High-speed printer

Claim 1

A printer, comprising a normally non-rotating printing drum, conveying means for conveying materials to be printed toward the drum, first pulse generator means coupled to said conveying means for responding to said conveying means and producing pulses indicative of the speed of said conveying means, detecting means along the path of the material on the input side of the drum for indicating the presence of the material, said drum having print positioned on the periphery thereof, regulating means for rotating the drum and thereby changing the position of the print on the drum, second pulse generator means coupled to the regulating means for responding to the speed of the drum and producing pulses indicative of the speed of the drum, print control means responsive to said first and second pulse generator means and said detecting means and coupled to said regulating means for comparing the speeds of the conveying means and the print when the material passes said detecting means and for controlling the speed of said regulating means on the basis of the comparison, said control means including, in combination, a first counter rendered effective upon the generation of an indication by the detecting means for responding to the pulse output of said first generator means and producing an output indicative of the speed of the conveying means after the material has passed said detecting means, a second counter responsive to said second generator means for responding to the position of said drum, and comparison means responsive to said counters for producing error signals indicative of the comparison in said counters and coupled to said regulating means for varying the position of said drum.