| 摘要 |
PURPOSE:To attain A-D conversion of a wide dynamic range with high quantization accuracy inexpensively effectively by applying A-D conversion to an input video signal depending on the quantity via a subtractor and a gain converter. CONSTITUTION:When a video signal 1 exceeds a prescribed MAX value of a comparator 2, an analog voltage equal to the MAX value is generated from an analog voltage generating circuit 4 and the result is subtracted by a subtractor 6. A gain converter 7 compresses the gain of an input signal to 2<-n> (n is an integer being 1 or over) time and its output signal 8 is converted into a digital signal by an A-D converter 9. A digital signal 10 is inputted to a bit shift circuit 11, where the level is multiplied by 2<n> and an adder 13 adds a signal corresponding to an excess input detection signal 16. |
