JPH09294241A - Recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent retrieval performance from being lost by providing a recording means recording a track number represented in a bit number larger than a prescribed bit number into a prescribed area of a track after a maximum track number denoted in a prescribed bit number to discriminate an accurate position of a recording medium. SOLUTION: A track number is expressed in 24-31 bits and the track number is divided into 7.8.8.1 from LSB to 8-bits and recorded in the 4-bits from the LSB side of an ID0 in a subcode ID area and in MSB side 4 bits of an ID1 while striding over 4 sync blocks. Sync blocks of a subcode in one recording track are 12, then the track number is recorded repetitively three times in total as shown in ABST for one recording track. Moreover, as to a write start position of the track number expressed in 24-31 bits, it may be the position from which the tape winding starts or the position after 8,388, or 608th from the start of recording.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording / reproducing apparatus suitable for use in a DV type home digital VTR or the like.

[0002]

2. Description of the Related Art In July 1993, 10 companies in Japan and overseas proposed the basic specifications of home VTRs, and an HD digital VTR conference was established to discuss standardization. In April 1994, both SD for current TV and HD baseband format (DV digital VTR) for high definition TV were approved. In this standard, the image recording rate after compression is 25 Mbps in the SD specification and is doubled in the HD specification, 50 Mbps. Based on an improved ME tape, track width 10 μm, shortest recording wavelength 0.49
The recording density of 2.5 μm ² / bit is realized in μm. 4 small cassettes that can record for 1 hour on SD
Two types are available, a standard type that can record for 30 minutes (recording time is 1/2 in HD), and the data storage capacity is 11 GByte for a small cassette and 50 GByte for a standard cassette.

In the DV system, which is a home digital VTR standard proposed by these 10 companies, Absol is included in the subcode areas of all recording tracks on the magnetic tape.
23 called ute track number (absolute track number, hereinafter simply referred to as track number)
A number represented by a binary number of bits is recorded. This is added for the purpose of improving the searchability and starts from 0 at a predetermined recording start position at the beginning of tape winding.
After that, each time one track is written, the number is increased by one. It should be noted that the track before the predetermined recording start position is set as an invalid track and a signal indicating that the track is invalid is recorded.
No. 6,086,045. Here, in order to distinguish it from an invalid track, the track after the above-mentioned predetermined recording start position will be referred to as an effective track.

All such track Nos. By writing, within the range where the number of effective tracks does not exceed 2 ²³ ,
That is, all the tracks from 0 to 8,388,608 can be distinguished.

FIG. 6 is a diagram showing a recording format on a tape. An ITI area, an audio area, a video area, and a subcode area are provided on the recording track. The subcode area includes 12 sync blocks having a data length of 12 bytes, and a preamble and a postamble are provided before and after the sync block. A subcode ID consisting of 2 bytes of ID0 and ID1 and AUX data of 5 bytes are written in each of the 12 sync blocks.

FIG. 7 shows a track number in the subcode ID. Is shown. Track No. Is represented by 23 bits, which is 7 bits / 8 bits from the LSB side.
As shown in FIG. 7, one track No. is divided into 32 sync blocks by recording the divided s.8 bits into three LSBs of ID0 and 4 bits of LSB of ID0 and 4 bits of MSB of ID1. (Indicated by ABST). Since there are 12 sync blocks in one track, recording is repeated four times in total. Thus, the same track N in the same track
o. It is possible to improve the reliability of the reproduced data by repeatedly recording and performing majority determination during reproduction, and it is possible to accurately determine the tape position even during high-speed search.

BF in FIG. 7 is a blank flag, which is track number. Is a flag for indicating whether or not is continuously recorded. When continuously recorded from a predetermined position at the beginning of tape winding, BF =
1, and otherwise BF = 0.

Pack data having a common structure with the AUX data recorded in the preceding audio area / video area is written in the 5-byte AUX data area inside the sync block of the subcode. The structure of the pack is shown in FIG. Of the 5-byte data, the first 1-byte PC0 is called a pack header and represents what the pack means (for example, date and time). 4 of the remaining PC1 to PC4
The format of the bytes is determined corresponding to the pack header, and arbitrary data is provided according to this format. Incidentally, such a format is described in JP-A-6-318373.

Now, track No. Is represented by 23 bits, so as shown below, when using a standard cassette, standard thick tape, and a track pitch of 10 μm,
It is possible to discriminate all the recording tracks of 4 hours and 30 minutes by SD. 2 ²³ ≈8,388,608 (Number of recording tracks in SD specification is about 7 hours and 46 minutes)> SD Number of recording tracks is about 4 hours and 30 minutes (≈4.8)
6 × 10 ⁶ ) This makes it possible to improve searchability, which was a fatal drawback of conventional tape media.

In addition to the standard track pitch recording mode (standard mode), this standard also permits recording with a non-standard track width. For example, by making the track width wider than the standard, it is possible to increase the reliability of data in recording and reproduction, and use it as a VTR for business or as an external storage device of a computer. Further, it is possible to reduce the tape consumption amount per unit time and extend the recording time by making the track width narrower than the standard. Furthermore, the standard thickness of the tape is 7 μm.
However, the use of tapes with other thicknesses is also permitted, and a combination of tapes thinner than the standard and narrow track recording enables longer recording time.

[0011]

However, since the above standard permits the use of a tape thinner than the standard and recording on narrow tracks, it is technically possible to record for a long time exceeding 7 hours 46 minutes in the future. It is conceivable that the total number of valid tracks will exceed 2 ²³ . At this time, the track No. Is expressed in 23 bits, the track number. When the number exceeds 2 ²³ , the track number starts from the first number again, so that there are a plurality of tracks having the same number. It will not be possible to distinguish all tracks by themselves.

For example, when a standard cassette (recorded) having a recording time of 2 times is inserted in the VTR due to the thinning of the tape and the narrowing of the recording track, the magnetic tape 11 starts winding as shown in FIG. It is assumed that it is located at a position of 7 hours and 56 minutes (track No. = 1.8 × 10 ⁵ places 10 minutes after the track No. overflows). 20 minutes after the beginning of winding, that is, track N
o. = 3.6 × 10 ⁵ , if there is an instruction to move the tape to the recording track, the current track number. Is the track number of the target position. Is smaller than the track number after the overflow. = The tape is advanced to the recording track of 3.6 × 10 ⁵ . In this way, the track No. Caused an overflow and the same track number. When there are a plurality of items, there is a problem that the searchability may be seriously inconvenient.

The present invention has been made in view of the above problems. Even when the number of effective tracks exceeds 2 ²³ due to the use of thin tape or narrow track recording, all recording tracks can be discriminated and distinguished. It is an object of the present invention to provide a recording / reproducing device having good searchability.

[0014]

SUMMARY OF THE INVENTION In the present invention, a recording / reproducing apparatus for recording a signal on a track on a recording medium and recording a track number represented by a predetermined number of bits in a predetermined area of the track. In the above, recording means is provided for recording a track number represented by a number of bits larger than the predetermined number of bits in at least the predetermined area of a track after the maximum track number represented by the predetermined number of bits.

[0015]

According to the present invention, when the number of recording tracks increases due to the use of the thin film tape, the narrow track recording, or both, and even if the total number of effective tracks exceeds the maximum track number, the excess amount is exceeded. Since the track number can be recorded, the accurate position of the recording medium can be determined and the searchability is not impaired.

[0016]

1 is a diagram of a subcode ID area according to a first embodiment of the present invention. In the present invention,
Track No. Is represented by 24 to 31 bits.
This track No. Is from LSB 7/8 / 8-1-8
It is divided into 4 bits, and it is spread over 4 sync blocks. 4 bits on the LSB side of ID0 in the subcode ID area
and 4 bits of the MSB side of ID1. The sync block of subcode in one recording track is 1
Since the number of tracks is two, the track number is repeated three times for each recording track. Will be recorded as indicated by ABST. The track No. represented by these 24-31 bits. For the position to start writing,
Even from the recording start position at the beginning of tape winding, the conventional 23 bits track No. (to keep upward compatibility with the standard).
May start from a position where overflow occurs, that is, from the effective tracks on the 8th, 388th, and 608th positions from the start of recording.

FIG. 2 is a diagram of a pack structure according to a second embodiment of the present invention. In the above-mentioned standard, the AUX data area has a part which is not defined yet, but one or more arbitrary parts are selected from this undecided part, and the track No. Assign to PC1 to PC4
The 4-byte pack data of the track No. represented by 24 to 31 bits. Are assigned as indicated by ABST. This pack starts from the recording start position at the beginning of tape winding on all tracks, or 23bi in the subcode ID.
ts track number. Is recorded at least once in the subcode data area of the track after the occurrence of overflow.

FIG. 3 shows the track No. 1 in FIGS. Information of 32 bits (4 bytes) before and after that and horizontally arranged is expressed. Here, BF is an abbreviation for a blank flag, and the track number is the same as that of the conventional example. Indicates whether or not they are continuously formed. In addition, the track No. When 24 is represented by 24 to 30 bits, 1 to 7 bits are left, but any data of the subcode ID may be repeatedly written therein as information for high speed search.

FIG. 4 is a diagram of a pack structure according to a third embodiment of the present invention. As described in the second embodiment, one or more arbitrary parts are selected from the undecided parts of the AUX data area, and this is selected as the track N of 23 bits.
o. It is defined as a pack that indicates the presence / absence and the number of overflows. As for the data in this pack, at least the track number. Record the binary number that indicates the presence / absence and the number of overflows at least once. Packed data is 4 bytes, but whether there is overflow or not
If there is a surplus in the data area after the number of times is assigned, the BF or the track number. Etc. may be recorded. This pack is used for all tracks from the recording start position at the beginning of tape winding, or for track numbers of 23 bits. Is recorded at least once in the subcode data area of the track after the occurrence of overflow.

As in the first and second embodiments,
Conventionally, the track number was 23 bits. By expressing 24 to 31 bits, it is possible to individually discriminate more tracks one by one as shown in the following formula 2 ²⁴ ≈16.78 × 10 ⁶ (≈32 hours for SD specification) 2 ³¹ ≈ 2.15 × 10 ⁹ (≈ SD specification 1988 hours and 24 minutes)

In addition, as in the third embodiment, 23 bi
The track No. represented by ts. By writing the presence / absence and the number of overflows of the track No. as pack data in the track, the track No. With the presence / absence and the number of overflows, more tracks can be individually identified.

FIG. 5 is a block diagram showing a schematic structure of a DV digital home VTR as a recording / reproducing apparatus according to the present invention. The structure and operation will be described below. In FIG. 5, 10 is a rotating drum, 11 is a magnetic tape which is drawn from a tape cassette (not shown) and wound around the rotating drum 10, 12 is a video signal and audio signal track No. And other information, and is a magnetic tape provided on the rotary drum 10 for reproducing a signal recorded on the magnetic tape 11.

The track No. 13 processes the video signal and the audio signal to be recorded and is based on the above-mentioned first to third embodiments. The recording / reproducing processing circuit supplies the magnetic head 12 with other predetermined data and processes the signal reproduced by the magnetic head 12 to output a reproduced video signal and a reproduced audio signal. Reference numeral 14 controls the recording / reproducing process, and at the time of recording, the track number. And a VTR mechanism system.

[0024]

As described above, according to the present invention,
Tape recording time by narrowing the track width of the thin-recording track is extended, even if the total number of recording tracks exceeds 2 ^23, it is possible to determine all recording tracks, intended searchability home digital VTR standard It will not damage.

[Brief description of drawings]

FIG. 1 is a diagram showing a track No. in a subcode ID area recorded by a recording / reproducing apparatus according to a first embodiment of the present invention. It is a block diagram explaining.

FIG. 2 is a configuration diagram illustrating a pack structure recorded by a recording / reproducing device according to a second embodiment of the present invention.

FIG. 3 is a diagram showing track numbers of the first and second embodiments of the present invention. And the part before and after that 32 bits (4 bytes)
It is a block diagram which expressed side by side information of minutes.

FIG. 4 is a configuration diagram illustrating a pack structure recorded by a recording / reproducing apparatus according to a third embodiment of the present invention.

FIG. 5 is a schematic configuration diagram of a DV system home digital VTR as a recording / reproducing device of the present invention.

FIG. 6 is a configuration diagram illustrating a recording format on a tape.

FIG. 7 shows a track No. inside a subcode ID in a conventional example. FIG.

FIG. 8 is a diagram illustrating the structure of a pack.

FIG. 9 is a diagram showing a positional relationship between recording tracks on a tape and tracks in a conventional example.

[Description of Reference Signs] 11 magnetic tape 12 magnetic head 13 recording / reproducing processing unit 14 control unit ABST track No. (Absolute track number)

Claims (5)

[Claims] 1. A signal is recorded on a track on a recording medium,
At this time, in a recording / reproducing apparatus adapted to record a track number represented by a predetermined number of bits in a predetermined area of the track, a track number represented by a number of bits larger than the predetermined number of bits is at least a maximum represented by the predetermined number of bits. A recording / reproducing apparatus comprising recording means for recording in the predetermined area of a track after a track number. 2. The recording means, when recording a track number represented by a number of bits larger than the predetermined number of bits, records information indicating how many times the track number overflows the maximum track number. The recording / reproducing apparatus according to claim 1, which is characterized in that. 3. The recording / reproducing apparatus is a DV type home digital VTR, and the recording means is at least the maximum track number from the recording start track to 8,3.
2. The recording / reproducing apparatus according to claim 1, wherein a track number represented by a binary number of 24 Bits or more and 31 Bits or less is written in the subcode ID area of the 88th, 608th and subsequent tracks. 4. The recording / reproducing apparatus is a DV-type home digital VTR, and the recording means has 24 bits or more 31 bytes for ancillary data represented by a fixed length of 5 bytes.
A track number represented by a binary number less than or equal to Bits is defined, and this track number is recorded at least once in subcode data of at least the above-mentioned maximum track number of 8,388,608 from the start of recording. The recording / reproducing apparatus according to claim 1, which is characterized in that. 5. The recording / reproducing apparatus is a DV type home digital VTR, and the recording means records at least information indicating the presence or absence of the overflow and the number of times of the incidental data represented by a fixed length of 5 bytes. 3. The recording / reproducing apparatus according to claim 2, wherein recording is performed at least once in the subcode data area of the 8th, 388th, and 608th tracks, which are the maximum track numbers from the start.