JPS61145705A - Pcm recorder - Google Patents

Abstract

PURPOSE:To prevent the generation of foreign sound by dividing a track train every (m) pieces of tracks, adding a proper number to each of these (m) pieces of continuous tracks in a record mode together with these numbers checked in a reproduction mode and setting up an interpolation flag to the data within a track having no matching properties to perform the interpolation processing. CONSTITUTION:A track train is divided ever (m) pieces of tracks and a proper segment number 15 is put for identification to each of those (m) pieces of continuous tracks. These numbers 15 are stored in an area of an identification code 7. In a decoding mode those track numbers are checked together with error corrections for correct tracks. The interpolation processing is applied to the uncorrectable data. If the wrong track data is decided, a flag is set up to the data (voice data) obtained by giving the PCM conversion to the analog signals of voices, etc. among those PCM data within a wrong segment. Then the interpolation processing is carried out. Thus the voice data on a wrong track is not reproduced. This decreases greatly the foreign sounds due to the reproduction of both old and new voice data mixed with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a PCM recording device that converts analog signals such as audio into PCM and records and reproduces them using a rotary head.

2. Description of the Related Art In recent years, a so-called digital audio tape recording and reproducing system has been proposed in which an analog signal such as audio is converted into a pay signal, and the PCM signal is recorded and reproduced on a magnetic tape using a rotary head.

An example of the above-mentioned conventional PGM recording method will be described below with reference to the drawings. Figure 5.

Figure 6 shows the track system and data format on a magnetic tape using two rotary heads, which has been proposed in the past. In the running direction, 3 is the running direction of the head, 4 is a track with an azimuth angle - α, and 5 is a track with an azimuth angle + α.The tape is in the tape running direction 2.
At the same time, the rotating head moves in the head running direction 3. At this time, the two heads each have a different azimuth angle +
Therefore, on the tape 1, a track such as track 4 having an azimuth angle of −α0 and a track such as track 5 having an azimuth angle of +α are recorded. In FIG. 6, the PCM area of one track of PCM signals is shown divided into blocks, indicating that the PCM area is constituted by blocks. In FIG. 6, 6 is a block synchronization signal, 7 is an identification code, 8 is a block address, 9 is a parity, and 10 is a block synchronization signal.
is PCM data, 11 is P parity for error correction, 12 is Q parity for error correction, 13 is an empty area in the PGM data area, and 14 is the recording direction. The PCM signal is recorded along the recording direction 14 in the order of -1 in blocks o, 1°2, . . . . Each block is composed of 32 symbols 1v (1 symbol=8 bits). Data 1Q has an empty area 13 of 256 bits per track when the sampling frequency is 48 KHz. The use of the identification code 7 is not particularly defined. In the above method, there is no erasing head, and new PCM signals are recorded by overwriting. Further, interleaving is applied over two adjacent tracks, and the error correction code is completed for each track.

Problems to be Solved by the Invention However, with the above configuration, the following problem occurs when the rotary head becomes clogged during recording. For example, if you have two heads and one of them has clogged heads, new signals will not be recorded by the clogged head, and as a result, old signals will be recorded on the magnetic tape. The PCM signal and the new PCM signal will coexist. At this time, if the positions of the old track and the new track roughly match, each track is read by a head with a matching azimuth angle, and an error correction code is completed for each track as described above. Because of this, there is a possibility that it will pass the error correction and be output. Since this output signal is a mixture of old 90M data and new PCM data, significant abnormal noise will be generated. That is, in the conventional example described above, there was a problem in that no information was added to the track to distinguish whether the overwritten data was new or old.

In view of the above-mentioned problems, the present invention provides a method of interpolating the remaining signals by regarding them as errors when a signal recorded by a head that is clogged is reproduced.

Means for Solving the Problems In order to solve the above problems, the present invention logically divides all tracks into m pieces, and when recording, assigns a unique number to each of the m consecutive tracks. During playback, the above-mentioned number is checked and data in inconsistent tracks is flagged for interpolation.

Effect of the present invention With the above-described configuration, it is possible to check whether the recorded data is temporally continuous data by determining whether the trunk numbers at the time of recording and playback match, and as a result, it is possible to check whether the recorded data is continuous data in time. If it is data, it is possible to significantly reduce abnormal noise by setting a flag for interpolation and passing the flag output through an interpolation circuit.

EXAMPLE An example of the present invention will be described below with reference to the drawings. FIG. 1 shows a track arrangement of tracks in a first embodiment of the present invention. The track arrangement in FIG. 1 is physically the same as that in FIG. 5, but logically it is divided into 9, m tracks. Second
The figure shows the PCM area of one track of PCM signals divided into blocks, and the physical configuration is the same as that in FIG. 6. In FIG. 2, 16 is a segment number.

The operation of the above embodiment will be explained below with reference to FIGS. 1, 2, and 3. As shown in FIG. 1, a track row on a magnetic tape is divided into m pieces and a unique number, for example 0, 1, etc., is used to identify each of the m consecutive tracks. .......

A segment number 16 of m-1 is assigned and stored in the area of the identification code 7 shown in FIG.

The inspection method on the playback side is shown in FIG. FIG. 3 shows part of the algorithm at the time of decoding.

In FIG. 3, 16 is a step for checking the track number, 17 is for determining whether the track is correct, 18 is for error correction, 19 is for interpolation processing, and 2o is for setting an interpolation flag on all the PGM data in the track. At the time of decoding, first check the track number in step 16 and proceed to step 1.
At step 7, it is determined whether the track number is correct, and for the correct track, error correction is performed at step 18, and at step 19, data that cannot be corrected is subjected to interpolation processing. On the other hand, if it is determined in step 17 that the track data is incorrect, step 2
Among the PCM data in the incorrect segment mentioned above in o, data in which analog signals such as audio are converted to PCM (
(hereinafter referred to as audio data) is flagged and interpolation processing is performed in step 19.

As described above, according to this embodiment, the track string is divided into m pieces, and during recording, each of the m consecutive tracks is given a unique number, for example, 0, 1°...9m-
1 is added to the identification code area, the above number is checked during playback, and a flag for interpolation is set on the audio data in the incorrect track.The audio data in the incorrect track will not be played, and the old audio will be replaced. Abnormal noise caused by mixing data and new audio data and playing it back is significantly reduced.

A second embodiment of the present invention will be described below with reference to the drawings. FIG. 4 shows a second embodiment of the invention. This figure is physically the same as FIG. 2, but logically differs in that track number 15 is added to empty area 13 instead of identification code 7. The operation of FIG. 4 configured as described above is basically the same as the first embodiment shown in FIGS. 1 to 3, and the location on the PCM data area where track number 16 is read during playback is They are only different.

As described above, according to this embodiment, track numbers 0 + 1 + 2 +...
・.

By adding m-1 and setting a flag for interpolation on the audio data of the erroneous track, the audio data of the erroneous track is not played back, but the old audio data and new audio data are mixed and played back. The noise caused by this is significantly reduced.

In the first embodiment, the identification code 7 of block 0 is stored in the storage location as shown in FIG. 2, but the identification code 7 belonging to another block may also be stored. The identification code 7 of a plurality of blocks may be used in consideration of the case where this occurs.

Further, in the second embodiment, the storage location is the free area 13 of the block 51 as shown in FIG. 4, but it may be stored in the free area 13 of another block. In consideration of such a case, the vacant area 13 may be a plurality of blocks.

Also, 1st. In either case of the second embodiment, the number added to each track is the first. Instead of the continuous integers o, 1゜2, ..., 1m-1 shown in the second embodiment, other number sequences 1, 2゜ ... 2m+1 or φr 2 z 4 + ..., 2m It is sufficient that the number is unique to each track, such as -2.

Effects of the Invention As described above, the present invention divides a track string into m pieces, adds a unique number to each of the m consecutive tracks during recording, and checks the numbers during playback to detect inconsistencies. By setting an interpolation flag on the data in the track and performing interpolation processing, it is possible to play back only the latest audio data among the audio data in the trunk row, and interpolate all the old audio data. This can be prevented from occurring.

[Brief explanation of drawings]

FIG. 1 is a diagram of a track row on a magnetic tape in the first embodiment of the present invention, and FIG. 2 is a diagram of a PCM on the track of FIG. 1.
Figure 3 shows the arrangement of track numbers in data, Figure 3 shows part of the algorithm at the time of decoding in the first embodiment, Figure 4 shows the in-track PCI in the second embodiment of the present invention. A diagram showing the arrangement of track numbers in data, FIG. 6 is a diagram of track rows on a conventional magnetic tape,
FIG. 6 is a diagram showing the track of FIG. 5. 1...Tape, 2...Tape running direction, 4 and 5...Track, 7...Identification code, 13...Empty area , 15...
・Track number, 16...Track number inspection,
17... Track number determination, 18...
・Error correction, 19... Interpolation processing, 2o...
・All flag processing. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 3

Claims (1)

[Claims] The PCM signal is transferred onto the recording medium by n rotating heads.
Each track is recorded as one track, and the track string is divided into m pieces. During recording, a unique number is added to each of the m consecutive tracks. During playback, the above number is inspected, and if it is incorrect, A PCM recording device characterized by interpolating and outputting data within a track.