DISPLAY BACKLIGHTS WITH ADJUSTABLE NARROW VIEWING ANGLE
First Claim
1. A backlight for a display surface, comprising:
- at least one wide-beam lamp configured to emit light at a wide angle;
at least one narrow-beam lamp configured to emit light at a narrow angle directed toward the display surface;
a light angle selector configured to activate one of the at least one wide-beam lamp and the at least one narrow-beam lamp;
an optical coupler positioned between at least one lamp and the display surface and configured to couple the light with the display surface; and
an optical light guide positioned between at least one lamp and the display surface and configured to distribute the light across the display surface.
2 Assignments
0 Petitions
Accused Products
Abstract
Display components (e.g., liquid crystal displays (LCDs)) are viewable at different viewing angles, such as by a first user positioned directly in front of the display and by a second user positioned to one side of the display. Many displays present a consistent display across a wide range of viewing angles, but these displays may consume energy and/or compromise user privacy. Presented herein are configurations of backlights for display devices featuring an adjustable viewing angle, such that a user may select a narrower viewing angle in usage scenarios involving power consumption or privacy, and may select a wider viewing angle in usage scenarios involving plentiful power and fewer privacy concerns. Such configurations may include multiple banks of backlight lamps generating backlight at different viewing angles; an electrowetting electrode as an adjustable collimator; adjustable diffusers that may adjustably scatter light passing therethrough; and/or a combination of such adjustable elements.
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Citations
20 Claims
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1. A backlight for a display surface, comprising:
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at least one wide-beam lamp configured to emit light at a wide angle; at least one narrow-beam lamp configured to emit light at a narrow angle directed toward the display surface; a light angle selector configured to activate one of the at least one wide-beam lamp and the at least one narrow-beam lamp; an optical coupler positioned between at least one lamp and the display surface and configured to couple the light with the display surface; and an optical light guide positioned between at least one lamp and the display surface and configured to distribute the light across the display surface. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A backlight for a display surface, comprising:
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at least one lamp emitting light; an optical coupler positioned between at least one lamp and the display surface and configured to couple the light with the display surface; an optical light guide positioned between at least one lamp and the display surface and configured to distribute the light across the display surface; and an adjustable collimator positioned between the optical light guide and the display surface and configured to align the light toward the display surface with a collimation angle of the light emitted by the at least one lamp, the collimation angle adjustable between a zero-degree collimation angle and a nonzero-degree collimation angle inversely proportional to a collimation magnitude. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A backlight for a display surface, comprising:
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at least one wide-beam lamp configured to emit light at a wide angle; at least one narrow-beam lamp configured to emit light at a narrow angle directed toward the display surface; at least one first light angle selector configured to activate one of the at least one wide-beam lamp and the at least one narrow-beam lamp; an optical coupler positioned between at least one lamp and the display surface and configured to couple the light with the display surface; an optical light guide positioned between at least one lamp and the display surface and configured to distribute the light across the display surface; an adjustable collimator positioned between the optical light guide and the display surface and configured to align the light toward the display surface with a collimation angle of the light emitted by the at least one lamp, the collimation angle adjustable between a zero-degree collimation angle and a nonzero-degree collimation angle inversely proportional to a collimation magnitude, the adjustable collimator comprising an electrowetting electrode providing an adjustable collimation angle proportional to an electrowetting voltage applied to the electrowetting electrode; a second light angle selector configured to apply to the electrowetting electrode an electrowetting voltage selected from at least three electrowetting voltages respectively producing a collimation angle; an adjustable diffuser positioned between the collimator and the display surface and configured to diffuse the light proportional to a diffuser voltage applied to the adjustable diffuser, the adjustable diffuser selected from a set of adjustable diffusers comprising; a polymer-dispersed liquid crystal, and a polymer-stabilized cholesteric texture; a third light angle selector configured to apply to the adjustable diffuser a diffuser voltage selected from at least three diffuser voltages respectively producing a collimation angle; a forward polarizer positioned between at least one lamp and the display surface and configured to transmit light having a light polarity approximately equal to a desired light polarity, the forward polarizer comprising a reflective forward polarizer configured to reflect backwardly light having a light polarity not approximately equal to a desired light polarity, and the forward polarizer selected from a set of forward polarizers comprising; a wire grid polarizer, and an interference reflector composed of a biaxial film; and a back reflector positioned around at least one lamp and configured to reflect light toward the display surface.
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Specification