Electro-optic display stack with segmented electrodes and method for making it

Abstract

A method of manufacturing a segmented electro-optic display includes providing an electro-optic display stack including a first substrate layer, a first layer of light-transmissive conductive material, a layer of electro-optic material, a lamination adhesive, a second layer of light-transmissive conductive material, and a second substrate layer. The method also includes forming electrically isolated conductive segments on the second layer of conductive material using a laser etching process including irradiating the second substrate and the second conductive layer at a plurality of locations with a laser emitting light within a first wavelength range. The second substrate layer is transparent to light within the first wavelength range and the light-transmissive conductive material is substantially absorptive to light within the first wavelength range. At each of the plurality of locations, the second substrate layer is substantially transparent to light emitted from the laser and the light-transmissive conductive material substantially absorbs the light and is removed.

Description

Technical Field

[0001] (Cross - Reference to Related Applications) This application claims the benefit of priority of U.S. Provisional Patent Application No. 63 / 335,507, filed Apr. 27, 2022, the entire content of which is incorporated herein by reference. Further, the entire content of any patent, published application, or other published writing referenced herein is incorporated herein by reference in its entirety.

[0002] The present invention relates to an electro - optical display stack having segmented electrodes and a finished electro - optical display formed therefrom. The present invention also provides a process for the production of such electro - optical display stacks. The present invention is particularly, but not exclusively, intended for use with displays comprising an encapsulated electrophoretic medium. However, the present invention can also utilize various other types of electro - optical media, which are "solid" in the sense that they have a solid outer surface, but the media can have internal cavities and often do, and the internal cavities contain a fluid (either a liquid or a gas). Such "solid electro - optical displays" include encapsulated electrophoretic displays, encapsulated liquid crystal displays, and other types of displays discussed below.

Background Art

[0003] An electro - optical display comprises a layer of electro - optical material, and the term is used herein to refer to a material having first and second display states with at least one optical property being different in its conventional meaning in the field of imaging technology, and the material is changed from its first display state to its second display state by the application of an electric field to the material. The optical property is typically a color perceptible to the human eye, but it can be another optical property such as a pseudo - color in the sense of a change in reflection of electromagnetic wavelengths outside the visible range for displays intended for machine reading, optical transmittance, reflectance, luminescence, etc.

[0004] The terms “bistable” and “bistable” are used herein to refer to a display having a display element having a first and second display state having at least one different optical property in its conventional sense in the art, thereby, after any given element is driven with a finite-duration address pulse to show either the first or second display state, and after the address pulse has terminated, the state will persist for at least several times, e.g., at least four times, the minimum duration of the address pulse required to change the state of the display element. U.S. Patent Application Publication 2002 / 0180687 (Patent Document 1) shows that several grayscale-compatible particle-based electrophoretic displays are stable not only in their extreme black and white state but also in their intermediate gray state, and that the same is true for several other types of electro-optic displays. This type of display is appropriately called “multistable” rather than “bistable,” but for convenience, the term “bistable” may be used herein to refer to both bistable and multistable displays.

[0005] Several types of electro-optical displays are known. One type of electro-optical display is the rotating dicolor member type, as described, for example, in U.S. Patents 5,808,783 (Patent Document 2), 5,777,782, 5,760,761, 6,054,0716,055,091, 6,097,531, 6,128,124, 6,137,467, and 6,147,791 (this type of display is often referred to as a “rotating dicolor ball” display, but in some of the patents mentioned above, the rotating member is not spherical, so the term “rotating dicolor member” is preferred as it is more accurate). Such displays use a number of small bodies (typically spherical or cylindrical), each body having two or more divisions with different optical properties and an internal dipole. These bodies are suspended within vacuoles filled with liquid in a matrix, and the vacuoles are filled with liquid so that the bodies can rotate freely. The appearance of the display is changed by applying an electric field to it, and thus rotating the bodies to various positions, thereby changing the position of the body segments seen through the viewing surface. This type of electro-optical medium is typically bistable.

[0006] Another type of electro-optical display uses an electrochromic medium, for example, an electrochromic medium in the form of a nanochromic film, which consists of electrodes formed at least partially from a semiconductor metal oxide and a plurality of color-reversible dye molecules attached to the electrodes (see, for example, O'Regan, B., et al., Nature 1991, 353, 737 and Wood, D, Information Display, 18(3), 24 (March 2002). See also Bach, U., et al., Adv. Mater., 2002, 14(11), 845. This type of nanochromic film is also described, for example, in U.S. Patents 6,301,038, 6,870,657, and 6,950,220. This type of medium is also typically bistable.

[0007] Another type of electro-optical display that has been the subject of vigorous research and development for many years is the particle-based electrophoretic display, in which multiple charged particles move through a suspension fluid under the influence of an electric field. Compared to liquid crystal displays, electrophoretic displays can have attributes such as good brightness and contrast, wide viewing angles, state bistability, and low power consumption. Nevertheless, problems associated with the long-term image quality of these displays have hindered their widespread use. For example, the particles that make up electrophoretic displays tend to settle, resulting in a poor usable lifespan for these displays.

[0008] As specifically mentioned above, electrophoretic media require the presence of a fluid. In most conventional electrophoretic media, this fluid is a liquid, but electrophoretic media can also be produced using a gaseous fluid. See, for example, Kitamura, T., et al., “Electrical toner movement for electronic paper-like display”, IDW Japan, 2001, Paper HCS1-1 and Yamaguchi, Y, . et a, l., “Toner display using insulative particles charged triboelectrically”, IDW Japan, 2001, Paper AMD4-4). See also U.S. Patent Application Publication No. 2005 / 0001810, European Patent Applications Nos. 1,462,847, 1,482,354, 1,484,635, 1,500,971, 1,501,194, 1,536,271, 1,542,067, 1,577,702, 1,577,703, and 1,598,694, and International Applications WO2004 / 090626, WO2004 / 079442, and WO2004 / 001498. Such gas-based electrophoretic media are susceptible to the same types of particle sedimentation problems as liquid-based electrophoretic media, for example, when used in a sign where the medium is positioned in a vertical plane and the medium is oriented in a way that allows such sedimentation. In fact, particle sedimentation is considered a more serious problem in gas-based electrophoretic media than in liquid-based electrophoretic media because the lower viscosity of gaseous suspension fluids compared to the viscosity of liquids allows for faster sedimentation of electrophoretic particles.

[0009] Numerous patents and applications, assigned to or filed in the names of the Massachusetts Institute of Technology (MIT) and E Ink Corporation, describing encapsulated electrophoretic media, have recently been published. Such encapsulated media comprise a number of small capsules, each of which comprises an inner phase containing electrophoretically mobile particles suspended in a liquid suspension medium, and a capsule wall surrounding the inner phase. Typically, the capsules form a coherent layer positioned between two electrodes by being held within a polymer binder. Examples of this type of encapsulation medium include U.S. Patent Nos. 5,930,026, 5,961,804, 6,017,584, 6,067,185, 6,118,426, 6,120,588, 6,120,839, 6,124,851, 6,130,773, 6,130,774, 6,172,798, 6,177,921, and 6,232,950. No. 6,249,271, No. 6,252,564, No. 6,262,706, No. 6,262,833, No. 6,300,932, No. 6,312,304, No. 6,312,971, No. 6,323 ,989, No. 6,327,072, No. 6,376,828, No. 6,377,387, No. 6,392,785, No. 6,392,786, No. 6,413,790, No. 6,422,687, No. 6,445,374, No. 6,445,489, No. 6,459,418, No. 6,473,072, No. 6,480,182, No. 6,498,114, No. 6,504,524, No. 6,506 ,438, No. 6,512,354, No. 6,515,649, No. 6,518,949, No. 6,521,489, No. 6,531,997, No. 6,535,197, No. 6,538,801, No. 6,545,291, No. 6,580,545, No. 6,639,578, No. 6,652,075, No. 6,657,772, No. 6,664,944, No. 6,680,725, No. 6,683 ,333, No. 6,704,133, No. 6,710,540, No. 6,721,083, No. 6,724,519, No. 6,727,881, No. 6,738,050, No. 6,750,473,No. 6,753,999, No. 6,816,147, No. 6,819,471, No. 6,822,782, No. 6,825,068, No. No. 6,825,829, No. 6,825,970, No. 6,831,769, No. 6,839,158, No. 6,842,167, No. 6, No. 842,279, No. 6,842,657, No. 6,864,875, No. 6,865,010, No. 6,866,760, No. 6,87 No. 0,661, No. 6,900,851, No. 6,922,276, No. 6,950,200, No. 6,958,848, No. 6,967, No. 640, No. 6,982,178, No. 6,987,603, No. 6,995,550, No. 7,002,728, No. 7,012,6 No. 00, No. 7,012,735, No. 7,023,430, No. 7,030,412, No. 7,030,854, No. 7,034,783 No. 7,038,655, No. 7,061,663, No. 7,071,913, No. 7,075,502, No. 7,075,703, No. 7,079,305, No. 7,106,296, No. 7,109,968, No. 7,110,163, No. 7,110,164, No. 7 ,116,318, 7,116,466, 7,119,759, and 7,119,772, and U.S. Patent Application Publications 2002 / 0060321, 2002 / 0090980, 2002 / 0180687, 2003 / 0011560, 2003 / 0102858, 2003 / 0151702, 2003 / 0222315, 2004 / 0014265, 2004 / 0075634, 2004 / 0094422, 2004 / 0105036, 2004 / 0112750, 2004 / 0 No. 119681, No. 2004 / 0136048, No. 2004 / 0155857, No. 2004 / 0180476, No. 2004 / 019 No. 0114, No. 2004 / 0196215, No. 2004 / 0226820, No. 2004 / 0239614, No. 2004 / 02576 No. 35, No. 2004 / 0263947, No. 2005 / 0000813, No. 2005 / 0007336, No. 2005 / 0012980 No. 2005 / 0017944, No. 2005 / 0018273, No. 2005 / 0024353, No. 2005 / 0062714,No. 2005 / 0067656, No. 2005 / 0078099, No. 2005 / 0099672, No. 2005 / 0122284, No. 2005 / 0122306, No. 2005 / 0122 No. 563, No. 2005 / 0122565, No. 2005 / 0134554, No. 2005 / 0146774, No. 2005 / 0151709, No. 2005 / 0152018, No. 2005 / No. 0152022, No. 2005 / 0156340, No. 2005 / 0168799, No. 2005 / 0179642, No. 2005 / 0190137, No. 2005 / 0212747, No. 2005 / 0213191, 2005 / 0219184, 2005 / 0253777, 2005 / 0270261, 2005 / 0280626, 2006 / 000752 No. 7, No. 2006 / 0024437, No. 2006 / 0038772, No. 2006 / 0139308, No. 2006 / 0139310, No. 2006 / 0139311, No. 2006 / 0 No. 176267, No. 2006 / 0181492, No. 2006 / 0181504, No. 2006 / 0194619, No. 2006 / 0197736, No. 2006 / 0197737, No. 20 This is described in patent applications 06 / 0197738, 2006 / 0198014, 2006 / 0202949, and 2006 / 0209388, and in international publications WO00 / 38000, WO00 / 36560, WO00 / 67110, and WO01 / 07961, and in European patents 1,099,207B1 and 1,145,072B1.

[0010] Many of the aforementioned patents and applications recognize that the walls surrounding individual microcapsules in an encapsulated electrophoretic medium may be replaced by a continuous phase, thus producing a so-called “polymer-dispersed electrophoretic display,” in which the electrophoretic medium comprises multiple individual droplets of electrophoretic fluid and a continuous phase of polymer material, and that individual droplets of electrophoretic fluid within such a polymer-dispersed electrophoretic display may be considered capsules or microcapsules even if individual capsule membranes are not associated with each individual droplet. See, for example, U.S. Patent No. 6,866,760. For the purposes of this application, such polymer-dispersed electrophoretic media are considered a variant of encapsulated electrophoretic media.

[0011] A related type of electrophoretic display is the so-called "microcell electrophoretic display." In a microcell electrophoretic display, charged particles and suspension fluids are not encapsulated within microcapsules, but instead are held within multiple cavities formed within a carrier medium (typically a polymer film). See, for example, International Patent Application Publication WO02 / 01281 and Published U.S. Patent Application 2002 / 0075556 (both assigned to SiPix Imaging, Inc.).

[0012] Another type of electro-optical display is the electrowetting display, developed by Philips and described in Hayes, RA., et al., “Video-Speed ​​Electronic Paper Based on Electrowetting”, Nature, 425, 383-385 (2003). U.S. Patent No. 7,420,549 shows that such an electrowetting display can be made bistable.

[0013] Other types of electro-optical materials may also be used in the present invention. Of particular note is the fact that bistable ferroelectric liquid crystal displays (FLCs) are known in the art.

[0014] Electrophoretic media are often impermeable (for example, in many electrophoretic media, the particles substantially block the transmission of visible light through the display) and can operate in reflective mode, but many electrophoretic displays can be designed to operate in a so-called "shielding mode" where one display state is substantially impermeable and the other is light-transmitting. See, for example, U.S. Patents 6,130,774 and 6,172,798, as well as U.S. Patents 5,872,552, 6,144,361, 6,271,823, 6,225,971, and 6,184,856. Dielectrophoretic displays (similar to electrophoretic displays but relying on variations in electric field strength) can operate in a similar mode. See U.S. Patent 4,418,346.

[0015] Encapsulated or microcell electrophoretic displays typically do not suffer from the clustering and sedimentation failure modes of conventional electrophoretic devices and offer further advantages such as the ability to print or coat displays on a wide variety of flexible and rigid substrates. (The use of the term "printing" is intended to include, but is not limited to, all forms of printing and coating, including pre-metering coatings such as patch die coating, slot or extrusion coating, slide or cascade coating, curtain coating; roll coatings such as knife over-roll coating, forward and reverse roll coating; gravure coating; immersion coating; spray coating; meniscus coating; spin coating; brush coating; air knife coating; silkscreen printing processes; electrostatic printing processes; thermal printing processes; inkjet printing processes; electrophoretic deposition; and other similar techniques.) Thus, the resulting displays can be flexible. Furthermore, since the display medium can be printed (using various methods), the displays themselves can be manufactured inexpensively.

[0016] An electro-optical display typically comprises a layer of electro-optical material and at least two other layers positioned opposite the electro-optical material, one of which is an electrode layer. In most such displays, both layers are electrode layers, and one or both of the electrode layers are patterned to define pixels on the display. For example, one electrode layer may be patterned into elongated row electrodes, and the other into elongated column electrodes extending perpendicular to the row electrodes, with pixels defined by the intersections of the row and column electrodes. Alternatively, and more commonly, one electrode layer may have the form of a single continuous electrode, and the other electrode layer may be patterned into a matrix of pixel electrodes, each of which defines one pixel on the display. In another type of electro-optical display intended for use with a separate stylus, print head, or similar movable electrode, only one of the layers adjacent to the electro-optical layer contains the electrode, and the layer opposite the electro-optical layer is typically a protective layer intended to prevent the movable electrode from damaging the electro-optical layer.

[0017] The manufacture of a three-layer electrophoretic display typically involves at least one lamination operation. For example, some of the aforementioned MIT and E INK patents and applications describe a process for manufacturing an encapsulated electrophoretic display in which an encapsulated electrophoretic medium having capsules in a binder is coated onto a flexible substrate having an indium tin oxide (ITO) or similar conductive coating (acting as one electrode in the final display) on a plastic film, and the capsule / binder coating is dried to form a coherent layer of electrophoretic medium firmly bonded to the substrate. Separately, a backplane is prepared, including an array of pixel electrodes and a suitable arrangement of conductors for connecting the pixel electrodes to a driving network. To form the final display, the substrate having the capsule / binder layer on top is laminated onto the backplane using a lamination adhesive (a very similar process can be used to prepare an electrophoretic display that is usable with a stylus or similar movable electrode by replacing the backplane with a simple protective layer such as a plastic film (on which a stylus or other movable electrode can slide)). In one form of such a process, the backplane is flexible itself and is prepared by printing pixel electrodes and conductors onto a plastic film or other flexible substrate. A readily understandable lamination technique for mass production of displays by this process is roll lamination using lamination adhesive. Similar manufacturing techniques can be used with other types of electro-optical displays. For example, microcell electrophoretic media or rotating bicolor component media can be laminated onto the backplane in substantially the same manner as encapsulated electrophoretic media.

[0018] As discussed in the aforementioned U.S. Patent No. 6,982,178, many of the components used in solid-state electro-optic displays and the methods used to manufacture such displays are derived from the techniques used in liquid crystal displays (LCDs) (which are also electro-optic displays), but use a liquid medium instead of a solid one. For example, a solid-state electro-optic display may utilize an active matrix backplane on a transparent substrate, comprising an array of transistors or diodes and a corresponding array of pixel electrodes, and a "continuous" front electrode (in the sense of multiple pixels, typically electrodes extending across the entire display), and these components are essentially the same as those in an LCD. However, the methods used to assemble an LCD cannot be used with a solid-state electro-optic display. LCDs are typically assembled by forming the backplane and front electrode on separate glass substrates, then bonding these components together with a gap between them, placing the resulting assembly under vacuum, and immersing the assembly in a liquid crystal bath so that the liquid crystal flows through the gap between the backplane and the front electrode. Finally, with the LCD in place, the gaps are sealed, providing the final display.

[0019] This LCD assembly process cannot be easily adapted to solid-state electro-optic displays. Because the electro-optic material is solid, it must be present between the backplane and the front electrode before these two complete units are fixed to each other. Furthermore, in contrast to the liquid crystal material, which is simply placed between the front electrode and the backplane without being attached to either, the solid-state electro-optic medium usually needs to be fixed to both, and in most cases the solid-state electro-optic medium is generally formed on the front electrode (as this is easier than forming the medium on the circuit-containing backplane), and the front electrode / electro-optic medium combination is then typically laminated onto the backplane by covering the entire surface of the electro-optic medium with adhesive and laminating it under heat, pressure, and possibly vacuum.

[0020] Electro-optical displays are often expensive; for example, the cost of a color LCD found in a portable computer typically accounts for a significant portion of the computer's overall cost. As the use of electro-optical displays expands to devices such as mobile phones and personal digital assistants (PDAs), which are far less expensive than portable computers, there is considerable pressure to reduce the cost of such displays. The ability to form layers of a solid electro-optical medium on a flexible substrate by printing techniques opens up the possibility of reducing the cost of electro-optical components of displays by using mass production techniques such as roll-to-roll coating, which utilize commercial equipment used for the production of coated paper, polymer films, and similar media, as discussed above. However, such equipment is expensive, and the area of ​​electro-optical media currently on the market may be insufficient to justify the use of dedicated equipment, thereby typically requiring the transfer of coated media from commercial coating plants to plants used for the final assembly of electro-optical displays without damaging the relatively fragile layers of the electro-optical medium.

[0021] Furthermore, most conventional methods for the final lamination of electrophoretic displays are essentially batch methods, where the electro-optical medium, lamination adhesive, and backplane are only joined together immediately before final assembly. It is desirable to provide a method more suitable for mass production.

[0022] U.S. Patent No. 6,982,178, mentioned above, describes a method for assembling a solid-state electro-optic display (including a particle-based electrophoretic display) that is well suitable for mass production. This patent describes a so-called “front-plane lamination” (“FPL”), which comprises, in order, a light-transmitting conductive layer, a layer of solid-state electro-optic medium in electrical contact with the conductive layer, an adhesive layer, and a release sheet. Typically, the light-transmitting conductive layer may be supported on a light-transmitting substrate, which is preferably flexible in the sense that the substrate can be manually wound around a drum of, for example, 10 inches (254 mm) in diameter without permanent deformation. The term “light-transmitting” is used in this patent and herein to mean that the thus designated layer transmits enough light to allow an observer looking through the layer to observe changes in the display state of the electro-optic medium, which would typically be visible through the conductive layer and adjacent substrates (if any). The substrate is typically a polymer film and will usually have a thickness in the range of about 1 to about 25 mils (25 to 634 μm), preferably about 2 to about 10 mils (51 to 254 μm). The conductive layer may conveniently be, for example, a thin metallic layer of aluminum or ITO, or a conductive polymer. Poly(ethylene terephthalate) (PET) films coated with aluminum or ITO are commercially available, for example, as "Aluminum-Coated Mylar" ("Mylar" is a registered trademark) from EIdu Pont de Nemours & Company (Wilmington DE), and such commercial materials may be used with good results in front-plane lamination.

[0023] U.S. Patent No. 6,982,178, mentioned above, also describes a method for testing the electro-optic medium within a front-plane lamination prior to its incorporation into a display. In this test method, a release sheet comprises a conductive layer, and a voltage sufficient to alter the optical state of the electro-optic medium is applied between this conductive layer and the conductive layer opposite the electro-optic medium. Observation of the electro-optic medium then reveals any defects within the medium, thus avoiding the lamination of a defective electro-optic medium into the display, which would incur costs resulting from scrapping not only a defective front-plane lamination but the entire display.

[0024] The aforementioned U.S. Patent No. 6,982,178 also describes a second method for testing the electro-optic medium in a front-plane lamination by charging a release sheet, and thus forming an image on the electro-optic medium. This image is then observed in the same manner as before to detect any defects in the electro-optic medium.

[0025] The aforementioned Patent No. 2004 / 0155857 describes a so-called “double release film,” which is essentially a simplified version of the front-plane lamination described in the aforementioned U.S. Patent No. 6,982,178. One form of the double release film comprises a layer of solid electro-optical medium sandwiched between two adhesive layers, with one or both adhesive layers covered by the release sheet. Another form of the double release film comprises a layer of solid electro-optical medium sandwiched between two release sheets. Both forms of the double release film are generally intended for use in a process similar to the process for assembling an electro-optical display from the front-plane lamination already described, but with two separate laminations, typically in the first lamination, the double release film is laminated to the front electrode to form a front subassembly, and then in the second lamination, the front subassembly is laminated to the backplane to form the final display, although the order of these two laminations may be reversed as desired.

[0026] U.S. Patent No. 7,839,564 describes a so-called "inverted front plane laminate", which is a variation of the front plane laminate described in the aforementioned U.S. Patent No. 6,982,178. This inverted front plane laminate comprises, in order, at least one of a light transmissive protective layer and a light transmissive conductive layer, an adhesive layer, a layer of a solid electro-optical medium, and a release sheet; this inverted front plane laminate is used to form an electro-optical display having a layer of laminate adhesive between the electro-optical layer and the front electrode or front substrate; a second layer of adhesive (typically, a thin layer) may or may not be present between the electro-optical layer and the backplane. Such an electro-optical display can combine good resolution with good low-temperature performance.

[0027] The aforementioned U.S. Patent No. 7,839,564 describes various methods designed for the mass production of electro-optical displays using an inverted front plane laminate. Some forms of these methods are "multi-up" methods designed to allow the lamination of components for multiple electro-optical displays at once.

[0028] U.S. Patent No. 6,982,178 mentioned above also explains the importance of protecting electro-optical media from environmental contaminants because some electro-optical media are sensitive to humidity and ultraviolet radiation, and most such media are vulnerable to mechanical damage. This patent, in FIG. 10, illustrates a process in which a protective film is laminated over a front-plane laminate in the same lamination operation where the front-plane laminate is laminated to a backplane, and such a protective film can protect the electro-optical media against the intrusion of moisture, other liquids, and some gases. However, even when using such a protective film, the edges of the electro-optical media are still exposed to the environment, and this patent teaches that it is also advisable for the display to include an edge seal, which serves to prevent the intrusion of moisture and other contaminants around the outer edges of the display. Various types of edge seals are illustrated in FIGS. 11 - 17 of this patent. Such an edge seal can consist of a metallized foil or other barrier foil adhered over the edge of the FPL, a dispensed sealant (thermally, chemically, and / or radiation curable), a polyisobutylene or acrylate-based sealant, etc. Hybrid radiation and thermosetting sealants (i.e., UV curable with heat after baking) have been found to offer certain advantages in display system performance. The Threebond 30Y - 491 material (manufactured by Threebond Corporation (Cincinnati, OH)) has been found to have favorable water vapor barrier properties, low viscosity at high temperatures for easy dispensing of the edge seal material, good wetting properties, and manageable curing properties. Those skilled in the art and experts in high-performance sealants will likely be able to identify other sealants that offer equivalent performance.

Prior Art Documents

Patent Documents

[0029]

Patent Document 1

Patent Document 2

[0030] As described in some of the aforementioned MIT and E INK patents and applications, in conventional assembly processes, FPL can be cut from larger sheets of material or from rolls of material formed in a roll-to-roll process. Laser cutting or die cutting can be used to separate continuous webs or sheets of FPL into appropriately sized pieces for lamination onto individual backplanes. The cutting process may result in the formation of debris from, for example, ruptured capsules of encapsulated electrophoretic media, and therefore, after cutting, it is necessary to remove the residue mechanically or chemically ("cleaning").

[0031] Laser cutting can also be used to “kiss-cut” the FPL using a laser, exposing the area for electrical connections to the backplane by removing a portion of the light-transmitting conductive layer, protective or barrier layers, release sheets, and any intervening adhesive layers, if present. Following kiss-cutting, it is again necessary to clean up any electro-optical and / or adhesive residue to ensure that the electrical connections to the backplane will be exposed when the FPL is laminated onto the backplane. In practice, after the cleaning step is complete, it is necessary to inspect each FPL piece before it is laminated onto the backplane.

[0032] Conventional electro-optical display stack assembly typically involves stacking FPLs onto a backplane, which includes a pre-formed array of pixel electrodes and several conductors for connecting the pixel electrodes to the driver network. (Top and bottom protective or barrier layers are typically applied to the FPL and backplane in separate stacking operations, either before or after stacking the FPLs onto the backplane, respectively.)

[0033] It has been observed that the resulting optical performance of a display can be adversely affected if the environmental conditions under which the FPL and backplane are stacked (both individually and in relation to each other) are not maintained within a specific range during the stacking process. For example, in the case of encapsulated electrophoretic displays, the conductivity of the capsule walls can be significantly affected by humidity. Therefore, stacking is recommended to be carried out at a relative humidity of 20–60 percent, optimally around 50 percent. Furthermore, for such electrophoretic displays, the stacking process is preferably carried out at room temperature (e.g., within the range of 15–25°C). Prior to any stacking operation, in addition to manufacturing the display stack components under a controlled environment, the FPL and / or backplane often must be conditioned to the desired temperature and relative humidity in an environmental chamber for several hours or even several days to reach relative humidity equilibrium.

[0034] Furthermore, even when protective or barrier films are laminated to FPL, electro-optical displays incorporating these films typically have adequate moisture diffusion protection on the display surface, but have been observed to have relatively weak moisture diffusion protection at the outer edges of the electro-optical medium layer. As already specifically mentioned, many electro-optical media are susceptible to environmental factors such as moisture, oxygen, and particulate matter. Therefore, many displays incorporate edge seals, such as those described in U.S. Patent Nos. 6,982,178, 7,110,164, and 7,649,674, and Japanese Patent Publication No. 2004 / 0155857, to prevent adverse effects on the electro-optical medium caused by such environmental factors and thus increase the operating life of the display. In addition, the lamination process is preferably carried out in a cleanroom environment with a low particle rate to improve the manufacturing yield.

[0035] From the above, it should be understood that conventional techniques for assembling electro-optical display stacks require several separate processing steps for each component, and many of these steps must be performed sequentially, such that the completion of one step leads to the execution of any subsequent step. For example, the kiss-cutting and cleaning processes described above must be performed before the FPL is stacked onto the backplane. In addition, the location and geometry of connections on the backplane must be determined before the stacking process in order to determine where cuts should be made within the FPL.

[0036] Furthermore, it is common for FPLs to be manufactured in different facilities or locations and under different environmental conditions than the backplane. Therefore, adjustment within the environmental chamber is required prior to the stacking of FPLs onto the backplane. However, adjustment is an energy-intensive process, and in some cases, the FPL or backplane may have already undergone the adjustment process when it is being assembled. In addition, as discussed above, adjustment is also a time-consuming process, taking several days to complete, which can result in increased manufacturing time.

[0037] In addition, each time individual components are removed from the cleanroom environment for, for example, packing and shipping to different manufacturing facilities, there are more opportunities for water vapor and other environmental contaminants to enter, which can adversely affect the electro-optical properties and operating life of the display. The larger area around the edges of certain sheets of FPL can also become unusable if there is a long delay between the fabrication of the FPL and the final assembly of the finished electro-optical display (including lamination onto the backplane and application of edge seals around the periphery of the display), thereby reducing the production yield. For example, edge seals are often formed using curable resins that are not easily removed. Therefore, the edges of the FPL may remain exposed until the FPL is laminated onto the backplane.

[0038] Therefore, there is a need for improved processes for the production of electro-optical display stacks. Accordingly, the electro-optical display stacks and processes of the present invention described herein include features to address the shortcomings of conventional electro-optical display stacks and their corresponding production processes.

[0039] Accordingly, in one aspect, the present invention includes a method for manufacturing a segmented electro-optical display. The method includes providing an electro-optical display stack. The electro-optical display stack includes a first substrate layer, a first layer of light-transmitting conductive material, a layer of electro-optical material, a laminated adhesive layer, a second layer of light-transmitting conductive material, and a second substrate layer. The method also includes forming a plurality of electrically insulated conductive segments on the second layer of light-transmitting conductive material using a laser etching process. The laser etching process includes irradiating the second substrate layer and the second layer of light-transmitting conductive material at a plurality of first locations using a laser that emits light within a first wavelength range. The second substrate layer is substantially transparent to light within the first wavelength range, and the light-transmitting conductive material of the second layer of light-transmitting conductive material is substantially absorbent to light within the first wavelength range. In each of the first multiple locations, the second substrate layer substantially transmits light within a first wavelength range, while the light-transmitting conductive material of the second layer substantially absorbs and removes light within the first wavelength range.

[0040] In another aspect, the present invention includes a segmented electro-optical display formed using the method described herein.

[0041] In some embodiments, the electro-optical display stack further includes a first barrier layer, a first adhesive layer, a second adhesive layer, and a second barrier layer. In some embodiments, the laser etching process further includes irradiating the second adhesive layer and the second barrier layer at a first plurality of locations with a laser emitting light within a first wavelength range, wherein the second adhesive layer and the second barrier layer are substantially transparent to light within the first wavelength range, and at each of the plurality of locations, the second adhesive layer and the second barrier layer are substantially transparent to light within the first wavelength range.

[0042] In some embodiments, the method further includes irradiating a first barrier layer, a first adhesive layer, a first substrate layer, and a first layer of light-transmitting conductive material at a second plurality of locations using a laser emitting light within a second wavelength range, wherein the light-transmitting conductive material of the first barrier layer, the first adhesive layer, the first substrate layer, and the first layer of light-transmitting conductive material is substantially absorbent of light within the second wavelength range, and at each of the second plurality of locations, the light-transmitting conductive material of the first barrier layer, the first adhesive layer, the first substrate layer, and the first layer of light-transmitting conductive material substantially absorbs and removes light within the second wavelength range. In some embodiments, the method further includes removing a plurality of volumes of electro-optic material and laminated adhesive layers adjacent to each of the second plurality of locations.

[0043] In some embodiments, the method further includes irradiating a second barrier layer, a second adhesive layer, a second substrate layer, and a second layer of light-transmitting conductive material at a third plurality of locations using a laser emitting light within a third wavelength range, wherein the light-transmitting conductive material of the second barrier layer, the second adhesive layer, the second substrate layer, and the second layer of light-transmitting conductive material is substantially absorbent of light within the third wavelength range, and at each of the third plurality of locations, the light-transmitting conductive material of the second barrier layer, the second adhesive layer, the second substrate layer, and the second layer of light-transmitting conductive material substantially absorbs and removes light within the third wavelength range. In some embodiments, the method further includes removing a plurality of volumes of electro-optic material and laminated adhesive layers adjacent to each of the third plurality of locations.

[0044] In some embodiments, the method further includes forming a plurality of electrically insulated conductive segments on a first layer of a light-transmitting conductive material using a second laser etching process. The second laser etching process includes irradiating a first substrate layer and a first layer of the light-transmitting conductive material at a plurality of fourth locations using a laser that emits light in the range of a fourth wavelength, wherein the first substrate layer is substantially transparent to light in the range of the fourth wavelength, and the light-transmitting conductive material of the first layer of the light-transmitting conductive material is substantially absorbent to light in the range of the fourth wavelength. Furthermore, at each location, the first substrate layer substantially transmits light in the range of the first wavelength, and the light-transmitting conductive material of the first layer of the light-transmitting conductive material substantially absorbs and removes light in the range of the fourth wavelength.

[0045] In some embodiments, the electro-optical display stack further includes a first barrier layer and a first adhesive layer. In some embodiments, a second laser etching process further includes irradiating the first adhesive layer and the first barrier layer at a plurality of locations with a laser emitting light in a fourth wavelength range, wherein the first adhesive layer and the first barrier layer are substantially transparent to light in the fourth wavelength range, and at each of the plurality of locations, the first adhesive layer and the first barrier layer are substantially transparent to light in the fourth wavelength range.

[0046] In some embodiments, the method further includes irradiating an electro-optical display stack at a fifth plurality of locations using a laser that emits light within a fifth wavelength range, wherein each layer of the electro-optical display stack is substantially absorbent to light within the fifth wavelength range, and at each of the fifth plurality of locations, the layers of the electro-optical display stack substantially absorb and remove light within the fifth wavelength range.

[0047] In some embodiments of the method, the first wavelength range is 940 nm to 1,440 nm. In some embodiments, the second wavelength range is 9,000 nm to 12,000 nm. In some embodiments, the third wavelength range is 9,000 nm to 12,000 nm. In some embodiments, the fourth wavelength range is 940 nm to 1,440 nm. In some embodiments, the fifth wavelength range is 9,000 nm to 12,000 nm.

[0048] In some embodiments, the second barrier layer, the second adhesive layer, and the second substrate layer transmit more than 85% of light within the first wavelength range. In some embodiments, the light-transmitting conductive material of the second layer transmits less than 80% of light within the first wavelength range.

[0049] In some embodiments, light within a first wavelength range cuts the light-transmitting conductive material of the second layer of the light-transmitting conductive material into discontinuous pieces at each of several locations. In some embodiments, light within a first wavelength range oxidizes the light-transmitting conductive material of the second layer of the light-transmitting conductive material into discontinuous pieces at each of several locations. In some embodiments, the laser emitting light within the first wavelength range is a YAG or ytterbium-doped fiber laser. In some embodiments, the laser emitting light within the second wavelength range is a CO2 laser. In some embodiments, several volumes of the electro-optic material layer and the laminated adhesive layer are removed using deionized water and isopropanol. This specification also provides, for example, the following: (Item 1) A method for manufacturing a segmented electro-optical display, wherein the method is To provide an electro-optical display stack, the electro-optical display stack is The first substrate layer, A first layer of light-transmitting conductive material, A layer of electro-optical material, Laminated adhesive layer, A second layer of light-transmitting conductive material, The second substrate layer and It has the following characteristics: Using a laser etching process, multiple electrically insulated conductive segments are formed on a second layer of the light-transmitting conductive material. Includes, The laser etching process includes irradiating the second substrate layer and the second layer of the light-transmitting conductive material at multiple locations using a laser that emits light within a first wavelength range, The second substrate layer is substantially transparent to light within the first wavelength range, and the light-transmitting conductive material of the second layer of the light-transmitting conductive material is substantially absorptive to light within the first wavelength range. In each of the aforementioned locations, The second substrate layer substantially transmits light within the range of the first wavelength, A method wherein the light-transmitting conductive material in the second layer of the light-transmitting conductive material substantially absorbs and removes light within the range of the first wavelength. (Item 2) The method according to item 1, wherein the electro-optical display stack further comprises a first barrier layer, a first adhesive layer, a second adhesive layer, and a second barrier layer. (Item 3) The laser etching process further includes irradiating the second adhesive layer and the second barrier layer at the plurality of locations using the laser that emits light within the range of the first wavelength, The second adhesive layer and the second barrier layer are substantially transparent to light within the range of the first wavelength. The method according to item 2, wherein in each of the plurality of locations, the second adhesive layer and the second barrier layer substantially transmit light within the range of the first wavelength. (Item 4) The first barrier layer, the first adhesive layer, the first substrate layer, and the first layer of the light-transmitting conductive material are irradiated at a second number of locations using a laser that emits light within a second wavelength range, The first barrier layer, the first adhesive layer, the first substrate layer, and the first layer of the light-transmitting conductive material are substantially absorbent of light within the second wavelength range. In each of the second plurality of locations, the first barrier layer, the first adhesive layer, the first substrate layer, and the light-transmitting conductive material of the first layer of the light-transmitting conductive material substantially absorb and remove light within the second wavelength range. Removing multiple volumes of the electro-optic material layer and the laminated adhesive layer adjacent to each of the second multiple locations: The method described in item 3, further including the method described in item 3. (Item 5) Irradiating the second barrier layer, the second adhesive layer, the second substrate layer, and the second layer of the light-transmitting conductive material at a third number of locations using a laser that emits light within a third wavelength range, The second barrier layer, the second adhesive layer, the second substrate layer, and the light-transmitting conductive material of the second layer of the light-transmitting conductive material are substantially absorbent of light within the third wavelength range. In each of the third of the multiple locations, the second barrier layer, the second adhesive layer, the second substrate layer, and the light-transmitting conductive material of the second layer of the light-transmitting conductive material substantially absorb and remove light within the third wavelength range. Removing multiple volumes of the electro-optic material layer and the laminated adhesive layer adjacent to each of the third multiple locations. The method described in item 3, further including the method described in item 3. (Item 6) The method further includes forming a plurality of electrically insulated conductive segments on a first layer of the light-transmitting conductive material using a second laser etching process, The second laser etching process includes irradiating the first substrate layer and the first layer of the light-transmitting conductive material at a fourth plurality of locations using a laser that emits light within a fourth wavelength range, The first substrate layer is substantially transparent to light within the fourth wavelength range, and the light-transmitting conductive material of the first layer of the light-transmitting conductive material is substantially absorptive to light within the fourth wavelength range. At each location, The first substrate layer substantially transmits light within the range of the first wavelength, The method according to item 1, wherein the first layer of the light-transmitting conductive material substantially absorbs and removes light within the range of the fourth wavelength. (Item 7) The method according to item 6, wherein the electro-optical display stack further comprises a first barrier layer and a first adhesive layer. (Item 8) The second laser etching process further includes irradiating the first adhesive layer and the first barrier layer at a plurality of fourth locations using the laser emitting light within the range of the fourth wavelength, The first adhesive layer and the first barrier layer are substantially transparent to light within the fourth wavelength range. The method according to item 7, wherein in each of the plurality of locations, the first adhesive layer and the first barrier layer substantially transmit light within the range of the fourth wavelength. (Item 9) The method further includes irradiating the electro-optical display stack at a fifth number of locations using a laser that emits light within a fifth wavelength range, Each layer of the electro-optical display stack is substantially absorbent of light within the fifth wavelength range, The method according to item 1, wherein in each of the second plurality of locations, the layers of the electro-optic display stack substantially absorb and remove light within the range of the fifth wavelength. (Item 10) A segmented electro-optical display formed using the method described in item 1. (Item 11) The method according to item 1, wherein the first wavelength range is 940 nm to 1,440 nm. (Item 12) The method according to item 4, wherein the second wavelength range is 9,000 nm to 12,000 nm. (Item 13) The method according to item 5, wherein the third wavelength range is 9,000 nm to 12,000 nm. (Item 14) The method according to item 6, wherein the fourth wavelength range is 940 nm to 1,440 nm. (Item 15) The method according to item 9, wherein the fifth wavelength range is 9,000 nm to 12,000 nm. (Item 16) The method according to item 3, wherein the second barrier layer, the second adhesive layer, and the second substrate layer transmit more than 85% of the light within the first wavelength range. (Item 17) The method according to item 1, wherein the light-transmitting conductive material in the second layer of the light-transmitting conductive material transmits 80% or less of light within the first wavelength range. (Item 18) The method according to item 1, wherein light within the range of the first wavelength cuts the second layer of the light-transmitting conductive material into discontinuous pieces at each of the plurality of locations. (Item 19) The method according to item 1, wherein light within the range of the first wavelength oxidizes the second layer of the light-transmitting conductive material into discontinuous pieces at each of the plurality of locations. (Item 20) The method according to item 1, wherein the laser emitting light within the first wavelength range is a YAG or ytterbium-doped fiber laser. (Item 21) The laser that emits light within the second wavelength range is CO 2 The method described in item 1, which is a laser. (Item 22) The method according to item 4, wherein the plurality of volumes of the electro-optic material layer and the laminated adhesive layer are removed using deionized water and isopropanol. [Brief explanation of the drawing]

[0050] Additional details of one or more embodiments of the subject matter described herein are provided in the accompanying drawings and in the description below. Other features, aspects, and advantages of the subject matter will be evident from the description and accompanying drawings contained herein. It should be emphasized that the accompanying drawings are schematic and not to scale. In particular, for ease of illustration, the thicknesses of various layers in the drawings do not correspond to their actual thicknesses. The thicknesses of the various layers are also not to scale with respect to their lateral dimensions. In general, elements of similar structures are noted throughout the drawings with similar reference numerals for illustrative purposes. However, the specific properties and functions of elements in different embodiments may not be the same. Furthermore, the drawings are intended only to facilitate the description of the subject matter. The drawings do not illustrate all aspects of the embodiments described and do not limit the scope of this disclosure or claims.

[0051] [Figure 1]Figure 1 is a schematic cross-sectional cutaway showing an exemplary embodiment illustrating segmentation and kiss-cutting operations performed on a segmented electro-optical display stack according to the subject presented herein.

[0052] [Figure 2] Figure 2 is a schematic cross-sectional cutaway showing an exemplary embodiment illustrating a cleaning operation performed on a segmented electro-optical display stack according to the subject presented herein.

[0053] [Figure 3] Figure 3 is a cutaway perspective view of an exemplary segmented electro-optical display stack according to the subject presented herein.

[0054] [Figure 4] Figure 4 is a partial cut perspective view of an exemplary segmented electro-optical display stack showing segmented layers of conductive material according to the subject presented herein.

[0055] [Figure 5] Figure 5 is a partial cut perspective view of an exemplary segmented electro-optical display stack showing a continuous layer of conductive material according to the subject presented herein. [Modes for carrying out the invention]

[0056] Segmented electro-optic displays, particularly those using encapsulated electrophoretic media, present significant new market opportunities. For example, large displays that can be stored in a compact form could be useful as additional display devices on electronic devices that currently only equip with small display screens, but where larger display screens would often be beneficial. Examples of such devices include mobile phones equipped for receiving emails. However, conventional electro-optic displays are often assembled from components manufactured in different facilities under different environmental conditions. This provides more opportunities for display stack components to be exposed to water vapor, dust, and other environmental contaminants that can adversely affect the electro-optical properties and operating life of the display. Furthermore, conventional assembly techniques do not enable mass production of complete display stacks because they require the backplane to be segmented into electrodes before being stacked on an FPL. Several techniques to overcome the shortcomings of conventional display stacks and their corresponding assembly techniques are discussed below.

[0057] For the purposes of the subsequent discussion, the term “backplane” is used herein in accordance with its conventional meaning in the field of electro-optical displays and in the aforementioned patents and published applications, and means a rigid or flexible material comprising one or more electrodes. The backplane may also comprise electronic equipment for addressing the display, or such electronic equipment may be provided in a unit separate from the backplane. In a flexible display, it is highly desirable that the backplane provides sufficient barrier properties to prevent the intrusion of moisture or other contaminants through the non-visible side of the display (the display is, of course, typically viewed from the side furthest from the backplane). If one or more additional barrier layers need to be added to the backplane to reduce the intrusion of moisture and other contaminants, the barrier layers should be located as close as possible to the electro-optical layer such that there is little or no cross-section of the edge of the low-barrier material between the front barrier layer (discussed below) and the back barrier layer.

[0058] The term “front substrate” is used herein in consistency with its conventional meaning in the art of electro-optical displays and in the aforementioned patents and published applications, and means a rigid or flexible material that is light-transmitting (preferably transparent). The front substrate will typically have at least one electrode, most commonly a single continuous front electrode extending across the entire display. Typically, the exposed surface of the front substrate forms the viewing surface through which the observer views the display, but additional layers may be inserted between the front substrate and the viewing surface, as in some of the embodiments described below. Like the backplane, the front substrate must provide sufficient barrier properties to prevent the ingress of moisture and other contaminants through the viewing side of the display.

[0059] Typically, electro-optical displays include one or more barrier layers to prevent the ingress of moisture, dust, gases, etc., or to prevent the escape of fluids within the display. If one or more additional layers need to be added to the front substrate to reduce the ingress of moisture and other contaminants, the barrier layers should be positioned as close as possible to the electro-optical layers so that when the barrier layers cover the display, their edge cross-sections are little to no relative to the back substrate.

[0060] As discussed in the aforementioned U.S. Patents 7,649,674, 6,982,178, and 7,110,164, and Patent Publication 2004 / 0155857, a common front substrate for electro-optical displays comprises a thin layer of ITO on PET, and such coated films are readily available commercially, for example, from Saint Gobain. In such a front substrate, the ITO layer acts as a barrier material, but in practice, it is inevitably plagued by micropores and cracks through which moisture and other contaminants can penetrate to the electro-optical material. To increase the sealing properties of such PET / ITO or similar front substrates, it is desirable to laminate a redundant barrier layer on top of the front substrate, which may be made of a homopolymer (e.g., polychlorotrifluoroethylene, available from Honeywell Corporation under the registered trademark "ACLAR") or a sputtered ceramic (e.g., AlO, available from Toppan Printing Company under the trade name Toppan GX Film). x ) is formed from. In other embodiments, flexible glass such as Corning WILLOW® brand glass may be used. The redundant barrier layer should be thin to provide a flexible display, ideally about 12 μm, but can be as thick as 5 mil (127 μm) if sufficient flexibility is still available. If an adhesive layer is required to attach the redundant barrier to the front substrate, the adhesive layer should be transparent, colorless, thin, flexible, have low creep (when the display is bent or rotated), and be durable at all temperatures within the operating range of the display. Certain crosslinked polyurethanes and polyacrylates may be used as such adhesives. Suitable optically clear adhesives are commercially available from Norland Adhesives.

[0061] Alternatively, the barrier properties of PET / ITO or similar front substrates can be improved by coating a redundant metal oxide layer (e.g., an alumina or zinc oxide layer) on the surface opposite the ITO layer of the front substrate, or beneath the ITO layer. The combination of the ITO layer and the redundant metal oxide layer improves the barrier properties of the front substrate without causing excessive yellowing of the substrate, which would occur if the barrier properties were improved by increasing the thickness of the ITO layer (e.g., by reducing the migration of water vapor through inevitable cracks and micropores within the ITO layer). Instead of a simple metal oxide layer, more complex structures including ceramic materials such as Barix® sealing material, available from Vitex Systems, Inc. (3047 Orchard Parkway, San Jose, CA 95134), can be used, and again, the barrier layer can be provided on the surface away from the ITO layer of the front substrate or beneath the ITO layer. Vitex Systems currently sells a polymer film under the product name FlexGlass 200, which contains both a Barix layer and an ITO layer, but the polymer film is 5 mil (127 μm) PEN.

[0062] Not only the barrier properties of the front substrate, but also properties such as flexibility, cost, and other special properties can be controlled by the careful selection of both the polymer and conductive material used in the front substrate. Almost any flexible and light-transmitting polymer can be used in principle; suitable polymers include PET, PEN, polycarbonate, poly(vinylidene chloride) (sold under the registered trademark "SARAN"), polychlorotrifluoroethylene (sold under the registered trademarks "ACLAR" and "CLARIS"), triacetylcellulose, materials sold by JSR Company under the registered trademark "ARTON", polyethersulfone (PES), and laminates of two or more of these materials. Suitable transparent conductive materials include organic conductive polymers such as ITO and Baytron P (registered trademark), carbon nanotubes, and about 10 4 This includes other well-conducting, light-transmitting conductors (with transmittance greater than 60 percent) having resistivity less than ohms / square.

[0063] Exemplary embodiments of electro-optic display stacks according to the present invention will be described herein for illustrative purposes only, with reference to the accompanying drawings. In all cases, the electro-optic layer may be an encapsulated electrophoretic layer, a polymer-dispersed electrophoretic layer, or any other type of electro-optic layer discussed above. The display stack may include one or two lamination adhesive layers for attaching the electro-optic material to a front substrate and / or backplane. The display stack may be visible through either of the lamination adhesive layers, and the display stack may be assembled by direct coating and lamination, or by front-plane lamination, inverted front-plane lamination, or by the use of double-release films, as described in the patents and applications cited in the “Cross-References of Related Applications” section herein. As described above, the final display is typically visible through a front substrate, but in some cases a light-transmitting backplane may be used to provide a double-sided display or one that operates in the aforementioned shielding mode. Such a structure may be used in a variable transmittance film, thereby the amount of light transmitted through the film can be electronically modified. In all accompanying drawings, the electro-optical display stack is shown with the viewing surface (alternatively referred to as the front surface) at the top, and thereafter, references to the front and rear surfaces, or the top and bottom surfaces, refer to the upper and lower surfaces, or the top and bottom surfaces, respectively, as shown in the relevant drawings.

[0064] Figure 1 of the accompanying drawings is a schematic cross-sectional cutaway showing an exemplary embodiment of a segmented electro-optical display stack 100 according to the subject presented herein.

[0065] The electro-optical display stack 100 typically includes a transparent upper substrate 115, a transparent upper conductive layer 110, and a layer of electrophoretic medium 120. The upper conductive layer 110 is typically supported on or formed on the upper substrate 115. For example, the upper conductive layer 110 can be a continuous layer of ITO coated on the upper substrate 115, and the upper substrate 115 can be a polymer film such as PET. The upper conductive layer 110 and the upper substrate 115 together are referred to as the upper electrode 116.

[0066] The electrophoretic medium 120 comprises electrophoretic particles 121 and electrophoretic particles 122. Electrophoretic particles 121 and 122 may have different charges and different optical properties. For example, electrophoretic particle 121 may be black and have a positive charge, while electrophoretic particle 122 may be white and have a negative charge. However, in some embodiments, the electrophoretic medium 120 comprises only a single type of electrophoretic particle, or three or more electrophoretic particles, each possibly having different optical, electro-optical, or chemical properties. The electrophoretic medium 120 typically contains a nonpolar solvent such as isoparaffin and may contain dispersed polymers and charge control agents to promote state stability, e.g., bistability (i.e., the ability to maintain an electro-optical state without inputting any additional energy).

[0067] The electrophoretic medium 120 shown in Figure 1 is partitioned by a plurality of microcapsules 126. However, in some embodiments, the electrophoretic medium 120 is partitioned by the walls of a plurality of microcells (not shown in Figure 1). The structure, consisting of the upper electrode 116 and the layer of electrophoretic medium 120 (collectively referred to as FPL125), is typically placed on a second layer of light-transmitting conductive material, the second layer of light-transmitting conductive material supported on or formed on a second substrate layer, which are identified in Figure 1 as the bottom conductive layer 150 and the bottom substrate 155, respectively. The bottom conductive layer 150 and the bottom substrate 155 are collectively referred to as the bottom electrode 156. The FPL125 is typically laminated onto the bottom electrode 156 using a laminating adhesive layer 165.

[0068] In some embodiments, the bottom conductive layer 150 is fabricated as a single continuous conductor formed from the same or similar light-transmitting material as the upper conductive layer 110, and the bottom substrate 155 is formed from the same or similar light-transmitting material as the upper substrate 115. In some embodiments, the bottom conductive layer 150 is formed from carbon paste or metal foil (not shown).

[0069] The electro-optical display stack 100 may also include an upper protective or barrier layer 160 for protecting the upper electrode 116 from damage, and a bottom protective or barrier layer 161 for protecting the bottom electrode 156 from damage. The electro-optical display stack 100 may also include an adhesive layer 140 between the upper electrode 116 and the upper barrier layer 160, and an adhesive layer 141 between the bottom electrode 156 and the bottom barrier layer 161.

[0070] Although not shown in Figure 1, the electro-optical display stack 100 may optionally include one or more additional adhesive layers (for example, between the upper electrode 116 and the layer of electrophoretic medium 120, and between the layer of electrophoretic medium 120 and the bottom electrode 156). In some embodiments, the adhesive layers may include an integrated primer component to improve adhesion, or a separate primer layer (not shown in Figure 1) may be used. (The structure of electrophoretic displays and their components, pigments, adhesives, electrode materials, etc., are described in numerous patents and patent applications published by E Ink Corporation, including U.S. Patent Nos. 6,922,276, 7,002,728, 7,072,095, 7,116,318, 7,715,088, and 7,839,564 (all of which are incorporated herein by reference in their entirety).) In some embodiments, the upper and lower barrier layers (160, 161) are fabricated to include a single adhesive material or layer on at least one surface.

[0071] In some embodiments, manufacturing a segmented electro-optical display involves providing an electro-optical display stack. The display stack may include a first substrate layer, such as a transparent upper substrate 115; a first layer of light-transmitting conductive material, such as a transparent upper conductive layer 110; and layers of electro-optical material, such as a layer of electrophoretic medium 120. The display stack may also include a laminated adhesive layer, such as a laminated adhesive layer 165; a second layer of light-transmitting conductive material, such as a bottom conductive layer 150; and a second substrate layer, such as a bottom substrate 155. As shown above, the bottom conductive layer 150 may be manufactured as a single continuous conductor.

[0072] Once the layers described above are fabricated and assembled together to form an electro-optical display stack, a laser etching process can be used to form multiple electrically insulated conductive segments on a second layer of light-transmitting conductive material. The laser etching process may include irradiating the second substrate layer and the second layer of light-transmitting conductive material at multiple locations using a laser that emits light within a first wavelength range. For example, a segmented laser 190 emitting light within a first wavelength range is used in an etching process to segment the bottom conductive layer 150 into an array or multiple electrically insulated conductive segments, which are identified in Figure 1 as segmented pixel electrodes 152.

[0073] This technique is made possible by the use of a segmented laser that emits light within a wavelength range that passes through the bottom substrate 155 but is absorbed by the conductive material of the bottom conductive layer 150. The segmented laser 190 irradiates the bottom substrate 155 and the bottom conductive layer 150. The bottom substrate 155 is substantially transparent to light within a first wavelength range, and the light emitted from the segmented laser 190 passes through it, leaving the bottom substrate 155 substantially intact. Conversely, the bottom conductive layer 150 is substantially absorbent to light within a first wavelength range and is therefore etched or cut by the segmented laser 190, leaving an electrically insulating gap or cut 170 at each location where the segmented laser 190 is focused.

[0074] In some embodiments, the electro-optical display stack also includes a first barrier layer such as an upper barrier layer 160, a first adhesive layer such as an adhesive layer 140, a second adhesive layer such as an adhesive layer 141, and a second barrier layer such as a bottom barrier layer 161.

[0075] Due to this configuration of the display stack, the segmented laser emits light within a wavelength range that passes through the bottom barrier layer 161, the adhesive layer 141, and the bottom substrate 155, but is absorbed by the conductive material of the bottom conductive layer 150. The segmented laser 190 irradiates the bottom barrier layer 161, the adhesive layer 141, the bottom substrate 155, and the bottom conductive layer 150. Of these layers, the bottom barrier layer 161, the adhesive layer 141, and the bottom substrate 155 are substantially transparent to light within a first wavelength range. As shown in Figure 1, the light from the segmented laser 190 passes through the bottom barrier layer 161, the adhesive layer 141, and the bottom substrate 155, leaving these layers substantially intact. Only the bottom conductive layer 150 is substantially absorbent of light within a first wavelength range and is therefore etched or cut by the segmented laser 190, leaving an electrically insulating gap or cut portion 170 where the segmented laser 190 is focused.

[0076] In some embodiments, the segmented laser 190 emits light with typical wavelengths in the near-infrared (NIR) spectrum. In some embodiments, the segmented laser 190 is a neodymium-doped yttrium aluminum garnet (Nd:YAG) or ytterbium-doped fiber laser that emits light with typical wavelengths of about 940 nm to about 1,440 nm. In some embodiments, the segmented laser 190 has an average output power of about 10 W to about 100 W. In such embodiments, the bottom barrier layer 161, the adhesive layer 141, and the bottom substrate 155 are formed from materials that are substantially transparent to light at those wavelengths, and the conductive material of the bottom conductive layer 150 substantially absorbs light at those wavelengths. Thus, the segmented laser 190 can be operated with an average power sufficient to cut the conductive material of the bottom conductive layer 150 without cutting the bottom barrier layer 161, the adhesive layer 141, or the bottom substrate 155. Advantageously, this allows the bottom conductive layer 150 to be divided into any number of electrically insulated segments without damaging the mechanical, optical, or barrier performance of the display stack. Furthermore, using a segmentation laser 190 that emits light with wavelengths invisible to the human eye (e.g., NIR spectrum) allows the optical properties of the display stack materials to be independent of the processing properties of those materials.

[0077] In one example, the segmented laser 190 is part of the Speedy Flexx 400 laser system from Trotec Laser GmbH, incorporating a ytterbium-doped fiber laser with an average output power of 20 W and emitting light with a typical wavelength centered around approximately 1,064 nm. Furthermore, the bottom barrier layer 161 is formed as a sputtered aluminosilicate barrier film, which transmits approximately 92% of light with a wavelength of 1,064 nm, and the adhesive layer 141 is an optical adhesive that transmits more than 90% of light with a wavelength of 1,064 nm. The bottom electrode 156 is a PET-ITO film, for which the bottom substrate 155 is formed from PET and the bottom conductive layer 150 is ITO. PET transmits approximately 90% of light with a wavelength of 1,064 nm, while ITO transmits approximately 70-80% of light at that wavelength.

[0078] In some embodiments, the conductive material of the bottom conductive layer 150 comprises aluminum, and light emitted by the segmented laser 190 divides the conductive material into discontinuous pieces, thereby blocking the conductive path between the segments of material on both sides of the cut. In some embodiments, the conductive material of the bottom conductive layer 150 comprises poly-3,4-ethyleneoxythiophene (PEDOT) or a derivative thereof, and the area of ​​the conductive material targeted by light emitted by the segmented laser 190 is made nonconductive by thermally changing the chemical composition of the conductive material. In some embodiments, the area of ​​the conductive material targeted by light emitted from the segmented laser 190 is made nonconductive by thermal oxidation. In some embodiments, the conductive material of the bottom conductive layer 150 comprises carbon nanotubes or carbon fibers. In some embodiments, the bottom substrate 155 comprises soda-lime glass.

[0079] Once multiple electrically insulated segmented pixel electrodes 152 are formed on the bottom conductive layer 150, kiss-cutting and cleaning techniques are used to expose areas for forming electrical connections to each segmented pixel electrode 152. For example, a laser can be used to irradiate the first barrier layer, the first adhesive layer, the first substrate layer, and the first layer of light-transmitting conductive material at a second number of locations using a laser that emits light within a second wavelength range.

[0080] The kiss-cutting technique is made possible by the use of a cutting laser 195 that emits light within a second wavelength range which is absorbed by the conductive materials of the upper barrier layer 160, adhesive layer 140, upper substrate 115, and upper conductive layer 110, and also absorbed by the conductive materials of the bottom barrier layer 161, adhesive layer 141, bottom substrate 155, and bottom conductive layer 150.

[0081] The cutting laser 195 emits light within a second wavelength range and irradiates the upper barrier layer 160, adhesive layer 140, upper substrate 115, and upper conductive layer 110. Each of these layers of the electro-optic display stack is substantially absorbent to light within the second wavelength range, and material from each of these layers is removed at each location irradiated by the cutting laser 195. As shown in Figure 1, the light emitted from the cutting laser 195 is used to create kiss cuts 180 by removing areas of the upper barrier layer 160, adhesive layer 140, upper substrate 115, and upper conductive layer 110 at locations corresponding to each segmented pixel electrode 152 formed on the bottom conductive layer 150. For example, each kiss cut 180 can be aligned perpendicularly to one of the segmented pixel electrodes 152.

[0082] Similarly, kiss-cutting and cleaning techniques are used to expose areas for forming electrical connections to the upper conductive layer 110 at locations corresponding to the upper conductive layer 150. For example, a laser can be used to irradiate the second barrier layer, the second adhesive layer, the second substrate layer, and the second layer of light-transmitting conductive material at a third number of locations, using a laser that emits light within a third wavelength range. A cutting laser 195 emits light within a third wavelength range and irradiates the bottom barrier layer 161, the adhesive layer 141, the bottom substrate 155, and the bottom conductive layer 150. Each of these layers of the electro-optical display stack is substantially absorbent to light within a third wavelength range, and material from each of these layers is removed at each location irradiated by the cutting laser 195.

[0083] As shown in Figure 1, the light emitted from the cutting laser 195 is used to create kiss cuts 181 and remove areas of the bottom barrier layer 161, adhesive layer 141, bottom substrate 155, and bottom conductive layer 150. In some embodiments, two or more kiss cuts 181 are created, allowing multiple electrical connections to be formed together with the top conductive layer 110.

[0084] In an alternative embodiment, the upper conductive layer 110 is divided into several electrically insulated segments similar to the bottom conductive layer 150. For example, a second laser etching process can be used to form a plurality of electrically insulated conductive segments on the first layer of the light-transmitting conductive material by irradiating the first substrate layer and the first layer of the light-transmitting conductive material at a plurality of fourth locations using a laser emitting light within a fourth wavelength range. A segmenting laser emitting light within a fourth wavelength range can be used in an etching process to segment the upper conductive layer 110 into an array or a plurality of electrically insulated conductive segments (not shown in Figure 1).

[0085] This technique is made possible by the use of a segmented laser (e.g., segmented laser 190) that emits light within a wavelength range that passes through the upper substrate 115 but is absorbed by the conductive material of the upper conductive layer 110. The segmented laser irradiates the upper substrate 115 and the upper conductive layer 110. The upper substrate 115 is substantially transparent to light within a fourth wavelength range, and the light emitted from the segmented laser passes through the upper substrate 115, leaving the upper substrate 115 substantially intact. Conversely, the upper conductive layer 110 is substantially absorbent to light within a fourth wavelength range and is therefore etched or cut by the segmented laser, leaving electrically insulating gaps or cuts at each location where the segmented laser is focused.

[0086] In some embodiments, the electro-optical display stack also includes a first barrier layer, such as an upper barrier layer 160, and a first adhesive layer, such as an adhesive layer 140. For this configuration of the display stack, the segmented laser emits light within a wavelength range that passes through the upper barrier layer 160, the adhesive layer 140, and the upper substrate 115, but is absorbed by the conductive material of the upper conductive layer 110.

[0087] The segmented laser irradiates the upper barrier layer 160, the adhesive layer 140, the upper substrate 115, and the upper conductive layer 110. Of these layers, the upper barrier layer 160, the adhesive layer 140, and the upper substrate 115 are substantially transparent to light within the fourth wavelength range. The light from the segmented laser passes through the upper barrier layer 160, the adhesive layer 140, and the upper substrate 115, leaving these layers substantially intact. Only the upper conductive layer 110 is substantially absorbent to light within the fourth wavelength range and is therefore etched or cut by the segmented laser, leaving electrically insulating gaps or cuts where the segmented laser is focused (not shown in Figure 1).

[0088] As indicated by the symbols for the segmented laser 190 and cutting laser 195 in Figure 1, the cutting laser 195 emits light with longer wavelengths than the segmented laser 190. In some embodiments, the cutting laser 195 emits light with typical wavelengths in the mid-infrared spectrum. In some embodiments, the cutting laser 195 is a carbon dioxide laser (CO2 laser) that emits light with typical wavelengths of about 9,000 nm (9 μm) to about 12,000 nm (12 μm). In some embodiments, the cutting laser 195 has an average output power of about 20 W to about 200 W.

[0089] Based on the above example, the cutting laser 195 is a CO2 laser (e.g., the CO2 laser portion of the Speedy Flexx 400 laser system from Trotec Laser GmbH) that has an average output power of 100 W and emits light with a typical wavelength centered around approximately 10,600 nm (10.6 μm). Furthermore, the upper barrier layer 160 and the bottom barrier layer 161 are formed as sputtered aluminosilicate barrier films that transmit approximately 0% of light with a wavelength of 10,600 nm (10.6 μm), and the adhesive layers 140 and 141 are optical adhesives manufactured by Norland Products that transmit approximately 0% of light with a wavelength of 10,600 nm (10.6 μm). The upper electrode 116 and the lower electrode 156 are formed from a PET-ITO film, and therefore the upper substrate 115 and the lower substrate 155 are formed from PET, and the upper conductive layer 110 and the lower conductive layer 150 are ITO. PET and ITO transmit approximately 0% of light having a wavelength of 10,600 nm (10.6 μm). Therefore, the layers of the display stack 100 are removed at the location where the cutting laser 195 is focused.

[0090] A cutting laser 195, or a similar laser, is used to cut the display stack into pieces of the size required to form individual displays for a specific application. For example, the cutting laser can be used to irradiate the electro-optic display stack at a fifth location using a laser that emits light within a fifth wavelength range. All layers of the electro-optic display stack are substantially absorbent of light within the fifth wavelength range, and material from each of these layers is removed at each location irradiated by the cutting laser.

[0091] In this cutting operation, instead of cutting through a portion of the layer (for example, performing kiss cutting), the laser cuts through the entire display stack. Therefore, the cutting laser can be used to cut several displays from a large sheet or roll of a fully formed display stack. The cutting operation can also be used to produce displays of any number of shapes, in addition to conventional rectangular displays.

[0092] In some embodiments, this cutting operation may be achieved using die cutting, wet saw cutting, or scissor cutting. In some embodiments, this cutting operation is performed after the bottom conductive layer 150 has been segmented.

[0093] The above process steps are described with reference to several uniquely identified wavelength ranges (e.g., a first wavelength range, a second wavelength range, a third wavelength range, etc.) to aid the reader's understanding of the present invention. Those skilled in the art will understand that two or more of these uniquely identified ranges may comprise substantially similar wavelengths. As an example, in some embodiments, the second wavelength range used to produce the kiss cut 180 shown in Figure 1 may comprise substantially similar wavelengths to the third wavelength range used to produce the kiss cut 181.

[0094] Referring here to Figure 2, after creating the kiss cut 180, the cleaning process removes multiple volumes of electro-optic material layers and laminating adhesive layers adjacent to each of the second and third multiple locations. For example, cleaning process 185 is performed to remove the layer of electrophoretic medium 120 and residue of laminating adhesive 165 in order to expose the electrical connections to each segmented pixel electrode 152. Similarly, cleaning process 186 is performed after creating the kiss cut 181 to remove the layer of electrophoretic medium 120 and residue of laminating adhesive layer 165 in order to expose the electrical connections to the upper conductive layer 110.

[0095] In some embodiments, cleaning processes 185 and 186 include mechanically or chemically removing residue from the electrophoretic medium layer 120 and the laminated adhesive layer 165. In some embodiments, cleaning processes 185 and 186 include cleaning exposed areas of conductive material on the upper conductive layer 110 and the bottom conductive layer 150 using deionized water and isopropanol.

[0096] After cleaning processes 185 and 186 have been performed, the connector can be attached to the exposed areas of conductive material on the upper conductive layer 110 and the bottom conductive layer 150 using a typical "tail" with a carbon-filled adhesive pad or silver-filled epoxy, or any other suitable method for making an electrical connection.

[0097] In some embodiments, a sealing material having a low water vapor permeability rate (WVTR) is applied to the display stack 100 after electrical connections have been made, to seal any gaps or pores within the layers of the display stack 100. (WVTR is the water vapor permeability rate of a given material, i.e., a measure of the mass of water vapor passing through a given area of ​​the material over a given period of time at a specified temperature and humidity.) In some embodiments, the sealing material is dispensed UV or thermosetting epoxy. In some embodiments, the sealing material is an adhesive-backed barrier tape wound along the edge from the top side of the display stack to the bottom side of the display stack. In some embodiments, the barrier tape is formed from a material having good barrier properties, including a polymer (e.g., a homopolymer such as polychlorotrifluoroethylene or similar material) or a ceramic sputtered onto PET, PEN, PC, or other transparent plastics. In some embodiments, seals such as those described in U.S. Patents 6,982,178, 7,110,164, and 7,649,674, and Japanese Patent Publication No. 2004 / 0155857 are applied to the display stack 100 after the electrical connections have been made.

[0098] Figure 3 is a cropped perspective view 300 of an exemplary segmented electro-optical display stack 100 according to the subject presented herein. Figure 300 shows the display stack 100 after all segmentation, kiss-cutting, and cleaning processes have been performed. As shown in Figure 3, each segmented pixel electrode 152 has an exposed area 154 on the upper side (e.g., the viewing side) of the bottom conductive layer 150 for making an electrical connection to a controller or driver circuit. Similarly, the upper conductive layer 110 has an exposed area 114 on the lower surface (e.g., opposite the viewing side) of the upper conductive layer 110 for making an electrical connection to a controller or driver circuit.

[0099] Figure 4 is a partial cut perspective view 400 of an exemplary segmented electro-optical display stack 100, showing the segmented layers of conductive material according to the subject presented herein. Figure 400 shows only the bottom barrier layer 161, adhesive layer 141, bottom substrate 155, and bottom conductive layer 150 after all segmenting, kiss-cutting, and cleaning processes have been carried out. The remaining layers of the display stack 100 are obscured in Figure 400 to show the shape of each segmented pixel electrode 152 and the insulating breaks 170 between them.

[0100] Figure 5 is a partial cut perspective view 500 of an exemplary segmented electro-optic display stack 100 showing a continuous layer of conductive material according to the subject presented herein. Figure 500 shows the same layers as in Figure 400, plus a layer of laminating adhesive 165, a layer of electrophoretic medium 120, and an upper conductive layer 110. Other layers of the display stack 100 are obscured in Figure 500 to show the shape of the continuous layer of conductive material on the upper conductive layer 110.

[0101] Therefore, the process of the present invention described herein allows the conductive layer of a fully assembled display stack to be divided into multiple electrically insulated segments (e.g., pixel electrodes) without damaging the mechanical, optical, or barrier performance of the display stack. Any number of segments and any variety of segment shapes or geometric shapes can be etched into the conductor. Multiple electrical connections can also be made in the segments to provide sufficient drive current, if required. Multiple electrical connections can also be used to wave-switch segments, provided that the segment aspect ratio is at least 2:1. Thus, the process of the present invention provides a means for producing custom segmented display devices using mass-produced stacked display stacks.

[0102] Furthermore, if the display design requires that areas be independently switchable, but the areas are not adjacent to the edges of the display stack, kiss cuts can be made through the upper layer at any point in the segmented pixel electrode area to expose the contact points to the segmented pixel electrodes. Advantageously, if the segmented pixel electrode material is transparent (e.g., ITO), the display can be designed to be visible from the rear, with wires or other connections to the pixel electrodes located behind the display and invisible to the viewer. In this case, only a small non-switching area at the kiss cut point is visible.

[0103] In addition, using the process of the present invention as described herein, all lamination steps can be carried out prior to the cutting and cleaning processes. This allows the roll-to-roll lamination process to be optimized, reducing manufacturing time and costs. For example, all lamination operations occur in the same equipment in a clean setting from start to finish, thereby improving manufacturing yield by reducing defects caused by particulate contamination and changes in environmental conditions. Furthermore, material preparation is required only once, as a complete display stack, including the barrier layer, can be assembled simultaneously in a continuous multi-stage roll-to-roll lamination process. Moreover, since the process of the present invention results in a fully protected display stack, there is no longer a delay period between when the FPL is assembled and when it is finally laminated onto the backplane. As a result, edge seals can be applied during or immediately after manufacturing, preventing humidity changes that would affect the performance of displays produced using conventional techniques, thereby increasing the usable area of ​​each sheet or roll of finished display stack material.

[0104] Those skilled in the art will understand that the processes and techniques of the present invention described herein are not limited to specific display stack configurations but can be used to process several other display stack configurations. For example, in one embodiment, the process of the present invention is used in a partial display stack similar to the display stack 100 in Figure 1, but without the application of top and bottom barrier layers (160, 161) or adhesive layers (140, 141). A segmentation laser (e.g., segmentation laser 190) can be used to segment one or both of the top and bottom conductive layers (110, 150) in a partial or complete display stack configuration.

[0105] Furthermore, the process of the present invention can be used on display stack components produced using conventional techniques. For example, the segmentation laser technique can be used to segment the conductive layer of a conventional FPL prior to being stacked on a backplane. Similarly, the segmentation laser technique can be used to segment the conductive layer of a backplane into an array of pixel electrodes before the FPL is stacked on the backplane. Assuming that the total film stack between the segmentation laser source and the conductive material is thin and transparent in the wavelength of light emitted by the segmentation laser, and that the laser is clean enough to cut the material, the conductive layer can still be segmented through a number of combinations of layers and other materials (e.g., release sheets).

[0106] In one embodiment of a display stack design where segmentation is not required on both conductive layers, the barrier layer on the non-etching side is made from a metal foil, such as aluminum foil, as a low-cost alternative to a barrier layer formed from other materials (e.g., homopolymer, sputtered ceramic, flexible glass). In some embodiments, the substrate and barrier layer on one side (e.g., top, bottom) are opaque, and all segmentation is performed through the transparent substrate and barrier layer on the other side of the display stack.

[0107] Those skilled in the art will understand that the techniques of the present invention can be applied to several different segmented display technologies, such as segmented signs, variable transmittance films, and architectural displays. The techniques of the present invention can also be applied to polymer-dispersed liquid crystal (PDLC) displays, which are designed in several custom products such as smart windows and glass displays and smart consumer electronics.

[0108] The electrode arrangements in various types of display stacks of the present invention can be integrated into any of the display types described in the aforementioned E INK and MIT patents and applications. For example, the display may be of the direct-drive type, in which the backplane is provided with multiple electrodes, each of which is provided with a separate connector by a controller that can control the voltage applied to a particular electrode. In such a direct-drive display, a single continuous front electrode is usually provided covering the entire display, but other front electrode arrangements are also possible. Depending on the type of electro-optic material used, it may be possible to use a passive matrix-driven arrangement in which (typically) the backplane supports multiple elongated parallel electrodes ("row electrodes"), while on the opposite side of the electro-optic material, multiple elongated parallel electrodes ("row electrodes") are provided extending perpendicular to the row electrodes, and the overlap between one particular row electrode and one particular row electrode defines one pixel of the display. The display may also be of the active-matrix type, typically with a single continuous front electrode covering the entire display and a matrix of pixel electrodes on the backplane, where each pixel electrode defines one pixel of the display and has an associated transistor or other nonlinear element, and the active-matrix display is scanned in a conventional manner to write to the display in a row-by-row manner. Finally, the display may also be of the stylus-driven type, (typically) with a single electrode on the backplane and without a permanent front electrode, where writing to the display is achieved by moving a stylus across the front surface of the display.

[0109] The display stack of the present invention can be used in any application in which a conventional electro-optical display stack is used. For example, the display stack can be incorporated into e-book readers, portable computers, tablet computers, mobile phones, smart cards, signs, watches, shelf signs, and flash drives.

[0110] It will be apparent to those skilled in the art that numerous changes and modifications can be made without departing from the scope of the invention, in the specific embodiments of the invention described above. Therefore, the entire preceding description should be interpreted as illustrative, not restrictive.

Claims

1. A method for manufacturing a segmented electro-optical display, wherein the method is: To provide an electro-optical display stack, the electro-optical display stack is The first substrate layer, A first layer of light-transmitting conductive material, A layer of electrophoretic material containing multiple charged electrophoretic particles, Laminated adhesive layer, A second layer of light-transmitting conductive material, The second substrate layer and It has the following characteristics: After providing the electro-optical display stack, a laser etching process is used to divide the second layer of the light-transmitting conductive material into a plurality of electrically insulated conductive segments. Includes, The laser etching process includes irradiating the second substrate layer and the second layer of the light-transmitting conductive material at multiple locations using a laser that emits light within a first wavelength range, The second substrate layer is substantially transparent to light within the first wavelength range, and the light-transmitting conductive material of the second layer of the light-transmitting conductive material is substantially absorptive to light within the first wavelength range. In each of the aforementioned locations, The second substrate layer substantially transmits light within the range of the first wavelength, The second layer of the light-transmitting conductive material substantially absorbs and removes light within the range of the first wavelength. The electro-optical display stack further comprises a first barrier layer, a first adhesive layer, a second adhesive layer, and a second barrier layer. The laser etching process further includes irradiating the second adhesive layer and the second barrier layer at the plurality of locations using the laser that emits light within the range of the first wavelength, The second adhesive layer and the second barrier layer are substantially transparent to light within the range of the first wavelength. In each of the aforementioned locations, the second adhesive layer and the second barrier layer substantially transmit light within the range of the first wavelength. The aforementioned method, The method further includes irradiating the first barrier layer, the first adhesive layer, the first substrate layer, and the first layer of the light-transmitting conductive material at a second number of locations using a laser that emits light within a second wavelength range, The first barrier layer, the first adhesive layer, the first substrate layer, and the first layer of the light-transmitting conductive material are substantially absorbent of light within the second wavelength range. In each of the second plurality of locations, the first barrier layer, the first adhesive layer, the first substrate layer, and the light-transmitting conductive material of the first layer of the light-transmitting conductive material substantially absorb and remove light within the second wavelength range. The aforementioned method, A method further comprising removing a plurality of volumes of the electrophoretic material layer and the laminated adhesive layer adjacent to each of the second plurality of locations.

2. A method for manufacturing a segmented electro-optical display, wherein the method is: To provide an electro-optical display stack, the electro-optical display stack is The first substrate layer, A first layer of light-transmitting conductive material, A layer of electrophoretic material containing multiple charged electrophoretic particles, Laminated adhesive layer, A second layer of light-transmitting conductive material, The second substrate layer and It has the following characteristics: After providing the electro-optical display stack, a laser etching process is used to divide the second layer of the light-transmitting conductive material into a plurality of electrically insulated conductive segments. Includes, The laser etching process includes irradiating the second substrate layer and the second layer of the light-transmitting conductive material at multiple locations using a laser that emits light within a first wavelength range, The second substrate layer is substantially transparent to light within the first wavelength range, and the light-transmitting conductive material of the second layer of the light-transmitting conductive material is substantially absorptive to light within the first wavelength range. In each of the aforementioned locations, The second substrate layer substantially transmits light within the range of the first wavelength, The second layer of the light-transmitting conductive material substantially absorbs and removes light within the range of the first wavelength. The electro-optical display stack further comprises a first barrier layer, a first adhesive layer, a second adhesive layer, and a second barrier layer. The laser etching process further includes irradiating the second adhesive layer and the second barrier layer at the plurality of locations using the laser that emits light within the range of the first wavelength, The second adhesive layer and the second barrier layer are substantially transparent to light within the range of the first wavelength. In each of the aforementioned locations, the second adhesive layer and the second barrier layer substantially transmit light within the range of the first wavelength. The aforementioned method, Irradiating the second barrier layer, the second adhesive layer, the second substrate layer, and the second layer of the light-transmitting conductive material at a third number of locations using a laser that emits light within a third wavelength range, The second barrier layer, the second adhesive layer, the second substrate layer, and the light-transmitting conductive material of the second layer of the light-transmitting conductive material are substantially absorbent of light within the third wavelength range. In each of the third of the multiple locations, the second barrier layer, the second adhesive layer, the second substrate layer, and the light-transmitting conductive material of the second layer of the light-transmitting conductive material substantially absorb and remove light within the third wavelength range. Removing multiple volumes of the electrophoretic material layer and the laminated adhesive layer adjacent to each of the third multiple locations. Methods that further include this.

3. A method for manufacturing a segmented electro-optical display, wherein the method is: To provide an electro-optical display stack, the electro-optical display stack is The first substrate layer, A first layer of light-transmitting conductive material, A layer of electrophoretic material containing multiple charged electrophoretic particles, Laminated adhesive layer, A second layer of light-transmitting conductive material, The second substrate layer and It has the following characteristics: After providing the electro-optical display stack, a laser etching process is used to divide the second layer of the light-transmitting conductive material into a plurality of electrically insulated conductive segments. Includes, The laser etching process includes irradiating the second substrate layer and the second layer of the light-transmitting conductive material at multiple locations using a laser that emits light within a first wavelength range, The second substrate layer is substantially transparent to light within the first wavelength range, and the light-transmitting conductive material of the second layer of the light-transmitting conductive material is substantially absorptive to light within the first wavelength range. In each of the aforementioned locations, The second substrate layer substantially transmits light within the range of the first wavelength, The second layer of the light-transmitting conductive material substantially absorbs and removes light within the range of the first wavelength. The aforementioned method, The method further includes irradiating the electro-optical display stack at a fifth number of locations using a laser that emits light within a fifth wavelength range, Each layer of the electro-optical display stack is substantially absorbent of light within the fifth wavelength range, A method wherein, in each of the second plurality of locations, the layers of the electro-optic display stack substantially absorb and remove light within the range of the fifth wavelength.

4. The method according to claim 1, wherein the second wavelength range is 9,000 nm to 12,000 nm.

5. The method according to claim 2, wherein the third wavelength range is 9,000 nm to 12,000 nm.

6. The method according to claim 3, wherein the fifth wavelength range is 9,000 nm to 12,000 nm.

7. The laser that emits light within the second wavelength range is CO ２ The method according to claim 1, wherein the laser is used.

8. The method according to claim 1, wherein the plurality of volumes of the electrophoretic material layer and the laminated adhesive layer are removed using deionized water and isopropanol.

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