Patent ID: 6154247
Filing Date: 2000-11-28
Classification: B41J,H04N

Abstract:
A lenticular image printer for creating an image on received media having a series of lenticules with parallel axes; said printer comprising:a transport system adapted to move received media in an in-track direction substantially perpendicular to the axes of the lenticules;an alignment beam generator arranged to transmit an alignment beam through the lenticules of received media such that the alignment beam is in-track position-modulated by the lenticules; andthree position-sensing detectors aligned in a cross-track direction perpendicular to the in-track direction so as to receive the position-modulated alignment beam whereby a position of the position-modulated alignment beam on the detectors provides an indication of relative alignment of the axes of the lenticules and the cross-track direction, said position-sensing detectors being aligned such that there are two outboard detectors and a third detector between the two outbound detectorswherein:the lenticules have a pitch;the outboard detectors are spaced apart by a spacing there between; andthe indication of the relative alignment of the axes of the lenticules and the cross-track direction is a true angle error signal E determined by an equationE=n*p/w+E.sub.f,, where:p is the lenticule pitch;w is the spacing between the two outboard detectors;E.sub.f is a fine angle error in radians determined by an equationE.sub.f =(D.sub.f *V)/w, whereD.sub.f is a phase difference in seconds between zero crossings of two outboard detectors, andV is a transport (media) velocity; andn is a number of integer lenticule errors determined by an equationn=Integer{(E.sub.c -E.sub.f)/(p/w)}, whereE.sub.c is a coarse angle error in radians determined by an equationE.sub.c =(D.sub.p *V)/a, whereD.sub.p is a phase difference (in seconds) between zero crossings of the third detector and its adjacent outboard detector anda is a spacing between third detector and its adjacent outboard detector.