Determining defective resistors in inkjet printers
US7448718B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 29, 2006 |
| Grant date | Nov 11, 2008 |
| Priority date | — |
| Expiry date | May 15, 2027 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41J2/0457
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A method and apparatus for determining defective heating resistors Ri in each of a plurality of inkjets in an inkjet printer, wherein each heating resistor Ri is connected in parallel with a common capacitor, the method for each heating resistor Ri includes providing a variable power supply effective in a first condition to produce a first operating DC voltage and, in a second condition, to produce a second known test DC voltage Vt, and inserting a known reference resistor Rr in series with the heating resistor Ri and capacitor and also open circuiting the capacitor in response to sensing that the power supply has changed from the first condition to the second condition. The method and apparatus further include digitizing the voltage Vi at the electrical junction between the heating resistor Ri and the reference resistor Rr, and using the digitized voltage to determine if the heating resistor Ri is defective.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.