CN2537073Y - Visual distance warning device for preventing myopia - Google Patents

Abstract

The utility model provides a sight distance alarm device for preventing myopia, wherein, a circuit comprises an infrared emitting and receiving circuit, a shaping amplification and modulating time delay circuit, a sound alarm circuit, a light alarm circuit, and a power supply circuit, wherein, the output infrared emitting and receiving circuit is connected with the input of the shaping amplification and modulating time delay circuit; the output of the shaping amplification and modulating time delay circuit is connected with the input of the light alarm circuit and the sound alarm circuit; when in use, the device is arranged on a desk; when the sight distance is short, a signal is emitted by the infrared ray so as to sent out a light alarm or a sound alarm. The utility model has the advantages of simple and single structure, and convenient use.

Description

Prevent near-sighted sighting distance caution instrument

Technical field

The utility model relates to a kind of device that prevents eyesight myopia, particularly relates to a kind of near-sighted sighting distance caution instrument that prevents.

Background technology

At present, the incidence of disease height of myopia, especially teenager's incidence of disease is higher.Cause the reason of myopia varied, as objective factors such as the flicker of insufficient light, light, tables and chairs height are improper; But subjective factor is the major reason that causes myopia, and promptly reading or writing posture are incorrect.See the posture of written word for rectification, design all kinds of myopia prevention utensils.As posture corrective belt, anti-myopia gesture-correction frame and various Preventing short-sighted instrument.Chinese patent discloses a kind of myopia prevention language alarm set, it is made up of two sensitive elements, language sheet, loudspeaker, wiring board, minicell, shell parts, sensitive element and language sheet, loudspeaker, wiring board, minicell are fixed as one, and another sensitive element then is fixed on actor chest neck and collar place.Mainly be to realize sighting distance control by two sensitive elements.

Summary of the invention

It is a kind of simple in structure, easy to use that the purpose of this utility model is to provide, and directly places the near-sighted sighting distance caution instrument that prevents of desktop.

The utility model prevents that its circuit of near-sighted sighting distance caution instrument from being made up of infrared and receiving circuit, amplification shaping and MDL modulation delay circuit, sound alarm circuit, optical alarm circuit and power circuit.Infrared and receiving circuit output connect amplifies shaping and the input of MDL modulation delay circuit, amplifies the output of shaping and MDL modulation delay circuit and connects sound alarm circuit and optical alarm circuit input.Wherein, infrared and receiving circuit are by infrared ray inspection emission/reflection slowdown monitoring switch IC ₁Constitute; Amplify shaping and MDL modulation delay circuit by not gate F ₁, F ₂And F ₃, resistance R ₁, R ₂And R ₃, capacitor C ₁, C ₂, C ₃, C ₄And C ₇, diode D ₁, potentiometer W ₁Constitute; Sound alarm circuit is by musical film IC ₂, loudspeaker Y, triode BG ₂, resistance R ₆And K switch ₂Constitute; Optical alarm circuit is by triode BG ₁, LED, resistance R ₄And R ₅, capacitor C ₅And K switch ₃Constitute; Power circuit is by transformer P, diode D ₂Battery V and K switch ₁Constitute.

The utility model circuit prevents that the principle of work of near-sighted sighting distance caution instrument from being Closing Switch K ₁, infrared/reflection detector switch IC ₁Send infrared ray, after the object blocks that runs into certain distance, then return, by infrared/reflection detector switch IC ₁Receive, the electric signal of generation is through not gate F ₁, F ₂After anti-phase shaping is amplified, by potentiometer W ₁To capacitor C ₇Charging, the duration of charging can be passed through W ₁Regulate, be generally 3 seconds (avoiding causing false alarm), work as C because of after accidental cause causes low coverage ₇Both end voltage does not reach not gate F ₃Level the time, capacitor C ₇Both end voltage is through diode D ₁Moment releases, and the caution instrument is not worked; After the sighting distance low coverage time surpasses 3 seconds, C ₇Both end voltage surpasses F ₃Level, F ₃Output low level triggers musical film IC ₂Or LED, to send corresponding acoustic alarm and/or light and report to the police, prompting user sighting distance is near excessively.Sighting distance generally is adjusted between 38～45mm, can pass through infrared/reflection detector switch IC ₁Regulate.In use, also can pass through On/Off K ₂, K ₃, realize single light warning or acoustic alarm.

It is simple in structure that the utility model circuit prevents that the advantage of near-sighted sighting distance caution instrument is, is single structure, and need not be worn on the user and put on, not overslaugh user's action, highly sensitive, safe and reliable, easy to use.

Specific embodiments

Fig. 1: the utility model circuit block diagram

Fig. 2: the utility model circuit connection diagram

The utility model prevents that its circuit of near-sighted sighting distance caution instrument from being made up of infrared and receiving circuit, amplification shaping and MDL modulation delay circuit, sound alarm circuit, optical alarm circuit and power circuit.Infrared and receiving circuit output connect amplifies shaping and the input of MDL modulation delay circuit, amplifies the output of shaping and MDL modulation delay circuit and connects sound alarm circuit and optical alarm circuit input.Wherein, infrared and receiving circuit are by infrared/reflection detector switch IC ₁(TX05D) constitute; Amplify shaping and MDL modulation delay circuit by not gate F ₁, F ₂And F ₃, resistance R ₁, R ₂And R ₃, capacitor C ₁, C ₂, C ₃, C ₄And C ₇, diode D ₁, potentiometer W ₁Constitute.Its annexation is C ₁One termination IC ₁Output terminal 3 pin, C ₁The other end and F ₁, C ₂, F ₂, C ₃, F ₃And C ₄Series connection, R ₁, R ₂With ₃Two ends are connected to F respectively ₁, F ₂And F ₃Input end and output terminal, D ₁And W ₁Back one termination F in parallel ₃Input end, another termination F ₃Output terminal and C ₇One end, C ₇Other end ground connection; Sound alarm circuit is by musical film IC ₂(HY100), loudspeaker Y, triode BG ₂, resistance R ₆And K switch ₂Constitute.Its annexation is IC ₂Input end 1 pin meets C ₄The other end, IC ₂Output terminal 3 pin series connection C ₆After meet BG ₂Base stage, BG ₂Grounded emitter, BG ₂Collector meets K ₂With Y one end; Optical alarm circuit is by triode BG ₁, LED, resistance R ₄And R ₅, capacitor C ₅And K switch ₃Constitute.Its annexation is K ₃One termination IC ₂Output terminal and K ₂The other end, K ₃Another termination BG ₁Emitter, BG ₁Base stage meets R ₄And C ₅One end, R ₄Another termination LED one end, another termination of LED R ₅One end, R ₅Another termination C ₅The other end and BG ₁Collector; Power circuit is by transformer P, diode D ₂Battery V and K switch ₁Constitute.Its annexation is that the initial termination civil power of P imports an end of holding and passes through K ₁Meet IC ₁Positive power source terminal 2 pin, IC ₂Positive power source terminal 5 pin import the other end series connection R that holds ₆After meet IC ₂ Negative power end 2 pin, the other end of Y, R ₄With LED be connected mid point and IC ₁Negative power end 1 pin.

Claims (2)

1, a kind of near-sighted sighting distance caution instrument that prevents, it is characterized in that circuit is made up of infrared and receiving circuit, amplification shaping and MDL modulation delay circuit, sound alarm circuit, optical alarm circuit and power circuit, infrared and receiving circuit output connect amplifies shaping and the input of MDL modulation delay circuit, amplifies the output of shaping and MDL modulation delay circuit and connects sound alarm circuit and optical alarm circuit input.

2, the near-sighted sighting distance caution instrument that prevents as claimed in claim 1 is characterized in that infrared and receiving circuit are by infrared/reflection detector switch IC ₁Constitute; Amplify shaping and MDL modulation delay circuit by not gate F ₁, F ₂And F ₃And peripheral cell constitutes; Sound alarm circuit is by musical film IC ₂, loudspeaker Y, triode BG ₂, resistance R ₆And K switch ₂Constitute; Optical alarm circuit is by triode BG ₁, LED, resistance R ₄And R ₅, capacitor C ₅And K switch ₃Constitute; Power circuit is by transformer P, diode D ₂Battery V and K switch ₁Constitute.

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