CN101382719B - Electro-optic displays - Google Patents

Abstract

An electrophoretic medium consists of a plurality of discrete droplets (104) in a polymeric binder (106'): each droplet (104) itself has a plurality of electrophoretic particles dispersed in a suspending fluid. An encapsulated electrophoretic display is produced by laminating the electrophoretic medium to a backplane (110) having at least one electrode at a temperature such that the polymeric binder (106') flows and secures the electrophoretic medium to the backplane (110).

Description

Electro-optic displays

The application is that application number is 200480031366.X, the applying date to be on October 22nd, 2004, dividing an application with the application of inscribing

The method and the device that the present invention relates to electro-optic displays and be used to produce this display.Institute is conspicuous like following description, and aspects more of the present invention are limited to electrophoretic display device (EPD), and the electro-optic displays of other types can be used in other aspects.More particularly, the present invention relates to electro-optical medium and display that (a) has bonding agent, said bonding agent can also be as the lamination tackifier; (b) be used to form the method for flexible display; (c) colour electrooptical display; (d) be used to form the method and the device of electro-optic displays; (e) be used to make the method for the combining display that forms by material with different heat expansion coefficient.

The application is relevant with disclosed application with following patent, the reader with reference to these to obtain more detailed background information:

(a) U.S. Patent Application Publication No.2002/0180688 (referring to relevant International Application No. WO 99/53373);

(b) U.S. Patent Application Publication No.2004/0136048;

(c) U.S. Patent Application Publication No.2004/0027327 (referring to relevant International Application No. WO 03/104884);

(d) U.S. Patent Application Publication No.2004/0155857 (referring to relevant International Application No. WO 2004/023195);

(e) United States Patent(USP) No. 6124851;

(f) United States Patent(USP) No. 6721083;

(g) United States Patent(USP) No. 6538801;

(h) United States Patent(USP) No. 6323989;

(i) United States Patent(USP) No. 6422687; With

(j) United States Patent(USP) No. 6120588.

In display of the present invention; Have at electro-optical medium on the meaning of solid outside surface; Although medium can and often have the space that internal liquid or gas are filled really; And on the meaning of the method for using this electro-optical medium assembling display, electro-optical medium (when non-electrophoresis electro-optical medium) will typically be a kind of solid (this display can followingly be called " solid electric optical display unit " for simplicity).Thereby term " solid electric optical display unit " comprises the electrophoretic display device (EPD) of encapsulation, the LCD of encapsulation and the display of following other types.

As be applied to the term " electric light " of material or display; Use with its conventional meaning in technical field of imaging in this article, to refer to have the material of first and second show states, said show state is different aspect at least one optical property; Through this material is applied electric field; Although this material is changed to its second show state from its first show state. optical property typically is the appreciable color of human eye, and it is another kind of optical property, like light transmission, reflectivity, luminous; Perhaps just be intended to machine-readable display, the false colour outside the visible range on the meaning of the long reflectivity vary of electromagnetic wave.

Term " bistable " and " bistability " are in this article with its conventional meaning use in the art; Be meant the display that comprises display element with first and second show states; Said show state is different aspect at least one optical property, makes after any given addressing pulse driving of element through finite duration, presents its first or second show state; After this addressing pulse stops; That state will continue several times at least, and for example at least four times, the minimum duration of the desired addressing pulse of change status display module.Show that in U.S. Patent Application Publication No.2002/0180687 some corpuscular type electrophoretic display device (EPD)s that can have gray scale are stable not only in its limit black and white state; And also be stable in the gray states therebetween, and the situation of the electro-optic displays of other type also is the same.This class display is called " multistable " rather than bistable rightly, but for simplicity, can use a technical term in this article " bistable " is to contain bistable state and multistable display.

The electro-optic displays of several types is known.One type electro-optic displays is the double-colored member type of rotation; As in following document, describing: (but this class display often is called as " rotating double-colored pearl " display to United States Patent(USP) Nos. 5808783,5777782,5760761,6054071,6055091,6097531,6128124,6137467 and 6147791; Because it is more accurate; It is preferred that term " rotates double-colored member "; Because in more above-mentioned patents, rotating member is not spherical). this display uses a large amount of little objects (typically being spherical or cylindrical), and said object has the section of two or more different optical characteristics; With internal dipole. these objects are suspended in the vacuole of liquid filling in the substrate; This vacuole full of liquid is so that this object rotates arbitrarily. apply electric field to display, therefore make these objects rotate to different positions and change the object section pass through to observe surperficial finding content, thereby the manifesting of change display. this type electro-optical medium typically is bistable.

The electro-optic displays of another kind of type makes electricity consumption cause the look medium; For example the electricity with nanometer color development (nanochromic) form of film causes the look medium, it comprise at least in part by partly lead electrode that metal oxide forms be connected to this electrode can reversible color a plurality of dye molecules; See, O ' Regan for example, B. waits the people, Nature1991,353,737; And Wood, D., Information Display, 18 (3); 24 (in March, 2002). also see Bach, U. waits the people, Adv.Mater.; 2002,14 (11), 845. such nanometer color development films also are described in; For example, United States Patent(USP) No. 6301038, open No.WO01/27690 of international application and U.S. Patent application 2003/0214695.This type electro-optical medium also typically is bistable.

The electro-optic displays (it has been the theme of a large amount of research and development for many years) of another kind of type is the corpuscular type electrophoretic display device (EPD); Wherein a plurality of charged particles pass through suspending liquid under influence. when comparing with LCD; Yet electrophoretic display device (EPD) can have the characteristic of good brightness and contrast, wide visual angle, state bistability and low power consumption., the problem relevant with these display long-term image quality hindered it to use widely.For example, the particle that constitutes electrophoretic display device (EPD) usually precipitates, and causes the serviceable life of these displays deficiencies.

The many transfer in Massachusetts Institute of Technology (MIT) (MIT) and E Ink company perhaps is disclosed with its nominal patent and application recently; It has described the electrophoretic medium of encapsulation. and the medium of this encapsulation comprises many folliculus; Phase and cyst wall in each folliculus comprises itself; Be suspended in the particle that the electrophoresis in the liquid suspension medium moves but comprise mutually wherein, cyst wall is around being somebody's turn to do interior phase. and typically, capsule itself is fixed in the polymer adhesive to form the adhesion layer between two electrodes.This type encapsulation medium is described in, for example, and United States Patent(USP) Nos. 5930026; 5961804; 6017584; 6067185; 6118426; 6120588; 6120839; 6124851; 6130773; 6130774; 6172798; 6177921; 6232950; 6249721; 6252564; 6262706; 6262833; 6300932; 6312304; 6312971; 6323989; 6327072; 6376828; 6377387; 6392785; 6392786; 6413790; 6422687; 6445374; 6445489; 6459418; 6473072; 6480182; 6498114; 6504524; 6506438; 6512354; 6515649; 6518949; 6521489; 6531997; 6535197; 6538801; 6545291; 6580545; 6639578; 6652075; 6657772; 6664944; 6680725; 6683333; 6704133; 6710540; 6721083; 6727881; 6738050; 6750473; With 6753999; And the open Nos.2002/0019081 of U.S. Patent application; 2002/0021270; 2002/0060321; 2002/0060321; 2002/0063661; 2002/0090980; 2002/0113770; 2002/0130832; 2002/0131147; 2002/0171910; 2002/0180687; 2002/0180688; 2002/0185378; 2003/0011560; 2003/0020844; 2003/0025855; 2003/0038755; 2003/0053189; 2003/0102858; 2003/0132908; 2003/0137521; 2003/0137717; 2003/0151702; 2003/0214695; 2003/0214697; 2003/0222315; 2004/0008398; 2004/0012839; 2004/0014265; 2004/0027327; 2004/0075634; 2004/0094422; 2004/0105036; 2004/0112750; With 2004/0119681; With the open Nos.WO99/67678 of international application; WO00/05704; WO00/38000; WO00/38001; WO00/36560; WO00/67110; WO00/67327; WO01/07961; WO01/08241; WO03/107315; WO2004/023195; And WO2004/049045.

The known electrophoretic medium, encapsulation with encapsulation not, can be divided into two main types, below be called " single-particle " and " two particle " for simplicity respectively.A single-particle medium only has the electrophoresis particle in the suspending medium that is suspended in of single type; At least one optical characteristics of suspending medium is different from the optical characteristics of particle. and (in referring to the particle of single type, we do not mean that all particles of the type is identical utterly.For example, if all particles of the type has the substantially the same optical characteristics and the electric charge of identical polar, under the condition that does not influence medium effectiveness, the significant change of parameter such as granularity and electrophoretic mobility can allow.) when this medium is placed between pair of electrodes; At least one of them is transparent; The relative electromotive force that depends on two electrodes, medium can show that the optical characteristics (when this particle is adjacent to the electrode near the observer, claiming " preceding " electrode hereinafter) of this particle or the optical characteristics of this suspending medium are (when this particle person's that is adjacent to the outlying observation electrode; Claim " back " electrode hereinafter, so that particle is hidden through suspending medium).

Two particle media have two dissimilar particles and suspending liquid; Said particle is different aspect at least one optical characteristics; Said suspending liquid is uncoloured or painted, but it typically is uncoloured. and the particle of these two types is different aspect electrophoretic mobility; This species diversity on mobility can be at polarity (this type can be described as " the two particles of opposite charges " medium hereinafter) and/or quantitative aspects.When this pair of particle medium is placed between the above-mentioned pair of electrodes; The relative electromotive force that depends on these two electrodes; Medium can show the optical characteristics of arbitrary type of particle, is at quantitative aspects aspect polarity although the difference of the concrete mode of this realization depends on the difference of mobility.Being convenient to explanation, considering a kind of electrophoretic medium, is white if the particle of one of them type is black and another type. the particle of two types different aspect polarity (if; For example, black particles is a positively charged, and white particles is electronegative); These particles will attracted to two different electrodes, the result if, for example; With respect to rear electrode, preceding electrode is a negative pole, electrode and white particles attracted to rear electrode before black particles will attracted to; This medium will present black to the observer as a result. on the contrary; Black particles attracted to rear electrode if preceding electrode is anodal with respect to rear electrode, and white particles will attracted to preceding electrode, and medium will present white to the observer as a result.

If the particle of two types has the electric charge of identical polar; But aspect electrophoretic mobility different (this type medium can be called " two particles of identical polar " medium hereinafter); The particle of two types will attracted to identical electrode; But one type will arrive electrode earlier than another kind of type, and the result depends on electrode that particle attracted to and difference towards observer's type.For example supposition; Changing above-mentioned instance and make black and white particle positively charged, if but black particles has higher electrophoretic mobility. electrode is a negative pole with respect to rear electrode now, and the black and white particle will attracted to preceding electrode; But black particles; Because the mobility that it is higher will at first arrive preceding electrode, electrode and this medium will present black to the observer before the black particles layer will apply as a result.On the contrary; If preceding electrode is anodal with respect to rear electrode, the black and white particle will attracted to rear electrode, but this black particles; Because the mobility that it is higher; To at first arrive rear electrode, the black particles layer will apply rear electrode as a result, make the leucoplastid sublayer face the observer away from rear electrode; This medium will present white to the observer as a result: it is that the enough transparent leucoplastid sublayer that makes easily makes the observer visible away from rear electrode that the two particle media of this type require suspending liquid. typically; Suspending liquid in this display is not painted, but some colorants can be combined, in order to revise through any undesirable color and luster in its being seen white particles.

Single-particle can have Intermediate grey states with two particle electrophoretic displays, and this gray states has between two has stated the middle optical characteristics of extreme optical state.

Some above-mentioned patents and disclosed application disclose the electrophoretic medium of encapsulation, and it has three or more how dissimilar particles in each capsule.Concerning the application, this multiparticle medium is considered to the subclass of two particle media.

Many above-mentioned patents and application for recognition can be replaced by external phase around the wall of discrete microcapsules in the electrophoretic medium of encapsulation; Thereby make the electrophoretic display device (EPD) of a kind of so-called polymkeric substance-dispersion; Wherein electrophoretic medium comprises the droplet of a plurality of discrete electrophoretic fluid and the external phase of polymeric material; And the discrete droplets of the electrophoretic fluid in the electrophoretic display device (EPD) of this polymkeric substance-dispersion can be considered to capsule or microcapsules, even do not have discrete cyst membrane and droplet that each is independent interrelates; For example see above-mentioned 2002/0131147.Therefore, concerning the application, the subclass of the electrophoretic medium that the electrophoretic medium of this polymkeric substance-dispersion is considered to encapsulate.

A kind of electrophoretic display device (EPD) correlation type is so-called " microcell electrophoretic display ".In microcell electrophoretic display, charged particle and suspending liquid are not to be encapsulated in the microcapsules, but remain in a plurality of chambeies that are formed in the mounting medium; Typically be thin polymer film. see; For example, open No.WO02/01281 of international application and disclosed US application No.2002/0075556; All transfer the possession of Imaging, Inc in Sipix.

Although electrophoretic medium usually be opaque (because, for example, in many electrophoretic mediums; Particle blocking visible light transmission basically passes through display) and turn round with the reflection mode; Many electrophoretic display device (EPD)s can be made with so-called " shutter mode " running, one of them show state be opaque basically and one be printing opacity. see, for example; Above-mentioned United States Patent(USP) Nos. 6130774 and 6172798, and United States Patent(USP) Nos. 5872552; 6144361; 6271823; 6225971 and 6184856. dielectrophoretic displays, it is similar to electrophoretic display device (EPD) but the variation of dependence electric field intensity can be turned round in a similar fashion; See United States Patent(USP) No. 4418346.The electro-optic displays of other types also can be operated with shutter mode.

Encapsulate or microcell electrophoretic display does not generally suffer the failure mode that clusters and precipitate of conventional electrophoretic device and additional advantage is provided, as can on multiple flexibility and stiff base, printing or apply display.(use word " printing " intention to comprise whole printings and form of application, including, but not limited to: metering-type applies like the sheet pattern and applies (patch diecoating), seam formula or squash type coating, ramp type or the coating of rank streaming, curtain coating in advance; Print roll coating such as the coating of roller scraper (knife over roll coating), forward and reverse print roll coating; Gravure coating; Dip coating; Spraying; Falcate applies (meniscuscoating); Spin coating; Brush; Airblade coating; Method for printing screen; Electrostatic printing method; Thermal printing method; The ink jet printing method; And other similar technology .) thereby, the display of gained is flexible.Further because (use several different methods) but typographical display device medium, itself can make this display at an easy rate.

Electro-optic displays generally includes electro-optical material layer and at least two other layers; It is configured on the opposite flank of electrooptical material; One of these two layers are electrode layers. in most of this displays, two layers all are electrode layers, and one or two patterned pixel with the qualification display of electrode layer. for example; Column electrode and another that electrode layer can be patterned to extension is patterned to and the meet at right angles row electrode of extension of running of this column electrode; Pixel is limited the point of crossing of column electrode and row electrode. and perhaps, more generally, an electrode layer has single continuous electrode form; Another electrode layer is patterned to the matrix of pixel electrode; Its each limit a pixel of display. in the electro-optic displays of another kind of type, its intention is used with travelling electrode displays separated with stylus, print head or similar, in the layer of contiguous electrooptic layer only one deck comprise electrode; Layer on the opposite flank of this electrooptic layer usually is a protective seam, and its intention prevents this electrooptic layer of travelling electrode infringement.

Make three layers of electro-optic displays and generally include at least one laminating operation. for example; In several above-mentioned MIT and E Ink patent and application; A kind of method of electrophoretic display device (EPD) of manufacturing and encapsulation has been described; The electrophoretic medium that wherein in bonding agent, comprises the encapsulation of capsule is applied on the flexible substrates; Said flexible substrates comprises that indium-Xi-oxide (ITO) or similar conductive coating (it is as an electrode of final display) are coated on the plastic sheeting, and this capsule/adhesive coating is dried to form the adhesion layer of electrophoretic medium, and it tightly adheres to substrate.Individually, the preparation tool back plane, its comprise pixel electrode array and suitable conductor arrangement to be connected pixel electrode driving circuit.For forming final display, use the lamination tackifier, the substrate that has capsule/adhesive phase on it is laminated to tool back plane.(through replacing tool back plane above that with simple protective layer such as plastic sheeting (stylus or other travelling electrodes can slide); Closely similar method can be used for preparing the electrophoretic display device (EPD) that can use with stylus or similar travelling electrode .) and in a preferred form of this quadrat method, tool back plane itself is flexible and can be through pixel electrode is prepared on plastic sheeting or other flexible substrates with conductor printing. and the conspicuous lamination that is used to produce in batches display by this method is to use the roll-type lamination of lamination tackifier. and similar manufacturing process can be used for the electro-optic displays of other types.For example, microcell electrophoretic media or rotate double-colored member medium can with basically with the encapsulation the identical mode of electrophoretic medium be laminated to tool back plane.

Described in above-mentioned 2004/0027327; Many devices that are used for the solid electric optical display unit and the method that is used to make this display stem from the LCD (technology that LCD ' s) is used; This LCD also is electro-optic displays certainly; Although use liquid rather than solid dielectric. for example; The solid electric optical display unit can use active matrix tool back plane (it array that comprises transistor or diode and corresponding pixel electrode array) and at " continuously " the preceding electrode on the transparent substrates (with regard to the electrode that on a plurality of pixels and typically whole display, extends), these devices basically with LCD ' s in identical.Yet; The method that is used to assemble LCD ' s can not be used for the solid electric optical display unit. and assembling LCD ' s normally forms tool back plane and preceding electrode on independent substrate of glass, then these devices are adhered fixed together, between them, stays aperture; Under vacuum condition, immerse in the liquid crystal bath with the placement of gained accessory and with accessory; So that liquid crystal flow is crossed the hole between tool back plane and the preceding electrode. last, liquid crystal is placed in suitable position, and seal bore is to provide final display.

This LCD assembly technology can not be transferred to the solid electric optical display unit easily.Because electrooptical material is a solid, before tool back plane and these two integral body of preceding electrode were fixed to one another, electrooptical material must be present between tool back plane and the preceding electrode.In addition; Before liquid crystal material is simply placed between electrode and the tool back plane and be free of attachment to any one; And it is opposite with liquid crystal material; The solid electro-optical medium need be fixed to both usually because this is easier than following method usually: contain on the tool back plane of circuit form medium with then with preceding electrode/electro light dielectric layer be pressed onto this tool back plane (through stick with glue that agent covers all surfaces of electro-optical medium and in the hot and pressure and the condition laminated of vacuum perhaps).

Of above-mentioned United States Patent(USP) No. 6312304; Make the solid electric optical display unit and also have following problem: optical device (electro-optical medium) has different performance standards with electron device (in tool back plane). for example; Expectation optical device optimization reflectivity, contrast ratio and response time; And expectation electron device optimization electric conductivity, voltage-to-current relation and electric capacity, or expectation has the electron device ability of memory, other high-orders of logical OR.Therefore the method for making optical device may not be desirable for making electron device, and vice versa. for example, the method for making electron device can be included in high temperature process. and reducible 300 ℃-Yue 600 ℃ of this processing temperatures.Yet many optical device that receive this high temperature can be harmful to optical device by the chemolysis electro-optical medium or by causing mechanical damage.

This patent has been described the method for making electro-optic displays, and it comprises provides regulating course (comprising the electrooptical material that first substrate and contiguous first substrate are provided), and this regulating course can change visual state when applying electric field; Pixel layer (comprising second substrate, a plurality of pixel electrodes that on second substrate front surface, provided and a plurality of contact mats that on surface after second substrate, provided) is provided, and each pixel electrode is connected to contact mat through the path that runs through second substrate; Circuit layer (comprising the 3rd substrate and at least one circuit component) is provided; Lamination regulating course, pixel layer and circuit layer are to form electro-optic displays.

Electro-optic displays usually is expensive; For example, the cost of the color LCD in the portable computer typically accounts for the significant proportion of the complete cost of computing machine.Because the purposes of electro-optic displays involves device such as cellular phone and personal digital assistant (PDA ' s); Be nothing like the portable computer costliness; So exist the immense pressure that reduces this display cost. as above discussion; The ability that on flexible substrates, forms some solid electric light dielectric layers through printing technology has been opened up the possibility that reduces display electro-optical device cost; This is through the used commercial unit of the production that utilizes art paper, thin polymer film and similar mediums; Use mass production processes such as volume to volume (roll-to-roll) however apply and realize.; This equipment is expensive and the perhaps not competent adjustment specialized equipment in area that sell electro-optical medium at present, and the medium that therefore typically can need to be coated with is transported to from the industrial coated workshop and is used for assembling the workshop of electro-optic displays at last and does not damage more crisp electro-optical medium layer.

In addition, the art methods that great majority are used for final lamination electrophoretic display device (EPD) is discontinuous method basically, and wherein electro-optical medium, lamination tackifier and tool back plane only exactly in the end are brought together before the assembling, and expectation provides the better method that is suitable for producing in batches.

Above-mentioned 2004/0027327 describes the method (comprising the corpuscular type electrophoretic display device (EPD)) of assembling solid electric optical display unit, and it is suitable for producing in batches very much.In essence, this pending application is described so-called " frontal plane lamination " (" FPL ") it is comprised the conductive layer of printing opacity in order; The solid electric light dielectric layer that electrically contacts with conductive layer; Adhesive layer and release lamella. typically, the conductive layer of printing opacity will be carried on the light-transparent substrate, (can be wound in diameter by hand in substrate is that rousing of 10 inches (254mm) do not have on the meaning of permanent strain) that this light-transparent substrate is preferably flexible.In this pending application and this paper; Term " printing opacity " meaning refers to that the enough light of layer emission of appointment thus is so that the observer; See through this layer and look, can observe the variation of electro-optical medium show state, said variation will be watched through conductive layer and contiguous substrate (if existence) usually.Substrate will typically be a thin polymer film; The thickness that will have the about 25mil of about 1-(25-634 μ m) usually; The preferred about 10mil of about 2-(51-254 μ m). conductive layer suits is the thin metal layer of for example aluminium or ITO or can be conducting polymer. (PET) film can be commercial to scribble gather (ethylene glycol terephthalate) of aluminium or ITO; For example available from E.I.du Pont de Nemours & Company; " Mylar that aluminizes " (" Mylar " is registered trademark) of Wilmington DE, this industrial materials can be used and have the effect of good frontal plane lamination.

Use this frontal plane lamination assembling electro-optic displays to remove and discharge lamella and under the condition of tool back plane adhesive layer is contacted to carry out with tool back plane causing that effectively adhesive layer adheres to, thereby adhesive layer, electro-optical medium layer and conductive layer are fixed to tool back plane through the past flat stack.This method extremely is suitable for producing in batches, because the frontal plane lamination can be produced in batches, typically uses the volume to volume coating technique, cuts into the fragment that any and concrete tool back plane uses required size then.

Above-mentioned 2004/0027327 also is described in the frontal plane lamination is incorporated into the method that detects electro-optical medium in the frontal plane lamination before the display. in this method of inspection; Discharge lamella and have conductive layer; So and between this conductive layer and the conductive layer on the electro-optical medium opposite flank, apply the voltage of enough change electro-optical medium optical states. the observation of electro-optical medium is with any defective in the display medium; Avoid thus defective electro-optical medium is laminated into display, and the cost that is caused (and being not only this defective frontal plane lamination) of scrapping whole displays.

Above-mentioned 2004/0027327 has also described second method that detects the electro-optical medium in the frontal plane lamination, and it forms image thus through on the release lamella, placing electrostatic charge on electro-optical medium.Then to observe this image to survey any defective in the electro-optical medium with previous identical mode.

Above-mentioned 2004/0155857 describes a kind of so-called " dual release film (doublerelease film) ", and it is the simplified version of above-mentioned 2004/0027327 frontal plane lamination in essence.A form of dual release lamella comprises and is clipped in two solid electric light dielectric layers between the adhesive layer that one or two this adhesive layer is released lamella and covers.Another form of dual release lamella comprises and is clipped in two solid electric light dielectric layers that discharge between the lamella. two kinds of forms of this of dual release film all are intended to be used for being similar to usually the method for having stated by frontal plane lamination assembling electro-optic displays, but comprise two independent laminations; Typically, in first lamination, this dual release lamella be laminated to before electrode with form before subassembly, in second lamination, this preceding subassembly is laminated to tool back plane to form final display then.

Staying at least one lamination adhesive layer between the method for whole above-mentioned assembling solid electric optical display units in electro-optical medium and electrode. this is disadvantageous; Because expecting electro-optic displays usually changes as early as possible; And for realizing this quick conversion; The high as far as possible electric field of crossing over electrooptic layer must be provided. the existence of the electrooptic layer between lamination adhesive layer and the electrode is inevitable to reduce the effect of electric field to electrooptic layer under any given interelectrode voltage conditions, because some voltage drops must appear at the lamination adhesive layer; In fact, lamination adhesive layer waste part effective voltage.

Although the WV that people can be through increasing display (promptly; Interelectrode voltage difference) voltage drop of adhesive layer is crossed in compensation; It is undesirable increasing the voltage of crossing over electrode in such a way; Because increase the power consumption of display, and can need to use more complicated and expensive control loop to control the voltage of contained increase.

As already mentioned, in the electrophoretic medium of encapsulation, electrophoresis layer typically comprises the bonding agent around capsule, and makes them keep the form of mechanical adhesion layer. other forms of solid electro-optical medium can comprise similar bonding agent; The matrix of for example rotating double-colored member display can be considered to bonding agent; As can be the end wall of micro unit display. have been found that at present; If select the performance of this bonding agent modestly and at least some situation, be present in the ratio of the bonding agent in the electrooptic layer; This bonding agent can also be removed the demand to independent lamination adhesive layer thus as the lamination tackifier, and thereby in final display, produces improved electro-optical properties.

Therefore, the present invention provides a kind of solid electric optical display unit with bonding agent in one aspect, and this bonding agent is also as the lamination tackifier.

Second aspect of the present invention relates to flexible display. and the flexible display technology is many display application high expectations. and wherein flexibility is that an application of key factor is that wherein display is used to the situation on machinery or the electrical sensor apparatus; Wherein through mechanically deform; For example, through applying conversion or through mechanically changing the reaction that capacitor or piezoelectric sensor or other spacings electric or electronic installation produce sensing device. the compliance and the flexibility of display are conclusive in these are used; If the display layer is too hard, need bigger power so that sensor operation and effective sensing resolution of installing reduces, because more than one sensitive element possibly turn round through pressurization at a set point.Wherein to be proved to be an instance of important use be in telephone keypad to the rigidity of display accessory; Its desired has the display on the microswitch array; Said microswitch is controlled by finger pressure. and be coated on the rigidity with the display present encapsulation of using the back plastic plane on the thicker plastic supporting and shown that to make these keypads assemblings complicated, and reduced the tactile sensation of conversion operations (when closing conversion " clicking ").

Thereby, in second aspect, the present invention relates to assemble the method for flexible electro-optic display; These methods are used the device that is similar to above-mentioned frontal plane lamination and dual release film slightly.

In addition, as already mentioned, the further aspect of the present invention relates to color monitor.One of problem relevant with many electro-optic displays is the limited range of the producible color of each pixel of display.As above discussion, single-particle only shows two kinds of colors at each pixel place, the color of the particle of two types in the particle in the single-particle display and the color of suspending liquid and the two particle display usually with two particle types electrophoretic display device (EPD)s.

Expansion is that the color filter array is positioned on the display picture element by the method for the limited range of the obtainable color of conventional electro-optic displays. for example; Consideration is placed on the display individual pixels influence to the display that comprises the white particles in the black fluid with colour filter (as red, green and blue) device array. and the observation surface that white particles is moved near the pixel that covers Red lightscreening plate will make this pixel manifest redness; And will make this pixel manifest black on the back surface that the white particles of same pixel moves near display. the pixelation that colorific in this way subject matter is color filter has limited the brightness of display. for example; If expectation red color; Be set up by the Red lightscreening plate covered pixels and present redness; And present dead color by green being set up with the cyan color filter covered pixels; Therefore only the part display surface has desired color and remainder is dark-coloured, therefore the brightness of any color of being obtained of restriction. and the reflected displaying device that can have three optical states (black, white and colour or black, white and transparent) will and be easy to manufacture view at picture quality, cost and have significant advantage.

One aspect of the present invention relate to use shutter mode electro-optical medium to make improved color monitor.

In addition, as already mentioned, further aspect of the present invention relates to uses aforesaid frontal plane lamination and dual release film, is used to form the method and the device of electro-optic displays.In the method for actual industrial high power capacity; Be necessary to use the heat lamination method to make FPL or dual release film be connected to tool back plane at present. this tool back plane can be the direct driving merogenesis type of the conductive traces (conductive trace) with one or more patternings; Perhaps can be non-linear circuit type (for example, active matrix).

With FPL or the active matrix tool back plane of dual release film laminating to glass (thin film transistor (TFT) array; Or during abbreviation TFT ' method development s); Running into the relevant problem of many and traditional laminating apparatus. the present invention provides modification required and conventional instrument expectation, so that processing FPL ' s and the last dual release film of glass TFT ' s.The present invention who describes in this article can be used for the design of FPL type or dual release film-type display lamination instrument, and said display also uses plastics or metal forming tool back plane.

At last; The present invention relates to make the method for combining display; Said combining display is formed by the material with different heat expansion coefficient. the display battery. and electro-optic displays can use two glass plate structures. and first plate forms front surface, and is provided for one or more electrodes of addressing electro-optical medium. and second plate forms the surface, back and is provided for one or more electrodes of addressing electro-optical medium (and perhaps being nonlinear element such as thin film transistor (TFT)).Ideally; The material of used formation front and rear panel is gone up similar in some mechanical property such as thermal expansivity (CTE) with relative humidity expansion coefficient (CHE). further; In some cases, the expectation material have thickness and Young modulus (Young ' s Modulus) (E) selected combination so that satisfy some requirement of manufacturing.

In other cases; As when using FPL and glass or similarly the rigid back plane forms display; " mixing " electro-optic displays of gained makes the material of " plate " before and after the display different on its mechanical property inevitably. this combining display brings new challenge in it is made. for example; In fact the display that the electrophoresis FPL of use encapsulation and glass TFT tool back plane are constructed has the plastics header board that is laminated to the glass tool back plane; Wherein be the asymmetrical stack layer of dissimilar materials basically. as the result of this structure; Display has shown undiscovered mechanical features in traditional glass/glass displays. especially, non-symmetrical configuration causes changing with panel temperature or humidity curl (warpage) of relevant composite panel.Stress relevant with warpage and tension force have proposed severe challenge to the design of this system.Therefore, counter plate processing, material and building method exist a kind of needs, require in very wide condition of work scope, to cause panel to have acceptable performance, and the present invention manage to satisfy these requirements.

Therefore, in one aspect, the present invention provides a kind of method of electrophoretic display device (EPD) of manufacturing and encapsulation, and this method comprises:

Electrophoretic medium is provided, and it comprises a plurality of discrete droplets in polymer adhesive, and each droplet comprises a plurality of charged particles, and said charged particle is dispersed in the suspending liquid, and when electric field put on suspending liquid, said charged particle can move through suspending liquid;

Tool back plane is provided, and it has at least one electrode; With

At a certain temperature electrophoretic medium is laminated to tool back plane, polymer adhesive will flow and electrophoretic medium directly contacts with tool back plane when this temperature, thereby cause that polymer adhesive flows and electrophoretic medium is fixed to tool back plane to form display.

As it is obvious that easily electro-optic displays to be made the technician in field, and this method is different from the conventional method that electro-optical medium is laminated to tool back plane and is between electro-optic displays and tool back plane, to need not the lamination tackifier; In fact, polymer adhesive plays bonding agent and lamination tackifier. and therefore, for simplicity, this method can be described as " non-adhesive " of the present invention method hereinafter.

In this method; Electrophoretic medium can be aforementioned any type. therefore; For example, electrophoretic medium can be the electrophoretic medium of conventional encapsulation, in the cyst wall scope that wherein each droplet is limited in separating with polymer adhesive (although this cyst wall itself can be made up of polymeric material).Perhaps, electrophoretic medium can be the type of polymkeric substance-dispersion, and the external phase that its droplets forms the discontinuous phase of binary system and is formed polymer adhesive centers on.

In non-adhesive method of the present invention, electrophoretic medium can be placed on the light-transparent substrate, makes that electrophoretic medium is sandwiched between substrate and the tool back plane behind the lamination.Euphotic electrode can be placed between electrophoretic medium and the substrate; Electrophoretic medium has the release lamella; Said release lamella covers away from the electrophoretic medium of this substrate surperficial (promptly; As above-mentioned 2004/0027327 said, electrophoretic medium can be incorporated into the frontal plane lamination), and this release lamella is removed before lamination.

In the non-adhesive method; Be laminated to and enough cause under the temperature conditions that polymer adhesive flows and carry out, to such an extent as to make bonding agent to flow and electrophoretic medium is fixed to tool back plane. used temperature certainly so height not cause unacceptable infringement to any other temperature sensitive device of electrophoretic medium or existence.Therefore, should select bonding agent, make it not damage electrophoretic medium or other devices in the temperature conditions current downflow that allows lamination to carry out.Usually; Expectation is used and to be no more than 150 ℃ and preferably be no more than the polymer adhesive of 100 ℃ condition current downflow. like what in above-mentioned 2003/0025855, detailed; The lamination tackifier that selection is used for electrophoretic display device (EPD) is complicated; Because must consider a large amount of factors, comprise the electrical properties of tackifier, and same factor is applicable to the polymer adhesive that plays the effect of lamination tackifier equally.Therefore, because the same reasons described in above-mentioned 2003/0025855, the polymer adhesive that is preferred for the non-adhesive method usually is a polyurethane.

Because the reason of following detailed description; The polymer adhesive that is used for the non-adhesive method and the ratio of the droplet of electrophoretic medium are usually above the art methods of using the tackifier that separates with bonding agent. in the non-adhesive method, typically the polymer adhesive 20wt% at least that will account for electrophoretic medium with make us desirably 30wt%. at least

The tool back plane that is used for the non-adhesive method can be any kind known in the art. and for example, tool back plane can be direct driving type, and it has a plurality of pixel electrodes and conductive traces, can control the electromotive force on the pixel electrode independently through conductive traces.Perhaps, tool back plane can be active matrix tool back plane, and it comprises the nonlinear element that a plurality of pixel electrodes and at least one are relevant with each pixel electrode.

The present invention also provides a kind of electrophoretic medium (it can be called as " non-adhesive medium " of the present invention hereinafter); Its intention is used for aforesaid non-adhesive method. and this electrophoretic medium comprises the discrete droplets of a plurality of electrophoretic mediums at polymer adhesive; Each droplet comprises a plurality of charged particles; Said charged particle be dispersed in the suspending liquid and when electric field puts on suspending liquid said charged particle can move through suspending liquid, wherein polymer adhesive is in the temperature current downflow that is no more than 150 ℃.

In this non-adhesive medium; Making us desirably, polymer adhesive is being no more than about 100 ℃ temperature current downflow. and electrophoretic medium can be aforementioned any type. therefore; For example; Electrophoretic medium can be the electrophoretic medium of conventional encapsulation, in the cyst wall scope that wherein each droplet is limited in separating with polymer adhesive (although this cyst wall itself can be made up of polymeric material).Perhaps, electrophoretic medium can be the type of polymkeric substance-dispersion, and the external phase that its droplets forms the discontinuous phase of binary system and is formed polymer adhesive centers on.

Non-adhesive medium of the present invention can be used in combination with the light-transparent substrate on a surface that covers this medium, chooses wantonly to combine with the euphotic electrode that is placed between electrophoretic medium and the substrate.Electrophoretic medium can have the release lamella, and said release lamella covers the electrophoretic medium surface (that is, electrophoretic medium can be incorporated into the frontal plane lamination, described in above-mentioned 2004/0027327) away from this substrate.

Because above-mentioned reason, in the non-adhesive medium, typically polymer adhesive will account for electrophoretic medium at least about 20wt% with make us desirably at least about 30wt%, and polymer adhesive can comprise polyurethane.

The present invention also is provided for making the film of display, and this film comprises in order:

The conductive layer of printing opacity;

Electrophoretic medium; It comprises the discrete droplets of a plurality of electrophoretic mediums in polymer adhesive; Each droplet comprises a plurality of charged particles; Said charged particle be dispersed in the suspending liquid and when electric field puts on suspending liquid said charged particle can move through suspending liquid, this polymer adhesive is in the temperature current downflow that is no more than 150 ℃; With

Discharge lamella, it contacts with polymer adhesive.

This film is actually like above-mentioned 2004/0027327 described frontal plane lamination; It is modified to replace with the electrophoretic medium with bonding agent (according to the present invention, it can also play the lamination tackifier) the lamination adhesive layer of electrophoretic medium and initial frontal plane lamination.

The present invention also is provided for making the film of display, and this film comprises:

Electrophoretic layer; It comprises the discrete droplets of a plurality of electrophoretic mediums in polymer adhesive; Each droplet comprises a plurality of charged particles; Said charged particle be dispersed in the suspending liquid and when electric field puts on suspending liquid said charged particle can move through suspending liquid, this polymer adhesive is in the temperature current downflow that is no more than 150 ℃, this layer has first and second surfaces on its opposite flank;

First discharges lamella, and it covers the first surface of electrophoretic layer; With

Second discharges lamella, and it covers the second surface of electrophoretic layer.

This film is actually like above-mentioned 2004/0027327 described dual release lamella; It is modified to replace with the electrophoretic medium with bonding agent (according to the present invention, it can also play the lamination tackifier) the lamination adhesive layer of electrophoretic medium and initial frontal plane lamination.

In one aspect of the method, the present invention is used to form the method for the used subassembly of electro-optic displays, and this method comprises:

The electro-optical medium layer is deposited on first to be discharged on the lamella;

The lamination adhesive layer is deposited on second discharges lamella; With

Thereafter; Causing that effectively the lamination adhesive bond is under the condition of electro-optical medium; Make first to discharge the lamination tackifier that the electro-optical medium and second on the lamella discharges on the lamella and contact, thus the formation subassembly, and it comprises and is clipped in two lamination tackifier and electro-optical mediums between the release lamella.This method; Although it mainly not exclusively is intended to be used to assemble flexible display; For simplicity, can be called as " flexible sub-assembly technology " of the present invention hereinafter. this method can comprise further that removing first from subassembly discharges lamella and electro-optical medium is laminated to the tool back plane that comprises at least one electrode.This method can further comprise, before electro-optical medium is laminated to it, the lamination adhesive layer is laminated to tool back plane.

In one aspect of the method; The present invention is provided for the equipment of color display; This equipment comprises the electro-optic displays with a plurality of pixels; Wherein each pixel can be set to the optical states of printing opacity or opaque basically optical states independently, and light-emitting device is arranged to glimmer the independent pulse of at least two different colours light to a surface of electro-optic displays.Further, the present invention is provided for producing the equipment of different colours light pulse, and this equipment comprises light source and arranged to accept the optical filtering accessory from the light of light source that this optical filtering accessory comprises:

Have light transmission state and first electrooptic layer with colored state of first optical characteristics;

First electrode, it is arranged to apply electric field to first electrooptic layer, and said electric field can make first electrooptic layer between its light transmission state and colored state, switch;

Have light transmission state and second electrooptic layer with colored state of second optical characteristics that is different from first optical characteristics; With

Second electrode, it is arranged to apply electric field to second electrooptic layer, and said electric field can make second electrooptic layer between its light transmission state and colored state, switch.

In one aspect of the method, the present invention is provided for making first method of combining display, and this first method comprises:

(a) the frontal plane lamination is provided, it comprises electrooptic layer and substrate, and this frontal plane lamination has first thermal expansivity (CTE);

(b) make electro-optic displays through the frontal plane lamination being laminated to tool back plane, said tool back plane comprises at least one electrode, and this tool back plane has the 2nd CTE;

(c) display is heated to the temperature more than the threshold temperature, thereby makes the display of heating with curvature; With

(d) little by little be cooled to environment temperature and make curvature fully reduce with releasing structure stress, said structural stress is because any differential expansion of frontal plane lamination and tool back plane causes.

In one aspect of the method, the present invention is provided for making second method of combining display, and this second method comprises:

(a) the frontal plane lamination is adhered to tool back plane, said frontal plane lamination comprises first material with first thermal expansivity (CTE), and said tool back plane comprises second material with the 2nd CTE, thereby makes the combining display with first curvature

(b) through forcing display temporarily to present the curvature that reduces combining display with respect to the torsion of first curvature.

In one aspect of the method, the present invention is provided for making third party's method of combining display, and this third party's method comprises:

(a) the frontal plane lamination is provided, it comprises first material with first thermal expansivity (CTE);

(b) tool back plane is adhered to the frontal plane lamination, said tool back plane comprises second material with the 2nd CTE; With

(c) through being adhered to tool back plane, the 3rd panel makes combining display; Said the 3rd panel comprises the material that is different from second material; Make and the display in comparison of only forming that the total curvature of mixing panel reduces fully by frontal plane lamination and tool back plane rather than the 3rd panel.

At last, the present invention is provided for making the cubic method of combining display, and this cubic method comprises:

(a) regulate frontal plane and be stacked to first temperature, said frontal plane lamination comprises first material with first thermal expansivity (CTE);

(b) regulate tool back plane to the second temperature, said tool back plane comprises second material with the 2nd CTE; With

(c) the frontal plane lamination of adjustment being crossed adheres to tool back plane that adjustment crosses to make combining display.

Be used for making the said method of combining display at each, the frontal plane lamination can comprise electrophoresis layer, and it can be any aforesaid type.

Fig. 1 of accompanying drawing is through the diagrammatic cross-section like above-mentioned 2004/0027327 described prior art frontal plane lamination, but releasing layer is removed in order to being laminated to tool back plane.

Fig. 2 is the diagrammatic cross-section of expression prior art display, and this display is by the frontal plane lamination shown in Fig. 1 being laminated to the tool back plane that contains pixel electrode and producing.

Fig. 3 is the diagrammatic cross-section that is similar to Fig. 1 through frontal plane lamination of the present invention, and releasing layer is removed in order to being laminated to tool back plane in addition.

Fig. 4 is the diagrammatic cross-section that is similar to Fig. 2 of expression display, and this display is by the frontal plane lamination shown in Fig. 1 being laminated to the tool back plane that contains pixel electrode and producing.Fig. 5 to 9 is diagrammatic side view, and it is illustrated in each step in the sub-assembly technology of flexibility of the present invention.

Figure 10 is the diagrammatic side view that the present invention is used for the equipment of color display.

Figure 11 is the diagrammatic side view that the present invention is used to produce the equipment of different colours light pulse.

Figure 12 is the diagrammatic cross-section of the display unit of the mixing electrophoretic display device (EPD) through can be constructed in accordance. Figure 13 A and 13B are the diagrammatic side view that illustrates the method that can be used to alleviate the warpage in display as shown in Figure 12.

Figure 14 is the diagrammatic side view that expression can be used to prevent the further method of the warpage in display as shown in Figure 12.

Figure 15 illustrates the method for making combining display, and wherein adjustment is used for controlling any display warpage trend. and Figure 16 compares with Figure 12 to amplify a lot of diagrammatic cross-sections, and it representes a possible banding form that can be used for Figure 12 display.

As pointed out; The present invention has several different relating to electro-optic displays and be used to produce the method for this display and the aspect of device. and these different aspects will mainly be described in detail respectively following; But should be understood that single display, method or device can use the more than one aspect of the present invention. for example, use frontal plane lamination of the present invention can carry out the distinct methods that the present invention makes combining display.

Non-adhesive method, medium, frontal plane lamination and dual release film

It is because they all relate to the lamination tackifier between at least one other device of getting rid of the electrophoretic medium that is generally used for encapsulating and electrophoretic display device (EPD) together that the above all aspects of the present invention are bonded to; These other devices typically are tool back planes, but in some cases, and the present invention can make and reject the lamination tackifier between electrophoretic medium and the preceding substrate, said before substrate provide and observe the surface, the observer watches display through its intention.As already mentioned; Rejecting the lamination tackifier carries out through in electrophoretic medium, using bonding agent; Said bonding agent can be in the used temperature conditions current downflow of lamination; Therefore in fact this bonding agent also as the lamination tackifier. mobile notion is complicated but it is meant a kind of polymeric material in this article, and it is through from elasticity to plasticity or the transformation of viscous state.

The present invention is used for that the selection of the bonding agent of non-adhesive medium and method certainly must consider is not only its flow temperature but also the compatibility of itself and another electrophoretic medium device and the requirement that drives this medium; Resistivity particularly including bonding agent. make us desirably; Bonding agent is in the temperature current downflow that is no more than 150 ℃; And preferably be no more than under 100 ℃ the temperature. usually, the preferred type of bonding agent is a polyurethane; Have been found that some polyurethane can satisfy these preferred flow temperatures and still can be compatible with whole another devices that are generally used in the electrophoretic medium.

In addition; At the bonding agent of selecting to be used for non-adhesive medium of the present invention and method; The type of adhesive therefor should be not only noted but also the ratio of bonding agent should be noted. like what in several above-mentioned E Ink and MIT patent and application, discussed; The electrophoretic medium that is applied to encapsulation prepared on the medium of type of substrate or polymkeric substance-dispersion by the potpourri with capsule and bonding agent often has non-planar surface; Because independent capsule or droplet form " convexity " on the surface of the electrophoretic medium of dry and/or curing, and when (according to preferable case) medium was made up of the single layer of capsule or droplet basically, situation was all the more so. in the conventional method of using the lamination tackifier; The lamination tackifier not only is used for electrophoretic medium is adhered to tool back plane or other devices; And make the initial non-planar surface complanation of electrophoretic medium, therefore avoid various problem (for example, forming the irregular reaction of hole and electrophoretic medium) to the electric field that applied; If when the non-planar surface of this electrophoretic medium is laminated to the planar surface of tool back plane or other devices, these problems can occur in addition.

When according to the present invention when avoiding this type problem to reject the lamination tackifier; Expect that very flowable bonding agent not only replaces the tackifier function of in the past used lamination tackifier; And replace its complanation function, and, have been found that for flowable bonding agent can be done like this; Compare with the used electrophoretic medium (its intention is used with the lamination tackifier) of prior art typically, more a high proportion of bonding agent in the electrophoretic medium of non-adhesive of the present invention is used in expectation usually.Consider; For example; A kind of electrophoretic medium of Utopian encapsulation; It comprises that the hexagon that relies on substrate closely fills out the single layer of the spherical capsule of match. and the volume fraction that this capsule accounts for this layer is about 60.5%, and the remaining 39.5vol% of this layer is by the binder constitutes certificate. and this hint capsule will be enough to make bonding agent can fill being had living space between capsule with the bonding agent volume ratio by about 3:2, so make the cystoblast complanation.Further consider that the bigger ratio (for example capsule and bonding agent volume ratio are 1:1) of this idealized system hint bonding agent expect, guaranteeing excess binder covering cystoblast, so be reduced in during the lamination process cyst wall can be undermined and the chance of explosion perhaps.

Yet; Like several above-mentioned E Ink and MIT patent and application said (seeing United States Patent(USP) Nos. 6067185 and 6392785 especially), electrophoretic medium and the idealized model of the encapsulation of in fact making have very big difference, wherein because of electrophoretic layer in drying or setting up period contraction and make initial spherical capsule be flattened into oblate ellipsoid; And at least some situation; Because shrink to continue, oblate ellipsoid contacts with each other and forms the plane contact area, fully extends perpendicular to the thickness of layer; Therefore final capsule has prismatic basically shape, hexagonal prism ideally.Similar effects is observed with the electrophoretic medium of polymkeric substance-dispersion. and with the spherical capsule of closely filling out match, the capsule of oblate ellipsoid and prism shape accounts for obviously bigger ratio of electrophoretic medium, therefore in former instance, needs bonding agent still less.In addition; Above-mentioned discussion concentrates on volume ratio; The density of most of bonding agents is often a little more than most of electrophoretic mediums; Forming by low density fat family hydrocarbon suspending liquid mostly of said electrophoretic medium; Therefore the weight ratio of bonding agent can be a little more than volume ratio. and the optimal proportion that is used for the bonding agent of any particular medium is preferably confirmed by rule of thumb, is that polymer adhesive should typically account at least 20% of electrophoretic medium but instruct accountable as generality, and (yes based on the weight of dry in fact capsule and calculate based on bonding agent solid matter (solid basis) for this ratio to make us desirably 30wt% at least; Because bonding agent typically is added into as a kind of latex). typically, optimum ratio will be the polymer adhesive of the every weight portion of capsule of 2 to 3 weight portions.Should avoid the use of excessive bonding agent,, the electro-optical properties of medium degenerated because this excessive often " dilution " this capsule makes it surpass their good points of filling out match.

The lamination step of non-adhesive method of the present invention can use any technology known in the art to carry out.Therefore, for example lamination can use the volume to volume method to carry out, make frontal plane lamination of the present invention (having the release lamella of peeling off from it) and be formed on the flexible substrates the rolling tool back plane laminating machine receive pass through between hot-rolling.

Frontal plane lamination of the present invention and dual release film can comprise any optional characteristic in above-mentioned 2004/0027327 and 2004/0155857 that is described in.Therefore, for example, the frontal plane lamination can have conductive path and contact mat, and is of 2004/0027327. and the release lamella of frontal plane lamination can have conductive layer so that detect the frontal plane lamination with aforesaid mode.

Frontal plane lamination of the present invention is not only rejected the layer (being the lamination adhesive layer) of prior art FPL but also is simplified general assembly (GA) technology. in the art methods that is described in above-mentioned 2004/0027327; FPL typically forms by capsule/binder paste is applied in the substrate; Said substrate comprises the thin polymer film that contains indium-Xi-oxide (ITO) layer; This slurry is applied on the ITO covered surfaces of film. and the film of the capsule-coating of gained stands first lamination then; Wherein the lamination adhesive layer is laminated to the exposed surface of capsule/adhesive phase, applies the release lamella then to form FPL.When FPL will be assembled into display; This release lamella is removed and carries out second lamination so that the lamination tackifier is fixed to tool back plane; Therefore forming final display. the present invention makes and can make first lamination disallowable, therefore simplifies total process of producing display.

This aspect of the present invention is illustrated referring now to Fig. 1-4 of accompanying drawing. and as already mentioned, Fig. 1 representes the frontal plane lamination like above-mentioned 2004/0027327 described prior art, but releasing layer is removed in order to being laminated to tool back plane.As shown in Figure 1; The frontal plane lamination comprises preceding substrate 100, and it is formed by thin polymer film, and (layer 102 thickness is compared with the thickness of substrate 100 and amplified widely to contain the layer 102 of indium oxygen oxide; Be convenient to explanation); It will form the public preceding electrode of final display. and the frontal plane lamination further comprises electrophoresis layer, and it is included in capsule 104 and lamination adhesive layer 108 in the bonding agent 106.

Fig. 2 representes to be laminated to the tool back plane 110 that contains the pixel electrode (not shown) and the structure that produces by the frontal plane lamination with Fig. 1.It will be appreciated that in the lamination of Fig. 2, two electrophoresis layer 104/106 and adhesive layer 108 are present between plane electrode layer 102 and the pixel electrode.

Fig. 3 representes frontal plane lamination of the present invention, and releasing layer is removed in order to being laminated to tool back plane in addition.The frontal plane lamination of Fig. 3 is similar to the frontal plane lamination of Fig. 1 usually, but has hot flowable bonding agent 106 ' and do not have adhesive layer.

At last, Fig. 4 representes to be laminated to tool back plane 110 and the structure of generation by the frontal plane lamination of Fig. 3.It will be appreciated that; In the lamination of Fig. 4; Only have electrophoresis layer 104/106. between frontal plane electrode layer 102 and the pixel electrode because eliminate the adhesive layer between the electrode, under any given WV condition, the lamination of Fig. 4 will typically be changed sooner than the lamination of Fig. 2 basically. provide following examples now; Yet only as explanation, to illustrate the preferred embodiments of the invention.

Embodiment

Basically of above-mentioned 2002/0185378 embodiment 30; Being prepared in the titania and two particle opposite polarity electrophoresis capsules carbon black particle and that have gel/gum arabic cyst wall that contain polymkeric substance-coating in the aliphatic hydrocarbon suspending liquid. these capsules mix with 1:1 weight ratio (capsule/bonding agent solid matter) with the conventional polyurethanes latex adhesive then; Basically of this embodiment 30; Gains seam formula is applied to 5mil (127 μ m) gathers (ethylene glycol terephthalate) (PET) on the film (this film is being coated with ITO on the surface); And solidify to produce final capsule/adhesive phase; It consists essentially of the individual layer of capsule and film that thickness is the capsule-coating of 15-30 μ m. gained is FPL of the present invention basically, and except it does not discharge the lamella, said release lamella is optional; Because and then the film of coating is used, be described below.

Use the hot-roll lamination machine; Then with the film laminating of capsule coating to the tool back plane that comprises the thin polymer film that covers graphite linings; Electrophoresis layer contacts with graphite linings; And the size that the structure of gained is cut into 2 inches squares (51mm square) to be to produce tentative single pixel display, and it manifests gratifying electro-optical properties.

Further similar experiment shows with lower bonding agent and the about 1:2-1:3 of capsule weight ratio, can obtain gratifying electro-optical properties.

Flexible sub-assembly method

The sub-assembly method of flexibility of the present invention makes the extremely flexible and compliance display of assembling will describe with reference to Fig. 5-9 of accompanying drawing to be applicable to the preferred sub-assembly method of application .A that for example above-mentioned wherein flexibility is a most important factor well.

It is starting point that preferable methods discharges lamella 500 (Fig. 5) with first. electro-optical medium is applied or is deposited in addition first for 502 layers and discharges on the lamella 500. respectively; 504 layers of lamination tackifier are formed on second and discharge on the lamella 506 and be laminated to electro-optical medium 502, make lamination tackifier 504 adhere to electro-optical medium 502.

In other operation; As shown in Figure 6; Tool back plane 508 (is seen above-mentioned E Ink/MIT patent and application through serigraphy or similar deposition process; Be used to form the appropriate method of this tool back plane) discharge on the lamella 510 the 3rd and form. respectively, 512 layers of lamination tackifier are formed on the 4th and discharge on the lamella 514 and be in turn laminated to tool back plane 508, make lamination tackifier 512 adhere to tool back plane 508.

In next step of this method, make the 4th to discharge lamella 514 and remove from structure shown in Figure 6, lamination tackifier 512 is exposed, and first thin plate 500 is removed from structure shown in Figure 5, electro-optical medium 502 is exposed.The structure of right latter two gained is laminated together with the lamination tackifier 512 that contacts with electro-optical medium 502, therefore forms sandwich construction shown in Figure 7.

In other operation, 516 layers of another lamination tackifier are coated on the 5th and discharge on the lamella 518. and the 3rd discharges that lamella 510 tears off and lamination tackifier 516 is laminated to its tool back plane surface to produce structure shown in Figure 8 with the 5th release lamella 518 from structure shown in Figure 7.

Next step of this method is fixed to substrate with the structure of Fig. 8, for example pressure-sensitive switch or sensing device, and it has covered the insulating material thin layer so that the electro-optic displays device isolation of Fig. 8 structure.This lamination is through discharging lamella 518 and with lamination tackifier 516 laminations thereby be exposed to substrate 520 (Fig. 9) and work from Fig. 8 structure spalling the 5th.Perhaps, this lamination adhesive layer (it contacts with sensing or switchgear) can be formed by the height pressure-sensitive adhesive agent material that insulate, and can reject insulation material layer in such cases.At last; Remove second and discharge lamella 506 so that lamination tackifier 504 exposes; Then lamination tackifier 504 is laminated to top plane electrode 522, on substrate such as the thin polymer film before top plane electrode 522 will typically be bearing in (it is used as protective seam to protect final electro-optic displays).Perhaps, top plane electrode 522 can form through coating process, for example through conducting polymer is deposited on the lamination tackifier 504.

Follow identical basic composition and can use different alternative methods. for example; Electro-optical medium can directly be coated on the conductance supporting in the first step of this method; Save fully thus second discharge lamella lamination or the formation with the top plane electrode of removing. this process causes being similar to the structure of Fig. 9 structure; But the lamination adhesive layer that does not have top. perhaps; Do not peel off first and discharge lamella, peel off to obtain having the duplex coating of exposed adhesive layer and can discharge lamella with second so that electro-optical medium exposes.Can this duplex coating be laminated to the conductive layer on the thin plastic support then.At this point, first discharges that lamella can be removed and the final step of this method is carried out as previously mentioned. and also can be susceptible to other assemblings changes, and therefore can use conventional method to construct multiple different electro-optic displays construction and device in many ways.

Here illustrational constructing technology the preparation of at least two new structures is provided especially, said structure comprises the electro-optic displays device that directly adheres to mechanical pick-up device.The difference of these two new structures is; One of them, the protection of the top of display device protected property thin plate (typically plastic sheeting), and second (wherein the top plane electrode is as conducting polymer materials; Like PEDOT) there is not a further protective seam. preferred construction depends on the durability of using with required device. passes through to press under the situation of button activation at mechanical pick-up device; The button cover that contact with electro-optical device surface should be made into level and smooth and/or slightly submissive, therefore, if needing protection property ductile bed not. the driving of sensor is through using finger or stylus or other sharp objects that (as in the touch screen application) takes place; For durability; No matter possibly need the top protective seam. but be which kind of situation, the durability of device will be improved, if electro-optical medium is the electrophoretic medium of polymer dispersed

Also can use other to use the method for electro-optical medium.Especially; The tool back plane that electrophoresis capsule and bonding agent is electro-deposited into patterning (is seen; International Application PCT/US2004/009421) will be the method that is particularly suitable for combining electro-optical medium, and will reject some laminations/delamination step in the said process. present technique also can be used except black or a plurality of special look the white and strengthen Presentation Function.

The sub-assembly method of flexibility of the present invention from the above can provide the electro-optic displays that is directly coupled to mechanical pick-up device and use a series of lamination steps to assemble the conventional method of this device. and the needs to the support sheet of at least one relative stiffness have been rejected in the direct coupling between display and the sensor, improve the resolution and the sense of touch of this coupling device. the touch screen that can be to use the electrophoretic display device (EPD) of encapsulation by this device that the present invention realizes; Another is the telephone keypad with convertible demand pusher indicator. this is a kind of purposes of extremely strong big constructing technology, the durability and the flexibility of the electrophoretic medium of said constructing technology encapsulation capable of using.

Be used for color display and the equipment that produces light pulse

As already mentioned, the present invention is provided for the equipment of color display and is used to produce the equipment of different colours light pulse, and back one device intends is as the subassembly in the color display equipment.

As stated; Yet the electrophoretic medium that has illustrated encapsulation is fit to color filtering array with similar electro-optical medium.; Existing several and integrate relevant fundamental challenge with making color filtering array, electrophoretic medium or other electro-optical mediums and electronic driver. the key issue relevant with this display design relates to utilizes subpixel to form the pixel of display. in this structure; Subpixel (for example red R, green G and blue B) must be by each addressing so that the deception human eye make it see the spectrum of basic colors. in other words, minimum addressable element only shows single color and its tone, promptly subpixel can not show whole spectrum of visible light.In preferred embodiments; The addressable element of the minimum of this display can show each Essential colour (R among we embodiment, G and B). the electro-optical medium of equipment use window shutter mode of the present invention and field-sequential method operative technique are (promptly; A kind of technology; " subimage " that wherein show total each color channel of image separates in time rather than on the space, is to see that with observer's eyes the mode of total coloured image carries out but separate) solved this problem.

There are two kinds of use field-sequential method method for addressing and reject aforesaid problem. first; Use the present invention to be used for the equipment of color display; In display, can use color sequential backlight device (backlight) (for example, by LumiLEDs Corporat ion, San Jose; And use the electro-optic optical sensor of " shutter mode " device backlight that CA makes).Field-sequential method device backlight periodically, the Essential colour of synchronously flashing display with the shutter speed of optical sensor; As red, green and blue. through making optical sensor conversion from distinct to opaque with suitable space-time control method, full-colour image can be presented to the observer.This type device illustrates with the mode of very signal in Figure 10 of accompanying drawing. and Figure 10 shows a kind of electro-optic displays; It comprises that the substrate 1000 that contains a plurality of pixel electrode (not shown)s, the layer 1002 of electro-optical medium (the for example electrophoretic medium of encapsulation) have field-sequential method device 1006 backlight with continuous preceding electrode 1004. these displays; Its flicker is red, green and blue, and the shutter speed of itself and electro-optical medium layer 1002 is synchronous. this sensor and device backlight should be enough rapidly conversion so that the color that human eye is integrated display in time and sent.

Secondly; The electro-optic film that use is piled up; Can construct color sequential backlight device (that is, being used to produce the equipment of the present invention of different colours light pulse). the electro-optic film that these pile up, its intention is used with " monochrome " light modulator (it can be electric light type shown in figure 10); Only need continuous electrode, so they will have low production cost.This type device illustrates with the mode of very signal in Figure 11 of accompanying drawing.Figure 11 has shown the look preface rear reflector that piles up; It electro-optical medium layer 1100 that comprises the blue shutter mode with continuous electrode 1102 and 1104 (for example; The electrophoretic medium of encapsulation), have continuous electrode 1108 and 1110 green shutter mode electro-optical medium layer 1106 and have the electro-optical medium layer 1112. of the red shutter mode of continuous electrode 1114 and 1116 (will it is obvious that to those skilled in the art; Through the voltage source that can produce a plurality of driving voltages is provided, adjacent electrode can be disallowable in 1104/1108 and 1110/1114 each.) in panchromatic optical sensor shown in figure 11; The electro-optical medium film should be stacked with its performance of optimization. for example; If be used for the transparent conductor of this film is that the part visible spectrum is had special absorbability; That color should present higher chroma than all the other in stack layer so. the shutter mode optical sensor, or any other optical sensor (liquid crystal, suspended particle displays, cholesteric crystal, bistable nematic liquid crystal etc.) can use as the monochromatic optical sensor with this equipment.

Use three films that pile up although Figure 11 illustrates, it is prevailing configuration (red/green or yellow/cyan/magenta look), and the present invention is not limited to and uses these three films that pile up; In some cases; Through careful selection Color Range, only use two films that pile up, perhaps possibly produce useful coloured image; Perhaps use more a plurality of films that pile up to improve the colour gamut of final image. likewise; Be used for the equipment of the present invention of color display, light-emitting device will typically be arranged the independent pulse of three various colors of flicker, but can use the color of less or greater number.

The electrophoretic medium that this aspect of the present invention can use the shutter mode electro-optical medium particularly to encapsulate is made full-color display. and the equipment of type shown in Figure 10 makes to have very high color saturation and brightness, because look preface LED-backlit device provides considerable colour gamut performance and light output.The back side equipment of the electrophoresis shutter mode that piles up of type shown in Figure 11 is low-power, potential low-cost design for the equipment that produces light pulse.

Form the method and the device of electro-optic displays

As already mentioned, (carry thin film transistor (TFT) array usually, or during abbreviation TFT ' method development s), run into many problems problem relevant FPL ' s being laminated to the active matrix tool back plane of glass with traditional laminating apparatus.The present invention provides modification required and conventional instrument expectation, so that also can be used for the design level press tool in these modification of glass TFT ' s laminated FPL ' s., it is used to use the FPL escope of plastics or metal forming tool back plane.Modification can suit to be divided into three main fields, i.e. the temperature of lamination control, with respect to the stacking of the FPL of tool back plane with carry out the design of the worktable of lamination, and these three fields are discussed respectively below.

The temperature control of lamination

The polarizer layer press that can be used for the routine of LCD (LCD) manufacturing is applicable to basically FPL ' s is laminated to tool back plane that condition is that this routine machine is modified to comprise the system that is used to heat the part of treating lamination.In the part of lamination is treated in heating, exist preferable methods, yet some are non-easily obvious.

What expect most is to apply heat by this way; The lamination tack temperature is raise to be enough to cause the plastic flow in the lamination tackifier (it typically is a polyurethane). have many standard of measurements that can be used to describe plastic flow, it is well-known to those skilled in the art.For this purpose; Temperature (hereinafter is called intersection point) when the accountable volume that is the bonding coat temperature should be equal to or higher than the lamination tackifier equates with modulus of shearing. can realize this temperature levels through following method simply, with this tool back plane be heated to than the high a lot of temperature of this intersection point and under pressure (through what unheated roller or mandrel applied) condition this FPL. of coating

In improved method; Can also heat this roller or mandrel; Make it possible to achieve the more refined control of bonding coat temperature. in another kind changed, roller, tool back plane and FPL itself can be heated to carry out the more control of height. and in this last variation, the preheating of FPL makes treatment capacity significantly improved; Because before getting into the zone that lamination takes place, this tackifier is softening by in advance.In all embodiments, heat-conducting plate (copper, aluminium etc.) can be used to improve the thermal uniformity of selected heating element.

Stack controlBe used for LCD industry traditional polarizer layer press can with the plastic sheeting utmost point accurately (it is ordinary for the state-of-the-art technology machine that ± 0.2mm-± 0.3mm stacks degree of accuracy) place glass substrate. when considering the heat laminating of FPL ' s; Yet, it is found that stack temperature so height so that FPL often slides during lamination process.Exist four to influence the major parameter that FPL slides:

1. the selection of lamination adhesive material;

2. lamination tackifier thickness;

Stack temperature and

4. in the power that puts on during the lamination on the FPL.

For example; For current preferred polyurethane laminated tackifier in FPL with the thick use of 18 μ m; Be necessary with the glass tool back plane be controlled at temperature less than 85 ℃ to prevent that in lamination process FPL is at obvious slip on glass (suppose in the lamination process normal tension on FPL with use unheated roller). for the thick tackifier of 15 μ m; Temperature is less than 95 ℃, and slip is acceptable (for the normal tension on FPL in this process). therefore, above-mentioned four parameters should Be Controlled in order to avoid the obvious slip of FPL in lamination process. expectation is slided less than 1mm; More make us desirably less than 0.5mm and make us most desirably less than 0.3mm.

Table design

With regard to the FPL lamination instrument, the present invention provides the improvement of two FPL supporting tables.First improvement is the heat control of supporting table. and this temperature control makes and can reach the tackifier on the FPL thus by preheating FPL, to such an extent as to the feasible laminate speed that increases widely. and heating can should not damage FPL certainly so strongly through the heating of conduction, convection current or radiation heating completion .FPL.

Secondly, worktable should be level and smooth, so that the frosting of its not scratch FPL.Worktable can be used teflon, and (it is sold by E.I.du Pont deNemours&Co. for for example " TEFLON ", registered trademark; Wilmington; Delaware, the U.S.) or some similar softnesses, the coating of non-scratch plastic material or formation. perhaps, worktable can be made up of metal; And with non-scratch surface coated or anodization. the porous stone vacuum tables is available, but these worktable can increase the tendency of instrument scratch FPL.

It is following for the further improvement that FPL is laminated to tool back plane that the present invention also provides:

The ability of the reference position of FPL that easy dancer rools contacts is provided. provide easy dancer rools to drop to the ability of the reference position of FPL. (in conventional LCD type equipment; Roller always falls at the edge of film; This is undesirable for the FPL lamination. the simple adjustment to this machine makes the reference position and the length that can change FPL, rather than the reference position of roller; Provide this adjustment to expect .)

Provide heated roller to produce better temperature homogeneity and control, reject possibility in the temperature drift of run duration lamination bonding coat.

The modification of various thin film work platforms comprises the finished form of vacuum hole with optimum matching FPL is set; Heating work platform (it can have side effect to guaranteeing uniform stack temperature, although the pair roller heating is prior); On worktable, flat surface is provided so that the scratch of FPL minimizes.

Make combining display

As already mentioned, the present invention provides several to make the method for combining display.This aspect of the present invention relates to design methodology, and it can make combining display, the display that promptly uses the front and rear surfaces be made up of dissimilar materials to construct. and this aspect of the present invention is applicable to various types of electro-optic displays.

As pointed out that it is extremely complicated making combining display, because almost non-existent problem in traditional display unit is made occurs.The present invention is provided for making the method and apparatus of combining display and comprises following:

1. normal note by CTE and CHE do not match that the panel curvature that produces discharges with applied stress or the reduction method and apparatus with correction curvature;

2. be controlled at the environmental baseline in the manufacture process modestly; And/or

3. produce a kind of zero stress curvature of balance, its matching product casing or the required curvature of structure.

In one embodiment of the invention, crooked reduction method comprises creep mechanism.The heating combining display is to the temperature more than the threshold value. and panel temperature little by little reduces then, in some cases through the long time, to discharge the structural stress that is produced by the differential expansion between this display pannel.

In another embodiment; Crooked reduction method temporarily presents opposite curvature and makes display " bullet " return the curvature that reduces combining display through forcing display. and for example, display can be crushed between weight and the curved surface with its congenital curvature of forced compensation.

In further embodiment; With the 3rd layer of back side that adheres to rear panel with the physical difference between compensation panel lamination and the rear panel; Itself otherwise will cause bigger degree of curvature. in many following physical properties, extra the 3rd layer can be different from rear panel: CTE, CHE, Young modulus and thickness.

In another embodiment, regulate panel lamination and rear panel to different temperatures and make that curvature reduces (if not rejecting) when they are adhered to the formation combining display.At least one can be the coiled material that roller moves in the panel.

According to this aspect of the invention, also improve the risk of other aspects of manufacture process with reduction display curvature, for example, in edge sealing process and structurizing process.

Figure 12 illustrates above-mentioned 2004/0027327 type shown in Figure 20 and electrophoretic display cell (the specifying 1210 usually) manufacturing of use FPL technology. and display unit 1210 can be flexible; Promptly; But bendable or roller and do not have a permanent strain. in this structure, the frontal plane 1212 of display 1210 be plasticity and tool back plane 1214 form by glass and have a tft array.Possibly on frontal plane 1212, there is further protective seam 1215.This protective seam 1215 can be the spacer that anti-ultraviolet protective seam or antioxygen gas or moisture get into display 1210.Perhaps, protective seam 1215 can provide extra resistance to impact maybe can improve some optical effect, for example, has ARC.

Electrophoretic layer 1216 is between frontal plane 1212 and tool back plane 1214.Electrophoresis layer 1216 can comprise one or more capsules 1218 (for clear, dispensing electrophoresis particle from Figure 12) in bonding agent 1220.Conductive layer 1222 is used as the public preceding electrode of display 1210, and is placed between frontal plane 1212 and the electrophoresis layer 1216.In one embodiment, conductive layer 1222 comprises thin printing opacity conductive material, for example, and ITO, aluminium oxide, or conducting polymer.Schematically display circuit board 1224, and it is connected with tool back plane 1214, are used for address electrophoretic layer 1216 and conductive layer 1222.

Adhesive layer 1226 can be placed between electrophoresis layer 1216 and the tool back plane 1214.Possibly in display 1210, exist further layer and part to be used for various functions; For example; Barrier film (further preventing external contamination thing such as moisture), contact mat (being used for detecting address electrophoretic layer 1216), helping adhesive layer etc. those embodiments of part are described in greater detail in above-mentioned 2004/0027327 and 2004/0155857. and sealing 1230 can center on the limit of one or more displays 1210. in one embodiment; As described, between frontal plane 1212 and adhesive layer 1226 and layer that comprise frontal plane 1212 and adhesive layer 1226 is at first made it as FPL1232 and is laminated to tool back plane 1214 subsequently.Protective seam 1215 can be thought part FPL, if before FPL is laminated to tool back plane 1214 its be attached to frontal plane 1212. in explanation for the sake of simplicity, the FPL1232 shown in the accompanying drawings comprises protective seam 1215.When accomplishing the manufacturing of FPL1232, discharge the adhesive layer 1226 that the lamella (not shown) is attached to relative electrophoresis layer 1216 temporarily.Before FPL1232 is laminated to tool back plane 1214, remove the release lamella.

The instance that can be used for making the material of frontal plane 1212 and/or protective seam 15 comprises that heat-staple gathering (ethylene glycol terephthalate), (for example, Melinex level 504 was from Dupont TeijinFilms; Wilmington, Delaware, the U.S.) and high-performance silicic acid boron glass (1737; From Corning Incorporated, Corning, New York; The U.S.). in other embodiments; The PET film can be replaced by PEN (PEN), polyethersulfone (PES), or under the condition that does not exceed scope of the present invention, transparent or diaphanous film can be configured on other optics.

Under the condition that does not exceed the scope of the invention, being similar to other display cell structures shown in Figure 1 can be configured.Other embodiments comprise the electrophoresis of encapsulation and similar electro-optic displays unit, its use:

1. metal forming tool back plane, its surface comprises one or more active or passive electronic circuits or device,

2. plastic sheeting tool back plane, its surface comprises one or more active or passive electronic circuits or device,

3.FPL it is included in lip-deep rigidity or flexible color filtering array between the viewer of electrophoretic medium and display, or

4. plastics or glass substrate have active or passive electronic circuit or device and color filtering array (in either case, the frontal plane lamination becomes the tool back plane lamination effectively).

The technician of electronic console design and integration field can easily discern other display device structures, and principle wherein of the present invention can be employed under the condition that does not exceed the scope of the invention.

In display unit shown in Figure 12; Between the material that constitutes display 1210 each layers; Especially between FPL1232 and tool back plane 1214; Mechanical property has significant difference. for example, the thermally stable P ET material that can be used for making FPL1232 typically have the about 18ppm/ of CTE ℃ with the about 7ppm/% relative humidity of CHE (relative humidity), and the glass that constitutes tool back plane 1214 has the about 3.76ppm/ of CTE ℃ and the about 0ppm/% relative humidity of CHH.Because the difference of these performances, display unit 1210 manifests the mechanical property of irregular. for example, and when running into heat or moisture; Display pannel 1210 is with downwarping (in the side view of Figure 12, becoming " shape of frowning "), when cooling or drying; Display pannel 1210 will be bent upwards (in Figure 12; Become " smile shape "). this performance is undesirable significantly in final products. and also common lamination process needs high temperature FPL1232 is connected to glass/TFT tool back plane 1214. therefore, no special measure; During combining display was made, panel bending almost must take place.

In order to reject or to reduce bending/warping phenomenon, provide several methods and relevant device with during manufacture and/or after manufacturing, reject or minimize panel bending. in order to put into practice the present invention, can the content of each method or these methods be combined.

Refer again to Figure 12; In first method; Partly or entirely display pannel 10 experience thermal cycles be reduced in be used in the panel manufacturing laminating operation at high temperature with CTE and the CHE relevant stress that do not match. in one embodiment; Partly or entirely display pannel is heated in baking oven or well heater and (for example reaches very first time section through threshold temperature (for example 50 ℃ or 60 ℃); 6-10 hour); Thereafter in second time period and perhaps longer time period, the even change of temperature descends. and cooling/annealing process makes polymer adhesive 1216 and lamination tackifier discharge inherent strain through creep mechanism, and said polymer adhesive 1216 is bonded together the electrophoresis material 1218 of encapsulation; Said lamination tackifier (for example adheres to basalis with the electrophoresis material 1218 of encapsulation; Conductive layer 1222). importantly thermophilic produce down in good time display unit 1210 with mitigation system fully to the state of expectation. in one embodiment, temperature little by little reduces (for example, 1-2 degree/hour) to environment temperature in second time period. detemperature rate needs not to be constant and can change.

Figure 13 A illustrates second method that reduces warpage, " resilience " mechanism, and it can be coupled with aforesaid creep mechanism.The sweep of display 1210 is placed on the curve with curvature temporarily and corrects the surface, and the curvature of said curvature and display 1210 is opposite.The curvature on this rectification surface can be level and smooth. and in one embodiment, correct surperficial outstanding 1340. display units 1210 that constitute simply on the flat surface and be fixed, for example to correcting surface 1340; Through the weight on opposite side 1342, perhaps under hot conditions, for example; 60 ℃. shown in Figure 13 B, display unit 1210 is forced and presents the curvature that is limited outstanding 1340. after the suitable time (its can from several minutes to a couple of days), the amount of removing thing 1342; Or display pannel 1210 is discharged in addition. display pannel 1210 resilience then; In some cases, little by little to the shape of expectation promptly, plane or have the curvature of regulation. resilience technology is also temperature controlled; For example, temperature little by little is reduced to environment temperature from previous high temperature.

Figure 14 illustrates the further method of the warpage that is used for preventing combining display as shown in Figure 12. in this method; One or more layers 1446 of one or more and tool back plane 1214 material different are connected to the back sides of tool back plane 1214; And with remaining display 1210 that comprises FPL1232 by lamination as final products. select to have the material in the extra play 1446 of specific CTE, CHE, Young modulus or thickness; Make in lamination and subsequent process; Display 1210 manifests not to be had or few warpage. because extra play 1446; Display 10 mainly manifests axial expansion and contraction and does not have very big warpage; Because it mechanically is a symmetrical structure. extra play 1446 remedies the difference of CTE, CHE, Young modulus or thickness between FPL1232 and tool back plane 1214, itself otherwise will cause warpage. in one embodiment, extra play 1446 is made up of the material such as heat-staple PET, PEN or the PES that are used to make FPL1232.

Figure 15 illustrates the further method that is used to control warpage; Its through before lamination process, in and/or the back regulate (i.e. heating or cooling) FPL1232 tool back plane 1214 to different temperatures and carry out. in Figure 15; Fold on the fold (flex-on-flex) structure or volume to volume lamination process are shown the embodiment as this method. peel off the coiled material that its coiled material that discharges the FPL1232 of lamella 1233 is laminated to the tool back plane 1214 that is formed on the flexible substrates. and the coiled material of tool back plane 1214 can use the transistor that is formed by polymer semiconductor; Of some above-mentioned E Ink and MIT patent and disclosed application. this volume to volume lamination can make two coiled materials carry out through the jaw between the pair roller 1548 and 1550 that maintains different temperatures. by rapidly through roller 1548 and 1550; FPL1232 is heated or cooled respectively to different medial temperatures with tool back plane 1214; Before lamination and/or in cause the differential expansion of FPL1232 and tool back plane 1214. behind the volume to volume lamination process, " display " coiled material of this combination is cut and produces independent display unit 1210. and with controlled way the total bending change of differential expansion with the final display unit 1210 of realizing expectation is set.

Can also use other lamination process. for example; In the process of " sheet is to sheet "; Wherein independent FPL section is laminated to independent tool back plane; Each FPL sheet can be preheated or be cooled to the temperature that is different from tool back plane. and other suitable lamination process comprise " coiled material is to sheet " process, and the continuous coiled material of wherein peelling off the FPL of any release lamella is laminated to the tool back plane of arranging in a plurality of anchor clamps.

Because heating causes the panel warpage potentially; Other steps in display production (comprising heating) can also be improved by the present invention. because the electrophoretic medium of encapsulation typically uses moisture coating technique manufacturing; Yet this material is suction inherently to a certain extent.; When water was absorbed in the system, the electrical properties of this material can change unfriendly. and in very wide range of environmental conditions, guaranteeing the operation of appropriate homogeneous, must seal display and get into to prevent moisture; For example, through above-mentioned 2004/0027327 disclosed banding and preceding barrier film technology.In some encapsulating methods, use heating and can help the panel warpage.

In a specific illustrational banding form of Figure 16 institute; Sealant 1652 is inhaled into thin chamber or the breach around display unit 1210 peripheries. and this chamber end face 1654 is formed by the outshot of the preceding protectiveness thin plate 1215 on the FPL1232 support; Bottom surface, chamber 1656 is formed by the front surface of tool back plane 1214. and in a form of display, display pannel 1210 uses by UV radiation and/or the liquid adhesive sealing that is heating and curing.The fluid sealant 1652 that comprises tackifier utilizes surface tension effects can be inhaled into this chamber, but because the viscosity of tackifier slows down these these effects. and for high productivity, the expectation optimization sucks speed.For this reason, but the following aspect Be Controlled of encapsulating method or improve:

1. increase panel temperature and reduce tackifier viscosity;

2. the temperature that increases the coating apparatus for sealant head reduces tackifier viscosity;

3. will be enough big adhesive bead deposits with this chamber of complete filling and the chamfering that exactly outside the chamber, stays tackifier;

4. optimization chamber height (it typically is 100 μ m-300 μ m);

5. the assurance tackifier is retouched the material in whole formation chamber basically;

6. around panel periphery, especially around the corner, make the chamber of homogeneous width;

7. utilize mixing system with XY (in the plane of panel) transmission control and Z (height that is higher than panel) correction;

8. utilize mixing system have xy θ (the θ dimension has increased rotatory power, for example allocate pin near end with right-angle bending) mixing system of transmission control and Z correction; And/or 9. utilize and can follow the tracks of the mixing system of limit characteristic through machine vision and appropriate software algorithm.

This banding can be formed by the correct combination of kapillary suction process and chamber design, material selection and process control system.For example; Has nominal size and is the tackifier that to use UV-curable in the high thin chamber of the wide x0.22mm of 1.5mm (Nagase Chemtex CorporationXNR-5516 type for example, Nagase Co., Ltd.; Tokyo; Japan) fill. when panel is maintained at high temperature (for example, 40 ℃-70 ℃), can realize sucking fast to reduce the viscosity of tackifier.The preferred temperature of control panel between the ultraviolet ray light period also. for example, when with UV consumption 40mW/cm ²Solidify 300-400 during second panel can be controlled in 40 ℃.

One of most critical aspect of encapsulating method comprises that the heating panel reduces tackifier viscosity (it can cause that stress develops and causes warpage in display material) as stated.For minimizing or reducing this warping effect; According to a method of the present invention; If heating is limited to the periphery of the panel 1210 that sealant 1652 applied. this heating can be undertaken by radiation, conduction or convection device. must apply the body heating; Can use in other crooked mitigation method of the present invention so, preferably before adhesive solidification.

In some embodiments, display pannel 1210 will be fixed in other structures in casing or the final products to guarantee that it appears flat or the homogeneous curved surface to the observer.Be formed and after making panel and casing or structure consistent at banding; The bending of display pannel 1210 is undesirable; Because it is added to extra-stress on lamination and the banding. according to another aspect of the present invention; Make display pannel to have " zero stress " balance curvature, the desired curvature that it matees or mate the final structure product basically in common working temperature and relative humidity scope.In one embodiment, should " zero stress " balance curvature be set at or near the mid point of this operating environment scope.

For example; The typical operating conditions of most of electro-optic displays is about 0 ℃-40 ℃ and 10%-90% relative humidity; But, operate in the wideer temperature and humidity scope and carry out in some cases. in addition, detect electro-optic displays and generally include thermal shock test; It makes display stand to be exposed to the circulation of extremely low and excessive temperature (for example ,-30 ℃-+80 ℃).For this wide temperature range, expectation makes panel with the minimise stress that receives through (the for example about 20-25 of temperature ℃ and 40-60% relative humidity) near the mid point that is arranged on the balance curvature of panel environmental field.

The method that a kind of manufacturing has the display pannel of unstressed curvature is the front and back panel material of selecting to have coupling mechanical property such as CTE and CHE.This design methodology can be used to except that the display device structure of the above-mentioned plastics of discussing structure on glass; For example, metal or plastic sheeting tool back plane, color filtering array (CFA) are in the structure on the frontal plane, CFA structure on tool back plane or the like. for example, and for the stainless steel foil tool back plane; CTE is about 17ppm/ ℃; CHE is about 0ppm/% relative humidity. in this case, compare in situation on glass with plastics, bending reduces significantly; But possible is to use aforesaid non-zero or the crooked reduction technology of part. for the back plastic flat-panel screens; If identical FPL and tool back plane material are used in expectation. these impossible words, and CTE or the CHE generation that do not match, can use aforesaid identical bending reduction technological.

In the display that combines color filtering array (CFA), the challenge described in this paper has combined the requirement of the addressed elements calibration on CFA subpixel and the tool back plane with degree of accuracy.For the glass CFA on metal or plastic sheeting tool back plane, CTE/CHE does not match causing and the opposite performance described in the foregoing description; Heating or humidification cause " smile shape ", cooling or drying cause " shape of frowning " although. the performance that this is opposite, identical aforesaid crooked relax or reduction process can be used with reduce or eliminating system in bending.Yet; In this structure; If the preferred banding that uses is so that to relax the FPL. banding that pins in the state after calibration the Cheng Qian too submissive carrying out bending, the differential expansion of preceding and tool back plane and contraction are with in the display relevant with temperature, causing undesirable gamut.

In preferred embodiments, make fold CFA structure, wherein flexible CFA is connected to the metal forming base plate with the CTE that closely matches with flexible CFA.For example; Flexible CFA can be configured in heat-staple PET, and (CTE is about 18ppm/ ℃; CHE is about 7ppm/% relative humidity) on; And tool back plane can be configured on the stainless steel foil (CTE is about 17ppm/ ℃, and CHE is about 0ppm/% relative humidity). and barrier film and moisture were isolated before preceding PET film can use. and the film option comprises SiO ₂, SO _x, SiO, ITO or other transparent pottery barrier films, or the material of polymkeric substance such as AclarTM (Honeywell International Corporation, Morristown, New Jersey, the U.S.).Because the CHB effect uses this spacer to make the expansion of PET and contraction minimize.With regard to this type assembling thing; Can under controlled environmental baseline, go up accurately calibration (the degree of accuracy scope is at several microns) flexible active matrix tool back plane by the sizable thin plate (a lot of tens of centimetres) high resolving power fold CFA (the subpixel spacing is hundreds of pixel/inch). certainly, reduce the embodiment of resolution and can easily construct by those skilled in the art.

In another embodiment, the multicolour pattern of CFA directly is configured under the TFT on the single glass substrate or directly on it, and watches display through TFT and color filter.Advantageously, this structure is without any need for aligning.

Yet; In preferred embodiments, use aforesaid and, electrooptic layer is connected in TFT/CFA. according to this method at " the dual release film " described in above-mentioned 2004/0155857; Electrooptic layer or film are applied to releasable material, transfer to TFT/CFA from this releasable material then.Dual method for releasing uses adhesive film that the front surface of electrooptic layer is connected to TFT/CFA, and the second layer that uses the lamination tackifier is connected to tool back plane with the structure of this gained.Dual method for releasing provides two basic advantages; Be that the electrooptic layer front surface provides than lamination adhesive faec wherein observer's the better optical characteristics of another kind of method; And because approaching most only to have thin tackifier on the side of TFT, owing to the crossview that has reduced between pixel has improved exploration on display resolution ratio.

Except above particularly point out; Used for the present invention; Prior art is identical like the method for optimizing homophase of the preferred material of manufacturing electrophoresis and other electro-optical mediums and this medium of formation; For thoroughly discussing of employed this preferred material of the electrophoretic medium of manufacturing and encapsulation and method, the reader can be with reference to patent and the application of above-mentioned E Ink and MIT.

Claims (1)

1. method that is used to form the used subassembly of electro-optic displays, this method is characterized as:

Electro-optical medium (502) layer is deposited on first to be discharged on the lamella (500);

Lamination tackifier (504) layer is deposited on second discharges lamella (506); With

Thereafter; Causing that effectively lamination tackifier (504) adheres under the condition of electro-optical medium (502); The lamination tackifier (504) that electro-optical medium (502) and second on the first release lamella (500) is discharged on the lamella (506) contacts; Thereby the formation subassembly, it comprises lamination tackifier (504) and the electro-optical mediums (502) that are clipped between two release lamellas (500,506).

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