Ultrasonic radiotelephone for an automobile

• US 5,410,587 A
• Filed: 03/01/1993
• Issued: 04/25/1995
• Est. Priority Date: 03/01/1993
• Status: Expired due to Fees

• Current Assignee: Matsushita Communication Industrial Corporation of USA (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Communication Industrial Corporation of USA (Panasonic Holdings Corporation)
• Inventors: Grunwell, Randall L.
• Primary Examiner(s): Kuntz, Curtis
• Assistant Examiner(s): Bost, Dwayne D.
• Application Number:
  US08/024,722
• Time in Patent Office: 785 Days
• Field of Search: 379/56, 379/58, 379/59, 379/388, 455/54.1, 455/151.2, 455/11.1
• US Class Current: 379/56.1
• CPC Class Codes: H04M 1/737 Characterised by transmission of electromagnetic waves other than radio waves, e.g. infrared waves
• CPC Class Codes: H04W 88/02 Terminal devices

Abstract

A car radiotelephone system having one or more wireless handsets communicating voice and control information via an ultrasonic link with a stationary unit connected functionally to a base station. The base unit (1) is connected by two cables, an audio-out cable (a) connected to the radio frequency receiver (2) and an audio-in cable (b) connected to the radio frequency transmitter (3), to a stationary transmitting/receiving unit (4). The stationary transmitting/receiving unit consists of two summing amplifiers, transmitting summing amplifier (5) and receiving summing amplifier (6), and any number of ultrasonic transmitters and receivers. Likewise, any number of handsets can be used. The handsets (15) comprise an ultrasonic receiver (19), an ultrasonic transmitter (20), transmitter and receiver circuitry (27), a keypad (28), display circuitry (29), microphone (30), earpiece/speaker (31), and a rechargeable battery and ringer. Each ultrasonic transmitter in the stationary unit and the handsets operate at a different frequency or other independent non-interfering methods so as to permit full duplex transmission. In order to insure that the transmission is obstacle free, the ultrasonic receiving and transmitting units in a handset are mounted on the top most side of the handset, pointing upward, and the stationary transmitting/receiving unit (4) is preferably mounted in the dome light housing unit (32).

Claims

1. A radiotelephone for use in an automobile, comprising:

a base unit for receiving first combined outgoing audio signals and transmitting an outgoing radio frequency signal, and for receiving incoming radio frequency signals and providing incoming audio signals;

a transmitting/receiving unit mounted within the dome light housing unit of said automobile, functionally connected to said base unit and comprising two ultrasonic receivers and two ultrasonic transmitters, each ultrasonic receiver for receiving incoming ultrasonic signals to provide outgoing audio signals and each ultrasonic transmitter for receiving second combined audio signals to provide outgoing ultrasonic signals;

first means interposed between said base unit and said ultrasonic receivers of said transmitting/receiving unit for combining said outgoing audio signals from said ultrasonic receivers of said transmitting/receiving unit to provide said first combined outgoing audio signals to said base unit;

second means interposed between said base unit and said ultrasonic transmitters in said transmitting/receiving unit for combining said incoming audio signals from said base unit and said first combined outgoing audio signals to provide said second combined audio signals to said ultrasonic transmitters; and

two handsets, each handset comprising a microphone, a speaker, an ultrasonic transmitter located on a predetermined end of said handset for transmitting signals from said microphone as said incoming ultrasonic signals to said transmitting/receiving unit, and an ultrasonic receiver located on said predetermined end of said handset for simultaneously receiving said outgoing ultrasonic signals from said transmitting/receiving unit to provide said second combined audio signals to said speaker, each said handset being associated with a predetermined ultrasonic transmitter and a predetermined ultrasonic receiver of said transmitting/receiving unit so that both said handsets may be used simultaneously.

2. The radiotelephone of claim 1 whereby said ultrasonic transmitter and said ultrasonic receiver of said handset comprise piezo-electric devices.

3. The radiotelephone of claim 1 whereby said ultrasonic transmitter and said ultrasonic receiver of said transmitting/receiving unit comprise piezo-electric devices.

4. The radiotelephone of claim 1 and further comprising a listen-only handset consisting essentially of a speaker and an ultrasonic receiver for receiving said outgoing ultrasonic signals from said transmitting/receiving unit to provide audio signals to said speaker.