Liquid crystal accelerometer

• US 3,946,616 A
• Filed: 08/09/1974
• Issued: 03/30/1976
• Est. Priority Date: 08/09/1974
• Status: Expired due to Term

• Current Assignee: Rockwell International Corporation
• Original Assignee: Rockwell International Corporation
• Inventors: Govan, Ronald M., Jones, Freeman B. Jr.
• Primary Examiner(s): Bauer, Edward S.
• Application Number:
  US05/496,429
• Time in Patent Office: 599 Days
• Field of Search: 73/71.3, 73/516 R, 73/517 R, 350/150, 350/160 LC, 356/28, 356/256
• US Class Current: 73/514.26
• CPC Class Codes: G01P 15/08 with conversion into electric or magnetic values
• CPC Class Codes: G01P 15/093 by photoelectric pick-up

Abstract

An accelerometer comprising a first glass plate mounted in a fixed position, a second glass plate mounted in spaced relation with said first plate and movable with respect to said first plate, an aligning agent coating the facing surfaces of said plates, a nematic liquid crystal mixture filling the space between said plates, means applying an electrical potential between the coated surfaces of said plates, and means for detecting optical characteristics within said liquid crystal mixture.

Claims

1. An accelerometer comprising;

a first plate formed of electrically non-conductive material fixedly mounted on an article whose acceleration is to be sensed,

a second plate formed of electrically non-conductive material mounted in spaced relation with said first plate and movable with respect to said first plate and resiliently connected to said article,

an inertial mass fixedly connected to said second plate,

an aligning agent coating the facing surfaces of said plates,

a nematic liquid crystal mixture filling the space between said plates,

means applying an electrical potential between the coated surfaces of said plates, and

optical means for detecting changes in the optical characteristics within said liquid crystal mixture to provide an indication of the acceleration of said article.

2. The device of claim 1 wherein;

said plates are transparent, and

said optical means including light source means passing a light beam through said plates and said liquid crystal mixture and photodetector means positioned to sense said light beam.

3. The device of claim 1 wherein;

one of said plates is transparent,

optically reflective coating means applied to the facing surfaces of said plates, and

said optical means includes light source means positioned to cause a light beam to undergo multiple reflections between the facing surfaces of said plates and photodetector means positioned to sense said light beam.