| 摘要 |
PURPOSE:To output an overflow signal as a black signal and to make the adjustment of density of a picture signal easy, every time the result of addition exceeds the storage capacity, by encoding an image pickup output of an original to be transmitted digitally and storing a prescribed capacity of the digital output accumulated in a storage circuit. CONSTITUTION:An output of a pickup circuit 1 reading the original to be transmitted is amplified at an amplifier 2 and encoded at a digital encoding circuit 8 for a prescribed bit. The value from the circuit 8 is added to an addition circuit 9, accumulated with the past value, and the accumulated result is stored in a storage circuit 10. The storage capacity of the storage circuit 10 is designated as a prescribed bit length, and when the result of accumulation exceeds the maximum gradation level, the overflow output is outputted from the addition circuit 9 and the residual is stored in the storage circuit 10. The overflow output is designated as the black signal and transmitted via a transmission encoding circuit 4, allowing to make the change of the number of gradations reproducing the intermediate tone and of the density of a reproducing screen easy. |
