JP3828692B2 - Sight meter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a visual acuity meter used for visual acuity inspection and the like.
[0002]
[Prior art]
There is known a vision meter that examines visual functions such as visual acuity by providing a binocular viewing window through which a subject's eye looks and observing a presentation target arranged in a housing through the viewing window. Conventionally, the distance measurement target presentation (distance vision test) and the near distance measurement target presentation (near vision test) using this type of a vision meter have been performed in the following configurations.
[0003]
At the time of distance measurement, the test target presented in the housing is presented optically at a predetermined far distance by the convex lenses arranged in the left and right viewing windows. At the time of near-field measurement, the test target presented in the housing is presented at a predetermined near-distance by removing the convex lens disposed on the left and right viewing windows from the optical path or by replacing the lens.
[0004]
[Problems to be solved by the invention]
However, the sight meter as described above has the following drawbacks. In other words, the subject was configured to view the inspection target presented forward through the same viewing window for both distance measurement and near distance measurement, so a progressive multifocal lens, a bifocal lens, etc. There was a problem that near vision measurement of the downward view when worn was impossible. Even in this case, it is possible for the subject to see the front target through the near part of the progressive multifocal lens or the bifocal lens by tilting the face upward. Since the examiner is forced into an unreasonable posture, accurate measurements cannot be made.
[0005]
In addition, when switching from distance measurement to near-field measurement, it is necessary to switch the lens arranged in the viewing window, so the structure of the switching mechanism is complicated, and when switching is performed manually. Take the trouble.
[0006]
In view of the above-described prior art, the present invention enables a subject to perform near vision measurement in a downward view in a natural state, and is compact without complicating the configuration for distance measurement and near vision measurement. It is a technical problem to provide a vision meter that can be configured at low cost.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, the present invention is characterized by having the following configuration.
[0008]
(1) by observing the presented optotype arranged in the housing in the optometer of testing visual acuity, and viewing window for far examined a pair of right and left provided on the casing, the viewing window for the distance test An inspection viewing window consisting of a pair of left and right inspection windows provided at the lower side , a left eye optical path and a right eye optical path, and separate left and right inspection target optical paths. With a target optical path that is vertically divided into a distance inspection target optical path and a near inspection target optical path, and a dedicated distance inspection target for both the left and right A target disc plate in which a target is arranged, and the left eye distance test target, the right eye distance test target, and the near vision test target are different from the rotation center of the target disk plate. Arranged on the circumference of the radius, and the same target is placed in the left and right distance target optical paths for distance inspection so that binocular inspection is possible And a shutter that selectively opens and closes the optical path, which is disposed in each of the near-view inspection viewing windows .
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a view showing the external appearance of a sight meter according to the present invention.
[0013]
Reference numeral 1 denotes an apparatus main body. At the upper part of the apparatus main body 1, the examinee looks into the left and right distance inspection windows 2R and 2L for looking into the distance target shown inside the main body, and the near target. Left and right near inspection windows 7R and 7L are provided (the near inspection window and the far inspection window may be formed so that the top and bottom are one in appearance). An operation panel 3 for an examiner and a printer 8 are disposed on the side surface of the apparatus main body 1. Further, on the front side of the lower part of the apparatus main body 1, there are provided a joystick 5 for the subject to respond to the target presented inside the main body and a response button 4 for responding when the target cannot be read. It has been. Reference numeral 6 denotes a start switch in the automatic inspection mode, and reference numeral 9 denotes a speaker to which a voice guidance instruction is output.
[0014]
FIG. 2 is a schematic view of the optical system arranged in the apparatus as viewed from the side, and also shows the configuration of the control system. FIG. 3 is a schematic view of the optical system inside the apparatus as viewed from above.
[0015]
Lenses 10R and 10L are respectively arranged on the left and right far-inspection inspection windows 2R and 2L, and the far-distance inspection targets switched to the rear far-distance target windows 15R and 15L are apparently seen from the eyes ER and EL to be examined. The inspection distance is optically 5 m. The left and right optical paths are divided by distance inner covers 11R and 11L having a partition plate at the center. The inner surfaces of the distance inner covers 11R and 11L are matt white painted, and are illuminated by the lighting of the distance illumination LEDs 12R and 12L.
[0016]
The left and right near-inspection windows 7R and 7L are provided with shutters 18R and 18L, which are opened and closed according to the eye to be measured and are closed except during near-field measurement. The near-inspection optical path is divided by the far-inner optical path and the near-inner cover 16. The near vision target that is switched to the near vision window 17 provided at the lower center of the distance vision windows 15R and 15L is presented in a state of downward vision by bending the optical path by the mirrors 27 and 28. And an inspection distance of 40 cm from the eye ER or EL to be examined. The inner surface of the near-use inner cover 16 has a matt white coating, and is illuminated when the near-use illumination LED 13 is turned on.
[0017]
The optotype presenting unit 20 that switches and arranges the inspection target on the distance target windows 15R and 15L and the near target window 17 rotates and drives one target disk plate 21 and the target disk plate 21. Pulse motor 22, two distance illumination LEDs 24 </ b> R and 24 </ b> L that illuminate the distance target on the target disk plate 21, and a near-field LED 26 that illuminates the near target on the target disk plate 21. . On the same surface of the target disc plate 21, a plurality of near targets are formed in addition to a right eye distance target and a left eye distance target which are pairs to be simultaneously presented to the left and right eyes. (The target structure and its arrangement will be described later). The pulse motor 22 for rotating the target disk plate 21 is disposed between the left and right presentation optical paths and the near presentation optical path so that the apparatus is compact.
[0018]
In FIG. 2, reference numeral 30 denotes a control unit that controls the entire apparatus. Each LED, pulse motor 22, voice guide generation unit 31 connected to the speaker 9, response button 4, joystick 5, operation panel 3, shutters 18R and 18L. In addition, a memory 33 storing an inspection program is connected.
[0019]
Next, the target formed on the target disk plate 21 will be described with reference to FIG. The target disc plate 21 is made of white glass and has translucency. On the target disc plate 21, a right-distance target row A in which various right-eye targets are arranged on the first circumference having the radius r ₁ from the rotation center O is formed. A far left target row B in which various left eye far targets are arranged on a second circumference having a radius r ₂ from O is formed. In the distance target rows A and B, a pair of the same targets are sequentially arranged, and the left and right and upper and lower four directions in 12 stages of visual acuity values 0.1 to 1.0, 1.2 and 1.5, respectively. The Landolt ring target is made of a light-shielding chrome coat.
[0020]
The positional relationship between the targets formed in the right distance target array A and the left distance target array B is as follows. In other words, the right distance target 101 on the right distance target row A (with visual acuity 0. 0 having a cut in the right direction) at the center of the distance target window 15R (indicated by a dotted frame 15R 'in FIG. 4). When the target for 1) is located, the same left distance target 201 on the left distance target array B (a visual acuity 0.1 having a cut in the right direction) is paired with the right distance target 101. Is formed at the center of the distance target window 15L (indicated by a dotted line frame 15L ′ in FIG. 4). The other visual targets sequentially arranged in the distance visual target rows A and B are also formed so that the same paired visual targets have the same positional relationship.
[0021]
Note that the distance between the centers of the distance target windows 15R and 15L is such that when the target is viewed through the lenses 10R and 10L, the subject having a standard interpupillary distance saw the target 5 m ahead. Designed to be the distance between pupils at the time of convergence. Therefore, the distance X between the centers of a pair of identical targets arranged in the distance target rows A and B is made equal to the distance between the centers of the distance target windows 15R and 15L.
[0022]
Thus, the pair of the right distance target and the left distance target formed on the target disk plate 21 are arranged so that the positional relationship with respect to the respective distance target windows 15R and 15L is identical. Therefore, when the subject observes the inside of the main body with both the left and right eyes, the left and right distance targets can be easily fused and viewed.
[0023]
In addition, on the third circumference having a radius r ₃ from the rotation center O, a target row C of near-field targets is formed. In the near vision target array C, the Landolt visual targets in four directions, left, right, up and down, respectively, in 12 stages of visual acuity values of 0.1 to 1.0, 1.2, and 1.5 as in the distance target index arrays A and B Are lined up. A near vision window 17 (indicated by a dotted frame 17 'in FIG. 4) for placing a near vision target on the near vision array C is a line connecting the distance vision windows 15R and 15L. The height position is determined such that the near visual target row C is positioned on the vertical bisector and located on the third circumference with the radius r ₃ from the rotation center O.
[0024]
As shown in FIG. 2, the luminous flux of the near vision target arranged in the near vision window 17 is guided to the subject's eyes ER and EL with the presented optical path bent by the mirrors 28 and 27. Here, the angle θ of the near-inspection optical axis L2 with respect to the optical axis L1 for far-inspection passes through the near portion corresponding to the wearing of a standard progressive multifocal lens or a bifocal lens, and near vision The arrangement of the mirrors 28 and 27 is set so that the target is guided to the eye to be examined. Therefore, even when the far vision target and the near vision target are presented at different heights, it is possible to reduce the size while arranging both targets on the single target disc plate 21.
[0025]
The pair of left and right distance and near targets may be formed in a line on the same circumference of the target disk plate 21, but the disk plate becomes larger when many types of targets are arranged. Disadvantageous. On the other hand, if the right distance, the left distance, and the near object are arranged on different circles as described above, the disk plate can be further reduced in size, and the entire apparatus can be reduced in size.
[0026]
The operation of the apparatus having the above configuration will be described using the switch configuration diagram of the operation panel 3 shown in FIG. In addition, this device has manual mode, automatic mode (mode in which the test proceeds according to the program when the subject switches to the voice guide), semi-automatic mode (the verbal response of the subject to the automatic mode) Three inspection modes (modes in which the inspection proceeds according to a program by inputting by the examiner) are prepared, and any one can be selected by the mode selection switch 40 of the operation panel 3. Here, the description will focus on the inspection in the automatic mode.
[0027]
When the examiner presses the start switch 6, the control unit 30 turns on the LEDs 12R and 12L and the LEDs 24R and 24L, and presents a visual target having a visual acuity value of 0.1 to the visual target windows 15R and 15L. From the speaker 9, a voice guide is generated: “Hold the lever lightly with your right hand and attach the left hand to the front button and look into the window.” Next, a voice guide is generated saying "Measure your eyesight. Lightly tilt the lever in the direction of the broken ring. If you do not know the direction, press the front button." If the response is 5, the vision test program is executed.
[0028]
The vision test is programmed so that distance vision and near vision are measured in the order of the right eye, left eye, and both eyes, respectively. First, as a right eye examination, a visual target with a visual acuity value of 0.5 is presented as an initial visual target in the visual target window 15R. The visual field of the left eye is made equivalent to the shielding state by turning off the internal illumination LED 12L and the target illumination LED 24L.
[0029]
Under the control of the control unit 30, the speaker 9 announces “What is the direction?” By the voice guide, and when the target direction can be determined, the subject is instructed to tilt the joystick 5 in that direction. When the subject responds with the joystick 5 with the target discrimination result, the controller 30 determines the correctness. If the response is correct, the visual target with the visual acuity value raised by one level is presented, and if the response is incorrect, the visual target with the visual acuity value lowered by one step is presented. If the answer is incorrect by one step up, or if there is an unreadable response by the response button 4, the visual acuity value is returned to the level at which it was visible, and the examination is continued by changing the direction of the visual target. In this way, the visual target to be presented to the subject is sequentially changed according to the program, and if there is a correct answer more than once for the same visual acuity by the correctness determination of the response, the visual acuity value is determined by the control unit 30 as having the visual acuity. The
[0030]
When the distance vision test for the right eye is completed, the left eye test and the binocular test are similarly performed, and the respective test results are obtained. When the binocular examination is completed, the speaker 9 says, “Measurement of distance vision has been completed. Next, measure the visual acuity of 40 cm at hand. To measure, push the lever down. If not, press the front button. Please give me a voice. " When the subject responds with the joystick 5, the near vision test program is executed.
[0031]
The control unit 30 turns off all the LEDs for remote inspection, and opens the shutters 18R and 18L of the near inspection windows 7R and 7L, and turns on the near inspection LED 13 and the near illumination LED 26. Also, under the control of the control unit 30, the voice guide from the speaker 9 gives a voice guide saying “Please push the lever lightly in the direction of the broken ring. If you do not know the direction, press the front button.” After being generated, a near vision target with a visual acuity value of 0.5 is presented in the near vision window 17 and a near vision test with both eyes is similarly performed according to the examination program.
[0032]
In the near-field inspection, the subject can see the near-field target by rotating the eyeball from the distance inspection state and looking downward, so that an accurate inspection result can be obtained.
[0033]
In the case of the inspection in the manual mode, the examiner selects each of the distance inspection and the near inspection by the switches 42a and 42b and performs each inspection. Further, the visual acuity value of the visual target presented by the visual acuity switch 45a is selected, and the direction of the visual target presented by the four visual target switches 46a to 46d provided in the center of the operation panel 3 is selected. Thereby, the selected desired target is presented to the subject. The examiner asks the subject about discrimination of the optotype, confirms the correctness of the verbal response of the subject by lighting the LEDs 37a to 37d, and proceeds with the examination. The visual acuity value is displayed at 45b, and the last displayed value is the measurement result.
[0034]
Note that the distinction between right and left individual examinations and binocular examinations in the manual mode is made by selecting with the switch 41. When the right eye is selected during the near-field inspection, the shutter 18R is opened, and when the left eye is selected, the shutter 18L is opened. Thereby, separate near-field inspections of the left and right eyes are also possible.
[0035]
【The invention's effect】
As described above, according to the present invention, the subject can perform near-field measurement for downward viewing in a natural state, and an accurate test result can be obtained. In addition, a compact and inexpensive apparatus can be realized without complicating the configuration for distance measurement and near distance measurement.
[Brief description of the drawings]
FIG. 1 is a diagram showing an external appearance of an apparatus.
FIG. 2 is a diagram showing an optical system and a control system.
FIG. 3 is a schematic view when an optical system inside the apparatus is viewed from above.
FIG. 4 is a diagram showing details of a target disc plate.
FIG. 5 is a diagram showing details of a control panel.
[Explanation of symbols]
2R, 2L Distant inspection window 7R, 7L Near inspection window 15R, 15L Distant target window 17 Near target window 18R, 18L Shutter 20 Target display unit 21 Target disk plate 27 Mirror 28 Mirror 30 Control unit 101 Right distance target 201 Left distance target

Claims (1)

By observing the presented optotype arranged in the housing in the optometer of testing visual acuity, provided a viewing window for far examined a pair of right and left provided on the casing, below the far vision viewing window for inspection a test viewing window consisting of a resulting pair of the near viewing window for inspection, has a far test target light path of the left and right dedicated partitions the optical path of the optical path for the right eye for the left eye, A target optical path that is vertically divided into a distance inspection target optical path and a near inspection target optical path, a dedicated distance inspection target on both the left and right sides, and a right and left common inspection target The target disc plate with the left eye, the distance test target for the left eye, the test target for the right eye, and the target for the near test are circles with different radii from the rotation center of the target disc plate. The same target is placed in the left and right inspection optical paths for far-distance inspection so that binocular visual inspection is possible. Optometer to the target disk plate, are arranged on each of the viewing window for the near inspection, a shutter for selectively opening and closing the optical path, comprising: a.

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