IR optical position sensor system

• US 6,323,487 B1
• Filed: 01/26/1999
• Issued: 11/27/2001
• Est. Priority Date: 01/26/1999
• Status: Expired due to Term

• Current Assignee: Aptiv Technologies Limited (BorgWarner Incorporated)
• Original Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Inventors: Wu, Cunkai
• Primary Examiner(s): Hannaher, Constantine
• Assistant Examiner(s): LEE, SHUN K
• Application Number:
  US09/237,309
• Time in Patent Office: 1,036 Days
• Field of Search: 250/341.1, 359/356
• US Class Current: 250/341.1
• CPC Class Codes: B60R 21/01534 using electromagneticwaves, e.g. infrared
• CPC Class Codes: B60R 21/01538 for image processing, e.g. cameras or sensor arrays
• CPC Class Codes: B60R 21/01556 Child-seat detection systems
• CPC Class Codes: G01J 5/0025 Living bodies ear thermometers G01J5/0011; detecting, measuring or recording for diagnostic purposes A61B5/00
• CPC Class Codes: G01J 5/08 Optical arrangements
• CPC Class Codes: G01J 5/0806 Focusing or collimating elements, e.g. lenses or concave mirrors
• CPC Class Codes: G01J 5/0893 Arrangements to attach devices to a pyrometer, i.e. attaching an optical interface; Spatial relative arrangement of optical elements, e.g. folded beam path G01J5/049 takes precedence
• CPC Class Codes: G01S 17/04 Systems determining the presence of a target
• CPC Class Codes: G01S 7/4816 of receivers alone

Abstract

In a preferred embodiment, an infrared optical position detection system, including: an infrared emitter to emit infrared radiation toward an object; a receiver to receive the infrared radiation scattered by the object and to determine position of the object; the receiver including a detector; and the receiver including an optical system having two and no more than two lenses.

Claims

1. An infrared optical position detection system, comprising:

(a) an infrared emitter to emit infrared radiation toward an object;

(b) a receiver to receive said infrared radiation scattered by said object and to determine position of said object;

(c) said receiver including a detector;

(d) said receiver including an optical system comprising two and no more than two lenses; and

wherein;

(e) said two and no more than two lenses comprise an aspheric lens having its convex aspheric surface directed toward said object and its spherical surface adjacent a symmetric-convex lens.

2. An infrared optical position detection system, as defined in claim 1, wherein:

said aspheric lens has a focal length of 12 mm, a lens diameter of 18 mm, and a back focal length of 6.9 mm;

said symmetric-convex spherical lens has focal length of 12 mm, a lens diameter of 15 mm, and a back focal length of 18.3 mm; and

said optical system has an effective focal length of 8.7 mm, a system aperture diameter of 15.7 mm, and a back focal length of 3.77 mm.

3. An infrared optical position detection system, as defined in claim 2, wherein:

said optical system has a field of view of 50 degrees.

4. An infrared optical position detection and classification system in combination with a vehicle air bag deployment system, comprising:

(a) an infrared emitter to emit infrared radiation toward a passenger;

(b) a receiver to receive said infrared radiation scattered by said passenger and to determine position and classification of said passenger,

(c) said receiver including a detector including an optical system comprising two and no more than two lenses;

(d) control means connected to said receiver to suppress enablement of a vehicle air bag if it is determined that an occupant is in an at-risk zone or is seated in a rear facing infant seat and to enable deployment of said vehicle air bag if it is determined that said occupant is not in said at-risk zone or is not seated in said rear facing infant seat and

wherein;

(e) said two and no more than two lenses comprise an aspheric lens having its convex surface directed toward said object and its spherical surface adjacent a symmetric-convex lens.

5. An infrared optical position detection and classification system in combination with a vehicle air bag deployment system as defined in claim 4, wherein:

said aspheric lens has aspheric lens has a local length of 12 mm, a lens diameter of 18 mm, and a back focal length of 6.9 mm; and

said symmetric-convex spherical lens has focal length of 12 mm, a lens diameter of 15 mm, and a back focal length of 18.3 mm; and

said optical system has an effective focal length of 8.7 mm, a system aperture diameter of 15.7 mm, and a back focal length of 3.77 mm.

6. An infrared optical position detection and classification system in combination with a vehicle air bag deployment system, as defined in claim 5, wherein:

said optical system has a field of view of 50 degrees.