| 摘要 |
<p>PURPOSE:To perform a fast forward reproduction when the main part of a program is in either a monophonic mode or a dual sound mode an the CM is in a stereophonic mode during the reproduction of a recorded audio multiplex broadcasting. CONSTITUTION:A control microcomputer 2 monitors the identifying signals, which indicate the sound mode from a sound multiplexing circuit 24, judges it to be a CM if a monophonic mode or a dual sound mode lasts a prescribed duration then it changes to a stereophonic mode, the control microcomputer 2 requests an identifying signal generating circuit 5 to generate an identifying signal only if it is the stereophonic mode, a mixing circuit 8 mixes the identifying signal and sound signals and records them with the sound signals in sound tracks. A timer 3 is provided to count the prescribed duration count. During a reproduction, an extracting circuit 15 extracts the identifying signal and when the control microcomputer 2 detects the identifying signal, it outputs a control signal to perform a fast forward reproduction. In order to correct the frequency increase in the reproduction frequencies caused by the fast forward reproduction back to the normal frequencies, a frequency multiplying circuit 14, which is only operable during a fast forward reproduction, is provided in front of the extracting circuit 15.</p> |
