JPH0225609B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention provides visual acuity testing optotypes in a plurality of optotype sets (hereinafter referred to as The present invention relates to a visual acuity testing device that divides one optotype set into one screen (one screen) and switches and presents a desired set of optotypes within a predetermined frame.

[Prior Art] A visual acuity test is generally performed based on the response of the test subject, so it is ideal to use one visual target per screen in order to obtain a smooth response from the test subject.

However, visual acuity tests require a variety of visual targets to test various visual functions, such as visual acuity charts, astigmatism charts, and stereoscopic vision charts. In addition, even when testing the same visual function, it is necessary to use different optotypes in consideration of the language used by the subject, age, etc.

It is practically impossible to fit all of these various visual targets into one screen due to economic and space constraints.

Therefore, a type of visual acuity testing device that displays a plurality of types of visual targets on one screen is generally used. In conventional visual acuity testing devices of this type, the examiner identifies the optotypes that the examinee needs to read verbally or using a pointing stick, and the results are displayed on the attached keyboard using a subjective ophthalmoscope, etc. It is common to enter .

[Problems to be Solved] In the above-mentioned conventional technology, not only is the operation of inputting data into a subjective ophthalmoscope or the like complicated and time-consuming, but there is also a considerable possibility that input errors may occur.

In addition, in order to test a large number of subjects, the roles of an optotype indicator, an inputter, an operator, etc. must be divided, and there is a problem in that it requires a lot of manpower.

An object of the present invention is to provide an apparatus that can clearly indicate to a subject the visual target to be read and can easily retrieve test results as electrical signals.

[Means for Solving] In order to achieve the above object, the present invention divides a visual acuity test target into a plurality of target sets so as to have at least one set of visual acuity targets each having a plurality of visual acuity targets having different visual acuity values. In the visual acuity test device that switches and presents a desired optotype set within a predetermined frame, the optotype set switching means switches to an optotype set having the optotype to be presented to the test subject; an optotype array specifying means for specifying an optotype array of visual acuity values that the examinee should interpret from the above; a visual acuity value retrieval means for extracting the visual acuity value of the target; a transition switch for transitioning to the next visual acuity measurement stage different from the above; and a visual acuity value immediately before the operation of the transition switch is tested in conjunction with the operation of the transition switch. A memory switch that stores the final visual acuity value that the test subject was able to read as the test subject's visual acuity value, and an output means that outputs the stored visual acuity value of the test subject. It is a feature.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 is an external view of an embodiment of the present invention.
Film 2 illuminated from the back in the center of housing 1
There are 3 optotypes with visual acuity of 0.2, 0.3, and 0.4 on the same screen.
-1, 3-2, and 3-3 are arranged. 4-
Reference numerals 1, 4-2, and 4-3 are lamps arranged next to the visual target rows for each visual acuity value. Since the visual acuity chart is placed several meters in front of the subject, an infrared light receiving window 5 is arranged so that it can be remotely controlled using infrared signals.

FIG. 2 shows a cross-sectional view of the device shown in FIG. 1, in which the film 2 is wound around the drums 6 and 7, and the drums 6 and 7 are rotated by a motor 8 and gears and belts (not shown). By sending film 2, the screen is switched to the screen of the required optotype set.

Reference numeral 9 denotes a photoelectric switch for detecting the initial film position located on the left side of the screen, and on the right side of the screen is a photoelectric switch 11 (FIG. 4) having the same shape as photoelectric switch 9 for detecting screen switching.

10-1 and 10-2 are lamps for illuminating the film 2 from the back side, and a relay 24 (fourth
(Fig.) is lit.

FIG. 3 is an external view of the visual target switching control section 12, which is connected to the subjective ophthalmoscope and formed integrally with the subjective ophthalmoscope control section 13.

14 is a display unit that displays measurement results. 15
is an optotype switching switch group consisting of 24 switches, which can be switched between optotypes for visual acuity tests, refraction tests, and other visual function tests. 16 is an optotype switching switch for each visual acuity value;
7 is a visual acuity value display section.

FIG. 4 is a block circuit diagram of the visual acuity testing device. The controller 18 is composed of a CPU, RAM, ROM, etc., receives signals from the optotype switching control section 12, and plays the role of controlling each section. Reference numeral 19 denotes a transmitting light emitting unit that converts the signal from the optotype switching control block 12 into infrared light and sends it to the optotype inspection apparatus main body. Reference numeral 20 denotes an infrared light receiving section attached to the housing 1, which is converted into a digital signal by a preamplifier 21 and a detection circuit 22. 23
is a relay for rotating the motor 8 in the forward or reverse direction.

The operation of the embodiment having the above configuration will be described next.

When the power is turned on, the motor 8 rotates forward and the drum 7
rotates counterclockwise, and the film 2 is wound downward. When the photoelectric switch 9 detects the initial position of the film, the controller 18 controls the relay 23 to stop the motor 8. At this time, Fig. 5-1 of Fig. 5 is presented to the subject on the screen, and the visual acuity value display section 17 shows
0.05 is displayed.

When the downward arrow part of the optotype changeover switch 16 for each visual acuity value is pressed, the motor 8 is reversed and the drum 6 is rotated clockwise. The screen switching photoelectric switch 11 detects an unillustrated mark provided on the film for each screen, and the screen shown in FIG. 5-2 is displayed in the center of the housing 1, and the visual acuity indicator lamp 4-1 lights up. do. At this time, 0.1 is displayed on the visual acuity value display section 17 in FIG.

Thereafter, by pressing the optotype switch 16 for each visual acuity value, the screen, display lamp for each visual acuity, and visual acuity value display section are changed from Fig. 5-3 → Fig. 5-4 → Fig. 5-5 → Fig. 5- It can be switched as shown in Figure 6.

Also, (0.5, 0.6, 0.7), (0.8, 0.9, 1.0), (1.
2,
1.5 and 2.0), it is possible to display the 15 levels of visual acuity required for standard visual acuity tests on a total of six screens. A total of 6 screens can display the 15 levels of visual acuity required for standard vision tests.

The subject is asked to read the optotype for visual acuity test in the row where the display lamp for each visual acuity is lit, and if it can be read, the down arrow switch of the optotype changeover switch 16 for each visual acuity value is further pressed. If the visual target cannot be read at this stage, press the up arrow switch of the visual target changeover switch for each visual acuity value to return to the state where the lamp is lit on the visual target with the visual acuity value that can be read.

Visual acuity values include unaided visual acuity, corrected visual acuity, right eye visual acuity, left eye visual acuity, and binocular visual acuity.
Switching is possible with 4, 25, 26, 27,
When these switches are pressed, the visual acuity values previously displayed on the visual acuity display section are automatically memorized and can be printed out using a printing device (not shown).

[Effects of the Invention] As is clear from the above description, according to the present invention, in order to identify the optotype that the examinee should read from among the optotypes with multiple optotype values on the screen, unnecessary examiner and This avoids interaction with the subject, and allows the subject to switch and give instructions to the target to be read simply by operating the visual target switching switch for each visual acuity value.

Furthermore, since the visual acuity value information can be automatically stored in memory by pressing the transition switch that moves to a different next visual acuity measurement stage, the information can be stored reliably without forgetting to press the memory switch.

[Brief explanation of drawings]

Fig. 1 is an external view of one embodiment of the present invention;
The figure is a sectional view of the device shown in FIG. 1, FIG. 3 is an external view of the optotype switching control section 12, FIG. 4 is a block circuit diagram of the visual acuity testing device, and FIG. 5 is an explanation for explaining the operation of the device. It is a diagram. 1... Housing, 4... Visual acuity indicator lamp, 9...
Photoelectric switch for detecting film initial position, 11...
Photoelectric switch for screen switching detection, 12... optotype switching control section, 16... optotype switching switch for each visual acuity value, 20... infrared light receiving section.

Claims (1)

[Scope of Claims] 1. Dividing a visual acuity test optotype into a plurality of optotype sets so as to have at least one optotype set consisting of a plurality of visual acuity targets having different visual acuity values, and predetermining a desired optotype set. A visual acuity testing device that switches and displays visual acuity within a frame, comprising: an optotype set switching means for switching to an optotype set having an optotype to be presented to a test subject; an optotype sequence specifying means for specifying an optotype sequence of values; and an acuity value extraction unit for extracting the visual acuity value of the optotype to be read by the subject from each signal from the optotype set switching means and the optotype sequence identification means. a transition switch that moves to the next visual acuity measurement stage different from the above, and a storage device that stores the visual acuity value immediately before the operation of the transition switch as the visual acuity value of the subject in conjunction with the operation of the transition switch. A visual acuity testing device comprising: and an output means for outputting the stored visual acuity value of the subject.