Patent ID: 7884816
Filing Date: 2011-02-08
Classification: G02B,G03B,G09G,H04N

Abstract:
1. A scanning beam display system, comprising: an optical module comprising a first scanner to scan along a first direction at least one scanning beam having optical pulses that are sequential in time and carry image information, and a second scanner having a polygon with a plurality of reflective facets, the polygon operable to rotate around a rotation axis that is along the first direction to scan the at least one scanning beam along a second direction perpendicular to the first direction; a screen positioned to receive the at least one scanning beam from the optical module and configured to include (1) a display region which displays images carried by the at least one scanning beam, and (2) reference marks positioned in paths along the second direction of the least one scanning beam on the screen and displaced from one another along the first direction, each reference mark operable to produce, in response to the at least one scanning beam, an optical monitor signal of light, and to direct the optical monitor signal of light to propagate in space away from the screen, the optical monitor signal of light containing information on a position offset of the least one scanning beam relative to the reference mark along the first direction on the screen when illuminated by the at least one scanning beam; an optical detector positioned to receive light of the optical monitor signals from the reference marks on the screen that propagate through space between the screen and the optical detector and to produce respective electrical detector signals, each detector signal containing the information on a position offset of the least one scanning beam relative to a respective reference mark along the first direction on the screen; and a first scanner control that measures a pyramidal error of the polygon from each detector signal and controls scanning of the first scanner to correct the position offset caused by the pyramidal error.