JPS61246903A - Helical scan magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To reduce the possibility of interruption of reproduced signals at the time of inversion by reading data in an area stored in a storage device when a magnetic tape is inverted and run in a opposite direction. CONSTITUTION:Supposing that the reproduction of an area A2 is designated uninterruptedly after an area A1, the running direction of a magnetic tape 1 is inverted by a device not shown in the figure and a switch 13 is changed to a contact point (b). A read clock is impressed to a memory circuit 22, and the data stored there are read out. The sequence of reading at this time is made reverse to the sequence of writing, and the data in the area A2 is read out in order of B1,B2...Bn. Accordingly, the possibility of interruption of signals while the running direction of the magnetic tape 1 is inverted and the state of running becomes stable. The excellent reproduction is made even if the running of the magnetic tape 1 is unstable at the time of inversion.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a helical scan magnetic recording and reproducing device, typified by a video tape recorder.

[Summary of the invention]

The present invention divides a track inclined with respect to the running direction of a magnetic tape into at least a first area and a second area, and
In a helical scan magnetic recording and reproducing device that records and reproduces data in an area or a second area using a rotating head,
When the magnetic tape is running in the first direction and data recorded in the first area is being reproduced, the data from the second area is stored in the storage means and the magnetic tape is running in the first direction. reads out the data in the second area stored in the storage means when reversing and traveling in the opposite second direction;
This prevents the reproduced signal from being interrupted when the magnetic tape is reversed.

[Conventional technology]

In the so-called 8m video tape recorder, which has recently been standardized among helical scan magnetic recording and reproducing devices, the magnetic tape is wound around a rotating drum by more than 180 degrees (221 degrees), and PCM audio is recorded in the 36 degree portion beyond 180 degrees. The signal can be recorded.

FIG. 5 is a block diagram of a circuit for reproducing PCM audio signals in such an 8 rrn video tape recorder. That is, a signal recorded on the magnetic tape 1 is reproduced by a rotary head 2 (generally two are provided 180 degrees apart from each other, but only one is shown for convenience) and output to a head amplifier 3. The signal amplified by the head amplifier 3 is demodulated by the demodulation circuit 4 and input to the correction/complementation circuit 5. The correction complement circuit 5 corrects signal errors.

It is complemented and output to the D/A conversion circuit 6. Here, the signal is converted from a digital signal to an analog signal and outputted via a buffer amplifier 7.

[Problem that the invention seeks to solve]

By the way, the present applicant previously proposed dividing the track into a plurality of areas in such an 8m video tape recorder and recording signals such as PCM audio signals in each area of each track (Japanese Patent Application No. 59-148190). ). That is, as shown in FIG. 4, tracks T
4 etc. is divided into a plurality of (six in this example) areas A1 to A. Then, the magnetic tape 1 is run, for example, to the left, and when the rotary head traces the track T1, the data B of the first block is recorded in the area A1, and then the other rotary head traces the second track T2. At this time, data B2 of the second block is recorded in the area A1. Thereafter, the data of each block is sequentially recorded in the area A1 of each track in the same manner. When the magnetic tape 1 has run to its end, its direction is reversed and it runs rightward in the figure, and data of each block is sequentially recorded, for example, in the area A2 of each track. Thereafter, data is recorded in each area of each track in the same manner.

When reproducing the data recorded in this way using the conventional device shown in FIG. 5, for example, when reproducing the area A Because it takes time to invert 1,
There was a drawback that the playback signal was interrupted during reversal.

[Means for solving problems]

FIG. 1 is a block diagram of a helical scan magnetic recording and reproducing apparatus according to the present invention, in which parts corresponding to those in FIG. 5 are given the same reference numerals, and detailed description thereof will be omitted. In the present invention, a switch 11, a storage means 12, and a switch 13 are connected between the demodulation circuit 4 and the correction complement circuit 5.

The storage means 12 is provided with six storage circuits 21 to 26 corresponding to each area A1 to A.6 Of course, these storage circuits 21 to 26 can be provided independently, but one memory It is also possible to use the means by dividing it into a plurality of parts for each predetermined address. Also switch 1
1.13 is for selecting one of the memory circuits 21 to 26 to input or output data, so it is also possible to omit it by controlling the write or read clock or the like. The other configurations are the same as in FIG. 5.

[Effect]

The operation will be explained with reference to FIGS. 2 and 3. It is now assumed that data is recorded in each area of each track on the magnetic tape as shown in FIG. For example, when reproducing area A1, magnetic tape 1 is run to the left in the figure. When the rotary head sequentially traces the areas A1 to A6 of the track T□, the switch 11 is activated by a microcomputer (not shown) to trace the areas A1 to A6 of the track T□.
The contacts a to f are sequentially switched in accordance with the above.

Therefore, the data of the area A□ is stored in the memory circuit 21, and the data of the area A2 is stored in the memory circuit 22. Similarly, storage circuits 23 to 26 have areas A to As.
data will be stored respectively. This also applies to the lower track 2 and below.

Therefore, data is written into each of the memory circuits 21 to 26 as shown in FIG. That is, the storage circuit 21 stores data B1 in area A1 of track T1 and area A in track T2.
1 data B2. Data B3 of area A1 of track T
, up to data Bn are written in the order of data B4 in area A1 of track T4 (each memory circuit 21 to 26 is
(It is assumed that data in blocks (areas) can be stored.)

On the other hand, the storage circuit 22 contains data Bn of the area A2 of the track work, data Bn-x of the area A2 of the track T2,
Data Bn-2 in area A2 of track T, data Bn-2 in area A2 of track T4,
Up to i is written. The same applies to the storage circuits 23 to 26 below.

On the other hand, since area A1 is now being reproduced, switch 13 is kept connected to contact a by means not shown. The data stored in the memory circuit 21 is processed by a clock output from a microcomputer or the like.
They are read out in the same order as they were written, as shown in FIG. That is, data B1. B2. B...
It is read out in the order of Bn. Therefore, these data are supplied to the correction and complementation circuit 5 via the contact a of the switch 13, where they are corrected and complemented, and then converted into analog signals by the D/A conversion circuit 6 and output.

Next, if reproduction of area A2 is specified following area A□, the running direction of magnetic tape 1 is reversed by means not shown, and switch 13 is switched to the contact position. A read clock is then applied to the memory circuit 22, and the data stored therein is read out. At this time, as shown in FIG. 3, the order of reading is reversed to the order of writing. In other words, the data of area A2 is
They are read out in the order of B, , B, . . . Bn. Therefore, there is little risk that the running direction of the magnetic tape 1 will be reversed and the open signal will be interrupted until the running state is stabilized.

Note that the data recorded in each area is not limited to PCM audio data, but may be computer data or the like.

〔effect〕

As described above, in the present invention, tracks that are inclined with respect to the running direction of the magnetic tape are provided in at least the first area and the second area.
In a helical scan magnetic recording and reproducing device that divides data into two areas and records and reproduces data in a first area or a second area using a rotary head, a magnetic tape is run in a first direction and data is recorded in the first area. when the data from the second area is being played back, the data from the second area is stored in the storage means;
When the magnetic tape is reversely run in a second direction opposite to the first direction, the data in the second area stored in the storage means is read out. Even if the signal is stable, there is little chance that the reproduced signal will be interrupted.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a helical scan magnetic recording/reproducing device of the present invention, FIG. 2 is a schematic plan view showing the write order of the memory circuit, and FIG. 3 is a schematic plan view showing the read order of the memory circuit. , FIG. 4 is a schematic plan view of the magnetic tape, and FIG. 5 is a block diagram of a conventional helical scan magnetic recording/reproducing apparatus. 1... Magnetic tape 2... Rotating head 3... Head amplifier 4... Demodulation circuit 5... Correction complement circuit 6... D/A conversion circuit 7... Buffer amplifier 11.13. ...Switch 12...Storage means 21.22.23.24.25.26...Storage circuit or higher

Claims (1)

[Claims] A track inclined with respect to the running direction of the magnetic tape is divided into at least a first area and a second area, and data is recorded in the first area or the second area by a rotating head. In a helical scan magnetic recording and reproducing apparatus for reproducing, when the magnetic tape is run in a first direction and the data recorded in the first area is being reproduced, the data from the second area is reproduced. is stored in the storage means, and when the magnetic tape is reversely run in a second direction opposite to the first direction, the data in the second area stored in the storage means is read out. Features a helical scan magnetic recording and reproducing device.