Cooldown timing system monitors inkjet cartridge ink levels
US5721573A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 24, 1995 |
| Grant date | Feb 24, 1998 |
| Priority date | — |
| Expiry date | May 24, 2015 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41J2/17566
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An inkjet cartridge cooldown time system is used to monitor the ink level remaining in the cartridge to provide an early warning before the cartridge is completely empty, so the cartridge may be either refilled or replaced. An ink level monitoring method selects first and second cartridge temperatures. Then the cartridge is paused during a printing operation, such as during a form feed, to measure the cooldown time required for the cartridge to transition from the first temperature to the second temperature. The measuring step is repeated to compile a set of cooldown times. In a signaling step, the operator is alerted of the approach of an out of ink condition when a cooldown time has increased a selected value, such as at least 20%, over the compiled set of cooldown times. An inkjet printing mechanism is also equipped for using this method to monitor ink levels.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.