JPH0365969B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ophthalmological apparatus that detects the blinking of an eye to be examined in an instrument that photographs the fundus of the eye, measures the refractive power of the eye, and the shape of the cornea.

Observation and photography of the fundus of the eye are widely practiced not only in ophthalmological diagnosis but also in the field of adult disease screening such as hypertension and diabetes testing, and non-mydriatic fundus cameras have become particularly popular in the field of adult disease screening. However, in the case of this non-mydriatic fundus photography, once the photographing light is emitted, miosis occurs, and a waiting time is required before the pupil can be naturally mydriatic again, and good photographic results cannot be obtained. If there is no such thing, there will be a huge waste of time redoing the shooting. Therefore, how to prevent failure due to blinking of the eye to be examined becomes an important issue.

An object of the present invention is to solve the above-mentioned problems, and to provide an ophthalmological apparatus that detects whether or not the subject's eye blinks and stops emitting light from a photographing light source as necessary. The gist is that in an apparatus equipped with means for projecting illumination light onto the subject's eye for photographing or measurement, and means for receiving the reflected light,
a projection means for projecting a light beam for eyelid detection separate from the illumination light from obliquely upward toward the upper part of the iris of the eye to be examined; Detection of blinking by determining the positional displacement of the reflected light in the movement direction of the eyelids on the light position detection means and the light position detection means to be detected due to the difference in level corresponding to the thickness of the eyelids when the eyelids are open and when the eyelids are closed. It is characterized by having means.

FIG. 1 is a block diagram showing one embodiment of the present invention applied to a fundus camera. Reference numeral 1 is an observation light source consisting of a tungsten lamp, etc. The light emitted from this observation light source 1 is transmitted through a condenser lens 2a, The light enters a mirror 5 through a filter 3, a photographing light source 4 consisting of a xenon discharge tube, etc., and a condenser lens 2b, where it is deflected and sequentially passes through a ring slit plate 6, relay lenses 7a and 7b, and then enters a perforated mirror 8. I'm starting to reach it. The light that enters the perforated mirror 8 from the above-mentioned illumination optical system is reflected by the perforated mirror 8 in the direction of the eye E to be examined, illuminates the fundus Ef of the examined eye E, returns to the original optical path, and then returns to the perforated mirror 8. and reaches the observation optical system. An objective lens 9 is arranged between the perforated mirror 8 and the subject's eye E, and a focusing lens 1 is arranged behind the perforated mirror 8 along the optical axis.
0, a projection lens 11, a flip-up mirror 12, a shutter 13, and a photographic film 14 are arranged in sequence. On the reflection side of the flip-up mirror 12, a field lens 15 placed at a position conjugate with the photographic film 14, a mirror 16 for changing the optical path, a TV lens 17, and an image pickup tube 18 are arranged in sequence along the optical axis. There is.

Further, an illumination light source 19 for eyelid detection is arranged on the side of the objective lens 9, and a mask plate having a slit-shaped opening 20a as shown in FIG. 20. Photographing lenses 21 are sequentially arranged, and the reflected light from the anterior segment of the subject's eye is transmitted to an image receiving lens 22 and a line sensor 2 placed symmetrically with the illumination light source 19 with an objective lens 9 in between.
It is designed to be incident on 3.

In this fundus camera, the illumination light source 1 and the photography light source 4 are substantially conjugate with respect to the condenser lens 2a, and the observation light source 1 is turned on during observation, and the photography light source 4 is turned on instantaneously during photography. A light source image is once formed near the ring slit plate 6 by another condenser lens 2b, and then an image of the annular opening of the ring slit plate 6 is formed near the perforated mirror 8 by relay lenses 7a and 7b.
Here, the illumination light is reflected and travels to the left. Then, after forming an image of the annular aperture near the cornea of the eye E to be examined using the objective lens 9, the fundus Ef is illuminated.

The reflected light from the fundus Ef travels to the right, and after being imaged by the cornea and objective lens 9, it passes through the perforated mirror 8 and is focused by the focusing lens 10 and the photographing lens 11. Become. During observation, the fundus image is guided upward by the flip-up mirror 12 located at the solid line position, and is converted into an image by the image pickup tube 18 via the TV lens 17. During photography, the flip-up mirror 12 rotates to the dotted line position. The fundus image is formed on a photographic film 14 via an open shutter 13.

The optical system from the illumination light source 19 to the line sensor 23 is for detecting blinking, and the illumination light source 19 is provided diagonally above the eye E to be examined, and in front of this illumination light source 19 is a system shown in FIG. A mask plate 20 having a slit 20a and a photographing lens 21 are arranged as shown in FIG.

The eyelid detection light flux emitted from the illumination light source 19 is
The light beam passes through the slit 20a of the mask plate 20, becomes a slit-shaped light beam at the photographing lens 21, and illuminates the upper part of the iris Ei of the eye E as shown in FIG. Then, the reflected light of the slit illumination light on the iris Ei is projected onto the line sensor 23 via the image receiving lens 22. The slit illumination section P1 on the iris Ei forms an image on the line sensor 23 at a position Q1. Here, when the eyelid El falls due to blinking of the eye E to be examined, the slit illumination part moves to the eyelid El, and the reflection position of the slit illumination part P2 moves forward due to the thickness of the eyelid El.
The image forming position on the line sensor 23 shifts to Q2 as shown in FIG. Therefore, when you blink, the illumination area on the line sensor 23 changes from Q1 to Q2.
, and is detected as a movement on the coordinates on the line sensor 23. This signal can be connected to a display means (not shown) to issue a warning by emitting light or making a sound, or to stop the light emission of the photographing light source 4, or the like.

Since the eyelid detection light beam is projected onto the upper part of the iris Ei from diagonally above, movement of the eyelid El can be detected quickly. Furthermore, the light projected onto the upper part of the iris Ei from above has the advantage that the influence of scattering by the corneal surface is less than that of light projected onto the upper part of the iris Ei from below.

Furthermore, in the above embodiment, the illumination light for eyelid detection from the illumination light source 19 is projected without using the objective lens 9;
It is also possible to receive images. FIG. 5 shows an embodiment in that case, in which the light flux emitted from the illumination light source 19 passes through the mask 20 and the photographing lens 21, becomes slit light, passes through the upper part of the objective lens 9, and is delivered to the eye E through the slit illumination section. It is designed to form a The reflected image of this illumination section passes through the lower part of the objective lens 9, the deflection mirror 24 disposed immediately behind it, the slit opening 25, and reaches the line sensor 23.
A light beam is projected onto the image receiving position of Q1 or Q2.

In addition, in order to distinguish it from the function of the original fundus camera, it is possible to use a method such as using light in a wavelength range different from that of observation light source 1 and photographing light source 4, which are used for observation and photographing, for the wavelength of the light flux for eyelid detection. Needless to say. Furthermore, in addition to application to a fundus camera, the present invention can also be applied to, for example, an eye refractive power measuring device or a corneal shape measuring device, and may be used to select or delete measured data.

As described above, the fundus device according to the present invention can easily control the blinking of the eyelid by detecting the difference in the reflection position due to the step corresponding to the thickness of the eyelid when the eyelid is open and when the eyelid is closed. It can be detected and can be effective in detecting erroneous operations in fundus photography and ophthalmological measurements.

[Brief explanation of drawings]

The drawings show an embodiment of the ophthalmological device according to the invention,
Fig. 1 is an optical layout diagram thereof, Fig. 2 is a front view of the mask, Fig. 3 is an explanatory diagram of the operation of the blink detection mechanism,
FIG. 4 is an explanatory diagram of image movement on the line sensor, and FIG. 5 is an optical layout diagram of another embodiment of the blink detection mechanism. 1 is an observation light source, 4 is a photographic light source, 6 is a ring slit plate, 8 is a perforated mirror, 9 is an objective lens, 12 is a flip-up mirror, 14 is a photographic film, 19 is an illumination light source, 20 is a mask plate, 21 is a photographing lens, 22 is an image receiving lens, 23 is a line sensor, 24 is a deflection mirror, 25 is a slit opening, E
is the eye to be examined, Ef is the fundus, Ei is the iris, El is the eyelid, P1,
P2 is an illumination section, and Q1 and Q2 are image receiving positions.

Claims (1)

[Scope of Claims] 1. In an apparatus equipped with means for projecting illumination light onto an eye to be examined for photographing or measurement, and means for receiving the reflected light, the illumination light is directed diagonally from above toward the upper part of the iris of the eye to be examined. a projection means for projecting a light beam for eyelid detection separate from the eyelid detection light beam; a light position detection means for detecting the position of the reflected light from the eye to be examined that is reflected diagonally downward in the eyelid detection light beam; An ophthalmological apparatus comprising: a detection means for detecting blinking by determining a positional displacement of reflected light on the optical position detection means in the movement direction of the eyelid due to a step corresponding to the thickness of the eyelid. 2. The ophthalmologic apparatus according to claim 1, wherein the eyelid detection light beam has a slit shape. 3. Claim 1, wherein the warning means is activated when blinking is detected by the detection means.
Ophthalmological devices as described in Section. 4. The ophthalmologic apparatus according to claim 1, wherein part or all of the functions are stopped when the detection means detects blinking.