CN101546539A - Circuit for adjusting brightness of liquid crystal display - Google Patents
Circuit for adjusting brightness of liquid crystal display Download PDFInfo
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- CN101546539A CN101546539A CN200810300745A CN200810300745A CN101546539A CN 101546539 A CN101546539 A CN 101546539A CN 200810300745 A CN200810300745 A CN 200810300745A CN 200810300745 A CN200810300745 A CN 200810300745A CN 101546539 A CN101546539 A CN 101546539A
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Abstract
The invention relates to a circuit for adjusting the brightness of a liquid crystal display, which is used for automatically adjusting the brightness of the liquid crystal display. The circuit comprises a photoelectric sensing circuit, a sampling circuit, a difference circuit, an amplifying circuit and a backlight drive circuit, wherein the photoelectric sensing circuit is used for sensing the brightness change in surrounding environment of the liquid crystal display and providing voltage which changes along with the change of the brightness of the environment for the difference circuit; the sampling circuit is used for sampling the voltage of the backlight drive circuit and providing the voltage for the difference circuit; the difference circuit receives the voltages provided by the photoelectric sensing circuit and the sampling circuit and outputs a difference value of the two voltages to the amplifying circuit; and the amplifying circuit is used for amplifying the voltages output by the difference circuit and providing the amplified voltages to the backlight drive circuit.
Description
Technical field
The present invention relates to a kind of brightness regulating circuit, particularly a kind of circuit that LCD is carried out the brightness adjustment.
Background technology
LCD is a kind of widely used display device, and its contrast, brilliance control technology are significant for the LCD that is operated under the light changing environment.Because along with the variation of extraneous light, as day and night change etc., the brightness that the user experiences LCD also constantly changes gradually, and promptly the visual brightness of LCD is in continuous variation.When extraneous light deepening, the visual brightness of LCD is along with brightening, and the user sees image on the display screen or literal also along with brightening, and eyes can irriate; When extraneous light brightened, the visual brightness of LCD was along with deepening, and the user sees image on the display screen or literal also along with deepening, and eyes see that screen can be easy to fatigue.
But the brightness of traditional LCD can only be adjusted by the control knob on user's manual adjustments liquid crystal panel, can not realize automatic control to LCD brightness, the visual brightness that can not keep LCD automatically within the specific limits, the eyesight to people causes damage easily.
Summary of the invention
In view of above content, be necessary to provide a kind of circuit for adjusting brightness of liquid crystal display, can control automatically the brightness of LCD, to reduce the variation that causes visual brightness because of the variation of ambient light, people's eyesight is shielded.
A kind of circuit for adjusting brightness of liquid crystal display, be used for adjusting automatically the brightness of LCD, comprise a photoelectric sensor circuit, one sample circuit, one difference channel, one amplifying circuit and a backlight drive circuit, the brightness that described photoelectric sensor circuit is used for the induction liquid crystal display surrounding environment changes, and the voltage that provides the brightness with environment to change to described difference channel, described sample circuit be used to take a sample described backlight drive circuit voltage and offer described difference channel, described difference channel receives the voltage that described photoelectric sensor circuit and sample circuit provide, and the difference of exporting two voltages is used for voltage to described difference channel output for described amplifying circuit, described amplifying circuit to amplify and offer described backlight drive circuit.
The brightness that described circuit for adjusting brightness of liquid crystal display is responded to extraneous light automatically by described photoelectric sensor circuit changes; adjustment by described sample circuit sampling, difference channel and amplifying circuit with the Control of Voltage of described backlight drive circuit within the specific limits again; it is stable that the visual brightness of display is kept, and people's eyesight is played a protective role.
Description of drawings
Below in conjunction with accompanying drawing and better embodiment the present invention is described in further detail:
Fig. 1 is the schematic diagram of the better embodiment of circuit for adjusting brightness of liquid crystal display of the present invention.
Fig. 2 is the circuit diagram of the better embodiment of circuit for adjusting brightness of liquid crystal display of the present invention.
Embodiment
With reference to figure 1, the better embodiment of circuit for adjusting brightness of liquid crystal display of the present invention comprises a photoelectric sensor circuit 300, a difference channel 400, a sample circuit 200, an amplifying circuit 100 and a backlight drive circuit 500.Described difference channel 400 links to each other with described photoelectric sensor circuit 300, described sample circuit 200 and described amplifying circuit 100 respectively, described backlight drive circuit 500 links to each other with described sample circuit 200 and described amplifying circuit 100 respectively, and described amplifying circuit 100 also links to each other with described photoelectric sensor circuit 300.
With reference to figure 2, in the better embodiment of circuit for adjusting brightness of liquid crystal display of the present invention, described amplifying circuit 100 comprises a triode Q7, a resistance R 13 and a resistance R 14.The base stage of described triode Q7 links to each other with described difference channel 400 by described resistance R 13, and collector links to each other with described backlight drive circuit 500, and emitter links to each other with described photoelectric sensor circuit 300 by described resistance R 14.
Described sample circuit 200 comprises a resistance R 3, a triode Q4, a stabilivolt D2 and a capacitor C 2.The base stage of described triode Q4 and collector all are connected in described backlight drive circuit 500 by described resistance R 3, and emitter is by the parallel circuit ground connection of described stabilivolt D2 and described capacitor C 2.
Described photoelectric sensor circuit 300 comprises a photoresistance M, an adjustable resistance R10, a resistance R 11, a resistance R 12 and a field effect transistor Q8, the source electrode of described field effect transistor Q8 is by described resistance R 11 ground connection, grid is by described resistance R 12 ground connection, drain electrode links to each other with an end of the resistance R 14 of described difference channel 400 and described amplifying circuit 100 respectively by described adjustable resistance R10, the end of described photoresistance M links to each other with the grid of described field effect transistor Q8, and the other end is connected in the node between described resistance R 14 and the described adjustable resistance R10.
Described difference channel 400 comprises some resistance R 4, R5, R6, R8, R9, an adjustable resistance R7, a triode Q5, a triode Q6 and a capacitor C 3.The base stage of described triode Q5 links to each other with the emitter of described triode Q4 by described resistance R 4, and collector links to each other with a power supply Vc by described resistance R 5, and emitter is connected in the end of described adjustable resistance R7.The base stage of described triode Q6 links to each other with the drain electrode of described field effect transistor Q8 by described resistance R 9, collector links to each other with described power supply Vc by described resistance R 6, and be connected to the node between described photoresistance M and the described adjustable resistance R10, emitter is connected in the other end of described adjustable resistance R7.The adjustable end of described adjustable resistance R7 is by the parallel circuit ground connection of described resistance R 8 with described capacitor C 3.
One end of described backlight drive circuit 500 is connected in the collector of described triode Q7, and a termination is received the brightness adjusting signal PWM of LCD, and an end is connected in an end of the resistance R 3 of described sample circuit 200, and the other end is exported an adjusted voltage U s.Can be during the manual adjustment LCD by adjusting the brightness that described brightness adjusting signal PWM adjusts LCD.
Suppose that described sample circuit 200 is U1 from the voltage of described backlight drive circuit 500 samplings, U1 is U2 through the voltage of described sample circuit 200 outputs.The voltage of described photoelectric sensor circuit 300 outputs is U3.Voltage U 2, U3 are U5, U4 by the voltage of described difference channel 400 outputs.Voltage U 5, U4 are U0 through the voltage of described amplifying circuit 100 outputs, this voltage U 0 is as the input voltage of LCD backlight driving circuit 500, the output voltage of described backlight drive circuit 500 is Us, Us may command LCD bright dark, because Us changes along with the variation of U0, just be equivalent to adjust Us so adjust U0.
When extraneous light brightened, constant but its visual brightness of the intrinsic brilliance of LCD diminished.The light resistance that makes described photoresistance M that brightens becomes big, voltage decreases on the described resistance R 12, this voltage voltage U 3 behind described field effect transistor Q8 also diminishes, and the output voltage U 3 of promptly described photoelectric sensor circuit 300 diminishes, and U3 diminishes through described difference channel 400 voltage U 4 again.At this moment described sample circuit 200 is from the described resistance R 3 of voltage U 1 process of described backlight drive circuit 500 samplings, described triode Q4, described stabilivolt D2 voltage stabilizing, described capacitor C 2 filtering, become stable voltage U 2, U2 remains unchanged substantially through output voltage U 5 behind the triode Q5 of described difference channel 400 again, and U4 reduces, be that the input voltage U2 of difference channel and the voltage that U3 exports behind difference channel (U5 and U4's is poor) become greatly, then the difference of the voltage at the base stage of triode Q7 and emitter two ends becomes big, and then the output voltage U 0 behind the triode Q7 in described amplifying circuit 100 also becomes big.It is big that the input voltage U0 of described backlight drive circuit becomes, i.e. the brightness of LCD increases.
When extraneous light deepening, the intrinsic brilliance of LCD is constant but its visual brightness becomes big.The light deepening diminishes the resistance of described photoresistance M, makes on the described resistance R 12 voltage become big, and voltage U 3 also becomes greatly behind described field effect transistor Q8, and output voltage U 3 changes of promptly described photoelectric sensor circuit 300 greatly.U3 also becomes big through described difference channel 400 voltage U 4 again.At this moment described sample circuit 200 is from the described resistance R 3 of voltage U 1 process of described backlight drive circuit 500 samplings, described triode Q4, described stabilivolt D2 voltage stabilizing, described capacitor C 2 filtering, become stable voltage U 2, U2 remains unchanged substantially through output voltage U 5 behind the triode Q5 of described difference channel 400 again, and U4 becomes big, be that the input voltage U2 of difference channel and the voltage that U3 exports behind difference channel (U5 and U4's is poor) diminish, then the difference of the voltage at the base stage of triode Q7 and emitter two ends diminishes, and then the output voltage U 0 behind the triode Q7 in described amplifying circuit 100 diminishes.The input voltage U0 of described backlight drive circuit 500 diminishes, i.e. the brightness of LCD reduces.When extraneous light deepening, by this circuit for adjusting brightness of liquid crystal display described backlight drive circuit 500 voltages are reduced, energy-conserving action is arranged.
Described circuit for adjusting brightness of liquid crystal display is the brightness of regulator solution crystal display automatically, makes liquid crystal display equipment screen that suitable visual brightness be arranged, and has the energy-conserving and environment-protective effect.By inserting described circuit for adjusting brightness of liquid crystal display; even external environment light or supply voltage have produced variation; the visual brightness of the observed LCD of people remains unchanged substantially, help protecting eyes, anti-eye strain, make eyes comfortable, increase work efficiency.
Claims (5)
- [claim 1] a kind of circuit for adjusting brightness of liquid crystal display, be used for adjusting automatically the brightness of LCD, comprise a photoelectric sensor circuit, one sample circuit, one difference channel, one amplifying circuit and a backlight drive circuit, the brightness that described photoelectric sensor circuit is used for the induction liquid crystal display surrounding environment changes, and the voltage that provides the brightness with environment to change to described difference channel, described sample circuit be used to take a sample described backlight drive circuit voltage and offer described difference channel, described difference channel receives the voltage that described photoelectric sensor circuit and sample circuit provide, and the difference of exporting two voltages is used for voltage to described difference channel output for described amplifying circuit, described amplifying circuit to amplify and offer described backlight drive circuit.
- [claim 2] circuit for adjusting brightness of liquid crystal display as claimed in claim 1, it is characterized in that: described amplifying circuit comprises one first triode, one first resistance and one second resistance, the base stage of described first triode links to each other with described difference channel by described first resistance, collector links to each other with described backlight drive circuit, and emitter links to each other with described photoelectric sensor circuit by described second resistance.
- [claim 3] circuit for adjusting brightness of liquid crystal display as claimed in claim 2, it is characterized in that: described sample circuit comprises one the 3rd resistance, one second triode, a stabilivolt and one first electric capacity, the base stage of described second triode and collector all are connected in described backlight drive circuit by described the 3rd resistance, emitter also links to each other with described difference channel by the parallel circuit ground connection of described stabilivolt and described first electric capacity.
- [claim 4] circuit for adjusting brightness of liquid crystal display as claimed in claim 3, it is characterized in that: described photoelectric sensor circuit comprises a photoresistance, one first adjustable resistance, one the 4th resistance, one the 5th resistance and a field effect transistor, the source electrode of described field effect transistor is by described the 4th resistance eutral grounding, grid is by described the 5th resistance eutral grounding, drain electrode links to each other with an end of second resistance of described difference channel and described amplifying circuit respectively by described first adjustable resistance, one end of described photoresistance links to each other with the grid of described field effect transistor, and the other end is connected in the node between described second resistance and described first adjustable resistance.
- [claim 5] circuit for adjusting brightness of liquid crystal display as claimed in claim 4, it is characterized in that: described difference channel comprises one the 6th resistance, one the 7th resistance, one the 8th resistance, one the 9th resistance, 1 the tenth resistance, one second adjustable resistance, one the 3rd triode, one the 4th triode and one second electric capacity, the base stage of described the 3rd triode links to each other with the emitter of described second triode by described the 6th resistance, collector links to each other with a power supply by described the 7th resistance, emitter is connected in an end of described second adjustable resistance, the base stage of described the 4th triode links to each other with the drain electrode of described field effect transistor by described the 8th resistance, collector links to each other with described power supply by described the 9th resistance, and be connected to the node between described photoresistance and described first adjustable resistance, emitter is connected in the other end of described second adjustable resistance, and the adjustable end of described second adjustable resistance is by the parallel circuit ground connection of described the tenth resistance and described second electric capacity.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200810300745A CN101546539B (en) | 2008-03-27 | 2008-03-27 | Circuit for adjusting brightness of liquid crystal display |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200810300745A CN101546539B (en) | 2008-03-27 | 2008-03-27 | Circuit for adjusting brightness of liquid crystal display |
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| Publication Number | Publication Date |
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| CN101546539A true CN101546539A (en) | 2009-09-30 |
| CN101546539B CN101546539B (en) | 2012-10-10 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN200810300745A Expired - Fee Related CN101546539B (en) | 2008-03-27 | 2008-03-27 | Circuit for adjusting brightness of liquid crystal display |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2016049949A1 (en) * | 2014-09-29 | 2016-04-07 | 深圳市华星光电技术有限公司 | Regulator circuit, method and optical measurement system for measuring optical parameter |
| CN107749273A (en) * | 2017-11-07 | 2018-03-02 | 京东方科技集团股份有限公司 | Electrical signal detection module, driving method, image element circuit and display device |
| CN109256087A (en) * | 2018-10-23 | 2019-01-22 | 深圳市华星光电技术有限公司 | Display device, pixel-driving circuit and its driving method |
| CN109523957A (en) * | 2018-12-24 | 2019-03-26 | 惠科股份有限公司 | Driving circuit, backlight module and display panel |
| CN110120208A (en) * | 2019-04-30 | 2019-08-13 | 努比亚技术有限公司 | A kind of method, wearable device and storage medium that automatic adjustment screen is shown |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1829301A (en) * | 2005-02-28 | 2006-09-06 | 华硕电脑股份有限公司 | Display system and method capable of automatically adjusting display brightness |
| CN1794044A (en) * | 2005-12-28 | 2006-06-28 | 南京Lg同创彩色显示系统有限责任公司 | Liquid crystal display capable of automatic regulating brightness and its regulating method |
| CN1996458A (en) * | 2006-01-08 | 2007-07-11 | 吴健 | Intelligent dimming system for liquid crystal device |
-
2008
- 2008-03-27 CN CN200810300745A patent/CN101546539B/en not_active Expired - Fee Related
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2016049949A1 (en) * | 2014-09-29 | 2016-04-07 | 深圳市华星光电技术有限公司 | Regulator circuit, method and optical measurement system for measuring optical parameter |
| GB2547141A (en) * | 2014-09-29 | 2017-08-09 | Shenzhen China Star Optoelect | Regulator circuit, method and optical measurement system for measuring optical parameter |
| EA033962B1 (en) * | 2014-09-29 | 2019-12-13 | Шэньчжэнь Чайна Стар Оптоэлектроникс Текнолоджи Ко., Лтд. | Optical system for measuring brightness and method of adjusting an amplification factor of an amplification module in measuring brightness |
| GB2547141B (en) * | 2014-09-29 | 2020-10-28 | Shenzhen China Star Optoelect | Adjustment circuit and method for measuring optical parameter and optical measurement system |
| CN107749273A (en) * | 2017-11-07 | 2018-03-02 | 京东方科技集团股份有限公司 | Electrical signal detection module, driving method, image element circuit and display device |
| US11222590B2 (en) | 2017-11-07 | 2022-01-11 | Boe Technology Group Co., Ltd. | Electrical signal detection module, driving method, pixel circuit and display device |
| CN109256087A (en) * | 2018-10-23 | 2019-01-22 | 深圳市华星光电技术有限公司 | Display device, pixel-driving circuit and its driving method |
| CN109256087B (en) * | 2018-10-23 | 2020-12-04 | 深圳市华星光电技术有限公司 | Display device, pixel driving circuit and driving method thereof |
| CN109523957A (en) * | 2018-12-24 | 2019-03-26 | 惠科股份有限公司 | Driving circuit, backlight module and display panel |
| CN109523957B (en) * | 2018-12-24 | 2021-06-18 | 惠科股份有限公司 | Drive circuit, backlight module and display panel |
| CN110120208A (en) * | 2019-04-30 | 2019-08-13 | 努比亚技术有限公司 | A kind of method, wearable device and storage medium that automatic adjustment screen is shown |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101546539B (en) | 2012-10-10 |
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Granted publication date: 20121010 Termination date: 20130327 |