TW201500823A - Active matrix structure and liquid crystal display panel - Google Patents

Abstract

An active matrix structure including a substrate, a plurality of active devices, and a plurality of pixel electrodes is provided. The active devices are disposed on the substrate. The pixel electrodes are respectively electrically connected to the active devices and arranged in an array. The active matrix structure has a display area, and each of the pixel electrodes has at least one slanted side inclined with respect to all sides of the display area. A liquid crystal display panel is also provided.

Description

Active matrix structure and liquid crystal display panel

The present invention relates to an electronic device and a display panel, and more particularly to an active matrix structure and a liquid crystal display panel.

In the display area of the display device, various types of spatial light modulators are applied to convert the illumination beam into an image beam, such as a liquid crystal display panel (LCD panel), a liquid crystal overlay ( Liquid-crystal-on-silicon, LCOS) panel or digital micro-mirror device (DMD). The light efficiency of the transmissive LCD panel is lower than that of the LCOS panel, and the cost of the DMD is greater than the cost of the LCOS panel.

In general, in a projector using an LCOS panel, an s-polarized beam is reflected to an LCOS panel by a polarizing beam splitter (PBS). Next, the LCOS panel modulates the s-polarized beam into a polarized beam of other polarization states and reflects the polarized beam to the PBS. The PBS filters the polarized beam into an image beam, which is then transmitted to an imaging lens. Finally, the imaging lens projects the image beam onto the screen to form an image on the screen. Or create a virtual image in the air or on any other virtual image plane.

When the size of the LCOS panel is reduced, the gap between two adjacent pixel electrodes is reduced, and the aperture ratio of the pixel electrode is also reduced. Therefore, the fringe field problem of the pixel electrode becomes more serious; for example, the orientation of the liquid crystal around the corners of the pixel electrode may be inaccurate, so that the light efficiency and color performance of the LCOS panel are lowered.

The invention proposes an active matrix which reduces the fringe field problem of the pixel electrode.

The invention also proposes a liquid crystal display panel which reduces the fringe field problem of the pixel electrode.

According to an embodiment of the present invention, an active matrix structure is provided, including a substrate, a plurality of active elements, and a plurality of pixel electrodes. The active components are disposed on the substrate. The pixel electrodes are electrically connected to the active elements and arranged in an array, respectively. The active matrix structure has a display area, and each of the pixel electrodes has at least one oblique side that is inclined with respect to all sides of the display area.

According to an embodiment of the present invention, there is provided a liquid crystal display panel comprising the aforementioned active matrix structure, a counter substrate, and a liquid crystal layer. The opposite substrate includes a transparent substrate and a transparent conductive layer. The transparent conductive layer is disposed on the transparent substrate and between the active matrix structure and the transparent substrate. The liquid crystal layer is disposed between the active matrix structure and the opposite substrate.

Active matrix structure and liquid crystal display panel in accordance with an embodiment of the present invention The fringe field effect of the pixel electrode is compensated because each of the pixel electrodes has at least one oblique side that is inclined with respect to all sides of the display area. As a result, the fringe field problem of the pixel electrode is reduced.

The above described features and advantages of the invention will be apparent from the following description.

100‧‧‧LCD panel

110‧‧‧ opposite substrate

112‧‧‧Transparent substrate

114‧‧‧Transparent conductive layer

116‧‧‧Second alignment layer

120‧‧‧Liquid layer

200‧‧‧Active Matrix Structure

210‧‧‧Substrate

220‧‧‧Active components

230‧‧‧ pixel electrodes

231‧‧‧Bevel

232‧‧‧ surface

240‧‧‧reflective layer

242‧‧‧through hole

244‧‧‧ surface

250‧‧‧Conducting components

260, 270, 280‧ ‧ insulation

290‧‧‧Color filter layer

291‧‧‧Filter area

292‧‧‧Red filter area

294‧‧‧Green filter area

296‧‧‧Blue filter area

310‧‧‧First alignment layer

320‧‧‧Polarized beam splitter

330‧‧‧ imaging lens

340‧‧‧Lighting system

A‧‧‧ display area

B1‧‧‧linearly polarized beam

D‧‧‧Distance

G‧‧‧ gap

I1‧‧‧ image beam

L1, L2‧‧‧ linearly polarized light

L3‧‧‧ elliptically polarized light

P1‧‧‧first polarization direction

P2‧‧‧second polarization direction

R‧‧‧Orientation

S, S1, S2‧‧‧

W‧‧‧Width

Φ1, φ1', φ2, φ2'‧‧‧ tilt angle

Θ1, θ2, θ3‧‧‧ interior angle

1 is a schematic front view of a liquid crystal display panel in accordance with an embodiment of the present invention.

2 is a schematic enlarged view of the liquid crystal display of FIG. 1 showing a front view of a pixel electrode and a filter region of the liquid crystal display of FIG. 1.

3 is a schematic cross-sectional view of the liquid crystal display of FIG. 1.

Figure 4 is a front elevational view of the pixel electrode of Figure 2.

Figure 5 is a front elevational view of the filter region of Figure 2.

Figure 6 is a schematic illustration of a projector in accordance with an embodiment of the present invention.

1 is a schematic front view of a liquid crystal display panel in accordance with an embodiment of the present invention. 2 is a schematic enlarged view of the liquid crystal display of FIG. 1 showing a front view of a pixel electrode and a filter region of the liquid crystal display of FIG. 1. 3 is a schematic cross-sectional view of the liquid crystal display of FIG. 1. Figure 4 is a pixel electrode of Figure 2 front view. Figure 5 is a front elevational view of the filter region of Figure 2. Referring to FIGS. 1 through 5, the liquid crystal display panel 100 of this embodiment includes an active matrix structure 200, a counter substrate 110, and a liquid crystal layer 120. The active matrix structure 200 includes a substrate 210, a plurality of active elements 220, and a plurality of pixel electrodes 230. The active element 220 is disposed on the substrate 210. In this embodiment, the substrate 210 is a germanium substrate and the active device 220 is a transistor. In this embodiment, the active component 220 is electrically coupled to the plurality of scan lines and the plurality of data lines on the substrate 210, and each of the active components is electrically coupled to one of the scan lines and one of the data lines.

The pixel electrodes 230 are electrically connected to the active elements 220, respectively, and arranged in an array. In this embodiment, the pixel electrode is a reflective electrode. The pixel electrode can be a metal electrode. In some embodiments, the pixel electrode is made of aluminum.

The opposite substrate 110 includes a transparent substrate 112 and a transparent conductive layer 114. The transparent conductive layer 114 is disposed on the transparent substrate 112 and located between the active matrix structure 200 and the transparent substrate 112. The liquid crystal layer 120 is disposed between the active matrix structure 200 and the opposite substrate 110. The transparent substrate 112 can be made of glass or plastic, and the transparent conductive layer 114 can be made of indium tin oxide or any other suitable transparent conductive material.

The active matrix structure 200 has a display area A, and each of the pixel electrodes 230 has at least one oblique side 231 that is inclined with respect to all sides S of the display area A (exemplarily shown in FIG. 2 Beveled edge 231). In this embodiment, each of the pixel electrodes 230 has a shape of a concave polygon (eg, a butterfly-shaped polygon). The concave polygon has at least one internal angle greater than 180 degrees. For example, the inner angles θ1, θ2, and θ3 in FIG. 4 are all greater than 180 degrees.

In the active matrix structure 200 and the liquid crystal display panel 100 in this embodiment, since each of the pixel electrodes 230 has at least one oblique side 231 that is inclined with respect to all sides S of the display area A, The fringe field of the prime electrode 230 (i.e., the electric field around the edge of the pixel electrode 230) is varied to compensate for fringing field effects due to conventional rectangular pixel electrodes with oblique sides that are parallel to the sides of the display A, respectively. Therefore, the orientation of the liquid crystal around the edge of the pixel electrode 230 can satisfy predetermined requirements. As a result, the fringe field problem of the pixel electrode 230 is reduced or prevented. In other words, the electric field of the pixel electrode 230 drives the liquid crystal in the liquid crystal layer 120 in a more conventional region.

In this embodiment, each of the pixel electrodes 230 has a polygonal shape, and the polygon has more than four sides. For example, each of the pixel electrodes 230 in FIG. 4 has nine sides, but the invention is not so limited.

In this embodiment, the display area A is rectangular, and at least two sides S (for example, the two sides S1 shown in FIG. 1) in the display area are substantially parallel to the arrangement direction R of the pixel electrodes 230. In this embodiment, the pixel electrodes 230 are in a delta arrangement. However, in other embodiments, the pixel electrodes 230 can be arranged in any other suitable manner.

When the linearly polarized light beam B1 having the first polarization direction P1 (for example, the y direction shown in FIGS. 1 and 3) enters the liquid crystal display panel 100, the liquid crystal display panel 100 may depend on the orientation distribution of the liquid crystal in the liquid crystal layer 120. The linearly polarized light beam B1 is reflected as linearly polarized light L1 having a first polarization direction P1, and linearly polarized light L2 having an second polarization direction P2 (for example, the x direction shown in FIGS. 1 and 3) At least one of circularly polarized light L3 and circularly polarized light (not shown). In this embodiment, the liquid crystal display panel 100 is a liquid crystal overlay (LCOS) panel. Further, the x direction is parallel to the side S1 of the display area A, the y direction is parallel to the side S2 of the display area A, the z direction is perpendicular to the display area A, and the x, y, and z directions are perpendicular to each other.

When the linearly polarized light beam B1 is incident on the oblique side 231 of the pixel electrode 230, since the oblique side 231 is inclined, the linearly polarized light beam B1 is reflected by the oblique side 231 and depolarized. For example, the linearly polarized beam B1 can be reflected as elliptically polarized light. In addition, when the linearly polarized light beam B1 is converted into a circularly polarized light beam incident on the oblique side 231 by the liquid crystal, since the oblique side 231 is inclined, the circularly polarized light beam can be reflected by the oblique side 231 and depolarized into an elliptical polarization. Light. Depolarization can degrade display performance due to, for example, light leakage. Therefore, in this embodiment, each of the oblique sides 231 has a plurality of inclination angles (for example, φ1 and φ2; or φ1' and φ2') with respect to the side S of the display area, respectively, and the inclination angle The smallest one (for example, φ1 selected from φ1 and φ2; or φ1' selected from φ1' and φ2') is less than or equal to 10 degrees. In this condition, the light leakage is negligible, the contrast and reflectance are retained, and the fringe field problem is effectively reduced, so that the display performance of the liquid crystal display panel 100 is improved.

In this embodiment, the active matrix structure 200 further includes a reflective layer 240 disposed between the substrate 210 and the pixel electrode 230. The reflective layer 240 may be a metal layer, for example, an aluminum layer, and reflects light passing through the gap G in order to improve the light efficiency of the active matrix structure 200 and the liquid crystal display panel 100. In this embodiment, the reflective layer 240 has a plurality of through holes 242, and the plurality of conductive elements 250 respectively pass through the through holes 242 and respectively respectively The pole 230 is coupled to the active component 220. In addition, the active matrix structure 200 can include an insulating layer 260 that isolates the reflective layer 240 from the substrate 210, an insulating layer 270 that isolates the pixel electrode 230 from the reflective layer 240, and a plurality of conductive elements 250 that are isolated from the reflective layer 240, respectively. Insulation layer 280.

In this embodiment, the gap G between any two adjacent pixel electrodes 230 has a width W ranging from 0.2 microns to 0.35 microns. In other words, the gap G can be small, and the aperture ratio of the pixel electrode 230 is increased, thereby improving the light efficiency and brightness of the liquid crystal display panel 100.

In this embodiment, the active matrix structure 200 further includes a color filter layer 290 disposed on the pixel electrode 230. The color filter layer 290 includes a plurality of sets of filter regions 291 having different colors, for example, a red filter region 292, a green filter region 294, and a blue filter region 296. The red filter region 292, the green filter region 294, and the blue filter region 296 are alternately arranged on the pixel electrode 230, for example, in a triangular arrangement or any other arrangement. The filter regions 291 correspond to the pixel electrodes 230, respectively, and the shape of each of the filter regions 291 conforms to the fringe field distribution range of the corresponding pixel electrode 230.

In this embodiment, each of the filter regions 291 may partially overlap the corresponding pixel electrode 230 and at least one other pixel electrode 230 adjacent to the corresponding pixel electrode 230 because of the fringe field. The shape of the distribution range is different from the shape of the corresponding pixel electrode 230.

In addition, in this embodiment, the surface 244 of the reflective layer 240 facing away from the substrate 210 and the surface 232 of each of the pixel electrodes 230 facing away from the substrate 210 The distance D between them falls within the range of 0.18 micrometers to 0.22 micrometers. The distance D may determine the degree of interference between the light reflected by the reflective layer 240 and the light reflected by the pixel electrode 230, and determine the reflection spectrum of the active matrix structure 200. When the distance D falls within the range of 0.18 micrometers to 0.22 micrometers, the reflection spectrum is suitable for the color filter layer 290, thereby improving the color performance of the liquid crystal display panel 100. In this embodiment, the color-to-white ratio of the liquid crystal display panel 100 is improved because the fringe field problem is reduced or prevented. Therefore, the pixel size can be reduced without adversely affecting the color performance of the liquid crystal display panel 100.

In one embodiment, the pixel electrodes 230 corresponding to the filter regions 291 having different colors have different sizes. Specifically, each of the pixel electrodes 230 corresponds to one sub-pixel. In this embodiment, each of the pixels of the liquid crystal display panel 100 includes a red sub-pixel corresponding to the red filter region 292, a green sub-pixel corresponding to the green filter region 294, and a corresponding blue The blue sub-pixel of the color filter region 296. The size of the pixel electrode 230 corresponding to the red sub-pixel, the size of the pixel electrode 230 corresponding to the green sub-pixel, and the size of the pixel electrode 230 corresponding to the blue sub-pixel may be different or partially identical to each other. Alternatively, in other embodiments, the pixel electrodes 230 corresponding to the filter regions 291 having different colors may be the same size. The size adjustment of the sub-pixels having different colors can satisfy the color requirements of the liquid crystal display panel 100.

In this embodiment, the liquid crystal display panel 100 further includes a first alignment layer 310 disposed between the color filter layer 290 and the liquid crystal layer 120 and a second alignment layer disposed between the transparent conductive layer 114 and the liquid crystal layer 120. 116. First alignment layer 310 and The second alignment layer 116 is configured to align liquid crystals in the liquid crystal layer 120.

Figure 6 is a schematic illustration of a projector in accordance with an embodiment of the present invention. Referring to FIGS. 3 and 6, the projector 300 in this embodiment includes the aforementioned liquid crystal display panel 100, illumination system 340, polarized beam splitter (PBS) 320, and imaging lens 330. The illumination system 340 can provide a linearly polarized beam B1 (eg, an s-polarized beam) having a first polarization direction P1, and the PBS 320 reflects the linearly polarized beam B1 to the liquid crystal display panel 100. The liquid crystal display panel 100 reflects and converts the linearly polarized light beam B1 into an image light beam I1 having a second polarization direction P2 (for example, a p-polarized light beam), and the image light beam I1 then passes through the PBS 320 and is transmitted to the imaging lens 330. The imaging lens 330 projects the image beam I1 onto a screen or object to form a real image on the screen or object, or the imaging lens 330 forms a virtual image in the air or in the virtual image plane.

In other embodiments, the PBS 320 can also be replaced with a reflective polarizer. Additionally, in other embodiments, illumination system 340 can provide a linearly polarized beam having a polarization direction parallel to side S1 of display area A.

In summary, in the active matrix structure and the liquid crystal display panel according to the embodiment of the present invention, since each of the pixel electrodes has at least one oblique side inclined with respect to all sides of the display area, the pixel The fringe field effect of the electrode is compensated. As a result, the fringe field problem of the pixel electrode is reduced.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any one of ordinary skill in the art can make some changes and refinements without departing from the spirit and scope of the present invention. The scope of the invention is defined by the scope of the appended claims.

230‧‧‧ pixel electrodes

231‧‧‧Bevel

291‧‧‧Filter area

292‧‧‧Red filter area

294‧‧‧Green filter area

296‧‧‧Blue filter area

R‧‧‧Orientation

Claims (20)

An active matrix structure comprising: a substrate; a plurality of active elements disposed on the substrate; and a plurality of pixel electrodes electrically connected to the plurality of active elements and arranged in an array, wherein the active matrix structure has a display area, and each of the plurality of pixel electrodes has at least one oblique side that is inclined with respect to all sides of the display area. The active matrix structure of claim 1, wherein each of the plurality of pixel electrodes has a concave polygonal shape. The active matrix structure of claim 1, wherein each of the plurality of pixel electrodes has a polygonal shape, and the polygon has more than four sides. The active matrix structure according to claim 1, wherein the display area is rectangular, and at least two sides of the display area are substantially parallel to an arrangement direction of the plurality of pixel electrodes. The active matrix structure according to claim 1, wherein the oblique side has a plurality of inclination angles respectively with respect to the side of the display area, and a minimum of the inclination angles is less than or equal to 10 degree. The active matrix structure according to claim 1, further comprising a color filter layer disposed on the plurality of pixel electrodes, the color filter layer comprising a plurality of sets of filters having different colors a region in which the plurality of sets of filter regions are Each of the filter regions respectively corresponds to one of the plurality of pixel electrodes, and the shape of the filter region in the plurality of filter regions conforms to the plurality of pixels The fringe field distribution range of the corresponding pixel electrode in the electrode. The active matrix structure according to claim 1, further comprising a color filter layer disposed on the plurality of pixel electrodes, the color filter layer comprising a plurality of sets of filters having different colors a region, wherein each of the plurality of sets of filter regions respectively corresponds to one of the plurality of pixel electrodes, and corresponds to the plurality of sets of filters having different colors The plurality of pixel electrodes of the region have different sizes. The active matrix structure of claim 1, wherein a gap between any two adjacent pixel electrodes of the plurality of pixel electrodes has a width ranging from 0.2 micrometers to 0.35 micrometers. The active matrix structure of claim 1, further comprising a reflective layer disposed between the substrate and the plurality of pixel electrodes, wherein a surface of the reflective layer facing away from the substrate The distance between the surfaces of each of the plurality of pixel electrodes facing away from the substrate is in the range of 0.18 micrometers to 0.22 micrometers. The active matrix structure according to claim 1, wherein the substrate is a germanium substrate, and the plurality of pixel electrodes are reflective electrodes. A liquid crystal display panel comprising: an active matrix structure, comprising: a substrate; a plurality of active elements disposed on the substrate; and a plurality of pixel electrodes electrically connected to the plurality of active elements and arranged in an array, wherein the active matrix structure has a display area, and the plurality of pictures Each of the element electrodes has at least one oblique side inclined with respect to all sides of the display area; an opposite substrate comprising: a transparent substrate; and a transparent conductive layer disposed on the transparent substrate and located at the An active matrix structure and the transparent substrate; and a liquid crystal layer disposed between the active matrix structure and the opposite substrate. The liquid crystal display panel of claim 11, wherein each of the plurality of pixel electrodes has a concave polygonal shape. The liquid crystal display panel of claim 11, wherein each of the plurality of pixel electrodes has a polygonal shape, and the polygon has more than four sides. The liquid crystal display panel of claim 11, wherein the display area is rectangular, and at least two sides of the display area are substantially parallel to an arrangement direction of the plurality of pixel electrodes. The liquid crystal display panel of claim 11, wherein the oblique side has a plurality of inclination angles with respect to the side of the display area, and a minimum of the inclination angles is less than or equal to 10 degree. The liquid crystal display panel of claim 11, wherein the The active matrix structure further includes a color filter layer disposed on the plurality of pixel electrodes, the color filter layer including a plurality of sets of filter regions having different colors, wherein the plurality of sets of filter regions are Each of the filter regions respectively corresponds to one of the plurality of pixel electrodes, and the shape of the filter region in the plurality of filter regions conforms to the plurality of pixels The fringe field distribution range of the corresponding pixel electrode in the electrode. The liquid crystal display panel of claim 11, wherein the active matrix structure further comprises a color filter layer disposed on the plurality of pixel electrodes, the color filter layer comprising different colors a plurality of sets of filter regions, each of the plurality of sets of filter regions respectively corresponding to one of the plurality of pixel electrodes, and corresponding to the one having a different color The plurality of pixel electrodes of the plurality of sets of filter regions have different sizes. The liquid crystal display panel of claim 11, wherein a gap between any two adjacent pixel electrodes of the plurality of pixel electrodes has a width ranging from 0.2 μm to 0.35 μm. The liquid crystal display panel of claim 11, wherein the active matrix structure further comprises a reflective layer disposed between the substrate and the pixel electrode, and wherein the The distance between the surface of the reflective layer and the surface of each of the plurality of pixel electrodes facing away from the substrate is in the range of 0.18 micrometers to 0.22 micrometers. The liquid crystal display panel of claim 11, wherein the substrate is a germanium substrate, and the pixel electrode is a reflective electrode.