Method for driving a multi-layered-type liquid crystal display device

Claim 1

A method for driving a multi-layered-type liquid crystal display device which includes stacked plural cell layers, each plural cell layer containing liquid crystal molecules twisted between two transparent substrates so as to have a large birefringence Δn x , a thickness d x , a twist angle θ x , wherein x, for birefringence, thickness and twist angle, is an integer corresponding to the cell layer, and having a varying light transmittance varying responsive to a voltage applied thereto, said method comprising the steps of: determining voltages to be applied to each of the plural cell layers so as to vary the light transmittances of the individual cell layers to pass a predetermined color light, and driving each of the plural cell layers by applying said determined voltages to corresponding ones of each of the plural cell layers to display an image having the predetermined color light on the liquid crystal display device due to the transmittance of each of the plural cell layers varying responsive to the determined voltages applied thereto.

Claim 2

A method for driving a multi-layered-type liquid crystal display device which includes stacked plural cell layers, each plural cell layer containing liquid crystal molecules twisted between two transparent substrates so as to have a large birefringence Δn x , a thickness d x , a twist angle θ x , wherein x, for birefringence, thickness and twist angle, is an integer corresponding to the cell layer, and having a varying light transmittance varying responsive to a voltage applied thereto, said method comprising the steps of: determining voltages to be applied to each of the plural cell layers so as to vary the light transmittances of the individual cell layers to pass a predetermined color light, and driving each of the plural cell layers by applying said determined voltages to corresponding ones of each of the plural cell layers to display an image having the predetermined color light on the liquid crystal display device due to the transmittance of each of the plural cell layers varying responsive to the determined voltages applied thereto.

Claim 4

The method as claimed in claims 1 or 2, wherein said liquid crystal display device is a double-layered liquid crystal display device composed of a first and a second cell layer.

Claim 9

The method as claimed in any one of the claims 1 or 2, wherein an absolute value of a product of the birefringence Δn 2 and the thickness d 1 of the first cell layer is set so as to satisfy the following equality:

Claim 12

The method as claimed in any one of the claims 1 or 2, wherein a ratio of a product of the birefringence Δn 2 and the thickness d 2 of the second cell layer to the product of the birefringence Δn 1 and the thickness d 1 of the first cell layer is set as to satisfy the following inequality: 0.8<Δn.sub.2 ·d.sub.2 /Δn.sub.1 ·d.sub.1 <1.5.

Claim 13

The method as claimed in any one of the claims 1 or 2, wherein the twist angle of the first cell layer is set so as to fall within the range of 180° to 360° and the twist angle of the second cell layer is set so as to fall within the range of 150° to 360° and to be different from that of the first cell layer.

Claim 14

The method as claimed in any one of the claims 1 or 2, wherein a ratio of the thickness d of each of the first and second cell layers to a helical pitch p of the liquid crystal therein is set so as to satisfy the following inequality under a condition that a pretilt angle of the liquid crystal thereof is at most 10°: θ/360°-1/4<d/p≦θ/360°, wherein θ is the twist angle of the liquid crystal in each of the first and second cell layers.