CN104616632B - A kind of liquid crystal display drive circuit and driving method for preventing lower electric ghost - Google Patents
A kind of liquid crystal display drive circuit and driving method for preventing lower electric ghost Download PDFInfo
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- CN104616632B CN104616632B CN201510083181.3A CN201510083181A CN104616632B CN 104616632 B CN104616632 B CN 104616632B CN 201510083181 A CN201510083181 A CN 201510083181A CN 104616632 B CN104616632 B CN 104616632B
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- 239000004973 liquid crystal related substance Substances 0.000 title claims abstract description 45
- 238000000034 method Methods 0.000 title claims abstract description 15
- 230000005611 electricity Effects 0.000 claims abstract description 52
- 239000000872 buffer Substances 0.000 claims description 95
- 238000001514 detection method Methods 0.000 claims description 9
- 238000007689 inspection Methods 0.000 claims description 2
- 230000000694 effects Effects 0.000 abstract description 7
- 230000001360 synchronised effect Effects 0.000 abstract description 4
- 230000008878 coupling Effects 0.000 description 11
- 238000010168 coupling process Methods 0.000 description 11
- 238000005859 coupling reaction Methods 0.000 description 11
- 238000010586 diagram Methods 0.000 description 8
- 230000003139 buffering effect Effects 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 4
- 239000000203 mixture Substances 0.000 description 3
- 230000003247 decreasing effect Effects 0.000 description 2
- 238000003491 array Methods 0.000 description 1
- 239000003086 colorant Substances 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 235000013399 edible fruits Nutrition 0.000 description 1
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Abstract
The invention discloses a kind of liquid crystal display drive circuit and driving method for preventing lower electric ghost, the drive circuit includes source circuit, for exporting a first voltage to multiple pixel electrodes；Common-battery volt circuit, for exporting a second voltage to common electrode；And switching circuit；Wherein, under system during electricity a to threshold value, by the effect of the switching circuit, the output of the source circuit is coupled to the output of the common-battery volt circuit together with synchronous discharge.The present invention couples the output of source circuit and the output of common electric voltage circuit during electricity a to threshold value under system, so can synchronously it be discharged, and then ensure that pressure difference is zero between the pixel electrode and public electrode of display panel after lower electricity, avoids lower electric ghost problem.Further, since this programme is only that the output of source circuit and the output of common electric voltage circuit link together, and without original source circuit and common electric voltage circuit are made and significantly changed, implement more easy.
Description
Technical field
The present invention relates to a kind of liquid crystal display drive circuit and driving method, more particularly to one kind can effectively prevent lower electricity
The liquid crystal display drive circuit and driving method of ghost.
Background technology
Liquid crystal display is because of its frivolous, radiationless, low power consumption, service life is long, picture is soft does not hinder the characteristics such as eye, each
It is at a relatively high using occupation rate in application field.Wherein with the tft type liquid crystal display (TFT-LCD) of active matric-type
For the main flow of in the market.
General TFT-LCD mainly includes display panel and display driver circuit.The schematic diagram of display panel as shown in figure 1,
In the whole framework of liquid crystal display panel 1, there are multiple pixels 11 arranged in arrays.Single sub-pixel (sub-pixel)
Circuit diagram is as shown in Fig. 2 transistor (TFT) Q grid level G provides control signal by gate driving circuit, and source S is by source
Polar circuit provides the data-signal of display, and drain D connects show electrode.Gate driving circuit according to provide voltage level height come
Controlling transistor Q closure and shut-off.When grid G voltage is high level, transistor Q closures, source circuit provides to source S
The data-signal of display be sent to show electrode.Between show electrode and common electrode electric capacity for parasitic liquid crystal capacitance Clc and
Storage capacitance Cs.Liquid crystal display content is determined by the pressure difference between show electrode and common electrode.
One base pixel (pixel) represents RGB three primary colors respectively, it is necessary to three sub-pixel (sub-pixel) compositions.
Its operation principle is the waveform sent out by gate driving circuit, successively opens the TFT of every a line, and source circuit will need aobvious
The data shown are sent to the TFT of this journey source S end, and the voltage for representing data is transferred into show electrode by TFT, and show not
Same gray scale.After this journey is charged, gate driving circuit stops providing voltage to this journey, by the gate driving circuit of next line
Voltage is provided to next line, then discharge and recharge is carried out to the show electrode of next line by source circuit.So sequentially go down, when substituting the bad for the good
The pixel of last column, a frame picture show completion completely.
In the liquid crystal panel module of TV or display, TFT grid G end is driven by gate driving circuit, source
Pole S ends are driven by source circuit 31, and common-battery extremely then provides voltage by common electric voltage circuit 32.When electricity order under system
After sending, system power supply starts to discharge to ground, and now source circuit 31 checks opening for output end electric under supply voltage, all
Close merging and connect together and discharged over the ground, as shown in Figure 3A.Common-battery volt circuit 32 is discharged by inside, such as Fig. 3 B
It is shown.But due to the difference that source circuit 31 and common-battery volt circuit 32 are set, the output fall off rate of source circuit 31 is with altogether
The fall off rate that potential circuit 32 exports is inconsistent, certain pressure difference between it be present, result in pixel electrode and common electrode it
Between pressure difference be present, waveform is as shown in Figure 4.The phenomenon then seen on liquid crystal panel is：After lower electricity order, Display panel is black picture
It is light again afterwards, finally slowly secretly go down or flower screen after secretly go down again, this phenomenon is referred to as ghost.
The content of the invention
The problem of existing for prior art, an object of the present invention are that electricity need not be driven to existing by providing one kind
Road is significantly changed, is easy to implement, and can effectively prevent the liquid crystal display drive circuit of lower electric ghost.
Another object of the present invention is to provide a kind of method for driving liquid crystal display that can effectively prevent lower electric ghost.
To achieve the above object, under preventing of the invention electric ghost liquid crystal display drive circuit, including：
Source circuit, for exporting a first voltage to multiple pixel electrodes；
Common-battery volt circuit, for exporting a second voltage to common electrode；And
Switching circuit；
Wherein, under system during electricity a to threshold value, by the effect of the switching circuit, by the output of the source circuit
Together with output with the common-battery volt circuit is coupled to.
Further, the output of the source circuit couples via the output of a first resistor element and the common-battery volt circuit
To together.
Further, the source circuit includes multiple first buffers, and each first buffer passes through a first via
Footpath one of exports the first voltage to the multiple pixel electrode；Under system during electricity to the threshold value, by described
The control of switching circuit, each first buffer is by one second path by the output of the source circuit via a first resistor
Together with element is coupled to the output of the common-battery volt circuit.
Further, the source circuit includes multiple first buffers, and the output end of each first buffer is corresponding
Couple one of the multiple pixel electrode；The switching circuit includes multiple switch element, and the of the multiple switch element
One end is correspondingly coupled to the output end of the multiple first buffer, and the second end of the multiple switch element passes through described
One resistive element and the output of the common-battery volt circuit couple；Under system during electricity to the threshold value, the multiple switch element
Close to form second path, by the output end of the multiple first buffer via the first resistor element and institute
The output for stating common-battery volt circuit is coupled to together.
Further, the common-battery volt circuit includes one second buffer, the output end coupling of the multiple first buffer
In the first end of the first resistor element, the output end of second buffer is coupled to the second of the first resistor element
End, the output of the source circuit is coupled to the output of the common-battery volt circuit together with.
Further, the liquid crystal display drive circuit also includes：
Power circuit, for providing voltage to the source circuit and the common-battery volt circuit；
Circuit is detected, when the voltage for detecting the power circuit offer drops to a predetermined voltage, described in judgement
Electricity sends the first control signal to the threshold value, and to the switching circuit under system, and the output of the source circuit is passed through
Together with being coupled to by a first resistor element with the output of the common-battery volt circuit.
Further, the detection circuit, it is additionally operable to detect that the voltage that the power circuit provides drops to described make a reservation for
During voltage, the second control signal is sent to the multiple first buffer and second buffer.
Further, when the voltage that the detection electric circuit inspection provides to the power circuit drops to the predetermined voltage
When, second buffer of the multiple first buffer and the common-battery volt circuit to the source circuit sends described
Second control signal turns off first buffer and second buffer, and to the multiple switch of the switching circuit
Element sends first control signal and closes the multiple switch element, makes the output short circuit of the multiple first buffer,
Coupled again via the output end of the first resistor element and second buffer.
Further, between second end of the multiple switch element and the first end of the first resistor element
The first end of second resistance element is also coupled to, the second end of the second resistance element controls and is grounded via first switching element
End coupling；When the voltage for detecting that the power circuit provides drops to the predetermined voltage, the detection circuit is to described
First switching element sends the 3rd control signal and closes the first switching element, with via where the second resistance element
Branch road discharges simultaneously.
Further, the source circuit and the switching circuit are arranged on the first chip, and the common-battery volt circuit is set
In on the second chip, and first chip and second chip are separate chip.
Further, the first resistor element is arranged in first chip.
Further, the first resistor element is arranged on the pcb board outside first chip and second chip.
Further, the source circuit, the switching circuit and the common-battery volt circuit are integrated on same 3rd chip.
Further, the first resistor element is integrated in the 3rd chip.
The liquid crystal display drive circuit of electric ghost under the preventing of the present invention, including：
Source circuit, for exporting a first voltage to multiple pixel electrodes；
Common-battery volt circuit, for exporting a second voltage to common electrode；And
Switching circuit；
Wherein, under system during electricity a to threshold value, by the effect of the switching circuit, by the output of the source circuit
Earth terminal is coupled to via a 3rd resistor element, the output of the common-battery volt circuit is coupled to via one the 4th resistive element
Earth terminal, and the resistance of the 3rd resistor element and the 4th resistive element is configured with predetermined ratio, so that the source
The output of polar circuit is consistent with the output discharge rate of the common-battery volt circuit.
Further, the switching circuit includes the 3rd switch element and the 4th switch element, the 3rd switch element coupling
It is connected between the 3rd resistor element and the earth terminal, the 4th switch element is coupled to the 4th resistive element and institute
State between earth terminal.
Further, the source circuit and the common-battery volt circuit are integrated on same 3rd chip；The source circuit
Including multiple first buffers, the common-battery volt circuit includes one second buffer；Each first buffer passes through one the
One path one of exports the first voltage to the multiple pixel electrode；Under system during electricity to the threshold value, pass through
The effect of the switching circuit, the output end of each first buffer are coupled to earth terminal by the 3rd resistor element, institute
The output end for stating the second buffer is coupled to earth terminal by the 4th resistive element.
The method for driving liquid crystal display of electric ghost under the preventing of the present invention, for including source circuit and common-battery volt circuit
The driving of liquid crystal display circuit, the source circuit are used to export a first voltage, the common-battery piezoelectricity to multiple pixel electrodes
Road, for exporting a second voltage to common electrode, it is characterised in that comprise the following steps：
Whether detecting system is lower electric to a threshold value；
When detecting electricity to the threshold value under system, by the effect of switching circuit, by the output of source circuit together
The output of potential circuit is coupled to together.
Further, the source circuit includes multiple first buffers, and each first buffer passes through a first via
Footpath one of exports first voltage to the multiple pixel electrode；Under the system that detects during electricity to the threshold value, pass through institute
The effect of switching circuit is stated, each first buffer is by one second path by the output of the source circuit via one first electricity
Together with resistance element is coupled to the output of the common-battery volt circuit.
Further, the source circuit includes multiple first buffers, and the output end of each first buffer is corresponding
Couple one of the multiple pixel electrode；The switching circuit includes multiple switch element, and the of the multiple switch element
One end is correspondingly coupled to the output end of the multiple first buffer, and the second end of the multiple switch element passes through one first
Resistive element and the output of the common-battery volt circuit couple；Under the system that detects during electricity to the threshold value, the multiple switch
Element is closed to form second path, by the output end of the multiple first buffer via a first resistor element with
The output of the common-battery volt circuit is coupled to together.
Further, the common-battery volt circuit includes one second buffer, the output end coupling of the multiple first buffer
In the first end of the first resistor element, the output end of second buffer is coupled to the second of the first resistor element
End, the output of the source circuit is coupled to the output of the common-battery volt circuit together with.
Further, the whether lower electricity of the detecting system a to threshold value comprises the following steps：
Detect the voltage that power circuit provides；
By the voltage that power circuit provides compared with a predetermined voltage；
Judge the whether lower electricity of system to the threshold value according to comparative result.
Further, the driving method also includes when detecting electricity to the threshold value under system, to the switching circuit
The first control signal is sent, the output by the output of the source circuit via a first resistor element and the common-battery volt circuit
It is coupled to together.
Further, the driving method also includes when detecting electricity to the threshold value under system, to the source circuit
Multiple first buffers and the second buffer of the common electric voltage circuit to send the second control signal shut-off described first slow
Device and second buffer are rushed, and sends first control signal to the multiple switch element of the switching circuit and closes institute
Multiple switch element is stated, makes the output short circuit of the multiple first buffer, then via the first resistor element and described the
The output coupling of two buffers.
Further, between second end of the multiple switch element and the first end of the first resistor element
The first end of second resistance element is also coupled to, the second end of the second resistance element controls and is grounded via first switching element
End coupling；Under the system that detects during electricity to the threshold value, the 3rd control signal closure institute is sent to the first switching element
First switching element is stated, to be discharged via the branch road where the second resistance element simultaneously.
The present invention couples the output of source circuit and the output of common electric voltage circuit during electricity a to threshold value under system, such as
This can synchronously be discharged, and then ensure that pressure difference is zero between the pixel electrode and public electrode of display panel after lower electricity, is kept away
Lower electric ghost problem is exempted from.Further, since this programme is only to be connected the output of source circuit with the output of common electric voltage circuit
Together, and without original source circuit and common electric voltage circuit are made and significantly changed, implement more easy.
Brief description of the drawings
Fig. 1 is the structural representation of liquid crystal display panel；
Fig. 2 is the circuit diagram of single sub-pixel in liquid crystal display panel；
Fig. 3 A are the electric discharge schematic diagram of source circuit in the existing liquid crystal display drive circuit when lower electric；
Fig. 3 B are the electric discharge schematic diagram of common-battery volt circuit in the existing liquid crystal display drive circuit when lower electric；
Fig. 4 is the waveform diagram of electric ghost phenomena under occurring；
Fig. 5 is the schematic diagram of the liquid crystal display drive circuit of one embodiment of the invention；
Fig. 6 is the structural representation of source circuit in liquid crystal display drive circuit；
Fig. 7-Fig. 8 collects respectively for source circuit in the liquid crystal display drive circuit of one embodiment of the invention and common-battery volt circuit
Into in the structural representation of two individual chips；
Fig. 9-Figure 11 integrates for source circuit in the liquid crystal display drive circuit of one embodiment of the invention and common-battery volt circuit
In the structural representation of same chip；
Figure 12 is the discharge waveform schematic diagram of the liquid crystal display drive circuit of the present invention.
Embodiment
To enable those skilled in the art to be further understood that, the present invention is exemplified below presently preferred embodiments of the present invention, and matches somebody with somebody
Accompanying drawing appended by conjunction, describe the constitution content of the present invention in detail.For convenience of explanation, each accompanying drawing of the invention is only to illustrate more to hold
The readily apparent present invention, its detailed ratio can be adjusted according to the demand of design.
As shown in figure 5, the present invention preventing under electric ghost liquid crystal display drive circuit 3, including：
Source circuit 31, for exporting gray scale voltage, i.e. first voltage to multiple pixel electrodes of display panel；
Common-battery volt circuit 32, for the common electrode outputting common voltage of display panel, i.e. second voltage；And
Switching circuit 33；
Wherein, under system during electricity a to threshold value, by the effect of the switching circuit 33, by the defeated of the source circuit
Go out together with being coupled to the output of the common-battery volt circuit, with synchronous discharge, and then make the pixel electrode and the common electrode
Between pressure difference be 0.
The present embodiment makes the output for exporting potential circuit together of source circuit be coupled to one by the control of switching circuit
Rise, so as to so that source circuit potential circuit synchronous discharge with electricity under system together so that the two discharge rate basic one
Cause, can avoid due between pixel electrode and common electrode pressure difference it is inconsistent caused by under electric ghost problem.
Source circuit 31 may include multiple source electrode buffers (Source buffer), i.e., the first buffering in above-described embodiment
Device 311.Each first buffer 311 one of is exported gray scale voltage to the multiple pixel electrode by first path D1；
Under system during electricity a to threshold value, by the control of switching circuit 33, each first buffer 311 will by one second path D2
The output of source circuit 31 is coupled to together via the output of first resistor element R potential circuits 32 together.Wherein, the first buffering
The quantity of device 311 is determined by the number of the pixel of a line.
In one embodiment of this invention, the output terminals A 1 of each first buffer 311 is corresponding couples the multiple pixel
One of electrode；Switching circuit 33 includes multiple switch element M2, and multiple switch element M2 first end is correspondingly coupled to multiple
The output terminals A 1 of first buffer 311, multiple switch element M2 the second end pass through a first resistor element R and common voltage electricity
The output on road 32 is coupled to together；Under system during electricity a to threshold value, multiple switch element M2 is closed to form the second path
D2, the output coupling by the output terminals A 1 of the multiple first buffer 311 via first resistor element R potential circuits 32 together
It is connected to together.
The present embodiment compares a upper embodiment, the composition structure to switching circuit 33 and the annexation with other circuits
Done specific restriction, but the composition of switching circuit and annexation are not limited with this embodiment, it is every can when lower electric
By the output of source circuit 31, potential circuit 32 is coupled to any switching circuit structure together, or switching circuit connection side together
Formula can be used.In addition, switch element M2 type is generally electronic switch, such as IGCT (SCR) in the present embodiment
Deng.
As shown in Figure 6, it is shown that the structural representation of source circuit 31.Source circuit 31 is except including the multiple first bufferings
Outside device 311, in addition to serioparallel exchange unit (Serial To Parallel Convertor), Latch units, DAC units.Its
In, the basic functional principle of source circuit：It is timely that source circuit receives the HSSI High-Speed Serial Interface data that timing control unit is sent
Clock signal, and parallel data is converted serial data into by serioparallel exchange unit.Shift register (not shown) exports
SR signals parallel data is sequentially transmitted in the DAC of respective respective channel by Latch circuits, this data selection Gamma
The Gamma reference voltages VGM of buffer outputs<N>, the input of the first buffer 311 is output to, will by the first buffer 311
Source electrode of this voltage (gray scale voltage) driving to TFT.
In above-described embodiment, common-battery volt circuit 32 may include common-battery compression buffer (VCOM buffer), i.e. the second buffer
321, the output terminals As 1 of multiple first buffers 311 is coupled to first resistor element R first end, the second buffer 321 it is defeated
Go out end and be coupled to first resistor element R the second end, while earth terminal is connected to via an electric capacity of voltage regulation C1.
In one embodiment of this invention, liquid crystal display drive circuit 3 also includes：
Power circuit (not shown), for providing voltage to source circuit 31 and common-battery volt circuit 32；
Circuit 34 is detected, when the voltage for detecting the power circuit offer is down to a predetermined voltage, decision-making system
Lower electricity sends the first control signal S1 to the threshold value, and to switching circuit 33, by the output of source circuit 31 via one first
The output of resistive element R potential circuits 32 together is coupled to together and is connected to earth terminal.In liquid crystal driving in the present embodiment
The detection circuit 34 of the whether lower electricity of increase detecting system in addition in circuit, while can also accurately be controlled by detecting circuit 34 and cut
Change the switch motion of circuit 33.The whether lower electricity of the detecting system of circuit 34 is detected in the present embodiment to threshold value is carried according to power circuit
The voltage of confession is judged that the right present invention is not limited thereto with a predetermined voltage comparative result, detects the detecting system of circuit 34
Down whether electricity a to threshold value can also be according to the fall off rate of power circuit voltage and the comparison knot of a predetermined voltage fall off rate
Fruit judges.
In another embodiment, circuit 34 is detected, it is predetermined to be additionally operable to detect that voltage that the power circuit provides is down to
During voltage, the second control signal S2 is sent to turn off the first buffer to multiple buffers 321 of first buffer 311 and second
311 and second buffer 321, its output be in high-impedance state, and described in sending to the multiple switch element M2 of switching circuit 33
First control signal S1 closes multiple switch element M2, makes the short circuit of output terminals A 1 of multiple first buffers 311, then via first
The output coupling of resistive element R and the second buffer 321.In the present embodiment, the voltage of the power circuit offer is being detected
When being down to predetermined voltage, detection circuit 34 can send the second control signal S2 to the first buffer 311 and the second buffer 321
The two is in high-impedance state for control, while sends the first control signal S1 so that multiple switch element M2 is closed to switch element M2
Close.However, the present invention is not limited thereto, may be selected when the voltage for detecting that the power circuit provides is down to predetermined voltage
Ground only sends the first signal to switch element M2, without sending the second control signal to the first buffer and the second buffer.Its
In, the first control signal S1 and the second control signal S2 belong to detection circuit 34 and sent to the same class signal of different elements, the
One control signal S1 and the second control signal S2 are interpreted as same signal herein, but the present embodiment is not limited thereto.
In one embodiment of this invention, multiple switch element M2 the second end and first resistor element R first end it
Between be also coupled to second resistance element R1 first end, second resistance element R1 the second end via first switching element M1 controls with
Ground terminal；When the voltage for detecting that the power circuit provides is down to predetermined voltage, circuit 34 is detected to first switch
Element M1 send the 3rd control signal S3 closure first switching element M1, with via the branch road where second resistance element R1 simultaneously
Electric discharge.The present embodiment adds a discharge paths in addition in liquid crystal display drive circuit, it is possible thereby to accelerate source circuit and
The velocity of discharge of common-battery volt circuit.
In one embodiment of this invention, as shown in fig. 7, switching circuit 33 and source circuit 31 are integrated in the first chip 41
On, common-battery volt circuit 32 is arranged on the second chip 42, and the first chip 41 and the second chip 42 are separate chip.
In addition, first resistor element R can also be integrated in the first chip 41 simultaneously.As shown in figure 8, first resistor element R can be with
It is selectively arranged in the pcb board (not shown) outside the first chip 41 and the second chip 42.
In another embodiment of the invention, as shown in figure 9, source circuit 31, common-battery volt circuit 32 and switching circuit 33
It is integrated on same 3rd chip 43.In addition, first resistor element R is integrated in the 3rd chip 43.
In one embodiment of this invention, as shown in Figure 10, second resistance element R1 is also integrated in by it compared with Fig. 9
In three chips 43.
In one embodiment of this invention, as shown in figure 11, source circuit 31 and common-battery volt circuit 32 are integrated in same
On three chips 43；The source circuit 31 includes multiple first buffers 311, and the common-battery volt circuit 32 includes one second buffering
Device 321；Gray scale voltage is exported into the multiple pixel electrode it by each first buffer 311 by a first path
One；Under the system that detects during electricity to the threshold value, by the control of the switching circuit 33, each first buffer 311 is logical
Cross a 3rd resistor element R1 and be coupled to earth terminal, second buffer 321 is coupled to by one the 4th resistive element R2 and connect
Ground terminal, the 3rd resistor element R1 and the 4th resistive element R2 are configured with predetermined ratio.The present embodiment passes through the 3rd electricity
Resistance element R1 and the 4th resistive element R2 are configured with predetermined ratio, can regard output and the common-battery piezoelectricity for making source circuit indirectly as
The output coupling on road, so that the output of the source circuit 31 is consistent with the output discharge rate of the common-battery volt circuit 32.
The liquid crystal display drive circuit of the present invention is described in detail above by specific embodiment.Referring to upper
The liquid crystal display drive circuit of embodiment is stated, its method for driving liquid crystal display is described further.
The method for driving liquid crystal display of the present invention comprises the following steps：
Whether detecting system is lower electric to a threshold value；
When detecting electricity to the threshold value under system, by the control of switching circuit 33, by the output of source circuit 31
Together potential circuit 32 output coupling, with synchronous discharge, so make pixel electrode together interelectrode pressure difference be 0.
Wherein, the whether lower electricity of the detecting system a to threshold value comprises the following steps：
Detect the voltage that power circuit provides；
By the voltage that power circuit provides compared with a predetermined voltage；
Judge the whether lower electricity of system to the threshold value according to comparative result.
The whether lower electricity of detecting system of the present invention to the step of threshold value, is not limited to above-described embodiment, and it can also be：
Detect the voltage decreasing rate that power circuit provides；
By the voltage decreasing rate that power circuit provides compared with a predetermined voltage fall off rate；
Judge the whether lower electricity of system to the threshold value according to comparative result.
In one embodiment of this invention, the driving method also includes when detecting electricity to the threshold value under system,
The first control signal is sent to switching circuit 33, by the output of source circuit 31 via a first resistor element R and common voltage electricity
The output coupling on road 32 is together.
In one embodiment of this invention, the driving method also includes when detecting electricity to the threshold value under system,
Second buffer of multiple first buffers and the common electric voltage circuit to the source circuit sends the second control signal
First buffer and second buffer are turned off, and described first is sent to the multiple switch element of the switching circuit
Control signal closes the multiple switch element, makes the output short circuit of the multiple first buffer, then via the described first electricity
The output of resistance element and second buffer couples.
In another embodiment of the invention, under the system that detects during electricity to the threshold value, circuit 34 to first is detected
Switch element M1 sends the 3rd control signal closure first switching element M1, with same via the branch road where second resistance element R1
Shi Fang electricity, to accelerate the velocity of discharge of source circuit and common-battery volt circuit.
The present invention couples the output of source circuit and the output of common electric voltage circuit during electricity a to threshold value under system, such as
This can synchronously be discharged, and then ensure that pressure difference is zero between the pixel electrode and public electrode of display panel after lower electricity, is put
Electrical schematic is as shown in figure 12, avoids lower electric ghost problem.Further, since this programme is only by the output of source circuit and public affairs
The output of common-battery volt circuit links together, and without original source circuit and common electric voltage circuit are made and significantly changed, it is real
Now get up more easy.
The illustrative embodiments of the present invention are particularly shown and described above.It should be understood that the invention is not restricted to institute
Disclosed embodiment, on the contrary, it is intended to cover comprising various modifications within the scope of the appended claims and equivalent put
Change.
Claims (7)
- A kind of 1. liquid crystal display drive circuit for preventing lower electric ghost, it is characterised in that including：Source circuit, for exporting a first voltage to multiple pixel electrodes, the source circuit includes multiple first buffers, Each first buffer one of is exported the first voltage to the multiple pixel electrode by a first path；Common-battery volt circuit, for exporting a second voltage to common electrode, the common-battery volt circuit includes one second buffer；AndSwitching circuit, including multiple switch element, the first end of the multiple switch element are correspondingly coupled to the multiple first The output end of buffer, the second end of the multiple switch element pass through a first resistor element and second buffer Output end couples；Wherein, under system during electricity a to threshold value, the multiple switch element is closed to form one second path, will be described more Together with the output end of individual first buffer is coupled to via the first resistor element with the output end of second buffer.
- 2. liquid crystal display drive circuit as claimed in claim 1, it is characterised in that the liquid crystal display drive circuit also wraps Include：Power circuit, for providing voltage to the source circuit and the common-battery volt circuit；Circuit is detected, when the voltage for detecting the power circuit offer is down to a predetermined voltage, is judged under the system Electricity to the threshold value, and to the switching circuit sends the first control signal, by the output of the source circuit via one the Together with one resistive element is coupled to the output of the common-battery volt circuit.
- 3. liquid crystal display drive circuit as claimed in claim 2, it is characterised in that the detection circuit, be additionally operable to detect When the voltage that the power circuit provides is down to the predetermined voltage, to the multiple first buffer and second buffer Send the second control signal；When the voltage that the detection electric circuit inspection provides to the power circuit is down to the predetermined voltage When, second buffer of the multiple first buffer and the common-battery volt circuit to the source circuit sends described Second control signal turns off first buffer and second buffer, and to the multiple switch of the switching circuit Element sends first control signal and closes the multiple switch element, makes the output end of the multiple first buffer short Connect, then coupled via the output end of the first resistor element and second buffer.
- 4. liquid crystal display drive circuit as claimed in claim 3, it is characterised in that described the second of the multiple switch element The first end of second resistance element is also coupled between end and the first end of the first resistor element, the second resistance element Second end is controlled via first switching element and ground terminal；It is down in the voltage for detecting the power circuit offer described During predetermined voltage, the detection circuit sends the 3rd control signal to the first switching element and closes the first switch member Part, to be discharged via the branch road where the second resistance element simultaneously.
- 5. liquid crystal display drive circuit as claimed in claim 1, it is characterised in that the source circuit and the switching circuit It is arranged on the first chip, the common-battery volt circuit is arranged on the second chip, and first chip and second core Piece is separate chip.
- 6. liquid crystal display drive circuit as claimed in claim 1, it is characterised in that the source circuit, the switching circuit It is integrated in the common-battery volt circuit on same 3rd chip.
- A kind of 7. method for driving liquid crystal display for preventing lower electric ghost, for including source circuit, common-battery volt circuit and switching electricity The driving of the liquid crystal display circuit on road, the source circuit are used to export a first voltage, the common-battery to multiple pixel electrodes Volt circuit, for exporting a second voltage to common electrode, it is characterised in that the source circuit includes multiple first buffers, Each first buffer one of is exported the first voltage to the multiple pixel electrode by a first path；Institute Stating common-battery volt circuit includes one second buffer；The switching circuit includes multiple switch element, the multiple switch element First end is correspondingly coupled to the output end of the multiple first buffer, and the second end of the multiple switch element passes through one The output end of one resistive element and second buffer couples, and methods described comprises the following steps：Whether detecting system is lower electric to a threshold value；When detecting electricity to the threshold value under system, the multiple switch element is closed to form one second path, by institute The output end for stating multiple first buffers is coupled to one via the output end of the first resistor element and second buffer Rise.
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| CN201510083181.3A CN104616632B (en) | 2015-02-16 | 2015-02-16 | A kind of liquid crystal display drive circuit and driving method for preventing lower electric ghost |
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| CN201510083181.3A CN104616632B (en) | 2015-02-16 | 2015-02-16 | A kind of liquid crystal display drive circuit and driving method for preventing lower electric ghost |
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| CN106710566B (en) * | 2017-03-31 | 2018-09-28 | 京东方科技集团股份有限公司 | Discharge circuit and its driving method, display device |
| CN108305592B (en) * | 2018-02-14 | 2021-01-22 | 京东方科技集团股份有限公司 | Synchronous output drive unit, display panel and display device |
| CN109192163A (en) * | 2018-10-10 | 2019-01-11 | 惠科股份有限公司 | Display device and method for eliminating shutdown ghost |
| CN109473078B (en) * | 2019-01-02 | 2020-08-28 | 合肥京东方显示技术有限公司 | Common voltage regulating circuit and method, display driving circuit and display device |
| CN109658902B (en) * | 2019-03-12 | 2019-05-28 | 南京中电熊猫平板显示科技有限公司 | Liquid crystal display device and the method and electronic equipment for improving panel flash |
| CN109754746B (en) * | 2019-03-28 | 2022-06-17 | 京东方科技集团股份有限公司 | Timing control unit, timing control method and display device |
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| US7698573B2 (en) * | 2002-04-02 | 2010-04-13 | Sharp Corporation | Power source apparatus for display and image display apparatus |
| CN101299322B (en) * | 2007-04-30 | 2011-12-07 | 联詠科技股份有限公司 | Display device and drive device for eliminating power-off residual image |
| TW200939192A (en) * | 2008-03-11 | 2009-09-16 | Novatek Microelectronics Corp | LCD with the function of eliminating the power-off residual images |
| CN101707048A (en) * | 2009-05-25 | 2010-05-12 | 彩优微电子(昆山)有限公司 | Source driver circuit of thin film transistor |
| CN102867491B (en) * | 2012-09-03 | 2014-12-10 | 京东方科技集团股份有限公司 | A liquid crystal panel driving circuit and method, and display device |
| CN103869516B (en) * | 2014-03-12 | 2016-04-06 | 京东方科技集团股份有限公司 | display panel discharge circuit and display device |
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