Abstract: The invention is concerned with a magnetic recording/playback apparatus in which a magnetic tape is pulled out from a tape cassette and wound around a cylindrical rotary head cylinder, having a rotary head built therein, over a predetermined angle to record/playback signals through the rotary head, and more particularly, with a tape guide post driving mechanism, a pinch roller pressing mechanism and a tension serve mechanism. Specifically, the invention provides a tape guide post driving device which can reduce the size, weight and thickness of the apparatus by ensuring a large angle of thickness of the apparatus by ensuring a large angle of rotation of a rotating member, which includes a tension arm, in a direct manner. Also, the invention realizes a pinch roller pressing mechanism in which a sufficient stroke can be obtained even when a cam gear is reduced in its diameter and can provide a sufficient stroke even with a small amount of rotation.

Abstract: The invention is concerned with a magnetic recording/playback apparatus in which a magnetic tape is pulled out from a tape cassette and wound around a cylindrical rotary head cylinder, having a rotary head built therein, over a predetermined angle to record/playback signals through the rotary head, and more particularly, with a tape guide post driving mechanism, a pinch roller pressing mechanism and a tension servo mechanism. Specifically, the invention provides a tape guide post driving device which can reduce the size, weight and thickness of the apparatus by ensuring a large angle of rotation of a rotating member, which includes a tension arm, in a direct manner. Also, the invention realizes a pinch roller pressing mechanism in which a sufficient stroke can be obtained even when a cam gear is reduced in its diameter and can provide a sufficient stroke even with a small amount of rotation.