Ink level sensing system for an ink jet printer
US5731824A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 18, 1995 |
| Grant date | Mar 24, 1998 |
| Priority date | — |
| Expiry date | Dec 18, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01G17/06
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
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, mult…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.