JPS62186841A - Eyeground camera - 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 [Industrial Field of Application] The present invention relates to a fundus camera that captures an image of the fundus of an eye to be examined.

[Prior Art] A fundus camera that examines and photographs the fundus of the eye has become indispensable for ophthalmological diagnosis. For example, this fundus camera is used for circulatory system examination using fluorescent angiography, diagnosis of intraocular P membrane, diagnosis of vascular disorders in urology, diagnosis of retinal detachment, etc., but in all cases, it is also necessary to examine the vascular structure. There are difficulties in obtaining diagnostic images.

In a conventional fundus camera, the fundus of the eye is illuminated by a light beam that has passed through the pupil of the eye to be examined, and the light beam reflected from the retina of the eye to be examined is supplied to an ophthalmoscope for image formation. Current fundus cameras are currently reaching their limits in terms of burden on patients; however, for diagnostic reasons, there is a desire to reduce the burden on patients as much as possible while obtaining fundus images with even better resolution and contrast. .

An attempt to do this is described in US Pat. No. 4,213,678. FIG. 2 shows the known device, in which a laser beam emitted from a laser light source 1 and horizontally and vertically deflected by galvano mirrors 2a and 2b passes through a mirror 3, a lens 4, etc. to the fundus Er of the eye E to be examined. scan continuously in a linear raster. Further, the laser beam reflected by the fundus Er is received by the light receiving element 6 through the lens 5 or the like through the pupil Ep, and becomes an electric signal. By synchronizing this signal with the scanning signal, the fundus image is displayed on a television monitor.

This known device uses weak illumination light, which can significantly reduce the burden on the patient during observation, and the image contrast is good, but the resolution of fundus photographs is comparable to that of conventional fundus cameras. and is inferior. Therefore, for detailed recording of the lesion, it is still necessary to rely on an ordinary fundus camera.

[Object of the Invention] An object of the present invention is to provide a fundus camera that incorporates the advantages of the above-mentioned two conventional devices, reduces the burden on the patient during the above-mentioned observation, and can obtain fundus records with sufficiently good resolution. It is.

[Summary of the Invention] The gist of the present invention for achieving the above-mentioned object is to provide a scanning optical system that forms a scanning surface by scanning a luminous flux emitted from a light source, and a scanning optical system that forms a scanning surface on the fundus surface of an eye to be examined. In an apparatus that has a projection optical system for projecting images, guides a light beam reflected from the fundus to a light receiving element by a light receiving optical system, and synthesizes a fundus image by a signal from the light receiving element and a scanning signal of the scanning optical system. The projection optical system and the light receiving optical system share an objective lens facing the eye to be examined, and the projection optical system and the received light beam are divided by a light splitting member arranged on a plane substantially conjugate to the pupil of the eye to be examined by the objective lens. A film surface is provided at a position equivalent to the scanning surface of the scanning optical system via an optical path switching means, and the film is photographed at a position substantially conjugate with the pupil of the eye to be examined in the light receiving optical system. The fundus camera is characterized in that a light source is provided, the optical path is switched by the optical path switching means in synchronization with the light emission of the photographing light source, and a fundus image by light from the photographing light source is recorded on the film.

[Embodiments of the Invention] The present invention will be explained in detail based on the embodiment shown in FIG.

FIG. 1 shows an embodiment of the present invention, in which a beam of light is emitted from a laser head 12 in which m laser controllers 10 and m laser light sources 11 are integrated.

Luminous flux expander 13, AOD (acousto-optic optical deflector) 14,
Imaging lens 15. Relay lens 17 with a vertical scanning galvanometer mirror 16 in the middle. The light reaches the subject's eye E via a flip-up mirror 18, a relay lens 19, a perforated mirror 20, and an objective lens 21. Further, on the side of the perforated mirror 20 that reflects the light flux from the objective lens 21 direction, there is a relay lens 23 having a small black spot 22 in the middle, a small light shielding object 24, a ring slit 25, a small light shielding object 26, and a mirror 2.
7. Condenser lens 28. A strobe light emitting tube 29, a condenser lens 30, a light shielding shutter 31, and a light receiving element 32 are arranged in this order. Further, a film 33 is provided behind the flip-up mirror 18.

40 is an electric controller, AOD dry/<
41 to the AOD 14 and the galvano mirror driver 42 to the galvano mirror 16, and from the light receiving element 32 to the controller 40 via the amplifier 43.
A signal is now being sent to. Furthermore, a signal is sent from the controller 40 to an image processing device 44, and a signal is sent from this image processing neckpiece 44 to a television monitor 46 via a character generator 45. Further, 47 is a control circuit including a strobe power source, and this control circuit 47
A current is supplied to the strobe light emitting tube 29 from the strobe light emitting tube 29, and the shutter 31 is controlled via the shutter driver 48. Furthermore, a control signal is sent from the control circuit 47 to the flip-up mirror 18 via the flip-up mirror driver 49, and a switch 50 is further connected to the control circuit 47.

First, I will explain the observation method using laser beam flux.
The laser beam emitted from the laser beam expander 13 is aligned with the aperture of the AOD 14 and is incident thereon. In response to the signal from the AOD driver 41, the AODl 4 performs high-speed deflection or continuous sweeping of the laser beam as shown in L1 to Ll'.

In reality, this deflection is perpendicular to the plane of the paper, but in the drawing it is shown parallel to the plane of the paper. The laser beam deflected by the AODl4 forms a one-dimensional point sequence on Sl by the imaging lens 15, and these point sequences are transferred to the first scanning surface S by the vertical scanning galvanometer mirror 16 and the relay lens 17.
Form a linear raster on 2. At this time, the galvano mirror 16 is driven by a galvano mirror driver 42, and the input signal to the AOD driver 41 and the input signal to the galvano mirror driver 42 are synchronized by the controller 40.

The scanning plane S2 is equivalent to the plane S2° of the film 33 of the fundus camera with respect to the flip-up mirror 18, and the relay lens 1
9 through the flip-up mirror 18 to the second scanning plane S
It is said to be conjugate with 3. Further, since S3 is made conjugate with the fundus Er of the eye E by the objective lens 21 and the optical system of the eye E, the linear raster of the first scanning plane S2 is conjugated with the fundus Er of the eye E by the action of the relay lens 19. It becomes possible to scan the fundus needle of E. On the other hand, the laser beam reflected from the fundus Er passes through the pupil Ep of the eye E to be examined, passes through the objective lens 21 that is common to the scanning optical system, and then passes through a perforated mirror placed at the conjugate point P1 of the pupil Ep by the objective lens 21. 20, and is focused on the light receiving surface P4 of the light receiving element 32 by the relay lens 23, mirror 27, and condenser lens 28.30.

Here, pupils Ep, PI, P2. P3 and P4 are each optically conjugate, and P2 is provided with a ring slit 25 that forms an image in the hole of the perforated mirror 20, and the scanning optical system and the light receiving optical system are combined in a pupil division format. This is similar to a conventional fundus camera.

In addition, there are small black dots 22 in the relay lens 23 that remove reflected light from each surface of the objective lens 21, and at points approximately conjugate to the cornea and crystalline lens positions of the eye E before and after P2, there are Small light shielding object 2 that cuts reflected light and scattered light from
4.26 is located.

In this way, the light receiving element 32 can receive only the reflected light from the fundus Er, with various harmful reflected and scattered lights removed. The output of the light receiving element 32 is inputted to the controller 40 via an amplifier 43, and then inputted to the controller 40.
AOD driver 41, galvano mirror driver 4 within 0
This signal is combined with the synchronization signal emitted toward 2 and becomes a signal that forms a fundus image. This signal is reprocessed into a standard television signal, and while a fundus image Er' is displayed on a television monitor 46 via a character generator 45, it is sent to an image processing device 44 at appropriate times to perform necessary image processing. The result of this image processing is, for example, if it is digitized, such as the diameter of the nipple.

The characters are synthesized on the screen of the television monitor 46 by the character generator 45.

Next, to explain about photography, the device also has P3
A strobe light emitting tube 29 is disposed at a position, and a light-shielding shutter 31 is arranged immediately before the light-receiving element 32.The light-shielding shutter 31 is connected via a shutter driver 48 to a control circuit 47 containing a strobe power supply. . Also, in the control circuit 47.

Since the flip-up mirror driver 49 and the switch 50 are also connected, when there is an input from the switch 50, this control circuit 47 moves the flip-up mirror 18 out of the optical path and at the same time inserts the light-shielding shutter 31 into the optical path. , and then causes the strobe light emitting tube 29 to emit light. At this time, a focal brain shutter (not shown) located between the flip-up mirror 18 and the film 33 is also opened. The light beam emitted from the strobe light tube 29 is transmitted through a condenser lens 28,
Mirror 27, relay lens 23. The fundus Er is uniformly illuminated through the perforated mirror 20 and the objective lens 21.
After being reflected at r, it passes through the objective lens 21, the aperture of the perforated mirror 20, and the relay lens /19 again to the surface S2'.
form a fundus image. Here, as explained earlier, the path of the light beam has the same configuration as a normal fundus camera, so if the photographic film 33 is placed on the surface S2',
A clear fundus image Er' can be recorded in the same way as a normal fundus camera.

Furthermore, among the above-mentioned configurations, the components within the broken lines are all housed in the same housing, and can be aligned in the front, back, Φ, left, right, and up and down directions with respect to the eye E to be examined. That is,
Since the optically connecting members are integrally formed, there is no need for special consideration for alignment, and the operability is no different from that of a normal fundus camera.

Naturally, the strobe light emitting tube 29 or the light receiving element 32 can be replaced with a halogen lamp or the like, and a mirror 34 can be installed between the relay lens 17 in the scanning optical system and the first scanning surface S2 as shown in the figure. If the eyepiece lens 35 is provided on the reflective side of the mirror 34, it becomes possible for the examiner O to visually observe the normal fundus image illuminated by a halogen lamp, in contrast to the conventional fundus camera. Functions can be combined.

[Effects of the Invention] As explained above, the fundus camera according to the present invention functions as a laser scanning fundus camera during observation and measurement,
It enables accurate measurements while reducing the burden on the patient, functions as a fundus camera using a normal silver halide film for recording lesions, and has the advantage of being able to record the fundus with good resolution. In addition, the device has the advantage of not being unnecessarily bulky and having the same operability as a conventional fundus camera.

[Brief explanation of drawings]

FIG. 1 shows a configuration diagram of an embodiment of a fundus camera according to the present invention, and FIG. 2 is a configuration diagram of a conventional device. 11 is a laser light source, 12 is a laser head, 14
is an AOD, 16 is a galvanometer mirror, 217 is a relay lens, 18 is a flip-up mirror, 20 is a perforated mirror, 21 is an objective lens, 29 is a strobe light emitting tube, 32 is a light receiving element,
33 is a photographic film, 40 is a controller, 44 is an image processing device, 45 is a character generator, 46 is a television monitor, 47 is a control circuit, and 50 is a switch.

Claims (1)

[Claims] 1. A scanning optical system that forms a scanning plane by scanning a light beam emitted from a light source, and a projection optical system that projects the scanning plane onto the fundus of the eye to be examined; In an apparatus that guides a light flux reflected from the fundus to a light receiving element by a light receiving optical system and synthesizes a fundus image using a signal from the light receiving element and a scanning signal of the scanning optical system, the projection optical system and the light receiving optical system are , the projection light beam and the received light beam are combined in a separate format by a light splitting member that shares an objective lens facing the eye to be examined and is arranged on a plane substantially conjugate to the pupil of the eye to be examined by the objective lens, and the scanning A film surface is provided at a position equivalent to the scanning surface of the optical system via an optical path switching means, a photographing light source is provided at a position substantially conjugate to the pupil of the eye to be examined in the light receiving optical system, and synchronized with the light emission of the photographing light source. The fundus camera is characterized in that the optical path is switched by the optical path switching means, and a fundus image produced by light from the photographing light source is recorded on the film. 2. The fundus camera according to claim 1, wherein the light splitting member is a perforated mirror. 3. The fundus camera according to claim 1, wherein the optical path switching means is a flip-up mirror. 4. A light source lamp is removably arranged at a position substantially conjugate with the pupil of the subject's eye in the light-receiving optical system, and an optical path switching mirror that is removable and removable in the scanning optical system is provided at a position conjugate with the film surface. The fundus camera according to claim 1, wherein the fundus camera can be observed with an optical finder.