JPH04216317A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To allow good tilted azimuth recording without guard bands by determining the steps and spacings, track pitches and rotary drum diameter in the respective required directions of plural head chips juxtaposed in proximity so as to satisfy specific conditions. CONSTITUTION:A head base 2 is mounted to the rotary drum by the screws inserted in through-holes 4 and plural, two pieces, etc., of the head chips 3a, 3b of the base 2 are juxtaposed proximity to each other on the rotary drum. The tilted azimuth recording is executed without forming the guard bands between respective recording tracks at the time of allowing a tape to travel in a forward direction and simultaneously recording the plural channel components when the step DA in the track pitch direction of the chips 3a, 3b, the spacing GL in the scanning direction, the track pitch TP and the rotary drum diameter D are so selected as to satisfy the conditions of equation I. The recording density is thus improved and the easy track pitch management is executed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention is applicable to magnetic recording and reproducing devices, particularly digital VTRs, for example.
The present invention relates to a digital magnetic recording/reproducing device suitable for use in the field.

[Summary of the invention]

The present invention provides a magnetic recording and reproducing device that has a rotating drum in which a plurality of head chips are arranged in close proximity to each other and records and reproduces a plurality of channels simultaneously in a digital manner. Multiple channels can be simultaneously recorded using multiple head chips by configuring the recording head to satisfy the following conditions: DA and GL are the steps and the spacing in the head scanning direction, respectively, TP is the track pitch, and D is the diameter of the rotating drum. In this case, it is possible to perform good inclined azimuth recording without a guard band.

[Conventional technology]

Recently, for example, converting video signals to digital video signals,
A so-called digital VTR has been developed that uses a rotating head to record on and reproduce information from a magnetic tape.

As shown in FIG. 7, a conventional digital VTR has two heads (31a) and (31b) mounted on a rotating drum (32) facing each other at 180 degrees.
By running the magnetic tape (33) wrapped around the magnetic tape (32) at a wrap angle of 180 degrees, the heads (31a) and (31b) move the recording track (3) as shown in FIG.
4a) and (34b) are formed.

However, in the above-mentioned digital VTR, since the two heads (31a) and (31b) are provided 180 degrees opposite each other, there may be problems with pairing between the heads (31a) and (31b) or straight lines of tracks formed. If the characteristics are different, there is an extremely large possibility that problems will arise with respect to compatibility and narrowing of tracks for high-density recording, etc., and moreover, it is necessary to form a plurality of head windows on the rotating drum (32). A plurality of head bases are required, and additional man-hours for adjustment such as angle division are required, resulting in problems such as a significant increase in manufacturing costs.

Therefore, in the past, two heads (31
A magnetic recording/reproducing device has been proposed in which the magnetic recording devices a) and (31b) are disposed close to each other in parallel and digitally records and reproduces two channels at the same time, in order to solve the above-mentioned inconvenience.

[Problem to be solved by the invention]

By the way, when recording two channels at the same time in the magnetic recording/reproducing apparatus according to the proposed example, as shown in FIG. ) (31a), (
31b) pairing needs to be adjusted. Adjustments are made according to the track pitch TP, but if the track pitch TP is the same as the recording track width TW (TP=TW)
think of. Here, as shown in FIG. 9, the step DA in the track pitch direction in each gap g between the two head chips (31a) and (31b) is defined as the track pitch TP.
If the settings are the same, the track pattern in the still state will be as shown in FIG.
4a) and (34b) are in contact with each other (so-called guard bandless recording), but in the case of FWD (running the magnetic tape in the forward direction), as shown in FIG. 10B, each recording track (34a) and (34b) with a guard band (
36) is formed, and TP=TW as assumed above does not hold. In other words, the track pitch TP changes and the recording density deteriorates significantly. This is due to the distance GL between each gap g in the two head chips (31a) and (31b), and this distance GL
The above-mentioned inconvenience occurs because the trailing head (for example, the head chip (31b)) records with a delay of 1 minute.

The present invention has been made in view of the above, and its object is to provide magnetic recording that allows good tilt azimuth recording without guard bands when recording multiple channels simultaneously using multiple head chips. The purpose is to provide a playback device.

[Means to solve the problem]

The present invention provides a magnetic recording and reproducing apparatus (A ), multiple head chips (
When the step in the track pitch direction and the interval in the head scanning direction in 3a) and (3b) are respectively DA and GL, the track pitch is TP, and the diameter of the rotating drum (8) is D, the structure is configured to satisfy the following.

[Effect]

According to the configuration of the present invention described above, a plurality of head chips (3
Step D in the track pitch direction in a) and (3b)
Let the relationship between A and track pitch TP be DA=TP-x,
Furthermore, when the interval in the head scanning direction between the head chips (3a) and (3b) is GL, and the diameter of the rotating drum (8) is D, then x = (TP/90) sin-1 (GL/D). Therefore, when the magnetic tape (17) is run in the forward direction and multiple channels are simultaneously recorded, recording can be performed without forming a guard band between each recording track (W1) and (W2). This makes it possible to improve the recording density and easily manage the track pitch TP.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 6.

FIG. 1 is a front view of a main part of a magnetic head (1) used in the magnetic recording/reproducing apparatus (A) of this embodiment, and FIG. 2 is a plan view thereof.

This magnetic head (1) has two magnetic heads on the same head base 2.
Two head chips (30 and (3b)) are arranged close to each other in parallel. In these figures, (4) is an insertion hole through which a screw for rotating the head base 2 to a rotating drum (not shown) is inserted. The two head chips (3a) and (3b) have a structure in which sendust is sputtered (sprayed) by cutting diagonally in the vicinity of the gap g of the ferrite head (5), and each gap g is , −ψ and −ψ, respectively, with respect to the vertical line (indicated by a dashed-dotted line) l
It is formed at an angle. Note that (6) indicates glass and (7) indicates sendust sputtered film. Further, a predetermined interval GL is provided between each gap g in the head scanning direction so as to prevent the influence of crosstalk or the like from occurring. Then, this magnetic head (1) is attached to the head mounting surface of a rotating drum (not shown) using screws, and each head chip (3a) and (3b) is attached using a pairing adjustment screw (not shown). )
Perform alignment in the track pitch direction.

However, in this example, the head chip (3a) and (
When the step in the track pitch direction in 3b) is DA, the interval in the head scanning direction is GL, the track pitch is TP, and the diameter of the rotating drum is D, the following equation is set. The basis for this is that the above x is a trailing head (for example, a head chip (
3b)), and its value depends on the above-mentioned interval GL and the diameter D of the rotating drum. Therefore, in this example, the level difference DA is set in advance in anticipation of the x minute.

That is, as shown in FIG. 3A, if the angular equivalent of the interval GL is θ° and the diameter of the rotating drum (8) is D, the magnetic tape (see FIG. (not shown)
Since it advances by 2TP, the following relational expression holds true.

Also, as can be seen from the approximate relationship in Figure 3B, therefore,
From the above equations (3) and (4), by setting the step difference DA smaller than the track pitch TP by this x, the FW can be adjusted as shown in FIG.
During D (running the magnetic tape in the forward direction), so-called guard bandless recording without a guard band between each recording track (W1) and (W2) can be realized.

Next, an example of realizing two-channel simultaneous recording and reproduction in the magnetic recording and reproducing apparatus (A) according to the present example will be described with reference to FIGS. 5 and 6.

The example shown in FIG. 5 is a magnetic recording/reproducing apparatus (
An example is shown in which A) is applied to a digital VTR. For example, by digitizing a video signal, one field of the video signal is subdivided into two channels, and the two channels are recorded and played back simultaneously. It is something.

That is, in FIG. 5, the video signal Vin supplied to the input terminal φin is digitized by the A/D converter (11), and this digital signal Din is sent to the ECC encoder (11).
In step 2), parity for error correction is generated and added. Digital signal Dinp with this parity added
is supplied to a channel coater (13), where coding is performed in accordance with the characteristics of the tape head system, etc. This coded signal Dc is transmitted to the channel division circuit (14
).

This channel division circuit (14) has a memory, in which the supplied signals are sequentially written, and where the number of divisions is n (n=2 in this example) and the period of the rotating drum (8) is T. The signals S1 and S2 are extracted at each delay time.

Signals S1 and S2 from this dividing circuit (14) are sent to the rotating drum (8
) are supplied to the head chips (31) and (3b) on the top. As a result, the input signal Din becomes 2 as shown in FIG.
Divided into channels and synchronized to the head chip (3
a) and (3b) and recorded on the magnetic tape (17).

Furthermore, during playback, the head chips (3a) and (3b)
Signals S1 and S2 from the switch (16a) respectively
and (16b) to playback amplifiers (18a) and (1
8b), and this amplifier (18a) and (18b
) are supplied to the channel synthesis circuit (21) through data and clock recovery circuits (19a) and (19b) and time base collectors (20a) and (20b), respectively. and the combined signal S0
is a channel decoder (22), an ECC decoder (23)
) is supplied to the D/A converter (24), where the original video signal Vout is restored and taken out to the output terminal φout.

As described above, according to this example, two head chips (3a
) and (3b) step difference DA in the track pitch direction
Letting the relationship between DA and track pitch TP be DA=TP-x, furthermore, let the interval in the head scanning direction between the head chips (3a) and (3b) be GL, and the diameter of the rotating drum (8) be D, then x=(TP /90) sin-1 (GL/D), so when the magnetic tape (17) is run in the forward direction and two channels worth of signals S1 and S2 are simultaneously recorded, each recording track ( W1) and (W2)
The above signal S1 without forming a guard band between
and S2, the recording density can be improved and the track pitch TP can be easily managed.

〔Effect of the invention〕

According to the magnetic recording/reproducing device of the present invention, when recording multiple channels simultaneously using multiple head chips disposed close to each other, it is possible to perform good tilt azimuth recording without a guard band, thereby increasing the recording density. The improvement and track pitch management can be easily performed.

[Brief explanation of the drawing]

FIG. 1 is a front view of the main parts of the magnetic head of the magnetic recording/reproducing device according to this embodiment, FIG. 2 is its plan view, FIG. 3 is an explanatory diagram showing the principle of this embodiment, and FIG. 4 is An explanatory diagram showing the recording state according to this example, FIG. 5 is a block diagram showing an example of the recording/reproducing method according to this example, and FIG. 6 is a signal processing according to this example (
7 is a schematic configuration diagram showing a magnetic head according to a conventional example, FIG. 8 is an explanatory diagram showing guard bandless recording according to a conventional example, and FIG. 9 is a magnetic head according to a proposed example. FIG. 10 is an explanatory diagram showing the recording state according to the proposed example. (A) is a magnetic recording/reproducing device, (1) is a magnetic head, (2 is
) is a head base, (3a) and (3b) are head chips, (8) is a rotating drum, and (17) is a magnetic tape. Agent Hidemori Matsukuma

Claims (1)

[Scope of Claims] A magnetic recording and reproducing device that has a rotating drum in which a plurality of head chips are arranged in close proximity to each other and records and reproduces a plurality of channels simultaneously in a digital manner, wherein: a track pitch in the plurality of head chips; A magnetic recording and reproducing device which satisfies the following, where the step in the direction and the interval in the head scanning direction are respectively DA and GL, the track pitch is TP, and the diameter of the rotating drum is D.