JPS632010Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ophthalmological apparatus in which a fixation target for guiding a subject's line of sight to a position conjugate with the fundus of the eye in an illumination optical system is arranged.

In fundus cameras, it has conventionally been done to guide the subject's line of sight by placing a fixation target at a position conjugate with the fundus in the illumination optical system.
-The fundus camera described in Publication No. 137413 had the fixation target positioned conjugate to the fundus in front of the imaging light source and in a position that blocked the imaging illumination light flux, so the fixation target was placed out of the optical path during imaging. This posed the problem of requiring a mechanism for evacuation, resulting in a complicated structure and high cost. Also, Japanese Patent Application Publication No. 1973
- In the fundus camera described in Publication No. 102715, a reflecting member is provided in the optical path within the illumination optical system, and the light flux from the fixation target provided outside the optical path of the illumination optical system is superimposed into the illumination optical system via the reflecting member. Because of this, the structure is complicated, and there are problems in that the amount of light from the photographing light source is reduced by the reflective member during photographing, or that the reflective member must be moved out of the optical path each time photographing is performed. It was hot.

In view of the above-mentioned problems, the present invention provides an ophthalmological apparatus in which a position conjugate with the fundus is set in the illumination optical system before it overlaps with the imaging optical system, and a fixation target is placed at the position in the illumination optical system. This will be explained below based on an embodiment shown in FIGS. 1 and 2. FIG. 1 shows the optical system, 1 is a light source for observation, 2 is an optical system. is a condensing lens, 3
is a light source for photography, 4 is a condensing lens, 5 is a movable mirror for switching between illumination light for observation and illumination light for photography, 6 is a ring slit, 7 and 8 are condenser lenses, 9 is a perforated mirror, and 10 is a The objective lens constitutes an illumination optical system. 11
is the eye to be examined. 12 is a photographing lens, and 13 is an eyepiece lens, which together with the objective lens 10 constitute an observation/photographing optical system. Reference numeral 14 indicates a fixation target placed between the movable mirror 5 and the observation light source 1 at a position conjugate with the fundus, and 15 indicates the fixation target 1.
4 is a fixation target moving device for freely moving the target within the optical path. FIG. 2 shows the detailed structure of the fixation target moving device 15, where 16 is a guide frame fixed to the mirror body of the fundus camera, and 17 is a guide frame that slides in a direction parallel to the optical axis O. A moving shaft is housed in the guide frame 16 so as to be able to rotate in a plane orthogonal to the moving shaft; 18 is a key screwed into the moving shaft 17;
20 is an operating rod having a keyway 19a that slidably passes through the moving shaft 17 in a direction orthogonal to the optical axis O and into which the key 18 is slidably fitted; The indicator rod 21 has a tip 20a parallel to the axis O and has the fixation target 14 fixed to the tip. Reference numeral 21 is an operation knob fixed to the outer end of the operation rod 19.

The fundus camera with a built-in fixation target according to the present invention is constructed as described above, and since the movable mirror 5 is at the position shown by the solid line during observation, the light emitted from the fixation target 14 is transmitted through the ring slit 6, the relay lenses 7 and 8. , the perforated mirror 9, and the objective lens 10. Since the fixation target 14 is placed at a position conjugate with the fundus, a fixation target image is clearly formed on the fundus. Therefore, if the fixation target 14 is moved vertically and horizontally by the fixation target moving device 15, the subject's line of sight will be aligned with the fixation target 1.
4. Next, when the movable mirror 4 is moved to the position shown by the dotted line for photographing, the illumination light emitted from the photographing light source 3 is transmitted through the condenser lens 4, the movable mirror 5, the ring slit 6, the relay lenses 7 and 8, and the aperture. The light is made to enter the eye 11 through the mirror 9 and the objective lens 10. In this case, fixation target 1
The movable mirror 5 is located at a position conjugate with the fundus where 4 is placed.
Since the fixation target 14 is provided between the observation light source 1 and the observation light source 1, that is, at a position where the photographing light beam is not blocked, there is no need to move the fixation target 14 out of the optical path. Furthermore, since the fixation target 14 is placed in the illumination optical system, there is no need for a reflective member or the like. Therefore, a mechanism for this purpose is not required, so the structure is simplified and the manufacturing cost is reduced.

FIG. 3 shows an optical system according to another embodiment, in which a photographing light source 3 and an observation light source 1 are arranged on the optical axis of the illumination optical system, and the fundus is located between the light sources 3 and 1. A conjugate position is provided and a fixation target 14 is placed at the position. In this case as well, since the fixation target 14 is located behind the photographing light source 3, the fixation target 14 and the reflective member do not block the photographing light beam.

As described above, the ophthalmological device according to the present invention has a simpler structure and lower manufacturing cost than the conventional device, which is an important practical advantage.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the optical system of one embodiment of the ophthalmological device according to the present invention, FIG. 2 is a sectional view of the fixation target moving device of the above embodiment, and FIG. 3 is a diagram showing the optical system of another embodiment. It is a diagram. 1...Light source for observation, 3...Light source for photography, 5...
Movable mirror, 11... eye to be examined, 14... fixation target,
15... Fixation target moving device.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A fixation target for guiding the examinee's line of sight is placed in a position in the illumination optical system that is conjugate with the fundus and does not block the imaging illumination light flux. In the ophthalmological apparatus, the position conjugate with the fundus of the eye is set in the illumination optical system before the imaging illumination light beam is superimposed, and the fixation target is arranged in the illumination optical system. Ophthalmology equipment. (2) The scope of the utility model registration claim, characterized in that the light source for photography and the light source for observation are switched by a movable mirror, and the position conjugate with the fundus is set between the movable mirror and the light source for observation ( The ophthalmological device described in 1). (3) Scope of claims for utility model registration (1) characterized in that a photographing light source and an observation light source are arranged on the optical axis of an illumination optical system, and a position conjugate with the fundus is set between the two light sources. The ophthalmological device described in .