PURPOSE: To easily obtain a suitable reproducing speed in response to the request of reproducing speed at reproduction, by automatically discriminating the speed at recording for a VTR or the like, through the provision of two specific frequency-dividers, a counter and a comparison means.
CONSTITUTION: A reference clock 2n times the control pulse frequency of a recording medium is frequency-divided at a frequency divider 14, for one time at normal/double speed/tripple reproducing speed, for 1/2 time at 1/2 time reproducing speed and for 1/3 time at 1/3 time speed reproduction, and a reproducing control pulse is frequency-divided at the 2nd frequency-divider 13, for one time at normal 1/2 speed 1/3 speed reproduction, for 1/2 time at double speed reproduction, and for 1/3 time at tripple speed reproduction. The period of pulse of an output of the frequency-divider 13 is counted 22 by taking an output of the frequency-divider 14 as a clock input, and the count value B and two constants A, C are compared 23 and 24, and whether or not the moving speed of the recording medium is suitable is discriminated from the result of comparison.
JPS5614785A | 1981-02-13 |