Ricoh Company, Ltd.

Other

Tohoku Ricoh Co., Ltd.

Masae Sugawara

Toshiaki Higaya

Tomotaka Takamura

Hiroto Ohishi

Akiko Miyahara

Naoki Sato

Keiichi Sugai

Masashi Ooi

Yuta Nomura

Masashi Oi

A charging unit charges a capacitor that is configured to be charged and discharged to drive a load. A switching unit switches on and off between the capacitor and the charging unit. A delay control unit delays an output of a switching control signal for controlling the switching unit until an output voltage of the charging unit exceeds a voltage of the capacitor, and outputs a delayed switching control signal. An output unit receives the delayed switching control signal from the delay control unit, and outputs the delayed switching control signal to the switching unit so that the charging unit charges the capacitor.

Power supply device and image forming apparatus

A voltage converting unit converts a first voltage of an auxiliary power supply unit into a second voltage. A voltage determining unit determines whether the second voltage exceeds a predetermined threshold. A first switch, which is arranged between the voltage converting unit and a load, switches on and off a supply of an electric power of the second voltage to the load. When it is determined that the second voltage exceeds the predetermined threshold, a voltage-conversion control unit controls the voltage converting unit to stop converting the voltage, and then a switching control unit controls the first switch to supply the electric power of the second voltage to the load.

An auxiliary power supply unit, which is attachable to and detachable from an apparatus, includes a charge unit configured to store electric charge, a terminal configured to establish electrical connection for discharge with the apparatus, and a discharge unit situated between the charge unit and the terminal to provide a discharge path that electrically connect the charge unit to the apparatus, the discharge path having an open/closed state thereof controlled during a period when an electric power is supplied from the apparatus, the discharge path being opened in response to a stoppage of supply of the electric power from the apparatus.

Auxiliary power supply unit and image forming apparatus

An induction heating type fixing device for an electrophotographic image forming apparatus is disclosed. An inducting heating coil has a plurality of bobbins each having a particular diameter and assembled in a telescopic manner. A particular conductor is wound round each bobbin beforehand with leads being laid inside of the conductor. The bobbin may be implemented as a plurality of bobbin members removably connected together.

Induction heating type fixing device for an image forming apparatus and induction heating coil therefor

A fixing roller in an image forming apparatus (such as a copier) has a fixing heater that is supplied power from a capacitor. The fixing heater, the capacitor, a mechanical switch (such as a relay) and a semiconductor switch (such as a FET) are serially connected. As a cover of the apparatus is opened, an interlock switch is turned on and outputs an off-signal to a CPU, which turns off the semiconductor switch prior to turning off the mechanical switch, and thereby prevents a counter-electromotive voltage due to an inrush current.

Method for controlling power supply to fixing roller in image forming apparatus

An induction heating device includes a plurality of induction coils connected to a single high-frequency power source and each being able to be ON/OFF controlled by a switch. A current is selectively fed only to desired part of the induction coils or to all of the induction coils connected in parallel. The coils are driven by a current fed thereto at the same time in the same phase. The device may include inverters for controlling power to be fed coil by coil. The device is free from interference and irregular heating and can readily cope with a change in a heating range while controlling power coil by coil.

Growing community of inventors

Miyagi, Japan

Masae Sugawara