PURPOSE: To generate the extracted signal of a picture signal in accordance with original width by using a converter that couples with a traveling guide rail on a transmitted original paper feed table and converts mechanical movement into electric variation.

CONSTITUTION: Converting element 2 coupling with guide rail 1a on paper feed table 1, e.g. variable resistor (VR)2 is installed to obtain an electric movement value from the mechanical movement value of the guide rail. This VR2 is used as an element that sets the time constant of monostable multivibrator 4 together with capacitor 3. Resistance value R of VR2 and capacity C of capacitor 3 are preset so that a scanning time, equivalent to original width, of the scanning time of a oneline picture signal can be obtained from output Q of monostable multivibrator 4. Consequently, when slide rail 1a is adjusted to a position equivalent to the B5 size, the output of AND 5 including only the extracted picture signal of the B5 size originl can be obtained.