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US 9,310,641 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.
Claims30
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 backlight unit comprising a first diode and a lamp reflector,
- wherein the lamp reflector is provided in the backlight unit at an opposite side of the display element,
- wherein the first polarizing plate and the second polarizing plate are stacked outside the first light-transmitting substrate,
- wherein the third polarizing plate is outside the second light-transmitting substrate,
- wherein the backlight unit is provided outside the third polarizing plate,
- wherein the first transmission axis is displaced so as to be parallel to a minor-axis direction of an ellipse of elliptically-polarized light passing through the display element, and
- wherein the first transmission axis and the second transmission axis are in a parallel nicol state.
10 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;
- and
- a backlight unit comprising a first diode and a lamp reflector,
- wherein the lamp reflector is provided in the backlight unit at an opposite side of the display element,
- 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 backlight unit is provided outside the third polarizing plate and the fourth polarizing plate,
- wherein the first transmission axis is displaced so as to be parallel to a minor-axis direction of an ellipse of elliptically-polarized light passing through the display element,
- wherein the first transmission axis and the second transmission axis are in a parallel nicol state, and
- wherein the third transmission axis and the fourth transmission axis are in a parallel nicol state.
11 more elements
A liquid crystal 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,
- wherein the display element comprises a first electrode and a second electrode over the second light-transmitting substrate, and a layer having liquid crystal molecules over the first electrode and the second electrode,
- wherein the first polarizing plate and the second polarizing plate are stacked outside the first light-transmitting substrate,
- wherein the third polarizing plate is outside the second light-transmitting substrate,
- wherein the first transmission axis is displaced so as to be parallel to a minor-axis direction of an ellipse of elliptically-polarized light passing through the display element,
- wherein the first transmission axis and the second transmission axis are in a parallel nicol state, and
- wherein the first electrode and the second electrode are configured to control the liquid crystal molecules by a horizontal electric field generated from a voltage between the first electrode and the second electrode so that the liquid crystal molecules are twisted in a plane parallel to the second electrode.
9 more elements
A liquid crystal 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;
- wherein the display element comprises a first electrode and a second electrode over the second light-transmitting substrate, and a layer having liquid crystal molecules over the first electrode and the second electrode,
- 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 first transmission axis is displaced so as to be parallel to a minor-axis direction of an ellipse of elliptically-polarized light passing through the display element,
- wherein the first transmission axis and the second transmission axis are in a parallel nicol state,
- wherein the third transmission axis and the fourth transmission axis are in a parallel nicol state, and
- wherein the first electrode and the second electrode are configured to control the liquid crystal molecules by a horizontal electric field generated from a voltage between the first electrode and the second electrode so that the liquid crystal molecules are twisted in a plane parallel to the second electrode.
10 more elements
Dependencies are inferred from the claim text.