US 7,460,803 B2
Electric potential measuring device using oscillating device, image forming apparatus, and electric potential measuring method
Yoshikatsu Ichimura, Tokyo (Japan); Yasuhiro Shimada, Kanagawa-ken (Japan); Yasushi Mizoguchi, Miyagi-ken (Japan); and Yoshitaka Zaitsu, Kanagawa-ken (Japan)
Assigned to Canon Kabushiki Kaisha, Tokyo (Japan)
Filed on Mar. 09, 2007, as Appl. No. 11/684,550.
Application 11/684550 is a division of application No. 10/540978, granted, now 7,242,882, previously published as PCT/JP2004/004191, filed on Mar. 25, 2004.
Claims priority of application No. 2003-092226 (JP), filed on Mar. 28, 2003.
Prior Publication US 2007/0154231 A1, Jul. 05, 2007
This patent is subject to a terminal disclaimer.
Int. Cl. G03G 15/00 (2006.01)
U.S. Cl. 399—48  [399/73; 324/458] 7 Claims
OG exemplary drawing
 
1. An electric potential measuring device, comprising:
a support member;
an oscillating body axially supported by the support member such that the oscillating body oscillates about the support member;
at least one pair of detection electrodes provided on a surface of the oscillating body with the oscillation axis between the pair of detection electrodes;
a drive portion for varying a distance between one of the detection electrodes and an electric potential measuring object disposed facing the detection electrodes and a distance between the other one of the detection electrodes and the electric potential measuring object by causing the oscillating body to oscillate; and
a signal detecting portion connected to the detection electrodes for detecting an output signal,
wherein lines of electric force from the electric potential measuring object reach the detection electrodes at all times while the oscillating body is oscillating, and
wherein the oscillating body is caused to oscillate such that when one of the pair of detection electrodes moves toward the electric potential measuring object, the other one of the pair of detection electrodes moves away from the electric potential measuring object.