Electrophotographic printing device
US5276461A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 13, 1990 |
| Grant date | Jan 4, 1994 |
| Priority date | — |
| Expiry date | Apr 13, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G2221/183
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A laser printer comprises a cartridge of a photosensitive unit, a printing mechanism for effecting a printing operation by electrifying a photosensitive member of the photosensitive unit, applying a light beam to the electrified photosensitive member to form an electrostatic latent image thereon, developing the electrostatic latent image to create a visible image and then transferring the image to printing paper, and a nonvolatile memory for storing data indicating the printing history of the photosensitive unit. The printing device further comprises a microprocessor for updating the data stored in the nonvolatile memory each time the printing operation is effected, checking whether the data stored in the nonvolatile memory has reached a value corresponding to a service life of the photosensitive unit, and generating a replacement requiring signal when it is detected that the data stored in the nonvolatile memory has reached the value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.