WO2016063345A1 - Observation device - Google Patents

Abstract

An observation device (100, 200, 300, 310, 400, 500) is provided with: a projection unit (10) equipped with a projection lens (12); and an objective lens (30, 31) for focusing light emitted from said projection unit via said projection lens onto the center of the radius of curvature of the cornea of an eye being tested. The projection lens is disposed so that light emitted from the projection unit is formed as an image on the retina of the eye being tested or near the corneal surface of the eye being tested.

Description

Observation device

The present invention relates to an observation apparatus for observing an eye, and particularly to the technical field of an observation apparatus for observing the corneal surface of an eye.

With the increase in VDT (Visual Display Terminals) work and the spread of mobile terminals such as smartphones and tablet terminals, the number of patients complaining of dry eye symptoms is increasing.

The examination of dry eye is performed by an ophthalmologist observing the state of tears using a slit lamp microscope after instilling a fluorescent stain on the patient's eyes. At this time, the ophthalmologist measures the time from when the patient opens to the time when the tear surface cracks, that is, BUT (Tear film Break Up Time), using a stopwatch. This measured time length is one of the diagnostic criteria for dry eye.

Although the above method is invasive, since the ophthalmologist directly observes the state of the tears, it can be caught without missing the tears. However, since the examination is performed by the ophthalmologist's subjectivity, the examination result may differ depending on the experience and skill level of the ophthalmologist.

By the way, a device capable of noninvasively observing the tear surface has been proposed as a device used for a dry eye screening test. Specifically, for example, an apparatus for observing the state of oil (oil layer) covering the tear surface without using a fluorescent staining liquid has been proposed (see Patent Document 1). Here, the oil layer is almost transparent to visible light like the tear, but has a reflectivity of several percent, and the oil surface reflected light and the back surface reflected light of the oil layer interfere with each other. The interference color corresponding to the thickness of the film appears.

In this type of apparatus, light emitted from a light source provided inside the apparatus is irradiated onto the corneal surface through the objective lens, and hence it is referred to as an “objective lens illumination method”.

In addition, an intraocular pressure measurement device that allows the subject himself to confirm the measurement situation has been proposed (see Patent Document 2).

Japanese Patent No. 3586039 JP-A-6-245907

The technique described in Patent Document 1 has a technical problem that the state of the oil layer can be observed, but the BUT cannot be measured. Although an apparatus for automatically measuring the BUT has been proposed, there is a technical problem in that it is necessary to separately provide an illumination plate engraved with a multiple ring pattern called a platide plate.

In the technique described in Patent Document 2, the illumination light of the anterior segment (cornea) and the light (that is, the image) visually recognized by the subject to confirm the measurement state are emitted from different light sources. This light is also a diffused light, so there is a technical problem that it is not suitable for observing the tear film surface.

The present invention has been made in view of the above problems, for example, and it is an object of the present invention to provide an observation apparatus capable of measuring a BUT by an objective lens illumination method or allowing a subject to observe the tear surface. And

In order to solve the above problems, an observation apparatus according to the present invention collects a projection unit including a projection lens and light emitted from the projection unit via the projection lens at the center of the radius of curvature of the cornea of the eye to be examined. An objective lens that emits light, and the projection lens is arranged so that the light emitted from the projection unit forms an image on the retina of the eye to be examined or in the vicinity of the corneal surface.

The operation and other advantages of the present invention will be clarified from the embodiments to be described below.

It is a conceptual diagram which shows the outline | summary of the optical system of the observation apparatus which concerns on 1st Example. It is a conceptual diagram which shows the outline | summary of the optical system of the observation apparatus which concerns on 2nd Example. It is a conceptual diagram which shows the outline | summary of the optical system of the observation apparatus which concerns on 3rd Example. It is a conceptual diagram which shows the outline | summary of the optical system of the observation apparatus which concerns on 4th Example. It is a conceptual diagram which shows the outline | summary of the optical system of the observation apparatus which concerns on 5th Example. It is a conceptual diagram which shows the outline | summary of the optical system of the observation apparatus which concerns on 6th Example.

Embodiments according to the observation apparatus of the present invention will be described.

An observation apparatus according to an embodiment includes a projection unit including a projection lens, and an objective lens that collects light emitted from the projection unit via the projection lens at the center of the radius of curvature of the cornea of the eye to be examined. Configured. Here, in particular, the projection lens is arranged so that light emitted from the projection unit forms an image on the retina of the eye to be examined or the vicinity of the corneal surface of the eye to be examined.

Here, “the light emitted from the projection unit forms an image on the retina of the eye to be examined” means that the subject is projected by the projection unit (for example, an image, a shadow (outline) of an object existing in front of the light source, etc. ) Can be recognized (that is, can be seen). On the other hand, “the light emitted from the projection unit forms an image in the vicinity of the corneal surface of the eye to be examined” means that the focus of the projection unit (strictly speaking, the focus of the projection unit through the objective lens) is the corneal surface of the eye to be examined. It means a state that is close to the vicinity (in this case, the subject cannot recognize what is projected by the projection unit).

When the projection lens is arranged so that the light emitted from the projection unit is imaged on the retina of the subject's eye, the corneal surface of the subject is totally illuminated by the light emitted from the projection unit. (Even if an image is projected, the cornea surface is not in focus, so the cornea surface can be illuminated with substantially uniform light).

For this reason, the tear film surface of the eye to be examined can be observed using the light emitted from the projection unit. In addition, if an image obtained by imaging the eye to be examined is projected from the projection unit, the subject can observe the tear fluid surface of his / her eye to be examined.

In addition, when a person other than the subject, such as an ophthalmologist, observes the tear fluid surface of the eye to be examined, it is desirable that an arbitrary image such as a landscape is projected by the projection unit. If comprised in this way, while being able to ease a test subject's tension | tensile_strength, the motion of the eye to be examined under observation can be suppressed.

On the other hand, when the projection lens is arranged so that light emitted from the projection unit is imaged near the corneal surface of the eye to be examined, for example, if an image of a multiple ring pattern is projected from the projection unit, Multiple ring patterns appear on the corneal surface of the optometer, and BUT can be measured without using a platide plate. Alternatively, for example, when white light is emitted or a solid white image is projected from the projection unit, the tear fluid surface of the eye to be examined is illuminated uniformly, so that the tear fluid surface can be observed. That is, two observations and tear surface observation can be performed by one observation device.

In one aspect of the observation apparatus according to the embodiment, the imaging device further includes an imaging unit that images the eye to be examined, and the projection unit emits projection light that projects the image captured by the imaging unit as light emitted from the projection unit. . The projection lens is arranged so that the projection light is imaged on the retina of the eye to be examined.

According to this aspect, the subject can observe the tear fluid surface of his / her eye to be examined relatively easily, which is very advantageous in practice.

In another aspect of the observation apparatus according to the embodiment, the position where the light emitted from the projection unit forms an image on the retina and the position where the light emitted from the projection unit forms an image near the corneal surface. A moving means for moving the projection lens so as to change is further provided.

According to this aspect, for example, when the image of the multiple ring pattern is projected by the projection unit, and the projection lens is moved to a position where the light emitted from the projection unit is imaged near the corneal surface of the eye to be examined. , BUT can be measured relatively easily. Alternatively, if an image obtained by imaging the eye to be examined or an arbitrary image is projected by the projection unit, and the projection lens is moved to a position where the light emitted from the projection unit is imaged on the retina of the eye to be examined, tears The liquid surface can be observed relatively easily.

The moving means may be configured such that the projection lens is manually moved, or may be configured such that the projection lens is mechanically and automatically moved. The moving means may be configured to move the projection lens itself, or may be configured to move the projection lens as a result by moving the entire projection unit.

In this aspect, the moving means is configured such that the position of the projection lens is such that the light emitted from the projection unit is focused on the retina of the eye to be examined and the light emitted from the projection unit is near the corneal surface of the eye to be examined. The projection lens may be moved so that the positions to be imaged are taken periodically and alternately.

If comprised in this way, a test subject himself can perform measurement of BUT which does not use a platide board, for example.

Specifically, for example, when the projection lens is at a position where the light emitted from the projection unit is imaged near the corneal surface of the eye to be examined, an image of a multiple ring pattern is projected from the projection unit, and the projection lens When the light emitted from the projection unit is at a position where the light is imaged on the retina of the eye to be examined, an image obtained by imaging the eye to be examined is projected from the projection unit. If the position of the projection lens is moved by the moving means at such a high speed that the subject cannot recognize the switching of the image, for example, every 1/60 second, the subject himself / herself measures the BUT without using the platide plate. It can be carried out.

In another aspect of the observation apparatus according to the embodiment, the projection unit emits projection light for projecting an image as light emitted from the projection unit. Here, in particular, the observation device is disposed on an optical path connecting the projection lens, the objective lens, and the eye to be examined, and forms projection light corresponding to the inner peripheral portion of the projected image on the retina of the eye to be examined. Further provided is a lens that forms an image of projection light corresponding to the outer peripheral portion of the projected image in the vicinity of the corneal surface of the eye to be examined.

According to this aspect, for example, if an image in which a multiple ring pattern is drawn on the outer peripheral portion and a landscape is drawn on the inner peripheral portion is projected by the projecting portion, the platid plate is suppressed while suppressing the movement of the eye to be examined. BUT can be measured without using it. Alternatively, if an image in which the outer periphery is solid white and a landscape is drawn on the inner periphery is projected by the projection unit, the tear surface can be observed while suppressing the movement of the eye to be examined. Furthermore, if the image which image | photographed the to-be-tested eye is included in the inner peripheral part of an image, a test subject himself can perform measurement of BUT or observation of the tears surface.

In another aspect of the observation apparatus according to the embodiment, the projection unit emits projection light for projecting an image as light emitted from the projection unit. Here, in particular, the projection light corresponding to the inner peripheral portion of the projected image is imaged on the retina of the eye to be examined and the projection light corresponding to the outer peripheral portion of the projected image is applied to the objective lens. An opening is formed in the vicinity of the corneal surface.

According to this aspect, similarly to the above-described aspect, it is possible to measure the BUT without using the platide plate or observe the tear surface while suppressing the movement of the eye to be examined. Furthermore, if the image which image | photographed the to-be-tested eye is included in the inner peripheral part of an image, a test subject himself can perform measurement of BUT or observation of the tears surface. Here, since an objective lens provided with an aperture may be used, an increase in the number of parts of the observation apparatus and a complicated optical system can be prevented, which is very advantageous in practice.

Embodiments according to the observation apparatus of the present invention will be described with reference to the drawings.

<First embodiment>
A first embodiment according to the observation apparatus of the present invention will be described with reference to FIG. FIG. 1 is a conceptual diagram showing an outline of the optical system of the observation apparatus according to the first example.

1, the observation apparatus 100 includes a projector 10, a beam splitter 20, an objective lens 30, a camera 40, and a projection image control apparatus 50. The “projector 10” and “camera 40” according to the embodiment are examples of the “projection unit” and the “imaging unit” according to the present invention, respectively.

The projector 10 includes a display element 11, a projection lens 12, and a projection diaphragm 13. The display element 11 has, for example, a liquid crystal panel as a spatial light modulator. For example, when the display element 11 is controlled by the projection image control apparatus 50 including a memory, a processor, and the like, for example, an image of the eye to be examined, an image of a multiple ring pattern, an image of a landscape, a single color, and the like Are projected by the projector 10.

The camera 40 includes an imaging lens 41 and a light receiving element 42. The camera 40 is connected to the projection image control device 50, and for example, an output signal of the light receiving element 42 is transmitted to the projection image control device 50.

In FIG. 1, the projection lens 12, the objective lens 13, and the imaging lens 41 are each depicted as a single lens, but may be configured by combining a plurality of convex lenses and concave lenses.

Light emitted from the display element 11 of the projector 10 (hereinafter referred to as “projection light” as appropriate) passes through the projection lens 12, the projection diaphragm 13, the beam splitter 20, and the objective lens 30, and the curvature radius of the cornea of the eye to be examined. (See the solid line in FIG. 1). The light reflected by the cornea of the eye to be examined enters the light receiving element 42 via the objective lens 30, the beam splitter 20, and the imaging lens 41 (see the dotted line in FIG. 1).

Note that the projection light can be incident substantially perpendicularly to the cornea by being focused on the center of the radius of curvature of the cornea of the eye to be examined.

In this embodiment, in particular, the projection lens 12 is arranged so that the projection light (that is, the projection image) is imaged on the retina of the eye to be examined. Here, in order to form the projection image on the retina of the eye to be examined, the projection image is temporarily formed in the vicinity of the position away from the front principal point of the objective lens 30 by the front focal length (see the broken line a in FIG. 1). . That is, the focus of the projector 10 matches the broken line a in FIG. In this case, since the focus of the projector 10 is greatly deviated on the corneal surface of the eye to be examined, the corneal surface is illuminated with light of substantially uniform intensity (so-called Koehler illumination).

Here, in this embodiment, the convergence of light emitted from the entire display element 11 (that is, the surface light source) to one point is called “condensing”. Focusing the light emitted from each of the plurality of pixels (that is, the point light source) constituting the display element 11 is called “imaging”.

According to the observation apparatus 100 according to the present embodiment, first, the tear fluid surface of the eye to be examined can be observed using the projection light of the projector 10. Next, if the image of the eye to be examined picked up by the camera 40 is projected by the projector 10, the subject can observe the tear fluid surface of his / her eye to be examined.

It should be noted that the camera 40 may be connected to a television monitor or the like not shown here, and an ophthalmologist or the like may observe the tear film surface, for example. In this case, an arbitrary image or video such as a landscape may be projected by the projector 10 in order to relieve the tension of the subject and to suppress the movement of the eye to be examined during observation.

The projection aperture 13 is configured such that the size of the opening can be changed. For this reason, it is possible to limit the projection light to only the light projected more perpendicularly to the cornea of the eye to be examined.

<Second embodiment>
A second embodiment according to the observation apparatus of the present invention will be described with reference to FIG. The second embodiment is the same as the first embodiment described above except that the position of the projection lens is different. Therefore, in the second embodiment, the description overlapping with that of the first embodiment is omitted, and the common portions on the drawing are denoted by the same reference numerals, and only fundamentally different points are described with reference to FIG. explain. FIG. 2 is a conceptual diagram showing an outline of the optical system of the observation apparatus according to the second example.

In the observation apparatus 200 according to the second embodiment, the projection lens 12 is arranged so that the projection light is imaged near the corneal surface of the eye to be examined. For this reason, the projector 10 is focused near the position away from the rear principal point of the objective lens 30 by the rear focal length (see the broken line b in FIG. 2).

For example, when an image of a multiple ring pattern is projected by the projector 10, the multiple ring pattern appears on the cornea surface of the eye to be inspected, so that BUT can be measured without using a platide plate.

Here, since the opening of the projection diaphragm 13 is configured to be changeable, by changing the opening, blurring of the ring pattern on the outer peripheral portion of the black eye of the eye to be examined is suppressed due to the curvature of the cornea. be able to. As a result, an image of the eye to be examined in which a relatively clear ring pattern appears can be taken by the camera 40, which is very advantageous in practice.

Alternatively, for example, when a white solid image is projected by the projector 10, the tear fluid surface of the eye to be examined is illuminated uniformly, so that the tear fluid surface can be observed.

As a result, BUT measurement and tear surface observation can be performed by one observation apparatus 200 according to the present embodiment.

<Third embodiment>
A third embodiment according to the observation apparatus of the present invention will be described with reference to FIG. The third embodiment is the same as the first embodiment described above except that the position of the projection lens can be changed. Accordingly, the description of the third embodiment that is the same as that of the first embodiment is omitted, and common portions in the drawing are denoted by the same reference numerals, and only fundamentally different points are described with reference to FIG. explain. FIG. 3 is a conceptual diagram showing an outline of the optical system of the observation apparatus according to the third example.

The observation apparatus 300 according to the third embodiment includes a projection lens moving mechanism 51 that can move the projection lens 12 along the optical axis direction.

The projection lens moving mechanism 51 is configured such that the position of the projection lens 12 is a position where the projection light is imaged on the retina of the eye to be examined (see the position of the projection lens 12 drawn by a solid line in FIG. 3), and the projection light is the eye to be examined. The projection lens 12 is moved so as to change between the position where the image is formed in the vicinity of the corneal surface (see the position of the projection lens 12 ′ drawn with a broken line in FIG. 3). The projection lens moving mechanism 51 may be configured to manually move the projection lens 12 or may be configured to automatically move the projection lens 12 in accordance with an operator's instruction.

The projection lens moving mechanism 51 is connected to the projection image control device 50. The projection image control device 50 changes the image displayed on the display element 11 based on the signal indicating the position of the projection lens 12 output from the projection lens moving mechanism 51.

Specifically, for example, when the projection lens 12 is located at a position where the projection light is imaged on the retina of the eye to be examined, the projection image control device 50 captures the image of the eye to be examined imaged by the camera 40 or scenery. The display element 11 is controlled so that an arbitrary image is displayed on the display element 11. As a result, the BUT can be measured by the subject himself or a person different from the subject such as an ophthalmologist without using the platide plate.

On the other hand, when the projection lens 12 is at a position where the projection light is imaged in the vicinity of the corneal surface of the eye to be examined, the projection image control device 50 causes the display element 11 to display an image of the multiple ring pattern. The display element 11 is controlled. As a result, the tear surface can be observed.

Note that when the position of the projection lens 12 is a position where the projection light is imaged on the retina of the eye to be examined, visible light is output, and the position of the projection lens 12 is connected to the vicinity of the corneal surface of the eye to be examined. The projector 10 may be configured to output infrared light when the position is an image.

Further, the projection lens moving mechanism 51 may be configured to change the position of the projection lens 12 by moving the entire projector 10 along the optical axis direction.

<Fourth embodiment>
A fourth embodiment according to the observation apparatus of the present invention will be described with reference to FIG. The fourth embodiment is the same as the third embodiment described above except that the projection lens moving mechanism is configured to move the projection lens at a relatively high speed. Accordingly, the description of the fourth embodiment that is the same as that of the third embodiment is omitted, and the same reference numerals are given to the common portions on the drawing, and only the points that are fundamentally different refer to FIG. explain. FIG. 4 is a conceptual diagram showing an outline of the optical system of the observation apparatus according to the fourth example.

In the observation apparatus 310 according to the fourth example, the projection lens 12 forms an image of the projection light on the retina of the eye to be examined at such a high cycle that the subject cannot recognize the switching of the image, for example, every 1/60 second. The projection lens moving mechanism 51a is configured to move the projection lens 12 so that the position where the projection light is imaged and the position where the projection light is imaged near the corneal surface of the eye to be examined are alternately taken.

When the projection lens 12 is at a position where the projection light is imaged on the retina of the eye to be examined, the projection image control device 50 displays the image of the eye to be examined captured by the camera 40 on the display element 11. When the display element 11 is controlled and the projection lens 12 is at a position where the projection light is imaged near the corneal surface of the eye to be examined, the display is performed so that an image of a multiple ring pattern is displayed on the display element 11. The element 11 is controlled. As a result, the subject himself / herself can perform BUT measurement without using the platide plate.

When the subject himself / herself does not measure BUT, the projection image control device 50 allows the projection lens 12 to be an arbitrary image such as a landscape when the projection lens 12 is in a position where the projection light is imaged on the retina of the eye to be examined. However, the display element 11 is controlled to be displayed on the display element 11. If comprised in this way, while being able to ease a test subject's tension | tensile_strength, the motion of the eye to be examined during measurement can be suppressed.

In addition, the switching of the imaging position is not necessarily periodic and alternating, and may be a non-periodic switching.

<Fifth embodiment>
5th Example which concerns on the observation apparatus of this invention is described with reference to FIG. The fifth embodiment is the same as the second embodiment described above except that a part of the optical system is different. Accordingly, the description of the fifth embodiment that is the same as that of the second embodiment is omitted, and common portions in the drawing are denoted by the same reference numerals, and only fundamentally different points are described with reference to FIG. explain. FIG. 5 is a conceptual diagram showing an outline of the optical system of the observation apparatus according to the fifth example.

In the observation apparatus 400 according to the fifth example, the projection lens 12 is arranged so that the projection light is imaged in the vicinity of the corneal surface of the eye to be examined, as in the second example. In other words, the focus of the projector 10 itself is in the vicinity of a position away from the rear principal point of the objective lens 30 by the rear focal distance (see the broken line b in FIG. 5).

As described above, the observation apparatus 200 according to the second embodiment can measure BUT without using a platide plate, but the subject himself cannot measure BUT.

Therefore, the observation apparatus 400 according to the present embodiment couples light corresponding to the inner peripheral portion of the image projected by the projector 10 on the optical path connecting the projector 10, the objective lens 30, and the eye to be examined to the retina of the eye to be examined. A Koehler illumination lens 60 for imaging is further provided.

The Koehler illumination lens 60 is large enough not to interfere with the light corresponding to the outer peripheral portion of the projected image so that the light corresponding to the outer peripheral portion of the projected image is imaged near the cornea surface of the eye to be examined. Is set.

Note that “light corresponding to the inner periphery of the projected image” ideally means light that illuminates (transmits) the pupil part of the eye to be examined, but practically illuminates the pupil part. It may mean light that illuminates a range that is somewhat wider or narrower than the pupil portion. “Light corresponding to the outer peripheral portion of the projected image” means light other than light corresponding to the inner peripheral portion of the projected image among the projected light.

The Koehler illumination lens 60 is located in the vicinity of a position away from the front principal point of the objective lens 30 by the front focal length in order to focus the light corresponding to the inner periphery of the projected image on the retina of the eye to be examined (FIG. 5). Once (see the broken line a). That is, the Kohler illumination lens 60 adjusts the focus on the inner periphery of the projected image to the broken line a in FIG.

If an image displayed on the display element 11 (that is, an image to be projected) is an image in which, for example, a multiple ring pattern is drawn around the image of the eye to be inspected captured by the camera 40, the Kohler illumination lens 60 By the action, an image of the eye to be examined corresponding to the inner periphery of the projected image is formed on the retina of the eye to be examined. On the other hand, a multiple ring pattern corresponding to the outer peripheral portion of the projected image without passing through the Koehler illumination lens 60 is imaged near the corneal surface of the eye to be examined. As a result, the subject himself / herself can perform BUT measurement without using the platide plate.

Note that the subject himself / herself can also perform BUT measurement in the observation apparatus 310 according to the fourth embodiment described above, but the observation apparatus 400 according to the present embodiment is a projection that is a drive mechanism, compared to the observation apparatus 310. Since there is no lens moving mechanism 51a, it is possible to reduce the probability of occurrence of a malfunction of the apparatus, and to reduce the size and weight.

When a BUT measurement is performed by observing an image of the eye to be examined captured by the camera 40 by a person other than the subject, such as an ophthalmologist, for example, an arbitrary image such as a landscape is projected on the image. It may be adopted as an image corresponding to the inner periphery of the.

<Sixth embodiment>
A sixth embodiment according to the observation apparatus of the present invention will be described with reference to FIG. The sixth embodiment is the same as the second embodiment described above except that a part of the optical system is different. Accordingly, the description of the sixth embodiment that is the same as that of the second embodiment is omitted, and common portions in the drawing are denoted by the same reference numerals, and only fundamentally different points are described with reference to FIG. explain. FIG. 6 is a conceptual diagram showing an outline of the optical system of the observation apparatus according to the sixth example.

In the observation apparatus 500 according to the sixth example, the projection lens 12 is arranged so that the projection light is imaged in the vicinity of the corneal surface of the eye to be examined, as in the second example. In other words, the focus of the projector 10 itself is in the vicinity of a position away from the rear principal point of the objective lens 30 by the rear focal distance (see the broken line b in FIG. 6).

As described above, the observation apparatus 200 according to the second embodiment can measure BUT without using a platide plate, but the subject himself cannot measure BUT.

Therefore, in the observation apparatus 500 according to the present embodiment, an opening 32 is provided in the objective lens 31 so that light corresponding to the inner peripheral portion of the image projected by the projector 10 is imaged on the retina of the eye to be examined. Yes. In other words, the projection lens 12 forms an image of projection light that passes through other than the opening 32 of the objective lens 31 on the corneal surface of the eye to be examined, and also forms projection light that passes through the opening 32 of the objective lens 31 on the retina of the eye to be examined. Is arranged to be.

If an image displayed on the display element 11 (that is, an image to be projected) is an image in which, for example, a multiple ring pattern is drawn around the image of the eye to be examined captured by the camera 40, the projected image An image of the eye to be examined corresponding to the inner periphery is formed on the retina of the eye to be examined, and a multiple ring pattern corresponding to the outer periphery of the projected image is formed in the vicinity of the corneal surface of the eye to be examined. As a result, the subject himself / herself can perform BUT measurement without using the platide plate.

The present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the gist or concept of the invention that can be read from the claims and the entire specification, and an observation apparatus with such a change can also be used. It is included in the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 10 ... Projector, 11 ... Display element, 12 ... Projection lens, 13 ... Projection aperture, 20 ... Beam splitter, 30, 31 ... Objective lens, 40 ... Camera, 41 ... Imaging lens, 42 ... Light receiving element, 50 ... Projection image control Device, 51, 51a ... Projection lens moving mechanism, 60 ... Kohler illumination lens, 100, 200, 300, 310, 400, 500 ... Observation device

Claims (6)

A projection unit comprising a projection lens;
An objective lens for condensing the light emitted from the projection unit via the projection lens at the center of the curvature radius of the cornea of the eye to be examined;
With
The observation device, wherein the projection lens is arranged so that light emitted from the projection unit forms an image on the retina of the eye to be examined or in the vicinity of the corneal surface. An imaging unit that images the eye to be examined;
The projection unit emits projection light that projects an image captured by the imaging unit as light emitted from the projection unit,
The observation apparatus according to claim 1, wherein the projection lens is arranged so that the projection light is imaged on the retina. The projection lens is moved so that the light emitted from the projection unit changes to a position where the light emitted from the projection unit forms an image on the retina and a position where the light emitted from the projection unit forms an image near the corneal surface. The observation apparatus according to claim 1, further comprising a moving unit. The moving means includes a position of the projection lens, a position where light emitted from the projection unit is imaged on the retina, and a position where light emitted from the projection unit is imaged near the corneal surface. The observation apparatus according to claim 3, wherein the projection lens is moved so as to be periodically and alternately. The projection unit emits projection light for projecting an image as light emitted from the projection unit,
The projection lens, the objective lens, and the eye to be examined are arranged on an optical path, and the projection light corresponding to the inner periphery of the projected image is imaged on the retina, and the outer periphery of the projected image The observation apparatus according to claim 1, further comprising: a lens that forms an image of projection light corresponding to the image near the corneal surface. The projection unit emits projection light for projecting an image as light emitted from the projection unit,
Projection light corresponding to the inner peripheral portion of the projected image is focused on the retina, and projection light corresponding to the outer peripheral portion of the projected image is condensed on the objective lens near the corneal surface. The observation apparatus according to claim 1, wherein an opening that is imaged is provided.

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