Electrostatographic copier/printer densitometer insensitive to power supply variations
US5148217A · kind A · utility
8Cited by
4References
8Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 24, 1991 |
| Grant date | Sep 15, 1992 |
| Priority date | — |
| Expiry date | Jun 24, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G2215/00042
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A densitometer includes a light source positioned to project light rays to a test surface. A photodetector is positioned to receive light rays from the surface, and has an output which is characteristic of the amount of light received. The densitometer includes a voltage source and a photodetector which generates an output signal which is a function of a measured density and of the voltage of the source. A log amp produces a signal which is substantially proportional to the ratio of the output of the photodetector and a second output signal which is also a function of the voltage of the source.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.