Magnetic record/playback system of rotating head type

Claim 1

In a magnetic record/playback system of the rotating head type, wherein a recording track having a plurality of fields or frames is scanned on a magnetic tape driven by a capstan motor, said system having a selectable normal play mode and a still play mode, said head operating in response to a head switching pulse generated by means in said system during a still play mode an apparatus for optimumally producing still pictures, comprising: means for switching the drive mode of said capstan motor to a low speed when said system is switched from a normal play mode to a still play mode; level detecting means for detecting an envelope signal from said rotating head, said detecting means producing a pulse having a period corresponding to the time said envelope signal magnitude is below the magnitude of a reference signal; gate means for providing a signal when said level detecting means pulse is time coincident with said switching pulse; braking means connected to stop said capstan motor in response to a signal from said gate means; and detected level control means connected to receive said pulse produced from said level detecting means, said control means providing an integrated voltage level from said produced pulse, said voltage level being applied as a reference signal to said level detecting means whereby said level control means provides a feedback signal for maintaining the width of pulses produced by said level detecting means substantially constant.