| 摘要 |
PURPOSE: An automatic display method of letter signal in a VCR is provided to improve the reliability of product by displaying a letter signal after stabilizing a deck. CONSTITUTION: A mode is selected and the selected mode is performed after inserting a tape. When a selective key of playing mode is inputted, a rotated speed of drum motor is controlled and a switching pulse inputted when the drum rotated once is received. An envelope value of frequency generated when the switching pulse is inputted is yielded, the yielded envelope value is stored and it is decided if a counted number of switching pulses is a certain value. When the number of switching pulses is certain value, it is decided if a changed amount of envelope value in a generating step of envelope signal is under a certain percentage. When the changed amount of envelope value is under the certain percentage, a letter signal is displayed after generating the letter signal corresponding to the playing mode. When the envelope value is not under the certain percentage, it is decided if a certain time after selecting the playing mode is passed. The generating step of letter signal is proceeded if the certain time is passed and the receiving step of pulse is proceeded if the certain time is not passed.
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