. In other words, the display control unit 154 displays the inspection image in the first display area 111a1 surrounding the second display area 111a2 and displays the inspection image in the second display area 111a2 surrounded by the first display area 111a1. The inspection image and the observation image are synthesized.

In FIG. 2 again, after that, the display control unit 154 controls the display element 111 so as to display the projection image generated in step S103 (that is, an image obtained by combining the inspection image and the observation image). (Step S104). As a result, the display element 111 displays a projection image (that is, an image obtained by combining the inspection image and the observation image) (step S104).

When the display element 111 displays the projection image, the inspection image is projected onto the eye from the first display area 111a1 of the display surface 111a (more specifically, the inspection image is projected onto the diffusion plate 120). Illumination light L11 is emitted. For this reason, as described above, the diffusion plate 120 functions as an illumination plate that illuminates the eyes with a light / dark pattern corresponding to the inspection image projected by the projection unit 110.

On the other hand, when the display element 111 displays the projection image, the observation image is projected onto the eye from the second display area 111a2 of the display surface 111a (more specifically, the observation image is formed on the retina). Illumination light L12 is emitted. The illumination light L12 enters the subject's cornea via the projection lens 112, the projection stop 113, the Koehler illumination lens 131, the beam splitter 132, and the eyepiece lens 124. As a result, the illumination light L12 forms an image on the retina of the subject. Accordingly, the subject can visually recognize an observation image that is an image of the surface of the cornea on which the inspection image is projected.

Thereafter, the image analysis unit 151 analyzes the observation image acquired by the imaging unit 140 in step S102 (step S111).

For example, when the observation apparatus 1 estimates the thickness of the oil layer, the imaging unit 140 images the surface of the cornea after the focus of the imaging lens 142 is matched to the surface of the cornea. For this reason, an observation image turns into an image of the surface of the cornea illuminated by the test | inspection image which is an all-white image. In this case, the image analysis unit 151 analyzes the observation image so as to identify interference colors generated in the inspection image included in the observation image (that is, interference colors appearing in the observation image). However, the image analysis unit 151 may analyze the observation image so as to estimate a feature different from the interference color among the features of the inspection image included in the observation image.

For example, when the observation apparatus 1 estimates the BUT, the imaging unit 140 images the surface 122 of the diffusion plate 120 after matching the focus of the imaging lens 142 with the diffusion plate 120 reflected on the cornea. For this reason, the observation image becomes a cornea reflection image of the diffusion plate 120 on which the inspection image which is a multiple ring pattern is projected. In this case, the image analysis unit 151 analyzes the observation image so as to determine temporal changes (in other words, temporal changes) of the plurality of rings included in the observation image. In particular, the image analysis unit 151 analyzes the observation image so as to determine the temporal destruction status of the plurality of rings included in the observation image. Even when the display element 111 displays an inspection image having a stripe pattern or a lattice pattern, the image analysis unit 151 changes over time in a plurality of lines or lattices included in the observation image (in particular, The observation image is analyzed so as to estimate the destruction state. However, the image analysis unit 151 may analyze the observation image so as to estimate a feature different from the temporal change (particularly, the destruction state) of the plurality of lines among the features of the inspection image included in the observation image. Good.

Thereafter, the state estimation unit 152 estimates the state of the tear film based on the analysis result of the image analysis unit 151 in step S111 (step S112).

For example, when the observation apparatus 1 estimates the thickness of the oil layer, the image analysis unit 151 analyzes the observation image so as to identify the interference color generated in the inspection image included in the observation image. In this case, the state estimation unit 152 estimates the thickness of the oil layer based on the interference color corresponding to the analysis result of the image analysis unit 151. Specifically, the interference color that appears in the observation image obtained by imaging the cornea illuminated by the diffuser plate 120 onto which the inspection image that is an all-white image is projected is a color unique to the thickness of the oil layer. It tends to be. Therefore, the state estimation unit 152 can estimate the thickness of the oil layer based on the interference color corresponding to the analysis result of the image analysis unit 151. However, the state estimation unit 152 may estimate a tear film state different from the thickness of the oil layer.

For example, when the observation apparatus 1 estimates a BUT, the image analysis unit 151 determines a change with time (particularly, a destruction state) of a plurality of rings included in an inspection image included in the observation image. The observation image is analyzed. In this case, the state estimation unit 152 estimates the BUT based on changes over time of the plurality of rings corresponding to the analysis result of the image analysis unit 151 (particularly, the destruction state). Specifically, when a crack is formed on the surface of the tear film, the shapes of a plurality of rings included in the observation image are disturbed. Therefore, the state estimation unit 152 starts from the time when the subject's eyes are opened until the shapes of the plurality of rings included in the observation image are disturbed (for example, the shape of at least one of the plurality of rings is disturbed in a predetermined manner). By estimating the time, the BUT can be estimated. However, the state estimation unit 152 may estimate a tear film state different from the BUT.

Note that, as described above, the BUT is used as one of indices for diagnosing whether or not the eye of the subject is dry eye. Therefore, the observation apparatus 1 supports diagnosis of whether or not the eye of the subject is dry eye by presenting the BUT estimated by the state estimation unit 152 to the user (for example, an ophthalmologist or a subject). Good.

On the other hand, it is known that the thickness of the oil layer has a certain correlation with BUT. Therefore, the observation apparatus 1 may support diagnosis of whether or not the eye of the subject is dry eye by presenting the thickness of the oil layer estimated by the state estimation unit 152 to the user. The observation apparatus 1 estimates the BUT based on the thickness of the oil layer estimated by the state estimation unit 152 and presents the estimated BUT to the user, thereby diagnosing whether or not the eye of the subject is dry eye. May be supported.

In the first example, in addition to the observation image analysis operation in step S111 and the tear film state estimation operation in step S112, the display control unit 154 displays based on the detection result of the pupil detection unit 153. The display position of the observation image on the display surface 111a of the element 111 is adjusted.

Specifically, the pupil detection unit 153 detects the position of the subject's pupil that appears in the observation image acquired by the imaging unit 140 (step S121). For example, the pupil detection unit 153 detects the position of the pupil appearing in the observation image by analyzing the observation image acquired by the imaging unit 140.

The pupil detection unit 153 performs pattern matching processing for detecting the pattern of the pupil (or at least a part of the eye including the pupil or the pupil that surrounds the pupil) from the observation image, thereby determining the position of the pupil appearing in the observation image. It may be detected. Since the pattern matching process itself is publicly known, detailed description of the pattern matching process is omitted.

Alternatively, for example, when a multiple ring pattern is projected on the surface of the cornea as an inspection image, typically, an alignment operation is performed when the display element 111 displays the inspection image in step S101. The alignment operation is, for example, an operation of adjusting the eye position of the subject or the projection position of the examination image or the projection image so that the centers of the plurality of rings constituting the multiple ring pattern coincide with the center of the pupil. That is, the positional relationship between the plurality of rings and the pupil is a predetermined positional relationship by the alignment operation. In this case, the pupil detection unit 153 may detect the position of the pupil based on the positions of a plurality of rings in the observation image.

Alternatively, the display control unit 154 may control the display element 111 such that a marker for detecting the position of the pupil is included in the examination image. In this case, the pupil detection unit 153 may detect the position of the pupil based on the position of the marker in the observation image.

In any case, the pupil detection unit 153 detects the position of the pupil of the subject appearing in the observation image using any known or novel method.

Thereafter, the display control unit 154 passes the illumination light L12 for forming an observation image on the retina based on the detection result of the pupil detection unit 153 in step S121 (that is, the position of the detected pupil). It is determined whether or not it is possible (step S122).

For example, the display control unit 154 may determine whether or not the illumination light L12 can pass through the pupil by performing the following operation. First, the display control unit 154 calculates an optical path of the illumination light L12 for forming an observation image displayed in the second display area 111a2 on the retina. As a result, the display control unit 154 can specify the passage position of the illumination light L12 on the cornea. Thereafter, the display control unit 154 determines whether or not the passage position of the illumination light L12 on the cornea matches the position of the pupil detected by the pupil detection unit 153. That is, the display control unit 154 determines whether the passage position of the illumination light L12 on the cornea is included in the position of the pupil detected by the pupil detection unit 153. When the passage position of the illumination light L12 on the cornea matches the position of the pupil detected by the pupil detection unit 153 (that is, included in the position of the pupil detected by the pupil detection unit 153), the display control unit 154 Determines that the illumination light L12 can pass through the pupil. However, the display control unit 154 may determine whether or not the illumination light L12 can pass through the pupil using a known or new method different from the method described above.

As a result of the determination in step S122, when it is determined that the illumination light L12 cannot pass through the pupil (step S122: No), the display control unit 154 causes the illumination light L12 to pass through the pupil. The display position of the observation image on the display surface 111a is adjusted (step S123). That is, the display control unit 154 adjusts the distribution position of the second display region 111a2 on the display surface 111a so that the illumination light L12 passes through the pupil (step S123).

Here, the operation of adjusting the display position of the observation image on the display surface 111a will be described with reference to FIGS. 6 (a) to 6 (d) and FIGS. 7 (a) to 7 (e). In the following, description will be given using an example in which an inspection image that is a multiple ring pattern is projected onto the eye.

FIG. 6A shows an example in which the observation image is displayed at the display reference position that is the center of the display surface 111a. That is, FIG. 6A shows an example in which the observation image is displayed at the display reference position on the display surface 111a so that the center of the observation image matches the center of the inspection image (that is, the centers of the plurality of rings). Is shown.

Suppose that the observation image displayed at the display reference position on the display surface 111a forms an image on the retina when the pupil is located at the pupil reference position. The state in which the pupil is located at the pupil reference position is a state in which the pupil is facing directly in front of the subject as shown in FIG. In this case, as shown in FIG. 6C, in the observation image, the centers of the plurality of rings constituting the observation image displayed at the display reference position coincide with the centers of the pupils positioned at the pupil reference position. Shall. That is, the state where the pupil is located at the pupil reference position is a state where the centers of a plurality of rings constituting the observation image displayed at the display reference position in the observation image coincide with the center of the pupil.

In this case, as shown in FIG. 6D, the illumination light L12 for forming the observation image on the retina can pass through the pupil located at the pupil reference position. As a result, the illumination light L12 forms an image on the retina. That is, the observation image is formed on the retina. Accordingly, the subject can visually recognize the observation image.

Suppose that the subject moves his / her eyes as shown in FIG. 7 (a) with reference to the state shown in FIGS. 6 (a) to 6 (d). Specifically, as shown in FIG. 7A, it is assumed that the pupil is located at a position shifted by a predetermined shift amount s0 from the pupil reference position. In the example shown in FIG. 7A, the subject moves his / her eyes toward the left side (however, the left side when viewed from the subject and the right side when viewed from the projection unit 110). That is, in the example shown in FIG. 7A, the pupil is located at a position shifted by a predetermined shift amount s0 toward the left side from the pupil reference position.

FIG. 7B shows an observation image acquired by imaging the eye shown in FIG. 7A (in other words, imaging a reflection image of the diffusion plate 120 by the eye shown in FIG. 7A). . As shown in FIG. 7B, when the pupil deviates from the pupil reference position, the centers of the plurality of rings constituting the observation image displayed at the display reference position in the observation image do not coincide with the pupil center. . Specifically, the center of the pupil is located at a position shifted by a predetermined shift amount s1 from the centers of the plurality of rings constituting the observation image displayed at the display reference position. In the example shown in FIG. 7B, the center of the pupil is shifted from the center of the plurality of rings constituting the observation image displayed at the display reference position to the right side (however, right side toward the observation image). It is located at a position shifted by an amount s1. The predetermined deviation amount s1 is typically proportional to the predetermined deviation amount s0.

In this case, as shown in FIG. 7C, the illumination light L12 for forming the observation image displayed at the display reference position on the retina has a pupil located at a position shifted from the pupil reference position. Can't pass. As a result, the illumination light L12 does not form an image on the retina. That is, the observation image is not formed on the retina. Therefore, the subject cannot visually recognize the observation image.

Therefore, in the first embodiment, the display control unit 154 adjusts the display position of the observation image on the display surface 111a (that is, the position of the second display area 111a2) so that the illumination light L12 passes through the pupil. Specifically, as illustrated in FIG. 7D, the display control unit 154 displays the display position of the observation image so that the display position of the observation image coincides with a position shifted by a predetermined shift amount s2 from the display reference position. Adjust. The predetermined deviation amount s2 is typically proportional to the predetermined deviation amount s0.

In the example shown in FIG. 7D, the display control unit 154 has the display position of the observation image on the left side from the display reference position (however, the left side when viewed from the projection unit 110, the right side when viewed from the subject, and so on. ), The display position of the observation image is adjusted so as to coincide with the position shifted by the predetermined shift amount s2. That is, in the example shown in FIG. 7D, the display control unit 154 moves the observation image display position in the direction opposite to the pupil shift direction from the display reference position (that is, the pupil shift direction with respect to the reference position). The display position of the observation image is adjusted so as to coincide with the position shifted by the predetermined shift amount s2. However, depending on the design of the optical system that guides the illumination light L12 to the eye, the display control unit 154 causes the display position of the observation image to be shifted from the display reference position by the predetermined shift amount s2 in the same direction as the pupil shift direction. The display position of the observation image may be adjusted so as to coincide with.

For this reason, as shown in FIG. 7E, the optical path of the illumination light L12 changes. As a result, as shown in FIG. 7E, the illumination light L12 for forming an observation image displayed at a position shifted from the display reference position on the retina is positioned at a position shifted from the pupil reference position. Can pass through the pupil. As a result, the illumination light L12 forms an image on the retina. That is, the observation image is formed on the retina. Therefore, the subject can visually recognize the observation image even when the eye (particularly the pupil) is moved.

In FIG. 2 again, on the other hand, as a result of the determination in step S122, when it is determined that the illumination light L12 can pass through the pupil (step S122: Yes), the display control unit 154 displays the display surface. It is not necessary to adjust the display position of the observation image on 111a.

Thereafter, the operations from step S102 to step S104, from step S111 to step S112, and from step S121 to step S213 are repeated until the observation operation by the observation apparatus 1 is completed (step S131).

As described above, the observation apparatus 1 of the first embodiment can adjust the display position of the observation image on the display surface 111a based on the position of the pupil of the subject. Therefore, the subject can visually recognize the observation image even when the eye (particularly the pupil) is moved. That is, the subject can visually recognize the observation image even when the position of the eye (particularly the pupil) changes.

In addition, the observation apparatus 1 of the first embodiment can detect the position of the pupil of the subject by analyzing the observation image. Therefore, the observation apparatus 1 can detect the position of the pupil of the subject relatively easily.

In addition, the observation apparatus 1 according to the first embodiment allows the observation image and the inspection so that the inspection image surrounds the observation image (in other words, the observation image is located at or near the center of the inspection image). A projected image obtained by combining the image can be projected. Here, there is a high possibility that the pupil is located at the center of the eye (that is, the center of the surface of the eye, the surface of the anterior eye portion, or the surface of the cornea). Then, when the observation image is located at the center of the projection image, the possibility that the illumination light L12 passes through the pupil is higher than when the observation image is not located at the center of the projection image. Therefore, the observation apparatus 1 can preferably project the observation image so that the possibility that the illumination light L12 passes through the pupil is relatively high.

On the other hand, when the inspection image is located around the center of the projection image, the possibility that the illumination light L11 passes through the pupil is lower than when the inspection image is located at the center of the projection image. . That is, the possibility that the illumination light L11 is projected around the pupil increases. As a result, the subject does not visually recognize a part or all of the inspection image whose necessity for visual recognition is relatively small while appropriately viewing the observation image. Therefore, the subject can appropriately view the observation image without being bothered by the inspection image projected onto the eye together with the observation image.

The display control unit 154 may adjust the display position of the inspection image on the display surface 111a in addition to adjusting the display position of the observation image on the display surface 111a. At this time, the display control unit 154 may adjust the display position of the inspection image on the display surface 111a in an adjustment manner similar to the adjustment manner of the display position of the observation image on the display surface 111a. For example, when an inspection image that is a multiple ring pattern is projected on the eye, the display control unit 154 displays the center of a plurality of rings projected on the surface of the cornea so that it matches the center of the pupil. The display position of the inspection image on the surface 111a may be adjusted. Alternatively, when an arbitrary examination image is projected on the eye, the display control unit 154 determines that the positional relationship between the examination image projected on the surface of the cornea and the pupil is predetermined regardless of the change in the position of the pupil. The display position of the inspection image on the display surface 111a may be adjusted so that the positional relationship is satisfied.

In addition to or instead of adjusting the display position of the observation image based on the position of the pupil, the display control unit 154 directly or indirectly indicates whether or not the illumination light L12 passes through the pupil. The display position of the observation image may be adjusted based on other characteristics.

In addition to or instead of controlling the display element 111 to display the observation image in the second display region 111a2, the display control unit 154 displays an arbitrary image different from the observation image in the second display region 111a2. The display element 111 may be controlled to display. For example, the display control unit 154 may control the display element 111 such that an image indicating information useful for observation of the eye state is displayed in the second display area 111a2. As a result, the subject can appropriately recognize various information even while the observation apparatus 1 is observing the eye state. That is, the subject can appropriately recognize various information without taking his eyes off the eyepiece 124 of the diffusion plate 120.

(2) Second Example Next, the observation apparatus 2 of the second example will be described with reference to FIG. FIG. 8 is a block diagram showing the configuration of the observation apparatus 2 of the second embodiment. In addition, about the structural requirement same as the structural requirement with which the observation apparatus 1 of 1st Example is provided, the detailed description is abbreviate | omitted by attaching | subjecting the same reference number.

As shown in FIG. 8, the observation device 2 of the second example is different from the observation device 1 of the first example in place of the diffuser plate 120 and the eyepiece lens 124 in the above-described embodiment. It is different in that it includes an objective lens 220 that is a specific example. Other configuration requirements provided in the observation device 2 of the second embodiment may be the same as other configuration requirements provided in the observation device 1 of the first embodiment.

The objective lens 220 forms the illumination light L11 incident on the objective lens 220 together with the projection lens 112 on the subject's cornea (or its vicinity, the same applies hereinafter). Specifically, the objective lens 220 is, together with the projection lens 112, the illumination light L11 incident on the objective lens 220 in contact with the cornea (particularly in contact with the central portion of the cornea or the vicinity thereof) or in the vicinity of the cornea. The image is formed on a virtual imaging plane.

The objective lens 220 forms an image of the illumination light L12 incident on the objective lens 220 on the retina of the subject together with the projection lens 112 and the Koehler illumination lens 131. Typically, an intermediate imaging plane on which the illumination light L12 forms an image is positioned between the Koehler illumination lens 131 and the objective lens 220. For example, the illumination light L12 forms an image on an intermediate image plane that coincides with the front focal point of the objective lens 220 located between the Koehler illumination lens 131 and the objective lens 220.

As a result, also in the second embodiment, as in the first embodiment, the objective lens 220 functions as an illuminating plate that illuminates the eyes with a light / dark pattern corresponding to the inspection image projected by the projection unit 110, and the projection An observation image projected by the unit 110 is formed on the retina.

On the other hand, the reflected light L31, which is the illumination light L11 reflected by the cornea, enters the reflecting surface of the beam splitter 132 via the objective lens 220. For this reason, also in the second embodiment, the reflected light L31, which is the illumination light L11 reflected by the cornea, enters the imaging unit 140. As a result, the imaging unit 140 can acquire an observation image.

In the second embodiment, it is preferable that the projection stop 113 and the center of curvature of the cornea have a conjugate relationship. In this case, the illumination light L11 is incident substantially perpendicular to the cornea. As a result, the reflected light L31, which is the illumination light L11 reflected by the cornea, passes through the objective lens 220 through the optical path substantially the same as the optical path of the illumination light L11 and enters the beam splitter 132. However, in FIG. 8, for the convenience of explanation that clearly explains that the illumination light L11 reflected by the cornea is the reflected light L31, the optical path of the illumination light L11 and the optical path of the reflected light L31 are largely distinguished and described. Yes.

The observation device 2 of the second embodiment can perform the operation (that is, the operation shown in FIG. 2) performed by the observation device 1 of the first embodiment described above. As a result, the observation apparatus 2 of the second embodiment can preferably enjoy the effects that the observation apparatus 1 of the first embodiment described above can enjoy.

Note that the observation apparatus 2 may not include the Koehler illumination lens 131. In this case, the observation apparatus 2 may move the projection lens 112 along the optical axis of the projection lens 112. For example, the projection lens 112 can image the illumination light L11 on the cornea together with the objective lens 220 when the projection lens 112 is located at the first position. Similarly, for example, when the projection lens 112 is located at a second position different from the first position, the projection lens 112 can image the illumination light L12 together with the objective lens 220 on the retina. Therefore, the observation apparatus 2 projects the projection image including the inspection image and the observation image by moving the projection lens 112 so that the inspection image is projected onto the surface of the cornea and the observation image is formed on the retina. be able to. In addition, the control unit 150 may control the display element 111 such that the display element 111 displays a projection image in synchronization with the movement of the projection lens 112. When the projection lens 112 is located at the first position, the imaging unit 140 can preferably acquire an observation image because the illumination light L11 forms an image on the cornea. However, since the illumination light L12 does not form an image on the retina, the subject cannot visually recognize the observation image. On the other hand, when the projection lens 112 is positioned at the second position, the subject can visually recognize the observation image because the illumination light L12 forms an image on the retina. However, since the illumination light L11 does not form an image on the cornea, the inspection image is blurred. Therefore, if the display element 111 displays the observation image obtained by the imaging unit 140 when the projection lens 112 is located at the first position and the display element 111 is displayed when the projection lens 112 is located at the second position, the frame rate is lowered. The subject can view the observed image without the Koehler illumination lens 113. Here, when the projection lens 112 is located at the first position, the projection image displayed by the display element 111 cannot be visually recognized by the subject, so it is not necessary to combine the observation image with the inspection image, and the projection image matches the inspection image. It may be.

Alternatively, when the observation apparatus 2 does not include the Koehler illumination lens 131, the objective lens 220 passes the illumination light L11 and the lens portion that forms the illumination light L11 on the cornea and the illumination light L12. In addition, a lens portion that focuses the illumination light L12 on the retina may be provided. Alternatively, the objective lens 220 may include a lens portion through which the illumination light L11 passes and the illumination light L11 forms an image on the cornea, while an opening through which the illumination light L12 passes may be formed in the objective lens 220. As a result, the observation apparatus 2 can project a projection image including the inspection image and the observation image so that the inspection image is projected onto the surface of the cornea and the observation image is formed on the retina.

(3) Third Example Next, the observation device 3 of the third example will be described with reference to FIG. FIG. 9 is a block diagram illustrating a configuration of the observation apparatus 3 according to the third embodiment. In addition, about the structural requirement same as the structural requirement with which the observation apparatus 1 of 1st Example is provided, the detailed description is abbreviate | omitted by attaching | subjecting the same reference number.

As shown in FIG. 9, the observation apparatus 3 of the third example includes a projection unit 310 that is a specific example of the “projection unit” in the above-described embodiment and one of the “projection unit” in the above-described embodiment. A platide plate 320 that is a specific example, an eyepiece 324 that is a specific example of the “projection unit” in the above-described embodiment, a beam splitter 332, an imaging unit 140, and a control unit 350 are provided.

The projection unit 310 is different from the projection unit 110 of the first embodiment in that a relay lens 314 is provided. The projection unit 310 is different from the projection unit 110 of the first embodiment in that the inspection image is not projected (that is, the illumination light L11 is not emitted). Other configuration requirements of the projection unit 310 of the third embodiment may be the same as other configuration requirements of the projection unit 110 of the first embodiment.

The relay lens 314, together with the projection lens 112 and the eyepiece lens 324, forms illumination light L12 for forming an observation image on the retina on the subject's retina. Typically, an intermediate image plane on which the illumination light L12 forms an image is located between the relay lens 314 and the objective lens 220. For example, the illumination light L12 forms an image on an intermediate image plane that coincides with the front focal point of the eyepiece lens 324 located between the relay lens 314 and the eyepiece lens 324. Therefore, it can be said that the relay lens 314 is a lens having substantially the same function as the Koehler illumination lens 131 described above.

The platide plate 320 is a plate that illuminates the surface of the cornea with a bright and dark pattern (illumination pattern) corresponding to the inspection image. A configuration example of the platide plate 320 that projects a multiple ring pattern, which is an example of the platide plate 320, will be described. A surface 322 of the platide plate 320 facing the subject (corneal side) is a concave surface. A light transmitting portion constituting a ring pattern having a predetermined width is formed on the surface 322 of the platide plate 320 facing the subject side (corneal side). A region other than the light transmitting portion of the surface 322 becomes a light shielding portion. The platide plate 320 includes a light source (not shown) therein. The illumination light L11 emitted from the light source passes through the light transmitting part and is irradiated on the surface of the cornea. As a result, the surface of the cornea is illuminated with a light / dark pattern corresponding to the inspection image which is a multiple ring pattern.

In the third embodiment, an opening 323 is formed in the platide plate 320. The eye of the subject is located at a position where the cornea can face the opening 323. The opening 323 is an opening that penetrates the platide plate 320 from the surface 322 toward the other surface of the platide plate 320. The opening 323 is an opening through which the reflected light L31 that is the illumination light L11 reflected by the cornea passes. An eyepiece 324 that guides the reflected light L31 to the beam splitter 132 is disposed in the opening 323.

The beam splitter 332 reflects the illumination light L12 emitted from the projection unit 310 toward the placido plate 320 (particularly, the eyepiece lens 324). On the other hand, the beam splitter 332 transmits the reflected light L31 that is the illumination light L11 reflected by the cornea.

The control unit 350 is different from the control unit 150 of the first embodiment described above in that the display control unit 154 does not have to control the display element 111 so as to display an inspection image. Other configuration requirements provided in the control unit 350 of the third embodiment may be the same as other configuration requirements provided in the control unit 150 of the first embodiment.

The observation device 3 of the third embodiment can perform the operation (that is, the operation shown in FIG. 2) performed by the observation device 1 of the first embodiment described above. However, in the third embodiment, the display element 111 displays the observation image (that is, projects the image on the eye), while the platide plate 320 illuminates the eye with a light / dark pattern corresponding to the inspection image. As a result, the observation apparatus 3 of the third embodiment can preferably enjoy the effects that the observation apparatus 1 of the first embodiment described above can enjoy.

The present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the scope or spirit of the invention which can be read from the claims and the entire specification. An observation apparatus, an observation method, and a computer program with such a change are also included in the technical scope of the present invention.

1, 2, 3 Observation apparatus 110 Projection unit 111 Display element 112 Projection lens 113 Projection stop 120 Diffusion plate 124 Eyepiece lens 131 Koehler illumination lens 132 Beam splitter 140 Imaging unit 141 Imaging stop 142 Imaging lens 143 Imaging element 150 Control unit 151 Image Analysis unit 152 State estimation unit 153 Pupil detection unit 154 Display control unit 220 Objective lens 310 Projection unit 320 Placido plate 332 Beam splitter

Claims (8)

1. An observation device for observing the eye condition of a subject,
   Projecting means capable of projecting onto the eye a first image to be projected onto the cornea surface of the eye and a second image to be imaged on the retina of the eye;
   Imaging means for acquiring an observation image by imaging the eye, and
   The projection unit uses the observation image as the second image, and adjusts the projection position of the second image so that light that forms the second image on the retina passes through the pupil of the eye. An observation apparatus characterized by:
2. Further comprising detecting means for detecting the position of the pupil;
   The projection means determines the projection position of the second image based on the position of the pupil detected by the detection means so that light for forming the second image on the retina passes through the pupil of the eye. The observation device according to claim 1, wherein the observation device is adjusted.
3. The projection unit is configured to adjust the second image so that the projection position of the second image is shifted from the projection reference position by an amount corresponding to the shift amount of the current position of the pupil detected by the detection unit from the pupil reference position. The observation apparatus according to claim 2, wherein the projection position is adjusted.
4. The observation device according to claim 2, wherein the detection unit detects a position of the pupil based on the observation image.
5. 5. The projection unit according to claim 1, wherein the projection unit adjusts a projection position of the first image so that light for projecting the first image onto a surface of the cornea is projected around the pupil. The observation device according to any one of the above.
6. The projection unit projects the first image and the second image so that the projection position of the first image is distributed around the projection position of the second image on the surface of the cornea. The observation apparatus according to any one of claims 1 to 5.
7. A projection unit capable of projecting a first image to be projected onto the cornea surface of a subject's eye and a second image to be imaged on the retina of the eye, and an observation image obtained by imaging the eye An observation method for observing the state of the eye using an imaging means for
   The observation image is used as the second image, and the projection position of the second image is adjusted so that light that forms the second image on the retina passes through the pupil of the eye. To observe.
8. A projection unit capable of projecting a first image to be projected onto the cornea surface of a subject's eye and a second image to be imaged on the retina of the eye, and an observation image obtained by imaging the eye A computer program for operating an observation device for observing the state of the eye using an imaging means,
   The operation of using the observation image as the second image and adjusting the projection position of the second image so that light that forms the second image on the retina passes through the pupil of the eye A computer program that is executed by an apparatus.

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