Audio muting apparatus
AssigneeFunai Electric Co., Ltd.
InventorKiyonori Hida
Life of this patent
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Abstract
An audio muting apparatus comprises control means 3 for gradually varying a converted output voltage 12 from a D/A converter 4 from an initial voltage to a prescribed voltage when performing muting and gradually varying the converted output voltage from the prescribed voltage to the initial voltage when releasing the muting; and muting means (muting section) 5 for passing an audio signal in such a manner that an impedance between an audio signal path and a ground level is increased when the converted output voltage 12 becomes the initial voltage and interrupting passage of the audio signal in such a manner that the impedance between the audio signal path and the ground level is decreased when the converted output voltage 12 becomes the prescribed value.
Claims7
An audio muting apparatus comprising:
- a D/A converter;
- control means for gradually varying a converted output voltage from said D/A converter from an initial voltage to a prescribed voltage when performing muting, and gradually varying the converted output voltage from the prescribed voltage to the initial voltage when releasing the muting;
- and
- muting means for passing an audio signal in such a manner that an impedance between an audio signal path and a ground level is increased when the converted output voltage becomes the initial voltage, and interrupting passage of the audio signal in such a manner that the impedance between the audio signal path and the ground level is decreased when the converted output voltage becomes the prescribed value.
An audio muting apparatus comprising:
- a D/A converter;
- envelope detecting means for extracting an envelope signal from an output from said D/A converter;
- control means for changing the state of said D/A converter between a first output state and a second output state at prescribed time intervals, said first output state being a state of producing a first voltage whereas said second output state being a state of producing a second voltage;
- and
- muting means for varying the impedance between the audio signal path and ground level to interrupt the passage of the audio signal according to a level of said envelope signal;
- wherein
- said control means gradually varies a difference between said first voltage and said second voltage from the vicinity of 0 V to a prescribed voltage when performing muting, and gradually varying the difference between the first voltage and the second voltage from the prescribed voltage to the vicinity of 0 V when releasing the muting.
Dependencies are inferred from the claim text.