JP3431298B2 - Projection perimeter - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a simple structure in which a plurality of optotypes consisting of bright spots or dark spots are formed on a screen and the visual field is measured from the visual state of the subject. A projection perimeter that is easy to operate.

[0002]

2. Description of the Related Art A conventional projection perimeter is disclosed in Japanese Patent Laid-Open No. 51-7.
As disclosed in Japanese Patent Publication No. 96, the optotype slide member is formed of a completely opaque member, and a plurality of holes having a predetermined shape are formed in the optotype slide member to form an optotype pattern.

[0003]

The conventional projection perimeter described above requires two light sources for forming a visual target and a light source for illuminating a background, that is, a portion other than the visual target. Also, a structure for adjusting the relative brightness of the optotype and the background is required. The present invention has been made in view of such a problem of the conventional projection perimeter, and has only one common light source for the target and the background, and the relative brightness of the target and the background. It is an object of the present invention to provide a projection type perimeter capable of easily measuring the visual field even by an unskilled person without the need for adjustment. The projection perimeter configured in this way should be used in a completely dark room.

[0004]

According to the present invention, in a perimeter for performing visual field measurement by forming an index by projecting a light beam on a screen, an index slide member on which different index patterns are formed, and the index slide member are projected. And a projection optical system, and a portion of the index slide member other than the index has a transmittance that provides a predetermined back surface brightness on the screen.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A projection perimeter according to an embodiment of the present invention will be described below with reference to the drawings. The projection perimeter of the first embodiment is shown in FIG.
As shown in, a fixation target 4 is provided at the center of the spherical screen 2. In order to position and fix the subject 6 at the center of the spherical surface of the spherical screen, the spherical screen 2
A chin rest 10 for fixing the face of the subject 6 is provided near the center of the spherical surface. An index projection device 20 is arranged near the upper part of the chin rest 10 in the spherical screen 2. The index projection device 20 includes a light source unit 22, an index slide 24, a projection optical system 26, and a reflection prism 28. The index projection device 20 is designed so that its image forming surface is a spherical surface that matches the spherical screen 2. The index slide 24 has bright spot inspection patterns 31, 3 as shown in FIG.
2, 33 and a scotoma inspection pattern 35 as shown in FIG.
36 and 37, both of which are provided on the index slide 24 in advance so that a portion other than the index mark T has a predetermined relative brightness difference with respect to the optotype mark T on the image plane. Are formed so as to have a difference in transmittance.

In the first embodiment, the fixation target 4 is already provided. However, the fixation target 4 is not used, but the fixation target mark S is formed at a predetermined position on the index slide 24 at the same time. It can also be displayed. Thereby, the fixation target having a shape that allows the subject to more easily fix his or her eyes can be changed corresponding to the subject. Next, the operation of the projection perimeter having the above configuration will be described. In the projection perimeter, the light source unit 22 is turned on, and the index slide 24 forms a predetermined index image in the background of constant brightness. The subject 6 is the fixation target 4
While paying attention to, tell the examiner the finger recognition state of the index image. The examiner determines the visual field of the subject from the state in which the index image of the subject is recognized. Here, the index image pattern projected is 1
In addition to the one that is displayed for each individual and the response of the subject is obtained, a device that simultaneously displays a plurality of indexes is used in order to shorten the examination time per subject such as group examination. Second
In the projection perimeter of the embodiment, as shown in FIG. 4, the index projection device 50 is provided so that the fixation target 42 is located near the center of the flat screen 40. In order to position and fix the eye 6 in front of the center of the screen of the flat screen, fixing means such as the chin rest 44 for fixing the face of the subject 6 is provided.

An index projection device 50 is arranged in front of the flat screen 40 and on the side of the subject. Index projection device 5
0 has almost the same configuration as the index projecting device 20 of the first embodiment, and substantially the same components are assigned the same reference numerals and the description thereof is omitted. The projection optical system 52 of the index projection device 50 is statistically designed such that its image forming plane is a plane that matches the plane screen 40. There is no reflecting member corresponding to the reflecting prism 28. The operation of the projection perimeter having the above configuration is almost the same as that of the projection perimeter of the first embodiment. The perimeter using the flat screen 40 is particularly suitable for a simple visual field inspection such as a mass examination because the device can be transported very easily. Moreover, by simply changing the index slide 24, various tests such as a test for simultaneously projecting a plurality of optotypes in a group medical examination or an inspection of a central visual field using a projection pattern centering on the fixation target can be performed. It is possible to quickly and easily deal with various visual field inspections.

[0008]

According to the present invention, only one light source is used for the optotype and the background in common, and there is no need to adjust the relative brightness of the optotype and the background, which is simple and easy to operate. A projection perimeter can be obtained, which has the advantage that even an unskilled person can easily perform visual field measurement.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a projection type perimeter according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of a bright spot inspection pattern.

FIG. 3 is an explanatory diagram of a dark spot inspection pattern.

FIG. 4 is a vertical sectional view of a projection type perimeter according to a second embodiment of the present invention.

[Explanation of symbols]

Two-sided screen 4 fixation target 6 eye 10 jaw rest 20 Index projection device 22 Light source 24 index slides 26 Projection optical system 28 Reflective prism 31 bright spot inspection pattern 32 bright spot inspection pattern 33 Bright spot inspection pattern 35 Dark Spot Inspection Pattern 36 Dark Spot Inspection Pattern 37 Dark Spot Inspection Pattern 40 flat screen 50 index projection device

Claims (5)

(57) [Claims] 1. A perimeter for performing visual field measurement by forming an index by projecting a light flux on a screen, and an index slide member on which different index patterns are formed,
A projection type visual field having a light source and a projection optical system for projecting the index slide member, wherein a portion other than the index of the index slide member has a transmittance that provides a predetermined back surface brightness on the screen. Total. 2. The projection perimeter according to claim 1, wherein the projection optical system is a projector. 3. The projection perimeter according to claim 1, wherein the projection optical system is a projector. 4. The screen has a spherical surface.
The projection perimeter described. 5. The screen is a flat surface.
The projection perimeter described.