CN100529854C - Power supply circuit and LCD using the same - Google Patents
Power supply circuit and LCD using the same Download PDFInfo
- Publication number
- CN100529854C CN100529854C CNB2006100622819A CN200610062281A CN100529854C CN 100529854 C CN100529854 C CN 100529854C CN B2006100622819 A CNB2006100622819 A CN B2006100622819A CN 200610062281 A CN200610062281 A CN 200610062281A CN 100529854 C CN100529854 C CN 100529854C
- Authority
- CN
- China
- Prior art keywords
- circuit
- output terminal
- input end
- power
- voltage output
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 239000004973 liquid crystal related substance Substances 0.000 claims description 26
- 230000005669 field effect Effects 0.000 claims description 16
- 238000001514 detection method Methods 0.000 abstract 2
- 238000010586 diagram Methods 0.000 description 6
Images
Landscapes
- Liquid Crystal Display Device Control (AREA)
- Control Of Indicators Other Than Cathode Ray Tubes (AREA)
Abstract
The invention provides an electrical source circuit including an electrical source integrate circuit, a detection circuit and a switch circuit. The electrical source integrate circuit includes an input end, a positive voltage output end and a negative voltage output end. The input end is to accept the outer voltage. When the system is closed, the detection circuit sends a controlling signal to the switch circuit which connects the positive voltage output end with the negative voltage output end to make the negative voltage increase output from the negative voltage. The invention provides a LCD using the electrical source circuit.
Description
Technical field
The invention relates to the LCD of a kind of power circuit and this power circuit of employing.
Background technology
LCD generally comprises a control panel (Control Board) and a liquid crystal display module, and (Liquid Crystal Display Module, LCM), this liquid crystal display module comprises that a plurality of display units show to realize image.This control panel comprises a power circuit, and this power circuit provides various positive voltages and negative voltage for this liquid crystal display module.
See also Fig. 1, it is a kind of circuit module figure of power circuit of prior art LCD.This power circuit 112 comprises a power IC 1120, one first electric capacity 1124 and one second electric capacity 1125, and this power IC 1120 comprises an input end 1121, a positive voltage output end 1122 and a negative voltage output terminal 1123.This input end 1121 is used to receive extraneous power source voltage Vcc, this power IC 1120 changes this power source voltage Vcc into liquid crystal display module required various voltages, this positive voltage output end 1122 is exported various positive voltages to this liquid crystal display module, as+5 volts ,+3.3 volts, grid operating voltage VGH etc.This negative voltage output terminal 1123 is exported various negative voltages to this liquid crystal display module, as grid operating voltage VGL etc.In order to guarantee the stability of each output voltage, this positive voltage output end 1122 and this negative voltage output terminal 1123 need respectively by this first electric capacity 1124 and second electric capacity, 1125 ground connection.
But, has the ability of store charge with first, second electric capacity 1124,1125 that this positive voltage output end 1122 is connected with this negative voltage output terminal 1123, when shutdown, the grid operating voltage VGL that loads on the liquid crystal display module can not become 0 volt rapidly, cause the residual electric charge of a plurality of display units of this liquid crystal display module not bled off rapidly, thereby easily make this LCD long power-off ghost shadow phenomenon occur.
Summary of the invention
In order to solve the power-off ghost shadow phenomenon of LCD in the prior art, the invention provides a kind of power circuit that can improve LCD power-off ghost shadow phenomenon.
Be necessary to provide a kind of LCD that adopts this power circuit simultaneously.
A kind of power circuit, it comprises a power IC, a testing circuit and an on-off circuit.This power IC comprises an input end, a positive voltage output end and a negative voltage output terminal, and this input end is used to receive external voltage.This testing circuit comprises a comparer, a first input end, one second input end and an output terminal.This first input end receives external voltage.External voltage during this second input end receiving system operate as normal.This comparer compares the voltage of this first, second input end input.When system closedown, the input voltage of this first input end is less than the input voltage of this second input end.The output terminal of this testing circuit sends a control signal to this on-off circuit, and this on-off circuit makes this positive voltage output end and this negative voltage output terminal conducting after receiving this control signal, thereby the negative voltage of this negative voltage output terminal output is raise rapidly.
A kind of LCD, it comprises a liquid crystal display module and a power circuit, and this liquid crystal display module comprises a plurality of display units, and this power circuit provides positive voltage and negative voltage for this liquid crystal display module.This power circuit comprises a power IC, a testing circuit and an on-off circuit, and this power IC comprises an input end, a positive voltage output end and a negative voltage output terminal.This input end is used to receive external voltage.This testing circuit comprises a comparer, a first input end, one second input end and an output terminal.This first input end receives external voltage.External voltage during this second input end receiving system operate as normal.This comparer compares the voltage of this first, second input end input.When system closedown, the input voltage of this first input end is less than the input voltage of this second input end.The output terminal of this testing circuit sends a control signal to this on-off circuit, this on-off circuit makes this positive voltage output end and this negative voltage output terminal conducting after receiving this control signal, the negative voltage of this negative voltage output terminal output raises rapidly, thereby the residual electric charge of a plurality of display units of this liquid crystal display module is bled off rapidly.
Compared with prior art, the testing circuit of LCD of the present invention sends a control signal to this on-off circuit when system closedown, this on-off circuit makes this positive voltage output end and this negative voltage output terminal conducting after receiving this control signal, the negative voltage of this negative voltage output terminal output raises rapidly, thereby effectively solves the power-off ghost shadow phenomenon of LCD.
Description of drawings
Fig. 1 is a kind of circuit module figure of power circuit of prior art LCD.
Fig. 2 is the electrical block diagram of LCD of the present invention.
Fig. 3 is the circuit module figure of LCD power circuit first embodiment shown in Figure 2.
Fig. 4 is the circuit structure diagram of testing circuit shown in Figure 3.
Fig. 5 is the circuit structure diagram of on-off circuit shown in Figure 3.
Fig. 6 is the circuit module figure of LCD power circuit second embodiment shown in Figure 2.
Embodiment
See also Fig. 2, it is the electrical block diagram of LCD of the present invention.This LCD 2 comprises a control panel 21 and a liquid crystal display module 22, and this control panel 21 comprises a signal processing circuit 211 and a power circuit 212.This signal processing circuit 211 provides various control signals for this liquid crystal display module 22, and this power circuit 212 provides various positive voltages and negative voltage for this liquid crystal display module 22, and this liquid crystal display module 22 comprises a plurality of display units, and it is used to realize that image shows.
See also Fig. 3, it is the circuit module figure of LCD power circuit first embodiment shown in Figure 2.This power circuit 212 comprises a power IC 214, a testing circuit 2141 and an on-off circuit 2142, and this testing circuit 2141 and on-off circuit 2142 all are arranged at this power IC 214 inside.This power IC 214 comprises an input end 213, a positive voltage output end 215 and a negative voltage output terminal 216.This input end 213 is used to receive extraneous power source voltage Vcc, and this power IC 214 changes this power source voltage Vcc into liquid crystal display module 22 required various voltages.This positive voltage output end 215 is to the various positive voltages of this liquid crystal display module 22 outputs, as+5 volts ,+3.3 volts, grid operating voltage VGH etc.This negative voltage output terminal 216 is to the various negative voltages of this liquid crystal display module 22 outputs, as grid operating voltage VGL etc.
See also Fig. 4, it is the circuit structure diagram of testing circuit shown in Figure 3.This testing circuit 2141 comprises a comparer 2140, a first input end 2143, one second input end 2144 and an output terminal 2145.This first input end 2143 is used to receive extraneous power source voltage Vcc, this second input end 2144 is used to receive reference voltage, extraneous power source voltage Vcc when this reference voltage is LCD 2 operate as normal, the voltage signal of 2140 pairs of these first, second input end 2143,2144 inputs of this comparer compares, when the voltage of this first input end 2143 during less than the voltage of this second input end 2144, this output terminal 2145 outputs one control signal, this control signal is used to control the break-make of this on-off circuit 2142.
See also Fig. 5, it is the circuit structure diagram of on-off circuit shown in Figure 3.This on-off circuit 2142 comprises a bipolar transistor 2146, one first resistance 2147 and one second resistance 2148, the base stage of this bipolar transistor 2146 is connected with the output terminal 2145 of this testing circuit 2141 by this first resistance 2147, the collector of this bipolar transistor 2146 is connected with this positive voltage output end 215 by this second resistance 2148, and the emitter of this bipolar transistor 2146 is connected with this negative voltage output terminal 216.When the base stage of this bipolar transistor 2146 receives a control signal, these bipolar transistor 2146 conductings.
When system closedown, the voltage signal of 2140 pairs of these first, second input end 2143,2144 inputs of this comparer compares, when the voltage of this first input end 2143 during less than the voltage of this second input end 2144, this output terminal 2145 outputs one control signal, these bipolar transistor 2146 conductings.This positive voltage output end 215 is connected with this negative voltage output terminal 216 by the collector and emitter of this second resistance 2148, this bipolar transistor 2146.The grid operating voltage VGL of these negative voltage output terminal 216 outputs raises rapidly, for example is elevated to 0 volt rapidly, thereby the residual electric charge of a plurality of display units of this liquid crystal display module 22 is bled off rapidly.
The bipolar transistor 2146 of this on-off circuit 2142 also can be replaced by a field-effect transistor, the connected mode of this field-effect transistor is roughly the same with this bipolar transistor 2146: the grid of this field-effect transistor is connected with the output terminal of this testing circuit by a resistance, the source electrode of this field-effect transistor is connected with this positive voltage output end by a resistance, and the drain electrode of this field-effect transistor is connected with this negative voltage output terminal.When the output terminal of this testing circuit is exported a control signal, this field-effect transistor conducting.
Compared with prior art, the testing circuit 2141 of LCD 2 of the present invention sends a control signal to this on-off circuit 2142 when system closedown, this on-off circuit 2142 makes this positive voltage output end 215 and these negative voltage output terminal 216 conductings after receiving this control signal, the grid operating voltage VGL of these negative voltage output terminal 216 outputs raises rapidly, the residual electric charge of a plurality of display units of this liquid crystal display module 22 is bled off rapidly, thereby effectively solves the power-off ghost shadow phenomenon of this LCD 2.
See also Fig. 6, it is the circuit module figure of LCD power circuit second embodiment shown in Figure 2.This power circuit 312 is roughly the same with the circuit structure of this first embodiment power circuit 212, and its difference is: this on-off circuit 3142 is arranged at this power IC 314 outsides.
Claims (8)
1. power circuit, it comprises a power IC, this power IC comprises an input end, one positive voltage output end and a negative voltage output terminal, this input end receives external voltage, it is characterized in that: this power circuit also comprises a testing circuit and an on-off circuit, this testing circuit comprises a comparer, one first input end, one second input end and an output terminal, this first input end receives external voltage, external voltage during this second input end receiving system operate as normal, this comparer to this first, the voltage of second input end input compares, when system closedown, the input voltage of this first input end is less than the input voltage of this second input end, the output terminal of this testing circuit sends a control signal to this on-off circuit, this on-off circuit makes this positive voltage output end and this negative voltage output terminal conducting after receiving this control signal, thereby the negative voltage of this negative voltage output terminal output is raise rapidly.
2. power circuit as claimed in claim 1, it is characterized in that: this on-off circuit comprises a bipolar transistor, the base stage of this bipolar transistor is connected with the output terminal of this testing circuit by a resistance, the collector of this bipolar transistor is connected with this positive voltage output end by a resistance, the emitter of this bipolar transistor is connected with this negative voltage output terminal, when this testing circuit is exported a control signal, this bipolar transistor conducting.
3. power circuit as claimed in claim 1, it is characterized in that: this on-off circuit comprises a field-effect transistor, the grid of this field-effect transistor is connected with the output terminal of this testing circuit by a resistance, the source electrode of this field-effect transistor is connected with this positive voltage output end by a resistance, the drain electrode of this field-effect transistor is connected with this negative voltage output terminal, when this testing circuit is exported a control signal, this field-effect transistor conducting.
4. power circuit as claimed in claim 1 is characterized in that: this testing circuit is arranged at this power IC inside, and this on-off circuit is arranged at this power IC inside.
5. power circuit as claimed in claim 1 is characterized in that: this testing circuit is arranged at this power IC inside, and this on-off circuit is arranged at this power IC outside.
6. LCD, it comprises a liquid crystal display module and a power circuit, this liquid crystal display module comprises a plurality of display units, this power circuit provides positive voltage and negative voltage for this liquid crystal display module, this power circuit comprises a power IC, this power IC comprises an input end, one positive voltage output end and a negative voltage output terminal, this input end is used to receive external voltage, it is characterized in that: this power circuit also comprises a testing circuit and an on-off circuit, this testing circuit comprises a comparer, one first input end, one second input end and an output terminal, this first input end receives external voltage, external voltage during this second input end receiving system operate as normal, this comparer to this first, the voltage of second input end input compares, when system closedown, the input voltage of this first input end is less than the input voltage of this second input end, the output terminal of this testing circuit sends a control signal to this on-off circuit, this on-off circuit makes this positive voltage output end and this negative voltage output terminal conducting after receiving this control signal, the negative voltage of this negative voltage output terminal output raises rapidly, thereby the residual electric charge of a plurality of display units of this liquid crystal display module is bled off rapidly.
7. LCD as claimed in claim 6, it is characterized in that: this on-off circuit comprises a bipolar transistor, the base stage of this bipolar transistor is connected with the output terminal of this testing circuit by a resistance, the collector of this bipolar transistor is connected with this positive voltage output end by a resistance, the emitter of this bipolar transistor is connected with this negative voltage output terminal, when this testing circuit is exported a control signal, this bipolar transistor conducting.
8. LCD as claimed in claim 6, it is characterized in that: this on-off circuit comprises a field-effect transistor, the grid of this field-effect transistor is connected with the output terminal of this testing circuit by a resistance, the source electrode of this field-effect transistor is connected with this positive voltage output end by a resistance, the drain electrode of this field-effect transistor is connected with this negative voltage output terminal, when this testing circuit is exported a control signal, this field-effect transistor conducting.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2006100622819A CN100529854C (en) | 2006-08-25 | 2006-08-25 | Power supply circuit and LCD using the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2006100622819A CN100529854C (en) | 2006-08-25 | 2006-08-25 | Power supply circuit and LCD using the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101131487A CN101131487A (en) | 2008-02-27 |
| CN100529854C true CN100529854C (en) | 2009-08-19 |
Family
ID=39128811
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2006100622819A Expired - Fee Related CN100529854C (en) | 2006-08-25 | 2006-08-25 | Power supply circuit and LCD using the same |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN100529854C (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101739967B (en) * | 2008-11-12 | 2012-11-07 | 瀚宇彩晶股份有限公司 | Method for eliminating residual image after shutdown of display, control panel and display thereof |
| CN101968952A (en) * | 2010-07-30 | 2011-02-09 | 南京中电熊猫液晶显示科技有限公司 | Method for improving picture quality of GIP (Gate-in-Panel) liquid crystal display panel |
| TWI441156B (en) * | 2011-09-15 | 2014-06-11 | Au Optronics Corp | Gate driving apparatus and method for removing residual image |
| CN102968975B (en) * | 2012-12-10 | 2015-06-17 | 京东方科技集团股份有限公司 | Liquid crystal display device and gate driving circuit voltage control method and control circuit thereof |
| CN104635362A (en) * | 2013-11-08 | 2015-05-20 | 群创光电股份有限公司 | Display panel and display device using the display panel |
| CN104036716A (en) * | 2014-06-24 | 2014-09-10 | 上海中航光电子有限公司 | Drive and control circuit and display device of display panel |
| CN105301814B (en) * | 2015-11-26 | 2019-04-26 | 深圳市华星光电技术有限公司 | Power supply circuit and display panel with detecting function |
| CN108962119B (en) * | 2018-08-01 | 2021-11-02 | 京东方科技集团股份有限公司 | Level shift circuit, driving method thereof and display device |
| CN110599977A (en) * | 2019-09-18 | 2019-12-20 | 福州京东方光电科技有限公司 | Shutdown ghost eliminating circuit and display device |
-
2006
- 2006-08-25 CN CNB2006100622819A patent/CN100529854C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CN101131487A (en) | 2008-02-27 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN100529854C (en) | Power supply circuit and LCD using the same | |
| CN103165091B (en) | Liquid crystal display device having discharge circuit and method of driving thereof | |
| US9830874B2 (en) | Electronic device having smaller number of drive chips | |
| CN105976755B (en) | A kind of display driver circuit and its control method, display device | |
| CN102867491A (en) | LCD (Liquid Crystal Display) panel drive circuit and method as well as display unit | |
| JP2017521717A (en) | Gate electrode drive circuit with bootstrap function | |
| CN104616615A (en) | Screen clearing circuit and display device | |
| JP2017530379A (en) | Gate electrode drive circuit with bootstrap function | |
| CN101101385A (en) | Discharge circuit and liquid crystal display device adopting the discharge circuit | |
| CN106920526B (en) | Shift register and driving method thereof and grid driving circuit | |
| CN104464673A (en) | Display device and control method and control circuit thereof | |
| CN108519838B (en) | Voltage supply circuit and method, touch display device and voltage supply method thereof | |
| CN104036716A (en) | Drive and control circuit and display device of display panel | |
| CN101604515A (en) | Discharge circuit and display device with discharge circuit | |
| CN110264971A (en) | Anti- splashette circuit and method, driving circuit, display device | |
| CN108962119B (en) | Level shift circuit, driving method thereof and display device | |
| CN100592374C (en) | Liquid crystal display device and power supply sequencing control circuit thereof | |
| CN105427818A (en) | Gate drive circuit and array substrate thereof | |
| CN103366695A (en) | Source electrode driving device and display equipment | |
| US8253720B2 (en) | Liquid crystal display with alternating current off control circuit | |
| CN110288956B (en) | Display device | |
| CN112133238B (en) | Drive circuit and electronic device | |
| TW200811792A (en) | Power supply circuit and liquid crystal display device using the same | |
| CN114038434B (en) | Power sequence control circuit and method for liquid crystal panel, liquid crystal panel and display device | |
| US8654107B2 (en) | Shading signal generating circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| 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: 20090819 Termination date: 20170825 |