CN100378794C - Digital-analog conversion unit and drive device employing same and panel display device - Google Patents
Digital-analog conversion unit and drive device employing same and panel display device Download PDFInfo
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- CN100378794C CN100378794C CNB2006101002353A CN200610100235A CN100378794C CN 100378794 C CN100378794 C CN 100378794C CN B2006101002353 A CNB2006101002353 A CN B2006101002353A CN 200610100235 A CN200610100235 A CN 200610100235A CN 100378794 C CN100378794 C CN 100378794C
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Abstract
The present invention relates to a digital-analog conversion unit and a drive unit and a panel display unit applying the digital-analog conversion unit. The driving voltage output by the digital-analog conversion unit can be distinguished as positive polarity voltage and negative polarity voltage, wherein the driving voltage output by an output buffer is the positive polarity voltage, and the driving voltage output by an output inverter is the negative polarity voltage. Under the condition of only one group of needed grey scale voltage, the present invention can reduce the layout area of the drive unit and reduce the phenomena of picture flicker and remnant shadow of the display panel.
Description
Technical field
The invention relates to a kind of drive unit of display panel, and particularly about a kind of board driving mchanism that utilizes the negative voltage mode.
Background technology
Be the ghost phenomena of avoiding the liquid crystal polarization to cause, therefore in order to drive display panels (liquidcrystal display panel, abbreviate the LCD panel as) driving voltage, its polarity of voltage just must periodically be changed, and produces the effect of counter-rotating to impel liquid crystal.The inversion driving method that the LCD panel is adopted for example has row counter-rotatings (line invers ion), row counter-rotating (column inversion) and some counter-rotating (dot inversion) or the like.Fig. 1 is the driving method synoptic diagram of some counter-rotating commonly used at present. the some counter-rotating is to adopt in same picture (frame) cycle, no matter be in level or vertical direction, adjacent inferior pixel (sub-pixel) all has opposite polarity, and same time pixel has arrived next picture cycle, and its polarity also can be reversed.
Learn that by above-mentioned the drive unit of display panels shows that at same GTG the driving voltage of two different polarity of voltages must be arranged.As shown in Figure 2, the tradition display panels adopts common voltage (common voltage, abbreviate Vcom as) design, allow driving voltage can be divided into the so-called positive polarity voltage (for example 14V) that is higher than common voltage, with the reverse voltage that is lower than common voltage (for example 0V).And be implemented on the conventional ADS driving device, the D/A conversion unit in the source electrode driver just must have the ability of exporting two groups of opposed polarity voltages.
For example, as shown in Figure 3, the source electrode driver of 8 display panels of tradition comprises gray scale voltage generator 301, data latching unit 302, conventional digital analog-converted unit 303 and switchgear 304.Gray scale voltage generator 301 output gray scale voltages are to D/A conversion unit 303.Data latching unit 302 is according to the breech lock result, export 8 bit digital data to conventional digital analog-converted unit 303., conventional digital analog-converted unit 303 becomes relative driving voltage with 8 bit digital data-switching, switches delivery channel (Ch via switchgear 304 again
1-Ch
2N), allow driving voltage to the inferior pixel that will drive.
The calcspar of gray scale voltage generator 301, conventional digital analog-converted unit 303 and switchgear 304, as shown in Figure 4.Wherein conventional digital analog-converted unit 303 comprises 2N digital analog converter DAC
1-DAC
2NWith 2N output buffer BF
1-BF
2N, switchgear 304 then comprises 2N switch SW
1-SW
2NOdd number digital analog converter (DAC1, DAC3, DAC5...), be coupled in after odd number output buffer (BF1, BF3, BF5...), be responsible for to produce positive polarity voltage.And even number digital analog converter (DAC2, DAC4, DAC6...), be coupled in after even number output buffer (BF2, BF4, BF6...), then be responsible for to produce reverse voltage.Pass through switchgear 304 at D/A conversion unit 303, to delivery channel Ch
1-Ch
2NUnder the situation about switching, same delivery channel just having/generation of reverse voltage.
Be responsible for providing gray scale voltage to digital analog converter DAC
1-DAC
2NGray scale voltage generator 301, its framework is as shown in Figure 5.Gray scale voltage generator 301 utilizes received aanalogvoltage V
A1-V
A8, the gray scale voltage V of generation positive polarity
G0+-V
G255+The gray scale voltage V of another group negative polarity
G0--V
G255-, then by aanalogvoltage V
A9-V
A16Collocation divider resistance R
256-R
510Form.Hence one can see that, and for the one source pole driver, the divider resistance R1-R510 in the gray scale voltage generator 301 has consumed a large amount of circuit layout spaces.
In addition, as shown in Figure 6,16 aanalogvoltage V that source electrode driver received among Fig. 3
A1-V
A16, be to produce, and export each source electrode driver 602-604 to via the aanalogvoltage cabling via aanalogvoltage generator 601.Wherein Fig. 7 is the detailed circuit diagram of aanalogvoltage generator 601, aanalogvoltage V
A1-V
A16Also be the mode that adopts electric resistance partial pressure, utilize divider resistance R
701-R
732Produced.The demand of therefore a large amount of gray scale voltages not only brings up a large amount of divider resistance R in the source electrode driver
1-R
510Demand, the aanalogvoltage cabling that related source electrode driver is outside a large amount of is with a large amount of divider resistance R in the aanalogvoltage generator 601
701-R
732, also be the big secret worry in the board driving mchanism design.
The conventional source driver is on framework, also because of adopting aanalogvoltage V
A1-V
A16Just produce/gray scale voltage (V of negative polarity
G0+-V
G255+With V
G0--V
G255-), film flicker and the phenomenon that has ghost appear and derive display panels.As shown in Figure 8, aanalogvoltage V
A1-V
A8Be with respect to common voltage Vcom, and be the aanalogvoltage of positive polarity.Another group aanalogvoltage V
A9-V
A18Then be with respect to common voltage Vcom, and be the aanalogvoltage of negative polarity.Solid line is in order to expression aanalogvoltage V among Fig. 8
A1-V
A16Under normal condition, with respect to the voltage quasi position of common voltage Vcom.As aanalogvoltage V
A9, V
A18, V
A12And V
A13During skew (as shown in phantom in Figure 8), aanalogvoltage V
A8With the pressure reduction of common voltage Vcom, can be greater than aanalogvoltage V
A9Pressure reduction with common voltage Vcom.Similar situation also can appear at aanalogvoltage V
A7With pairing aanalogvoltage V
A10On, aanalogvoltage V by that analogy
A5With V
A12, and aanalogvoltage V
A4With V
A13As with one, be the display panel of benchmark with common voltage Vcom, in the time of can causing the liquid crystal counter-rotating because of the skew of aanalogvoltage, to the deviation angle difference of same GTG demonstration, and then the problem of generation film flicker.Except that this, in order to represent the aanalogvoltage V of dark attitude picture
A1With V
A16If, produce when being offset, can cause liquid crystal may not have the mechanism of counter-rotating, cause the liquid crystal polarization and make picture have ghost.
Summary of the invention
The drive unit that the purpose of this invention is to provide a kind of display panel utilizes the mechanism of output phase inverter as the polarity of voltage counter-rotating, reaches the consumption that reduces circuit layout area, and then reduces manufacturing cost.
A further object of the present invention provides a kind of D/A conversion unit, significantly to reduce its required gray scale voltage cabling, economization circuit layout area and cost whereby.
For reaching above-mentioned and other purpose, the present invention proposes a kind of drive unit of display panel, comprises data latching unit, gray scale voltage generator, D/A conversion unit and switchgear. and wherein D/A conversion unit comprises first digital analog converter, second digital analog converter, output buffer and output phase inverter at least.A plurality of M bit digital data are exported to D/A conversion unit in the data latching unit.The gray scale voltage generator produces 2
MThe gray scale voltage that individual polarity of voltage is identical. D/A conversion unit is with the M bit digital data of input, converting relative driving voltage to. the polarity of voltage of driving voltage can be divided into the positive polarity voltage of being exported by output buffer, with the reverse voltage of being exported by the output phase inverter.Just/reverse voltage is to be that benchmark is judged with the common voltage, and common voltage of the present invention is a ground connection accurate.Afterwards, same delivery channel just can provide positive polarity voltage or reverse voltage by the switching of switchgear.
The drive unit of above-mentioned display panel, in one embodiment, switchgear comprises first switch and second switch at least. first switch and second switch are the switch of three terminals, its relation of coupling is as follows, first end of first switch and second end are coupled to output buffer and output phase inverter respectively, and first end of second switch and second end then are coupled to output phase inverter and output buffer respectively.When between the first phase, respectively between first end and the 3rd end of conducting first switch and second switch.And when the second phase, respectively between second end and the 3rd end of conducting first switch and second switch.Whereby, allow the 3rd end of first switch and second switch, the positive polarity voltage of being exported by output buffer can be provided, or the reverse voltage of exporting by the output phase inverter.
The drive unit of above-mentioned display panel, in one embodiment, the output phase inverter comprises first resistance, second resistance, first amplifier and second amplifier.First resistance, second resistance and first amplifier form the framework of an inverting amplifier, and the voltage that allows the output phase inverter export is a reverse voltage.And being coupled in second amplifier after first amplifier, the output electric property of its first input end and second amplifier itself interconnects, and forms the buffer stage of a single gain, in order to strengthen the driving force of output phase inverter.
The drive unit of above-mentioned display panel, in another embodiment, the output phase inverter comprises the 3rd resistance, the 4th resistance, the 5th resistance, the 6th resistance, variable resistor, the 3rd amplifier and the 4th amplifier.The 3rd resistance, the 4th resistance and the 3rd amplifier form the framework of an inverting amplifier, and by the 5th resistance, the 6th resistance and the formed dividing potential drop of variable resistor, allow second input end of the 3rd amplifier be biased in node voltage.Whereby, allow the output phase inverter can adjust panel by the fine adjustment point voltage, the voltage deviation that causes because of penetration effect (feed-through effect).Be coupled in the 3rd amplifier the 4th amplifier afterwards, the output electric property of its first input end and the 4th amplifier itself interconnects, and forms the buffer stage of a single gain, in order to strengthen the driving force of exporting phase inverter.
From another viewpoint, the present invention proposes a kind of D/A conversion unit in addition, comprises 2N digital analog converter, a N output buffer and N output phase inverter, and wherein N is the positive integer greater than 0.(i) individual output buffer is coupled to (2i-1) individual digital analog converter, and (i) individual output phase inverter then is coupled to (2i) individual digital analog converter, and wherein i is integer and 1≤i≤N.Each output buffer is exported a positive polarity voltage separately, and each relative output phase inverter is exported a reverse voltage separately, wherein just/and reverse voltage is to be that benchmark is judged with the common voltage, and common voltage of the present invention is a ground connection accurate.
In addition, the present invention proposes a kind of display apparatus in addition, comprises display panel, gate driver circuit and drive unit.Gate driver circuit allows drive unit cooperate under the sweep signal, and provides at least one first driving voltage and one second driving voltage by delivery channel respectively in order to export one scan signal at least.Drive unit is in the process that produces first driving voltage and second driving voltage, be to utilize the gray scale voltage generator to produce the gray scale voltage of a plurality of identical polarity of voltages earlier, allow D/A conversion unit can be according to the numerical data that is received the gray scale voltage that determines whether to reverse, and then provide first driving voltage and second driving voltage at least.Afterwards, utilize switchgear to switch first driving voltage and second driving voltage path, allowing delivery channel provide first driving voltage, and provide second driving voltage in next picture cycle in a picture cycle to delivery channel.
Described according to preferred embodiment of the present invention, the drive unit of above-mentioned display panel, utilize the main mechanism of output phase inverter as the polarity of voltage conversion, the driving voltage that allows D/A conversion unit export can be divided into positive polarity voltage or reverse voltage.Thus, the gray scale voltage that is supplied to D/A conversion unit is under situation about reducing, and the layout area of the drive unit of display panel will be lowered effectively, and display panel film flicker occurs and also will be reduced with the phenomenon that has ghost.
Description of drawings
Fig. 1 is traditional some inversion driving method synoptic diagram.
Fig. 2 is the driving voltage sequential chart of conventional source driver.
Fig. 3 is the primary structure calcspar of conventional source driver.
Fig. 4 is the inner detailed block diagram of the conventional source driver of key diagram 3.
Fig. 5 is the detailed circuit diagram of traditional gray scale voltage generator.
Fig. 6 is routed to the synoptic diagram of each source electrode driver for aanalogvoltage.
Fig. 7 is the detailed circuit diagram of traditional analog voltage generator.
Fig. 8 is the voltage quasi position figure of the aanalogvoltage of conventional source driver with respect to common voltage.
Fig. 9 is driving voltage sequential chart according to an embodiment of the invention.
Figure 10 is the drive unit primary structure calcspar according to a preferred embodiment of the present invention.
Figure 11 is the inner detailed block diagram of the drive unit of explanation Figure 10.
Figure 12 A, Figure 12 B are the detailed circuit diagram of the reference voltage generator and the aanalogvoltage generator of the preferred embodiment according to the present invention.
Figure 13 is the aanalogvoltage of the preferred embodiment according to the present invention and the driving voltage voltage quasi position figure with respect to common voltage.
Figure 14 is the output phase inverter detailed circuit diagram of the preferred embodiment according to the present invention.
Figure 15 is another output phase inverter detailed circuit diagram of the preferred embodiment according to the present invention.
Figure 16 is display apparatus according to an embodiment of the invention.
Symbol description:
301,901: the gray scale voltage generator
302,902: the data latching unit
303: conventional digital analog-converted unit
304,904: switchgear
601: the aanalogvoltage generator
602-604: source electrode driver
900: drive unit
903: D/A conversion unit
1101,1102: arrow
1401,1402,1501,1502: amplifier
1601: display panel
1602: gate driver circuit
DAC1-DAC2N: digital analog converter
BF1-BF2N, BF91-BF9N: output buffer
IN91-IN9N: output phase inverter
SW1-SW2N: switch
R1-R510, R701-R732, R1401-R1402, R1501-R1504: resistance
R1505: variable resistor
Vcom: common voltage
VA1-VA16: aanalogvoltage
Vdr1+-Vdr8+, Vdr1--Vdr8-: driving voltage
Embodiment
For above and other objects of the present invention, feature and advantage can be become apparent, preferred embodiment of the present invention cited below particularly, and cooperate appended graphicly, be described in detail below.
Fig. 9 is the driving voltage sequential chart according to one embodiment of the invention explanation.In order to impel liquid crystal to produce reversal effect, it is the mode of the accurate position of a ground connection that present embodiment adopts a common voltage Vcom, distinguish the polarity of voltage of driving voltage. as shown in Figure 9, when driving voltage is higher than common voltage Vcom, then be a positive polarity voltage (for example 7V).Relative, when driving voltage is lower than common voltage Vcom then be a reverse voltage (for example-7V).Wherein positive polarity voltage is again a positive voltage, and reverse voltage is again a negative voltage.Therefore, from another viewpoint, present embodiment is the mode that adopts a kind of negative pressure (negative voltage), realizes the driving voltage of display panel.
Figure 10 is the drive unit 900 primary structure calcspars according to a kind of display panel of present embodiment explanation.Please refer to Figure 10, it comprises gray scale voltage generator 901, data latching unit 902, D/A conversion unit 903 and switchgear 904.D/A conversion unit 903 is coupled to data latching unit 902 and gray scale voltage generator 901, and switchgear 904 is coupled to D/A conversion unit 903.Wherein a plurality of M bit digital data are exported according to the breech lock result in data latching unit 902, and gray scale voltage generator 901 is then in order to produce 2
MIndividual gray scale voltage. 903 M bit digital data with input of D/A conversion unit convert relative driving voltage to.Afterwards, driving voltage switches to desired delivery channel Ch by switchgear 904
1-Ch
2NWherein M is the positive integer greater than 0.
The detailed block diagram of gray scale voltage generator 901, D/A conversion unit 903 and switchgear 904, as shown in figure 11.D/A conversion unit 903 comprises 2N digital analog converter DAC
1-DAC
2N, a N output buffer BF
91-BF
9N, and N output phase inverter IN
91-IN
9N304 of switchgears comprise 2N switch SW
1-SW
2NWherein N is the positive integer greater than 0.Gray scale voltage generator 901 is coupled to digital analog converter DAC
1-DAC
2N(2i-1) individual digital analog converter DAC
1-DAC
2NBe coupled to (i) individual output buffer BF
91-BF
9N, (2i) individual digital analog converter DAC
1-DAC
2NBe coupled to (i) individual output phase inverter IN
91-IN
9N, wherein i is integer and 1≤i≤N.In addition, (2j-1) individual switch SW
1-SW
2NFirst end be coupled to (j) individual output buffer BF
91-BF
9N, and (2j-1) individual switch SW
1-SW
2NSecond end be coupled to (j) individual output phase inverter IN
91-IN
9N(2j) individual switch SW
1-SW
2NFirst end be coupled to (j) individual output phase inverter IN
91-IN
9N, and (2j) individual switch SW
1-SW
2NSecond end be coupled to (j) individual output buffer BF
91-BF
9NAnd each switch SW
1-SW
2NThe 3rd end all export a driving voltage, wherein j is integer and 1≤j≤N.
Gray scale voltage generator 901 with produced 2
MIndividual gray scale voltage offers each digital analog converter DAC
1-DAC
2NDigital analog converter DAC
1-DAC
2NBe responsible for converting M bit digital data to relative gray scale voltage.Afterwards, output buffer BF
91-BF
9NWith digital analog converter DAC
1-DAC
2NOutput amplify and output phase inverter IN
91-IN
9NThen in order to converting digital analog converter DAC
1-DAC
2NThe polarity of voltage of output voltage.In the present embodiment, output buffer BF
91-BF
9NBe to be responsible for output cathode voltage (positive voltage), and output phase inverter IN
91-IN
9NThen be to be responsible for output negative pole voltage (negative voltage).Therefore, same delivery channel Ch
1-Ch
2NJust can provide positive polarity voltage or reverse voltage by the switching of switchgear 904.
For example, between the first phase odd number delivery channel (Ch1, Ch3 ..., Ch
2N-1) need output cathode voltage, and the even number delivery channel (Ch2, Ch4 ..., Ch
2N) when needing output negative pole voltage, via the switching of switchgear 904, the odd number delivery channel (Ch1, Ch3 ..., Ch
2N-1) will be coupled to output buffer BF
91-BF
9NOutput, shown in the arrow among Figure 11 1101.And the even number delivery channel (Ch2, Ch4 ..., Ch
2N) then be coupled to and export phase inverter IN
91-IN
9NOutput. relative, in second phase during just in next picture cycle, the driving voltage polarity of same channel need be changed.At this moment, via the switching of switchgear 904, the odd number delivery channel (Ch1, Ch3 ..., Ch
2N-1) then be coupled to and export phase inverter IN
91-IN
9NOutput, shown in the arrow among Figure 11 1102, and the even number delivery channel (Ch2, Ch4 ..., Ch
2N) then be coupled to output buffer BF
91-BF
9NOutput.By this, D/A conversion unit 903 just can be by the switchings of 904 pairs of switchgears output itself, allow same delivery channel just have/generation of reverse voltage.
Above-mentioned gray scale voltage generator 901, with conventional architectures compare following, only need to produce one group of gray scale voltage, therefore reduced circuit layout area widely.For example, the gray scale voltage generator in the source electrode driver of 8 display panels of tradition just must produce/gray scale voltage of negative polarity. and with this understanding, as Fig. 5-shown in Figure 7, traditional gray scale voltage generator must produce two groups of gray scale voltage (V
G0+-V
G255+With V
G0--V
G255-), and have two groups of aanalogvoltage (V
A1-V
A8With V
A9-V
A16) be supplied to the gray scale voltage generator.Relatively, just need a large amount of divider resistance R in traditional source electrode driver
1-R
510, and a large amount of aanalogvoltage cablings is connected to outside aanalogvoltage generator 601.Shown in Figure 12 A and 12B, the gray scale voltage generator in the source electrode driver of 8 display panels only needs to produce one group of gray scale voltage (V but in the present embodiment,
G0-V
G255), relative also need only one group of aanalogvoltage (V
A1-V
A8) be supplied to reference voltage generator 901, because of on circuit layout, present embodiment has not only reduced the quantity of divider resistance, has also reduced the consumption of aanalogvoltage cabling.
In addition, as shown in figure 13, present embodiment is because of need only one group of aanalogvoltage (V
A21-V
A28) be supplied to reference voltage generator 901 to get final product.Therefore by reference voltage (V
A21-V
A28) formed gray scale voltage, the reverse voltage (V that obtains by the output phase inverter again
Dr1--V
Dr8-), with the positive polarity voltage (V that produces by output buffer
Dr1+-V
Dr8+), with respect to common voltage Vcom.Same GTG show just/reverse voltage (V
Dr1+With V
Dr1-..., V
Dr8+With V
Dr8-) with respect to the pressure reduction of common voltage Vcom, can be as conventional architectures, because of aanalogvoltage (V
A21-V
A28) skew and cause panel film flicker to occur and have the phenomenon of ghost.
Figure 14 is a kind of detailed circuit diagram of exporting phase inverter according to present embodiment explanation, comprises amplifier 1401 and 1402 and resistance R 1401 and R1402.
For convenience of description, indicate node voltage V at this
14Resistance R
1401First termination receive an input voltage V
Ln14The first input end of amplifier 1401 is coupled to resistance R
1401Second end and resistance R
1402First end, second input end of amplifier 1401 then is coupled to ground.Resistance R
1402Second end be coupled to the output of amplifier 1401.Second input end of amplifier 1402 is coupled to the output of amplifier 1401, and the output electric property of the first input end of amplifier 1402 and amplifier 1402 interconnects.In the present embodiment, the output phase inverter is in order to output negative pole voltage, just negative voltage. so present embodiment utilizes resistance R
1401, R
1402Framework with amplifier 1401 formation one inverting amplifier produces a negative voltage, as the formula (1):
The negative voltage of this moment, just node voltage V
14, can export switches set 904 to via amplifier 1402 formed single gain buffer stages, so output voltage V
Out14Also as the formula (1), with input voltage V
In14Polarity of voltage opposite.Wherein exporting phase inverter operates between common voltage Vcom and the negative voltage Vee.Relatively and opinion, output buffer then operates in positive voltage with jointly between the voltage Vcom, and the magnitude of voltage of positive voltage equates with the absolute value of the magnitude of voltage of negative voltage Vee.
Below, as shown in figure 15, comprise amplifier 1501 and 1502, resistance R again for another embodiment of output phase inverter
1501-R
1504, and variable resistor R
1505For convenience of description, indicate node voltage V at this
15With V
REFResistance R
1501First termination receive an input voltage V
In15The first input end of amplifier 1501 is coupled to resistance R
1501Second end and resistance R
1502First end, second input end of amplifier 1501 then is coupled to resistance R
1503Second end.Variable resistor R
1505First end be coupled to resistance R
1503Second end, and variable resistor R
1505Second end be coupled to resistance R
1504First end.Resistance R
1502Second end be coupled to the output of amplifier 1501.Second input end of amplifier 1502 is coupled to the output of amplifier 1501, and the output electric property of the first input end of amplifier 1502 and amplifier 1502 interconnects.The output phase inverter that present embodiment and Figure 14 are mentioned, all roughly the same on principle and framework.Present embodiment utilizes amplifier 1501 and resistance R
1501, R
1502Form the framework of inverting amplifier, produce and input voltage V
In15Opposite polarity node voltage V
15, exporting by amplifier 1502 formed single gain buffer stages afterwards.With the foregoing description maximum different be in, form the amplifier 1501 of inverting amplifier framework, its second input end is not coupled to ground, but is biased in node voltage V
REF, so node voltage V
15Magnitude of voltage just as the formula (2), except with resistance R
1501, R
1502Node voltage V is arranged outside the connection
REFAlso be one of change factor.
At this, can pass through fine adjustment point voltage V
REFAdjust panel, the voltage deviation that causes because of penetration effect (feed-througheffect). wherein be by node voltage V
REFMagnitude of voltage can pass through variable resistor R again
1505Adjust, and reference voltage V
REF1501With V
REF1502Then can define according to the actual panel demand.
On the other hand, the present invention has proposed a kind of display apparatus in addition.As shown in figure 16 comprise display panel 1601, gate driver circuit 1602 and drive unit 900.Gate driver circuit 1602 is electrically connected to display panel 1601, and drive unit 900 then is electrically connected to display panel 1601 by delivery channel Ch1-Ch4.Present embodiment is according under the spirit of the present invention, utilizes a display apparatus of realizing as the described drive unit 900 of Figure 10 embodiment.Gate driver circuit 1602 allows drive unit 900 cooperate under the sweep signal, and provides at least one first driving voltage and one second driving voltage by delivery channel Ch1-Ch4 respectively in order to export one scan signal at least.The generation of first driving voltage and second driving voltage is to utilize gray scale voltage generator 901 to produce the gray scale voltage of a plurality of identical polarity of voltages earlier.Be coupled to the D/A conversion unit 903 of gray scale voltage generator 901 afterwards, then with gray scale voltage according to numerical data that D/A conversion unit 901 received and determine whether reverse, and then provide the first opposite each other driving voltage of polarity of voltage and second driving voltage.At last, be coupled to the switchgear 904 of D/A conversion unit 903, then in order to switch first driving voltage and second driving voltage path to delivery channel Ch1-Ch4, two wherein adjacent delivery channels provide the voltage of different polarity of voltages (to provide first driving voltage such as delivery channel Ch1 respectively separately, then delivery channel Ch2 provides second driving voltage), and each delivery channel Ch1-Ch4 then provides second driving voltage in next picture cycle if provide first driving voltage in a picture cycle.The first wherein above-mentioned driving voltage is a positive polarity voltage, and second driving voltage is a reverse voltage.As for the detailed block diagram and the associated inner circuit of drive unit 900, among the embodiment that has been contained in Figure 11, Figure 14 and Figure 15 and is carried, just do not add narration at this.
In sum, the present invention utilizes the main mechanism of output phase inverter as the polarity of voltage conversion, and the driving voltage that allows D/A conversion unit export can be divided into positive polarity voltage or reverse voltage.Thus, the gray scale voltage that is supplied to D/A conversion unit is under situation about reducing, and the layout area of the drive unit of display panel will be lowered effectively, and display panel film flicker occurs and also will be reduced with the phenomenon that has ghost.
Though the present invention discloses as above with preferred embodiment; right its is not in order to limiting the present invention, anyly has the knack of this skill person, without departing from the spirit and scope of the present invention; when can doing a little change and retouching, so protection scope of the present invention claim scope person of defining is as the criterion.
Claims (24)
1. the drive unit of a display panel, in order at least one first driving voltage and one second driving voltage to be provided by a plurality of delivery channels, the drive unit of this display panel comprises:
A plurality of M bit digital data are exported in one data latching unit, and wherein M is the positive integer greater than 0;
One gray scale voltage generator produces 2
MIndividual gray scale voltage, the polarity of voltage of wherein said gray scale voltage is identical;
One switchgear, be coupled to this D/A conversion unit, in order to switch this first driving voltage and this second driving voltage path,, then provide this second driving voltage in next picture cycle if this delivery channel provides this first driving voltage in a picture cycle to described delivery channel;
One D/A conversion unit is coupled to this data latching unit and this gray scale voltage generator, and it comprises at least:
One first digital analog converter is coupled to this data latching unit and this gray scale voltage generator;
One second digital analog converter is coupled to this data latching unit and this gray scale voltage generator;
One output buffer is coupled to this first digital analog converter, in order to export this first driving voltage; And
One output phase inverter is coupled to this second digital analog converter, in order to export this second driving voltage.
2. the drive unit of display panel as claimed in claim 1, wherein this switchgear comprises at least:
One first switch, its first end is coupled to this output buffer, second end of this first switch is coupled to this output phase inverter, and between first end and the 3rd end of this first switch of conducting between a first phase, between second end and the 3rd end of this first switch of second phase conducting; And
One second switch, its first end is coupled to this output phase inverter, second end of this second switch is coupled to this output buffer, and between first end and the 3rd end of this second switch of conducting between this first phase, between second end and the 3rd end of this this second switch of second phase conducting.
3. the drive unit of display panel as claimed in claim 1, wherein this output phase inverter comprises:
One first resistance;
One first amplifier, its first input end are coupled to second end of this first resistance, and second input end of this first amplifier is coupled to ground;
One second resistance, its first end is coupled to the first input end of this first amplifier, and second end of this second resistance is coupled to the output of this first amplifier; And
One second amplifier, the output electric property of its first input end and this second amplifier interconnects, and second input end of this second amplifier is coupled to the output of this first amplifier.
4. the drive unit of display panel as claimed in claim 1, wherein this output phase inverter comprises:
One the 3rd resistance;
One the 3rd amplifier, its first input end are coupled to second end of the 3rd resistance;
One the 4th resistance, its first end is coupled to the first input end of the 3rd amplifier, and second end of the 4th resistance is coupled to the output of the 3rd amplifier;
One the 5th resistance, its second end is coupled to second input end of the 3rd amplifier;
One variable resistor, its first end is coupled to second end of the 5th resistance;
One the 6th resistance, its first end are coupled to this variable-resistance second end; And
One the 4th amplifier, its first input end couples the output of the 4th amplifier, and second input end of the 4th amplifier is coupled to the output of the 3rd amplifier.
5. the drive unit of display panel as claimed in claim 1, wherein this first driving voltage is opposite with the polarity of voltage of this second driving voltage.
6. the drive unit of display panel as claimed in claim 1, wherein this first driving voltage is a positive polarity voltage, this second driving voltage is a reverse voltage.
7. the drive unit of display panel as claimed in claim 1, the polarity of voltage of this first driving voltage and this second driving voltage wherein is to be that benchmark is judged with a common voltage.
8. the drive unit of display panel as claimed in claim 7, wherein this common voltage is the accurate position of a ground connection.
9. the drive unit of display panel as claimed in claim 7, wherein this output buffer operates between this common voltage and one first voltage, and this output phase inverter operates between one second voltage and this common voltage.
10. the drive unit of display panel as claimed in claim 9, wherein this first voltage is a positive voltage, this second voltage, one negative voltage, and this first voltage equates with the absolute value of the magnitude of voltage of this second voltage.
11. a D/A conversion unit comprises:
2N digital analog converter, wherein N is the positive integer greater than 0;
N output buffer, this (i) individual output buffer is coupled to this (2i-1) individual digital analog converter, and wherein i is integer and 1≤i≤N, and each described output buffer is exported one first driving voltage separately; And
N output phase inverter, the individual output phase inverter of this (i) is coupled to this (2i) individual digital analog converter, and each described output phase inverter is exported one second driving voltage separately;
Wherein this first driving voltage is opposite with the polarity of voltage of this second driving voltage.
12. D/A conversion unit as claimed in claim 11, wherein each described output phase inverter comprises separately:
One first resistance;
One first amplifier, its first input end are coupled to second end of this first resistance, and second input end of this first amplifier is coupled to ground;
One second resistance, its first end is coupled to the first input end of this first amplifier, and second end of this second resistance is coupled to the output of this first amplifier; And
One second amplifier, its first input end couples the output of this second amplifier, and second input end of this second amplifier is coupled to the output of this first amplifier.
13. D/A conversion unit as claimed in claim 11, wherein each described output phase inverter comprises separately:
One the 3rd resistance;
One the 3rd amplifier, its first input end are coupled to second end of the 3rd resistance;
One the 4th resistance, its first end is coupled to the first input end of the 3rd amplifier, and second end of the 4th resistance is coupled to the output of the 3rd amplifier;
One the 5th resistance, its second end is coupled to second input end of the 3rd amplifier;
One variable resistor, its first end is coupled to second end of the 5th resistance;
One the 6th resistance, its first end are coupled to this variable-resistance second end; And
One the 4th amplifier, its first input end couples the output of the 4th amplifier, and second input end of the 4th amplifier is coupled to the output of the 3rd amplifier.
14. D/A conversion unit as claimed in claim 11, wherein this first driving voltage is a positive polarity voltage, and this second driving voltage is a reverse voltage.
15. D/A conversion unit as claimed in claim 11, the polarity of voltage of this first driving voltage and this second driving voltage wherein is to be that benchmark is judged with a common voltage.
16. D/A conversion unit as claimed in claim 15, wherein this common voltage is the accurate position of a ground connection.
17. D/A conversion unit as claimed in claim 15, wherein said output buffer operate between this common voltage and one first voltage, and described output phase inverter operates between one second voltage and this common voltage.
18. D/A conversion unit as claimed in claim 17, wherein this first voltage is a positive voltage, and this second voltage is a negative voltage, and this first voltage equates with the absolute value of the magnitude of voltage of this second voltage.
19. a display apparatus comprises at least:
One display panel;
One gate driver circuit is electrically connected to this display panel, in order to export one scan signal at least; And
One drive unit is electrically connected to this display panel by a plurality of delivery channels, provides at least one first driving voltage and one second driving voltage by described delivery channel respectively in order to cooperate this sweep signal, and this drive unit comprises:
One gray scale voltage generator, in order to produce a plurality of gray scale voltages, the polarity of voltage of wherein said gray scale voltage is identical; And
One D/A conversion unit, be coupled to this gray scale voltage generator, in order to numerical data according to this D/A conversion unit received, and the decision described gray scale voltage that whether reverses, and then this first driving voltage and this second driving voltage are provided at least, wherein this first driving voltage is opposite with the polarity of voltage of this second driving voltage; And
One switchgear, be coupled to this D/A conversion unit, in order to switch this first driving voltage and this second driving voltage path,, then provide this second driving voltage in next picture cycle if this delivery channel provides this first driving voltage in a picture cycle to described delivery channel.
20. display apparatus as claimed in claim 19, wherein this D/A conversion unit comprises at least:
One first digital analog converter is coupled to this gray scale voltage generator;
One second digital analog converter is coupled to this gray scale voltage generator;
One output buffer is coupled to this first digital analog converter, in order to export this first driving voltage; And
One output phase inverter is coupled to this second digital analog converter, in order to export this second driving voltage.
21. display apparatus as claimed in claim 20, wherein this switchgear comprises at least:
One first switch, its first end is coupled to this output buffer, second end of this first switch is coupled to this output phase inverter, and between first end and the 3rd end of this first switch of conducting between a first phase, between second end and the 3rd end of this first switch of second phase conducting; And
One second switch, its first end is coupled to this output phase inverter, second end of this second switch is coupled to this output buffer, and between first end and the 3rd end of this second switch of conducting between this first phase, between second end and the 3rd end of this this second switch of second phase conducting.
22. display apparatus as claimed in claim 19, wherein this first driving voltage is a positive polarity voltage, and this second driving voltage is a reverse voltage.
23. display apparatus as claimed in claim 19, the polarity of voltage of this first driving voltage and this second driving voltage wherein is to be that benchmark is judged with a common voltage.
24. display apparatus as claimed in claim 23, wherein this common voltage is the accurate position of a ground connection.
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| CNB2006101002353A CN100378794C (en) | 2006-07-05 | 2006-07-05 | Digital-analog conversion unit and drive device employing same and panel display device |
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| CNB2006101002353A CN100378794C (en) | 2006-07-05 | 2006-07-05 | Digital-analog conversion unit and drive device employing same and panel display device |
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| CN100378794C true CN100378794C (en) | 2008-04-02 |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| JP5074916B2 (en) * | 2007-12-25 | 2012-11-14 | ルネサスエレクトロニクス株式会社 | Signal line drive device with multiple outputs |
| CN101221716B (en) * | 2008-01-24 | 2010-06-02 | 友达光电股份有限公司 | Data driver using gamma selection signal, and plane display device and driving method |
| JP5055605B2 (en) * | 2008-03-17 | 2012-10-24 | 奇美電子股▲ふん▼有限公司 | Source drive circuit for liquid crystal display device and liquid crystal display device including the same |
| CN101738764B (en) * | 2008-11-18 | 2013-07-17 | 群创光电股份有限公司 | Liquid crystal display panel, driving method of liquid crystal display panel and liquid crystal display device |
| TWI545553B (en) * | 2014-09-30 | 2016-08-11 | 友達光電股份有限公司 | Drive circuit and drive method |
| CN109697965B (en) * | 2017-10-23 | 2021-02-23 | 新相微电子(上海)有限公司 | Low-power thin film transistor liquid crystal display control chip and driving device |
| CN111951741B (en) * | 2019-05-15 | 2022-04-12 | 华为技术有限公司 | Method, device and storage medium for eliminating ghost |
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