Sonic autofocus camera having variable sonic beamwidth
First Claim
1. A capacitance-type combination transmitting and receiving ultrasonic transducer comprising a diaphragm, a backplate having a grooved surface for cooperative engagement with said diaphragm, and means for coupling a source of voltage to said diaphragm and said backplate, said grooved surface backplate having a plurality of electrically isolated segments, and said coupling means including means for selectively interconnecting said segments to vary the effective diameter of said backplate to provide a given sonic beam angle in accordance therewith.
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Accused Products
Abstract
A photographic camera having a plurality of interchangeable, adjustable focus lenses and having a focus control system capable of focusing each such lens over a range of subject distances in response to a rangefinder derived signal is provided with a sonic ranging system that includes an ultrasonic, capacitance-type transducer having a multiple segment backplate whose sonic beam angle is automatically correlated to the field-of-view angle of the image forming lens by selecting a particular combination of backplate segments when or as a particular interchangeable lens is attached to the camera body.
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Citations
2 Claims
- 1. A capacitance-type combination transmitting and receiving ultrasonic transducer comprising a diaphragm, a backplate having a grooved surface for cooperative engagement with said diaphragm, and means for coupling a source of voltage to said diaphragm and said backplate, said grooved surface backplate having a plurality of electrically isolated segments, and said coupling means including means for selectively interconnecting said segments to vary the effective diameter of said backplate to provide a given sonic beam angle in accordance therewith.
Specification