Directional back-up alarm
A directional back-up alarm deployed in a vehicle moving in an open space, in accordance with one embodiment of the present invention includes, in part, a first ultrasonic generator adapted to generate a first ultrasound signal; a second ultrasonic generator adapted to generate a second ultrasound signal; an audible sound generator adapted to generate an audible signal; a modulator adapted to modulate the first ultrasonic signal with the audible signal to generate a modulated signal; and a summing circuit adapted to receive and sum the modulated signal with the second ultrasonic signal to generate a combined signal. The combined signal is transmitted with a transmit antenna. The transmit antenna may include a Piezoelectric or silicon device.
1. A directional back-up alarm for use in a vehicle moving in an open space, the directional back-up alarm comprising:
a first ultrasonic generator adapted to generate a first ultrasound signal;
a second ultrasonic generator adapted to generate a second ultrasound signal;
an audible sound generator adapted to generate an audible signal;
a modulator adapted to modulate the first ultrasonic signal with the audible signal to generate a modulated signal; and
a summing circuit adapted to receive and sum the modulated signal with the second ultrasonic signal to generate a combined signal, a transmit antenna adapted to transmit the combined signal into a vehicle back-up open space.
2. The directional back-up alarm of claim 1 wherein the transmit antenna includes a Piezoelectric device.
3. The directional back-up alarm of claim 1 wherein the transmit antenna includes a silicon device.
4. A method of producing an audible alarm from a vehicle moving in an open space, the method comprising:
generating a first ultrasound signal;
generating a second ultrasound signal;
generating an audible signal;
modulating the first ultrasonic signal with the audible signal to generate a modulated signal; and
summing the modulated signal with the second ultrasonic signal to generate a combined signal, transmitting the combined signal over the air in the vehicle moving open space.
5. The method of claim 4 wherein the combined signal is transmitted via a transmit antenna that includes a Piezoelectric device.
6. The method of claim 5 wherein the combined signal is transmitted via a transmit antenna that includes a silicon device.