Daylight readable liquid crystal display
First Claim
1. A display that is daylight readable in ambient light, external to the display exceeding about 5,000 foot candles of incident illumination, including:
- (a) a backlight source for providing initial transmitted light;
(b) a display element adjacent the backlight source for modulating the initial transmitted light to display images; and
(c) a front filter adjacent the display element and having the characteristics of;
(1) absorbing at least about 30% of incident ambient light;
(2) reflecting less than about 2% of incident ambient light;
(3) transmitting the modulated initial transmitted light as output light;
wherein the combination of backlight source, display element, and filter provide a ratio of output light to reflected incident ambient light of at least about 5;
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2 Assignments
0 Petitions
Accused Products
Abstract
A daylight readable LCD which may be used to communicate information as high contrast images (static or dynamic, color or monochrome) in bright ambient lighting conditions over a wide temperature range in direct sunlight. A contrast enhancement filter assembly is disposed at the interface between a backlit display and a user. The contrast enhancement filter assembly includes a triple bandpass contrast enhancement filter that preferably passes light efficiently in each of the red, green, and blue primary wavelengths and substantially absorbs all other wavelengths. Display contrast is increased because of the absorption of incident light having wavelengths that differ from the light produced by the internal backlight source within the display. This results in the display having a blacker background and enhanced purity of the color primaries. The display element is disposed generally behind the contrast enhancement filter assembly. An air gap separation is preferably provided between the contrast enhancement filter assembly and the display element to allow a heat conducting medium to flow therebetween to control thermal loading of the display. A fluorescent backlight assembly provides at least about 5,000 fL of illumination. An air gap separation is preferably provided between the display element and the backlight to allow a heat conducting medium to flow therebetween to control thermal loading of the display. The ratio of output light to reflected incident ambient light is at least about 5:1.
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Citations
31 Claims
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1. A display that is daylight readable in ambient light, external to the display exceeding about 5,000 foot candles of incident illumination, including:
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(a) a backlight source for providing initial transmitted light; (b) a display element adjacent the backlight source for modulating the initial transmitted light to display images; and (c) a front filter adjacent the display element and having the characteristics of; (1) absorbing at least about 30% of incident ambient light; (2) reflecting less than about 2% of incident ambient light; (3) transmitting the modulated initial transmitted light as output light; wherein the combination of backlight source, display element, and filter provide a ratio of output light to reflected incident ambient light of at least about 5;
1. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 31)
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16. A daylight readable display for use in bright ambient light comprising:
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(a) a back light source for providing initial transmitted light, (b) a display element adjacent the backlight source for modulating the initial transmitted light to display images; (c) a selective-pass front filter in front of the display element having a characteristic of transmitting the modulated initial transmitted light from the display element and selectively filtering incident ambient light; and (d) a thermal conduction medium disposed between said front filter and the display element to reduce heating of the display element by the incident ambient light wherein the combination of backlight source, display element, and filter provide a ratio of output light to reflected incident ambient light of at least about 5;
1. - View Dependent Claims (17, 18, 19, 20, 21, 22, 24, 25, 26)
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23. A daylight readable display for use in bright ambient light comprising:
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(a) a backlight source for providing initial transmitted light; (b) a display element adjacent the backlight source for modulating the initial transmitted light to display images; (c) a selective-pass front filter in front of the display element, having characteristics of; (1) absorbing heat energy in a solar radiant spectrum of incident ambient light; (2) transmitting the modulated initial transmitted light from the display element; (3) selectively filtering the incident ambient light; and (d) a thermal conduction medium disposed between said display element and said front filter to reduce heating of the display element by the absorbed heat energy; wherein the combination of backlight source, display element, and filter provide a ratio of output light to reflected incident ambient light of at least about 5;
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27. A display that is daylight readable in ambient light, external to the display, exceeding about 5,000 foot-candles of incident illumination, including:
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(a) a backlight source for providing initial transmitted light; (b) a display element adjacent the backlight source for modulating the initial transmitted light to display images; and (c) a front filter adjacent the display element and having the characteristics of; (1) absorbing at least about 50% of incident ambient light; (2) reflecting less than about 0.3% of incident ambient light; (3) transmitting the modulated initial transmitted light as output light; wherein the combination of backlight source, display element, and filter provide a ratio of output light to reflected incident ambient light of at least about 5;
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28. A display that is daylight readable in ambient light external to the display exceeding about 5,000 foot-candles of incident illumination, including:
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(a) a fluorescent backlight source for providing initial transmitted light of at least about 5,000 fL; (b) a display element adjacent the backlight source for modulating the initial transmitted light to display images, the display element including; (1) a first polarizer for polarizing light; (2) a liquid crystal cell adjacent the first polarizer for selectively altering the orientation of the E-field of incident light polarized by the first polarizer; and (3) a second polarizer adjacent the liquid crystal cell for polarizing light altered by the liquid crystal cell; (c) a homogenous composition triple-pass front filter adjacent the display element and having the characteristics of; (1) absorbing at least about 50% of incident ambient light; (2) reflecting less than about 0.3% of incident ambient light; (3) transmitting the modulated initial transmitted light as output light; wherein the combination of backlight source, display element, and filter provide a ratio of output light to reflected incident ambient light of at least about 5;
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29. A method of displaying daylight readable images in ambient light, external to the display exceeding about 5,000 foot candles of incident illumination, including the steps of:
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(a) providing a backlight source for generating initial transmitted light; (b) providing a display element adjacent the backlight source for modulating the initial transmitted light to display images; and (c) providing a front filter adjacent the display element and having the characteristics of; (1) absorbing at least about 30% of incident ambient light; (2) reflecting less than about 2% of incident ambient light; (3) transmitting the modulated initial transmitted light as output light; wherein the combination of backlight source, display element, and filter provide a ratio of output light to reflected incident ambient light of at least about 5;
1. - View Dependent Claims (30)
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Specification