This Application claims priority of Taiwan Patent Application No. 103128043, filed on Aug. 15, 2014, the entirety of which is incorporated by reference herein.
1. Field of the Invention
The present invention relates to a display panel, and in particular to a display panel with a photo-alignment layer.
2. Description of the Related Art
A conventional display panel includes a TFT (thin-film transistor) substrate, a photo-alignment layer and a liquid crystal. In the conventional photo-alignment process, an alignment layer is pre-formed on the TFT substrate, and aligning masks of different aligning directions respectively cover different areas of the alignment layer. In an exposure step, the photo-alignment layer with two different aligning directions is formed on the TFT substrate. When light passes through each sub-pixel of the TFT substrate, the display panel shows a dark line pattern. The area of the dark line pattern is reduced to be as small as possible to improve the aperture opening ratio of the display panel. Along with reducing the area of the dark line pattern, the transmittance variation of the horizontally rotated display panel is increased. With reference to
In one embodiment, a display panel is provided. The display panel includes a TFT substrate and a photo-alignment layer. The TFT substrate includes a plurality of pixel units, wherein each pixel unit includes a plurality of sub-pixels. The photo-alignment layer is located on the pixel units, wherein the photo-alignment layer has at least two different aligning directions corresponding to each sub-pixel. When light passes through each sub-pixel, the display panel shows a dark line pattern. The dark line pattern includes a first major line and a first minor line. The first major line is located on the boundary between the two different aligning directions in the photo-alignment layer, and extends along a first direction, wherein a central section of the first major line has a first major line width. The first minor line is connected to the first major line, and extends along a second direction, wherein a central section of the first minor line has a first minor line width, the first direction differs from the second direction, and the first major line width is greater than the first minor line width.
In one embodiment, a method for manufacturing a display panel is provided. First, an alignment layer is formed on the pixel units. Then, a first area of the sub-pixel is covered with a first aligning mask, and an exposure process is performed to form a portion of the photo-alignment layer with a first aligning direction. Next, a second area of the sub-pixel is covered with a second aligning mask, and the exposure process is performed to form another portion of the photo-alignment layer with a second aligning direction, wherein a gap is formed between the first area and the second area.
A detailed description is given in the following embodiments with reference to the accompanying drawings.
The present invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:
The following description is of the best-contemplated mode of carrying out the invention. This description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. The scope of the invention is best determined by reference to the appended claims.
With reference to
As shown in shaped
. The dark line pattern 100 further comprises a second major line 121, a second minor line 122, a third major line 131, a third minor line 132, a fourth major line 141 and a fourth minor line 142. The shape of the dark line pattern 100 is related to the aligning directions of the photo-alignment layer 20 and the boundary electric field of ITO (indium tin oxide). In one embodiment, the first major line 111, the second major line 121, the third major line 131 and the fourth major line 141 are connected to the center 101 of the sub-pixel 12 (which is also the center of the dark line pattern 100). At the center 101 of the sub-pixel 12, the tilt of the liquid crystal molecules are disorderly, and a bright-dark whirlpool image is generated. Conventionally, a capacitor 13 of the TFT substrate 10 corresponds to the dark line pattern 100 (such as center of the dark line pattern 100), the bright-dark whirlpool image is therefore covered by the capacitor 13, and the aperture opening ratio is maintained.
An end of the second major line 121 connects to the first major line 111 in the center 101 of the sub-pixel 12. The second major line 121 extends along a direction (−X) opposite to the first direction, and a central section of the second major line 121 has a second major line width d21. The second minor line 122 is connected to the other end of the second major line 121, and extends along a direction (−Y) opposite to the second direction, wherein a central section of the second minor line 122 has a second minor line width d22, and the second major line width d21 is greater than the second minor line width d22. In one embodiment, the second minor line 122 is parallel and adjacent to a second border 152 of the sub-pixel 12. The second border 152 is opposite to the first border 151.
An end of the third major line 131 connects the first major line 111, and the second major line 121 in the center 101 of the sub-pixel 12. The third major line 131 extends along the second direction Y, and a central section of the third major line 131 has a third major line width d31. The third minor line 132 is connected to the other end of the third major line 131, and extends along the direction (−X) opposite to the first direction, wherein a central section of the third minor line 132 has a third minor line width d32, and the third major line width d31 is greater than the third minor line width d32. In one embodiment, the third minor line 132 is parallel and adjacent to a third border 153 of the sub-pixel 12. The third border 153 connects the first border 151 to the second border 152.
An end of the fourth major line 141 connects the first major line 111, the second major line 121 and the third major line 131 in the center 101 of the sub-pixel 12. The fourth major line 141 extends along the direction (−Y) opposite to the second direction, and a central section of the fourth major line 141 has a fourth major line width d41. The fourth minor line 142 is connected to the other end of the fourth major line 141, and extends along the first direction X, wherein a central section of the fourth minor line 142 has a fourth minor line width d42, and the fourth major line width d41 is greater than the fourth minor line width d42. In one embodiment, the fourth minor line 142 is parallel and adjacent to a fourth border 154 of the sub-pixel 12. The fourth border 154 is opposite to the third border 153.
In one embodiment, the first major line width d11, the second major line width d21, the third major line width d31 and the fourth major line width d41 are substantially the same. In one embodiment, the first minor line width d12, the second minor line width d22, the third minor line width d32 and the fourth minor line width d42 are substantially the same.
Conventionally, when the ratio between the major line width and the minor line width is close to 1 (for example, 1.05), the transmittance variation of the horizontally rotated display panel is about 14%, and the front view transmittance is 18%. When the ratio between the major line width and the minor line width is increased (from 1 to 2), the transmittance variation of the horizontally rotated display panel is rapidly dropped to 12% from 14%, and the front view transmittance is dropped to 17% from 18%. When the ratio between the major line width and the minor line width is further increased (from 2 to 5.27), the transmittance variation of the horizontally rotated display panel is slowly dropped to 11.5% from 12%, and the front view transmittance is rapidly dropped to 13.5% from 17%.
When the ratio between the major line width and the minor line width is increased, the major line width is far greater than the minor line width, the aperture opening ratio is decreased, and the front view transmittance is decreased. As shown in
In the embodiment above, by designing the major line width (d11, d21, d31 and d41) of the dark line pattern 100 greater than the minor line width (d12, d22, d32 and d42) of the dark line pattern 100, for example, the ratio between the major line width (d11, d21, d31 and d41) and the minor line width (d12, d22, d32 and d42) being designed between 1 and 2 (preferred between 1.4 and 2), the transmittance variation of the horizontally rotated display panel is effectively improved by slightly sacrificing the front view transmittance.
In one embodiment, the dark line pattern can be formed by the following method. In the manufacturing process of the display panel, the photo-alignment layers are respectively formed on the TFT substrate (between the TFT substrate and the liquid crystal) and the color filter (between the color filter and the liquid crystal). In this embodiment, the photo-alignment layer on the TFT substrate is illustrated for example. With reference to
As mentioned above, by maintaining the ratio between the major line width and the minor line width with in the range between 1 and 2 (preferred between 1.4 and 2), the transmittance variation of the horizontally rotated display panel is effectively improved by slightly sacrificing the front view transmittance.
In one embodiment, by controlling the dark lines respectively, the chromaticity of a white light generated by the display panel can be controlled. With reference to
Utilizing the embodiments of the invention, the transmittance variation of the horizontally rotated display panel is effectively improved, the loss of the aperture opening ratio is reduced, and the chromaticity of the white light generated by the display panel can be modified without additional processing.
Use of ordinal terms such as “first”, “second”, “third”, etc., in the claims to modify a claim element does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed, but are used merely as labels to distinguish one claim element having a certain name from another element having the same name (but for use of the ordinal term).
While the invention has been described by way of example and in terms of the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.
Number | Date | Country | Kind |
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103128043 | Aug 2014 | TW | national |