| 摘要 |
<p>PROBLEM TO BE SOLVED: To output a slice level signal with a constant ratio with respect to an input signal regardless of the size of the input signal, in a slice ratio control circuit controlling the ratio of a slice level with respect to the input signal at the time of generating the slice level used for the binarization of a bar code. SOLUTION: A signal Vin outputted from a differentiating circuit is set to be the slice level signal Vout through a peak holding circuit. For compensating the drop of the level of Vout by forward voltage Vf of a diode, voltage Vlim is applied to one end of a resistor R2 constituting a voltage-dividing circuit. Thus, the influence of forward voltage Vf of the diode is removed and the slice level having the prescribed ratio to the input signal can be generated.</p> |
