US 4,302,117 AGranted

High speed variable intensity printing system

AssigneeFujitsu Limited

InventorOsamu Tomita

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Abstract

The present invention relates to a high speed printing system, in which the printing intensity of each type element, applied onto a record media, is varied in accordance with the surface area of the type element. The system employs a double control mode, in each hammering operation, for carrying out the variation of the printing intensity. The double control mode is comprised of a first control mode and a second control mode, which follows immediately after the first control mode. In the first control mode, a maximum energizing current is supplied to a hammer means, comprising a dc motor, for hammering a selected type element to produce a desired character on the record media. In the second control mode, an energizing current is applied to the hammer means. The latter energizing current has variable peak amplitude which is suitable for carrying out fine control of the printing intensity in accordance with the size of the surface area of each type element.

Claims14

Dependent claims

A high speed printing system, for printing on a record media, comprising:

means for providing printing data;
a platen for supporting the record media;
a carrier which traverses back and forth in parallel to the platen;
a printing head having a plurality of type elements, said printing head being mounted on the carrier, said printing head being selectively positioned in one of an idling position, an impact position located at said platen, and a floating stable position located between the idling position and the impact position;
first means for rotating the printing head so as to move a selected one of the type elements to a position facing the platen;
second means for hammering the printing head so that the selected type element impacts on the platen, said second means locating said printing head at the idling position when no printing data is being provided, said second means moving said printing head between the floating stable position and the impact position when successive printing data is being provided;
a third means for controlling a variable impact intensity of the selected type element to be applied to the platen said third means operating to supply at least a first energizing current and a second energizing current successively to the second means, said first energizing current having a maximum constant peak amplitude with respect to any of the type elements, and said second energizing current having a peak amplitude which varies in dependence upon the selected type element;
fourth means for spacing said carrier along the platen;
fifth means for supplying information to said third means, said information specifying the peak amplitude of the second energizing current, said information predetermined with respect to each type element;
and
sixth means for controlling said third means so as to vary the timing for supplying the second energizing current to said second means in dependence upon the selected type element.

8 more elements

A control circuit for a high speed printing system, having type elements and having a hammering means including a dc motor, comprising:

a digital controller circuit for providing first, second and third hammer position signals, first and second hammer energy specifying signals, and a hammer firing signal;
an energizing pulse setting circuit, operatively connected to said digital controller circuit, for receiving said hammer firing signal and said first and second hammer energy specifying signals and for providing, as an output, a hammer driving pulse signal;
a printing impact controller circuit, operatively connected to said energizing pulse setting circuit, for receiving said hammer driving pulse signal and for providing, as an output, a hammer energy controlling pulse signal;
a hammer energy specifying circuit, operatively connected to said digital controller circuit and said printing impact controller circuit, for receiving said first and second hammer energy specifying signals and said hammer energy controlling pulse signal and for providing, as an output, first and second energizing current signals;
a potentiometer, operatively connected to the dc motor for providing a displacement signal;
hammer control means, operatively connected to said digital controller circuit and said potentiometer, for receiving said first, second and third hammer position signals and said displacement signal and for providing a hammer velocity position signal;
and
analog switch means, operatively connected to said energizing pulse setting circuit, said hammer energy specifying circuit, said hammer control means, and the dc motor, for receiving said hammer driving pulse signal, said first and second energizing current signals, and said hammer velocity position signal, and for providing an output signal for driving the dc motor;
said analog switch means operating to supply at least said first energizing current signal and said second energizing current signal successively to the dc motor, the first energizing current signal having a maximum constant peak amplitude with respect to any of the type elements, and the second energizing current signal having a peak amplitude which is variable in dependence upon which of the type elements is selected.

6 more elements

Dependencies are inferred from the claim text.