Controlling Method for Capacitive Sensors

• US 20080218182A1
• Filed: 08/10/2006
• Published: 09/11/2008
• Est. Priority Date: 06/30/2006
• Status: Active Grant

• Current Assignee: Han's Laser Technology Company Limited
• Original Assignee: Han's Laser Technology Company Limited
• Inventors: Gao, Yunfeng, Chen, Kesheng
• Granted Patent: US 8,125,227 B2
• Time in Patent Office: Days
• US Class Current: 324/676
• CPC Class Codes: G01D 3/032 affecting incoming signal, e.g. by averaging; gating undesired signals
• CPC Class Codes: G01D 5/24 by varying capacitance

Abstract

A controlling method for capacitive sensors in a vibrating mirror motor system includes a capacitive sensor, a subtraction circuit and an adder circuit connected to the capacitive sensor, a high frequency power supply providing power for the capacitive sensor, a D/A converter, and a gain stage adjustment device, wherein values obtained at the capacitive sensor are summed through the adder circuit, then the summed value and a value processed by the D/A converter are input to a comparator which comparing the values, and a gain adjusting value is obtained and supplied to the high frequency power supply, meanwhile the values obtained by capacitive sensor are subtracted by the subtraction circuit and then adjusted by the gain stage adjustment device, finally a position signal is outputted.

Claims

1-7. -7. (canceled)

8. A method for controlling a capacitive sensor in a vibrating mirror motor system comprising a capacitive sensor, a subtraction circuit and an adder circuit connected with the capacitive sensor, a high-frequency power supply for providing energy to the capacitive sensor, a digital-analog converter, and a gain stage adjuster, wherein the method comprises:

summing, by the adder circuit, values obtained by the capacitive sensor;

Inputting the value resulted from the adder circuit and a value from the digital-analog converter together into a comparison circuit;

Providing a gain adjustment value obtained through comparison in the comparison circuit to the high-frequency power supply;

Outputting a position signal by the gain stage adjuster after adjusting a value resulted from the subtraction circuit performing subtraction on values obtained at said capacitive sensor.

9. The method as claimed in claim 8, wherein the capacitive sensor comprises one or more pairs of differential capacitance pole-pairs.

10. The method as claimed in claim 8, wherein the capacitive sensor comprises a common energy emission source surface, a displacement detection area, and an intermediate medium related to the displacement.

11. The method as claimed in claim 9, wherein the capacitive sensor comprises a common energy emission source surface, a displacement detection area, and an intermediate medium related to the displacement.

12. The method as claimed in claim 10, wherein the intermediate medium is ceramic.

13. The method as claimed in claim 11, wherein the intermediate medium is ceramic.

14. The method as claimed in claim 8, wherein a microprocessor is connected to a computer and the computer operates the microprocessor.

15. The method as claimed in claim 14, wherein the gain stage adjuster employs a digital potentiometer which is connected to the microprocessor, and the microprocessor set a stage selection coefficient of the digital potentiometer.

16. The method as claimed in claim 14, wherein the digital-analog converter is connected respectively to a precision voltage source and the microprocessor, a voltage value set by the microprocessor and a voltage value provided by the precision voltage source together are input into the digital-analog converter for processing.

17. A circuit for controlling a capacitive sensor in a vibrating mirror motor system comprising:

a capacitive sensor, a subtraction circuit and an adder circuit connected with the capacitive sensor, a high-frequency power supply for providing energy to the capacitive sensor, a digital-analog converter, and a gain stage adjuster.

18. A method for controlling a capacitive sensor in a vibrating mirror motor system comprising:

summing, by the adder circuit, values obtained by the capacitive sensor;

inputting the value resulted from the adder circuit and a value from the digital-analog converter together into a comparison circuit;

providing a gain adjustment value obtained through comparison in the comparison circuit to the high-frequency power supply;

outputting a position signal by the gain stage adjuster after adjusting a value resulted from the subtraction circuit performing subtraction on values obtained at said capacitive sensor.