Automatic toner density adjusting device of electrophotographic device

Abstract

Abstract PURPOSE:To correct a variation of environmental humidity, and also to prevent generation of background fog, by constituting a device so that a variation of a toner charged quantity is reduced, in order to maintain developing performance of a developer in a desirable state. CONSTITUTION:A toner density detecting element measures a reflection factor of a developer by a photoelectric detecting element TR consisting of a light diode DL and a phototransistor. An amplification output signal by an amplifier IC2 for receiving a detecting signal from the photoelectric detecting element TR is compared with a reference signal applied by resistances R3, R4 and R5, and a humidity detecting element R6, and a control signal is generated. For instance, when toner density in a developer drops and a reflection factor of the developer increases, a toner density detecting signal increases, a signal generated by being amplified from the amplifier IC2 also becomes large, becomes large than a reference signal voltage value applied to a connecting point of the resistances R3 and R4, and an amplifier IC3 executing a comparator operation is set to an on-state. When an output signal from the amplifier IC3 is received, a transistor TR1 is operated, a driving means M of a toner supplying device connected to a collecting circuit, that is to say, a solenoid, a clutch, a motor, etc. are operated, and a toner is supplied.

Inventors

• 👤 Masaharu Nishikawa
• 👤 正治 西川

Bibliographic Details