| US 7,548,066 B2 | ||
| Potential measuring device and image forming apparatus using the same | ||
| Yoshikatsu Ichimura, Tokyo (Japan); Takashi Ushijima, Yokohama (Japan); Atsushi Kandori, Ebina (Japan); and Yoshitaka Zaitsu, Kawasaki (Japan) | ||
| Assigned to Canon Kabushiki Kaisha, Tokyo (Japan) | ||
| Filed on May 10, 2006, as Appl. No. 11/430,992. | ||
| Claims priority of application No. 2005-142011 (JP), filed on May 16, 2005. | ||
| Prior Publication US 2006/0267593 A1, Nov. 30, 2006 | ||
| Int. Cl. G01R 29/12 (2006.01); G03G 15/00 (2006.01); G03G 15/06 (2006.01) | ||
| U.S. Cl. 324—458 [324/457; 399/48; 399/56] | 13 Claims |
| 1. A potential measuring device for measuring a potential of a measurement object, said device comprising:
a detection electrode;
a reference electrode that is electrostatically shielded constantly during potential measurement by an electrostatic shield
structure with respect to the measurement object;
a capacitance modulator for modulating an electrostatic coupled capacitance between said detection electrode and the measurement
object; and
a measuring circuit for measuring a potential of the measurement object by using an electrical signal generated on said detection
electrode and an electrical signal generated on said reference electrode.
|