CROSS REFERENCE TO RELATED APPLICATIONSThis application is a continuation application of co-pending application Ser. No. 12/694,365, filed on Jan. 27, 2010, which is a divisional of U.S. Ser. No. 11/261,944, filed Oct. 28, 2005, which claims the benefit of Taiwan patent application No. 93132909, filed Oct. 29, 2004, and Taiwan patent application No. 94135843, filed Oct. 14, 2005, which are hereby incorporated by reference.
TECHNICAL FIELDThis invention relates to a display, more particularly to a multi-domain vertically aligned liquid crystal display.
BACKGROUNDThe ever-increasing demand for displays has motivated display manufacturers to develop various types of displays. The cathode ray tube (CRT) display, in particular, has long dominated the display market. However, because of high power consumption and high radiation emission of CRT displays, other types of displays, such as the transistor liquid crystal display (TFT-LCD), have become more popular. TFT-LCDs have the advantages of providing high display quality, space efficiency, low power consumption, and no radiation emission.
Generally, LCDs exhibit high contrast ratio, no gray scale inversion, small color shift, high luminance, excellent color richness, high color saturation, quick response, and wide viewing angle. Example types of LCDs that are able to provide wide viewing angles include the following: twisted nematic LCDs with wide viewing film, in-plane switching (IPS) LCDs, fringe field switching LCDs, and multi-domain vertically aligned (MVA) LCDs.
MVA LCDs are able to have wide viewing angles due to provision of alignment protrusions and/or slits disposed on a color filter substrate or thin film transistor array substrate. The alignment protrusions and/or slits enable liquid crystal molecules of the LCD to align in various directions so that multiple alignment domains are achieved. However, with conventional MVA LCDs, when viewing angle changes, the brightness of the MVA LCD may change as well, leading to color shift and insufficient color saturation.
BRIEF DESCRIPTION OF THE DRAWINGSFIG. 1A is a sectional view of a pixel unit of a multi-domain vertically aligned (MVA) liquid crystal display (LCD) according to a first embodiment.
FIG. 1B is a schematic circuit diagram of the pixel unit of the first embodiment.
FIG. 2 is a schematic circuit diagram of a pixel unit of an MVA LCD according to a second embodiment.
FIG. 2A is a schematic circuit diagram of a pixel unit according to another embodiment.
FIG. 2B is a schematic circuit diagram of a pixel unit according to yet another embodiment.
FIG. 3 is a sectional view of a pixel unit of an MVA LCD according to a third embodiment.
FIG. 4 is a sectional view of a pixel unit of an MVA LCD according to a fourth embodiment.
FIG. 5A is a sectional view of a pixel unit of an MVA LCD according to a fifth embodiment.
FIG. 5B is a chart of curves representing relationships of voltage to transmittance.
FIG. 6A is a schematic top view of a pixel unit of an MVA LCD according to a sixth embodiment.
FIG. 6B is a chart of curves representing relationships of voltage to normalized transmittance percentage.
FIG. 7A is a sectional view of a pixel unit of an MVA LCD according to a seventh embodiment.
FIG. 7B is a schematic circuit diagram of the pixel unit of the MVA LCD according to the seventh embodiment.
FIG. 8 is a schematic circuit diagram of a pixel unit of an MVA LCD according to an eighth embodiment.
DETAILED DESCRIPTIONIn the following description, numerous details are set forth to provide an understanding of the present invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these details and that numerous variations or modifications from the described embodiments are possible.
In accordance with some embodiments, a multi-domain vertically aligned (MVA) LCD panel is provided that is able to reduce changes in brightness when the viewing angle changes. An MVA LCD panel can include an active component array substrate, an opposite substrate, and a liquid crystal layer, where the active component array substrate has a plurality of pixel units (arranged in an array of pixel units) and the liquid crystal layer is disposed between the active component array substrate and the opposite substrate. The liquid crystal layer proximal each pixel unit is divided into a plurality of domain sets, wherein each domain set has various domains and the effective voltage applied on the liquid crystal layer proximal each domain set is different.
To reduce changes in brightness of an MVA LCD when the viewing angle changes according to some embodiments, each of the pixel units of the active component array substrate is divided into multiple domain sets to achieve the objective of reducing brightness changes. For example, each pixel unit is divided into a first domain set and a second domain set, where both the first domain set and the second domain set include several domains (e.g., four domains, A, B, C, and D).
Conventionally, to drive an LCD panel, a driving voltage is input into the pixel electrode of each individual pixel unit via a data line so that the effective voltage supplied to the liquid crystal layer proximal the individual pixel unit is the same. Note, however, that according to some embodiments, in response to the same driving voltage input, the effective voltages supplied to portions of the liquid crystal layer proximal the domain sets are different. As the effective voltage supplied to the liquid crystal layer in each domain set is different, the transmittance of the liquid crystal layer in different domain sets is different so that the problem of steep change in brightness when the viewing angle changes is alleviated. The following describes embodiments that include mechanisms to cause the effective voltages supplied to portions of the liquid crystal layer in the plural domain sets to differ from each other.
First EmbodimentFIG. 1A is a sectional view of apixel unit100 of an MVA LCD according to a first embodiment, andFIG. 1B is a schematic circuit diagram of the pixel unit. The pixel unit depicted is repeated to provide an array of pixel units in the MVA LCD. The MVA LCD comprises an activecomponent array substrate1300, anopposite substrate1100, and aliquid crystal layer1200 portion disposed between the activecomponent array substrate1300 and theopposite substrate1100. Additionally, theopposite substrate1100 comprises afirst substrate1110 and acommon electrode layer1120 which is disposed on the surface of thefirst substrate1110, where thecommon electrode layer1120 faces the activecomponent array substrate1300.
The activecomponent array substrate1300 has a plurality ofscan lines1314, a plurality ofdata lines1312, and a plurality ofpixel units100, where thepixel units100 are controlled by thecorresponding scan lines1314 and data lines1312 (as shown inFIG. 1B). Additionally, thepixel units100 are disposed above asecond substrate1310 and comprise an active component1316 (as shown inFIG. 1B), a first pixel electrode1330a, a second pixel electrode1330b, and a metal layer1312a. The first and second pixel electrodes1330a,1330bare considered to be divided pixel electrodes provided to apply different voltages on portions of theliquid crystal layer1200 in different first and second domain sets I and II. Furthermore, theactive component1316 is, for example, a thin film transistor (TFT) or otherwise a three-end active component. The metal layer1312aand thedata line1312 are, for example, formed at the same time. The metal layer1312ais electrically connected to the drain of theTFT1316, and thedata line1312 is connected to the source of theTFT1316. Note that the terms “source” and “drain” can be used interchangeably. The gate of theTFT1316 is connected to ascan line1314.
Theactive component1316 is disposed on thesecond substrate1310, and aninsulation layer1322 extends from the active component and covers thesecond substrate1310, wherein the insulation layer is, for example, a gate insulation layer. Additionally, the metal layer1312ais disposed above theinsulation layer1322, and theinsulation layer1324 covers the metal layer1312aandinsulation1322, wherein theinsulation layer1324 is, for example, a protection layer. In one embodiment, the metal layer1312ais in a location which, for example, overlaps that of a sharedline1314a. In other words, the metal layer1312ais above the sharedline1314a.
Note that the first pixel electrode1330aand the second pixel electrode1330bare separately disposed (and spaced apart from each other horizontally) above theinsulation layer1324, wherein the first pixel electrode1330aelectrically connects to theactive component1316 and is in a location that corresponds to that of a first domain set I. Additionally, the second pixel electrode1330bis coupled to the metal layer1312ato form acapacitance1318, and is in a location that corresponds to that of a second domain set II. Both the first domain set I and the second domain set II include multiple domains, such as four domains with different liquid crystal alignment. The overlapping area of the second pixel electrode1330band the metal layer1312adefines thecapacitor1318 and will determine the effective voltage applied on the portion of theliquid crystal layer1200 proximal the second pixel electrode1330b. A liquid crystal layer portion “proximal” a pixel electrode means that the liquid crystal layer is in the vicinity of the pixel electrode such that the liquid crystal layer portion will be electrically affected by the pixel electrode.
In eachpixel unit100, the first pixel electrode has a direct electrical connection with theactive component1316, while the second pixel electrode1330belectrically couples to theactive component1316 via thecapacitance1318. Such an arrangement results in the voltage applied on the second pixel electrode1330bbeing different from that applied on the first pixel electrode, so that the effective voltage applied on theliquid crystal layer1200 portion in the first domain set I is different from that applied on theliquid crystal layer1200 portion in the second domain set II. When a particular driving voltage is input into the pixel unit via thedata line1312, the first pixel electrode1330awill receive a higher voltage than the second pixel electrode1330bso that the effective voltage applied on theliquid crystal molecules1210ain the first domain set I is greater than that applied on theliquid crystal molecules1210bin the second domain set II, resulting in an obliquity of the liquid crystal molecules of the first domain set I different from that of the liquid crystal modules of the second domain set II, so that when the viewing angle changes, changes in brightness will be reduced because the first domain set I and the second domain set II will compensate each other in brightness.
Note that in this embodiment, a plurality ofalignment protrusions1130 are disposed on thecommon electrode layer1120 of theopposite substrate1100, and a plurality ofalignment protrusions1340 are disposed on the second pixel electrode1330band the first pixel electrode1330aof the activecomponent arrays substrate1300 so that the liquid crystal molecules within theliquid crystal layer1200 portion will be arranged in multi-domain pattern.
However, in another embodiment, the method by which the liquid crystal molecules within theliquid crystal layer1200 portion are caused to be arranged in multi-domain pattern is, for example, to form slits on thecommon electrode layer1120, the first pixel electrode1330aand the second pixel electrode1330b. In another embodiment, the method by which the liquid crystal molecules within theliquid crystal layer1200 portion are caused to be arranged in multi-domain pattern is, for example, to form either one of alignment protrusions and slits on the common electrode layer1120aand form the other one of alignment protrusions and slits on the first pixel electrode1330aand the second pixel electrode1330b.
Second EmbodimentFIG. 2 is a schematic circuit diagram of apixel unit200 in an MVA LCD according to a second embodiment. The arrangementFIG. 2 is similar to that ofFIG. 1B with the difference being that in thepixel unit200 of the second embodiment, thesecond pixel electrode2330belectrically connects to theactive component1316 through aresistance component2318. Note that theresistance component2318 is a transistor but it can also be a resistor or any other device capable of generating a voltage drop. Additionally, thefirst pixel electrode2330aelectrically connects to theactive component1316 directly. The gate of the component2318 (if implemented as a transistor) is connected to thesame scan line1314 as the gate of theactive component1316.
Thefirst pixel electrode2330acorresponds to the location of the first domain set I and thesecond pixel electrode2330bcorresponds to the location of the second domain set II, so that the effective voltages applied on theliquid crystal layer1200 portion in the first domain set I and that applied on theliquid crystal layer1200 portion in the second domain set II are different (similar to what is illustrated inFIG. 1A). The voltage drop generated byresistance component2318 will determine the effective voltage applied to theliquid crystal layer1200 portion in the second domain set II (similar to what is illustrated inFIG. 1A).
In summary, it can be seen from the first and the second embodiments that the first pixel electrode corresponds to the location of the first domain set and the second pixel electrode corresponds to the location of the second domain set. Additionally, the first pixel electrode electrically connects to the active component directly while the second pixel electrode connects to the active component via a capacitance or a resistance component so that the effective voltage applied to the liquid crystal layer in the first domain set and that applied to the liquid crystal layer in the second domain set are different. In other implementations, instead of defining just two domain sets, additional domain sets can also be defined.
A First Variant of the Second EmbodimentFIG. 2A is a schematic circuit diagram of a pixel unit in an MVA LCD according to a variation of the second embodiment. This pixel unit is similar to the second embodiment with the main difference being the way in which the gate oftransistor2318 is connected. InFIG. 2A, the gate oftransistor2318 electrically connects to the source of the active component1316 (rather than to scanline1314 as inFIG. 2). This will cause a voltage on thedata line1312 to turn on thetransistor2318 so that an input voltage signal can be provided to thepixel electrode2330bonce thescan line1314 turns on theactive component1316.
Note that the voltage signal output fromdata line1312 may vary from one time frame to another time frame, which causes the channel size of thetransistor2318 to change with the varying voltage signal. Therefore, thetransistor2318 provides a variable resistance. This variable resistance will generate a voltage drop that can cause the voltage received by thefirst pixel electrode2330a(located in the first domain set I) to be different from that received by thesecond pixel electrode2330b(located in the second domain set II). In other words, the effective voltage applied on the liquid crystal layer in the first domain set I is different from that applied on the liquid crystal layer in the second domain set II.
A Second Variant of the Second EmbodimentFIG. 2B is a schematic circuit diagram of a pixel unit in an MVA LCD according to a second variant of the second embodiment. This pixel unit is similar to the second embodiment with the main difference being that in this second variant, the pixel unit further includes a shared line2314awhich electrically connects to the gate of thetransistor2318. Generally, the shared line2314amay electrically connect to a reference voltage source so that thetransistor2318 will stay in the on state. Thetransistor2318 provides a resistance and it is this resistance that enables this second variant to generate a voltage drop so that the voltage received by thefirst pixel electrode2330a(located in the first domain set) is different from that received by thesecond pixel electrode2330b(located in the second domain set II).
Additionally, the pixel unit of this second variant may further include a storage capacitor, Cs, which electrically connects the shared line2314aand the firstactive component1316. This storage capacitor Cs can be located inside the first domain set I or the second domain set II, or alternatively, be located inside both the first domain set I and the second domain set II.
Third EmbodimentFIG. 3 is a sectional view of a pixel unit of a third embodiment. The third embodiment is similar to the first embodiment with the difference being that thepixel electrode3320 of the third embodiment is not divided and adielectric layer3330 is disposed above thepixel electrode3320 that corresponds to the location of the second domain set II. Such a dielectric layer is not provided in the first domain set I. Thedielectric layer3330 provides a dielectric constant between thepixel electrode3320 and theliquid crystal layer1200 portion in the second domain set II that is higher than the dielectric constant between thepixel electrode3320 and theliquid crystal layer1200 portion in the first domain set I, so that the effective voltage applied to theliquid crystal layer1200 portion in the second domain set II is different from that applied on theliquid crystal layer1200 portion in the first domain set I.
Thedielectric layer3330 can be made of, for example, resin or another dielectric material and it is also electrically connected to the active component. The dielectric constant and thickness of thedielectric layer3330 will determine the effective voltage applied to theliquid crystal layer1200 portion in the second domain set II.
Note that this embodiment is not limited to use of thealignment protrusions1130 and1340 in order to cause the liquid crystal molecules within theliquid crystal layer1200 portion to be arranged in a multi-domain pattern. Another method by which the liquid crystal molecules within theliquid crystal layer1200 portion are caused to arrange in multi-domain pattern is, for example, to form slits on both the activecomponent array substrate1300 and theopposite substrate1100 at the same time. In another embodiment, alignment protrusions and slits are formed on the activecomponent array substrate1300 and the opposite substrate110.
Fourth EmbodimentFIG. 4 is a sectional view of a pixel unit in an MVA LCD according to a fourth embodiment. The fourth embodiment is similar to the third embodiment with the difference being that thepixel electrode4320 has a plurality ofslits4322 and theseslits4322 are at a location that corresponds to that of the second domain set II. Additionally, thepixel electrode4320 is also provided withalignment protrusions1340 and thealignment protrusions1340 are at a location that corresponds to that of the first domain set I. In other words, in this embodiment, theprotrusions1340 andslits4322 are both formed on the activecomponent array substrate1300 so that the driving voltage applied to theliquid crystal layer1200 portion in the first domain set I has a different characteristic as compared to the driving voltage applied on theliquid crystal layer1200 portion in the second domain set II, such that the first domain set I and the second domain set II will have different obliquities of liquid crystal molecules even with the same voltage input. This enables the two domain sets to compensate for the difference in brightness caused by changes in the viewing angle so that the problem of color drift is alleviated.
Note that in this embodiment, slits andalignment protrusions1130 may also be formed on theopposite substrate1100 while thealignment protrusions1340 are formed on the activecomponent array substrate1300 so that the driving voltage applied to theliquid crystal layer1200 portion in the first domain set I has a different characteristic as compared to the driving voltage applied on theliquid crystal layer1200 portion in the second domain set II. Furthermore, in this embodiment, thealignment protrusions1340,1130, and slits4322 combined will cause the liquid crystal molecules within theliquid crystal layer1200 portion to be arranged in a multi-domain pattern. However, the method by which the liquid crystal molecules are caused to be arranged in multi-domain pattern is not limited to this kind of combination. For example, thealignment protrusions1130 may be substituted by slits formed on thecommon electrode layer1120 of the opposite substrate.
Fifth EmbodimentFIG. 5A is a sectional view of a pixel unit in an MVA LCD according to a fifth embodiment, andFIG. 5B is a chart of curves (for different distances) showing the relationship of driving voltage versus transmittance. Thepixel electrode5320 has a plurality ofslits5322 and5324 and electrically connects to the active component. Additionally, theopposite substrate1100 is provided with a plurality ofalignment protrusions1130 and the combination of thealignment protrusions1130,slits5322 and5324 will cause the liquid crystal molecules within theliquid crystal layer1200 portion to arrange in a multi-domain pattern.
Eachalignment protrusion1130 is separated by a minimum first distance D1 and a minimum second distance D2 fromslit5324 and slit5322, respectively, on the two sides, respectively, of theprotrusion1130. The first distance D1 is different from (e.g., greater than) the second distance D2. Additionally, the space between eachalignment protrusion1130 and theslit5324 is in the first domain set I, and the space between thealignment protrusion1130 and theslit5322 is in the second domain set II.
As thealignment protrusion1130 has different minimum distances fromslits5324 and5322, theliquid crystal molecules1210aand1210bin the first and second domain sets, respectively, will have different rotation angles when subjected to the action of an electrical field so that different transmittances are generated even with the same voltage input.
InFIG. 5B, the horizontal axis represents the driving voltage, and the vertical axis represents the transmittance. Example distances for D1, D2 represented inFIG. 5B are 15 μm (micron) (solid line), 20 μm (dashed line), and 25 μm (dotted line). Note that by X μm it is meant that both the first distance D1 and the second distance D2 are X μm.
It can be seen fromFIG. 5B that the wider the distance the higher the transmittance if the driving voltage is kept unchanged. In other words, when the first distance D1 is provided with the second distance D2 as a pair (such as in the arrangement ofFIG. 5A), the liquid crystal molecules at the location of the first domain set I and that at the location of the second domain set II will have different rotation angles when both are subjected to the action of the same electrical field. In other words, the driving voltage applied to theliquid crystal layer1200 portion in the first domain set I and that applied on theliquid crystal layer1200 portion in the second domain set II will have different characteristics. The higher the difference between the first distance D1 and the second distance D2, the greater the difference between their driving voltage-transmittance curves. In some examples, the distance difference is greater than or equal to one μm. In other examples, the distance difference is greater than or equal to 10 μm.
In the embodiment ofFIG. 5A, theopposite substrate1100 is provided with first alignment structures (alignment protrusions1130) and the activecomponent array substrate1300 is provided with the second alignment structures (slits5324 and5322) so that the liquid crystal molecules within theliquid crystal layer1200 portion are arranged in a multi-domain pattern.
Alternatively, a different arrangement of theFIG. 5A embodiment can be used. For example, the first alignment structures can include slits and the second alignment structures can includeslits5324 and5322. Alternatively, the first alignment structures can includealignment protrusions1130, and the second alignment structures can include alignment protrusions. In yet another arrangement, the first alignment structures can include slits and the second alignment structures can include alignment protrusions.
Sixth EmbodimentFIG. 6A is a top view of the pixel unit of a sixth embodiment, andFIG. 6B is a graph of curves (for different form factors of slits) representing relationships of driving voltage versus normalized transmittance percentage. Thepixel unit600 includes anactive component1316 and apixel electrode6320, wherein thepixel electrode6320 electrically connects to theactive component1316. Furthermore, thepixel electrode6320 has a plurality ofnon-jagged slits6322 and a plurality ofjagged slits6324, wherein saidnon-jagged slits6322 are in a location that corresponds to that of the first domain set I and saidjagged slits6324 are in a location that corresponds to that of the second domain set II.
InFIG. 6B, the horizontal coordinate represents the driving voltage, and the vertical coordinate represents the normalized transmittance percentage. Additionally, the solid line curve represents non-jagged slits and the dashed line curve represents jagged slits. It can be seen fromFIG. 6 that with the same driving voltage, an MVA LCD that uses non-jagged slits will have a higher transmittance. In other words, the driving voltage supplied to theliquid crystal layer1200 portion in the first domain set I and that supplied to theliquid crystal layer1200 portion in the second domain set II will have different voltage-transmittance characteristics.
Seventh EmbodimentFIG. 7A is a sectional view of apixel unit700 of an MVA LCD according to a seventh embodiment, andFIG. 7B is a schematic circuit diagram of thepixel unit700. The MVA LCD includes anopposite substrate1100, aliquid crystal layer1200 portion, and an activecomponent array substrate1300, wherein theliquid crystal layer1200 portion is disposed between the activecomponent array substrate1300 and theopposite substrate1100. Additionally, theopposite substrate1100 comprises afirst substrate1110 and acommon electrode layer1120 which is disposed on the surface of thefirst substrate1110, wherein thecommon electrode layer1120 faces the activecomponent array substrate1300.
The activecomponent array substrate1300 has a plurality ofdata lines1312, a plurality ofscan lines1314, and a plurality ofpixel units700, wherein thepixel units700 are controlled by the correspondingdata lines1312 and scan lines1314 (as shown inFIG. 7B). Additionally, thepixel unit700 is disposed above asecond substrate1310 and includes a firstactive component1316a, a secondactive component1316b, a thirdactive component1316c, afirst pixel electrode1331a, asecond pixel electrode1331b, and a capacitor1319 (as shown inFIG. 7B). The firstactive component1316a, secondactive component1316b, and thirdactive component1316care each, for example, a thin film transistor or otherwise a three-end active component.
The firstactive component1316aelectrically connects to thefirst pixel electrode1331aand thefirst pixel electrode1331ais in a location that corresponds to that of the first domain set I (as shown inFIG. 7A), wherein the firstactive component1316aelectrically connects to thefirst pixel electrode1331avia, for example, its drain1312a. Additionally, the secondactive component1316belectrically connects to thesecond pixel electrode1331band thesecond pixel electrode1331bis in a location that corresponds to that of the second domain set II (as shown inFIG. 7A), wherein the secondactive component1316belectrically connects to thefirst pixel electrode1331avia, for example, itsdrain1312b. Note that the drains1312a(ofTFT1316a) and1312b(ofTFT1316b) are, for example, formed at the same time with thedata line1312, andgate1314aof the firstactive component1316aandgate1314bof the secondactive component1316aelectrically connect to thescan line1314, separately. The sources of theactive components1316a,1316bare connected to thedata line1312.
InFIG. 7B, both the firstactive component1316aand the secondactive component1316belectrically connect to thedata line1312 andscan line1314 corresponding to thepixel unit700, while the gate of the thirdactive component1316celectrically connects to thenext scan line1315, and thecapacitor1319 electrically connects to thesecond pixel electrode1331bthrough the thirdactive component1316c. The gate of the thirdactive component1316celectrically connects to thenext scan line1315 so that thescan line1315 can turn on/off the thirdactive component1316c. Additionally, the source of the thirdactive component1316celectrically connects to thesecond pixel electrode1331bwhile the drain of the thirdactive component1316celectrically connects to an electrode of thecapacitor1319.
In this arrangement, voltage V1 (atpixel electrode1331a) is the same as voltage V2 (atpixel electrode1331b) when the firstactive component1316aand the secondactive component1316bare driven at the same time by thedata line1312 andscan line1314. However, when thenext scan line1315 is activated to turn on the thirdactive component1316c, thecapacitor1319 will cause the voltage V2 to drop. At this time, both the firstactive component1316aand the secondactive component1316bare in the off state. This causes the driving voltage applied on theliquid crystal layer1200 portion in the first domain set I and that applied on theliquid crystal layer1200 portion in the second domain set II to have different voltage-transmittance characteristics.
Thecapacitor1319 includes a first electrode1319aand asecond electrode1319b(FIG. 7A), wherein thesecond electrode1319bis disposed below the first electrode1319a, and the first electrode1319a, thefirst pixel electrode1331aand thesecond pixel electrode1331bare of the same material, while thesecond electrode1319band thedata line1312 are of the same material.
Eighth EmbodimentFIG. 8 is a schematic circuit diagram of the pixel unit in an MVA LCD according to an eighth embodiment. In this embodiment, thepixel unit800 includes a firstactive component1316a, afirst pixel electrode1331a, a secondactive component1316b, and asecond pixel electrode1331b. The gate of the firstactive component1316aelectrically connects to the scan line1314 (the nthline inFIG. 8) corresponding to thepixel unit800, and thefirst pixel electrode1331aelectrically connects to the drain of the firstactive component1316a. The source of the firstactive component1316ais connected to the drain of the secondactive component1316b.
Additionally, thefirst pixel electrode1331ais in a location that corresponds to that of the first domain set I. The source of the secondactive component1316belectrically connects to thedata line1312 corresponding to thepixel unit800, and the gate of the secondactive component1316belectrically connects to the next scan line1314 (the n+1thline as shown inFIG. 8). The secondactive component1316bis turned on or off by the next scan line1314 (the n+1thline as shown inFIG. 8). Furthermore, thesecond pixel electrode1331bis electrically connected to both the secondactive component1316band the firstactive component1316aand is in a location that corresponds to that of the second domain set II.
Specifically, when the nthscan line1314 is activated to turn on the firstactive component1316a, the signal voltage of the (k−1)thtime frame (previous time frame) retained at thesecond pixel electrode1331bwill be written to thefirst pixel electrode1331a(located in the first domain set I) as voltage V1. Next, when the (n+1)thscan line1314 activates to turn on the secondactive component1316b, thedata line1312 will write the signal voltage of the kthtime frame to thesecond pixel electrode1331b(located in the second domain set II) as voltage V2. Note that at this time the firstactive component1316ais off.
This will cause the liquid crystal molecules disposed in the first domain set I and the second domain set II to receive different effective voltages. In other words, the obliquity of the liquid crystal molecules in these two domain sets (first domain set I and second domain set II) will be different so that the transmittance will differ as well. This enables the two domain sets (I and II) to compensate each other to provide viewers a wider angle of view.
Note that the display quality of an MVA LCD panel according to some embodiments of the invention will be improved by changing the surface area ratio of the first domain set Ito the second domain set II in the above embodiments.
In summary, an MVA LCD according to some embodiments may have at least the following features:
I. The MVA LCD has multiple domains, in which the liquid crystal molecules have the same alignment but different obliquity so that changes in brightness due to viewing angle changes will be reduced to improve the display quality.
II. The MVA LCD does not need an additional light shield and is compatible with existing manufacturing facilities.
While the invention has been disclosed with respect to a limited number of embodiments, those skilled in the art will appreciate numerous modifications and variations therefrom. It is intended that the appended claims cover such modifications and variations as fall within the true spirit and scope of the invention.