| 摘要 |
<p>A miniature helical scan video tape recorder (VTR) utilizes a reduced-diameter guide drum, but the video signals recorded thereby onto the tape have a standard track pattern and can be reproduced using a standard VTR having a guide drum of standard diameter D1. In the miniature VTR, the tape is wrapped for a tape wrap angle .alpha. (e.g., substantially 300 degrees) at a still angle .THETA.2, whereas the standard VTR uses a wrap angle of 180.degree. and a still angle of .THETA.1. In order to ensure that the miniature VTR achieves the same record track length ?'N and recording angle .THETA.0 as the standard VTR, the diameter D2 of the miniature VTR is selected to satisfy the equation < IMG >; where fV is the video field frequency. The still angle .THETA.2 satisfies the equation < IMG > , and the video signal to be recorded is given a non-standard horizontal scanning frequency f'H according to the relation < IMG > , where fH is the standard horizontal scanning frequency. The recording head can be provided with two gaps for double-azimuth recording of the video signal.</p> |
