Direct view LC display
First Claim
Patent Images
1. A display having a first and second direct view modes of operation and comprising:
- a liquid crystal display device;
a backlight disposed behind said display device and arranged, during said first mode, to render an image, displayed by said display device during said first mode, visible throughout an extended viewing region in front of said display device;
a first holographic element; and
a first front light source disposed in front of said display device and said first holographic element and arranged to be actuated during said second mode, said first holographic element being arranged to redirect light from said first front light source into a part of said extended viewing region so that at least one image displayed by said display device during said second mode is visible only in a restricted portion of said extended viewing region,wherein said first holographic element is a holographic optical element arranged to redirect light from said first front light source to said restricted portion, which comprises at least one spatially limited viewing window, and said backlight is arranged to be deactuated during said second mode,the display further comprising a second holographic optical element and a second front light source disposed in front of said display device, said first and second holographic elements being disposed behind said display device and being arranged to redirect light from said first and second front light sources, respectively, to first and second viewing windows, respectively.
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Accused Products
Abstract
A display is provided having first and second direct view modes of operation. The display comprises a liquid crystal display panel and a backlight which is illuminated during the first mode so that the displayed image is visible throughout an extended viewing region in front of the device. The display also comprises a holographic element and a front light source, which is switched on for the second direct view mode. The holographic element redirects light from the front light source into part of the extended viewing region so that an image displayed by the device is visible in only a restricted portion of the viewing region.
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Citations
11 Claims
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1. A display having a first and second direct view modes of operation and comprising:
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a liquid crystal display device; a backlight disposed behind said display device and arranged, during said first mode, to render an image, displayed by said display device during said first mode, visible throughout an extended viewing region in front of said display device; a first holographic element; and a first front light source disposed in front of said display device and said first holographic element and arranged to be actuated during said second mode, said first holographic element being arranged to redirect light from said first front light source into a part of said extended viewing region so that at least one image displayed by said display device during said second mode is visible only in a restricted portion of said extended viewing region, wherein said first holographic element is a holographic optical element arranged to redirect light from said first front light source to said restricted portion, which comprises at least one spatially limited viewing window, and said backlight is arranged to be deactuated during said second mode, the display further comprising a second holographic optical element and a second front light source disposed in front of said display device, said first and second holographic elements being disposed behind said display device and being arranged to redirect light from said first and second front light sources, respectively, to first and second viewing windows, respectively. - View Dependent Claims (2, 3, 4, 5)
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6. A display having a first and second direct view modes of operation and comprising:
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a liquid crystal display device; a backlight disposed behind said display device and arranged, during said first mode, to render an image, displayed by said display device during said first mode, visible throughout an extended viewing region in front of said display device; a first holographic element; and a first front light source disposed in front of said display device and said first holographic element and arranged to be actuated during said second mode, said first holographic element being arranged to redirect light from said first front light source into a part of said extended viewing region so that at least one image displayed by said display device during said second mode is visible only in a restricted portion of said extended viewing region, wherein said backlight and said first front light source are arranged to be actuated simultaneously during said second mode; and
said first holographic element, when illuminated by said first front light source, redirects light to said extended viewing region outside said restricted portion so as to render said at least one image displayed by said display device unintelligible when viewed from said extended viewing region outside said restricted portion. - View Dependent Claims (7, 8, 9, 10, 11)
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Specification