Proximity detector

• US 5,396,070 A
• Filed: 03/14/1994
• Issued: 03/07/1995
• Est. Priority Date: 01/29/1991
• Status: Expired due to Fees

• Current Assignee: The Proximeter Company Limited
• Original Assignee: The Proximeter Company Limited
• Inventors: Lee, Mark A.
• Primary Examiner(s): Hannaher, Constantine
• Assistant Examiner(s): Glick, Edward J.
• Application Number:
  US08/209,912
• Time in Patent Office: 358 Days
• Field of Search: 250/338.1, 250/341, 250/349, 367/112, 367/116, 367/903, 340/901, 340/932.2, 340/431, 340/435, 340/436, 340/437, 340/438
• US Class Current: 250/349
• CPC Class Codes: B60Q 9/006 using a distance sensor
• CPC Class Codes: G01S 17/931 of land vehicles

Abstract

A proximity detector for motor cars, to aid parking, has 3 infra-red transmitter units 10-1 to 10-3 producing a zone of radiation 36 and two receiver units 20-1 and 20-2 producing a zone 46 of sensitivity to the radiation. Each transmitter unit has 3 transmitter elements housed behind a common aperture, and each receiver unit has 2 receiver elements housed behind a common aperture, giving for each unit a polar diagram with at least two distinct directions of high magnitude, the axes of peak radiation or sensitivity from the elements of a unit being divergent through the aperture and forming the directions of high magnitude. An indicating device indicates the amplitude of the combined signal from the receivers by means of a pulsed tone the pulse frequency of which is varied.

Claims

1. A proximity detecting system for manned motor vehicles and trailers for said vehicles comprising transmitter means producing a zone of infra-red radiation, receiver means having a zone of sensitivity to the infra-red radiation intersecting with the zone of infra-red radiation of the transmitter means, and indicating means indicating the amplitude of a signal from the receiver means, the transmitter and receiver means together comprising at least three units spaced along a line with the units being alternately transmitter units and receiver units, the zones of the transmitter units and the receiver units both being divergent and the receiver and transmitter units being spaced substantially equally along said line of units, wherein each such unit has a polar diagram with at least two distinct directions of high magnitude approximately coplanar with the line of units and is constructed from a plurality of elements behind a common aperture, the axis of each element through the aperture forming one of the directions of high magnitude.

2. The proximity detecting system of claim 1, wherein the indicating means indicates the amplitude of the signal by means of a pulsed tone, the pulse frequency of which is varied.