JPH02232027A - Visual function inspection device - Google Patents

Abstract

PURPOSE:To make target screen data on the side of a control box coincident with a real target screen by receiving a signal from a response signal transmission means, which is connected with a target presenting part, and transmitting the signal to a presenting target selecting means. CONSTITUTION:An infrared signal transmitted toward a sight-testing chart (the target presenting part) is taken-in from an infrared light reception and emission window 5 to the sight-testing chart converted to a digital signal by a reception part 45 and inputted to a microcomputer 49. A motor 9 is rotated forward and a film 2 is wound downward. A symbol for position detection of each screen is detected by a photoelectric switch 10 for film initial position detection and a photoelectric switch 11 for screen switching detection. When the symbol for position detection showing the position of the picture including the target for stereoscopic vision check is detected by the photoelectric switch 11 for screen switching detection, the microcomputer 49 controls a back and forth rotary relay 44 and stops the motor 9. The response signal is sent to a transmission part 40, converted to an encoded infrared pulse signal and transmitted toward the reception part of a target switching control part.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a visual function testing device, and more particularly, to a visual function testing device for testing multiple visual functions, and an optotype display for switching and displaying visual function testing targets for testing multiple visual functions within a predetermined housing. and converts a signal selected by a presentation optotype selection means disposed apart from the optotype presentation section into a wireless communication signal to switch the optotype of the optotype presentation section and send the signal to the optotype presentation section. The present invention relates to a visual function testing device that performs transmission.

[Prior art] A conventional device abbreviated as an acuity chart has an optotype presentation unit (this part is also sometimes called an acuity chart) that has an optotype for visual function testing placed several meters in front of the subject. The most common format is

The simplest way to control the optotype selection of the optotype presentation section in this type of device is to control the optotype presentation section using a control box connected to the optotype presentation section via a communication cable. However, this method has disadvantages such as the risk of wire breakage due to hooks and restrictions on movement.

Therefore, recently, a device has been proposed in which the control box has a built-in transmitting means and the optotype presenting section has a receiving means. For example, there are methods that use light, ultrasonic waves, electromagnetic waves, etc. for transmission and reception.

[Problems to be Solved by the Present Invention] However, according to the method of the prior art described above, when the operation of the optotype presentation unit is controlled by a control box that is separate from the optotype presentation unit, the signal transmitted from the control box is Due to a temporary disturbance from the outside, the target screen may not be switched because the target cannot reach the target presentation unit. That is, when light or ultrasonic waves are used for transmission and reception, the light may be temporarily interrupted by a person moving. Furthermore, when using electromagnetic waves, there is a possibility that the device may be temporarily affected by electromagnetic waves from other devices.

If there is a temporary failure such as this, the visual target screen data on the control box side and the actual visual target screen will not match.

If the examiner continues the test without noticing this, a discrepancy will occur between the data on the device and the true test result.

In addition, if you try to switch the screen from the visual acuity test optotype to the astigmatism test optotype by operating the control box, but the optotype presentation part does not work, it may be unnecessary for the test subject. This will cause confusion.

Therefore, a first object of the present invention is to provide a visual function testing device in which the optotype screen data on the control box side and the actual optotype screen reliably match.

Furthermore, since the conventional wireless communication between the visual target presentation unit and the control box is one-way, complex control cannot be performed. For example, in order to place multiple optotypes on the same screen and use one-way communication to identify the optotype to be presented to the subject, a large number of switch groups are required, making it difficult to increase the size of the device. do not have.

Therefore, a second object of the present invention is to provide a visual function testing device that allows complex control between the optotype presenting section and the control box.

[Means for Solving the Problems] In order to achieve the above object, the present invention includes an optotype presentation unit that switches and displays optotypes for visual function testing for testing a plurality of visual functions in a predetermined housing, and Switching of the optotype in the optotype presentation unit is performed by converting a signal selected by a presentation optotype selection means located apart from the optotype presentation unit into a wireless communication signal and transmitting the signal to the optotype presentation unit. In visual function testing equipment,
a response signal transmitting means connected to the visual target presentation section that responds when receiving a signal from the presentation visual target selecting means; and a presentation visual target selecting means that receives a signal from the response signal transmitting means. A signal receiving means for transmitting a signal to.

Further, the response signal of the presentation optotype selection means is characterized in that information possessed by the presentation optotype selection means is added to the signal transmitted by the presentation optotype selection means.

The information added to the presented optotype selection means is characterized in that it is information for individualizing a plurality of optotypes within the screen.

[Embodiments of the invention] An embodiment of the present invention will be described below with reference to the drawings.

The device of this embodiment consists of an optotype presentation unit (vision chart) and an optotype (screen).
In addition to communication with the switching control unit, it is also possible to communicate with a subjective ophthalmoscope.

FIG. 1 is an external view of an optotype presentation unit (visual acuity chart) that switches and displays optotypes for visual function testing, which is an embodiment of the present invention.

At the center of the casing 1 is a film 2 that is illuminated from the back by a film illumination lamp 8, and on the film 2 are printed or pasted indicators for visual function testing. In FIG. 1, a film 2 is shown positioned in the center of a housing 1 on which optotypes 3 for testing visual acuity values of 0.2, 0.3, 0, and 4 are placed. Reference numeral 4 denotes a lamp placed next to each optotype row for each visual acuity value, which is used to distinguish when a plurality of optotype rows are presented on the same screen and to convert them into electrical signals. For details, refer to the patent application filed by the applicant on November 21, 1986 for "Visual acuity testing device"
It is described in

5 is an infrared light receiving/emitting window for receiving and transmitting infrared signals for remote control.

FIG. 2 shows a cross-sectional view of the embodiment shown in FIG.
The film 2 is wound between the drums 6 and 7, and the screen is switched by rotating the drums 6 and 7 using a motor 9, gears and belts (not shown). Reference numeral 10 denotes a photoelectric switch for detecting the initial film position located on the left side of the screen, and a photoelectric switch 11 of the same shape for detecting screen switching is located on the right side of the screen. Reference numeral 8 denotes a lamp for illuminating the film from the back, and is lit by a relay.

FIG. 3 is an external view of the optometry switching control unit 12 that selects the optotype to be presented to the subject, and the subjective ophthalmoscope control unit 13 that selects the optical element to be placed in front of the subject's eye. It is formed in one piece.

14 is an optotype selection switch, and a code signal corresponding to each optotype selection switch is transmitted to the visual acuity chart 1.

Reference numeral 15 is one of the optotype selection switches, and 16 is a switch for stereoscopic vision testing to select an optotype for testing the stereoscopic vision for testing the stereoscopic vision of the subject's eye. This is a 4-light test switch.

FIG. 4 is a block circuit diagram of the optotype switching control unit 12.

The target switching control unit 12 includes a receiving unit 20 including a light receiving element 23, a preamplifier 22, and a detection circuit 21, a transmitting unit 26 including a code modulation circuit 27, an output buffer 28, and a light emitting element 29, and a target selection switch. 14.CPU,
It is composed of a microcomputer section 25 consisting of a ROM and the like. 24 is a subjective ophthalmoscope.

FIG. 5 is a block diagram of the optotype presenting section (visual acuity chart) 1 that operates in response to signals from the optotype switching control section 12.

45 is a receiving section that receives a signal from the target switching control section 12. 46 is an infrared light receiving element attached to the housing, which is converted into a digital signal by a preamplifier 47 and a detection circuit 48. Reference numeral 39 denotes a motor for driving the film 2, which is rotated in the forward or reverse direction by a microcomputer circuit 49 and a forward/reverse rotation relay 44. 40 is a transmitting unit that receives a signal from the target switching control unit 12 and transmits a response signal, and includes a code modulation circuit 43 and an output buffer 4.
2. Consists of a light emitting element 41, which converts the response signal from a digital signal to an infrared signal. 50 is a relay for lighting the lamp 8 that illuminates the film 2 from the back side.

Next, the operation of the embodiment having the above configuration will be explained according to the flowchart shown in FIG.

When testing the subject's stereopsis, when the examiner presses the stereoscopic vision test switch 15 in the optotype selection switch 14 to select an optotype for the stereoscopic vision test (step 61), the microcomputer circuit 25 generates a predetermined coded digital signal A, which is converted into a coded infrared light pulse signal by the transmitter 26 consisting of a code modulation circuit 27, an output buffer 728, and a light emitting element 29. (step 62).

In this embodiment, the same signal is repeatedly transmitted twice to ensure signal transmission and reception (step 63). The infrared signal transmitted towards the visual acuity chart (visual chart presentation section) 1 is taken into the visual acuity chart (visual chart presentation section) 1 through the infrared light reception/emission window 5, and is transmitted through the light receiving element 46, the preamplifier 47, and the detection circuit 4.
8 is converted into a digital signal by the receiving section 45 and input to the microcomputer 49 (step
, 82, 83, 84). Microcomputer circuit 49
Based on the signal, the motor 9 rotates forward, the drums 6 and 7 rotate counterclockwise, and the film 2 is wound downward. A film initial position detection photoelectric switch 10 and a screen change detection photoelectric switch 11 detect a position detection symbol provided at the edge of the film for each screen. When the photoelectric switch 11 for detecting screen switching detects a position detection symbol indicating the position of the screen including a stereoscopic visual inspection target (not shown) composed of a polarizing plate, the microcomputer 49 rotates forward and backward. The relay 44 is controlled to stop the motor 9 (step 85). When the stereoscopic test target is presented on the screen in this manner, a response signal, which is a digital signal A' coded by the microcomputer 49, is sent to the transmitting section 40, which sends it to the code modulation circuit 43 and the output buffer 4.
2. It is converted into a coded infrared pulse signal by the light emitting element 41, and is transmitted from the infrared light receiving/emitting window 5 to the receiving section 20 of the target switching control section 12 (steps 86, 87).

In this embodiment, the signal A generated by the optotype switching control section 12 is different from the signal A' generated by the visual acuity chart 1, and the reason for this will be explained. In this embodiment, the signal A is only a signal for selectively arranging one specific screen of the film 2 in the center of the housing 1.

Therefore, when a plurality of optotypes exist on the same screen, the optotype that the subject is instructed to read and the data held by the optotype switching control unit 12 do not necessarily match. For example, when the selection switch 17 is pressed in the optotype switching control section 12 to switch to a screen that arranges three types of optotype columns: Landolt 0.2, 0.3, and 0.4, as described above, each optotype The lamp 4 placed next to the column makes it impossible to distinguish which optotype column the subject is instructed to read. In this embodiment, as a method of individualizing these three types of visual acuity values and matching the optotype sequence that the examinee is instructed to read with the data held by the optotype switching control unit 12, the illumination data of the lamp 4 is used. This is realized by individualizing the transmission signal A' from the visual acuity chart (visual target presentation unit) 1 side based on the above.

In this embodiment, as shown in the flowchart of FIG. 6, the screen to be presented is moved to a predetermined position in order to cope with the case where the visual acuity chart drive mechanism does not operate due to a failure. Photoelectric switch for screen switching detection 1
Although the response signal is sent after confirmation using signal 1, the order of steps 86 and 87 may be changed.

After t seconds have elapsed from step 63, which is preset in consideration of the time required to drive the chart (step 69), the signal is received by the receiving section 20, which includes a light receiving element 23, a pre-amplifier 22, and a detection circuit 21, and is converted into a digital signal. The signal is
Processed by a microcomputer (step 64)
, 65, 66, 67), a predetermined signal is sent to the subjective ophthalmoscope 24 via the communication cable, and the auxiliary lens of the subjective ophthalmoscope is switched to a polarized lens for stereoscopic vision testing (step 68).

In the same way, for example, when the 4-light test switch 16 is pressed to test the visual acuity of both eyes simultaneously, the subjective ophthalmoscope 24
The auxiliary lens can also be switched to a red filter for the right eye and a green filter for the left eye.

In this way, the optotype presentation part (vision chart) and the optotype (screen)
Communication between the switching control unit and the subjective ophthalmoscope can be realized. [Effects of the Invention] As is clear from the above description, according to the present invention, it is possible to realize a visual function testing device in which the optotype screen data on the control box side and the actual optotype screen reliably match.

In addition, since the optotype presentation unit and the control box each have a communication function with the other, complex control can be performed between the two.
There is no need to increase the size of the device.

[Brief explanation of the drawing]

Fig. 1 is an external view of the visual acuity chart (visual indicator presenting unit) according to an embodiment of the present invention, Fig. 2 is a cross-sectional view of the embodiment of Fig. 1, and Fig. 3 is a visual indicator switching control unit 12, a subjective type. An external view of the optometrist control section 13, FIG. 4 is a block circuit diagram of the optotype switching control section, FIG. 5 is a block circuit diagram of the visual acuity chart (optotype presentation section), and FIG. 6 is an embodiment of the present invention. FIG. 2 is a flowchart showing the operation of FIG. 1...Visual acuity chart (optotype presentation unit) 5...Infrared receiving/emitting window 12...Optotype switching control unit 13...
...Subjective ophthalmoscope control unit 14...Optotype selection switch 25...Microcomputer circuit 40 of optotype switching control section...Transmission unit 41 that transmits a response signal ...
... Light emitting element 42 ... Output buffer 43 ... Code modulation circuit

Claims (3)

[Claims] (1) It has an optotype presentation unit that switches and displays optotypes for visual function testing for testing multiple visual functions in a predetermined housing, and
Switching of the optotype in the optotype presentation unit is performed by converting a signal selected by a presentation optotype selection means located apart from the optotype presentation unit into a wireless communication signal and transmitting the signal to the optotype presentation unit. In the visual function testing device, a response signal transmitting means connected to the optotype presentation section that responds when receiving the signal from the presentation optotype selection means; A visual function testing device comprising: signal receiving means for transmitting a signal to the presented optotype selection means. (2) A visual function testing device characterized in that the response signal of the presentation optotype selection means of item 1 is a signal transmitted by the presentation optotype selection means with information possessed by the presentation optotype selection means added. (3) A visual function testing device characterized in that the information added in item 2 is information that individualizes a plurality of visual targets within the screen.