Video cassette recorder with automatic tracking adjustment during special playback

摘要

The present invention relates to a video cassette recorder having an automatic tracking adjustment function at a special reproduction so as to be able to automatically perform tracking adjustment even while a special reproduction such as a still function or a triple speed reproduction function is executed, A drum motor 34 for rotating a drum provided with a recording / reproducing head 6 in accordance with a predetermined drive signal; a control unit 33 for controlling the operation of the drum motor 34. A video cassette recorder comprising: An envelope detector 45 for detecting an envelope carrying a predetermined DC voltage from an image reproduced signal reproduced and output by the recording / reproducing head 6, and a local oscillator circuit 45 for generating a sampling frequency signal for sampling the envelope A sampling circuit 47 for sampling the envelope waveform at predetermined intervals on the basis of a sampling frequency outputted from the local oscillation circuit 46, An upper adjustment maximum level storage section 48 for storing drum motor control data at which the reproduction video signal reaches a maximum detection level as it is upwardly adjusted at a predetermined rate, and a control section for controlling the rotation speed of the drum to a predetermined ratio And a downward adjustment maximum level storage unit 49 for storing drum motor control data at which the reproduced video signal reaches the maximum detection level as it is down-The control unit 33 reads the drum motor control data stored in the upward adjustment maximum level storage unit 48 and the drum motor control data set in the downward adjustment maximum level storage unit 49 when the special playback is executed, The control data having the larger sampling level is selected from the data, and then the drum motor driving section 35 is controlled to the selected value.