JPH0538491Y2 - - Google Patents

Description

[Detailed explanation of the idea]

Industrial Application Fields This invention is suitable for use with switches, especially commands during visual acuity tests,
This invention relates to the structure of a visual acuity meter switch that is suitably used for responses, answers, etc. BACKGROUND OF THE INVENTION Switches are used to command the operating direction of mechanical devices and to respond to test and inspection devices. By the way, for example, a visual acuity meter observes an optotype board placed in a dark box and illuminated by a light source through a lens, and answers the cut direction of the optotype presented on the optotype board, such as the Landolt optotype, and then calculates the answer. The system is configured to test the visual acuity of the test subject based on whether the test subject is correct or incorrect. Therefore, since the subject needs to constantly observe the index board through the lens, when operating the switch to answer the cut direction, there is no need for the subject's eye to move his or her line of sight in order to see the switch itself. A switch is required. A conventional example of a joystick type switch that satisfies this requirement is a joystick type switch, which allows answers to be answered by tilting the joystick in accordance with the cut directions of the Landolt optotype (for example, four directions, up, down, left, and right). However, this visual acuity meter has a complicated structure, so it has low reliability in long-term use, is expensive, and is large, so the visual acuity meter itself becomes large, and the design process is also disadvantageous. Purpose of the invention The purpose of the invention is to create a device that can be operated without looking at the switch when answering a visual acuity test, has a simple structure, is highly reliable, is compact, and is low in cost, and also has a design for a device that incorporates the switch. It is an object of the present invention to provide a new and useful eye meter switch that is easy to process. Structure of the invention The structural feature of the invention to achieve the above object is that it is formed of a pyramid-shaped protrusion with a high apex in the center and an inclined surface arranged in a direction corresponding to the cut direction of the Landolt optotype. A plurality of push-button switches are provided in a peripheral area around the central identification part, which corresponds to the above-mentioned inclined surface and are arranged in substantially the same plane as the upper surface of the operation surface, so that the subject can It is used as an answer switch for answering the direction of the break in the Landolt optotype. Effects of the invention According to the invention, when operating a switch in response to a break in the Landolt optotype, the subject can easily operate the switch without visually recognizing it, and the position of the push button switch to be operated can be adjusted. It is a switch that can be easily identified by sliding your finger along an inclined surface without visual recognition, centering on the apex of the central identification part formed from a pyramid-shaped protrusion, and its structure is simple. It is possible to provide a highly reliable and low-cost vision meter switch. Furthermore, the present invention can provide a visual acuity meter switch that is advantageous in designing a device incorporating the same. Embodiment (1) External configuration FIG. 1 is an external perspective view showing an embodiment of an automatic visual acuity testing device (hereinafter simply referred to as a visual acuity meter) according to the present invention. On the operation panel 11 located in front of the pedestal 10 on the subject's side, there is a start switch 12 consisting of a push button switch for starting the measurement.
and an answer switch 13 for answering the cut direction of the Landolt optotype visually recognized by the subject. An apparatus housing 15 stands upright on the pedestal 10, and two windows 16 are provided on the front side of the housing 15 on the subject's side to allow the subject to look at the optotype with both eyes.
a, 16b, and a forehead rest member 17 are provided. Furthermore, a printer 19 is attached to the housing 15 to print out the test results. This printer has a calendar input device 19a for inputting the year, month, and day of the inspection date. The answer switch 13 has a pyramid-shaped central projection 20, as shown in FIGS. 2A and 2B.
, push button switches 21 to 24 are arranged front to back, left and right around this center, and each switch is used to indicate to the subject which cut direction of the Landolt optotype each of these push button switches corresponds to. It is composed of Landolt marks 21a to 24a displayed close to each other. Even if the examinee constantly looks into the windows 16a and 16b,
With this configuration, it is possible to know the overall arrangement of the response switch 13 and the positions of the push button switches 21 to 24 based on the tactile sensation of the central protrusion 20. An examiner operation panel 30 shown in FIG. 3 is disposed behind the top surface 18 of the housing 15. This operation panel 30 includes a power switch 301 consisting of a toggle switch with a built-in pilot lamp, a measurement sequence setting knob 302, an optotype presentation time setting knob 303, and examination menu setting switches 304 to 310 consisting of push button switches. A switch 311 for turning on the astigmatism chart, an optical path selection switch 312 for selecting whether to put the astigmatism chart into the left eye optical path or the right eye optical path, and a push-button end switch provided to end the measurement. 313, pilot lamps 304a to 310a for displaying the ON-OFF status of each test menu setting switch, pilot lamps 315a and 315b for indicating which of the left eye or right eye is being measured, and a visual acuity of 0.7. Judgment lamps 316a and 316b for indicating the judgment result of the measurement using the optotype as "pass" or "fail", and a liquid crystal display panel 320 for indicating the optotype presented to the subject during the measurement as a visual acuity value. is installed.
Here, each of the above-mentioned pilot lamps 304a to 316b is composed of an LED. (2) Optical system Figure 4 shows the optical layout of this visual acuity meter. The right eye optical path OR and the left eye optical path OL have the same configuration. The light emitted from the optotype illumination light sources 40R, 40L is reflected by the concave mirrors 41R, 41L, and then the light emitted from the optotype illumination light source 40R, 40L is reflected by the optotype plate 42.
Illuminate R and 42L. The optotype plates 42R, 42L are arranged at the focal positions of the distance lenses 43R, 43L arranged in the windows 16a, 16b. The light from the optotype plates 42R and 42L is passed through a half mirror 44.
After being reflected by R, 44L, mirrors 45R, 45
Reflected by L, 46R, 46L and lens 43R, 4
The light is made into a parallel light beam by 3L and enters the eye E to be examined. Normally, when testing the visual acuity of one eye, a visual target is not presented to the other eye, but it is said that it is necessary to provide a bright field similar to that of the eye to be measured. Therefore, in this embodiment, the bright field light sources 47R, 47
L and diffusion plates 48R and 48L. For example, when testing the right eye, the light source 40R illuminates the optotype plate 42R and presents the optotype to the subject's right eye ER.
At this time, the light source 47L of the left eye optical path OL is also turned on, and the light diffused by the diffuser plate 48L is transmitted through the half mirror 44L and then reflected by the mirrors 45L and 46L, giving a bright field to the subject's left eye EL. The distance lenses 43R and 43L have auxiliary lens groups 49R and 49L. These auxiliary lens group 4
9R and 49L are, for example, lenses 491R and 491L for farsightedness examination having a refractive power of +0.5D, for example, +
Near vision inspection lens 492R with 3.0D refractive power,
492L and pinhole plates 493R and 493L each having a large number of pinholes. These auxiliary lens groups 49R, 49L are mounted on turret plates 495R, 495L, as shown in FIG.
and selectively inserted into their respective optical paths. Transparent apertures 494R and 494L are also formed in the turret plates 495R and 495L, and are placed in the respective optical paths during long-distance inspection. These turret plates 495R, 495L have gears 4 on their rotating shafts 497R, 497L, respectively.
It has 98R and 498L. These gears 49
8R, 498L has tension belt 499R,
499L is hung, and two belts 499
R and 499L are connected to a gear 496a attached to one end of the rotating shaft of the pulse motor 496. With this configuration, the rotation of the motor 496 rotates the turret plates 495R and 495L. On the other hand, a slit plate 500 having a slit 500a is provided at the other end of the rotating shaft 496a of the motor 496.
is installed. This slit 500a corresponds to apertures 494R and 497L,
When this slit 500a is rotated to the position of the photo interrupter 501 which is its detector, the apertures 494R and 494L are set in the respective optical paths.
It is configured to be located within OR and OL. The optotype plates 42R and 42L each include a diffuser plate 421, a liquid crystal plate 422, and a mask plate 423, as shown in FIG. The diffusion plate 421 functions to diffuse the light from the light source 40. As shown in FIG. 6, various patterns 401 to 409 are formed on the liquid crystal plate 422, which turn black when energized. Landolt optotype pattern 401
Among patterns 409 to 409, patterns 401 to 405 corresponding to visual acuity of 0.1 to 0.5 have circular arc portions 40 so that cuts in four directions can be selectively switched and displayed.
1a and each cut portion 401b are formed independently. Then, for example, the rightward Landolt optotype is obtained by energizing and blackening everything except the right cut portion 416b. On the other hand, patterns 406 to 409 corresponding to a visual acuity of 0.6 to 0.9 are configured as a group of four Landolt optotypes whose cut directions are vertical, horizontal, and vertical. Further, a sunburst type astigmatism table pattern 410 is formed on the liquid crystal panel 422, and a clock time display pattern 411 is formed on each meridian so that the direction thereof can be easily determined. Below the astigmatism table pattern 410 are 16 rectangular patterns 412a.
Shutter row pattern 41 formed by arranging in a row
2 is formed. Shutter row pattern 41
Further below 2, a shutter group 413 for stereoscopic viewing charts is formed to control the presentation of stereoscopic viewing charts, which will be described later. The mask plate 423, as shown in FIG.
Visual acuity 1.0, 1.2, 1.5 and
A total of 16 Landolt optotypes 415 in four directions (up, down, left, and right) corresponding to 2.0 are arranged in groups of four. In this example, from the right side of the figure, 1.0, 1.2,
Visual targets corresponding to visual acuity of 1.5 and 2.0 are arranged. Below the Landolt optotype column 416, there is a diamond-shaped 5
Openings 416a, 416b, 416c, 41
A mask portion 417 is formed in which 6d and 416e are formed to correspond to the above-described shutter group 413 for stereoscopic viewing charts. Four small diamond shapes 418 are formed in each of the openings, one of which is shifted in position from the other small diamond shapes in the horizontal direction. For example, the small diamond shape 419a within the opening 416a has a center-to-center distance of D ₁ (D ₁ >S) with respect to the reference center-to-center distance S of other small diamond shapes.
One of the diamond shapes 419b to 419e in the other openings 416b to 416e also has a center-to-center distance of D ₂ to D ₅ , respectively. Here D ₁ > D ₂ >
There is a relationship of D ₃ >D ₄ >s>D ₅ , and the deflection directions in this embodiment are all in the right horizontal direction. In this embodiment, the stereoscopic chart 416a represents a parallax of 4', and the chart 416b represents a parallax of 1'.
16c has a parallax of 3', and chart 416d has a parallax of 3.
0'', and the chart 416e is configured to give a parallax of 2'. The embodiment shown in FIG. 7 is a mask plate for the right eye, and the mask plate for the left eye is the same as the mask plate shown in FIG. The patterns 415 and 415 described above are formed mirror-symmetrically.
417 is formed by depositing chromium on a glass substrate. (3) Electrical system Figure 8 is a block diagram showing the electrical system of this vision meter. The electrical system is a ROM (read-only) that stores the inspection sequence program described later.
memory) 606 and RAM (random access
to control the entire electrical system according to the sequence stored in memory) 608 and ROM 606.
CPU (Central Processing Unit)
607 and a drive system 60 for each of the aforementioned components.
0 and an interface 605 that communicates between the drive system 600 and the CPU 607. The CPU607 has a CTC (counter timer)
circuit) 609 is connected. CTC6
09 is a pulse for controlling the rotation of the pulse motor 496 and a liquid crystal plate 4 of the optotype plates 42R and 42L.
The CPU sends pulses to select the cut direction of the Landolt optotype presented by 22R and 422L.
607. That is, the CTC 609 is configured as a down counter whose lower four digits decrease sequentially from "1111" to "0000" as shown in Table 1. This down counter starts at the same time as the power is turned on and is constantly executed.

[Table] The CPU 607 uses CTC 6 immediately before the visual target presentation step.
Read the count of 09, and if the last two digits of the count value are "11", the break of the Landolt optotype is on the "top", and if it is "10", it is on the "bottom", so it is "01". If "right" is "00"
In this case, select each Landolt optotype as shown on the "left". With this configuration, the direction of the break in the Landolt optotype is randomly presented due to the randomness of both the time from power-on until the test subject turns on the start switch 12 and the time from power-on to the response time from the answer switch 13. The drive system 600 includes the operation panel 30, a driver circuit 601 for driving the liquid crystal panel 320,
Driver circuit 602 for lighting the light sources 40R, 40L, 47L, 47R, optotype plates 42R, 42
It is roughly composed of driver circuits 603 and 604 for driving the liquid crystal panels 422R and 422L, respectively, and a speaker 610 and its driver circuit 611 for producing sound when an answer is input by the answer switch. Measuring Method and Operation of the Apparatus (1) Overall Measurement Flow FIG. 9 shows a flowchart showing the entire measurement procedure by this visual acuity meter, which will be explained in detail below. Step 1-1: Switch the power switch 301 on the operation panel 30 to "on" to turn on the power. Step 1-2: The CPU 607 communicates with the photo interrupter 50 via the interface 605.
1 detects the slit 500a, that is, whether the transparent aperture 494R, 4
94L is located within the optical path. When the photo interrupter 501 does not detect the slit 500a, the pulse motor 496 is rotated by the pulse output from the CTC 609, and the aperture 494 is rotated.
R, 494L is located in the optical path. Also,
The CPU 607 erases the previous data stored in the RAM 608. Step 1-3: The examiner uses the operation panel 30 to select and set the measurement sequence, examination menu, and optotype presentation time. That is,
The measurement sequence is set using the setting knob 302, and in the case of testing only with the naked eye or with correction, the knob 302 is set to the "naked eye" or "correction" position. If it is desired to automatically perform the correction examination after the naked eye examination, the knob 302 is set to the "naked eye+correction" position. Next, consider the age of the test subject and whether or not he or she has experience with testing.
The knob 303 adjusts the visual target presentation time in consideration of habituation etc.
Determined by. In this embodiment, the visual target presentation time is 3 seconds when set to "1", 5 seconds when set to "2", and 7 seconds when set to "3". Timing is CTC60
9 and when the desired time has arrived.
The driver circuit 603 is controlled by the CPU 607 to erase the visual target. The inspection menu is a push button switch 304.
to 310. The "binocular" menu (switch 310) automatically shifts to binocular testing after the right eye test and left eye test. If this "binocular" menu is not selected, a monocular examination will be performed for each of the left and right eyes. Step 1-4: The CPU 607 reads the measurement sequence, examination menu, and optotype presentation time set in the previous step, and then turns on the light source 40R in the right eye optical path and the light source 47b in the left eye optical path to complete measurement preparation. Step 1-5: The CPU 607 determines whether or not the start switch 12 has been turned on by the subject. If it has been turned on, the process proceeds to the next step 1-6. If it remains OFF, return to the previous step 1-3 so that you can respond to changes in the measurement sequence or inspection menu. Step 1-6: A measurement processing subroutine to be described later is executed based on the setting measurement sequence, setting inspection menu, etc. read in step 1-4. Step 1-7: The CPU 607 counts the number of times the set inspection menu is passed, that is, the number of times it is executed. Step 1-8: The CPU 607 determines whether or not it is necessary to proceed to step 1-9, which determines the number of passes in the previous step 1-7, according to the set measurement sequence. If the measurement sequence is set to "naked eye + correction", proceed to the next step 1-9. If the setting is "naked eye" or "correction", the process skips over the next step 1-9 and moves to step 1-10. Step 1-9: Check whether the number of passes counted in Step 1-7 is 2 or more, that is, inspect all setting test menus with the naked eye;
It is determined whether two tests of the all settings test menu in the correction state have been executed. If two tests have been performed, move on to the next step 1-10. If it is less than twice, the process moves to step 1-11, where the subject is made to wear glasses or contact lenses and prepare for a vision test in a corrected state. After completing the preparations, the subject presses the start switch 12 again.
Turn on (step 1-12), step 1-
Re-execute the steps below 6 and perform a correction status efficacy test. Step 1-10: Number of passes N≧ in Step 1-9
If it is determined as 2, the measurement result, that is, the visual acuity of the subject is printed out using the printer 19. In addition to visual acuity values for the left and right eyes, the printout also includes binocular visual acuity, 0.7 precision test pass/fail judgment results, stereoscopic vision ability results, etc., depending on the setting test menu. The examination date set by the calendar input device 19a is also printed. When the printout is completed, the apparatus returns to step 1-2 and enters the initial state for the next patient. (2) Measurement processing subroutine FIG. 10 is a subroutine flowchart showing steps 1-6 of the above-mentioned measurement processing in more detail. Based on the inspection menu read in step 1-4, the CPU 607 determines whether or not to execute the measurement processing steps (steps 2-1 to 2-6), and if the determination result is "YES", each test ( Step 2-7 or Step 2
-12) is executed. The subroutines of each test will be explained below. Note that when the hyperopia check test (step 2-9) or pinhole check test (step 2-10) is selected alone,
The CPU607 first performs a distance visual acuity test (Step 2).
-7), each test step is executed, and the test results of the two are compared. (3) Screening test Figure 11 shows a flowchart of the screening test. This screening test includes the distance visual acuity test (step 2-7), the near visual acuity test (step 2-8), and the hyperopia check test (step 2-7) of the measurement processing subroutine described above.
9) and pinhole check test (Step 2)
-10) are commonly performed for testing the left eye, right eye, and both eyes. However, during the near visual acuity test, lenses 492R and 492L, and during the far vision check test, lenses 491R and 491L
Pinhole plate 4 during pinhole check test
The difference is that 93R and 493L are each inserted into the optical path. Insertion of these lenses requires CPU6
07 is executed by rotating the motor 496 by associating the number of pulses previously stored in the ROM 606 corresponding to each lens with the number of pulses input from the CTC 609. The operation of each step will be explained below using a distance visual acuity test as an example. Step 3-1: The CPU 607 first activates the pilot lamp 304a,
Turn on 315b. Next, CPU607
The previous data stored in the failure number storage area of the RAM 608 is cleared and reset to 0. Step 3-2: The CPU 607 adjusts the visual acuity of the liquid crystal panel 422R to 0.7 via the driver circuit 603.
Of the Landolt optotypes 407, at that time
Based on the combination of the last two digits of the CTC609 count value, the Landolt optotype in either the left, right, top, or bottom cut direction is presented, and the answer switch 13
Wait for a response from the subject. switch 1
When 3 is pressed, the speaker 611 utters "Pitsu" to confirm the switch response. At the same time, the visual acuity value of 0.7 of the presented optotype is digitally displayed on the liquid crystal panel 320. Here, each Landolt optotype is presented for a predetermined period of time, for example, 0.5 seconds, at the initial stage of presentation.
The optotype is blinked to make it easier for the subject to visually recognize the presentation position. In this example, the counter from CTC609 is read by CPU607, the count of CTC609 is 0.1msec.
When the last digit of the count value is "1", the liquid crystal plate 422R is driven to present the optotype, and when the last digit is "0", the drive is stopped and the optotype is not presented. This is achieved by controlling the driver circuit 603 with the CPU 607. If the answer from the subject matches the cut direction of the presented Landolt optotype, the CPU 607 causes the process to proceed to step 3-4. If the answers do not match or if there is no answer within the visual target presentation time, the process moves to step 3-3. When the answers do not match, the speaker 611 utters "Peets" to warn the subject. Step 3-3 and Step 3-11: CPU60
7 determines the cutting direction of the Landolt optotype from the last two digits of the count value of the CTC 609 at the start of execution of this step, and the driver circuit 60
Landolt optotype 40 with visual acuity 0.1 by controlling 3
1 is presented. FIG. 12 shows an example of the presentation. At the same time, the display on the liquid crystal board 320 is
Can be changed to 0.1. The CPU 607 determines whether or not there is an answer from the subject within the presentation time and the direction of the cut in the presented Landolt optotype of that answer.
If “YES”, move on to step 3-4.
If there is no match or no answer, step 3-11
The test subject's visual acuity is 0.1 or less.
The data is stored in the RAM 608, and the process proceeds to the next step 3-12. Step 3-4: A visual target that is one step smaller than the visual target presented last time (a visual target with visual acuity of 0.7 if the previous step is Step 3-2, a visual target with visual acuity of 0.1 if the previous step is Step 3-3), that is, visual acuity value. The target is one step higher (previous step is step 3)
-2, a visual target of 0.8 is presented; if the previous step is step 3-3, a visual target of 0.2 is presented).
At this time as well, the cutting direction of the Landolt optotype to be presented is determined from the last two digits of the count value of the CTC 609 at that time. 12th B
The figure shows an example of the presentation of the Landolt optotype of 0.6. The liquid crystal panel 320 displays 0.8 or 0.2. Step 3-5: Determine whether or not the subject answers the direction of the cut in the Landolt optotype via the answer switch 13 within the optotype presentation time, and whether the answer matches the cut in the Landolt optotype that was presented. The CPU 607 determines whether or not it was.
If the judgment is ``YES'', proceed to step 3-6; if the judgment is ``NO'', proceed to step 3.
-Move to 7. Step 3-6 and Step 3-8: Step 3
- Determine whether the Landolt optotype presented in Step 4 is the minimum optotype, that is, the Landolt optotype with visual acuity of 2.0, and if ``YES'', step 3-
8, and the visual acuity of the eye to be tested is 2.0 in RAM608.
Then, proceed to the next step 3-12.
Move to. If the determination is "NO", the process returns to step 3-4 and a Landolt optotype that is one step smaller than the previously presented optotype is presented. 12th C
The figure shows an example of Landolt optotype presentation for a visual acuity of 1.5. For the optotypes 1.0, 1.2, 1.5, and 2.0, not the Landolt optotype itself but the corresponding Landolt optotype on the mask plate 423 can be observed by erasing the rectangular pattern 412a of the shutter row pattern. Step 3-7: Since the determination of “NO” was made in the previous step 3-5, the CPU 607
Store 1 in the failure number storage area of 08.
If the number of failures N is already stored in the failure memory area, 1 is added to it. Step 3-9 and Step 3-10: Determine whether the number of failures N is 2 or not. If ``YES'', proceed to step 3-10, and compare the number of failures N to 2. The visual acuity value of the presented optotype is stored in the RAM 308 as the visual acuity of the eye to be examined, and the process proceeds to the next step 3-12. If the determination is "NO", the process returns to step 3-4 and presents an optotype that is one step smaller than the currently presented optotype. Step 3-12: Execute the next inspection program.
For example, if the main screening is the right eye test for distance visual acuity test (step 2-7),
The next test program will be the left eye test, light sources 40L, 47R, pilot lamp 315.
Turn on a and execute steps 3-1 to 3-12 described above. If the main screening is a left eye test and the binocular mode (switch 310) is selected, the next test will be a binocular test with light sources 40R and 40L pilot lamps 315.
Turn on lights a and 315b and proceed to step 3-1 described above.
or 3-11. If the binocular examination is the main screening test, the next step will be step 2-2. In the distance visual acuity test, near visual acuity test, hyperopia check test, and pinhole check test described above, when astigmatism check is necessary, operate the astigmatism chart light switch 311 and optical path selection switch 312 on the operation panel 30. The astigmatism chart can be presented to the subject at any time (even during the measurement). FIG. 12D is an example of presenting an astigmatism table. The subject is asked to judge whether each meridian of the presented astigmatism chart can be seen with uniform shading. If there is a difference in shading depending on the direction of the meridian, have the students verbally answer in which direction the meridian appears darker using the ``time'' written on the meridian. This invention has the advantage that the astigmatism test is not incorporated into the measurement routine and can be inserted at any time during the measurement, allowing the tester to perform the test whenever they suspect astigmatism. be. Furthermore, if the test subject's answer, which is the basis for the judgment in step 3-2 above, is based on estimation rather than visual recognition, even if it is determined to be a correct answer, in the flow of Figure 11, it is less than 0.7. should not be recognized as true vision. As a countermeasure for this, the first
It is a good idea to add step 3-2b, which is marked with a broken line in Figure 1. In step 3-2b, as shown in Figure 13, if the answer is ``YES'' in step 3-2, the visual acuity remains the same as before until the number of correct answers Y becomes Y=2.
Present the Landolt optotype, which is 0.7 but whose cut direction is different from the previous optotype, and have the child answer again. The purpose of using an optotype with a cut in a direction different from the previous one is to make it easier to detect the effects of astigmatism. In addition, the number of correct answers Y is
When =2, proceed to the next step. If it is desired to add a step for excluding measurements due to coincidence, the above-mentioned step 3-2b-1 can be added after step 3-6. In addition, there are lenses 491R and 49 for farsightedness inspection in the optical path.
If the far vision check test performed by inserting the 1L or the pinhole check test performed by inserting the pinhole plates 493R and 493L into the optical path is selected, the results of the distance vision test stored in the RAM 608 and Each test result
The CPU 607 compares the visual acuity values, and if the visual acuity value improves, the printer 19 prints out, for example, "Shiriyoku Koujiyou". (3) 0.7 precision test This 0.7 precision test is used to test visual acuity for the issuance of a driver's license, and uses 0.3 optotypes and 0.7 optotypes as shown in Figure 14. That is, in the 0.7 precision test, first, in step 4-1, 0.3 optotypes are displayed for the right eye in four directions, and it is determined whether or not the correct answer has been given in three or more directions. Step 4-
If a correct answer is given in 3 or more directions in step 1, the process advances to step 4-2. In step 4-2, 0.3 optotypes for the left eye are displayed in four directions, and it is determined whether or not a correct answer has been given in three or more directions. Step 4-
If a correct answer is given in 3 or more directions in step 2, the process advances to step 4-3. In step 4-3, 0.7 optotypes are displayed for both eyes in 4 directions, and 3
It is determined whether a correct answer has been given regarding the direction or more. If the correct answer is given in three or more directions in step 4-3, the process proceeds to step 4-4, where it is determined that the 0.7 precision test has passed, and the pass judgment lamp 31
6a, and step 4-1, 4-2,
If no correct answer is given in any of the three directions in step 4-3, the process proceeds to step 4-5, where it is determined that the 0.7 precision test has failed, and the failure determination lamp 316b is turned on. Each step 4- of the flowchart in Figure 14
The flow common to 1, 4-2 and 4-3 is the 15th flow.
As shown in the figure, it consists of the following steps. Step 5-1: Reset the number of failures N in the failure number storage area in the RAM 608 to 0. At the same time, the number of correct answers Y in the correct answer number storage area in the RAM 608 is also reset to zero. Since the measurement starts from the right eye (step 4-1), the light sources 40R and 47L are turned on. Also,
CPU607 is photo interrupter 501
It is confirmed that the transparent apertures 494R and 494L are located in the optical path by the ON signal from the. Step 5-2: The CPU 607 calculates the lower two counts from the CTC 609 at the time of transition to this step.
Determine the direction of the break in the Landolt optotype from the number of digits, and set the visual acuity of 0.3 in the direction of the break (Step 4-
3, visual acuity 0.7) Landolt optotype 40
3 (407) is presented. to the liquid crystal board 320
0.3 or 0.7 is displayed. The cut direction of the presented Landolt visual target is stored in the RAM 608. Step 5-3: Check whether the test subject answered within the visual target presentation time or whether the answer was correct.
The CPU 607 makes a determination. If the determination is ``YES'', the process proceeds to step 5-4, and if the determination is ``NO'', the process proceeds to step 5-5. Step 5-4: Add 1 to the number of correct answers Y in the correct answer number storage area of the RAM 608 and store it again. Step 5-5: Add 1 to the failure number N in the failure number storage area of the RAM 608 and store it again. Step 5-6: CPU 60 determines whether Y+N=4 or not.
7 is judged. That is, a Landolt target of 0.3 (or a target of 0.7 in the case of step 4-3)
It is determined whether all four types of breaks have been presented to the subject. Number of presentations Y+
If it is determined that N is Y+N<4, the process proceeds to step 5-7. If it is determined that the number of presentations is Y+N≧4, the process proceeds to step 5-8. Step 5-7: A Landolt optotype having a cut direction other than the Landolt optotype stored in the RAM 608, that is, a cut direction that has not been presented yet, is presented. Then, the process returns to step 5-3 again. Step 5-8: Determine whether the number of correct answers Y is Y≧3. When Y≧3, it is determined that the test has failed and the process proceeds to step 5-10, and immediately proceeds to step 4-5, where the judgment lamp 316b is turned on. If the number of correct answers Y is Y≧3, the process moves to step 4-2 and steps 5-1 to 5-8 are executed again for the left eye. If the actual step is step 4-3, i.e. in binocular vision,
0.7 If it is an optotype inspection step, proceed to step 4-4 based on the judgment in step 5-9.
The determination lamp 316a is turned on. (4) Stereoscopic vision test The stereoscopic vision test 2-12 consists of the following steps, as shown in Fig. 16. Step 6-1: The CPU 607 controls the driver circuit 602 to turn on the light sources 40R and 40L and turn off the light sources 47R and 47L. Next, by controlling the driver circuits 603 and 604 to open the shutter 413 at a position corresponding to the stereoscopic chart 416a of the parallax 4' of the mask plate 423 for the left and right eyes, the image of the stereoscopic chart is shown to the subject. 416a' is presented. Figure 17 shows stereoscopic chart image 4 with parallax 4'.
16a' shows the presented state. Step 6-2 and Step 6-4: The subject:
Among the charts presented, the answer switch 13 is used to answer whether the diamond-shaped image 419', which appears to stand out from the other diamond-shaped images 418 in stereoscopic vision, is located in the left, right, top, or bottom. In the example of FIG. 17, the diamond on the left side appears to be floating, so the switch 21 is pressed. The CPU 607 compares the answer from the subject with the answer stored in advance in the ROM 606 and determines whether the answer is correct or not. If the answer is correct, step 6-3
Move to. If the answer is incorrect, the process moves to step 6-4, where the printer 19 prints out the discrimination ability with a parallax of 4' or more, that is, level 0, and the test ends. Steps 6-3 to 6-15: Similarly, the stereoscopic chart 416c with a parallax of 3', the stereoscopic chart 416e with a parallax of 2', the stereoscopic chart 416b with a parallax of 1', and the stereoscopic chart 416d with a parallax of 30'' are applied. The examiner's answers are presented sequentially depending on whether they are correct or incorrect, and based on the parallax value of the stereoscopic chart in which the incorrect answer was given, it is determined to be either level 1 or level 4, and the result is printed on the printer 19. Operation panel The end switch 313 of 30 causes the CPU 607 to cancel the subsequent tests by pressing it when you want to cancel an erroneous test in the middle of any of the tests mentioned above, and returns to the initial state (step 1-1 in FIG. 9).
2). In addition, if there is a possibility that a person who is taking a test using this vision meter for the first time may not understand how to answer and may receive an incorrect test result, a "Practice" switch can be installed as shown by the broken line in Figure 3. By turning ON, a program is activated that presents the Landolt optotype with visual acuity of 0.1 in a binocular distance visual acuity test and allows the user to practice answering methods using the answer switch 13.

[Brief explanation of the drawing]

Fig. 1 is an external perspective view showing an embodiment of an automatic visual acuity meter according to the present invention, Fig. 2A is a plan view showing the configuration of an answer switch, and Fig. 2B is a B--B in Fig. 2A.
B' cross-sectional view, Figure 3 is a plan view showing the configuration of the operation panel, Figure 4 is a perspective view showing the optical arrangement, Figure 5 is a plan view showing the configuration of the auxiliary lens group, and Figure 6 is the liquid crystal panel. 7 is a plan view showing an example of a mask plate pattern, FIG. 8 is a block diagram showing the configuration of the electrical system, FIG. 9 is a flowchart showing the overall flow of the inspection routine, and FIG. Figure 10 is a flowchart showing the measurement processing subroutine, No. 11.
The figure is a flowchart showing a screening routine, Figures 12A to 12D are diagrams showing an example of visual target presentation, Figure 13 is a flowchart showing a subroutine for preventing erroneous measurements due to coincidence, and Figure 14 is a flowchart showing a subroutine for preventing erroneous measurements due to coincidence.
0.7 A flowchart showing a precision test subroutine. FIG. 15 is a flowchart showing a routine within each step common to each step in FIG. 14. FIG. 16 is a flowchart showing a stereoscopic vision test routine. FIG. 17 FIG. 3 is a diagram showing an example of stereoscopic presentation. 10...Pedestal, 11...Operation panel, 12...
Start switch, 13...Answer switch, 20
...Central protrusion, 21-24...Push button switch, 21a-24a...Landolt mark, 3
0...Operation panel.

Claims (1)

[Claims for Utility Model Registration] (1) A central identification portion formed from a pyramid-shaped protrusion having a high apex at the center and an inclined surface arranged in a direction corresponding to the cut direction of the Landolt optotype; A plurality of push button switches are provided in a peripheral area around the identification part, corresponding to the inclined surface, and arranged in substantially the same plane as the upper surface of the operation surface,
A switch for a visual acuity meter, characterized in that it is used as an answer switch for a subject to answer the cut direction of the Landolt optotype. (2) The vision meter switch according to claim 1, wherein the push button switches are disposed at four locations on the front, rear, left and right sides of the central identification section.