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:
Feb. 15, 1983
Filed:
May. 15, 1981
Carl R Bildstein, Lafayette, CO (US);
Harry P Heibein, Longmont, CO (US);
Harlan P Mathews, Louisville, CO (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
An ink jet pump is switched from a mechanically off or idle state to a mechanically on or active state with no drift in pressure output by maintaining the pump at the same point in its force-temperature characteristic when it is on and off. This is accomplished by driving the pump in both the active and idle states with signals that dissipate the same amount of power in the pump. The frequency of the idle state signal is high enough that the pump can not mechanically respond. The power dissipations in the active and idle states are matched by adjusting the current build-up and current decay through the coil of the pump during the idle state. When the RMS current through the coil in the active state equals the RMS current in the idle state, the power dissipations are matched.