JPS6257537A - Eyeground observing and photographing apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fundus observation and photographing device used for fundus examination and diagnosis in ophthalmology clinics and the like.

[Prior Art] In conventional fundus observation and photographing devices, the fundus of the eye is illuminated by focusing the illuminating light flux into a ring shape on the pupil of the eye being examined and spreading this light flux to a predetermined angle of view. It is common for there to be.

However, with this conventional illumination method, the illumination field is illuminated in a flat manner, making it difficult to decipher subtle edema on the fundus of the eye or blood vessels, slight cross-over phenomena of blood vessels, etc.

[Object of the Invention] The object of the present invention is to provide so-called three-dimensional illumination by imparting directionality to the light flux that illuminates the eye to be examined, thereby making it possible to detect subtle irregularities in the fundus of the eye, blood vessels, and the appearance of blood vessel intersections. An object of the present invention is to provide a high-precision fundus observation and photographing device that enables precise observation and photographing.

[Summary of the invention] The gist of the present invention is to achieve the above objects.

A fundus observation and photographing apparatus having an optical system for illuminating the fundus of an eye to be examined and an optical system for observing and photographing the fundus, the apparatus comprising means for selectively dividing and restricting a passage area of an illumination light beam in the illumination optical system. This is a fundus observation and photographing device characterized in that the fundus is provided at a position substantially conjugate with the pupil plane of the eye to be examined.

[Embodiments of the invention] The present invention will be explained in detail based on illustrated embodiments.

FIG. 1 is a configuration diagram showing an embodiment of the optical system of a fundus observation and photographing device, in which reference numeral 1 is an observation light source consisting of a tungsten lamp, etc., and the light emitted from this observation light source 1 is transmitted through a condenser lens 2, a xenon Photography light source 3 consisting of a discharge tube or the like;
The light enters the mirror 5 via the condenser lens 4, is deflected there, and sequentially passes through the liquid crystal ring slit plate 6, the relay lens 7, the liquid crystal aperture plate 8, and the relay lens 9, and reaches the perforated mirror 10. ing. The light incident on the perforated mirror IO from the above-mentioned illumination optical system is reflected by the perforated mirror 10 in the direction of the eye E to be examined, illuminates the fundus Ef of the examined eye E, passes through the original optical path, and then returns to the perforated mirror 10. It passes through the hole and reaches the observation optical system. An objective lens 11 is arranged between the perforated mirror 10 and the subject's eye E, and behind the perforated mirror 10, along the optical axis, a focusing lens 12, an imaging lens 13, a flip-up mirror 14, A shutter (not shown) and a photographic film 15 are arranged in sequence. On the reflection side of the flip-up mirror 14, a field lens 16 placed in a position conjugate with the photographic film 15, a mirror 17 for changing the optical path, and an eyepiece lens 18 are arranged in this order. Note that e is presbyopia.

In this fundus observation/photography apparatus, the observation light source 1 and the photographing light source 3 are substantially conjugate with respect to the condenser lens 2, and the observation light source 1 is turned on during observation, and the photographing light source 3 is turned on instantaneously during photography. The light source image is once formed in the vicinity of the liquid crystal ring slit plate 6 by the condenser lens 4, and then is focused on the ring slit plate 6 by the relay lens 7.9.
An image of the annular aperture is formed near the perforated mirror 10,
Here, the illumination light is reflected and travels to the left. Then, after forming an image of the annular aperture near the iris of the eye E to be examined using the objective lens 11, the fundus Ef is illuminated.

The reflected light from the fundus lj travels to the right, passes through the objective lens 11, forms an image, and then passes through the hole in the perforated mirror 10.
A focused image is formed by the focusing lens 12 and the imaging lens 13.

During observation, the fundus image is shown in the flip-up mirror 1 located at the solid line position.
4, and is observed by the examiner's eye e through the eyepiece 18. When taking a photograph, the flip-up mirror 1
4 rotates to the dotted line position, and the fundus image is formed on the photographic film 15 via the opened shutter.

The liquid crystal ring slit plate 6 is arranged at a position substantially conjugate with the pupil plane of the eye E to be examined, and has a ring-shaped opening 6A made of liquid crystal, as shown in FIG.
is further divided into a plurality of openings 6a, 6b, 6C,...
・It is made up of a transparent part that can be used as a partially transparent part by selectively changing the transmission density. On the other hand, the liquid crystal aperture plate 8
is disposed at a position substantially conjugate with the fundus Ef, and has a circular opening 8A as shown in FIG. 3, and the density within this opening 8A is variable by liquid crystal. Furthermore, the opening 8A
A plurality of openings 6 of the liquid crystal ring slit plate 6 are provided at the periphery of the liquid crystal ring slit plate 6.
A, 6b, 6C1, . . . are provided with direction marks 8a, 8b, 8C1, . It looks like this.

Therefore, by using the liquid crystal ring slit plate 6, it is possible to select illumination light beams from various directions on the pupil of the eye E to be examined as the illumination light beam for mold bottom illumination, and the accompanying increase or decrease in the amount of light can be controlled by the liquid crystal diaphragm plate 8. Since it can be selected based on density, the amount of light for observation or photography can always be kept constant. In addition,
The light amount may be adjusted by controlling the light source 1.3.
In addition, regarding the direction of the illumination luminous flux, direction marks 8a, 8
It can be displayed by b, 8c, φsha・.

FIG. 4 shows an example of a shell bottom image that is observed or photographed by illuminating with a directional light flux, that is, a light flux that has passed through the opening 6a of the liquid crystal ring slit plate 6. For example, when a blood vessel P has a raised part, shows how the shadow pt of the blood vessel P appears due to the light beam in the direction of the direction mark 8a.

Next, FIG. 5 shows an embodiment in which the above-mentioned observation or photographing is performed with further emphasis. In this Figure 5,
Components common to those in FIG. 1 are given the same reference numerals, and the mirror 17 in FIG. 1 is now a movable mirror 17a. When the movable mirror 17a is retracted from the optical path, the light beam passing through the field lens 16 is deflected by the mirror 19 and enters the imaging tube 21 via the imaging lens 20. The output of the image pickup tube 21 passes through an A/D converter 22, a frame memory 23, and a subtraction image processing section 24, and is displayed on a monitor television 25.

In this embodiment, as shown in FIG. 6, the transparent part of the liquid crystal ring slit plate 6 is made into an opening 6a, and the time is changed so that the transparent part is made almost symmetrical to the opening 6a with respect to the optical axis center O. Two fundus images when the opening 6e is in the same position are both reflected by the mirror 19 and formed on the image pickup tube 21 by the imaging lens 20, and their outputs are digitally converted by the A/D converter 22. frame memory 2
3 is stored. After that, the two fundus images enter the subtraction image processing unit 24 and undergo subtraction processing, and the pixels of the same screen, that is, the same light information, lose their characteristics due to the subtraction, and only the different parts are imaged. . Therefore, the image displayed on the monitor television 25 can show only the mutually interpolated parts, that is, the protruding parts of blood vessels that are different parts of the two fundus images, as shown by P2, for example.

[Effects of the Invention] As explained above, the fundus observation and photographing device according to the present invention has the following advantages:
By giving directionality to the light flux that illuminates the subject's eye,
The irregularities of the fundus and blood vessels are shaded and displayed three-dimensionally, making it possible to precisely observe or photograph the subtle irregularities of the fundus and blood vessels and the intersections of blood vessels, greatly improving the diagnostic ability of the fundus. This has the effect of improving the

[Brief explanation of the drawing]

The drawings show an embodiment of the fundus observation and photographing device according to the present invention. Fig. 1 is a configuration diagram of the first embodiment, Fig. 2 is a front view of a liquid crystal ring slit plate, and Fig. 3 is a liquid crystal diaphragm. FIG. 4 is a front view of the plate, FIG. 4 is an explanatory diagram of a fundus image, FIG. 5 is a configuration diagram of the second embodiment, and FIG. 6 is a front view of an example of use of the liquid crystal ring-slit plate. 1 is a light source for illumination, 3 is a strobe tube, 6 is a liquid crystal ring slit plate, 8 is a liquid crystal aperture plate, 10 is a perforated mirror, 1
1 is an objective lens, 12 is a focusing lens, 13 is an imaging lens, 14 is a flip-up mirror, 15 is a photographic film, and 17 is a mirror. 17a is a movable mirror, 18 is an eyepiece lens, 20 is an imaging lens, 2] is an image pickup tube, 22 is an A/D converter, 23 is a frame memory, 24 is a subtraction image processing unit, 25
is a monitor television. Patent applicant Canon Co., Ltd. Figure 5 Figure 6

Claims (1)

[Scope of Claims] 1. A fundus observation and photographing device having an optical system for illuminating the fundus of an eye to be examined and an optical system for observing or photographing the fundus, comprising:
A fundus observation and photographing apparatus, characterized in that means for selectively dividing and restricting the passage area of the illumination light beam is provided in the illumination optical system at a position substantially conjugate with the pupil plane of the eye to be examined. 2. The fundus observation and photographing device according to claim 1, wherein the area for selectively dividing and restricting the passage area of the illumination light beam on the pupil plane of the eye to be examined is a part of a ring-shaped area. 3. The fundus observation and photographing apparatus according to claim 1, wherein the means for selectively dividing and restricting the passage area of the illumination light beam on the pupil plane of the eye to be examined is an electro-optical light shielding means. 4. Claim 1, further comprising a light amount correction means for making the light amount of the illumination light beam constant in response to selectively dividing and restricting the passage area of the illumination light beam on the pupil plane of the subject eye. The described fundus observation and photography device. 5. Claim 1, further comprising means for creating and displaying a subtraction image based on an image obtained by operating a means for selectively dividing and restricting the passage area of the illumination light beam in the pupil plane of the subject's eye. The described fundus observation and photography device.