Optical compensator for improved gray scale performance in liquid crystal display
First Claim
1. A liquid crystal display for viewing at various angles with respect to a normal axis perpendicular to the display, comprising:
- a polarizer layer having an absorbing axis;
an analyzer layer having an absorbing axis substantially perpendicular to the absorbing axis of the polarizer layer;
a liquid crystal layer disposed between the polarizer layer and the analyzer layer and having a director exhibiting an azimuthal twist through the layer with respect to the normal axis;
a first electrode proximate to a first major surface of the liquid crystal layer;
a second electrode proximate to a second major surface of the liquid crystal layer, the first and second electrodes being adapted to apply a voltage across the liquid crystal layer when the electrodes are connected to a source of electrical potential; and
a compensator, including a positively birefringent O-plate compensator layer disposed between the polarizer layer and the analyzer layer with its principal symmetry axis oriented at a substantially oblique angle of between 25 and 65 degrees with respect to the normal axis.
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Accused Products
Abstract
A liquid crystal display for viewing at various angles with respect to a normal axis perpendicular to the display includes a polarizer layer having an absorbing axis, an analyzer layer having an absorbing axis substantially perpendicular to the absorbing axis of the polarizer layer, a liquid crystal layer disposed between the polarizer layer and the analyzer layer and having a director exhibiting an azimuthal twist through the layer with respect to the normal axis, a first electrode proximate to a first major surface of the liquid crystal layer, a second electrode proximate to a second major surface of the liquid crystal layer, the first and second electrodes being adapted to apply a voltage across the liquid crystal layer when the electrodes are connected to a source of electrical potential, and a compensator, including a positively birefringent O-plate compensator layer disposed between the polarizer layer and the analyzer layer with its principal symmetry axis oriented at a substantially oblique angle with respect to the normal axis.
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Citations
12 Claims
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1. A liquid crystal display for viewing at various angles with respect to a normal axis perpendicular to the display, comprising:
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a polarizer layer having an absorbing axis; an analyzer layer having an absorbing axis substantially perpendicular to the absorbing axis of the polarizer layer; a liquid crystal layer disposed between the polarizer layer and the analyzer layer and having a director exhibiting an azimuthal twist through the layer with respect to the normal axis; a first electrode proximate to a first major surface of the liquid crystal layer; a second electrode proximate to a second major surface of the liquid crystal layer, the first and second electrodes being adapted to apply a voltage across the liquid crystal layer when the electrodes are connected to a source of electrical potential; and a compensator, including a positively birefringent O-plate compensator layer disposed between the polarizer layer and the analyzer layer with its principal symmetry axis oriented at a substantially oblique angle of between 25 and 65 degrees with respect to the normal axis. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A liquid crystal display for viewing at various angles with respect to a normal axis perpendicular to the display, comprising:
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a polarizer layer having an absorbing axis; an analyzer layer having an absorbing axis substantially perpendicular to the absorbing axis of the polarizer layer; a liquid crystal layer disposed between the polarizer layer and the analyzer layer and having a director exhibiting an azimuthal twist through the layer with respect to the normal axis; a first electrode proximate to a first major surface of the liquid crystal layer; a second electrode proximate to a second major surface of the liquid crystal layer, the first and second electrodes being adapted to apply a voltage across the liquid crystal layer when the electrodes are connected to a source of electrical potential; and a compensator, including; a positively birefringent O-plate compensator layer disposed between the polarizer layer and the analyzer layer with its optic axis oriented at a substantially oblique angle of between 25 and 65 degrees with respect to the normal axis; and a positively birefringent A-plate compensator layer disposed between the liquid crystal layer and the O-plate layer, the A-plate layer being oriented with its optic axis relative to the optic axis of the O-plate layer such that retardation of light passing through the compensator at normal incidence is minimized.
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8. A liquid crystal display for viewing at various angles with respect to a normal axis perpendicular to the display, comprising:
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a polarizer layer having an absorbing axis; an analyzer layer having an absorbing axis substantially perpendicular to the absorbing axis of the polarizer layer; a liquid crystal layer disposed between the polarizer layer and the analyzer layer and having a director exhibiting an azimuthal twist through the layer with respect to the normal axis; a first electrode proximate to a first major surface of the liquid crystal layer; a second electrode proximate to a second major surface of the liquid crystal layer, the first and second electrodes being adapted to apply a voltage across the liquid crystal layer when the electrodes are connected to a source of electrical potential; and a compensator, including; a positively birefringent O-plate compensator layer disposed between the polarizer layer and the liquid crystal layer with its optic axis oriented at a substantially oblique angle of between 25 and 65 degrees with respect to the normal axis; a first positively birefringent A-plate compensator layer disposed between the polarizer layer and the O-plate layer; and a second positively birefringent A-plate compensator layer disposed between the O-plate layer and the liquid crystal layer, the first and second A-plate layers being oriented with their optic axes relative to the optic axis of the O-plate layer such that retardation of light passing through the compensator at normal incidence is minimized.
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9. A liquid crystal display for viewing at various angles with respect to a normal axis perpendicular to the display, comprising:
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a polarizer layer having an absorbing axis; an analyzer layer having an absorbing axis substantially perpendicular to the absorbing axis of the polarizer layer; a liquid crystal layer disposed between the polarizer layer and the analyzer layer and having a director exhibiting an azimuthal twist through the layer with respect to the normal axis; a first electrode proximate to a first major surface of the liquid crystal layer; a second electrode proximate to a second major surface of the liquid crystal layer, the first and second electrodes being adapted to apply a voltage across the liquid crystal layer when the electrodes are connected to a source of electrical potential; and a compensator, including; a positively birefringent O-plate compensator layer disposed between the polarizer layer and the liquid crystal layer with its optic axis oriented at a substantially oblique angle of between 25 and 65 degrees with respect to the normal axis; a first positively birefringent A-plate compensator layer disposed between the O-plate layer and the liquid crystal layer; and a second positively birefringent A-plate compensator layer disposed between the liquid crystal layer and the analyzer layer, the first and second A-plate layers being oriented with their optic axes relative to the optic axis of the O-plate layer such that retardation of light passing through the compensator at normal incidence is minimized.
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10. A liquid crystal display for viewing at various angles with respect to a normal axis perpendicular to the display, comprising:
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a polarizer layer having an absorbing axis; an analyzer layer having an absorbing axis substantially perpendicular to the absorbing axis of the polarizer layer; a liquid crystal layer disposed between the polarizer layer and the analyzer layer and having a director exhibiting an azimuthal twist through the layer with respect to the normal axis; a first electrode proximate to a first major surface of the liquid crystal layer; a second electrode proximate to a second major surface of the liquid crystal layer, the first and second electrodes being adapted to apply a voltage across the liquid crystal layer when the electrodes are connected to a source of electrical potential; and a compensator, including; a positively birefringent O-plate compensator layer disposed between the polarizer layer and the liquid crystal layer with its optic axis oriented at a substantially oblique angle with respect to the normal axis; a positively birefringent A-plate compensator layer disposed between the O-plate layer and the liquid crystal layer, the A-plate layer being oriented with its optic axis relative to the optic axis of the O-plate layer such that retardation of light passing through the compensator at normal incidence is minimized; and a negatively birefringent C-plate compensator layer disposed between the A-plate layer and the liquid crystal layer.
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11. A liquid crystal display for viewing at various angles with respect to a normal axis perpendicular to the display, comprising:
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a polarizer layer having an absorbing axis; an analyzer layer having an absorbing axis substantially perpendicular to the absorbing axis of the polarizer layer; a liquid crystal layer disposed between the polarizer layer and the analyzer layer and having a director exhibiting an azimuthal twist through the layer with respect to the normal axis; a first electrode proximate to a first major surface of the liquid crystal layer; a second electrode proximate to a second major surface of the liquid crystal layer, the first and second electrodes being adapted to apply a voltage across the liquid crystal layer when the electrodes are connected to a source of electrical potential; and a compensator, including; a first positively birefringent O-plate compensator layer disposed between the polarizer layer and the liquid crystal layer with its optic axis oriented at a substantially oblique angle with respect to the normal axis; a second positively birefringent O-plate compensator layer disposed between the first O-plate layer and the liquid crystal layer, with its optical axis oriented at a substantially oblique angle with respect to the normal axis and such that the azimuth angles of the first and second O-plate layers are crossed; a first positively birefringent A-plate compensator layer disposed between the polarizer layer and the first O-plate layer; and a second positively birefringent A-plate compensator layer disposed between the second O-plate layer and the liquid crystal layer, the first and second A-plate layers being oriented with their optic axes relative to the optic axis of the O-plate compensator layer such that retardation of light passing through the compensator at normal incidence is minimized.
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12. A liquid crystal display for viewing at various angles with respect to a normal axis perpendicular to the display, comprising:
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a polarizer layer having an absorbing axis; an analyzer layer having an absorbing axis substantially perpendicular to the absorbing axis of the polarizer layer; a liquid crystal layer disposed between the polarizer layer and the analyzer layer and having a director exhibiting an azimuthal twist through the layer with respect to the normal axis; a first electrode proximate to a first major surface of the liquid crystal layer; a second electrode proximate to a second major surface of the liquid crystal layer, the first and second electrodes being adapted to apply a voltage across the liquid crystal layer when the electrodes are connected to a source of electrical potential; and a compensator, including; a first positively birefringent O-plate compensator layer disposed between the polarizer layer and the liquid crystal layer with its optic axis oriented at a substantially oblique angle with respect to the normal axis; a second positively birefringent O-plate compensator layer disposed between the liquid crystal layer and the analyzer layer with its optic axis oriented at a substantially oblique angle with respect to the normal axis; a positively birefringent A-plate compensator layer disposed between the polarizer layer and the first O-plate layer, the A-plate layer being oriented with its optic axis relative to the optic axis of the first O-plate layer such that retardation of light passing through the compensator at normal incidence is minimized; and a first negatively birefringent C-plate compensator layer disposed between the first O-plate layer and the liquid crystal layer; and a second negatively birefringent C-plate compensator layer disposed between the liquid crystal layer and the second O-plate layer.
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Specification