Back to results
US 7,804,559 B2Granted
Display device
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorsYuji Egi, Tetsuji Ishitani, Takeshi Nishi
Life of this patent
Estimating the term…
Abstract
A display device with a higher contrast ratio is provided. The display device is provided with stacked polarizing plates arranged displaced from a parallel nicol state. Moreover, in the display device, at least one of a pair of stacked polarizing plates is displaced from a parallel state. The pair of stacked polarizing plates is arranged in a cross nicol state. A retardation plate may be provided between the polarizing plate and the substrate. As a result, the contrast ratio can be increased.
Claims18
A display device comprising:
- a first light-transmitting substrate;
- a second light-transmitting substrate;
- a display element sandwiched between the first light-transmitting substrate and the second light-transmitting substrate;
- a first polarizing plate having a first transmission axis and a second polarizing plate having a second transmission axis;
- and
- a third polarizing plate having a third transmission axis and a fourth polarizing plate having a fourth transmission axis,
- wherein the first polarizing plate and the second polarizing plate are stacked outside the first light-transmitting substrate,
- wherein the third polarizing plate and the fourth polarizing plate are stacked outside the second light-transmitting substrate,
- wherein the second transmission axis is displaced so as to correspond to a minor-axis direction of an ellipse of elliptically-polarized light emitted from the first polarizing plate, and
- wherein the third transmission axis and the fourth transmission axis are in a parallel nicol state.
7 more elements
A display device comprising:
- a first light-transmitting substrate;
- a second light-transmitting substrate;
- a display element sandwiched between the first light-transmitting substrate and the second light-transmitting substrate;
- a first polarizing plate having a first transmission axis and a second polarizing plate having a second transmission axis;
- a third polarizing plate having a third transmission axis and a fourth polarizing plate having a fourth transmission axis;
- a first retardation plate between the first polarizing plate and the first light-transmitting substrate;
- and
- a second retardation plate between the third polarizing plate and the second light-transmitting substrate,
- wherein the first polarizing plate and the second polarizing plate are stacked outside the first light-transmitting substrate,
- wherein the third polarizing plate and the fourth polarizing plate are stacked outside the second light-transmitting substrate,
- wherein the second transmission axis is displaced so as to correspond to a minor-axis direction of an ellipse of elliptically-polarized light emitted from the first polarizing plate, and
- wherein the third transmission axis and the fourth transmission axis are in a parallel nicol state.
9 more elements
Dependencies are inferred from the claim text.