PURPOSE: To remove the frequency component of a signal from a lamp driving source without installing a complicated circuit by providing the detected signal processing circuit of an original density detecting sensor with a prescribed filter.
CONSTITUTION: Light reflected by an original 2 makes incident on an optical sensor 1 being an original detecting sensor. According to a method to detect density based on a signal detecting the prescribed range of the original 2, the sensor 1 arranged below the reflector 3 of a light source receives reflected light from the original 2 of a length l through a slit provided on the reflector 3, and an AMP4 amplifies its output signal and passes it through a low-pass filter 5. Then, an A/D converter 6 digitizes the signal and a CPU fetches it. By installing the filter 5, the noise of a power source frequency component from the signal outputted from the sensor can be removed, and only the detecting signal corresponding to original density is outputted to the converter 6.
TOKISHIGE MASATO
INAMOTO KIYOSHI
ONISHI KAZUYUKI
AIDA KAZUNORI
OKANO TOKIYUKI
| JPS62143945U | 1987-09-10 | |||
| JPS61110002A | 1986-05-28 |