LOG OUTPUT BLACK OPTICAL SENSOR
Original Publication Date: 1994-Jun-30
Included in the Prior Art Database: 2004-Apr-07
Xerox Disclosure Journal
Proposed is the use of a logarithmic type amplifier at the output of an optical reflectance sensor in an Infrared (IR) densitometer. The logarithmic amplifier replaces a linear circuit having digitally selectable modes for high gain operation that provide low quantization errors. A logarithmic output sensor simplifies the sensor circuitry and does away with digital control lines when the reflectance sensor light emitting diode (LED) is continuously on. The high dynamic range of the logarithmic amplifier improves signal to noise ratio quantization errors at low level outputs.