JPH0377563B2 - - Google Patents

Description

[Detailed description of the invention] For example, if an audio signal is converted to PCM,
A device is known that uses a VTR to record PCM audio signals by sequentially forming diagonal tracks on a magnetic tape.

In this type of recording device, the audio signal is converted to PCM so that it can be recorded on a VTR.
The PCM audio signal has the same signal format as the video signal, i.e. horizontal sync signal, vertical sync signal,
It is a signal that has equalization pulses, etc., and for example, multiple words of the PCM signal for one horizontal period are
Record as data block. Therefore, one field contains, for example, PCM audio signals for 245 horizontal periods, that is, 245 data blocks.
Normally, a control signal block corresponding to one horizontal period is added to this data block corresponding to one field.

This control signal block consists of coded information necessary for the audio signal to be recorded as data, such as a cue signal, track title, manufacturer name, etc.

As shown in FIG. 1, this control signal block is inserted after the vertical synchronizing signal VD for one field of information, and in the recording track pattern on tape 1 in FIG. The information is recorded in the shaded position in the section.

By the way, when reproducing such a PCM-recorded audio signal, high-speed reproduction may be performed to find the beginning of a song, etc. This is called a high-speed search, and the tape is fed at several times the speed of normal running, so that the rotating head spans multiple tracks as shown by the thick arrow in Figure 2. The content of the recorded signal is searched in advance. During this high-speed search, if the tape is wrapped around the drum in the same angular range as during normal playback, the head damage and guide roller damage will be significant. This is natural since the tape running speed is high. Furthermore, if the wrapping angle is the same as during normal playback, the friction will be the same as during normal playback, so during high-speed search, the tape travels at high speed, which consumes a lot of power. Battery consumption becomes a serious problem.

In consideration of the above, it is conceivable that during high-speed search, the tape is wound around the drum by an angle range narrower than the tape winding angle during normal playback. FIGS. 3 and 4 are examples. That is, the third
In the figure, the solid line indicates the position of the tape during normal playback, and in the case of a two-head VTR, the tape 1 is wound around the rotary head drum 3 over an angular range of 180 degrees. In this case, the tape guides 4 and 5 that regulate the winding angle pull out the tape 1 from the cassette half and rotate the tape onto the drum 3.
5 moves in the direction of the arrow. During high-speed search, the amount of movement of the guides 4 and 5 corresponding to the amount of tape pulled out is reduced so that the tape 1 is only brought to the drum 3 to the position shown by the dotted line in the figure. is wound around the drum 3 in an angle range narrower than 180 degrees, for example, around 90 degrees. In this way, the head damage, guide damage and power consumption problems mentioned above are alleviated.

The case in Figure 4 is an example of a special PCM tape recorder, in which the winding angle of the tape around the drum is smaller than the interval between the head mounting angles, so that it can record time-base compressed PCM audio signals. The wrapping angle of the tape around the drum is small, for example in the case of 2 heads, it can be around 90 degrees, so instead of pulling out the tape with a tape guide, the drum 3 is wrapped around the cassette half 6.
This is a case where the tape is wound around a predetermined angular range by inserting the tape into a recess 7 provided in the . In the case of the example shown in Fig. 4, during normal driving, the drum is brought to the position shown by the solid line in the figure,
During high-speed reproduction, the drum is brought to the position shown by the dashed line in the figure, and the winding angle of the tape 1 around the drum 3 is made even smaller than during normal reproduction. In this example as well, the above-mentioned drawbacks during high-speed reproduction are improved.

By the way, even during these high-speed searches, it is necessary to always be able to extract control blocks indicating data contents with good accuracy.
This is because the control signal block is usually encoded with the song title, manufacturer, and other necessary information of the recorded audio signal as described above, and if this control signal block can be extracted, it will be possible to record it on the tape. This is because it is possible to know what kind of audio information is available.

Furthermore, this control signal block usually contains a code necessary for locating the beginning of a song, and by detecting this during a high-speed search, you can immediately find the beginning of a song. This is also because it can achieve good operation.

However, in order to improve problems such as head damage, guide damage, and power consumption during high-speed searching, when the tape winding angle is made smaller than during normal running, the recording position of the control signal block must be Since this is the end of the track, there is a risk that it will not be played. This is because, in the case of the examples shown in Figures 3 and 4, the rotary heads come into contact with each other even during high-speed searches at the center of each track, but the heads do not scan the ends of each track. It is.

The present invention seeks to propose a device that can reproduce control signal blocks favorably during high-speed reproduction as described above, even when the winding angle of the tape is made smaller than during normal running.

That is, in the present invention, the control signal block is recorded approximately at the center of each track.

FIG. 5 shows an example of a recording track pattern when an audio PCM signal is recorded on the tape 1 by the recording apparatus according to the present invention, and the diagonal line in the approximate center of each track 2 indicates the recording of the control signal block. It's the location.

In this way, even when performing a high-speed search as shown in FIGS. 3 and 4, the recording position of the control signal block will be reliably scanned by the rotary head, so that the control signal block during this high-speed search will be This allows the signal block to be reliably extracted.

The example in FIG. 6 shows the signal recording track pattern when the tape 1 is divided into two areas each half in the width direction and the upper and lower ends of the tape 1 are turned over to enable reciprocating recording. be. That is, for example, when the tape 1 is run in the direction of arrow A in the lower half of the figure, a recording track 2A is formed in this area to record a signal. On the other hand, turn the upper and lower ends of the tape 1 in the width direction and mark the area indicated by arrow B in the upper half of the diagram.
When the tape 1 is run in this direction, recording tracks 2B are sequentially formed in this area to record signals. Therefore, in the figure, the tape transport direction is
The direction is opposite to the area. In the case of a device capable of reciprocating recording in this way, each half of the area is wrapped around the drum during normal running, so if the tape is wound around that area or a narrower angular range during high-speed search, In this case, although the center portion of the track is scanned, both ends of the track no longer come into contact with each other. Therefore, even during this reciprocating recording, control signal blocks are recorded at the positions indicated by diagonal lines in each track 2A, 2B in FIG. In other words, a control signal block is recorded approximately at the center of each track.

In this way, even in the case of reciprocating recording and reproducing, the control signal block can be reliably extracted during high-speed search, and the content of the recorded audio information can be clearly known. This also has the effect of making it easier to find the beginning of a song.

The above example uses an audio signal as an information signal.
We have explained all the examples of converting to PCM, but for example, digitizing a video signal and recording/playing it.
In a VTR, VITS or
VIRS etc. may be inserted. Since the vertical synchronization signal recording position is at the end of the track, the recording position of these signals such as VITS and VIRS is also at the end of the track. VITS or
VIRS is recorded as a control signal block for a video data block, but when reproducing it during a high-speed search,
As mentioned above, when performing high-speed search with a smaller tape wrapping angle than during normal running,
The recording positions of these VITS and VIRS may be set approximately at the center of each track.

[Brief explanation of drawings]

Fig. 1 shows an example of the format of an audio PCM signal, Fig. 2 shows a recording pattern of a signal recorded by a helical scan rotary head device, and Figs. 3 and 4 show an example of the format of an audio PCM signal. FIGS. 5 and 6 are diagrams showing examples of track patterns in which signals are recorded by the recording device according to the present invention. FIGS. It is. 1 is a tape, 2 is a recording track, and 3 is a rotating head drum.

Claims (1)

[Claims] 1. In an apparatus in which a plurality of data blocks formed into blocks for each of a plurality of PCM words and a control signal block are formed as diagonal recording tracks by a rotating head,
By recording the control signal block near the center of each of the recording tracks, the tape winding angle can be controlled at least at the center of the recording track during high-speed playback of signals from the recording tracks. A recording device in which the control signal block can be reliably reproduced even if the control signal block is reproduced in a smaller angular range than during normal reproduction by making the control signal block a part that is in contact with the head.