Phase control for ink jet printer

Claim 2

In an ink jet printer system wherein ink under pressure is delivered to a nozzle which is vibrated by a transducer connected to a source of synchronizing signals and driven by said synchronizing signals to produce a stream of drops, and a charging electrode is positioned adjacent said nozzle to charge some of said drops in accordance with variable value information input signals from input information signal means applied to said electrode for deflecting said drops to print data in accordance with said information input signals as said drops move in an electric field between a pair of deflecting electrodes; all other of said drops not being so charged being discard drops not used to print data; the improvement in the phase of formation of said ink drops relative to the occurrence of said information input signals comprising means producing a continuous fixed frequency calibration signal having an amplitude less than the minimum information input signal value; circuit means including means responsive to the relative values of said information input signals and said calibration signal connecting said input information signal means and said calibration signal means to said charging electrode to selectively apply said fixed frequency signal and said information input signals to said charging electrode so that all of said discard drops not charged by information input signals even during the printing of data are charged by said fixed frequency signal; phase control circuit means connected to said circuit means and said source of synchronizing signals to vary the phase relation between said input information signals and said synchronizing signals, and a single means positioned to catch all said discard drops and having electrode means positioned to be responsive to said charge on said discard drops connected to said phase control means to control the phase relation between said information input signals and said synchronizing signals, and thereby control the phase relation of said input information signals relative to the formation of said ink drops.

Claim 3

The invention as defined in claim 1 characterized by said means producing said fixed frequency calibration signal comprising a positive sawtooth waveform generator.

Claim 4

The invention as defined in claim 2 characterized by said catching means responsive to the charge on all discard drops comprising a multisection discard drop gutter having said electrode means positioned in at least one of said sections to detect charged discard drops, said electrode means being connected to said phase control means to control the phase relations of said information input signals and said synchronizing signals.

Claim 5

The invention as defined in claim 3 characterized by said multisection gutter comprising a three-section gutter with said electrode means comprising spaced electrodes in two of said sections and a two-position time delay device which is connected to said phase control means and to said spaced electrodes to control the phase relations of said fixed frequency signal and said information input signal relative to said synchronizing signals.

Claim 6

The invention as defined in claim 3 characterized by said multisection gutter comprising a two-section gutter having a divider therebetween and said electrode means comprising spaced sensing electrodes in one only of said sections, said spaced sensing electrodes being connected to said phase control means to vary the phase relations of said information input signals and said synchronizing signals.

Claim 7

The invention as defined in claim 5 characterized by said catching means including a continuous controlled voltage source connected to be energized from said electrode means, said electrode means comprising a pair of spaced electrodes in said one section of said gutter and connected to said phase control means which comprises a variable delay circuit controlling the phase relations of said information input signals and said fixed frequency signal relative to said synchronizing signals.

Claim 8

The invention as defined in claim 3 characterized by a differential amplifier connected between said electrode means and said phase control means, said multisection gutter comprising a two-section gutter with each section having said electrode means connected to said differential amplifier for controlling said phase control means which includes a variable time delay circuit to change the phase relations of said input information signals and said fixed frequency signals with said synchronizing signals.

Claim 9

The invention as defined in claim 3 characterized by a binary counter and a multilevel voltage source, said multisection gutter comprising a three-section gutter with said electrode means positioned in two sections and connected to control said binary counter and said multilevel voltage source being connected to said phase control means which comprises a multiposition time delay device connected in circuit relation with said information input signal and said fixed frequency signal means.

Claim 10

A discard drop catching gutter for in ink drop printer comprising a sensor plate having a cut-away edge portion defining an ink drop receiving groove and having front and back sides, electrode means positioned on the cut-away edge portion, a front plate positioned on one side of said sensor plate, and a back plate positioned on the other side of said sensor plate, said front and back plates at least partially enclosing said cut-away edge portion on the front and back sides, at least one of said front and back plates having an opening therethrough providing access to drain ink from said cut-away portion.

Claim 11

A discard drop catching gutter for in ink drop printer comprising a sensor plate having a cut-away edge portion defining an ink drop receiving groove and having front and back sides, electrode means positioned on the cut-away edge portion, a front plate positioned on one side of said sensor plate, and a back plate positioned on the other side of said sensor plate, said front and back plates at least partially enclosing said cut-away edge portion on the front and back sides, at least one of said front and back plates having an opening therethrough providing access to drain ink from said cut-away portion.

Claim 12

A dicard drop catching gutter as defined in claim 9 characterized by a plurality of sensor plates positioned in side-by-side relation, and separators sandwiched between said sensor plates to substantially separate said cut-away portions of said sensor plates.

Claim 13

In an ink jet printer system wherein ink under preSsure is delivered to a nozzle which is vibrated by a transducer connected to a source of synchronizing signals to be driven by synchronizing signals to produce a stream of drops, and a charging electrode is positioned adjacent said nozzle to charge some of said drops in accordance with variable value information input signals from input information signal means applied to said electrode for deflecting said drops to print data in accordance with said information input signals as said drops move in an electric field between a pair of deflecting electrodes, all others of said drops not being charged in accordance with said variable value information input signals being discard drops, and said information input signals having a preferred phase relation with said synchronizing signals so as to maintain said information input signals in phase with said ink drop formation; the improvement in the phase of formation of said ink drops relative to the occurrence of said information input signals comprising means producing a continuous fixed frequency calibration signal in phase with said information input signal but having an amplitude less than the minimum information input signal value; circuit means including means responsive to the relative values of said information input signals and said calibration signal connecting said input information signal means and said calibration signal means to said charging electrode to selectively apply said fixed frequency signal and said information input signals to said charging electrode so that all said discard drops not charged by information input signals during at least a portion of cycle for printing of data are charged by said fixed frequency signal; phase control circuit means connected to said source of synchronizing signals and one of said transducer and said input information signal means to vary the phase relation between said input information signals and said synchronizing signals and maintain said phase relation between said information input signals and said ink drop formation, and means positioned to sense the charge on all of said discard drops deflected by said electric field in response to said fixed frequency signal charge on said discard drops, said sensing means being connected to said phase control means to operate said phase control means to control the phase relation between said information input signals and said synchronizing signals applied to said transducer.

Claim 14

In an ink jet printer system wherein ink under preSsure is delivered to a nozzle which is vibrated by a transducer connected to a source of synchronizing signals to be driven by synchronizing signals to produce a stream of drops, and a charging electrode is positioned adjacent said nozzle to charge some of said drops in accordance with variable value information input signals from input information signal means applied to said electrode for deflecting said drops to print data in accordance with said information input signals as said drops move in an electric field between a pair of deflecting electrodes, all others of said drops not being charged in accordance with said variable value information input signals being discard drops, and said information input signals having a preferred phase relation with said synchronizing signals so as to maintain said information input signals in phase with said ink drop formation; the improvement in the phase of formation of said ink drops relative to the occurrence of said information input signals comprising means producing a continuous fixed frequency calibration signal in phase with said information input signal but having an amplitude less than the minimum information input signal value; circuit means including means responsive to the relative values of said information input signals and said calibration signal connecting said input information signal means and said calibration signal means to said charging electrode to selectively apply said fixed frequency signal and said information input signals to said charging electrode so that all said discard drops not charged by information input signals during at least a portion of cycle for printing of data are charged by said fixed frequency signal; phase control circuit means connected to said source of synchronizing signals and one of said transducer and said input information signal means to vary the phase relation between said input information signals and said synchronizing signals and maintain said phase relation between said information input signals and said ink drop formation, and means positioned to sense the charge on all of said discard drops deflected by said electric field in response to said fixed frequency signal charge on said discard drops, said sensing means being connected to said phase control means to operate said phase control means to control the phase relation between said information input signals and said synchronizing signals applied to said transducer.

Claim 15

The invention as defined in claim 11 characterized by said sensing means comprising a multisection discard drop gutter having drop sensing means positioned in at least one of said sections to detect charged discard drops, said drop sensing means being connected to said phase control means to control the phase relations of said information input signals and said synchronizing signals and maintain said phase relation between said input information signals and said drop formation.

Claim 16

The invention as defined in claim 12 characterized by said multisection gutter comprising a two-section gutter means having said drop sensing means in one of said sections, said drop sensing means being connected to said phase control means to vary the phase relations of said information input signals and said synchronizing signals in accordance with the charge on said discard drops sensed by said drop sensing means.

Claim 17

The invention as defined in claim 11 characterized by said means producing said fixed frequency signal comprising a generator producing a waveform which changes amplitude throughout the interval in which discard drops may be formed so that the charge on said discard drops varies with and is a measure of the phase relation between said fixed frequency signal and said drop formation.

Claim 18

The invention as defined in claim 14 in which said waveform of said means producing said fixed frequency signal changes gradually during said interval so as to provide a charge on discard drops which changes gradually in accordance with different phasE relations between said drop formation and said fixed frequency signal.

Claim 19

The invention as defined in claim 15 in which said waveform of said means producing said fixed frequency signal changes in a straight line manner during said interval so that there is a linear relation between the charge on said discard drops and the phase relation of said drop formation and said fixed frequency signal.

Claim 20

The invention as defined in claim 12 characterized by counter means connecting said drop sensing means to said phase control means for selectively effecting operation of said phase control means in response to the charge on said discard drops.

Claim 21

The invention as defined in claim 17 characterized by said counter means comprising a binary counter which operates the phase control means to correct an out-of-phase relation between said drop formation and said fixed frequency signal.

Claim 22

The invention as defined in claim 17 characterized by said counter means connecting said drop sensing means and said phase control means comprising a two-position binary counter operable to vary the phase relations of said information input signals and said synchronizing signals on plural steps and said phase control means comprising a four-position delay circuit.

Claim 23

The invention as defined in claim 11 characterized by said means connecting said sensing means to said phase control means including a controlled voltage source having a plurality of voltage levels connected between said sensing means and said phase control means to vary said phase relations with each level of voltage and restore means connected to said source operable to place the voltage of said source in the middle of its operating range during start up.