CN100480791C - LCD boosted circuit - Google Patents
LCD boosted circuit Download PDFInfo
- Publication number
- CN100480791C CN100480791C CNB2006100621892A CN200610062189A CN100480791C CN 100480791 C CN100480791 C CN 100480791C CN B2006100621892 A CNB2006100621892 A CN B2006100621892A CN 200610062189 A CN200610062189 A CN 200610062189A CN 100480791 C CN100480791 C CN 100480791C
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- inductance
- transistor
- circuit
- lcd
- electric capacity
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Abstract
The utility model relates to a booster circuit for a liquid crystal display, which comprises a step-up unit, a step-down unit and a dividing unit that are serially connected in order. The utility model is characterized in that an input voltage from the external power supply is converted into a working voltage required as the power supply of liquid crystal display by the step-up unit and the step-down unit, the working voltage is divided in the a plurality of levels by the dividing unit which comprises a plurality of resistors and a direct current chopper circuit with the function of stepping and stepping down, wherein a resistor is variable, the direct current chopper circuit is connected to the voltage output terminals between the two neighboring resistors and between the resistor and the earthing terminal and steps up or steps down the output voltage, then the driving voltage at each level for driving the liquid crystal display to display are output.
Description
Technical field
The present invention relates to a kind of LCD boosted circuit.
Background technology
Along with the widespread use of LCD, industry is more and more higher to the display quality requirement of LCD, especially aspect anti-crosstalking (Crosstalk) ability of LCD, very high requirement is arranged also.Crosstalk phenomenon is meant produced by the mutual interference of neighbor phase a kind of visible from metal patterns, its design performance with the characteristic of display panels itself and drive integrated circult (Drive Integrated Circuit) is relevant, has a strong impact on the display quality of picture.
Fig. 1 is a kind of circuit diagram of prior art LCD boosted circuit.This booster circuit 10 is arranged on the drive integrated circult of this LCD, and it can provide multistage voltage so that drive this LCD, and this multistage driving voltage is designated as V respectively
Op", V
1", V
2", V
3", V
4" and V
Ss".This booster circuit 10 comprises a boosting unit 12, a pressure unit 14 and a partial pressure unit 16 that is electrically connected successively.This boosting unit 12 will be from a low-voltage V of external circuit
Ci" convert a high voltage V to
1cd", and export it to this pressure unit 14.This pressure unit 14 is with this high voltage V
1cd" convert an operating voltage V to
Op", and export this partial pressure unit 16 to.This partial pressure unit 16 is by resistance R
4', R
3', R
w', R
2', R
1' be in series successively, wherein, resistance R
1', R
2', R
3', R
4' be substitutional resistance, resistance R
w' be a variable resistor.This resistance R
1' ground connection, and at this earth terminal GND place output one voltage V
Ss".This resistance R
2' with this resistance R
1' between output one voltage V
1".This resistance R
2' with this variable resistor R
w' between output one voltage V
2".This variable resistor R
w' with this resistance R
3' between output one voltage V
3".This resistance R
3' with this resistance R
4' between output one voltage V
4".
Because resistance R
1', R
2', R
3', R
4' resistance is identical, all is designated as R, default variable resistor R
w'=xR, x are any natural number, according to the series circuit voltage divider principle, can get each outputting drive voltage and are:
V
ss″＝0V；
V
1″＝(1/bias)×V
op″；
V
2″＝(2/bias)×V
op″；
V
3″＝(1-2/bias)×V
op″；
V
4″＝(1-1/bias)×V
op″；
Wherein, bias=(R
1'+R
2'+R
3'+R
4'+R
w')/R=4+x.
By above formula as can be known, each driving voltage V
1", V
2", V
3" and V
4" magnitude of voltage and operating voltage V
Op" relevant with the bias value.Therefore, only need regulate operating voltage V
Op" magnitude of voltage and bias value, i.e. each driving voltage V of may command
1", V
2", V
3" and V
4".At present, thus industry utilizes the switching frequency of software adjustment boosting unit 12 and pressure unit 14 to realize operating voltage V usually
Op" adjusting, and by regulating variable resistor R
wThereby ' resistance realize the adjusting of bias value.
Yet,, cause driving voltage V owing to when manufacturing and designing the drive integrated circult of LCD, have certain processing procedure defective
1", V
2", V
3", V
4" and the electromotive force of earth terminal GND is driving voltage V
Ss" upper and lower drift takes place, make the error of its actual value and theoretical value existence ± 0.15V.To have ± driving voltage of 0.15V error when driving LCD, can cause the image quality of this LCD not good, even can produce crosstalk phenomenon.
Summary of the invention
In order to solve in the prior art, be necessary to provide a kind of output voltage LCD boosted circuit accurately owing to the LCD boosted circuit output voltage does not precisely cause the not good problem of LCD picture quality.
A kind of LCD boosted circuit, it comprises a boosting unit of series connection in regular turn, one pressure unit and a partial pressure unit, this boosting unit and this pressure unit will convert the required operating voltage of this LCD device electric supply from the input voltage of external power source to, this partial pressure unit is carried out multistage dividing potential drop with this operating voltage, it is by a plurality of resistance in seriess and have the DC chopper circuit that boosts with buck functionality and constitute, wherein a resistance is variable resistor, and between adjacent two resistance and resistance and earth terminal, all has a power supply exit, this DC chopper circuit is series at each power supply exit respectively, and this output voltage boosted and reduction regulation, thereby output drives each required rank driving voltage of liquid crystal display displays.
Compared with prior art, the user only needs to regulate this transistorized ON time and turn-off time by software control, can realize boosting and reduction regulation via the driving voltage behind each electric resistance partial pressure, make driving voltage more near theoretical value, thereby reduce that original LCD boosted circuit produces ± the 0.15V error range, the approximate effect that reaches zero error effectively avoids taking place crosstalk phenomenon, guarantees the image quality of this LCD.
Description of drawings
Fig. 1 is a kind of circuit diagram of prior art LCD boosted circuit.
Fig. 2 is the structural drawing of LCD boosted circuit first embodiment of the present invention.
Fig. 3 is the circuit diagram of the stepping-up/stepping-down chopper circuit of LCD boosted circuit shown in Figure 2.
Fig. 4 is the circuit diagram of the Cuk chopper circuit that adopted of invention LCD boosted circuit second embodiment.
Fig. 5 is the circuit diagram of the Sepic DC chopper circuit that adopted of LCD boosted circuit the 3rd embodiment of the present invention.
Embodiment
Seeing also Fig. 2, is the circuit diagram of LCD boosted circuit first embodiment of the present invention.This booster circuit 20 is arranged on the drive integrated circult of this LCD, and it can provide multistage voltage so that drive this liquid crystal display displays, and this multistage voltage is V
Op, V
1, V
2, V
3, V
4And V
Ss
This booster circuit 20 comprises a boosting unit 22, a pressure unit 24 and a partial pressure unit 26 that is electrically connected successively.This boosting unit 22 will be from a low tension V of external circuit
CiConvert a high voltage V to
1cd, and export it to this pressure unit 24.This pressure unit 24 is with this high voltage V
1cdConvert an operating voltage V to
Op, and export this partial pressure unit 26 to.This partial pressure unit 26 is by resistance R
4, R
3, R
w, R
2, R
1Be in series successively, wherein, resistance R
1, R
2, R
3, R
4Be substitutional resistance, resistance R
wIt is a variable resistor.This resistance R
1Ground connection, resistance R
4Be electrically connected with this pressure unit 24, and in this resistance R
1And between the earth terminal GND, resistance R
1With R
2Between, resistance R
2With R
wBetween, resistance R
wWith R
3Between and resistance R
3With R
4Between all have a power supply exit 261,262,263,264 and 265, this power supply exit 261,262,263,264 and 265 stepping-up/stepping-down chopper circuit (Buck-Boost Chooper) 27 of connecting respectively makes the voltage V of this electricity exit 261,262,263,264 and 265 outputs
Ss', V
1', V
2', V
3' and V
4' calibrate via this stepping-up/stepping-down chopper circuit 27, thus output drives each required driving voltage V of liquid crystal display
Ss, V
4, V
3, V
2And V
1
Because resistance R
1, R
2, R
3, R
4Resistance is identical, all is designated as R, default variable resistor R
w=xR, x are any natural number, and according to the series circuit voltage divider principle, the output voltage that can get each power supply exit 261,262,263,264 and 265 is approximately:
V
ss′＝0V；
V
1′＝(1/bias)×V
op；
V
2′＝(2/bias)×V
op；
V
3′＝(1-2/bias)×V
op；
V
4′＝(1-1/bias)×V
op；
Wherein, bias=(R
1+ R
2+ R
3+ R
4+ R
w)/R=4+x.
Seeing also Fig. 3, is the circuit diagram of the stepping-up/stepping-down chopper circuit 27 of LCD boosted circuit 20 shown in Figure 2.Being connected with stepping-up/stepping-down chopper circuit 27 with this power supply exit 261 is example, and this stepping-up/stepping-down chopper circuit 27 is a voltage raising and reducing hybrid circuit, and it can be to voltage V
SsThereby ' boost with reduction regulation export one with the opposite polarity driving voltage V of voltage Vss '
SsThis stepping-up/stepping-down chopper circuit 27 comprises a transistor 271, a diode 272, an inductance 273 and an electric capacity 274, and the driving voltage Vss after calibration is via a first node 281 outputs between this diode 272 and this electric capacity 274.
This transistor 271 is that (Insulted Gate BipolarTransistor, IGBT), it comprises a base stage 2711, a collector 2712 and an emitter 2713 to an insulation grounded base transistor.This base stage 2711 is control ends of this transistor 271, and it is received from the periodic signal 290 that this drive integrated circult sends, thereby controls the conducting and the shutoff of this transistor 271 by the pulse width that changes this periodic signal 290.This collector 2712 is connected with this power supply exit 261.This emitter 2713 has two branch roads, the one branch road is via these inductance 273 ground connection, and another branch road is successively via mutual diode in series 272 and electric capacity 274 ground connection, wherein, the negative electrode 2721 of this diode 272 links to each other with emitter 2713, and anode 2722 links to each other with first node 281.
If the cycle of periodic signal 290 is T, this transistor 271 ON time t
On=kT, turn-off time t
Off=(1-k) T, then the principle of work of this stepping-up/stepping-down chopper circuit 27 is:
At 0≤t≤t
OnPeriod, these transistor 271 conductings, these diode 275 reverse bias turn-off, output voltage V
Ss' via this transistor 271 to 273 power supplies of this inductance and make its energy storage, this moment, the electric current by inductance 273 was I
L, this electric current I
LTo these electric capacity 274 chargings, then by driving voltage V
SsOutput terminal, electric capacity 274 and the loop conducting that constitutes of earth terminal GND.
At t
On≤ t≤t
OffPeriod, this transistor 271 turn-offs, and these inductance 273 energy storage finish, and to driving voltage V
SsOutput terminal release energy its driving voltage V
SsWith voltage V
Ss' polarity is opposite.
The output voltage of this stepping-up/stepping-down chopper circuit 27 is:
By following formula as seen, thus the user only need change the ON time and the turn-off time of this transistor 271 by the pulse width of software adjustment periodic signal 290, can realize voltage V
Ss' boost and reduction regulation, make driving voltage V
SsMore near theoretical value, thereby reduce that original LCD boosted circuit produces ± the 0.15V error range, the approximate effect that reaches zero error effectively avoids taking place crosstalk phenomenon, guarantees the image quality of this LCD.
Seeing also Fig. 4, is the circuit diagram of the Cuk chopper circuit that adopted of LCD boosted circuit second embodiment of the present invention.The booster circuit shown in this second embodiment and first embodiment are basic identical, and its difference is: this booster circuit adopts Cuk chopper circuit 37 as the voltage raising and reducing regulating circuit.
Being connected with Cuk chopper circuit 37 with a power supply exit 361 is example, and this Cuk chopper circuit 37 is a voltage raising and reducing hybrid circuit, and it can be to voltage V
SsThereby ' boost with reduction regulation export one with voltage V
Ss' opposite polarity driving voltage V
Ss
This Cuk chopper circuit 37 comprises a transistor 371, a diode 372, one first inductance 373, one second inductance 374 and an electric capacity 375, the driving voltage V after calibration
SsVia these second inductance, 374 outputs.This transistor 371 is an insulation grounded base transistor, and it comprises a base stage 3711, a collector 3712 and an emitter 3713.This base stage 3712 is control ends of this transistor 371, and it accepts the periodic signal 390 that sends from this drive integrated circult, thereby realizes the conducting and the shutoff of this transistor 371 of control by the pulse width that changes this periodic signal 390.This collector 3712 with link to each other these emitter 3713 ground connection at this first inductance 373 with a first node 381 between this electric capacity 375.This voltage V
Ss' having two circulation branch roads, the one branch road is connected to this driving voltage V via this first inductance 373, this electric capacity 375 and this second inductance 374 successively
SsOutput terminal.Another branch road is connected in ground via the anode 3721 and the negative electrode 3722 of this first inductance 373, this electric capacity 375, this diode 372 successively.
If the minimum period of periodic signal 390 is T, this transistor 371 ON time t
On=kT, turn-off time t
Off=(1-k) T, then the principle of work of this Cuk DC chopper circuit 37 is:
At 0≤t≤t
OnPeriod, these transistor 371 conductings, electric current is via 375 chargings of 373 pairs of these electric capacity of this first inductance, and charging voltage makes these diode 372 reverse bias and turn-offs, and makes this second inductance, 374 energy storage.
At t
On≤ t≤t
OffPeriod, this transistor 371 turn-offs, and these electric capacity 375 discharges make this diode 372 forward conductions, and this second inductance 374 releases energy to driving voltage V
SsOutput terminal.
The output voltage of this Cuk chopper circuit 37 is:
Seeing also Fig. 5, is the circuit diagram of the Sepic chopper circuit that adopted of LCD boosted circuit the 3rd embodiment of the present invention.The booster circuit shown in the 3rd embodiment and first embodiment are basic identical, and its difference is: this booster circuit adopts a Sepic chopper circuit 47 as the buck regulating circuit.
Being connected with Sepic chopper circuit 47 with a power supply exit 461 is example, and this Sepic chopper circuit 47 is a voltage raising and reducing hybrid circuit, and it can be to voltage V
SsThereby ' boost with reduction regulation export one with voltage V
SsThe driving voltage V that ' polarity is identical
Ss
This Sepic chopper circuit 47 comprises a transistor 471, a diode 472, one first electric capacity 473, one second electric capacity 474, one first inductance 475 and one second inductance 476, driving voltage V
Ss First node 481 outputs via 474 of these diode 472 negative electrodes 4721 and this second electric capacity.This transistor 471 is an insulation grounded base transistor, and it comprises a base stage 4711, a collector 4712 and an emitter 4713.This base stage 4711 is control ends of this transistor 471, and the periodic signal 490 that its acceptance is sent from this drive integrated circult is realized the conducting and the shutoff of this transistor 471 of control by the pulse width that changes this periodic signal 490.This collector 4712 be positioned at this first inductance 475 and link to each other these emitter 4713 ground connection with a Section Point 482 of 473 of this first electric capacity.The voltage V of these power supply exit 461 outputs
Ss' having two circulation branch roads, the one branch road is connected in ground via this first inductance 475, this first electric capacity 473 and this second inductance 476 successively; Another branch road is connected in ground via anode 4721, negative electrode 4722 and this second electric capacity 474 of this first inductance 475, this first electric capacity 473, this diode 472 successively.
If the minimum period of periodic signal 490 is T, this transistor 471 ON time t
On=kT, turn-off time t
Off=(1-k) T, then the principle of work of this Sepic chopper circuit 47 is:
At 0≤t≤t
OnPeriod, these transistor 471 conductings, the electric current of this power supply exit 461 this first inductance 475 of flowing through makes this first inductance, 475 energy storage, and this first electric capacity 473 charged, charging voltage makes these diode 472 reverse bias and turn-offs, charging current this second inductance 476 of flowing through then, these second inductance, 476 energy storage.
At t
On≤ t≤t
OffPeriod, this transistor 471 turn-offs, and these first electric capacity, 473 discharges make this diode 472 conductings, and this first inductance 475 and second inductance 476 are simultaneously to this driving voltage V
SsOutput terminal release energy.
The outputting drive voltage of this Sepic chopper circuit 47 is:
By following formula as can be known, the user only needs by the pulse width of software adjustment by this periodic signal 490, thereby changes the conducting and the turn-off time of this transistor 471, can realize voltage V
Ss' boost and reduction regulation, make driving voltage V
SsMore near theoretical value, thereby reach the effect that reduces error, avoid crosstalk phenomenon to produce, guarantee the display quality of this LCD.In addition, because the driving voltage V of these Sepic chopper circuit 47 outputs
SsVoltage V with power supply leading-in end 461
Ss' polarity is identical, when therefore carrying out the load connection, and need not be with the load reversal connection at this driving voltage V
SsOutput.
In the above-mentioned LCD boosted circuit, circuit structure with voltage raising and reducing regulatory function also can be made of other DC chopper circuit (DC-DCChopper) with voltage raising and reducing function, and this DC chopper circuit is the circuit structure that constitutes by as the transistor of on-off element, the electric capacity with power transfer function or inductance element.
Claims (10)
1. LCD boosted circuit, it comprises a boosting unit of series connection in regular turn, one pressure unit and a partial pressure unit, this boosting unit and this pressure unit will convert the required operating voltage of this LCD device electric supply from the input voltage of external power source to, this partial pressure unit is carried out multistage dividing potential drop with this operating voltage, it is made of a plurality of resistance in seriess, wherein a resistance is variable resistor, and between adjacent two resistance and resistance and earth terminal, all has a power supply exit, it is characterized in that: this partial pressure unit further comprises having boosts and the DC chopper circuit of buck functionality, it is series at each power supply exit respectively, and this output voltage boosted and reduction regulation, thereby output drives each required rank driving voltage of liquid crystal display displays.
2. LCD boosted circuit as claimed in claim 1, it is characterized in that: this DC chopper circuit is a stepping-up/stepping-down chopper circuit, this stepping-up/stepping-down chopper circuit comprises a transistor, a diode, an inductance and an electric capacity, exporting each rank driving voltage exports via the first node between this diode and this electric capacity, each element constitutes two branch roads, the one branch road is successively via this transistor and this inductance ground connection, and another branch road is successively via this transistor, this diode and this capacity earth.
3. LCD boosted circuit as claimed in claim 2, it is characterized in that: this transistor is an insulation grounded base transistor, it comprises a base stage, a collector and an emitter, this base stage is this transistorized control end, be received from the periodic signal that booster circuit sends, this collector is connected this power supply exit, and this emitter has two branch roads, the one branch road is via this inductance ground connection, and another branch road is successively via negative electrode, anode and the capacity earth of this diode.
4. LCD boosted circuit as claimed in claim 3 is characterized in that: this transistor is as an on-off element, and this electric capacity is as an energy transmission.
5. LCD boosted circuit as claimed in claim 1, it is characterized in that: this DC chopper circuit is a Cuk chopper circuit, this Cuk chopper circuit comprises a transistor, one diode, one first inductance, one second inductance and an electric capacity, this driving voltage is via this second inductance output, this first inductance is connected in this power supply exit and between the first node between this first inductance and this electric capacity, this transistor is connected between this first node and the earth terminal, the electric current of this first inductance of flowing through has two branch roads, via this electric capacity and this second inductance output terminal to respective drive voltage, another branch road is successively via this electric capacity successively for the one branch road, the anode and the negative electrode of this diode are connected to ground.
6. LCD boosted circuit as claimed in claim 5, it is characterized in that: this transistor is an insulation grounded base transistor, it comprises a base stage, a collector and an emitter, this base stage is the control end of this transistor, it is received from the pulse signal that this booster circuit sends, this collector links to each other with this first node, this grounded emitter.
7. LCD boosted circuit as claimed in claim 6 is characterized in that: this transistor is as on-off element, and this second inductance is as energy transmission.
8. LCD boosted circuit as claimed in claim 1, it is characterized in that: this DC chopper circuit is a Sepic chopper circuit, it comprises a transistor, one diode, one first electric capacity, one second electric capacity, one first inductance and one second inductance, this driving voltage is exported via the first node between this diode and this second electric capacity, the electric current of this first inductance of flowing through has two branch roads, the one branch road is connected in ground via this first electric capacity and this second inductance successively, another branch road is successively via this first electric capacity, the anode of this diode, negative electrode and this second electric capacity are connected in ground, and this transistor is connected between the Section Point and ground between this first inductance and this first electric capacity.
9. LCD boosted circuit as claimed in claim 8, it is characterized in that: this transistor is an insulation grounded base transistor, it comprises a base stage, a collector and an emitter, this base stage is this transistorized control end, it is received from the pulse signal that this booster circuit sends, this collector links to each other with this Section Point, this grounded emitter.
10. LCD boosted circuit as claimed in claim 9 is characterized in that: this transistor is as on-off element, and this first inductance and this second inductance are as energy transmission.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2006100621892A CN100480791C (en) | 2006-08-18 | 2006-08-18 | LCD boosted circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2006100621892A CN100480791C (en) | 2006-08-18 | 2006-08-18 | LCD boosted circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101126846A CN101126846A (en) | 2008-02-20 |
| CN100480791C true CN100480791C (en) | 2009-04-22 |
Family
ID=39094918
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2006100621892A Expired - Fee Related CN100480791C (en) | 2006-08-18 | 2006-08-18 | LCD boosted circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN100480791C (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102857155B (en) * | 2011-06-30 | 2016-03-02 | 费月升 | A kind of buck-boost dual-motor parallel controller |
| CN107256698B (en) * | 2013-12-06 | 2021-04-06 | 矽创电子股份有限公司 | Driving circuit of display panel, driving module of driving circuit, display device and manufacturing method of display device |
| CN105489181B (en) | 2016-01-04 | 2019-03-12 | 京东方科技集团股份有限公司 | Cut-in voltage supply circuit, method, defect analysis method and display device |
| CN109192127B (en) * | 2018-10-29 | 2022-06-24 | 合肥鑫晟光电科技有限公司 | Time schedule controller, driving method thereof and display device |
-
2006
- 2006-08-18 CN CNB2006100621892A patent/CN100480791C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CN101126846A (en) | 2008-02-20 |
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Granted publication date: 20090422 Termination date: 20170818 |