Patent CA-2151064-A1 (CA)
Title: Driving distance detector (3-d safety)
Inventor: WHITE DOUGLAS STEWART
IPC: B60Q1/52
Filed: 1995-06-06
Abstract: The Driving Distance Detector (3-D SAFETY) is a device that is installed at the rear-end of a vehicle and detects a specific area behind the vehicle.   When another vehicle approaches this first vehicle and remains behind the first vehicle at an unsafe travelling distance a warning light comes on at the rear of the first vehicle and informs the second vehicles driver that he/she is at an unsafe distance behind the first vehicle. The sign will remain illuminated until there is a safe distance between the vehicles. This will occur when the driver who is behind slows down or goes around the vehicle in front of them.  When a driver remains at an unsafe distance behind another vehicle for an extended period of time it is commonly referred to as "tailgating". The device operates by utilizing one or more infra-red or radar sensors placed at the rear-end of the vehicle(see diagram 1,D), preferably, but not exclusively, behind the plastic covered taillights of the vehicle (see diagram 3,M). Infra-red sensors are able to detect the change in heat within a specific area behind the vehicle(see diagram 2,F & diagram 4,T,X,Y,Z,Q), whereas the radar is able to detect and analyze radio pulses which allow it to determine vehicle distances. The infra-red sensors are placed so that they are angled down at the road behind the vehicle. By angling the sensors down at the road it is possible to have them detect temperature change within a specific area behind the vehicle(see diagram 2,F).  However, the radar is able to be aimed straight back out of the vehicle and does not need to be angled down at the road in order to serve its function within a specific area (see diagram 4,Q).   When another vehicle enters the detection area behind the vehicle equipped with the Driving Distance Detector (3-D SAFETY) the infra-red sensors detect the change in heat and/or the radar detects the distance of the other vehicle behind the 3-D SAFETY vehicle and a warning/indicator light comes on(see diagram 3,C). The warning/indicator light is located at the rear of the vehicle,  preferably  in  the  rear  window  of  the  vehicle,  but  not exclusively. This warning/indicator light illuminates a coloured sign, preferably yellow, that displays the words "TOO CLOSE" or "STAY BACK" or something to the effect that informs the vehicle behind of their proximity and/or politely instructs the driver to stay back or slow down or go around(see diagram 1,C. & 3,C). The sign will illuminate for a specified time during which the vehicle behind must increase the distance between his/her vehicle and the vehicle to the front of him/her. If the driver changes speed after the allotted "sign on" time frame, but still remains within the sensing area of the device, the warning/indicator sign will illuminate again and will continue in this way as long as the offence continues to be committed under these guidelines(see diagram 2 E,F,G,Q). The specific distance behind the vehicle with the Driving Distance Detector is based on the legal travelling distance between two vehicles moving at a specified M.P.H.or K.P.H..  The Driving Distance Detector (3-D SAFETY) may have one or more areas of detection behind the vehicle depending on the type of radar or amount of infra-red detectors used by the device.  More than one distance of detection behind the vehicle allows the device to operate within a wider speed range and operate within different distances behind the vehicle.   The operation of this device works on a speed/distance ratio. Depending on the travelling speed of the vehicle the device will determine the safe driving distance behind the vehicle. This safe driving distance is intended to allow vehicles driving behind to stop safely should the need arise. Also, this Driving Distance Detector (3-D SAFETY) is intended to inform drivers who are tailgating that they are practising unsafe driving habits and are putting themselves and others at a potential risk.  To insure the detector does not operate in bumper to bumper traffic a cut-off/regulator switch is connected to the speedometer which only allows operation of the device at speeds at or above a specified M.P.H. or K.P.H.(see diagram 1,A) although the range of detection of the device may vary depending on the speed and regulator setting (see diagram 4,T,X,Y,Z,Q), and/or type of detection device used. The device may draw its electrical power source from either the vehicles battery or use a separate power source (see diagram 1,B).