Liquid crystal display device

A liquid crystal display device comprising:

• a liquid crystal cell that includes:
• a pair of transparent substrates which are arranged opposite to each other;
• a liquid crystal layer which is provided between the pair of transparent substrates;
• a common electrode and an alignment film that are sequentially provided on an inner surface of one of the transparent substrates;
• a plurality of switching elements which are provided on an inner surface of the other substrate of the transparent substrates;
• a plurality of pixel electrodes which are connected to the respective switching elements;
• and
• an alignment film that is provided on the switching elements and the pixel electrodes;
• first and second retardation plates and a first polarizing plate that are sequentially formed on an outer surface of the one transparent substrate;
• and
• third and fourth retardation plates and a second polarizing plate that are sequentially formed on an outer surface of the other transparent substrate,
• wherein a plurality of pixel regions corresponding to the pixel electrodes are formed in the liquid crystal cell,
• a portion of each pixel region having a reflective pixel electrode serves as a reflective portion,
• the reflective portion has a reflector that reflects light incident from the other transparent substrate,
• the other portion of each pixel region serves as a transmissive portion that transmits light from the other transparent substrate to the one transparent substrate, and
• optical characteristics of the liquid crystal cell, the first to fourth retardation plates, and the first and second polarizing plates are set so as to the following conditions:
• the direction of an absorption axis c of the first polarizing plate:
• (ψ+15°)−30° to (ψ+15°)+30°;
• a retardation value ΔndRF2 of the second retardation plate:
• 250 nm to 290 nm;
• the direction of a slow axis d of the second retardation plate:
• (ψ−60°)−15° to (ψ−60°)+15°;
• a retardation value ΔndRF1 of the first retardation plate:
• 80 nm to 120 nm;
• the direction of a slow axis e of the first retardation plate:
• (ψ−15°) to (ψ+15°);
• a twist angle φ of the liquid crystal layer:
• 0° to 40°;
• a retardation value ΔndLT of the transmissive portion of the liquid crystal cell which is set to satisfy the following expression 3:
• |ΔndLT−550√{square root over ((½)2+(φ/180)1)}|≦100(nm) [Expression 3]
• a retardation value ΔndLR of the reflective portion of the liquid crystal cell which is set to satisfy the following expression 4:
• |ΔndLR−550√{square root over ((¼)2+(φ/180)2)}|≦40(nm) [Expression 4]
• a retardation value ΔndRF3 of the third retardation plate:
• 80 nm to 120 nm;
• the direction of a slow axis f of the third retardation plate:
• (ψ−15°) to (ψ+15°);
• a retardation value ΔndRF4 of the fourth retardation plate:
• 250 nm to 290 nm;
• the direction of a slow axis g of the fourth retardation plate:
• (ψ+60°)−15° to (ψ+60°)+15°;
• and
• the direction of an absorption axis h of the second polarizing plate:
• (ψ+75°)−30° to (ψ+75°)+30°,
• where, when the alignment direction of the alignment film formed on the one transparent substrate is a direction a, the alignment direction of the alignment film formed on the other transparent substrate is a direction b, and the a direction that divides a narrow angle formed between the directions a and b into two equal angles is a center direction ψ, ψ±N° (N is an integer) indicates the directions of each axis indicates, that is, positive and negative angles N with respect to the center direction ψ,
• ψ−N° indicates an angle rotating on an intersecting point O from the center direction ψ by an angle of N° in the clockwise direction, as viewed from the one transparent substrate, and
• ψ+N° indicates an angle rotating on the intersecting point O from the center direction ψ by an angle of N° in the counter clockwise direction, as viewed from the one transparent substrate.

A liquid crystal display device comprising:

• a liquid crystal cell that includes:
• a pair of transparent substrates which are arranged opposite to each other;
• a liquid crystal layer which is provided between the pair of transparent substrates;
• a common electrode and an alignment film that are sequentially provided on an inner surface of one of the transparent substrates;
• a plurality of switching elements which are provided on an inner surface of the other substrate of the transparent substrates;
• a plurality of pixel electrodes which are connected to the respective switching elements;
• and
• an alignment film that is provided on the switching elements and the pixel electrodes;
• first and second retardation plates and a first polarizing plate that are sequentially formed on an outer surface of the one transparent substrate;
• and
• third and fourth retardation plates and a second polarizing plate that are sequentially formed on an outer surface of the other transparent substrate,
• wherein a plurality of pixel regions corresponding to the pixel electrodes are formed in the liquid crystal cell,
• a portion of each pixel region having a reflective pixel electrode serves as a reflective portion,
• the reflective portion has a reflector that reflects light incident from the other transparent substrate,
• the other portion of each pixel region serves as a transmissive portion that transmits light from the other transparent substrate to the one transparent substrate, and
• optical characteristics of the liquid crystal cell, the first to fourth retardation plates, and the first and second polarizing plates are set so as to the following conditions:
• the direction of an absorption axis c of the first polarizing plate:
• (ψ+75°)−30° to (ψ+75°)+30°;
• a retardation value ΔndRF2 of the second retardation plate:
• 250 nm to 290 nm;
• the direction of a slow axis d of the second retardation plate:
• (ψ+60°)−15° to (ψ+60°)+15°;
• a retardation value ΔndRF1 of the first retardation plate:
• 80 nm to 120 nm;
• the direction of a slow axis e of the first retardation plate:
• (ψ−15°) to (ψ+15°);
• a twist angle φ of the liquid crystal layer:
• 0° to 40°;
• a retardation value ΔndLT of the transmissive portion of the liquid crystal cell which is set to satisfy the following expression 5:
• |ΔndLT−550√{square root over ((½)2+(φ/180)2)}|≦100(nm) [Expression 5]
• a retardation value ΔndLR of the reflective portion of the liquid crystal cell which is set to satisfy the following expression 6:
• |ΔndLR−550√{square root over ((¼)2)}|≦40(nm) [Expression 6]
• a retardation value ΔndRF3 of the third retardation plate:
• 80 nm to 120 nm;
• the direction of a slow axis f of the third retardation plate:
• (ψ−15°) to (ψ+15°);
• a retardation value ΔndRF4 of the fourth retardation plate:
• 250 nm to 290 nm;
• the direction of a slow axis g of the fourth retardation plate:
• (ψ−60°)−15° to (ψ−60°)+15°;
• and
• the direction of an absorption axis h of the second polarizing plate:
• (ψ+15°)−30° to (ψ+15°)+30°,
• where, when the alignment direction of the alignment film formed on the one transparent substrate is a direction a, the alignment direction of the alignment film formed on the other transparent substrate is a direction b, and the a direction that divides a narrow angle formed between the directions a and b into two equal angles is a center direction ψ, ψ±N° (N is an integer) indicates the directions of each axis indicates, that is, positive and negative angles N with respect to the center direction ψ,
• ψ−N° indicates an angle rotating on an intersecting point O from the center direction ψ by an angle of N° in the clockwise direction, as viewed from the one transparent substrate, and
• ψ+N° indicates an angle rotating on the intersecting point O from the center direction ψ by an angle of N° in the counter clockwise direction, as viewed from the one transparent substrate.

A liquid crystal display device comprising:

• a liquid crystal cell that includes:
• a pair of transparent substrates which are arranged opposite to each other;
• a liquid crystal layer which is provided between the pair of transparent substrates;
• a common electrode and an alignment film that are sequentially provided on an inner surface of one of the transparent substrates;
• a plurality of switching elements which are provided on an inner surface of the other substrate of the transparent substrates;
• a plurality of pixel electrodes which are connected to the respective switching elements;
• and
• an alignment film that is provided on the switching elements and the pixel electrodes;
• first and second retardation plates and a first polarizing plate that are sequentially formed on an outer surface of the one transparent substrate;
• and
• third and fourth retardation plates and a second polarizing plate that are sequentially formed on an outer surface of the other transparent substrate,
• wherein a plurality of pixel regions corresponding to the pixel electrodes are formed in the liquid crystal cell,
• a portion of each pixel region having a reflective pixel electrode serves as a reflective portion,
• the reflective portion has a reflector that reflects light incident from the other transparent substrate,
• the other portion of each pixel region serves as a transmissive portion that transmits light from the other transparent substrate to the one transparent substrate, and
• optical characteristics of the liquid crystal cell, the first to fourth retardation plates, and the first and second polarizing plates are set so as to the following conditions:
• the direction of an absorption axis c of the first polarizing plate:
• (ψ−15°)−30° to (ψ−15°)+30°;
• a retardation value ΔndRF2 of the second retardation plate:
• 250 nm to 290 nm;
• the direction of a slow axis d of the second retardation plate:
• (ψ+60°)−15° to (ψ+60°)+15°;
• a retardation value ΔndRF1 of the first retardation plate:
• 80 nm to 120 nm;
• the direction of a slow axis e of the first retardation plate:
• (ψ−15°) to (ψ+15°);
• a twist angle φ of the liquid crystal layer:
• 0° to 40°;
• a retardation value ΔndLT of the transmissive portion of the liquid crystal cell which is set to satisfy the following expression 7:
• |ΔndLT−550√{square root over ((½)2+(φ/180)2)}|≦100(nm) [Expression 7]
• a retardation value ΔndLR of the reflective portion of the liquid crystal cell which is set to satisfy the following expression 8:
• |ΔndLR−550√{square root over ((¼)2+(φ/180)2)}|≦40(nm) [Expression 8]
• a retardation value ΔndRF3 of the third retardation plate:
• 80 nm to 120 nm;
• the direction of a slow axis f of the third retardation plate:
• (ψ−15°) to (ψ+15°);
• a retardation value ΔndRF4 of the fourth retardation plate:
• 250 nm to 290 nm;
• the direction of a slow axis g of the fourth retardation plate:
• (ψ−60°)−15° to (ψ−60°)+15°;
• and
• the direction of an absorption axis h of the second polarizing plate:
• (ψ−75°)−30° to (ψ−75°)+30°,
• where, when the alignment direction of the alignment film formed on the one transparent substrate is a direction a, the alignment direction of the alignment film formed on the other transparent substrate is a direction b, and the a direction that divides a narrow angle formed between the directions a and b into two equal angles is a center direction ψ, ψ±N° (N is an integer) indicates the directions of each axis indicates, that is, positive and negative angles N with respect to the center direction ψ,
• ψ−N° indicates an angle rotating on an intersecting point O from the center direction ψ by an angle of N° in the clockwise direction, as viewed from the one transparent substrate, and
• ψ+N° indicates an angle rotating on the intersecting point O from the center direction ψ by an angle of N° in the counter clockwise direction, as viewed from the one transparent substrate.