Seiko Epson Corporation

Kunihiro Inoue

Hajime Miyazaki

Tetsushi Takahashi

Yusuke Sakagami

Kazuhiko Sato

Masahisa Ikejiri

Tadaaki Hagata

Tsukasa Muranaka

Michio Yanagisawa

Shouichi Uchiyama

Tadashi Shimizu

Method and apparatus for printing images on a stack of recording sheets

A humidity sensing apparatus which includes a humidity sensor which detects humidity as a function of impedance is provided. A reference resistor has a predetermined resistance value. A charge switching circuit selectively couples one of the reference resistor or the humidity sensor in series with a reference capacitor which has a predetermined capacitance. A voltage judging circuit determines whether the terminal voltage of the reference capacitor is high or low. A charge/discharge switch selectively charges and discharges the reference capacitor in accordance with the output of the voltage judging circuit. A sensor direction switching circuit inverts the direction of current flowing through the humidity sensor during charging of the reference capacitor. An oscillation frequency counter counts the number of charge/discharge cycles which are repeated during a predetermined time period. A humidity sensor resistance value calculating circuit calculates the resistance value of the humidity sensor in accordance with the number of repeated charge/discharge cycles when the reference capacitor is coupled to the reference resistor for charging and the number of repeated charge/discharge cycles when the reference capacitor is coupled to the humidity sensor during charging. A humidity determining circuit determines the humidity from the resistance value of the humidity sensor calculated by the humidity sensor resistance value calculating circuit.

Humidity measuring apparatus

Growing community of inventors

Suwa, Japan

Kunihiro Inoue