Unneeded-screen erasing transmission system of facsimile transmitter

Abstract

Abstract PURPOSE: To improve band compressibility by transmitting a needed screen part of an original screen while masking an unneeded screen part by white substitution. CONSTITUTION: Marks M 1 and M 2 are written at the initial point and terminal point of a part on an original surface to be white-substituted respectively, and two position detection circuits are provided which detect the both. Position detection circuits 1 and 2 make a run-length counter count picture elements in the main scan direction and then outputs a position detection status signal until the count value reaches a fixed value. This signal is used to gate original signal A and inputted to AND gates 5 and 6. Outputs of gates 5 and 6 are inputted to picture signal pattern comparator circuits 3 and 4 respectively. Circuits 3 and 4, composed of various run-length counters, output a picture-signal coincidence status signal when output run-length patterns of gates 5 and 6 agree with marks M 1 and M 2 . Since the output of circuit sets R-SFF7 and that of circuit 4 resets FF7, putting AND gate 8 into operation by signal A allows the output of gate 8 to provide white conversion of a part between marks M 1 and M 2 . COPYRIGHT: (C)1980,JPO&Japio

Inventors

• 👤 Kiyoshi Kobayashi

Bibliographic Details