JPH03109032A - Eye ground camera - Google Patents

Abstract

PURPOSE:To determine a delicate change to a morbid state of eye ground and initial condition of an eye disease or the like by a method wherein the eye ground of an eye to be inspected is lighted by a luminous flux emitted from an illumination optical system to make the luminous flux emitted from a specified part on the eye ground incident into a photo detecting optical system arranged being branched off an image pickup optical system and a spectroscopic distribution is measured to give a universal color information value. CONSTITUTION:In the observation of the eye ground, light from a light source 8 is condensed again on a ring slit 13. Light leaving the slit 13 is reflected with lenses 14 and 15 once forming an image about a hole of a perforated mirror 2 to light the eye ground Ef forming an image near iris of an eye E to be inspected with an objective lens 1. Light reflected on the eye ground Ef enters the lens 1 passing through the iris again and passes through the hole of the perforated mirror 2 to form an image near a lens 16 via a half mirror 5, a spring mirror 6 and the like. Then, the light is incident into a spectroscope 20 through a mirror 18 and a lens 19 passing through a half mirror 17. Information obtained with the spectroscope 20 enters an information processing means 21 and a spectroscopic distribution characteristic is calculated to be shown on a liquid crystal display means 23.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a fundus camera that measures the spectral distribution at a predetermined position on the fundus of an eye to be examined and calculates the spectral distribution based on the measured value. .

[Prior Art] Conventionally, the use of fundus cameras has been limited to recording images of the fundus on a recording means such as film.

[Problems to be Solved by the Invention] Therefore, in addition to recording fundus images, methods for increasing the diagnostic value of fundus images include, for example, determining the progress of a disease or the state of healing based on the amount of change in a lesion. in general,
Bleeding is easy to determine when there is an obvious change in appearance, such as the appearance of vitiligo, but it is important to judge the amount of subtle change from images and diagnose subtle progress or early symptoms. It is difficult to do.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and provide a fundus camera equipped with means for measuring spectral distribution at a predetermined position on the fundus and obtaining universal color information values.

[Means for Solving the Problems] In order to achieve the above object, a fundus camera according to the present invention includes an illumination optical system that illuminates the fundus of the eye to be examined;
an imaging optical system that images the fundus; a light-receiving optical system disposed branching from the optical path of the imaging optical system; and a spectral distribution of the light flux emitted from a predetermined part on the fundus and incident on the light-receiving optical system. The present invention is characterized by comprising means for measuring the spectral distribution, means for calculating a color information value based on the spectral distribution, and display means for displaying the color information value.

[Function] The fundus camera having the above configuration illuminates the fundus of the eye to be examined with the light beam emitted from the illumination optical system.

A light beam emitted from a predetermined location on the fundus of the eye is made incident on a light-receiving optical system branched from the optical path of the imaging optical system, and the spectral distribution of the predetermined location on the fundus of the eye is measured.

[Example] The present invention will be explained in detail based on illustrated embodiments.

FIG. 1 shows a 41i diagram of the optical system, in which an objective lens 1 is provided facing the subject's eye E, and a perforated mirror 2 is provided behind it.
, focusing lens 3. A photographic lens 4, a half mirror 5, a flip-up mirror 6, and a film 7 are arranged in this order. An illumination optical system is provided on the incident side of the perforated mirror 2, and a condenser lens 9, a strobe tube 10, a condenser lens 11, a mirror 12, a ring slit 13, and a relay are sequentially arranged on the optical path from the light source 8 toward the perforated mirror 2. Lenses 14.15 are arranged. In addition, a field lens 16, a half mirror 17, a mirror 18, a relay lens 19, and a spectrometer 20 are arranged in sequence in the reflection direction when the flip-up mirror 6 is inserted into the optical path, and the output of the spectrometer 20 is It is connected to the information processing means 21. FIG. 2 is a front view of the field lens 16, in which a small circle mark 16a for determining a measurement point is drawn in the center, and a crosshair mark 16b for focusing is drawn on the outside. An eyepiece lens 22 is provided in the direction of reflection of the half mirror 17.
is provided so that the examiner's eye I can look into the eyepiece lens 22. Further, the output of the information processing means 21 is connected to a liquid crystal display means 23, and a mirror 24. relay lens 2
5 are arranged.

During fundus observation, the light emitted from the light source 8 passes through the strobe tube 10 while being focused by the condenser lens 9, and is ring-slit by the condenser lens 9 and mirror 12).
The light is again focused on 13.

The light emitted from the ring slit 13 passes through the relay lens 14.1.
5, the light is reflected while forming an image around the hole of the perforated mirror 2, and is imaged near the iris of the eye E to be examined by the objective lens 1, thereby illuminating the fundus Ef.

The light reflected by the fundus Ef passes through the iris of the eye E again, enters the objective lens l, and forms an aerial image, and then passes through the hole of the perforated mirror 2, then passes through the focusing lens 3, the photographing lens 4. The image is again formed near the field lens 16 via the half mirror 5 and the flip-up mirror 6 inserted in the optical path. Then, it passes through the half mirror 17 and the mirror 17. enters the spectrometer 20 through the relay lens 19,
The information obtained at 0 is input to the information processing means 21, where 1 spectral distribution characteristics are calculated and displayed on the liquid crystal display means 23.

Further, when photographing the fundus, the flip-up mirror 6 is removed out of the optical path and the fundus image is formed on the film 7, and the spectral information displayed on the liquid crystal display means 23 is displayed on the mirror 24, relay lens 25,
The image is imprinted on the film 7 via the half mirror 5 and photographed together with the fundus image.

In measuring the spectral distribution, the examiner determines the measurement point using the small circular mark 16a at the center of the field lens 16 through the eyepiece 22, and sets the measurement site by focusing using the crosshair mark 16b. In other words, the examiner sees a fundus image Ef' as shown in FIG. 3 through the eyepiece 22.
and marks 18a and 16b on the field lens 16.
A composite screen is observed. Then, first, the spectrometer 20 reads the information and calculates the result. here,
When S (on) is the spectral distribution of the light source 8 and P (λ) is the spectral reflectance distribution of the fundus Ef, the reflected light distribution is: S (on)・P (on) ... (1)
The number of isochromatic intervals of the human eye is Xo (in) , Yo (in) , Zo
By setting (2) and weighting equation (1) with equation (2), the tristimulus values x, y, and z of the object color can be obtained. Here, x=X (X+Y+Z) y =y (X+Y+Z), the coordinates on the CIE chromaticity diagram are obtained. Fundus Ef
Since the spectral reflectance distribution P (in) is measured by the spectrometer 20 and the information processing means 21, the x and y coordinates of a predetermined portion of the eye E on the CIE chromaticity diagram are determined by the above calculation. After the x and y coordinates are calculated by the information processing means 21, they are input to the liquid crystal display means 23 and displayed. The display on the liquid crystal display means 23 is, for example, a display screen as shown in FIG. There is. These displays 23a, 23
b is the fundus image Ef' when photographing the fundus, as shown in FIG.
At the same time, the measurement position display mark is imprinted on the film 7 and corresponds accurately to the measurement point on the limit base Ef.

In addition, the color display is as shown in Figure 6 (this, CIE
It may be displayed as a specific coordinate point P on the chromaticity diagram; the coordinate point W indicates the coordinate of white.

In the embodiment, a method of recording color information on the film 7 has been described, but it is also possible to display this on a CRT or output it to a printer. Furthermore, information can be input into a digital image recording device and saved, and used for managing personal information as the amount of change over time.

In the above embodiment, the position at which the spectral distribution on the fundus Ef is measured is fixed, but it is also possible to arbitrarily determine the measurement point. FIG. 7 shows an embodiment of the invention, in which a chart board 26 as shown in FIG. 2 is attached to the lower surface of the field lens 16 so as to be movable in a plane perpendicular to the optical axis, and this movement information is input to a position detector 27. , further connected to an image processor 28.

On the other hand, a television camera 29 is arranged instead of the film 7,
Its input is also connected to image processor 28.

Therefore, by moving the chart board 26, measurement point information at an arbitrary position and fundus image information can be synthesized.2For example, as shown in FIG.
can be recorded.

[Effects of the Invention] As explained above, the fundus camera according to the present invention is capable of measuring the spectral distribution of a predetermined region on the fundus,
Since universal color information values can be obtained based on the measured values, it is possible to grasp subtle changes in fundus lesions, ophthalmological diseases, or early symptoms of adult diseases.

[Brief Description of the Drawings] The drawings show an embodiment of the fundus camera according to the present invention, in which Fig. 1 is a configuration diagram, Fig. 2 is a front view of the field lens, Fig. 3 is an explanatory diagram of the observation screen, and Fig. 4 The figure is a front view of the liquid crystal display means.
FIG. 5 is an explanatory diagram of the photographed film, FIG. 6 is a chromaticity diagram of color information values, FIG. 7 is a configuration diagram of another embodiment, and FIG. 8 is an explanatory diagram of an observation screen. 1 is an objective lens, 2 is a perforated mirror, 3 is a focusing lens, 4 is a photographing lens, 6 is a flip-up mirror,
16 is a field lens, 20 is a spectroscope, 21 is an information processing means, 23 is a liquid crystal display means, 26 is a chart board, 27
is a position detector, 28 is an image processor,
29 is a TV camera, 30 is an image recording? is placed.

Claims (1)

[Scope of Claims] 1. An illumination optical system that illuminates the fundus of the eye to be examined, an imaging optical system that images the fundus, a light-receiving optical system that is branched from the optical path of the imaging optical system, and a predetermined area on the fundus. means for measuring the spectral distribution of the light flux emitted from the portion and incident on the light receiving optical system; means for calculating a color information value based on the spectral distribution; and display means for displaying the color information value. A fundus camera characterized by comprising: 2. The fundus camera according to claim 1, wherein the color information values are displayed as tristimulus values, chromaticity coordinates, or coordinate points drawn on a chromaticity diagram.