CN87201117U

CN87201117U - Eye-sight tester

Info

Publication number: CN87201117U
Application number: CN 87201117
Authority: CN
Inventors: 周振民; 沈琅
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-03-09
Filing date: 1987-03-09
Publication date: 1987-12-30

Abstract

The utility model discloses an eye-sight tester, comprising an eyesight target tape, a light source, a code hole, a photoelectric detector, a decoding circuit, a digital display, an electrical machine, an automatic positioning control circuit and a control knot. The utility model adopts perspective type, displays one international standard eyesight symbol every time, and displays the eyesight value by an LED digitron, thereby, to avoid fraud of an examined person and reduce labor strength of an operating person. The utility model has the advantages of small size, convenient portability.

Description

Eye-sight tester

This utility model belongs to ophthalmology checking Instrument.

Traditional eyesight exam method, the visual acuity chart of adopting international standards, promptly on a blank sheet of paper, stamp whole international standard vision symbols, give directions the vision symbol by the medical worker with rod, the measured presses the indication position, judges the vision symbol, determines measured's vision at last, use the shortcoming of this inspection method to have: all the vision symbol is printed on the table, causes measured's asthenopia easily; The measured can learn off visual acuity chart, influence test correctness; The medical worker gives directions the vision symbol with rod, causes easily and gives directions the position to misunderstand.

Task of the present utility model is that a kind of new vision tester will be provided, and shows a vision symbol at every turn, and shows the vision value by character display, can prevent measured's malpractices.

Task of the present utility model is finished in the following way: whole international standard vision symbols of 0.1 to 1.5 are printed on the paper tape, become sighting target band 1, be equipped with a light source 2 behind the sighting target band 1.Motor 6 transmission rolling shafts 10 drive sighting target band 1 and move, and Automatic Positioning Control circuit 7 control sighting target bands 1 location shows a vision symbol at every turn.The edge of sighting target band 1 has code holes 9 and photoelectric detector 3 to record code through decoding, shows the vision value on character display 5.

Below in conjunction with accompanying drawing this utility model is described in further detail.

Fig. 1 is the functional-block diagram of vision tester

Fig. 2 is the appearance shape figure of vision tester

Fig. 3 is the internal structure internal anatomy of vision tester

Wherein 1 is the sighting target band, the 2nd, and light source, the 3rd, photoelectric detector, the 4th, decoding circuit, the 5th, character display, the 6th, motor, the 7th, Automatic Positioning Control circuit, the 8th, control knob, the 9th, code holes, the 10th, roller bearing.

Fig. 4 is decoding, the layout of display part

Fig. 5 is the layout of Automatic Positioning Control part

Sighting target band 1 is the paper tape that is printed on international standard vision symbol, and the shape of vision symbol, size, color and quantity are consistent with the vision symbol on the international standard visual acuity chart.The vision symbol becomes word order, and the material of sighting target band can be the thin film of handling through sheen, and the edge is shown and the corresponding code holes 9 of each vision symbol.The back of sighting target band 1 is equipped with a light source 2, can adopt H type fluorescence cold light source, can put a softbox between light source 2 and sighting target band 1.

On code holes 9 limits at edge, sighting target band 1 limit, be equipped with light source detection device 3, photoelectric detector 3 adopts one group of silicon photosensor.When code holes 9 were passed through, silicon photosensor was just received one group of code signal, and the code signal is after decoding circuit 4 decodings, converting number to is presented on the nixie display 5, nixie display 5 can adopt the LED seven segment digital tubes, and the numeral on the LED seven segment digital tubes is the vision value.

Sighting target band 1 adopts roll type to be installed on two roller bearings 10, drives roller bearing 10 rotations by motor 6, makes sighting target band 1 do upper and lower moving, and Automatic Positioning Control circuit 7 links to each other with motor 6, to guarantee to show a vision symbol at every turn.

Press control knob 8, motor 6 rotates, and drives sighting target band 1 by roller bearing 10 rotations and moves.Decontrol control knob 8, in the center, then the code holes 9 at the edge of sighting target band 1 do not enter in the photoelectric detector 3 as the display position of vision symbol, and the photoelectricity signal level is a low level, enters audion T by diode ₁Base current very little, make T ₁End.At this moment audion T ₂The base current generation is arranged, and (power supply, voltage passes through resistance R ₂Add T ₂), T ₂Conducting.Motor 6 continues operation.But motor passes through R ₃The resistance blood pressure lowering descends motor 6 rotating speeds, and sighting target band 1 translational speed slows down, in case the code holes 9 at sighting target band 1 edge enter light inspection detector 3.A ₀, B ₀, C ₀, D ₀, A ₁As long as in have a place to detect signal (generation high level), then expression this moment has the vision symbol occur, then by by D ₁～D ₅The diode OR gate of forming, level just is added in audion T ₁, make T ₁Conducting, audion T like this ₂Just end.Motor 6 stops operating, and the vision symbol is presented at center position.

This utility model is easy to use.During use, vision tester is hung on the wall, examination of visual acuity person presses control knob 8, and identification vision symbol can record the vision value.

Claims

1, a kind of vision tester, comprise sighting target band 1, light source 2, photoelectric detector 3, decoding circuit 4, character display 5 and Automatic Positioning Control circuit 7, it is characterized in that: become word order international standard vision symbol on the sighting target band 1, the edge of sighting target band 1 has code holes 9, sighting target band 1 to be installed on two roller bearings 10, roller bearing 10 links to each other with a motor 6, light source 2 places the back of sighting target band 1, and a softbox is arranged between light source 2 and sighting target band 1.

2, vision tester according to claim 1 is characterized in that described light source 2 can be a H type fluorescence cold light source.

3, vision tester according to claim 1, the material that it is characterized in that described sighting target band 1 can be the thin film of handling through sheen.