Patent ID: 7271383

Claim:
A scanning system comprising: a beam source producing a light beam; a scanning mirror that receives the light beam from the beam source and sweeps the light beam from a position “A” to a position “B”; a lens that receives the light beam from the scanning mirror as the scanning mirror sweeps the light beam from position “A” to position “B” and that directs the light beam as a scanning beam to an image plane surface; a photo detection system having at least one photo detector and having a minimum light ray threshold detection level; a first synchronizing mirror positioned to intercept and reflect at least a portion of the scanning beam as a synchronizing light ray when the light beam is at a position “A′” that is in the vicinity of position “A” and that is between position “A” and position “B” such that when the light beam is at position “A′” the first synchronizing mirror intercepts a first light ray of the scanning beam and reflects at least a portion of the first light ray as a second light ray of the scanning beam to a first single photo detector of the photo detection system, where the intensity of the second light ray of the scanning beam is at least equal to the minimum light ray threshold detection level of the first single photo detector of the photo detection system; a second synchronizing mirror positioned to intercept and reflect at least a portion of the scanning beam as a synchronizing light ray when the light beam is at a position “B′” that is in the vicinity of position “B” and that is between position “A” and position “B” such that when the light beam is at position “B′” the second synchronizing mirror intercepts a third light ray of the scanning beam and reflects at least a portion of the third light ray as a fourth light ray of the scanning beam to a folding mirror that is positioned to reflect at least a portion of the fourth light ray as a fifth light ray of the scanning beam to the first single photo detector of the photo detection system, where the intensity of the fifth light ray of the scanning beam is at least equal to the minimum light ray threshold detection level of the photo detection system; and an electronic circuit that generates an electronic signal when the photo detection system detects a light ray that is at least equal to the minimum light ray threshold detection level of the first single photo detector of the photo detection system.