A METHOD OF OPERATING AN INK JET PRINTER AND A DROP-ON-DEMAND INK JET PRINTER

    公开(公告)号:DE3164297D1

    公开(公告)日:1984-07-26

    申请号:DE3164297

    申请日:1981-07-06

    Applicant: IBM

    Abstract: The drawing shows part of the print head and associated drive circuitry of an ink jet printer. The head comprises a tubular piezo-electric transducer (11, 12, 13b) driven from a periodic source 37 running at the resonant frequency of the piezoelectric cavity 17 or from a clock source 46 gated by print signals. During driving by source 37 the transducer is energized with a series of pulses for a preselected short time period (delay 39) and at a repetition rate substantially equal to a resonant frequency of the ink cavity (17). This effectively purges any entrapped air from the ink system. Except during purging, the transducer operates asynchronously in drop-on-demand mode in response to discrete binary print signals. … Purging is accomplished automatically as a part of the start up operation and also if, during operation, the velocity V5 of the ink droplets (26), as sensed by a sensor (41), drops below a preselected reference value Vr.

    DROP-ON-DEMAND INK JET PRINTERS
    3.
    发明专利

    公开(公告)号:DE3469699D1

    公开(公告)日:1988-04-14

    申请号:DE3469699

    申请日:1984-11-06

    Applicant: IBM

    Abstract: An ink jet drop-on-demand printing system comprising an ink jet print head (10) having an ink cavity (23) supplied with a suitable ink. An electromechanical transducer (16) is mounted in mechanical communication with the ink cavity, and a control means (14) is provided to selectively actuate the transducer to produce an ink drop of a selected size. To produce ink drops of a selected size a source of electrical signals comprised in the control means produces electrical drive signals (60a to 60n) each separated by a fixed time delay (τ) which is short with respect to the drop-on-demand drop production rate (T). Each electrical drive signal (60a to 60n) is capable of ejecting a predetermined volume of ink and all ejected the volumes of ink merge to form a single drop prior to the time the ink drops reach the print medium for printing. By selecting groups (e.g. 60a to 60d, or 60a to 60f) from the signals (60a to 60n) the size of the merged drop can be selected.

    INK JET PRINTING SYSTEM AND METHOD OF GENERATING LIQUID DROPLETS

    公开(公告)号:DE3064482D1

    公开(公告)日:1983-09-08

    申请号:DE3064482

    申请日:1980-05-09

    Applicant: IBM

    Abstract: A drop-on-demand ink jet printer in which the print head includes a cavity having a nozzle portion at one end and a transducer mounted to contract a wall portion of the cavity when energized by a suitable voltage drive pulse. The drive pulses are produced at a predetermined rate but at a selectively controlled amplitude in response to the print data. In cases where no drop is required to print the data, the drive pulse is at a lower amplitude than the threshold voltage level, and for the first drop to be formed following a time at which no drop was formed, the amplitude of the drive pulse is greater than the threshold voltage level. At steady state operation of producing drops in sequence, the amplitude of the drive pulses equals the threshold voltage level.

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