JPS63255808A - Composite thin film magnetic head - Google Patents

Abstract

PURPOSE:To attain the recording and reproducing of an information signal except an image signal by providing the magnetic gap of first and second magnetic heads in the inside of a secondary annular interference fringe to occur between a sliding surface and an optical flat plates with a monochromatic light with the wavelength of 0.546mum. CONSTITUTION:The head is equipped with magnetic heads 10 and 20 for an image signal and a magnetic head 30 for a sound signal which forms the azimuth of an angle theta and adjoins with the magnetic heads 10 and 20 for the image signal in a track width Tw direction. Magnetic heads 10, 20 and 30 are thin film magnetic heads and respective heads slide and connect insulating layer gap parts 13a, 23a and 33a sandwiched by upper part magnetic layers 11, 21 and 31 and lower part magnetic layers 12, 22 and 32 to a flexible magnetic recording disk. Here, the gap parts 13a, 23a and 33a are positioned in the inside of the secondary interference fringe formed by the light of a wavelength 0.546mum to pass a monochromatic filter while any part overlaps an optical flat plate on a sliding surface. Thus, the image signal and the sound signal can be recorded and reproduced with a satisfactory head touch.

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 thin film magnetic head capable of recording and reproducing information signals other than image signals such as music.

(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 signals recorded thereon. Still image playback devices that reproduce images on display devices such as television receivers, and convert images of objects obtained through a lens into electrical signals and record them on flexible magnetic recording disks to receive still images on television. So-called electronic still camera devices, etc., which reproduce images on display devices such as cameras, have been developed.

In these magnetic recording devices and reproducing devices, 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. Furthermore, 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 playback. . 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. Also, these circular tracks usually have 60
It has a width of about μm and is formed in a concentric ring shape with a gap (guard band) 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 causes the inconvenience that the number of tracks for image signals decreases by the number of tracks allocated for recording information signals, but also However, a means for determining whether the signal recorded on the 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 racks for image signals from decreasing, information signals are recorded in gaps separating each annular track, so-called guard bands, and the information signals and image signals are azimuthally aligned with each other. A recording method for recording is proposed in Japanese Patent Laid-Open No. 153803/1983. However, since the magnetic head for image signals and the magnetic head for information signals are usually provided independently, it is difficult to ensure good helad touch of these magnetic heads at the same time in extremely close positions as described above. It is extremely difficult to track each magnetic head with high precision. ! Since a complicated mechanism is required, the device becomes complicated, resulting in an increase in size and cost. In addition, when magnetic heads are provided for image signals and information signals, the re-magnetic heads must be precisely positioned, so the relative position of each head differs slightly depending on the device, making it difficult to record with one device. When a magnetic disk is played back by another device, so-called tracking is difficult, resulting in inconveniences such as a drop in playback output and S/N ratio, and it also becomes difficult to replace each head, making it virtually incompatible. There are also serious practical problems, such as how it becomes a commercial product.

In view of the above problems, the present invention enables highly accurate tracking without increasing the size of the device.
It is an object of the present invention to provide a magnetic head that has good head touch and can record and reproduce both image signals and information signals on the same disk without reducing the number of tracks for image signals.

(Means for solving the problem) In recent years, thin-film magnetic heads, in which a magnetic layer, a conductor layer, and an insulating layer are laminated as thin films on a substrate, have been developed as magnetic heads for high-density recording. . As a result of extensive research to achieve the above-mentioned objective, the applicant has developed a magnetic head for image signals and a magnetic head for information signals both of the WI film type, and has integrated these magnetic heads into a composite thin film magnetic head. The inventors have found that it is possible to obtain a magnetic head that satisfies all of the above objectives.

Based on the above knowledge, the composite film magnetic head of the present invention, which was derived as a result of further research into the specific structure, integrates a first magnetic head and a second magnetic head, which are thin film magnetic heads. The remagnetic heads are provided azimuthally and substantially adjacent to each other in the track width direction, and the magnetic gap between the first magnetic head and the second magnetic head is such that the composite thin Il! On the sliding surface of the magnetic head, an optical flat plate is closely stacked on the sliding surface, and annular interference fringes are formed between the sliding surface and the optical flat plate using monochromatic light having a wavelength of 0.546 μm. It is characterized in that when generated, it is arranged inside the secondary annular interference fringes.

In this composite thin film magnetic head, the first magnetic head can be used as a magnetic head for image signals, and the second magnetic head can be used as a magnetic head for information signals such as audio. Both heads may be used for image signals, and both remagnetic heads may be used for information signals. In addition, this composite thin-film magnetic head 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.
It may be a magnetic head of a truck, or it may be a magnetic head of a truck.
Frame recording and reproduction is performed using book tracks, and information signals are recorded and reproduced on the tracks sandwiched between these tracks 3
The magnetic head of the track or the image signal is recorded and reproduced in frames, and the information signal is recorded and reproduced on the track sandwiched between the two image recording signal tracks and the track adjacent to the inner or outer circumference of the two tracks. Any 4-track magnetic head may be used. Furthermore, the fact that the first magnetic head and the second magnetic head are substantially adjacent to each other in the track width direction means that the magnetic layer and the insulating layer on the sliding surface that define the track width are adjacent to each other on the disk. This means that the remagnetic head is arranged to form a track, and the remagnetic head may be misaligned in the direction perpendicular to the width direction of the track. Further, the remagnetic head may be arranged so that tracks formed adjacent to each other on the disk overlap with each other, or there is a slight gap between them. Further, in the remagnetic head, portions such as conductor layers that are away from the sliding surface may partially overlap each other.

(Function) According to the composite thin film magnetic head configured as described above, the first
By making the first magnetic head and the second magnetic head each a thin film magnetic head, when integrating both heads, it is easy to arrange both heads at positions adjacent to each other in the track width direction in an azimuthal manner. A composite head with such a structure can significantly reduce crosstalk between heads. Further, by integrating both heads, tracking can be performed with high precision without requiring a complicated mechanism for both heads. Further, since it is relatively easy to set the relative position of the gap between both heads and the azimuth angle with high precision, compatibility can be ensured.

Further, when the first magnetic head and the second magnetic head are integrated as described above, there is a risk that the two heads will be separated from each other by a large distance in the track length direction due to the design. If the position of the re-magnetic head is too thick (if it is too far away, the balance of the helad touch of the re-magnetic head will be poor, making it difficult for both heads to obtain good head touch at the same time.If the head touch becomes uneven in this way, both heads will The recording and playback characteristics of the head become unbalanced, resulting in inconveniences such as unstable playback output level and dropout.The applicant has conducted intensive research to solve this problem, and as a result, both heads have the same characteristics. The gap part is the sliding surface of the composite thin S magnetic head, and the optical flat plate is closely stacked on the sliding surface,
When annular interference fringes are generated between the sliding surface and this optical flat plate using monochromatic light with a wavelength of 0.546μ, a good head is determined if the ring is located inside the secondary interference fringes. Found that you can get a touch.

Therefore, the composite WiIII of the present invention! According to J magnetic head,
By arranging the gap portions of both the first magnetic head and the second magnetic head within this range, it is possible to ensure stable and good recording and reproducing characteristics.

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

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

This composite thin film magnetic head 50 includes two image signal magnetic heads 10 and 20, and two image signal magnetic heads 10 and 20.
The audio signal magnetic head 30 has an azimuth of 0.20 and an angle θ and is adjacent to the image signal magnetic head 10.20 in the track width 1w direction of the image signal magnetic head 10.20. The above three magnetic heads 10.
As will be described in detail later, 20 and 30 are thin film magnetic heads each formed of a thin film, each of which is an insulating layer sandwiched between an upper magnetic layer 11, 21, 31 and a lower magnetic layer 12, 22, 32. Certain gap portions 13a, 2
Recording and reproduction of image or audio signals is performed by bringing 3a and 33a into sliding contact with a flexible magnetic recording disk.

This composite thin-film magnetic head 50 is a three-track composite 7iI film magnetic head that records and reproduces image signals in frames.As shown in FIG.
, image signals are recorded on two image signal tracks 61 and 62 of one field each by the two image signal magnetic heads 10 and 20 of the present magnetic head 50, and the gap between these two image signals is , an audio signal track 63 is formed by the audio signal magnetic head 30 in a portion that was conventionally a guard band. Therefore, according to the composite @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.

When manufacturing the composite film magnetic head 50, first, as shown in FIG. 3(a), a two-track image signal magnetic head 10, 20 is formed of a thin film by a conventionally known method. Referring to FIG. 4, which is a cross-sectional view taken along the line A-A in FIG. By doing so, the lower magnetic layer 22 is formed.

Next, on this lower magnetic layer 22, an insulating material of 5iOz1 is applied.
3 and coil material Cu are appropriately formed into films by a known method, and etched or the like to form an insulation @ 23 and a coil conductor 25 as shown. 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. Furthermore, a protective layer 26 is formed above this by 3i02 sputtering. This protective layer 26 is polished and planarized to the position shown by the dashed line in FIG. 4, thereby obtaining the image signal magnetic head 20. Note that the portion of the insulating layer 23 sandwiched between the upper magnetic layer 21 and the lower magnetic layer 22 becomes the gap portion 23a. The other image signal magnetic head 10 has a lower magnetic layer 12 formed integrally with the lower magnetic layer 22 on the same substrate as the image signal magnetic head 20.
After this is formed, the same process is followed.

On the other hand, as shown in FIG. 3(b), on a substrate 34 separate from the substrate 24, the above-mentioned image signal magnetic head 2 is mounted.
0, an upper magnetic layer 31 and a lower magnetic layer 32 are laminated with thin films together with a conductor layer and an insulating layer to form a magnetic head 30 for audio signals. The audio signal magnetic head 30 has a flattened protective layer 36, and a protective plate 38 made of non-magnetic ferrite is adhered onto the protective layer 36 using an adhesive 37 such as low melting point glass. This audio signal magnetic head 30 is then cut at a position shown by a dashed line in the figure to form a joint surface 39 with the image signal magnetic head 10.20. Note that the angle θ between the bonding surface 39 and the substrate 34 determines the relative azimuth angle between the information signal magnetic head 30 and the image signal magnetic head. It is desirable to select the angle θ in the range O<θ≦50°, and in this embodiment, the angle θ is 45°.

After the audio signal magnetic head 30 is further cut as required, as shown in FIG.
It is placed on the protective layer 26 of No. 0 and bonded with an adhesive 40 such as low melting point glass. The thus obtained composite thin film magnetic head 50 has a sliding surface processed into a curved surface such as a spherical or ellipsoidal surface, as shown by the broken line in FIG. 3(C). completed.

In this composite thin film magnetic head 50, as shown in FIG.
The track width Tw of the image signal magnetic head 10 and 20 is both 60 μm, and the track width Tw of the audio signal magnetic head 30 is 60 μm.
The track width Tw l is also 60 μm. Also, the gap portion 13 of these magnetic heads 10, 20, 30
The thickness of a, 23a, and 33a is each 0.3μ
m. Further, as shown in FIG. 1, the contour of the sliding surface is approximately square, and the length of one side thereof is 440 μm. Furthermore, the sliding surface is formed into a spherical shape with a radius of curvature of 16M#+, and the magnetic head for image signals 10.2
The distance d in the track length direction (in the direction of arrow B in FIG. 1) from the gap portions 13a, 23a of 0 to the center of the gap portion 33a of the audio signal magnetic head 30 is 85.
I am employed by μ. In addition, the above three magnetic heads 10.2
Gap portions 13a, 23a, 33a of 0.30
In each case, an optical flat plate was placed on the counterfeit surface, and annular interference fringes were formed using light with a wavelength of 0.546 μl that passed through a monochromatic filter. It was confirmed that it was located inside. Using this composite thin film magnetic head, 360O
An image signal and a 10 second audio signal were recorded and reproduced on the flexible magnetic recording disk which rotated at rllllll. FIG. 5 is a block diagram showing a circuit for recording and reproducing image signals and audio signals using the composite thin film magnetic head 50.

The still image color signal obtained from the image carrier system 70 is modulated and numbed by the FM modulators 71A and 71B, and then
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, and this compressed audio signal is sent to the composite thin film magnetic The audio signal magnetic head 30 in the head 50 records the audio signal 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 similarly 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. Further, the image signal recorded on the magnetic recording disk 60 is also transmitted to the image signal magnetic head 10.
and 20, and displayed as a still image on a display device such as a television set by a well-known reproduction system (not shown). When this still image was played back, the interference from the audio signal, or crosstalk, was -44 dB, and no screen disturbance was observed. Conversely, no noise from the image signal was observed during audio playback. Also image signal.

The output level of both audio signals was stable, and no noise was generated.

As another example, the substrates of the image signal magnetic head and the audio signal magnetic head are made of non-magnetic ferrite, and the upper and lower magnetic layers of each magnetic head are Co-Nb-7r.
The amorphous magnetic material is quite large, and the relative azimuth angle is 306
and the track width TW' of the thin film magnetic head for audio signals is
is 46 μm, and the radius of curvature of the sliding surface is 20 ttn.Other than that, the material and structure are the same as those of the above-mentioned embodiment, and the gap portion of each head is all inside the above-mentioned primary interference fringe. Using a three-track composite Ti film magnetic head that has been confirmed to be installed in An audio signal was recorded on a track adjacent to the image signal track using a thin film magnetic head for audio signals. When the image and audio signals recorded on the magnetic disk were played back using this composite thin-film magnetic head, both the image and audio outputs were stable, and no image disturbance or noise was observed. .

In this way, the composite of the present invention is 111g! According to the magnetic head, by using thin-film magnetic heads as both the magnetic head for image signals and the magnetic head for audio signals, it is possible to easily integrate both magnetic heads so that they are adjacent to each other in the track width direction and azimuthal to each other. can be formed. Therefore, each magnetic head can perform highly accurate tracking and can prevent crosstalk from entering. Furthermore, in the magnetic head of the present invention, as described above, the V-shaped portions of each magnetic head are arranged inside the secondary interference fringes caused by light with a wavelength of 0.546 μm, and are placed close to each other. can ensure equally good head touch. In each of the embodiments described above, each gap portion is arranged within the first-order interference fringe, and if the position of each gap portion is within the first-order interference fringe, an extremely good head touch can be achieved. However, if each gap portion is placed within the secondary interference fringes, good head touch can be maintained without causing any practical problems.

Although the composite thin film magnetic head of the present invention has been described above using a three-track composite WI film magnetic head as an example, the composite thin film magnetic head of the present invention has a sixth track.
As shown in FIG.
It may be a two-track composite thin film magnetic head having a one-track audio signal magnetic head 130, or as shown in FIG. A four-track magnetic head having two audio signal magnetic heads 230 and 240 may also be used. 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. Further, in each of the above embodiments, the case where the information signal other than the image signal is an audio signal has been explained as an example, but it goes without saying that the information signal is not limited to an audio signal, but may be music or other various information signals. stomach. Further, the specific shape and material of each thin film magnetic head constituting the present composite W1 film magnetic head are not limited to those shown in the above embodiments; for example, each conductor layer may be one layer, The substrate may be made of a ferromagnetic material to also function as a lower magnetic layer. Furthermore, the head of one track is not limited to being used for image signals and the head of the other track is not limited to being used for information signals, and the head of either track may be used for image signals, and either It goes without saying that the track head may also be used for information signals other than image signals.

(Effects of the Invention) As described in detail above, according to the composite thin film magnetic head of the present invention, the first magnetic head for image signals, etc. and the second magnetic head for information signals, etc. are both thin film magnetic heads. Since it is formed and integrated, there is no need for a complicated R structure for tracking each head, so there is no inconvenience such as an increase in the size or cost of the entire device.

In addition, since the two heads have a relative azimuth, crosstalk can be sufficiently reduced, making it possible to use the conventional guard band between the image signal tracks as an information signal track. Information signals can be recorded and reproduced without reducing the number of tracks.

Furthermore, both magnetic heads are arranged close to each other with their respective gap portions within the predetermined range defined by the interference fringes as described above, so that both can ensure good head touch and reduce noise. Efficient recording and reproduction can be performed without causing any problems such as dropout or dropout.

[Brief explanation of the drawing]

Fig. 1 is a front view showing the sliding surface of a composite film magnetic head according to embodiments of the present invention, Fig. 2 is a schematic plan view of a flexible magnetic recording disk, and Figs. 3 (a) and (b). , (c) is a perspective view illustrating the structure of the composite 7S film magnetic head shown in FIG. 1, including its manufacturing process, FIG. 10 is a block diagram of a recording and reproducing circuit for image signals and audio signals, and FIGS. , 20... Image signal magnetic head 11, 21.
31... Upper magnetic layer 12, 22
．． 32...lower magnetic layer 13a,
23a, 33a...Gap portion 30...Audio signal magnetic head 50...Composite II1 film magnetic head 60...Flexible magnetic recording disk Figure 1 Figure 4 Figure 6 October 1988 23rd, 1986 Patent Application No. 091.382 @2, Title of the invention: Composite Shoulder/Knee Magnetic Head 3, Relationship to the case of the person making the amendment Name of the patent applicant: 210 Nakanuma, Minamiashigara City, Kanagawa Prefecture Name (
520) Fuji Photo Film Co., Ltd. Representative Ohnishi
Fact 4. Agent address: 7th floor, Hauraiya Building, 5-2-1 Roppongi, Minato-ku, Tokyo Voluntary amendment 6 Subject of amendment: "Detailed description of the invention" column 7 of the specification, Contents of amendment 1) Specification Insert "or barium titanate, etc." after "non-magnetic ferrite" on page 14, line 20.

Claims (1)

[Claims] A first magnetic head for recording and reproducing signals on an annular track on a flexible magnetic recording disk, and a second magnetic head for recording and reproducing signals other than the signal on an annular track adjacent to the annular track are integrated. The first magnetic head and the second magnetic head are thin film magnetic heads each having a magnetic layer, an insulating layer, and a conductive layer formed of thin films, and are azimuthal to each other in the track width direction. A composite thin-film magnetic head provided substantially adjacent to each other, wherein the magnetic gap between the first magnetic head and the second magnetic head is on the sliding surface of the composite thin-film magnetic head. When optical flat plates are stacked closely together and an annular interference fringe is generated between the sliding surface and the optical flat plate using monochromatic light having a wavelength of 0.546 μm, a secondary annular interference fringe among the annular interference fringes is generated. A composite thin-film magnetic head characterized by being disposed inside the.