Accelerometer

• US 8,413,511 B2
• Filed: 01/28/2011
• Issued: 04/09/2013
• Est. Priority Date: 06/07/2010
• Status: Active Grant

• Current Assignee: AAC Technologies Pte Limited (AAC Technologies Holdings Inc.), American Audio Components, Inc.
• Original Assignee: AAC Acoustic Technologies Company Limited, American Audio Components, Inc.
• Inventors: Ge, Zhou, Yang, Bin, Meng, Zheng-Kui, Yan, Yi-Lin, Zhang, Rui
• Primary Examiner(s): CHAPMAN JR, JOHN E
• Application Number:
  US13/015,987
• Publication Number:
  US 20110296916A1
• Time in Patent Office: 802 Days
• Field of Search: 735/143.2, 735/10
• US Class Current: 73/514.32
• CPC Class Codes: G01P 15/125 by capacitive pick-up
• CPC Class Codes: G01P 15/18 in two or more dimensions
• CPC Class Codes: G01P 2015/082 for two degrees of freedom of movement of a single mass
• CPC Class Codes: G01P 2015/0848 using a plurality of mechanically coupled spring-mass systems, the sensitive direction of each system being different
• CPC Class Codes: G01P 2015/0854 using a particular shape of the mass, e.g. annular

Abstract

A accelerometer includes a substrate define a stationary electrode thereon, a first moveable mass defining a conductive-layer thereon facing the stationary electrode, a plurality of first elastic elements coupled with a peripheral side of the first moveable mass, a first fixed element surrounding the first moveable mass and fixedly attached to the substrate, a plurality of first fixed electrodes extending outwardly from the first fixed element, a second moveable mass surrounding the first fixed electrodes, a plurality of first moveable electrodes extending inwardly from the second moveable mass toward the first fixed element and parallel to the first fixed electrodes, respectively, a plurality of second elastic elements coupled with a peripheral side of the second moveable mass, and a second fixed element surrounding the second moveable mass and fixedly attached to the substrate.

Claims

1. An accelerometer comprising:

a substrate define a stationary electrode thereon,

a first moveable mass defining a conductive-layer thereon facing the stationary electrode;

a plurality of first elastic elements coupled with a peripheral side of the first moveable mass;

a first fixed element surrounding the first moveable mass, coupled with the first elastic elements and fixedly attached to the substrate;

a plurality of first fixed electrodes extending outwardly from the first fixed element;

a second moveable mass surrounding the first fixed electrodes;

a plurality of first moveable electrodes extending inwardly from the second moveable mass toward the first fixed element and parallel to the first fixed electrodes, respectively;

a plurality of second elastic elements coupled with a peripheral side of the second moveable mass;

and a second fixed element surrounding the second moveable mass, coupled with the second elastic element and fixedly attached to the substrate.

2. The accelerometer as described in claim 1, wherein a plurality of holes is defined on the first moveable mass or the second moveable mass.

3. The accelerometer as described in claim 1, wherein outlines of the first moveable mass, the first fixed element, the second moveable mass and the second fixed element are configured as squares.

4. A tri-axis accelerometer, comprising:

a substrate supporting a first frame, and including a first conductive-layer thereon;

a first moveable mass connected to the first frame by a plurality of first elastic members and being capable of moving along both directions parallel to the substrate;

a plurality of first moveable electrodes extending from an inner side of the first moveable mass;

a second frame surrounded by the first moveable electrodes, the second frame defining a plurality of first fixed electrodes extending from an outer side of the second frame toward the first moveable mass;

each of the first fixed electrode being located between two adjacent first moveable electrodes, and each of the first moveable electrodes being located between two adjacent fixed electrodes;

a second moveable mass surrounded by the second frame and connected to the second frame by a plurality of second elastic members, the second moveable mass being capable of moving a direction perpendicular to the substrate, the second moveable mass defining a second conductive-layer facing the first conductive-layer on the substrate;

wherein

the first fixed electrodes and the first moveable electrodes form a comb capacitor having variable capacitance according to variable overlapped area therebetween; and

the first conductive-layer and the second conductive-layer form a plate capacitor having variable capacitance according to variable distance therebetween.