1.
    发明专利
    未知

    公开(公告)号:BR8300058A

    公开(公告)日:1983-09-20

    申请号:BR8300058

    申请日:1983-01-07

    Applicant: IBM

    Abstract: A hammer timing control system for a line printer has a register for continually storing a digital delay fire quantity representative of the actual flight of a controlled hammer. A delay fire counter activated by an initiate fire pulse from hammer selection circuitry of the printer control system counts the timing pulses from a clock means until it registers a count equal to the delay quantity stored in the delay fire register. A comparator circuit is connected to both the delay value register and the counter and generates a hammer fire signal when the delay quantity and the count are equal. The single counter continues counting clock pulses until a second count is registered which is equal to a terminate fire value. The control system provides circuit means responsive to the second count registered in the counter to terminate the hammer fire signal. In one embodiment, the terminate fire circuitry comprises a decode connected to the output of the counter means for detecting the second count condition. In a second embodiment, the control system has a second register which stores a terminate fire quantity which represents a fixed time after the initiate fire signal and prior to hammer impact. In a third embodiment, the counter is an up/down counter which counts in one direction to turn on the hammer driver circuit and in the other direction to turn off the hammer driver circuit. The delay fire quantities for the plurality of hammers are preferably stored in an external memory device for transfer to the individual registers for each of the print hammers. The external storage may be a magnetic record such as a disk.

    CONTROL SYSTEM FOR TIMING HAMMERS OF IMPACT PRINTERS

    公开(公告)号:DE3279602D1

    公开(公告)日:1989-05-18

    申请号:DE3279602

    申请日:1982-10-14

    Applicant: IBM

    Abstract: A hammer timing control system for a line printer has a register for continually storing a digital delay fire quantity representative of the actual flight of a controlled hammer. A delay fire counter activated by an initiate fire pulse from hammer selection circuitry of the printer control system counts the timing pulses from a clock means until it registers a count equal to the delay quantity stored in the delay fire register. A comparator circuit is connected to both the delay value register and the counter and generates a hammer fire signal when the delay quantity and the count are equal. The single counter continues counting clock pulses until a second count is registered which is equal to a terminate fire value. The control system provides circuit means responsive to the second count registered in the counter to terminate the hammer fire signal. In one embodiment, the terminate fire circuitry comprises a decode connected to the output of the counter means for detecting the second count condition. In a second embodiment, the control system has a second register which stores a terminate fire quantity which represents a fixed time after the initiate fire signal and prior to hammer impact. In a third embodiment, the counter is an up/down counter which counts in one direction to turn on the hammer driver circuit and in the other direction to turn off the hammer driver circuit. The delay fire quantities for the plurality of hammers are preferably stored in an external memory device for transfer to the individual registers for each of the print hammers. The external storage may be a magnetic record such as a disk.

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