CN101630489B - Power supply circuit of liquid crystal display - Google Patents
Power supply circuit of liquid crystal display Download PDFInfo
- Publication number
- CN101630489B CN101630489B CN2009101092300A CN200910109230A CN101630489B CN 101630489 B CN101630489 B CN 101630489B CN 2009101092300 A CN2009101092300 A CN 2009101092300A CN 200910109230 A CN200910109230 A CN 200910109230A CN 101630489 B CN101630489 B CN 101630489B
- Authority
- CN
- China
- Prior art keywords
- liquid crystal
- power supply
- crystal display
- semiconductor
- oxide
- 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.)
- Active
Links
Images
Landscapes
- Control Of Indicators Other Than Cathode Ray Tubes (AREA)
Abstract
The invention discloses a power supply circuit of a liquid crystal display, comprising a power supply used for providing power supply voltage, a liquid crystal display TCON panel, an MOS tube Q3 which is connected between the power supply and the liquid crystal display TCON panel and used for controlling the power supply voltage to be transmitted to the liquid crystal display TCON panel, a control unit which is connected with the MOS tube Q3 and used for controlling the on-off of the MOS tube Q3, an MCU which is connected to the control unit and used for providing a control signal and a detection circuit used for detecting a voltage drop on the MOS tube Q3 and outputting a detection signal. The power supply circuit of a liquid crystal display can provide automatic protection and give an alarm when a supplied TCON voltage value is too high, can also guarantee the rise time and the drop time of the supplied voltage and has simple circuit, low cost, safety and reliability.
Description
[technical field]
The present invention relates to technical field of television sets, particularly a kind of power supply circuit of liquid crystal display.
[background technology]
Along with the raising of science and technology development and people's living standard, LCD TV (LCD TV) replaces kinescope TV (CRT TV) gradually and gets into huge numbers of families.Liquid crystal display is as one of LCD TV most important component; On most of liquid crystal display a sequential logic disposable plates is arranged all; Be the TCON plate, to be used for handling the picture intelligence that the liquid crystal TV motherboard is seen off, control signal; And the clock signal, the control signal that produce necessity are given the liquid crystal display chip for driving, the image demonstration of realization liquid crystal display.The TCON plate of different liquid crystal displays has the various power requirement, mainly is magnitude of voltage and the requirement of voltage sequential.The supply voltage value is generally+5V or+the 12V power supply, power supply timing mainly is voltage rise time and voltage fall time, power supply timing is different because of screen.The TCON plate of LCD TV generally links to each other through connecting line with mainboard, and the power supply of TCON plate is provided by mainboard and controls, and mainboard must provide rational supply voltage and sequential, works normally to guarantee TCON plate safety.LCD TV mainly supplies power for the circuit of TCON plate power supply through the break-make of simple CS at present; Mainboard provides if liquid crystal display TCON plate requirement+5V supplies power+the 12V power supply, then will burn out the TCON plate, if the connecting line short circuit; Will burn out mainboard, dangerous reliable.In addition, feed circuit generally can only guarantee the rise time of sequential, can not reliably guarantee the fall time of sequential, so there is certain hidden danger.
[summary of the invention]
Determine to separating the problems referred to above, fundamental purpose of the present invention is to provide a kind of power supply circuit of liquid crystal display, when the TCON of liquid crystal display plate magnitude of voltage is too high, can protect automatically and report to the police, and can guarantee the rise time and the fall time of service voltage.
For realizing above-mentioned purpose, technical scheme of the present invention is:
A kind of power supply circuit of liquid crystal display; Include the power supply, the liquid crystal display TCON plate that are used to provide supply voltage, be connected in the metal-oxide-semiconductor Q3 that is used to control supply voltage between power supply and the liquid crystal display TCON plate and is delivered to liquid crystal display TCON plate, be connected control module with metal-oxide-semiconductor Q3, be connected to control module and be used to the MCU of control signal is provided and be used to detect the pressure drop on the said metal-oxide-semiconductor Q3 with the connection that is used to control metal-oxide-semiconductor Q3 and shutoff, and the testing circuit of output detection signal.
Compared to prior art, power supply circuit of liquid crystal display of the present invention can be protected and reported to the police when too high supplying with the TCON magnitude of voltage automatically, can guarantee the rise time and the fall time of service voltage simultaneously, and circuit is simple, cost is low, safe and reliable.
[description of drawings]
Fig. 1 is a theory diagram of the present invention.
Fig. 2 is the circuit theory diagrams of metal-oxide-semiconductor of the present invention and control module.
Fig. 3 is a testing circuit schematic diagram of the present invention.
[embodiment]
See also shown in Figure 1; A kind of power supply circuit of liquid crystal display of the present invention; Include the power supply, the liquid crystal display TCON plate that are used to provide supply voltage, be connected in the metal-oxide-semiconductor that is used to control supply voltage between power supply and the liquid crystal display TCON plate and is delivered to liquid crystal display TCON plate, be connected with metal-oxide-semiconductor the connection that is used to control metal-oxide-semiconductor and shutoff control module, be connected to control module and be used to provide the MCU of control signal and be used to detect the pressure drop on the said metal-oxide-semiconductor, and the testing circuit of output detection signal.
Power supply provides VCC supply voltage, and this voltage inputs to metal-oxide-semiconductor, testing circuit and control module simultaneously.Metal-oxide-semiconductor is conducting or shutoff under the control of control module, for the TCON plate of liquid crystal display provides VCC_Panel voltage.MCU_S is to control module for MCU output control signal, and testing circuit detects the pressure drop on the metal-oxide-semiconductor, i.e. voltage difference between VCC and the VCC_Panel, output detection signal DET_S then under the control of control signal MCU_S.Control module makes metal-oxide-semiconductor conducting or shutoff under the control of control signal MCU_S and detection signal DET_S, for liquid crystal display TCON plate provides VCC_Panel, and the safety of protection liquid crystal display TCON plate and metal-oxide-semiconductor.
Shown in Figure 2 is metal-oxide-semiconductor of the present invention and control unit circuit schematic diagram.Wherein, metal-oxide-semiconductor Q3 provides VCC_Panel voltage for the TCON plate of liquid crystal display for the power supply pipe under the situation of conducting.Control unit circuit includes the first triode Q1 of connection control signal MCU_S, the 8th triode Q8 of joint detection signal DET_S, the 5th metal-oxide-semiconductor that is connected with the 8th triode Q8.Wherein, the base stage of the 8th triode Q8 is passed through the 9th resistance R 9 joint detection signal DET_S, grounded emitter, and collector connects power supply VCC through the 6th resistance R 6.The base stage of the first triode Q1 is passed through first resistance R, 1 connection control signal MCU_S, grounded emitter, and collector is connected to power supply VCC through the 3rd resistance R 3.Conducting or the shutoff of control module control metal-oxide-semiconductor Q3 are for the TCON plate of liquid crystal display provides rational voltage VCC_Panel.
See also shown in Figure 3, the light emitting diode D2 that testing circuit includes the 4th triode Q4, the 7th metal-oxide-semiconductor Q7 that is connected with the 4th triode Q4, connects the 6th triode Q6 of the 7th metal-oxide-semiconductor and be connected to the 4th triode Q4 through the 7th resistance R 7 through the 14 resistance R 14.Wherein, the base stage of the 6th triode Q6 is through the 15, the 16 resistance R 15, R16 connection control signal MCU_S, grounded emitter, and collector connects the 7th metal-oxide-semiconductor Q7 through 14 resistance R 14.The collector of the 4th triode Q4 is connected to detection signal DET_S, and emitter connects the 7th metal-oxide-semiconductor Q7.
LCD TV is the moment of start just, and power supply provides supply voltage VCC, and the control signal MCU_S signal that this moment, MCU provided is a low level.Control signal MCU_S be low level then the 6th triode Q6 end, the 7th metal-oxide-semiconductor Q7 ends, then the 4th triode Q4 also ends, detection signal DET_S is a low level.Control signal MCU_S be low level then the first triode Q1 end, detection signal DET_S be low level then the 8th triode Q8 end, then metal-oxide-semiconductor Q3 ends.VCC through second, third resistance R 2, R3 and second capacitor C the 2, the 11 resistance R 11 to 1 rapid charge of first capacitor C to VCC voltage, metal-oxide-semiconductor Q3 ends, through metal-oxide-semiconductor Q3, then VCC_Panel is not a 0V voltage to VCC.Wherein, the capacitance of second capacitor C 2, the 4th capacitor C 4 is very little, to guarantee that metal-oxide-semiconductor Q3, the 5th metal-oxide-semiconductor Q5 are in start not conducting of moment.
The control signal MCU_S of LCD TV start back MCU output is a high level, and the first triode Q1 is saturation conduction at once.First capacitor C 1 is through 2 discharges of second resistance R, and metal-oxide-semiconductor Q3 becomes saturation conduction by conducting, and power supply VCC voltage is that liquid crystal display TCON plate provides VCC_Panel voltage through metal-oxide-semiconductor Q3.Through adjusting the value of second resistance R 2 and first capacitor C 1, the rise time that can satisfy VCC_Panel voltage.Control signal MCU_S through the 15 resistance R 15 and the time-delay of the 3rd capacitor C 3 after, make the 6th triode Q6 saturation conduction, then after the dividing potential drop of power supply VCC through the 13, the 14 resistance R 13, R14, make the 7th metal-oxide-semiconductor Q7 saturation conduction.Select reasonably value through the 15 resistance R 15 and the 3rd capacitor C 3, can guarantee behind the metal-oxide-semiconductor Q3 saturation conduction just saturation conduction of the 7th metal-oxide-semiconductor Q7.
When VCC_Panel correctly is connected to the TCON plate, and the magnitude of voltage of supply voltage VCC is when meeting requiring of TCON plate, and metal-oxide-semiconductor Q3 pressure drop is almost 0V, and VCC_Panel and VCC voltage are almost equal.Because VCC_Panel and VCC voltage are almost equal, voltage stabilizing diode D3 ends, and the 4th triode Q4 ends, and detection signal DET_S is 0V.Detection signal DET_S be low level then the 8th triode Q8 end, the 5th metal-oxide-semiconductor Q5 ends, then VCC_Panel voltage is normal, the LCD TV operate as normal.Be shorted to ground and work as VCC_Panel, when perhaps the magnitude of voltage of supply voltage VCC did not meet requiring of TCON plate, then the pressure drop of metal-oxide-semiconductor Q3 was very big, and promptly the voltage difference of VCC and VCC_Panel is very big.Because the voltage difference of VCC and VCC_Panel is very big, voltage stabilizing diode D3 conducting.Owing to the 7th metal-oxide-semiconductor Q7 saturation conduction this moment, the 4th triode Q4 is saturation conduction also.VCC through the 7th metal-oxide-semiconductor Q7, the 4th triode Q4 after pressure drop very little, the magnitude of voltage of detection signal DET_S is about the magnitude of voltage of supply voltage VCC, light emitting diode D2 conducting this moment, light emitting diode D2 is luminous, reminds power supply trouble.Simultaneously, the 8th triode Q8 saturation conduction, then the 5th metal-oxide-semiconductor Q5 saturation conduction.VCC through the 5th metal-oxide-semiconductor Q5 to 1 rapid charge of electric capacity first capacitor C to VCC, then metal-oxide-semiconductor Q33 ends, the TCON plate and the metal-oxide-semiconductor Q3 of liquid crystal display are protected, and can not be burnt out.
The control signal MCU_S that MCU provides after the LCD TV standby is a low level, and after the 3rd capacitor C 3 was passed through 15 discharge a period of times of the 15 resistance R, the 6th triode Q6 ended, and then detection signal DET_S is a low level, and the 5th metal-oxide-semiconductor Q5 ends.Simultaneously, when control signal MCU_S was low level, the first triode Q1 ended, and to 1 charging of first capacitor C, metal-oxide-semiconductor Q3 ends VCC through second, third resistance R 2, R3, and VCC_Panel is 0V.Through regulating the value of the two, the 3rd resistance R 2, R3 and first capacitor C 1, can adjust the fall time of VCC_Panel, to satisfy the requirement of fall time of liquid crystal display TCON plate supply voltage.
Power supply circuit of liquid crystal display of the present invention can provide the voltage of reasonable rise time and fall time for the TCON plate of liquid crystal display; Protection LCD TV mainboard and liquid crystal display TCON plate can not burnt out when power supply is broken down simultaneously; And carry out fault and remind, the circuit advantages of simple, safe and reliable.
Most preferred embodiment described above only is that the present invention is set forth and explains, but is not limited to disclosed any concrete form, and it is possible carrying out many modifications and variation.
Claims (3)
1. power supply circuit of liquid crystal display; Include the power supply, the liquid crystal display TCON plate that are used to provide supply voltage; It is characterized in that: also include and be connected in the metal-oxide-semiconductor (Q3) that is used to control supply voltage between power supply and the liquid crystal display TCON plate and is delivered to liquid crystal display TCON plate, be connected control module, be connected to control module and be used to the MCU of control signal is provided and be used to detect the pressure drop on the said metal-oxide-semiconductor (Q3) with the connection that is used to control metal-oxide-semiconductor (Q3) and shutoff with metal-oxide-semiconductor (Q3), and the testing circuit of output detection signal; Said control unit circuit includes first triode (Q1) of connection control signal (MCU_S), the 8th triode (Q8) of joint detection signal (DET_S), the 5th metal-oxide-semiconductor (Q5) that is connected with the 8th triode (Q8); The base stage of said the 8th triode (Q8) is passed through the 9th resistance (R9) joint detection signal (DET_S), grounded emitter, and collector connects power supply (VCC) through the 6th resistance (R6); The base stage of said first triode (Q1) is passed through first resistance (R1) connection control signal (MCU_S), grounded emitter, and collector is connected to power supply (VCC) through the 3rd resistance (R3).
2. power supply circuit of liquid crystal display as claimed in claim 1 is characterized in that: the light emitting diode (D2) that said testing circuit includes the 4th triode (Q4), the 7th metal-oxide-semiconductor (Q7) that is connected with the 4th triode (Q4), connects the 6th triode (Q6) of the 7th metal-oxide-semiconductor (Q7) and be connected to the 4th triode (Q4) through the 7th resistance (R7) through the 14 resistance (R14); The base stage of said the 6th triode (Q6) through the 15, the 16 resistance (R15), (R16) connection control signal (MCU_S), grounded emitter, and collector connects the 7th metal-oxide-semiconductor (Q7) through 14 resistance (R14); The collector of said the 4th triode (Q4) is connected to detection signal (DET_S), and emitter connects the 7th metal-oxide-semiconductor (Q7).
3. liquid crystal TV set, it is characterized in that: it includes power supply circuit of liquid crystal display as claimed in claim 2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009101092300A CN101630489B (en) | 2009-08-03 | 2009-08-03 | Power supply circuit of liquid crystal display |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009101092300A CN101630489B (en) | 2009-08-03 | 2009-08-03 | Power supply circuit of liquid crystal display |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101630489A CN101630489A (en) | 2010-01-20 |
| CN101630489B true CN101630489B (en) | 2012-02-01 |
Family
ID=41575577
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2009101092300A Active CN101630489B (en) | 2009-08-03 | 2009-08-03 | Power supply circuit of liquid crystal display |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101630489B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103117047B (en) * | 2013-03-14 | 2015-04-22 | 深圳市华星光电技术有限公司 | Backlight driving circuit, liquid crystal display device and driving method |
| US9165511B2 (en) | 2013-03-14 | 2015-10-20 | Shenzhen China Star Optoelectronics Technology Co., Ltd | Backlight driving circuit, LCD device, and driving method |
| CN104683714B (en) * | 2015-02-04 | 2017-06-23 | 四川长虹电器股份有限公司 | A kind of sequential control method of two-stage V BY ONE signal systems |
| CN105304047B (en) * | 2015-11-19 | 2018-07-03 | 深圳市华星光电技术有限公司 | Protect circuit and the liquid crystal display with the protection circuit |
| CN107255947B (en) * | 2017-06-22 | 2019-08-23 | 青岛海信电器股份有限公司 | Display device and its liquid crystal display backlight sequential control circuit |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005110065A (en) * | 2003-10-01 | 2005-04-21 | Nec Corp | Differential amplification circuit and drive circuit of liquid crystal display using it |
| CN1701645A (en) * | 2002-08-26 | 2005-11-23 | 三星电子株式会社 | Apparatus for supplying power, backlight assembly and liquid crystal display apparatus having the same |
| CN101303823A (en) * | 2007-05-09 | 2008-11-12 | 晨星半导体股份有限公司 | Circuit for providing voltage and correlation technique thereof |
-
2009
- 2009-08-03 CN CN2009101092300A patent/CN101630489B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1701645A (en) * | 2002-08-26 | 2005-11-23 | 三星电子株式会社 | Apparatus for supplying power, backlight assembly and liquid crystal display apparatus having the same |
| JP2005110065A (en) * | 2003-10-01 | 2005-04-21 | Nec Corp | Differential amplification circuit and drive circuit of liquid crystal display using it |
| CN101303823A (en) * | 2007-05-09 | 2008-11-12 | 晨星半导体股份有限公司 | Circuit for providing voltage and correlation technique thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101630489A (en) | 2010-01-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101630489B (en) | Power supply circuit of liquid crystal display | |
| US8421277B2 (en) | Switched mode power supply for an electronic device with auxiliary power for powering an evaluation unit during an energy-saving state | |
| KR101744927B1 (en) | A method for controling a monitor having the most power saving function during the sleep mode | |
| JP4593231B2 (en) | Power supply device and liquid crystal display device having the same | |
| CN101604515B (en) | Discharge circuit and display device with the same | |
| CN101582645A (en) | Power supply circuit and method for controlling same | |
| US11355073B2 (en) | Control circuit, display apparatus and method for supplying power to light source in display apparatus | |
| CN105185346A (en) | Display device | |
| US20090251205A1 (en) | Power supply circuit having standby detection circuit | |
| CN101556772B (en) | Liquid crystal display drive circuit | |
| CN109712590A (en) | Driving circuit of display panel and display device | |
| CN101465112B (en) | Display | |
| US20050264239A1 (en) | Cold cathode fluorescent lamp drive apparatus and method | |
| CN101751881B (en) | Liquid crystal display device of external image signal source | |
| CN101813733B (en) | MSP85 mode panel-selecting driving tester | |
| CN114724525B (en) | Display device, panel driving circuit thereof and charge discharging method | |
| CN104079850B (en) | A kind of protection circuit of television set | |
| CN103258510A (en) | Method and device for backlight driving protection | |
| US9201483B2 (en) | Image processing unit, image processing apparatus and image display system | |
| CN205753352U (en) | Servo-driver dual power supply low pressure sync detection circuit | |
| CN210574344U (en) | Teaching all-in-one machine capable of turning off power supply at regular time | |
| CN106097998A (en) | A kind of power interruption protector for LCD monitor | |
| CN210781455U (en) | Startup and shutdown display device and mirror surface all-in-one machine | |
| CN207572047U (en) | Lcd screen backlight power supply control circuit and receiver | |
| CN216471859U (en) | Crane protection function validity detection device |
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 |