PURPOSE: To enable an operation without caring about matters other than watching a video screen by detecting the rotation operation of a rotary body by a rotation detecting means and performing a mode operation by an operation control means in accordance with the rotational operation of the rotary body.

CONSTITUTION: A 1st slider 10 is slid over a conductive pattern 6 on a 1st substrate 5 together with a 1st rotary plate 7 in accordance with the rotation of a rotation dial 30, and variable speed reproducing, fast feeding and rewinding operations of a tape running system are performed by the resistance value of the conductive pattern corresponding to a rotatioal angle of the dial 30. Thus, when the rotational angle is increased from the reference position of the dial 30 in the forward direction, the tape running system becomes the mode of fast feeding operation from variable speed reproduction. When the dial 30 is turned to the reverse direction, the tape running system becomes the mode of unwinding operation from variable speed reproduction. The reproduction is displayed on one pressing part 26a of a push-button 26, and the stop is displayed on another pressing part 26b, and further a frame feeding of the reproduced picture in the forward direction is made by turning a rotary knob 23 in the right direction, and the frame feeding in the reverse direction is made by turning in the left direction.