JPH0556919A - Target device - Google Patents

Abstract

PURPOSE:To make other part than a target mark and a necessary designated mark invisible to a person to be examined, and also, to allow the person to know surely the designation of the target mark by providing a means for varying the designated mark positioned in the vicinity of the target mark, and brightness of the designated mark. CONSTITUTION:When it is desired to show a specific target mark M to a person S in the case a light source 8 in the rear of the corresponding opening 5 is lighted the target surface 2 of the part for covering the opening 5 is lighted and functions as a designated mark. The target mark M is selected by a program assembled into a control part 9, and the person S decides the direction of a cut of the target mark M and inputs it to an input means 10, and judges whether it is correct or erroneous by a control part 9. Also, the light source 8 shines brightly or flickers so as to be surely visible to the person S in the beginning of lighting, thereafter, drops brightness so as not to affect on the decision of the person S and executes continuously lighting or stops flickering. In such a manner, the person can designate surely the designated target mark.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optotype apparatus for use in an optometry device such as a optometer used in an ophthalmology clinic.

[0002]

2. Description of the Related Art In order to specify a specific mark from a large number of optotype marks by an automatic optometer, etc., a light source is provided near each optotype mark and turned on to specify the optotype mark to be seen. The method to do is proposed.

Further, Japanese Laid-Open Patent Publication No. 62-144632 discloses a method of providing an incandescent lamp behind each optotype mark and illuminating a designated optotype mark from behind. Further, a method of lighting a designated mark near each optotype mark is also known.

[0004]

However, in the method of illuminating the optotype mark by providing the light source in the vicinity of the optotype mark, the light source is seen by the subject, which is confusing with the optotype mark, which is not preferable. In addition, it is difficult to uniformly illuminate the target surface by the method of illuminating the target mark from behind the target mark with an incandescent lamp.

Further, in the method of lighting the designated mark in the vicinity of the optotype mark, it is necessary to emit a certain intensity of light in order to make the subject surely recognize it. In order not to be mistaken for an adjacent optotype mark, the optotype mark and the designated mark corresponding to the optotype mark must be arranged close to each other. Therefore, the designated mark will emit strong light near the optotype mark.
Since the appearance of the optotype may be affected and accurate measurement may not be possible, if the designated mark is turned on and then turned off, which one is the designated optotype mark after blinking? There is a problem that you do not understand.

An object of the present invention is to prevent the subject from seeing anything other than the optotype mark and the necessary designated mark. Further, the designation of the optotype mark by the designated mark can be surely understood by the subject, and An object of the present invention is to provide an optotype device that enables accurate measurement without influence.

[0007]

A target device according to the present invention for achieving the above object is a target device including a plurality of target marks, wherein a designation mark located in the vicinity of the target mark. And a means for changing the brightness of the designated mark.

The optotype apparatus according to the present invention related to the above specified invention includes a light transmitting / diffusing member having a plurality of optotype marks,
Aperture members that are disposed in close contact with the light transmission / diffusion member and that have openings that function as designated marks in the vicinity of the designated marks, light sources that illuminate each of the openings, and the light amount of the light source is changed. It has a means to make it.

[0009]

The optotype device having the above-described configuration specifies the optotype mark by displaying the specified mark corresponding to the optotype mark desired to be shown to the subject. The designated mark shines so that the subject can surely see it in the initial stage, and thereafter has a light amount that does not affect the subject to observe the optotype mark.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail based on the illustrated embodiments. FIG. 1 is a configuration diagram of the first embodiment, in which a target surface 2 is installed on one side of a box-shaped target presenting apparatus 1.
A lens 3 for the subject S to observe the optotype surface 2 and a light source 4 for uniformly illuminating the optotype surface 2 are installed on the opposite side. The optotype surface 2 is made of a light transmitting / diffusing material such as paper or a synthetic resin sheet, and as shown in FIG. 2, the optotype mark M composed of a Landolt ring is drawn on the surface.

FIG. 3 shows an aperture plate 6 having an aperture 5 near the position corresponding to each optotype mark M.
Is made of a metal plate or the like, and the optotype surface 2 is in close contact with the surface of the opening plate 6. Behind each opening 5 of the opening plate 6, light sources 8 such as LEDs arranged on a substrate 7 are provided respectively as shown in FIG. 4, and these light sources 8 emit light according to a command from the control unit 9. Is being done. The output of the input means 10 is connected to the control unit 9.

When it is desired to show the specific optotype mark M to the subject S, the light source 8 behind the opening 5 corresponding thereto is turned on, and the optotype surface 2 covering the corresponding opening 5 becomes bright. By functioning as a designated mark, the subject S can know which optotype mark M should be viewed. The other openings 5 are not visible to the subject S because they are on the back side of the optotype surface 2 made of a light diffusing material.

The selection of the optotype mark M is performed by a program incorporated in the control section 9, and the subject S judges the direction of the cut of the designated optotype mark M and inputs it to the input means 10, The control unit 9 determines whether it is right or wrong. Then, this is sequentially repeated to measure the visual acuity.

Further, the light source 8 shines brightly or blinks so that the subject S can surely see it in the initial stage of lighting, and it influences the determination at the stage where the subject S thereafter determines the direction of the optotype mark M. Do not turn it off so that it stays on or stops blinking. The distinction between the initial state and the time of determination may be determined by time, and may be made to blink in the sense of a reminder when it takes time to input.

Further, instead of drawing the optotype mark M on the light diffusing material, the optotype mark M may be drawn on a transparent material and overlapped with the light diffusing member. Further, in the present embodiment, the optotype mark M is automatically selected by a program, but it may be done by an examiner, and the method of illuminating the optotype surface 2 does not use the special illumination light source 4. Alternatively, room lighting may be used.

FIG. 5 shows a second embodiment, in which the target surface 11
Is made of an opaque material, and the target mark M is drawn here. Further, in front of the optotype surface 11, a light source 12 and an optotype plate 1 having an arrow-shaped opening are provided as a designated mark projection system.
3, a lens 14, and movable mirrors 15 and 16 are arranged.

The designated mark projection system comprises movable mirrors 15 and 16
By moving, the designated mark P which is the opening shape of the visual target plate 13 can be projected at an arbitrary position on the visual target surface 11, and the brightness of the designated mark P can be changed by changing the brightness of the light source 12. Can be changed.

Also in this embodiment, as in the case of the first embodiment, the designated mark P is made bright at the initial stage of projection, and when the subject S makes a judgment, the brightness is reduced to make it easy to see the optotype mark M. Is preferred.

FIG. 6 shows a third embodiment, in which an annular designated mark P is generated so as to surround the optotype mark M on the optotype surface 17 made of a liquid crystal plate, and is superposed on it. A target mark M is drawn on the transparent body. Designated mark P
The brightness of can be changed by changing the voltage applied to the liquid crystal, and the subject S can be informed of the optotype mark M to be recognized.

[0020]

As described above, in the optotype apparatus according to the present invention, the designated mark is provided close to the optotype mark, and the designated mark other than the designated mark cannot be seen. The designated optotype mark can be specified with certainty without being mistaken for another optotype mark.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a first embodiment.

FIG. 2 is a front view of a target surface.

FIG. 3 is a front view of an opening member.

FIG. 4 is a cross-sectional view of a target surface or the like.

FIG. 5 is a configuration diagram of a second embodiment.

FIG. 6 is a configuration diagram of a third embodiment.

[Explanation of symbols]

 2, 11, 17 Target plane 5 Opening 6 Opening plate 8, 12 Light source 13 Target plate 15, 16 Movable mirror M Target mark P Designated mark

Claims (2)

[Claims] 1. An optotype device including a plurality of optotype marks, a designation mark located near the optotype mark,
And a means for changing the brightness of the designated mark. 2. A light transmitting / diffusing member provided with a plurality of optotype marks, and an aperture provided in close contact with the light transmitting / diffusing member and provided with an aperture functioning as a designated mark near each of the designated marks. An optotype apparatus comprising: a member, a light source that illuminates each of the openings, and a unit that changes a light amount of the light source.