JPH06295571A - Recording and reproducing device - Google Patents

Abstract

PURPOSE:To decrease the number of bits required for ID information by letting azimuth angle information on recording and reproducing heads which are determined at every sink blocks be a part of the ID information and performing recording and reproduction by the heads which have the same azimuth angles. CONSTITUTION:The recording heads 12 and 13 have a plus and a minus azimuth and are enabled to perform guard-band-less recording, thereby improving the recording density on a tape. Then the heads 12 and 13 record input signals on the tape 14. On the tape, azimuth recording is performed with the signals from the heads 12 and 13 per one field on two tracks respectively, i.e., as four tracks in total. Further, the reproducing heads 15 and 16 also have the plus and minus azimuths; and the signal recorded by the head 12 is reproduced by only the head 15 having the same azimuth angle and the signal recorded by the head 13 is reproduced by only the head 16. That is utilized to add plus/ minus information on an azimuth angle as one bit of the ID information and then the number of the bits of the ID information which is added at every the sink block is reducible to the total recording bit rate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for recording / reproducing video signals and audio signals, and more particularly to a recording / reproducing apparatus in which the number of bits of ID information required for recording is reduced.

[0002]

2. Description of the Related Art The structure of a conventional video tape recorder will be described below. During recording, the input signals are
AD recording, shuffling / interleaving, addition of error correction code, addition of ID information, and recording modulation are performed, and recording is performed by the recording head. During reproduction, the output signal from the reproducing head is sequentially demodulated corresponding to recording modulation, ID information separation,
Error correction, deshuffling, DA conversion are performed, and the reproduced signal is output.

The addition / separation of ID information at this time will be described in detail with reference to the drawings. Figure 1 (A)
Indicates a recording pattern when recording on a tape with 2 channels, 2 segments, that is, 1 field and 4 tracks. Here, 28 is a tape, and 29 to 32 are four recording tracks. Further, the structure of one sync block at this time is 34 in FIG. 3, the structure of ID information is 35,
The structure of the track number is shown at 36. At the time of recording, since there are 4 tracks in 1 field, 2 bits are required in the track number portion of the ID information as shown by 36. During playback,
The track number portion 36 of the ID information is detected from the reproduction signal, and the track number is determined by the data 0 and 1 as shown in (Table 1).

[0004]

[Table 1]

[0005]

However, the above-mentioned conventional method has a big problem that a large number of bits are required for the ID information.

The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide a recording / reproducing apparatus in which the number of bits of ID information required for recording is reduced.

[0007]

In order to achieve this object, the present invention uses an azimuth recording method to produce a video signal or audio signal by a head having a first azimuth angle and a head having a second azimuth angle. Signal on recording medium 1
There is provided a means for recording / reproducing by adding a field number identification signal with the number of n tracks (n: integer, n ≧ 2) per field, and when recording, when n is an even number, n / 2 types, n is When the number is odd, (n + 1) / 2 types of track number identification signals are added.

[0008]

With this configuration, the information on the azimuth angle of the recording / reproducing head determined for each sync block is used as a part of the ID information, and the fact that recording and reproduction are performed by the head having the same azimuth angle is utilized. The number of bits required for ID information is reduced. Also, during special reproduction such as search / jog, the effect of azimuth recording is effective, and therefore, the same effect as during normal reproduction is obtained.

The ID information indicating the address on the tape is important data for specifying the position on the screen or the temporal position of the sync block data. Therefore, high error resistance is required, but by making the information of the azimuth angle part of the ID information by using the present invention, an error does not occur in this bit, and thus the error resistance of the ID information is improved. It is possible.

[0010]

【Example】

(Embodiment 1) An embodiment of the present invention will be described below with reference to the drawings. 1A is a track pattern diagram, FIG. 1B is a diagram showing track number identification bits in a sync block, and FIG. 2 is a block diagram of a recording / reproducing apparatus in an embodiment of the present invention. In the present embodiment, it is assumed that the video signal is recorded in two channels and two segments and azimuth recording is performed in four tracks per field.

At the time of recording, in FIG. 2, the analog luminance signal Y and the analog color difference signals PB and PR input from the terminals 1, 2 and 3 are converted from analog signals to digital signals by the AD circuits 4, 5 and 6, respectively. It The converted digital signal is input to the signal processing circuit 7 and processed as a digital signal. In the digital signal processing circuit 7, a burst error, shuffling for special reproduction, and addition of an error correction code for correcting an error generated in the recording / reproduction process are performed. The output of this digital signal processing circuit 7 is 2
It is divided into channels and input to the ID adding circuits 8 and 9, respectively.

In the ID adding circuits 8 and 9, ID information indicating an address on the tape is added to each sync block.
This ID information is indispensable for identifying the position of each sync block data on the screen during reproduction (particularly during special reproduction). The outputs of the ID adding circuits 8 and 9 are input to the recording signal processing circuits 10 and 11, respectively. The ID information added by this ID adding circuit is only one track number identification bit, as shown at 33 in FIG. Recording modulation and recording amplification are performed in the recording signal processing circuits 10 and 11, and the signals are input to the recording heads 12 and 13, respectively.

The recording heads 12 and 13 each have a plus azimuth and a minus azimuth, enable guard bandless recording, and improve the recording density on the tape. In the recording modulation, the signal is modulated into a signal suitable for the physical recording / reproducing characteristics of the recording medium. The recording heads 12 and 13 record the input signal to the recording heads on the tape 14. On the tape, the signals from the recording heads 12 and 13 are recorded in two tracks for each field, and four tracks in total are recorded in azimuth. This state is shown in FIG.

In FIG. 1A, 28 is a tape on which recording is performed, and 29 to 32 are recording tracks. As a result,
The tracks 29, 31 and 30, 32 are tracks having the same azimuth angle. The reproducing heads 15 and 16 are heads having positive azimuth and negative azimuth, respectively.
Therefore, the signal recorded by the recording head 12 is reproduced only by the reproducing head 15 having the same azimuth angle. Similarly, the signal recorded by the recording head 13 is reproduced only by the reproducing head 16.

Reproduction outputs from the reproduction heads 15 and 16 are input to reproduction processing circuits 17 and 18, respectively. In the reproduced signal processing circuits 17 and 18, the signal is reproduced and amplified and then demodulated.
The output of the reproduction signal processing circuits 17 and 18 is the ID conversion circuit 1.
Input to 9 and 20. The ID conversion circuits 19 and 20 determine the track number of the input signal for each sync block based on the ID information and the channel of the ID conversion circuit. The determined track number is input to the digital signal processing circuit 21 together with the sync block data. The method of determining the track number at this time will be described with reference to (Table 2).

[0016]

[Table 2]

In the present embodiment, since the number of tracks is 4, the number of bits of ID information for identifying the track number should be 2 bits. However, here, the plus and minus of the azimuth angle are considered as one bit of azimuth information bit. When the track number identification bit 33 and the azimuth information bit are assigned to the 2 bits necessary for identifying the track number, the track identification bit 1 is set in the ID adding circuits 8 and 9.
Only the bits need to be added. ID when playing
In the conversion circuits 19 and 20, the track number can be determined by the track number identification bit and the azimuth angle of the channel of the ID conversion circuit as shown in (Table 2).

The digital signal processing circuit 21 performs error correction, deshuffling, etc. on the basis of the ID information of the input signal and inputs it to the DA circuits 22, 23, 24. The DA circuits 22, 23 and 24 convert digitally input signals into analog signals. The signals converted into analog are output as reproduced video signals from the output terminals 25, 26, and 27.

As described above in the present embodiment, the recording signal of the head having the azimuth angle is reproduced only by the head having the plus azimuth angle, and the fact that the head having the minus azimuth angle is also similar is utilized. By setting the plus and minus information of the azimuth angle to 1 bit of the ID information, it is possible to reduce the number of bits of the ID information added to each sync block, and it is possible to reduce the total recording bit rate. There is an excellent effect.

In the present embodiment, the case of recording with two types of heads of positive and negative azimuth is shown, but when recording and reproducing with heads of m (m: integer and m ≧ 3) types of azimuth angle. Also achieves this object, and in this case is also outside the scope of the present invention.

In this embodiment, the case where the track number in the ID information is identified has been shown, but the present invention can also be achieved when identifying the segment number or field number. It does not come out.

Further, in the present embodiment, the case where one field has an even number of tracks and no field number identification signal is added is shown. However, when the number of tracks is an even number as in this embodiment, A field number identification signal is not required, and even in this case, this object can be achieved and is not beyond the scope of the present invention.

[0023]

As described above, according to the present invention, by using the azimuth recording system, the video signal or the audio signal is recorded on the recording medium by the head having the first azimuth angle and the head having the second azimuth angle. There is provided a means for recording / reproducing by adding a field number identification signal with the number of n tracks (n: integer, n ≧ 2) per field, and when recording, when n is an even number, n / 2 types, n is When odd (n + 1) /
By providing means for adding two types of track number identification signals, it is possible to realize the excellent effect that the number of bits of ID information added for each sync block can be reduced.

[Brief description of drawings]

FIG. 1A is a recording track pattern diagram, and FIG. 1B is a diagram showing track number identification bits in a sync block in the present embodiment.

FIG. 2 is a block diagram of a recording / reproducing apparatus according to an embodiment of the present invention.

FIG. 3 is a diagram showing a configuration of a sync block in a conventional example.

[Explanation of symbols]

 28 tapes 29-32 recording tracks

Claims (1)

[Claims] 1. A head having a first azimuth angle and a head having a second azimuth angle are used to record a video signal or an audio signal on a recording medium in n lines (n: integer). , N ≧ 2), and a means for adding and recording a field number identification signal for recording / reproducing. When recording, when n is an even number, n / 2 types, n
Is an odd number, a recording / reproducing apparatus is provided with means for adding (n + 1) / 2 types of track number identification signals.