发明授权
- 专利标题: Noise reduction system
- 专利标题(中): 降噪系统
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申请号: US412001申请日: 1982-08-27
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公开(公告)号: US4473852A公开(公告)日: 1984-09-25
- 发明人: Yasuo Kominami , Kazuo Watanabe , Fumihiko Yokogawa , Nobuhiro Suzuki
- 申请人: Yasuo Kominami , Kazuo Watanabe , Fumihiko Yokogawa , Nobuhiro Suzuki
- 申请人地址: JPX Tokyo JPX Tokyo
- 专利权人: Hitachi, Ltd.,Pioneer Electronic Corporation
- 当前专利权人: Hitachi, Ltd.,Pioneer Electronic Corporation
- 当前专利权人地址: JPX Tokyo JPX Tokyo
- 优先权: JPX56-134004 19810828
- 主分类号: H04B1/62
- IPC分类号: H04B1/62 ; G11B20/04 ; G11B20/24 ; H03G9/02 ; H04B1/64 ; G11B5/47 ; G11B5/02
摘要:
Conventional Dolby B-type or C-type noise reduction systems respond sensitively to an A.C. bias signal during recording onto a magnetic tape. As a result, the system might exhibit a large encode error. In order to reduce such encode error, the gain - frequency characteristic control sensitivity of a side chain in the system to the A.C. bias signal to be supplied to a recording head is set at a value smaller than that of the gain - frequency characteristic control sensitivity of the side chain to an encode input signal at an audio frequency. Such a reduction of the encode error is achieved by connecting a bias trap circuit to a gain control amplifier included in the side chain.