The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 24, 1988
Filed:
Oct. 03, 1986
Robert D Johnston, Brownsburg, IN (US);
Other;
Abstract
An approaching vehicle informing system and method for informing the driver of a vehicle of the presence of a relatively approaching emergency vehicle and providing the driver with information regarding the amount of time until vehicles meet. Included are a transmitting station for simultaneously emitting periodic electromagnetic and sound pulses of preselected frequencies located on the emergency vehicle, and a receiving station located on the driver's vehicle. The receiving station includes circuitry to receive the electromagnetic and sound pulses and discriminate signals of the preselected frequencies. A microcomputer is programmed to measure the time interval between simultaneously emitted electromagnetic and sound pulses, determines the Doppler frequency shift of the received sound pulse, and calculates the time until vehicles meet, which is displayed in numerical form to the driver in the event the Doppler frequency of received sound pulses exceeds the frequency of emitted sound pulses.