Spacing compensating electrostatic voltmeter

• US 6,806,717 B2
• Filed: 08/21/2002
• Issued: 10/19/2004
• Est. Priority Date: 09/27/2001
• Status: Expired due to Fees

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Wallace, Stanley J., Werner, Alan J. Jr., Kubby, Joel A., Peeters, Eric, Viturro, R. Enrique, Hubble, Fred F. III
• Primary Examiner(s): Nguyen, Vincent Q.
• Application Number:
  US10/225,555
• Publication Number:
  US 20030057977A1
• Time in Patent Office: 790 Days
• Field of Search: 324/457, 324/458, 324/658, 324/661, 324/663, 324/665, 324/713, 399/73
• US Class Current: 324/458
• CPC Class Codes: G01R 29/12 Measuring electrostatic fields or voltage-potential

Abstract

An electrostatic type voltmeter for measuring the potential on a surface, the voltmeter including a probe; a support for supporting the probe in spaced relationship with the surface, the probe having a plurality of spacing element sites thereon for measuring a distance between each of the plurality of spacing element sites and a corresponding area on the surface opposite of each of the plurality of spacing element sites; a plurality of electrostatic element sites, intermixed and adjacent to the plurality of spacing element sites on the probe, for measuring a voltage between each of the plurality of spacing element sites and an area on the surface adjacent to the corresponding area opposite of each of the plurality of spacing element sites. A processor for compensating an output signal of the probe in response to the measurements received from the plurality of spacing element sites and the plurality of electrostatic element sites.

Claims

1. In an electrostatic type voltmeter for measuring the potential on a surface, the voltmeter including:

a probe;

support means for supporting said probe in spaced relationship with said surface, said probe having a plurality of spacing element sites thereon for measuring a distance between each of said plurality of spacing element sites and a corresponding area on said surface opposite of each said plurality of spacing element sites;

a plurality of electrostatic element sites, intermixed and adjacent to said plurality of spacing element sites on said probe, for measuring a voltage between each of said plurality of spacing element sites and an area on said surface adjacent to said corresponding area opposite of each said plurality of spacing element sites each of said plurality of electrostatic element sites includes;

a sensor component for measuring a voltage by capacitive coupling;

a movable shutter that selectively overlays the sensor component; and

a shutter driver for opening and closing said movable shutter;

a modulator for shuttering each driver of each of said plurality of electrostatic element site independently from each other and

means for compensating an output signal of said probe in response to the measurements received from said plurality of spacing element sites and said plurality of electrostatic element sites.

2. The voltmeter of claim 1, wherein said each of said plurality of spacing element sites includes:

a sensor component for measuring a voltage by capacitive coupling;

a movable shutter that selectively overlays the sensor component; and

a shutter driver for opening and closing said movable shutter; and

a processor for translating voltage measurement to a distance measurement to said surface.

3. The voltmeter of claim 2, further comprising a modulator for shuttering each driver of each of said plurality of spacing element sites independently from each other.

4. The voltmeter of claim 2, wherein said shutter defines a plurality of windows movable between a first position where the sensor component is exposed and a second position where the sensor component is covered, the shutter being adjacent to the sensor component.

5. The electrostatic voltmeter of claim 4, where the shutter driver comprises:

a micro-electro-mechanical system having an electrostatic comb drive defining a maximum displacement (.delta .x) along an axis parallel to the comb fingers.

6. The electrostatic voltmeter of claim 5, where each of the plurality of windows defines a length (1) perpendicular to the comb fingers and a width (w) parallel to the comb fingers, the width being equal to the maximum displacement.

7. In an electrostatic type voltmeter for measuring the potential on a surface, the voltmeter including:

a probe;

support means for supporting said probe in spaced relationship with said surface, said probe having a plurality of spacing element sites thereon for measuring a distance between each of said plurality of spacing elements sites and a corresponding area on said surface opposite of each said plurality of spacing element sites;

a plurality of electrostatic element sites, intermixed and adjacent to said plurality of spacing element sites on said probe, for measuring a voltage between each of said plurality of spacing element sites and an area on said surface adjacent to said corresponding area opposite of each said plurality of spacing element sites;

each of said plurality of electrostatic element sites includes;

a sensor component for measuring a voltage by capacitive coupling;

a movable shutter that selectively overlays the sensor component; and

a shutter driver for opening and closing said movable shutter; and

said shutter defines a plurality of windows movable between a first position where the sensor component is exposed and a second position where the sensor component is covered, the shutter being adjacent to the sensor component and means for compensating an output signal of said probe in response to the measurements received from said plurality of spacing element sites and said plurality of electrostatic element sites.

8. The electrostatic voltmeter of claim 7, where the shutter driver comprises:

a micro-electro-mechanical system having an electrostatic comb drive defining a maximum displacement (.delta .x) along an axis parallel to the comb fingers.

9. The electrostatic voltmeter of claim 8, where each of the plurality of windows defines a length (1) perpendicular to the comb fingers and a width (w) parallel to the comb fingers, the width being equal to the maximum displacement.