Detection of developer powder amount contained in a developer reservoir
US4174902A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 21, 1977 |
| Grant date | Nov 20, 1979 |
| Priority date | — |
| Expiry date | Oct 21, 1997 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S222/01
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An opening is formed in a bottom wall of a developer reservoir, where a U-shaped diaphragm is secured. The diaphragm is bent downward when developer powder is present in the developer reservoir more than a predetermined amount. When the quantity of developer powder decreases below the predetermined amount during a development operation, the diaphragm returns to its initial configuration, that is, the diaphragm is bent upward. The bent conditon of the U-shaped diaphragm is detected through the use of a suitable detection device such as a microswitch, whereby an alarm lamp is activated when the developer powder decreases to below the predetermined amount.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.