HK40031048A - Assemblies of electro-optic displays - Google Patents

Description

Assembly of electro-optic display

Cross Reference to Related Applications

This application claims benefit and priority from U.S. provisional application No.62/643,802 filed on 3, 16, 2018, the entire contents of which are incorporated herein by reference.

Technical Field

The present invention relates to electro-optic displays. More particularly, in one aspect, the invention relates to an assembly in the form of alphanumeric characters comprising a plurality of electro-optic displays and a method of making the same.

Background

As applied to materials or displays, the term "electro-optic" is used herein in its conventional sense in the imaging arts to refer to a material having first and second display states differing in at least one optical property, the material being changed from its first display state to its second display state by application of an electric field to the material. Although the optical property is typically a color perceptible to the human eye, it may be another optical property, such as light transmission, reflection, luminescence, or, in the case of a display for machine reading, a false color in the sense of a change in reflectivity of electromagnetic wavelengths outside the visible range.

The term "gray state" is used herein in its conventional sense in the imaging art to refer to a state intermediate two extreme optical states of a pixel, but does not necessarily imply a black-and-white transition between the two extreme states. For example, several patents and published applications by the incorporated of lngk referred to below describe electrophoretic displays in which the extreme states are white and dark blue, so that the intermediate "gray state" is effectively pale blue. In fact, as already mentioned, the change in optical state may not be a color change at all. The terms "black" and "white" may be used hereinafter to refer to the two extreme optical states of the display and should be understood to generally include extreme optical states that are not strictly black and white, such as the white and deep blue states mentioned above. The term "monochromatic" may be used hereinafter to denote a driving scheme in which a pixel is driven only to its two extreme optical states, without an intermediate gray state.

Some electro-optic materials are solid in the sense that the material has a solid outer surface, although the material may, and often does, have a space filled with a liquid or gas inside. For convenience, such displays using solid electro-optic materials may be referred to hereinafter as "solid electro-optic displays". Thus, the term "solid state electro-optic display" includes rotating bichromal member displays, encapsulated electrophoretic displays, microcell electrophoretic displays, and encapsulated liquid crystal displays.

The terms "bistable" and "bistability" are used herein in their conventional sense in the art to refer to displays comprising display elements having first and second display states differing in at least one optical characteristic such that, after any given element is driven to assume its first or second display state by an addressing pulse of finite duration, that state will persist for at least several times (e.g. at least 4 times) the minimum duration of the addressing pulse required to change the state of that display element after the addressing pulse has terminated. It is shown in U.S. patent No.7,170,670 that some particle-based electrophoretic displays that support gray scale can be stabilized not only in their extreme black and white states, but also in their intermediate gray states, as well as some other types of electro-optic displays. This type of display is properly referred to as "multi-stable" rather than bi-stable, but for convenience the term "bi-stable" may be used herein to cover both bi-stable and multi-stable displays.

Several types of electro-optic displays are known. One type of electro-optic display is a rotating bichromal member type, as described in, for example, 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 (although this type of display is commonly referred to as a "rotating bichromal ball" display, the term "rotating bichromal member" is preferably more accurate because in some of the patents mentioned above, the rotating member is not spherical). Such displays use a number of small bodies (usually spherical or cylindrical) comprising two or more parts with different optical properties and an internal dipole. These bodies are suspended in liquid-filled vacuoles within a matrix, the vacuoles being filled with liquid so that the bodies are free to rotate. The appearance of the display is changed by: an electric field is applied to the display, thereby rotating the body to various positions and changing which part of the body is seen through the viewing surface. This type of electro-optic medium is generally bistable.

Another type of electro-optic display uses an electrochromic medium, such as in the form of a nano-electrochromic (nanochromic) film that includes an electrode formed at least in part from a semiconducting metal oxide and a plurality of dye molecules capable of reverse color change attached to the electrode; see, e.g., O' Regan, b. et al, Nature 1991,353,737; and Wood, d., Information Display,18(3),24 (3 months 2002). See also Bach, u. et al, adv.mater, 2002,14(11), 845. Nano-electrochromic films of this type are described, for example, in U.S. patent nos. 6,301,038; 6,870,657, respectively; and 6,950,220. This type of media is also generally bistable.

Another type of electro-optic display is the electro-wetting display developed by Philips, which is described in Hayes, R.A. et al, "Video-Speed Electronic Paper Based on electric wetting", Nature,425,383-385 (2003). Such electrowetting displays can be made bistable as shown in us patent No.7,420,549.

One type of electro-optic display that has been the subject of intensive research and development for many years is a particle-based electrophoretic display in which a plurality of charged particles move through a fluid under the influence of an electric field. Electrophoretic displays may have attributes of good brightness and contrast, wide viewing angles, state bistability, and low power consumption compared to liquid crystal displays. However, problems with the long-term image quality of these displays have prevented their widespread use. For example, the particles that make up electrophoretic displays tend to settle, resulting in insufficient lifetime of these displays.

As mentioned above, electrophoretic media require the presence of a fluid. In most prior art electrophoretic media, the fluid is a liquid, but the electrophoretic medium can be produced using a gaseous fluid; see, e.g., Kitamura, T. et al, "electronic Toner movement for electronic Paper-like display", IDW Japan,2001, Paper HCS 1-1, and Yamaguchi, Y. et al, "Toner display using organic substrates charged semiconductor, IDW Japan,2001, Paper AMD 4-4). See also U.S. patent nos. 7,321,459 and 7,236,291. When such gas-based electrophoretic media are used in a direction that allows the particles to settle, such as in signs where the media are arranged in a vertical plane, such gas-based electrophoretic media are susceptible to the same type of problems due to the same settling of particles as liquid-based electrophoretic media. In fact, the problem of particle settling in gas-based electrophoretic media is more severe than in liquid-based electrophoretic media, because the lower viscosity of gaseous suspending fluids allows faster settling of the electrophoretic particles compared to liquids.

A number of patents and applications assigned to or in the name of the Massachusetts Institute of Technology (MIT), intemck corporation, intemcakania llc, and related companies describe various techniques for encapsulated microcell electrophoresis and other electro-optic media. Encapsulated electrophoretic media comprise a plurality of microcapsules, each microcapsule itself comprising an internal phase containing electrophoretically-mobile particles in a fluid medium, and a capsule wall surrounding the internal phase. Typically, the capsules themselves are held in a polymeric binder to form a coherent layer between two electrodes. In microcell electrophoretic displays, the charged particles and fluid are not encapsulated within microcapsules, but rather are held within a plurality of cavities formed within a carrier medium (typically a polymer film). The techniques described in these patents and applications include:

(a) electrophoretic particles, fluids, and fluid additives; see, e.g., U.S. Pat. Nos. 7,002,728 and 7,679,814;

(b) capsule, adhesive and packaging process; see, e.g., U.S. patent nos. 6,922,276 and 7,411,719;

(c) microcell structures, wall materials, and methods of forming microcells; see, e.g., U.S. patent nos. 7,072,095 and 9,279,906;

(d) a method for filling and sealing a microcell; see, e.g., U.S. patent nos. 7,144,942 and 7,715,088;

(e) films and sub-assemblies comprising electro-optic material; see, e.g., U.S. Pat. Nos. 6,982,178 and 7,839,564;

(f) backsheets, adhesive layers, and other auxiliary layers and methods for use in displays; see, e.g., U.S. patent nos. 7,116,318 and 7,535,624;

(g) color formation and color adjustment; see, e.g., U.S. patent nos. 7,075,502 and 7,839,564;

(h) a method for driving a display; see, e.g., U.S. Pat. Nos. 7,012,600 and 7,453,445;

(i) an application for a display; see, e.g., U.S. patent nos. 7,312,784 and 8,009,348; and

(j) non-electrophoretic displays, as described in U.S. patent No.6,241,921 and U.S. patent application publication No. 2015/0277160; and applications of packaging and microcell technology other than displays; see, for example, U.S. patent application publication nos. 2015/0005720 and 2016/0012710.

Many of the aforementioned patents and applications recognize that the walls surrounding discrete microcapsules in an encapsulated electrophoretic medium can be replaced by a continuous phase, thereby producing a so-called polymer-dispersed electrophoretic display, 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 capsules or microcapsules, even if no discrete capsule film is associated with each individual droplet; see, for example, the aforementioned U.S. patent No.6,866,760. Accordingly, for the purposes of this application, such polymer-dispersed electrophoretic media are considered to be a subclass of encapsulated electrophoretic media.

Encapsulated electrophoretic displays are generally not plagued by the aggregation and settling failure modes of conventional electrophoretic devices and provide further benefits such as the ability to print or coat the display on a variety of flexible and rigid substrates. (the use of the word "printing" is intended to include all forms of printing and coating including, but not limited to, pre-metered coating such as slot or extrusion coating, slide or stack coating, curtain coating, roll coating such as knife coating, forward and reverse roll coating, gravure coating, dip coating, spray coating, meniscus coating, spin coating, brush coating, air knife coating, screen printing processes, electrostatic printing processes, thermal printing processes, ink jet printing processes, electrophoretic deposition (see U.S. patent No.7,339,715), and other similar techniques.) thus, the resulting display may be flexible. In addition, because the display media can be printed (using a variety of methods), the display itself can be inexpensively manufactured.

An electro-optic display typically comprises a layer of electrophoretic material and at least two further layers, one of which is an electrode layer, disposed on opposite sides of the electrophoretic material. In most such displays, both layers are electrode layers, and one or both electrode layers are patterned to define the pixels of the display.

One application of electrophoretic displays includes signage. For example, referring to fig. 1, a design pattern 10 for one of the electrode layers of an electrophoretic display is shown, where the pattern 10 provides a clock sign. For example, a clock sign may be used to display the start of a performance. The design pattern 10 is divided into a plurality of differently shaped regions of conductive material. Each region defines a "pixel". A single layer of electrophoretic material is applied over the pattern 10 and a different voltage may be applied to each pixel to switch the optical state of the electrophoretic medium within the boundaries of each pixel. However, the pattern 10 includes a plurality of regions 14, which plurality of regions 14 will never change color during operation, unlike the plurality of regions 12, which may change periodically over time. Thus, the conductive material within the area 14 and the electrophoretic material applied on the area 14 are substantially wasted, which may comprise a large portion of the entire display area, and unnecessarily increase the cost of the display.

Accordingly, there is a need for improved electro-optic displays that reduce or eliminate electrically conductive and electro-optic materials that may remain in a constant optical state during operation of the display in the area of the display.

Disclosure of Invention

According to one aspect, the assembly may comprise a plurality of separate and independently controllable electro-optic displays arranged to form the shape of alphanumeric characters in a mounted state.

According to another aspect, an assembly may include a substrate and a plurality of individual and independently controllable electro-optic displays. The substrate may include a surface having an opaque region and a plurality of light-transmissive regions, wherein each of the electro-optic displays is aligned with one of the light-transmissive regions, and the opaque region is optically coupled to a plurality of separate and independently controllable electro-optic displays.

These and other aspects of the invention will be apparent from the following description.

Drawings

The drawings depict one or more embodiments in accordance with the present concepts by way of example only and not by way of limitation. The figures are not drawn to scale. In the drawings, like reference numerals designate identical or similar elements.

FIG. 1 is an example of an electrode design pattern that may be used in electro-optic displays found in the prior art.

Fig. 2A is a front plan view of a light-transmissive substrate that may be included in a first embodiment of the invention.

Fig. 2B is a front plan view of the light-transmitting substrate of fig. 2A coated with a color pigment.

FIG. 2C is a rear plan view of the light-transmissive substrate of FIG. 2A with a plurality of electro-optic displays disposed on the rear surface of the substrate.

FIG. 2D is a front plan view of the light-transmissive substrate and electro-optic display of FIG. 2C showing the numeral "8".

Fig. 2E is a front plan view of the light-transmissive substrate and electro-optic display of fig. 2C showing the numeral "4".

Fig. 3 is a cross-sectional view of the first embodiment along axis I-I in fig. 2E.

Fig. 4 is a top view of a back plate for a first display included in a second embodiment of the present invention.

Fig. 5A is a top view of a back plate for a second display included in a second embodiment of the present invention.

FIG. 5B is a top view of a modified version of the backplane shown in FIG. 5A.

Fig. 6 is a top view of components of the first and second displays of fig. 5 and 6.

Fig. 7 is a top view of a plurality of the components of fig. 6.

Detailed Description

In the following detailed description, numerous specific details are set forth by way of examples in order to provide a thorough understanding of the relevant teachings. It should be apparent, however, to one skilled in the art that the present teachings may be practiced without these specific details.

Assemblies made in accordance with various embodiments of the present invention may include a plurality of electro-optic displays arranged in the form of alphanumeric characters. For example, referring to fig. 2A to 2E, a plurality of electro-optic displays 24 may be arranged on one side of the substrate 20. An electro-optic display is capable of switching between two optical states, for example black and grey. As shown in fig. 2A, the substrate 20 may be provided in the form of a light-transmissive panel, as shown in fig. 2B, which is coated on at least one side with a substantially opaque ink or paint. The ink or paint is preferably optically coupled to one of the optical states of the electro-optic display. As used herein, "optically coupled" with respect to a substrate refers to exhibiting an optical state that is similar to at least one of the optical states of an electro-optic display. For example, if the electro-optic display is switched between black and gray, the substrate 20 may be coated with a black pigment or a gray pigment so that the permanent optical state of the substrate 20 is similar to one of the optical states of the electro-optic display 24.

When the substrate 20 is coated with ink or paint, the plurality of regions 22 are uncoated such that they remain light transmissive, as shown in fig. 2B. In an alternative embodiment, the substrate 20 may be provided in the form of an opaque sheet, and the plurality of regions 22 may be obtained by removing portions in the opaque sheet to form windows or holes. Also, the optical state of the opaque sheet is preferably similar to one of the optical states of the electro-optic display 24.

Referring to fig. 2C, a plurality of electro-optic displays 24 are arranged on one side of the substrate 20 such that each display is aligned with only one of the plurality of light-transmissive regions 22. In other words, each window is paired with or associated with a single display. Preferably, the area of the light transmissive region is at least 70%, more preferably at least 80%, and most preferably at least 90% of the display area of the electro-optic display with which it is aligned. Any means known in the art may be used to secure the electro-optic display, such as fasteners or adhesives. As shown in fig. 2D and 2E, each of the individual electro-optic displays may be independently controlled to change the image displayed on the front side of the overall assembly. The display may be operatively connected to at least one controller and/or at least one power source (not shown). The assembly may further include a rear panel (not shown) to house one or more of the plurality of displays, controllers and power supplies, and the front substrate may serve as a cover for the housing, for example.

In an alternative embodiment, a plurality of electro-optic displays may be arranged on the front surface of the substrate having an optical state similar to one of the optical states of the electro-optic displays. In this embodiment, multiple light transmissive regions are not necessary, and this embodiment may further include some masking material around the edges of the electro-optic display so that the appearance of the display blends with the surrounding regions. The masking material may include, but is not limited to, ink, paint, or colored tape. The appearance of the mask material may be similar to the optical state of the front surface of the substrate.

Each of the electro-optic displays included in assemblies according to various embodiments of the present invention may include multiple layers. As shown in FIG. 3, for example, each electro-optic display may include, in order, a light-transmissive protective layer 20, a front light-transmissive layer 32 of conductive material, a layer of electro-optic medium 36, a rear layer 34 of conductive material, and a rear substrate 38. In some embodiments, one of the front and back layers of conductive material may not be present.

The rear substrate 38 and the rear layer 34 of conductive material may together form what is commonly referred to in the industry as a "backplane". The rear substrate 38 may be formed of an ablatable polymeric material such as polyimide. The substrate may also include other optional layers, such as reflective/moisture barrier. Any method known to those skilled in the art may be used to manufacture the back sheet for use in the various embodiments made in accordance with the present invention, such as U.S. patent 7,223,672.

The back plate is mainly divided into three categories: active matrix, passive matrix, and direct drive backplane. Any type of backing plate may be used in various embodiments of the present invention; however, a direct drive backplate is preferred. For an active matrix backplane, an array of Thin Film Transistors (TFTs) is formed on the substrate surface, each transistor acting as a switch for a pixel. Passive matrix backplanes use a simple grid to provide charge to specific pixels on the display. Grids are formed on the top and bottom of the substrate. In a direct drive backplane, the rear substrate may include electrical connectors on the edges of the substrate that are electrically connected to the layer of conductive material that serves as the pixel electrodes.

In a preferred embodiment of the invention, the plurality of electro-optic displays included in the assembly may comprise a first display and a second display. The first display may comprise a direct drive backplane in the form of a rectangular area, for example as shown in fig. 4. The backplane may include a back substrate 40, on which a layer of conductive material 42 is applied, and connectors 44. Conductive traces (not shown) may be applied to the surface of the rear substrate 40 leading to the connectors 44 prior to applying the layer of conductive material 42. The conductive traces are used to electrically connect the conductive material 42 to the connector 44. The rectangular area formed by the layer of conductive material 42 is not segmented; therefore, the entire region appears as one pixel. The second display may comprise a segmented backplane and most of the display area is dynamic. As used herein, "dynamic" means that the electrically conductive material may switch the electro-optic medium during operation of the display.

In one embodiment, the back plate of the second segment may have an electrode design pattern having a plurality of pixel electrodes as shown in fig. 5A. The second display may comprise a rear substrate 50 and a plurality of conductive tracks (not shown) applied to a surface of the rear substrate 50, wherein one end of each track has a conductor to be associated with a respective pixel electrode and the opposite end of the track is connected to a connector 57. A layer of insulating material may then be coated on the rear substrate 50. The insulating layer is preferably made of a dielectric material such as silicon nitride, an insulating polymer or a crosslinkable monomer or oligomer. An insulating layer is applied to cover the traces while leaving the ends including the conductors exposed. A pattern of segments of conductive material forming the pixel electrodes 52, 53, 54, 55, 56 is then printed onto the insulating material so that each segment is electrically connected to a respective conductor. In an alternative embodiment, the back-plate of the second segment shown in fig. 5A may be slightly modified such that a slanted version of the segmented electrode pattern as shown in fig. 5B is provided on the back-plate. In fig. 5A and 5B, the boundaries between the different regions of conductive material forming the pixel electrodes 52, 53, 54, 55, 56 comprise insulating material.

The pattern of the pixel electrode of the second display shown in fig. 5A may comprise two rectangular regions 52 having an area equal to the area of the pixel electrode of the first display shown in fig. 4. The pattern of pixel electrodes of the second display may also comprise three square areas containing four different pixel electrodes, such that the overall pattern of pixel electrodes on the backplane is symmetrical. By providing a symmetrical pattern, the manufacture of the assembly can be simplified, as only two types of displays are required to form the alphanumeric characters. For example, referring to FIG. 6, the combination of only three displays 60 having backplanes as shown in FIG. 4 and two displays 62 having backplanes as shown in FIG. 5A may be arranged to form an alphanumeric character, e.g., the number "8". As a result, most of the display area of the component is dynamic; thus, the amount of conductive material and electro-optic medium required to construct the display is reduced. If a display having the electrode pattern shown in FIG. 5B is included in an assembly according to the present invention, displays having a backplate (such as those shown in FIG. 4) may be similarly modified to an inclined shape, e.g., a parallelogram, so that the displays may be arranged as alphanumeric characters.

Assemblies made according to various embodiments of the present invention also enable the construction of large electro-optic displays, particularly electrophoretic displays. For example, the transverse dimension of the entire assembly may be at least 20cm, more preferably at least 50cm, and most preferably at least 1 m.

Electro-optic displays used in various embodiments of the present invention may comprise any type of electro-optic medium. The electro-optic medium is preferably bistable and most preferably an electrophoretic medium.

The manufacture of electrophoretic displays incorporated in various embodiments of the present invention typically involves at least one lamination operation. For example, in the aforementioned several patents and applications to MIT and inck, a process is described for manufacturing an encapsulated electrophoretic display, in which an encapsulated electrophoretic medium comprising capsules in an adhesive is coated onto a flexible substrate comprising an Indium Tin Oxide (ITO) or similar conductive coating (serving as one electrode of the final display) on a thin plastic film, the capsules/adhesive coating being dried to form a coherent layer of electrophoretic medium that adheres strongly to the substrate. Separately, a backplane is prepared comprising one or more pixel electrodes and an appropriate arrangement of conductors connecting the pixel electrodes to the drive circuitry. To form the final display, the substrate with the capsule/adhesive layer thereon is laminated to a backplane using a laminating adhesive. (in a preferred form of this process, the backplane itself is flexible and is prepared by printing the pixel electrodes and conductors on a plastic film or other flexible substrate.

The aforementioned U.S. patent No.6,982,178 describes a method of assembling a solid state electro-optic display, including an encapsulated electrophoretic display, which is well suited for mass production. Essentially, this patent describes a so-called "front plane laminate" ("FPL") which comprises, in order, a light-transmissive electrically-conductive layer, a layer of a solid electro-optic medium in electrical contact with the electrically-conductive layer, an adhesive layer, and a release sheet. (variants of FPL include the so-called "double release tab" described in U.S. Pat. No.7,561,324 and the so-called "inverted front plane laminate" described in U.S. Pat. No.7,839,564.)

Typically, the light transmissive, electrically conductive layer will be carried on a light transmissive substrate, which is preferably flexible in the sense that the substrate can be manually wound onto a 10 inch (254 mm) diameter drum, for example, without permanent deformation. The term "light transmissive" is used in this patent and refers herein to a layer so designated transmitting sufficient light to enable a viewer to observe through the layer a change in the display state of the electro-optic medium, which would normally be observed through the conductive layer and the adjacent substrate (if present); where the electro-optic medium exhibits a change in reflectivity at non-visible wavelengths, the term "optically transmissive" should of course be construed to relate to transmission at the relevant non-visible wavelengths. The substrate is typically a polymeric film and will typically have a thickness in the range of about 1 to about 25 mils (25 to 634 micrometers), preferably about 2 to about 10 mils (51 to 254 micrometers). The conductive layer is conveniently a thin metal or metal oxide layer, for example of aluminium or ITO, or may be a conductive polymer. Polyethylene terephthalate (PET) films coated with aluminum or ITO are commercially available, for example, "aluminized Mylar" ("Mylar" is a registered trademark) from dupont, wilmington, tera, and such commercial materials may work well in front plane laminates.

Assembly of an electro-optic display using such a front plane laminate may be achieved by: the release sheet is removed from the front plane laminate and the adhesive layer is contacted with the backplane under conditions effective to adhere the adhesive layer to the backplane, thereby securing the adhesive layer, the electro-optic medium layer, and the conductive layer to the backplane. This process is well suited for mass production, as the front plane laminate can be mass produced, typically using roll-to-roll coating techniques, and then cut into pieces of any size for a particular backing sheet.

Electro-optic displays fabricated using the aforementioned front plane laminate or dual release film typically have a laminating adhesive layer between the electro-optic layer itself and the backplane, for example, the presence of the laminating adhesive layer affects the electro-optic characteristics of the display. In particular, the electrical conductivity of the lamination adhesive layer affects the low temperature performance and resolution of the display. The low temperature performance of the display (which has been empirically found) can be improved by increasing the conductivity of the lamination adhesive layer, for example doping the layer with tetrabutylammonium hexafluorophosphate or other materials, as described in U.S. Pat. nos. 7,012,735 and 7,173,752.

While preferred embodiments of the present invention have been shown and described herein, it will be understood that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will occur to those skilled in the art without departing from the spirit of the invention. It is therefore intended that the appended claims cover all such variations as fall within the spirit and scope of the invention.

The entire contents of the above patents and applications are incorporated herein by reference in their entirety.

Claims (20)

1. An assembly comprising a plurality of separate and independently controllable electro-optic displays arranged to form the shape of alphanumeric characters in a mounted state.

2. The assembly of claim 1, wherein the plurality of electro-optic displays includes at least one display having a single pixel electrode.

3. The assembly of claim 2, wherein the plurality of electro-optic displays further comprises at least one display having a plurality of segmented pixel electrodes.

4. The assembly of claim 3, wherein at least one of the segmented pixel electrodes has an area equal to the single pixel electrode.

5. The assembly of claim 1, wherein at least one of the plurality of individual and independently controllable electro-optic displays comprises a layer of electrophoretic material comprising an encapsulated dispersion of charged pigment particles.

6. The assembly of claim 5, wherein the charged pigment particles comprise a first set of particles having a first color and a second set of particles having a second color, wherein the first color and the second color are different.

7. The assembly of claim 6, further comprising a substrate and the plurality of individual and independently controllable electro-optic displays are disposed on a surface of the substrate.

8. The assembly of claim 7, wherein the substrate comprises a plurality of light-transmissive regions, and each of the individual and independently controllable electro-optic displays is aligned with only one of the light-transmissive regions.

9. The assembly of claim 7, wherein the substrate is optically coupled to the plurality of electro-optic displays.

10. The assembly of claim 1, wherein each of the individual and independently controllable electro-optic displays has a lateral dimension greater than or equal to 20 centimeters.

11. The assembly of claim 10, wherein each of the individual and independently controllable electro-optic displays has a lateral dimension greater than or equal to 1 meter.

12. The assembly of claim 10, wherein each of the separate and independently controllable electro-optic displays has only a single pixel electrode configured to control an optical state of the display.

13. A system comprising the assembly of claim 1 and a controller operably connected to each of the separate and independently controllable electro-optic displays.

14. An assembly, comprising:

a substrate having a surface including an opaque region and a plurality of light transmissive regions; and

a plurality of individual and independently controllable electro-optic displays,

wherein each of the electro-optic displays is aligned with one of the light-transmissive regions.

15. The assembly of claim 14, wherein the plurality of electro-optic displays comprises at least one display having a single pixel electrode.

16. The assembly of claim 15, wherein the plurality of electro-optic displays further comprises at least one display having a plurality of segmented pixel electrodes.

17. The assembly of claim 16, wherein at least one of the segmented pixel electrodes has an area equal to the single pixel electrode.

18. The assembly of claim 14, wherein at least one of the plurality of individual and independently controllable electro-optic displays comprises a layer of electrophoretic material comprising an encapsulated dispersion of charged pigment particles.

19. The assembly of claim 18, wherein the charged pigment particles comprise a first set of particles having a first color and a second set of particles having a second color, wherein the first color and the second color are different.

20. The assembly of claim 19, wherein the opaque regions are optically coupled to the plurality of electro-optic displays.