Abstract: A wire fire control mechanism is provided for use in a wire matrix printer for controlling the firing of the print wires as the printhead moves across a print receiving medium. This wire fire control mechanism enables printing to be accomplished for a wide range of different printhead speeds. It also enables printing to be accomplished while the printhead is accelerating or decelerating. It further enables dots to be printed at positions which are not dependent on or limited to the fixed points defined by the emitter signals which are used to keep track of the position of the printhead as it moves across the print receiving medium. In a representative embodiment, the wire fire control mechanism includes emitter means for sensing movement of the printhead and producing emitter signals which define fixed points across the print receiving medium.

Abstract: A control system for a printer having a print head bidirectionally movable at speeds selected from either a first group of speeds or a second group of speeds which employs a microcomputer to generate a digital signal representing the percentage of time a preselected voltage level should be applied to drive the motor which controls the print head speed. The motor includes an integral dual channel incremental optical encoder which generates a pulse each time an emitter is detected, the pulse being directed back to the microcomputer as measured speed information. The microcomputer compares the measured speed information with the desired speed information during predetermined time intervals and if they differ changes the value of the digital signal by an equal amount for each time interval until the desired speed is obtained or until a different print head speed is desired.

Abstract: There is disclosed herein printer control logic for controlling a matrix printer. The control logic includes an interruptable microprocessor, together with associated memory. Additionally the control logic includes a programmable timer which provides a signal a determined time after being programmed. The control logic responds to print emitter signals manifesting an incremental movement of the print head by interrupting the microprocessor. The microprocessor then programs the timer to provide signals after a programmed delay time to again interrupt the microprocessor. The microprocessor then provides signals causing the operation of the print elements on print head.