CN110366747A

CN110366747A - Driving method for color display apparatus

Info

Publication number: CN110366747A
Application number: CN201880014602.9A
Authority: CN
Inventors: C·林; J-C·黄; H-c·陈; P·B·雷克斯顿; 王铭; P-Y·程; 臧宏玫
Original assignee: Iyco California Co Ltd
Current assignee: E Ink Corp
Priority date: 2017-04-25
Filing date: 2018-04-17
Publication date: 2019-10-22
Anticipated expiration: 2038-04-17
Also published as: TW201843669A; EP3616188A1; JP6967082B2; WO2018200252A1; CN110366747B; TWI734572B; EP3616188A4; TW202117691A; TW202201099A; JP2021107936A; KR20190101488A; JP2020513114A; TWI700679B; CA3051003C; TWI807370B; KR102373217B1; CA3051003A1

Abstract

The invention relates to the driving method of the color state of high-quality can be shown for colour display device.The display device utilizes an electrophoretic fluid, which includes the pigment particles of three types, respectively has different optical characteristics, and not only show the color of the particle of three types on the viewing surface, but also show the color of its binary mixture.

Description

Driving method for color display apparatus

Cross reference to related applications

Present application requires on April 25th, 2017 to apply for and be disclosed as U.S. Patent Publication the 2017/0263176th The priority that U.S. Patent Application No. 15/496,604.Entire contents are incorporated herein in a manner of reference herein.? The content of every other United States Patent (USP) cited below and published application case is incorporated herein by this in a manner of reference.

Technical field

The present invention relates to the driving methods that high quality color state is shown for color display apparatus.

Background technique

In order to realize colored display, colored filter is commonly used.The most common method is in the black of pixellated display Colored filter is added in color/white sub-pixels top, to be displayed in red, green and blue.When it is expected red, green and indigo plant Sub-pixels become black state, so that the color uniquely shown is red.When it is expected blue, green and red sub-pixel become At black state, so that the color uniquely shown is blue.When it is expected green, red and blue subpixels become black powder State, so that the color uniquely shown is green.When desired black state, all three sub-pixels all become black state.When It is expected that three sub-pixels respectively become red, green, blue, as a result, viewer sees white states when white states.

The disadvantage of such technology is because the reflectivity of each sub-pixel be about it is expected white states three/ One (1/3), so white states are quite dim.To remedy this, can be added can only show black and white state The 4th sub-pixel so that white level is doubled in the case where sacrificing red, green or blue scale, (wherein, each sub-pixel only has The a quarter of elemental area).Brighter color can be obtained by adding the light from white pixel, but this is to sacrifice color It realizes under domain, is always on and unsaturated so that color be made to become non-.Similar result can pass through the color of three sub-pixels of reduction Saturation degree is realized.Even if white level is usually generally lower than the half of the white level of black and white display using these methods, Become display equipment (for example, display of electronic reader or needs good readable black and white brightness and contrast) Unacceptable selection.

Summary of the invention

First part of the invention is about a kind of driving method for electrophoretic display device (EPD), which is included in The first surface of viewing side, second surface and electrophoretic fluid in non-viewing, the electrophoretic fluid include the pigment of the first kind The pigment particles of particle, the pigment particles of Second Type and third type, all types of pigment particles disperse in a liquid, In

A) pigment particles of the three types have optical characteristics different from each other；

B) pigment particles of the first kind and the pigment particles of the Second Type carry opposite charge polarity；And

C) pigment particles of the third type have the charge polarity for the pigment particles for being identical to the Second Type, but have There is lower zeta potential (zeta potential),

This method includes the following steps:

(i) apply pixel of first driving voltage into the electrophoretic display device (EPD) and reach first segment time, first driving voltage With polarity of the pigment particles of the first kind towards the first surface is driven, to promote the pixel on the first surface Show the optical characteristics of the pigment particles of the first kind；

(ii) apply the second driving voltage to the pixel and reach the second segment time, which, which has, drives the third The pigment particles of type towards the first surface polarity, to drive the pixel to the third type on the first surface The optical characteristics of pigment particles；And

Repeat step (i) and (ii).

In one embodiment, the pigment particles of the first kind are negatively charged, and the pigment particles of the Second Type are positively charged. In one embodiment, the amplitude of second driving voltage is less than the 50% of the first driving voltage amplitude.In one embodiment, weight Multiple step (i) and (ii) at least four times.In one embodiment, this method further comprises the previous vibrational waveform in step (i). In one embodiment, this method further comprises but before step (i), driving the pixel to should after the vibrational waveform The full optical characteristics of the pigment particles of the first kind.In one embodiment, which is 40 to 140 milliseconds, this second The section time is greater than or equal to 460 milliseconds, and repeats step (i) and (ii) at least seven times.

Second part of the invention is but this method packet about a kind of driving method for as above-mentioned electrophoretic display device (EPD) It is as follows to include additional step: after step (ii), but before repeating step (i) and (ii), not applying driving voltage and extremely should Pixel reaches the third section time；And repeat step (i), (ii) and (iii).

In one embodiment, the pigment particles of the first kind are negatively charged, and the pigment particles of the Second Type are positively charged. In one embodiment, the amplitude of second driving voltage is less than the 50% of the first driving voltage amplitude.In one embodiment, weight Multiple step (i), (ii) and (iii) at least four times.In one embodiment, this method further comprises one before step (i) Vibrational waveform.In one embodiment, this method further comprises but before step (i), reaching this after the vibrational waveform The actuation step of the full-color state of the pigment particles of the first kind.

Part III of the invention is about a kind of driving method for electrophoretic display device (EPD), which is included in The first surface of viewing side, non-viewing second surface with and electrophoretic fluid, the electrophoretic fluid include the face of the first kind Expect that particle, the pigment particles of Second Type and the pigment particles of third type, all types of pigment particles disperse in a liquid, Wherein

C) pigment particles of the third type have be identical to the Second Type pigment particles charge polarity, have compared with Low zeta potential,

And this method has at least insensitive range of the voltage of 0.7V.

Part IV of the invention relates to a kind of driving for electrophoretic display device (EPD) of first part according to the present invention Method, but include that additional step is as follows:

(iii) after step (i), but before step (ii), when not applying driving voltage to the pixel up to third section Between；

(iv) after step (ii), but repeat to be somebody's turn to do and etc. before, do not apply driving voltage to the pixel up to the 4th The section time；And

It repeats step (i)-(iv).

In one embodiment, the pigment particles of the first kind can be negatively charged, and the pigment particles band of the Second Type Positive electricity.In one embodiment, the amplitude of second driving voltage is less than the 50% of the first driving voltage amplitude.In an embodiment In, repeat step (i)-(iv) at least three times.In one embodiment, this method further comprises the vibration before step (i) Dynamic waveform.In one embodiment, this method further comprises but before step (i), driving the picture after the vibrational waveform Element to the first kind pigment particles full-color state.

Part V of the invention is about a kind of driving method for electrophoretic display device (EPD), which is included in The first surface of viewing side, second surface and electrophoretic fluid in non-viewing, the electrophoretic fluid are clipped in a shared electrode and one Between pixel electrode layer and the pigment grain of the pigment particles including the first kind, the pigment particles of Second Type and third type Son, all types of pigment particles are dispersed in solvent or solvent mixture, wherein

C) pigment particles of the third type have the charge polarity for the pigment particles for being identical to the Second Type, but locate In lower intensity,

This method includes the following steps:

(i) apply pixel of first driving voltage into the electrophoretic display device (EPD) and reach the first segment time, wherein first driving Voltage has the polarity for the pigment particles for being identical to the first kind, to drive the pixel to the first kind in the viewing side The color state of pigment particles；

(ii) apply the second driving voltage to the pixel and reach the second segment time, wherein second driving voltage has identical In the polarity of the pigment particles of the Second Type, to drive the pixel to the face of the pigment particles of the Second Type in the viewing side Color state；And

Repeat step (i) and (ii).

In one embodiment, this method further comprises not applying the waiting time of driving voltage.In one embodiment, should The pigment particles of the first kind are negatively charged, and the pigment particles of the Second Type are positively charged.In one embodiment, when the second segment Between at least the first segment time two double-lengths.In one embodiment, step (i) and (ii) is repeated at least three times.It is real one It applies in example, this method further comprises the vibrational waveform before step (i).In one embodiment, this method is further wrapped It includes after the vibrational waveform, but before step (i), drives the pixel to the full-color shape of the pigment particles of the Second Type State.

Part VI of the invention is about a kind of driving method for electrophoretic display device (EPD), which is included in The first surface of viewing side, second surface and electrophoretic fluid in non-viewing, the electrophoretic fluid are clipped in a shared electrode and one Between pixel electrode layer and the pigment grain of the pigment particles including the first kind, the pigment particles of Second Type and third type Son, all types of pigment particles are dispersed in solvent or solvent mixture, wherein

This method includes the following steps:

(i) apply pixel of first driving voltage into the electrophoretic display device (EPD) and reach the first segment time, wherein first driving Voltage has the polarity for the pigment particles for being identical to the Second Type, to drive the pixel to the Second Type in the viewing side The color state of pigment grain；

(ii) apply the second driving voltage to the pixel and reach the second segment time, wherein second driving voltage has identical In the polarity of the pigment particles of the first kind, to drive the pixel to the face of the pigment particles of the first kind in the viewing side Color state；

(iii) driving voltage is not applied to the pixel up to during third section；And

It repeats step (i), (ii) and (iii).

In one embodiment, the pigment particles of the first kind are negatively charged, and the pigment particles of the Second Type are positively charged. In one embodiment, step (i), (ii) and (iii) is repeated at least three times.In one embodiment, the width of second driving voltage It spends and drives the pixel to the color of the pigment particles of the Second Type from the color state of the pigment particles of the first kind The amplitude of driving voltage needed for state is identical, and vice versa.In one embodiment, the amplitude of second driving voltage, which is higher than, incites somebody to action The pixel drives from the color state of the pigment particles of the first kind to the color state institute of the pigment particles of the Second Type The amplitude of the driving voltage needed, vice versa.In one embodiment, this method further comprises a vibrational waveform.Implement one In example, this method further comprises but before step (i), driving the pixel to the first kind after the vibrational waveform Pigment particles full-color state.

Part VII of the invention relates to a kind of driving method for electrophoretic display device (EPD), which includes First surface in viewing side, the second surface in non-viewing and electrophoretic fluid, the electrophoretic fluid be clipped in a shared electrode with Between one pixel electrode layer and the pigment grain of the pigment particles including the first kind, the pigment particles of Second Type and third type Son, all types of pigment particles are dispersed in solvent or solvent mixture, wherein

This method includes the following steps:

(i) apply pixel of first driving voltage into the electrophoretic display device (EPD) and reach first segment time, first driving voltage Polarity with the pigment particles for being identical to the Second Type, to drive the pixel to the color of the pigment particles of the Second Type State, wherein the first segment time be not enough to the viewing side drive the pixel to the pigment particles of the Second Type it is full-color State；

(ii) apply the second driving voltage to the pixel and reach the second segment time, second driving voltage have be identical to this The polarity of the pigment particles of one type, to drive the pixel mixing to the pigment particles of first and second type in the viewing side Conjunction state；And

Repeat step (i) and (ii).

In one embodiment, the pigment particles of the first kind are negatively charged, and the pigment particles of the Second Type are positively charged. In one embodiment, the amplitude of second driving voltage is less than the 50% of the first driving voltage amplitude.In one embodiment, weight Multiple step (i) and (ii) at least four times.In one embodiment, this method further comprises the vibration wave before step (i) Shape.In one embodiment, this method further comprises but before step (i), driving the pixel extremely after the vibrational waveform The full-color state of the pigment particles of the first kind.

4th driving method of the invention can be applied to the pixel of the color state in the first kind pigment particles, Or it can be applied to the pixel that pixel color state is not in the color state of the first kind pigment particles.

The present invention also provides the optical characteristics mixing for showing two kinds of particles in aforementioned electrophoresis showed fluid in three kinds of particles Driving method." mixed characteristic " method as first includes the following steps:

(iii) apply third driving voltage and reach the third section time, which, which has, is identical to first driving The polarity of voltage, and the third section time is also shorter than the first segment time, thus generated in the viewing face this first and The mixing of the optical characteristics of the particle of three types.

In the first mixed characteristic method, when the duration of the third section time can be the first segment time persistently Between about 20% to 80%, and preferably, about 20% to 40%.A vibrational waveform can be applied before step (i), And one can be applied before the vibrational waveform and drive driving electricity of the pigment particles of the first kind towards the first surface Pressure.

One second " mixed characteristic " method includes the following steps:

(i) apply pixel of first driving voltage into the electrophoretic display device (EPD) and reach first segment time, first driving voltage With polarity of the pigment particles of the Second Type towards the first surface is driven, to promote the pixel on the first surface Show the optical characteristics of the pigment particles of the Second Type；

(ii) apply the second driving voltage to the pixel and reach the second segment time, second driving voltage have be identical to this The polarity of one driving voltage, but there is the amplitude smaller than first driving voltage, thus drive on the first surface this The pigment particles of three types, and generate on the first surface this second and third type particle optical characteristics it is mixed It closes.

In the second mixed characteristic method, the duration of the second segment time can be continuing for first segment time About the 100% to 150% of time.Can apply a vibrational waveform before the step (i), and can the vibrational waveform it Preceding application one drives driving voltage of the pigment particles of the first kind towards the first surface.

One third " mixed characteristic " method includes the following steps:

(ii) apply the second driving voltage to the pixel and reach the second segment time, which, which has, drives the third Polarity of the pigment particles of type towards the first surface；And

Step (i) and (ii) is repeated,

Wherein, the duration of set-up procedure (i) and (ii) and its applied in voltage size, in first table The optical characteristics of one of the particle of the third type and the particle of first and second type particle of type is generated on face Mixing.

In the third mixed characteristic method, a vibrational waveform can be applied before step (i), and can be in the vibration Apply one before dynamic waveform and drives driving voltage of the pigment particles of the first kind towards the first surface.

Detailed description of the invention

Fig. 1 is the diagrammatic cross-section of the electrophoresis showed fluid in driving method for use in the present invention.

Fig. 2A, 2B and 2C are similar to the diagrammatic cross-section of Fig. 1, and display is in black, the white for showing fluid respectively With the position of red (coloring) state particle.

Fig. 3 is the typical waveform for pixel to be driven to the red status to Fig. 2 C from the white states of Fig. 2 B.

Fig. 4 is can to realize the first driving method of the invention in the part of period t3 in the waveform to replace Fig. 3 Waveform.

Fig. 5 and Fig. 6 describes the waveform that Fig. 3 is modified to realize the first driving method of the invention with the portion waveshape of Fig. 4 Generated waveform.

Fig. 7 is can to realize the second driving method of the invention in the part of period t3 in the waveform to replace Fig. 3 The second waveform.

Fig. 8 and Fig. 9 describes the waveform that Fig. 3 is modified to realize the second driving method of the invention with the portion waveshape of Fig. 7 Generated waveform.

Figure 10 A and Figure 10 B are the optical results as caused by third driving method of the invention.Figure 10 A is based on Fig. 3 The relationship and Figure 10 B of driving voltage and optical states performance (a*) that waveform applies are that the portion waveshape based on Fig. 4 is modified Fig. 3 waveform apply driving voltage and optical states performance (a*) relationship.

Figure 11 be can part in the waveform to replace Fig. 3 in period t3 realize the 4th driving side of the invention The waveform of method.

Figure 12 and Figure 13 describes to realize the 4th driving method of the invention by modifying Fig. 3 with the portion waveshape of Figure 11 Waveform caused by waveform.

Figure 14 describes for driving pixel from the white states of Fig. 2 B to the typical waveform of the black state of Fig. 2A.

Figure 15 is can to add in the end of Figure 14 waveform the waveform for realizing the 5th driving method of the invention.

Figure 16 is the waveform of constitutional diagram 14 and Figure 15 to realize the composite wave-shape of the 5th driving method of the invention.

Figure 17 describes for driving pixel to the typical waveform of the white states of Fig. 2 B.

Figure 18 A and Figure 18 B are that of the invention can be realized to replace part of the waveform of Figure 17 in period t17 Two waveforms of six driving methods.

Figure 19A and Figure 19B is described to realize the 6th driving method of the invention respectively with the part of Figure 18 A or Figure 18 B Waveform modifies waveform caused by the waveform of Figure 17.

Figure 20 A and Figure 20 B are similar to the diagrammatic cross-section of Fig. 1, respectively black and ash of the display in display fluid The position of the particle of color state.

Figure 21 is the typical waveform of the gray states for driving pixel to Figure 20 B.

Figure 22 is can to realize the 7th driving side of the invention to replace part of the waveform of Figure 21 in period t23 The waveform of method.

Figure 23 is the waveform of constitutional diagram 21 and Figure 22 to realize the composite wave-shape of the 7th driving method of the invention.

Figure 24 is the waveform used in the 8th driving method of the invention.

Figure 25 is the waveform of constitutional diagram 14 and Figure 24 to realize the composite wave-shape of the 8th driving method of the invention.

Figure 26 A and Figure 26 B are the generations of the gray states of the pixel since the white states of pixel.

Figure 26 C and Figure 26 D are the generations of the gray states of the pixel since the black state of pixel.

Figure 27 is to can be used for driving display extremely via white states in the first mixed characteristic driving method of the invention The waveform of light red state.

Figure 28 is to can be used for driving display to peony state in the second mixed characteristic driving method of the invention Waveform.

Figure 29 is to can be used for driving display to peony state in third mixed characteristic driving method of the invention Second waveform.

Specific embodiment

The invention relates to the driving methods for color display apparatus.

Device uses electrophoretic fluid as shown in Figure 1.(usually dielectric solvent or solvent are mixed including being dispersed in liquid for fluid Close object) in three types pigment particles.In order to facilitate elaboration, the pigment particles of three types are properly termed as white particles (11), black particles (12) and colored particle (13).Colored particle is non-white and non-black.

However, the scope of the present invention is wide it is understood that as long as the pigment particles of three types have differentiable optical characteristics Cover the pigment particles of any color generally.Therefore, the pigment particles of three types can also be known as the pigment grain of the first kind The pigment particles of son, the pigment particles of Second Type and third type.

White particles (11) can be by as TiO₂、ZrO₂、ZnO、Al₂O₃、Sb₂O₃、BaSO₄、PbS O₄Deng inorganic pigment shape At.

Black particles (12) can be Cl pigment black 26 (Cl pigment black 26) or 28 etc. (for example, ferrimanganic is black (manganese ferrite black spinel) or copper-chrome black (copper chromite black spin el)) or carbon It is black.

The particle of third type can have the color as red, green, blue, carmetta, cyan or yellow.For this The pigment of seed type particle may include but be not limited to CI pigment PR254, PR122, PR149, PG36, PG58, PG7, PB15:3, PY138, PY150, PY155 or PY20.Those are in pigment index manual " New Pigment Application Technology " (CMC Publishing Co.Ltd.1986) and " Printing Ink Technology " (CMC Publishing Co.Ltd.1984) described in common organic pigment.Particular example includes Clariant Hostaperm Red D3G 70-EDS、Hostaperm Pink E-EDS、PV fast red D3G、Hostaperm red D3G 70、 Hostaperm Blue B2G-EDS、Hostaperm Yellow H4G-EDS、Hostape rm Green GNX、BASF Irgazine red L 3630, Cinquasia Red L 4100HD and Irgazine Red L 3660HD；Sun Chemical phthalocyanine blue, phthalocy anine green, diarylide yellow or diarylide AAOT yellow。

Besides colour, the optical characteristics that the particle of the first, second, and third type can also have other different, example Such as, light transmission, reflectivity and light emission luminance, or in the case where being intended for the display of machine reading, in visible range False color (p seudo-color) in the variation meaning of the reflectivity of outer electromagnetic wavelength.

Be dispersed with the pigment particles of three types liquid can be it is limpid and colourless.For high particle mobility, it Preferably have low-viscosity and dielectric constant in the range of about 2 to 30 (preferably, about 2 to 15).Suitable dielectric stream The example of body includes hydrocarbon (for example, isoalkane class solvent (Iso par), decahydronaphthalene (decahydronaphthalene, DECALIN), -2 norbornene of 5- ethylidene-(5-ethy lidene-2- Norbornene), fat oil (fatty oils), paraffin oil (paraffin oil), silicon fluid (silico n fluids), Aromatic hydrocarbons (aromatic hydrocarbons) is (for example, toluene (toluene), dimethylbenzene (xylene), diphenyl dimethyl ethane (phenylxylylethane)), dodecyl benzene (dodecylbenzene) or alkylnaphthalene (al kylnaphthalene)), halogen Change solvent (halogenated solvents) (for example, perfluorodecalin (perfluorod ecalin), octafluoro toluene (perfluorotoluene), perfluoroxylene (perfluoroxylene), two chlorobenzotrifluorides (dichlorobenzotrifluoride), 3,4,5-Trichloro-trifluoromethyl-benzene (3,4,5-trichlorobenzotrifluo Ride), chlorine phenyl-pentafluoride (chloropentafluorobenzene), two chlorononanes (dichlorononane) or pentachlorobenzene (pentachlorobenzene)) and and perfluoro solvent (perfluorinated solvents) (for example, come from 3M FC-43, FC-70 or FC-5060 of Company, St.Paul MN)), halogenic polymer containing low molecular weight (for example, come from TCI Homopolymer (pol y (the perfluoropropylene of the hexafluoropropylene oxide of America, Portland, Oregon Oxide)), poly- (chlorotrifluoroethylene) (poly (chlorotrifluoroethylene)) is (for example, come from Halocarbon The halocarbon of Product Corp., River Edge, NJ is oily (Halocarbon Oils)), perfluoropolyalkylethers (perfluoropolyalkylether) (for example, Galden from Ausimont or DuPont is come from, Delaware's Krytox Oils and Greases K-Fluid Series), from Dow-corning with dimethyl silicone polymer (polydimethylsiloxane) silicone oil (DC-200) based on.

Using the display layer tool of display fluid of the invention, there are two surfaces, first surface (16) on the viewing side and Show on opposite sides second surface (17) of the fluid layer far from first surface (16).Therefore, second surface is located at non-viewing. Term " viewing side " means to watch the side of image.

Display fluid is clipped between the two surfaces.In first surface (16) side, have shared electrode (14), is transparent Electrode layer (for example, ITO) is distributed in the entire top of display layer.In second surface (17) side, having includes multiple pixel electrodes The electrode layer (15) of (15a).However, because as known electrophoretic display technology personage it is clear that various particles (11,12, 13) it only reacts to the electric field applied in display fluid layer, it is possible to use other electrode configurations；For example, shared electrode can To be replaced by a series of strip shaped electric poles or electrode matrix similar with pixel electrode 15a.

Display fluid is filled in display unit.Display unit can be aligned or not aligned with pixel electrode.Term is " aobvious Show unit " mean micro- container filled with electrophoretic fluid.The example of " display unit " may include such as U.S. Patent No. 6,930, Cup-shaped micro unit described in No. 818 and the microcapsules as described in U.S. Patent No. 5,930,026.Micro- container can have any Shape or size, it is all these all in the range of present application.

A region corresponding with a pixel electrode is properly termed as a pixel (or a sub-pixel).Correspond to One region of one pixel electrode be driven through between shared electrode and pixel electrode apply potential difference (or for driving Voltage or electric field) Lai Shixian.

Pixel electrode is described in U.S. Patent No. 7,046,228.Herein by its entire content with reference pattern simultaneously Enter herein.Although it is noted that refer to the active matrix drive using thin film transistor (TFT) (TFT) backboard for pixel electrode layer, As long as being that electrode provides desired function, the scope of the present invention includes other kinds of electrode addressing.

Space representation pixel (or sub-pixel) between two vertical dotted lines.For simplicity, when in driving method When referring to " pixel ", this term also includes " sub-pixel ".

Two kinds in the pigment particles of three types carry opposite charge polarity, and the pigment particles of third seed type are slightly Micro-strip electricity.Term " slightly charging " or " lower charge density " are intended to refer to the charge density about 50% less than stronger charged particle The charge level of the particle of (preferably, about 5% to 30%).In one embodiment, charge density can be surveyed according to zeta potential Amount.In one embodiment, by ColloidalDynamics AcoustoSizer IIM using CSPU-100 signal processing unit, ESA EN#Att n circulation groove (flow through cell) (K:127) measures zeta potential.Before testing, input is as testing The density of solvent used in sample at temperature (25 DEG C), the dielectric constant of solvent, the velocity of sound in solvent, solvent viscosity instrument Device constant.Pigment sample is dispersed in solvent (it is usually the hydrocarbon fluid having less than 12 carbon atoms) and dilutes At 5-10 weight percent.Sample also includes that (Solsperse 17000, can be from Lubrizol for charge control agent Corporation, Berkshire Hathaway company are bought, and " Solsperse " is registered trademark), charge control agent Weight ratio with particle is 1:10.Sample, is then loaded into circulation groove by the quality for measuring dilute sample, to measure ζ electricity Position.

For example, if black particles are positively charged, and white particles are negatively charged, then so colored pigment particles can slightly band Electricity.In other words, in this example, the charge as entrained by black and white particle is than the charge as entrained by colored particle It is much better than.

In addition, the colored particle for carrying slight charge any one of has with other two kinds of stronger charged particles The identical charge polarity of entrained charge polarity.Hereinafter, it will be assumed that colored particle (13) carries and second (black) grain The charge of sub (12) identical polar.

It is worth noting that, in the pigment particles of three types, the particle for the type slightly charged preferably have compared with Big size.

In addition, in the context of present application, high driving voltage (V_H1Or V_H2) be defined as being enough by pixel from a pole End color state drives to the driving voltage of another extreme color state.If the pigment particles of the first and second types are higher Charged particle, then high driving voltage (V_H1Or V_H2) mean that driving voltage is enough the color by pixel from first kind pigment particles State-driven is to the color state of Second Type pigment particles, and vice versa.For example, high driving voltage V_H1Mean to be enough pixel The driving voltage of the color state to the pigment particles of Second Type is driven from the color state of the pigment particles of the first kind, and And V_H2Mean to be enough from the color state of the pigment particles of Second Type to drive pixel to the face of the pigment particles of the first kind The driving voltage of color state.It is described in this case, low driving voltage (V_L) be defined as being enough by pixel from The color state of the pigment particles of one type drives that (it is with less charge and its size can to the pigment particles of third type With larger) color state driving voltage.For example, low driving voltage can be enough to drive to the color state of colored particle, And it can't see black and white particle in viewing side.

In general, V_LLess than V_H(for example, V_H1Or V_H2) amplitude 50%, or preferably, less than 40%.

Here is the example for illustrating the driving method that different colours state how can be shown by above-mentioned electrophoretic fluid.

Example 1

This example is shown in figs. 2 a-2 c.White pigment particle (21) is negatively charged, and black pigment particle (22) band is just Electricity, and two kinds of pigment particles are smaller than colored particle (23).

Colored particle (23) has charge polarity identical with black particles, but slightly charges.As a result, in certain driving electricity Pressure, black particles are moved more quickly than than colored particle (23).

In fig. 2, the driving voltage of application is+15V (also that is, V_H1, also that is, pixel electrode relative to shared electrode be+ 15V).In this case, negative white particles (21) are moved to relatively positive pixel electrode (25) nearby or relatively positive pixel At electrode (25), and positive black particles (22) and positive colored particle (23) are moved to the shared electrode (24) born relatively nearby or phase At negative shared electrode (24).As a result, seeing black in viewing side.Shared electrode (24) of the colored particle (23) towards viewing side It is mobile；However, they are more mobile than black particles slowly since their charge density is lower and size is larger.

In fig. 2b, when application -15V is (also that is, V_H2) driving voltage when, negative white particles (21) are moved in viewing side Relatively positive shared electrode (24) nearby or at relatively positive shared electrode (24), and positive black particles and positive colored particle move It moves to the nearby or relatively negative pixel electrode (25) of relatively negative pixel electrode (25).As a result, seeing white in viewing side.

It is worth noting that, V_H1And V_H2With opposite polarity, and amplitude having the same or different amplitudes.? In example shown in Fig. 2, V_H1It is positive (polarity identical with black particles), and V_H2It is negative (identical with white particles Polarity).

Drive the driving to the colored state of Fig. 2 C that can be summarized as follows from the white states of Fig. 2 B:

A kind of driving method for electrophoretic display device (EPD), electrophoretic display device (EPD) include in the first surface of viewing side, in non-sight See the second surface and electrophoretic fluid of side, fluid is clipped between shared electrode and pixel electrode layer and the pigment including the first kind The pigment particles (also that is, colored) of particle (also that is, white), the pigment particles (also that is, black) of Second Type and third type, All types of pigment particles are dispersed in solvent or solvent mixture, wherein

A) pigment particles of three types have optical characteristics different from each other；

B) pigment particles of the first kind and the pigment particles of Second Type carry opposite charge polarity；And

C) pigment particles of third type have be identical to Second Type pigment particles charge polarity, but in compared with Low intensity,

The method includes being enough to drive the pigment particles of third type to the low driving voltage of viewing side by applying, The pigment particles of the first and second types are made to be in non-viewing simultaneously, by the pixel in electrophoretic display device (EPD) from the face of the first kind Expect that the color state of particle drives towards the color state of the pigment particles of third type, and the pole of the low driving voltage applied Property is identical as the polarity of the pigment particles of third type.

In order to by the color state of the pigment particles of pixel driver to third type, also that is, red (C referring to fig. 2), described Method is since the color state (also that is, white (B referring to fig. 2)) of the pigment particles of the first kind.

When seeing the color of particle of third seed type in viewing side, other two kinds of particles may be in non-viewing Side (opposite side of viewing side) mixing, leads to the intermediate color states between the color of the first and second particles of types.If The particle of first and second types is black and white, and the particle of third type be it is red, then in fig. 2 c, when When viewing side sees red, grey is in non-viewing.

In the case where Fig. 2 C, driving method will ideally ensure colour brightness (also that is, black particles is prevented to be seen) With colour purity (also that is, white particles is prevented to be seen).However, in fact, due to various reasons (including particle size distribution And particle charging distribution) be difficult to reach this desired result.

A solution to this be the pigment particles from the first kind color state (also that is, white) driving extremely Vibrational waveform is used before the color state (also that is, red) of the pigment particles of third type.Vibrational waveform is by repeating a pair of of phase Anti- driving pulse is formed up to repeatedly circulation.For example, vibrational waveform can by 20msec+15V pulse and 20msec- 15V pulse composition, and such a pair of of pulse repeats 50 times.The total time of this vibrational waveform is 2000msec.Symbol " msec " represents millisecond.

No matter what optical states (black, white or red) before a driving voltage is applied are, can apply vibration Waveform is moved to pixel.After applying vibrational waveform, optical states will not be pure white, ater or pure red.It replaces , color state will be made of the mixing of the pigment particles of three types.

For the above method, by the color state (also that is, white) of the pigment particles of pixel driver to the first kind it Preceding application vibrational waveform.There is the vibrational waveform of this addition, even if white states and the white states of not vibrational waveform exist Be in measurement it is identical, the color state of the pigment particles of third type (also that is, red) is in colour brightness and colour purity side Face will be substantially better than the color state of not vibrational waveform.This expression white particles has with red particles preferably to be separated, and Black particles have with red particles preferably to be separated.

The application time of each driving pulse is no more than and drives from full black state to needed for full white state in vibrational waveform The half of driving time, vice versa.For example, pixel is driven from full black state to full white state if necessary to 300msec, instead , then vibrational waveform can be made of positive pulse and negative pulse, and the application time of each pulse is no more than 150msec.It is real On border, it is preferred that vibrational waveform pulse is shorter.

It is worth noting that, vibrational waveform is truncated (also that is, the quantity of pulse in all attached drawings of entire application case Less than actual quantity).

Display is for driving display to the waveform of colored (red) state of Fig. 2 C in Fig. 3.In this waveform, After vibrational waveform, apply high negative driving voltage (V_H2, for example, -15V) and up to during t2, pixel is driven towards white states It is dynamic.It, can be by applying low positive voltage (V from white states_L, for example,+5V) and up to during t3, by pixel towards colored shape State (also that is, red) driving, (also that is, driving pixel from Fig. 2 B to Fig. 2 C).

Driving period " t2 " is as application V_H2When be enough pixel driver to white states during, and driving period " t3 " It is as application V_LWhen be enough from white states to drive pixel to red status during.Preferably apply before vibrational waveform During driving voltage reaches t1, to ensure DC balance.In entire application case, term " DC balance " is intended to indicate when to one When the section time (for example, during entire waveform) is integrated, the driving voltage for being applied to pixel is essentially a zero.

First driving method:

Fig. 4 is the waveform in the first driving method for use in the present invention；This waveform can be used to replace the drive in Fig. 3 Dynamic period t3.

In the initial step, apply high negative driving voltage (V_H2, for example, -15V), then apply positive driving voltage (+ V'), pixel is driven towards red status.The amplitude of+V' is less than V_H(for example, V_H1Or V_H2) amplitude 50%.

In this drive waveforms, apply high negative driving voltage (V_H2) period t4 is reached, white particles are pushed to watch Side, then the positive driving voltage of application+V' reaches period t5, and white particles are pulled down and push red particles to viewing side.

In one embodiment, t4 can be in the range of 20-400msec, and t5 can be more than or equal to 200msec.

At least four times circulations (N >=4) of waveform of Fig. 4 are repeated, preferably, at least eight times circulations.Red is followed in each driving It can become stronger after ring.

The driving method of Fig. 4 can be summarized as follows:

A kind of driving method for electrophoretic display device (EPD), electrophoretic display device (EPD) include in the first surface of viewing side, in non-sight See the second surface and electrophoretic fluid of side, electrophoretic fluid is clipped between shared electrode and pixel electrode layer and including the first kind The pigment particles of pigment particles, the pigment particles of Second Type and third type, all types of pigment particles are dispersed in solvent Or in solvent mixture, wherein

The method includes the following steps:

(i) apply pixel of first driving voltage into electrophoretic display device (EPD) and reach the first segment time, the first driving voltage has It is identical to the polarity of the pigment particles of the first kind, to drive pixel to the color shape of the pigment particles of the first kind in viewing side State；

(ii) apply the second driving voltage to pixel and reach the second segment time, the second driving voltage, which has, is identical to third type Pigment particles polarity, with viewing side drive pixel to third type pigment particles color state；And

Repeat step (i) and (ii).

In one embodiment, the pigment particles of the first kind are negatively charged, and the pigment particles of Second Type are positively charged.

In one embodiment, 50% of the amplitude of the second driving voltage less than the first driving voltage amplitude.

As described above, it is to take that drive waveforms shown in Fig. 4, which may be substituted for driving period t3 and Fig. 5 in Fig. 3, Combined waveform after generation.In other words, driving sequence may is that vibrational waveform, then towards white states driving up to period t2, so Apply the waveform of Fig. 4 afterwards.

In another embodiment, the step of reaching period t2 to white states driving can be deleted, and in this case, Apply vibrational waveform immediately before the waveform for applying Fig. 4 (referring to Fig. 6).

In one embodiment, the driving sequence of Fig. 5 or Fig. 6 is DC balance.

Second driving method:

In the waveform that Fig. 7 is in the second driving method for use in the present invention.This waveform is replacing for the drive waveforms of Fig. 4 Generation, and can also be used to replace the driving period t3 in Fig. 3.

It is red to pulse (red-going pulse) later and in period in period t5 in this alternative wave White in t4 repeats red to addition waiting time " t6 " before pulse (white-going pulse) in period t5 To pulse.During the waiting time, do not apply driving voltage.Also repeat the entire waveform of Fig. 7 up to repeatedly circulation (for example, N >= 4)。

The Waveform Design of Fig. 7 is to discharge the charge unbalance being stored in electro phoretic display device dielectric layer, especially It is when the resistance value of dielectric layer is high, such as at low temperature.

In the context of present application, term " low temperature " means the temperature below about 10 DEG C.

Waiting time can eliminate the unwanted charge of storage in the dielectric layer by inference, and make for driving picture Element to white states short pulse (" t4 ") and for drive pixel to red status longer pulse (" t5 ") more efficiently.Knot Fruit, this substitution driving method have low charged pigment particles with higher band electricity pigment particles preferably to separate.Waiting time (" t6 ") can be in the range of 5-5,000msec, this depends on the resistance value of dielectric layer.

The driving method of Fig. 7 can be summarized as follows:

The method includes the following steps:

(ii) apply the second driving voltage to pixel and reach the second segment time, the second driving voltage, which has, is identical to third type Pigment particles polarity, with viewing side drive pixel to third type pigment particles color state；

(iii) driving voltage is not applied to pixel up to during third section；And

It repeats step (i), (ii) and (iii).

In one embodiment, the amplitude of the second driving voltage less than the first driving voltage amplitude 50%.

As described above, drive waveforms shown in Fig. 7 can also be used to replace the driving period t3 in Fig. 3 (referring to Fig. 8).It changes Sentence is talked about, and driving sequence may is that vibrational waveform, then towards white states driving up to period t2, then applies the waveform of Fig. 7.

In another embodiment, the step of reaching period t2 to white states driving can be deleted, and in this case, Apply vibrational waveform before the waveform for applying Fig. 7 (referring to Fig. 9).

In another embodiment, the driving sequence of Fig. 8 or Fig. 9 is DC balance.

It should be noted that the length of mentioned any driving period is likely to be dependent on temperature in this application.

Third driving method:

Figure 10 A is that the waveform based on Fig. 3 shows the relationship applied between driving voltage (V') and optical property.As indicated, The positive driving voltage V' applied may influence the red status performance of above-mentioned color display apparatus.Utilize L*a*b* color system The red status performance for showing equipment is expressed as a* value.

The driving voltage V'(that maximum a* in Figure 10 A applies in Fig. 3 is about 3.8V) at.However, if applying Driving voltage generation ± 0.5V variation, then obtained a* value will be about 37, this is about the 90% of maximum a*, therefore still It is so acceptable.This tolerance for adapt to by for example show the electronic building brick of equipment variation, cell voltage at any time Decline, TFT backplate batch change, driving voltage caused by the batch of display equipment changes or temperature and humidity fluctuation Change is advantageous.

The data gone out according to given in Figure 10 A, is studied, and can be driven with finding to 90% or more with maximum a* value Red status driving voltage V' range.In other words, when applying any driving voltage within this range, optics Performance will not be significantly affected.Therefore, this range is properly termed as " voltage is insensitive " range." voltage is insensitive " range is got over Width, driving method can more tolerate batch variation and environmental change.

In Fig. 4, need to consider three parameters t4, t5 and N for this research.Three parameters are to the insensitive range of voltage Influence is interactive and nonlinear.

According to the model of Figure 10 A, the best value set for three parameters can be found, to realize the most wide of Fig. 4 waveform The insensitive range of voltage.As a result it is summarized in Figure 10 B.

When t4 is between 40-140msec, t5 is more than or equal to 460msec and when N is greater than or equal to 7, according to Figure 10 B's The insensitive range of voltage (that is, 3.7V to 6.5V) is two according to the insensitive range of voltage (also that is, 3.3V-4.7V) of Figure 10 A It is wide again.

The optimal parameter being discussed above also is applicable to any driving method of the invention.

Therefore, third driving method can be summarized as follows:

And the method has at least insensitive range of the voltage of 0.7V.

In such method, when the driving voltage being applied in such range, the light of accessible color state Learning quality is at least the 90% of maximum acceptable " a* " value.

Also it is worth noting that, data shown in Figure 10 A and Figure 10 B are to collect at ambient temperature.

4th driving method:

It is the waveform in the 4th driving method for use in the present invention shown in Figure 11.This drive waveforms can be used to replace Driving period t3 in Fig. 3.

In the initial step, apply high negative driving voltage (V_H2, for example, -15V) to pixel up to period t7 (referring to fig. 4 Respective pulses in period t4).It is waiting time t8 after this pulse, does not apply voltage during this period.The waiting time it Afterwards, apply positive driving voltage (V', for example, being less than V_H1Or V_H250%) to pixel up to period t9 (referring to fig. 4 in period t5 Respective pulses).After the pulse of t9, but before each step of repetitive pattern, there are the second waiting time t10, herein Period does not apply voltage.Repeat the waveform n times of Figure 11.Above-mentioned term " waiting time " means one section that does not apply driving voltage Time.

This driving method is not only especially effective at low temperature, but also can provide display equipment and be made during its manufacture At structural change more preferable tolerance.Therefore, effectiveness is not limited to low temperature driving.

In the waveform of Figure 11, the first waiting time t8 is very short, and the second waiting time t10 longer.Period t7 also compares Period, t9 was also short.For example, t7 may be in the range of 20-200msec；T8 is likely less than 100msec；T9 may be in 100- In the range of 200msec；And t10 is likely less than 1000msec.

Figure 12 shows the waveform by being inserted into Figure 11 to replace waveform caused by t3 during Fig. 3.In Fig. 3, in t2 Period is displayed in white state.As general rule, white states during this period are better, the red shown by the end of waveform State is better.

In vibrational waveform, positive/negative pulse pair is preferably repeated 50-1500 times, and preferably apply each pulse and reach 10msec。

In one embodiment, the step of reaching period t2 to white states driving can be deleted, and in this case, Apply vibrational waveform before applying the waveform of Figure 11 (referring to Figure 13).

The 4th driving method of Figure 11 can be summarized as follows:

The method includes the following steps:

(i) apply pixel of first driving voltage into electrophoretic display device (EPD) and reach the first segment time, wherein the first driving voltage Polarity with the pigment particles for being identical to the first kind, to drive pixel to the face of the pigment particles of the first kind in viewing side Color state；

(ii) do not apply driving voltage to pixel and reach the second segment time；

(iii) apply the second driving voltage to pixel and reach the third section time, wherein the second driving voltage, which has, is identical to the The polarity of the pigment particles of three types, to drive pixel to the color state of the pigment particles of third type in viewing side；

(iv) driving voltage is not applied to pixel up to the 4th time；And

It repeats step (i)-(iv).

In one embodiment, step (i)-(iv) is repeated at least three times.

In one embodiment, the second driving voltage is less than the color state being enough by pixel from the pigment particles of the first kind The 50% of the driving voltage of the color state to the pigment particles of Second Type is driven, vice versa.

In another embodiment, the driving sequence of Figure 12 or Figure 13 is DC balance.

5th driving method:

As shown in Fig. 2 (a), because black particles and red particles carry identical charge polarity, they tend to It moves in the same direction.Even if black particles under certain driving voltages due to its higher charge and also may due to its compared with Small size and moved more quickly than than red particles, but some red particles still may be driven to together with black particles Viewing side, thus lead to the reduction of black state quality.

Figure 14 describes for driving pixel to the typical waveform of black state.Comprising vibrational waveform (as described above), with true Protect colour brightness and purity.As indicated, applying high positive driving voltage (V after vibrational waveform_H1, for example,+15V) and reach period T12 drives pixel towards black state.Apply driving voltage before vibrational waveform and reach period t11, to ensure that direct current is flat Weighing apparatus.

Figure 15 can be added for driving pixel to the waveform of Figure 14 waveform extremities of black state.Combined waveform can It is red colored less be saturated black state more further such that black particles have with red particles preferably separates.

In Figure 15, apply V_H2The short pulse " t13 " of (negative), followed by V_H1(just) longer pulse " t14 " and t15's Waiting time (0V).Apply such sequence at least once, preferably, at least three times (also that is, N >=3), more preferably, at least five To seven times.

Pulse " t14 " is typically at least two double-lengths of pulse " t13 ".

V_H2Short pulse " t13 " push black and red particles to pixel electrode, and V_H1Longer pulse " t14 " by it Push shared electrode side (also that is, viewing side) to.Because the speed of the pigment particles of two types is under same drive voltage Different, so this asymmetric driving sequence is more advantageous to red particles to black particles ratio.As a result, black particles can be with Preferably separated with red particles.

Waiting time " t15 " be it is optional, this depend on display equipment in dielectric layer.In general, at a lower temperature, The resistance value of dielectric layer is more obvious, and in this case, it may be necessary to the waiting time falls into dielectric layer to discharge Charge.

The 5th driving method of Figure 15 can be summarized as follows:

The method includes the following steps:

(ii) apply the second driving voltage to pixel and reach the second segment time, wherein the second driving voltage, which has, is identical to the The polarity of the pigment particles of two types, to drive pixel to the color state of the pigment particles of Second Type in viewing side；

(iii) optionally, do not apply driving voltage to pixel and reach the third section time；And

Repeat step (i), (ii) and (iii) (if present).

Figure 16 shows the composite wave-shape of constitutional diagram 14 waveform and Figure 15 waveform.However, also it is worth noting that, according to particle The recurring number (N) of speed and sequence, can shorten " t12 ".In other words, at the end of " t12 ", pixel is not necessarily in entirely Black state.Instead as long as the number (N) of the waveform sequence of Figure 15 is enough finally by pixel driver to black powder State, then can be (including grey) at since black to white any state.

Method described in Figure 14-16 can also be at low temperature by pixel driver to black state.In this case, Period t14 should be than t13 long, and waiting time t15 should be at least 50msec.

In one embodiment, the driving sequence of Figure 16 is DC balance.

6th driving method:

Figure 17 describes for by the typical waveform of pixel driver to white states.Comprising vibrational waveform (as described above), with Ensure colour brightness and purity.Apply V after vibrational waveform_H2Driving voltage reach period t17.Apply before vibrational waveform V_H1Driving voltage reach period t16, to ensure DC balance.

Figure 18 A and Figure 18 B show the waveform that may be substituted for the t17 of the pulse in Figure 17 waveform.

This driving method drives especially suitable for low temperature, but is not limited to low temperature driving.

In Figure 18 A, apply V_H1(just) short pulse " t18 ", followed by V_H2The longer pulse " t19 " of (negative) and t20's Waiting time (0V).As shown in figure 18b, the amplitude of the negative driving voltage (V ") applied during t19 can be higher than V_H2Vibration Width (for example, -30V rather than -15V).

Apply such sequence at least once, preferably, at least three times (also that is, in Figure 18 A and Figure 18 B, N >=3, more Goodly, at least five to seven times).

T19 should be also longer than t18.For example, t18 may be in the range of 20-200msec, and t19 is likely less than 1000msec.Waiting time t20 should be at least 50msec.

6th driving method shown in Figure 18 A and Figure 18 B can be summarized as follows:

The method includes the following steps:

(i) apply pixel of first driving voltage into electrophoretic display device (EPD) and reach the first segment time, wherein the first driving voltage Polarity with the pigment particles for being identical to Second Type, to drive pixel to the face of the pigment particles of Second Type in viewing side Color state；

(ii) apply the second driving voltage to pixel and reach the second segment time, wherein the second driving voltage, which has, is identical to the The polarity of the pigment particles of one type, to drive pixel to the color state of the pigment particles of the first kind in viewing side；

(iii) do not apply driving voltage to pixel and reach the third section time；And

Repeat step (i) and (ii).

In the embodiment shown in Figure 18 A, second voltage is the color state by pixel from the pigment particles of the first kind Driving voltage needed for color state driving towards the pigment particles of Second Type, vice versa.

In another embodiment shown in 18B figure, second voltage has than the pigment particles by pixel from the first kind Color state towards Second Type pigment particles color state driving needed for the higher amplitude of driving voltage, otherwise also So.

Figure 19A and Figure 19B shows the composite wave-shape of the waveform Yu Figure 18 A or Figure 18 B waveform that are respectively combined Figure 17.

In vibrational waveform, positive/negative pulse 50-1500 times is preferably repeated, and preferably applies each pulse and reaches 10msec。

In one embodiment, the driving sequence of Figure 19 A or Figure 19 B is DC balance.

7th driving method:

7th driving method of the invention is to drive pixel towards intermediate color states (for example, grey).

Figure 20 A and Figure 20 B are related Particles Movings.As indicated, when applying low negative driving voltage (V_L, for example,- When 5V), the pixel (0A referring to fig. 2) in black state is driven towards gray states.In the process, low driving voltage will be red Colored particle pushes pixel electrode to, and sees the mixture of black and white particle in viewing side.

Display is used for the waveform of this driving method in Figure 21.After vibrational waveform, apply high positive driving voltage (V_H1, for example,+15V) and period t22 is reached, pixel is driven towards black state.It, can be by applying low bear from black state Driving voltage (V_L, for example, -5V) and period t23 is reached, pixel is driven towards gray states, also that is, driving from Figure 20 A to Figure 20 B.

Driving period t22 is as application V_H1When be enough pixel driver to black state during, and t23 be when apply V_L When be enough from black state to drive pixel to gray states during.Before vibrational waveform, preferably apply V_H1Pulse Up to period t21, to ensure DC balance.

Figure 22 can be used to the drive waveforms for replacing pulse t23 in Figure 21.In the initial step, apply high positive driving Voltage (V_H1, for example,+15V) and up to t24 between short-term, push black particles to viewing side, but t24 is not enough to pixel driver To full black state, then apply low negative driving voltage (V_L, for example, -5V) and period t25 is reached, pixel is driven towards gray states It is dynamic.V_LAmplitude be less than V_H(for example, V_H1Or V_H2) 50%.

At least four times circulations (N >=4) of waveform of Figure 22 are repeated, preferably, at least eight times circulations.

At ambient temperature, period t24 is less than about 100msec, and t25 is typically larger than 100msec.

7th driving method shown in Figure 22 can be summarized as follows:

The method includes the following steps:

(i) apply pixel of first driving voltage into electrophoretic display device (EPD) and reach the first segment time, the first driving voltage has It is identical to the polarity of the pigment particles of Second Type, to drive pixel to the color state of the pigment particles of Second Type, wherein The first segment time is not enough to the panchromatic state in viewing side by the pigment particles of pixel driver to Second Type；

(ii) apply the second driving voltage to pixel and reach the second segment time, the second driving voltage, which has, is identical to the first kind Pigment particles polarity, with viewing side drive pixel to the first and second types pigment particles admixture；And

Repeat step (i) and (ii).

As described above, in this approach, the second driving voltage is about the 50% of the first driving voltage.

Figure 23 shows the composite wave-shape of the waveform of constitutional diagram 21 and the waveform of Figure 22, wherein replacing figure with the waveform of Figure 22 Driving period t23 in 21.This composite wave-shape is made of four-stage.First stage is DC balance stage (t21)；The Two-stage is vibrating step；And the phase III is by pixel driver to black state (t22).Wave used in the phase III Shape can be any waveform of pixel driver to good black state.Fourth stage includes have high positive driving voltage short Period t24, followed by the long period with low negative driving voltage.Repeat the fourth stage for several times.

It is worth noting that, in Figure 23 t22 can be it is optional.

It can be by changing low negative voltage (V_L), by gray states modulation Cheng Gengliang or darker.In other words, waveform sequence Column and shape can remain unchanged；But V_LVariable amplitude (for example, -4V, -5V, -6V or -7V), to cause display different Grayscale.This feature can potentially reduce space needed for look-up table in driving circuit, thus reduce cost.The driving Method can produce the intermediate state of (pigment particles of the pigment particles and Second Type of the first kind) high quality, and have There is the very small color interference of the pigment particles from third type.

In one embodiment, the driving sequence of Figure 23 is DC balance.

8th driving method:

Figure 24 is the waveform used in the 8th driving method of the invention.This waveform, which is intended to be applied to, to be not in The pixel of white states (also that is, color state of the pigment particles of the first kind).

In the initial step, apply high negative driving voltage (V_H2, for example, -15V) and period t26 is reached, followed by the waiting time t27.After the waiting time, apply positive driving voltage (V', for example, being less than V_H1Or V_H250%) reach period t28, followed by Second waiting time t29.Repeat the waveform n times of Figure 24.Above-mentioned term " waiting time " means not apply the one of driving voltage The section time.

This driving method is especially effectively, and when can also foreshorten to the whole driving of red status at low temperature Between.

It is worth noting that, period t26 is extremely short, usually the time required to driving from full black state to full white state In the range of about 50%, therefore it is not enough to pixel driver to whole white state.Period, t27 was likely less than 100msec；Phase Between t28 may be in the range of 100-200msec；And period t29 is likely less than 1000msec.

Except the waveform of Figure 11 will be applied to the picture in white states (also that is, color of the pigment particles of the first kind) Element, and the waveform of Figure 24 is intended to be applied to except the non-pixel in white states, the waveform of Figure 24 is similar to the wave of Figure 11 Shape.

Figure 25 is an example, wherein the waveform of Figure 24 is applied in black state (also that is, the face of Second Type Expect particle color state) pixel.

In vibrational waveform, positive/negative pulse pair is preferably repeated 50-1500 times, and preferably apply each pulse Up to 10msec.

As the driving method of Figure 11, the 8th driving method of Figure 24 can be summarized as follows:

The method includes the following steps:

(ii) do not apply driving voltage to pixel and reach the second segment time；

(iv) driving voltage is not applied to pixel up to the 4th time；And

It repeats step (i)-(iv).

In one embodiment, step (i)-(iv) is repeated at least three times.

In one embodiment, the driving sequence of Figure 25 is DC balance.

The generation of intermediate color:

Advantageously, driving method of the invention can also show intermediate color (also other than the color of single particle That is, the mixing of two kinds of particle colors).In many cases, it is desirable that show grey-tone image using the display of this method, this is just needed Want the region modulation (areal modulation) of display.The number of colors that such region modulation increase can be shown, but Cost is to reduce the resolution ratio of display, because multiple pixels of display are by region modulation, to form a grayscale " super picture Element ".Each pixel for providing display has the ability for showing intermediate color and increases the centre that each pixel can be shown The quantity of color can reduce the quantity for the pixel that must be used in each super-pixel, and thus increase point that grayscale is shown Resolution.

Figure 20 A and Figure 20 B have been referred to above discusses one kind for Intermediate grey (also that is, black and white particles color Mixing) production method.By first by pixel driver to black or white states (respectively Fig. 2A or Fig. 2 B), then apply ± The high driving voltage of 15V, with respectively drive pixel to white or black state, but reach white or black state before terminate This driving voltage can also generate grey to generate gray states in this way.It is to be noted, however, that making in the method In three kinds of particle systems, since reason illustrated by Figure 26 A-26D will be referred to, using since white states rather than from The method that black state starts is advantageous to generate gray states.

Figure 26 A and Figure 26 B is to generate gray states since white states.Figure 26 A (it is substantially identical as Fig. 2 B) It is by applying high negative driving voltage (- 15V, V_H2) white states are generated, high negative driving voltage drives white particles 21 It moves to viewing side, and black particles 22 and red particles 23 is driven towards pixel electrode.It is high since the white states of Figure 26 A Positive voltage (+15V, V_H1) of short duration driving pulse driving white particles towards pixel electrode, and drive black and red particles Towards viewing side.Of short duration driving pulse is terminated when white and black particles mix near viewing side.Because of red particles With the electrophoretic mobility also lower than black particles, so red particles ratio relatively slowly moves away pixel electrode, thus its By black and white particles masking without being seen by the viewer under gray states, wherein black and white particle is located at red Between particle and viewing face.Then, " bright " grey is presented in Figure 26 B, only by the color mixing institute group of black and white particle At and not by the color stain of red particles.

On the contrary, Figure 26 C and Figure 26 D is to generate gray states since black state.Figure 26 C (its substantially with figure 2A is identical) it is by applying high positive driving voltage (+15V, V_H1) generating black state, high positive driving voltage is by black grain Son 22 and red particles 23 drive towards viewing side, and white particles 21 are driven into neighborhood pixels electrode.From the black powder of Figure 26 C State starts, negative voltage (- 15V, V_H2) of short duration driving pulse driving white particles towards viewing side, and drive black and red Particle is towards pixel electrode.Of short duration driving pulse is terminated when white and black particles mix near viewing side.However, because Red particles have the electrophoretic mobility also lower than black particles, so red particles ratio relatively slowly moves away viewing side, Thus mixed under gray states with black and white particle；In fact, red particles may tend to more connect than black particles Nearly viewing side.Then, " dimness " grey is presented in Figure 26 D, wherein face of the color mixing of black and white particle by red particles Color significantly pollutes.

As set forth above, it is possible to generate the gray states of pixel since black state or white states.Likewise it is possible to Light red state (color mixing of white and red particles) is generated since red status or white states.In former instance Under, first whole red state (C referring to fig. 2) is arrived in driving, then applies high negative driving voltage (- 15V, V_H2) up to being not enough to reach figure The one of short duration time of the white states of 2B.High negative driving voltage causes white particles 21 rapidly mobile towards viewing side, black Colored particle 22 is rapidly mobile towards pixel electrode, and red particles 23 are more mobile towards pixel electrode than relatively slowly.When white and When red particles mix, driving voltage is terminated, thus leaves visible light red in viewing side.Black particles are located at pixel electrode Near, thus it is covered by white and red particles without being seen by the viewer.In the latter cases, it first drives to full white state (B referring to fig. 2), and apply low positive driving voltage (+5V, V_L) up to one section of the red status that is not enough to reach Fig. 2 C when Between.Low negative driving voltage keeps white particles 21 mobile towards pixel electrode, and red particles are mobile towards viewing side, thus again Generate red and the mixing of white particles and the display of light red.Replace using continuous low negative driving voltage, from white shape The conversion of state to light red state can be used recommends waveform (pus h-pull waveform) as shown in Fig. 5,6,8 or 9 It realizes.

It finds by experience, the light red state generated by red status is more than the light red state that is generated by white states Unevenly.Although the reason of without understanding this uniform sex differernce completely, it is believed that in microcapsules (if present) The variation of the shift in position of various particles and the electrophoretic mobility of individual particle and the various parts of electrophoretic display device (EPD) is related. And, it appears that the low driving voltage from red status for driving is influenced than high driving voltage by power supply variation bigger.

Figure 27 is for driving display to the waveform of light red state via white states.In the waveform of Figure 27, Apply high negative driving voltage (V_H2, for example, -15V) and period t31 is reached, pixel is driven towards white states.It is opened from white states Begin, by applying low positive voltage (V_L, for example,+5V) reach period t32, by pixel towards red status drive, thus by pixel from The state-driven of Fig. 2 B to Fig. 2 C state.Finally, by applying high negative driving voltage (V_H2, for example, -15V) and reach period T33 drives pixel to light red state from red status, wherein t31 is also short during period t33 ratio and is not enough to pixel It drives to full white state.White in period t31 is wished to applying vibrational waveform before pulse, and preferably, vibrating Apply negative driving voltage (for example, V before waveform_H2, for example, -15V) and period t30 is reached, to ensure DC balance.It will be seen, scheme 27 waveform is substantially the wave mode of Fig. 3, but added with white to pulse in period t33.By adjusting holding for period t33 The continuous time can change the definite coloration of light red obtained, and period t33 is usually in about 20-300msec (usually 20- In the range of 100msec).The duration of period t33 is usually about the 10% to 60% of the duration of period t31.

Reaching peony state (also that is, color mixing of black and red particles), light red state is difficult to be obtained than reaching It is more, because black and red particles carry the charge of identical polar, and therefore tend to the electricity to application in a similar manner It reacts field.For example, if first by pixel driver to the red status of Fig. 2 C, then by applying for driving pixel to figure Positive driving voltage (+15V, the V of the height of the black state of 2A_H1) attempt to generate red and black particles mixing, then red particles (as shown in Figure 2 C, adjacent with preceding electrode) will keep adjacent with preceding electrode and will not be moved to side, be reached with accommodating Black particles.As a result, even having applied high positive driving voltage, up to a rapid lapse of time, (it is than the white by pixel from Fig. 2 B Time needed for black state of the state-driven to Fig. 2A is also longer) after, obtained " peony " state actually will only It is slightly deeper than previous red status.

It has been discovered and can achieve satisfactory peony state there are two types of method.First method uses Figure 28 institute The waveform shown, and substantially since dark gray states.As shown, this waveform first apply high positive driving voltage (+ 15V, V_H1), by pixel driver to dark gray states (not being full black state).After this high positive driving voltage, apply Low positive driving voltage (V_L, for example,+5V) and period t36 is reached, period t36 would generally be more much longer than t35, extremely by pixel driver Peony state.For these reasons, be optionally before the positive driving pulse of height in period t35 vibrational waveform and/or Negative drive voltage pulses (the V of height of period t34_H2, such as.-15V).The duration of t36 can vary greatly, but usually can be with It is about 300-2000msec, more generally 500-1000msec；The wine-colored darkness generated can be by changing continuing for t36 Time changes, and the longer duration tends to the rubescent of color produced by increasing.

Reach the second method of satisfactory peony state using waveform as shown in figure 29, Figure 29 substantially with Fig. 5 is identical, but due to discussed below, the duration of various driving pulses shown in Figure 29 will differ from Fig. 5 Those of the driving pulse duration.It will wander back to from the discussion of above figure 5, the major part of waveform correlation includes indicating For the low positive driving voltage (V of the duration t39 in Figure 29_L, for example,+5V) it is red to pulse, and be expressed as in Figure 29 Duration t40 the negative driving voltage (V of height_H2, for example, -15V) white to pulse replace.In the sequence of this ALT pulse It can be following middle one or more before column: (a) being intended for the negative driving voltage of height of the duration t37 of DC balance (V_H2, for example, -15V) white to pulse；(b) vibrational waveform；And (c) negative driving voltage (V of height of duration t38_H2, For example, -15V) white to pulse, can with that the white duration t40 to pulse below has been mentioned is similar and different.

The waveform of Fig. 5 is described above as generating pure red state.However, finding by experience to by adjusting figure Duration t39 and t40 in 29 and/or by adjusting the driving voltage V' and V applied during these_H2, this seed type Waveform not only can produce pure red state, but also can produce peony and light red state.If increasing the size of V', Then red becomes relatively deep, however if reducing the size of V', red becomes shallower.Similarly, if increased relative to t39 The duration of t40 will then generate shallower red, however if increasing the duration of t39 relative to t40, it will generate Deeper red.Obviously, driving voltage can be used to combine with the variation of duration.The duration of t39 and t40 can be Variation in very roomy range；For example, at 25 DEG C, t40 can drop to 20msec from 60msec, and t39 can be from 300msec rises to 600msec.In a low temperature of as 0 DEG C, in the latter example it can even be desired to broader range；For example, in this temperature Under, t40 can be 60ms ec, and t39 is 3000msec.

Example 2

By being coated with polymer in middle 30 weight percent of mixing of isoalkane solvent (isoparaffin solvent) TiO 2 particles (white), 8 weight percent the mixed-metal oxides particle (black) for being coated with polymer and 7 The red pigment particle of weight percent and add charge control agent (Solsperse19000) come prepare substantially such as above with reference to Electrophoretic medium described in Fig. 1.White particles are negatively charged, and black and red particles are positively charged, but red particles have The also low charge density than black particles.Obtained electrophoretic medium is loaded to the standard testing for the preceding electrode for having essence transparent In unit and driving is to above respectively with reference to white, black, red and gray states described in Fig. 2A, 2B, 2C and 26B.It uses Standard technique measures L*, a* and b* value of all four colored states, as a result as follows:

Table 1

Color	L*	a*	b*
				White	60.2	-1.0	-1.4
Black	12.6	7.7	-0.8
				It is red	27.0	37.9	17.6
Grey	38.4	-1.0	-4.0

The reflectivity Y of gray states is 10.3%.From such results, it can be seen that test medium of the invention can be shown Good white, black and red status, and can also show gray states.

Although describing the present invention with reference to specific embodiments of the present invention, be familiar with this those skilled in the art it should be understood that In the case where not departing from true spirit and scope of the present invention, various modifications may be made and can be replaced with equipollent.This Outside, many modifications can be carried out to the purpose of the present invention and range, to adapt to specific condition, material, form, processing procedure, processing procedure step Suddenly.All such modifications are intended in the range of appended claims.

Claims

1. a kind of driving method for electrophoretic display device (EPD), which includes in the first surface of viewing side, in non-sight See the second surface and electrophoretic fluid of side, which includes the pigment particles of the pigment particles of the first kind, Second Type With the pigment particles of third type, all types of pigment particles disperse in a liquid, wherein

C) pigment particles of the third type have be identical to the Second Type pigment particles charge polarity, but have compared with Low zeta potential,

This method includes the following steps:

(i) apply pixel of first driving voltage into the electrophoretic display device (EPD) and reach the first segment time, which has Polarity of the pigment particles of the first kind towards the first surface is driven, so that the pixel be promoted to show on the first surface The optical characteristics of the pigment particles of the first kind；

(ii) apply the second driving voltage to the pixel and reach the second segment time, which, which has, drives the third type Pigment particles towards the first surface polarity, thus to driving the pixel to the third type on the first surface The optical characteristics of pigment particles；And

Repeat step (i) and (ii).

2. according to the method described in claim 1, wherein, the pigment particles of the first kind are negatively charged, and the Second Type Pigment particles are positively charged.

3. according to the method described in claim 1, wherein, the amplitude of second driving voltage is less than the first driving voltage amplitude 50%.

4. according to the method described in claim 1, wherein, repeating step (i) and (ii) at least four times.

5. according to the method described in claim 1, further comprising applying a vibrational waveform before step (i).

6. according to the method described in claim 5, further comprise after the vibrational waveform, but before step (i), driving The pixel to the first kind pigment particles full optical characteristics.

7. according to the method described in claim 1, further comprising:

(iii) after step (ii), but before repeating step (i) and (ii), driving voltage is not applied to the pixel up to the Three times；And

It repeats step (i), (ii) and (iii).

8. according to the method described in claim 7, wherein, repeating step (i), (ii) and (iii) at least four times.

9. according to the method described in claim 7, further comprising applying a vibrational waveform before step (i).

10. according to the method described in claim 9, further comprising but before step (i), being driven after the vibrational waveform Move the pixel to the first kind pigment particles full optical characteristics.

11. according to the method described in claim 1, wherein, which is 40 to 140 milliseconds, which is More than or equal to 460 milliseconds, and repeat step (i) and (ii) at least seven times.

12. according to the method described in claim 1, further comprising:

(iii) after step (i), but before step (ii), do not apply driving voltage to the pixel and reach the third section time；

(iv) after step (ii), but before repeating these described steps, driving voltage is not applied to the pixel up to the 4th The section time；And

It repeats step (i)-(iv).

13. according to the method for claim 12, wherein repeat step (i)-(iv) at least three times.

14. according to the method for claim 12, further comprising applying a vibrational waveform before step (i).

15. according to the method for claim 12, further comprising but before step (i), being driven after the vibrational waveform Move the pixel to the first kind pigment particles full optical characteristics.

16. a kind of driving method for electrophoretic display device (EPD), which includes in the first surface of viewing side, in non-sight See the second surface and electrophoretic fluid of side, which includes the particle of the first kind, the particle of Second Type and third class The particle of type, all types of particles disperse in a liquid, wherein

B) pigment particles of the first kind should carry opposite charge polarity with the pigment particles of Second Type；And

This method includes the following steps:

(ii) apply the second driving voltage to the pixel and reach the second segment time, which, which has, drives the third type Pigment particles towards the first surface polarity, to drive the pixel to the pigment of the third type on the first surface The optical characteristics of particle；And

(iii) apply third driving voltage and reach the third section time, which, which has, is identical to first driving voltage Polarity, and the third section time is also shorter than the first segment time, thus generated in the viewing face this first and third class The mixing of the optical characteristics of the particle of type.

17. according to the method for claim 16, wherein the duration of the third section time is holding for the first segment time About the 20% to about 80% of continuous time.

18. according to the method for claim 17, wherein the duration of the third section time is holding for the first segment time About the 20% to about 40% of continuous time.

19. according to the method for claim 16, further comprising applying a vibrational waveform before step (i).

20. it according to the method for claim 19, further comprise applying a driving voltage before the vibrational waveform, The driving voltage drives the pigment particles of the first kind towards the first surface.

21. a kind of driving method for electrophoretic display device (EPD), which includes in the first surface of viewing side, in non-sight See the second surface and electrophoretic fluid of side, which includes the pigment particles of the pigment particles of the first kind, Second Type With the pigment particles of third type, all types of pigment particles disperse in a liquid, wherein

This method includes the following steps:

(i) apply pixel of first driving voltage into the electrophoretic display device (EPD) and reach the first segment time, which has Polarity of the pigment particles of the Second Type towards the first surface is driven, so that the pixel be promoted to show on the first surface The optical characteristics of the pigment particles of the Second Type；

(ii) apply the second driving voltage to the pixel and reach the second segment time, which, which has, is identical to first drive The polarity of dynamic voltage, but there is the amplitude smaller than first driving voltage, to drive the third class on the first surface The pigment particles of type, and generate on the first surface this second and third type particle optical characteristics mixing.

22. according to the method for claim 21, wherein the duration of the second segment time is holding for the first segment time About the 100% to 150% of continuous time.

23. according to the method for claim 21, further comprising applying a vibrational waveform before step (i).

24. it according to the method for claim 23, further comprise applying a driving voltage before the vibrational waveform, The driving voltage drives the pigment particles of the first kind towards the first surface.

25. a kind of driving method for electrophoretic display device (EPD), which includes in the first surface of viewing side, in non-sight See the second surface and electrophoretic fluid of side, which includes the pigment particles of the pigment particles of the first kind, Second Type With the pigment particles of third type, all types of pigment particles disperse in a liquid, wherein

This method includes the following steps:

(ii) apply the second driving voltage to the pixel and reach the second segment time, which, which has, drives the third type Pigment particles towards the first surface polarity；And

Step (i) and (ii) is repeated,

Wherein, the size of the duration and the voltage applied in it of set-up procedure (i) and (ii), on the first surface Generate the mixed of one of the particle of the third type and the particle of first and second type optical characteristics of the particle of type It closes.

26. according to the method for claim 25, further comprising applying a vibrational waveform before step (i).

27. it according to the method for claim 26, further comprise applying a driving voltage before the vibrational waveform, The driving voltage drives the pigment particles of the first kind towards the first surface.

28. a kind of driving method for electrophoretic display device (EPD), which includes in the first surface of viewing side, in non-sight See the second surface and electrophoretic fluid of side, which includes the pigment particles of the pigment particles of the first kind, Second Type With the pigment particles of third type, all types of pigment particles disperse in a liquid, wherein

And wherein this method has at least about insensitive range of the voltage of 0.7V, wherein " the insensitive range of voltage " refers to, A* value is able to maintain at least while about the 90% of obtainable maximum a* value, when driving pixel is from the particle of the first kind Optical characteristics to third particles of types optical characteristics when, the acceptable variation range of driving voltage.

29. a kind of driving method for electrophoretic display device (EPD), which includes in the first surface of viewing side, in non-sight See the second surface and electrophoretic fluid of side, which includes the pigment particles of the pigment particles of the first kind, Second Type With the pigment particles of third type, all types of pigment particles disperse in a liquid, wherein

This method includes the following steps:

(ii) apply the second driving voltage to the pixel and reach the second segment time, which, which has, drives the Second Type Pigment particles towards the first surface polarity, to drive the pixel to the pigment of the Second Type on the first surface The optical characteristics of particle；And

Repeat step (i) and (ii).

30. the method according to claim 11, further comprising:

(iv) after step (ii), but before repeating step (i) and (ii), do not apply driving voltage to the pixel and reach third The section time；And

Repeat step (i) and (ii) and (iii).

31. a kind of driving method for electrophoretic display device (EPD), which includes in the first surface of viewing side, in non-sight See the second surface and electrophoretic fluid of side, which includes the pigment particles of the pigment particles of the first kind, Second Type With the pigment particles of third type, all types of pigment particles disperse in a liquid, wherein

This method includes the following steps:

(i) apply pixel of first driving voltage into the electrophoretic display device (EPD) and reach the first segment time, which has Polarity of the pigment particles of the Second Type towards the first surface is driven, which is not enough to drive in the first surface Move the pixel to the Second Type pigment particles full optical characteristics；

(ii) apply the second driving voltage to the pixel and reach the second segment time, which, which has, drives the first kind Pigment particles polarity, to drive the pixel to the mixing shape of the pigment particles of first and second type in the viewing side State；And

Repeat step (i) and (ii).