Ultrasonic sensor
First Claim
1. An ultrasonic sensor for determining objects in air or other gaseous media which contains a first ultrasonic transducer having a piezoelectric body as a transmitting means, the sensor comprising reflector means having a concave surface facing said first ultrasonic transducer means, said concave surface forming a segment of an ellipsoid and having first and second focal points, the first focal point being closer to said concave surface than said second focal point, and second ultrasonic transducer means comprising receiver means disposed between said first ultrasonic transducer means and said reflector means at the first focal point of said reflector means, the surface of said second ultrasonic transducer means facing said reflector means comprising a convex surface.
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Accused Products
Abstract
An ultrasonic sensor for determining objects in air or other gaseous media is disclosed. The sensor comprises a first ultrasonic transducer having a piezoelectric transmitter. A reflector is provided having a concave surface facing the first ultrasonic transducer which forms a segment of an ellipsoid. The reflector has two focal points, the first of which is closer to the reflector and the second of which is near the object to be detected. Between the first ultrasonic transducer and the reflector, a second ultrasonic transducer is provided which is arranged at the first focal point of the reflector. Preferably, the surface of the second ultrasonic transducer facing the reflector forms a spherical segment. By this arrangement, an increase of the receiving aperture is achieved, and objects can be determined which have a normal to the reflection surface inclined with respect to the axis of the sound lobe by an object position angle which is substantially larger than ±3°. Additionally, objects with a curved reflection surface can be determined unambiguously.
26 Citations
6 Claims
- 1. An ultrasonic sensor for determining objects in air or other gaseous media which contains a first ultrasonic transducer having a piezoelectric body as a transmitting means, the sensor comprising reflector means having a concave surface facing said first ultrasonic transducer means, said concave surface forming a segment of an ellipsoid and having first and second focal points, the first focal point being closer to said concave surface than said second focal point, and second ultrasonic transducer means comprising receiver means disposed between said first ultrasonic transducer means and said reflector means at the first focal point of said reflector means, the surface of said second ultrasonic transducer means facing said reflector means comprising a convex surface.
Specification