Method and circuit for detecting auto tracking find error in a video cassette recorder and accordingly controlling capstan phase for correct video head tracking

摘要

A method and A circuit for detecting an auto tracking find error in a VCR, wherein a phase control range for a capstan motor is widened as compared with the prior art so that, when a phase of the capstan motor is widely detuned, the following speed for stabilization of the phase of the capstan motor can be made fast. According to the invention, in an interval of -&pgr;-&pgr; of the phase of the capstan motor, first latch data is selected as a phase error signal for control of the phase of the capstan motor. In intervals of -2&pgr;--&pgr; and &pgr;-2&pgr; of the phase of the capstan motor, second latch data is multiplied by two and is then of the same polarity as that of the first latch data. The second latch data multiplied by two is added to the first latch data. In result, the added value is selected as the phase error signal. Also, a portion of the data above double the upper limit value is cut in the interval of -2&pgr;-- &pgr; and a portion of the data below double the lower limit value is cut in the interval of &pgr;-2&pgr;.