Patent · US Expired

Device for detecting remaining level of toner

US5587770A · kind A · utility

33Cited by
20References
21Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 17, 1995
Grant dateDec 24, 1996
Priority date
Expiry dateFeb 17, 2015

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03G15/0875
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

The present invention provides a developing device of an electrophotographic recording system for developing an electrostatic latent image formed on a photosensitive drum. The developing device includes a hopper which stores toner and a developing roller which develops the electrostatic latent image formed on the photosensitive drum using the toner stored in the hopper. On one side of the hopper at a predetermined height from its bottom, a light-emitting element for emitting light is positioned. A toner detecting device detects the existence or non-existence of toner by using a light-receiving element positioned on the interior of the hopper which outputs signals corresponding to the existence or non-existence of toner in the hopper in response to the amount of the light received from the light-emitting element. An agitator conveys the toner to the developing roller and simultaneously cleans a light-emitting side of the light-emitting element and a light-receiving side of the light-receiving element in synchronism with a conveyance period of the toner. A signal transmitting device transmits signals from the light-receiving element to a CPU which compares the number of signals with …

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.