JPH0485719A - Rotary scanning type magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To perform the high quality recording and reproducing with less jutters by using an in-line multigap magnetic head having plural gaps formed on the same straight line as a magnetic head. CONSTITUTION:As to the magnetic heads 2A-2D, each head chip 7 having M pieces (M=2 for this example) of magnetic gaps 6 on the same straight line is fixed on a head base 8. Thus, by the in-line multigap magnetic heads 2A-2D, each having M pieces of magnetic gaps disposed on the same straight line, a video signal by one field is divided into M.N segments and recorded, thus decreasing to 1/M. Consequently, the heads 2A-2D are easily fitted to a rotary cylinder 1, and impact jutters caused by vibrations at the time of starting the heads 2A-2D to be in contact with a tape 4 on a rotary drum 1 is decreased in accordance with a decrease in the number of heads.

Description

[Detailed Description of the Invention] [Purpose of the Invention (Field of Industrial Application) The present invention relates to a rotary scanning magnetic recording and reproducing device used for recording and reproducing video signals and audio signals, and particularly relates to a rotary scanning magnetic recording and reproducing device mounted on a rotating cylinder. This article relates to the structure of a magnetic head and its arrangement.

(Prior Art) A rotary scanning magnetic recording/reproducing device is a device that performs recording/reproducing by winding and running a magnetic tape around a rotating cylinder to which a magnetic head is attached. In recent years, digital VTRs that digitize and record video signals have been commercialized, and high-definition television (HDT) systems have been widely used to replace the current NTSC system.
Development of high-definition VTRs compatible with the V) system is also underway.

As a method for recording high-definition television signals, the video signal is digitized and temporarily stored in a semiconductor memory, and the video signal of one screen is divided into multiple segments through signal processing and distributed to multiple magnetic heads to create multiple tracks. A method has been proposed in which the video signals of each segment are recorded on the top of the screen, and during playback, the video signals of each segment obtained by a plurality of magnetic heads are combined to form one screen. Specifically, for example, if a high-definition television signal is a digital signal with a bit rate of 1.2 Gbps, the signal of one field is divided into 8 segments, and the signal from the cylinder rotation surface to the track position is displayed on the rotating cylinder. 16 placed at slightly different distances
A method has been considered in which 16 magnetic heads are used to record on 16 tracks arranged in sequence on a tape.

However, in this method, the recording band per head becomes extremely wide, 1.2×10 9 /16-75 MHz, and the frequency itself becomes extremely high, resulting in an extremely low magnetic permeability of the core material of the magnetic head. As a result, head efficiency (core efficiency) decreases. If the number of divided segments of the video signal is further increased, the recording band per head becomes narrower, but the number of heads increases, making it difficult to attach the heads to the rotating cylinder. Furthermore, as the number of heads on the rotating cylinder increases, jitter that occurs in the reproduced video signal due to collision between the heads and the tape when they begin to come into contact, so-called impact jitter, increases, causing a reduction in S/N.

(Problems to be Solved by the Invention) As described above, in the conventional rotary scanning magnetic recording/reproducing device, when recording a wideband signal such as a high-definition television signal, if the number of heads is small, the head 1 There is a problem that the recording band per head increases and head efficiency decreases. In addition, increasing the number of heads makes it difficult to attach the heads to the rotating cylinder, and also increases the impact jitter that occurs when the head starts contacting the tape.
There was a problem that /N decreased.

The present invention has been made in view of these points, and an object of the present invention is to provide a rotary scanning magnetic recording and reproducing device that can record and reproduce wideband signals such as high-definition television signals while suppressing an increase in the number of heads. shall be.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a rotating cylinder in which a plurality of magnetic heads are attached at different positions along the rotation direction, and the magnetic tape is wound around the circumferential surface of the cylinder while running the cylinder. , a rotary scanning magnetic recording and reproducing apparatus for recording and reproducing, which is characterized by using an in-line multi-gap magnetic head each having a plurality of gaps formed on the same straight line.

In addition, the present invention provides a rotary scanning type magnetic recording/reproducing apparatus in which one field of video signals is divided into adjacent M-N
When recording video signals divided into multiple tracks (MSN is an arbitrary integer) and reproducing the recorded video signals, N inline multi-gap magnetic heads each having M gaps formed on the same straight line are used. Recording and playback are performed using the

(Function) When using an inline multi-gap magnetic head, if the number of gaps in each magnetic head is M, it is easier to record and reproduce signals in the same band than when using a normal magnetic head with one gap. The total number of heads required for this decreases by 1/M.

Therefore, it becomes easier to attach the head to the rotating cylinder, and impact jitter that occurs when the head starts contacting the tape is also reduced.

(Example) Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a plan view showing the head arrangement of a rotary scanning magnetic recording/reproducing device according to an embodiment of the present invention, and FIG. 2 is a schematic diagram showing the configuration of the rotary scanning mechanism section (scanner section) of the same device. FIG.

As shown in FIGS. 1 and 2, the rotary scanning mechanism includes a rotary cylinder 1, N magnetic heads 28 to 2D attached at predetermined intervals in the rotational direction of the rotary cylinder 1,
It is composed of a fixed cylinder 3 provided coaxially with the rotating cylinder 1 and a motor 4 that rotates the rotating cylinder 1. In this example, since it is N-4, the magnetic head 28-2
D will be attached to the rotating cylinder 1 at intervals of 360°/4-90°. Magnetic tape 5 is rotary cylinder 1
The tape is wound diagonally around the fixed cylinder 3 and driven to travel by a tape drive mechanism (not shown).

The magnetic heads 2A to 2D have a head chip 7 fixed to a head base 8, which has M (M-2 in this example) magnetic gaps 6 on the same straight line, as shown in FIGS. 3(a) and 3(b). This is an inline multi-gap magnetic head. In FIG. 3, θ is the inclination angle of the magnetic gap 6, that is, the angle corresponding to the azimuth angle of the magnetization pattern on the magnetic tape 5, and in FIGS. 3(a) and (b), the azimuths are It's in the opposite direction. Here, the magnetic head 2A
, 2C use the magnetic head shown in FIG. 3(a), and the magnetic heads 2B and 2D use the magnetic head shown in FIG. 3(b).

FIG. 4 shows that in the rotary scanning magnetic recording and reproducing apparatus configured as described above, the distance between the two magnetic gaps of each of the magnetic heads 2A to 2D is set to twice the track pitch of adjacent tracks on the magnetic tape 5. , and shows the magnetization pattern (referred to as tape pattern) on the magnetic tape 5 when signals are recorded by appropriately setting the height positions of the magnetic heads 2A to 2D in the axial direction of the rotating drum 1. In the figure, AI and A2 are track patterns formed simultaneously by two magnetic gaps of the magnetic head 2A, and similarly, Bl, B2, C1, C2, Dl, and D2 are track patterns of the magnetic heads 2B, 2C, and 2D, respectively. Track patterns formed simultaneously by two magnetic gaps are shown.

Taking the case of recording a video signal as an example, one field of video signal is divided into M-N-8 segments, and each segment's signal is recorded using one magnetic gap. The data will be divided into eight tracks and recorded. In this case, as shown in FIG. 4, the pitch of the track patterns A1 and A2 formed simultaneously by the same magnetic head, for example 2A, that is, the pitch Tq of the two magnetic gaps, is the distance between adjacent tracks on the tape 5. The track pitch of Tp is 12 times (Tq- is -"rp, and is -2).

Further, as shown in FIG. 4, the azimuth angle is shown as θ, as in the conventional VTR, adjacent tracks have opposite azimuths to reduce crosstalk between tracks. In addition, in this way, the azimuth angle θ
When recording is performed without providing guard bands between tracks as shown in FIG. 4 (guard panless recording), the track pitch Tp is equal to the track width.

In this way, the in-line multi-gap magnetic heads 28 to 2D, in which M magnetic gaps are arranged on the same straight line, divide one field's worth of video signals into M-N segments and record them. The gap is reduced to 1/M compared to the M-N gap required when using a single magnetic head. Therefore, it becomes easy to attach the magnetic heads 2A to 2D to the rotating cylinder 1, and the impact jitter caused by vibrations when the heads 2A to 2D and the tape 4 begin to come into contact on the rotating drum 1 can be reduced in the number of heads. decreases accordingly.

In the above embodiment, Tq-27p is used, but Tq- can be set to -Tp, and k can be selected as any integer, such as 4 or 6, for example. By doing so, the area on the magnetic tape 5 can be used effectively without any gaps. Also, if azimuth is not attached, that is, θ−
In the case of 〇°, k may be an odd number.

Next, the manufacturing method and structure of the in-line multi-gap magnetic head used in the present invention will be explained.

First, as shown in FIGS. 5(a) and 5(b), two heat-resistant non-magnetic substrates 11 and 12 are prepared, and a plurality of magnetic thin film layers 13 are placed on each of them through an insulating layer]4. Laminate them and add a spacer on top of one! 115 is formed. The magnetic thin film layer 13 serves as a magnetic core and is made of a metal ferromagnetic thin film, for example, a FeAl5f film with a thickness of several μm.The insulating layer 14 is made of a SiO2 film with a thickness of, for example, 0.5 μm. Formed by vapor deposition.

In this case, the thickness and number of laminated layers of the magnetic thin film layer 13 and the insulating layer 14 are set so that the total thickness of the laminated film is approximately equal to the gap width (corresponding to the track width on the magnetic tape). The spacer film 15 maintains a predetermined distance between tracks on the tape formed by the two magnetic gaps of the magnetic head.
In other words, if the track pitch is an integer multiple of the track pitch (track pitch is 2)
In the case of 0 .mu.m, the separation is 20 .mu.m, 140 .mu.m, 160 .mu.m, etc.), and for example, a SiO2 film is used.

Next, as shown in FIG. 6, the nonmagnetic substrates 11 and 12 shown in FIGS. , that is, in a direction perpendicular to one side A and inclined at an angle corresponding to the azimuth angle with respect to the bonding surface B. Thereafter, the cut end surfaces are mirror-finished to obtain two parallelogram blocks as shown in FIG. These two blocks are called first and second members 21 and 22.

Next, as shown in FIGS. 8 and 9, the first member 2
A spiral thin film coil 23 is formed on the mirror-finished cut end surface of No. 1 by a manufacturing process similar to that of conventionally known normal thin film magnetic heads. The first magnetic thin film 24, the second magnetic thin film 25 located in the magnetic gap forming part which is the front gap part, and the bonding pad 2
6 and an insulating film 27 are formed.

That is, a first layer insulating film is formed on the entire surface of the first member 21 by sputtering or vapor deposition, and after patterning using photolithography technology, a conductive film such as C is formed.
A thin film 23 is formed over the entire surface by sputtering or vapor deposition, and patterning is performed using photolithography to form a thin film coil 23 and a bonding pad 26. After this, a second layer insulating film is formed and patterned in the same way, and then
A metal ferromagnetic thin film, for example a FeAlSi film, is formed on the entire surface and patterned to form magnetic thin films 24 and 25. The thin film coil 23 and the magnetic thin films 24 and 25 are provided on the magnetic core portion of the first member 21, that is, on the end surface of the magnetic thin film layer 13. Then, a magnetic gap spacer film 28 made of an insulating film, for example a 5i02 film, is formed on the magnetic thin film 25 in the front gap portion.

Here, when compared with the manufacturing process of a conventional thin film magnetic head, the difference is that the first and second magnetic thin films 24.degree. 25 are formed. These magnetic thin films 24.25 are connected to both members 21.22 by mechanical bonding of the first and second members 21.22.
This is because a magnetic gap of a predetermined gap length cannot be formed unless the magnetic thin film protrudes from the thin film coil 23 and the insulating film 27 in the pack gap portion and front gap portion. . When these magnetic thin films 24.25 are formed on the first member 21, when the first member 21 and the second member 22 are joined as described later, the magnetic thin films 24.25 will be attached to the second member 22. come into contact with.

On the other hand, as shown in FIG. 10, magnetic flux leakage prevention grooves 29, which correspond to the winding holes in a normal bulk magnetic head, are formed in the second member 22 by a method such as cutting, and unnecessary portions shown by broken lines are formed in the second member 22. Separate.

Next, as shown in FIGS. 8 and 9, the thin film coil 2
3. The first member 21 on which the magnetic thin films 24, 25, the bonding pad 26, the insulating film 27 and the magnetic gap spacer film 28 are formed, and the winding hole 29 is formed as shown in FIG. 10, and unnecessary parts are removed. The cut end surfaces of the mirror-finished second member 22 are made to face each other, and as shown in FIG. 11, they are joined and integrated by fusion using glass 30. Then, as shown by the broken line in FIG. 11, the end surface on the side where the magnetic gap spacer film 28 is formed is processed into a predetermined curved shape to form a sliding surface with the magnetic tape.

Through the above steps, a head chip 31 having a predetermined azimuth angle θ and two magnetic gaps formed on the same straight line is obtained as shown in FIG.

Next, as shown in FIG. 13, the head chip 31 shown in FIG. 12 is mounted on a commonly used head base plate 32 by adhesive or other method, and the lead wires 33 and wires 34 on the head base plate 32 are attached. If the wires are connected by bonding or the like, an in-line dual gap magnetic head is completed.

The above-described manufacturing method can also be applied to an in-line multi-gap magnetic head having three or more gaps. For example, when manufacturing a magnetic head with three gaps, as shown in FIG. 14(a), the magnetic thin film layer 13 and the insulating layer 1 on the first magnetic substrate 11 shown in FIG.
A spacer film 15 is also formed on the laminated film of No. 4, and
As shown in FIG. 4(b), a laminated film of a magnetic thin film layer 13 and an insulating layer 14 is further formed on the spacer film 15 on the second magnetic substrate 12 shown in FIG. 5(b). And the 15th
As shown in the figure, the non-magnetic substrates 1.1.12 shown in FIGS. By performing the same steps as in the previous embodiment using the member No. 2, an in-line magnetic head having three magnetic gaps can be obtained.

In the above example, a case was described in which a single in-line multi-gap magnetic head was manufactured. Next, a method for simultaneously manufacturing a plurality of inline multi-gap magnetic heads will be described. As shown in FIG. 16, a laminated film of a magnetic thin film layer 43 and an insulating layer 44 is formed on both sides of a non-magnetic substrate 42 having a relatively high heat resistance of, for example, about 1 inch square, and a spacer is formed on one of the laminated films. Form 45.

A large number of blocks 41 shown in FIG. 16 are prepared, and the first
After stacking and joining as shown in FIG. 7, the obtained joined body 46 is cut to produce a large number of first and second members similar to those in the previous embodiment.

Next, as shown in FIG.
Thin film coil 23, first magnetic thin film 24, second magnetic thin film 25, and bonding pad 2 explained in FIGS.
6. A large number of patterns 53 made of the insulating film 27 and the magnetic gap spacer film 28 are formed. Then, as shown in FIG. 19, after joining the first member 51 and the second member 52 in which the magnetic flux leakage prevention groove 29 described in FIG. Slice along the chain line and divide into head chips.

Considering the size of one Herad chip, this embodiment has advantages over the previous embodiments in that lithography and machining are easier and mass production is easier. Note that when forming laminated films on both sides of the nonmagnetic substrate 42 as described above, a conductive film may be used as the spacer 45. This will result in less crosstalk between the two gaps.

Still another example of the in-line multi-gap magnetic head used in the present invention will be described. As shown in FIG. 20, the first member 51 shown in FIG. 17 and the second member 52 shown in FIG. After bonding a non-magnetic substrate 61 in which the first member 51 is embedded and a non-magnetic substrate 62 in which the second member 52 is embedded as shown, the head chip is processed as shown in FIG. obtain. Although this method increases the number of man-hours, it suppresses an unnecessarily large size of the magnetic thin film layer forming the magnetic core, suppresses an increase in inductance due to magnetic flux leakage from the magnetic core, and improves the S
This has the advantage that /N is improved.

In addition, in each of the above-mentioned embodiments, the magnetic thin film layers serving as the magnetic core were laminated with an insulating layer interposed in between, but this was done in order to make it difficult for eddy current to flow through the magnetic core. If there is no need to take this into consideration, a single layer may be used.

Further, although the first and second magnetic thin films 24.25 are formed on the first member 2], it goes without saying that they may be formed on the second member 22. One of the magnetic thin films 24.25 may be dispersed in the first member 2 and the other in the second member 22, and one or both of the magnetic thin films 24.25 may be formed in both the first and second members 21.22. It may be formed into

In the above-described in-line multi-gap magnetic head, a magnetic gap is formed facing the end face of a magnetic thin film layer formed on a non-magnetic substrate. In this case, the core thickness of the magnetic core formed by the magnetic thin film layer is a dimension in the in-plane direction of the magnetic thin film layer, and can be easily made larger than in the film thickness direction. Therefore, although it is basically a thin film head, it is possible to increase the depth of the magnetic gap without causing magnetic saturation of the magnetic core, and it is suitable for systems such as VTRs where the amount of head wear is large.

[Effects of the Invention] According to the present invention, by using an in-line multi-gap magnetic head, it becomes possible to record and reproduce signals in the same frequency band with a smaller number of magnetic heads.

Therefore, when creating a VTR that handles extremely wide-band video signals such as high-definition television signals, reducing the number of heads not only makes it easier to attach the heads to the rotating cylinder. , impact jitter at the start of contact between the head and tape is reduced,
High-quality recording and playback with little jitter can be performed.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the arrangement of a magnetic head on a rotary cylinder in a rotary scanning magnetic recording/reproducing device according to an embodiment of the present invention, and FIG. 2 is a perspective view of a rotary scanning mechanism in the same embodiment. 3(a) and 3(b) are views of the in-line multi-gap magnetic head used in the same embodiment as seen from the tape sliding surface, FIG. 4 is a diagram showing the tape pattern in the same embodiment, and FIGS. 5 to 13. 5(a) and 5(b) are cross-sectional views of two non-magnetic substrates that serve as starting substrates for head chips; Figure 6 is similar to Figure 5 (a
) (b) A perspective view of the joined body made by joining the two non-magnetic substrates, FIG. 7 is a perspective view of the first and second members obtained by cutting the joined body of FIG. 6, and FIG. A perspective view showing the thin film pattern formed on the first member, FIG. 9 is C of FIG.
-A cross-sectional view taken along line C, Figure 10 is a diagram showing the processed state of the second member, Figure 11 is a cross-sectional view of the main parts of the Herad chip, and Figures 12 (a) and (b) are the entire Herad chip. FIGS. 13(a) and 13(b) are bottom views and front views of a magnetic head completed by attaching a head chip to a head base, and FIGS. 14(a) and (b) are views showing the present invention. Figure 15 is a cross-sectional view of two non-magnetic substrates that serve as starting substrates for head chips in other manufacturing processes for in-line multi-gap magnetic heads used in 16 to 19 are perspective views of the bonded assembly, and are diagrams for explaining another manufacturing process of the in-line multi-gap magnetic head used in the present invention. FIG. 17 is a cross-sectional view of a nonmagnetic substrate having a laminated film, FIG. 17 is a diagram showing the first bonded body, and FIG. 18 is a thin film pattern formed on the second member obtained by cutting the first bonded body. FIG. 19 is a perspective view of the second joined body; FIG. 20 is a diagram showing an intermediate step in yet another manufacturing process of the in-line multi-gap magnetic head used in the present invention; FIG. 21 21 is a perspective view of a head chip obtained by the manufacturing process shown in FIG. 20. FIG. 1... Rotating cylinders 2A to 2D... Magnetic head 3... Fixed cylinder 4... Motor 5... Magnetic tape 6... Magnetic gap 7... Head chip... Helad base plate

Claims (4)

[Claims] (1) In a rotary scanning magnetic recording and reproducing device that performs recording and reproducing by winding and running a magnetic tape around the circumferential surface of a rotating cylinder to which a plurality of magnetic heads are attached at predetermined intervals along the rotational direction, the magnetic head What is claimed is: 1. A rotary scanning magnetic recording/reproducing device characterized in that an in-line multi-gap magnetic head having a plurality of gaps formed on the same straight line is used. (2) A magnetic tape is wound around the circumferential surface of a rotating cylinder to which a plurality of magnetic heads are attached at predetermined intervals along the rotational direction, and the magnetic tape is run while being wound around the circumferential surface of the cylinder, and one field of video signal is recorded in M.N.
In a rotary scanning magnetic recording and reproducing device that records and reproduces data by dividing it into tracks (M and N are arbitrary integers), N in-line multi-gap magnetic heads each having M gaps formed on the same straight line are used. A rotary scanning magnetic recording and reproducing device characterized by using. (3) The pitch of the track pattern formed by the same inline multi-gap magnetic head on the magnetic tape is approximately an integral multiple of the track pitch between adjacent tracks on the magnetic tape. or 2
The rotary scanning magnetic recording/reproducing device described above. (4) The rotary scanning magnetic recording and reproducing apparatus according to claim 1, 2 or 3, wherein recording and reproducing are performed simultaneously on a plurality of different tracks using the same inline multi-gap magnetic head.