Liquid crystal displays having color dots with embedded polarity regions

A multi-domain liquid crystal display is disclosed. The display includes embedded polarity regions within the color dots of the display. Specifically, the embedded polarity regions have a polarity that is different from the polarity of the color dot containing the embedded polarity region. This difference in polarity enhances the fringe fields of the color dot or in some situations may create additional fringe fields. The enhanced fringe fields or additional fringe fiends can more quickly restore liquid crystals to their proper position.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to liquid crystal displays (LCDs). More specifically, the present invention relates large-pixel multi-domain vertical alignment LCDs, which can be manufactured with smooth substrates.

2. Discussion of Related Art

Liquid crystal displays (LCDs), which were first used for simple monochrome displays, such as calculators and digital watches, have become the dominant display technology. LCDs are used routinely in place of cathode ray tubes (CRTs) for both computer displays and television displays. Various drawbacks of LCDs have been overcome to improve the quality of LCDs. For example, active matrix displays, which have largely replaced passive matrix displays, reduce ghosting and improve resolution, color gradation, viewing angle, contrast ratios, and response time as compared to passive matrix displays.

However, the primary drawback of conventional twisted nematic LCDs is the viewing angle is very narrow and the contrast ratio is low. Even the viewing angle of active matrixes is much smaller than the viewing angle for CRT. Specifically, while a viewer directly in front of an LCD receives a high quality image, other viewers to the side of the LCD would not receive a high quality image. Multi-domain vertical alignment liquid crystal displays (MVA LCDs) were developed to improve the viewing angle and contrast ratio of LCDs.FIGS. 1(a)-1(c) illustrate the basic functionality of a pixel of a vertical alignment LCD100. For clarity, the LCD ofFIG. 1uses only a single domain. Furthermore, for clarity, the LCDs ofFIGS. 1(a)-1(c) (andFIG. 2)described in terms of gray scale operation. Furthermore,FIGS. 1(a)-1(c) is simplified to clarity and omits many processing layers. For example, between substrate110and electrode120, actual displays would likely include various metal layers used for electrical connections as well as insulating layers that separate the metal layers.

LCD100has a first polarizer105, a first substrate110, a first electrode120, a first alignment layer125, liquid crystals130, a second alignment layer140, a second electrode145, a second substrate150, and a second polarizer155. Generally, first substrate110and second substrate150are made of a transparent glass. First electrode120and second electrode145are made of a transparent conductive material such as ITO (Indium Tin Oxide). First alignment layer125and second alignment layer140, which are typically made of a polyimide (PI) layer, align liquid crystals130vertically in a resting state. In operation, a light source (not shown) sends light from beneath first polarizer105, which is attached to first substrate110. First polarizer105is generally polarized in a first direction and second polarizer155, which is attached to second substrate150, is polarized perpendicularly to first polarizer105. Thus, light from the light source would not pass through both first polarizer105and second polarizer155unless the light polarization were to be rotated by 90 degrees between first polarizer105and second polarizer155. For clarity, very few liquid crystals are shown. In actual displays, liquid crystals are rod like molecules, which are approximately 5 angstroms in diameter and 20-25 angstroms in length. Thus, there are over 12 million liquid crystal molecules in a pixel that is 120 μm width by 300 μm length by 3 μm height. Although not shown, many liquid crystal displays (particularly active matrix LCDs) include a passivation layer on bottom of first electrode120. The passivation layer serves as an insulating layer between the first electrode120and devices and conductors that may be formed on the substrate. The passivation layer is commonly formed using silicon nitrides.

InFIG. 1(a), liquid crystals130are vertically aligned. In the vertical alignment, liquid crystals130would not rotate light polarization from the light source. Thus, light from the light source would not pass through LCD100and gives a completely optical black state and a very high contrast ratio for all color and all cell gap. Consequently MVA LCDs provide a big improvement on the contrast ratio over the conventional low contrast twisted nematic LCDs. However, as illustrated inFIG. 1(b), when an electric field is applied between first electrode120and second electrode145, liquid crystals130reorientate to a tilted position. Liquid crystals in the tilted position rotate the polarization of the polarized light coming through first polarizer105by ninety degrees so that the light can then pass through second polarizer155. The amount of tilting, which controls the amount of light passing through the LCD (i.e., brightness of the pixel), is proportional to the strength of the electric field. Generally, a single thin-film-transistor (TFT) is used for each pixel. However for color displays, a separate TFT is used for each color component (typically, Red, Green, and Blue)

However, the light passing through LCD120is not uniform to viewers at different viewing angles. As illustrated inFIG. 1(c), a viewer172that is left of center would see a bright pixel because the broad (light rotating) side of liquid crystals130face viewer172. A viewer174that is centered on the pixel would see a gray pixel because the broad side of liquid crystals130is only partially facing viewer174. A viewer176that is right of center would see a dark pixel because the broad side of liquid crystals130is barely facing viewer176.

Multi-domain vertical alignment liquid crystal displays (MVA LCDs) were developed to improve the viewing angle problems of single-domain vertical alignment LCDs.FIG. 2illustrates a pixel of a multi-domain vertical alignment liquid crystal display (MVA LCD)200. MVA LCD200includes a first polarizer205, a first substrate210, a first electrode220, a first alignment layer225, liquid crystals235, liquid crystals237, protrusions260s, a second alignment layer240, a second electrode245, a second substrate250, and a second polarizer255. Liquid crystals235form the first domain of the pixel and liquid crystals237form the second domain of the pixel. When an electric field is applied between first electrode220and second electrode245, protrusions260cause liquid crystals235to tilt in a different direction than liquid crystals237. Thus, a viewer272that is left of center would see the left domain (liquid crystals235) as black and the right domain (liquid crystals237) as white. A viewer274that is centered would see both domains as gray. A viewer276that is right of center would see the left domain as white and the right domain as black. However, because the individual pixels are small, all three viewers would perceive the pixel as being gray. As explained above, the amount of tilting of the liquid crystals is controlled by the strength of the electric field between electrodes220and245. The level of grayness perceived by the viewer directly related to the amount of tilting of the liquid crystals. MVA LCDs can also be extended to use four domains so that the LC orientation in a pixel is divided into4major domains to provide wide symmetrical viewing angles both vertically and horizontally.

Thus, multi-domain vertical alignment liquid crystal displays, provide wide symmetrical viewing angles, however, the cost of manufacturing MVA LCDs are very high due to the difficulty of adding protrusions to the top and bottom substrates and the difficulty of properly aligning the protrusions on the top and bottom substrates. Specifically, a protrusion on the bottom substrate must be located at the center of two protrusions on the top substrate; any misalignment between the top and bottom substrates will reduce the product yield. Other techniques of using physical features to the substrates, such as ITO slits, which have been used in place of or in combination with the protrusions, are also very expensive to manufacture. Furthermore, the protrusions and ITO slits inhibit light transmission and thus reduce the brightness of the MVA LCDs.

However, MVA LCDs have been developed that do not require the use of physical features (such as protrusions or ITO slits) on the substrate. Specifically, these MVA LCDs use fringe fields to create multiple-domains. Without the requirement of physical features the difficulty of aligning the physical features of the top and bottom substrate is eliminated. Thus, MVA LCDs using fringe fields have higher yield and are less expensive to manufacture than MVA LCDs that use physical features on the substrates.

FIGS. 3(a) and3(b) illustrate the basic concept used to create a multi-domain vertical alignment liquid crystal display (MVA LCD)300without resorting to physical features on the substrates. SpecificallyFIG. 3shows pixels310,320, and330in between a first substrate305and a second substrate355. A first polarizer302is attached to first substrate305and a second polarizer357is attached to second substrate355. Pixel310includes a first electrode311, liquid crystals312, liquid crystals313and a second electrode315. Pixel320includes a first electrode321, liquid crystals322, liquid crystals323and a second electrode325. Similarly, pixel330includes a first electrode331, liquid crystals332, liquid crystals333and a second electrode335. Although not shown, many liquid crystal displays include a passivation layer on top of electrodes311,321, and331. The electrodes are typically constructed using a transparent conductive material such as ITO. Furthermore, a first alignment layer307covers the electrodes on first substrate305. Similarly a second alignment layer352covers the electrodes on second substrate355. Both LC alignment layers307and352provide a vertical LC alignment. As explained in more detail below, electrodes315,325, and335are held at a common voltage V_Com. Therefore, to ease manufacturing, electrodes315,325, and335are created as a single structure (as shown inFIGS. 3(a) and3(b)). MVA LCD300operates pixels310,320, and330using alternating polarities. For example, if the polarities of pixels310and330are positive then the polarity of pixel320would be negative. Conversely, if the polarities of pixel310and330are negative then the polarity of pixel320would be positive. Generally, the polarity of each pixel would switch between frames, but the pattern of alternating polarities is maintained in each frame. InFIG. 3(a), pixels310,320, and330are in the “OFF” state, i.e. with the electric field between the first and second electrodes turned off. In the “OFF” state some residual electric field may be present between the first and second electrode. However, the residual electric field is generally too small to tilt the liquid crystals.

InFIG. 3(b), pixels310,320, and330are in the “ON” state.3(b) uses “+” and “−” to denote the voltage polarity of the electrodes. Thus, electrodes311, and331have positive voltage polarity and electrodes321has negative voltage polarity. Substrate355and electrodes315,325, and335are kept at common voltage V_com. The voltage polarity is defined with respect to the V_com voltage, where a positive polarity is obtained for voltages higher than V_com, and a negative polarity is obtained for voltage smaller than V_com. Electric field327(illustrated using field lines) between electrodes321and325causes liquid crystals322and liquid crystals323to tilt. In general, without protrusions or other features the tilting direction of the liquid crystals is not fixed for liquid crystals with a vertical LC alignment layers at307and352. However, the fringe field at the edges of the pixel can influence the tilting direction of the liquid crystals. For example, electric field327between electrode321and electrode325is vertical around the center of pixel320but is tilted to the left in the left part of the pixel, and tiled to the right in the right part of the pixel. Thus, the fringe field between electrode321and electrode325cause liquid crystals323to tilt to the right to form one domain and cause liquid crystals322to tilt to the left to from a second domain. Thus, pixel320is a multi-domain pixel with a wide symmetrical viewing angle

Similarly, the electric field (not shown) between electrode311and electrode315would have fringe fields that cause liquid crystals313to reorientate and tilt to the right in the right side in pixel312and cause liquid crystals312to tilt to the left in the left side in pixel310. Similarly, the electric field (not shown) between electrode331and electrode335would have fringe fields that cause liquid crystals333to tilt to the right in the right side in pixel330and cause liquid crystals332to tilt to the left in the left side in pixel330.

Alternating polarity of adjacent pixels amplifies the fringe field effect in each pixel. Therefore, by repeating the alternating polarity pattern between rows of pixels (or columns of pixels), a multi domain vertical alignment LCD is achieved without physical features. Furthermore, an alternating polarity checkerboard pattern can be used to create four domains in each pixel.

However, fringe field effects are relatively small and weak, in general. Consequently, as pixels become larger, the fringe fields at the edge of the pixels would not reach all the liquid crystals within a pixel. Thus, in large pixels the direction of tilting for the liquid crystals not near the edge of the pixels would exhibit random behavior and would not produce a multi-domain pixel. Generally, fringe field effects of pixels would not be effective to control liquid crystal tilt when the pixels become larger than 40-60 μm. Therefore, for large pixel LCDs pixel division methods are used to achieve multi-domain pixels. Specifically, for color LCDs, pixels are divided into color components. Each color component is controlled by a separate switching element, such as a thin-film transistor (TFT). Generally, the color components are red, green, and blue. The color components of a pixel are further divided into color dots.

The polarity of each pixel switches between each successive frame of video to prevent image quality degradation, which may result from twisting the liquid crystals in the same direction in every frame. However, the dot polarity pattern switching may cause other image quality issues such as flicker if all the switching elements are of the same polarity. To minimize flicker, the switching elements (e.g. are transistors) are arranged in a switching element driving scheme that include positive and negative polarities. Furthermore, to minimize cross talk the positive and negative polarities of the switching elements should be arranged in a uniform pattern, which provides a more uniform power distribution. The three main switching element driving schemes are switching element point inversion driving scheme, switching element row inversion driving scheme, and switching element column inversion driving scheme. In the switching element point inversion driving scheme, the switching elements form a checkerboard pattern of alternating polarities. In the switching element row inversion driving scheme, the switching elements on each row have the same polarity; however, each switching element in one row has the opposite polarity as compared to the polarity of switching elements in adjacent rows. In the switching element column inversion driving scheme, the switching elements on each column have the same polarity; however, a switching element in one column has the opposite polarity as compared to the polarity of switching elements in adjacent columns. While the switching element point inversion driving scheme provides the most uniform power distribution, the complexity and additional costs of switching element point inversion driving scheme over switching element row inversion driving scheme or switching element column inversion driving scheme may not be cost effective. Thus, most LCD displays for low cost or low voltage applications are manufactured using switching element row inversion driving scheme while switching element point inversion driving scheme is usually reserved for high performance applications.

Pixels may include various key components arranged to achieve high quality low cost display units. For example, pixel can include color components, color dots, fringe field amplifying regions (FFAR), switching elements, device component areas, and associated dots. Displays using these various components are described in U.S. Patent Application “Cite various KYO Patents KYO-001 KYO-003, KYO-005, KYO-006”, which are incorporated herein by reference.

Device component area encompasses the area occupied by the switching elements and/or storage capacitor as well as the area that was used to manufacture the switching elements and/or storage capacitors. For clarity, a different device component area is defined for each switching element.

Associated dots and fringe field amplifying regions are polarized areas that are not part of the color components. Associated dots cover the device component areas. Generally, the associated dots are manufactured by depositing an insulating layer over the switching element and/or storage capacitors. Followed by depositing an electrically conductive layer to form the associated dot. The associated dots are electrically connected to specific switching element and or other polarized components (such as color dots). The storage capacitors are electrically connected to specific switching element and color dot electrodes to compensate and offset the capacitance change on the liquid crystal cells during the switching-on and switching-off processes of the liquid crystal cells. Consequently, the storage capacitors are used to reduce the cross-talk effects during the switching-on and switching-off processes of the liquid crystal cells. A patterning mask is used when it is necessary to form the patterned electrode for the associated dots. A color layer is added to form a light shield for the associated dot. In general, the color layer is black however some displays use different color to achieve a desired color pattern or shading. Generally, the color layer is achieved by depositing a color filter layer on the corresponding ITO glass substrate. Specifically, a patterned color filter layer is deposited between second substrate150and second electrode140with pattern corresponding to the color for the color dot and associated dots. However, some displays may also place a patterned color filter layer underneath the electrode layer of the color dots, associated dots, or DCA on the substrate.

In some displays, the associated dot is an area independent of the switching elements. Furthermore, displays have additional associated dots not directly related to the switching elements. Generally, the associated dot includes an active electrode layer such as ITO or other conductive layer, and is connected to a nearby color dot or powered in some other manner. For opaque associated dots, a black matrix layer can be added on the bottom of the conductive layer to form the opaque area. The black matrix can be fabricated on the ITO glass substrate side to simplify the fabrication process. The additional associated dots improve the effective use of display area to improve the aperture ratio and to form the multiple liquid crystal domains within the color dots. Some displays also use associate dots to improve color performance. For example, careful placement of associated dots can allow the color of nearby color dots to be modified from the usual color pattern.

Fringe field amplifying regions are more versatile than associated dots. Specifically, fringe field amplifying regions may have non-rectangular shapes, although generally, the overall shape of the fringe field amplifying regions can be divided into a set of rectangular shapes. Furthermore, fringe field amplifying regions extend along more than one side of a color dot. In addition, fringe field amplifying regions may be used in place of associated dots in some displays. Specifically, in these displays the fringe field amplifying region cover the device component areas but also extend along more than one side of color dots adjacent to the device component areas.

In general, the color dots, device component areas, and associated dots are arranged in a grid pattern and are separated from adjacent neighbors by a horizontal dot spacing HDS and a vertical dot spacing VDS. When fringe field amplifying regions are used in place of associated dots, part of the fringe field amplifying regions would also fit in the grid pattern. In some displays multiple vertical dot spacings and multiple horizontal dot spacings may be used. Each color dot, associated dot, and device component area has two adjacent neighbors (e.g. color dots, associated dots, or device component areas) in a first dimension (e.g. vertical) and two adjacent neighbors in a second dimension (e.g. horizontal). Furthermore, two adjacent neighbors can be aligned or shifted. Each color dot has a color dot height CDH and a color dot width CDW. Similarly, each associated dot has an associated dot height ADH and an associated dot width ADW. Furthermore, each device component area has device component area height DCAH and a device component area width DCAW. In some displays, color dots, associated dots and device component areas are the same size. However in many displays color dots, associated dots and device component areas could be of different size or shapes. For example in many displays associated dots have a smaller height than color dots.

When a LCD panel is subject to external touch pressure on the panel substrate, touch mura occurs. Touch mura effects due to physical disturbance of the liquid crystals is a major issue with vertically aligned liquid crystal displays (both single domain and multiple domain). Touch mura effects refer to irregular patterns or regions causing uneven screen uniformity. Physical disturbance of the liquid crystals may be caused by shaking, vibration, and pressure on the display. In particular, vertically aligned liquid crystal displays are very susceptible to touch mura effects caused by pressure on the display. Specifically, pressure on a vertically aligned liquid crystal display may flatten the liquid crystals and cause a disturbance effect on the display. Unfortunately, devices incorporating touch screen functionality (i.e. users of a device apply pressure on the surface of the display as a means of providing user input to the device) has become increasingly popular which may hinder acceptance of vertically aligned liquid crystal displays. Hence there is a need for a method or system to minimize touch mura effects in a vertically aligned liquid crystal display.

SUMMARY

Accordingly, the present invention provides a vertically aligned liquid crystal display with reduced touch mura effects. Specifically, embodiments of the present invention use novel pixel designs that have color dots with embedded polarity regions (EPR) which amplifies fringe fields that more quickly restore the liquid crystals to their proper positions. For example, in accordance with one embodiment of the present invention, pixels are sub-divided into color components having one or more color dots (CDs). Furthermore in some embodiments of the present invention, the embedded polarity regions can be used to create or enhance fringe field effects that can induce multiple domains in the liquid crystals to enhance the viewing angle of the display.

In one embodiment of the present invention, a display includes a first pixel having a first first-pixel switching element; a first electrode coupled to the first first-pixel switching element, and a second pixel. The second pixel includes a first second-pixel color component that includes a first second-pixel first-component color dot and a second second-pixel first-component color dot. The second pixel also includes a first second-pixel switching element coupled to the first second-pixel first-component color dot and a second second-pixel first-component color dot. The first electrode is located between the first second-pixel first-component color dot and a second second-pixel first-component color dot. The first second-pixel first-component color dot includes a first embedded polarity region and a second second-pixel first-component color dot includes a second embedded polarity region. In general, when the first first-pixel switching element is configured to have a first polarity, the first second-pixel switching element is configured to have a second polarity. The first electrode could be for example a color dot, an associated dot, or a fringe fiend amplifying region.

DETAILED DESCRIPTION

As explained above, conventional vertically aligned LCDs are very susceptible to touch mura effects caused by physical disturbances to the liquid crystals. However, vertically aligned LCDs in accordance with the principles of the present invention use color dots that have embedded polarity regions (EPR) that enhance additional lateral fringe fields that help restore the liquid crystals to their proper orientation after a physical disturbance. Thus, vertically aligned LCDs in accordance with the present invention can quickly resolve touch mura effects caused by physical disturbance of the liquid crystals.

FIGS. 4(a) and4(b) show different dot polarity patterns of a pixel design410(labeled410+ and410− as described below) in accordance with one embodiment of the present invention. In actual operation a pixel will switch between a first dot polarity pattern and a second dot polarity pattern between each image frame. For clarity, the dot polarity pattern, in which the first color dot of the first color component has a positive polarity, is referred to as the positive dot polarity pattern. Conversely, the dot polarity pattern in which the first color dot of the first color component has a negative polarity is referred to as the negative dot polarity pattern. Specifically, inFIG. 4(a), pixel design410has a positive dot polarity pattern (and is thus labeled410+) and inFIG. 4(b), pixel design410has a negative dot polarity pattern (and is thus labeled410−). Furthermore, the polarity of each polarized component in the various pixel designs are indicated with “+” for positive polarity or “−” for negative polarity.

Pixel design410has three color components CC_1, CC_2and CC_3. Each of the three color components includes one color dots. For clarity, the color dots are referenced as CD_X_Y, where X is a color component (from 1 to 3 inFIGS. 4(a)-4(b)) and Y is a dot number (InFIGS. 4(a)-4(b) Y is always 1). Pixel design410also includes a switching element for each color component (referenced as SE_1, SE_2, and SE_3) and a device component area for each color component (referenced as DCA_1, DCA_2, and DCA_3). Switching elements SE_1, SE_2, and SE_3are arranged in a row. Device component areas DCA_1, DCA_2, and DCA_3surround switching elements SE_1, SE_2, and SE_3, respectively.

First color component CC_1of pixel design410has one color dots CD_1_1. Color dots CD_1_1is horizontally aligned with drive component area DCA_1and vertically separated from drive component area DCA_1by a vertical dot spacing VDS1. Switching element SE_1is coupled to the electrodes of color dot CD_1_1to control the polarity of color dot CD_1_1. Color dot CD_1_1includes an embedded polarity region EPR_1_1_1. For clarity, the embedded polarity regions are referenced as EPR_X_Y_Z, where X is a color component, Y is a dot number, and Z is enumerates the embedded polarity regions within a color dot. Embedded polarity regions can have different shapes. For example, in pixel design410embedded polarity regions have a square shape. However other embodiments may have circular shapes, polygonal shapes (such as squares and hexagons), or even other irregular shapes.

In general polarity refers to the direction of polarity usually denoted as positive or negative. More precisely, polarity also includes a magnitude of polarity. Embedded polarity regions may have the same direction of polarity (i.e. positive or negative) as the color dot but have a different magnitude of polarity. Furthermore, embedded polarity regions may have different polarity (i.e. “direction of polarity”) than the color dot (e.g. positive polarity for color dot polarity with negative polarity for embedded polarity regions). In addition, embedded polarity regions can have neutral polarity. Different embodiments of the present invention use different novel techniques or combination of novel techniques to create the embedded polarity regions within the color dots. These techniques are described in detail below. In the embodiment ofFIGS. 4(a) and4(b), color dots have opposite polarity with the embedded polarity region within the color dot.

Second color component CC_2of pixel design410has one color dots CD_2_1. Color dots CD_2_1is horizontally aligned with drive component area DCA_2and vertically separated from drive component area DCA_2by vertical dot spacing VDS1. Color dot CD_2_1is vertically aligned with color CD_1_1and horizontally separated from color dot CD_1_1by a horizontal dot spacing HDS1. Switching element SE_2is coupled to the electrodes of color dot CD_2_1to control the polarity of color dot CD_2_1. Color dot CD_2_1includes an embedded polarity region EPR_2_1_1.

Third color component CC_3of pixel design410has one color dots CD_3_1. Color dots CD_3_1is horizontally aligned with drive component area DCA_3and vertically separated from drive component area DCA_3by vertical dot spacing VDS1. Color dot CD_3_1is vertically aligned with color CD_2_1and horizontally separated from color dot CD_2_1by a horizontal dot spacing HDS1. Switching element SE_3is coupled to the electrodes of color dot CD_3_1to control the polarity of color dot CD_3_1. Color dot CD_3_1includes an embedded polarity region EPR_3_1_1.

The polarities of the color dots, embedded polarity regions, and switching elements are shown using “+” and “−” signs. Thus, inFIG. 4(a), which shows the positive dot polarity pattern of pixel design410+, switching elements SE_1and SE_3; color dots CD_1_1and CD_3_1, and embedded polarity region EPR_2_1_1have positive polarity. However, switching element SE_2; color dot CD_2_1, and embedded polarity region2EPR_1_1_1and EPR_3_1_1have negative polarity.

FIGS. 5(a) and5(b) show portions of a color dot500, having a square shape electrode510, with four square shaped embedded polarity regions512,514,516, and518.FIG. 5(b) is a cross sectional view of color dot500along the A1-A1′ cut ofFIG. 5(a). As shown inFIG. 5(b), the embedded polarity regions of color dot500are created by changing the conductivity of electrode510in the areas of embedded polarity regions. Specifically, changed conductivity regions517and519, which correspond to embedded polarity regions516and518, respectively, are formed in electrode510. In one embodiment of the present invention, the changed conductivity regions are heavily doped to reduce the conductivity of the changed conductivity regions. In other embodiments of the present invention, the embedded polarity regions can be formed by etching portions of conductor510and filling the regions with a less conductive material, such as electroactive polymers (such as polyacetylene, polythiophene, polypyrrole (PPy), polyaniline (PANI), and polystyrene), silicon-germanium and aluminum gallium arsenide, or a non-conductive material, such as silicon dioxide. Due to the different conductivity in the changed conductivity regions, the electric fields in the embedded polarity regions differ from the electric fields around the rest of electrode510. The interactions between the electric fields of the embedded polarity regions and the rest of electrode510creates lateral forces that can more quickly reorient the liquid crystals to their proper position after a physical disturbance. In embodiments of the present invention, that use non-conductive material for embedded polarity regions, the embedded polarity regions would have a neutral polarity.

FIG. 6(a)-6(c) show portions of a color dot600, having a square shape electrode610, with an embedded polarity region612, having a circular base shape.FIG. 6(b) is a cross sectional view of color dot600along the A1-A1′ cut ofFIG. 6(a).FIG. 6(c) is a cross sectional view of color dot700along the B1-B1′ cut ofFIG. 6(a). As shown inFIG. 6(b), embedded polarity region612is created by a field reduction layer614, which reduces the electric field from the portion of conductor610in embedded polarity region612. Thus, the magnitude of the polarity within embedded polarity region612differs from the rest of color dot600. Depending on the specific properties of field reduction layer614, the magnitude of the polarity in embedded polarity region612can be selectively reduced. With complete reduction, the polarity of embedded polarity region612can be set to neutral. A dielectric material, passivation layer, or black matrix material, can be used as the field reduction material in field reduction layer614. As shown inFIGS. 6(a),6(b) and6(c), field reduction layer614has a three dimensional cylindrical shape.

However, in other embodiments of the present invention, field reduction layer614can have a variety of three dimensional shapes with varying combination of base shapes and sides. For example,FIG. 7(a)-7(c) show portions of a color dot700, having a square shape electrode710, with an embedded polarity region712, having a square base shape in accordance with one embodiment of the present invention.FIG. 7(b) is a cross sectional view of color dot700along the A1-A1′ cut ofFIG. 7(a).FIG. 7(c) is a cross sectional view of color dot700along the B1-B1′ cut ofFIG. 7(a). As shown inFIGS. 7(b) and7(c), field reduction layer714has sloping sides which form a three-dimensional pyramidal shape.

FIG. 8(a)-8(c) show portions of a color dot800, having a square shape electrode810, with an embedded polarity region812, having a circular base shape in accordance with one embodiment of the present invention.FIG. 8(b) is a cross sectional view of color dot800along the A1-A1′ cut ofFIG. 8(a).FIG. 8(c) is a cross sectional view of color dot800along the B1-B1′ cut ofFIG. 8(a). As shown inFIGS. 8(b) and8(c), field reduction layer814has sloping sides which form a three-dimensional cone shape.

FIG. 9(a)-9(c) show portions of a color dot900, having a square shape electrode910, with an embedded polarity region912, having a circular base shape in accordance with one embodiment of the present invention.FIG. 9(b) is a cross sectional view of color dot900along the A1-A1′ cut ofFIG. 9(a).FIG. 9(c) is a cross sectional view of color dot900along the B1-B1′ cut ofFIG. 9(a). As shown inFIGS. 9(b) and9(c), field reduction layer914has curved sloping sides which form a three-dimensional rounded concave shape, which could be an oblate spheroid or other ellipsoid.

FIG. 10(a)-10(c) show portions of a color dot1000, having a square shape electrode1010, with an embedded polarity region1012, having a circular base shape in accordance with one embodiment of the present invention.FIG. 10(b) is a cross sectional view of color dot1000along the A1-A1′ cut ofFIG. 10(a).FIG. 10(c) is a cross sectional view of color dot1000along the B1-B1′ cut ofFIG. 10(a). As shown inFIG. 10(b) along the A1-A1′ cut, field reduction layer has a triangular shape. However as shown inFIG. 10(c) along the B1-B1′ cut, field reduction layer1014has a rectangular shape. Thus, field reduction layer1014has a three dimensional triangular solid shape.

FIG. 11(a)-11(c) show portions of a color dot1100, having a square shape electrode1110, with an embedded polarity region1112, having a circular base shape in accordance with one embodiment of the present invention.FIG. 11(b) is a cross sectional view of color dot1100along the A1-A1′ cut ofFIG. 11(a).FIG. 11(c) is a cross sectional view of color dot1100along the B1-B1′ cut ofFIG. 11(a). As shown inFIGS. 11(b) and11(c), field reduction layer1114has curved sloping sides which form a three-dimensional rectangular solid having a rounded convex depression on top, similar to a hyperboloid. Other embodiments of the present invention may use other shapes for field reduction layers.

FIG. 12illustrates another embodiment of the present invention in which a field reduction layer1214is formed using an insulating layer1214_I on electrode1210and a conducting layer1214_C on top of insulating layer1214_I. Conducting layer1214_C reduces the electric field from electrode1210in embedded polarity region1212. Insulating layer1214_I isolates conducting layer1214_C from electrode1210. A dielectric lateral layer or passivation layer can be used to replace the insulating layer1214_I, and to reduce the electric field. In another embodiment of the present invention, conducting layer1214_C is polarized. For example, if electrode1210has positive polarity, conducting layer1214_C is driven to a negative polarity. The interaction from the fields of electrode1210and conducting layer1214creates lateral forces that can more quickly reorient liquid crystals to their proper position after a physical disturbance. In general, a black matrix layer can be added to prevent the light leakage from the field reduction layer1214or1214_I. Various embodiments of the present invention can have different shapes for conducting layer1214_C. For example, conducting layer1214_C could use any of the shapes illustrated inFIGS. 6(a)-(c) to11(a)-(c) as well as other shapes.

In other embodiment of the present invention, the embedded polarity regions are induced from below the conductor to allow greater uniformity of the interface between the electrodes and the liquid crystal medium.FIGS. 13(a) and13(b) illustrate a color dot1300in accordance with another embodiment of the present invention. Color dot1300includes a square shaped electrode1310with a square shaped embedded polarity region1312.FIG. 13(b) is a cross sectional view of color dot1300along the A1-A1′ cut ofFIG. 13(a). As shown inFIG. 13(b), embedded polarity region1312is created by an embedded electrode1316underneath electrode1310. Embedded electrode1316is separated from electrode1310by an insulating layer1314. Embedded electrode1316is electrified to generate an electric field through electrode1310. In most embodiments of the present invention electrode1310and embedded electrode1316have opposite polarity directions. For example, when electrode1310has positive polarity, embedded electrode1316would have a negative polarity. The interaction of the electric field generated by electrode1310and embedded electrode1316creates lateral forces that can more quickly reorient liquid crystals to their proper position after a physical disturbance.

As shown inFIG. 13(c), the techniques to create embedded polarity regions can be combined. Specifically, inFIG. 13(c), a changed conductive region1318is created in electrode1310within embedded polarity region1312. In the embodiment ofFIG. 13(c), changed conductive region1318is made non-conductive so that the electric field in embedded polarity region1312is predominantly controlled by embedded electrode1316. The interaction of the electric field generated by electrode1310and embedded electrode1316creates lateral forces that can more quickly reorient liquid crystals to their proper position after a physical disturbance.

FIGS. 14(a)-14(b) illustrate portions of a color dot1400in accordance with another embodiment of the present invention. Color dot1400includes a square shaped electrode1410with a square shaped embedded polarity region1412. However, electrode1410does not extend into embedded polarity region1412. In the embodiment ofFIG. 14(a), electrode1410is etched to create a void in embedded polarity region1412. In other embodiments of the present invention, electrodes are formed with the voids.

FIG. 14(b) is a cross sectional view of color dot1400along the A1-A1′ cut ofFIG. 14(a). As shown inFIG. 14(b), embedded polarity region1412is created by an embedded electrode1416underneath electrode1410. Embedded electrode1416is separated from electrode1410by an insulating layer1414. In the embodiment ofFIG. 14(b) insulating layer1414is etched to create a void in embedded polarity region1410. In other embodiments, of the present invention, insulating layer1414does not include voids. Embedded electrode1416is electrified to generate an electric field through the void in electrode1410. In most embodiments of the present invention electrode1410and embedded electrode1416have opposite polarity directions. For example, when electrode1410has positive polarity, embedded electrode1416would have a negative polarity. The interaction of the electric field generated by electrode1410and embedded electrode1416creates lateral forces that can more quickly reorient liquid crystals to their proper position after a physical disturbance.

As explained above, multiple domains can be created using intrinsic fringe fields. However, intrinsic fringe fields are only applicable on small color dots. Thus, for larger displays pixels are created with color components having many color dots. Each color component is controlled by a separate switching element such as a thin-film transistor (TFT). Generally, the color components are red, green, and blue. In accordance with the present invention, the color components of a pixel are further divided into color dots.FIG. 15(a) illustrates a pixel design using multiple color dots per color component and embedded polarity regions in accordance with one embodiment of the present invention. Specifically,FIG. 15(a) shows a pixel design1500which includes three color components. Each of the three color components is further divided into three color dots. For clarity, the color dots are referenced as CD_X_Y, where X is a color component (from 1 to 3) and Y is a dot number (from 1 to 3). Specifically, pixel1500is a pixel formed by nine color dots. Each of the color dots include an embedded polarity region at the center of the color dot. The embedded polarity region of a color dot CD_X_Y is labeled EPR_X_Y.

Color dots CD_1_1(i.e., the first color dot of color component1), CD_2_1(i.e., the first color dot of the second color component), and CD_3_1(i.e., the first color dot of the third color component) form the first row of pixel design1500. Color dots CD_1_2, CD_2_2, and CD_3_2form a second row of pixel design1500. However the second row is offset from the first row so that color dot CD_1_2is adjacent to color dot CD_2_1. Color dots CD_1_3, CD_2_3, and CD_3_3form the third row of pixel design1500. However the third row is aligned with the first row so that color dot CD_2_3is adjacent to color dot CD_1_2.

The color dots of a color component are controlled by a switching element, such as a thin-film transistor (TFT), thus the polarity of all the color dots of one color components are the same. Various designs can be used to make the electrical connections between the color dots of a color component. For example, some embodiments of the present invention use ITO connections, which are optically transparent, from the switching element to the color dots.FIG. 15(b) shows a perspective view of a portion of an LCD1501with pixel1502of pixel design1500. Specifically,FIG. 15(b) shows a polarizer1503attached to a substrate1505. Electrodes E11, E12, E13, E21, E22, E23, E31, E32, and E33of pixel1502are formed on the top surface of substrate1505. Various electrodes (E) of other pixels are also formed on substrate1505. The electrodes include an embedded polarity region (shaded square within each electrode) that can be formed using the various methods discussed above. Due to space constraints the embedded polarity regions are not specifically labeled inFIG. 15(b). For clarity, the electrodes E of other pixels are shown with dotted lines. An alignment layer (not shown) would cover the electrodes. Also shown inFIG. 15(b) are transistors T1, T2, and T3of Pixel1502. For clarity the transistors of other pixels are not shown inFIG. 15(b).

Electrodes E11, E12, E13, E21, E22, E23, E31, E32, and E33correspond with color dots CD_1_1, CD_1_2, CD_1_3, CD_2_1, CD_2_2, CD_2_3, CD_3_1, CD_3_2, and CD_3_3respectively. As explained above color dots CD_1_1, CD_1_2, and CD_1_3are electrically connected and electrically controlled and switched by a single switching element such as a thin-film transistor, which is located at color dot CD_1_1. Thus as shown inFIG. 15(b), transistor T1is coupled to electrode E11and electrodes E11, E12, and E13are electrically connected by connectors1511and1512. Connectors1511and1512are usually formed of a transparent conductive material such as ITO. As explained above, the polarity of the embedded polarity region differs from that of the color dot. Thus, the polarity of the embedded polarity regions EPR_1_1, EPR_1_2, and EPR_1_3(not labeled inFIG. 15(b) are controlled by a polarity source different from transistor T1(which controls the polarity of color dots CD_1_1, CD_1_2, and CD_1_3). For example in one embodiment of the present invention, embedded polarity regions EPR_1_1, EPR_1_2, and EPR_1_3(not labeled inFIG. 15(b) are coupled to electrodes E21, E22, and E23, respectively.

Color dots CD_2_1, CD_2_2, and CD_2_3are electrically connected and electrically controlled and switched by a single switching element, which is located at color dot CD_2_1. Thus as shown inFIG. 15(b), transistor T2is coupled to electrode E21and electrodes E21, E22, and E23are electrically connected by connectors1521and1522. Likewise, Color dots CD_3_1, CD_3_2, and CD_3_3are electrically connected and electrically controlled and switched by a single switching element, which is located at color dot CD_3_1. Thus as shown inFIG. 15(b), transistor T3is coupled to electrode E31and electrodes E31, E32, and E33are electrically connected by connectors1531and1532.

To achieve multiple domains, the first and third color components of a pixel have the same polarity and the second component has the opposite polarity. However for adjacent pixels the polarities are reversed. For MVALCDs using the pixel design ofFIG. 15, two different dot polarity patterns are used for the pixels.FIGS. 15(c) and15(d) illustrate the two dot polarity patterns. InFIG. 15(c), a pixel1510using pixel design1500is an example of the first dot polarity pattern, which has positive polarity at the second color component, i.e., color dots CD_2_1, CD_2_2, and CD_2_3, and negative polarity at the first and third color components, i.e., CD_1_1, CD_1_2, CD_1_3, CD_3_1, CD_3_2, and CD_3_3. As explained above, the polarity of the embedded polarity region differs from that of the color dot containing the embedded polarity region. Thus, the polarity of the embedded polarity regions are controlled by a polarity source different from the source controlling the polarity of color dots containing the embedded polarity regions.

InFIG. 15(d), pixel1520is an example of the second dot polarity pattern, which has negative polarity at the second color component, i.e., color dots CD_2_1, CD_2_2, and CD_2_3, and positive polarity at the first and third color components, i.e., CD_1_1, CD_1_2, CD_1_3, CD_3_1, CD_3_2, and CD_3_3. As explained above, the polarity of the embedded polarity region differs from that of the color dot containing the embedded polarity region. In actual operation a pixel will switch between the first dot polarity pattern and the dot second polarity pattern between each image frame. For clarity, the dot polarity pattern, in which the first color dot of the first color component has a positive polarity, is referred to as the positive dot polarity pattern. Conversely, the dot polarity pattern in which the first color dot of the first color component has a negative polarity is referred to as the negative dot polarity pattern. Thus,FIG. 15(c) is the negative dot polarity pattern andFIG. 15(d) is the positive dot polarity pattern for the pixel design ofFIG. 15(a).

Pixels using the pixel design ofFIG. 15(a) can be arranged in a checkerboard pattern with half the pixels having the positive dot polarity pattern and half the pixels having the negative dot polarity pattern.FIG. 15(e) illustrates the checkerboard pattern with pixels P(0, 0), P(1, 0), P(2, 0), P(0, 1), P(1, 1), and P(2, 1). Specifically, as illustrated inFIG. 5(c), a pixel P(x,y) is in the xth column (from the left and the y-th row starting from the bottom, with pixel P(0,0) being the bottom left corner. Pixels P(0, 0), P(2, 0) and P(1, 1) have the positive dot polarity pattern and pixels P(1, 0), P(0, 1), and P(2, 1) have the negative dot polarity pattern. Thus, in general a pixel P(x, y) has the negative dot polarity pattern if x plus y is an odd number. Conversely, pixel P(x, y) has the positive dot polarity pattern if x plus y is an even number. However, at the next frame the pixels will switch dot polarity patterns. Thus, a MVALCD using the pixel design ofFIG. 15(a) has a first set of pixels having a first dot polarity pattern and a second set of pixels having a second dot polarity pattern. The first set of pixels and the second set of pixels are arranged in a checkerboard pattern.

A close examination ofFIG. 15(e) reveals that the color dots also have a checkerboard pattern in terms of polarity. Thus, for each color dot of a first polarity, the four adjacent color dots will be of a second polarity. For example, color dot CD_3_1of pixel P(0, 0), which has a positive polarity, is surrounded by four color dots of negative polarity. Specifically, color dots CD_3_3of pixel P(0, 1), color dot CD_1_1, of pixel P(1, 0), and color dots CD_2_1and CD_2_2of pixel P(0, 0). As explained above, polarity inversion between neighboring color dots enhances the fringe field of the color dots. Because the color dots are quite small, fringe fields from the color dots will cause multiple domains in the liquid crystals of each color dot under the principles explained above with respect toFIGS. 3(a) and3(b).

FIG. 16(a)-16(b) shows another pixel design having multiple color dots per color component that incorporate embedded polarity regions in accordance with the present invention. Specifically,FIGS. 16(a) and16(b) show different dot polarity patterns of a pixel design1610(labeled1610+ and1610− as described below) that is often used in displays having a switching element row inversion driving scheme. In actual operation a pixel will switch between a first dot polarity pattern and a second dot polarity pattern between each image frame. For clarity, the dot polarity pattern, in which the first color dot of the first color component has a positive polarity, is referred to as the positive dot polarity pattern. Conversely, the dot polarity pattern in which the first color dot of the first color component has a negative polarity is referred to as the negative dot polarity pattern. Specifically, inFIG. 16(a), pixel design1610has a positive dot polarity pattern (and is thus labeled1610+) and inFIG. 16(b), pixel design1610has a negative dot polarity pattern (and is thus labeled1610−). Furthermore, the polarity of each polarized component in the various pixel designs are indicated with “+” for positive polarity or “−” for negative polarity.

Pixel design1610has three color components CC_1, CC_2and CC_3(not labeled inFIGS. 16(a)-16(b)). Each of the three color components includes two color dots. For clarity, the color dots are referenced as CD_X_Y, where X is a color component (from 1 to 3 inFIGS. 16(a)-16(b)) and Y is a dot number (from 1 to 2 inFIGS. 16(a)-16(b)). Pixel design1610also includes a switching element for each color component (referenced as SE_1, SE_2, and SE_3) and a fringe field amplifying region for each color component (referenced as FFAR_1, FFAR_2, and FFAR_3). Switching elements SE_1, SE_2, and SE_3are arranged in a row. Device component areas around each switching element are covered by the fringe field amplifying regions and are thus not specifically labeled inFIGS. 16(a) and16(b). Fringe field amplifying regions FFAR_1, FFAR_2, and FFAR_3are also arranged in a row and described in more detail inFIG. 16(c).

First color component CC_1of pixel design1610has two color dots CD_1_1and CD_1_2. Color dots CD_1_1and CD_1_2form a column and are separated by a vertical dot pacing VDS1. In other words, color dots CD_1_1and CD_1_2are horizontally aligned and vertically separated by vertical dot spacing VDS1. Furthermore, color dots CD_1_1and CD_1_2are vertically offset by vertical dot offset VDO1which is equal to vertical dot spacing VDS1plus the color dot height CDH. Switching element SE_1is located in between color dots CD_1_1and CD_1_2so that color dot CD_1_1is on a first side of the row of switching elements and color dot CD_1_2is on a second side of the row of switching elements. Switching element SE_1is coupled to the electrodes of color dots CD_1_1and CD_1_2to control the voltage polarity and voltage magnitude of color dots CD_1_1and CD_1_2.

Each color dot of color component CD_1_1includes an embedded polarity region which would minimize any touch mura effects in the color dot. Specifically, color dots CD_1_1and CD_1_2include embedded polarity regions EPR_1_1and EPR_1_2, respectively. As shown inFIG. 16(a), embedded polarity regions EPR_1_1and EPR_1_2are centered within color dots CD_1_1and CD_1_2, respectively. Any of the various techniques used to form embedded polarity regions described herein can be used with pixel design1610. In a particular embodiment of the present invention, the techniques illustrated inFIGS. 14(a)-(b) are used. However, other embodiments of the present invention can use other techniques to form embedded polarity regions, can include multiple embedded polarity regions, or can offset the embedded polarity region.

As explained above, the polarity of the embedded polarity region differs from that of the color dot. Thus, the polarity of the embedded polarity regions EPR_1_1and EPR_1_2are controlled by a polarity source different from switching element SE_1(which controls the polarity of color dots CD_1_1and CD_1_2). In some embodiments of the present invention, a display includes dedicated embedded-polarity-region switching elements to control the polarity of the embedded polarity regions (SeeFIG. 16(d) for one such embodiment). Other embodiments of the present invention, may couple the embedded polarity regions to other elements of the pixel that have a differing polarity. For example, in some embodiments of the present invention, embedded polarity regions CD_1_1and CD_1_2are coupled to fringe field amplifying region FFAR_1, which is described below.

Similarly, second color component CC_2of pixel design410has two color dots CD_2_1and CD_2_2. Color dots CD_2_1and CD_2_2form a second column and are separated by a vertical dot spacing VDS1. Thus, color dots CD_2_1and CD_2_2are horizontally aligned and vertically separated by vertical dot spacing VDS1. Switching element SE_2is located in between color dots CD_2_1and CD_2_2so that color dot CD_2_1is on the first side of the row of switching elements and color dot CD_2_2is on a second side of the row of switching elements. Switching element SE_2is coupled to the electrodes of color dots CD_2_1and CD_2_2to control the voltage polarity and voltage magnitude of color dots CD_2_1and CD_2_2. Second color component CC_2is vertically aligned with first color component CC_1and separated from color component CC_1by a horizontal dot spacing HDS1, thus color components CC_2and CC_1are horizontally offset by a horizontal dot offset HDO1, which is equal to horizontal dot spacing HDS1plus the color dot width CDW. Specifically with regards to the color dots, color dot CD_2_1is vertically aligned with color dots CD_1_1and horizontally separated by horizontal dot spacing HDS1. Similarly, color dot CD_2_2is vertically aligned with color dots CD_2_1and horizontally separated by horizontal dot spacing HDS1. Thus color dot CD_1_1and color dot CD_2_1form a first row of color dots and color dot CD_1_2and color dot CD_2_2form a second row of color dots. Like color dots CD_1_1and CD_1_2, Color dots CD_2_1and CD_2_2include embedded polarity regions EPR_2_1and EPR_2_2, respectively.

Similarly, third color component CC_3of pixel design410has two color dots CD_3_1and CD_3_2. Color dots CD_3_1and CD_3_2form a third column and are separated by a vertical dot spacing VDS1. Thus, color dots CD_3_1and CD_3_2are horizontally aligned and vertically separated by vertical dot spacing VDS1. Switching element SE_3is located in between color dots CD_3_1and CD_3_2so that color dot CD_3_1is on the first side of the row of switching elements and color dot CD_3_2is on a second side of the row of switching elements. Switching element SE_3is coupled to the electrodes of color dots CD_3_1and CD_3_2to control the voltage polarity and voltage magnitude of color dots CD_3_1and CD_3_2. Third color component CC_3is vertically aligned with second color component CC_2and separated from color component CC_2by horizontal dot spacing HDS1, thus color components CC_3and CC_2are horizontally offset by a horizontal dot offset HDO1. Specifically with regards to the color dots, color dot CD_3_1is vertically aligned with color dots CD_2_1and horizontally separated by horizontal dot spacing HDS1. Similarly, color dot CD_3_2is vertically aligned with color dots CD_2_2and horizontally separated by horizontal dot spacing HDS1. Thus color dot CD_3_1is on the first row of color dots and color dot CD_3_2is on the second row of color dots. Like color dots CD_1_1and CD_1_2, Color dots CD_3_1and CD_3_2include embedded polarity regions EPR_3_1and EPR_3_2, respectively.

For clarity, the color dots of pixel design1610are illustrated with color dots having the same color dot height CDH. However, some embodiments of the present invention may have color dots with different color dot heights. For example in one embodiment of the present invention that is a variant of pixel design1610, color dots CD_1_1, CD_2_1and CD_3_1have a smaller color dot height than color dots CD_1_2, CD_2_2, and CD_3_2.

Pixel design1610also includes fringe field amplifying regions FFAR_1, FFAR_2, and FFAR_3.FIG. 16(c) shows a more detailed view of fringe field amplifying region FFAR_1of pixel design1610. For clarity fringe field amplifying regions FFAR_1is conceptually divided into a vertical amplifying portion VAP and a horizontal amplifying portion HAP. InFIG. 16(c) horizontal amplifying portion HAP is vertically centered on and extends to the left of vertical amplifying portion VAP. Use of horizontal amplifying portions and vertical amplifying portions allows clearer description of the placement of fringe field amplifying region FFAR1. In most embodiments of the present invention, the electrodes of the fringe field amplifying regions are formed by one contiguous conductor. Horizontal amplifying portion HAP has a horizontal amplifying portion width HAP_W and a horizontal amplifying portion height HAP_H. Similarly, vertical amplifying portion VAP has a vertical amplifying portion width VAP_W and a vertical amplifying portion height HAP_H. Fringe field amplifying regions FFAR_2and FFAR_3have the same shape as fringe field amplifying region FFAR_1. In embodiments of the present invention having different sized color dots, horizontal amplifying region HAP would be located in between the color dots rather than centered on vertical amplifying portion VAP.

As shown inFIG. 16(a), fringe field amplifying regions FFAR_1, FFAR_2, and FFAR_3are placed in between the color dots of pixel design1610. Specifically, fringe field amplifying region FFAR_1is placed so that the horizontal amplifying portion of fringe field amplifying region FFAR_1lies in between color dots CD_1_1and CD_1_2and is separated from color dots CD_1_1and CD_1_2by a vertical fringe field amplifying region spacing VFFARS. The vertical amplifying portion of fringe field amplifying region FFAR_1is placed to the right of color dots CD_1_1and CD_1_2and is separated from color dots CD_1_1and CD_1_2by a horizontal fringe field amplifying region spacing HFFARS. Thus, fringe field amplifying region FFAR_1extends along the bottom and the right side of color dot CD_1_1and along the top and right side of color dot CD_1_2. Furthermore, this placement also causes the vertical amplifying portion of fringe field amplifying region FFAR_1to be in between color dots CD_1_1and CD_2_1and in between color dots CD_1_2and CD_2_2.

Similarly, fringe field amplifying region FFAR_2is placed so that the horizontal amplifying portion of fringe field amplifying region FFAR_2lies in between color dots CD_2_1and CD_2_2and is separated from color dots CD_2_1and CD_2_2by a vertical fringe field amplifying region spacing VFFARS. The vertical amplifying portion of fringe field amplifying region FFAR_2is placed to the right of color dots CD_2_1and CD_2_2and is separated from color dots CD_2_1and CD_2_2by a horizontal fringe field amplifying region spacing HFFARS. Thus, fringe field amplifying region FFAR_1extends along the bottom and the right side of color dot CD_2_1and along the top and right side of color dot CD_2_2. This placement also causes the vertical amplifying portion of fringe field amplifying region FFAR_2to be in between color dots CD_2_1and CD_3_1and in between color dots CD_2_2and CD_3_2.

Fringe field amplifying region FFAR_3is placed so that the horizontal amplifying portion of fringe field amplifying region FFAR_3lies in between color dots CD_3_1and CD_3_2and is separated from color dots CD_3_1and CD_3_2by a vertical fringe field amplifying region spacing VFFARS. The vertical amplifying portion of fringe field amplifying region FFAR_3is placed to the right of color dots CD_3_1and CD_3_2and is separated from color dots CD_3_1and CD_3_2by a horizontal fringe field amplifying region spacing HFFARS. Thus, fringe field amplifying region FFAR_3extends along the bottom and the right side of color dot CD_3_1and along the top and right side of color dot CD_3_2.

The polarities of the color dots, fringe field amplifying regions, and switching elements are shown using “+” and “−” signs. Thus, inFIG. 16(a), which shows the positive dot polarity pattern of pixel design1610+, all the switching elements (i.e. switching elements SE_1, SE_2, and SE_3); all the color dots (i.e. color dots CD_1_1, CD_1_2, CD_2_1, CD_2_2, CD_3_1, and3_2) have positive polarity. However, all the fringe field amplifying regions (i.e. fringe field amplifying regions FFAR_1, FFAR_2, and FFAR_3) have negative polarity. As explained above, Embedded polarity regions may have the same direction of polarity (i.e. positive or negative) as the color dot but have a different magnitude of polarity. Alternatively, embedded polarity regions may have different polarity (i.e. “direction of polarity”) than the color dot (e.g. positive polarity for color dot polarity with negative polarity for embedded polarity regions). In addition, embedded polarity regions can have neutral polarity. In a particular embodiment of the present invention, the embedded polarity regions of pixel design1610have different polarity than the color dots. Thus for this embodiment, embedded polarity regions EPR_1_1, EPR_1_2, EPR_2_1, EPR_2_2, EPR_3_1, and EPR_3_2would have negative polarity inFIG. 16(a).

FIG. 16(b) shows pixel design1610with the negative dot polarity pattern. For the negative dot polarity pattern, all the switching elements (i.e. switching elements SE_1, SE_2, and SE_3) and all the color dots (i.e. color dots CD_1_1, CD_1_2, CD_2_1, CD_2_2, CD_3_1, and3_2) have negative polarity. However, all the fringe field amplifying regions (i.e. fringe field amplifying regions FFAR_1, FFAR_2, and FFAR_3) have positive polarity. In the particular embodiment of the present invention in which the embedded polarity regions of pixel design1610has different polarity than the color dots, embedded polarity regions EPR_1_1, EPR_1_2, EPR_2_1, EPR_2_2, EPR_3_1, and EPR_3_2would have positive polarity inFIG. 16(b).

Fringe fields in each of the color dots are amplified if adjacent components have opposite polarities. Pixel design1610makes use of the fringe field amplifying regions to enhance and stabilize the formation of multiple domain in the liquid crystal structure. In general, the polarities of the polarized components are assigned so that a color dot of a first polarity has neighboring polarized components of the second polarity. For example for the positive dot polarity pattern of pixel design1610(FIG. 16(a)), color dot CD_2_2has positive polarity. However the neighboring polarized components (fringe field amplifying regions FFAR_2and FFAR_1) have negative polarity. Thus, the fringe field of color dot CD_2_2is amplified. Furthermore, as explained below, the polarity reversing scheme is carried out at the display level as well so that the color dot of another pixel that is placed next to color dot CD_1_2would have negative polarity (seeFIG. 16(d)).

Because, all the switching elements in pixel design1610have the same polarity and the fringe field amplifying regions require the opposite polarity, the fringe field amplifying regions are driven by an external polarity source, i.e. a polarity source from outside the specific pixel of pixel design1610. Various sources of opposite polarity can be used in accordance with differing embodiments of the present invention. For example specific fringe field amplifying region switching elements may be used or switching elements of nearby pixels having an opposite dot polarity could also used to drive the fringe field amplifying regions. In the embodiments ofFIGS. 16(a)-16(b), switching elements of nearby pixels having an opposite dot polarity could also used to drive the fringe field amplifying regions. Therefore, pixel design1610includes conductor to facilitate coupling the fringe field amplifying regions to switching elements in other pixels. Specifically, a conductor1612of a current pixel would couple the electrode of fringe field amplifying region FFAR_1to switching element SE_1(seeFIGS. 16(d) and16(e)) of a pixel above the current pixel. The connection to the switching element would be via the electrodes of the color dots of the pixel above the current pixel. Similarly, a conductor1614of a current pixel would couple the electrode of fringe field amplifying region FFAR_2to switching element SE_2(seeFIG. 16(d)) of a pixel above the current pixel. The connection to the switching element would be via the electrodes of the color dots of the pixel above the current pixel. A conductor1616of a current pixel would couple the electrode of fringe field amplifying region FFAR_3to switching element SE_3(seeFIGS. 16(d) and16(e)) of a pixel above the current pixel. The connection to the switching element would be via the electrodes of the color dots of the pixel above the current pixel.

These connections are better shown inFIG. 16(d), which shows a portion of display1620using pixels P(0, 0), P(1, 0), P(0, 1), and P(1, 1) of pixel design1610with a switching element row inversion driving scheme. Display1620could have thousands of rows with thousand of pixels on each row. The rows and columns would continue from the portion shown inFIG. 16(d) in the manner shown inFIG. 16(d). For clarity, the gate lines and source lines that control the switching elements are omitted inFIG. 16(d). Furthermore, to better illustrate each pixel, the area of each pixel is shaded; this shading is only for illustrative purposes inFIG. 16(d) and has no functional significance. The pixels of display1620are arranged so that all pixels in a row have the same dot polarity pattern (positive or negative) and each successive row should alternate between positive and negative dot polarity pattern. Thus, pixels P(0, 0) and P(1, 0) in the first row (i.e. row0) have positive dot polarity pattern and pixels P(0, 1) and P(1, 1) in the second row (i.e. row1) have the negative dot polarity pattern. However, at the next frame the pixels will switch dot polarity patterns. Thus in general a pixel P(x, y) has a first dot polarity pattern when y is even and a second dot polarity pattern when y is odd. Internal conductors1612,1614, and1616in pixel design1610, provide polarity to the fringe field amplifying regions. Specifically, fringe field amplifying regions of a first pixel receive voltage polarity and voltage magnitude from a second pixel. Specifically, the second pixel is the pixel above the first pixel. For example, the electrodes of fringe field amplifying region FFAR_1of pixel P(0, 0) is coupled to switching elements SE_1of pixel P(0, 1) via the electrodes of color dots CD_1_2of pixel P(0, 1). Similarly, the electrodes of fringe field amplifying regions FFAR_2and FFAR_3of pixel P(0, 0) are coupled to switching elements SE_2, and SE_3of pixel P(0, 1) via color dots CD_2_2, and CD_3_2of pixel P(0, 1), respectively.

Display1620also includes embedded-polarity-region switching elements EPR_SE_X_Y, for each row of embedded polarity regions. InFIG. 16(d), “X” represents the row number of the pixel, and “Y” represents the row number of embedded polarity regions within a pixel. Thus, embedded-polarity-region switching elements EPR_SE_0_1and EPR_SE_0_2are used for the pixels in row0(i.e. pixel P(0, 0) and pixel P(1, 0)). Specifically, embedded-polarity-region switching element EPR_SE_0_1is coupled to embedded polarity regions EPR_1_1, EPR_2_1, and EPR_3_1of pixel P(0,0) and to embedded polarity regions EPR_1_1, EPR_2_1, and EPR_3_1of pixel P(1, 0). Embedded-polarity-region switching element EPR_SE_0_2is coupled to embedded polarity regions EPR_1_2, EPR_2_2, and EPR_3_2of pixel P(0, 0) and to embedded polarity regions EPR_1_2, EPR_2_2, and EPR_3_2of pixel P(1, 0). Likewise, embedded-polarity-region switching elements EPR_SE_1_1and EPR_SE_1_2are used for the pixels in row1(i.e. pixel P(0, 1) and pixel P(1, 1)). Specifically, embedded-polarity-region switching element EPR_SE_1_1is coupled to embedded polarity regions EPR_1_1, EPR_2_1, and EPR_3_1of pixel P(0, 1) and to embedded polarity regions EPR_1_1, EPR_2_1, and EPR_3_1of pixel P(1, 1). Embedded-polarity-region switching element EPR_SE_1_2is coupled to embedded polarity regions EPR_1_2, EPR_2_2, and EPR_3_2of pixel P(0, 1) and to embedded polarity regions EPR_1_2, EPR_2_2, and EPR_3_2of pixel P(1, 1). Generally, an embedded-polarity-region switching element would have different polarity as compared to the switching elements in the pixel corresponding to the embedded-polarity-region switching element. Thus, inFIG. 16(d), embedded-polarity-region switching elements EPR_SE_0_1and EPR_SE_0_2would have negative polarity. Conversely, embedded-polarity-region switching elements EPR_SE_1_1and EPR_SE_1_2would have positive polarity. In some embodiments of the present invention, the embedded-polarity-region switching elements would be placed in a more balanced manner. For example, in a particular embodiment of the present invention, half of the embedded-polarity-region switching elements are placed on the right side of the display and half of the embedded-polarity-region switching elements are placed on the left side of the display.

Due to the switching of polarities on each row in display1620, if a color dot has the first polarity, any neighboring polarized components and embedded polarity regions would have the second polarity. For example, color dot CD_3_2of pixel P(0, 1) has negative polarity while, embedded polarity region EPR_3_2of pixel P(0, 1), color dot CD_3_1of pixel P(0, 0), fringe field amplifying regions FFAR_2and FFAR_3of pixel P(0, 1) have positive polarity. In a particular embodiment of the present invention, each color dot has a width of 40 micrometers and a height of 60 micrometers. Each embedded polarity region has a width of 10 micrometers and a height of 10 micrometers Each fringe field amplifying region has a vertical amplifying portion width of 5 micrometers, a vertical amplifying portion height of 145 micrometers, a horizontal amplifying portion width of 50 micrometers, a horizontal amplifying height of 5 micrometers. Horizontal dot spacing HDS1is 15 micrometers, vertical dot spacing VDS1is 25 micrometers, horizontal fringe field amplifying spacing HFFARS is 5 micrometers, and vertical fringe field amplifying spacing VFFARS is 5 micrometers.

In another embodiment of the present invention, embedded polarity regions are polarized using switching elements of nearby pixels rather than having dedicated embedded polarity switching elements.FIG. 16(e) shows a portion of a display1630using pixels P(0, 0), P(1, 0), P(0, 1), and P(1, 1) of pixel design1610with a switching element row inversion driving scheme. Display1630could have thousands of rows with thousand of pixels on each row. The rows and columns would continue from the portion shown inFIG. 16(e) in the manner shown inFIG. 16(e). For clarity, the gate lines and source lines that control the switching elements are omitted inFIG. 16(e). Furthermore, to better illustrate each pixel, the area of each pixel is shaded; this shading is only for illustrative purposes inFIG. 16(e) and has no functional significance. Due to space limitations color dots are labeled as CDXY as opposed to CD_X_Y and embedded polarity regions are labeled as EPRXY as opposed to EPR_X_Y.

Because display1630and display1620are very similar only the differences are described in detail. For example, the pixels of display1630are arranged in the same manner as the pixels of display1620. Furthermore, the polarity of the color dots, switching elements and fringe field amplifying regions are the same. Thus like in display1620, a pixel P(x, y) in display1630also has a first dot polarity pattern when y is even and a second dot polarity pattern when y is odd. The primary difference between display1620and display1630is that the polarity for the embedded polarized regions in display1630is provided from the switching elements of nearby pixels rather than from dedicated embedded polarity switching elements which were used in display1620.

In display1630, a first pixel is paired with a second pixel, so that the embedded polarity regions of the first pixel is coupled to the switching element of the second pixel and the embedded polarity regions of the second pixel is coupled to the switching elements of the first pixel. Specifically, pixels on even numbered rows are paired with the pixel in the odd numbered row above the even numbered row. Thus inFIG. 16(e), pixel P(0,0) is paired with Pixel P(0,1) and pixel P(1,0) is paired with pixel P(1,1). In general, a pixel P(X, Y) is paired with a pixel P(X, Y+1) if Y is even. Conversely, a pixel P(x, Y) is paired with pixel P(X, Y−1) if Y is odd.

As illustrated inFIG. 16(e), in display1630each embedded polarity regions is coupled to a switching element of paired pixel by a conductor C_I_J_X_Y (labeled with CIJXY inFIG. 16(e) due to space constraints), where I, J denotes the pixel (e.g. pixel P(I, J) containing the embedded polarity region, X is the color component, and Y denotes the color dot (e.g. color dot CD_X_Y (shortened inFIG. 16(e) as CDXY)) within the pixel. For example, conductor C0112couples embedded polarity region EPR12of pixel P(0,1) to switching element SE_1of pixel P(0, 0). The conductors for the embedded polarity regions are shown with dashed lines to indicate that the conductors are in a different plane from the color dots. Typically, the color dots are formed with ITO in a first plane and the conductors are formed with a metal layer in a second plane.

As explained above in pixels on odd numbered rows, embedded polarity elements of a first pixel are coupled to switching elements of the pixel below the first pixel. For example, embedded polarity region EPR_2_2(labeled EPR22inFIG. 16(e)) of pixel P(0, 1) is coupled to switching element SE_2of pixel P(0, 0) by conductor C_0_1_2_2(labeled C0122inFIG. 16(e)). Similarly, embedded polarity region EPR_2_1(labeled EPR21inFIG. 16(e)) of pixel P(0, 1) is coupled to switching element SE_2of pixel P(0, 0) by conductor C_0_1_2_1(labeled C0121inFIG. 16(e)). In general, a conductor C_I_J_X_Y, couples embedded polarity region EPR_X_Y of a pixel P(I, J) to switching element SE_X of pixel P(I, J−1), when J is an odd number.

In pixels on even numbered rows, embedded polarity elements of a first pixel are coupled to switching elements of the pixel above the first pixel. For example, embedded polarity region EPR_2_2(labeled EPR22inFIG. 16(e)) of pixel P(0, 0) is coupled to switching element SE_2of pixel P(0, 1) by conductor C_0_0_2_2(labeled C0022inFIG. 16(e)). Similarly, embedded polarity region EPR_2_1(labeled EPR21inFIG. 16(e)) of pixel P(0, 0) is coupled to switching element SE_2of pixel P(0, 1) by conductor C_0_0_2_1(labeled C0021inFIG. 16(e)). In general, a conductor C_I_J_X_Y, couples embedded polarity region EPR_X_Y of a pixel P(I, J) to switching element SE_X of pixel P(I, J+1), when J is an even number.

As explained above adjacent row of pixels have opposite polarity in display1630. Thus, providing polarity from switching elements in pixels from adjacent rows to embedded polarity regions as described above causes the polarity of the embedded polarity regions to be different from the polarity of the color dot. This differing polarity serves to enhance the fringe field in the color dots and reduce the touch mura effect in display1630.

FIG. 16(f) shows another embodiment of the present invention in which the embedded polarity regions receive polarity from the fringe field amplifying region. Specifically,FIG. 16(f) shows a portion of a display1640using pixels P(0, 0), P(1, 0), P(0, 1), and P(1, 1) of pixel design1610with a switching element row inversion driving scheme. Display1640could have thousands of rows with thousand of pixels on each row. The rows and columns would continue from the portion shown inFIG. 16(f) in the manner shown inFIG. 16(f). For clarity, the gate lines and source lines that control the switching elements are omitted inFIG. 16(f). Furthermore, to better illustrate each pixel, the area of each pixel is shaded; this shading is only for illustrative purposes inFIG. 16(f) and has no functional significance. Due to space limitations color dots are labeled as CDXY as opposed to CD_X_Y and embedded polarity regions are labeled as EPRXY as opposed to EPR_X_Y.

Because display1640and display1620are very similar only the differences are described in detail. For example, the pixels of display1640are arranged in the same manner as the pixels of display1620. Furthermore, the polarity of the color dots, switching elements and fringe field amplifying regions are the same. Thus like in display1620, a pixel P(x, y) in display1640also has a first dot polarity pattern when y is even and a second dot polarity pattern when y is odd. The primary difference between display1620and display1640is that the polarity for the embedded polarized regions in display1640is provided from the fringe field amplifying regions rather than from dedicated embedded polarity switching elements which were used in display1620.

Specifically, as illustrated inFIG. 16(f), in display1640each embedded polarity regions is coupled to the nearest fringe fiend amplifying region. Specifically, an embedded polarity region EPR_X_Y of a pixel P(I, J) is coupled to fringe field amplifying region FFAR_X by a conductor C_I_J_X_Y (labeled with CIJXY inFIG. 16(f) due to space constraints), where I, J denotes the pixel (e.g. pixel P(I, J), X is the color component, Y denotes the color dot (e.g. color dot CD_X_Y (shortened inFIG. 16(f) as CDXY)) within the pixel. For example, conductor C0112couples embedded polarity region EPR12of pixel P(0,1) to fringe field amplifying region FFAR_1(not specifically labeledFIG. 16(f)) of pixel P(0, 1). The conductors for the embedded polarity regions are shown with dashed lines to indicate that the conductors are in a different plane from the color dots. Typically, the color dots and fringe field amplifying regions are formed with ITO in a first plane and the conductors are formed with a metal layer in a second plane. Thus, a via (labeled V) is used to connect the fringe field amplifying regions to the conductors. InFIG. 16(f) the fringe field amplifying regions are coupled to a switching element of a neighboring pixel as explained above with respect toFIG. 16(d). However, in other embodiments of the present invention the fringe field amplifying regions may receive polarity using other methods, such as dedicated fringe field amplifying region switching elements.

As explained above the fringe field amplifying regions have an opposite polarity as compared to the color dots. Thus, providing polarity from the fringe field amplifying regions to the embedded polarity regions causes the polarity of the embedded polarity regions to be different from the polarity of the color dot. This differing polarity serves to enhance the fringe field in the color dots and reduce the touch mura effect in display1630.

Pixel design1610can be easily modified for use with switching element point inversion driving schemes in accordance with another embodiment of the present invention.FIG. 17(a)-17(b) show different dot polarity pattern of a pixel design1710that is a modified version of pixel design1610(FIGS. 16(a)-16(b)). Specifically, inFIG. 17(a), pixel design1710has a positive dot polarity pattern (and is thus labeled1710+) and inFIG. 17(b), pixel design1710has a negative dot polarity pattern (and is thus labeled1610−). Furthermore, the polarity of each polarized component in the various pixel designs are indicated with “+” for positive polarity or “−” for negative polarity.

Pixel design1710has three color components CC_1, CC_2and CC_3(not labeled inFIGS. 17(a)-17(b)). Each of the three color components includes two color dots. Pixel design1710also includes a switching element for each color component (referenced as SE_1, SE_2, and SE_3) and a fringe field amplifying region for each color component (referenced as FFAR_1, FFAR_2, and FFAR_3). The layout of the color dots, switching elements and fringe field amplifying regions in pixel design1710are identical to the layout of pixel design1610. Thus, for brevity the description of the layout is not repeated. Switching elements SE_1, SE_2, and SE_3are coupled to color components CC_1, CC_2, and CC_3, respectively, in the same manner as described above with regards to pixel design1610.

Just as in pixel design1610, each color dot of pixel design1710includes an embedded polarity region which would minimize any touch mura effects in the color dot. Because the placement of the embedded polarity regions are the same in pixel design1710and pixel design1610, the description is not repeated. Generally, each color dot has an embedded polarity region centered within the color dot.

As explained above, the polarity of the embedded polarity region differs from that of the color dot. Thus, the polarity of the embedded polarity regions are controlled by a polarity source different from switching element SE_1controlling the color dot containing the embedded polarity region. As described above, in some embodiments of the present invention, a display includes dedicated embedded-polarity-region switching elements to control the polarity of the embedded polarity regions (SeeFIG. 16(d) for one such embodiment). Other embodiments of the present invention, may couple the embedded polarity regions to other elements of the pixel that have a differing polarity (See,FIG. 16(f)).

The fringe field amplifying regions (FFAR_1, FFAR_2, and FFAR_3) of pixel design1710are the same as in pixel design1610. Thus the detailed view provided inFIG. 16(c) and described above, also applies to pixel design1710. Furthermore, the placement of the fringe field amplifying region in pixel design1710is the same as in pixel design1610as described above.

The polarities of the color dots, fringe field amplifying regions, and switching elements are shown using “+” and “−” signs. Pixel design1710is designed for use in displays having switching element point inversion driving schemes, but can also be used with displays having switching element column inversion driving scheme. Thus, inFIG. 17(a), which shows the positive dot polarity pattern of pixel design1710+, switching elements SE_1and SE3, color dots CD_1_1, CD_1_2, CD_3_1, and3_2; and fringe field amplifying region FFAR_2have positive polarity. In contrast, switching element SE_2, color dots CD_2_1and CD_2_2; and fringe field amplifying regions FFAR_1and FFAR2have negative polarity. As explained above, Embedded polarity regions may have the same direction of polarity (i.e. positive or negative) as the color dot but have a different magnitude of polarity. Alternatively, embedded polarity regions may have different polarity (i.e. “direction of polarity”) than the color dot (e.g. positive polarity for color dot polarity with negative polarity for embedded polarity regions). In addition, embedded polarity regions can have neutral polarity. In a particular embodiment of the present invention, the embedded polarity regions of pixel design1710have different polarity than the color dots. Thus for this embodiment, embedded polarity regions EPR_1_1, EPR_1_2, EPR_3_1, and EPR_3_2would have negative polarity inFIG. 17(a); while embedded polarity regions EPR_2_1EPR_2_2would have positive polarity.

The polarities of the color dots, fringe field amplifying regions, and switching elements are shown using “+” and “−” signs. Pixel design1710is designed for use in displays having switching element point inversion driving schemes, but can also be used with displays having switching element column inversion driving scheme. Thus, inFIG. 17(a), which shows the positive dot polarity pattern of pixel design1710+, switching elements SE_1and SE3, color dots CD_1_1, CD_1_2, CD_3_1, and3_2; and fringe field amplifying region FFAR_2have positive polarity. In contrast, switching element SE_2, color dots CD_2_1and CD_2_2; and fringe field amplifying regions FFAR_1and FFAR2have negative polarity. As explained above, embedded polarity regions may have the same direction of polarity (i.e. positive or negative) as the color dot but have a different magnitude of polarity. Alternatively, embedded polarity regions may have different polarity (i.e. “direction of polarity”) than the color dot (e.g. positive polarity for color dot polarity with negative polarity for embedded polarity regions). In addition, embedded polarity regions can have neutral polarity. In a particular embodiment of the present invention, the embedded polarity regions of pixel design1710have different polarity than the color dots. Thus for this embodiment, embedded polarity regions EPR_1_1, EPR_1_2, EPR_3_1, and EPR_3_2would have negative polarity inFIG. 17(a); while embedded polarity regions EPR_2_1EPR_2_2would have positive polarity.

InFIG. 17(b), which shows the positive dot polarity pattern of pixel design1710+, switching elements SE_1and SE3, color dots CD_1_1, CD_1_2, CD_3_1, and3_2; and fringe field amplifying region FFAR_2have negative polarity. In contrast, switching element SE_2, color dots CD_2_1and CD_2_2; and fringe field amplifying regions FFAR_1and FFAR2have positive polarity. As explained above, embedded polarity regions may have the same direction of polarity (i.e. positive or negative) as the color dot but have a different magnitude of polarity. Alternatively, embedded polarity regions may have different polarity (i.e. “direction of polarity”) than the color dot (e.g. positive polarity for color dot polarity with negative polarity for embedded polarity regions). In addition, embedded polarity regions can have neutral polarity. In a particular embodiment of the present invention, the embedded polarity regions of pixel design1710have different polarity than the color dots. Thus for this embodiment, embedded polarity regions EPR_1_1, EPR_1_2, EPR_3_1, and EPR_3_2would have positive polarity inFIG. 17(b); while embedded polarity regions EPR_2_1and EPR_2_2would have negative polarity.

Unlike the switching elements if pixel design1610, the switching elements in pixel design1710have both positive and negative polarity. Specifically, switching elements SE_1and SE_3have one polarity while switching element SE_2has the other polarity. Thus, the fringe field amplifying regions could be polarized from the switching elements within pixel design1710.FIG. 17(c) described below shows a pixel design1710-1, in accordance with one embodiment of the present invention in which the fringe field amplifying regions are polarized from within pixel design1710. In other embodiments, the fringe field amplifying regions are driven by an external polarity source, i.e. a polarity source from outside the specific pixel of pixel design1710. Various sources of opposite polarity can be used in accordance with differing embodiments of the present invention. For example specific fringe field amplifying region switching elements may be used or switching elements of nearby pixels having the appropriate dot polarity could also used to drive the fringe field amplifying regions. In the embodiments ofFIGS. 17(a)-17(b), switching elements of nearby pixels having the appropriate dot polarity could also used to drive the fringe field amplifying regions. Therefore, pixel design1710includes conductor to facilitate coupling the fringe field amplifying regions to switching elements in other pixels. Specifically, a conductor1712of a current pixel would couple the electrode of fringe field amplifying region FFAR_1to switching element SE_1(seeFIGS. 17(d) and17(e)) of a pixel above the current pixel. The connection to the switching element would be via the electrodes of the color dots of the pixel above the current pixel. Similarly, a conductor1714of a current pixel would couple the electrode of fringe field amplifying region FFAR_2to switching element SE_2(seeFIG. 17(d)) of a pixel above the current pixel. The connection to the switching element would be via the electrodes of the color dots of the pixel above the current pixel. A conductor1716of a current pixel would couple the electrode of fringe field amplifying region FFAR_3to switching element SE_3(seeFIGS. 17(d) and17(e)) of a pixel above the current pixel. The connection to the switching element would be via the electrodes of the color dots of the pixel above the current pixel. These connections are better shown inFIGS. 17(d) and17(e) which are described below.

FIG. 17(c) shows a pixel design1710-1which is a modified version of pixel design1710. Since the pixel designs are similar only the differences are described. Specifically in pixel design1710-1, conductors1712,1714, and1716are replaced with conductors1713,1715, and1717, respectively. Conductor1713couples fringe field amplifying region FFAR_1to switching element SE_2, which has negative polarity. Conductor1715couples fringe field amplifying region FFAR_2to switching element SE_3, which has positive polarity. Conductor1717couples fringe field amplifying region FFAR_3to switching element SE_2, which has negative polarity.

FIG. 17(d) shows a portion of display1720using pixels P(0, 0), P(1, 0), P(0, 1), and P(1, 1) of pixel design1710with a switching element row inversion driving scheme. Display1720could have thousands of rows with thousand of pixels on each row. The rows and columns would continue from the portion shown inFIG. 17(d) in the manner shown inFIG. 17(d). For clarity, the gate lines and source lines that control the switching elements are omitted inFIG. 17(d). Furthermore, to better illustrate each pixel, the area of each pixel is shaded; this shading is only for illustrative purposes inFIG. 17(d) and has no functional significance. Due to space limitations color dots are labeled as CDXY as opposed to CD_X_Y and embedded polarity regions are labeled as EPRXY as opposed to EPR_X_Y.

The pixels of display1720are arranged so that pixels in a row alternate between the positive dot polarity pattern and the negative dot polarity pattern. Furthermore, pixels in a column also alternate between the positive dot polarity pattern and the negative dot polarity pattern. Thus, pixels P(0, 0) and P(1, 1) have the positive dot polarity pattern and pixels P(0, 1) and P(1, 0) have the negative dot polarity pattern. However, at the next frame the pixels will switch dot polarity patterns. Thus in general a pixel P(x, y) has a first dot polarity pattern when x+y is even and a second dot polarity pattern when x+y is odd. Internal conductors1712,1714, and1716in pixel design1710, provide polarity to the fringe field amplifying regions. Specifically, fringe field amplifying regions of a first pixel receive voltage polarity and voltage magnitude from a second pixel. Specifically, the second pixel is the pixel above the first pixel. For example, the electrodes of fringe field amplifying region FFAR_1of pixel P(0, 0) is coupled to switching elements SE_1of pixel P(0, 1) via the electrodes of color dots CD_1_2of pixel P(0, 1). Similarly, the electrodes of fringe field amplifying regions FFAR_2and FFAR_3of pixel P(0, 0) are coupled to switching elements SE_2, and SE_3of pixel P(0, 1) via color dots CD_2_2, and CD_3_2of pixel P(0, 1), respectively.

In display1720, a first pixel is paired with a second pixel, so that the embedded polarity regions of the first pixel is coupled to the switching element of the second pixel and the embedded polarity regions of the second pixel is coupled to the switching elements of the first pixel. Specifically, pixels on even numbered rows are paired with the pixel in the odd numbered row above the even numbered row. Thus inFIG. 17(d), pixel P(0,0) is paired with Pixel P(0,1) and pixel P(1,0) is paired with pixel P(1,1). In general, a pixel P(X, Y) is paired with a pixel P(X, Y+1) if Y is even. Conversely, a pixel P(x, Y) is paired with pixel P(X, Y−1) if Y is odd.

As illustrated inFIG. 17(d), in display1720each embedded polarity regions is coupled to a switching element of paired pixel by a conductor C_I_J_X_Y (labeled with CIJXY inFIG. 17(d) due to space constraints), where I, J denotes the pixel (e.g. pixel P(I, J) containing the embedded polarity region, X is the color component, and Y denotes the color dot (e.g. color dot CD_X_Y (shortened inFIG. 17(d) as CDXY)) within the pixel. For example, conductor C0112couples embedded polarity region EPR12of pixel P(0,1) to switching element SE_1of pixel P(0, 0). The conductors for the embedded polarity regions are shown with dashed lines to indicate that the conductors are in a different plane from the color dots. Typically, the color dots are formed with ITO in a first plane and the conductors are formed with a metal layer in a second plane.

As explained above in pixels on odd numbered rows, embedded polarity elements of a first pixel are coupled to switching elements of the pixel below the first pixel. For example, embedded polarity region EPR_2_2(labeled EPR22inFIG. 17(d)) of pixel P(0, 1) is coupled to switching element SE_2of pixel P(0, 0) by conductor C_0_1_2_2(labeled C0122inFIG. 17(d)). Similarly, embedded polarity region EPR_2_1(labeled EPR21inFIG. 17(d)) of pixel P(0, 1) is coupled to switching element SE_2of pixel P(0, 0) by conductor C_0_1_2_1(labeled C0121inFIG. 17(d)). In general, a conductor C_I_J_X_Y, couples embedded polarity region EPR_X_Y of a pixel P(I, J) to switching element SE_X of pixel P(I, J−1), when J is an odd number.

In pixels on even numbered rows, embedded polarity elements of a first pixel are coupled to switching elements of the pixel above the first pixel. For example, embedded polarity region EPR_2_2(labeled EPR22inFIG. 17(d)) of pixel P(0, 0) is coupled to switching element SE_2of pixel P(0, 1) by conductor C_0_0_2_2(labeled C0022inFIG. 17(d)). Similarly, embedded polarity region EPR_2_1(labeled EPR21inFIG. 17(d)) of pixel P(0, 0) is coupled to switching element SE_2of pixel P(0, 1) by conductor C_0_0_2_1(labeled C0021inFIG. 17(d)). In general, a conductor C_I_J_X_Y, couples embedded polarity region EPR_X_Y of a pixel P(I, J) to switching element SE_X of pixel P(I, J+1), when J is an even number.

As explained above adjacent row of pixels have opposite polarity in display1720. Thus, providing polarity from switching elements in pixels from adjacent rows to embedded polarity regions as described above causes the polarity of the embedded polarity regions to be different from the polarity of the color dot. This differing polarity serves to enhance the fringe field in the color dots and reduce the touch mura effect in display1720.

As explained above adjacent row of pixels have opposite polarity in display1720. Thus, providing polarity from switching elements in pixels from adjacent rows to embedded polarity regions as described above causes the polarity of the embedded polarity regions to be different from the polarity of the color dot. This differing polarity serves to enhance the fringe field in the color dots and reduce the touch mura effect in display1720.

FIG. 17(e) shows another embodiment of the present invention in which the embedded polarity regions receive polarity from the fringe field amplifying region. Specifically,FIG. 17(e) shows a portion of a display1730using pixels P(0, 0), P(1, 0), P(0, 1), and P(1, 1) of pixel design1710with a switching element point inversion driving scheme. Display1730could have thousands of rows with thousand of pixels on each row. The rows and columns would continue from the portion shown inFIG. 17(e) in the manner shown inFIG. 17(e). For clarity, the gate lines and source lines that control the switching elements are omitted inFIG. 17(e). Furthermore, to better illustrate each pixel, the area of each pixel is shaded; this shading is only for illustrative purposes inFIG. 17(e) and has no functional significance. Due to space limitations color dots are labeled as CDXY as opposed to CD_X_Y and embedded polarity regions are labeled as EPRXY as opposed to EPR_X_Y.

Because display1730and display1720are very similar only the differences are described in detail. For example, the pixels of display1730are arranged in the same manner as the pixels of display1720. Furthermore, the polarity of the color dots, switching elements and fringe field amplifying regions are the same. Thus like in display1720, a pixel P(x, y) in display1730also has a first dot polarity pattern when x+y is even and a second dot polarity pattern when x+y is odd. The primary difference between display1720and display1730is that the embedded polarized regions in display1730is coupled to the fringe field amplifying regions to receive polarity.

Specifically, as illustrated inFIG. 17(e), in display1730each embedded polarity regions is coupled to the nearest fringe fiend amplifying region. Specifically, an embedded polarity region EPR_X_Y of a pixel P(I, J) is coupled to fringe field amplifying region FFAR_X by a conductor C_I_J_X_Y (labeled with CIJXY inFIG. 17(e) due to space constraints), where I, J denotes the pixel (e.g. pixel P(I, J), X is the color component, Y denotes the color dot (e.g. color dot CD_X_Y (shortened inFIG. 17(e) as CDXY)) within the pixel. For example, conductor C0112couples embedded polarity region EPR12of pixel P(0,1) to fringe field amplifying region FFAR_1(not specifically labeledFIG. 17(e)) of pixel P(0, 1). The conductors for the embedded polarity regions are shown with dashed lines to indicate that the conductors are in a different plane from the color dots. Typically, the color dots and fringe field amplifying regions are formed with ITO in a first plane and the conductors are formed with a metal layer in a second plane. Thus, a via (labeled V) is used to connect the fringe field amplifying regions to the conductors. InFIG. 17(e) the fringe field amplifying regions are coupled to a switching element of a neighboring pixel as explained above with respect toFIG. 17(d). However, in other embodiments of the present invention the fringe field amplifying regions may receive polarity using other methods, such as dedicated fringe field amplifying region switching elements.

As explained above the fringe field amplifying regions have an opposite polarity as compared to the color dots. Thus, providing polarity from the fringe field amplifying regions to the embedded polarity regions causes the polarity of the embedded polarity regions to be different from the polarity of the color dot. This differing polarity serves to enhance the fringe field in the color dots and reduce the touch mura effect in display1720.

In the various embodiments of the present invention, novel structures and methods have been described for creating a multi-domain vertical alignment liquid crystal display without the use of physical features on the substrate. The various embodiments of the structures and methods of this invention that are described above are illustrative only of the principles of this invention and are not intended to limit the scope of the invention to the particular embodiment described. For example, in view of this disclosure those skilled in the art can define other pixel definitions, embedded polarity regions, field reduction layers, insulating layers, conducting layers, voids, dot polarity patterns, pixel designs, color components, polarity extension regions, polarities, fringe fields, electrodes, substrates, films, and so forth, and use these alternative features to create a method or system according to the principles of this invention. Thus, the invention is limited only by the following claims.