CN1163861C - Method and device for driving a screen and the screen therefor - Google Patents

Abstract

During the time of choosing an access interval Tr, the display array electrode incept polarity relativing to the reference voltage V0 is the third additive V0 level of the invariable duration between the symmetrical two adding the same voltage level and level set in the different polarity voltage. The additive level with contrary polarity is distributed to boundary of the access interval Tr. All the levels is brought to the signal polarity positively or reversely. The distribution of levels alternates in the subsequent frame cycle, the adjacent column electrodes, and subsequent access interval Tr. The pressure impulse brought to the signal electrode is disassembled to several groups relating to the different electrodes and shifted in time. The shifting time is changed in the time process. The driving device with output unit has the same value for the output resistance of different voltage level. The display electrodes receive the compensating voltage irrespective to the picture mode. The impulse figure provided the self-compensation of parasitical change of the square mean voltage in LC unit. A tier driving voltage has the information and quasi standard equilibrium quantity. Line and column voltage levels are equal to and , wherein [eta] is voltage tuning parameter. The display Nmax is not less than Nmaxo which is defined by control diagram. All the embodiments supplement each other. Aiming to improve the uniformity and contrast of pictures and increase the size of display and work speed.

Description

The driving method, the drive unit that are used for display, and display

Invention field

The present invention relates to electron device, microelectronic component, flat-panel screens, be used to drive LCD (LCD), computing machine and television equipment method and apparatus, with other and the engineering field of using flat-panel screens.

Background of invention

The driving method, the drive unit that are used to drive LCD are known.

Known direct light type (U.S. Patent No. 5,099,435) or porjection type (U.S. Patent No. 5,465,102) display include a LC panel.This panel includes the transparent substrates of at least two non-conducting electric currents, and relatively one is positioned on another and has a gap therebetween.This gap is filled with the LC material, for example component and chemical formula known to row material (U.S. Patent No. 5,099,345 and 5,262,881).The specific LC material of this orientation is with the angular turn that depends on root mean square (rms) voltage that is applied to it the polarization direction of light from this substrate transmission.

This voltage self-configuring on the inside surface of these substrates optical clear and the electrode side of conduction be applied in to this LC material.The electrode that the electrode that is referred to as a substrate of column electrode or scan electrode or public electrode or Y electrode was placed and was referred to as another substrate of row electrode or segment electrode or signal electrode or X electrode intersects.In these scan electrodes of their joinings and the LC material layer between the signal electrode, be formed with lc unit.

This lc unit is together with some other elements, and for example the glass at polarizing coating, color filter or other wave filters, compensating color distortion and expansion visual angle or film constitute " point " display image element that a basic display unit and is referred to as " pixel " together.The brightness of this pixel is by the driven on this lc unit electrode.

Be called as " supertwist is to row (STN) molecule " with the angle from 90 ° (or 180 °) to 360 ° distortion to row molecule (T.J.Sheffer and J.Nehring, Appl.Phys., Lett., v.45, N10,1021-1023 page or leaf, 1984).The STN lc unit allows to set up passive matrix (PM) the LC panel that has a large amount of multiple scaaning electrodes (having enough row) and shows to realize computing machine and TV double scanning.

Expression has the part of the PM LCD panel in the plane in Fig. 1.Signal electrode is represented as X ₁, X ₂..., X _j..., X _M, scan electrode is represented as Y ₁, Y ₂..., Y _i... Y _NVoltage is imposed on show electrode from the row and column driver.

By various method, drive PMLCD according to the select progressively of display line electrode.These column electrodes are pressed one by one or are selected by group's order.Scanning voltage is applied in to a selecteed electrode and a reference voltage and is applied in to non-selected voltage.The voltage setting value of the brightness of display element is applied in to these row electrodes.

In order to determine display characteristic, at the rms magnitude of voltage of the electrode of these lc units, and the family curve of driving voltage, the photoelectric characteristic of this display element (EOB) is used.

In Fig. 2 and Fig. 3, provide modification with the EOB of the display element of the form of voltage-light characteristic.U _IjBe the rms voltage on one (ij) lc unit that is placed between the capable and j row electrode of i.B is the brightness of the pixel that is connected with this (ij) unit.The perform region of this VBC is that margin is at brightness B _MinAnd B _MaxValue on one suddenly the district.Brightness is by with Kd/m ²For unit is measured.Ratio B _Max/ B _MinThe maximum of determining this display shows contrast.The feature of this perform region is two main rms parameters equally.First is the threshold voltage U on the VBC shown in Fig. 2 _Th, disconnected (off) the border state of sign is provided with B _Min, and be represented as U _Off, so U _Th=U _OffSecond is to add to U at the step voltage Δ _ThAfter provide, by U _OnExpression and B on the VBC shown in Fig. 2 is set _MaxLogical (on) border state,, therefore, U _On=U _Th+ Δ.U _ThAnd U _ThRms value between the+Δ has been stipulated the intermediate value of the brightness among Fig. 3 (gray level), U _OffSet B _MaxAnd U _OnSet B _Min

First prototype of the present invention is the Alt-Pleshko method that drives PM LC display by delegation's addressing, as in U.S. Patent No. 5,162, and the prototype described in 923.

At the time diagram of first method shown in two accompanying drawings (Fig. 4 and Fig. 5), there be not the width modulation of column signal (PWM) (Fig. 4) and set at the PWM of column signal (Fig. 5) under the situation of " gray level ".In the drawings, Vri and Vcj represent to be applied to the voltage of the capable and j row electrode of i, V _Ij=V _Cj-V _RiBe the voltage that imposes on the ij electrode of this lc unit.The brightness of the pixel that " logical (On) " in these and other accompanying drawing, " disconnected (Off) " or " gray scale (Gray) " expression are relevant with selecteed unit.Term " gray scale " means different luminance level between " leading to " and " breaking ".

This method comprises: sequentially select scan electrode one by one.Selection cycle T in a constant duration _rDuring this time, have from some reference voltage V ₀The scan voltage V that derives with a constant amplitude _r(horizontal pulse) is applied in to this selecteed scan electrode, and this reference voltage is applied in to non-selected scan electrode, is not equal to V ₀Level and one (or a plurality of) signal voltage level (row pulse) that has the variable duration under normal conditions are applied in to the current value of a signal electrode with the brightness of setting selecteed display element.

In a frame time period T _F=N _xT _rDuring this time, these horizontal pulses are applied in all N scan electrode to this display.After each a little time cycle, the polarity of two horizontal pulse skews and row pulse skew is (with respect to V ₀-level) be inverted, thereby a zero mean that imposes on the voltage of lc unit is provided.In order to reduce supply voltage, with changing the horizontal pulse skew opposite, by with reference voltage V ₀From V ₀₁Change over V ₀₂Or from V ₀₂Change over V ₀₁Realize the counter-rotating of each polarity.

At every turn, reference voltage V ₀(V ₀₁Or V ₀₂) be applied in to N-1 non-selected column electrode.At (N-1) T _rIn, during a frame time, it is maintained on the column electrode.If relative V ₀Level V _cPolarity be different from polarity V _r, state " leads to " and is set, and therefore, such level is by V _{C (on)}Expression.Therefore, has the polarity of equaling V _rThe level V of polarity _cBy V _{C (off)}Expression.Two V _{C (on)}And V _{C (off)}The duration t of pulse _OnAnd t _OffCan be determined is variable (under PWM), and according to information to be shown, each duration is changed over Tr from 0.Yet their total duration must equal select time Tr, i.e. t _On+ t _Off=Tr.

On the other hand, a kind of frame modulator approach is widely used and forms gray level.This method comprises: in several image durations, apply voltage combination V _{C (on)}And V _{C (off)}The lc unit of give selecting, each voltage have a constant duration and equal Tr.This method also is a prototype of the present invention.Term " frame " and " field " often are used as synonym.We refer to term " field " as time of the single selection of all display elements and term " frame " are referred to time as the full detail of the single brightness that relevant all pixels are provided.(therefore, substitute " frame modulation ", term " modulation " should be proper more, because at four or eight field intervals of a frame, about the information of the gray scale intensities of these pixels is provided for signal electrode.Yet it is usually received that term " frame modulation " here uses).

Rms voltage on this ij unit by with horizontal pulse repeatedly (tens times) impose on i column electrode and with the row level of constant or variable duration repeatedly (tens times) impose on j row electrode and be set.

Use the VBC of this unit and be dependent on Alt﹠amp; The theory of Pleshko (Alt P.M., Pleshko P., IEEE Trans.Electron Devices, v.ED-21, N2,146-155 page or leaf, 1974) is determined by the parameter of the PM LC of this prototype method driving and the value of row and row pulse.

Alt and Pleshko introduce the formation parameter p=Δ/Uth of the nonlinear measured value of representing EOB.Parameter p allows to obtain the lc unit parameter N that is accurately defined by following equation _Max:

N _max＝[(1+p) ²+1] ²/[(1+p) ²-1] ² (1)

Determine the multiple column electrode of maximum quantity.

At the less (N of p _MaxBigger) under the situation, equation (1) can be reduced to:

N _amx≈1/p ²＝U _th ²/Δ ² (2)

According to Alt and Pleshko, in the LCD that satisfies following equation, realized the maximum scan chance:

N _max＝N (3)

Each LC display unit that satisfies equation (3) will be provided potential pulse, from reference voltage V ₀The mould of skew satisfy

$V_r=\frac{U_{\mathrm{th}}}{2}\frac{{[{(1+p)}^2+1]}^{\frac{3}{2}}}{{(1+p)}^2-1}.$

Perhaps, consider (1), (3) and less p,

$V_r=\frac{U_{\mathrm{th}}}{\sqrt{2}}\sqrt{N}---\left(4\right)$

Similarly, these row electrodes must be provided voltage level:

$V_c=\frac{U_{\mathrm{th}}}{2}\sqrt{{(1+p)}^2+1},$

Perhaps, for less p,

$V_c=U_{\mathrm{th}}/\sqrt{2}---\left(5\right)$

Be the relation of characterization driving voltage, they use one to be defined as being used for the b=V that state " leads to " _c/ (V _r-V _c) parameter " biasing than ":

b＝1/(N ^1/2+1) (6)

The defective of known method is the display than AM LC, and its contrast deficiency and operating rate are lower.Significantly the loose line pulse has brought the remarkable vibration on the orientation of LC molecule, therefore, and to having brought significant vibration about the optical characteristics of the display element of the state determined at the rms of this lc unit voltage and the pulsation of light.This is illustrated by the time diagram corresponding to Fig. 6 of voltage-light characteristic of Fig. 2 and Fig. 3.Set by row and column voltage, the rms voltage level U th and the Uth+ Δ that are used for " leading to " and " breaking " state are represented by the dot-and-dash line on two time diagrams of Fig. 6.The generation state " leads to " and the difference between current of " breaking " | V _Cj-V _Ri| mould be illustrated in the time diagram of top.In the figure of bottom, solid line is followed a value of some parameters of this unit.Be referred to as " accurate rms " voltage.Each accurate rms magnitude of voltage is corresponding under the voltage of the constant mould on these electrodes of this lc unit, certain spatial orientation of the LC molecule that can take place in lc unit.Be expert at and the shape and the amplitude of the accurate rms voltage oscillation that the vibration of the spatial orientation of column voltage and brightness panting action LC molecule down can these unit of leisure estimated.Parameter " accurate rms voltage " for example is characterised in that the notion of " relaxation time " and " response time ", and does not resemble the result that parameter " rms " only is average arithmetic routine.(further for the calculating of transient process, notion " accurate rms voltage " is replaced by notion " all square voltage of standard ").

Static accurate rms voltage oscillation under the exact value of relaxation time of LC molecule makes the optical states pulsation of light and display element.During a relaxation time, in a small amount a drive cycle causes the big accurate rms voltage oscillation in the pixel brightness,, pulsation and fuzzy.Around level " lead to " and the accurate rms mains ripple of " breaking " to cause " in vain " to shade shinny and reduced picture contrast and brightness with " deceiving " image.This phenomenon is referred to as " frame response " effect.

Big relaxation time (during electrode be provided with a large amount of drive cycles) the accurate rms voltage oscillation amplitude that reduces is provided and has improved contrast but reduced speed responsive.

" fast " shows should be by the pulsed drive of high frequency.Yet, high-frequency impulse, both shapes of row and column are deformed along the RC column electrode.Because lc unit electric capacity, concluded at high frequency from influence each other (the crosstalking) of the signal of different electrodes.Two influences that are associated to a certain extent cause in the distortion of the rms of lc unit electrode voltage, brightness and contrast's the distortion of inhomogeneous and picture structure, fragment and color on the viewing area.

The influence that has the long transmission line of the electric capacity of distribution and resistance has limited the exploitation of large-sized display and the exploitation of high quality graphic, not only for passive matrix display, and also is the same for active matrix.The control of above-mentioned influence has exceeded the theme of PM LC display.

The intermediate value of the relaxation time of the LC material that uses in driven PM LC display in known method allows cheap (with respect to the AM LC) display of exploitation, yet it has deficiency on speed, contrast and brightness of image.The method of the effect of looking genuine of control frame response, distorted signals and electrode coupling is known.Method discussed below is as other prototypes of the present invention.

Second prototype of the present invention is a U.S. Patent No. 5,301, and 047 (Hitachi) is relevant to pulse (delegation's addressing) when propagating long electrode, reduces some modification of a kind of method of the effect that driving pulse is out of shape.The formation that these modification are based on various forms of HF voltage is added to row or column continuously, or row and column voltage level.The purpose of this method is to improve the inconsistency of the image of demonstration.

Shape by continuous copped wave being superimposed to the row and column driving voltage produces shown in Figure 7 at the Vij of voltage as a result of ij unit.

The positive influences of this method are because the level and smooth pulse that has precipitous edge (front portion and afterbody) by increasing bucking voltage, and the amplitude of high-frequency harmonic that imposes on the pulse of these electrodes reduces, and filters level and reduce.

Yet this method does not make the tangible raising of operating rate and since ancillary relief more the formation of HF voltage caused the generation of the higher frequency harmonic wave in the driving pulse frequency spectrum, and deterioration image.On the other hand, the described additional signal that superposes has hindered use WPM to form gray level.

Triarch of the present invention is a U.S. Patent No. 5,162,932 (Matsushita), and relevant a kind of delegation drives the method for PM LC display, and this method allows to reduce the minimizing of the distortion of row drive signal when the long line electrode is crossed in pulse propagation.For realizing this effect, less than the duration T of duration of row selection cycle Ts _rSelection voltage V _rBe applied in to column electrode.Additional level V _{C (on)}And V _{C (off)}Be assigned to this scan period T _sA start-up portion and a latter end, at the interval of subsequently scan period, these distribution are inverted.

Above-mentioned content is illustrated by the synoptic diagram (Fig. 8) of row and column voltage.Voltage Vri and Vcj are imposed on the i and the j row electrode of display respectively.On the ij cell electrode, form voltage V _IjV ₀₁And V ₀₂It is the reference voltage in the frame period subsequently.Additional levels entry time interval T _sAnd leave T _r, that is to say at time interval T _s-T _rIn.

Seen in from following accompanying drawing, under any pixel brightness (" leading to ", " breaking " or " gray scale "), from V _{C (on)}To V _{C (off)}And vice versa at select time T _sChange in voltage number during this time becomes and equals one (twice change in the time interval of any " gray scale " state of Fig. 5).Therefore, this method has realized V _cThe quantity of change in voltage and reduce to 1/2nd on electrode by the layered values that change in voltage is responded to.

Yet, than row selection cycle T _sThe minimizing of capable strobe pulse duration T r cause the horizontal pulse amplitude to increase T _s/ T _rDoubly.As a result, the distortion of these pulses for accurate rms mains ripple square influence increase (T _s/ T _r) ²Doubly.

The 4th prototype of the present invention is U.S. Patent No. 5,151,690 (Seiko Epson), relevant a kind of method that delegation drives PM LC display that is used for.Except drive voltage is applied in time interval (" driving time ") to electrodes for display, also has cycle time (" make-up time ").During this cycle make-up time, signal electrode is encouraged by an auxiliary voltage, and this auxiliary voltage is the distortion that is caused by the image change in the previous cycle to be proceeded to small part compensate required.Set this bucking voltage according to variation number about between " leading to " and " breaking " state of a row electrode for previous cycle of a time of carrying out this make-up time.In this additional period interim, all column electrodes are provided to reference voltage.This method make to reduce since column voltage from V _{C (on)}Fade to V _{C (off)}And the image unevenness that distortion occurred that vice versa.

Above-mentionedly describe by row and column voltage pattern (Fig. 9).Voltage V _RiAnd V _CjImposed on the i column electrode and the j row electrode of this display respectively, voltage V _IjBe provided for the ij electrode of this unit.V ₀₁And V ₀₂Be the reference voltage of subsequent frame in the cycle.Driving voltage according to first driving method of being discussed in the frame time interval T _FIn be provided for electrodes for display.At all after dates of the selection of finishing all column electrodes, at additional period t _cDuring this time, these row electrodes are fed the voltage that is dependent on display mode.

This method weakness is that efficient is restricted.Best, the maximum distortion of brightness of image can be reduced half, and the cost of paying is the former undistorted local distortion of additional same magnitude and the opposite polarity of occurring.

The 5th prototype of the present invention is U.S. Patent No. 5,157,387 (Seiko Epson), relevant a kind of method that delegation drives PM LC display that is used for.The purpose of this method is to be created on the uniform basically crosstalk noise on the whole display.It is implemented like this: in period T _rDuring this time, two voltage levels are imposed on the row electrode, the voltage of one (height) level is applied in a first stage time interval and the voltage of another (low) level is applied in time stage time interval.Just stage time interval determines that with the relative duration of time stage time interval this resembles the contrast gray level of rope.

The time diagram of the driving voltage that forms according to pentarch is illustrated among Figure 10 and Figure 11.Be used for row voltage V _RiTime diagram (Figure 10) be different from the similar time diagram (Fig. 4) of the first method prototype.For column voltage V _CjAccompanying drawing (Figure 10 and Figure 11) with for V _CjThe difference of accompanying drawing (Fig. 5) be selecting interval T _rDuring this time, apply the auxiliary voltage level of several types.

In Figure 10, provide and do not have the column voltage of PWM (V _Cj1, V _Cj2And V _Cj3) the modification of time diagram.

V _Cj1An additional levels be to apply the after-applied reference voltage V of basic (" lead to " or " breaking ") level to this row electrode ₀₁Or V ₀₂V _Cj2And V _Cj3An additional levels be level with respect to the relativity shift of this reference voltage with respect to basic (" leading to " or " breaking ") level.V _Cj1And V _Cj2Additional levels always be assigned to T by the wire tag that has arrow among Figure 10 _rEnd at interval is (at time t ₁In).V _Cj3Additional levels always be dispensed on time t ₂Interior T _rAt interval begin the place.Level t ₂And t ₃Also by the wire tag that has arrow.

Use the PWM method, two voltage levels are at time interval T _rIn be applied in to the row electrode.The PWM that does not resemble first method drives, and one of these level are assigned to time interval T _rThe center and another level is assigned to before the described interval and afterwards.Figure 11 shows the V that is used for that forms eight kinds of brightness steps _CjEight kinds of modification of time diagram.Another difference of the PWM method of being discussed is to be used for that luminance level " is led to " and the existence of one second voltage level of the figure of " breaking " (at first and the last figure of Figure 11).

Yet this method does not reduce the rms distortion significantly.According to this method, the part of the duration of each value of described value was changed and regardless of duration of auxiliary voltage level.This is used to by Alt﹠amp; The method of the display of Peshko method design can cause the reduction of picture contrast.

Hexarch of the present invention is a row method that drives PM LC display by the amplitude modulation(PAM) that forms " gray level " gradient.This method is proposed by T.N.Ruckmonganthan in (JAPAN DISPLAY ' 92,77-80 page or leaf).Brightness value is represented that by value k wherein k from-1 to+1 ground on a pixel brightness scope changes.Time interval T in the pixel selection _rDuring this time, the row electrode is by twice of feed.Information voltage by conversion especially so that at the first half interval T _r, this electrode is by voltage $(k+\sqrt{1-k^2})V_c$ Feed, and at the second half interval Tr, this electrode is by voltage $(k-\sqrt{1-k^2})V_c$ Feed, wherein V _cBe for Alt﹠amp; The situation of Peshko addressing from reference voltage V ₀The mould of the voltage of skew.

An advantage of the method for Ruckmonganthan is that the duration of drive signal is constant for any " gray scale " level, and the duration that does not resemble drive level in the PWM method can be very little.Therefore, the method for Ruckmonganthan is reinforced on speed.

The weakness of the method for Ruckmonganthan is to impose on the change in voltage of row electrode in a frame period value is variable.Their distortion has limited the possibility of improving picture quality and display speed.

The 7th prototype of the present invention is U.S. Patent No. 5,093,736 (SeikoEpson), relevant a kind of method that delegation drives the PM LC display with a plurality of scan electrodes (being no less than 300) that is used for.The purpose of this method is to improve picture contrast and display speed.By change driving voltage in the display that has up to a plurality of column electrodes of 500, the high-contrast of this display is reached.These displays have used the various LC components that have the molecule from 240 ° to 300 ° of distortions to be manufactured.These row and column electrodes by present with have " biasing factor " b, not elephant (6), be not equal to 1/ (N ^1/2+ 1), at 1/ (N ^1/2-N/200) to 1/ (N ^1/2Driving voltage in-N/50) the scope.

Yet this method does not produce high speed PM LC display.The result can not be by the Alt﹠amp that is instructed to an imperfection in driving theoretical general knowledge; The Peshko theory makes an explanation.

The 8th prototype of the present invention is U.S. Patent No. 5,489,919 (Asahi Glas companies), relevant a kind of method that multirow drives PM LC display that is used for.Scan electrode is selected by group ground.The a group scan electrode according to for a certain order of a given selection kind defined and by feedback with scanning voltage (+V _RoOr-V _Ro).Described order will apply the identical column electrode selecting voltage to offer in a frame, to be selected simultaneously several times (for example respectively two, three and the frame of four lines under selecting in two, three, four inferior).The reference voltage of this steady state value is provided for non-selected column electrode.

The voltage group who is applied in during this frame period to the column electrode of selecting is looked at as the column voltage vector, and can be described tout court by the matrix of Hadamard, and the value of this matrix+1 and-1 corresponds respectively to+V _RoWith-V _RoOther forms of matrix is available.For example, wherein represent voltage-V _RoThe matrix replaced by value 0 of value-1.

The V of selecteed four lines electrode simultaneously that imposes on shown in Figure 12 _R1, V _R2, V _R3And V _R4Four time group of graphs (in possible some modification a kind of).On these figure, illustrate in two frames with respect to reference level V ₀₁The variation of polarity of voltage, this variation is provided at one zero average voltages of display unit.This frame comprises four fields, and each is a duration T _FldThe duration of one selectivity action is T _rMatrix corresponding to two described types of the time diagram among Figure 12 is presented in Figure 13.

According to the brightness of the pixel that is placed on the row electrode place of handing over selected column electrode faciation, this row electrode is presented the voltage that calculates with according to a certain program.According to this program, one row electrode by feedback with the summation proportional voltage of obtain to be used for from the value of each pixel of the pixel of selecting, the pixel of this selection is to select by the computing of carrying out " can not hold concurrently or " under two logical values (corresponding to the brightness of the pixel of selecting), and this logical value is corresponding to the polarity (the right matrix among Figure 13) of the selection voltage of the column electrode that imposes on this pixel.

Suppose some the time, four j row electrodes that have brightness value corresponding to the brightness logical value that is called " data " (1,1,0,0) (for example logical, logical, disconnected, disconnected) respectively are selected.When these voltages some electric current row according to (Figure 13) the right matrix are applied in to the column electrode of selecting, for example has train value (1,1,1,1) first, this driving voltage be synthesized one with the described summation 11+11+10+10=2 that represents by symbol i, wherein this symbolic representation " can not hold concurrently or " function.Similarly, at next, when selecting these pixels (having identical data), when second group of driving voltage being described by value (1,0,1,0) was applied in to column electrode, column voltage and i=11+01+10+00 were synthesized pro rata, because 00=1.In a frame period, so respectively realize four times.

The value of this column voltage be used for scope that four lines selects 0 in 4, or it is proportional to be used for the integer i of scope in 0 to L that L capable (L-pixel) selects.The value of voltage that is applied to the row electrode at current time is by V _c(2i-L)/and the L definition, its intermediate value V _cAuthor by this prototype of the present invention is called " maximal value of row electrode voltage ".

Each brightness combination of selecteed pixel is produced as the multiple result who presents who follows the synthetic voltage of described program.

The purpose of this method is to reduce frame response effect, promptly increases contrast, display size and the operating rate of homogeneity and image.

Yet this method does not produce enough quick demonstrations.The analysis showed that the frame that does not have to reduce under the AD HOC type in the response of the frame under the four lines addressing responds.If the four lines addressing uses the row of the described type of Figure 12 to select the luminance patterns for 50%: (1,1,1,1) or (1,1,0,0) or (1,0,1,0) or (1,0,0,1) or (0,0,0,0) or (0,0,1,1) or (0,1,0,1), (0,1,1,0), this frame response is increased to delegation's addressing level.In addition, being designed to this these displays that have the work of four lines method for addressing can be under an embargo under the situation of triplex row or seven row.

As mentioned above, the potential pulse corresponding to concrete grammar is formed by the row and column driver chip usually.These time clock are presented to driver from the control device that has (or comprising) RAM or ROM with the signal that comprises pixel brightness information.Provide voltage by from power feed to driver, controller and other devices.Circuit characteristic and the driver block scheme of carrying out the device of said method in applied patent, have been provided.

Summary of the invention

The various driving methods that are used for the LC display of being advised, drive unit and be according to theory based on the Alt-Pleshko theory by the LC display that these drive units drive.In order to understand theme of the present invention, check its feasibility and positive effect, this theory is summarized as follows

Theoretical background

1) in Fig. 2 and Fig. 3, provided the common electro-optical characteristic (EOB) of one (ij) image component of LCD of the form of one voltage-brightness (VBC).

Our theory be based on substitute rms voltage one all the notion of side's (ms) voltage constant use and based on an all square voltage-light characteristic (seeing the EOB of all square voltage-light characteristic form among Figure 14) as EOB.The boundary parameter U of perform region _Th1 ²And U _Th2 ²Be introduced into and substitute U _Th, U _Th+ Δ and Δ.Running parameter U _Gr ²=(U _Th2 ²+ U _Th1 ²)/2 (intermediate point of perform region, a working point, " grey level ") and D=U _Th1 ²-U _Th2 ²(width of perform region) is introduced into.

When applying these potential pulses and cause frame response effect among the LCD, we introduce standard-all square voltage (standard-ms voltage) notion of lc unit to study this phenomenon.Each current instantaneous value of the standard of this lc unit-ms voltage is the value of ms voltage of the same static direction of the mapping and equaling of the direction of a current time LC molecule these LC molecules that same lc unit is set.The notion of standard-ms voltage makes may study the interior transient process of this lc unit, calculates in the vibration that applies the pictorial element brightness under the row and column voltage condition.Do not resemble parameter " ms voltage ", notion " standard-ms voltage " is characterised in that time response " relaxation time ", " response time " etc.Except the static EOB shown in Figure 14, we have introduced the dynamic EOB of representative according to the variation of the brightness of frame rate.Two types, static and dynamic EOB is illustrated in Figure 15, wherein brightness B is plotted as the function of ms voltage and average accurate ms voltage.By the curve representation of dot-dash, represented by block curve by performance graph in Figure 15 for static curve.In Figure 15, cause the displacement of static threshold,＜U with respect to the stable oscillation stationary vibration of the accurate ms voltage of its mean value _Th1 ²To＜U _Th3 ²With＜U _Th2 ²To＜U _Th4 ²Value＜Ugr 〉 ²Be changed a bit.

Figure 15 allows estimation from K=B _Max/ B _MinTo K ₁=B _Max1/ B _Min1The value that descends of contrast.

2) constitute parameter P=D/U _Gr ²Be set and substitute p.

The LCD parameter N of this unit _Max≡ (U _Th1 ²+ U _Th2 ²) ²/ (U _Th2 ²-U _Th1 ²) ²Accurately write as N _Max≡ 4/P ²≡ 4U _Gr ⁴/ D ²

Parameter＜U _Gr ²And D permission calculating LCD parameter N _Max.

N _max＝4<U _gr> ⁴/(<U _th2> ²-<U _th1> ²) ² (7)

Accurately as (1) and simple as (2).

Another form

N _max＝<U _gr> ²/Δ ² (8)

Have than (2) good * * * * doubly precision.

3) our any method of requiring to set the ms voltage on the lc unit is correct, if the ms voltage of being set by this method is in the work zone of this unit that comprises these borders and not outside this work zone.

Min (the M that correct addressing LCD is required _Max) be labeled as N ₀

Draw situation N from (3) for delegation's addressing ₀=N.

Theoretical analysis illustrates has the N of satisfying _Max＞N ₀The LCD of lc unit can be by delegation's addressing and correctly being driven by additive method.

Be labeled as V _RoAnd V _CoThe driving voltage V that is used for any correct addressing LCD _rAnd V _cValue have min (N _Max)=N or min (N _Max)=N ₀With having N _Max＞N or N _Max＞N ₀LCD replace such LCD after, the amplitude of correct driving voltage must satisfy two types simultaneous equation set

$V_r={\mathrm{<figure-callout\; id="1"\; label="V\; ro"\; filenames="C9981138400781.png,C9981138400821.png"\; state="\{\{state\}\}">V</figure-callout>}}_{\mathrm{ro}}\sqrt{1+\sqrt{1-\mathrm{\&xi;}}},V_c=V_{\mathrm{co}}\stackrel{15}{\sqrt{1-\sqrt{1-\mathrm{\&xi;}}}}---\left(9\right)$

$\mathrm{or}{V}_r=V_{\mathrm{ro}}\sqrt{1-\sqrt{1-\mathrm{\&xi;}}},V_c={\mathrm{<figure-callout\; id="1"\; label="V\; co"\; filenames="C9981138400781.png,C9981138400821.png"\; state="\{\{state\}\}">V</figure-callout>}}_{\mathrm{co}}\sqrt{1+\sqrt{1-\mathrm{\&xi;}}},---\left(10\right)$

ξ=min (N wherein _Max)/N _Max(that is to say ξ=N/N _MaxOr ξ=N _o)/N _Max), V _RoAnd V _CoBe to be used to have N _MaxThe driving voltage mould of the display of=N.

We can be written as formula (9) and (10):

$V_r={\mathrm{<figure-callout\; id="1"\; label="V\; ro"\; filenames="C9981138400781.png,C9981138400821.png"\; state="\{\{state\}\}">V</figure-callout>}}_{\mathrm{ro}}\sqrt{1+\mathrm{\&eta;}},V_c=V_{\mathrm{co}}\sqrt{1-\mathrm{\&eta;}},---\left(11\right)$

$V_r=V_{\mathrm{ro}}\sqrt{1-\mathrm{\&eta;}},V_c={\mathrm{<figure-callout\; id="1"\; label="V\; co"\; filenames="C9981138400781.png,C9981138400821.png"\; state="\{\{state\}\}">V</figure-callout>}}_{\mathrm{co}}\sqrt{1+\mathrm{\&eta;}},---\left(12\right)$

Wherein

$\mathrm{\&eta;}=\sqrt{1-\mathrm{\&xi;}}---\left(13\right)$

Vice versa, wherein because the voltage V that applies _rAnd V _cBe different from (4) and (5) of introducing or have the biasing coefficient b that does not satisfy formula (6) and in fact a display of obtaining maximum-contrast has a value N who satisfies following formula by Alt and Pleshko _Max

N _max＝N/(1-η ²)， (14)

Wherein η be non-unit,

For example, U.S. Patent No. 5,093,736 (heptarch of the present invention) have been described having N 〉=300 a multiplexing electrode and its value and have been defined in 1/ (N ^1/2-N/200) to 1/ (N ^1/2-N/50) delegation's method for addressing in the display of the biasing ratio in the scope.

The author thinks that this scope provides the contrast of high value.Yet, from analyzing as seen, only for having setting N _MaxThe LC display of formation parameter, N _MaxBe greater than number of electrodes one fixedly multiple (in the scope of described b) picture quality for N=400 from 1.026 to 1.4 to improve be possible.Other have littler or bigger value N _MaxDisplay is for the value b that changes in above-mentioned scope, can not reach high-contrast, no matter use a large amount of N 〉=300 electrodes.In order to realize for the N that has the scope that satisfies described b _MaxThe high contrast values of display, it takes to generate the correct driving that is provided by the driving voltage mould according to (10) or (12).Consider accurate ms vibration (seeing Figure 15), additionally need to improve quiescent value N _Max

4) according to the employing U of delegation's addressing of classics _GrThe formula that is used for row and column voltage (4) and (5) of (not considering polarity) are written as:

$V_r=U_{\mathrm{gr}}\sqrt{N}/\sqrt{2}---\left(15\right)$

$V_c=U_{\mathrm{gr}}/\sqrt{2}---\left(16\right)$

The formula of these types according to two row addressing (not considering polarity) of classics is:

$V_r=U_{\mathrm{gr}}\sqrt{N}/2,---\left(17\right)$

V _c＝U _gr，and/or?V _c＝0. (18)

According to the multi-line addressing of classics, have selecteed any integer L column electrode simultaneously:

$V_r=U_{\mathrm{gr}}\sqrt{N/2L},---\left(19\right)$

$V_c=U_{\mathrm{gr}}\sqrt{L/2},\mathrm{and}/\mathrm{or}=U_{\mathrm{gr}}\sqrt{L/2-1},\mathrm{and}/\mathrm{or}=U_{\mathrm{gr}}\sqrt{L/2-2},---\left(20\right)$

And so until V _c=0, if L is an even number; Perhaps so until XXXX, if L is an odd number.

If L is an even number, V _cThe number of possible amplitude equal L/2+1, if L is an odd number, V _cThe number of possible amplitude equal (L-1)/2+1.Consider polarity of voltage, possible V _cThe number of level equals L+1.

Note having equal 2 or the power integer (2,4,8 ...) the MLA of L require to use and have minimum value N _MaxThe LCD of=N.In all other circumstances, min (N _Max)＞N.For example, for L=3, min (N _Max)=1.33N.

5) frame rate to improve, this frame response is increased but picture quality is compromised, because the pulse shape distortion of the row and column voltage of propagating along the row and column electrode.

For the rect.p. that imposes on the electrode of not crosstalking, rms square＜Uij in the ij unit 〉 ²Conduct can be write

${<U_{\mathrm{ij}}>}^2={<U_{\mathrm{gr}}>}^2[1+I(i,j)/\sqrt{N_{\max }}]\&CenterDot;[1-{\mathrm{\&tau;}}_r\left(j\right)/T_r-{\mathrm{\&tau;}}_c\left(i\right)/T_r],---\left(21\right)$

Wherein I (i, j) be-1 and+numerical value of the brightness of ij pixel in the working range (the steep district among Figure 15) that changes between 1, ${<U_{\mathrm{gr}}>}^2[1+I(i,j)/\sqrt{N_{\max }}]$ Be the ij unit currency of the accurate ms voltage in the working range (the steep district among Figure 15) at the ms voltage of not considering distortion,

τ _r(i) and τ _c(j) during a select time Tr, regulation is by (i, j) value of the time of the relative value of the accurate ms voltage drop that causes of the distortion of the row and column pulse shape of unit the.

The ratio of the frame rate of the static ms magnitude of voltage of the accurate ms voltage deviation of formula (21) expression.These are worth τ _rAnd τ _cAlong with this unit with apply the increase of the distance between the point of driving voltage and increase.When driving voltage is imposed on the two ends of a column electrode, maximal value τ _rBe reduced to 1/4th.

This electrode resistance and electric capacity depend on size of display.

These are worth τ _rAnd τ _cDepend on the pulse voltage V that forms by voltage source _rAnd V _cThe shape, the output resistance and the image model of voltage source of lead and leave edges.This cell capacitance depends on the direction of LC molecule, promptly depends on the ms voltage of these unit.

6) at an one pole or the bipolar pulse (V of any point of-long line of RC _rOr V _c) rising edge and the analysis of Transient that causes of trailing edge illustrate:

-by the τ of (21) _r(i) or τ _c(j) the accurate ms voltage of the LCD unit of Que Dinging the each point of this long line and an input pulse square amplitude change (reduction) pro rata;

-at level V ₀The two sharp-pointed potential pulses that separate wide to be enough to give security its half by with respect to V ₀The damping of the transient process of the variation of the accurate ms voltage that variation symmetry, that a single unipolar pulse causes is equally big.

The potential pulse that has the step edge edge provides τ several times _r(i) and τ _cReducing (j).In pulse rising edge RC/2 width or outside the single ladder of (the RC/8 width that is used for the column electrode that two ends are powered) can reduce the variation nearly four times (times) of the accurate ms voltage of unit.Two such ladder permissions reach the augmenting portions of the accurate ms change in voltage of rising edge in almost whole compensation of the minimizing part of the accurate ms change in voltage of rising edge.This technology importantly provides the capacitor C that will be suppressed to by the undesired variation of the accurate ms voltage that causes of pulse shape of distortion almost with discrete cell _IjIrrelevant degree.

7) cause the variation (cross stratification is crosstalked) of the voltage on the unit of cross capacitance coupling electrode in any variation of the voltage on the distributed resistance electrode.This cross stratification (cross-laying) reduces in the recharge time of the capacitor C ij of unit gradually.Cross stratification on the obvious row electrode be cause by the change in voltage on the column electrode and vice versa.The distribution of the cross stratification on the electrodes for display has nothing to do with the brightness of concrete display element (display mode), the order of driving pulse arrival electrode and the amplitude of driving pulse.

Cross stratification on the column electrode can be divided into two types.

First kind of layering appears on the i column electrode during the selection cycle Tr.This layering causes (i, j) variation of roughly being determined by the difference between the number of the positive and negative polar impulse on all the row electrodes in the period T r of the accurate ms voltage of unit.With this approximate representation, the accurate ms voltage of all unit of selecteed row stands undesired variation $\&PlusMinus;{{2\mathrm{<figure-callout\; id="2"\; label="U\; gr"\; filenames="C9981138400851.png,C9981138400881.png"\; state="\{\{state\}\}">U</figure-callout>}}_{\mathrm{gr}}}^2{\mathrm{\&tau;}}_r\sqrt{A}/\sqrt{N}{T}_r$ (wherein A is a display aperture).The variation of this accurate ms voltage can cause 50% luminance distortion of the luminance distortion that causes up to the pulse shape by the distortion on this column electrode.

Maximum negative effect to image quality is caused by second kind of layering.This kind layering appear on the column electrode of the time except that selection cycle and cause can be first kind of layering cause * * (i, j) distortion of the accurate ms voltage of unit doubly.

The variation of the accurate ms voltage of lc unit is subjected to being responsible for the influence of changes in resistance of (the microcircuit driver) output transistor of the charging of load capacitance and discharge more: these transistors are set the rising edge of driving pulses and the width of trailing edge.The driver that its transistor has identical output resistance causes the minimum cross stratification of accurate ms voltage to change.

8) another time diagram needs the not only variation of voltage level, and needs display to influence parameter N _MaxDesign characteristics.

Let as assume that each line time interval T of the row of selecting at delegation or multirow _rDuring this time, set that selecteed (i, the basic signal voltage usually of the j) brightness of pixel (by the modulation of width modulation and/or frame) and some additional voltage levels that reduce ghost effect are applied in to the row electrode.Every kind of additional voltage level has identical constant amplitude and identical constant duration.First kind of level has duration t ₀With equal one and be called the reference voltage V of zero level at this ₀Value.Second kind by having t _m/ 2 duration, identical mould V _mWith with respect to V ₀Two voltage levels of opposed polarity form.That is to say that this group voltage level formation has total t _mThe zero level surely of duration.Let us is written as k _m=(V _m/ V _c) ², V wherein _cBe to have identical t _oAnd t _mDuration and equal V _cLevel V _mThe column voltage value of the delegation's addressing that is used for correct (in these cases).Write out and find the solution characteristic of correspondence formula (not providing at this), we obtain by the described time diagram N of LCD driven correctly _MaxMust have value:

$N_{\max o}=N\frac{1-t_o/T_r-t_m(1-k_m)/T_r}{{(1-t_o/T_r-t_m/T_r)}^2}---\left(22\right)$

If t _o＜＜T _r, t _m＜＜T _r, and k _m=1, formula (22) can be written as

$N_{\max o}\&cong;N[1+({2t}_m+t_o)/T_r]---\left(23\right)$

In the time diagram of being considered, the correct driving has N _Max=N _MaxoSTN LCD be possible, if row and column voltage V _Ro1And V _Co1All amplitudes satisfy:

V _ro1＝V _ro， (24)

${\mathrm{<figure-callout\; id="1"\; label="V\; co"\; filenames="C9981138400781.png,C9981138400821.png"\; state="\{\{state\}\}">V</figure-callout>}}_{\mathrm{co}}=\frac{V_{\mathrm{co}}}{\sqrt{1-t_o/T_r-t_m\left({1-k}_m\right)/T_r}}---\left(25\right)$

For different types of addressing, the value of providing V in formula (15) and (16), (17) and (18), (19) and (20) _RoAnd V _Co

V _mWith U _GrBe associated for

$V_m=\frac{\sqrt{k_m}{U}_{\mathrm{gr}}/\sqrt{2}}{\sqrt{1-t_o/T_r-t_m\left({1-k}_m\right)/T_r}}---\left(26\right)$

Draw at T from it _rDuring the selection cycle, has width t _oAdditional levels V ₀With two additional equal amplitude V _m=U _GrRelative polarity t _mTwo row addressing of/2 width level require row (signal) voltage V _Co1Equal U _GrBy the correct N that drives of this option program _MaxMinimum value determine by following formula:

$N_{\max o}=\frac{N}{{(1-2t_o/T_r)}^2}---\left(27\right)$

Let as assume that at each frame period T _FThe frame select time beyond, some time interval T _aBe coupled with.In this case, have equation T _F=NT _r+ T _aSubstitute common equation T _F=NT.Suppose in time T _aDuring this time, voltage V ₀Be applied in to column electrode and accurate no-voltage V _M1(be meant ± V _M1) be applied in to the row electrode.Let us is written as k _M1=(V _M1/ V _c) ², V wherein _cBe to have identical additional T _aDuration equal V _cAccurate zero level V _M1The column voltage value that is used for correct delegation's addressing.And let us writes out r=T _a/ T _FFrom characteristic of correspondence formula (not providing at this), we obtain by the described time diagram N of LCD driven correctly _MaxMust have value _Nmaxo:

N _maxo＝N+k _m1r (28)

In the time diagram of being considered, the correct driving has N _Max=N _MaxoSTN LCD be possible, if row and column voltage V _Ro2And V _Co2All amplitudes satisfy:

${\mathrm{<figure-callout\; id="2"\; label="V\; ro"\; filenames="C9981138400851.png,C9981138400881.png"\; state="\{\{state\}\}">V</figure-callout>}}_{\mathrm{ro}}={\mathrm{<figure-callout\; id="1"\; label="V\; ro"\; filenames="C9981138400781.png,C9981138400821.png"\; state="\{\{state\}\}">V</figure-callout>}}_{\mathrm{ro}}\sqrt{1+r/N},---\left(29\right)$

${\mathrm{<figure-callout\; id="2"\; label="V\; co"\; filenames="C9981138400851.png,C9981138400881.png"\; state="\{\{state\}\}">V</figure-callout>}}_{\mathrm{co}}={\mathrm{<figure-callout\; id="1"\; label="V\; co"\; filenames="C9981138400781.png,C9981138400821.png"\; state="\{\{state\}\}">V</figure-callout>}}_{\mathrm{co}}\sqrt{\frac{1+r/\mathrm{<figure-callout\; id="1"\; label="N"\; filenames="C9981138400781.png,C9981138400821.png"\; state="\{\{state\}\}">N</figure-callout>}}{1+k_{\mathrm{ml}}r/N}}---\left(30\right)$

For different types of addressing, the value of providing V in formula (15) and (16), (17) and (18), (19) and (20) _RoAnd V _Co

These results can be applicable to this situation: when the voltage of accurate zero level is put on electrode fifty-fifty, when this level that adds a polarity in first frame and when adding this level of another polarity in second frame.These results also are available for this situation: when at each time interval T _rIn or fifty-fifty, have different value V _mSeveral (one, two ...) plant accurate zero level when being applied in to signal electrode.

Above-mentioned drive scheme can have N _Max＞N _MaxoDisplay in be used, if the driving voltage that is used for the row and column electrode by relational expression (11) or (12) decision, wherein η is defined as $\mathrm{\&eta;}=\sqrt{1-{\mathrm{<figure-callout\; id="0"\; label="N\; ma"\; filenames="C9981138400761.png,C9981138400771.png"\; state="\{\{state\}\}">N</figure-callout>}}_{\mathrm{ma}}/N_{\max }}$ And V _RoShould be by V _Ro1, V _Ro2Or V _Ro3Replace and V _CoBy V _Co1, V _Co2Or V _Co3Replace.

Be used for parameter N _MaxAnd the expression formula that is used for row and column voltage allows the influence of estimated voltage-time diagram form to the image quality of display.This estimates at and helps determine the good required condition of image quality.

Above-mentioned theory introduction is used to support the feasibility of following driving method.

Summary of the invention

The present invention includes several embodiment, and each embodiment has improved the image uniformity and the contrast of LC display and increased operating rate and yardstick.These embodiment allow the characteristic of passive matrix display to be comparable to the display characteristics of active matrix.

First embodimentBe the first kind of modification that drives the method for a LCD.This LC display has a plate, and this panel includes substrate, the array of one scan (OK) electrode is arranged in the substrate therein and the array of a signal (row) electrode is arranged in another substrate.Be inserted in LC material between two substrates and be arranged on lc unit between the point of crossing of described electrode.Lc unit generates the display element (or pixel) of this display, its size (directly or as the initial element of a projection display) is set and determines to change the function of its brightness as the voltage on this cell electrode.

Scan electrode by scanning voltage being applied to selection and with a reference voltage (V ₀Level) is applied to unselected scan electrode and sequentially selects scan electrode one by one or by the group.

At a selection cycle T _rDuring this time, by or be different from reference level V ₀Voltage (being referred to as significant level) or V ₀Level or both combinations and be energized.When difference (current) brightness of selecteed pixel combination or their duration and when obtained, the voltage level of these meaningful (signified) and reference voltage level are called as basic level by changing them.

In addition, at a selection cycle T _rDuring this time, has a constant duration (t _o) an additional V ₀Voltage level is applied in to signal electrode.Value V ₀These wide (to-wide) level are the main points that realize first kind of modification of this method.This additional levels is applied between two level of opposite polarity (this polarity is determined with respect to level V0).When in period T _rIn when not having dipolar significant level, auxiliary voltage is applied in to the row electrode, with reference voltage, if there be (width that has increased reference voltage level like this) in it or at T _rAny part, if the non-existent words of reference voltage.

First kind of modification of this method makes the dual increase that the parasitism (parasitic) of accurate ms voltage of lc unit changes.First kind of modification of this method causes the improvement of image quality and contrast and bigger screen size and operating rate (latter's realization is because speed is selected in the unit that improves).

Apply auxiliary voltage and reduced modulation that is applicable to pulse-length modulation, frame modulation or any other kind and the interval T that needs the variation of display parameter _rPart.

Change is at T _rThe width of the fundamental voltage level on the interior signal electrode should be followed certain rule.According to this rule, for the situation of delegation's selection, at T _rThe duration altogether of interior significant level is held constant and equals T _r-t _oWhen selecting a group row simultaneously, with respect to each period T of selecting _r, a certain mean parameter is held constant and equals T _r-t _oThis parameter is defined as period T _rOn duration of each significant substantially level and described significant level mould (with respect to V ₀) to the inverse ratio of the mould of the correct delegation addressing that is used for same display square the average summation of product.The addressing of described delegation is with described additional V ₀The same constant duration t of level _oBe implemented.Period T _rOn mean value be by during all selection cycles of in frame time, selecting identical display element described summation being carried out time average and by the result is doubled into T _rAnd obtain.

The correct driving of this modification by this method requires design and makes to have the formation parameter N _MaxScreen be equal to or greater than it in the relevant minimum value (N of the time diagram of this modification _Maxo).According to (22), $N_{\max o}=\frac{N}{(1-t_o/T_r)}.$ Drive level V _Ro1And V _Ro2Suitable amplitude can be determined from (24) and (25).From (25), draw at width t _oWith amplitude V ₀The help of additional levels under correct L capablely select to comprise the level amplitude that is used for all significant level $\frac{1}{\sqrt{1-t_o/T_r}}$ Multiplication is big.

This prototype of this modification of this method is the delegation's method for addressing (United States Patent (USP) 5,157,387 of Seiko Epson that does not have a LC display of pulse-length modulation; See pentarch).The key feature of this method is two level that generate signal voltage in each selection cycle.

Figure 10 shows the realization of this prototype method (to be seen and is used for V _Cj1, V _Cj2And V _Cj3Accompanying drawing), comprise the use reference voltage V ₀Realization as one of two level.

This prototype method has reduced the unevenness of the demonstration that causes by crosstalking.

For delegation's addressing, the first kind of modification of this method and the difference of this prototype method are the period T of its use between two significant level of opposite polarity _rIn be applied in an additional reference voltage V to signal electrode ₀In this case, at T _rDuring this time, according to the image that shows, three level but not two level can be applied in to signal electrode.

Another difference is multi-line addressing.

Figure 16 shows the voltage V that imposes on scan electrode and signal electrode under the situation of delegation's addressing _RiAnd V _CjTime diagram, in they should be in first kind of modification of this method.Pixel is set to " leading to ", " breaking ", and to middle (" gray scale ") state.Be used for V _CjFigure in, indicator marker voltage V ₀Be applied in cycle to signal electrode.

Do not resemble all figure (pentarch method) among the figure shown in Fig. 5 (first kind of prototype) and Figure 10, these figure V _CjHave in interval T _rOn be applied to the significant level V of two opposite polarities _cBetween additional levels V ₀Be used for V among Figure 10 _Cj1Figure seem to resemble very much and be used for V among Figure 16 _CjFigure but do not have T _rThree interior voltage levels.

Figure 17 shows row and selects voltage V _RiAnd V _{R (i+1)}With column signal voltage V _CjTime diagram.These figure have covered the length in two frame periods and the work of first kind of prototype of this method under two row addressing modes have been described.This addressing is comparable to the 8th prototype method as a modification of the multi-line addressing pattern of the method for being discussed.Be used for V _CjFigure in, indicator marker apply reference voltage V ₀Cycle t _oIn these figure of the 8th prototype method, there are not these at interval.Under the help of pulse length modulation, figure V _CjThe right state of selecteed pixel of while is set to (all), (absolutely), and (gray scale gray scale).This technology but in the 11 kind of prototype of this method, be introduced into not in the 8th prototype method.

Second embodimentBe the second kind of modification that drives the method for a LCD.This LC display is described in first embodiment.

Scan electrode by scanning voltage being applied to selection and with a reference voltage (V ₀Level) is applied to unselected scan electrode and sequentially selects scan electrode one by one or by the group.

At a selection cycle T _rDuring this time, by or be different from reference level V ₀(significant) voltage or V ₀Level or both combinations and be energized.These basic level are arranged on the pixel of selecting or the currency of brightness on a selection group the pixel by combination or their width that changes them.The undesired distortion (it influences pixel brightness) of this unit quasi ms voltage compensated also be applied in to scan electrode.

The characteristic of second kind of modification of this method is during selection cycle, applies to have opposed polarity and V ₀The identical constant mould that level departs from constant and equate the two auxiliary voltage level of duration.This is two additional with respect to reference level V ₀The t of opposite polarity _mThe V of/2 duration _mHigh level is called t by us _mThe accurate reference level of duration.These level are not controlled present picture element brightness, but the voltage that is provided with for the constant number on the signal electrode on the frame period of any pattern on the screen switches.The feasible pulsation of almost all removing the accurate ms voltage that causes by the porch distortion of these characteristics.The indelible residue pulsation of this method is determined the dependence of this unit ms voltage by cell capacitance and is less relatively.These characteristics have also increased the efficient that is used with the bucking voltage of the variation that reduces the brightness of undesired unit significantly.The example of concrete bucking voltage is presented in the 7th and the 8th kind of modification of this method.Remaining undesired pulsation is removed (seeing the tenth embodiment) by the 9th kind of modification of this method.

The use of second kind of modification of this method has improved image quality and contrast, and has increased display size and operating rate.

This prototype of second kind of modification of this of this method is the method (United States Patent (USP) 5,157,387 of Seiko Epson that activates a LC display; See the pentarch method) it has following feature:

---select voltage to be applied in to one of scan electrode,

-during period T r, two level voltages are applied in to these signal electrodes, and the voltage that the voltage of one (height) level is applied in a first stage time interval and another (low) level is applied in time stage time interval,

-this primary and secondary relative duration has at interval been determined the contrast grey level of this pixel.

The use of this prototype method causes being created on the uniform basically crosstalk noise in the whole demonstration.

The second kind of modification of this method and the difference of this prototype method are:

-it also uses multirow to select,

The voltage compensation of-its use unit quasi ms change in voltage,

-during cycle tr, opposite polarity, identical constant amplitude and the two auxiliary voltage level of constant equal duration are applied in to signal electrode,

The duration of-these opposite polarity additional levels does not determine the image contrast of this pixel.

In second kind of modification of this method, be used for the period T of pulse length modulation or frame modulation _rPart be reduced to T _r-t _mUnder this correct delegation addressing mode, for period T _r, the width altogether of significant level is held constant and equals T _r-t _mIn this correct multi-line addressing, this parameter is defined as duration of each the significant substantially level on the period T r and described significant level mould (with respect to V ₀) to the inverse ratio of the mould of the correct delegation addressing that is used for same display square the average summation of product.The addressing of described delegation is the duration t with the right identical steady state value of described additional levels _m/ 2 with identical constant V _mAmplitude is implemented.Period T _rOn mean value be by during all selection cycles of in frame time, selecting identical display element described summation being carried out time average and by the result is doubled into T _rAnd obtain.

Use first and second modification of this method to gear to actual circumstances together.In this case, T _r-t _mBy T _r-t _m-t _oSubstitute.

The realization of second kind of prototype of this method requires the N of display _MaxBe not less than the N that obtains from (22) and (23) _Maxo

Can have a value N from what (24) and (25) determined that assurance may be used for an addressing mode that provides _AmxoThe drive voltage amplitude V of correct driving of display _Ro1And V _Co1

Figure 18 shows for the situation of delegation's addressing, according to the driving voltage V to i scan electrode and j signal electrode of being applied in of the described modification of this method _RiAnd V _CjTime diagram.These figure have covered the length in two frame periods.Be used for V _CjFigure in, indicator marker width t _m/ 2 additional accurate reference level.Here the amplitude of these level is illustrated and equals these basic level, may not be this situation usually.(in the tenth embodiment of the present invention, for example be not equal to the level V of fundamental voltage _mCan be used to obtain the signal voltage pulse of the shape of front ladder).These pointers also illustrate according to first of this method and drive the V that modification is introduced into ₀Level.Be used for V _CjFigure concrete pixel is set to " leading to ", " breaking " and " gray scale " state.

Figure 19 shows the situation in two row addressing for two frame lengths, is applied in the driving voltage V to i and i+1 scan electrode and j signal electrode _Ri, V _{R (i+1)}And V _CjTime diagram.These figure are presented the use that is illustrated in second driving method under the multi-line addressing pattern.Indicator marker impose on the width t of signal electrode _m/ 2 and the additional levels of opposite polarity.These additional levels are illustrated and also equal these basic level.These pointers also mark amplitude V ₀With width t _oAdditional levels.Be used for V _CjThe state right (logical, logical) that illustrate, (disconnected, disconnected) and (gray scale, gray scale) according to the selecteed pixel of the pulse length modulation of the 11st embodiment of the present invention.

This embodiment is the main aspect of this method of providing and helpful in the every other modification of this method.

The 3rd embodimentIt is the third modification that drives the method for a LCD.This LC display is described in first embodiment.

Scan electrode by scanning voltage being applied to selection also is applied to unselected scan electrode with a reference voltage (V0 level) and sequentially selects scan electrode one by one or by the group.

At a selection cycle T _rDuring this time, basic level voltage (perhaps significant level or reference level or combination significant and reference level) is together with constant and the duration (tm/2) that equate and the identical constant mould V of opposite polarity _mAdditional levels be applied in to signal electrode together.The duration of this basic level can fade to the control of a certain value with the brightness of pixel clusters that a pixel of selecting or selection are provided from zero duration.

The new feature of this modification of this method comprises that these voltage levels are in period T _rOn be applied in a certain order to signal electrode.This order is forward or reverse.With respect to basic level V ₀The skew V of a polarity _mAdditional levels be assigned to period T _rBoundary member (level is assigned to beginning part and another level is assigned to T _rLatter end).

In follow-up period T _rIn, these voltage levels are imposed on the described order basis of signal electrode from period T _rBeginning part (therefore, at latter end) in V ₀The change of the polarity of the voltage level of level deviation and changing.Positive polarity is set at one-period T _rBegin the place and negative polarity is set at next period T _rBegin the place.This characteristic makes one-period T _rIn the significant level of end and next period T _rIn begin locate level and converge mutually.

These are alternately continued during some alternation times.The period T that these polarity alternations occur _rNumber can be limited (for example seeing the 8th embodiment) by the additional period that bucking voltage is provided for scan electrode.These level are applied in may different (seeing the 5th embodiment) or the order difference (seeing Figure 18) of the change of the reference voltage level under delegation's addressing etc. to the order of signal electrode.

Being used in combination at Figure 18 (delegation's addressing mode) and Figure 19 (two row addressing modes) of the 3rd, second and first modification that is used for driving a lcd screen is illustrated.In two accompanying drawings, be used for V _CjFigure polarity of voltage has been described, comprise period T _rBeginning and the alternation of the additional levels of end (just-negative, bear-just wait).The quantity that voltage changes and the parasitism of the accurate ms voltage of LCD unit changes reduces doubly.

The prototype of the 3rd modification of this method is the United States Patent (USP) 5,162,932 (triarch method) of Matsushita, and the purpose of this patent-prototype is to improve the image quality on the screen.

Fig. 8 shows the time diagram corresponding to the row and column voltage of this prototype.

This prototype is characterised in that:

-delegation addressing mode;

-at scan period T _s(NTs=T wherein during this time _FAnd N is the number of the row that is scanned, T _FBe the frame period), two level V _OnAnd V _OffBe applied in to signal electrode and be used for illumination or this selecteed pixel that do not throw light on;

-row selection cycle T _rLess than scan period T _s

-to scan period T _sBeginning part and the V of latter end _OnAnd V _OffThe interval that is distributed in the follow-up scan period is inverted.

This modification of the method for being advised and the difference of this prototype method are:

-capable selection cycle T _rLess than scan period T _sSign;

-in period T _rThe voltage level of going up more than two is applied in to row;

-multi-line addressing also arranged;

-in period T _rDuring this time, equal amplitude, width and opposite polarity are (with respect to reference level V ₀) two additional levels be applied in to a signal electrode;

-these additional levels are in period T _rBegin the place and end work;

-during Tr, all voltage levels are applied in according to a certain order to a signal electrode;

The sign of the alternation at the interval of-follow-up scan period is that the alternation (just-negative, negative-just) of polarity but not the alternation of state " lead to "-" breaking ", " breaking "-" leading to ".

Row in this modification of this method selects the amplitude of level to select the amplitude of level less than the row in this prototype method.This has reduced the frame response effect.

The use of the third modification of this method has improved image quality and contrast, and makes and can increase display sizes and operating rate.

The 4th embodimentBe the 4th kind of modification that drives the method for a LCD.This LC display is described in first embodiment.

Scan electrode by scanning voltage being applied to selection and with a reference voltage (V ₀Level) is applied to unselected scan electrode and sequentially selects scan electrode one by one or by the group.

At a selection cycle T _rDuring this time, reference level voltage (perhaps significant level or reference level or combination significant and reference level) is together with duration (t constant and that equate _m/ 2) and opposite polarity, from V ₀The identical constant mould V of the skew of level _mAdditional flat be applied in to signal electrode together.The duration of this basic level can fade to the control of a certain value with the brightness of pixel clusters that a pixel of selecting or selection are provided from zero duration.

In period T _rDuring this time, driving pulse is applied in to signal electrode by a certain order (forward ground or oppositely).The additional levels V of one polarity _mBe assigned to period T _rBeginning part and the additional levels V of opposite polarity _mBe assigned to period T _rLatter end.

The new feature of this modification of this method is that the level of opposite polarity is applied in to the row electrode so that the space compensation of the layering of crosstalking to be provided.For this reason, in period T _rDuring this time, voltage level is applied in to adjacent signal electrode or imposes on away from the signal electrode of one or two electrode or impose on and has the another kind of signal electrode of sequence that activates so that distribute to period T _rThe level of beginning part (and therefore giving latter end) have from V ₀The skew of the opposite polarity of level.

The the 3rd, second and the one LCD that is used for this method of two row addressing drives being used in combination at Figure 20 of modification and is presented.This accompanying drawing shows capable driving voltage V _RiAnd V _{R (i+1)}With row driving voltage V _CjAnd V _{C (j+1)}With at (i, the j) (V of voltage as a result of unit _Cj-V _Ri) time diagram.These time diagrams have covered two fields of a frame and first beginning of next frame.These time diagrams have been described when all display units has same brightness, and promptly they are in the moment of " leading to " state entirely.Do not use this modification of this method, in the case, this image will have the white pixel of the crosstalk layering and the maximum shade of the highest possibility level.The little black region in dialogue Pekinese will have maximum white and this image will have minimum contrast.Figure 20 shows the capable due to voltage spikes (first and second kinds the layerings of crosstalking) that the synchronous variation in the column voltage causes.

Draw the compensation of variation that opposite polarity at the driving voltage on the adjacent signals electrode causes the accurate ms voltage of the opposite polarity of first kind of layering of crosstalking on the column electrode of selecting and corresponding unit from Figure 20.Best compensation is (this design by the almost equal minimum of the opposite polarity voltage spike (spike) on unit quasi ms voltage that provides of the amplitude that makes them in conjunction with effect) by adopting that drive electronics according to the 7th embodiment work realizes.

The vibration of the unit quasi ms voltage that the 4th modification of this method also will be caused by second kind of layering of crosstalking (this kind layering appears in cycle between the continuous capable strobe pulse and causes the full swing of this unit quasi ms voltage) has reduced more than the twice.This effect is by in period T _rIn, separate driving voltage in time and cross the moment of adjacent signals electrode (carrying the pixel of same brightness) and realize.Figure 20 show when second kind opposite polarity layering spike in first of this frame separated and in second almost by the concrete condition of full remuneration.Under this concrete condition and some other situations, this technology allows the influence of the capable layering of second kind of dual as much as possible minimizing to this unit quasi ms voltage.(for example have unit quasi ms voltage U for the uniform luminance image _Gr ²A gray level image), use this modification of the present invention the unit quasi ms change in voltage that is caused by second kind crosstalk almost can be reduced to zero.

The prototype of the 3rd modification of this method is the United States Patent (USP) 5,162,932 (triarch method) of Matsushita, wherein uses delegation's addressing mode.In each period T _rIn, a signal electrode receives two voltage levels, " leading to " and " breaking ", both one of (perhaps " leading to " or " breaking ") appear at period T _rBegin the place, another appears at end, and along with individual Tr in succession, two level switches.

This modification of this method is different from the prototype in the or six that illustrates in the description to the 3rd modification of this method and the difference between its prototype, and in this point that adjacent or alternating signal electrode or given number electrode are presented, and also has to have with respect to V ₀Opposite polarity and period T r begin locate or in the pulse of end.

The use of the 4th kind of modification of this method has improved image homogeneity and contrast, and has increased display size and operating rate.

The 5th embodimentBe the 5th kind of modification that drives the method for a LCD.This LC display is described in first embodiment.

Scan electrode by scanning voltage being applied to selection and with a reference voltage (V ₀Level) is applied to unselected scan electrode and sequentially selects scan electrode one by one or by the group.

At a selection cycle T _rDuring this time, reference level voltage (perhaps significant level or reference level or combination significant and reference level) is together with duration (t constant and that equate _m/ 2) and opposite polarity, apart from V ₀The identical constant mould V of the skew of level _mAdditional levels be applied in to signal electrode together.The duration of this basic level can fade to the control of a certain value with the brightness of pixel clusters that a pixel of selecting or selection are provided from zero duration.

In period T _rDuring this time, driving pulse is applied in to signal electrode by a certain order (forward ground or oppositely).The additional levels V of one polarity _mBe assigned to period T _rBeginning part and the additional levels V of opposite polarity _mBe assigned to period T _rLatter end.

This modification of this method provides in time course the compensation to cross stratification.For this reason, in period T _rIn these voltage levels be applied in that (wherein these scanning voltages or scanning voltage group have and V at the scan electrode of selecting same scan electrode or same cluster to the order of signal electrode ₀The polarity that level is identical or opposite) T _rIt in cycle alternation.This alternation is set in the cycle at follow-up frame time, perhaps in a frame time or in two frame times or according to other comparison order in time course.The rule of this alternation alternately is provided with and is dispensed to period T _rBeginning (and therefore, finish) part signal voltage level (apart from V ₀The voltage V of skew level) and the scan electrode of scan electrode that imposes on identical selection or selected group's identical selection _r(apart from V ₀Identical and the opposite direction of skew level).

The characteristics of this modification of this method are that first and second kinds the influence to unit quasi ms voltage of crosstalking is along with the time is cancelled, because they have opposite polarity in continuous frame.Similarly, this modification of this method has been removed the layering of inducting on the signal electrode by the change in voltage on the column electrode.

The the 5th, the 4th, the 3rd, second and the one LCD that has provided this method under the situation of two row addressing in Figure 20 drives an example that is used in combination of modification.

Figure 20 shows than the corresponding intervals T in first of first frame _rFirst kind of interior these continuous level, second kind of continuous voltage V in first of second frame _CjAnd V _{C (j+1)}The interval T that is provided with _rThe above-mentioned alternation of interior signal level, this alternation depends on period T _rVoltage V on an interior significant level of guiding and the column electrode of selecting _rWhether has identical polarity.The due to voltage spikes of signal voltage transitions improves this unit quasi ms voltage in an image duration $\frac{1}{T_r}\underset{0}{\overset{\mathrm{Tr}}{\&Integral;}}{V}_{\mathrm{ri}}^2\left(t\right)\mathrm{dt}-$ Component and reduce it in another image duration makes the pulsation of this unit quasi ms voltage offset.

The prototype of this modification of this method is the United States Patent (USP) 5,162,932 (triarch method) of Matsushita, wherein uses delegation's addressing mode.In each period T _rIn, a signal electrode is presented with two voltage levels, " leading to " and " breaking ", both one of (perhaps " leading to " or " breaking ") appear at period T _rBegin the place, another appears at end, and along with individual T in succession _r, two level switches (Fig. 8).

The 5th modification of this method is different from the prototype in the or six that illustrates in the description to the 3rd modification of this method and the difference between its prototype, additional difference is to select according to the significant level of guiding in period T r with on a row of selecting or with respect to V ₀Has the voltage V on the concrete row among the group that one of identical polar selects _r, perhaps or alternately or impose on the order of the significant level of a signal electrode during the period T r in other concrete frames of selecting in successive frames.

The r of interval T in succession that occurs in this prototype begins the pulsation that place and end exchange that level " leads to " and the position of " breaking " provides the alternating polarity of the layering spike of discrete cell place same type in consecutive frame and do not compensate the unit quasi ms voltage that is caused by these layering spikes.

When being used in combination, the residue imperfection of the deletion of the 5th modification of this method by removing the unit quasi ms change in voltage cause by crosstalking has increased the effect of the 4th modification of this method.The residue imperfection of the 4th modification of this method and then the deletion by removing the unit quasi ms voltage oscillation that is caused by compensating delay on frame time is replenished pentarch.

The use of the 7th embodiment has increased the effect of the 5th modification of this method.

The use of this modification of this method has reduced the pulsation of unit quasi ms voltage, has improved image homogeneity and contrast, and has increased display size and operating rate.

The 6th embodimentBe the 6th kind of modification that drives the method for a LCD.This LC display is described in first embodiment.

Scan electrode by scanning voltage being applied to selection and with a reference voltage (V ₀Level) is applied to unselected scan electrode and sequentially selects scan electrode one by one or by the group.

At a selection cycle T _rDuring this time, potential pulse is applied in to signal electrode.These pulses are provided with reference level voltage (perhaps significant level or reference level or combination significant and reference level) together with duration (t constant and that equate _m/ 2) and opposite polarity, apart from V ₀The identical constant mould V of the skew of level _mAdditional levels together.The duration of this basic level can fade to the control of a certain value with the brightness of pixel clusters that a pixel of selecting or selection are provided from zero duration.

In period T _rDuring this time, driving pulse is applied in to signal electrode by a certain order (forward ground or oppositely).With respect to V ₀The additional levels V of one polarity of level _mBe assigned to the beginning part of period T r and the additional levels V of opposite polarity _mBe assigned to period T _rLatter end.In period T _rGo up these level and be applied in order to signal electrode in follow-up period T _rIn by alternation.

The potential pulse that the characteristic of this modification of this method is to impose on signal electrode is broken down into a plurality of groups and in this period T _rIn the nominal position with them be shifted in relevant time, these groups are correlated with different electrodes.The value of these shift times is set to identical for a single group pulse, but the pulse for distinct group is provided with differently, and for certain one-period be constant (for example for a part of one or one whole or an entire frame, perhaps two frames).This applies all after dates in end, the value of other shift time is in certain a group or all be set in group's the potential pulse or the potential pulse group of other groups (aggregate) is formed among the different groups and has different shift time values, and these described other shift time values are set to constant for next time cycle.After this next time cycle finishes, described or change or the described processing of setting the steady state value of shift time is continued, provide apart from the zero mean deviation of the duration of each described additional levels of its nominal position.This shift time should not surpass t _m/ 2 and can be just or negative or zero.

Cause due to voltage spikes on the unit to have low amplitude and opposite polarity and offset in the signal voltage transitions of different current times.

Yet the signal electrode group with random time displacement of driving pulse may cause the non-homogeneous inhibition of crosstalking.Crosstalk for suppressing more effectively, the shift time of the potential pulse among the group should be changed according to concrete rule.Promptly be held after the constant time cycle finishes in potential pulse group's shift time value therein, up-to-date shift time value is set in this burst of pulses, respectively has shift time value the earliest, previous shift time value is set in this burst of pulses, respectively has next the shift time value after the shift time value the earliest, and the variation of such shift time value is employed in other pulse trains until each pulse wherein and has the earliest shift time value, is changed to the pulse train of up-to-date shift time value.

The signal electrode group who has K equal sizes, whether the above-mentioned rule of pulse displacement makes the LCD according to this method drive modification and is used and makes second kind of unit quasi ms pulsation of causing of crosstalking produce 2K respectively doubly or K reducing doubly.

For the unit such as brightness such as grade in big zone, this effect is the most obvious.Be the pulsation in the little viewing area that reduces uniform luminance, these pulses of forming a pulse train of identical displacement should belong to the signal electrode and/or this group that have than enough separating greatly should change its composition in time.

Figure 21 shows and imposes on three pulse train V that three signal electrode groups reach the isopulse displacement in two frame length cycles _C1, V _C2And V _C3The row strobe pulse is not illustrated.For simplicity's sake, delegation's addressing mode is illustrated.These fundamental voltage level are set to " leading to " state with suitable unit.Selection cycle T _rHave two additional t _m/ 2 wide parts, each several part are used for " breaking " and " leading to " value.Pulse width is illustrated and exceeds yardstick.The possible variation of the pulse polarity from a frame to another frame is not illustrated.Be in from selecting the capable period T of n _{R (n)}To the period T of selecting (n+1) row _{R (n+1)}In the alternation of voltage level be illustrated.Two pulse train V _C1And V _C2Has rightabout different time displacement t with respect to their original (not being shifted) position ₁And t ₂The 3rd pulse train V _C3Be not shifted..Figure V _RiThe voltage as a result of these three display units is shown, index (c ₁, c ₂, c ₃) give (attributing) appropriate signals electrode group with the non-selected row of i.

Be determined the average (they must be considered with respect to the polarity of driving pulse) as the spike of inducting, the influence of crosstalking on the unit quasi ms voltage in each of this three one-element groups reduces doubly, on average in period T _rSingle spike of crosstalking in three interior possibilities.

Another example shown in Figure 22.The driving pulse V that is used for signal electrode directly is not shown in the figure _C1, V _C2And V _C3The group.Figure (the V that is used for display unit _Cj-V _Ri) can determine them by analyzing Figure 21.Opposite with Figure 21, a plurality of displacement (t of use equidirectional in Figure 22 _dOr 2t _d).Although two displacement change cycles are enough to reduce cross talk effects, keep equaling t _mThe mean breadth of/2 extra-pulse requires at the capable selection cycle T of n _{R (n)}The order of interior these pulses changes in subsequent frame, for example drives in the modification in the 5th of this method.As a result, the complete cycle of displacement change becomes four constant in time shift cycles.Other rules that are used to change the pulse displacement are possible, for example continuous combination of four reference period shown in Figure 22.

For driving the big viewing area of constant luminance, all prototype methods, the United States Patent (USP) 5 that comprises Matsushita, 162,932 (the third prototype methods, this prototype of itself and this method is similar), use cause second kind significantly crosstalking and with the driving voltage of the relatively poor color of high frame speed performance.Think that by the paper (SID ' 97, M75-M87 page or leaf) that the researcher at the Sharp of the SID of Toronto Symposium and Hitachi delivered in Dec, 1997 these technology can make minimizing by the dissimilar vertical and horizontal deepenings of crosstalking and causing.These technology do not use pulse displacement and their efficient not high, when using with pulse length modulation especially.

Except removing the deepening effect, this modification of this method has been improved image homogeneity and contrast, has increased display size and operating rate, and makes and show good color.

The 7th embodimentIt is the device that drives a LC display.

This LC display has a plate, and this panel comprises some substrates, the array of one scan (OK) electrode is arranged in the substrate therein and the array of a signal (row) electrode is arranged in another substrate.Be inserted in LC material between two substrates and be arranged on lc unit between the point of crossing of described electrode.Lc unit generates the display element of this display and determines to change the function of its brightness as the voltage on this cell electrode.Scan electrode by scanning voltage being applied to selection and with a reference voltage (V ₀Level) is applied to unselected scan electrode and sequentially selects scan electrode one by one or by the group.Signal voltage is applied in to the brightness of a signal electrode with the pixel clusters of setting a pixel of selecting or selection.This display is driven according to these modification of given method.

This device that drives a LC display comprises a collection of row and column driver (voltage impulse generator, VP) with one to other unit or device power supply and be provided for the voltage level generator (VLG of the level of row and column, one power supply unit) this VP is combined with unit that a timing voltage level that is set to an output electrode is provided with (briefly, timing unit, TB), this TB unit comprises that a voltage changer unit (VCB) and that a logical block (LB) and is electrically connected to this LB is electrically connected to the output transistor unit (OTB) of this VCB.The output lead of this OTB is connected to this show electrode.These LB that are used for column electrode are connected by a two-way shift register and these LB of being used for the row electrode are connected by another shift register.All unit are connected to this VLG.When this display for example was operated in for 2 row addressing mode following times, the VP that is used for the row electrode can not have a VCB, and in the case, this LB is connected directly to this OTB.This LB input lead is applied in clock and gating pulse.This LB that is used for the row electrode is also presented with the data-signal from a data processing unit.

The characteristic of this device is to be provided with the OTB design of identical shaped dipolar due to voltage spikes.This result is the better crosstalk compensation (for this method the 4th, the 5th and the 6th modification the best) to any driving modification of this method of using, and therefore, improve picture quality (homogeneity and contrast), and can increase the operating rate and the size of display.

Figure 23 shows the block scheme of LC panel 4 drive units.It is made up of with row and column voltage pulse producer 2 and 3 the voltage level generator 1 to other unit feeds.This device generates gating pulse and starts this LCD work that (comprises delegation's addressing, two row addressing or multi-line addressings) under any capable preference pattern of the present invention.

Voltage impulse generator 2 has many show electrode Y that are used to drive ₁, Y ₂..., Y _i..., Y _NPassage and driver 3 has many show electrode X that are used to drive ₁, X ₂..., X _i..., X _NPassage.Each passage of driver 2, for example the i passage is combined with logical block 5 (LB _i), voltage changer unit 6 (VCB _i) and output transistor unit 7 (OTB _i), this logical block 5 (LB wherein _i) be provided with strobe pulse is imposed on passage Y _iThe moment.Unit 5 is connected to unit 6, and unit 6 is connected to unit 7, and unit 7 is connected to show electrode Y _iEach passage of driver 3, for example the j passage is combined with process data signal and is provided with signal level is imposed on channel X _jThe logical block 8 (LB in the moment _j) and be connected to unit 8 and electrode X _jOutput circuit unit 9 (OTB _j).Unit 5 and 8 input lead 10 and 11 by feedback with clock and gating pulse, the input lead 12 of unit 8 by feedback with data-signal.Unit 5 is connected to LB _I-1And LB _I+1And unit 8 be connected to adjacency channel to LB _J-1And LB _J+1, respectively by the bidirectional shift register of oneself, the filp-flop stage of these shift registers is incorporated in in the suitable logical block.

Logical block 5 and 8 generates low level voltage, and its time diagram provides the formation of the driving voltage in the unit 6,7 and 9.

Voltage generator 1 generates five voltage level V at least ₀, V ₁, V ₂, V ₃And V ₄, these level are measured from a certain common level.Reference level V ₀To voltage impulse generator 2 and 3, level V ₁And V ₄To row voltage impulse generator 2, level V ₂And V ₃To column voltage pulse producer 3.Make like this | V ₁-V ₀|=| V ₄-V ₀| and | V ₂-V ₀|=| V ₃-V ₀|, and must make lc unit have the accurate ms voltage of the working range of the dynamic squared voltage-optical characteristics that is positioned at the unit corresponding to the combined voltage level of the time diagram of the driving modification of this method.This dynamic squared voltage-optical characteristics determines to influence the dynamic N of picture quality _MaxAnd dynamic contrast.

One of these column voltage level are V for example ₂Can be applied in to unit 2 and be used to offer unit 5 and 6 with low level voltage.

A kind of possible design of unit 7 is illustrated in Figure 24.From VCB _iSignal sets with voltage V ₀, V ₁Or V ₄Impose on the moment of output electrode.The design class of unit 9 is similar to the design of unit 7.Difference is to use V ₂Replaced V ₁And use V ₃Replaced V ₄

The dipolar spike that causes by crosstalking is of similar shape, because the transistor of combination provides identical output resistance to different magnitudes of voltage among the OTB (for example 13 among Figure 24,14,15 and 16), perhaps skew does not exceed 10%.Such characteristic of these output transistors causes selecteed relation between the transistor junction constitutive element (length of transistor channels and width, the thickness of gate oxide etc.).

In the dissimilar transistor of manufacturing characteristic, has difficulty with the resistance value that provides approaching.For avoiding these difficulties and improve inhibitions of crosstalking, another OTB constructs and is combined with additional transistor (17 among Figure 25,18,19 and 20).Transistor 17 and 18 is introduced into so that they and transistor 13 common output resistances equal the output resistance of transistor 14, the output resistance of transistor 14 initially what less than the resistance of transistor 13.Have the output resistance common with transistor 15, transistor 19 and 20 is introduced into and makes described resistance equal the output resistance of transistor 16, the output resistance of transistor 16 initially what less than the resistance of transistor 15. Additional lead 21 and 22 all unit 7 (for unit 9) for drive system are common.After by the electric conductivity of selecting the suitable suitable voltage correction transistor 17 that is applied to lead-in wire 21 and 22 two ends and 19, they are in logical state.These output resistances are held for all voltages that impose on (in all passages) output lead and equate like this.

The function class of unit 9 is similar to the function (Figure 25) of unit 7, except voltage V ₁By V ₂Substitute and V ₄By V ₃Outside substituting.

The prototype of the modification of this method is to be used for the drive device for display that these patents of these prototype methods provide and to be combined with the output transistor that is electrically connected to output lead.Yet they do not provide transistorized output resistance, and a concrete voltage is applied in to output lead having identical or approaching value by it, and skew is no more than 10%.

The 8th embodimentBe the 7th kind of modification that drives the method for a LCD.This LC display is described in first embodiment.

Scan electrode by scanning voltage being applied to selection and with a reference voltage (V ₀Level) is applied to unselected scan electrode and sequentially selects scan electrode one by one or by the group.

Signal electrode is driven by potential pulse.These pulse settings provide unit all reference level voltage of the nominal currency of square voltage (perhaps significant level or reference level or combination significant and reference level) and duration (t constant and that equate _m/ 2), opposite polarity and identical constant mould V _mAdditional levels.The accurate ms mains ripple that these additional levels settings are caused by its distortion when long electrode is propagated by the row driving pulse one almost with the irrelevant component of image.Normally negative on the polarity, this component impose on along with the distance drive voltage pulses row electrode point distance increase and amplitude increases.Almost irrelevant by the similar unit quasi ms mains ripple that the distortion of horizontal driving pulse causes with image model.Therefore any image pixel that is caused by these pulse distortions depends on pixel location to a great extent apart from the variation of nominal value.

The difference part of this modification of this method is to generate additional bucking voltage V _Com(i) be used for from a specific initial i column electrode and/or generate additional bucking voltage V _Com(j) be used for initial j row electrode from another specific.The amplitude V of these bucking voltages _Com(i) or their duration on experience or be determined with analyzing and be used for each column electrode (for given time diagram and frame rate) so that the The optimal compensation of the accurate ms mains ripple that the propagation distortion by the row pulse is caused to be provided.Similarly, the amplitude V of these bucking voltages _Com(i) or their duration on experience or be determined with analyzing and be used for each column electrode (for given time diagram and frame rate) so that the The optimal compensation of the accurate ms mains ripple that the propagation distortion by horizontal pulse is caused to be provided.Duration t _cOne or several time interval be added to N selection cycle Tr on this frame period.One or several t _cDuring the sub-fraction of interim, each bucking voltage V _Com(i) be applied in column electrode to i.One or several t _cDuring the sub-fraction of interim, each bucking voltage V _Com(j) be applied in to j row electrode.Be not applied to voltage V _Com(i) and V _Com(j) row and column electrode in t interim, are applied in reference voltage V ₀Instead of voltage V ₀, can use accurate reference voltage or average, or combination, comprise and voltage V ₀The accurate reference voltage of combination.

The main points of this modification of this method are to use constant (in the time course) value of the bucking voltage that is used for special electrodes or the wide scope of shape and the unit quasi ms mains ripple that can be compensated.

Be used for being illustrated at Figure 26 corresponding to the example of the time diagram of the horizontal pulse of this modification of this method.Under delegation's addressing mode, strobe pulse Vr is applied in to first on two frames, i, (i+m) and N column electrode and under two row addressing modes, strobe pulse Vr is applied in to first on two, i, (i+m) and N column electrode.The bucking voltage δ V of different amplitudes _i, δ V _I+m, δ V _NBe applied in all column electrodes (except that first) that are illustrated in the identical time to each.At this moment, all row electrodes comprise the j row, pass through reference voltage V ₀Be energized.

Example when undeclared capable bucking voltage has equal amplitude with different duration in Figure 26 and for other times t at interval _c, the example when bucking voltage is applied in to the row electrode, but can be considered in a similar fashion (synthesizing).

Can derive for given addressing mode from (28), (29) and (30), offer and have N _Max=N _MaxoThe display of minimum possible value with the driving voltage V of correct driving _R02And V _C02Amplitude.N _MaxoCan obtain from (31).

The prototype of this modification of this method is the United States Patent (USP) 5,151 of Seiko Epson, the method for the driving one active matrix LC display described in 690, and it has stated following feature in first of this patent scheme:

-use delegation addressing mode;

-except driving voltage is applied in time interval (" driving time ") to electrodes for display, occur image fault in the cycle formerly to cycle time (" make-up time ") that the small part compensation takes place;

-during cycle make-up time, strobe pulse is not applied to column electrode, and the encouraging to the required auxiliary voltage of small part compensation of the distortion that caused by the image change in the cycle formerly of one or more signal electrode.

For realizing this technology, second suggestion of this patent scheme should come setting compensation voltage according to the variation number between " leading to " and " breaking " state on the particular column electrode for the previous time cycle before this make-up time.

These row and column voltage patterns corresponding to this prototype method are illustrated in Fig. 9.Voltage V _RiBe applied in to row Y _i, voltage V _CjBe applied in to row X _j, V _IjBe (i, j) voltage of unit.V ₀₁And V ₀₂It is the reference voltage in the consecutive frame.After having selected all column electrodes, bucking voltage is applied in to row X _jReach time t _c(its length depends on during the cycle formerly at electrode X _jOn the change in voltage number).

The modification of this method and the difference of prototype method are:

-multirow preference pattern is possible;

-by using some means, for example by accurate reference voltage is imposed on signal electrode, the propagation distortion of pulse shape is caught with image irrelevant to the influence of unit quasi ms voltage;

-voltage V _Com(i) be applied in to the i column electrode and compensate with influence to row pulse propagation distortion;

-at bucking voltage V _Com(i), V _Com(j) parameter and cross in the time cycle formerly between the luminance distortion of display and do not have correlativity.

The 7th modification of this method has been improved image homogeneity and contrast, and has increased display size and operating rate.

The 9th embodimentBe the 8th kind of modification that drives the method for a LCD.This LC display is described in first embodiment.

Scan electrode by scanning voltage being applied to selection also is applied to unselected scan electrode with a reference voltage V 0 and sequentially selects scan electrode one by one or by the group.

Signal electrode is driven by potential pulse.These pulse settings provide unit all reference level voltage of the nominal current value of square voltage (perhaps significant level or reference level or combination significant and reference level) and duration (t constant and that equate _m/ 2), opposite polarity and identical constant mould V _mAdditional levels.

The accurate ms mains ripple that these additional levels settings are caused by its distortion when long electrode is propagated by the row driving pulse one almost with the irrelevant component of image.This component impose on along with the distance drive voltage pulses row electrode point the increase of distance and amplitude increases.Any pixel brightness that is caused by these pulse distortions depends on pixel location apart from the variation of its nominal value.

The difference part of this modification of this method is to generate from the initial capable bucking voltage V of a particular row _Com(i).The amplitude V of these bucking voltages _Com(i) or their duration on experience or be determined with analyzing and be used for each column electrode (for given time diagram and frame rate).Be expert at particular moment in the selection cycle this bucking voltage V _Com(i) be added to the compensation of scanning voltage that (to be superimposed upon) put on the i column electrode with the accurate ms voltage of reduction that the capable unit of i that the propagation distortion by the row driving pulse is caused is provided.

Be used for being illustrated at Figure 27 corresponding to the example of the time diagram of the capable voltage of this modification of this method.Under delegation's addressing mode, strobe pulse V _rBe applied in to first, i, (i+m) and the N column electrode reached for two frame periods and under two row addressing modes, strobe pulse Vr is applied in to first, i, (i+m) and N column electrode reach two.The bucking voltage δ V of the different amplitudes that add _i, δ V _I+m, δ V _NBe shown in broken lines.Vcj shows the time diagram of the driving voltage that is used for the j signal electrode.

The prototype of this modification of this method is the method for the driving one active matrix LC display described in the United States Patent (USP) 5,151,690 (tetrarch method) of Seiko Epson.

Except the 7th modification of this method is different from these aspects of tetrarch method, the use that the 8th modification of this method does not have this prototype imposes on bucking voltage the difference part in one time interval of separating of signal electrode

The main points of this modification of this method are to use constant (in the time course) value of the bucking voltage that is used for each column electrode and the wide scope of the unit quasi ms mains ripple that can be compensated.At the N that distributes and increase this display _MaxIn need be in the frame period yet duration t _cThe backoff interval of separation.

The 8th modification of this method has been improved image homogeneity and contrast, and has increased display size and operating rate.

The tenth embodimentBe the 9th kind of modification that drives the method for a LCD.This LC display is described in first embodiment.

Scan electrode by scanning voltage being applied to selection and with a reference voltage V ₀Be applied to unselected scan electrode and sequentially select scan electrode one by one or by the group.These pulse settings that impose on signal electrode provide all reference level voltage of the nominal currency of square voltage (combination of perhaps significant level or reference level or significant and reference level) of unit.

Yet the shape deterioration of the driving pulse of propagating along a long column electrode causes the undesired variation of accurate ms voltage of these unit and the worse optical property of these pixels.The value of these variations is the functions of cell capacitance that depend on the current value of reformed accurate ms voltage.These known technologies can not solve with the cell capacitance that depends on display mode and change relevant negative effect like this.

The 9th modification of this method is designed to eliminate by these pulse edge long electrodes on the accurate ms voltage of unit and propagates the influence of the pulse shape distortion that causes and suppress the effect of the deepening that the variation by cell capacitance causes.

The difference part of this modification of this method is specific pulse shape.This pulse shape provide on the one hand required place, unit at a long electrode ms voltage value and the self compensation of the caused accurate ms change in voltage of distortion of porch when being propagated by this electrode of these pulse edges (comprising the electrode that has nonlinear characteristic) is provided on the other hand.The rising edge of one pulse and trailing edge (front portion and afterbody) are considered to apart from reference voltage V at this ₀A voltage jump and voltage is jumped and to be fallen.

Follow the transient process of the potential pulse on a long electrode can be approximate with an index (exponent), this transient time depend on a discrete cell the position (i, j).When this rising edge had the identical transient time with trailing edge, the driving pulse that has stepped rising edge can provide unit quasi ms the reduction of voltage, and it equals or increasing near this value that equals to be caused by this trailing edge.For guaranteeing the self compensation of this unit quasi ms mains ripple, the reduction of the unit quasi ms voltage that the profile of this rising edge provides should be littler three times than the reduction of the unit quasi ms voltage that is caused by the pulse that has precipitous rising edge.

Figure 28 illustrates the example of time diagram that self propagation produces the driving pulse that has stepped rising edge of distortion.The reduction of unit quasi ms voltage is with respect to level V ₀The rising edge and the trailing edge of opposed polarity be illustrated.Than the rect.p. of routine, pulse V ₁Can reduce unit quasi ms mains ripple doubly.Have two ladders in rising edge, if this ladder top long enough is to provide enough the finishing (dying) of the transient process in this long electrode, pulse V2 can eliminate unit quasi ms mains ripple.

Front portion with stairstepping can form by additive method.One of method is at each T _rApply two or three additional accurate reference levels in cycle fifty-fifty and give signal electrode, described level has identical constant duration (t _m/ 2) with different mould value (V _M1, V _M2...).

Being used in combination of the 9th and the 5th modification of this method reduced or eliminated at these porches and arrived the unit quasi ms mains ripple that the non-similarity of voltage of comparative electrode of the time of one of electrodes causes.

The method of describing in the United States Patent (USP) 5,301,047 of Hitachi approaches this modification of this method most.This prototype method uses as the delegation's addressing mode in the modification of this first prototype method, and multi-form HF voltage is added to row or column or row and column voltage level continuously.The purpose of this prototype method is to improve the homogeneity of display image.Fig. 7 has provided by copped wave is imposed on the voltage profile in the ij unit that the row and column driving voltage generates continuously.

The 9th modification of this method and the difference of second prototype method are:

-driving voltage does not superpose continuously with the high-frequency impulse of Any shape;

-be used for show electrode driving pulse ladder or be provided at the self compensation of the pulse distortion influence on the unit quasi ms voltage near the rising edge of ladder.

The 9th modification of this method has been improved image homogeneity and contrast, can increase display size and operating rate.

The 11 embodimentBe the tenth kind of modification that drives the method for a LCD.This LC display is described in first embodiment.

With by two select progressively scan electrodes, on the frame period at least twice.Polarity (the V of scanning voltage _R1And V _R2) according to an ad hoc rules alternation, for example these voltages have identical polarity (with respect to V in first ₀) and in second, have opposite polarity.Can use other rules that described alternation is provided fifty-fifty.Non-selected column electrode carries reference voltage V ₀

During a selection cycle Tr, basic level is applied in to a signal electrode together with additional levels.

The difference of this modification of this method is to be called information and accurate benchmark equilibrium (equalizing), and two components of these significant level are applied in to signal electrode with the pulse length modulation of unit that selection is provided but not the frame modulation of using in the multi-line addressing pattern.

The brightness a of pixel according to the joining that is positioned at i and (i+1) column electrode and j row _IjAnd a _{(i+1) j}(a _IjAnd a _{(i+1) j}For example can from-1 change to+1), these row receive a half-sum (a of its duration and brightness value under the capable strobe pulse of identical polar _Ij+ a _{(i+1) j})/2, or half poor (a of the brightness value under the horizontal pulse of opposite polarity _Ij-a _{(i+1) j}The message level that)/2 are proportional and polarity is identical.The nonlinear optical electrical characteristics of the duration of this message level for the LC display element can be corrected.

This message level can be the same with period T r wide or shorter than it.For example, if according to first and second modification of this method, except message level, additional levels is applied in to signal electrode, and the maximum duration of message level is set and equals T _r-t _m-t ₀

Obviously the total duration of these message levels can change for the time of two selection cycles.For the total duration that makes all significant level relevant with these given pixels constant.Use variable and amplitude of duration to equal the accurate benchmark equalization of level of message level.Do not have additional levels, define with respect to V from (18) ₀The amplitude of row driving pulse.Otherwise, use (25) to obtain this amplitude.All information on the two period T r and the total duration of equalization of level are equal to or greater than the maximum duration of information component, for example go up the T in the example _r-t _m-t ₀The total duration of all the significant level in the two given selection cycles becomes and equals T _r+ t _m-t ₀

The duration of these information component level strictly according to above-mentioned rule in each two period T _rIn be set, and the equalizing voltage level can be distributed between two cycles of at random following this accurate baseline profile closely or fifty-fifty.

Foregoing shown in Figure 29, wherein on two pairs of field frames, illustrate provide selection to the (i, j) and (i+1, j) the row control voltage V of unit _RiAnd V _{R (i+1)}And row driving voltage V _CjAt each selection cycle T _rDuring this time, these row receive the row drive voltage pulses that includes information and equalization of level and additional levels, and these additional levels comprise t ₀Wide reference level V ₀And t _mWide accurate reference voltage, the latter's amplitude equals the amplitude of fundamental sequence driving voltage.On each period T r, have and strobe pulse V _RiThe total duration t of the meaningful level of identical polar _OffAnd have and strobe pulse V _RiThe total duration t of the meaningful level of opposite polarity _OnComprise corresponding to one constant of duration of this additional meaningful level and can comprise a variable item corresponding to the summation of duration of accurate benchmark equalization of level and message level.Because additional meaningful level is in each period T _rIn have meaningful level.In Figure 29, these meaningful level are placed on period T _rBegin the place and end.At item t _OffAnd t _OnOn indication numbers 1 and 2 be meant that meaningful level belongs to the first or second frame field.

The pixel of selecting according to the figure among Figure 29 is assumed to be to have different intensity levels: a _Ij=-0.5 and a _{(i+1) j}=-0.25.Negative polarity " is led to " corresponding to level.According to this modification of this method, the duration of message level and polarity are set-0.375 (T in first _r-t _m-t ₀) and in second, be set-0.125 (T _r-t _m-t ₀).Total duration for each equalization of level of given pixel is 0.25 (T on two frame fields _r-t _m-t ₀).The accurate reference level of this equilibrium component or their mark can be in any form in interval T _rOn be distributed.In Figure 29, they all are positioned in the second frame field.As a result, in first in selection cycle, the total duration t that level " breaks " _Off1=t _m/ 2 and the total duration t that " leads to " of level _On1=t _m/ 2+0.375 (T _r-t _m-t ₀).In second of select time, the total duration t that level " breaks " _Off2=t _m/ 2+0.25 (T _r-t _m-t ₀) and the total duration t that " leads to " of level _On2=t _m/ 2+0.375 (T _r-t _m-t ₀).The total duration of all the meaningful level in two period demands is (T _r+ t _m-t ₀).

Its intensity level of providing in Figure 17 and Figure 19 example corresponding to two field voltage figure of the pixel clusters of (logical, logical), (disconnected, disconnected), (gray scale, gray scale) has been discussed in other paragraphs.

The prototype of the tenth modification of this method is presented in the United States Patent (USP) 5,489,919 (the 8th prototype method) of Asashi Glass, wherein uses a multi-line addressing.Figure 12 shows the capable driving voltage that is used for the four lines addressing.Provided the algorithm of obtaining column voltage at the chapters and sections that are used for the 8th prototype method " background of invention ".This algorithm comprises continuously to corresponding in period T _rOn be that the logical value of constant row and column voltage is carried out " can not hold concurrently or " computing, with result's summation of computing, and with these with convert the row driving voltage to.This algorithm does not allow pulse length modulation is carried out in two row addressing, does not have additional improvement.

The tenth modification of this method and the difference of prototype method are:

-in period T _rOn, significant level component, information and accurate benchmark equalization of level are applied in to these row;

-do not carry out " can not hold concurrently or " logical operation on corresponding to the logical value of row and column voltage, also not to these result's and carry out " can not hold concurrently or " logical operation.

Opposite with the delegation addressing, two row addressing reduce the amplitude of horizontal driving pulse according to (17) or (24) * * a factor, and, reduce the unit quasi ms mains ripple that causes by the frame response for the display mode of many types.Than the modulation of the frame that in prototype method, uses, use pulse length modulation also to provide frame updating rate faster (only in two field times or at cycle NT for any gray level image grade _rIn).

The tenth modification of this method, special combined with other modification, improved image homogeneity and contrast and feasible display operating rate and the size of having increased.

The 12 embodimentBe the 11 kind of modification that drives the method for a LCD.This LC display is described in first embodiment.

The EOB of this LCD unit (photoelectric characteristic) has setup parameter N _MaxBe equal to or greater than N _MaxoThreshold value ms voltage.

According to (7), N _Max≡ (U _Th1 ²+ U _Th2 ²) ²/ (U _Th2 ²-U _Th1 ²) ²Be display parameter, U _Th1 ²Be the minimum border of working range EOB, U _Th2 ²It is the upper bound of working range EOB.N _MaxoBe the N of the display that can correctly drive by voltage waveform (by the driving voltage of a particular group) according to this modification (or some modification) of this method _MaxMinimum value.Should correctly drive and to set (maybe can set) scope corresponding to the unit ms voltage of the working range of this unit EOB.Because any driving method allows the significant variation of unit quasi ms voltage about working value, parameter U _Th3And U _Th4(seeing Figure 15) be display parameter under this mode of operation of characterization and have to be used to substitute U more exactly _Th1And U _Th2Be used for determining N _MaxoScan electrode by scanning voltage being applied to selection and with a reference voltage V ₀Be applied to unselected scan electrode and sequentially select scan electrode one by one or by the group.At a selection cycle T _rDuring this time, the fundamental voltage level is applied in to a signal electrode together with the auxiliary voltage level.

The feature of the modification of this method is to use amplitude to be $\left|V_{\mathrm{ro}}\right|\sqrt{1-\mathrm{\&eta;}}$ Capable strobe pulse and amplitude be $|{\mathrm{<figure-callout\; id="1"\; label="V\; co"\; filenames="C9981138400781.png,C9981138400821.png"\; state="\{\{state\}\}">V</figure-callout>}}_{\mathrm{co}}\sqrt{1+\mathrm{\&eta;}}$ The row driving pulse, η is no more than a number of several 1 and passes through formula here $\mathrm{\&eta;}=\sqrt{1-\mathrm{\&xi;}}$ Determine by display parameter.Parameter ξ=N _Maxo/ N _MaxBe not more than 1.N _MaxoBe the N that the correct driving of display is provided according to a specific time diagram _MaxMinimum value.| V _Ro| and | V _Co| be to be applied in to having the N of equaling _Max0The N of value _MaxThe voltage V that shows of another (benchmark) _rAnd V _cMould, described another shows that this modification by described method correctly drives.Value η can be used as and is used for voltage V _rAnd V _cAmplitude finishing (adjustings) to determining correct or having N near correct driving _Max＞N _Max0The parameter of value of display.But to defining by the permissible value that is trimmed to the best image image of correct driving near value.In chapters and sections " theoretical background ", provided the N that is used for several driving figure _Max0, V _RoAnd V _CoExample.

For having for the treatment of correctly to be driven comparing N _MaxoThe N of (ξ=0.5) big twice _MaxDisplay, the row strobe pulse should have 1.31V _C0Amplitude.This result is that the amplitude of accurate ms mains ripple (is defined as V with respect to accurate ms voltage power supply scope _Th2 ²-V _Th1 ²) descend 2.3 factor of the ratio of width.Under the situation of two row addressing, use this modification of this method, than delegation's addressing of Alt and Pleshko, the amplitude of accurate ms mains ripple has been reduced by 4.6 factor, and made dynamic EOB (seeing Figure 15) almost accord with its static simulation amount.

The prototype of the 11 modification of this method is the delegation's method for addressing (the 7th kind of prototype method) described in the United States Patent (USP) 5,093,736 of Seiko Epson.According to this method, a display that has a large amount of column electrodes (being no less than 300) has the row and column driven of biasing than b, and this biasing is defined in 1/ (N than the value of b ^1/2-N/200) to 1/ (N ^1/2In-N/50) the scope.The purpose of this driving method is to improve picture contrast and display operating rate.

Yet these features that theoretical the 3rd section of introducing illustrates this prototype method neither need also insufficient for the stated features that realizes display.

The difference of this modification of this method and the 7th kind of prototype method is:

-multi-line addressing is possible;

-for the display that has more than a large amount of column electrodes of 300, there be not described " biasing is than b " can change scope therein with the value that generates the row and column voltage level;

The amplitude V of-row strobe pulse _rDepend on the V in the aforesaid way _R0And N _Maxo/ N _Amx

The amplitude V of-row driving pulse _cDepend on the V in the aforesaid way _C0And N _Maxo/ N _Max

The use of the 11 modification of this method has improved picture contrast and has not changed frame rate, has improved the image homogeneity that follows electrode, has reduced power consumption, and the possibility that increases display operating rate and size is provided.

Improving the opinion of these prototypes of this method of driving LC display of their performance finishes herein.

Yet because these modification make the image quality improvement technology relevant with the display parameter of the technical result that realizes being stated, this display further is considered to the target of technology implementation example of the present invention.

The 13 embodimentIt is a LC display.This LC display has a plate, and this panel includes substrate, the array of one scan electrode is arranged in the substrate therein and the array of a signal electrode is arranged in another substrate.Be inserted in LC material between two substrates and be arranged on lc unit between the point of crossing of described electrode.Lc unit generates the display element of this display and determines the function of its brightness as the voltage on this cell electrode.

The modification of any said method or its combination are used and drive.The device that use is described in the 7th embodiment drives this display.

The difference of this display design is that its lc unit generates display element and made and have N _MaxBe provided with to such an extent that be not less than N _AmxoThreshold value U _Th1 ²And U _Th2 ²Here, N _Max=(U _Th1 ²+ U _Th2 ²) ²/ (U _Th2 ²-U _Th1 ²) ²Be the parameters of display of in the text, synthetically being thought, U _Th1 ²Be the minimum border of working range of EOB and U _Th2 ²It is the upper bound of described working range.N _Max0Be that this display can be according to the N that (a bit) modification correctly drives by a particular group driving voltage that is somebody's turn to do of described method _MaxMinimum value.Should correctly drive the scope of necessary setting corresponding to the unit ms voltage of the working range of this unit EOB.In the case, this display can provide best picture quality.In this theory introduction, provided the N that is used for some time diagrams _Max0Some values.When the driving of this display is attended by the marked change of accurate ms voltage, the dynamic U of EOB _Th3 ²And U _Th4 ²Should be used to substitute U _Th1 ²And U _Th2 ²Be used for determining N _Max

This prototype of this technical scheme can be to use the driven any LC driver of described any prototype method.

The difference of described display and this prototype is that its design should be provided at the N in the particular range _Max, particularly, it should be not less than N _Max0And then, N _Max0Depend on the display time diagram under the form described in the text.

All modification of this driving method of the present invention (replenishing mutually), drive unit and display design provide picture contrast and homogeneity, the quality of color representation and the dual raising of display operating rate and size.

Draw from these assessments, it is 4 electrical phenomena that described prototype method summation can reduce the undesired order of magnitude (order).This result is not strengthened to the picture quality of STN LCD the level of approaching modern TFT LCD.The a plurality of modified drive method summations that provide have realized the influence of this electrical phenomena has been reduced by one tens factor, disclose this method to use high-quality STN LCD on video and TV speed.Have repressed crosstalking and to have the same good characteristic with Active Matrix Display even better with the passive matrix display of other influences.

Simple design, manufacturability.High-quality image and low-cost manufacture smooth, high-speed color passive matrix display, the scope of a kind of main candidate's cheap and popular TV monitor-today cathode-ray tube (CRT).Active Matrix Display can not reach this position, because it is not enough to manufacture the speed of slight level performance of cost height and color and gray scale.

The accompanying drawing summary

Fig. 1 is the view of a part that is connected to a LC display of these drive units.

Fig. 2 is the voltage-light characteristic synoptic diagram of the display element of first modification.

Fig. 3 is the voltage-light characteristic synoptic diagram of the display element of second modification.

Fig. 4 is corresponding to the driving voltage that does not have pulse length modulation of first prototype method and the time diagram of cell voltage.

Fig. 5 is corresponding to the driving voltage that has pulse length modulation of first method and the time diagram of cell voltage.

Fig. 6 is the corresponding time diagram of the static state vibration of the time diagram of cell voltage amplitude and unit quasi ms voltage.

Fig. 7 is the cell voltage time diagram corresponding to second prototype method.

Fig. 8 is corresponding to the driving voltage of triarch method and the time diagram of cell voltage.

Fig. 9 is corresponding to the driving voltage of tetrarch method and the time diagram of cell voltage.

Figure 10 is the time diagram corresponding to the driving voltage that does not have pulse length modulation of pentarch method.

Figure 11 is the time diagram corresponding to the driving voltage that is used for signal electrode that pulse length modulation is arranged of pentarch method.

Figure 12 is the time diagram corresponding to the capable driving voltage that is used for the four lines addressing of the 8th prototype method.

Figure 13 is the matrix corresponding to the capable driving voltage that is used for the four lines addressing of the 8th prototype method.

Figure 14 is the static squared voltage-light characteristic (not considering " frame response ") of a display element.

Figure 15 is the dynamic squared voltage-light characteristic (considering " frame response ") of a display element.

Figure 16 is the time diagram corresponding to delegation's addressing of first embodiment.

Figure 17 is the time diagram corresponding to the two row addressing of the first and the 11 embodiment.

Figure 18 is the time diagram corresponding to delegation's addressing of first, second and the 3rd embodiment.

Figure 19 is the time diagram corresponding to the two row addressing of the first, second, third and the 11 embodiment.

Figure 20 is the time diagram corresponding to the two row addressing of the first, second, third, fourth and the 5th embodiment.

Figure 21 is the time diagram corresponding to the pulse displacement that is used for three groups of signal electrodes of the 6th and the 3rd embodiment.

Figure 22 is the time diagram corresponding to the pulse displacement that is used for three groups of signal electrodes of the 6th and the 5th embodiment.

Figure 23 is the block scheme of drive device for display.

Figure 24 is the output circuit figure of the 7th embodiment.

Figure 25 is an output circuit figure who has the 7th embodiment of the extra transistor that is used to regulate output resistance.

Figure 26 is the time diagram corresponding to the 8th embodiment.

Figure 27 is the time diagram corresponding to the 9th embodiment.

Figure 28 is the shape view corresponding to the potential pulse of the tenth embodiment.

Figure 29 is the time diagram that has pulse length modulation corresponding to the 11 embodiment.

Realize best mode of the present invention

Technical scheme described in this patent application is feasible. Because these changes of the method Type has good correlation mutually, realizes that best mode of the present invention is to use all or connect Nearly these whole technical schemes.

In the accompanying drawing of suitable paragraph and correspondence, provided the combination of these modification of the method The example of using and the result who realizes like this.

Feasibility

The present invention can be used to the video-frequency monitor in scheduler and the television industry.

Figure 23 illustrates can realize according to the driving voltage of these modification of the method and the time Between the drive device for display of figure. Under the help of conventional method at logical block LB_iMiddle shape Become to be used for the time diagram of a particular row. This logical block can comprise flip-flop element, be shifted and post Storage and other circuit and have different designs. (comprise for any driving method Seven kinds of methods, it has different time diagrams for different passages) these logical blocks formation With the irrelevant line time figure of specific image pattern.

When using the 7th and the 8th modification of this driving method, in the tuning stage, at voltage Form these voltage levels that depend on port number in the level generator. This situation, voltage The quantity of level increases.

At logical block LB_jThe middle time diagram that is used for a particular column electrode that generates. Relevant LB_iDescribed content is for LB_jKeep truly constant. With LB_iOn the contrary, LB_jHaving the row of realization drives The adjunct circuit of the pulse length modulation of pulse. For according to the tenth control method for two row Addressing realizes pulse length modulation, logical block LB_jCan be combined with additional register and hold The addition of the data-signal that row is relevant with the pixel of the adjacent lines electrode of two current selections and subtracting each other Summing circuit, and be designed to determine the summing circuit of the accurate reference voltage of compensation and post Storage. Also may use other design, wherein (this unit is at figure at data processing unit Not shown in 23) realize to determine the duration of compensated pulse and the addition of data-signal/mutually Subtract, the outputting data signals of this data processing unit arrives unit 3 by data/address bus.

According to the 6th kind of driving method, constantly potential pulse is imposed on different signal electrodes, logical block LB for making in difference_jOr one clock pulse generator (this unit is in Figure 23 Not shown) can be combined with pulse daley element or circuit.

(be to realize that the 9th kind of driving method is required for making driving pulse have the staged rising edge Want), voltage generator 1 provides additional voltage level, the voltage level root that these are additional Be converted by logical block according to specific time diagram. For example these voltage levels can carried Supply leads of transistor 13 and 14 (Figure 24 or Figure 25) before at electric pressure converter unit VCB_iBe converted (Figure 23).

For having greater than N_maxoN_maxDisplay, according to the 11 kind of method, at electricity Press and form and set the row and column voltage level in the generator 1.

Feasibility according to the device of the 7th embodiment provides in it is described.

The device according to time diagram generation driving voltage of in these modification of the present invention, describing Can use drive circuit or be implemented at display pannel.

The feasibility of the scheme of in " summary of the invention ", describing result from chapters and sections " theoretical background ", Suitable formula and numerical estimation.

Claims (15)

1, a kind of method that is used to drive a display, this display has a plate, this panel includes substrate, the array of one scan electrode is arranged in the substrate therein and the array of a signal electrode is arranged in another substrate, and the liquid crystal cells between the point of crossing of described electrode, described unit generates the display element of this display, and this method includes step:

Sequentially select scan electrode one by one or by the group, scanning voltage is applied to the scan electrode of selection, and with a reference voltage level (V ₀) be applied to unselected scan electrode;

During a selection cycle, will be by being not equal to and/or equaling said reference voltage level (V ₀) one or more fundamental voltage electricity impose on a signal electrode pulse of setting voltage, described level is set all nominal values of square voltage on a selected unit or a plurality of unit, so that obtain the currency of the brightness of the display element of a selection or the display element that a group is selected;

At a selection cycle (T _r) during, will have constant and equal duration (t _m/ 2), apart from reference voltage level (V ₀) the identical constant mould (V of skew _m), relative datum voltage level (V ₀) the first and second additional voltage levels of opposed polarity impose on signal electrode.

2, according to the process of claim 1 wherein after first voltage that applies one first polarity to signal electrode and applying before second voltage of one second polarity, at selection cycle (T _r) during, will have a constant duration (t ₀) and equal said reference voltage level (V ₀) the 3rd auxiliary voltage level (V ₀) impose on signal electrode.

3, according to the process of claim 1 wherein

The described first and second additional voltage levels are distributed to cycle (T _r) boundary member so that make first level be assigned to the cycle (T _r) a beginning part and second level is assigned to the cycle (T _r) a latter end;

At cycle (T _r) during, voltage level is imposed on signal electrode with forward order or reverse order; And

At follow-up cycle (T _r) during, according in period T _rBeginning and the described reference voltage level (V of the distance in the latter end ₀) the variation of polarity of variation, the alternating voltage level imposes on the described order of signal electrode, so that positive polarity is set at one-period (T _r) beginning part in and negative polarity is set at following one-period (T _r) beginning part in.

4, according to the process of claim 1 wherein that the described first and second additional voltage levels are assigned to the cycle (T _r) boundary member so that first level is assigned to the cycle (T _r) a beginning part and second level is assigned to the cycle (T _r) a latter end;

At cycle (T _r) during, voltage level is imposed on signal electrode with forward order or reverse order; And

At cycle (T _r) during, voltage level imposed on adjacent signal electrode or impose on to be positioned at away from the signal electrode of one or two electrodes or to impose on and have the another kind of signal electrode that activates sequence, so that distribute to cycle (T _r) beginning part and the level of latter end have apart from described reference voltage level (V ₀) the skew of opposite polarity.

5, according to the process of claim 1 wherein that described additional first and second voltage levels are assigned to the cycle (T _r) boundary member so that make first level be assigned to the cycle (T _r) a beginning part and second level is assigned to the cycle (T _r) a latter end;

At cycle (T _r) during, voltage level is imposed on signal electrode with forward order or reverse order; And

At the cycle (T that selects same scan electrode or same cluster scan electrode _r) during in, wherein scanning voltage or scanning voltage group have with respect to said reference voltage level (V ₀) identical or opposite polarity, distribute to cycle (T by alternately being provided with _r) beginning and the signal voltage level of latter end and apart from reference voltage level (V ₀) the identical and reverse direction of skew, and the voltage (V of scan electrode of identical selection that the group of the scan electrode that imposes on described identical selection or described identical selection alternately is set _r), apart from said reference voltage level (V ₀) the identical and reverse direction of skew, alternation subsequent frame in the time cycle or in a frame time or in two frame times or according to time ratio other order apply signal voltage level give signal electrode described order.

6, according to the process of claim 1 wherein that the described first and second additional voltage levels are assigned to the cycle (T _r) boundary member so that first level is assigned to the cycle (T _r) a beginning part and second level is assigned to the cycle (T _r) a latter end;

At cycle (T _r) during, voltage level is imposed on signal electrode with forward order or reverse order so that they impose on the order of signal electrode at follow-up cycle (T _r) in by alternation; And

The potential pulse that imposes on signal electrode resolved into the relevant group of a plurality of and different electrodes and at cycle (T _r) in relate to their these pulses of time superior displacement of nominal position so that for these pulses of a single group, the value of these shift times is identical, but these pulses for distinct group, the value of these shift times is different, and for certain one-period be constant, after the described time cycle finishes, at some or other values of shift time are set in all potential pulse groups or the potential pulse group of other set is formed the value that has the different shift time in the distinct group, and for next time cycle, other values of these shift times are set up constant, after it finishes, the described process that perhaps changes or the value of constant shift time is set is continued, and the zero mean deviation of each described additional levels apart from the duration of its nominal position is provided.

7, according to the method for claim 6, the mould of shift time that wherein imposes on the potential pulse of a group signal electrode is set at from zero to above-mentioned constant duration (t _mIn the scope of value/2).

8, according to the method for claim 6, wherein be held after the constant time cycle finishes in the potential pulse group's who imposes on signal electrode shift time value, up-to-date shift time value is set in this burst of pulses, each pulse has shift time value the earliest, previous shift time value is set in this burst of pulses, each pulse has next the shift time value after this shift time value the earliest, and these changes of shift time value are employed in other pulse trains until the shift time value that respectively has the earliest, are changed to the pulse train of up-to-date shift time value.

9, according to the method for claim 6, a potential pulse group who wherein has identical shift time is formed for a signal electrode group, so that each electrode and other electrodes keep away in this group.

10, according to the method for claim 1, wherein during this selection cycle, with the described first and second additional voltage levels be arranged to have apart from unit that signal electrode is connected on the substantially invariable skew of nominal value of all square voltage, described skew is caused along its shape distortion in the signal electrode communication process by potential pulse;

During a frame time cycle, provide the single or several additional time interval (t _c);

At some described single or several interval (t _c) during, with a bucking voltage (V _Com(i)) impose on each i scan electrode, begin with a certain electrode,

Or/and at other described single or several interval t _cDuring this time, with another bucking voltage (V _Com(j)) impose on each j scan electrode, begin described one and/or two voltage (V with another certain electrode _Com(i), V _Com(j)) have respectively specific to the value of each electrode or/and the duration and give to all square voltage on the unit of i scan electrode apart from the skew of its nominal value or/and all square voltage on the unit of j scan electrode apart from all or part of compensation of the skew of its nominal value, described skew is caused by its shape distortion in the signal voltage pulse edge signal electrode communication process, or/and caused by its shape distortion in the scanning voltage pulse edge scan electrode communication process respectively; And

At described interval (t _c) during, with reference voltage or surely reference voltage or an average accurate reference voltage or their combination impose on do not have described bucking voltage scanning or/and signal electrode.

11, according to the method for claim 1, the wherein said first and second additional voltage levels be configured to have apart from unit that signal electrode is connected on the substantially invariable skew of nominal value of all square voltage, described skew is caused along its shape distortion in the signal electrode communication process by potential pulse; And

During these selection cycles, additional bucking voltage is imposed on the scan electrode of selection, begin with a certain electrode, and on scanning voltage overlapping described bucking voltage, described bucking voltage has specific to the value of the scan electrode of selecting or/and duration and to all or part of compensation of all square voltage on the unit of the scan electrode selected according to the skew of its nominal value, and described skew is caused by its shape distortion in the signal voltage pulse edge signal electrode communication process.

12, according to the process of claim 1 wherein

All or part of self-compensating shape so that the parasitism of all square voltage on the unit that selection is provided changes forms potential pulse, and described variation is being caused along its anterior and afterbody distortion in the electrodes for display communication process by these pulses.

13, according to the method for claim 12, wherein the front portion of pulse is formed the stepwise shape or is similar to the shape of stepwise.

14, a kind of device that is used to drive a display, this display has a plate, this panel includes substrate, the array of one scan electrode is arranged in the substrate therein and the array of a signal electrode is arranged in another substrate, and the liquid crystal cells between the point of crossing of described electrode, described unit generates the display element of this display, and this display is driven by the method according to claim 1, and this device includes:

One voltage level generator (i.e. a power supply unit) and a collection of voltage impulse generator that is used for electrodes for display, each voltage impulse generator comprises a unit that is set to the timing voltage level of an output electrode, the output transistor unit that this output electrode is connected with unit with this output electrode, voltage level generator and this setting timing voltage level, this unit of setting the timing voltage level is connected with this voltage level generator, it is characterized in that:

This unit pack that is set to the timing voltage level of an output electrode contains the technique device of the auxiliary voltage level of the constant duration that regularly imposes on signal electrode; And

This output transistor unit is fixed so that the output resistance for different voltage levels of described unit has identical value, or the skew of value does not exceed 10%.

15, a kind of display, has a panel, this panel includes substrate, the array of one scan electrode is arranged in the substrate therein and the array of a signal electrode is arranged in another substrate, and the liquid crystal cells between the point of crossing of described electrode, described unit generates the display element of this display, it is characterized in that:

These display elements are caught to have more than or equal to digital N _Max0Display parameter N _MaxValue, N wherein _Max0Be to count N and N greatly _Max0The N that to be display correctly drive by voltage waveform according to the method for claim 1 _MaxMinimum value.

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