CN206249871U - LCD screen backlight control system - Google Patents
LCD screen backlight control system Download PDFInfo
- Publication number
- CN206249871U CN206249871U CN201621168722.9U CN201621168722U CN206249871U CN 206249871 U CN206249871 U CN 206249871U CN 201621168722 U CN201621168722 U CN 201621168722U CN 206249871 U CN206249871 U CN 206249871U
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- brightness
- unit
- control unit
- led backlight
- backlight
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- Led Devices (AREA)
Abstract
The utility model is related to LED backlight technical field, more particularly to a kind of LCD screen backlight control system, including control unit, temperature detecting unit, brightness detection unit, LED backlight driver element and key input unit, the temperature detecting unit detects environment temperature using temperature sensor, brightness detection unit is respectively used to detect ambient brightness and LED backlight brightness using two photoelectric sensors, temperature detecting unit connects control unit, it is attached by filter amplification circuit between brightness detection unit and control unit, described control unit connects LED backlight driver element, LED backlight driver element is adjusted to LED backlight brightness.The system architecture is simple, low cost, it is capable of achieving to automatically adjust background illumination intensity, is consistent the brightness of LCDs and ambient brightness, and can guarantee that the continuity of luminosity change, can be widely applied to personal computer monitor, television set, and industry spot display device.
Description
Technical field
The utility model is related to LED backlight technical field, more particularly to a kind of LCD screen backlight control system.
Background technology
LCDs background illumination mainly uses cathode fluorescent tube and White-light LED illumination, and LED backlight is with it
Application of the advantages such as luminous efficiency is high, energy consumption is small, reliability and durability, long service life, environmental protection on each field display product
It is more and more extensive.With the continuous maturation of LED-backlit technology, people are also improving its performance constantly, allow LED-backlit
Technology performs to the benefit of its maximum.In particular cases there is special requirement to display brightness at some, such as mobile phone shows
Once being in dark state, when not having manual operation, it should in blank screen, to reach the purpose of power saving, this requires to show screen
Show the ability that device possesses Automatic adjusument, therefore ensure the automatically adjusting with important work of liquid crystal display background illumination light intensity
With.
Utility model content
The purpose of this utility model is to provide a kind of LCD screen backlight control system, can be shone according to environment and background
Bright and environment temperature situation, automatically adjusts the background illumination intensity of display screen, makes the brightness of LCDs and ambient brightness
It is consistent.
In order to solve the above technical problems, the utility model employs a kind of LCD screen backlight control system, including control
Unit processed, temperature detecting unit, brightness detection unit, LED backlight driver element and key input unit, the temperature detection
Unit detects environment temperature using temperature sensor, and brightness detection unit is respectively used to detect environment using two photoelectric sensors
Brightness and LED backlight brightness, temperature detecting unit connection control unit, by filter between brightness detection unit and control unit
Ripple amplifying circuit is attached, and described control unit connection LED backlight driver element, LED backlight driver element is carried on the back to LED
Light-source brightness is adjusted.
In above-mentioned technical proposal, further, described control unit is using STM32F030F4 microcontrollers and its periphery
The system of circuit composition.
In above-mentioned technical proposal, further, the brightness detection unit uses BPW21 photoelectric sensors.
In above-mentioned technical proposal, further, the filter amplification circuit includes the letter being made up of operational amplifier LM324
Number amplifying circuit and the filter circuit being made up of resistance R4 and electric capacity C2.
In above-mentioned technical proposal, further, the backlight driver unit is to be driven using the backlight of LTM3598 chips
Dynamic circuit, is provided with the overheating protection circuit being made up of R13 and R14 in the backlight source driving circuit.
The utility model is realized to background illumination by Real-time Collection environmental light intensity and background illumination light intensity and environment temperature
Automatically adjusting for intensity, is consistent the brightness of LCDs and ambient brightness, eliminates because environmental light intensity changes what is caused
Visual fatigue.The system architecture is simple, low cost, and can guarantee that the continuity of luminosity change, can be widely applied to individual
Computer monitor, television set, and industry spot display device.
Brief description of the drawings
Fig. 1 is the utility model system architecture diagram.
Fig. 2 is microprocessor and its peripheral circuit diagram in the utility model control unit.
Fig. 3 is the utility model brightness detection unit detection circuit diagram.
Fig. 4 is the utility model luminance detection signal treatment filter amplification circuit figure.
Fig. 5 is the utility model backlight driver element circuit figure.
Fig. 6 is overheating protection circuit figure in the utility model backlight driver unit.
Specific embodiment
The utility model is further described with specific embodiment below in conjunction with the accompanying drawings.
Control system described in the present embodiment gathers ambient brightness and back light source brightness respectively using two photoelectric sensors,
Respectively through the A/D interfaces that control unit is accessed after filter and amplification, control unit gathers environment temperature, root by temperature sensor
The dutycycle that output is analyzed and calculated according to the parameter control unit of collection drives the change of backlight driver unit to flow through backlight LED
Size of current, so as to realize the closed-loop control of backlight LED brightness.
Ambient brightness is measured using photoelectric sensor BPW21, and environmental light brightness can be converted into electric current letter by BPW21
Number, 2nA is output as under conditions of complete darkness, its ambient brightness sensing range is 0 to 5000lx, and maximum is defeated by LM324
Go out maximum decision.Photoelectric sensor BPW21 is acquired to ambient brightness, after collection after the filtered amplifying circuit treatment of signal
Changed in the microcontroller STM32F030F4 inside A/D for sending into control unit.
System carries out data acquisition using a photoelectric sensor BPW21 to LED light emitting sources luminosity in addition, will gather
After data are filtered enhanced processing, then A/D conversions are carried out, be compared for the data of collection and a reference value, see by control unit
Difference is whether there is, is had, then be controlled, without then continuing to keep, wait subsequent cycle.Setting value is previous moment ambient brightness pair
The binary number answered, the corresponding binary number of LED backlight brightness is actual value, by both differences, draws control unit control
The foundation of system, and then control PWM ripple dutycycles.
Because LED luminous efficiencies are influenceed by operating ambient temperature, to LED luminous efficiencies in the range of different temperatures
It is different, it is therefore desirable to which that operating ambient temperature is detected；Entered using digital temperature sensor DS18B20 in the present embodiment
The detection and collection of trip temperature, the temperature signal feeding control unit after collection, at data of the control unit according to collection
After reason, the size of corresponding PWM ripple control electric currents is produced, so as to be compensated to the influence that temperature is caused.
Backlight driver unit use backlight driver chip LT3598, the PWM ripples that reception control unit sends during work,
Dutycycle size according to PWM ripples determines the size of output current；LT3598 has six driving mouths, and two drive mouth to drive one
The LED light bar of string 10.
If Fig. 3 is luminance detection circuit, the measurement to ambient brightness and display brightness is realized using BPW, it will collection
To amplifying circuit, after amplified treatment, the A/D converter for sending into microcontroller carries out analog-to-digital conversion to the signal transmission come；
It is consistent with ambient brightness to ensure display brightness, using the target that the ambient brightness of last moment collection is controlled as subsequent time
Value, used as actual value, both differences are processed the display brightness of subsequent time collection through microcontroller, and microprocessor sends finger
Order, produces control signal, PWM is sent to LT3589, so as to realize the control to brightness.As shown in figure 4, being for luminance signal
The filter amplification circuit for the treatment of, the signal demand amplified filtering process of weaker need gathered by BPW21, here using operation amplifier
Device LM324 is amplified to signal, and control unit is sent into after filtered processing of circuit.
If Fig. 5 is the utility model backlight source driving circuit, system uses the size of the form control electric current of control PWM ripples
It is adjusted come the luminosity to LED.Because the backlight source driving circuit needs to be powered 6 string LED light bars, and LED
Voltage between lamp bar mismatches the excess loss that will cause power, causes drive circuit to overheat, so as to cause backlight driver
Chip temperature is raised, it is therefore desirable to overheating protection circuit is used, with the influence for avoiding temperature rise too high to circuit normal work.As schemed
It is overheating protection circuit schematic diagram, in the T of LT3598 shown in 6setPin meets resistor voltage divider circuit a R13 and R14, by setting
Determining the ratio of R13 and R14 can just set the junction temperature value of maximum, and after environment temperature reaches the junction temperature value of setting, LT3598 is opened
Beginning linearly reduces LED current, and is maintained at the temperature levels, if environment temperature exceedes the maximum junction temperature value of setting, LED current
The 5% of substantially all LED current is will be reduced to, the normal work of circuit is influenceed so as to avoid environment temperature rise too high.
The control principle of the utility model control system is：By temperature sensor collecting temperature signal, the letter that will be gathered
In number feeding microcontroller, signal is amplified treatment, then carries out analog-to-digital conversion and sent by optical sensor collection external environment brightness
Enter microcontroller, microcontroller sends the luminosity that corresponding PWM ripples control LED.
Specification and drawings of the present utility model are considered as illustrative and not restrictive, on the utility model basis
On, those skilled in the art are according to disclosed technology contents, it is not necessary to which performing creative labour just can be to some of them technology
Feature is made some and replaces and deform, in protection domain of the present utility model.
Claims (5)
1. LCD screen backlight control system, it is characterised in that：It is single including control unit, temperature detecting unit, brightness detection
Unit, LED backlight driver element and key input unit, the temperature detecting unit detect environment temperature using temperature sensor
Degree, brightness detection unit is respectively used to detect ambient brightness and LED backlight brightness, temperature detection using two photoelectric sensors
Unit connects control unit, is attached by filter amplification circuit between brightness detection unit and control unit, the control
Unit connects LED backlight driver element, and LED backlight driver element is adjusted to LED backlight brightness.
2. LCD screen backlight control system according to claim 1, it is characterised in that：Described control unit is use
The system of STM32F030F4 microcontrollers and its peripheral circuit composition.
3. LCD screen backlight control system according to claim 1, it is characterised in that：The brightness detection unit is adopted
Use BPW21 photoelectric sensors.
4. LCD screen backlight control system according to claim 1, it is characterised in that：The filter amplification circuit bag
Include the signal amplification circuit being made up of operational amplifier LM324 and the filter circuit being made up of resistance R4 and electric capacity C2.
5. LCD screen backlight control system according to claim 1, it is characterised in that：The backlight driver unit
It is the backlight source driving circuit using LTM3598 chips, is provided with what is be made up of R13 and R14 in the backlight source driving circuit
Overheating protection circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201621168722.9U CN206249871U (en) | 2016-11-02 | 2016-11-02 | LCD screen backlight control system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201621168722.9U CN206249871U (en) | 2016-11-02 | 2016-11-02 | LCD screen backlight control system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN206249871U true CN206249871U (en) | 2017-06-13 |
Family
ID=58997064
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201621168722.9U Expired - Fee Related CN206249871U (en) | 2016-11-02 | 2016-11-02 | LCD screen backlight control system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN206249871U (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107240380A (en) * | 2017-07-19 | 2017-10-10 | 广州捷宝电子科技股份有限公司 | Diaphragm, LCD screen and vision-control method |
| CN110960189A (en) * | 2019-09-12 | 2020-04-07 | 中国人民解放军陆军特色医学中心 | Wireless cognitive regulator and eye movement treatment and treatment effect evaluation method |
| CN112866599A (en) * | 2021-01-04 | 2021-05-28 | 深圳铭薪曙能科技有限公司 | Television set with both AC and DC power supply |
-
2016
- 2016-11-02 CN CN201621168722.9U patent/CN206249871U/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107240380A (en) * | 2017-07-19 | 2017-10-10 | 广州捷宝电子科技股份有限公司 | Diaphragm, LCD screen and vision-control method |
| CN110960189A (en) * | 2019-09-12 | 2020-04-07 | 中国人民解放军陆军特色医学中心 | Wireless cognitive regulator and eye movement treatment and treatment effect evaluation method |
| CN112866599A (en) * | 2021-01-04 | 2021-05-28 | 深圳铭薪曙能科技有限公司 | Television set with both AC and DC power supply |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20170613 Termination date: 20181102 |