The present invention relates to data recording and reproducing apparatuses such as R-DATs (rotary head type digital audio tape recorders), 8-mm video tape recorders, and compact disk players. More particularly, the invention relates to a data recording and reproducing apparatus in which reproduction is carried out with the tops (start position) of programs to be reproduced detected with high accuracy.
For instance in an R-DAT, in addition to PCM audio signals, sub-code data for retrieving programs are recorded in different regions of the magnetic recording medium (such as a magnetic tape), and the sub-code data are read by a high-speed searching operation so that the tops of the programs can be detected quickly.
The sub-code data thus recorded for detection of the tops of programs are referred to as "program top detecting signals"or "start identification signals" (ST-ID). The start identification signal is an index signal for detecting a predetermined position on the magnetic tape. In general, the start identification signals are recorded for a predetermined period of time at the tops of pieces of music to facilitate the selection of the music program and reproduction operation.
Heretofore, in recording a plurality of pieces of music on a magnetic tape, the above-described start identification signals have been automatically recorded by, while the pieces of music are being recorded, the rise time of each of the pieces of music is detected, and simultaneously the start identification signal is recorded.
In the magnetic tape automatically recorded in the above-described manner, the start point of each of the pieces of music and the rise of its start identification signal are recorded simultaneously. Therefore, in the music selection and reproduction operation, the selected music is reproduced starting from the rise of the start identification signal. However, since a muting operation is effected for a certain period of time to squelch noise such as may be produced by various elements in the mechanical system, a part of the top portion of the music may not be reproduced.
This difficulty may be overcome by employing a method in which, with the muting time taken into account, after the detection of the rise of the start identification signal the magnetic tape is rewound for a certain period of time before the start of reproduction of the music. However, such a method is nevertheless disadvantageous in that the last part of the preceding piece of music may be reproduced.
USPTO Backgrounds
USPTO Backgrounds