Abstract: A scan frame (12) is mounted to a stationary frame (10) for rotation about a scan circle (14). A two speed resolver (20) has one circular core (36) mounted to the gantry and another circular core (32) mounted to the stationary frame. A primary winding (30a, 30b) on one of the cores receives AC excitation power from an excitation generator (58). Quadrature coarse resolution windings (54, 56) and quadrature fine resolution windings (50, 52) both in quadrature produce output signals indicative of the relative angle of the scan frame to the stationary frame. An angular position digitizing circuit (60) converts the analog sine/cosine signals into a digital angle signal.

Abstract: An apparatus for remote control of a printing press having a plurality of printing units each having a number of ink fountain key actuators, avoids duplication of remote control circuitry and of wiring by multiplexing a small number of remote controls and control wires. Command data are produced at a remote station, and temporarily stored there. Command data for all of the printing units which are to be controlled are then transmitted as a serial data stream over a pair of wires to storage registers located at the printing press. Thereafter, all of the actuators are energized in accordance with the data stored in their respective registers. A complete serial data stream is transmitted to the press once for each AC cycle of the power line frequency, and the actuators move in accordance with every such transmission of data.

Abstract: A method for compensating measurements of optical density of ink printed by a printing press in which amounts of light reflected from a printed test patch area and from an adjacent unprinted reference area are measured. The measurement sensitivity of sensing apparatus for measuring light from the printed test area need not be equal to the measurement sensitivity of sensing apparatus for measuring light from the unprinted reference area because the relative sensitivities of the two sensing apparatuses are ascertained before the press starts printing. The relative sensitivities are ascertained by making preliminary measurements of light from areas known to have equal reflection densities, for example unprinted paper. The results of these preliminary measurements are stored in a memory and employed later automatically to compensate density measurements based on readings made by the two sensing apparatuses while the press is printing.