CN203941604U - Prevention adolescent myopia alarm - Google Patents

Abstract

Prevention adolescent myopia alarm, it comprises power circuit, ligh-ranging circuit, optical alarm circuit and control circuit, power circuit comprises low-voltage circuit and booster circuit, ligh-ranging circuit comprises infrared circuit for detecting and photosensitive circuit for detecting, and control circuit comprises the micro computer MCU that controls respectively booster circuit, infrared and photosensitive circuit for detecting, LED alarm indication circuit working.The lateral light electrical effect of infrared sensor makes the photosignal of different distance, through micro computer, carry out analog digital processing and compare with database alerting signal, with eye distance, when being less than 30cm, micro computer MCU sends alerting signal, makes LED show that red light reports to the police.Micro computer adopts booster circuit to control, and regularly boosts and reduces the power consumption of boosting, and free time quits work, and computer enters dormancy low power consumpting state, greatly improves the battery operating period, is particularly suitable for middle and primary schools's desk and uses.

Description

Prevention adolescent myopia alarm

Technical field

The utility model relates to a kind of smooth display alarm, specifically detects the teen-age utensil of seeing in the time that written word distance being less than safe distance with regard to luminous prompting.

Background technology

Current teen-age A nearsighted person's increasing year by year, this has correlativity with long-time close eye, the particularly universal use of computer and mobile phone in recent years, adolescent myopia patient is increased sharply, therefore how to prevent that this trend from becoming very concerned issue of numerous teenagers and the head of a family thereof, the safe distance of teenager's reading and writing object for appreciation computer etc. is 30～40cm, be less than 30cm apart from very easily causing adolescent myopia with eye for a long time, if when teenager is when the viewing distance with is at the moment less than 30cm, can remind in time, correct at any time, this has tangible good effect to prevention adolescent myopia.CN202205332U proposes a kind of hypometropia prevention alarm, adopt infrared distance sensor and hummer, because battery and infrared probe are fixedly mounted on clamping plate, use inconvenience, during buzzer warning, noise is outside other people, battery power consumption is large, and serviceable life is short, is also one of defect affecting result of use.

Summary of the invention

The utility model has problems for above-mentioned anti-myopia alarm apparatus, propose a kind of can be on desk for each student when seeing written word with eye distance from improper, display alarm immediately, can not disturb other people, little power consumption, anti-myopia alarm apparatus esy to use, safe and reliable.

Technical solution of the present utility model is:

Prevention adolescent myopia alarm, it comprises power circuit, ligh-ranging circuit, optical alarm circuit and control circuit, it is characterized in that power circuit comprises low-voltage circuit and booster circuit, ligh-ranging circuit comprises infrared circuit for detecting and photosensitive circuit for detecting, and control circuit comprises the micro computer MCU that controls respectively booster circuit, infrared and photosensitive circuit for detecting, LED alarm indication circuit working; The output terminal of low-voltage circuit connects respectively booster circuit, high-low pressure testing circuit and micro computer MCU, the input end of micro computer MCU connects respectively low-voltage circuit, booster circuit, high-low pressure testing circuit, infrared and photosensitive circuit for detecting, and the output terminal of micro computer MCU connects respectively booster circuit and LED alarm indication circuit.

Described booster circuit also comprises the power control circuit that boosts.

Described infrared circuit for detecting comprises infrared transmitting circuit, infrared light receive signal processing circuit, internal oscillator circuit and analog voltage output circuit.

Described LED alarm indication circuit comprises that LED red light display alarm signal circuit and LED green light show safety signal circuit.

The beneficial effects of the utility model are, utilize the lateral light electrical effect position transducer of infrared sensor, make the position of object and infrared signal voltage just be certain proportionate relationship, the photoelectric effect signal of different distance carries out analog digital processing and compares with database alerting signal through micro computer, with eye distance from being less than 30cm, micro computer MCU sends alerting signal, makes LED show red light warning.Micro computer adopts booster circuit to control, can timing sampling, regularly boost and reduce the power consumption of boosting, free time stops booster circuit and sensing circuit work, computer enters dormancy low power consumpting state, greatly reduce battery power consumption, the raising battery operating period reaches practical reliable, is particularly suitable for middle and primary schools's desk and uses.

Accompanying drawing explanation

Fig. 1 is the utility model circuit block diagram.

Fig. 2 is the implementing circuit figure of Fig. 1.

Fig. 3 is infrared processor U2 cut-away view.

Embodiment

One-piece construction is by power circuit part, ligh-ranging slowdown monitoring circuit, optical alarm circuit, and control section is comprised of booster circuit, high low-voltage detection circuit, LED display circuit and micro computer MCU.Each control section work is dispatched according to outside sensing data by micro computer MCU, reaches function technical requirement.

Power circuit comprises low-voltage circuit 1 and booster circuit 2.

Low-voltage circuit 1 comprises battery, SW1 switch, diode D5 and D1, resistance R 20.

SW1 is battery power switch, controls whole power supply.Diode D5 and D1 can prevent reverse power connection, avoid short circuit to burn out.Because diode has one-way conduction functional characteristic, when power positive cathode is correctly connected, diode current flow, normally works.If power supply connects instead, diode cut-off work.Protection components and parts below can not damage because of reverse power connection.

By triode Q1, resistance R 1, resistance R 2, resistance R 3, resistance R 4, capacitor C 1, capacitor C 2, triode Q2 and micro computer P10 pin, form the power control circuit that boosts.

When the pin P10 of U2 output high level, triode Q2 work, controls triode Q1 work, and battery starts to capacitor C 1 energising.Because the conducting internal resistance of triode Q1 is very little, the voltage of capacitor C 1 almost equates with cell voltage.When the pin P10 of micro computer U2 output low level, triode Q2, Q1 do not work, and battery stops to capacitor C 1 energising.And capacitor C 1 is the power supply of booster circuit below.Can be according to functional requirement by such on-off circuit, the duty of booster circuit is controlled in timesharing, reaches the optimization effect that reduces power consumption.

Inductance L 1, the device U1 that boosts, diode D3, capacitor C 4, capacitor C 5 and micro computer P9 pin form booster circuit.The device U1 that boosts is PFM switching mode DC/DC boost converter, exports 5 volts of voltages, and oscillation frequency is 180KHZ.Utilize the storage of 1 pair of energy of inductance L, and by the common effect of releasing of itself and input end power supply, thereby the output voltage higher than input voltage obtained.Itself there is certain power consumption.The voltage of output is to capacitor C 4 energising, for infrared sensor U3 and light sensor RL provide working power.The pin P9 of diode D4, resistance R 5, capacitor C 3 and micro computer U2 forms switching off control circuit of the device U1 that boosts, when pin P9 is high level, and the device U1 that boosts work.During for low level, do not work, greatly reduce the power consumption of device itself.

Low pressure detector tube Q6, resistance R 6 and capacitor C 9 composition valencys are pressed testing circuit 5, and high pressure detector tube Q7, resistance R 7, capacitor C 8 form the testing circuit 5 of high pressure.If the operating voltage of battery is during lower than 3 volts, low pressure detector tube Q6 output LOW voltage, triode Q5 work, driving LED 3 lamps flicker, the in time new batteries of reminding user to replace.High pressure detector tube Q7 detects whether 5 volts of voltages of stable output of booster circuit.When high pressure detector tube Q7 output HIGH voltage is during to micro computer U2, instructed voltage reaches steady state (SS), can sample to infrared sensor U3 and photoresistance RL, draws current environment for use situation.Micro computer U2 carries out high-pass filtering Software for Design to the simulating signal of sampling, improves the accuracy of data, simultaneously corresponding output display.Triode Q3, Q4 control respectively LED flicker indication.

The principle of work of infrared distance measurement is to utilize the position transducer of the horizontal infrared electro effect based on PSD technology, the 80cm that can effectively find range, and it is 40 degree that angle is estimated, and outputting analog signal.To the processing of Infrared, be to utilize cross-correlation detection principle, light signal is carried out to modulation and demodulation.Due to modulation the free correlativity of light signal and have functional relation with the time, the signals such as veiling glare do not have this characteristic, at receiving unit, again this function is carried out to the accumulation of certain hour and veiling glare etc. cannot accumulate, so just the function light signal with time content can be peeled off out from veiling glare, thereby filtering the impact of veiling glare etc., obtain accurate position signalling.

Infrared circuit for detecting comprises the P12 pin of infrared sensor U3, capacitor C 6, resistance R 8 and micro computer U2.Infrared sensor U3 is horizontal photoelectric position transducer, and Validity Test distance is: 10-80cm.Adopt optical signal modulation and demodulator circuit, its modulation signal is 1KHz.By infrared emission and the synthetic integral body of receiving circuit, internal work circuit block diagram is as Fig. 3, and the electric circuit constitute comprises, infrared transmitting circuit, infrared light receive signal processing circuit, power supply stabilization circuit, internal oscillator circuit and analog voltage output circuit.Infrared signal is processed (PSD) and is comprised again i-Vchange-over circuit, comparator circuit, sync detection circuit, demodulator circuit etc.Owing to having used the principle design of mutual detection, be subject to hardly the impact of veiling glare.When sensor obtains operating voltage, by the Infrared of infrared transmitting circuit output 800nm wavelength, survey outside object distance with it.By the infrared ray of object reflecting part, through modulation and demodulation internal signal treatment circuit, export specific analog signal voltage.

The height of analog signal voltage has certain relation of gesticulating with the distance of object space.Position is near, and voltage is high, and position is far away, and voltage is low.In from 10cm to 50cm, change in voltage is very sensitive, can obtain higher resolution, improves the degree of accuracy of range finding.By signal sampling resistance R 8, the analog voltage of output is transported to micro computer MCU and carries out AD(analog digital) process, generate the positional distance database corresponding with voltage, at 30cm place, set alert data point.In Software for Design, carry out boost charge work to infrared sensor every 5 seconds, obtain and calculate current alarm and the range data between eyes, by the alert data comparison in database, if be less than the data point of 30cm, MCU can send alerting signal makes red LED lamp bright, thereby have to prevent and treat, causes myopia because of reading and writing near distance.

When boosting device U1 work, whether the voltage that high voltage detector part Q7 just constantly monitors U1 output is raised to 5V.If voltage, lower than 5V, with regard to output low level, higher than 5V, is exported high level.Whether U2 is connected with detecting Q7 output by I/O mouth P1, survey booster circuit and normally work.When P1 is high level, represent that infrared sensor and light sensor have been under normal working voltage (5V) state.At this moment, Infrared is surveyed outside object distance, and the light reflecting is processed to calculating, exports an analog voltage corresponding with outer distance, is added in resistance R 8 two ends.Infrared sensor and object distance are near, and resistance R 8 both end voltage are high, on the contrary, distance, voltage is just low.The distance voltage of 10cm is the highest, and the distance voltage of 50cm is minimum.The variation of voltage swing, can draw the far and near data of distance.

In micro computer U2, there is AD analog digital modular converter, can, the voltage of P12 mouth end, convert the binary code of micro computer identification to.AD is the converter that adopts the successive approximation of 10 precision, and conversion is fast, and precision is high.The binary data of conversion is stored in the data register of MCU, at the different voltage of P15 mouth, can convert corresponding binary data to.These data and positional distance form relation one to one.10cm, to these corresponding binary data of 50cm, is formed to positional distance database in software, as the foundation of reporting to the police and differentiating.U2 carries out Multiple-Scan sampling to P12 port, utilizes MCU high-speed computational capability, carries out high-pass filtering program design on software, removes power supply and disturbs, and improves binary data sampling precision and accuracy.If current positional distance data are less than in the data area of 30cm, I/O mouth P16 output low level, triode Q3 work, LED1 red colored lamp is bright, indication is in alarm condition, and LED red light Display and Alarm Circuit is by triode Q3, LED1 red light, resistance R 11, R12, R13 and micro computer P16 pin; At 30cm within the scope of 50cm, I/O mouth P15 output low level, triode Q4 work, LED2 green light is bright, indication is in safe condition.

Micro computer U2 also carries out AD(analog digital to the analog voltage of photoresistance RL output simultaneously) process, by photoresistance RL, resistance R 9 and capacitor C 7, form photosensitive circuit for detecting, photoresistance utilizes the electric resistance sensor changing a little less than a kind of resistance value that semi-conductive photoconductive effect makes high light with incident, is called again photoconductive detector; Incident intensity, resistance reduces, and a little less than incident light, resistance increases.A little less than also having another kind of incident light, resistance reduces, incident intensity, and resistance increases.The feature changing by resistance value own, can obtain and incident intensity analog voltage one to one.The I/O mouth P13 of micro computer U2 carries out repeatedly AD conversion to current voltage, and form binary data, is stored in the data register of MCU.The size of light intensity represents with lux (LUX).When the binary data gathering, to be greater than 200LUX(illumination very strong), or it is very weak to be less than 1LUX(illumination) time, MCU output low level, triode Q3 work, LED1 red colored lamp is bright, and indication is in alarm condition.

Claims (10)

1. prevent adolescent myopia alarm, it comprises power circuit, ligh-ranging circuit, optical alarm circuit and control circuit, it is characterized in that power circuit comprises low-voltage circuit and booster circuit, ligh-ranging circuit comprises infrared circuit for detecting and photosensitive circuit for detecting, and control circuit comprises the micro computer MCU that controls respectively booster circuit, infrared and photosensitive circuit for detecting, LED alarm indication circuit working; The output terminal of low-voltage circuit connects respectively booster circuit, high-low pressure testing circuit and micro computer MCU, the input end of micro computer MCU connects respectively low-voltage circuit, booster circuit, high-low pressure testing circuit, infrared and photosensitive circuit for detecting, and the output terminal of micro computer MCU connects respectively booster circuit and LED alarm indication circuit.

2. prevention adolescent myopia alarm according to claim 1, is characterized in that described infrared circuit for detecting comprises the P12 pin of infrared sensor U3, capacitor C 6, resistance R 8 and micro computer U2.

3. prevention adolescent myopia alarm according to claim 2, is characterized in that described infrared sensor U3 comprises: infrared transmitting circuit, infrared signal receiving processing circuit, power supply stabilization circuit, internal oscillator circuit and analog voltage output circuit.

4. prevention adolescent myopia alarm according to claim 1, is characterized in that described booster circuit also comprises the power control circuit that boosts.

5. prevention adolescent myopia alarm according to claim 4, the power control circuit that boosts described in it is characterized in that is by triode Q1 and Q2, resistance R 1, R2 and R3, capacitor C 1 and C2, and micro computer P10 pin forms.

6. prevention adolescent myopia alarm according to claim 1, is characterized in that described booster circuit is by inductance L 1, boost device U1, triode D3 and Q2, and capacitor C 4, C5 and micro computer P9 pin form.

7. prevention adolescent myopia alarm according to claim 1, is characterized in that described low-voltage testing circuit is comprised of low pressure detector tube Q6, resistance R 6 and capacitor C 9.

8. prevention adolescent myopia alarm according to claim 1, is characterized in that described high-voltage detecting circuit is comprised of high pressure detector tube Q7, resistance R 7 and capacitor C 8.

9. prevention adolescent myopia alarm according to claim 1, is characterized in that described photosensitive detection circuit is comprised of photosensitive RL1, resistance R 9 and capacitor C 7.

10. prevention adolescent myopia alarm according to claim 1, is characterized in that described LED alarm indication circuit is by triode Q3, LED1 red light, resistance R 11, R12 and R13, and micro computer P16 pin forms.