| 摘要 |
PURPOSE:To enable conversion including neutral tints with simple circuit constitution by superposing a signal of a constant frequency and constant amplitude upon a video signal then by converting it into a binary signal. CONSTITUTION:A video signal is applied to input terminal 1 and supplied to adder 3. Simultaneously, a signal of constant amplitude is supplied at a constant repetitive frequency from generator 2. The best output waveform of this generator 2 is triangular, but any wave except a rectangular wave may be used. Such two signals are added together by adder 3 at a proper ratio and the mixture is sliced by slicing circuit 4 at a proper level. This signal is written and stored in a semiconductor digital memory. Such a method prolongs the time when output terminal 5 is held at a high level according to the level of the video signal and the data stored in the digital memory has the high-low ratio varying with the level of the video signal, so that information including the halftone is stored. |
