Surface wave device for use in a ghost cancellation system
AssigneeZenith Radio Corporation
InventorAdrian J. DeVries
Life of this patent
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Abstract
A ghost cancellation system includes a surface-wave device operable for developing a replica of the ghost component of a video signal, which replica is combined with the video signal to eliminate or cancel the ghost component. The surface-wave device comprises an input transducer responsive to a modulated video signal for launching uniform acoustic surface-waves along a path traversing a balanced pair of output transducers and impinging upon a reflector array. The reflector array includes means for initiating non-uniform surface-wave reflections suitable for causing the output transducers to develop an output electrical signal comprising the ghost replica.
Claims21
An acousto-electric surface-wave signal translating device comprising:
- an acoustic surface-wave propagating medium;
- an input surface-wave transducer coupled to said medium and responsive to an input signal for propagating a uniform acoustic surface-wave along a predetermined path in said medium;
- an output surface-wave transducer coupled to said medium along said path and spaced from said input transducer for developing an output electrical signal only in response to non-uniform exposure to surface-waves;
- and
- reflection means coupled to said medium along said path and spaced from said input and output transducers, said reflection means being responsive to said uniform surface-wave for initiating reflections along said path comprising non-uniform surface-waves for causing said output transducer to develop an electrical output signal comprising delayed replica of said input signal.
An acousto-electric surface-wave device for use with a television receiver ghost cancellation system of the type including means for combining a television signal having a main component and a ghost component with a replica of said ghost component for effecting ghost cancellation, comprising:
- an acoustic surface-wave propagating medium;
- an input surface-wave transducer coupled to said medium and responsive to said video signal for propagating a uniform acoustic surface-wave along a predetermined path in said medium;
- an output surface-wave transducer coupled to said medium along said path at a position spaced from said input transducer for developing an electrical output signal only in response to non-uniform energization thereof;
- and
- reflection means coupled to said medium along said path and spaced from said input and output transducers, said reflection means being responsive to said uniform surface-wave for initiating reflections along said path comprising a non-uniform surface-waves for causing said output transducer to develop an electrical output signal comprising said ghost replica.
Dependencies are inferred from the claim text.