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:
Mar. 24, 1998
Filed:
Dec. 18, 1995
Gary A Kneezel, Webster, NY (US);
Joseph F Stephany, Williamson, NY (US);
William R Burger, Fairport, NY (US);
Xerox Corporation, Stamford, CT (US);
Abstract
The invention discloses a system and method for sensing changes in the weight of an ink reservoir which supplies ink to a printhead which ejects ink onto a recording medium during a printer operational mode. The ink reservoir, whether located separately from the printhead, as in a plotter or pagewidth printer embodiment, or mechanically attached to the printhead and moved in a scanning printhead architecture, has its weight supported by a structure. A strain gage or other weight sensor is affixed to the supporting structure and incorporated in a circuit which produces an output signal representative of resistive changes in the weight sensor. Since a resistive change in the weight sensor is caused by a decrease in the supply of ink in the reservoir during continued printer operation, the output signal is proportional to the ink level. The output signal is digitized and sent to a system controller where it is compared to a predetermined reference level and a low level output signal is generated for use as a warning to a operator or user. In one embodiment, the strain gage is a leg of a resistor in a bridge circuit and provides continuous ink level readout. In another embodiment, multiple warning levels are enabled by inserting the resistor in a circuit where comparators compare the resistance of the strain gage to reference resistance levels.