| 摘要 |
PURPOSE:To improve the picture quality and to reduce the number of components and the cost by generating a virtual vertical synchronizing signal in response to the variable speed reproducing mode while suppressing jitter within a permissible range, by means of a microcomputer having a comparatively slow processing speed. CONSTITUTION:A head start signal (d) multilying a head switching signal (a) by two interrupts the microcomputer 12, and the generating processing of the virtual vertical synchronizing signal is executed to the microcomputer 12 with a delayed start signal (f) delayed for a prescribed time to the head start signal (d) so as to generate the virtual vertical synchronizing signal (g) having a timing in response to the variable speed reproducing mode. The jitter of the virtual vertical synchronizing signal (g) is limited within the permissible range by setting the said prescribed time to a time being a maximum time or over required for the execution of an instruction, and the processing of the generation of the optimum virtual vertical synchronizing signal is attained at the variable speed reproduction. |
