Accelerometer

• US 7,412,888 B2
• Filed: 11/02/2006
• Issued: 08/19/2008
• Est. Priority Date: 12/23/2005
• Status: Expired due to Fees

• Current Assignee: Delta Electronics Incorporated
• Original Assignee: Delta Electronics Incorporated
• Inventors: Wang, Horng-Jou, Chen, Huang-Kun, Hsieh, Hsieh-Shen, Shing, Tai-Kang, Chang, Heng-Chung, Wang, Chuan-Wei, Fang, Wei-Leun, Lu, Shiang-Cheng, Sun, Chih-Ming, Chu, Chia-Yi
• Primary Examiner(s): Kwok; Helen C.
• Application Number:
  US11/591,617
• Publication Number:
  US 20070144258A1
• Time in Patent Office: 656 Days
• Field of Search: 735/143.2, 735/143.6, 735/143.8, 735/141.6, 735/142.9, 735/040.4, 735/041.2, 735/041.4
• US Class Current: 73/514.32
• CPC Class Codes: G01P 15/125 by capacitive pick-up
• CPC Class Codes: G01P 2015/0814 for translational movement of the mass, e.g. shuttle type

Abstract

An accelerometer includes a fixing unit and a movable unit. The fixing unit has a plurality of first electrode parts and a plurality of second electrode parts. The movable unit is connected with the fixing unit and includes a body having an opening, a plurality of third electrode parts and a plurality of fourth electrode parts. The third electrode parts are disposed at an outer side of the body with respect to the first electrode parts, respectively. The fourth electrode parts are disposed at the inner side of the body in the opening, and are disposed respectively with respect to the second electrode parts, respectively.

Claims

1. An accelerometer, comprising:

a fixing unit comprising a plurality of first electrode parts and a plurality of second electrode parts; and

a movable unit connected with the fixing unit and comprising a body, a plurality of third electrode parts and a plurality of fourth electrode parts, wherein the body has an opening, the third electrode parts are located at an outer side of the body and are disposed respectively with respect to the first electrode parts, and the fourth electrode parts are located in the opening and are disposed respectively with respect to the second electrode parts,

wherein a plurality of capacitance sensors formed by the first electrode parts and the third electrode parts and a plurality of capacitance sensors formed by the second electrode parts and the fourth electrode parts sense an acceleration.

2. The accelerometer of claim 1, wherein the movable unit is connected with a fixing block by an elastic element.

3. The accelerometer of claim 2, wherein the elastic element is a spring or an elastic sheet.

4. The accelerometer of claim 1, wherein the first electrode parts and the third electrode parts are arranged interdigitatedly, and a distance between one of the first electrode parts and adjacent one of the third electrode parts is not greater than 1 μ

m.

5. The accelerometer of claim 1, wherein the second electrode parts and the fourth electrode parts are arranged interdigitatedly, and a distance between one of the second electrode parts and adjacent one of the fourth electrode parts is not greater than 1 μ

m.

6. The accelerometer of claim 1, wherein the fixing unit comprises a substrate, a conductive element and a positioning structure, the first electrode parts or the second electrode parts are disposed on the conductive element, and the conductive element is separable from the substrate, and the conductive element is fixedly positioned on the substrate by the positioning structure.

7. The accelerometer of claim 6, wherein the positioning structure comprises a fastening part and an elastic part, the fastening part is on the conductive element while the elastic part is on the substrate, or the fastening part is on the substrate while the elastic part is on the conductive element, the fastening part is a pin, and the elastic part is a spring or an elastic sheet.

8. The accelerometer of claim 6, wherein the positioning structure includes an adhering part and an elastic part, and the adhering part is located on the conductive element while the elastic part is located on the substrate, or the adhering part is located on the substrate while the elastic part is located on the conductive element.

9. The accelerometer of claim 1, wherein the accelerometer is a capacitance accelerometer.

10. An accelerometer, comprising:

a fixing unit comprising a substrate, a first conductive element, and a positioning structure, wherein the first conductive element has a plurality of first electrode parts, and the first conductive element is separable from the substrate and the first conductive element is fixedly positioned on the substrate by the positioning structure; and

a movable unit connected with a fixing block and comprising a body and a plurality of second electrode parts, wherein the second electrode parts are located at an outer side of the body and are disposed respectively with respect to the first electrode parts.

11. The accelerometer of claim 10, wherein the positioning structure includes a fastening part and an elastic part, the fastening part is on the conductive element while the elastic part is on the substrate, or the fastening part is on the substrate while the elastic part is on the conductive element, the fastening part is a pin, and the elastic part is a spring or an elastic sheet.

12. The accelerometer of claim 11, wherein the positioning structure includes an adhering part and an elastic part, and the adhering part is located on the conductive element while the elastic part is located on the substrate, or the adhering part is located on the substrate while the elastic part is located on the conductive element.

13. The accelerometer of claim 10, wherein the first electrode parts and the second electrode parts are arranged interdigitatedly, and a distance between one of the first electrode parts and adjacent one of the second electrode parts is not greater than 1 μ

m.

14. The accelerometer of claim 10, wherein the body of the movable unit has an opening, and the movable unit further includes a plurality of third electrode parts located at an inner side of the body in the opening.

15. The accelerometer of claim 14, wherein the fixing unit further includes a second conductive element, and the second conductive element has a plurality of fourth electrode parts disposed with respect to the third electrode parts, respectively.

16. The accelerometer of claim 14, wherein the third electrode parts and the fourth electrode parts are arranged interdigitatedly, and a distance between one of the third electrode parts and adjacent one of the fourth electrode parts is not greater than 1 μ

m.

17. The accelerometer of claim 10, wherein the accelerometer is a capacitance accelerometer.