JPS627297Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an illumination device for ophthalmological equipment such as a fundus camera.

The optical system of a conventional fundus camera is as shown in FIG. In this figure, reference numeral 1 denotes a light source for observation, and light from this light source is transmitted through a semi-transmissive mirror 5 through a collector lens 2 and then formed into an image on a ring slit 6. Further, the illumination light that has passed through the ring slit 6 forms a ring slit image near the perforated mirror 8 by the ring slit projection relay lens 7, and is re-imaged near the cornea of the eye 10 by the upper objective lens 9. Illuminating the fundus. The reflected light from the illuminated fundus passes through the objective lens 9 and the aperture 8a of the perforated mirror 8, and is reflected by the observation and photographing relay lens 11, the switching reflector 12 and the reflector 13, and then onto the focusing plate 14. form a fundus image. The fundus image on the focusing plate 14 is observed through the eyepiece 15. On the other hand, when photographing, the photographing light source 3 emits light, which is reflected by the semi-transmissive mirror 5 through the collector lens 4, and then an image is formed in the vicinity of the ring slit 6. This illumination light for photographing passes through the ring slit 6 and illuminates the fundus of the eye to be examined in exactly the same manner as the illumination light for observation. Light from the fundus of the eye passes through the objective lens 9 and the aperture 8a of the perforated mirror 8, and is formed into an image by the relay lens 11, as in the case of observation. During this photographing, the switching reflector 12 is switched to the position shown by the chain line, so that a fundus image is formed on the film 16 by the relay lens.

FIG. 2 shows another example of a conventional illumination device for a fundus camera, in which an observation light source and a photographing light source are arranged on the same optical axis. Therefore, no semi-transmissive mirror is used. In other words, observation light source 1
A photographing light source 3 is arranged near the image position formed by the collector lens 2. Therefore, observation light source 1
The stray light is once connected near a photographing light source 3 by a collector lens 2, and then focused near a ring slit 6 by a collector lens 4.
On the other hand, the light from the photographing light source 3 is directly imaged near the ring slit 6 by the collector lens.
After the illumination light passes through the ring slit, the first
Since the structure and function are exactly the same as those shown in the figure, other structures are not shown in FIG. Also, the explanation will be omitted.

In the conventional fundus camera as described above, the illumination device is such that the light from the light source is restricted by the aperture of the collector lens, and there is also a loss of light due to reflection on the surface of the collector lens. There is also light loss due to the semi-transparent mirror, and these causes result in insufficient brightness. In order to compensate for this lack of brightness, it is necessary to make the illumination light source brighter, but if the light source is made brighter, the inside of the fundus camera becomes hot due to the heat generated by the light source. Therefore, it becomes necessary to provide heat dissipation means such as a fan. In particular, as fundus cameras have recently become wider in angle, it is necessary to widen the illumination range, resulting in an even more insufficient amount of light.

The present invention was developed in view of the above points, and instead of a condensing lens, a condensing reflector with a mirror surface on the inner surface of a spheroid is used, and an observation light source is placed at one focal point, and the other is The present invention provides an illumination device in which a photographing light source is arranged at a focal position.

The contents of the lighting device of the present invention will be explained below based on one embodiment shown in the drawings. In FIG. 3, 21 is a light source for observation, 22 is a light source for photographing, and 23 is a reflecting mirror whose inner surface is a mirror surface of a spheroid. An observation light source 21 is disposed at one focal position of the reflecting mirror 23, and a photographing light source 22 is disposed at the other focal position. In other words, the mirror lamp with the observation light source 21 attached to the focal position of the almost elliptical reflecting mirror 23 and the position where the light from this mirror lamp is focused (reflecting mirror 23
A photographing light source 22 is placed at a focal position of . With such a configuration, the observation light source 21
The reflected light is focused near the position of the photographing light source 22 by a reflector 23, and then is focused by a lens 24 to a ring slit 6 (this is the same as the conventional example shown in Fig. 1, and the optical system after this is also the same). ). The illumination light passing through the ring slit 6 is reflected by a perforated mirror and illuminates the fundus of the eye to be examined, similarly to a conventional fundus camera. Similarly, the light from the photographic light source also illuminates the fundus.

As described above, since the present invention does not use a collector lens or a semi-transmissive mirror, it is extremely bright, and therefore, in the case of a wide-angle fundus camera, even if a wide range of the retina is illuminated, there will be no insufficient brightness. Furthermore, since there is no shortage of light even when observing at high magnification with a wide-angle fundus camera or when observing the fluorescent fundus, which requires a particular amount of light, it is particularly effective in these observations.

Since the filament of the light source lamp has a certain area, the reflecting mirror 23 only needs to be approximately ellipsoidal, and the light collected by the reflecting mirror from the observation light source has a certain spread. Since both light sources do not need to be placed at exact focal positions.

FIG. 4 shows another embodiment of the present invention, in which the photographing light source is placed just in front of the ring slit 6, so the lens 24 is not used.

FIG. 5 shows still another embodiment in which, when the observation light source 21 has uneven illumination, a frosted glass 25 is inserted into the optical path to eliminate the uneven illumination. In this embodiment, the amount of light from the photographing light source 22 can be reduced by pushing the frosted glass 25 out of the optical path during photographing. Therefore, the frost glass 25 is configured to be inserted into and removed from the optical path using a solenoid or the like, and at the same time when the switching reflector 12 shown in FIG. 1 is switched to the position shown by the chain line in FIG. What is necessary is to make the photographing light source 22 flash after the object is pushed away. The insertion position of the frost glass is between the observation light source 21 and the photography light source 22 (2 in the drawing).
5' position).

Further, in a non-mydriatic fundus camera that does not use a mydriatic agent, infrared rays are used as illumination light for observation. Therefore, an infrared filter is inserted between the observation light source and the photography light source. In the present invention, if a filter that does not transmit visible light but transmits invisible light is inserted at the 25 or 25' position, and one or both sides of this filter are frosted, observation without uneven illumination due to infrared light illumination is possible. becomes.

As explained above, the illumination device for ophthalmic equipment of the present invention can provide bright illumination because unlike conventional ones, the light from the light source is not greatly restricted by the aperture of the lens or there is no loss of light amount due to semi-transparent mirrors, etc. . In addition, the reflecting mirror does not have to have an exact spheroidal surface, but it is easy to manufacture as long as it has an approximately spheroidal surface, and since both light sources need be located approximately on the focal point plane, adjustment is easy. Furthermore, since no lens is used between the observation light source and the photography light source, it can be manufactured at low cost. Furthermore, since the illumination light can be used effectively, no unnecessary load is placed on the light source lamp, the life of the lamp is extended, and the inside of the fundus camera does not become hot due to heat generation, which prevents the softening of grease and other causes. There is no problem in the internal operation of the fundus camera due to the cause.

Although the description has been made regarding an illumination device for a fundus camera, the present invention can also be used for illumination devices for other ophthalmological equipment.

[Brief explanation of drawings]

Fig. 1 is a diagram showing an example of the optical system of a conventional fundus camera, Fig. 2 is a diagram showing another example of the illumination system of a conventional fundus camera, and Figs. It is a figure showing an example. 21...Light source for observation, 22...Light source for photography, 2
3...Spheroidal reflector.

Claims (1)

[Scope of utility model registration request] A light source for observation and a light source for photography are provided separately, and the light from one light source is once focused in the vicinity of the other light source by a condensing device, and then the object is illuminated. In an illumination device that can be switched to either illumination at the light source, a mirror made of a part of a spheroid is used as the light condensing device, and the observation light source is placed at one focal position and the observation light source is placed at the other focal position. An illumination device for ophthalmological equipment, characterized in that a photographing light source is disposed in the ophthalmological equipment.