Flat display device

DETAILED DESCRIPTION OF THE INVENTION Semitransmission liquid crystal display devices according to preferred embodiments of the present invention will now be described with reference to the accompanying drawing.
The basic structure of a liquid crystal display device 10 of this embodiment will be described below.
As shown in FIGS.
1 to 4A, the liquid crystal display device 10 has a polarization plate 11, .
lambda.
/4 plate 12, color filter layer 50, vertical alignment liquid crystal layer 15, cholesteric liquid crystal layer 18, and back-surface light source 21, all of which are arranged in this order from the observation side.
The liquid crystal layer 15 serves as an optical phase modulation layer, and the liquid crystal layer 18 serves as a selective reflecting layer upon polymerizing the cholesteric liquid crystal.
The liquid crystal display device 10 has a display element formed by sandwiching the liquid crystal layer 15 between two opposing glass substrates 13 and 14.
The .
lambda.
/4 plate 12 and polarization plate 11 are stacked in this order on the observation side of the display element, i.
e.
, the outer surface of the glass substrate 13.
A .
lambda.
/4 plate 25, a polarization plate 26, and the back-surface light source 21 are formed in this order to oppose the outer surface of the other glass substrate 14.
The plate 12 serves as a fixed retarder layer, while the liquid crystal layer 15 serves as a variable retarder layer.
The fixed and variable retarder layers construct a variable retarder.
The glass substrate 13 on the observation side of the liquid crystal element constructs an array substrate.
A color filter layer 50 is formed on the inner surface of the glass substrate 13.
A large number of pixel electrodes 16 made of transparent ITO form a matrix on the color filter layer.
Signal lines 32 and scanning lines 34 including gate electrodes 33 form a matrix on the glass substrate 13.
Auxiliary capacitance electrodes (not shown) are formed, as needed.
Thin film transistors (to be referred to as TFTs hereinafter) 31 serving as switching elements are formed at the intersections between the signal lines 32 and scanning lines 34