Hammer driving circuits for high-speed printers

Claim 2

In a high-speed printer, the combination of a group of registers settable to store signals indicating whether or not a character is to be printed in each of several columns, and AND gate for each register having two input terminals and an output terminal, a first of said input terminals being connected to said register, said gates each being responsive to a timing signal applied to the second input terminal and a signal stored by the corresponding register indicating that a character is to be printed to produce an output signal, each of said gates comprising a resistor having one terminal connected between said first input terminal and said output terminal and a diode connected between said second input terminal and said output terminal, pulse-generating means for simultaneously applying a timing signal to the second input terminals of said gates, and print control means connected to the output terminals of said gates and responsive to said output signals for printing characters in the columns directed by said output signals.

Claim 3

The apparatus of claim 1, in which said print control means comprises a source of electrical energy, a winding for each column, and an electronic switch for each winding connected in series with the winding and with said source and closed by said output signal.

Claim 4

The apparatus of claim 2, in which each electronic switch comprises means responsive to the level of said output signal to control the current flowing in said winding when said switch is closed to a value predetermined by the level of the output signal.

Claim 5

In a high-speed printer having a printing solenoid comprising a winding, a source of electrical energy, an electronic switch having load terminals connected in series with said winding and said source, said switch having a control terminal and being closed when a predetermined potential is applied to said control terminal with respect to one of said load terminals, storage means having a first output terminal settable to a first or a second potential, a resistor connected between said first output terminal and said control terminal, a pulse generator having a second output terminal and actuable to produce a pulse between said first and said second potential on said second output terminal, and a diode connected between said second output terminal sand said control terminal, said predetermined potential being between said first potential and said second potential.

Claim 6

In a high-speed printer having a printing solenoid comprising a winding, a source of electrical energy, an electronic switch having load terminals connected in series with said winding and said source, said switch having a control terminal and being closed when a predetermined potential is applied to said control terminal with respect to one of said load terminals, storage means having a first output terminal settable to a first or a second potential, a resistor connected between said first output terminal and said control terminal, a pulse generator having a second output terminal and actuable to produce a pulse between said first and said second potential on said second output terminal, and a diode connected between said second output terminal sand said control terminal, said predetermined potential being between said first potential and said second potential.

Claim 7

The apparatus of claim 4, wherein which said switch comprises a variably impedance and a fixed impedance connected between said load terminals, and means responsive to the voltage across said fixed impedance when said switch is closed and to the potential on said control terminal for adjusting said variably impedance to fix the current between said load terminals.

Claim 8

In combination, a first terminal, pulse-generating means operable to apply a pulse of predetermined amplitude and durAtion to said first terminal, a set of gates each having first and second input terminals and an output terminal, said first terminal being connected to each of said first input terminals, each gate comprising a diode connected between said first input terminal and said output terminal and a resistor connected between said output terminal and said second input terminal, a set of registers, each connected to a different one of said second input terminals and each settable to apply a first or a second signal to the corresponding second input terminal, whereby each output terminal produces a first or a second output signal when said pulse is present according as the corresponding register applies said first or said second signal to the second input terminal of the corresponding gate, an electronic switch connected to the output terminal of each gate and closed when said first output signal is present, a source of electrical energy, and a different winding connected in series with each switch and with said source.

Claim 9

In combination, a first terminal, pulse-generating means operable to apply a pulse of predetermined amplitude and durAtion to said first terminal, a set of gates each having first and second input terminals and an output terminal, said first terminal being connected to each of said first input terminals, each gate comprising a diode connected between said first input terminal and said output terminal and a resistor connected between said output terminal and said second input terminal, a set of registers, each connected to a different one of said second input terminals and each settable to apply a first or a second signal to the corresponding second input terminal, whereby each output terminal produces a first or a second output signal when said pulse is present according as the corresponding register applies said first or said second signal to the second input terminal of the corresponding gate, an electronic switch connected to the output terminal of each gate and closed when said first output signal is present, a source of electrical energy, and a different winding connected in series with each switch and with said source.

Claim 10

The apparatus of claim 6, further comprising an operational amplifier connected between said first terminal and said first input terminals.

Claim 11

The apparatus of claim 7, in which each switch comprises a variably impedance and a fixed impedance connected in series with said winding and said source, and means responsive to the voltage across said fixed impedance when said switch is closed and to said output signal for controlling the current through said fixed impedance to value determined by the amplitude of said output signal.

Claim 12

In a high-speed printer, a group of hammer-driving solenoids each having a winding, an electrical source, a group of electronic switches, one for each winding, each of said switches having load terminals connected in series with said source and with a different on of said windings, each of said switches having a control terminal, a group of control circuits, one for each switch, each control circuit comprising an output terminal connected to a different one of said control terminals and two input terminals, each of said control circuits comprising a resistor connected between a first of said input terminals and said output terminal, each of said control circuits comprising a diode connected between the second of said input terminals and said output terminal, a group of register means, one for each control circuit, for storing a signal indicating whether or not a winding is to be energized, each register means being operatively connected to a different one of said first input terminals to close the associated switch when and only when the stored signal indicates the associated winding is to be energized and a predetermined second signal is applied to the second input terminal of the control circuit, and pulse-generating means connected to all of said second input terminals and actuable to apply said second signal to said second input terminals for a predetermined time.

Claim 13

In a high-speed printer, a group of hammer-driving solenoids each having a winding, an electrical source, a group of electronic switches, one for each winding, each of said switches having load terminals connected in series with said source and with a different on of said windings, each of said switches having a control terminal, a group of control circuits, one for each switch, each control circuit comprising an output terminal connected to a different one of said control terminals and two input terminals, each of said control circuits comprising a resistor connected between a first of said input terminals and said output terminal, each of said control circuits comprising a diode connected between the second of said input terminals and said output terminal, a group of register means, one for each control circuit, for storing a signal indicating whether or not a winding is to be energized, each register means being operatively connected to a different one of said first input terminals to close the associated switch when and only when the stored signal indicates the associated winding is to be energized and a predetermined second signal is applied to the second input terminal of the control circuit, and pulse-generating means connected to all of said second input terminals and actuable to apply said second signal to said second input terminals for a predetermined time.

Claim 14

The apparatus of claim 9, in which said switches each comprise a variable impedance and a fixed impedance connected in series with said load terminals, and means responsive to said second signal and the voltage across said fixed impedance for controlling said variable impedance to maintain the current through said load terminals substantially constant when said switch is closed.

Claim 15

In a high-speed printer comprising a group of electromagnetic windings each energizable to effect printing in a different column, a control circuit comprising a source of electrical energy, current control means for each winding connected in series with that winding and said source and responsive to the amplitude and duration of an applied signal for supplying current from said source to energize the winding in an amount determined by the amplitude of the applied signal for the duration of the applied signal storage means for each winding for storing a signal indicating whether or not the winding is to energized, signal generating means operable to produce a signal having a predeTermined amplitude and duration, and gate means controlled by said storage means and said pulse-generating means for supplying a signal resistor an amplitude and duration determined by the amplitude and duration of the signal produced by said signal generating means to each of said current control means for which the corresponding storage means is storing a signal indicating that the corresponding winding is to be energized, each of said gate means comprising a diode having a first terminal connected to said signal-generating means and a second terminal connected to the corresponding current control means, and a resistor connected between the second terminal of the diode and the corresponding storage means.

Claim 16

In a high-speed printer comprising a group of electromagnetic windings each energizable to effect printing in a different column, a control circuit comprising a source of electrical energy, current control means for each winding connected in series with that winding and said source and responsive to the amplitude and duration of an applied signal for supplying current from said source to energize the winding in an amount determined by the amplitude of the applied signal for the duration of the applied signal storage means for each winding for storing a signal indicating whether or not the winding is to energized, signal generating means operable to produce a signal having a predeTermined amplitude and duration, and gate means controlled by said storage means and said pulse-generating means for supplying a signal resistor an amplitude and duration determined by the amplitude and duration of the signal produced by said signal generating means to each of said current control means for which the corresponding storage means is storing a signal indicating that the corresponding winding is to be energized, each of said gate means comprising a diode having a first terminal connected to said signal-generating means and a second terminal connected to the corresponding current control means, and a resistor connected between the second terminal of the diode and the corresponding storage means.

Claim 17

In combination, a set of storage means each having an output terminal and actuable to produce a first or a second voltage on said output terminal, a resistor for each storage means having a first terminal connected to said output terminal and a second terminal, a diode for each resistor having a first terminal connected to said second terminal of the resistor and a second terminal, and pulse-generating means connected to the second terminals of all the said diodes and actuable to apply a pulse of voltage between said first voltage and said second voltage to said second terminals.

Claim 18

In combination, a set of storage means each having an output terminal and actuable to produce a first or a second voltage on said output terminal, a resistor for each storage means having a first terminal connected to said output terminal and a second terminal, a diode for each resistor having a first terminal connected to said second terminal of the resistor and a second terminal, and pulse-generating means connected to the second terminals of all the said diodes and actuable to apply a pulse of voltage between said first voltage and said second voltage to said second terminals.

Claim 19

The apparatus of claim 12, further comprising an electronic switch for each resistor, each switch being connected to the second terminal of the resistor and closed when and only when said pulse is applied to said second terminal of the corresponding diode and said second voltage is applied to the first terminal of the resistor, a source of electrical energy, and an electromagnetic winding for each switch connected in series with the switch and said source.

Claim 20

In combination, a plurality of register means for storing a corresponding plurality of signals each having a first value or a second value, a gate for each register means, each gate comprising a resistor having one terminal connected to the corresponding register means to receive said signal, a diode having two terminals for each resistor, each resistor having a second terminal connected to one terminal of the corresponding diode, pulse-generating means connected to the other terminal of said diodes and actuable to apply a pulse of predetermined amplitude and duration to said diodes and to bring the signals at the junctions of said diodes and said resistors to first or second values determined by the amplitude of said pulse and the presence of said first or said second signal applied to the corresponding resistor, a winding for each register means, a source of electrical energy, and switching means for each winding connected in series with the winding and with the source, each of said switching means being connected to a different one of the junctions of said resistors and diodes for closing or not closing a circuit path between said source and the corresponding winding according as the signal at the junction when said pulse is produced has said first or said second value, respectively.

Claim 21

In combination, a plurality of register means for storing a corresponding plurality of signals each having a first value or a second value, a gate for each register means, each gate comprising a resistor having one terminal connected to the corresponding register means to receive said signal, a diode having two terminals for each resistor, each resistor having a second terminal connected to one terminal of the corresponding diode, pulse-generating means connected to the other terminal of said diodes and actuable to apply a pulse of predetermined amplitude and duration to said diodes and to bring the signals at the junctions of said diodes and said resistors to first or second values determined by the amplitude of said pulse and the presence of said first or said second signal applied to the corresponding resistor, a winding for each register means, a source of electrical energy, and switching means for each winding connected in series with the winding and with the source, each of said switching means being connected to a different one of the junctions of said resistors and diodes for closing or not closing a circuit path between said source and the corresponding winding according as the signal at the junction when said pulse is produced has said first or said second value, respectively.

Claim 22

A print control circuit for a high-speed printer in which there are a group of electromagnetic coils each energizable to effect printing in a different column, comprising a source of electrical energy, a different switching means connected in series with each of said coils and with said source and responsive to an applied signal to supply or not supply energy from said source to said coil according as said signal has a first or a second value, respectively, gate means for each switching means comprising a resistor and a diode each having a first terminal and a second terminal, said first terminals of each resistor and diode being connected together and to said switching means to apply a signal to the switching means determined by the potential at said first terminals, storage means for each gate means for applying a first or a second potential to the second terminal of the resistor according as the corresponding coil is to be energized or nOt energized, respectively, and pulse-generating means connected to the second terminal of all of said diodes and actuable to apply a pulse to said second terminals produce said first signal or said second signal at the said first terminals according as the corresponding storage means is applying said first or said second potential to the second terminal of the corresponding resistor.

Claim 23

A print control circuit for a high-speed printer in which there are a group of electromagnetic coils each energizable to effect printing in a different column, comprising a source of electrical energy, a different switching means connected in series with each of said coils and with said source and responsive to an applied signal to supply or not supply energy from said source to said coil according as said signal has a first or a second value, respectively, gate means for each switching means comprising a resistor and a diode each having a first terminal and a second terminal, said first terminals of each resistor and diode being connected together and to said switching means to apply a signal to the switching means determined by the potential at said first terminals, storage means for each gate means for applying a first or a second potential to the second terminal of the resistor according as the corresponding coil is to be energized or nOt energized, respectively, and pulse-generating means connected to the second terminal of all of said diodes and actuable to apply a pulse to said second terminals produce said first signal or said second signal at the said first terminals according as the corresponding storage means is applying said first or said second potential to the second terminal of the corresponding resistor.