Rotation angle detector

• US 20040145364A1
• Filed: 10/30/2003
• Published: 07/29/2004
• Est. Priority Date: 12/04/2002
• Status: Active Grant

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Nomura, Toshihiro, Nishikawa, Hisashi, Onishi, Masahide, Nakade, Yoshiyuki, Tateishi, Ichiro
• Granted Patent: US 6,909,282 B2
• Time in Patent Office: Days
• US Class Current: 324/207.2
• CPC Class Codes: B62D 15/0215 by measuring on the steering column
• CPC Class Codes: G01D 2205/28 The target being driven in rotation by additional gears
• CPC Class Codes: G01D 5/04 using levers; using cams; using gearing

Abstract

A rotation angle detector includes a rotor, first and second detecting elements which rotate according to a rotation of the rotor, first and second detecting units for detecting rotations of the first and second detecting elements, respectively, and a control unit for detecting a rotation angle of the rotor based on a first signal when a difference between the first and second signals output from the first and second detecting units ranges within a predetermined range. The rotation angle detector has a simple structure and detects the rotation angle of the rotor accurately

Claims

1. A rotation angle detector comprising:

a rotor;

first and second detecting elements which rotate according to a rotation of said rotor;

first and second detecting units for detecting rotations of said first and second detecting elements, respectively; and

a control unit for detecting a rotation angle of said rotor based on a first signal when a difference between said first and second signals output from said first and second detecting units ranges within a predetermined range.

2. The rotation angle detector of claim 1, further comprising:

a third detecting element which rotates according to the rotation of said rotor; and

a third detecting unit for detecting a rotation of said third detecting element,

wherein said control unit detects said rotation angle of said rotor based on said first signal and a third signal output from said third detecting unit.

3. The rotation angle detector of claim 1, further comprising:

a third detecting element which moves according to the rotation of said rotor; and

a third detecting unit for detecting a movement of said third detecting element,

wherein said control unit detects said rotation angle of said rotor based on said first signal and a third signal output from said third detecting unit.

4. The rotation angle detector of claim 1, wherein said first detecting unit includes a first magnet and a first magnetic sensor which detects a magnetic field from said first magnet.

5. The rotation angle detector of claim 4, wherein said second detecting unit includes a second magnet and a second magnetic sensor which detects a magnetic field from said second magnet.

6. The rotation angle detector of claim 4, wherein said second detecting unit includes a second magnet and a Hall element which detects a magnetic field of said second magnet.