Ricoh Company, Ltd.

Masashi Ooi

Naoki Sato

Masae Sugawara

Keiichi Sugai

A reference voltage generating unit generates a plurality of analog reference voltages, and an A/D converting unit converts the analog reference voltages thus generated and an analog input voltage input from an external device to digital reference values. A CPU generates, based on the analog reference voltages and the digital reference values converted from the analog reference voltages, an equation for correcting the analog input voltage to be converted to a digital value falling in a range of the digital reference values. With the equation generated, the CPU calculates the analog input voltage for the digital value obtained by conversion.

A/D convertion controlling device and image forming apparatus

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.

Growing community of inventors

Miyagi, Japan

Masashi Ooi