Multiple pitch color registration system

Claim 1

An image registration control system in a color printer for electronically synchronizing a means for recirculating paper in a loop for transfer of a plurality of colors, with a plurality of latent images on a photoreceptor surface, the control system being operable with a pitch mode of at least two, comprising: a) means for generating a belt hole signal corresponding to a seam on the photoreceptor surface; b) means for generating a pitch reset at a time t 1 , for partitioning the belt into at least two segments in response to said belt hole signal; c) means for generating a first reference signal at a time t 2 based on a first number of time signals, each time signal corresponding to the printing of a scan line of a latent image, said first number of time signals counted between said pitch reset and a scan start signal; d) means for generating a second reference signal at a time t 3 after time t 2 based on a second number of time signals corresponding to the printing of each scan line, said second number of time signals counted between said pitch reset and the arrival of a scanner at a lead edge of an original document to be scanned; e) means for measuring an actual pitch length corresponding to one latent image of the plurality of latent images on the photoreceptor based on a measurement in phase clocks at a time t 4 of the phase position of said second reference signal at time t 3 with respect to a machine clock; f) means for repeatedly actuating said means for generating a second reference signal and said means for measuring an actual pitch length according to the pitch mode to determine a pitch length for each subsequent latent image of the plurality of latent images; g) means for measuring the spatial separation of the plurality of latent images on the photoreceptor as a function of the pitch length and first and second reference signals measured for each latent image; h) means for assuming a pitch length for each latent image; i) means for correcting a position of said means for recirculating relative to each latent image based on a difference between said actual and assumed corresponding measured pitch lengths; wherein at said reference signal t 3 , said means for recirculating is locked onto the machine clock encoder edge such that the means for recirculating is phase locked onto the photoreceptor position so that a timing repeatability of the means for recirculating between successive transfers is identical to said latent image separation.

Claim 14

A method for image registration control in a color printer for synchronizing the placement of at least two latent images on a photoreceptor surface with the movement of a paper transfer loop, the method comprising the steps of: electronically partitioning the photoreceptor surface into at least two pitches corresponding to said at least two latent images; scanning an original document with a scanner; applying said at least two latent images onto the photoreceptor surface corresponding to scanned color images of the original document; electronically signaling when the scanner arrives at a lead edge of the original document for each scan; and electronically synchronizing the movement of a paper transfer loop in response to each electronic signal.

Claim 15

A method for image registration control in a color printer for synchronizing the placement of at least two latent images on a photoreceptor surface with the movement of a paper transfer loop, the method comprising the steps of: electronically partitioning the photoreceptor surface into at least two pitches corresponding to said at least two latent images; scanning an original document with a scanner; applying said at least two latent images onto the photoreceptor surface corresponding to scanned color images of the original document; electronically signaling when the scanner arrives at a lead edge of the original document for each scan; and electronically synchronizing the movement of a paper transfer loop in response to each electronic signal.