Self-masking viewing apparatus
AssigneeSmartlight Ltd.
InventorsDan Inbar, Hanan Wolf, Benzion Levy
Life of this patent
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Abstract
A transparency viewing device including a faceplate adapted for mounting at least one transparency thereon, an LCD array defining an array of pixels, a driver which selectively varies the transparency of the pixels, a source of back illumination for the LCD array wherein the LCD is substantially effective to effectively block light within a relatively limited range of angles around the normal to the LCD and is relatively ineffective to block light reaching it from angles outside the limited range of angles and a light detector which views the array from an angle outside the range of angles at which the LCD is substantially effective to block the light.
Claims30
A transparency viewing device comprising:
- a faceplate adapted for mounting at least one transparency thereon;
- an LCD array defining an array of pixels;
- a driver which selectively varies the transparency of the pixels;
- a source of back illumination for the LCD array wherein the LCD is substantially effective to effectively block light within a relatively limited range of angles around the normal to the LCD and is relatively ineffective to block light reaching it from angles outside the limited range of angles;
- and
- a light detector which views the array from an angle outside the range of angles at which the LCD is substantially effective to block the light.
A method of determining the extent of a transparency mounted on a viewing surface which is illuminated by light which passes through an LCD array comprising the steps of:
- acquiring an image of the transparency and the viewing surface, while the LC elements are in a light blocking mode of operation, at an angle sufficiently far from the normal to the LCD array, at which angle LCD is relatively highly transmisive as compared to its normal transmission in the light blocking mode;
- and
- determining the extent of the transparency responsive to the acquired image.
A method of determining the extent of an image on a transparency mounted on a viewing surface which is illuminated by light which passes through an LCD array comprising the steps of:
- acquiring an image of the transparency and the viewing surface, while the LC elements are in a light blocking mode of operation, at an angle sufficiently far from the normal to the LCD array, at which angle LCD is relatively highly transmisive as compared to its normal transmission in the light blocking mode;
- and
- determining the extent of an image on the transparency responsive to the acquired image.
Dependencies are inferred from the claim text.