Capacitive device and method with an enhanced measurement error correction capability

• US 7,743,667 B2
• Filed: 02/12/2007
• Issued: 06/29/2010
• Est. Priority Date: 02/12/2007
• Status: Expired due to Fees

• Current Assignee: Ypoint Capital, Inc,
• Original Assignee: Loadstar Sensors Incorporated (Ypoint Capital, Inc,)
• Inventors: Schultz, John, Lim, Jonathan T, Harish, Divyasimha, Wong, King
• Primary Examiner(s): Caputo; Lisa M
• Assistant Examiner(s): DAVIS-HOLLINGTON, OCTAVIA L
• Application Number:
  US11/705,273
• Publication Number:
  US 20080190210A1
• Time in Patent Office: 1,233 Days
• Field of Search: 737/80
• US Class Current: 73/780
• CPC Class Codes: G01L 1/142 using capacitors

Abstract

A capacitive device and method with an enhanced measurement error correction capability is disclosed. In one embodiment, an apparatus includes a sensor capacitor based on one or more pairs of parallel conductor surfaces, a housing to encompass the sensor capacitor, a digitizer module in the housing to generate a digital measurement based on a change in a capacitance of the sensor capacitor when a contact zone of the housing is deflected by a force applied on the contact zone. The apparatus also includes a compensation module of the digitizer module to apply another digital measurement of one or more distortion factors to the digital measurement to minimize an effect of the one or more distortion factors to the apparatus. In addition, the apparatus includes a communication module to communicate an analog signal and/or a digital signal through a wired channel and/or a wireless channel.

Claims

1. An apparatus, comprising:

a sensor capacitor based on at least one pair of parallel conductor surfaces;

a housing to encompass the sensor capacitor, wherein the housing is composed of a low creep material which includes at least one of a 17-4 PH stainless steel, a 15-5 PH stainless steel, and a maraging stainless steel;

a digitizer module in the housing to generate a digital measurement based on a change in a capacitance of the sensor capacitor when a contact zone of the housing is deflected by a force applied on the contact zone;

a compensation module of the digitizer module to apply another digital measurement of at least one distortion factor to the digital measurement to minimize an effect of the at least one distortion factor to the apparatus; and

a communication module to communicate at least one of an analog signal and a digital signal through at least one of a wired channel and a wireless channel, wherein the at least one of the analog signal and the digital signal to include at least the change in the capacitance.

2. The apparatus of claim 1, further comprising a reference capacitor having an upper reference surface and a lower reference surface in the housing to compensate an error in the digital measurement based on at least one environmental condition.

3. The apparatus of claim 1, wherein the change in the capacitance of the sensor capacitor is based on a displacement of a distance between an upper sensor surface of the sensor capacitor and a lower sensor surface parallel to the upper sensor surface.

4. The apparatus of claim 1, wherein the change in the capacitance of the sensor capacitor is based on a displacement of an overlap area between an inner conductive area and an outer conductive area parallel to the inner conductive area.

5. The apparatus of claim 1, wherein the change in the capacitance of the sensor capacitor is based on both a displacement of a distance between an upper sensor surface of the sensor capacitor and a lower sensor surface parallel to the upper sensor surface and a displacement of an overlap area between an inner conductive area and an outer conductive area parallel to the inner conductive area.

6. The apparatus of claim 1, further comprising a processor module having a central procession unit (CPU) to execute a set of instructions associated with at least the digitizer module, the compensation module, and the communication module.

7. The apparatus of claim 1, further comprising a wireless communication module of the communication module to wirelessly communicate with an external device based on at least one of a wireless universal serial bus (USB), a Wi-Fi, a Bluetooth, and a Zigbee.

8. The apparatus of claim 1, further comprising a wired communication module of the communication module to communicate with an external device, wherein the at least one of the analog signal and the digital signal to include at least one of a universal serial bus (USB) signal, a voltage signal, a frequency signal, and a current signal.

9. The apparatus of claim 1, further comprising a tilt adaptor surface surrounding the lower sensor surface to minimize the another digital measurement of the at least one distortion factor associated with a tilting effect of the force applied on the contact zone.

10. The apparatus of claim 1, wherein the housing is composed of a low creep material which includes at least one of a 17-4 PH stainless steel, a 15-5 PH stainless steel, and a maraging stainless steel, and wherein at least one printed circuit board in the housing is composed of a plurality of materials including at least one of a flame resistant 4 (FR4), a ceramic, and a glass.

11. The apparatus of claim 1, further comprising a sensor module in the housing to measure a plurality of environmental conditions of the apparatus, wherein the plurality of environmental conditions to include at least one of a temperature, a pressure, a radiation, a humidity, a vibration, and a motion.

12. The apparatus of claim 11, wherein the another digital measurement of the at least one distortion factor is based on at least one of the plurality of environmental conditions.

13. The apparatus of claim 1, further comprising an alarm module associated with the sensor capacitor to generate a sensory data when a parameter of the digital measurement exceeds a threshold value.

14. The apparatus of claim 1, further comprising a capacitance-to-frequency converter module to generate a frequency value based on the change in the capacitance of the sensor capacitor, wherein the frequency value is processed by the digitizer module.

15. The apparatus of claim 1, further comprising a groove surrounding the contact zone to perform at least one of substantially confining a deflection of the contact zone in the groove and adjusting a degree of the deflection of the contact zone.

16. The apparatus of claim 1, further comprising at least one of an upper mounting structure and a lower mounting structure to fasten the housing to an external structure, wherein the at least one of the upper mounting structure and the lower mounting structure to include at least a threaded stud.