ILLUMINATION SYSTEM AND DISPLAY DEVICE
First Claim
1. An illumination system for producing output light having a variable angular illumination range for illuminating a display panel in a display device, comprising first and second light sources and operable selectively in a first mode in which the output light comprises light derived from the first light source with substantially no light derived from the second light source, and in a second mode in which the output light comprises light derived from at least the second light source, wherein the output light derived from the first light source has a first angular illumination range and the output light derived from the second light source has a second angular illumination range different to the first angular illumination range.
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Accused Products
Abstract
An illumination system (32) is provided for producing output light having a variable angular illumination range for illuminating a display panel (31) in a display device (30). The illumination system (32) comprises first and second light sources (34 and 36) and is operable selectively in a first mode in which the output light comprises light derived from the first light source (34) with substantially no light derived from the second light source (36), and in a second mode in which the output light comprises light derived from at least the second light source (36). The output light derived from the first light source (34) has a first angular illumination range and the output light derived from the second light source (36) has a second angular illumination range wider than the first angular illumination range. The first mode can be used as a private mode and the second mode can be used as a public mode. The private mode can be used to prevent widespread reading of information or images displayed using the display device (30).
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Citations
91 Claims
- 1. An illumination system for producing output light having a variable angular illumination range for illuminating a display panel in a display device, comprising first and second light sources and operable selectively in a first mode in which the output light comprises light derived from the first light source with substantially no light derived from the second light source, and in a second mode in which the output light comprises light derived from at least the second light source, wherein the output light derived from the first light source has a first angular illumination range and the output light derived from the second light source has a second angular illumination range different to the first angular illumination range.
- 65. An illumination system for illuminating a display panel in a display device, comprising a first light source arrangement arranged in first and second modes of operation to produce output light having a second-mode angular illumination range, and a second light source arrangement arranged in the first mode but not the second mode to produce output light mainly in an overlap range of the second-mode angular illumination range not including a first-mode angular illumination range contained within and narrower than the second-mode angular illumination range.
Specification