JPS62133930A - Vision analyser - 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 [Field of Industrial Application] The present invention relates to a visual acuity meter, and particularly to a visual acuity meter that displays visual targets sequentially so as to reduce temporal overlap.

[Prior Art] There is a method in which visual indicators are sequentially displayed in a visual acuity meter so that there is less temporal overlap so that the subject does not make a mistake in reading the visual indicators.

In this case, a liquid crystal may be used for the optotype presentation section since there is no mechanical drive section and it is easy to handle.

However, with the above method, when a new target is displayed, the previous target disappears, so it is difficult to adjust the focus of the eyes, and in the case of binocular vision, it is difficult to determine the fusion. was there.

[Problems to be Solved by the Invention and Means for Solving the Problems] The object of the present invention is to provide a visual acuity meter that makes it easier to adjust focus and fusion, and to fix the convergence, thereby allowing stable visual acuity tests. Our goal is to provide the following.

This objective is achieved by providing a pattern with high contrast around the periphery of the optotype presentation section.

[Example] Fig. 1 shows an example of the visual acuity meter of the present invention.A transmission type liquid crystal plate l for displaying a test optotype 2 such as a Landolt ring has a plurality of liquid crystal optotype patterns, and selectively different Visual targets can be displayed. A high-contrast pattern 4 is drawn in the peripheral area 3 around the transmissive liquid crystal plate l. This pattern 4 is a spotted black and white pattern. The light beam emitted from the light source 5 is reflected by a reflection mirror 6 to illuminate the transmission type liquid crystal plate 1 from behind, and the test optotype 2 is observed by the eye S to be examined using the transmitted light. On the other hand, a part of the light beam emitted from the light source 5 is reflected by the reflection mirror 7 to illuminate the peripheral area 3, and the pattern 4 is observed by the eye S to be examined by the reflected light. Test eye S
The pattern 4 with high contrast can be observed at all times during the examination, and there is no need to adjust the focus every time the displayed examination target 2 changes.

In addition, when the test index 2 in Fig. 1 is used as a common visual target for the left and right eyes of the subject, the pattern 4 can be seen by the left and right eyes of the subject at all times, so when the displayed test target 2 is switched. image fusion becomes easier. It also makes it easier to fix the road.

FIG. 2 shows an optotype section of another embodiment. The high-contrast pattern 4 forms a black frame around the transmissive liquid crystal panel l using a different material from the peripheral part 3, and the transmissive liquid crystal plate l and the pattern 4 are the same in the field of view on the left and right sides. are placed respectively. Since the pattern 4 is always displayed on the left and right eyes of the subject, it facilitates image fusion.

In FIG. 2, when a monocular test is performed, the test optotype 2 for the eye to be tested is displayed, and when a binocular test is performed, test optotypes are displayed for each of the left and right eyes of the subject.

By the way, in the above-mentioned embodiment, the pattern 4 was in the form of speckles or frames, but it may be in any other shape, and although the pattern 4 has been described as a black and white pattern, a color pattern may also be used.

In the above embodiment, the peripheral area is illuminated by reflection, but the pattern 4 may be provided on a transparent glass plate and illuminated by transmission.

Furthermore, although the optotypes are displayed using a transmissive liquid crystal, it is also possible to use a reflective liquid crystal or to project the optotypes onto an optotype display board.

[Effect] As described above, according to the present invention, by providing a high-contrast pattern in the peripheral area around the optotype, it helps the subject to adjust focus or image fusion when performing a visual acuity test, and also improves convergence. This makes it easier to fix the eyesight and allows for stable visual acuity tests.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the visual acuity meter according to the present invention, and FIG. 2 is a diagram showing an optotype section of another embodiment. In the figure, 1 is a transmission type liquid crystal plate, 2 is an inspection target, 3 is a peripheral area,
4 is a pattern, 5 is a light source, 6.7 is a reflecting mirror, and S is an eye to be examined.

Claims (1)

[Scope of Claims] 1. A visual acuity meter that includes an optotype section in which an optotype is displayed and a peripheral section where the surroundings of the optotype are illuminated, and performs a visual acuity test by sequentially displaying the optotype, wherein the peripheral section comprises: A visual acuity meter featuring a high-contrast pattern. 2. The visual acuity meter according to claim 1, wherein the optotype section displays an optotype using a transmissive liquid crystal. 3. The visual acuity meter according to claim 2, wherein the peripheral portion is reflectively illuminated. 4. The visual acuity meter according to claim 1, wherein the high contrast pattern is a black and white pattern. 5. The visual acuity meter according to claim 1, wherein the high contrast pattern is a color pattern.