Method and apparatus for detecting charge and proximity

• US 20060092022A1
• Filed: 10/29/2004
• Published: 05/04/2006
• Est. Priority Date: 02/06/2003
• Status: Active Grant

• Current Assignee: Thomas G. Cehelnik
• Original Assignee: Thomas G. Cehelnik
• Inventors: Cehelnik, Thomas G.
• Granted Patent: US 7,242,298 B2
• Time in Patent Office: Days
• US Class Current: 340/561
• CPC Class Codes: G01V 3/088 operating with electric fields G01V3/082 takes precedence
• CPC Class Codes: G06F 3/011 Arrangements for interaction with the human body, e.g. for user immersion in virtual reality blind teaching G09B21/00
• CPC Class Codes: G08B 31/00 Predictive alarm systems characterised by extrapolation or other computation using updated historic data

Abstract

A method and apparatus is invented that provides unambiguously detection of the charge and proximity to an object. The method and apparatus are passive and function by using the background electric fields from electrical power wiring and equipment. The invention is useful for detecting plastic and other charged objects concealed by nonconductive covering materials. Applications of this lead to plastic detectors to scan people and cargo for dangerous dielectric items similar to metal detectors. It is also useful to warn of hazards due to static electricity buildup on objects or individuals. The technology also offers touchless control capability of computers, apparatus, and games, with plastic objects such as pointers, styluses, swords, sticks, and wands. The sensors are able to detect motion while discerning between proximity to bodies with dielectric or plastic objects. It is also useful for providing people, robots, and machines with obstacle avoidance, and vision capabilities. Medial imaging possibilities also exist with the technology of this invention.

Claims

1. A passive proximity sensor that uses changes in the background electric field strength to sense motion of charged and uncharged objects relative to the sensor that consists of:

a. where the A.C. background field is due to energy in the electric power wiring or due to operating machinery or other common devices.

b. uses said A.C. and D.C. dual band E-field sensor to detect charge and proximity of an object simultaneously by signal characteristic recognition.

c. performs proximity measurement by recognizing a monotonically increasing or decreasing change in the background field with decreasing separation between the sensor and object.

d. performs proximity measurement by recognizing a monotonically decreasing change in the background field with decreasing separation between the sensor and object for earth grounded objects.

e. Performs charge and plastic detection by recognizing a D.C. offset in the sensor output while observing the proximity signal in claim c.

2. A device described in claim 1 used to detect charged and uncharged objects concealed by nonmetallic covering material.

3. A device described in claim 1 used to detect plastics.

4. A device described in claim 1 used to detect plastics concealed by nonmetallic covering material.

5. A device described in claim 3 or claim 4 that is integrated into a metal detector device.

6. A device described in either claim 1, claim 3, or claim 4, that is used to detect explosives.

7. A device described in either claim 1, claim 3, or claim 4 used to detect explosives concealed by nonmetallic covering material.

8. Case where the object in claim 1 and claim 2 is a person or part thereof such as the hand.

9. Case where the object in claim 1 and claim 2 is a person or part thereof concealed behind by a nonmetallic covering material such as a wall.

10. A device described in claim 1 used in a medical examination to scan bodies for broken bones or location of nerves or other covered substructures such as skin or bone.

11. Claim is made when the object or body in claim 8, claim 9, or claim 10 is an animal, plant, or other body.

12. A device as in claim 1 where the A.C. output of the preamplifier is processed digitally or it is fed into a possibly amplified detector circuit such as FIG. 2.

13. A device in claim 1 using filters to achieve good equalized signal strength across the frequency band from DC to 60 Hz range so to observe quasistatic charge signals from the DC side of the band and the proximity signals from the 50-60 Hz side of the band.

a. A Device using the method of claim 13, with another proximity detection band of AC from local equipment or environmental signal other than that from the power line.

14. A device as in claim 1 and claim 2 that uses another frequency band of characteristic radiation from local equipment to derive the proximity signal.

15. A device as in claim 1 used to switch or control the flow and temperature of a water faucet.

16. A device as in claim 1 used to control lighting, electronic devices, and appliances without touching the device.

17. A device as in claim 2 used to control lighting, electronic devices, and appliances without touching the device.

18. A device as in claim 1 used to switch the keys of a computer keyboard.

19. A device as in claim 2 used to make a touchless computer pointing device or mouse clicking.

20. A capacitance balanced circuit layout where the traces between input to the preamplifier and ground plane are balanced in spacing and path length to give same input capacitance.