Acceleration sensor

• US 6,895,819 B1
• Filed: 09/16/1999
• Issued: 05/24/2005
• Est. Priority Date: 09/18/1998
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Yachi, Masanori
• Primary Examiner(s): Kwok, Helen C.
• Application Number:
  US09/397,675
• Time in Patent Office: 2,077 Days
• Field of Search: 735/143.4, 735/10, 735/11, 735/12, 735/040.3, 735/140.1, 735/140.2, 735/040.2, 736/52, 735/143.3
• US Class Current: 73/514.34
• CPC Class Codes: G01P 15/097 by vibratory elements
• CPC Class Codes: G01P 2015/0828 the mass being of the paddle type being suspended at one of its longitudinal ends

Abstract

An acceleration sensor which has a vibrator, a weight portion that is connected to the vibrator, and supported at a position different from the center of gravity of the vibrator plus its own structure, and a detecting section which detects the amount of characteristic corresponding to an angular moment that is exerted in the vibrator upon application of an acceleration in one direction to the vibrator and the weight portion. When an acceleration in one direction is applied to the vibrator and the weight portion connected thereto, an angular moment is exerted in the vibrator due to the difference between the supporting point of the weight portion and the center of gravity of the vibrator plus the weight portion, and the amount of characteristic corresponding to the angular moment is detected by the detecting section so that the acceleration of a linear motion is detected.

Claims

1. An acceleration sensor for detecting acceleration, comprising:

a base having a first surface delineated by a first plurality of edges;

a transducer that is not permanently oscillating, is supported at the base and exhibits torsion vibration only when acceleration is caused;

a weight portion that is connected to the not permanently oscillating transducer, and supported at a position different from the center of gravity of the transducer and the weight portion itself, the weight portion having a first surface delineated by a second plurality of edges, each edge of the first plurality of edges being adjacent to a respective edge of the second plurality of edges; and

a detecting section which is formed on the transducer and detects the amount of characteristic corresponding to a torsion of the transducer caused by an angular moment centered on the supporting position of the weight portion upon application of acceleration in one direction to the transducer and the weight portion;

wherein a face of the transducer is made flush with a face of the weight portion, and the base, the transducer and the weight portion are stacked in the height direction, and the transducer is a torsion vibrator having two sliding vibrators.

2. The acceleration sensor according to claim 1, wherein the amount of characteristic is a voltage caused by sliding stresses having directions different from each other on the two sliding vibrators.