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US 4,459,053 AGranted
Serial dot printer for office machines
AssigneeIng. C. Olivetti & C., S.p.A.
InventorLuciano Ceresa
Life of this patent
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AssigneeIng. C. Olivetti & C., S.p.A.
InventorLuciano Ceresa
Estimating the term…
The printer comprises a solid or liquid ink jet head 100 arranged to print one dot at a time on paper running over a platen 80. The head is carried by a carriage 48 movable transversely with simple harmonic reciprocating motion. In order to reduce the effect of inertial forces when the carriage reverses its movement, the drive is effected by an eccentric peg 70 on a disc 276, the peg engaging in a guide slot 54 of the carriage perpendicular to the direction of reciprocation. An eccentric can track 71 in the disc engages a peg 92 on a counterweight 90 for counterbalancing the inertial forces of the carriage. In order to synchronize the printing operation with the carriage movement, an optical strobe disco 258 is rigid with the disc 276 and has slots 258 disposed at a pitch varying according to the harmonic motion. The platen 80 in rotated intermittently by a helical cam 277 carried by the disc 276 and a peg wheel 280, 281. In order to compensate for discharge of a smoothing or reservoir circuit feeding the printing head 100, the duration of the pulses applied thereto can be increased in accordance with the rate at which dots are being printed. In a modification the strobe disc is replaced by a linear transducer of capacitive type, with one part carried by the carriage.
A serial dot printer for printing dots in a series of printing positions on the paper, comprising a printing head including an ink container having a nozzle through which ink particles are ejected, an operating circuit selectively activable by a control signal to supply printing pulses between an electrode connected with an electrically conductive ink and a counterelectrode located outside said nozzle, said operating circuit comprising a control circuit selectively settable for varying the voltage and duration of said control signal for causing said operating circuit to supply printing pulses having a predetermined energy, whereby the black intensity of the printed dots can be adjusted.
A serial dot printer for printing dots in a series of printing positions on the paper, comprising an ink jet printing head to direct on demand uncharged ink dots on the paper, an operating circuit selectively activable by a control signal to supply printing pulses of suitable energy to said ink to maintain the black intensity of the printed dots constant, voltage generating means to generate a voltage depending on the time interval of two consecutive pulses, and a timer circuit selectively settable to vary the duration of said control signal in accordance with said depending voltage, in order to keep said pulse energy constant.
A serial dot printer for printing dots in a series of printing positions on the paper, comprising a printing head of ink jet type, an operating circuit selectively activable by a control signal to supply printing pulses to said ink, a timer circuit selectively settable for varying the duration of said control signal for causing said operating circuit to supply printing pulses having a desired energy and a power supply unit for the timer circuit to supply a constant voltage at an output terminal and having a first inductance, connected to an oscillator transistor, a second inductance coupled to the first inductance and connected to said oscillator transistor in order to establish a feedback voltage and further connected in series with a second transistor in order to modify the feedback voltage in response to the voltage variations at the output terminal.
A serial dot printer for printing dots in a series of printing positions on the paper, comprising a printing head of ink jet type, an operating circuit selectively activable by a control signal to supply printing pulses to an electrically conductive ink, a voltage generator, an electric power storage adapted to be progressively charged in a given time by said voltage generator, said power storage being conditionable by said control signal to activate said operating circuit, a timer circuit selectively settable by the voltage charged in said power storage for varying the duration of said control signal for causing said operating circuit to supply printing pulses having a constant energy independently from the time interval between two subsequent printing pulses.
Dependencies are inferred from the claim text.