Foldable electrophoretic display module including non-conductive support plate

Abstract

A foldable electrophoretic display is disclosed, which is flexible and can be folded like a book. The foldable electrophoretic display module can be manufactured separately and integrated into various foldable devices with different functions as needed by the consumer. In some embodiments, the resulting foldable electrophoretic display may include touch sensing, front lighting, color, and a digitization layer to record interactions with a stylus. In some embodiments, the display includes a color filter array.

Description

[0001] Related applications

[0002] This invention claims priority to U.S. Provisional Patent Application No. 63 / 033,954, filed June 3, 2020, the entire contents of which are incorporated herein by reference. All patents disclosed herein and their entire contents are incorporated herein by reference. Technical Field

[0003] This invention relates to a foldable electrophoretic display, the formation of such a display, and component modules for manufacturing the foldable electrophoretic display. The integrated foldable electrophoretic display module can be manufactured in one location and then transported to different manufacturing sites, where different components providing different functions can be integrated into the final foldable display. These different functions include, for example, different types of front lighting, different types of touch sensing, or different types of stylus recognition, depending on consumer needs and desired price points. Background Technology

[0004] In some instances, flexible displays can be folded for portability and / or easy storage. If the display folds simply like a book, it can be folded to have a radius of curvature smaller than a minimum radius designed to prevent breakage. To prevent such problems, various mechanisms, such as hinges and / or other structures, have been applied to the curved portions of the display. For example, Polymer Vision has disclosed a product called Readius. TM It uses one or more mechanical hinge mechanisms to facilitate the folding of the flexible display.

[0005] In another example, Japanese Patent Publication No. 2014-161009 discloses a flexible mobile terminal device configured to bend at various angles. The proposed terminal device includes a folding portion for bending the device to a front or rear upper position of the terminal device body. A flexible display mounted on the upper portion of the terminal device body can be bent to either the front or rear surface depending on the bending direction of the folding portion. The device also includes a sliding portion for sliding one end of the flexible display through a difference in compression / stretch caused by the difference in the elongation rate of the folding portion and the flexible display during bending of the folding portion.

[0006] Both examples above result in thick and heavy products. (Readius, Polymer Vision) TM The mechanical hinge mechanism used is complex in structure and bulky in appearance. The device in Japanese Patent Publication No. 2014-161009 has a corrugated shape and the sliding part is not easy to adjust. The device is also complex and bulky.

[0007] Besides being bulky and thick, an additional drawback of the aforementioned device is that such a design makes it difficult to integrate all the features consumers expect into a high-quality electrophoretic display device, such as touch sensing, front light, stylus recognition, and color. Summary of the Invention

[0008] In response to these needs, this disclosure describes a foldable electrophoretic display module and various foldable electrophoretic displays that incorporate a foldable electrophoretic display module and provide various sensing functions. In a first aspect, the invention includes an electrophoretic display module comprising: a support plate having material pores in a central folded region; a low-modulus adhesive layer adjacent to the support plate; a flexible backplate spanning the central folded region and adjacent to the low-modulus adhesive layer; an electrophoretic display dielectric layer adjacent to the flexible backplate; and a conductive integrated barrier layer including light-transmitting electrodes and moisture-blocking portions. In some embodiments, the electrophoretic display module further includes a protective layer between the low-modulus adhesive layer and the flexible backplate. In some embodiments, the flexible backplate includes an active matrix of organic thin-film transistors. In some embodiments, the electrophoretic display module further includes edge seals coupled to the flexible backplate, the electrophoretic display dielectric layer, and the conductive integrated barrier layer. In some embodiments, the electrophoretic display dielectric layer is contained within a microcell layer. In some embodiments, the electrophoretic display dielectric layer is contained within microcapsules held in place by a polymeric adhesive. In some embodiments, the electrophoretic display module further includes a protective sheet adjacent to the conductive integrated barrier layer. In some embodiments, the electrophoretic display module further includes edge seals coupled to the flexible backplane, the electrophoretic display dielectric layer, the conductive integrated barrier layer, and the protective sheet. In some embodiments, the support plate comprises a non-conductive polymer. In some embodiments, the thickness of the support plate is between 250 micrometers and 50 micrometers.

[0009] In a second aspect, the invention includes a foldable electrophoretic display configured to interact with a stylus. The foldable display includes: a support plate having material pores in a central fold region; a low-modulus adhesive layer adjacent to the support plate; a flexible backplate spanning the central fold region and adjacent to the low-modulus adhesive layer; an electrophoretic display medium layer adjacent to the flexible backplate; a conductive integrated barrier layer including light-transmitting electrodes and moisture-blocking portions; a protective sheet coupled to the conductive integrated barrier layer; an electromagnetic resonance (EMR) sensor layer adjacent to the support plate; a foldable base adjacent to the EMR sensor layer; and a housing surrounding the foldable base and providing a border that contacts the protective sheet, allowing a user to view the electrophoretic display medium through the protective sheet. In some embodiments, the foldable electrophoretic display further includes a low-modulus adhesive interlayer disposed between the EMR sensor layer and the support plate. In some embodiments, the foldable electrophoretic display further includes a high-modulus adhesive interlayer disposed between the EMR sensor layer and the support plate. In some embodiments, the low-modulus adhesive interlayer and the high-modulus adhesive interlayer do not span the central fold region. In some embodiments, the foldable electrophoretic display additionally includes a touch-sensitive layer disposed between the EMR sensor layer and the foldable base. In some embodiments, the foldable electrophoretic display additionally includes a low-modulus adhesive interlayer disposed between the touch-sensitive layer and the foldable base. In some embodiments, the foldable electrophoretic display additionally includes a high-modulus adhesive interlayer disposed between the touch-sensitive layer and the foldable base. In some embodiments, the low-modulus adhesive interlayer and the high-modulus adhesive interlayer do not span the central folding region. In some embodiments, the conductive integrated barrier layer additionally includes a color filter array (CFA).

[0010] In a third aspect, a foldable electrophoretic display is configured to interact with a stylus and includes: a support plate having material pores in a central folding region; a low-modulus adhesive layer adjacent to the support plate; a flexible backplate spanning the central folding region and adjacent to the low-modulus adhesive layer; an electrophoretic display medium layer adjacent to the flexible backplate; a conductive integrated barrier layer including light-transmitting electrodes and moisture-blocking portions; a flexible front light plate coupled to the conductive integrated barrier layer; a flexible capacitive touch layer adjacent to the flexible front light plate; a protective sheet adjacent to the flexible capacitive touch layer; a foldable base adjacent to the support plate; and a housing surrounding the foldable base and providing a border that contacts the protective sheet, allowing a user to view the electrophoretic display medium through the protective sheet. In some embodiments, the foldable electrophoretic display further includes a low-modulus adhesive intermediate layer disposed between the foldable base and the support plate. In some embodiments, the foldable electrophoretic display further includes a high-modulus adhesive intermediate layer disposed between the foldable base and the support plate. In some embodiments, the low-modulus adhesive intermediate layer and the high-modulus adhesive intermediate layer do not span the central folding region. In some embodiments, the conductive integrated barrier layer additionally includes a color filter array (CFA). Attached Figure Description

[0011] Figure 1A An embodiment of a foldable electrophoretic display is shown, comprising a support plate having material pores in a central folding area.

[0012] Figure 1B An embodiment of a module for a foldable electrophoresis display is shown, the electrophoresis display including a support plate with material pores in a central folded area.

[0013] Figure 2A An embodiment of a foldable electrophoretic display is shown, comprising a support plate having material pores in a central folding area. Figure 2A The foldable electrophoretic display includes an electromagnetic resonance (EMR) sensing layer that can sense the stylus.

[0014] Figure 2B An embodiment of a foldable electrophoretic display is shown, comprising a support plate having material pores in a central folding area. Figure 2B The foldable electrophoretic display includes an electromagnetic resonance (EMR) sensing layer that can sense the stylus. Figure 2B One side of the electrophoretic display includes a low-modulus adhesive layer, while Figure 2B The other side of the electrophoretic display includes a high-modulus adhesive layer. Therefore, one side of the display stack can move laterally as the display is folded.

[0015] Figure 3 An embodiment of a foldable electrophoretic display is shown, comprising a support plate having material pores in a central folding area. Figure 3The foldable electrophoretic display includes a capacitive touch sensing layer and a front light.

[0016] Figure 4A A side view of an embodiment of a support plate having material pores in the central folding area is shown.

[0017] Figure 4B A top view of an embodiment of a support plate having material pores in the central folding area is shown.

[0018] Figure 5A A side view of an embodiment of a support plate having material pores in the central folding area is shown.

[0019] Figure 5B A top view of an embodiment of a support plate having material pores in the central folding area is shown. Detailed Implementation

[0020] As previously described, the present invention provides a flexible electrophoretic display that can be folded like a book, and a module for use in the production of such a foldable display. This design is thin and lightweight, and because the support plate is non-conductive, it can be positioned between the electrophoretic display layer and the electromagnetic resonance sensing device.

[0021] This invention is well-suited for use with electrophoretic media of the type developed by Billerica (MA) and described in the following patents and patent disclosures. The encapsulated electrophoretic media comprises multiple small capsules, each comprising an inner phase and a capsule wall surrounding the inner phase, the inner phase comprising electrophoretically moving particles in a fluid medium. Typically, the capsules themselves are held within a polymer binder to form a coherent layer between two electrodes. In microcell electrophoretic displays, charged particles and fluid are not encapsulated within microcapsules, but rather held within multiple cavities formed within a carrier medium (typically a polymer film). The technologies described in these patents and applications include: (a) electrophoretic particles, fluids, and fluid additives; see, for example, U.S. Patent Nos. 7,002,728 and 7,679,814; (b) capsules, binders, and encapsulation processes; see, for example, U.S. Patent Nos. 6,922,276 and 7,411,719; (c) microcell structures, wall materials, and methods of forming microcells; see, for example, U.S. Patent Nos. 7,072,095 and 9,279,906; and (d) methods for filling and sealing microcells; see, for example, U.S. Patent No. 7,144,9 42 and 7,715,088; (e) thin films and sub-components comprising electro-optic materials; see, for example, U.S. Patent Nos. 6,982,178 and 7,839,564; (f) backplanes, adhesive layers, and other auxiliary layers for use in displays, and methods thereof; see, for example, U.S. Patent Nos. D485,294; 6,124,851; 6,130,773; 6,177,921; 6,232,950; 6,252,564; 6,312,304; 6,312,971; 6,376,828; 6,392,786; 6 413,790;6,422,687;6,445,374;6,480,182;6,498,114;6,506,438;6,518,949;6,521,489;6,535,197;6,545,291;6,639,578;6,657,772;6,664,944;6,680,725;6,683,333;6,724,519;6,750,473;6,816,147;6,819,471;6,825,068; 6,831,769;6,842,167;6,842,279;6,842,657;6,865,010;6,873,452;6,909,532;6,967,640;6,980,196;7,012,735;7,030,412;7,075,703;7,106,296;7,110,163;7,116,318;7,148,128;7,167,155;7,173,752;7,176,880;7,190,008;7,206,119;7,223,672;7,230,751;7,256,766;7,259,744;7,280,094;7,301,693;7,304,780;7,327,511;7,347,957;7,349,148;7,352,353;7,36 5,394; 7,365,733; 7,382,363; 7,388,572; 7,401,758; 7,442,587; 7,492,497; 7,535,624; 7,551,346; 7,554,712; 7,583,427; 7,598,173; 7,605,79 9; 7,636,191; 7,649,674; 7,667,886; 7,672,040; 7,688,497; 7,733,335; 7,785,988; 7,830,592; 7,843,626; 7,859,637; 7,880,958; 7,893,435; 7, 898,717;7,905,977;7,957,053;7,986,450;8,009,344;8,027,081;8,049,947;8,072,675;8,077,141;8,089,453;8,120,836;8,159,636;8,208,1 93; 8,237,892; 8,238,021; 8,362,488; 8,373,211; 8,389,381; 8,395,836; 8,437,069; 8,441,414; 8,456,589; 8,498,042; 8,514,168; 8,547,628; 8 576,162;8,610,988;8,714,780;8,728,266;8,743,077;8,754,859;8,797,258;8,797,633;8,797,636;8,830,560;8,891,155;8,969,886;9,147 ,364; 9,025,234; 9,025,238; 9,030,374; 9,140,952; 9,152,003; 9,152,004; 9,201,279; 9,223,164; 9,285,648; and 9,310,661; and U.S. Patent Application Publication Nos. 2002 / 0060321; 2004 / 0008179; 2004 / 0085619; 2004 / 0105036; 2004 / 0112525; 2005 / 0122306; 2005 / 0122563; 2006 / 0215106; 2006 / 0255322; 2007 / 0052757;2007 / 0097489; 2007 / 0109219; 2008 / 0061300; 2008 / 0149271; 2009 / 0122389; 2009 / 0315044; 2010 / 0177396; 2011 / 0140744; 2011 / 0187683; 2011 / 0187689; 2011 / 0292319; 2013 / 0250397; 2013 / 0278900; 2014 / 0078024; 2014 / 0139501; 2014 / 0192000; 2014 / 0210701; 2014 / 0300837; 2014 / 0368753; 2014 / 0376164; 2015 / 0171112; 2015 / 0205178; 2015 / 0226986; 2015 / 0227018; 2015 / 0228666; 2015 / 0261057; 2015 / 0356927; 2015 / 0378235; 2016 / 077375; 2016 / 0103380; and 2016 / 01807759; and International Application Publication No. WO 00 / 38000; European Patent Nos. 1,099,207 B1 and 1,145,072 B1; (g) color formation and color adjustment; see, for example, U.S. Patent Nos. 7,075,502 and 7,839,564; and (h) methods for driving a display; see, for example, U.S. Patent Nos. 7,012,600 and 7,453,445. The entire contents of all the patents and patent applications listed herein are incorporated herein by reference. Many of the foregoing patents and applications recognize that the walls surrounding discrete microcapsules in an encapsulated electrophoretic medium can be replaced by a continuous phase, thereby producing so-called polymer-dispersed electrophoretic displays, wherein the electrophoretic medium comprises a plurality of discrete droplets of electrophoretic fluid and a continuous phase of polymeric material, and the discrete droplets of electrophoretic fluid within such polymer-dispersed electrophoretic displays can be considered as capsules or microcapsules, even without a discrete capsule film associated with each individual droplet; see, for example, the foregoing U.S. Patent No. 6,866,760. Therefore, for the purposes of this application, such polymer-dispersed electrophoretic media are considered a subclass of encapsulated electrophoretic media.

[0022] Encapsulated electrophoretic displays are generally free from the aggregation and sedimentation failure modes of conventional electrophoretic apparatus and offer more beneficial effects, such as the ability to print or coat displays on a variety of flexible and rigid substrates. (The term "printing" is used to include all forms of printing and coating, including but not limited to: pre-metering coating such as patch die coating, slot or extrusion coating, slide or stack coating, curtain coating; roller coating such as roller blade coating, forward and reverse roller coating; concave coating; dip coating; spray coating; meniscus coating; spin coating; brush coating; air knife coating; screen printing; electrostatic printing; thermal printing; inkjet printing; electrophoretic deposition (see U.S. Patent No. 7,339,715); and other similar techniques.) Therefore, the resulting displays can be flexible. Furthermore, because the display medium can be printed (using a variety of methods), the display itself can be manufactured inexpensively.

[0023] While this invention primarily relates to the types described above and the electrophoretic media in the listed patents and patent applications, other types of electro-optic materials may also be used in this invention. Alternative electro-optic media are generally reflective in nature, i.e., they rely on ambient lighting for illumination rather than having a backlight like an emissive LCD display. Alternative electro-optic media include, for example, rotating dual-color component-type media described below: U.S. Patent Nos. 5,808,783; 5,777,782; 5,760,761; 6,054,071; 6,055,091; 6,097,531; 6,128,124; 6,137,467; and 6,147,791. Such displays employ a large number of small bodies (typically spherical or cylindrical) having two or more portions with different optical properties, and internal dipoles. These bodies are suspended within liquid-filled cavities within a matrix, allowing the bodies to rotate freely. By applying an electric field to alter the appearance of the display, the subject can be rotated to different positions, changing which part of the subject is seen through the viewing surface. This type of electro-optic medium is typically bistable.

[0024] Another alternative electro-optic display medium is electrochromic, such as an electrochromic medium in the form of a nanochromic film, which comprises electrodes at least partially formed of semiconductor metal oxides and multiple dye molecules attached to the electrodes capable of reversing color changes; 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. Patent Nos. 6,301,038; 6,870,657; and 6,950,220. This type of medium is also typically bistable.

[0025] Example of a foldable electrophoresis display (FEPID) such as Figure 1A As shown. The foldable display 10 generally includes an electrophoretic display medium layer 80 and at least two other conductive layers 75 and 90 disposed on opposite sides of the electrophoretic display medium layer 80. The conductive layers and the electrophoretic display medium layer 80 are stacked on a support plate 50, which has material pores 55 in a central folding region 57. Typically, a flexible backplate 75 is coupled to the support plate 50 having a low-modulus adhesive 60, which provides good adhesion between the layers such that the display surface remains flat when opened, but also allows sufficient lateral sliding so that the flexible backplate 75 can move slightly relative to the support plate 50 when the FEPID is opened and closed. Suitable low-modulus adhesives 60 may include adhesive foam polymers from 3M (Minneapolis, Minnesota) and CGR Products (Greensboro, NC). Low-modulus adhesives may include polyurethane, polyacrylate, and / or silicone. Example low-modulus adhesives are known as It is a registered trademark of Rogers Corporation, or It is a registered trademark of Dow Chemical Corporation. In some instances, low-modulus adhesive 60 provides compressive strength between support plate 50 and flexible backing plate 75. Although Figure 1A The low-modulus adhesive layer 60 is described as spanning the central fold region 57, but the low-modulus adhesive layer 60 may also be interrupted at the central fold region 57, thereby providing more space for flexibility in the portion of the support plate 50 with material pores 55 (i.e., in the central fold region 57). The thickness of the low-modulus adhesive layer is typically between 500 micrometers and 50 micrometers, for example, between 300 micrometers and 100 micrometers.

[0026] While the standalone support plate 50 provides sufficient rigidity for the foldable display 10, the foldable display 10 typically additionally includes a base frame 20 coupled via hinge 25 to provide mechanical shock protection and to prevent the support plate from extending beyond its flat position (i.e., opening beyond 180°), at which point the flexible backplate 75 could fail due to the flexible traces (not shown) in the flexible backplate 75 being stretched to a point of fracture. The base frame structure may include a two-part base frame, such as... Figure 1A As shown, however, the base frame can include a three-part system, whereby the central "spine" region is coupled to two different plates via two different hinges, or a complex hinge spanning three parts. Therefore, through... Figure 1A The stacking shown creates a lightweight electrophoretic display 10 that can be folded between flat (as shown) and closed, just like a regular book.

[0027] exist Figure 1A In this example, the top conductive layer has been incorporated into a conductive integrated barrier layer 90, which includes a light-transmitting conductive material and a flexible moisture-blocking portion. For example, the conductive integrated barrier layer 90 may include a sputtered conductive material that transmits visible light, such as indium tin oxide (ITO), or the conductive integrated barrier layer 90 may include conductive filaments, nanowires, or nanotubes, thereby providing the desired combination of conductivity, light transmittance, and flexibility. Alternatively, the conductive integrated barrier layer 90 may incorporate one or more light-transmitting conductive polymers, such as poly(3,4-ethylenedioxythiophene) (PEDOT), which can be dissolved by adding polystyrene sulfonate. The conductive integrated barrier layer 90 typically also includes a moisture-blocking material, such as a waterproof material, such as an inorganic ceramic, an organic polymer, or an organic / inorganic composite. Inorganic ceramics include, for example, silicon oxide (SiOx) or silicon nitride (SiNx). Organic polymers include, for example, parylene or polypropylene, or polyethylene terephthalate (PET). Organic / inorganic composites include, for example, amorphous silicon / parylene composites, or polypropylene / polyacrylate / aluminum composites. In some embodiments, the conductive integrated barrier layer 90 may also include an integrated color filter array (CFA), such as the type described in U.S. Patent No. 10,209,556, the entire contents of which are incorporated herein by reference. Alternative constructions of the color filter array incorporated into the conductive integrated barrier layer 90 are also possible, for example, using stacked color films, offset printing, or lithography. The CFA of such a device may include four colored subpixels, such as red, green, blue, and transparent (white), three colored subpixels, such as red, green, and blue, or stripes extending from top to bottom, from left to right, or diagonally. Combinations of subpixels and stripes are possible, and the color group is not limited to red, green, and blue, as other suitable color groups are available, provided that the combination of colors provides an acceptable palette for reproducing a color image.

[0028] In the foldable display 10, a flexible backplane 75 includes a plurality of driving electrodes on a flexible substrate. In FEPID, an electrical driving waveform is transmitted via flexible conductive traces (not shown) coupled to thin-film transistors (TFTs) that typically include pixel electrodes on the flexible backplane 75, which allows the pixel electrodes to be addressed in a column-row addressing scheme. In other embodiments, the pixel electrodes of the flexible backplane 75 can be directly driven, i.e., each pixel is directly turned on and off by driving circuitry. In some embodiments, the conductive integrated barrier layer 90 is grounded only and drives the image by providing positive and negative potentials to the individually addressable flexible backplane pixel electrodes. In other embodiments, a potential can also be applied to the conductive integrated barrier layer 90 to provide a larger variation in the field that can be provided between the conductive integrated barrier layer 90 and the flexible backplane 75. Active matrix flexible backplanes suitable for the present invention are available from, for example, FlexEnable (Cambridge, UK) and other suppliers. Flexible active matrix backplanes typically use thin films of conductive organic materials to create flexible thin-film transistors. For further details regarding suitable flexible backsheets and backsheet components, see U.S. Patent Nos. 7,223,672, 7,902,547, and 8,431,941, the entire contents of which are incorporated herein by reference.

[0029] In many embodiments, the flexible backplane 75 includes an active matrix for image driving. In an active matrix arrangement, each pixel electrode is coupled to a thin-film transistor patterned as an array and connected to an elongated row electrode and an elongated column electrode extending perpendicular to the row electrode. In some embodiments, the pixel comprises a transistor made of a metal oxide or conductive polymer material. In some embodiments, the pixel is flexible. In some embodiments, the pixel is rigid, but because the substrate and the traces between the pixels are flexible, the backplane can be sufficiently flexible to create a flexible backplane. Typically, a data driver is connected to the column electrode and provides a source voltage to all TFTs to be addressed in the column. Additionally, a scan driver is connected to the row electrode to provide a bias voltage that turns on (or off) the gate of each TFT along the row. The gate scan rate is typically around 60-100 Hz. It should be understood that the allocation of the "row" and "column" electrodes is somewhat arbitrary and the TFT array can be fabricated with the roles of the row and column electrodes interchanged. In some embodiments, the TFT array is generally flexible; however, individual components, such as individual pixel transistors or driving circuitry, may not be flexible. The flexible traces used to apply voltage to individual pixels can be formed from flexible materials, such as conductive polymers or polymers doped with conductive materials (such as metal particles, nanoparticles, nanowires, nanotubes, graphite, and graphene).

[0030] like Figure 1BAs shown, the present invention further includes a foldable electrophoresis display module 15. Such a foldable display module 15 can be manufactured as a separate foldable electrophoresis display component, thereby allowing it to be supplied to various manufacturers who can integrate the module 15 into foldable electrophoresis displays, the types of which are described below. Figure 2A , 2B As shown in Figure 3. The foldable display module 15 is typically conditioned and sealed before shipment so that it can be laminated to additional components, such as a front light or capacitive touch sensor, or an electromagnetic resonance sensing layer, both of which will be discussed below. To maintain the integrity of module 15, the module typically includes an edge seal 93 or a typical type of electrophoretic display. For a further description of the EPD edge seal, see U.S. Patent No. 7,554,712, the entire contents of which are incorporated herein by reference.

[0031] The flexible display module 15 includes: a support plate 50 having material pores 55 in a central folded region 57; a low-modulus adhesive layer 60; a flexible backplate 75 spanning the central folded region 57; an electrophoretic display dielectric layer 80; and a conductive integrated barrier layer 90, which includes features of both light-transmitting electrodes and moisture-blocking portions. Figure 1B As shown in more detail, the electrophoretic display medium layer 80 may include microcapsules 88 that hold electrophoretic pigment particles 83 and 87 and solvent 82, the microcapsules 88 being dispersed in a polymer binder 81. However, it should be understood that the electrophoretic medium (particles 83 and 87 and solvent 82) may be encapsulated in microcells (microcups) or distributed in the polymer without surrounding microcapsules (e.g., the aforementioned PDEPID design). Typically, the pigment particles 83 and 87 are controlled (displaced) using an electric field generated between the conductive integrated barrier layer 90 and the flexible backplane 75. The module of the present invention may additionally include a top protective sheet 95, which may be a hardened, transparent, anti-glare cover made of a polymer (e.g., polyacrylate or polyimide). The top protective sheet 95 may be integrated into the edge seal 93, or the top protective sheet 95 may actually encapsulate the edge seal to provide an additional level of environmental protection for the electrophoretic display layer 80 and the flexible backplane 75. In some instances, module 15 will additionally include a protective layer 70 between the low-modulus adhesive 60 and the flexible backsheet 75 to prevent the low-modulus adhesive from entering the flexible backsheet 75 material. The protective layer 70 may be a thin polymer layer, such as polyethylene terephthalate, or the protective layer 70 may be a flexible dielectric layer, such as parylene, applied to the “back” side of the flexible backsheet 75.

[0032] Although EPD media are described as “black / white,” they are typically driven to multiple different states between black and white to achieve various hues or “grayscales.” Furthermore, a given pixel can be driven between first and second grayscale states (which include the endpoints of white and black) by driving the pixel through a transition from an initial grayscale level to a final grayscale level (which may be different from or the same as the initial grayscale level). The term “waveform” will be used to describe the curve of the entire voltage versus time used to achieve the transition from a particular initial grayscale level to a particular final grayscale level. Typically, such a waveform will include multiple waveform elements; where these elements are essentially rectangular (i.e., where a given element includes the application of a fixed voltage for a period of time); these elements may be referred to as “pulses” or “drive pulses.” The term “drive scheme” refers to a set of waveforms sufficient to achieve all possible transitions between grayscale levels of a particular display. A display can utilize more than one drive scheme; for example, the aforementioned U.S. Patent No. 7,012,600 teaches that drive schemes may need to be modified according to parameters such as display temperature or the duration of operation during the lifespan of the display, thus a display can be provided with a variety of different drive schemes for use at different temperatures, etc. A set of driver schemes used in this way can be called a "set of related driver schemes". It is also possible to use more than one driver scheme simultaneously in different areas of the same display, and a set of driver schemes used in this way can be called a "set of simultaneous driver schemes".

[0033] Foldable electrophoretic display including touch sensing and digitization layers

[0034] Advanced implementations of the foldable electrophoresis display (FEPID) utilizing the design of the present invention, for example Figure 2A and Figure 2B As shown. The FEPID 100 is roughly similar to a foldable version of the premium dual-panel electrophoretic tablet computer sold by GVIDO Music Co., LTD. (Tokyo, Japan) as a digital electronic paper music score. However, this invention allows the folded area to be active, enabling a continuous reading and writing experience across the entire spine. Figure 2A and 2B The FEPID 100 design shown does not need to be as large as two full A4 sheets of paper, and can be the size of a single A4 sheet when opened flat, providing two panes of approximately 100mm x 150mm when opened as a book-holding section. The FEPID 100 can include all the features currently anticipated in such a device, including Wi-Fi communication, Bluetooth, color-adjustable front light, stylus recognition and writing reproduction, touch sensing, and color. The color electrophoretic display can include a color filter array used with conventional black and white ink, or the color electrophoretic display can incorporate IENK's advanced electrophoretic display technologies, such as Advanced Color e Paper (ACEP).TM ) or E InkSpectra TM ACeP TM and E Ink Spectra TM For details, see U.S. Patent Nos. 9,921,451 and 10,032,419, the entire contents of which are incorporated herein by reference.

[0035] Back Figure 2A The foldable electrophoretic display (FEPID) 100 includes a housing 110 extending around the back of the display 100, with a notch in the middle to allow the display 100 to fold like a book. The housing 110 covers a base frame 120, which includes two plates providing shock absorption and preventing back bending of the display 100, as described above. Figure 1A The casing can be a durable polymer, such as nylon, or it can be a "finished" material, such as wood or leather. Although Figure 1A Not shown, but housing 110 may also be integrated into frame 120 and optionally coupled to a hinge (not shown) that provides the radius of folding of frame 120. Housing 110 surrounds the display and ends with bezel 105, which may be above or flush with the top surface of display 100. Figure 1A In one example, the border 105 is above the top protective sheet 195, which may be a hardened, transparent anti-glare cover made of a polymer such as polyacrylate or polyimide.

[0036] Figure 2A The illustrated embodiment includes two pressure touch sensor layers 130 on each of the base plate 120. Due to the use of a thin support plate 150 with material pores 155 and a low-modulus adhesive 160 between the flexible back plate 175 and the support plate 150, sufficient compressive force exists to activate the pressure touch sensor layers 130 when a user pushes the protective sheet 195 with their finger. Such pressure-sensitive layers may include micro-deformation piezoresistive sensors, which are relatively thin and available from Uneo Inc. (New Taipei City, Taiwan, China). Alternative thin touch-sensitive technologies, such as the QTC force sensing technology pioneered by Peratech (Richmond, United Kingdom), can also be used for the pressure touch sensor layers 130.

[0037] The display 100 of Figure 2 further includes a flexible electromagnetic resonant (EMR) sensor layer 140 for sensing an active stylus, which can be used for, for example, handwriting capture, sketching, marking, or manipulating objects on the display. The flexible EMR layer 140 may include stacked loops of wire in a flexible medium, thereby allowing proximity sensing of an active or passive stylus. Suitable styluses are available, for example, from Wacom (Kazo, Japan). The EMR layer 140 may be a single continuous unit, or it may be an collection of individual EMR layers 140. Figure 2A In alternative embodiments not shown, the EMR layer 140 may comprise two separate semi-rigid EMR layers, which are of the type available from Wacom and have a dedicated flexible EMR with a smaller area spanning the central fold region. In some embodiments, one or both surfaces of the flexible EMR layer 140 will be roughened, or have a roughened surface 145, to help the EMR layer remain relatively flat and move only laterally, rather than vertically, as... Figure 2A As shown.

[0038] In the center of the foldable display 100 is a support plate 150 with material pores 155 in the central folding area. (See also: Regarding...) Figure 4A , 4B As detailed in 5A and 5B, the support plate can be made of various materials, such as polymers, metals (e.g., stainless steel), carbon fiber, or wood veneer. Figure 2A In some embodiments, the support plate 150 comprises a non-conductive polymer, such as polyethylene terephthalate, which does not interfere with electromagnetic resonant position sensing between the flexible EMR layer 140 and the stylus used on the top surface of the display 100. The thickness of the support plate is typically between 250 micrometers and 50 micrometers. For simplicity, in Figure 2A The central folding area of ​​the support plate 150 is not specifically marked, but it is roughly the area where the hole 155 is removed from the support plate 150. The central folding area may be less than 20% of the total surface area of ​​the support plate 150, for example, less than 10% of the total surface area of ​​the support plate 150, for example, less than 5% of the total surface area of ​​the support plate 150.

[0039] As described above, a low-modulus adhesive layer 160 is disposed between the support plate 150 and the flexible backplate 175. Ultimately, in some embodiments, a protective layer 170 may be disposed between the flexible backplate 175 and the low-modulus adhesive layer 160 to protect the flexible backplate 175 from corrosion or electrical failures caused by contact with the low-modulus adhesive layer 160. The low-modulus adhesive layer 160 may include conductive materials or solvents that could corrode the flexible backplate 175. However, with the selection of a suitable low-modulus adhesive layer 160, the protective layer 170 may not be necessary. (Elements 180, 181, 182, 183, 187, 188, and 190 are the electrophoretic display layer 80, polymer binder 81, electrophoretic medium solvent 82, first particle group 83, second particle group 87, capsule wall 88, and conductive integrated barrier layer 90, as described above regarding...) Figure 1B As stated above.

[0040] In commercial applications, when the foldable electrophoretic display (FEPID) includes an EMR sensing layer 140 and a pressure touch sensor layer 130, additional components may be present in the FEPID 101, such as... Figure 2B As shown. First, as regarding Figure 1B As shown, a hinge 125 may be included to facilitate the opening and closing of the two plates of the base 130. Hinges 125 are merely exemplary and various alternative hinges may be used. Additionally, one or more additional low-modulus adhesive layers are typically added between the layers of the FEPID display 101 to help the display 101 maintain a smooth profile during repeated opening and folding. For example, a first intermediate low-modulus adhesive layer 133 may be provided between the pressure touch sensor layer 130 and the flexible EMR layer 140. A second intermediate low-modulus adhesive layer 143 may be provided between the flexible EMR layer 140 and the support plate 150. Note that the first and second intermediate low-modulus adhesive layers do not need to span the entire width of the display, i.e., from... Figure 2B From left to right. The partial misalignment of this low-modulus adhesive provides greater porosity during the folding process, resulting in less pressure on the electrophoretic display layer 180 during folding and reducing the likelihood of failure or delamination due to repeated folding. In addition to the low-modulus adhesive layers 143 and 147, a high-modulus adhesive, such as polyurethane or polyacrylate, can be used on opposite sides of the FEPID 101 to ensure that the layers of the display 101 are locked together and that most lateral movement occurs on one side of the display while the other side remains fixed. Specifically, a first intermediate high-modulus adhesive layer 137 can be provided between the pressure touch sensor layer 130 and the flexible EMR layer 140, while a second intermediate high-modulus adhesive layer 147 can be provided between the flexible EMR layer 140 and the support plate 150. The high-modulus adhesive helps the layers remain aligned during repeated opening and closing cycles.

[0041] Foldable electrophoretic display including front light and capacitive touch sensing

[0042] The foldable electrophoretic display (FEPID) 200 includes a capacitive touch sensing layer 294, a front light panel 292, and a light source 291, such as Figure 3 As shown. Many of the components in the FEPID 200 are related to... Figure 2A The FEPID 100 is identical. FEPID 200 includes a housing 210 extending around the back of the display 200, with a notch in the middle to allow the display 200 to fold like a book. The housing 210 covers a base frame 220, which includes two plates providing shock absorption and preventing back bending of the display 200, as described above. Figure 2A The housing 210 surrounds the display and terminates at a bezel 205, which may be above or flush with the top surface of the display 200. Figure 3 In one example, the border 105 is above the top protective sheet 195, which may be a hardened, transparent anti-glare cover made of a polymer such as polyacrylate or polyimide.

[0043] In the center of the foldable display 200 is a support plate 250 with material pores 255 in the central folding area. (See also: ...) Figure 4A , 4B As detailed in 5A and 5B, the support plate can be made of various materials, such as polymers, metals (such as stainless steel), carbon fiber, or wood veneer. Figure 3 In this embodiment, the support plate 250 can be made of conductive or non-conductive material because there is no sensing mechanism behind the support plate 250. The thickness of the support plate is typically between 250 micrometers and 50 micrometers. For simplicity, in Figure 3 The central folding area of ​​the support plate 250 is not specifically marked, but it roughly represents the area where the aperture 255 is removed from the support plate 250. A low-modulus adhesive layer 260 is disposed between the support plate 250 and the flexible backplate 275. Ultimately, in some embodiments, a protective layer 270 may be disposed between the flexible backplate 275 and the low-modulus adhesive layer 260 to protect the flexible backplate 275 from corrosion or electrical failures caused by contact with the low-modulus adhesive layer 260, which may include conductive materials or solvents that could corrode the flexible backplate 275. Elements 280, 281, 282, 283, 287, 288, and 290 are the electrophoretic display layer 80, polymer binder 81, electrophoretic medium solvent 82, first particle group 83, second particle group 87, capsule wall 88, and conductive integrated barrier layer 90, as described above. Figure 1B As stated above.

[0044] In the FEPID 200, sensing is achieved through a flexible capacitive touch layer 294 positioned near the surface of the display 200 and protected by a top protective sheet 95. The top protective sheet 95 can be a hardened, transparent, anti-glare cover made of a polymer such as polyacrylate or polyimide. The flexible capacitive touch layer 294 can be used for touch input by a user's finger and for touch writing using a capacitive stylus supplied by, for example, N-Trig Technologies (Tel Aviv, Israel). Since the flexible capacitive touch layer 294 is located between the observer and the electrophoretic display medium, it must also be translucent. Figure 3 The FEPID 200 shown also includes a front light panel 292 illuminated by one or more light sources 291, which can be white or light-emitting diodes (LEDs) with various LED colors, and the color of the front light can be adjusted according to the user's needs.

[0045] Therefore, it can be seen that module 15 of the present invention can be incorporated into various foldable electrophoretic display designs. However, these designs are not limited to... Figure 2A , 2B And 3. Conversely, various different digital systems can be used with the foldable electrophoretic display module shown herein. For example, active electrostatic sensing (Wacom), or infrared sensing from Planar Technologies (Hillsboro, Oregon), can be used with this invention. Furthermore, various foldable electrophoretic display devices can be integrated into the device ecosystem, including Wi-Fi, Bluetooth, ZigBee, etc.

[0046] Creation of a support plate with material pores

[0047] As described above, the support plates (50, 150, 250) used in the present invention described herein can be made of polymers, metals (e.g., stainless steel), carbon fibers, or wood veneers. In instances where the sensing layer is disposed beneath the support plates (50, 150, 250), the support plates (50, 150, 250) are preferably made of a non-conductive polymer such as polyethylene terephthalate, which does not interfere with electromagnetic resonant position sensing between the flexible EMR layer 140 and the stylus used on the top surface of the display 100, as per [reference to...]. Figure 2A As described. However, for example, in the case where there is no sensor on the back side of the support plate (50, 150, 250), such as Figure 3 As shown, the support plates (50, 150, 250) do not need to be non-conductive. Therefore, alternatives such as stainless steel can be used. Figure 3 In most cases, the thickness of the support plate is typically between 250 micrometers and 50 micrometers, for example, between 150 micrometers and 100 micrometers.

[0048] Two implementations of the support plate with material pores in the central folding area. Figure 4A , 4B As shown in 5A and 5B ( Figure 4A This is a side view of the first embodiment, and Figure 4B This is a top view. Figure 5A This is a side view of the second embodiment, and Figure 5B (This is a top view.) (To create...) Figure 4A In one embodiment, the single piece of material 451 can be milled, cut, embossed, ablated, or laser-processed to create pores 455, allowing the support plate 450 to bend repeatedly with a small force in the desired direction. The rigidity of the support plate 450 can be adjusted by selecting an appropriate depth of the pores relative to the total thickness of the workpiece 451. The depth of the pores does not need to be uniform across the entire workpiece; for example, it can be cut in a Gaussian distribution, with the maximum depth at the center and the cut gradually becoming shallower away from the center. For simplicity, the central folding area of ​​the support plate 450 is... Figure 4A There is no specific marking, but it roughly refers to the area where the aperture 455 is removed from the support plate 450. The central folding area can be less than 20% of the total surface area of ​​the support plate 450, for example, less than 10% of the total surface area of ​​the support plate 150, for example, less than 5% of the total surface area of ​​the support plate 450.

[0049] Support plates with material pores are not limited to Figure 4A and 4B The cutting pattern is shown. For example, workpiece 551 may have a series of holes 555 cut from workpiece 551 to create a central folded area. Figure 5A and 5B In one embodiment, the support plate may be metal, in which case the apertures can be stamped or milled from the workpiece 551. Alternatively, if the workpiece 551 is polymer or carbon fiber, the apertures 555 can be created by laser cutting.

[0050] definition

[0051] The term "electro-optic," used here in the context of materials or displays, refers to a material having first and second display states, where at least one optical property differs, and the material is changed from its first display state to its second display state by applying an electric field. While the optical property is typically color perceptible to the human eye, it can be another optical property, such as light transmission, reflection, emission, or, in the case of displays used for machine reading, a pseudocolor in the sense of a change in reflectivity at electromagnetic wavelengths outside the visible light range.

[0052] The terms "grayscale" or "gray state" are used here in their conventional meaning in the imaging field, referring to a state between the two extreme optical states of a pixel, but not necessarily a black-and-white transition between those two extremes. For example, several patents and publications of IENK, discussed below, describe electrophoretic displays where the extreme states are white and dark blue, making the intermediate "gray state" actually a pale blue. In fact, as already mentioned, a change in optical state may not be a change in color at all. The terms "black" and "white" may be used below to refer to the two extreme optical states of a display, and should be understood to generally include extreme optical states that are not strictly black and white, such as the white and dark blue states mentioned above. The term "monochrome" may be used below to refer to a driving scheme that drives pixels only to their two extreme optical states, without an intermediate gray state.

[0053] In the sense that a material has a solid outer surface, some electro-optic materials are solid, although the material may and often does indeed have internal spaces filled with liquid or gas. For convenience, such displays using solid electro-optic materials may be referred to as "solid-state electro-optic displays" below. Therefore, the term "solid-state electro-optic display" includes rotating dual-color component displays, encapsulated electrophoretic displays, microcell electrophoretic displays, and encapsulated liquid crystal displays.

[0054] The terms “bistable” and “bistable” are used herein in their conventional sense in the art, referring to a display comprising display elements having first and second display states, at least one optical characteristic of which differs such that, after any given element is driven to present its first or second display state using an addressing pulse of finite duration, the state will persist for at least several times (e.g., at least four times) the minimum duration of the addressing pulse required to change the state of the display element after the addressing pulse terminates. As shown in U.S. Patent No. 7,170,670, some particle-based electrophoretic displays supporting grayscale are stable not only in their extreme black and white states but also in intermediate gray states, as are some other types of electro-optical displays. This type of display is aptly referred to as “multistable” rather than bistable, but for convenience, the term “bistable” may be used herein to encompass both bistable and multistable displays.

[0055] It will be apparent to those skilled in the art that many changes and modifications can be made to the specific embodiments of the present invention described above without departing from the scope of the invention. Therefore, all of the above description is to be interpreted as illustrative rather than restrictive.

Claims

1. A foldable electrophoretic display configured to interact with a stylus, the foldable display comprising: Electrophoresis display module, including: A support plate comprising a non-conductive polymer and having material pores in a central folded region; A low-modulus adhesive layer, which is adjacent to the support plate; A flexible backsheet that spans the central folded area and is adjacent to the low-modulus adhesive layer; Electrophoretic display dielectric layer, which is adjacent to the flexible backplate; and A conductive integrated barrier layer, comprising a light-transmitting electrode and a moisture-blocking portion. The foldable display also includes: A protective sheet coupled to the conductive integrated barrier layer; An electromagnetic resonance (EMR) sensor layer, which is adjacent to the support plate; A low-modulus adhesive interlayer is disposed between the EMR sensor layer and the support plate; and a high-modulus adhesive interlayer is disposed between the EMR sensor layer and the support plate; A foldable base frame, adjacent to the EMR sensor layer; and A housing that surrounds the foldable base and provides a border that contacts the protective sheet, allowing the user to view the electrophoretic display medium through the protective sheet; The low-modulus adhesive layer and the low-modulus adhesive intermediate layer help the foldable display maintain a smooth shape during repeated opening and folding, while the high-modulus adhesive helps the layers remain aligned during repeated opening and closing cycles.

2. The foldable electrophoresis display according to claim 1, wherein, The electrophoretic display module also includes a protective layer between the low-modulus adhesive layer and the flexible backplate.

3. The foldable electrophoresis display according to claim 1, wherein, The flexible backplane includes an active matrix of organic thin-film transistors.

4. The foldable electrophoresis display according to claim 1, wherein, The electrophoretic display module also includes an edge seal coupled to the flexible backplate, the electrophoretic display medium layer and the conductive integrated barrier layer.

5. The foldable electrophoresis display according to claim 1, wherein, The electrophoretic display medium layer is contained within the micro-unit layer.

6. The foldable electrophoresis display according to claim 1, wherein, The electrophoretic display medium layer is contained within microcapsules, and the microcapsules are held in place by a polymer binder.

7. The foldable electrophoresis display according to claim 1, wherein, The electrophoretic display module includes a protective sheet adjacent to the conductive integrated barrier layer, and the electrophoretic display module also includes an edge seal coupled to the flexible backplate, the electrophoretic display medium layer, the conductive integrated barrier layer, and the protective sheet.

8. The foldable electrophoresis display according to claim 1, wherein, The thickness of the support plate is between 250 micrometers and 50 micrometers.

9. The foldable electrophoresis display according to claim 1, wherein, The low-modulus adhesive interlayer and the high-modulus adhesive interlayer do not cross the central fold area.

10. The foldable electrophoresis display according to claim 1, further comprising a touch-sensitive layer disposed between the EMR sensor layer and the foldable base.

11. The foldable electrophoretic display of claim 10, further comprising a low-modulus adhesive interlayer disposed between the touch-sensitive layer and the foldable base.

12. The foldable electrophoretic display according to claim 11, further comprising a high-modulus adhesive intermediate layer disposed between the touch-sensitive layer and the foldable base frame.

13. The foldable electrophoretic display according to claim 12, wherein, The low-modulus adhesive interlayer and the high-modulus adhesive interlayer do not cross the central fold area.

14. The foldable electrophoresis display according to claim 1, wherein, The conductive integrated barrier layer further includes a color filter array (CFA).

15. A foldable electrophoretic display configured to interact with a stylus, the foldable display comprising: Electrophoresis display module, including: A support plate comprising a non-conductive polymer and having material pores in a central folded region; A low-modulus adhesive layer, which is adjacent to the support plate; A flexible backsheet that spans the central folded area and is adjacent to the low-modulus adhesive layer; Electrophoretic display dielectric layer, which is adjacent to the flexible backplate; and A conductive integrated barrier layer, comprising a light-transmitting electrode and a moisture-blocking portion. The foldable display also includes: A flexible front light panel, coupled to the conductive integrated barrier layer; A flexible capacitive touch layer is adjacent to the flexible front light panel; A protective sheet is adjacent to the flexible capacitive touch layer; A foldable base frame, adjacent to the support plate; and A housing surrounding the foldable base and providing a border that contacts the protective sheet, allowing a user to view the electrophoretic display medium through the protective sheet; and A low-modulus adhesive intermediate layer is disposed between the foldable base frame and the support plate; and a high-modulus adhesive intermediate layer is disposed between the foldable base frame and the support plate; The low-modulus adhesive layer and the low-modulus adhesive intermediate layer help the foldable display maintain a smooth shape during repeated opening and folding, while the high-modulus adhesive helps the layers remain aligned during repeated opening and closing cycles.

16. The foldable electrophoretic display according to claim 15, wherein, The low-modulus adhesive interlayer and the high-modulus adhesive interlayer do not cross the central fold area.

17. The foldable electrophoretic display according to claim 15, wherein, The conductive integrated barrier layer further includes a color filter array (CFA).

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