JPS62259249A - Rotary head type recorder - Google Patents

Abstract

PURPOSE:To perform the program searching of an optional musical composition out of plural ones recorded continuously by detecting a soundless section and recording an index signal in the soundless section at the recording of an audio signal by a rotary head. CONSTITUTION:An audio signal from input terminals 1R, 1L is supplied to a PCM processing circuit 2 and peak detecting circuits 3R, 3L. The outputs of the circuits 3R, 3L are supplied to an LPF6 and a comparator 7 through an adder 5. When the level of the audio signal supplied to the terminals 1R, 1L is less than a prescribed value, the output of the comparator 7 is turned to a low level. The output of the comparator 7 is sent to a system controller 8 and the controller 8 generates an index writing control signal corresponding to the soundless section. Consequently, an index writing circuit 11 outputs an index signal to an adder 4 to record the index signal on a magnetic tape 14. Thus, the program searching of an optional musical composition can be performed by using the index signal.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a rotary head type recording device that records audio signals using a rotary head, and particularly relates to cueing.

[Summary of the invention]

The present invention detects a silent section in a rotary head type recording device that records an audio signal using a rotary head.
By recording an index signal in this silent section, an index signal is automatically recorded between songs.1. It has been designed so that you can easily find the beginning of any song.

[Conventional technology]

In a so-called high-fidelity VTR, an audio signal is FM-modulated and recorded together with a video signal by a rotating head, so that an audio signal of very high quality can be reproduced. Furthermore, in the so-called 8mm VTR, in addition to the method of FM modulating the audio signal and recording it with a rotating head, there is also an option of digitizing the audio signal for the field, compressing the time, and recording it at the end of the track. Standardized. Therefore, extremely high quality audio signals can be reproduced. Also, in 8mm VTR, multi-PCM
There is a mode that can be set called . In multi-PCM, the recording area for one field is divided into six areas, and digital audio signals are recorded in these recording areas. Therefore, when used exclusively for audio, multi-PCM can record audio signals for 24 hours, for example, six times as long as in the normal mode.

Since such VTRs can reproduce audio signals of very high quality, they are often used exclusively for audio, recording only audio signals. When recording audio signals with a VTR, there is an advantage that high-quality audio signals can be recorded for a long time, compared to recording audio signals with a cassette tape recorder exclusively for audio.

[Problem that the invention seeks to solve]

When only audio signals are recorded on a VTR, it is desirable to be able to freely locate the beginning of all songs.

In particular, when audio signals are recorded with an 8mm VTR multi-PCM, the recording time is very long, so the cue function is important, and if the cue cannot be found, it will take a lot of time to search for a song.

Conventionally, an index signal is recorded on a tape, and this index signal is used to locate the beginning of the VTr2. In a VTR with a CTL track, a control signal with a different duty ratio is used as an index signal.
Recorded in TLI-Rank. For 8mm VTRs that do not have a CTL trunk, all r
OJ data is input as an index signal by a rotary head. (Patent Application No. 60-64554).

Conventionally, this index signal is automatically input at the start of recording. Furthermore, if necessary, it is possible to manually input an index signal during recording.

Therefore, in a conventional VTR, when a plurality of songs are continuously recorded, the index signal is only input at the recording start position unless the index signal is manually input at a predetermined position between the songs. For this reason, conventional VT
In R, there is a problem in that when a plurality of songs are recorded in succession, it is not possible to locate the beginning of a song other than the first song recorded.

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to provide a rotary head type recording device that can freely locate the beginning of a song from among a plurality of continuously recorded songs.

[Means for solving problems]

The present invention is a rotary head type recording device that detects a silent section when recording an audio signal using a rotary head, and records an index signal in this silent section.

[Effect]

The level of the input audio signal is detected by the peak detection circuit 3R13L. When the level of this audio signal is above a predetermined value, the output of the comparator 7 becomes a high level, and when the level of this audio signal is below a predetermined value, the output of the comparator 7 becomes a low level. When the output of the comparator 7 is at a low level for a predetermined period of time or longer, the index write circuit 11 writes an index signal.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment in which the present invention is applied to an 8 mm VTR. In the 8 mm VTR, audio signals can be converted into digital format and recorded, and a mode exclusively for recording audio signals called multi-PCM can be set. In multi-PCM, a track for one field is divided into six, and a digital audio signal is recorded on each track. Figure 1 shows '? This shows a case where audio signals are recorded in multi-PCM mode.

In FIG. 1, IR and l+- are input terminals for right channel and left channel audio signals. Audio signals from input terminals IR and IL are supplied to the PCM processing circuit 2 and also to peak detection circuits 3R and 3L. The input audio signal is digitized and time-compressed in the PCM processing circuit 2. The output of the PCM processing circuit 2 is supplied to an adder circuit 4.

The outputs of the peak detection circuits 3R and 3L are supplied to an adder circuit 5, and the output of the adder circuit 5 is supplied to a comparator 7 via a low-pass filter 6. The output of core valley 91 is supplied to system controller 8.

When audio signals are supplied to the input terminals IR and 1L, outputs corresponding to the audio signal levels appear from the peak detection circuits 3R and 3L. These outputs are added by an adder circuit 5, and passed through a low-pass filter 6 to a comparator 7.
supplied to As shown in FIG. 2, when the signal level of the audio signal (FIG. 2A) supplied to the input terminals tR and IL is above a predetermined value, the output of the comparator 7 goes high as shown in FIG. 2B. become the level. Input subject; child I
When the signal level of the audio signal (FIG. 2A) supplied to R and IL is below a predetermined value, the output of the comparator 7 becomes low level, as shown in FIG. 2B.

When recording a plurality of songs in succession, a silent section occurs between the end of one song and the start of the next song. Therefore, by detecting this silent section, the position between songs can be detected.

The output of the comparator 7 is supplied to the system controller 8, and the system controller I/roller 8 measures the time when the output of the comparator 7 becomes low level using the clock shown in FIG. 2C. A manual index write signal is supplied to the system controller 8 from the key switch 9. The system controller 8 also has a terminal 10.
A mode signal is supplied from.

When the setting mode is other than the video recording mode, when the output of the comparator 7 is at a low level for a predetermined period of time or more, the system controller 8 outputs an index write control signal. When the setting mode is the video recording t& mode, the index write control signal is not output from the system controller 8 even if the output of the comparator 7 remains at a low level for a predetermined period of time or more. This is to prevent an index signal from being written in a silent section between lines during video recording. Furthermore, when a manual index write signal is supplied from the key switch 9, an index write control signal is output from the system controller 8.

An index write control signal output from the system controller 8 is supplied to the index write circuit 11. An index signal is output from the index write circuit 11, and this index signal is supplied to the adder circuit 4. As the index signal, a 2.9M1lz signal is used which indicates data "0" by bi-phase mark modulation.

The output of the index write circuit 11 is supplied to the adder circuit 4, and the adder circuit 4 writes rOJ data into the postamble portion of the PCM data as an index signal. The output of the adder circuit 4 is sent to the recording amplifier 12 and the rotating transformer (
(not shown) to the rotary head 13 and recorded on the magnetic tape 1,t.

As a result, data of "0" is placed at index 13 in the postamble part of l) CM data corresponding to the silent section.
It is typed as a number. Using this index signal, it is possible to locate the beginning of a song.

FIG. 3 shows the reproduction system. In FIG. 3, signals recorded on a magnetic tape 21 are reproduced by a rotary head 22. In FIG.

This reproduction signal is supplied to the reproduction amplifier 23 via a rotary transformer (not shown), and the output of the reproduction amplifier 23 is PCM.
The signal is supplied to the processing circuit 24 and also to the index detection circuit 25. Processing such as error correction is performed in the PCM processing circuit 24, and the output of the PCM processing circuit 24 is taken out from the output terminal 26. This output reproduces the audio signal.

An index detection circuit 25 detects the index signal recorded in the postamble section. This detection signal is supplied to the system controller 27. system controller 1
- The roller 27 is supplied with the output of the key switch 28. Keysui 7chi 28 sets which track to cue.

The system controller 27 includes the index detection circuit 2
The detection signals output from 5 are counted and the key switch 28 is
to determine whether the specified song has been reached. When the system controller 27 determines that the magnetic tape 21 has reached the beginning of the designated song, a command is given to the mode control circuit 29 to set it to stop mode.

As a result, the 6N tape 21 is stopped at the start position of the designated song.

By detecting silent sections on the magnetic tape 21,
It is rare that index signals are input corresponding to all positions between songs. Therefore, it is possible to locate the beginning of all songs.

Further, by using this index signal, repeat playback and program playback can be performed.

In the above embodiment, the case of a multi-PCM 8 mm VTR has been described, but the present invention can be similarly applied to a VTR in which an audio signal is FM-modulated and recorded using a rotary head.

〔Effect of the invention〕

According to this invention, when recording audio signals on a VTR, index signals are recorded between songs by detecting silent sections. By using this index signal, users can freely locate the beginning of their own songs. Further, by using this index signal, repeat playback and program playback can be easily performed.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a recording system according to an embodiment of the present invention, FIG. 2 is a waveform diagram used to explain an embodiment of the present invention, and FIG.
The figure is a block diagram of a reproduction system according to an embodiment of the present invention. Explanation of main symbols in the drawings 1R, IL: Input terminal, 3R, 3L: Peak detection circuit, 11: Index writing circuit, 13.22: Rotating head, 25: Index detection circuit, 27:
system controller.

Claims (1)

[Claims] A rotary head type recording device that detects a silent section and records an index signal in the silent section when recording an audio signal using a rotary head.