Facsimile graphic input device

Abstract

Abstract PURPOSE: To decrease the quantization noise and thus to obtain a pattern free from batter by varying the standard voltage of the A/D converter and then securing the quantization between the maximum and minimum densities into the natural step number. CONSTITUTION: The output of sensor 1 is amplified up to the prescribed level through amplifier 2, and electric signal 4 proportional to the pattern density is obtained through logarithm converter 3 to be supplied to the A/D converter. The A/D converter consists of comparators 5-1∼5-n, resistances 8-1∼8-(n-1) and encoder 9, and is capable of the quantization of 16 levels. And the upper and lower limits of the standard level are decided by the voltage of variable power sources 6 and 7 respectively. Comparator 5 is provided in 16 units to supply signal 4 to each positive terminal, and the voltage difference between power sources 6 and 7 is supplied to each negative terminal through resistance 8 and in the form of the divided voltage. Each output of comparator 5 is supplied to encoder 9 to obtain coded output 10. With such constitution, the quantization into 16 levels is possible to any kind of the original just by varying the reference voltage, thus avoiding the batter phenomenon occurring at the upper and lower limits of the density. COPYRIGHT: (C)1980,JPO&Japio

Inventors

• 👤 Kazuo Nakano

Bibliographic Details