US 5594432

Patent Overview: US 5,594,432 A

Title: Traffic information warning system
Patent number: US 5,594,432 A
Inventors: David C. Oliva; Max W. Rogers
Original/current assignee: Cobra Electronics Corp (Cobra Electronics Corporation)
Priority date: 1994-08-30 (claimed from US 08/297,969, which issued as US 5,497,148 A)
Filing date: 1995-11-29 (application US 08/564,468)
Publication/grant date: 1997-01-14
Legal status (as listed): Expired – Lifetime; anticipated expiration 2014-08-30
Source: https://patents.google.com/patent/US5594432/en

Purpose: To warn or otherwise advise motorists of traffic hazards and conditions in their operating vicinity. The advisory site may be an emergency vehicle or a roadside hazard.

Plain-language scope: The system has a transmitter at the advisory site and a receiver in the vehicle. The transmitter uses a first oscillator (first carrier frequency S₁) and a second oscillator (second carrier frequency S₂) spaced apart by a predetermined frequency difference—preferably 80 MHz, e.g., 24.11 GHz and 24.19 GHz. A modulator modulates both carriers with an identical modulating signal M reflecting the traffic situation. The receiver uses scanning circuitry, such as a programmed microprocessor, to scan a frequency range and detect carriers separated by that predetermined difference (optionally by constant sweep rate and timing the two detections). A demodulator retrieves modulating signals M₁ and M₂; the receiver compares them and, if identical, announces a message based on them, preferably via a look-up table in microprocessor memory. Alternative embodiments compare M₁, or then M₂, against acceptable stored messages. Announcement may be visual (e.g., LCD), audible (tones, or a stored voice-synthesized message), or both.

What the excerpt does not establish: It does not provide the full claims, complete description, or all drawing details (FIGS. 1–6 are referenced but not fully reproduced). It does not establish the accuracy of the legal status, assignee list, priority date, or the security-agreement/reassignment events, which Google Patents expressly characterizes as assumptions or unverified. It also does not establish validity, enforceability, infringement, or the content of any prior art. No litigation or ownership analysis is included here.