摘要:
The present invention relates to a wire matrix printer of the type comprising a printhead (42) including a plurality of print wires (44) for printing dots, means for moving the printhead across a print receiving medium, means for detecting the position of each print wire relative to the print receiving medium as the printhead moves across the print receiving medium, means for establishing a plurality of target positions (45, 46) on the print receiving medium in each of which a dot is to be printed, firing means for selectively firing each print wire so that it causes a dot to be printed on the print receiving medium, and a print wire fire control mechanism for controlling the operation of the firing means so that each selected print wire prints a dot in a predetermined target position on the print receiving medium. A printer according to the invention is characterised in that the print wire fire control mechanism comprises means for calculating the flight time distance (FTD) through which the printhead will move during the time interval between the time each selected print wire is fired and the time the selected print wire will cause a dot to be printed, and control means for firing each selected print wire when the distance between the selected print wire and a predetermined target position (TD) is substantially equal to the flight time distance (FTD).
摘要:
® In a control system for a bidirectional printer capable of printing at different speeds on different lines and in which processor means (28) compares the actual velocity of the print carriage with a desired velocity profile to generate an error count, the error count is measured and averaged out for each direction and speed of carriage movement to compensate for the effect of changes in the printer system dynamics such as aging, wear, debris buildup, etc.
摘要:
A control system for a bidirectional printer having a print head carriage movable at different speeds on different printing lines employs a microcomputer (28) which generates a desired velocity profile for the carriage motion. This desired velocity profile is continuously compared with the actual velocity and the error voltage generated is used to control pulse width modulator circuitry which supplies driving power to carriage drive motor (36).
摘要:
The arrangement according to the invention is provided with facilities for detecting emitter changes that have occurred during operating intervals. In a typical operation, a microprocessor (210) initiates a command to a moving assembly (170), such as a forms feed assembly, then once the operation is initiated the microprocessor transfers to other responsibilities, meanwhile periodically checking the status of the forms feed assembly. The forms feed assembly supplies emitter signals to the processor which are utilized by the microprocessor to determine whether or not any emitter changes have occurred during the intervals between the checking operations. The microprocessor has a stored data table and logic responsive to emitter signal conditions that had previously occurred (WAS) and that is further responsive to emitter signals that are presently occurring (IS) to supply an output in numbers of emitters indicative of both the extent and direction of movement of the assembly during the intervening interval.