CN1315002C - Active matrix liquid crystal display system and its driving method - Google Patents
Active matrix liquid crystal display system and its driving method Download PDFInfo
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- CN1315002C CN1315002C CNB99127542XA CN99127542A CN1315002C CN 1315002 C CN1315002 C CN 1315002C CN B99127542X A CNB99127542X A CN B99127542XA CN 99127542 A CN99127542 A CN 99127542A CN 1315002 C CN1315002 C CN 1315002C
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Abstract
The present invention relates to a film transistor type liquid crystal display system having the advantages of low height power consumption and high image quality without interference. The present invention comprises an electric pole, a liquid crystal composition and a drive device, wherein the electric pole is used for adding an almost parallel electric field onto the surface of a base sheet, the liquid crystal composition is used for obtaining an element structure in a bright state and a dark state through an apolarization device, and the drive device is used for outputting scan signals with at least two kinds of non-selective voltage values to a scan electric pole.
Description
The application be submitted on June 24th, 1994, application number is 94190231.5, denomination of invention is divided an application for the Chinese patent application of " active matrix liquid crystal display system and driving method thereof ".
Technical field
The present invention relates to a kind of active matrix liquid crystal display system and driving method thereof, this system is such as the display unit that is used for personal computer.
Background technology
At present, active array type (film transistor type) liquid crystal display systems is widely used in various fields, but need improved aspect the multi-stage grey scale (panchromatic).
A kind of display type as liquid crystal display systems, so-called twisted nematic display mode (hereinafter referred to as " vertical electric field type ") is arranged, wherein liquid crystal is filled in mutually between aspectant two substrates, contain flat show electrode on the apparent surface of every substrate, the electric field that is approximately perpendicular to substrate surface is applied to liquid crystal and is used for driving.This type of liquid crystal display systems is on sale on market.
On the other hand, for example 63-21907 (1988) number Jap.P. has been recommended another kind of different new, wherein be made on the same substrate, drive liquid crystal (hereinafter referred to as " parallel electric field type ") on the liquid crystal by electric field being added to the direction that almost is parallel to substrate surface in order to the pair of electrodes that electric field is added on the liquid crystal.
Show in order in a kind of film transistor type liquid crystal display systems, to produce multi-stage grey scale, in order to the voltage output of the circuit that picture signal is added to signal electrode, promptly signal driver integrated circuit (IC) need have and the corresponding multistage output valve of multi-stage grey scale quantity.For example under the situation that produces 16 grades of gray scales, signal driver IC requires to provide 16 * 2 (because liquid crystal need drive with alternating current, each gray scale needs positive and negative binary numerical value)=32 output voltage values.For enough electric currents can be provided, each output stage of signal driver IC all has operational amplifier, and therefore 32 operational amplifiers must be provided in these cases.The operational amplifier of output stage is done more for a short time, and the volume of signal driver IC also can be done more for a short time thus, and the absolute value of maximum power consumption is also low more.Because the throughput rate of signal driver IC can be improved, and the physical dimension of display system is because of the reducing and can do very for a short time of signal driver IC size, also can reduce thus as the maximum output voltage of signal voltage.
On the other hand, in the parallel electric field pattern, voltage is added to liquid crystal layer, and in above-mentioned vertical electric field pattern, then voltage is added to liquid crystal layer with mutual aspectant a pair of transparent flat electrode with being made in same on-chip a pair of nontransparent wire electrode.Therefore, in the parallel electric field pattern, opening ratio has diminished.In the case, because two distance between electrodes can not be very little, so compare with the vertical electric field pattern, two distance between electrodes of parallel electric field pattern are bigger, and its electric field intensity is more weak.Therefore, in order to produce the electric field intensity of same amplitude, the former need be added in higher voltage between each electrode compared with the latter.
Summary of the invention
The object of the present invention is to provide a kind of active matrix liquid crystal display system and driving method thereof that adopts the parallel electric field pattern, wherein, in fact display system available signal driving circuit is enough to low driving voltage operation.Another object of the present invention is to provide active matrix liquid crystal display system and the driving method thereof that adopts the parallel electric field pattern, the phenomenon of especially laterally smearing of wherein can not crosstalking, and can obtain higher picture quality.
According to an aspect of the present invention, provide a kind of active matrix liquid crystal display system, comprising:
First substrate, comprise a plurality of scan electrodes at the one face, the a plurality of signal electrodes that intersect to form with described a plurality of scan electrodes, the on-off element that forms in each crossover sites of described a plurality of scan electrodes and described a plurality of signal electrodes, be connected to the pixel electrode of described on-off element, and the counter electrode that forms corresponding to described pixel electrode;
Second substrate towards described first substrate setting;
Place the liquid-crystal composition in the gap between described first substrate and described second substrate;
Picture signal is added to the signal driver of each electrode of a plurality of signal electrodes;
Sweep signal is added to described a plurality of scan electrode to produce the scanner driver that shows;
Wherein, between described pixel electrode and described counter electrode, apply first voltage, to provide electric field to described liquid-crystal composition, described liquid-crystal composition parallels with described first and second substrates basically, second voltage is added to described counter electrode, at least one electrode to a plurality of scan electrodes applies tertiary voltage, with at non-selection cycle at described scan electrode voltage and be applied between second voltage of described counter electrode of neighbor scanning electrode and keep a constant difference.
According to a further aspect in the invention, provide a kind of active matrix liquid crystal display system, comprising:
First substrate, comprise a plurality of scan electrodes at the one face, the a plurality of signal electrodes that intersect to form with described a plurality of scan electrodes, on-off element in that each crossover sites of described a plurality of scan electrodes and described a plurality of signal electrodes forms is connected to the pixel electrode of described on-off element and the counter electrode that forms corresponding to described pixel electrode;
Second substrate towards described first substrate setting;
Place the liquid-crystal composition in the gap between described first substrate and described second substrate;
Picture signal is added to the signal driver of each electrode of a plurality of signal electrodes;
Each electrode that sweep signal is added to described a plurality of scan electrodes is to produce the scanner driver that shows;
Along the direction parallel, each counter electrode is connected to the public part of one of the counter electrode of contiguous described counter electrode with described scan electrode;
Wherein, between described pixel electrode and described counter electrode, apply first voltage, to provide electric field to described liquid-crystal composition, described liquid-crystal composition parallels with described substrate basically, second voltage is added to described counter electrode, at least one electrode to a plurality of scan electrodes applies tertiary voltage, with at non-selection cycle at described scan electrode voltage and be applied between second voltage of described counter electrode of neighbor scanning electrode and keep a constant difference.
To achieve these goals, the structure according to active matrix liquid crystal display system of the present invention is as follows:
(1) a kind of active matrix liquid crystal display system, wherein liquid-crystal composition is inserted between first and second substrate, constitute a plurality of pixel portion by a plurality of scan electrodes and a plurality of signal electrode, and be provided with on-off element in each pixel portion that forms on-off element by arranged.
Pixel electrode is provided with in such a way with the counter electrode that is connected to on-off element, be that electric field is parallel to substrate and applies, liquid crystal in the liquid-crystal composition layer is driven by the voltage that is applied between two electrodes, keep the main axis of liquid crystal molecule to be parallel to substrate surface, native system comprises the shinny state that can obtain liquid-crystal composition and component structure and polarization device with dark state of directed state, comprises extinguishing its drive unit more than the sweep signal of two non-selection voltages on scan electrode.
(2) active matrix liquid crystal display system of another feature according to the present invention, counter electrode wherein are the common electrodes that same scan electrode, signal electrode, pixel electrode branch are arranged.
(3) active matrix liquid crystal display system of another feature according to the present invention, counter electrode wherein are a part of scan electrode of neighborhood pixels part.
(4) active matrix liquid crystal display system of another feature according to the present invention, wherein the threshold value V of switching transistor element
THWith maximum voltage V
ONBetween relation satisfy following equation:
V
TH＞|V
ON|
V wherein
ONFor in order to obtain bright state or the pixel electrode of dark state and the maximum voltage between the counter electrode.
(5) active matrix liquid crystal display system of another feature according to the present invention, wherein the threshold value V of switching transistor element
TH, maximum voltage V
ONAnd minimum voltage V
OFFBetween relation satisfy following equation:
V
TH＞(|V
ON|-|V
OFF|)/2
Wherein, V
ONFor in order to obtain bright state or the pixel electrode of dark state and the maximum voltage between the counter electrode; V
OFFFor in order to obtain bright state or the pixel electrode of dark state and the minimum voltage between the counter electrode.
(6) active matrix liquid crystal display system of another feature according to the present invention, the order line spread that switching transistor element wherein replaces by every capable P type and n type feature.
(7) active matrix liquid crystal display system of another feature according to the present invention, form at least two switching transistor elements in one of them pixel, thin-film transistor element has at least a source electrode or drain electrode to be connected to signal electrode, and thin-film transistor element has at least a source electrode or drain electrode being electrically connected the scan electrode that is right after next line.
(8) active matrix liquid crystal display system of another feature according to the present invention, form at least two switching transistor elements in one of them pixel, thin-film transistor element has at least a source electrode or drain electrode to be connected to signal electrode, and thin-film transistor element has at least a source electrode or drain electrode to be connected to the scan electrode that is right after next line by capacity cell.
(9) active matrix liquid crystal display system of another feature according to the present invention, distance between liquid-crystal composition wherein, the formation of polishing direction, polarising sheet, the distance between the substrate and pixel electrode and the counter electrode is provided with to such an extent that make the difference of voltage that obtains bright state and the voltage that obtains dark state be lower than 5V.
(10) active matrix liquid crystal display system of further feature according to the present invention, at least two kinds of non-selected magnitudes of voltage of sweep signal output wherein.
(11) active matrix liquid crystal display system of further feature according to the present invention, wherein change the voltage of pixel electrode by the non-selection voltage that changes sweep signal, this sweep signal mainly is applied to scan electrode by the electric capacity between scan electrode and the pixel electrode.
(12) active matrix liquid crystal display system of further feature according to the present invention wherein is applied to the sweep signal of scan electrode in all row, and its non-selection voltage changes with same amplitude, same cycle and same phase place.
(13) active matrix liquid crystal display system of further feature according to the present invention, wherein every frame is alternately contained binary non-selection voltage value and be applied to scan electrode in the sweep signal that non-selection cycle remains on constant voltage, signal electrode receives the picture signal of emission by this way, and promptly pixel electrode alternately is different polarity with voltage between the counter electrode by every row.
(14) active matrix liquid crystal display system of further feature according to the present invention wherein equals the voltage difference setting between two kinds of non-selection voltage values in order to obtain bright state or the pixel electrode of dark state and the maximum voltage V between the counter electrode
ONWith minimum voltage V
OFFSum.
(15) active matrix liquid crystal display system of further feature according to the present invention wherein equals the voltage difference setting between two kinds of non-selection voltage values in order to maximum voltage V between the pixel electrode that obtains bright state or dark state and the counter electrode
ONWith minimum voltage V
OFFHalf of sum.
(16) active matrix liquid crystal display system of further feature according to the present invention, the mid-point voltage that wherein is applied to non-selection voltage in the sweep signal of the scan electrode that contains P type switching transistor element is higher than the mid-point voltage of non-selection voltage in the sweep signal that is applied to the scan electrode that contains N type switching transistor element, and its voltage difference exceeds in order to obtain bright state and the pixel electrode of dark state and the maximum voltage V between the counter electrode
ON
(17) active matrix liquid crystal display system of further feature according to the present invention, counter electrode voltage is wherein provided by scan electrode.
(18) active matrix liquid crystal display system of further feature according to the present invention, wherein the counter electrode voltage that is provided by scan electrode changes according to the polarity of image signal voltage.
Below operation of the present invention will be described.
Be added to non-selection voltage (OFF voltage) in the sweep signal of scan electrode by changing at non-selection cycle, and adopt the parallel electric field pattern as driving pattern, finish following operation of the present invention by the voltage that the electric capacity that is coupled between pixel electrode and the scan electrode changes in the pixel electrode, this operation has been done disclosure by the present inventor.
(first kind of operation)
In the parallel electric field type, the electric capacity C between pixel electrode and the common electrode
LCLess than the electric capacity in the vertical electric field type, because in vertical electric field type, pixel electrode and counter electrode form a parallel plate capacitor.Therefore, in the parallel electric field type, the capacitor C between pixel electrode and the scan electrode
SRelatively greater than the capacitor C between pixel and the counter electrode
LC, so just can enough bias voltage be applied to pixel electrode according to the change in voltage in the scan electrode.Can reduce formed capacity cell C between pixel electrode and the scan electrode thus
SShared space and the ratio that pixel element took up space are improved opening ratio with this.
(second kind of operation)
Because the capacitor C between pixel electrode and the counter electrode
LCLess, the load capacity of scan electrode diminishes, so in order to a modulation voltage is added to the driving method of scan electrode, its advantage is that the distortion in the modulation waveform is very little.Reduced ratio thus, reduced the ratio of wave form distortion in the non-selection voltage of sweep signal simultaneously with load capacity in the scan electrode of image modification.Therefore, can apply modulation voltage equably, and the generation of can suppress to crosstalk (wherein the level of the horizontal tow line of appearance is smeared).
(the third operation)
In the parallel electric field pattern, adjacent scan electrode can be used as counter electrode.For this reason, can be by the used zone of counter electrode main part as the gap to improve opening ratio.Moreover, reduced the point of crossing number of interconnect electrode like this, so reduced the short trouble in the electrode.
Exchange electrically-driven liquid crystal in order to use, picture signal is added to signal electrode in such a way, and the voltage waveform that promptly is added to pixel electrode becomes AC wave shape with respect to counter electrode.Yet, used typical active component in the active matrix liquid crystal display system such as amorphous silicon film transistor (a-SiTFT), polycrystalline SiTFT (P-SiTFT) or the like, has such specific character, being that leakage current begins to flow when scanning voltage is almost 0V, also is threshold voltage V
THBe almost 0V.Therefore, when the non-selection voltage of scanning voltage (cut-off level) is used as counter electrode voltage,, also fail to keep negative voltage with respect to counter electrode voltage even above-mentioned transistor unit has added negative voltage.Its reason is that the cut-off level of scanning voltage is in the level higher than pixel electrode voltage, threshold voltage V
THThe transistor unit that is almost 0V enters conducting state, and pixel electrode voltage lowers until the cut-off level that reaches scanning voltage by leaking.Therefore,, need provide a kind of counter electrode separately, be provided with counter electrode voltage to such an extent that be higher than the cut-off level of scanning voltage for exchanging electrically-driven liquid crystal.By utilizing the transistor of high threshold voltage, just can be with exchanging electrically-driven liquid crystal, even because work as scan electrode as counter electrode, the cut-off level of scanning voltage is used as counter electrode voltage, pixel electrode also can apply and keep a negative voltage with respect to inverse voltage.Characteristics of the present invention are, the threshold values V of switching transistor element
THSurpassed the maximum voltage V that is added on the liquid crystal
ON, or surpassed maximum voltage V
ONWith minimum voltage V
OFFThe half of difference.For this reason, even negative voltage is added to liquid crystal, pixel electrode voltage can not leak yet and can keep, and available alternating current and low-voltage driving liquid crystal.
Moreover, the transistor unit that constitutes makes it to characterize in every line P type or n type characteristic, like this, be added to the mid-point voltage of non-selection voltage in the sweep signal on the scan electrode that contains P type switching transistor element, the mid-point voltage that will be higher than non-selection voltage in the sweep signal that is added on the scan electrode that contains n type switching transistor element, this voltage difference surpass between pixel electrode and the counter electrode for obtaining bright state or the dark required maximum voltage V of state
ONFor this reason, even threshold voltage V
THNear 0V or be lower than 0V, still available alternating current and low-voltage driving liquid crystal.
In addition, constitute two thin-film transistor elements in the pixel, image signal voltage is provided by one of them thin-film transistor element, and counter electrode voltage is provided by another thin-film transistor element.For this reason, can be with exchanging electrically-driven liquid crystal.Moreover, by changing counter electrode voltage, can use the low voltage drive liquid crystal corresponding to image signal voltage polarity.
Description of drawings
Fig. 1 according to the present invention first embodiment of liquid crystal display systems, along the sectional view of A-A ' line among Fig. 3.
Fig. 2 is the front elevation of the structure of a pixel among the expression embodiment 1, comprising adjacent pixels.
Fig. 3 is the front elevation of expression according to a dot structure in the embodiments of the invention 1.
Fig. 4 is the cross sectional side view along B-B ' line among Fig. 3.
Fig. 5 is the cross sectional side view along C-C ' line among Fig. 3.
Fig. 6 is the structural drawing of expression according to a display system in the embodiments of the invention 1.
Fig. 7 represents according to the drive waveforms in the embodiments of the invention 1.
Fig. 8 represents according to the drive waveforms in the embodiments of the invention 2.
Fig. 9 is the front elevation of a dot structure among the expression embodiment 3, has wherein comprised adjacent pixels.
Figure 10 is the front elevation of expression according to a dot structure in the embodiments of the invention 3.
Figure 11 is the cross sectional side view along Figure 10 D-D ' line.
Figure 12 is the structural drawing of expression according to a display system in the embodiments of the invention 3.
Figure 13 represents the drive waveforms according to embodiments of the invention 3.
Figure 14 is the front elevation of a dot structure among the expression embodiment 4, wherein comprises adjacent pixels.
Figure 15 is the front elevation of expression according to a dot structure in the embodiments of the invention 4.
Figure 16 represents the structure according to a display system in the embodiments of the invention 4.
Figure 17 represents according to the drive waveforms in the embodiments of the invention 4.
Figure 18 represents according to the drive waveforms in the embodiments of the invention 5.
Figure 19 represents according to the drive waveforms in the embodiments of the invention 6.
Figure 20 represents according to the drive waveforms in the embodiments of the invention 7.
Figure 21 is the front elevation of expression according to a dot structure in the embodiments of the invention 8.
Figure 22 is the communication line of a pixel among the embodiment 8.
Figure 23 is the cross sectional side view along Figure 21 E-E ' line.
Figure 24 is the cross sectional side view along Figure 21 F-F ' line.
Figure 25 is the cross sectional side view along Figure 21 G-G ' line.
Figure 26 represents the structure according to a display system in the embodiments of the invention 8.
Figure 27 represents according to the drive waveforms in the embodiments of the invention 8.
Figure 28 is the front elevation of expression according to a dot structure in the embodiments of the invention 9.
Figure 29 represents the connection circuit of a pixel among the embodiment 9.
Figure 30 represents according to the drive waveforms in the embodiments of the invention 10.
Figure 31 is illustrated in the operation according to liquid crystal in the liquid crystal display systems of the present invention.
Figure 32 is illustrated on the interface of relative direction of an electric field, direction (polishing direction) the angle φ of molecule main shaft orientation
LCAnd the orientation angle φ of the polaxis of polarising sheet
P
Figure 33 represents according to the photoelectric characteristic in the embodiments of the invention, is example with the closed type.
Figure 34 represents photoelectric characteristic and molecule main shaft direction of orientation (polishing direction) angle φ on the interface
LCRelation curve, be example with the closed type.
Embodiment
Fig. 1 represents the cross-section structure of a pixel region in the display panels.This liquid crystal panel comprises upper strata substrate, lower floor's substrate and the liquid crystal layer that injects between this two substrate gap.By applying voltage between formed pixel electrode 3 and the counter electrode 4 on lower floor's substrate, control the electric field that is produced between two electrodes, with the state of orientation of control liquid crystal, and change light from the transmittance by panel backlight.A relative side backlight from liquid crystal panel is applied to voltage between pixel electrode and the counter electrode by control, can observe bright state, dark state or marginal intermediateness.Pixel electrode and counter electrode extend by the direction linear pattern that is orthogonal to Fig. 1 paper, and two distance between electrodes are about 15 μ m.Because the thickness of liquid crystal layer is about 4 μ m, gap less than 15 μ m between pixel electrode and the counter electrode, so the direction of the electric field 101 (line of electric force) that is produced in liquid crystal layer inside almost becomes the horizontal direction (compare with real system, Fig. 1 is the figure along the expansion of display panel thickness direction) of Fig. 1.
Figure 31 is shown schematically in and adds between pixel electrode 3 and the counter electrode 4 and not under the making alive situation, the state of orientation of liquid crystal molecule.Figure 31 (a) and 31 (b) are from laterally seeing the figure of liquid crystal panel, and Figure 31 (c) and 31 (d) are the figure that sees liquid crystal panel from top and bottom.Figure 31 (a) and 31 (c) are the figure during making alive not, and Figure 31 (b) and 31 (d) are alive figure.By different voltage is applied to pixel electrode and counter electrode respectively, between two electrodes, produce potential difference (PD), and electric field is applied to the liquid-crystal composition layer, liquid crystal molecule reacts with the dielectric anisotropy and the reacting to each other of electric field of liquid-crystal composition, to change the orientation to direction of an electric field.As Fig. 1 and shown in Figure 31, polarising sheet 8 forms at the end face of liquid crystal panel and bottom surface, and the anisotropy of the refractive index by the liquid-crystal composition layer and the interaction of polarising sheet have changed the transmittance of light via liquid crystal panel.For this reason, can change the brightness of display.
Among Figure 32, stipulated that the angle that liquid crystal molecule main shaft (optical axis) approaches the direction 102 at interface is φ
LC, polarising sheet polaxis direction 103 is φ with respect to the angle of the direction of electric field 101
POwing at end face and bottom surface a pair of polarising sheet and liquid crystal interface are arranged respectively, so these angles must be used φ
P1, φ
P2, φ
LC1, and φ
LC2Expression.Not during the added electric field, relative pixel electrode 3 of the orientation of bar shaped liquid crystal molecule 5 and counter electrode 4 a low-angle (seeing the front elevation of Figure 31 (c)) vertically arranged, promptly satisfy relational expression 45 degree≤| φ
LC|＜90 degree.Among Figure 31 and 32, represent liquid crystal molecule main shaft orientation (polishing) direction 103 on the interface with arrow.For the direction of liquid crystal molecule main shaft orientation on top and bottom interface, best-case is to be parallel to each other, i.e. φ
LC1=φ
LC2(=φ
LC).Here the dielectric anisotropy of supposing liquid-crystal composition is for just.
Figure 33 represents to be added in the voltage V between pixel electrode and the counter electrode
LCAnd the family curve that concerns between the brightness, promptly so-called light-electrical characteristics.If the brightness maximal value is, on ordinate, represent brightness at 100% o'clock with relative value.When institute's making alive increases, at voltage V
OFFPlace's brightness increases fast, then, and along with institute's making alive increases until approaching voltage V
OnThe time, brightness is singlely increases.
As shown in Figure 1, also forming a color filter 11 on the substrate of upper strata shows in order to colour, improve contrast with respect to the light shield around the pixel via the light of territory, noncontrolled area (transmittance can not by the zone of institute's making alive control between pixel electrode and the counter electrode) with screened film (black matrix") 23, surface with flatted membrane 12 smooth substrates, with the orientation of directional controling film 6 control liquid crystal molecules, when making alive not, make it with given direction orientation.These films are made on the transparent substrates 7 such as glass, plastic resin.
On lower floor's substrate, rather than on pixel electrode or counter electrode, form the thin film transistor (TFT) (TFT) of various interconnection, be added to the voltage of pixel electrode or the like in order to switching, this will describe afterwards.These all form on such as the transparent substrate 7 of glass or the like, are similar to the situation in the substrate of upper strata.In the present embodiment, for example be that the transparent glass substrate of 1.1mm is as substrate 7 with its surface finish thickness.On a substrate, form thin film transistor (TFT), on its highest face temperature, form oriented film 6 again.In the present embodiment, as oriented film 6, its surface is through polishing processing, in order to directional crystal 5 with polyimide.On another substrate, also adopt polyimide and through polishing processing.The direction of polishing on top and bottom interface almost is parallel to each other, and the angle of polishing direction and direction of an electric field is 88 degree (φ
LC1=φ
LC2=88 °).The forward dielectric anisotropy Δ ε of nematic liquid-crystal composition is 4.5, and refractive index anisotropy Δ n is 0.072 (589nm, 20 ℃), and it is inserted between two substrates.Gap d below the filling liquid crystal is 3.9nm, and it is by diffusion and insert the maintenance of sphere polymers globule.Therefore, Δ nd is 0.281 μ m.Panel is folded by two polarising sheets (for example using the G1220DU type of NittoDenkou company) 8, and wherein the polarization transmission axle of a polarising sheet is provided with to such an extent that make it to become a low-angle, i.e. φ with respect to polishing direction
P1=80 ° of (event/φ
LC1-φ
P1/=8 °), the polarization transmission axle of another piece polarising sheet is provided with to such an extent that make it to intersect with right angle and the former, i.e. φ
P2=-10 °.For this reason, realized such specific character, as the voltage V that is applied to pixel according to the present invention
LC(voltage between pixel electrode 3 and counter electrode 4) starts from scratch when increasing, and brightness is lowered until minimum value (Figure 33).Present embodiment adopts normally closed characteristic, wherein at low-voltage (V
OFF) obtain dark state, at high voltage (V
ON) obtain bright state), V wherein
OFFBe 6.9V, V
ONBe 9.1V.Although adopted normally closed family curve in the present embodiment, also can adopt the family curve of often opening.In addition, also can adopt the liquid crystal of negative sense dielectric anisotropy.
Fig. 2 is illustrated in the various electrodes that form on lower floor's substrate liquid crystal layer one side, connect and the planar structure of TFT.Label 1 expression scan electrode (grid), it is along horizontal expansion in the drawings, and forms with a plurality of electrodes that are parallel to each other.Label 2 expression signal electrodes (drain electrode) extend longitudinally among the figure, and it intersects with scan electrode and forms with each electrode that is parallel to each other.A pair of signal electrode is made up of two adjacent signal electrodes, wherein forms many to signal electrode.Counter electrode 4 forms between a pair of signal electrode and contiguous a pair of signal electrode.Each counter electrode comprises the main part of extending along vertical direction among the figure, and from the main part component that extends of both sides to the left and right.As shown in FIG., a pixel is by signal electrode 2, main part and two adjacent scan electrode institute area surrounded of the counter electrode 4 of contiguous this signal electrode.Form on the scan electrode of TFT15 in each pixel.Label 3 remarked pixel electrodes (source electrode), it extends with inverted U-shaped bending from each TFT.The one part of pixel electrode is overlapping with contiguous scan electrode, goes up in this section to form a storage capacitors element.
In the present embodiment, pel spacing is 110 μ m on the scan electrode direction, is 330 μ m on the signal electrode direction.About electrode width, the main body of scan electrode 1, signal electrode 2, counter electrode 4 forms along a plurality of pixels, adopts the width of 10 μ m to avoid damaging because of puncture.
On the other hand, in order to improve opening ratio, the component that pixel electrode 3 and counter electrode 4 are extended by main part adopts the narrower width of 6 μ m.In addition, by being that two transversely arranged pixels form a counter electrode, the quantity of counter electrode can reduce half.For this reason, neutral gear part can further expand, and the possibility (in direct ratio with the electrode crossing area) that is short-circuited at counter electrode 4 and scan electrode 1 cross section reduces.In the present embodiment, the signal electrode number is made as 640 * 3, and the scan electrode number is made as 480, and the counter electrode number is made as 960.Like this, the quantity of pixel is about 1,000,000.
Fig. 3 is the enlarged drawing of a pixel portion in the presentation graphs 2.Above-mentioned Fig. 1 is the sectional view along A-A ' line planar interception among Fig. 3.Fig. 4 and Fig. 5 are respectively the sectional views along B-B ' line among Fig. 3 and the intercepting of C-C ' line.
As shown in Figure 4, TFT has one and falls cover type structure, and gate insulator 9 (for example silicon nitride) forms on scan electrode 1, and amorphous silicon layer 22 forms on gate insulator 9.Moreover drain electrode 2 and source electrode 3 form by being connected to amorphous silicon layer.Drain electrode among the TFT and source electrode are made of a part of signal electrode and pixel electrode respectively.Between drain electrode, source electrode and amorphous silicon layer 22, form a n+-type amorphous silicon layer, as an ohmic contact layer (not shown).In the present embodiment, signal electrode 2, pixel electrode 3 and counter electrode 4 are made up of identical metal material (for example aluminium).
As shown in Figure 5, gate insulator 9 is inserted between scan electrode 13 and the pixel electrode 3, with the capacitive element 16 that forms a storage capacitance.In the present embodiment, the zone of storage capacitance is significantly smaller than the zone in the conventional vertical electric field type, and electric capacity is less, is C
s=200fF.
Although the storage capacitance in the present embodiment is formed by previous row scan electrode and pixel electrode, can certainly form by back delegation's scan electrode and pixel electrode.Although the main part with counter electrode is used for two adjacent transversely arranged pixels usually, it can not change effect of the present invention basically, even a main body of counter electrode is formed for one in the transversely arranged pixel, still it belongs to scope of the present invention.
Below circuit theory diagrams and drive waveforms will be described.
Fig. 6 represents the schematic circuit according to a liquid crystal display systems of the present invention.Label 21 expression viewing areas form a plurality of scan electrodes 1 in the horizontal, form a plurality of signal electrodes 2 and counter electrode in the vertical, and TFT forms at each cross section of scan electrode and signal electrode.The grid G of TFT is connected to scan electrode, and drain electrode is connected to signal electrode.Liquid crystal capacitance C
LCBetween the source S of TFT and counter electrode 4, form, in the storage capacitor C
sBetween source S and scan electrode, form.Pixel electrode 3 shown in Fig. 1, counter electrode 4 and liquid crystal layer form a capacitor C on electric
LCStorage capacitance C
sBe a kind of electric capacity of absolute key, when the scanning voltage signal of scan electrode 1 was non-selection voltage from selecting voltage transitions, this electric capacity was in order to suppress bypass voltage via the grid of TFT and the capacitor C between the source electrode
GSEnter the voltage of pixel electrode 3, and with respect to capacitor C
GSRequirement has bigger capacity (for example to be about capacitor C
GS10 times big).
Characteristics of the present invention are to adopt driver LSI to produce at least three kinds of numerical value for scanner driver 18, and promptly scanner driver 18 can produce at least three kinds of magnitudes of voltage.
On the other hand, signal driver 19 comprises that the voltage waveform that can will contain image information is added to the circuit on the signal electrode 2, and its formation makes the amplitude peak V in the voltage waveform signal
DP-P(the V among Fig. 7
DH-VDL) become Δ V (referring to Figure 33: Δ V=V
ON-VOFF).In the present embodiment, a constant voltage is added on the counter electrode.
Fig. 7 represents in the present embodiment drive waveforms by driving circuit output.Wherein, Fig. 7 (a) expression is added to the sweep signal waveform V of (i-1) individual scan electrode by scanner driver 18
G(i-1), Fig. 7 (b) expression is added to the sweep signal waveform V of i scan electrode by scanner driver 18
G(i), Fig. 7 (C) expression is added to the signal waveform V of j signal electrode by signal driver 19
D (j), Fig. 7 (d) expression is added to the voltage waveform V of counter electrode
CFig. 7 (e) expression is added to the voltage V on the pixel electrode 3 of the pixel of the cross section formation of i scan electrode and j signal electrode when above-mentioned voltage is added to scan electrode, signal electrode and counter electrode
SThe signal waveform that contains image information is added to signal electrode 2, and sweep signal waveform and picture signal synchronous waveform are added to scan electrode 1.Image signal voltage is sent to pixel electrode 3 by signal electrode 2 through TFT15, and this voltage is added to the lcd segment between pixel electrode and counter electrode 4.Wherein, to being added to scan electrode 1, being used as sweep signal waveform V
GNon-selection voltage (cut-off voltage) modulate, when TFT15 is cut-off state, change voltage on the pixel electrode 3, bias voltage V by capacitive coupling
B (+)And V
B (-)Be added to the voltage on the pixel electrode 4.Wherein, V
B (+)Expression is used for the bias voltage of even frame (forward frame), V
B (-)Expression is used for the bias voltage of odd-numbered frame (negative sense frame).For this reason, with to being added to the waveform V on the scan electrode
GIn cut-off voltage do not do the modulation (constant voltage) situation compare the voltage V on the pixel electrode 3
SDeduct the voltage V on the counter electrode 4
CGained voltage promptly is added to the voltage V on the liquid crystal
LC=V
S-V
CBe actually and increased.Be added to the biasing piezoelectricity V of pixel electrode 3
B (+)And V
BC (-)Amplitude according to changes delta V
GL(Δ V
GL (+)=VGL-V
GLLOr Δ V
GL (-)=V
GLH-V
GL) represent with following formula:
V
B＝(C
S/C
T)ΔV
GL (1)
Wherein, C
SBe the capacity of storage capacitance element 16, C
TBe total capacitance (C
S+ C
LC+ C
GS+ C
DS).Therefore, by setting bias voltage V
BAmplitude, during normally closed be
V
B＝V
OFF+ΔV/2 (2)
When normally opening be
V
B＝V
ON+ΔV/2 (3)
When bright state (under the even frame situation), voltage Δ V/2 is added on the center voltage VD-CENTER (being added to signal electrode 2 from signal driver 19) of drain voltage, when dark state (under the even frame situation), then adds a Δ V/2.Maximum amplitude V
DP-p(=V
DH-VDL) be decreased to Δ V (Figure 33).(under the odd-numbered frame situation, voltage when bright state-Δ V/2 is added to center voltage, then adds Δ V/2 when dark state.The voltage that obtains medium tone adopts above-mentioned identical method).
Adopt in the liquid crystal display cells of parallel electric field type at present embodiment, because wire pixel electrode 3 and wire counter electrode 4 are arranged in parallel on same substrate liquid crystal capacitance C
LCBe 33fF, it almost is liquid crystal capacitance 1/10th like that little that is about 370fF in the traditional vertical electric field type, and the latter's liquid crystal capacitance forms by flat pixel electrode and flat counter electrode are provided with mutually face-to-face.Therefore, in the parallel electric field type, adopt with bias voltage when scan electrode is added to the driving method of pixel electrode (the capacitor C between grid and the source electrode especially if stray capacitance in the TFT
GS) and C
SLittler, C then
TC
SFrom equation 1 as seen, the changes delta V in the non-selection voltage
GLItself become bias voltage V
B, can apply enough bias voltage.In the present embodiment, the predetermined value of voltage waveform shown in Figure 7 is as follows: VD-CENTER=23.0V, V
GH=28.6V, V
GL=0, V
DH=24.5V, V
DL=21.6V, V
GLH=9.0V, V
GLL=-.0V, V
C=22.3V.As a result, because of stray capacitance C between grid level and the source electrode
GSAnd the variation Δ V that causes
GS (t), Δ V
GS (-), Δ V
B, bias voltage V
BAnd be added to voltage V on the liquid crystal
LCRoot-mean-square value V
RmsBe shown in table 1.
The various magnitudes of voltage of table 1
| Show state | Bright | Secretly |
| ΔV GS(+) | 0.44 | 0.59 |
| ΔV GS(-) | 0.82 | 0.78 |
| V B(+) | 7.61 | 8.31 |
| V B(-) | 7.61 | 8.31 |
| ΔV B(-) | 0.14 | 0.15 |
| ΔV B(+) | 0.14 | 0.15 |
| V rms | 9.11 | 6.80 |
As shown in table 1, be added to the voltage V on the liquid crystal
LCMaximum voltage be 9.11V, the voltage V when it equals to obtain bright state
ONAnd minimum voltage is 6.80V, the voltage V when equaling to obtain dark state
OFFAs seen, obtain the maximal value and the minimum value of brightness curve among Figure 33, can obtain ratio and be 80 sufficiently high contrast.In addition, the maximum amplitude of voltage waveform signal can be reduced to V
DP-P=V
DH-VDL=2.9V.
Wherein, in the described a kind of like this scanning voltage waveform of present embodiment, at the selection voltage V of scanning voltage signal
GHNon-selection voltage V
GLHBetween higher voltage must be set, to satisfy following equation:
V
GH≥VDH+V
TH+V
M (4)
V
GLH≤V
SI+VTH-V
M (5)
Wherein, V
SIBe the voltage that Fig. 7 (e) marks, V
SI=VDL-Δ V
GS (-)-V
B (-)V
THBe the threshold value of TFT, V
MFor guaranteeing the margin voltage of TFT conduction and cut-off operation.In the present embodiment, above-mentioned voltage is set at V
TH=0V, V
M=4V.In order to eliminate flip-flop, counter electrode voltage V
CSet than the low Δ V of center voltage VD-CENTER
C=0.5V.
Moreover, at previous row scanning voltage V
G (i-1)From forward voltage V
GHJump to non-selection voltage V
GLHOr V
GLLTime after, scanning voltage V
G (i)Begin to rise to forward voltage V
HG, the mistiming is t
D1And at previous row scanning voltage V
G (i-1)From forward voltage V
GHJump to non-selection voltage V
GLHOr V
GLLTime after, scanning voltage V
G (i)Fall non-selection voltage V
GLHOr V
GLL, the mistiming is T
D2This is because considered the distortion of voltage waveform, in the present embodiment, and t
D1 and td2All be made as 3 μ s.Yet (, in the present embodiment, when storage capacitance 16 is connected to the scan electrode of previous row, and when carrying out scanning with the descending order of row; The perhaps scan electrode of delegation after storage capacitance 16 is connected to, and when carrying out scanning with the increasing order of row, t
D1 and td2Just not necessarily needed.When storage capacitance 16 is connected to the scan electrode of previous row, when finishing scanning with the increasing order of row, the perhaps scan electrode of delegation when storage capacitance 16 is connected to after, when finishing scanning with capable descending order, t
D1 and td2Always need.
As mentioned above, even liquid crystal capacitance is so small to have only 33fF, the little extremely just 200fF of storage capacitance is with 9V (Δ V
G=V
GLH-V
GL=VGLLH-V
GL) modulation voltage compare, still can apply the bias voltage that is about 8V.For this reason, display system can drive with extremely low driving voltage, wherein V
DP-P(referring to Fig. 7 (c)) only is 2.9V.Therefore, the power consumption of the signal driver 19 that power consumption is maximum reduces, and has reduced the total power consumption of display system thus.Moreover because the chip size of signal driver reduces, the framework that centers on display panel can reduce, thereby realizes undersized display system.In addition, because the shared number percent in viewing area increases, the visibility performance can be improved.Simultaneously, because storage capacitance is less, thus regional little as to be enough to obtain 53% high opening ratio by opening wide of taking of storage capacitance, thereby the brightness of display screen can improve.
Capacitor C on each bar scanning bus line
GBe expressed from the next:
C
G＝M·{C
S(C
GS-CLC)+C
GS(C
S+C
LC)}/(C
S+C
GS+CLC) (6)
Wherein, M is the total amount of pixel on the horizontal direction.Because the liquid crystal capacitance of vertical electric field type is bigger, C
GS＜＜C
LCTherefore:
C
G＝C
S·C
LC/(C
S+C
LC) (7)
Suppose that the bias voltage amplitude is modulation voltage Δ V
GL80%, obtain C
S=4C
LC, C
GMinimum value be (4/5) C
LCOn the other hand, in the parallel electric field type, because C
GS ≌ CLC＜＜C
S,
C
S＝2C
GS+CLC (8)
Work as C
GS=CLCThe time, C
S=3C
LCAs mentioned above, owing to liquid crystal capacitance C in the parallel electric field type
LCBe about 1/10th of vertical electric field type, so the C of parallel electric field type
GBe about C in the vertical electric field type
G0.4 times such little.Usually, because of different images changes the voltage wave shape distortion produce with crosstalk (laterally smearing), visible horizon tow line wherein.Especially in employing was modulated with the driving method that reduces the signal voltage amplitude to the voltage on the scan electrode, the voltage wave shape distortion on the scan electrode had changed effective bias voltage with being changed significantly.Therefore, by the voltage on the modulated scanning electrode is combined with driving method and the parallel electric field type that reduces the signal voltage amplitude, can apply bias voltage fully and also can suppress laterally to smear.
In the present embodiment, the electric capacity of each scan electrode is very little, and its value is 69fF.In this case, the result who observes the scanning voltage waveform is that the waveform distortion in the modulation voltage exists hardly, and naked eyes can not confirm the generation of laterally smearing.As mentioned above, in the present embodiment, can realize low driving voltage, the compatibility of high opening ratio and high image quality.In addition, in the present embodiment, owing to show the voltage V of bright state
ONWith the voltage V that shows dark state
OFFBetween voltage difference be lower than 5V, in signal driver 19, can adopt LSI by general LSI (for example C-MOS) technology manufacturing, its maximum mains voltage is lower than 5V, has improved the throughput rate of display system thus and has reduced manufacturing cost.
When superposition modulated voltage not, i.e. V
GLH=V
GLL=V
GLSuppose V
DH=22.5V, V
DL=4.3V just obtains V
DP-P=18.2V.Because V in the present embodiment
DP-PSo=2.9V is V
DP-PCan ease down to as 1/6 under the superposition modulated voltage condition not little.
Drive waveforms in the present embodiment is different from embodiment 1.
Fig. 8 represents the drive waveforms of present embodiment.Although among the embodiment 1 at the added modulation voltage Δ of same frame V
GL (+), Δ V
GL (-)In all scan lines, have identical positive or negative polarity, but in the present embodiment, the polarity of modulation voltage is opposite between the contiguous mutually scan line.Therefore, be applied to the voltage V of pixel electrode
SPolarity opposite with the every row of the order that replaces, so-called select lines reverse drive (gatelineinversiondriving) method that Here it is.In the present embodiment, provide corresponding to the equation of embodiment 1 (equation 4) and (equation 5) as follows:
V
GH≥VDH+V
TH+V
M (9)
V
GL≤VS1+V
TH-V
M (10)
V
GLH≤V
S2+VTH-V
M (11)
V wherein
S2Be magnitude of voltage shown in Figure 8, and V
S2=VDL-Δ V
GS (+)When this voltage is set at V
MDuring=4V, the result is VD-CENTER=15.0V, V
GH=20.5V, V
GL=0, V
DH=16.5V, V
DL=13.6V, V
GLH=9.0V, V
GLL=9.0V, V
C=14.5V.Table 2 shows the voltage deviation Δ V that produces because of the stray capacitance between grid and the source electrode
GS (+), Δ V
GS (-), Δ V
B, bias voltage V
BAnd the voltage V that is applied to liquid crystal
LCRoot-mean-square value V
Rms
Each magnitude of voltage of table 2
| Show state | Bright | Secretly |
| ΔV GS(+) | 0.31 | 0.45 |
| ΔV GS(-) | 0.69 | 0.65 |
| V B(+) | 7.61 | 8.31 |
| V B(-) | 7.61 | 8.31 |
| ΔV B(-) | 0.14 | 0.15 |
| ΔV B(-) | 0.14 | 01.5 |
| V rms | 9.11 | 6.80 |
By adopting select lines reverse drive method in the present embodiment, the amplitude peak of scan electrode voltage can ease down to 20.5V from 28.6V, although margin voltage V
MBe set in same sample value.For this reason, the absolute maximum mains voltage of scanner driver IC18 and power consumption all can reduce.
As mentioned above, in the present embodiment, except having the effect identical, can also use the low scanner driver IC of absolute maximum mains voltage, and further reduce power consumption with embodiment 1.
Present embodiment is being different from embodiment 1 aspect electrode structure and the driving method.
Fig. 9 represents to cover on the subtegulum planar structure in the zone of a plurality of pixels.Figure 10 is the enlarged drawing of expression one part of pixel.Figure 11 is the sectional view along Figure 10 D-D ' line plane.Figure 12 represents the circuit theory diagrams according to a display system of the present invention.
Shown in Fig. 9 to 12, the main body of counter electrode 4 is parallel to scan electrode 1, and is arranged into the edge of the panel of scanner driver 18 reverse side, is connected to counter electrode driver 20 after main part connects together.Component extends up and down from each main body of counter electrode.In order to realize high as far as possible high opening ratio, a main body of counter electrode is used for two vertical contiguous pixels that are in line and arrange so that with the decreased number of counter electrode interconnection half.Scan electrode 1 and the same metal material of counter electrode 4 usefulness are made.
As shown in figure 11, by gate insulator 9 being clipped between pixel electrode and the counter electrode 4, form reservoir capacitor 16.Because counter electrode 4, can be short-circuited between counter electrode 4 and the signal electrode 2 being different from formation on another layer of pixel electrode 3 and signal electrode 2 hardly via gate insulator 9, distance between the two can accomplish that about 3 μ m are so short.For this reason, because the non-region area that is used to show can reduce between signal electrode 2 and the contiguous counter electrode, compare with embodiment 1, by the component that utilizes pixel electrode 3 and counter electrode 4 pixel is divided into 4 parts (being to be divided into 3 parts) in embodiment 1, although reduced each gaps between electrodes width, but still can keep being equivalent to the high opening ratio of embodiment 1.By reducing each gaps between electrodes, can reduce institute's making alive between each electrode, be added to liquid crystal with electric field with same amplitude.As mentioned above, in the present embodiment, compare with embodiment 1, driving voltage can reduce, but has the brightness identical with embodiment 1.
Owing to directly form counter electrode 4 at adjacent signal electrode 2 places, most electric fields from signal electrode 2 stop at counter electrode 4, so the shielding action by counter electrode can prevent the capacitive coupling between signal electrode 2 and the pixel electrode 3, and can suppress the voltage fluctuation of the pixel electrode that the voltage fluctuation because of signal electrode causes.For this reason, can suppress crosstalking on the vertical direction (vertically smearing), improve display quality.In the present embodiment, the signal electrode number is 640 * 3, and the scan electrode number is 480, and the counter electrode interconnecting number is 240, and sum of all pixels is about 1,000,000, and is identical with embodiment 1.Because the counter electrode interconnecting number is than embodiment 1 much less in the present embodiment, thus can reduce the possibility that interconnection destroys in a large number and interconnect between the possibility of short trouble, and can improve the output of panel.Although the main part of counter electrode is generally used for the pixel of adjacent two homeotropic alignments in the present embodiment, can not change effect of the present invention basically yet, if a main body of counter electrode is used for the pixel of each homeotropic alignment, belong to scope of the present invention.
Figure 13 represents the drive waveforms of present embodiment display system.The voltage (first voltage) that applies between plain electrode of (e) voltage table aspect and the counter electrode wherein, (d) voltage represents to be applied to the voltage (second voltage) on the counter electrode, should (d) voltage be to be added in fundamental voltage (V by its AC wave shape
CHAnd V
CLBetween intermediate value) go up to form.In addition, (b) voltage represents to be applied to voltage (tertiary voltage) on the scan electrode.Sweep signal V
G (i-1), V
G (i)Non-selection voltage with V
GLHWith V
GLLBetween the order that replaces of each scan period change, synchronous therewith, the voltage V of counter electrode 4
CAlso at V
CHWith V
CCBetween change.Wherein, cut-off voltage | V
GLH-V
GLL| amplitude and counter electrode voltage | V
CH-V
CL| amplitude be set at same value, like this, pixel electrode 3, scan electrode 1 and 13 and counter electrode 4 between relative voltage become constant.By modulating the voltage V of counter electrode simultaneously
C, can make sweep signal non-selection voltage phase modulation each the row homophase.For this reason, although the output of scanner driver IC needs four kinds of magnitudes of voltage among the embodiment 1, yet in the present embodiment, because display system can drive with three kinds of magnitudes of voltage, the circuit scale of scanner driver IC inside can reduce.In addition, if modulation voltage is applied to the ground voltage among the scanner driver IC, or via the drive IC of the OFF voltage of exporting as scanning one side, then can utilize the scan-side drive IC with scale-of-two output, display system can further reduce.
As mentioned above, in the present embodiment, except having the effect identical with embodiment 1, driving voltage can further reduce, and crosstalk phenomenon can be inhibited, and the output of panel can further improve.In addition, because the sweep test drive IC can be done for a short time, the whole dimension of display system can be done little.
Because the driving method of present embodiment can be applied to the dot structure among the embodiment 1, so that the sweep test drive IC among the embodiment 1 also can be done is little.
In the present embodiment, although the order that modulation voltage replaced with each scan period changes,, also can obtain same effect if modulation voltage changes with per two scan periods or each frame period alternating sequence ground.
Figure 14 is illustrated in the structure that covers the zone of a plurality of pixels in the liquid crystal display systems of present embodiment.Figure 15 is the enlarged drawing of expression one part of pixel.
In the present embodiment, do not adopt counter electrode 4, the scan electrode 13 that utilizes previous row is as the anti-electricity level in the face of pixel electrode 3.The orientation of liquid crystal molecule is mainly controlled with the electric field E that is extended between the also vertical with it branch electrodes by previous row scan electrode 13 by pixel electrode 3 in the liquid crystal layer.In the present embodiment, although branch electrodes is drawn from the previous row scan electrode, branch electrodes also can be drawn from the scan electrode of back delegation.By gate insulator 9 being clipped between pixel electrode 3 and the previous row scan electrode 13, in this structure, form stray capacitance 16.Because previous row scan electrode 13 is arranged on another layer different with signal electrode 2, so the distance between scan electrode 5 and the signal electrode 2 can be reduced to 3 μ m via this insulator.In addition, owing to do not dispose counter electrode, can will be used as the gap by the shared zone of counter electrode circuit part among the embodiment of front.As mentioned above, owing to reduced the region area that can not control the transmittance state, so although reduced each gaps between electrodes because of pixel is divided into four parts, but still can obtain the opening ratio bigger than embodiment 1 and embodiment 3.Therefore, in the present embodiment, brightness further improves, and driving voltage little than embodiment 1.By forming the branch electrodes of scan electrode 13 at the previous row of adjacent signal electrode 2, stop at the branch sub-electrode place of scan electrode 13 from most of electric field of signal electrode 2.Therefore, the voltage fluctuation of the pixel electrode that causes owing to the voltage fluctuation of signal electrode can be inhibited, and crosstalking on the vertical direction also can be inhibited.
Figure 16 represents the wiring diagram of the display system of present embodiment.Owing to do not dispose counter electrode, so the counter electrode driver is also unnecessary.Owing to cancelled counter electrode circuit and counter electrode driver, the output of panel is improved.
Figure 17 represents the drive waveforms of present embodiment.(a) and (b) represent scanning voltage signal, (c) expression signal voltage, (d) expression is added to the voltage of pixel electrode, (e) voltage difference between remarked pixel electrode and the scan electrode.In the present embodiment, identical among sweep signal and the embodiment 3.Because being applied to the modulation voltage of scanning voltage signal of scan electrode 1 and the modulation voltage of the scanning voltage signal that is added to previous row scan electrode 13 is identical waveform, so eliminated the phase-shifted of the modulation voltage waveform that the difference because of the voltage waveform of counter electrode and scan electrode causes, bias voltage can be used as the voltage that is added to the high fidelity liquid crystal.
As shown in figure 17, the maximum gate voltage note that is applied is made V ', V '=V during non-selection cycle
ONIn the present embodiment, owing to AC current waveform is added on the voltage that is applied to liquid crystal, so the starting voltage V of control TFT
THTo satisfy V
TH＞VONFor this reason, even this voltage is applied to voltage (V on the liquid crystal of band negative value according to the situation of the non-selection voltage of sweep signal
ON) increase, pixel electrode also can keep this voltage.In the present embodiment, by making the attenuation of amorphous silicon membrane thickness, control grid starting voltage V
THMove towards high voltage one lateral deviation.Grid starting voltage V
THScope be V
TH＜V
G＜V
D+ V
TH, the grid starting voltage is by grid voltage V
GThe axle with a straight line point of crossing on grid voltage V
GDetermine that this straight line is the square root by the leakage current that draws
To grid voltage V
GRelation curve and make it be approximately a straight line and make.In the present embodiment, although the grid starting voltage is controlled by making the semiconductive thin film attenuation, can also be by other method control grid starting voltage, for example by selecting materials such as gate electrode material, gate insulator, semiconductive thin film, mix up back of the body raceway groove control or the like.Can adopt the combination of any or N kind method in the said method, these methods all belong to scope of the present invention, as long as it satisfies the condition of grid starting voltage.
As mentioned above, except embodiment 1 and 3 effects that had, present embodiment also has the further effect of improving brightness and improving the panel batch process.
Especially, by making V
THSurpass V
ON, this voltage is charged according to the situation of the non-selection voltage of sweep signal and remain negative, therefore can be with exchanging electrically-driven liquid crystal.Thus, can obtain the high and active matrix liquid crystal display system that can not smear of long service life, picture quality.
Driving method among the embodiment 1 and 2 also can be applied to the dot structure in the present embodiment.
This embodiment is different from embodiment 4 on driving method.
Figure 18 represents the drive waveforms of present embodiment.In the present embodiment, scan electrode receives scanning voltage signal, and the non-selection voltage in the wherein same frame is constant, but the every frame of non-selection voltage value changes, and the phase differential between every row is { 1+ (scan period)/(frame period) }.Make image signal voltage V
DBe added to pixel electrode via TFT in selection cycle, expression is added to signal electrode with this voltage in such a way: when the non-selection voltage that is added to previous row scan electrode 13 is V
GLH, and V
GLHBe two non-selection voltage V
GLHAnd V
GLLDuring higher voltage, negative voltage is added to signal electrode 2; When the non-selection voltage that is added to previous row scan electrode 13 is V
GLL, and V
GLLBe two non-selection voltage V
GLHAnd V
GLLDuring lower voltage, positive voltage is added to signal electrode 2.For this reason, the AC driving waveform can be added on the liquid crystal.
In the present embodiment, as shown in figure 18, because V '=V
ON, require the starting voltage of TFT to satisfy V
TH＞VONMake the polarity of every row can be reverse during realization, power consumption be little and need not to change non-selection voltage in each scan period as embodiment 4, and can suppress flicker.In the present embodiment, by with higher non-selection voltage V
GLHWith lower non-selection voltage V
GLLBetween voltage difference V
GLH-V
GLLSetting equals V
ON+VOFF, can be with image signal voltage V
PP-PAmplitude peak be restricted to V
ON-VOFFThereby, can realize being equivalent to the low starting voltage of embodiment 4.
As mentioned above, in the present embodiment, the power consumption of scanner driver is littler than embodiment's 4.
Figure 19 represents the drive waveforms of the liquid crystal display systems of present embodiment.Although the drive waveforms in the present embodiment is identical with embodiment 5 basically.But wherein the difference with embodiment 5 is, higher non-selection voltage V
GLHWith lower non-selection voltage V
GLLBetween voltage difference V
GLN-V
GLLBe set to (V
ON+VOFF)/2.For this reason, shown in Figure 19 (c), though the amplitude peak V of image signal voltage
PP-PBecome (3V
ON-VOFF)/2 higher voltage, still, the starting voltage V of TFT
THBecome greater than V '=Δ V/2=(V
ON-VOFFSo)/2 are maximum negative voltage (V
ON) still can be added on the liquid crystal.Thus, compare with 5, can utilize the lower TFT of starting voltage, the amplitude peak V under the amplitude peak of image signal voltage and the monodrome non-selection voltage situation with embodiment 4
DP-P=2V
ONCompare, can ease down to (V
ON+VOFF)/2.In addition, in the present embodiment, by making angle Φ
LCBig, difference (V
ON-VOFF) can accomplish forr a short time, can utilize the lower TFT of starting voltage, image signal voltage can lower thus.
As mentioned above, present embodiment has the effect that it is compared with 5 with embodiment 4, can utilize the lower TFT of threshold voltage.
Figure 20 represents the drive waveforms of the liquid crystal display systems of present embodiment, in the present embodiment, is arranged alternately P type TFT and n type TFT by row.For this reason, can adopt and have negative starting voltage V
THTFT.Has negative threshold voltage V in order to use
THTFT, contain the central value V of the non-selection voltage of P type TFT scan electrode
GL-PThe central value V that must be higher than the non-selection voltage that contains n type TFT scan electrode
GL-NSimultaneously, voltage difference must surpass V
ON+ Δ V
S, wherein, Δ V
SMaximal value for feed-trough voltage.For this reason, the amplitude peak V of image signal voltage
DP-PCan be reduced to V
ON+ Δ V
S+ Δ V.
As mentioned above, compare, can adopt in the present embodiment to have negative threshold voltage V with embodiment 4
THTFT, image signal voltage can lower.
This embodiment all is being different from embodiment 1 aspect dot structure and the driving method.
In the present embodiment, dot structure as shown in figure 21.The equivalent electrical circuit of Figure 22 remarked pixel.Figure 23 represents along the sectional view of Figure 21 E-E ' line.Figure 24 represents along the sectional view of Figure 21 F-F ' line.Figure 25 represents along the sectional view of Figure 21 G-G ' line.As shown in figure 21, in pixel, form thin-film transistor element 15a and 15b.As shown in figure 21, be added to the drain electrode 25a of thin-film transistor element 15a, and deliver to pixel electrode 3 via source electrode 26a and through hole 31 corresponding to the signal voltage of image.In order to the voltage of counter electrode 4 that a voltage difference is provided,, be added to pixel electrode 3 by the scan electrode 13a of next line drain electrode 25b and source electrode 26b via through hole 32, thin-film transistor element 15b.As shown in figure 25, storage capacitance element 16a is formed by pixel electrode 3, counter electrode 4 and gate insulator 9.This storage capacitance element 16a is used for making the voltage of pixel electrode be maintained at a steady state value by absorbing the noise that produces because of signal.As mentioned above, two thin-film transistor elements are set in single pixel, thus, as shown in figure 24, it is horizontal composition that the direction of the electric field E between pixel electrode 3 and the counter electrode 4 mainly comprises parallel.Although adopted two thin-film transistor elements here, can certainly use three or more thin-film transistor element to other structure.Similarly, also can adopt two or more storage capacitance element 16a.Here, because aiming at by photomask between pixel electrode 3 and the counter electrode 4 finished, the deviation that is added to the electric field of liquid crystal layer can suppress lessly.In addition, because two kinds of source electrodes form on one deck, the range deviation d between pixel electrode 3 and the anti-electroplax 4 can be suppressed to less than 5%.
Below driving method will be described.Figure 27 represents to be added to the voltage waveform of each electrode.Here adopted each delegation method of write signal line by line.Scanning voltage waveform 40:V
G (i)Comprise in order to select the TFT in the delegation and to make it to be in the strobe pulse 41:V of conducting state
GON (i)And in order to voltage V
COffer the counter electrode voltage pulse 51:V of previous row counter electrode
C (i)The counter electrode voltage pulse 52:VGC (i+1) of (i+1) row is the strobe pulse 41:V of capable scan line with being used for i almost
GON (i)Synchronously apply.Therefore, when selecting pulse 41 to be added to the scanning voltage waveform 40 of the capable scan line of i, thin-film transistor element 15a and 15b conducting, the voltage waveform signal 61:V of (i+1) row
D(j) and counter electrode voltage pulse 52:VGC (i+1) write storage capacitance 16a, liquid crystal 5a is connected to signal electrode 2 and scan electrode 13a via thin-film transistor element 15a and 15b respectively.After the write cycle (1H) of finishing to row, scanning voltage waveform 40:V
G(i) fall cut-off level (non-selection voltage), thin-film transistor element 15a and 15b enter cut-off state, write voltage and keep.Yet in fact the coupled noise that causes because of the stray capacitance of thin-film transistor element 5a and 5b will produce feed-trough voltage 76,77, write voltage and remain on this voltage.Here, the voltage that is applied to liquid crystal is to lay respectively at the voltage between the source voltage 71 and 72 78 among thin-film transistor element 15a and the 15b.The brightness of pixel (transmittance) is determined by voltage 78.
In the present embodiment, offer the way of inverse voltage, need not to connect in order to the counter electrode that this voltage is added to counter electrode by voltage with the next line scan electrode.Different with embodiment 4,5 and 6 is, this TFT need not high starting voltage, this starting voltage approach zero or be lower than zero TFT can be with exchanging electrically-driven liquid crystal.In conventional driving method, when thin-film transistor element when conducting state transfers cut-off state to, be applied to DC component in the voltage of liquid crystal by 76,77 generations of feed-trough voltage via the stray capacitance of thin-film transistor element.In the present embodiment, the DC component that is applied in the voltage of liquid crystal can not produce, because it has been offset by two thin-film transistor elements.Therefore, in traditional system,, and need not in the present embodiment to proofread and correct although proofread and correct DC component with a counter electrode voltage at all.And, owing to can therefore, can not produce scintillation with exchanging electrically-driven liquid crystal.Similarly, do not see that also the image that produces because of DC component keeps, brightness degree is also not obvious.In addition, under situation about adopting, because two elements have been offset the element threshold deviation, so eliminated the image deterioration that causes the non-homogeneous class of brightness because of deviation such as MIM diode one class two ends element.
Except with the lower part, identical among the structure of present embodiment and the embodiment 8.Figure 28 is the planimetric map of a pixel in the expression present embodiment, and Figure 29 represents its equivalent electrical circuit.Voltage is supplied with the thin-film transistor element 15b of counter electrode 4, and its drain electrode is connected to the scan electrode 4 of next line by capacity cell 101.The noise that capacity cell 6 produces because of the signal that is connected between pixel electrode 3 and the counter electrode 4 in order to filtering, it is made up of two capacity cell 6a and 6b.Adopt this structure, through hole required among the embodiment 8 can be cancelled.For this reason, just no longer need be such as the manufacturing process of the drawing or the class of punching on the interlevel insulator in the pixel that requires accurately drawing, layer short circuit that the fault of processing because of the insulator manufacturing causes or connection defective are also eliminated.In addition, can also improve opening ratio, obtain high-quality liquid crystal display systems by reducing with showing irrelevant via regions.
As shown in figure 29, voltage is being offered under the situation of counter electrode 4 by capacitive coupling, the voltage of counter electrode 4 depends on the ratio of the combined capacity of capacity cell 101 and storage capacitance 16b and 16c.Here, the voltage of pixel electrode 3 is set at Vds, and the voltage of next line scan electrode is set V
GC (i), the voltage of counter electrode 4 is made as V
C (i), the electric capacity of liquid crystal and storage capacitance 16b and 16c are made as C respectively
17, C
6a and C6b, the combined capacity of these electric capacity is made as C
102, the electric capacity of capacity cell 101 is made as C
101Because the liquid crystal capacitance between pixel electrode 3 and the anti-electroplax 4 is very little, so obtain down routine relational expression:
C
102＝C
17+(C
6a×C6b)/(C
6a+C6b)
≌(C
6a×C6b)/(C
6a+C6b)
The voltage that is added to liquid crystal is:
V
D(j)-V
C(i)＝V
D(j)-{(V
D(j)-V
GC(i))×C
102/(C
101+C102)+V
GC(i)}
＝(V
D(i)-V
GC(i))×C
102/(C
101+C
102)
Therefore, if the capacitor C of capacity cell 101
101Obviously greater than combined capacity C
102, capacity cell 101 can apply enough big driven liquid crystal.Even the capacitor C of capacity cell 101
101Be combined capacity C
1022 to 3 times such big, display characteristic can be not influenced yet, just the voltage amplitude of next line scan electrode has increased 25% to 33%.
According to present embodiment, because the voltage of counter electrode is supplied with by the capacitive coupling, just need not, so improved opening ratio because of having reduced with showing irrelevant via regions such as class manufacturing processing such as drawing or punching on the insulator of interlayer.In addition, can obtain a kind of high-quality liquid crystal display systems, wherein because of the defective of insulator manufacturing processing cause defective few.
Except following part, the structure of present embodiment is identical with embodiment's 8.
Figure 30 represents drive waveforms.Although identical in dot structure and equivalent electrical circuit and Figure 21 and 22, the characteristics of present embodiment are, scanning voltage waveform 40:V
G (i+1)The relative V of polarity of middle counter electrode voltage pulse 5:VGC (i+1)
CcMid point is alternately opposite line by line.Because liquid crystal voltage equals the voltage difference between signal voltage 61 and the counter electrode voltage pulse 52, by replacing reverse counter electrode voltage pulse 52 in the scanning voltage waveform in being right after the delegation of selected row, can realize the low voltage grid row reverse drive of liquid crystal.By the amplitude of suitable selection counter electrode voltage 51 and 52, and the central value of signal voltage and counter electrode voltage is set at almost equates mutually, can make the amplitude of signal voltage reduce to minimum.
In the present embodiment, by selecting aforesaid drive condition, can utilize the capable inverse approach of grid to reduce the amplitude peak of signal driver voltage and reduce to glimmer.
Except with the lower part, identical among the structure of present embodiment and the embodiment 10.
Figure 31 is the planimetric map of 2 row * 2 row pixels in the expression present embodiment, and Figure 32 is an equivalent circuit diagram.Figure 33 represents drive waveforms.Whole viewing area constitutes by repeating these dot structures.Although identical among this dot structure and first embodiment shown in Figure 21, present embodiment also possesses following performance characteristics.The counter electrode 4 that receives scan electrode voltage alternately is connected to scan electrode 1 or 13a by each row; About driving method, in the scan period, there are two kinds of counter electrode voltages alternately to be added to scan electrode by each example.And in embodiment 10, two kinds of counter electrode voltages are alternately to be added to scan electrode by each row.
According to present embodiment, the polarity that is applied to the voltage on the liquid crystal can be alternately reverse by row, further can find, signal voltage by applying reversed polarity on scan electrode is to eliminate crossfire, the level that can prevent is smeared, and simultaneously, signal voltage is also lower.In addition, by replacing reversed polarity, also can prevent from vertically to smear, and can realize high picture quality and low voltage drive by row.
Although the present invention describes with reference to the embodiment of transmission type liquid crystal display systems, can certainly be effectively applied to the reflective liquid crystal display system.As for thin film transistor (TFT), its structure (conventional staggered structure, reverse interleaved arrangement architecture, coplanar structure or the like) and material are not limited to the foregoing description.
Part or whole peripheral circuit (signal driver, scanner driver, counter electrode driving circuit) can directly append on the substrate 7 forms panel, forms the IC chip.Part or whole peripheral circuit can for example be used polysilicon, form as parts on substrate 7 surfaces.So, its effect is that whole display system can be done forr a short time than the situation that forms peripheral circuit in the display panel outside.
By this liquid crystal display systems and processor, storer, input block, output unit, communication unit or the like are combined, can constitute office automated machine or portable machine.
According to the present invention, in the method for switchable liquid crystal, adopt the electric field be parallel to substrate interface, the voltage decreases by the modulated scanning electrode voltage of signal electrode, and realized high opening ratio and the low driving voltage in the pixel.Film transistor type liquid crystal display systems with low-power consumption, high brightness and high-quality visibility like this, just can be provided.In addition, by the driving method of modulated scanning electrode voltage, can suppress is crosstalk (level is smeared) of a difficult problem always, and a kind of tft liquid crystal display system with high quality graphic can be provided.Moreover by starting voltage or the structure N type thin-film transistor element and the P type thin-film transistor element of control TFT element, scan electrode also can connect as counter electrode, and available low voltage drive.In addition, by adopt two thin-film transistor elements in a pixel, counter electrode voltage can provide by scan electrode, and driving voltage can reduce, and picture quality improves.
Claims (26)
1. active matrix liquid crystal display system comprises:
First substrate, comprise a plurality of scan electrodes at the one face, the a plurality of signal electrodes that intersect to form with described a plurality of scan electrodes, the on-off element that forms in each crossover sites of described a plurality of scan electrodes and described a plurality of signal electrodes, be connected to the pixel electrode of described on-off element, and the counter electrode that forms corresponding to described pixel electrode;
Second substrate towards described first substrate setting;
Place the liquid-crystal composition in the gap between described first substrate and described second substrate;
Picture signal is added to the signal driver of each electrode of a plurality of signal electrodes;
Sweep signal is added to described a plurality of scan electrode to produce the scanner driver that shows;
It is characterized in that, between described pixel electrode and described counter electrode, apply first voltage, to provide electric field to described liquid-crystal composition, described liquid-crystal composition parallels with described first and second substrates basically, second voltage is added to described counter electrode, at least one electrode to a plurality of scan electrodes applies tertiary voltage, with at non-selection cycle at described scan electrode voltage and be applied between second voltage of described counter electrode of neighbor scanning electrode and keep a constant difference.
2. active matrix liquid crystal display system as claimed in claim 1 is characterized in that, each counter electrode is connected to the counter electrode that be arranged in parallel with the scan electrode that is close to described counter electrode.
3. active matrix liquid crystal display system as claimed in claim 1 is characterized in that, each counter electrode is connected to the counter electrode that be arranged in parallel with the signal electrode that is close to described counter electrode.
4. active matrix liquid crystal display system as claimed in claim 2 is characterized in that, at least one described counter electrode is conducted to few two pixel capacitors and uses, and one of it and described signal electrode be arranged in parallel, are close to described at least one counter electrode.
5. active matrix liquid crystal display system as claimed in claim 3 is characterized in that, at least one described counter electrode is conducted to few two pixel capacitors and uses, and one of it and described signal electrode be arranged in parallel, are close to described at least one counter electrode.
6. active matrix liquid crystal display system as claimed in claim 1 is characterized in that, is added to change direction and second voltage that is added to described counter electrode identical of amplitude direction of the tertiary voltage of each scan electrode during its non-selection.
7. active matrix liquid crystal display system as claimed in claim 1 is characterized in that, is added to phase place identical with second voltage that is added to described counter electrode basically of the tertiary voltage of each scan electrode during its non-selection.
8. active matrix liquid crystal display system as claimed in claim 1 is characterized in that, is added to amplitude identical with second voltage that is added to described counter electrode basically of the tertiary voltage of each scan electrode during its non-selection.
9. active matrix liquid crystal display system as claimed in claim 2 is characterized in that, is added to change direction and second voltage that is added to described counter electrode identical of amplitude direction of the tertiary voltage of each scan electrode during its non-selection.
10. active matrix liquid crystal display system as claimed in claim 2 is characterized in that, is added to phase place identical with second voltage that is added to described counter electrode basically of the tertiary voltage of each scan electrode during its non-selection.
11. active matrix liquid crystal display system as claimed in claim 2 is characterized in that, is added to amplitude identical with second voltage that is added to described counter electrode basically of the tertiary voltage of each scan electrode during its non-selection.
12. active matrix liquid crystal display system as claimed in claim 3 is characterized in that, is added to change direction and second voltage that is added to described counter electrode identical of amplitude direction of the tertiary voltage of each scan electrode during its non-selection.
13. active matrix liquid crystal display system as claimed in claim 3 is characterized in that, is added to phase place identical with second voltage that is added to described counter electrode basically of the tertiary voltage of each scan electrode during its non-selection.
14. active matrix liquid crystal display system as claimed in claim 3 is characterized in that, is added to amplitude identical with second voltage that is added to described counter electrode basically of the tertiary voltage of each scan electrode during its non-selection.
15. active matrix liquid crystal display system as claimed in claim 1 is characterized in that, the tertiary voltage that is added to each scan electrode during its non-selection is synchronous with second voltage of the counter electrode that is added to contiguous described scan electrode.
16. active matrix liquid crystal display system as claimed in claim 1 is characterized in that, each pixel capacitors is superimposed upon on the corresponding electrode of described scan electrode via insulation film.
17. active matrix liquid crystal display system as claimed in claim 1, it is characterized in that, a corresponding electrode of each pixel capacitors and described counter electrode has a part, described pixel capacitors and described counter electrode form electric capacity in this part mutual superposition and in this part, and described electric capacity is greater than formed electric capacity between the part of described pixel capacitors and relative described counter electrode.
18. active matrix liquid crystal display system as claimed in claim 17, it is characterized in that, a corresponding electrode of each pixel capacitors and described scan electrode has a part, described pixel capacitors and described scan electrode form electric capacity in this part mutual superposition and in this part, and described electric capacity is greater than formed electric capacity between the corresponding electrode of described pixel capacitors and described counter electrode.
19. active matrix liquid crystal display system as claimed in claim 1, it is characterized in that, a corresponding electrode of each pixel capacitors and described scan electrode has a part, described pixel capacitors and described scan electrode form electric capacity in this part mutual superposition and in this part, and described electric capacity is greater than formed electric capacity between the corresponding electrode of described pixel capacitors and described counter electrode.
20. an active matrix liquid crystal display system comprises:
First substrate, comprise a plurality of scan electrodes at the one face, the a plurality of signal electrodes that intersect to form with described a plurality of scan electrodes, on-off element in that each crossover sites of described a plurality of scan electrodes and described a plurality of signal electrodes forms is connected to the pixel electrode of described on-off element and the counter electrode that forms corresponding to described pixel electrode;
Second substrate towards described first substrate setting;
Place the liquid-crystal composition in the gap between described first substrate and described second substrate;
Picture signal is added to the signal driver of each electrode of a plurality of signal electrodes;
Each electrode that sweep signal is added to described a plurality of scan electrodes is to produce the scanner driver that shows;
Along the direction parallel, each counter electrode is connected to the public part of one of the counter electrode of contiguous described counter electrode with described scan electrode;
It is characterized in that, between described pixel electrode and described counter electrode, apply first voltage, to provide electric field to described liquid-crystal composition, described liquid-crystal composition parallels with described substrate basically, second voltage is added to described counter electrode, at least one electrode to a plurality of scan electrodes applies tertiary voltage, with at non-selection cycle at described scan electrode voltage and be applied between second voltage of described counter electrode of neighbor scanning electrode and keep a constant difference.
21. active matrix liquid crystal display system as claimed in claim 20 is characterized in that, is added to change direction and second voltage that is added to described counter electrode identical of amplitude direction of the tertiary voltage of each scan electrode during its non-selection.
22. active matrix liquid crystal display system as claimed in claim 20 is characterized in that, is added to phase place identical with second voltage that is added to described counter electrode basically of the voltage of each scan electrode during its non-selection.
23. active matrix liquid crystal display system as claimed in claim 20 is characterized in that, is added to amplitude identical with the tertiary voltage that is added to described counter electrode basically of the tertiary voltage of each scan electrode during its non-selection.
24. active matrix liquid crystal display system as claimed in claim 20 is characterized in that, the tertiary voltage that is added to each scan electrode during its non-selection is synchronous with second voltage of the counter electrode that is added to contiguous described scan electrode.
25. active matrix liquid crystal display system as claimed in claim 20 is characterized in that, each pixel capacitors is superimposed upon on the corresponding electrode of described counter electrode via insulation film.
26. active matrix liquid crystal display system as claimed in claim 25, it is characterized in that, a corresponding electrode of each pixel capacitors and described counter electrode has a part, described pixel capacitors and described counter electrode form electric capacity in this part mutual superposition and in this part, and described electric capacity is greater than formed electric capacity between the part of described pixel capacitors and relative described counter electrode.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN94190231.5A CN1055769C (en) | 1994-03-17 | 1994-06-24 | Active matrix type liquid crystal display device and its driving method |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN94190231.5A Division CN1055769C (en) | 1994-03-17 | 1994-06-24 | Active matrix type liquid crystal display device and its driving method |
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| CN1315002C true CN1315002C (en) | 2007-05-09 |
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| KR101602091B1 (en) * | 2012-05-10 | 2016-03-09 | 샤프 가부시키가이샤 | Liquid-crystal-driving method and liquid crystal display device |
| CN104867473B (en) * | 2015-06-16 | 2018-03-20 | 深圳市华星光电技术有限公司 | Driving method, drive device and display device |
| KR102544322B1 (en) * | 2016-09-26 | 2023-06-19 | 삼성디스플레이 주식회사 | Light emitting display device |
| CN113409721B (en) * | 2021-04-21 | 2022-08-12 | 福州大学 | Electric field driving modulation device for light-emitting device |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4345249A (en) * | 1979-12-25 | 1982-08-17 | Citizen Watch Company Limited | Liquid crystal display panel |
| JPH02293722A (en) * | 1989-05-08 | 1990-12-04 | Fujitsu Ltd | Active matrix type liquid crystal display device |
| JPH03168617A (en) * | 1989-11-28 | 1991-07-22 | Matsushita Electric Ind Co Ltd | Method for driving display device |
| JP3168617B2 (en) * | 1990-07-13 | 2001-05-21 | 株式会社日立製作所 | Manufacturing method of nonvolatile semiconductor memory device |
-
1994
- 1994-06-24 CN CNB99127542XA patent/CN1315002C/en not_active Expired - Lifetime
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4345249A (en) * | 1979-12-25 | 1982-08-17 | Citizen Watch Company Limited | Liquid crystal display panel |
| JPH02293722A (en) * | 1989-05-08 | 1990-12-04 | Fujitsu Ltd | Active matrix type liquid crystal display device |
| JPH03168617A (en) * | 1989-11-28 | 1991-07-22 | Matsushita Electric Ind Co Ltd | Method for driving display device |
| JP3168617B2 (en) * | 1990-07-13 | 2001-05-21 | 株式会社日立製作所 | Manufacturing method of nonvolatile semiconductor memory device |
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