BACKLIGHT RECIRCULATION IN TRANSFLECTIVE LIQUID CRYSTAL DISPLAYS
Techniques are provided to recycle light from a backlight unit that is otherwise blocked in a reflective part of a pixel in a transflective LCD. The light is redirected into a transmissive part of the pixel and hence enhances light efficiency and luminance of the pixel. The techniques can be used in a transflective LCD that transmits light in a circularly polarized state, or a linearly polarized state.
1 . A transflective liquid crystal display comprising a plurality of pixels, each pixel comprising:
a first polarizing layer;
a second polarizing layer;
a first substrate layer and a second substrate layer opposite to the first substrate layer, wherein the first substrate layer and the second substrate layer are between the first polarizing layer and the second polarizing layer;
a liquid crystal material between the first substrate layer and the second substrate layer;
an over-coating layer adjacent to the first substrate layer, wherein the over-coating layer comprises at least one opening that forms in part a transmissive part and wherein a remainder of the over-coating layer forms in part a reflective part;
a first reflective layer adjacent to the first substrate layer, wherein the first reflective layer covers at least a portion of the reflective part; and
a second reflective layer between the over-coating layer and the second substrate layer, wherein the second reflective layer substantially covers the reflective part;
wherein the first reflective layer is between the second reflective layer and the first substrate layer.
2 . The transflective liquid crystal display according to claim 1 , wherein the first polarizing layer and the second polarizing layer are linear polarizers.
3 . The transflective liquid crystal display according to claim 1 , wherein the first polarizing layer and the second polarizing layer are circular polarizers.
4 . The transflective liquid crystal display according to claim 1 , wherein the over-coating layer is a scattering and diffusive over-coating layer.
5 . The transflective liquid crystal display according to claim 1 , wherein the over-coating layer is a phase tuning film.
6 . The transflective liquid crystal display according to claim 1 , further comprising a light source that directs light through the at least one opening in the over-coating layer; wherein the first polarizing layer is adjacent to an outer surface of the first substrate layer, and wherein the pixel comprises a polarization recycling film between the light source and the first polarizing layer.
7 . The transflective liquid crystal display according to claim 6 , wherein the pixel comprises a light redirecting film between the light source and the first polarizing layer.
8 . The transflective liquid crystal display according to claim 7 , wherein the light redirecting film covers both some of the transmissive part and some of the reflective part.
9 . The transflective liquid crystal display according to claim 7 , wherein the light redirecting film only covers an area of the reflective part.
10 . The transflective liquid crystal display according to claim 1 , further comprising a first electrode layer adjacent to the first substrate layer.
11 . The transflective liquid crystal display according to claim 9 , wherein the first electrode layer is an oxide layer.
12 . The transflective liquid crystal display according to claim 1 , wherein the pixel comprises a switching element that is configured to determine an intensity of light transmitting through the transmissive part.
13 . The transflective liquid crystal display according to claim 12 , wherein the switching element further comprises a Transistor-Transistor-Logic interface.
14 . The transflective liquid crystal display according to claim 1 , wherein the transmissive part is covered by a color filter.
15 . The transflective liquid crystal display according to claim 1 , wherein the pixel further comprises a third reflective layer between the first substrate layer and the second substrate layer, wherein the third reflective layer covers a portion of an area of the pixel.
16 . A computer, comprising:
one or more processors;
a transflective liquid crystal display coupled to the one or more processors and comprising a plurality of pixels, a pixel comprising:
a first polarizing layer;
a second polarizing layer;
a first substrate layer and a second substrate layer opposite to the first substrate layer, wherein the first substrate layer and the second substrate layer are between the first polarizing layer and the second polarizing layer;
a liquid crystal material between the first substrate layer and the second substrate layer;
an over-coating layer adjacent to the first substrate layer, wherein the over-coating layer comprises at least one opening that forms in part a transmissive part and wherein a remainder of the over-coating layer forms in part a reflective part;
a first reflective layer adjacent to the first substrate layer, wherein the first reflective layer covers at least a portion of the reflective part; and
a second reflective layer between the over-coating layer and the second substrate layer, wherein the second reflective layer substantially covers the reflective part;
wherein the first reflective layer is between the second reflective layer and the first substrate layer.
17 . The computer according to claim 16 , wherein the first polarizing layer and the second polarizing layer are linear polarizers.
18 . The computer according to claim 16 , wherein the first polarizing layer and the second polarizing layer are circular polarizers.
19 . The computer according to claim 16 , wherein the over-coating layer is a scattering and diffusive over-coating layer.
20 . The computer according to claim 16 , wherein the over-coating layer is a phase tuning film.
21 . The computer according to claim 16 , further comprising a light source that directs light through the at least one opening in the over-coating layer; wherein the first polarizing layer is adjacent to an outer surface of the first substrate layer, and wherein the pixel comprises a polarization recycling film between the light source and the first polarizing layer.
22 . The computer according to claim 21 , wherein the pixel comprises a light redirecting film between the light source and the first polarizing layer.
23 . The computer according to claim 16 , wherein the pixel comprises a switching element that is configured to determine an intensity of light transmitting through the transmissive part.
24 . The computer according to claim 16 , wherein the pixel further comprises a third reflective layer between the first substrate layer and the second substrate layer, wherein the third reflective layer covers a portion of an area of the pixel.
25 . A method of fabricating a transflective liquid crystal display, comprising:
providing a plurality of pixels, a pixel comprising:
a first polarizing layer;
a second polarizing layer;
a first substrate layer and a second substrate layer opposite to the first substrate layer, wherein the first substrate layer and the second substrate layer are between the first polarizing layer and the second polarizing layer;
a liquid crystal material between the first substrate layer and the second substrate layer;
an over-coating layer adjacent to the first substrate layer, wherein the over-coating layer comprises at least one opening that forms in part a transmissive part and wherein a remainder of the over-coating layer forms in part a reflective part;
a first reflective layer adjacent to the first substrate layer, wherein the first reflective layer covers at least a portion of the reflective part; and
a second reflective layer between the over-coating layer and the second substrate layer, wherein the second reflective layer substantially covers the reflective part;
wherein the first reflective layer is between the second reflective layer and the first substrate layer.
26 . The method according to claim 25 , wherein the first polarizing layer and the second polarizing layer are linear polarizers.
27 . The method according to claim 25 , wherein the first polarizing layer and the second polarizing layer are circular polarizers.
28 . The method according to claim 25 , wherein the over-coating layer is a scattering and diffusive type.
29 . The method according to claim 25 , wherein the over-coating layer is a film with a phase tuning function.
30 . The method according to claim 25 , further comprising providing a light source that provides light through the at least one opening in the over-coating layer; wherein the first polarizing layer is adjacent to an outer surface of the first substrate layer, and wherein the pixel comprises a polarization recycling film between the light source and the first polarizing layer.
31 . The method according to claim 30 , wherein the pixel comprises a light redirecting film between the light source and the first polarizing layer.
32 . The method according to claim 25 , wherein the pixel comprises a switching element that is configured to determine an intensity of light transmitting through the transmissive part.
33 . The method according to claim 25 , wherein the pixel further comprises a third reflective layer between the first substrate layer and the second substrate layer, wherein the third reflective layer covers a portion of an area of the pixel.