Electric potential measuring apparatus, and image forming apparatus
AssigneeCanon Kabushiki Kaisha
InventorsYoshikatsu Ichimura, Yoshitaka Zaitsu, Takashi Ushijima, Atsushi Kandori
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Abstract
An electric potential measuring apparatus including a substrate disposed facing a measurement object, a detecting electrode provided insulated from the substrate, and a capacity modulating unit for modulating a coupling capacity between the detecting electrode and the measurement object. In the electric potential measuring apparatus, a region with a dielectric constant less than a dielectric constant of the substrate is formed in the substrate to achieve an increase in resistivity of a portion of the substrate between detecting electrodes, or a decrease in a stray capacity between the detecting electrode and the substrate.
Claims10
An electric potential measuring apparatus operable to measure an electric potential of a measurement object, comprising:
- a substrate formed of a semiconductor material;
- an insulator layer;
- a plurality of detecting electrodes provided on the substrate with the insulator layer therebetween using MEMS techniques;
- a capacitance modulating unit configured to modulate a coupling capacitance between the detecting electrodes and the measurement object;
- a detecting unit configured to detect an electric potential of the measurement object based on a signal detected by the detecting electrodes;
- and
- an insulator portion formed in at least a portion of the substrate,
- wherein the insulator portion is provided at least one of a position where a length of an electric path between the detecting electrodes that is created in the substrate through a stray capacitance caused in the insulator layer is elongated, a position where the electric path is narrowed in a thickness direction of the substrate, and a position where the electric path is insulated.
Dependencies are inferred from the claim text.