Transflective liquid crystal display with particular first and second adjusted thickness and method of fabricating the same
First Claim
Patent Images
1. A transflective liquid crystal display, comprising:
- upper and lower substrates facing into and spaced apart from each other, wherein the upper and lower substrates include a plurality of pixel regions that display images;
a liquid crystal layer interposed between the upper and lower substrates, wherein the liquid crystal layer has a first adjusted thickness to compensate a residual optical retardation of incident light caused by anchored liquid crystals near an alignment layer when a maximum operation voltage is applied;
an upper quarter wave plate (QWP) on the upper substrate, wherein the upper quarter wave plate has a second adjusted thickness to compensate the residual optical retardation caused by the liquid crystal layer when the maximum operation voltage is applied;
an upper polarizer on the upper quarter wave plate;
a transparent common electrode on a surface of the upper substrate facing into the lower substrate;
a pixel electrode over a first surface of the lower substrate, wherein the pixel electrode corresponds to each pixel region, and the pixel electrode is divided into transparent and reflective portions;
a lower quarter wave plate (QWP) on a second surface of the lower substrate;
a lower polarizer below the lower quarter wave plate; and
a backlight device arranged to be adjacent to the lower polarizer, wherein the first adjusted thickness is d+d1, where d is a normal thickness of the liquid crystal layer and d1 is calculated using the following equation. where T is a value of transmittance when a maximum operation voltage is applied, φ
is an angle between an optical axis of the liquid crystal layer and a transmissive axis of the polarizer, Δ
n is a birefringence of the liquid crystal layer.
1 Assignment
0 Petitions
Accused Products
Abstract
The invention relates to a transflective liquid crystal display device that has a high contrast ratio. The transflective liquid crystal panel includes a homogeneous liquid crystal such that the transflective liquid crystal display device will have an optical retardation when the voltage is applied. Therefore, in order to compensate the optical retardation caused by this liquid crystal, a thickness of the liquid crystal layer is adjusted. Moreover, a thickness of the retardation film is also adjusted. Accordingly, the complete dark state and the high contrast ratio are achieved in the liquid crystal display.
80 Citations
14 Claims
-
1. A transflective liquid crystal display, comprising:
-
upper and lower substrates facing into and spaced apart from each other, wherein the upper and lower substrates include a plurality of pixel regions that display images;
a liquid crystal layer interposed between the upper and lower substrates, wherein the liquid crystal layer has a first adjusted thickness to compensate a residual optical retardation of incident light caused by anchored liquid crystals near an alignment layer when a maximum operation voltage is applied;
an upper quarter wave plate (QWP) on the upper substrate, wherein the upper quarter wave plate has a second adjusted thickness to compensate the residual optical retardation caused by the liquid crystal layer when the maximum operation voltage is applied;
an upper polarizer on the upper quarter wave plate;
a transparent common electrode on a surface of the upper substrate facing into the lower substrate;
a pixel electrode over a first surface of the lower substrate, wherein the pixel electrode corresponds to each pixel region, and the pixel electrode is divided into transparent and reflective portions;
a lower quarter wave plate (QWP) on a second surface of the lower substrate;
a lower polarizer below the lower quarter wave plate; and
a backlight device arranged to be adjacent to the lower polarizer, wherein the first adjusted thickness is d+d1, where d is a normal thickness of the liquid crystal layer and d1 is calculated using the following equation. where T is a value of transmittance when a maximum operation voltage is applied, φ
is an angle between an optical axis of the liquid crystal layer and a transmissive axis of the polarizer, Δ
n is a birefringence of the liquid crystal layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A transflective liquid crystal display, comprising:
-
upper and lower substrates facing into and spaced apart from each other, wherein the upper and lower substrates include a plurality of pixel regions that display images;
a liquid crystal layer interposed between the upper and lower substrates, wherein the liquid crystal layer has a first adjusted thickness to compensate a residual optical retardation of incident light caused by anchored liquid crystals near an alignment layer when a maximum operation voltage is applied;
an upper quarter wave plate (QWP) on the upper substrate, wherein the upper quarter wave plate has a second adjusted thickness to compensate the residual optical retardation caused by the liquid crystal layer when the maximum operation voltage is applied;
an upper polarizer on the upper quarter wave plate;
a transparent common electrode on a surface of the upper substrate facing into the lower substrate;
a pixel electrode over a first surface of the lower substrate, wherein the pixel electrode corresponds to each pixel region, and the pixel electrode is divided into transparent and reflective portions;
a lower quarter wave plate (QWP) on a second surface of the lower substrate;
a lower polarizer below the lower quarter wave plate; and
a backlight device arranged to be adjacent to the lower polarizer, wherein the second adjusted thickness of the upper QWP is d+d2, where a normal thickness of the upper QWP is d and d2 is calculated from the following equation, where T is a value of transmittance, φ
is an angle between a slow axis of the upper QWP and a transmissive axis of the polarizer, Δ
n is a birefringence of the upper QWP. - View Dependent Claims (11)
-
-
12. A transflective liquid crystal display, comprising:
-
upper and lower substrates facing into and spaced apart from each other, wherein the upper and lower substrates include a plurality of pixel regions that display images;
an upper quarter wave plate (QWP) on the upper substrate;
an upper polarizer on the upper quarter wave plate;
a lower quarter wave plate (QWP) below the lower substrate;
a lower polarizer below the lower quarter wave plate;
a backlight device arranged to be adjacent to the lower polarizer;
a liquid crystal layer interposed between the upper and lower substrates;
a transparent common electrode on a surface of the upper substrate facing into the lower substrate;
an upper alignment layer between the transparent common electrode and the liquid crystal layer;
a pixel electrode over the lower substrate, wherein the pixel electrode corresponds to each pixel region, and the pixel electrode is divided into transparent and reflective portions; and
a lower alignment layer between the pixel electrode and the liquid crystal layer;
wherein a transmissive axis of the upper polarizer is perpendicular to a transmissive axis of the lower polarizer, a slow axis of the upper QWP is perpendicular to a slow axis of the lower QWP, the slow axis of the upper QWP forms an angle of 45°
with the transmissive axis of the upper polarizer, an optical retardation of the upper QWP is λ
d/4+α
, α
a ranges from zero to 100 nm, and the slow axis of the lower QWP is parallel to an orientation direction of the liquid crystal display layer, and wherein the first adjusted thickness is d+d1, where d is a normal thickness of the liquid crystal layer and d1 is calculated using the following equation.where T is a value of transmittance when a maximum operation voltage is applied, φ
is an angle between an optical axis of the liquid crystal layer and a transmissive axis of the polarizer, Δ
n is a birefringence of the liquid crystal layer. - View Dependent Claims (13, 14)
-
Specification