| 摘要 |
PURPOSE:To actuate a tape reader always under proper conditions by automatically altering a slice level so that a duty ratio of a binary signal of a read element output will be a specified value. CONSTITUTION:A control circuit 30 controls a capstan motor 12, feed magnet 14, brake magnet 11, etc. A waveform shaping circuit 34 compares a signal from an element 8b for receiving light of a read element with a slice level VT to turn the signal into a binary signal and sends out read information. The slice level VT is changed so that a duty ratio of a binary signal is determined and that the ratio becomes a prescribed value at the time of the first tape feed command after the device is applied an electric power source. After the slice level is decided, the tape is back to the position at the time of applying the power source, and the device resumes tape running. |
