Recording-reproduction apparatus applying double reset to the phase of

Abstract

A magnetic recording-reproduction apparatus records and reproduces a wide-band video signal without a color burst signal. For this purpose, a two-step phase resetting operation is conducted on the FM carrier at the front porch and the horizontal sync pulse of the video signal so as to permit those phases to coincide with reference phases. A synchronizing panel clock generator generates the first reference signal with the first FM frequency corresponding to a peak level of the horizontal sync pulse and the second reference signal with the second FM frequency corresponding to a front porch level. In this case, the reference signals are phase-synchronous with each other at the leading edge of the horizontal sync pulse, and each of the FM frequencies is set to be an integer multiple of the horizontal scanning frequency. In another arrangement, a secondary FM carrier whose frequency has been shifted to a low-band is formed by generating a frequency conversion signal synchronous with the horizontal sync pulse and combining the phase-reset FM carrier with the frequency conversion signal. Either of the above arrangements can eliminate unwanted higher harmonic wave components and transient distortions in the frequency-demodulated output, thereby improving the image quality.