Abstract: A ribbon tension control for controlling the tension of ribbon traveling between a rotating supply spool and a rotating take-up spool varies the amount of braking torque applied to the supply spool to hold ribbon tension constant as the distribution of ribbon between the spools changes. A generator rotationally coupled to the supply spool produces braking torque to resist the rotation of the spool when the generator windings are electrically loaded. The loading of the generator is controlled by processing feedback signals emitted by the generator to provide periodic load switching signals. Processing of the feedback signal is accomplished in the exemplary embodiment by a drag lookup table which is addressed by the feedback signal. The drag lookup table produces a duty cycle value which is used to determine the duty cycle of the switching signal, which, in turn, controls the electrical loading of the generator.

Abstract: In a drive circuit for an electromagnetic printing element of a matrix impact printer, a drive pulse drives the printing element from the backstop toward a record medium to print indicia, and a damping pulse, applied to the printing element after its return to the backstop, urges it toward the backstop to limit rebound therefrom. Logical control circuitry is responsive to overlap of a drive pulse with a preceding damping pulse for terminating the damping pulse and for decreasing the width of the drive pulse in proportion to the amount of overlap. Blanking means are provided to prevent application of a damping pulse to the printing element until after the completion of a preceding drive pulse and after impact of the printing element with the record medium and with the backstop.

Abstract: An arrangement for processing data by modifying selected bit portions of coded control signals for comparison with coded input signals to control printing by a printer.

Abstract: A regulator for a two phase shaft encoder used in sensing irregular body movements which determines when the light transmission of a photocoupler is maximum and corrects the photocoupler output to agree with a reference value.

Abstract: Print control apparatus which combines a first in - first out memory for storing received data with a random access memory for feeding data to a movable type printer to eliminate the need for suspension of receiving input characters or the adding of fill characters or time delays during the period when printer action is suspended during execution of control actions, such as paper feed. The apparatus controls the transfer of data from the first in - first out memory to the random access memory by keeping the latter memory continuously replenished with data as the printer executes its printing action and printed characters are erased from the random access memory.

Abstract: An arrangement for detecting a change in the number of printing characters associated with a set of such characters employed in a printer and for automatically modifying the print control algorithm employed in the printing process in accordance with said detected change.

Abstract: Maximizing the printing rate of an electronic printer by causing it to print data characters at a relatively constant rate despite variations in the pattern of the incoming data. The number of characters in an incoming data pattern to be printed substantially simultaneously is monitored and the printing rate controlled within certain limits to provide a maximum printing rate consistent with the power and mechanical limits of the printer design.