JPS6358609A - Composite magnetic head - Google Patents

Abstract

PURPOSE:To record two types of signals on the same disk and to ensure a highly accurate tracking action by using magnetic heads to form the sound signal tracks adjacently to the picture signal tracks via the prescribed guard bands. CONSTITUTION:A sound signal magnetic head 30 and a gap part 33a are provided at the positions in parallel to gap parts 13a and 23a of picture signal magnetic heads 10 and 20 and also distant toward the track width Tw by a distance l respectively. The picture signals are recorded on tracks 61 and 62 of a magnetic recording disk 60 by heads 10 and 20. While the sound signals are recorded by the head 30 onto a track 63 set between both tracks 61 and 62 via a minute guard band corresponding to the distance l. Thus the sound signals are recorded without decreasing the number of tracks for picture signals. Furthermore, the crosstalk can be satisfactorily reduced because both heads are separate from each other by a prescribed distance. Thus, a highly accurate tracking action is ensured without using a large magnetic head.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a magnetic head for recording and reproducing signals on a rotating flexible magnetic recording disk, and more particularly, the present invention relates to a magnetic head for recording and reproducing signals on a rotating flexible magnetic recording disk. The present invention relates to a composite magnetic head capable of recording and reproducing information signals other than image signals such as 8-track.

(Prior art) A magnetic recording/reproducing device using a flexible magnetic recording disk as a recording medium rotates a flexible magnetic recording disk on which image signals have been recorded in advance, and then freezes the image signal recorded thereon. There are still image playback devices that reproduce images on display devices such as television receivers, and still images that convert images of objects obtained through a lens into electrical signals and record them on flexible magnetic recording disks as still images. So-called electronic still camera devices and the like that reproduce images on a display device such as a television receiver have been developed.

These magnetic records! ! In the i-position and reproducing apparatus, the image signal is recorded for one field per round of the annular track. This method of reproducing one still image using one field of image signals is called field recording and reproduction. Also,
A method in which one field of the same frame is recorded on two annular tracks, one frame is composed of image signals from the two annular tracks, and one still image is reproduced is called frame recording and reproduction. That is, frame recording and reproduction requires twice as many annular tracks as field recording and reproduction, and the number of still images that can be recorded on a flexible magnetic recording disk is halved. Further, these annular tracks are usually formed in a concentric ring shape with a gap (guard bind) of about 40 μm interposed therebetween.

(Problems to be Solved by the Invention) By the way, when displaying still images on a television receiver or the like, there is a strong demand for simultaneously outputting audio, music, etc. corresponding to the image signal.

In response to the above request, information signals other than image signals such as audio are temporally compressed and recorded on a part of the annular track conventionally used for image signals, and the information signals are compressed in time and recorded. A method has been proposed in which the audio signal is expanded and played back, but such a method not only reduces the number of tracks for image display by the number of tracks allocated for recording information signals, which is not only inconvenient, but also causes problems in playback. Sometimes, a means for determining whether a signal recorded on a track is an image signal or another information signal such as audio is required, making the apparatus complicated and expensive.

In addition, in order to prevent the number of tracks for image signals from decreasing, information signals are recorded in the gaps separating each annular track, so-called guard byes, and the information signals and image signals are recorded so as to be azimuthal to each other. A method has been proposed by JP-A-Sho (31-153803@). However, since the magnetic head for image signals and the magnetic head for information signals are usually provided independently, it is difficult to use the helad touch of these magnetic heads. It is extremely difficult to simultaneously maintain good tracking at extremely close positions as described above, and a complicated mechanism is required to perform high-precision tracking of each magnetic head, making the device complex. This has the disadvantage of increasing the size and cost.Furthermore, if magnetic heads for image signals and information signals are provided separately, the positions of both magnetic heads must be precisely adjusted, which causes problems with the device. The relative device of each head is slightly different for each device, which causes inconvenience when a magnetic disk recorded with one device is played back by another device, and also makes it difficult to replace each head, making compatibility virtually impossible. There are also serious practical problems such as the fact that the

Therefore, an information signal was recorded in the guard band between the annular tracks for image signals by using a magnetic head that integrated a magnetic head for image signals and a magnetic head for information signals.
i, position is disclosed in Japanese Patent Application Laid-open No. 129701/1983. However, the above-mentioned magnetic head has serious drawbacks as described below when used in actual use.

That is, the above-mentioned magnetic head has a structure in which one magnetic head for audio signals is held between a pair of magnetic heads for image signals. Both side surfaces of the a-pole are in close contact with the side surfaces of the magnetic pole of the image signal magnetic head over a wide area. In a magnetic head with such a structure, the magnetic coupling between adjacent magnetic heads is strong, and each signal magnetic flux leaks to the adjacent magnetic head, resulting in significant so-called crosstalk that causes noise, and the reproduced image becomes large. Problems arise in that the sound is disturbed and 'li sounds are produced.

Therefore, the integrated magnetic head described above is completely unsuitable for practical use, and a magnetic head that can successfully record and reproduce both image signals and information signals on a flexible magnetic recording disk has not yet been developed. is the current situation.

In view of the above problems, the present invention enables highly accurate tracking without increasing the size of the device.
We developed a magnetic head that has good head touch, avoids problems such as crosstalk, and can record and reproduce both image signals and information signals on the same disk without reducing the number of tracks for image signals. The purpose is to provide

(Means for Solving the Problems) A magnetic head of the present invention that achieves the above object is a composite magnetic head that integrally includes a magnetic head for image signals and a magnetic head for information signals. The head has a magnetic gap that is a predetermined distance l1m1 apart from the magnetic gap for image information in the track width direction and parallel to the magnetic gap, and the head has a magnetic gap that is parallel to the magnetic gap for image information and that is located on the annular track for image information formed by the magnetic head for image signals. This method is characterized in that information signals are recorded and reproduced in adjacent annular tracks via a predetermined guard band.

The composite magnetic head may be a two-track magnetic head that records and reproduces image signals in the field and records and reproduces information signals such as audio on tracks adjacent to the inner or outer circumference of the image signal track, or A three-track magnetic head that records and reproduces image signals in frames using two tracks and records and reproduces information signals on tracks sandwiched between these tracks, or a three-track magnetic head that records and reproduces image signals in frames and records and reproduces information signals in frames between these tracks. It may be any four-track magnetic head that records and reproduces information signals on the tracks sandwiched between the recording signal tracks and on the tracks adjacent to the inner or outer circumference of the two tracks.

In addition, in recent years, thin-film magnetic heads have been developed in which a magnetic layer, a conductor layer, and an insulating layer are formed on a substrate using thin films.
If the image signal magnetic head and information signal magnetic head described above are formed using thin film magnetic heads, it will be more effective in reducing crosstalk and can be easily miniaturized, so that it will be within the range of the conventional guard band. Another advantage is that the entire head can be easily formed so that the magnetic gap of the information signal magnetic head and the interval between the magnetic gap of the image signal magnetic head and the magnetic gap of the information signal magnetic head are located. It is particularly preferable because it has.

(Function) According to the composite magnetic head configured as described above, since the image signal magnetic head and the information signal magnetic head are integrated, equally good head touch is ensured for both heads. Further, tracking can be performed with high precision without requiring a complicated mechanism. In addition, since the magnetic gaps of both magnetic heads are separated by a predetermined distance, this distance acts as a guard band.
Crosstalk between the heads can be reduced.Furthermore, since it is relatively easy to set the relative positions of both heads with high precision, compatibility can be ensured.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a front view showing the sliding movement of a composite thin film magnetic head which is an embodiment of the composite magnetic head of the present invention.

This composite 5pAla air head 50 includes two image signal magnetic heads 10.20 and an audio signal magnetic head provided between the two magnetic heads 10.20 in the track width 7w direction of the two image signal magnetic heads 10.20. It has a magnetic head 30. As will be detailed later, these magnetic heads 10, 20, 30 are thin film magnetic heads formed of thin films, and upper magnetic layers 11, 21, 31, respectively.
and gap portions 13a, 23a, which are insulating layers, sandwiched by lower magnetic layers 12, 22, and 32.

By slidingly touching the flexible magnetic recording disk 33a, images or audio signals are recorded and reproduced. The magnetic gap portion 33a of the audio signal magnetic head 3o is parallel to the magnetic gap portions 13a and 23a of the image signal magnetic head 10°20, and is spaced apart from each other by a distance l111 in the direction of the track width 7w.

This composite head 50 is a three-track composite thin film magnetic head that records and reproduces image signals in frames.As shown in FIG.
0, images and other signals are recorded on two image signal tracks 61 and 62 of one field each by the two image signal heads 10 and 20 of the magnetic head 5o, and these two image signals are An audio signal track 63 is formed between the signals by the audio signal magnetic head 30 via a minute guard band 64 corresponding to the distance between the signals, which was conventionally a guard band. Therefore, according to this composite thin film magnetic head 50, audio signals can be recorded and reproduced without reducing the number of tracks for image signals. Hereinafter, the structure of the composite thin film magnetic head 50 will be explained in detail based on its manufacturing process with reference to FIGS. 3 and 4.

FIG. 3 is a perspective view of the composite thin film magnetic head, and FIG. 4 is a sectional view showing the manufacturing process thereof.

composite:? When manufacturing the four-film magnetic head 50, the two-track image signal magnetic head 10, 20 is first formed of a thin film using a conventionally known method. Figure 4 (a
) will explain the formation method using the Wi film deposition head 20 as an example. First, the lower magnetic layer 22 is deposited on a substrate 24 made of magnetic ferrite by sputtering sendust alloy. Next, 5iOz as an insulating material and Cu as a coil material are appropriately formed on this lower magnetic layer 22 by a known method, and etched by etching etc. to form an insulating layer 23 and a coil conductor 25 as shown in the figure. It is formed. Next, on top of these laminates, a sendust alloy is further deposited by sputtering or the like in the same manner as the lower magnetic layer 22 to form the upper magnetic layer 21. Further above this, 5iO
A protective layer 2G is formed by z-sputtering. This protective layer 2G is polished and planarized to the position shown by the dashed line in FIG. 4(a), thereby obtaining the image signal magnetic head 20. Note that the portion of the insulating layer 23 that is sandwiched between the lower magnetic layer 21 and the lower magnetic layer 22 becomes the groove portion 23a. The other image signal magnetic head 10 is formed in exactly the same process after the lower magnetic layer 12 is formed integrally with the lower magnetic layer 22 on the same substrate as the image signal magnetic head 20. .

Furthermore, a Sendust alloy is deposited on the entire surface of the flattened protective layer 26 by sputtering or the like, thereby forming the lower magnetic layer 32 of the audio signal magnetic head 30. Image recording magnetic heads 10 and 20 on this lower magnetic layer 32
At a position between them, an audio signal magnetic head 30 made of the same material and process as the image recording magnetic head 20 described above is installed.
is formed (Fig. 4 (b)). Then above this is 5
iOz is deposited by sputtering to form a protective layer 36.
is formed. This protective layer 36 is flattened to the position shown by the dotted line in FIG. 4(b), and on this flattened protective layer 36, as shown in FIG. Holder 11 made of non-magnetic ferrite using adhesive 31
i140 is glued. The composite thin film magnetic head 50 thus obtained is completed by subjecting the sliding surface to processing as required.

In this composite thin film magnetic head 50, as shown in FIG.
The track width TV of the image signal magnetic head 10 and 20 is both 60μ, and the audio signal magnetic head 30
The track width Twr of is 20B plane. Also, the distance between the image signal magnetic head 10.20 and the audio signal magnetic head 30 forming the guard band 64 on the magnetic recording disk 60 is 1! lll9! , is 10 μm. Furthermore, the thickness (length in the vertical direction) of the gap portions 13a, 23a, and 33a of each magnetic head 10, 20, and 30 is 0.3 μm. Using this reproducing magnetic head, an image signal and a 10 second audio signal were recorded and reproduced on the flexible magnetic recording disk rotating at 360 rpm.

FIG. 5 is a block diagram showing a circuit for recording and reproducing image signals and audio signals using the composite source FJ magnetic head 50.

The still image color signals obtained from the dynamic image system 70 are modulated by FM modulators 71A and 71B and then added.
The image signals are recorded on the magnetic recording disk 60 through the gate 72 by the image signal magnetic heads 10 and 20 in the three-track composite thin film magnetic head 50. On the other hand, the audio signal obtained from the microphone 80 is amplified by the amplifier 81 and then compressed to 1/60 seconds by the time axis compression circuit 82.
The audio signal magnetic head 30 in the film magnetic head 50 records on the aforementioned audio signal track of the magnetic recording disk 60. When reproducing an audio signal, the audio signal recorded on the magnetic recording disk 60 is also detected by the information signal magnetic head 30, amplified by the amplifier 84, and then FM demodulated by the FM demodulator 85.
The time axis expansion circuit 86 restores the original 10 second audio signal. This restored audio signal passes through an amplifier 87 and is output as an audio signal. Also, the magnetic recording disk 11
The image signals recorded in the image signals are detected by the image signal magnetic heads 10 and 20, and are displayed as still images on a display device such as a television receiver by a well-known reproduction system (not shown). When this still image was played back, the interference from the audio signal, or crosstalk, was -42 dB, and no screen disturbance was observed. Conversely, no noise from the image signal was observed during audio playback.

In yet another embodiment, the substrate is made of non-magnetic ferrite, and the upper and lower magnetic layers of each magnetic head are C0-Nb-
7r amorphous magnetic material, the track width Tw I of the audio signal magnetic head is 28 μm, the distance Mi (guard band) is 6 μm, and other than that, the material and structure are the same as in the above-described embodiment. Using a 3-track composite thin-film magnetic head, one of the two image signal magnetic heads is used to field-record an image signal on a magnetic recording disk, and the audio signal thin-film magnetic head is used to record one image signal. ~Audio (number i) was recorded on the track adjacent to the rack.When the image and audio signals recorded on the magnetic disk were reproduced using this composite thin-film magnetic head, there was almost no image disturbance. The noise level was also low enough to cause no practical problems.

As described above, according to the one-gas head with composite thin film of this embodiment,
By integrating the magnetic head for image signals and the magnetic head for audio No. 4+E, it is possible to ensure good head touch with each magnetic head and perform highly accurate tracking. By arranging the magnetic gap portions of the magnetic heads parallel to each other at a predetermined distance, the magnetic coupling between the respective magnetic heads is weakened, and an increase in the a-stalk can be prevented.

Although the above description has been made using a three-track composite thin-film magnetic head as an example, in the composite thin-film magnetic head of the present invention, as shown in FIG. 6(a), the mutual magnetic gaps are at a distance! ! 1
It may be a two-track composite 7A film magnetic head having one track of an image signal magnetic head 10' and one track of an audio signal magnetic head 30', which are provided in parallel and separated by 1'. As shown in FIG. 6(b), there are two-track image signal magnetic heads 10', 20' and two-track audio signal magnetic heads 30'', 40.
A four-track magnetic head may be used, in which the magnetic gap portions of the respective magnetic heads are separated by a distance of 111t9J''. In the case of a 4-track composite thin-film magnetic head, it is possible to record audio for twice the time or to perform stereo recording compared to a 2-track or 3-track composite thin-film magnetic head. In any case, the specific shape and material of each thin-film magnetic head constituting the composite thin-film magnetic head are not limited to those shown in the above embodiments. Alternatively, the substrate may be formed of a ferromagnetic material to also function as a lower magnetic layer.

Further, the composite magnetic head of the present invention is not limited to the above-mentioned thin film type, but may be of a bulk type. FIG. 7 shows a bulk type composite magnetic head of the present invention.

The composite magnetic head 100 shown in FIG. 7<a) includes two bulk type image signal magnetic heads 110. 120 and
This is a three-track composite magnetic head having one bulk type audio signal magnetic head 130, each magnetic head 110. 120. 130 are the coils 111,
121. 131 winding coil window 112. 12
The first Herad chip half piece 1 formed with 2°132
13, 123. 133, and second head chip half piece 114°124, 13. It is equipped with 'l. The first and second Herad tips are made of Sendust alloy, and the second head tip 114. 124. 13
4 are the first Herad chips 113. 123.
133 and the magnetic gap portion 115. 125. They are joined via 135.

Also, two image signal magnetic heads 110. 120 and the audio signal magnetic head 130 are arranged so that their side surfaces partially overlap as shown in the figure, and each magnetic gap portion 11
5. 125. 135 are aligned on the same plane, and two image signal magnetic heads 110, 1
20 and the joint surface of the audio signal magnetic head 130,
A shield plate 140 made of titanium foil and magnetically shielding the magnetic heads is provided. In this composite magnetic head, the width of this shield plate defines the size of the guard band on the magnetic recording disk. Note that the three magnetic heads 110. 120. 130 is arrow B
The lengths in the directions are approximately equal, and the shield plate 140
．． The length of the head chip 150 in the direction of arrow B is approximately twice the length of the second head chip half piece 114, 124, 134. Also, the track width TV of the image signal magnetic head 110°120 of this composite magnetic head is 60 μm, and the track width Tw J of the magnetic head 130 for @Seishinkyu is 2
0 μm, the width of the shield plate 140 is 10tt m, and the width of each gap is 7 parts 115. The thickness of 125 and 135 is 0.3
It is μm.

Using the composite magnetic head described above, image signals were recorded in frames on a magnetic recording disk rotating at 360 rpm, and audio signals for 10 seconds were also recorded, and reproduced by the same composite magnetic head. Both image signal magnetic heads 110. The crosstalk between the magnetic head 120 and the audio signal magnetic head 130 was -37 dB, and the influence of the audio signal on the reproduced image and the noise caused by the image signal on the reproduced audio were hardly observed.

The bulk type composite magnetic head may also be a two-channel type in which one image signal magnetic head and one audio signal magnetic head are provided via a shield plate, or as shown in Fig. 7 (b). ), two image signal magnetic heads 210.degree. 220 and two audio signal magnetic heads 230. 240 may be provided alternately with shield plates 250 interposed in four channels.

Furthermore, the magnetic gap of the magnetic head for image signals and the audio a
The magnetic gaps of the 3-channel magnetic heads only need to be parallel to each other.
As shown in FIG. 8(1)), the four-channel magnetic heads are not shown in each magnetic head (FIG. 8(a)).
115', 125', 135' in
, 215', 225' in FIG. 8(b)
, 245') in a direction perpendicular to the track width (direction of arrow B).

Further, in each of the above embodiments, the case where the information signal other than the image signal is an audio signal has been described as an example, but the information signal is not limited to an audio signal, but may be music or other various information signals. Needless to say.

<Effects of the Invention> As described in detail above, according to the composite magnetic head of the present invention, the image signal magnetic head and the information signal magnetic head are integrated so that their magnetic gaps are parallel to each other with a predetermined distance apart. This arrangement ensures equally good head touch for both heads, and also eliminates the need for a complicated mechanism for tracking, so there is no inconvenience such as an increase in the size or cost of the entire device. Also,
Each head can be easily formed in a predetermined relative position with high accuracy, resulting in excellent compatibility. Further, since the magnetic gap portions of both heads are separated by a predetermined distance, crosstalk can be sufficiently reduced, and highly reliable recording and reproduction can be performed. Furthermore, with the information signal magnetic head, it is also possible to form information signal tracks in the guard bands between conventional image signal tracks, so information signal recording and playback can be performed without reducing the number of image signal tracks. The present invention has extremely great practical value.

[Brief explanation of the drawing]

FIG. 1 is a front view showing the sliding surface of a composite thin film magnetic head according to an embodiment of the present invention, FIG. 2 is a schematic plan view of a flexible magnetic recording disk, and FIG. 3 is a composite thin film shown in FIG. 1. A perspective view of the magnetic head; FIGS. 4(a), (b), and (c) are cross-sectional views showing the manufacturing process of the composite thin-film magnetic head; FIG. 5 is a block diagram of a recording/reproducing circuit for image signals and audio signals. , FIG. 6(a>, (b) is a front view showing the sliding surface of a composite thin film magnetic head according to another embodiment of the present invention, FIG. 7(a>,
(b) and FIG. 8(a). (b) is a perspective view showing a bulk type composite magnetic head of the present invention. 10.10', 10'', 20.20', 20'',
110. 120°210, 220... Image signal magnetic head 30, 30', 30'', 40'',
130. 230. 240...Audio signal magnetic heads 13a, 23a, 33a, 115. 1
25. 135...Magnetic gap portion 50...Composite thin film magnetic head 60...Flexible magnetic recording disk 100...Engraving on the surface of bulk type composite magnetic head (no change in content) Fig. 1 Fig. 2 Figure 3, Item 7, Figure 8, A (Voluntary) Procedure ``■ Dear Commissioner of the Patent Office, October 1988
February 3, 2, Name of the invention Composite magnetic head 3, Relationship with the case of the person making the amendment Patent applicant Location 210 Nakanuma, Minamiashigara City, Kanagawa Prefecture Name Name
Fuji Photo Film Co., Ltd. 4, Agent (7318) Patent Attorney Yanagi Ro] Seishi (and 2 others)
5. Date of amendment order None 6. Number of inventions increased by amendment None 7. Target of amendment Drawing 8. Contents of amendment Hand-drawn drawings will be amended to inked drawings. (No change in content) Director General of the Patent Office December 1986
May 8, 1, Indication of the case 3, Person making the amendment Relationship with the case Patent applicant Address 210 Nakanuma, Minamiashigara City, Kanagawa Prefecture Name Name
Fuji Photo Film Co., Ltd. 4, Agent Address: 5-2-1 Roppongi, Minato-ku, Tokyo 160 6, Number of inventions increased by amendment None 7, "Detailed description of the invention" column of the specification subject to amendment and Drawing 8, contents of amendment 1) "Information" on page 7, line 5 of the specification is corrected to "signal". 2) On the same page, "magnetic" is corrected to "magnetic head". 3) Insert [235-, J after page 20, line 19 r225'', J. 4) Correct box 7 (a) in the drawing as attached.

Claims (1)

[Scope of Claims] 1) An image signal magnetic head for recording and reproducing image signals on an annular track on a flexible magnetic recording disk, and a predetermined distance in the track width direction from a magnetic gap portion of the image signal magnetic head. An information signal magnetic head is integrated, which has a magnetic gap part separated from and parallel to the magnetic gap part, and records and reproduces information signals other than image signals in an annular track adjacent to the annular track via a predetermined guard band. Composite magnetic head that is equipped for various purposes. 2) The first aspect of the present invention is characterized in that the image signal magnetic head and the information signal magnetic head are thin film magnetic heads in which a magnetic layer, a conductor layer, and an insulating layer are each formed of thin films. Composite magnetic head described in Section 1.