| 摘要 |
PURPOSE:To provide the natural feeling to pictures and to obtain well-balanced picture signals with a simple constitution and regardless of the incident light volume, by increasing the coloring range for the output of an image pickup tube and the same time approximating gradually the output color of said pickup tube to white without having green coloring with high luminance. CONSTITUTION:The output of an image pickup tube 202 is applied to an LPF 204, a narrow band LPF206 and a BPF208 respectively via a preamplifier 203. The output of the LPF204 is applied to a gamma compensating circuit 205. At the same time, the output of the LPF206 is applied to adders 41 and 42, and the output of the BPF208 is applied to adder and subtractor circuits 210 and 213 via a 1H delay line 209 to be added to adders 41 and 42 after addition and substration. The outputs of adders 41 and 42 are applied to red and blue gamma compensating circuits 212 and 215 respectively, and at the same time the output of the LPF206 is applied to a gamma compensating circuit 207. Then the coloring range of the tube 202 is increased, and the output color of the tube 202 is gradually put close to white without having green coloring with high luminance. This presents the natural feeling to pictures. |
