| 摘要 |
PURPOSE:To have a constant S-shaped corrective property by allowing gate signals to have the polarity corresponding to a base line of gain control circuits, by changing over gate circuits as well as polarity inversions together with the polarity of gate signals which supply to gate inputs of each gate circuit of both the negative and positive polarity. CONSTITUTION:In case of an A base, the negative polarity gate circuit 16-2 is operated and the positive polarity gate 16-3 takes a state of OFF. In case of a B base, a KEY signal which is supplied to an input terminal 3 is reversed by a polarity inversion changing circuit 16-1 and an inversion output is supplied to a negative polarity gate circuit 16-2. Then the negative polarity gate circuit 16-2 takes the state of OFF and signals gated by the gate signals from an input terminal 4 are obtained through the positive polarity gate circuit 16-3. Since the above steps permit the gate signals to have the polarity corresponding to the base line of the gain control circuits, prior to its S-shaped corrective circuit, the gate signals have the constant S-shaped corrective property by the base line.
|
