The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 24, 1988
Filed:
May. 23, 1986
Roberto Realis Luc, Ivrea, IT;
Alessandro Crotti, Strambino, IT;
Ing. C. Olivetti & C., S.p.A., Turin, IT;
Abstract
In an ink jet printing element in which the drop is expelled by generating a current pulse through the ink in the nozzle, in order to reduce the control voltage, a first pulse (Tr) for heating the ink is generated, followed by a vaporization pulse (Tv) with a delay such as to make the printing position independent of the direction of movement of the element with respect to the paper. The heating pulse (Tr) is generated by a circuit (31) controlled by a temperature sensor (34) so that the duration of the heating pulse has a negative temperature coefficient. The vaporization pulse (Tv) is generated by a circuit (32) manually controlled (potentiometer 39) to determine the pulse duration on the basis of the desired strength of the printing. The delay between the two pulses is controlled by a delay circuit (38), e.g. a monostable circuit. The two pulses are applied to a transformer (35) which generates the voltage between the electrodes. The two circuits (31, 32) may be constituted by one monostable circuit with separate RC networks sequentially enabled for determining the durations of the heating and vaporization pulses.