Patent Publication Number: US-10330918-B1

Title: Display device support plate having recessed region

Description:
BACKGROUND 
     Electronic displays are found in numerous types of electronic devices including, without limitation, electronic book (“eBook”) readers, mobile phones, laptop computers, desktop computers, televisions, appliances, automotive electronics, and augmented reality devices. Electronic displays may present various types of information, such as user interfaces, device operational status, digital content items, and the like, depending on the type and the purpose of the associated electronic device. The appearance and the quality of a display may affect a user&#39;s experience with the electronic device and the content presented thereon. Accordingly, enhancing user experience and satisfaction continues to be a priority. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The detailed description is set forth with reference to the accompanying figures. The use of the same reference numbers in different figures indicates similar or identical items or features. 
         FIG. 1  is a cross-sectional view of a portion of an example electrowetting display device including adjacent electrowetting pixel regions, according to various embodiments; 
         FIG. 2  is a cross-sectional view of a portion of an example electrowetting display device including adjacent electrowetting pixel regions, according to various embodiments; 
         FIG. 3  is top view of a portion of an example electrowetting display device including a plurality of electrowetting pixel regions, according to various embodiments; 
         FIG. 4  illustrates an example method for fabricating an electrowetting display device such as shown in  FIGS. 1-3 , according to various embodiments; 
         FIGS. 5-18  are schematic views of a portion of a color filter structure of the example electrowetting display device during various steps of the example method illustrated in  FIG. 4 ; and 
         FIG. 19  illustrates an example electronic device that may incorporate an electrowetting display device, according to various embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     In example embodiments described herein, a light-blocking layer, such as an organic material layer, e.g., a black matrix organic material layer, is disposed on an inner surface of a top support plate. The light-blocking layer includes a plurality of light-blocking portions on the inner surface of the top support plate. Each light-blocking portion of the plurality of light-blocking portions is positioned over, e.g., aligned with, a pixel wall portion forming at least a portion of a perimeter of an associated electrowetting pixel region. In certain embodiments, the plurality of light-blocking portions forms a first grid pattern on the inner surface of the top support plate. A recessed region is aligned with, e.g., positioned over an inner surface of, each light-blocking portion. In example embodiments, an electrically conductive layer is disposed on the light-blocking layer. More specifically, the electrically conductive layer includes a plurality of electrically conductive portions forming a second grid over the first grid pattern of light-blocking portions. Each electrically conductive portion is disposed on at least a portion of a respective light-blocking portion such that the electrically conductive layer forms a continuous common electrode associated with each pixel region. In certain embodiments, the electrically conductive layer is disposed in the recessed region and positioned over an area of the pixel region, e.g., a first area, such as a first liquid collection area, of a hydrophobic surface of the pixel region, in which the first liquid, e.g., oil, forms a droplet with the first liquid in a contracted state. 
     In example embodiments, a color filter portion is disposed on the inner surface of the top support plate adjacent the light-blocking portion. A conforming layer including a photo-definable material, e.g., a planarization layer, such as a suitable organic planarization layer, is disposed on or over the color filter portion. The conforming layer at least partially forms a recessed region or trench including sidewalls over at least a portion of a respective electrically conductive portion. The recessed region is aligned with, e.g., positioned over, a first or inner surface of the respective electrically conductive portion. In an alternative embodiment, the electrically conductive layer is associated with, e.g., positioned within, the pixel region but not disposed in the recessed region. 
     In certain embodiments, the color filter portion has a thickness of 2.0 micrometers to 4.0 micrometers and the conforming layer has a thickness of 1.0 micrometers to 3.0 micrometers. With a light-blocking portion having a thickness of 1.0 micrometer to 2.0 micrometers, for example, and the electrically conductive layer having a thickness of 100 nanometers to 300 nanometers, in certain embodiments the recessed region may provide an additional 1.0 micrometer to about 5.0 micrometers to provide sufficient clearance between the common electrode and the oil as the oil contracts to form the droplet with the oil in the contracted state. As a result, a distance, referred to as a cell gap, of the electrowetting pixel region between a hydrophobic surface of the pixel region and a first or inner surface of the conforming layer can be decreased. In example embodiments described herein, the distance is defined by a height of a spacer coupled between the pixel wall portion and the conforming layer and at least a portion of a height of the pixel wall portion. In example embodiments, the distance is less than 20 micrometers and, more particularly, the distance is not greater than 15 micrometers and, even more particularly, the distance is 15 micrometers. When an electrical potential is applied between a pixel region electrode and a common electrode on the top support plate, the associated pixel region is activated, e.g., is in an activate state. The first fluid, e.g., a first liquid such as an electrowetting oil, in the activated pixel region contracts to form a droplet under the light-blocking portion formed on an inner surface of the top support plate. In at least some conventional electrowetting display devices, the light-blocking portion has a width extending into the electrowetting pixel region of about 30 micrometers in order to extend over the oil droplet, having a width or diameter of 20 micrometers to 22 micrometers, and the respective pixel wall portion, having a width of 8 micrometers to 10 micrometers. 
     In many conventional electrowetting display devices, the cell gap is defined between an inner surface of a top support plate and a surface of the pixel region over the bottom support plate. A main factor determining the cell gap is a height of a spacer positioned between the top support plate and the bottom support plate, e.g., coupled between a pixel wall portion and the top support plate. In conventional display devices, an aspect ratio of the spacer, i.e., a ratio of a height of the spacer (h) and a width of a base of the spacer contacting a contact surface of the respective pixel wall portion (w) is relatively high. This relatively high aspect ratio may create a significant mechanical force on the underlying material layer, e.g., the underlying ITO layer, during processing, particularly at various temperature changes during the processing steps. The mechanical force created between the spacer and the underlying material layer can form cracks in the underlying material layer. While this crack formation can be avoided by removing the ITO material under the spacer at the edges of the display area, the ITO material in the display area cannot be removed because the ITO material must be continuously connected as the common electrode within the display area. As a result, one or more contact points may appear within the display area where a spacer contacts a surface of the ITO material layer. 
     In electrowetting display devices, the electrically conductive layer, e.g., the ITO layer, on the top support plate functions to apply a specific potential to a second fluid, e.g., a second liquid such as an electrolyte solution, disposed within the pixel region. When the physical and electrical contact between the electrically conductive layer and the electrolyte solution is made via a contact area, e.g., within the recessed region, the specific potential is applied to the electrolyte solution and the electrolyte solution functions as a common electrode for the pixel region. In example embodiments described herein, an electrowetting display device includes an electrowetting pixel region, such as an electrowetting sub-pixel, having an electrically conductive layer, e.g., an indium tin oxide (ITO) layer, disposed on an inner surface of a light-blocking portion. A color filter layer is disposed on the inner surface of the top support plate. The color filter layer is coplanar with the light-blocking layer and includes a plurality of color filter portions each adjacent one or more respective light-blocking portions. A conforming layer is disposed over each color filter portion to form a recessed region aligned with a respective portion of the electrically conductive layer. The recessed region provides the contact area between the electrically conductive layer and the electrolyte solution. A spacer is coupled between a respective pixel wall portion and the inner surface of the conforming layer adjacent the recessed region. A distance between the inner surface of a hydrophobic layer of the pixel region and the inner surface of the conforming layer, defined by a height of the spacer and at least a portion of a height of the pixel wall portion coupled to the spacer, is sufficient to allow the oil in the electrowetting sub-pixel to form a droplet under and, in certain embodiments, extending into, the recessed region without contacting the electrically conductive layer. 
     In example embodiments, the light-blocking layer and the electrically conductive layer can be patterned in a similar “self-aligning” design. As a result of the self-aligning design, a total resistance of the common electrode is lowered because the common electrode formed by the electrically conductive layer has a grid pattern within the display area. Additionally, the spacers in the display area are applied directly on the conforming layer, which results in reducing or eliminating undesirable contact points or “crossover” between the electrically conductive layer and the spacers, as well as significantly improving an adhesion between the spacers and the conforming layer. Moreover, because the innermost surface of the top support plate includes only the organic conforming layer, the subsequent surface treatment step is simplified. Further, because the light-blocking layer is formed on the top support plate as a flat surface with a generally planar topography, no planarization layer is required over the light-blocking layer. As a result, materials other than ITO that are inert and inactive to the electrolyte solution within the pixel region, such as a suitable metal material, e.g., chromium, titanium, molybdenum, tungsten, and/or tantalum, can be used to form the transparent electrically conductive layer. In alternative embodiments, the transparent electrically conductive layer includes zinc oxide or fluorine-doped tin oxide. In further alternative embodiments, the transparent electrically conductive layer includes an organic material including, without limitation, poly(3,4-ethylenedioxythiophene)(PEDOT) or poly(styrene sulfonate)(PDOT:PSS). 
     Referring now to the figures,  FIG. 1  is a cross-sectional view of a portion of an example electrowetting display device, such as a reflective electrowetting display device  10 , according to various embodiments. While the example embodiments described herein are related to a reflective display device, the example embodiments may also be suitable for use with alternative display technology including, for example, a transmissive or transflective display device.  FIG. 1  shows two electrowetting pixel regions in a resting state and one electrowetting pixel region in an active state. With the electrowetting pixel regions in a resting state, the first fluid, e.g., a liquid such as an electrowetting oil, is dispersed across a hydrophobic surface of the pixel region. With the electrowetting pixel region in an active state, the first fluid, e.g., a liquid such as an electrowetting oil, contracts to form a droplet in a first area of the hydrophobic surface, e.g., a first liquid collection area.  FIG. 2  is a cross-sectional view of a portion of an example electrowetting display device, such as a reflective electrowetting display device  10 , including adjacent electrowetting pixel regions between opposing support plates of the electrowetting display device, e.g., a first electrowetting pixel region and an adjacent second electrowetting pixel region arranged in a column of a plurality of electrowetting pixel regions, according to various embodiments. 
     As shown in  FIG. 1 , each electrowetting pixel region includes an active portion, e.g., a display surface area. More specifically, in this embodiment, the display surface area is defined by pixel wall portions, as described below, having a first dimension, such as a width, between opposing lateral pixel wall portions, and a second dimension, such as a height, between the remaining opposing pixel wall portions. The electrowetting display device may include any number (usually a very large number, such as thousands or millions) of electrowetting pixel regions. 
     Referring further to  FIG. 1 , a plurality of pixel regions, such as electrowetting pixel regions  12 , is positioned over a first or bottom support plate  14 , e.g., positioned between bottom support plate  14  and a second or top support plate  16  opposing bottom support plate  14 . In example embodiments, electrowetting pixel region  12  includes an electrowetting sub-pixel  18  formed over bottom support plate  14  to define a display surface area  20 , as shown in  FIG. 1 . A plurality of pixel wall portions  22  is formed over bottom support plate  14  to form a perimeter of each electrowetting pixel region  12 . In the example embodiment, pixel wall portions  22  may include a photoresist material such as, for example, epoxy-based negative photoresist SU-8. Electrowetting pixel regions  12  may have a width and a height in a range of about 50 to 500 micrometers, for example. In certain embodiments, a pixel region may include a pixel, a sub-pixel, or a pixel having two or more sub-pixels of a display device. Such pixels or sub-pixels may be the smallest light transmissive, reflective or transflective unit of a display that is individually operable to directly control an amount of light transmission through or reflection from the pixel region. For example, in some embodiments, a pixel region may include a red sub-pixel, a green sub-pixel, a blue sub-pixel, or a white sub-pixel for RGBW displays. In other embodiments, a pixel may be a smallest component, e.g., the pixel does not include any sub-pixels. 
     An electrode layer  24  having a plurality of pixel electrodes  26  is formed on bottom support plate  14 , for example, between electrowetting pixel regions  12  and bottom support plate  14 . Electrode layer  24  and/or one or more pixel electrodes  26  are operatively coupled to an electrically conductive layer  28  forming a second or common electrode  30  positioned under top support plate  16 . In conjunction with common electrode  30 , electrode layer  24  creates a voltage differential between electrode layer  24  and common electrode  30  to cause relative displacement of a first fluid  32 , e.g., an oil, and a second fluid  34 , e.g., a liquid electrolyte solution, within electrowetting pixel region  12 . These example embodiments are not limiting with respect to the location of the first and second electrode, and claimed subject matter is not limited in this respect. In particular embodiments, one or more additional layers may be positioned between electrode layer  24  and bottom support plate  14 , in which TFT structures, gates, and/or source lines are located, for example. In these embodiments, electrode layer  24  may not be formed directly on bottom support plate  14 . In various embodiments, electrode layer  24  may be connected to any number of transistors, such as suitable thin film transistor (TFT) structures (not shown in  FIG. 1 ), that are switched to either select or deselect corresponding electrowetting pixel regions  12  using active matrix addressing, for example. A TFT structure is a particular type of field-effect transistor that includes thin films of an active semiconductor layer as well as a dielectric layer and metallic contacts over a supporting (but non-conducting) substrate, which may be glass or any suitable transparent or non-transparent material, for example. 
     A reflective layer  36  is positioned adjacent, e.g., on or over electrode layer  24 , as shown in  FIGS. 1 and 2 , for example. In particular embodiments, one or more additional layers may be positioned between reflective layer  36  and electrode layer  24 . In these embodiments, reflective layer  36  may not be formed directly on electrode layer  24 . In an alternative embodiment, reflective layer  36  is positioned under a transparent electrode layer. In this alternative embodiment, reflective layer  36  is positioned between the transparent electrode layer  24  and bottom support plate  14 . Reflective layer  36  may reflect light within the entire visible spectrum, making the layer appear relatively bright, or reflect a portion of light within the visible spectrum, making the layer have a color. In this embodiment, reflective layer  36  is positioned within the pixel region, e.g., within each electrowetting pixel region  12 , to provide specular reflection. 
     As shown in  FIG. 1 , in the example embodiment, reflective layer  36  is positioned on electrode layer  24  and in electrowetting pixel region  12 . In alternative embodiments, reflective layer  36  is position on electrode layer  24  and under electrowetting pixel region  12 . In certain embodiments, reflective layer  36  includes one or more suitable materials such as, for example, a metal (90%, 95% or greater than 95% metal), an alloy, a doped metal, and/or a dielectric reflective material. Suitable metal materials for reflective layer  36  include, without limitation, aluminum, silver, gold, copper, nickel, platinum, rhodium, lanthanum, and/or silicon nickel. Suitable alloy materials for reflective layer  36  include, without limitation, aluminum with copper or aluminum with nickel. In further alternative embodiments, reflective layer  36  is made of any suitable material providing a desired specular reflectance. In alternative embodiments, reflective layer  36  includes a suitable diffuse reflective material deposited on or over electrode layer  24 . In this alternative embodiment, any suitable diffuse reflective material, such as titanium dioxide (TiO 2 ), providing a desired diffuse reflectance may be used. 
     Electrowetting pixel regions  12  may have specific and/or additional structural features. Additionally or alternatively, reflective layer  36  may have structural features, for example, one or more relatively thinner areas and/or one or more relatively thicker areas within reflective layer  36  to control movement of the fluids. Alternatively, reflective layer  36  may be deposited on a structural feature conforming to a shape of the structural feature. 
     A suitable dielectric barrier layer  38  may at least partially separate electrode layer  24  and reflective layer  36  from a hydrophobic layer  40 , such as an amorphous fluoropolymer layer forming a hydrophobic surface  42  of electrowetting pixel region  12 . For example, dielectric barrier layer  38  in certain embodiments is deposited on reflective layer  36 . Dielectric barrier layer  38  may be formed from various materials including one or more organic material layers or a combination of organic and inorganic material layers. A thickness of the insulating dielectric barrier layer  38  may be less than 2 micrometers and may be less than 1 micrometer; for example, the insulating dielectric barrier layer  38  may be 100 nanometers to 800 nanometers in thickness in certain embodiments. In some embodiments, hydrophobic layer  40  is an amorphous fluoropolymer layer including any suitable fluoropolymer(s), such as AF1600®, produced by DuPont, based in Wilmington, Del. Hydrophobic layer  40  is transparent in the example embodiment. Reflective layer  36  below hydrophobic layer  40  may reflect light within the entire visible spectrum, making the layer appear white, or reflect a portion of light within the visible spectrum, making the layer have a color. As described above, in certain embodiments, reflective layer  36  itself can act both as a pixel electrode and a reflective layer. 
     First fluid  32 , which may have a thickness (e.g., a height) in a range of about 1 micrometer to 10 micrometers, for example, overlays hydrophobic layer  40 , as shown in  FIG. 1 . First fluid  32  is partitioned by pixel wall portions  22 . Second fluid  34 , such as a liquid electrolyte solution, overlays first fluid  32  and pixel wall portions  22 . In certain embodiments, as described above, second fluid  34  may be electrically conductive and/or polar. For example, second fluid  34  may be water or a water solution, or a salt solution such as a solution of potassium chloride in water or a mixture of water and ethyl alcohol. In certain embodiments, second fluid  34  is transparent, but may be colored or absorbing. First fluid  32  is electrically non-conductive and may, for example, be an alkane like hexadecane or (silicone) oil. As described herein, first fluid  32  is immiscible with second fluid  34 . 
     As described above, hydrophobic layer  40  is arranged over bottom support plate  14  to create hydrophobic surface  42 . The hydrophobic character of hydrophobic layer  40  causes first fluid  32  to adjoin preferentially to hydrophobic layer  40  because first fluid  32  has a higher wettability with respect to hydrophobic surface  42  of hydrophobic layer  40  than second fluid  34  in the absence of a voltage. Wettability relates to the relative affinity of a fluid for the surface of a solid. Wettability increases with increasing affinity, and it may be measured by the contact angle formed between the fluid and the solid and measured internal to the fluid of interest. For example, such a contact angle may increase from relative non-wettability for a contact angle of more than 90° to complete wettability for a contact angle of 0°, in which case the fluid tends to form a film on the surface of the solid. 
     Top support plate  16  covers second fluid  34  and one or more spacers  44  to maintain second fluid  34  in electrowetting pixel regions  12 . In one embodiment, spacer  44  extends between pixel wall portion  22  and conductive electrode layer  28 . In alternative embodiments, spacer  44  does not rest on pixel wall portion  22  but is substantially aligned with pixel wall portion  22 . This arrangement may allow spacer  44  to come into contact with pixel wall portion  22  upon a sufficient pressure or force being applied to top support plate  16 . An edge seal  46  extends about a perimeter of electrowetting display device  10  to contain first fluid  32  and second fluid  34  within electrowetting pixel regions  12 . A voltage applied across, among other things, second fluid  34  and electrode layer  24  of individual electrowetting pixel regions  12  may control transmittance or reflectance of the individual electrowetting pixel regions  12 . 
     In example embodiments, a light-blocking layer  50  is disposed on top support plate  16 . For example, in certain embodiments, light-blocking layer  50  is disposed on an inner surface  52  of top support plate  16 . Light-blocking layer  50  includes a plurality of light-blocking portions  54  disposed on, e.g., deposited or formed on, inner surface  52  of top support plate  16 . In certain embodiments, light-blocking portions  54  are coupled to form a first grid pattern  55  of light-blocking portions  54  on inner surface  52  of top support plate  16  (as shown in  FIG. 5 ). In these embodiments, light-blocking portion  54  (or light-blocking portions  54 ) positioned over the respective TFT structure(s), as described below, may have a width greater than a width of the remaining light-blocking portions  54  associated with a respective pixel region  12 . 
     As shown in  FIG. 1 , a first light-blocking portion  54   a  is positioned over a first pixel wall region  22   a  of the plurality of pixel wall portions  22 . First light-blocking portion  54   a  extends over an area, e.g., a first liquid collection area  56 , of electrowetting pixel region  12  in which first fluid  32  forms a droplet  58  with first fluid  32  in a contracted state when electrowetting pixel region is activated. In certain embodiments, first liquid collection area  56  includes an area of hydrophobic surface  42  under first light-blocking portion  54   a , for example, that is adjacent or a portion of display surface area  20 , as shown in  FIG. 1 . In a particular embodiment, a first edge  60  of first light-blocking portion  54   a  is positioned over and aligned with a corresponding first edge  62  of first pixel wall portion  22   a . First light-blocking portion  54   a  extends over or into first electrowetting pixel region  12  (in a plane of light-blocking layer  50  parallel to inner surface  52  of top support plate  16 ) to cover first liquid collection area  56 . In example embodiments, electrowetting pixel region  12  has a first dimension, e.g., a width, of 60 micrometers and a second dimension, e.g., a height, perpendicular to the first dimension of 120 micrometers. In these embodiments, first liquid collection area  56  has a dimension of 20 micrometers to 22 micrometers along the second dimension of electrowetting pixel region  12  and first pixel wall portion  22   a  has a dimension of 8 micrometers to 10 micrometers along the second dimension of electrowetting pixel region  12 . In order to extend over droplet  58  in first liquid collection area  56 , in certain embodiments, first light-blocking portion  54   a  has a dimension of 30 micrometers along the second dimension of electrowetting pixel region  12 . 
     In example embodiments, electrically conductive layer  28 , e.g., an indium tin oxide (ITO) layer, forming common electrode  30  associated with each electrowetting pixel region  12  is disposed on and contacts light-blocking layer  50 . For example, in certain embodiments, 
     In certain embodiments, electrically conductive layer  28  includes a plurality of electrically coupled portions  70  coupled to form a second grid pattern  71  of electrically conductive portions  54  on associated light-blocking portions  54  (as shown in  FIG. 7 ). For example, at least a portion of electrically conductive layer  28 , e.g., an electrically conductive portion  70  as shown in  FIGS. 1 and 2 , is disposed on and contacts a first or inner surface  72  of an associated light-blocking portion  54 , e.g., a first electrically conductive portion  70   a  is disposed on and contacts a first or inner surface  72  of associated first light-blocking portion  54   a . In example embodiments, electrically conductive layer  28  includes a transparent layer, e.g., a transparent indium tin oxide (ITO) layer, forming a plurality of electrically conductive portions  70 . In alternative embodiments, electrically conductive layer  28  may include any suitable electroconductive material including, without limitation, a suitable metal material such as chromium, titanium, molybdenum, tungsten, and/or tantalum. In example embodiments, electrically conductive portion  70  is aligned with or positioned over first liquid collection area  56  of electrowetting pixel region  12  in which first fluid  32  forms droplet  58  with first fluid  32  in a contracted state. 
     In example embodiments, electrowetting display device  10  includes one or more color filter layers  76  disposed on inner surface  52  of top support plate  16  and coplanar with light-blocking layer  50 . As shown in  FIG. 1 , color filter layer  76  is disposed on, e.g., formed or deposited on, inner surface  52  of top support plate  16  using a suitable method. Color filter layer  76  includes a plurality of color filter portions, collectively referred to as color filter portions  78 . In example embodiments, each color filter portion  78  is positioned in a respective electrowetting pixel region  12 . Each color filter portion  78  may be configured to be substantially transparent to particular ranges of wavelengths of light, while absorbing others. For example, a red color filter portion  78  may be transparent to red light having wavelengths ranging from 620 nanometers (nm) to 750 nm, while absorbing light having other wavelengths. A blue color filter portion  78  may be transparent to blue light having wavelengths ranging from 450 nm to 495 nm, while absorbing light having other wavelengths. Green color filter portion  78  may be transparent to green light having wavelengths ranging from 495 nm to 570 nm, while absorbing light having other wavelengths. Transparent (white) color filter portion  78  may be transparent to all wavelengths of visible light, namely white light. As used herein, visible light refers to wavelengths of electromagnetic radiation visible to the human eye. Generally, this includes electromagnetic radiation having wavelengths between about 400 nm to about 800 nm. 
     Color filter portions  78 , therefore, may be utilized to assign each electrowetting pixel region  12 , e.g., each electrowetting sub-pixel, a color, so that when a particular electrowetting sub-pixel is in an open state, light reflected by that electrowetting sub-pixel will take on the color of the color filter portion associated with that electrowetting sub-pixel. In other embodiments, different ranges of light wavelengths may be associated with the red color filter portion, the green color filter portion, and the blue color filter portion. In still other embodiments, color filter portions  78  may be configured to block or transmit electromagnetic radiation of different wavelengths entirely. For example, electrowetting display device  10  may be configured to generate images using electrowetting sub-pixels having color filter portions  78  configured to transmit electromagnetic radiation of the colors cyan, magenta, and yellow. In short, color filter portions  78  may be developed and utilized within electrowetting display device  10  in accordance with any display color model. 
     Color filter portions  78  may be constructed with a generally transparent material such as a photoresist material or photo-definable polymer, including electromagnetic radiation filtering materials suspended within the material. Color filter portions  78  may be formed by the addition of pigments or dyes to a clear photo-definable polymer, for example. The amount of additive depends on system requirements, such as absorbance or transmission specifications. In some cases, polyacrylates are used as photoresist material. Generally, the organic dyes and pigments used within color filter portions  78  can have molecular structures containing chromophoric groups generating the color filtering properties. Some examples for chromophoric groups are azo-, anthraquinone-, methine- and phtalocyanine-groups. Color filter portions  78  may also be formed using a dichromated gelatin doped with a photosynthesizer, dyed polyimides, resins, and the like. 
     In a particular embodiment, each color filter portion  78  is configured to overlay an associated electrowetting pixel region  12  so that each color filter portion  78  extends from one pixel wall portion  22  on a first side of electrowetting pixel region  12  to an opposing pixel wall portion  22  on a second side of electrowetting pixel region  12 . In one embodiment, electrowetting display device  10  includes a combination of red, blue, green, and transparent (white) color filter portions  78 , with one color filter portion  78  being positioned in or over each electrowetting pixel region  12 . Using color filter portions  78 , each electrowetting pixel region  12  in electrowetting display device  10  can be associated with a particular wavelength of electromagnetic radiation. By controlling which electrowetting pixel regions  12  are active within electrowetting display device  10 , electrowetting display device  10  can generate color images viewable by a user. 
     In example embodiments, light-blocking layer  50  includes one or more light-blocking portions  54 , e.g., including a black matrix material such as a suitable photoresist material, disposed and positioned around at least a portion of each color filter portion  78  to form a perimeter around at least a portion of the associated color filter portion  78 . In example embodiments, the black matrix material is aligned with or positioned over pixel wall portions  22 . More specifically, a plurality of light-blocking portions  54  are aligned over the plurality of pixel wall portions  22  and form first grid pattern  55  on inner surface  52 . For example, in certain embodiments, each light-blocking portion  54  is aligned over a respective pixel wall portion  22  of the plurality of pixel wall portions  22 . As shown in  FIG. 1 , electrowetting display device  10  includes first light-blocking portion  54   a  positioned over first pixel wall portion  22   a . More specifically, first light-blocking portion  54   a  is positioned along an edge of color filter portion  78   a , between color filter portion  78   a  and an adjacent color filter portion  78   b . Color filter portions  78  are adjacent when they are next to one another in the display device with no intervening color filter portion  78 . Light-blocking portion  54   a  is formed between color filter portion  78   a  and color filter portion  78   b  such that light-blocking portion  54   a  is between the adjacent color filter portion  78   a  and color filter portion  78   b . In a particular embodiment, light-blocking portion  54   a  has a width between color filter portion  78   a  and color filter portion  78   b  of 16.0 micrometers to 30.0 micrometers, and, more particularly, a width of 25.0 micrometers to 30.0 micrometers. In example embodiments, each color filter portion  78  is disposed over or in a respective electrowetting pixel region  12  between light-blocking portions  54  such that light-blocking portions  54  form a perimeter of each color filter portion  78 . Referring further to  FIG. 1 , first color filter portion  54   a  is disposed on inner surface  52  of top support plate  16  adjacent first light-blocking portion  54   a.    
     A conforming layer  80  having a suitable photo-definable material, such as a photo-definable polymer, is disposed over color filter layer  76  to cover each color filter portion  78 , such as first color filter portion  78   a . In example embodiments, conforming layer  80  includes a planarization layer, such as an organic planarization layer, disposed over, e.g., deposited or formed on, color filter layer  76  to cover each color filter portion  78  without overlying or covering at least a portion of light-blocking portion  54 , e.g., without overlying or covering inner surface  72  of light-blocking portion  54   a  facing an interior volume of electrowetting pixel region  12 . 
     Conforming layer  80  at least partially forms a recessed region or trench  84 , which may be referred to herein as a trench or a recessed region, over a portion of electrically conductive portion  70 . In example embodiments, recessed region  84  is aligned with, e.g., positioned over, first electrically conductive portion  70  a to provide communication between electrically conductive portion  70   a  and second fluid  34 , e.g., the liquid electrolyte solution disposed in electrowetting pixel region  12 . As shown in  FIGS. 1 and 2 , recessed region  84  includes sidewalls, such as a first sidewall  86  and a second sidewall  88 . In a particular embodiment, conforming layer  80  extends onto a portion of an inner surface  90  of electrically conductive portion  70 . In certain embodiments, recessed region  84  includes an opening formed through a thickness of conforming layer  80 . The opening is aligned with first electrically conductive portion  70   a  to provide fluid communication between first electrically conductive portion  70   a  and second fluid  34 , e.g., the liquid electrolyte solution disposed in electrowetting pixel region  12  such that second fluid  34  is disposed in recessed region  84  and contacts first electrically conductive portion  70   a.    
     In example embodiments, first light-blocking portion  54   a  has a thickness of 1.0 micrometer to 2.0 micrometers and, more particularly, a thickness of 1.2 micrometers to 1.5 micrometers, and electrically conductive portion  70   a  includes an ITO layer or ITO portion having a thickness of 100 nanometers to 300 nanometers and, more particularly, a thickness of 150 nanometers. First color filter portion  78   a  has a thickness of 2.0 micrometers to 4.0 micrometers and, more particularly, a thickness of 3.2 micrometers, and conforming layer  80  has a thickness of 1.0 micrometers to 3.0 micrometers and, more particularly, a thickness of 2.0 micrometers. As a result, the combined thickness of first color filter portion  78   a  and conforming layer  80  is between 3.0 micrometers and 7.0 micrometers, in the example embodiments. In these example embodiments, recessed region  84  provides an additional 1.0 micrometer to 5.0 micrometers (generally a difference between a combined thickness of first color filter portion  78   a  and conforming layer  80  and a combined thickness of first light-blocking portion  54   a  and first electrically conductive portion  70   a ) to provide sufficient clearance between common electrode  30  and first fluid  32  as first fluid  32  contracts to form droplet  58  in the contracted state. As a result, a distance  92 , referred to as a cell gap, of electrowetting pixel region  12  between hydrophobic surface  42  of electrowetting pixel region  12  and a first or inner surface  94  of conforming layer  80  can be decreased. In example embodiments, referring to  FIG. 1 , distance  92  is defined by a height of spacer  44  coupled between first pixel wall portion  22   a  and conforming layer  80  and at least a portion of a height of first pixel wall portion  22   a . In example embodiments, distance  92  is less than 20 micrometers and, more particularly, distance  92  is not greater than 15 micrometers and, even more particularly, distance  92  is 15 micrometers. In alternative embodiments, distance  92  is at least 20 micrometers. 
     With first fluid  32  and second fluid  34  that is immiscible with first fluid  32  disposed within electrowetting pixel region  12 , second fluid  34  contacts common electrode  30 . As shown in  FIG. 1 , with electrowetting pixel region  12  in an active state, first fluid  32  forms droplet  58  in first liquid collection area  56  with first fluid  32  in a contracted state. In certain example embodiments, a height of droplet  58 , e.g., a height of first fluid  32  in the contracted state, is greater than distance  92  such that droplet  58  extends into recessed region  84 , as shown in  FIG. 1 . In alternative embodiments, the height of droplet  58  is less than distance  92  and, thus, does not extend into recessed region  84 . Electrode layer  24  positioned over bottom support plate  14  is coupled to common electrode  30  for creating a voltage differential between electrode layer  24  and common electrode  30  to cause displacement of first fluid  32  to expose at least a portion of reflective layer  36 . 
     Reflective electrowetting display device  10  has a viewing side  96  corresponding to top support plate  16  through which an image formed by reflective electrowetting display device  10  may be viewed, and an opposing rear side  98  corresponding to bottom support plate  14  as shown, for example, in  FIG. 1 . Reflective electrowetting display device  10  may be a segmented display type in which the image is built of segments. The segments may be switched simultaneously or separately. Each segment includes one electrowetting pixel region or a number of electrowetting pixel regions that may be neighboring or distant from one another. The electrowetting pixel regions included in one segment are switched simultaneously, for example. Electrowetting display device  10  may also be an active matrix driven display type or a passive matrix driven display, for example. 
     Referring now to  FIG. 2 , in certain embodiments, reflective electrowetting display device  10  includes a thin film transistor (TFT) structure  120  disposed over, e.g., formed on, bottom support plate  14  and associated with, e.g., operatively coupled to, a respective electrowetting pixel region  12 . In example embodiments, TFT structure  120  is positioned in electrowetting pixel region  12  and operatively coupled to common electrode  30  positioned under top support plate  16  for creating, in conjunction with common electrode  30 , a voltage differential between TFT structure  120  and common electrode  30  to cause displacement of first fluid  32  (not shown in  FIG. 2 ), e.g., a liquid such as an opaque electrowetting oil, in electrowetting pixel region  12 , e.g., in electrowetting sub-pixel  18 . 
     Each TFT structure  120  includes a first metal layer  122 , e.g., an electrode layer or gate electrode layer that includes a gate  124  and a metal portion  126 , disposed on or over bottom support plate  14 . TFT structure  120  is coupled in signal communication with associated electrowetting sub-pixel  18  within electrowetting pixel region  12 . In the example embodiment, TFT structure  120  is switched to either select (activate) or deselect (deactivate) associated electrowetting sub-pixel  18  using active matrix addressing, for example. 
     A silicon layer, such as a silicon semiconductor layer  128 , e.g., a silicon semiconductor layer including an active amorphous silicon, is disposed on or over, e.g., formed or deposited on, a suitable non-conducting substrate, such as a dielectric layer or first passivation layer  130 , shown in  FIG. 2 , which may include a silicon nitride layer, for example. 
     A second metal layer  132  is disposed, e.g., formed or deposited on, on first passivation layer  130  and at least a portion of silicon semiconductor layer  128 . Second metal layer  132  includes a suitable metal material, such as ITO. Second metal layer  132  forms a source  134  and a drain  136  of TFT structure  120 . Source  134  includes a source line not shown in  FIG. 2 , to electrically couple source  134  to a source driver for transmitting signals to or from the source driver for driving, e.g., activating or deactivating, electrowetting sub-pixel  18 . In example embodiments, source  134  and drain  136  are positioned over silicon semiconductor layer  128  and, in combination, cover a first portion of silicon semiconductor layer  128  leaving a second portion of the silicon semiconductor layer uncovered. A second passivation layer  138 , e.g., a passivation layer comprising silicon nitride, is disposed on, e.g., formed or deposited on or over, second metal layer  132 . Second passivation layer  138  is made of a suitable material to isolate source  134  and drain  136  from ambient conditions. 
     A conducting channel region  140 , formed between source  134  and drain  136 , is susceptible to undesirable photoleakage current. In one embodiment, second passivation layer  138  is at least partially positioned on or in conducting channel region  140  and contacts at least a portion of silicon semiconductor layer  128 . In certain embodiments, light-blocking portion  54  has suitable dimensions to extend over at least a portion of source  134 , at least a portion of drain  136 , and silicon semiconductor layer  128  entirely to act as a light shield to protect silicon semiconductor layer  128 , which is highly photosensitive, from undesirable exposure to light. In example embodiments, light-blocking portion  54  has suitable dimensions to extend over silicon semiconductor layer  128  to block, e.g., absorb, light and prevent or limit light entering electrowetting pixel regions  12  from impinging on the respective TFT structure  120 , e.g., on a surface of silicon semiconductor layer  128 . For example, light-blocking portion  54  has a length and a width greater than a respective length and width of silicon semiconductor layer  128 . More particularly, silicon semiconductor layer  128  has a first width along a width of gate  124  and a first length perpendicular to the first width and light-blocking portion  54  has a second width along the width of gate  124  greater than the first width and a second length perpendicular to the second width greater than the first length. 
     A contact, such as a contact hole  142  or a piece of conductive material is formed through a thickness of second passivation layer  138  to electrically couple a third metal layer, e.g., a reflective layer  144  disposed on or over, e.g., formed or deposited on, second passivation layer  138  to drain  136  formed in second metal layer  132  positioned under second passivation layer  138 . In example embodiments, reflective layer  144  is electrically coupled to drain  136  of second metal layer  132 . In certain embodiments, reflective layer  144  can act as a pixel electrode and a reflective layer. In example embodiments, reflective layer  144  may include any suitable material including, for example, a metal (90%, 95% or greater than 95% metal), an alloy, a doped metal, or a dielectric reflective material. Suitable metal materials for reflective layer  144  include, without limitation, aluminum, silver, gold, copper, nickel, platinum, rhodium, lanthanum, and/or silicon nickel. Suitable alloy materials for reflective layer  144  include, without limitation, aluminum with copper or aluminum with nickel. In further alternative embodiments, reflective layer  144  is made of any suitable material providing a desired specular reflectance. In alternative embodiments, reflective layer  144  includes a suitable diffuse reflective material deposited on or over second passivation layer  138 . In this alternative embodiment, any suitable diffuse reflective material, such as titanium dioxide (TiO 2 ), providing a desired diffuse reflectance may be used. 
     Referring further to  FIG. 2 , one or more dielectric barrier layers  146  may at least partially separate respective TFT structure  120  from a hydrophobic layer  148 . More specifically, in the embodiment shown in  FIG. 2 , dielectric barrier layer  146  at least partially separates reflective layer  144  from hydrophobic layer  148 , such as an amorphous fluoropolymer layer forming a bottom surface of respective electrowetting sub-pixel  18 . For example, dielectric barrier layer  146  may be disposed on, e.g., formed or deposited on, reflective layer  144 . Dielectric barrier layer  146  may include various materials including one or more organic material layers or a combination of organic and inorganic material layers. A thickness of the insulating dielectric barrier layer  146  may be less than 2 micrometers and may be less than 1 micrometer; for example, insulating dielectric barrier layer  146  may be 100 nanometers to 800 nanometers in thickness in certain embodiments. In example embodiments, hydrophobic layer  148  is an amorphous fluoropolymer layer including any suitable fluoropolymer(s), such as AF1600® fluoropolymer produced by DuPont based in Wilmington, Del. Hydrophobic layer  148  is transparent in the example embodiments. 
     An additional organic material layer  150  is disposed on, e.g., formed or deposited on, a portion of dielectric barrier layer  146  near and/or under pixel wall portion  22 . Organic material layer  150  may include any suitable organic material including, without limitation, a polyacrylate, an epoxy, or a polyimide material, and combinations thereof. 
     In example embodiments, one or more pixel wall portions  22  form a patterned electrowetting pixel grid pattern over, e.g., on, hydrophobic layer  148 . Pixel wall portions  22  may include a photoresist material such as, for example, an epoxy-based negative photoresist material SU-8. The patterned electrowetting pixel grid pattern includes a plurality of rows and a plurality of columns of pixel wall portions  22  that form a perimeter of each electrowetting pixel region in an array of electrowetting pixel regions. Each electrowetting pixel region  12  may have a width and a height in a range of about 50 to 500 micrometers, for example, and, more particularly, in one embodiment, electrowetting pixel regions  12  have a width of 60 micrometers and a height of 120 micrometers. 
     As described above, first fluid  32 , e.g., a liquid such as an opaque electrowetting oil, which may have a thickness in a range of 1 micrometer to 10 micrometers, for example, overlays hydrophobic layer  148 . First fluid  32  is partitioned by pixel wall portions  22 . Second fluid  34 , e.g., a liquid such as a liquid electrolyte solution, overlays first fluid  32  and, in certain embodiments, at least a portion of pixel wall portions  22 . In certain embodiments, as described above, second fluid  34  may be electrically conductive and/or polar. For example, second fluid  34  may be water or a water solution, or a salt solution such as a solution of potassium chloride in water or a mixture of water and ethyl alcohol. In certain embodiments, second fluid  34  is transparent, but may be colored or absorbing. First fluid  32  is electrically non-conductive and may, for example, be an alkane-like hexadecane or (silicone) oil. As described herein, second fluid  34  is immiscible with first fluid  32 . Light transmission through the electrowetting pixel regions is controlled by the application of an electric potential to the respective electrowetting pixel region, which results in a movement of second fluid  34  in the electrowetting pixel region, thereby displacing first fluid  32  in the electrowetting pixel region. 
     As described above, hydrophobic layer  148  is arranged on or over bottom support plate  14  to form a hydrophobic surface having an electrowetting surface area. The hydrophobic character of hydrophobic layer  148  causes first fluid  32  to adjoin preferentially to hydrophobic layer  148  because first fluid  32  has a higher wettability with respect to a top surface of hydrophobic layer  148  than second fluid  34  in the absence of a voltage. Wettability relates to the relative affinity of a fluid, e.g., a liquid, for the surface of a solid. Wettability increases with increasing affinity, and it may be measured by the contact angle formed between the fluid and the solid and measured internal to the fluid of interest. For example, such a contact angle may increase from relative non-wettability for a contact angle of more than 90° to complete wettability for a contact angle of 0°, in which case the fluid, e.g., the liquid, tends to form a film on the surface of the solid. 
     Top support plate  16 , as shown in  FIGS. 1 and 2 , covers second fluid  34  and one or more spacers  44  to maintain second fluid  34  over electrowetting pixel grid pattern. In example embodiments, spacers  44  are positioned between top support plate  16  and pixel wall portions  22 . More specifically, in certain example embodiments, spacer  44  is coupled to a contact surface on a first or distal end of corresponding pixel wall portions  22 . In certain embodiments, one or more components or layers may be positioned between top support plate  16  and spacer  44 . In this arrangement, a contact surface of spacer  44  contacts a contact surface of corresponding pixel wall portion  22  to provide a stable contact joint at an interface between pixel wall portion  22  and spacer  44 , providing mechanical strength at the interface that is less sensitive to overflow and/or leakage of first fluid  32  and/or second fluid  34  contained within electrowetting pixel regions  12 . In alternative embodiments, spacer  44  does not rest on pixel wall portion  22  but is substantially aligned with pixel wall portion  22 . This arrangement may allow spacer  44  to come into contact with pixel wall portion  22  upon a sufficient pressure or force being applied to top support plate  16 . Multiple spacers  44  may be interspersed throughout the electrowetting pixel grid pattern. Edge seal  46  extends about a perimeter of electrowetting display device  10  to contain first fluid  32  and second fluid  34  within the fluid region of the display cavity. A voltage applied across, among other things, second fluid  34  and respective TFT structure  120  of individual electrowetting pixel regions  12  controls transmittance or reflectance of the associated electrowetting pixel region  12 . 
     Spacers  44  and edge seal  46  mechanically couple bottom support plate  14  with the overlying, opposing top support plate  16 , forming a separation between bottom support plate  14  and top support plate  16 , and contributing to the mechanical integrity of electrowetting display device  10 . Spacers  44  can be at least partially transparent so as to not hinder throughput of light in the electrowetting display. The transparency of spacers  44  may at least partially depend on the refractive index of the spacer material, which can be similar to or the same as the refractive indices of surrounding media. Spacers  44  may also be chemically inert to surrounding media. Edge seal  46 , for example, disposed along a periphery of an array of electrowetting pixel regions  12 , may contribute to retaining fluids (e.g., first fluid  32  and second fluid  34 ) between bottom support plate  14  and the overlying top support plate  16 . 
     In various embodiments described herein, electronic devices include electrowetting displays (EWDs) for presenting content. In some examples, the electronic devices may include one or more components associated with the electrowetting display, such as a touch sensor component layered atop the electrowetting display for detecting touch inputs, a front light and/or a back light component for lighting the electrowetting display, and/or a cover layer component, which may include anti-glare properties, anti-reflective properties, anti-fingerprint properties, and/or anti-cracking properties, for example. 
     For a reflective EWD, when the electrowetting sub-pixel is in a resting state (i.e., the closed or off state, with no electric potential applied), the first liquid, e.g., the opaque electrowetting oil, is distributed throughout the electrowetting sub-pixel to substantially cover a display surface area of the electrowetting sub-pixel (see  FIG. 1 ). The first liquid absorbs light and the electrowetting sub-pixel in this condition appears dark, e.g., black, in one embodiment. But when the electric potential is applied, the electrowetting sub-pixel is in an active state (i.e., an at least partially open state—the on state—with an electric potential applied), the second liquid moves into the electrowetting sub-pixel displacing the first liquid so that the first liquid is no longer distributed throughout the electrowetting sub-pixel. Light can then enter the electrowetting sub-pixel and impinge upon a surface of a reflective portion or layer, for example, positioned at or near a bottom of the electrowetting pixel region. The light is then reflected by the reflective portion or layer to reflect out of the electrowetting pixel region. If the reflective surfaces reflect only a portion of the light spectrum or if color filters are incorporated into the electrowetting pixel structure, the electrowetting sub-pixel may appear to be gray or have color. 
     A display device, such as an electrowetting display device, may include a transmissive, reflective or transflective display that generally includes an array of pixel regions (e.g., an array of sub-pixels) configured to be operated by an active matrix addressing scheme. For example, rows and columns of electrowetting sub-pixels are operated by controlling voltage levels on a plurality of source lines and gate lines. In this fashion, the display device may produce an image by selecting particular sub-pixels to transmit, reflect or block light. Sub-pixels are addressed (e.g., selected) via rows and columns of the source lines and the gate lines that are electrically connected to transistors (e.g., TFT structures used as switches) included in each pixel region. The transistors occupy a relatively small fraction of the area of each pixel region to allow light to efficiently pass through (or reflect from) the sub-pixel. 
     The array of pixel regions is sandwiched between two support plates, such as bottom support plate  14  and opposing top support plate  16 . The support plates may be made of any suitable material including, without limitation, plastic, glass, quartz, and semiconducting materials, and may be made of a rigid material or a flexible material, for example. The pixel regions include various layers of materials built upon the bottom support plate, e.g., within or under the sub-pixels. One example layer is an amorphous fluoropolymer (AF1600®) with hydrophobic behavior. The pixel wall portions may be formed on a top surface of the hydrophobic layer. The bottom support plate may be opaque while the top support plate is transparent. Describing a component or material as being “transparent” generally means that the component or the material may transmit a relatively large fraction of the light incident upon it. For example, a transparent material or layer might transmit more than 70% or 80% of the light impinging on its surface, although in other examples a transparent material or structure might transmit a different percentage of incident light. In general, transparent materials or structures need not be perfectly transparent. 
     Example embodiments described herein include, but are not limited to, reflective electrowetting displays having a clear or transparent top support plate and a bottom support plate, which need not be transparent. In general, “top” and “bottom” may be used to identify opposing support plates of an electrowetting display and do not necessarily refer to a direction referenced to gravity or to a viewing side of the electrowetting display device. In example embodiments, the top support plate is the surface through which pixels of a (reflective) electrowetting display are viewed. 
     As described above, individual reflective electrowetting pixel regions may include an electrode layer or gate electrode layer containing or coupled to the drive electronics like TFT structures, source lines, and gate lines on the bottom support plate, a reflective layer over the electrode layer, a pixel electrode adjacent to the reflective layer, a barrier layer on the reflective layer, and a hydrophobic layer on the barrier layer. The pixel electrode in principle is close to the liquids in the pixel region to minimize power consumption. In one alternative embodiment, a patterned layer of indium tin oxide (ITO) is deposited as the pixel electrode over the reflective layer. In another alternative embodiment, the pixel electrode is under the reflective layer. The electrode layer, for example, can be an electrode layer containing at least part of the drive electronics if the reflective layer is used as the electrode or the electrode layer can contain the pixel electrodes in contact with the reflective layer. Pixel wall portions of each pixel region, the hydrophobic layer, and the transparent top support plate at least partially enclose a liquid region within the display cavity that contains the first liquid which is electrically non-conductive, e.g., an opaque oil retained in the individual electrowetting sub-pixels by pixel wall portions, and the second liquid, e.g., an electrolyte solution, that is electrically conductive or polar and may be a water or a salt solution, such as a solution of potassium chloride in water. The second liquid may be transparent or may be colored. The second liquid is immiscible with the first liquid. In general, substances are “immiscible” with one another if the substances do not substantially form a solution, although in a particular embodiment the second liquid might not be perfectly immiscible with the first liquid. In general, an “opaque” liquid is a liquid that appears black to an observer. For example, an opaque liquid strongly absorbs a broad spectrum of wavelengths (e.g., including those of red, green and blue light) in the visible region of electromagnetic radiation appearing black. However, in certain embodiments an opaque liquid may absorb a relatively narrower spectrum of wavelengths in the visible region of electromagnetic radiation and may not appear perfectly black. 
     In some embodiments, the opaque liquid is a nonpolar electrowetting oil. In certain embodiments, the first liquid may absorb at least a portion of the visible light spectrum. The first liquid may be transmissive for a portion of the visible light spectrum, forming a color filter. For this purpose, the first liquid may be colored by addition of pigment particles or a dye. Alternatively, the first liquid may be black, for example by absorbing substantially all portions of the visible light spectrum, or reflecting. A reflective first liquid may reflect the entire visible light spectrum, making the layer appear white, or a portion of the entire visible light spectrum, making the layer have a color. In example embodiments, the first liquid is black and, therefore, absorbs substantially all portions of an optical light spectrum. 
     In some embodiments, the electrowetting display device as described herein may be incorporated into a system that includes one or more processors and one or more computer memories, which may reside on a control board, for example. Display software may be stored on the one or more memories and may be operable with the one or more processors to modulate light that is received from an outside source (e.g., ambient room light) or out-coupled from a lightguide of the electrowetting display device. For example, display software may include code executable by a processor to modulate optical properties of individual pixels of the electrowetting display device based at least in part on electronic signals representative of static image and/or video data. The code may cause the processor to modulate the optical properties of pixels by controlling electrical signals (e.g., voltages, currents, and fields) on, over, and/or in layers of the electrowetting display device. 
       FIG. 3  is top view of a portion of electrowetting display device  200  including a plurality of electrowetting pixel regions  202 , such as electrowetting pixel regions  12  formed over a first or bottom support plate (shown in  FIGS. 1 and 2 ), according to one embodiment. As shown in  FIG. 3 , a first column  204  of electrowetting pixel regions  202  includes a first light-blocking portion  206 , such as a light-blocking portion  54 , positioned in or over a first (red) electrowetting pixel region  208  and a second light-blocking portion  210  positioned in or over a second (blue) electrowetting pixel region  212 . When first electrowetting pixel region  208  is activated, the first fluid in first electrowetting pixel region  208  moves in a first direction  214  toward a first TFT structure, such as a respective TFT structure  120 , in first electrowetting pixel region  208  adjacent a first pixel wall portion (not shown in  FIG. 3 ) positioned under first light-blocking portion  206  and, when second electrowetting pixel region  212  is activated, the first fluid in second electrowetting pixel region  212  moves in first direction  214  toward a second TFT structure, such as a respective TFT structure  120 , adjacent a second pixel wall portion positioned under second light-blocking portion  210 . Similarly, a second column  222  of electrowetting pixel regions  202  adjacent first column  204  includes a third light-blocking portion  224  positioned in or over a third (green) electrowetting pixel region  226  adjacent first electrowetting pixel region  208  and a fourth light-blocking portion  228  positioned in or over a fourth (transparent (white)) electrowetting pixel region  230  adjacent second electrowetting pixel region  212 . When third electrowetting pixel region  226  is activated, the first fluid in third electrowetting pixel region  226  moves in first direction  214  toward a third TFT structure, such as a respective TFT structure  120 , in third electrowetting pixel region  226  adjacent a third pixel wall portion (not shown in  FIG. 3 ) collinear with the first pixel wall portion and positioned under third light-blocking portion  224  and, when fourth electrowetting pixel region  230  is activated, the first fluid in fourth electrowetting pixel region  230  moves in first direction  214  toward a fourth TFT structure, such as a respective TFT structure  120 , in fourth electrowetting pixel region  230  adjacent a fourth pixel wall portion (not shown in  FIG. 3 ) collinear with the second pixel wall portion and positioned under fourth light-blocking portion  228 . 
     In an example embodiment, an electrowetting display device includes a first support plate and a second support plate. A first electrowetting sub-pixel is between the first support plate and the second support plate. The first electrowetting sub-pixel includes a plurality of pixel wall portions over the first support plate forming a perimeter of the first electrowetting sub-pixel. An oil and an electrolyte solution that is immiscible with the oil are disposed in the first electrowetting sub-pixel. A light-blocking layer is disposed on an inner surface of the second support plate. The light-blocking layer includes a first light-blocking portion disposed over a first pixel wall portion of the plurality of pixel wall portions. An indium tin oxide (ITO) layer is disposed on the light-blocking layer. The ITO layer includes a first ITO portion disposed on the first light-blocking portion. A color filter layer is disposed on the inner surface of the second support plate. The color filter layer is coplanar with the light-blocking layer and includes a first color filter portion adjacent the first light-blocking portion. A layer having a photo-definable material is disposed on the color filter layer and includes a recessed region formed through a thickness of the layer. The recessed region is aligned with the first ITO portion and provides fluid communication between the first ITO portion and the electrolyte solution such that the electrolyte solution contacts the first ITO portion. In certain embodiments, a spacer is coupled between the first pixel wall portion and the layer having a photo-definable material adjacent the recessed region. A distance between a hydrophobic surface of the electrowetting sub-pixel and an inner surface of the layer having a photo-definable material is defined by a height of the spacer and at least a portion of a height of the first pixel wall portion. The ITO layer provides a common electrode associated with the first electrowetting sub-pixel. The electrowetting display device further includes a reflective layer disposed over the first support plate in the first electrowetting sub-pixel. An electrode layer is positioned over the first support plate for creating, in conjunction with the common electrode, a voltage differential between the electrode layer and the common electrode to cause displacement of the oil in the first electrowetting sub-pixel to expose at least a portion of the reflective layer. 
     In one embodiment, a second electrowetting sub-pixel is between the first support plate and the second support plate and adjacent the first electrowetting sub-pixel. The color filter layer further includes a second color filter portion in the second electrowetting sub-pixel and adjacent the first light-blocking portion. The layer having a photo-definable material is disposed on the second color filter portion to form the recessed region between the first color filter portion and the second color filter portion. 
     In another example embodiment, a display device includes a first support plate having a top surface and an opposing bottom surface and a second support plate having a first surface and an opposing second surface. A pixel region between the top surface of the first support plate and the second surface of the second support plate includes a plurality of pixel wall portions over the top surface of the first support plate forming a perimeter of the pixel region. A first liquid and a second liquid that is immiscible with the first liquid are disposed in the pixel region. A light-blocking layer is disposed on the second surface of the second support plate. The light-blocking layer includes a light-blocking portion positioned over a first pixel wall portion of the plurality of pixel wall portions. An electrically conductive layer including an electrically conductive portion is disposed on the light-blocking portion. A conforming layer is disposed over at least a portion of the second surface of the second support plate. The conforming layer includes a recessed region extending through a thickness of the conforming layer and aligned with the electrically conductive portion to provide fluid communication between the electrically conductive portion and the second liquid such that a portion of the second liquid is disposed within the recessed region and contacts the electrically conductive portion when the pixel region is open, i.e., with the pixel region in an active state. In one embodiment, a first color filter portion is disposed on the second surface of the second support plate adjacent a first side edge of the light-blocking portion, wherein the conforming layer is disposed on the first color filter portion. In one embodiment, an opening is formed through the conforming layer to form the recessed region. A second color filter portion is disposed on the second surface of the second support plate adjacent a second side edge of the light-blocking portion opposing the first side edge. In this embodiment, the conforming layer is disposed on the second color filter portion to form the recessed region between the first color filter portion and the second color filter portion. A hydrophobic layer is disposed over the first support plate. The hydrophobic layer forms a hydrophobic surface of the pixel region. A spacer is coupled between the first pixel wall portion and the conforming layer. A distance between the hydrophobic surface and a first surface of the conforming layer is defined by a height of the spacer and at least a portion of a height of the first pixel wall portion. 
     In one embodiment, the light-blocking layer includes a plurality of light-blocking portions forming a first grid pattern and the electrically conductive layer includes a plurality of electrically conductive portions forming a second grid pattern aligned with the first grid pattern. In this embodiment, the second grid pattern provides a continuous common electrode for the display device. The first liquid forms a droplet that extends into the recessed region with the first liquid in a contracted state. 
     The electrically conductive layer provides a common electrode associated with the pixel region. A reflective layer is positioned over the first support plate in the pixel region. An electrode layer is positioned over the first support plate. The electrode layer is coupled to the common electrode for creating a voltage differential between the electrode layer and the common electrode to cause displacement of the first liquid to expose at least a portion of the reflective layer. 
     In another example embodiment, a display device includes a first support plate having a first surface. A light-blocking layer including a light-blocking portion is disposed on the first surface of the first support plate. A transparent, electrically conductive layer is disposed on the light-blocking layer. The transparent electrically conductive layer includes an electrically conductive portion disposed on the light-blocking portion. A color filter layer is disposed on the first surface of the first support plate. The color filter layer is coplanar with the light-blocking layer and includes a color filter portion adjacent the light-blocking portion. A conforming layer is disposed on the color filter layer and a recessed region extends through the conforming layer and is aligned with the electrically conductive portion. The light-blocking layer includes a plurality of light-blocking portions forming a first grid pattern and the transparent, electrically conductive layer includes a plurality of electrically conductive portions forming a second grid pattern aligned with the first grid pattern. The second grid pattern provides a continuous common electrode for the electrowetting display device. Each electrically conductive portion of the plurality of electrically conductive portions is aligned with and disposed on a respective light-blocking portion of the plurality of light-blocking portions. In example embodiments, a spacer is disposed on the conforming layer and positioned adjacent the recessed region. A second support plate is coupled to the first support plate. The second support plate having a first surface. A hydrophobic layer is disposed over the first surface of the second support plate. A plurality of pixel wall portions is disposed on the hydrophobic layer. The plurality of pixel wall portions forms a perimeter of a pixel region such that the spacer is coupled to a first pixel wall portion of the plurality of pixel wall portions and a height of the spacer and at least a portion of a height of the first pixel wall portion define a distance between the conforming layer and the hydrophobic layer. A second support plate is coupled to the first support plate. The second support plate has a first surface. A plurality of pixel wall portions is formed over the first surface of the second support plate. The plurality of pixel wall portions forms a perimeter of a pixel region. A first liquid and a second liquid that is immiscible with the first liquid are disposed in the pixel region. The recessed region includes an opening extending through a thickness of the conforming layer to provide fluid communication between the transparent, electrically conductive portion and the second liquid. In certain embodiments, the conforming layer is disposed on a portion of light-blocking portion and the recessed region includes an opening extending through a thickness the conforming layer. 
       FIG. 4  is a flow diagram of an example method  300  for fabricating an electrowetting display device, such as electrowetting display device  10 , as shown in  FIGS. 1 and 2 , or electrowetting display device  200  as shown in  FIG. 3 .  FIGS. 5-18  are cross-sectional schematic views of a portion of the color filter structure of the example electrowetting display device during various steps of the method illustrated in  FIG. 4 . Though claimed subject matter is not limited in this respect, method  300  may be performed manually (e.g., by humans) and/or using automated equipment. At block  302 , a thin film transistor (TFT) structure is formed over a first support plate in a pixel region adjacent a first pixel wall portion partially forming a perimeter of the first pixel region. In one embodiment, forming  302  a TFT structure over the first support plate includes forming a first metal layer over the first support plate. The first metal layer includes a gate. In an example embodiment, the first metal layer is deposited on the first support plate using a suitable physical vapor deposition process (PVD) such as sputtering. Additional layers may be positioned between the first metal layer and the first support plate. In certain embodiments, a gate line is formed to operatively couple a gate driver to the TFT structure. The gate driver is configured to activate the associated electrowetting pixel regions as described herein. 
     A first passivation layer, e.g., a dielectric layer, is formed over, e.g., deposited on, the first metal layer. In example embodiments, the first passivation layer includes a suitable silicon nitride layer. Alternatively, the first passivation layer may include SiON, SiO, or TaO, for example. Any suitable deposition technique may be used, such as CVD, PVD, MBE, or a sputtering technique, for example. A silicon layer, e.g., a semiconductor layer, such as a silicon semiconductor layer including an amorphous silicon material, is formed on the first passivation layer and over the gate. A second metal layer is formed over the first metal layer and on the silicon layer. The second metal layer includes a source and a drain covering a first portion of the silicon layer. A second passivation layer is formed on the second metal layer. 
     A reflective layer is disposed over, e.g., formed on, the second passivation layer. A contact extends through a thickness of the second passivation layer. In example embodiments, the reflective layer is electrically coupled to the drain formed in the second metal layer positioned under the second passivation layer through the contact. In example embodiments, the reflective layer may include any suitable material including, for example, a metal (90%, 95% or greater than 95% metal), an alloy, a doped metal, or a dielectric reflective material, as described above. In alternative embodiments, the reflective layer includes a suitable diffuse reflective material deposited on or over the second passivation layer. 
     In certain embodiments, a suitable dielectric barrier layer is formed on or over the reflective layer and over the TFT structure. For example, the dielectric barrier layer may be deposited on the reflective layer. The dielectric barrier layer may be formed from various materials including one or more organic material layers or a combination of organic and inorganic material layers. In certain embodiments, an organic material layer is formed over, e.g., deposited on, a portion of the dielectric barrier layer near and/or under the pixel wall portions. The organic material layer may include any suitable organic material including, without limitation, a polyacrylate, an epoxy, or a polyimide material, and combinations thereof. A hydrophobic layer, such as an amorphous fluoropolymer layer forming a bottom surface of the electrowetting pixel regions, is formed over the dielectric barrier layer and, in certain embodiments, over the organic material layer. The dielectric barrier layer may at least partially separate the TFT structure from the hydrophobic layer. More specifically, in one embodiment, the dielectric barrier layer at least partially separates the reflective layer from the hydrophobic layer. 
     At block  304 , a plurality of pixel wall portions forming a patterned electrowetting pixel grid pattern is formed over the first support plate. In the example embodiment, one or more pixel wall portions form a patterned electrowetting pixel grid pattern over, e.g., on, the hydrophobic layer. The pixel wall portions may include a photoresist material such as, for example, an epoxy-based negative photoresist material SU-8. The patterned electrowetting pixel grid pattern includes a plurality of rows and a plurality of columns of pixel wall portions that form a perimeter of each electrowetting pixel region in an array of electrowetting pixel regions. Each electrowetting pixel region may have a width and a height in a range of about 50 to 500 micrometers, for example, and, more particularly, in one embodiment, electrowetting pixel regions have a width of 60 micrometers and a height of 120 micrometers. 
     Referring further to  FIGS. 5 and 6 , a light-blocking layer, e.g., an organic material layer, such light-blocking layer  50 , is formed  306  on a second support plate, e.g., top support plate  16 . In example embodiments, the light-blocking layer includes a suitable black matrix material forming a plurality of light-blocking portions  54  in a first grid pattern  55 , as shown in  FIG. 5 , for example. In certain embodiments, the light-blocking layer is deposited on a surface of the second support plate using a suitable deposition process or a suitable printing process, e.g., an ink jet printing process. For example, in one example embodiment, at block  306 , a photoresist material is deposited on a first surface of the second support plate. The photoresist material is patterned to form a patterned photoresist material and the patterned photoresist material is developed to form the light-blocking layer including a plurality of light-blocking portions, such as light-blocking portions  54 . More specifically, in one embodiment, at block  306 , the photoresist material is deposited on top support plate  16 . Once the photoresist material is deposited, a photomask is positioned over the photoresist material and the photoresist material is exposed to ultra-violet (UV) light through the photomask. The photoresist material is then patterned and developed to form the light-blocking layer including a first grid pattern of a plurality of interconnected light-blocking portions. In alternative embodiments, these structures may be printed using suitable methods other than photolithography, including, without limitation, direct writing and electron beam lithography (EBL). 
     Referring to  FIGS. 7 and 8 , at block  308 , an electrically conductive layer, such as an electrically conductive layer  28  forming common electrode  30 , is formed over the second support plate, e.g., top support plate  16 . In example embodiments, electrically conductive layer  28  is formed on light-blocking layer  50 . More specifically, in example embodiments, electrically conductive layer  28  includes a plurality of electrically conductive portions  70  formed in a second grid pattern  71 , as shown in  FIG. 7 . As shown in  FIG. 7 , second grid pattern  71  of electrically conductive portions  70  is disposed on and aligned with first grid pattern  55  of light-blocking portions  54  shown in  FIG. 5  such that each electrically conductive portion  70  of electrically conductive layer  28  is disposed on and aligned with a respective light-blocking portion  54  of light-blocking layer  50 . Referring to  FIGS. 7 and 8 , electrically conductive layer  28  is disposed on at least a portion of light-blocking layer  50 , e.g., light-blocking portion  54 , to contact light-blocking portion  54 . In the embodiment shown, each electrically conductive portion  70  is aligned with and has a substantially identical width to the respective light-blocking portion  54  on which it is disposed. In example embodiments, the “self-aligning” electrically conductive portion  70  can be formed on a respective light-blocking portion  54  using an example method as illustrated in  FIGS. 9-12 . 
     Referring to  FIGS. 9-12 , a transparent electrically conductive layer  28 , such as an indium tin oxide (ITO) layer, is formed on the support plate and the light-blocking layer using a suitable deposition process, for example. In this embodiment, at block  308 , the ITO layer is applied directly on a surface of the light-blocking layer using a suitable sputtering process, as illustrated in  FIG. 9 . A positive tone photoresist layer  309  is then formed, e.g., deposited, on electrically conductive layer  28  as shown in  FIG. 10 . Once positive tone photoresist material  309  is deposited on the ITO layer, the ITO layer and the positive tone photoresist layer are exposed to a suitable UV light through support plate  16  utilizing light-blocking layer  50  as a photomask. For example, in one embodiment, during step  308 , an ultra-violet (UV) light source (not shown) is positioned adjacent a second surface of support plate  16  opposite the first surface, as illustrated in  FIG. 11 , and the positive tone photoresist layer and the electrically conductive layer are exposed to a portion of UV light (as indicated by arrows in  FIG. 11 ) emitted by the UV light source that propagates through support plate  16 . More specifically, a portion of the UV light emitted by the UV light source impinges on and is absorbed by light-blocking portions  54 . Portions of the UV light not absorbed by light-blocking portions  54  propagate through the transparent electrically conductive portions  70  to impinge on positive tone photoresist layer  309 . As a result, portions of the electrically conductive material and the positive tone photoresist layer not protected from exposure to the UV light by the light-blocking portions are cured. The electrically conductive layer is patterned to form second grid pattern  71 , as shown in  FIG. 7 , aligned with first grid pattern  55 , shown in  FIG. 5 , and including a plurality of electrically conductive portions  70 . Each electrically conductive portion  70  of the plurality of electrically conductive portions  70  is aligned with a respective light-blocking portion  54  of the plurality of light-blocking portions  54  of light-blocking layer  50 . During this processing, positive tone photoresist layer  309  is developed using suitable developing techniques to remove portions of the positive tone photoresist material disposed on portions of the electrically conductive layer exposed to UV light. 
     Referring to  FIG. 12 , portions of transparent electrically conductive layer  28 , e.g., portions of the ITO material, exposed to the UV light are then removed using a wet-etching process and the remaining positive tone photoresist material is striped using a suitable stripping process to form the patterned electrically conductive layer as shown in  FIGS. 7 and 8  forming a common electrode in a respective electrowetting pixel region. In example embodiments, the ITO layer is formed, e.g., deposited, directly on a surface of the light-blocking layer using a suitable deposition process, such as a sputtering technique, and the ITO layer is patterned using a photolithography technique utilizing the light-blocking layer as a photomask. The black matrix material forming the light-blocking portions of the light-blocking layer absorbs UV light while the ITO layer and the glass support plate are transparent to UV light. As a result, the ITO layer can be patterned by exposing the ITO layer and the overlying photoresist layer to UV light using a backside UV light source, with the light-blocking layer acting as a photomask in combination with a positive tone photoresist material. Because the electrically conductive layer is formed directly on the light-blocking layer, there is no air gap between the layers, i.e., a hard contact exposure method; therefore, unlike conventional processing methods, no light collimation is required to provide the desired shape and/or dimensions of the photoresist material identical to the corresponding shape and/or dimensions formed through the photomask. Further, conventional UV light sources, such as a suitable mercury lamp or UV LED array, can be used as the UV light source. Thus, tooling costs can be reduced. 
     In example embodiments, the light-blocking portion and the associated electrically conductive portion are self-aligned, i.e., the second grid pattern of the electrically conductive layer is identical to the underlying first grid pattern of the light-blocking layer. In contrast to conventional processing methods, an overlay, i.e., an amount of misalignment between the light-blocking portion and the electrically conductive portion, will inherently be substantially zero. As a result, a width of the light-blocking portions is finer or narrower to enhance light propagation into the associated electrowetting pixel region. Moreover, fewer photomask are needed to fabricate the electrowetting display device using example method  300  described herein. 
     At block  310 , a color filter layer, such as color filter layer  76  shown in  FIGS. 13 and 14 , is formed over top support plate  16  and coplanar with light-blocking layer  50 , e.g., disposed on inner surface  52  of top support plate  16  adjacent light-blocking portion  54 . A photoresist material is deposited over the electrically conductive layer to cover the electrically conductive portions and the voids between adjacent electrically conductive portions. Referring further to  FIGS. 13 and 14 , the photoresist material is patterned to form a patterned photoresist material and the patterned photoresist material is developed to form a plurality of color filter portions, such as color filter portions  78 . In one embodiment, at block  310 , once the photoresist material is deposited, a photomask is positioned over the photoresist material and the photoresist material is exposed to UV light through the photomask to form the plurality of color filter portions. In alternative embodiments, these structures may be printed using suitable methods other than photolithography, including, without limitation, direct writing and electron beam lithography (EBL). 
     In this embodiment, each color filter portion is positioned between adjacent light-blocking portions such that the light-blocking portions at least partially form a perimeter of the associated color filter portion. While a portion of the color filter portion may overlap or extend onto an edge of the respective electrically conductive portions formed on respective light-blocking portions, the color filter portion is removed from the surface of at least a portion of the electrically conductive portion. As described above, each color filter portion may be a red color filter portion, a green color filter portion, a blue color filter portion, or a transparent (white) color filter portion. 
     At block  312 , a layer having a photo-definable material, such as a suitable conforming layer or a suitable planarization layer, e.g., as organic conforming layer  80 , is disposed over, e.g., deposited or formed on, the color filter layer to cover each color filter portion as shown in  FIGS. 15 and 16 . In example embodiments, a photoresist material is disposed over electrically conductive layer  28  and color filter layer  76  to cover color filter portions  78  and form a recessed region or trench, such as recessed region  74 , aligned with, e.g., positioned over, electrically conductive portions  70  between adjacent color filter portions  78 . In a particular embodiment, an opening  313  is formed through the layer having a photo-definable material, e.g., conforming layer  80 , to form recessed region  74  and provide communication between electrically conductive portion  70  and an electrolyte solution disposed in the associated electrowetting pixel region  12 . Referring further to  FIGS. 15 and 16 , the photoresist material is patterned to form a patterned photoresist material and the patterned photoresist material is developed to form the layer having a photo-definable material on each color filter portion  78 . In one embodiment, at block  312 , once the photoresist material is deposited, a photomask is positioned over the photoresist material and the photoresist material is exposed to UV light through the photomask to form the layer having recessed regions  74 . In alternative embodiments, these structures may be printed using suitable methods other than photolithography, including, without limitation, direct writing and electron beam lithography (EBL). 
     In this embodiment, the layer having a photo-definable material includes a plurality of portions disposed on or over a respective color filter portion. In particular embodiments, the layer may extend over the edges of the color filter portions to contact the associated electrically conductive portions; however, the layer is removed from the surface of at least a portion of the electrically conductive portion to partially form the recessed region or trench aligned with, e.g., positioned over, the electrically conductive portion. As shown in  FIG. 16 , conforming layer  80  forms recessed region  74  aligned with, e.g., positioned over, electrically conductive portion  70 . In certain embodiments, recessed region  74  will have a width of 15.0 micrometers to 20.0 micrometers along a width of electrically conductive portion  70  and a height of 1.0 micrometer to 5.0 micrometers perpendicular to the width of recessed region  74 . The recessed region, such as recessed region  74 , is aligned over the hydrophobic surface of the electrowetting pixel region, such as over first liquid collection area  56  of electrowetting pixel region  12  in which first fluid  32  forms droplet  58  with first fluid  32  in a contracted state. 
     At block  314 , at least one spacer  44  is formed over top support plate  16  and on conforming layer  80  adjacent recessed region  74 , as shown in  FIGS. 17 and 18 . Multiple spacers  44  may be interspersed throughout the electrowetting pixel grid pattern. In example embodiments, the spacers, such as spacers  44 , are formed over top support plate  16  to align with respective pixel wall portions  22  when top support plate  16  is coupled to bottom support plate  14 . More specifically, in example embodiments, method  300  includes forming hydrophobic layer  40  over bottom support plate  14 . A plurality of pixel wall portions  22  is then formed on hydrophobic layer  40 . The plurality of pixel wall portions  22  forms a perimeter of a pixel region  12 . With spacer  44  aligned with at least one pixel wall portion  22  of the plurality of pixel wall portions  22 , top support plate  16  is coupled to bottom support plate  12 . In these embodiments, a height of spacer  44  and at least a portion of a height of the at least one pixel wall portion  22  define a distance between an inner surface of conforming layer  80  and an inner surface of hydrophobic layer  40 . In certain example embodiments, spacer  44  is coupled to and extends between surface  94  of conforming layer  80  to contact a contact surface on a first or distal end of corresponding pixel wall portions  22 . In this arrangement, a contact surface of spacer  44  contacts a contact surface of corresponding pixel wall portion  22  to provide a stable contact joint at an interface between pixel wall portion  22  and spacer  44 , providing mechanical strength at the interface that is less sensitive to overflow and/or leakage of first fluid  32  and/or second fluid  34  contained within electrowetting pixel regions  12 . 
     In one embodiment, at block  314 , a photoresist material is deposited over the layers formed on top support plate  16 . The photoresist material is exposed to a photomask to form each spacer. Referring to  FIGS. 17 and 18 , once the photoresist material is deposited, a photomask is positioned over the photoresist material and the photoresist material is exposed to UV light through the photomask. In alternative embodiments, these structures may be printed using suitable methods other than photolithography, including, without limitation, direct writing and electron beam lithography (EBL). The spacers can be at least partially transparent so as to not hinder throughput of light in the electrowetting display. The transparency of the spacers may at least partially depend on the refractive index of the spacer material, which can be similar to or the same as the refractive indices of surrounding media. The spacers may also be chemically inert to surrounding media. 
     A first fluid and a second fluid (e.g., the oil and the liquid electrolyte solution) can be disposed in the electrowetting pixel regions of the electrowetting display device. The second support plate is coupled to the electrowetting display device. The second support plate is positioned opposite the first support plate, forming opposing outer surfaces of the electrowetting display device. The first support plate is then coupled to the second support plate. With the first support plate coupled to the second support plate, the electrically conductive portion is positioned over a first liquid collection area on the hydrophobic surface of the electrowetting pixel region and the electrically conductive portion is in communication with the second fluid, e.g., the liquid electrolyte solution, via the recessed region formed by the conforming layer. A spacer is coupled between the conforming layer and one or more respective pixel wall portions such that a distance between the hydrophobic surface of the electrowetting pixel region and the conforming layer is defined by a height of the spacer and at least a portion of a height of the associated one or more pixel wall portions. 
     In an example method for fabricating at least a portion of an electrowetting display device, a light-blocking layer including a light-blocking portion is formed on a first surface of a support plate. An electrically conductive layer is formed on the light-blocking layer. The electrically conductive layer includes an electrically conductive portion contacting the light-blocking portion. A color filter layer is formed on the first surface of the support plate. The color filter layer is coplanar with the light-blocking layer. A conforming layer is formed on the color filter layer. The conforming layer forms a recessed region aligned with the electrically conductive portion. In one embodiment, an opening is formed through a thickness of the conforming layer to form the recessed region and provide communication between the electrically conductive portion and an electrolyte solution disposed in the pixel region. 
     In example embodiments, the electrically conductive layer is wet-etched and a portion of the photoresist layer and a portion of the electrically conductive layer exposed to the UV light are removed. A spacer is formed on the conforming layer, positioned adjacent the recessed region. A hydrophobic layer is formed over a second support plate. A plurality of pixel wall portions is formed on the hydrophobic layer. The plurality of pixel wall portions forms a perimeter of a pixel region. The spacer is aligned with at least one pixel wall portion of the plurality of pixel wall portions. The first support plate is coupled to the second support plate, wherein a height of the spacer and at least a portion of a height of the at least one pixel wall portion define a distance between an inner surface of the conforming layer and an inner surface of a hydrophobic layer over the second support plate. 
     In certain embodiments, forming an electrically conductive layer on the light-blocking layer includes forming a transparent electrically conductive layer on the light-blocking layer, forming a photoresist layer on the electrically conductive layer, positioning an ultra-violet (UV) light source adjacent a second surface of the support plate opposite the first surface, and exposing the photoresist layer and the electrically conductive layer to UV light emitted by the UV light source and propagating through the support plate. 
     In certain embodiments, forming an electrically conductive layer on the light-blocking layer includes patterning the electrically conductive layer to form a second grid pattern aligned with the first grid pattern. The second grid pattern includes a plurality of electrically conductive portions. Each electrically conductive portion of the plurality of electrically conductive portions is aligned with a respective light-blocking portion of the plurality of light-blocking portions. 
     In certain embodiments, forming a light-blocking layer including a light-blocking portion on a first surface of a support plate includes forming a first grid pattern including a plurality of light-blocking portions and forming an electrically conductive layer on the light-blocking layer comprises forming a second grid pattern including a plurality of electrically conductive portions, wherein the electrically conductive portion is disposed on the light-blocking portion.  FIG. 19  illustrates select example components of an example image display apparatus  400  that may be used with electrowetting display device  10 , for example, according to some implementations. Other types of displays may also be used with the example image display apparatus  400 . Such types of displays include, but are not limited to, LCDs, cholesteric displays, electrophoretic displays, electrofluidic pixel displays, photonic ink displays, and the like. 
     Image display apparatus  400  may be implemented as any of a number of different types of electronic devices. Some examples of image display apparatus  400  may include digital media devices and eBook readers  400 - 1 ; tablet computing devices  400 - 2 ; smart phones, mobile devices and portable gaming systems  400 - 3 ; laptop and netbook computing devices  400 - 4 ; wearable computing devices  400 - 5 ; augmented reality devices, helmets, goggles or glasses  400 - 6 ; and any other device capable of connecting with electrowetting display device  100  and including a processor and memory for controlling the display according to the techniques described herein. 
     In a very basic configuration, image display apparatus  400  includes, or accesses, components such as at least one control logic circuit, central processing unit, or processor  402 , and one or more computer-readable media  404 . Each processor  402  may itself comprise one or more processors or processing cores. For example, processor  402  can be implemented as one or more microprocessors, microcomputers, microcontrollers, digital signal processors, central processing units, state machines, logic circuitries, and/or any devices that manipulate signals based on operational instructions. In some cases, processor  402  may be one or more hardware processors and/or logic circuits of any suitable type specifically programmed or configured to execute the algorithms and processes described herein. Processor  402  can be configured to fetch and execute computer-readable instructions stored in computer-readable media  404  or other computer-readable media. Processor  402  can perform one or more of the functions attributed to timing controller  102 , source driver  104 , and/or gate driver  106  of electrowetting display device  100 . Processor  402  can also perform one or more functions attributed to a graphic controller (not illustrated) for the electrowetting display device. 
     Depending on the configuration of image display apparatus  400 , computer-readable media  404  may be an example of tangible non-transitory computer storage media and may include volatile and nonvolatile memory and/or removable and non-removable media implemented in any type of technology for storage of information such as computer-readable instructions, data structures, program modules or other data. Computer-readable media  404  may include, but is not limited to, RAM, ROM, EEPROM, flash memory or other computer readable media technology, CD-ROM, digital versatile disks (DVD) or other optical storage, magnetic cassettes, magnetic tape, solid-state storage and/or magnetic disk storage. Further, in some cases, image display apparatus  400  may access external storage, such as RAID storage systems, storage arrays, network attached storage, storage area networks, cloud storage, or any other medium that can be used to store information and that can be accessed by processor  402  directly or through another computing device or network. Accordingly, computer-readable media  404  may be computer storage media able to store instructions, modules or components that may be executed by processor  402 . 
     Computer-readable media  404  may be used to store and maintain any number of functional components that are executable by processor  402 . In some implementations, these functional components comprise instructions or programs that are executable by processor  402  and that, when executed, implement operational logic for performing the actions attributed above to image display apparatus  400 . Functional components of image display apparatus  400  stored in computer-readable media  404  may include the operating system and user interface module  406  for controlling and managing various functions of image display apparatus  400 , and for generating one or more user interfaces on electrowetting display device  100  of image display apparatus  400 . 
     In addition, computer-readable media  404  may also store data, data structures and the like, that are used by the functional components. For example, data stored by computer-readable media  404  may include user information and, optionally, one or more content items  408 . Depending on the type of image display apparatus  400 , computer-readable media  404  may also optionally include other functional components and data, such as other modules and data  410 , which may include programs, drivers and so forth, and the data used by the functional components. Further, image display apparatus  400  may include many other logical, programmatic and physical components, of which those described are merely examples that are related to the discussion herein. Further, while the figures illustrate the functional components and data of image display apparatus  400  as being present on image display apparatus  400  and executed by processor  402  on image display apparatus  400 , it is to be appreciated that these components and/or data may be distributed across different computing devices and locations in any manner. 
       FIG. 19  further illustrates examples of other components that may be included in image display apparatus  400 . Such examples include various types of sensors, which may include a GPS device  412 , an accelerometer  414 , one or more cameras  416 , a compass  418 , a gyroscope  420 , a microphone  422 , and so forth. 
     Image display apparatus  400  may further include one or more communication interfaces  424 , which may support both wired and wireless connection to various networks, such as cellular networks, radio, Wi-Fi networks, close-range wireless connections, near-field connections, infrared signals, local area networks, wide area networks, the Internet, and so forth. Communication interfaces  424  may further allow a user to access storage on or through another device, such as a remote computing device, a network attached storage device, cloud storage, or the like. 
     Image display apparatus  400  may further be equipped with one or more speakers  426  and various other input/output (I/O) components  428 . Such I/O components  428  may include a touchscreen and various user controls (e.g., buttons, a joystick, a keyboard, a keypad, etc.), a haptic or tactile output device, connection ports, physical condition sensors, and so forth. For example, operating system  406  of image display apparatus  400  may include suitable drivers configured to accept input from a keypad, keyboard, or other user controls and devices included as I/O components  428 . Additionally, image display apparatus  400  may include various other components that are not shown, examples of which include removable storage, a power source, such as a battery and power control unit, a PC Card component, and so forth. 
     Various instructions, methods and techniques described herein may be considered in the general context of computer-executable instructions, such as program modules stored on computer storage media and executed by the processors herein. Generally, program modules include routines, programs, objects, components, data structures, etc., for performing particular tasks or implementing particular abstract data types. These program modules, and the like, may be executed as native code or may be downloaded and executed, such as in a virtual machine or other just-in-time compilation execution environment. Typically, the functionality of the program modules may be combined or distributed as desired in various implementations. An implementation of these modules and techniques may be stored on computer storage media or transmitted across some form of communication. 
     Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described. Rather, the specific features and acts are disclosed as illustrative forms of implementing the claims. 
     One skilled in the art will realize that a virtually unlimited number of variations to the above descriptions are possible, and that the examples and the accompanying figures are merely to illustrate one or more examples of implementations. 
     It will be understood by those skilled in the art that various other modifications can be made, and equivalents can be substituted, without departing from claimed subject matter. Additionally, many modifications can be made to adapt a particular situation to the teachings of claimed subject matter without departing from the central concept described herein. Therefore, it is intended that claimed subject matter not be limited to the particular embodiments disclosed, but that such claimed subject matter can also include all embodiments falling within the scope of the appended claims, and equivalents thereof. 
     In the detailed description above, numerous specific details are set forth to provide a thorough understanding of claimed subject matter. However, it will be understood by those skilled in the art that claimed subject matter can be practiced without these specific details. In other instances, methods, devices, or systems that would be known by one of ordinary skill have not been described in detail so as not to obscure claimed subject matter. 
     Reference throughout this specification to “one embodiment” or “an embodiment” can mean that a particular feature, structure, or characteristic described in connection with a particular embodiment can be included in at least one embodiment of claimed subject matter. Thus, appearances of the phrase “in one embodiment” or “an embodiment” in various places throughout this specification are not necessarily intended to refer to the same embodiment or to any one particular embodiment described. Furthermore, it is to be understood that particular features, structures, or characteristics described can be combined in various ways in one or more embodiments. In general, of course, these and other issues can vary with the particular context of usage. Therefore, the particular context of the description or the usage of these terms can provide helpful guidance regarding inferences to be drawn for that context.