| 摘要 |
PURPOSE:To attain correct identification with a range of wide mark rate by clamping a base line of an electric signal corresponding to an optical signal at an adjusting voltage fluctuated according to the mark rate. CONSTITUTION:An input signal attended with fluctuation of a mark rate is branched into two and inputted to capacitors 1, 2. A signal from the capacitor 2 becomes a DC voltage in response to the change in the mark rate via a differentiating circuit 3, a rectifier circuit 4 and an integration circuit 5. An output of the circuit 5 is inputted to a DC/DC conversion circuit 6, where the level is converted, the result is fed to a signal from the capacitor 1 via a resistance 7 and inputted to an identification reproduction circuit 8. Thus, an optimum identification voltage in response to the mark rate is given with respect to the input signal whose mark rate is fluctuated and the deterioration in the identification range is relieved. |
