JPS607831A - Non-mydriasis type 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 The present invention relates to a so-called non-mydriatic fundus camera that uses natural mydriasis in a dark room to observe and photograph the fundus without using mydriatic agents.

In a non-mydriatic fundus camera, the fundus image obtained using invisible light is converted into a fundus image using visible light to observe and focus the fundus.In this case, the contrast of the fundus image obtained using visible light is It was so bad that it was difficult to focus. For this reason, in order to project the index image for focusing onto the fundus of the eye and improve the visibility of this index image, a light shielding plate is installed on the fundus of the illumination optical system to block the illumination light that reaches the projection area of the index image. A non-mydriatic fundus camera installed at the conjugate position i6 is known from Japanese Patent Application Laid-Open No. 53-94922. 3 is an objective lens, 4 is a perforated reflector having a central opening 4a and a slot portion 4b following it, and 5 is a reflection of the perforated reflector 4. 6 is a relay lens provided in the optical path, 6 is a light-shielding plate that is removably disposed at a position conjugate with the fundus 2 and is pushed out of the optical path when it is in the shape of a J drum, 7 is a condensing lens, and 8 is a ring slit. , 9 is a light source for photographing, 1o is an infrared filter, 11 is a condenser lens, and 12 is a light source for observation.The above optical elements constitute an illumination optical system.

Reference numeral 13 is disposed near a position conjugate to the aperture of the eye 1 to be examined, and as shown in FIG.
3b, 14 is a focusing lens, 15 is an imaging lens, 16 is a movable mirror that can be raised when photographing, 17
18 is a film surface, 18 is a field lens, 19 is a reflecting mirror, 2° is an imaging lens, 21 is an image pickup tube, and 22 is a TV monitor, which together constitute an observation and photographing optical system.

Further, 23 is a transparent plate having a reflecting portion 23a as shown in FIG. 4, 24 is a reflecting mirror, 25 is a relay lens, 2
Reference numeral 6 denotes an index plate disposed conjugately with the film surface 17 and has a slit index 26a, 27 a deflection prism disposed in close contact with the index plate 26, 28 a condenser lens, 29
is an index light source, and these constitute an index projection optical system for focusing. In addition, the relay lens 25° index plate 26. Deflection prism 27. The condensing lens 28° index light source 29 moves together with the focusing lens 14 of the cherry blossom viewing optical system along the optical axis. According to the undefeated type fundus camera configured as described above, the light emitted from the observation light source 2 is passed through the infrared filter 1 by the condensing lens 11.
0 and becomes invisible light, forming an image on the ring slit 8. The light passing through the ring slit 8 is passed through the condensing lens 7,
The light is reflected by the perforated reflector 4 via the relay lens 5 and illuminates the fundus 2 of the eye 1 to be examined via the objective lens 3 . When the light shielding plate 6 is inserted at a position conjugate with the fundus 2, the slit index 26 moved by the light shielding plate 6
Illumination light to the region of the fundus 2 on which the image a is to be projected is blocked. The light from the illuminated fundus 2 passes through the objective lens 3, the central aperture 4a of the single-hole reflection theory 4, and the central aperture hole 13a of the diaphragm 13, and then passes through the transparent plate 231 and the focusing lens 14.
．． The light is reflected by the movable mirror 16 via the imaging lens 15, and further formed into an image on the image pickup tube 21 via the field lens 181, the reflecting mirror 19°, and the imaging lens 20f, and is displayed on the TV monitor 22. The light that passes through the slit index 26a of the index plate 26 illuminated by the index light source 29 through the condensing lens 28'f is split into two beams symmetrical with respect to the optical axis by the action of the deflection prism 27. It is reflected by the two reflecting portions 23a of the transparent plate 23 via the relay lens 25° reflecting mirror 24, passes through the two aperture holes 13b of the aperture 13 and the slot portion 4b of the perforated reflecting mirror 4, and is reflected by the objective lens 3. A slit index 26 is inserted into the fundus 2 of the eye 1 to be examined through the
Project the image of a. Here, as shown in FIG. 5, the projected image 26a' of the slit index 26a is
When the illumination light is inserted into the optical path, the illumination light is projected onto the shaded portion 6' (FIG. 5) blocked by the light shielding plate 6, so that it can be clearly seen. Also, slit index projection image 2
When 6a' is out of focus, the left and right parts of the center are shifted vertically as shown in Figure 5, but when in focus, the left and right parts match, so you can easily check the focus status. can be done. When photographing, the light shielding plate 6 is moved out of the optical path, and the light from the photographing light source 9 passes through the ring slit 8 and then the condensing lens 7° relay lens 5. Perforated reflector 4. The fundus 2 is uniformly illuminated through the objective lens 3. The light from the illuminated fundus 2 travels in the same way as during observation, but an image is formed on the dome film surface 17 on which the movable mirror 16 is raised. Conventional non-mydriatic fundus cameras have the above-described configuration and operation, but since the reflectance of the fundus is generally extremely low, a large amount of light is required when photographing, and the power source for the photographic light source 9 is large and generates a lot of heat. There were drawbacks.

In view of the above points, the present invention provides a non-mydriatic system that enables the use of an auxiliary observation light source in addition to the photographic light source during photographing, thereby realizing miniaturization of the power source of the photographing light source and reduction of the number of heat meters. The purpose of the present invention is to provide a type fundus camera that illuminates the fundus of the eye to be examined from a direction along the optical path of an observation and photography optical system with illumination light from an observation light source and a photography light source through a reflective member, and focuses. In a fundus camera that projects an index for alignment onto the fundus of the examinee's eye and performs focusing by observing the projected image of the index, the fundus of the examinee's eye is located between the observation light source and the reflective member. A light-shielding plate that is removably disposed at a co-located position and blocks illumination light in a portion corresponding to the area of the index projected image, and a light-shielding plate that is integrally disposed with the light-shielding plate and blocks visible light. The above object is achieved by a non-mydriatic fundus camera, which includes a filter, and the light shielding plate and filter are inserted into the optical path during observation and retracted out of the optical path during imaging.

The present invention will be explained below with reference to an embodiment shown in the drawings.
Reference numeral 30 denotes an illumination optical system, which is removably disposed at a position conjugate with the fundus 2 of the eye 1 to be examined, and illuminates a portion of the slit index 26a of the index plate 26 corresponding to the region of the projected image on the fundus 2. The light shielding plate 31 that blocks light is a filter that blocks visible light, such as an infrared filter, which is disposed integrally with the light shielding plate 30, and the others are of the non-mydriatic type shown in FIG. It has the same configuration as a fundus camera.

According to the non-mydriatic fundus camera configured in this way, during observation, the light blocking plate 30 and the filter 31 are inserted into the optical path, and the light from the observation light source 12 passes through the condenser lens 11.
The image is formed on the ring slit 8, and the ring slit 8
The light that has passed through is reflected by a perforated reflector 4 via a condensing lens 7 and a relay lens 5, and illuminates the fundus 2 of the eye to be examined via an objective lens 3. At the same time, the light that should reach the area of the projected image on the fundus 2 of the slit index 26a of the index plate 26 is blocked by the light shielding plate 30 located at a position conjugate with the fundus 2. Ru. In this way, the index can be easily observed as in the conventional example shown in FIG. In addition, when photographing, the light shielding plate 30 and the filter 31
is retracted out of the optical path, and after passing through the light beam/jislit 8 emitted from the photographing light source 9, it is moved to the condenser lens 7, the relay lens 5. Perforated reflector 4. Fundus 2' through objective lens 3
ff: Uniform illumination. At the same time, the light from the observation light source 12 uniformly illuminates the fundus 2 of the eye 1 to be examined, without blocking visible light since the light shielding plate 30 and the filter 31 are outside the optical path. Thus, during photographing, the fundus 2 of the eye to be examined 1 is illuminated by light from the photographing light source 9 and the observation light source 12.

As described above, according to the present invention, the focus detection index is easy to see as before during observation, and when photographing, an auxiliary observation light source is used in addition to the photographic light source to illuminate the fundus of the eye to be examined. Very bright illumination light is obtained from t,
Therefore, in order to obtain the same amount of illumination light, the amount of light emitted by the photographic light source is smaller than before, so the power source of the photographic light source can be downsized and the amount of heat generated can be reduced, and these effects are simply due to light shielding. This is achieved by simply inserting and removing the plate and filter into the optical path as one unit, so the structure is the same as that of conventional light shielding plate insertion and removal mechanisms, and the cost is not high. There are other effects. Note that, for example, a filter for adjusting the light quality of the photographing light source and the observation light source may be provided at the position i4 where a conventional filter has been provided.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram showing the optical system of a conventional non-mydriatic fundus camera, Figure 2 is a front view of a perforated reflector, Figure 3 is a front view of the aperture, and Figure 4 is a front view of the transparent plate. , FIG. 5 is a view showing the field of view during observation, and FIG. 6 is a view similar to FIG. 1 showing an embodiment of the present invention. ■... Eye to be examined, 2... Fundus, 3... Objective lens, 4... Perforated reflector, 5... Relay lens, (3... Light shielding plate, 7...Condensing lens, 8...
・・Linges 1 knot, 9・・・Photography light source, lO・
... Infrared filter, 11... Condensing lens, 12.
...observation light source,] 3...stop, 14...focusing lens, 15...Itoyoshi (4, lens, 16...
・Movable mirror, 17...Fill L, (white 1.18・
...field lens, 19...reflection" party, 20
...imaging lens, 21...imaging tube, 22...
・TV monitor, 23...transparent plate, 24...antibody 1! Gun, 25... Relay lens, 26... Finger R
8M, 2q...deflection prism, 28...condensing lens, 2B...4 light source for sign, 30...shading plate; 31...filling. Agent Nashi Shinohara? 2 Figure 23C173Q Figure 3 Figure 5

Claims (1)

[Scope of Claims] The fundus of the eye to be examined is illuminated from a direction along the optical path of an observation and photographing optical system through a reflective member with illumination light from an observation light source and a photography light source, and an index for focusing is provided. In a fundus camera that performs focusing by projecting onto the fundus of the eye to be examined and observing this projected index image, the fundus camera is inserted at a position that is a light-shielding plate that is removably disposed and blocks illumination light in a portion corresponding to the region of the index projected image; and a filter that blocks visible light that is disposed integrally with the light-shielding plate; A non-mydriatic fundus camera characterized in that the light shielding plate and the filter are inserted into an optical path during observation, and are retracted out of the optical path during imaging.