Patent ID: 7524069
Filing Date: 2009-04-28
Classification: G03B

Abstract:
1. A projector having a transmitter information receiver, for use in combination with a transmitter having an ultrasonic transmission unit for transmitting an ultrasonic wave and an infrared transmission unit for emitting an infrared radiation, comprising: an infrared detector, and a first ultrasonic receiver and a second ultrasonic receiver which are spaced from each other; a transmission time information reception unit; and an image correcting information calculation unit; wherein said transmission time information reception unit calculates a distance between said transmitter and said first ultrasonic receiver and a distance between said transmitter and said second ultrasonic receiver based on reception times of the ultrasonic wave and the infrared radiation transmitted by said transmitter which points to a position on a projection surface, and stores the calculated distances as distance information; and wherein when a test pattern made up of a plurality of reference points including a plurality of points near corners of upper and lower edges of the projection surface is projected onto the projection surface, based on said distance information on the projection surface which is acquired by said transmission time information reception unit through said transmitter with respect to the reference points projected onto said projection surface and positional information of desired corrective points for the reference points including points near the corner of the upper edge, said image correcting information calculation unit generates a coordinate transformation table for bringing the coordinates of the reference points near the upper edge into conformity with the coordinates of the desired corrective points corresponding thereto.