PURPOSE: To remarkably reduce the transmission and recording time, by changing the transmission density per line according to whether the picture information is sparse or dense, transmitting the picture information, and recording it by changing the packing density in accordance with the picture information which has been transmitted, by the receiving side.

CONSTITUTION: In case when it has been decided by the sparse or dense deciding circuit 7 that a binary picture signal of 1 line portion which has been read from the transmission original 1 is dense, the first detection signal is generated, and the binary picture signal V and the phase signal P are modulated by the carrier frequency and are sent. The number of scanning lines per unit length, namely, the scanning line density becomes 6 pieces/mm. In case it has been decided that the binary picture signal of 1 line portion is scarse, the second detection signal is generated, a control signal C is generated in the latter half period of the phase signal period by the control signal generating and modulating circuit 11, and this signal C is modulated and sent out by the carrier frequency which is different from that of the binary picture signal V and the phase signal P. Accordingly, the scanning line density becomes 3 pieces/mm. In case the control signal C has been detected by the receiving side, the scanning line density is recorded as 3 pieces/mm.