US 4,419,541 AGranted

Pulsive noise removing apparatus

AssigneesSanyo Electric Co., Ltd., Tokyo Sanyo Electric Co., Ltd.

InventorsHiroyasu Kishi, Junji Sakamoto, Sadao Kondou

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Abstract

A pulsive noise removing apparatus comprises a subtracting circuit (35) receiving one input thereto a stereo composite signal directly from a delay circuit (31). A stereo switching signal is generated as a function of a stereo pilot signal included in the stereo composite signal and a cancel signal of the same level, the same frequency and the same phase as those of the stereo pilot signal is generated as a function of the stereo switching signal. A gate (67) is interposed between the output of the cancel signal generating circuit (65) and the other input of the subtracting circuit and the gate is interrupted responsive to detection of a pulsive noise included in the composite signal. The pulsive noise is removed due to interruption of the gate and the stereo pilot signal is prevented from appearing at the output of the subtracting circuit irrespective of conduction or interruption of the gate.

Claims9

Dependent claims

A pulsive noise removing apparatus, comprising:

composite signal providing means for providing a composite signal including an information signal and a reference signal,
subtracting circuit means having two inputs and receiving said composite signal at one input thereto,
electric charge storing means coupled between said two inputs of said subtracting circuit means,
cancel signal generating means for generating a cancel signal for cancelling said reference signal upon application of said cancel signal to the other input of said subtracting circuit means,
noise detecting means for detecting a pulsive noise included in said composite signal, and
gate means interposed between said cancel signal generating means and said other input of said subtracting circuit means for being rendered conductive or interrupted responsive to said noise detecting means, whereby said gate means is interrupted upon detection of a pulsive noise for removing said pulsive noise and said information signal with said reference signal removed is obtained from said subtracting circuit means irrespective of conduction or interruption of said gate means.

3 more elements

Dependencies are inferred from the claim text.