JPS60126137A - 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 The present invention relates to a fundus observation and photographing device that detects the opacity of the crystalline lens of an eye to be examined.

Generally, when observing and photographing the fundus using a fundus camera,
It is well known that reflected and scattered light from illumination light on the cornea and crystalline lens of the eye to be examined mixes into the photographing light flux and deteriorates image quality. On the other hand, it is well known that even if the light beams are completely separated in regions such as the cornea and crystalline lens, as the opacity of the crystalline lens increases, the amount of scattering increases, resulting in a decline in image quality.

An object of the present invention is to provide a fundus observation and photographing device that detects the degree of opacity of a transparent body such as a crystalline lens in an eye to be examined, and improves the diagnostic function of a transparent body opaque eye. This patent is characterized by having means for projecting an index image onto the fundus in an optical system that illuminates the fundus, and means for measuring the amount of light corresponding to the opacity of the eye to be examined in a portion corresponding to the index image. .

The present invention will be explained in detail below based on illustrated embodiments.

FIG. 1 is a configuration diagram showing an example of the optical system of a fundus camera. 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 discharge tube, etc. The light enters a mirror 5 through a photographic light source 3 and a condenser lens 4, is deflected there, and then passes through a ring slit plate 6, a relay lens 7, an index 8 that can be inserted and removed from the optical path, and a relay lens 9. and reaches the perforated mirror IO.

The light incident on the perforated mirror 10 from this illumination optical system is
It is reflected in the direction of the eye E by the perforated mirror 10, irradiates the fundus Ef of the eye E, is reflected there, passes through the original optical path, and is further transmitted through the perforated mirror 10 to reach the observation optical system. Become. An objective lens 11 is arranged between the perforated mirror 10 and the subject's eye E, and behind the perforated mirror 10, a photographic lens 12, a flip-up mirror 13, and a photographic film 14 are sequentially arranged along the optical axis. Arranged. On the reflective side of the flip-up mirror 13, a half mirror 15, a field lens 16 placed in a position conjugate with the photographic film 14, a mirror 17 for changing the optical path, are arranged in sequence along the optical axis.
Finders 18 are arranged. Also, half mirror
15, a -dimensional solid-state image sensor 19 is placed at a position conjugate with the photographic film 14, and a field lens 16
A display device 20, such as a light emitting diode, is provided near the viewfinder 18. Note that e is the examiner's eye, and a short wavelength cut filter 21 is arranged in a removable manner between the mirror 5 and the ring slit [6].

In this fundus camera, 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 is turned on during observation, and the photographing light source 3 is turned on instantaneously during photography. The light source image is once formed near the ring slit plate 6 by the condenser lens 4, and then an image of the annular opening of the ring slit plate 6 is formed near the perforated mirror 10 by the relay lens 7.9, where the illumination is performed. The light is reflected and travels to the left. Then, after forming an image of the annular aperture near the crystalline lens of the eye E to be examined using the objective lens 11, the fundus Ef is illuminated.

The reflected light from the fundus Ef travels to the right and is once imaged by the crystalline lens and objective lens 11, then passes through the perforated mirror 10 and a photographing aperture (not shown), and is focused and imaged by the photographing lens 12.

During observation, the fundus image is shown in the flip-up mirror 1 located at the solid line position.
3 and is observed by the examiner's eye e through the finder 18. When taking a photograph, the flip-up mirror 13 rotates to the dotted line position as shown by the arrow, and the fundus image passes through an open shutter (not shown). Shooting film 14
image on top.

The index 8 inserted into the illumination optical system to form a target image on the fundus Ef is movable in the optical axis direction, and performs linear imaging in a direction perpendicular to the longitudinal direction of the -dimensional solid-state image sensor 19. It has an image pattern. For example, when moving the photographic lens 12 for focusing,
The index 8 is configured to maintain a conjugate relationship with the fundus Ef and the photographic film 14 in conjunction with the photographic lens.

FIG. 2 shows an image observed through the finder 18 when the index 8 is well focused on the fundus Ef, and an index image 8a of the index 8 is observed on the fundus Ef.

An index image 8a of the index 8 formed on the fundus Ef is orthogonally projected onto the one-dimensional solid-state image sensor 19 via the half mirror 15. Figure 3 shows this situation.The output on the image sensor 19 when the image is well-focused on the fundus Ef differs depending on the opacity of the transparent body of the eye to be examined, so the opacity can be detected by the magnitude of the output. can do.

FIGS. 4 and 5 are examples showing the output of the image sensor 19 for a standard eye and a cloudy eye, respectively. At the position of the index image 8a on the image sensor 19, the outputs are II and I2, respectively. That is, since the output in FIG. 5 is due to a cloudy eye, I2>I, due to an increase in flare components due to scattered light.
becomes.

For example, in Fig. 1, this result shows that the field lens 1
This can be indicated by the display means of the display 20 placed near 6. FIG. 6 shows an example in which the indicator 20 is turned on when the intensity exceeds the degree of turbidity, and the viewfinder 18 displays the lighting 20a as a warning. Here, if the display 20 is to display numbers, the numerical value of the turbidity will be displayed on the seventh screen.
It can be observed as shown in the figure.

Next, to describe the procedure for photographing the fundus, after focusing on the fundus Ef, the index 8 and flip-up mirror 13 are
The photographing light source 3 is caused to emit light. As a result, fundus E
The image of f is recorded on the photographic film 14. At this time, data on the opacity of the subject's eye from the previous observation is simultaneously recorded on the photographic film 1.
4 can also be recorded. FIG. 9 shows an example of this recording device, in which data is displayed on a display 22 such as a light emitting diode, and is recorded on a photographic film 14 via a lens 23 and a mirror 24. FIG. 10 shows an example of the recording. For example, the turbidity is expressed numerically as 5.6.

Furthermore, if the turbidity exceeds the standard value during imaging, it is preferable to insert a removable short-wavelength filter 21 into the optical path as shown in Fig. 1. . For example, as shown in FIG. 8, this filter 21 has a characteristic of cutting light of 45 Or+m or less, which is likely to cause scattering. This short wavelength cut is generally performed when the wavelength input is ≦λ.

(However, a filter that cuts light in the short wavelength region of 500 r+m > 350 r+m) is practically sufficient. By using this short wavelength cut filter 21, scattering in the eye to be examined can be reduced and the freshness of the image can be improved.

Although the above embodiment shows the case where the turbidity is measured using observation light, if the index 8 is always placed, it is also possible to measure and calculate the turbidity using strobe light during photographing. It goes without saying that fundus photography can also be performed by inserting the short wavelength cut filter 21 according to the above procedure.

As explained above, the fundus observation and photographing device according to the present invention,
By detecting the opacity of the transparent body of the subject's eye, it is possible to accurately determine the degree of cataract, etc., and if necessary, by inserting a short wavelength cut filter that reduces scattered light according to the degree, It becomes possible to obtain a fundus observation photographed image with excellent image quality, which can greatly contribute to the diagnosis of opaque eyes.

[Brief explanation of the drawing]

The drawings show an embodiment of the fundus observation and photographing device according to the present invention,
Figure 1 is its configuration diagram, Figure 2 is an explanatory diagram of the index projected onto the fundus of the eye, Figure 3 is an explanatory diagram of the index image projected onto the image sensor, and Figures 4 and 5 are the index images. Figure 6 is an explanatory diagram showing the turbidity warning display from one light on, Figure 7 is an explanatory diagram showing the turbidity based on the measured value, and Figure 8 is the scattering according to the turbidity. FIG. 9 is a block diagram of a device for recording turbidity on film, and FIG. 10 is an explanatory diagram of a fundus photograph displaying turbidity. 1 is an observation light source, 3 is a photography light source, 6 is a ring slit plate,
8 is an index, 8a is an index image, 10 is a six-opening mirror, 11 is an objective lens, 12 is a photographic lens, 13 is a flip-up mirror, 14 is a photographic film, 15 is a half mirror, 119 is a one-dimensional solid-state image sensor, 20. 22 is a display, and 21 is a short wavelength cut filter. Patent applicant: Canon Co., Ltd. Drawings Figure 2 Figure 3 JP-A-Sho GO-126137 (4) Figure 4

Claims (1)

[Scope of Claims] 1. Means for projecting an index image onto the fundus of the eye into an optical system that illuminates the fundus of the eye to be examined, and means for measuring the amount of light corresponding to the opacity of the eye to be examined in a portion corresponding to the index image. A fundus observation and photographing device characterized by having the following. 2. The fundus observation and photographing apparatus according to claim 1, wherein the display means displays a display according to the degree of opacity of the eye to be examined depending on the amount of light. 3. The fundus observation and photographing apparatus according to claim 1, wherein means for projecting the index image onto the fundus is provided in a manner that can be freely inserted into and removed from the illumination optical path. 4. The fundus observation and photographing apparatus according to claim 2, wherein the display by the display means is recorded on a photographic film when photographing the fundus. 5. The fundus observation and photographing device according to claim 1, wherein a short wavelength cut filter for cutting short wavelength region light is provided in the optical path so as to be freely inserted into and removed from the optical path.