发明名称 |
Analog magnetic recording system for binary signals |
摘要 |
Digital data is recorded onto a cassette tape by utilizing an audio cassette tape recorder under the control by a microprocessor. The microprocessor assigns "0" digital data bit a time sequence of a shorter pulse of a single period (T1) and having a duty cycle of 50% and a longer pulse of a single period (T2) and having a duty cycle of 50%. Assigned to "1" data bit is a time sequence of a single period of T2 pulse and a single period of T1 pulse. An analog signal applied to the recording unit of the audio cassette tape recorder initiates a gradual increase in its level at a point of transition from the low level L to the high level H of either T1 or T2 pulse, and returns to a start level at a point of transition from the H to the L level and also initiates a gradual decrease in the level. In this manner, a waveform conversion is performed. As a result of such waveform conversion, a signal reproduced from the cassette tape has a waveform which can be easily determined to represent either one of the binary data bits. The use of pulses having duty cycles of 50% as reference waves minimizes a level fluctuation in the reproduced signal which may be caused by a time constant of the reproducing unit of the tape recorder.
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申请公布号 |
US4473851(A) |
申请公布日期 |
1984.09.25 |
申请号 |
US19820350910 |
申请日期 |
1982.02.22 |
申请人 |
AISIN SEIKI KABUSHIKI KAISHA |
发明人 |
NAGURA, NOBUYOSHI;KAWAI, TANEICHI |
分类号 |
G11B20/10;G11B20/14;(IPC1-7):G11B5/09 |
主分类号 |
G11B20/10 |
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