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4 records (took 0.016 seconds)

    1.
    发明专利
    未知

    公开(公告)号：DE3684565D1

    公开(公告)日：1992-04-30

    申请号：DE3684565

    申请日：1986-12-10

    Applicant: IBM

    Inventor： CAVILL BARRY RICHARD ,  MALKEMES CHARLES DAVID ,  REINBERG KEVIN MICHAEL ,  SCHULZ RAYMOND ANDREW

    IPC: B41J19/18 ,  B41J19/20 ,  G05B19/23 ,  H02P7/00 ,  B41J19/14

    Abstract: The present invention relates to a printer of the type which comprises a print head (24) for performing printing operations on a print medium, a drive system for moving the print head across a print medium at a selected speed, and a print head control system. The control system includes generating means for generating print head movement signals (ENC A, ENC B) corresponding to print head movement, a processor (2, 10), responsive to the print head movement signals and a command signal representing a required print head movement speed, to generate a drive signal (PWM) for supplying to the drive system so as cause movement of the print head at the required speed. According to the invention the printer is characterised in that the processor comprises means (2) for repeatedly comparing the print head movement signals with the command signals at predetermined time intervals and for changing the drive signal by an equal amount, for each comparison operation that indicates that the print head movement speed differs from the command signal speed, until the print head attains the required speed. The present invention also relates to a method of controlling the movement of the print head of a printer utilising a print head control system as above.

    Electronic switching circuit
    3.
    发明专利
    Electronic switching circuit 未知

    公开(公告)号：GB1107313A

    公开(公告)日：1968-03-27

    申请号：GB858067

    申请日：1967-02-22

    Applicant: IBM

    Inventor： HUTH GERALD OWEN ,  SCHULZ RAYMOND ANDREW ,  WOLTERMAN ARDEN JOHN

    IPC: H03K17/687 ,  H03K17/04 ,  H03K17/041

    Abstract: 1,107,313. Transistor gating circuits. INTERNATIONAL BUSINESS MACHINES CORPORATION. 22 Feb., 1967 [25 July, 1966], No. 8580/67. Heading H3T. A gating circuit comprises two field effect transistors connected in series between input and output terminals with their source electrodes together, a first diode 16 connected to a source of supply, a resistive element 14 connected between the source terminals and a common connection to the gates and a twolevel control signal connected through a second diode 18 to the common connection. When the control voltage in the circuit shown is at its lower level both diodes conduct, the sources are clamped at Va and the gates have a cut-off bias applied to them. Both transistors are in the most favourable blocking direction. When the control voltage is at its higher level both diodes are blocked and the bias is removed so that the transistors may conduct. The control source is isolated by the diode and resistor 14 provides a bleed path for negative charge accumulating at the gates. This resistor may be replaced by a further field effect transistor arranged to have a high constant current type resistance when the main transistors are off and a low resistance when they are on so as to increase switching speeds.

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