JPS62262205A - Precedent erasing device for rotary magnetic recording medium - Google Patents

Abstract

PURPOSE:To eliminate necessity of adjustment by making a permanent magnet piece for erasing brought into sliding contact with a rotary magnetic recording medium automatically at specified low contact pressure by the displacement driving mechanism of an erasing head. CONSTITUTION:A damper 40 makes an erasing head He in contact with a rotary magnetic recording medium D at low contact pressure when the head is brought into contact with the medium by a displacement driving mechanism DDM for bringing the erasing head He into contact with the recording medium D or separating from the medium. When current is not supplied to an exciting winding 37, the movable piece 39 made of ferromagnetic material of the displacement driving mechanism DDM is separated from a center pole 36 by elastic force of a suspension 38 made of elastic material fixed to a yoke 35, and the erasing head He is held in the state off from the rotary magnetic recording medium. When current is supplied, the movable piece 39 is magnetically attracted to the center pole 36 resisting elastic force of the suspension 38 and made to the state of sliding contact.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a advance erasing device for a rotating magnetic recording medium that can be favorably used in a high-density magnetic recording/reproducing device.

(Prior Art) In recent years, video tape recorders (VTRs) have been miniaturized, and television cameras (hereinafter referred to as TVs) have been developed using various types of solid-state image sensors and integrated circuits. With the aim of achieving ultra-miniaturization, research and development are actively underway on an ultra-compact and lightweight camera-integrated VTR (so-called electronic 8mm device 1), which has a configuration that integrates the above-mentioned ultra-compact TV camera and ultra-compact VTR. It began to be practiced.

In addition, research and development is being conducted on so-called electronic cameras that can record still images electrically instead of still cameras that use photographic film. Electronic cameras that use disks to record video signals have been made as small as a 35mm digital camera.
The modeled version has already been announced as having reached the stage of practical application.

The applicant company also developed an ultra-compact imaging and recording device capable of frame-by-frame recording and short-term continuous recording using a cylindrical rotating magnetic recording medium about the size of a 35 mm photographic film cartridge. We have been making proposals regarding. In other words, in a cylindrical rotating magnetic recording medium, the relative linear velocity between the magnetic film and the recording/reproducing element is constant over the entire circumference of the rotating magnetic recording medium. There is a possibility that it can be effectively used as a recording and reproducing area, and for example, it is possible that it can be used effectively as a recording and reproducing area.
Alternatively, you can use a case (total length: 5
3 mm, diameter 31 mm), the relative linear velocity (per second 5.8 m) is obtained, so for example, a cylindrical rotating magnetic recording medium with a diameter of 31 mm and a length of 50 mm is rotated at 3600 revolutions per minute, and its circumferential speed is 5.8 m per second. If one field of the TV video signal is to be recorded for each rotation, if the length of the recording path is 3 μm, the guard band is 1.5 μm, and the interval between recording traces is 4.5 μm, the above-mentioned A cylindrical rotating magnetic recording medium with such a shape and size can record 10,800 frames of still images, and can also record 10,800 frames of still images.
A large recording capacity can be obtained with a small size, such as continuous recording for 1 minute or 6 minutes of recording using the field skip method. By installing a motor for driving a recording medium, it is easy to miniaturize a magnetic recording/reproducing device capable of magnetic recording or magnetic recording/reproducing operation, and the imaging type recording device can be configured to be small and lightweight. It is also valid above.

The present applicant's company has proposed a hollow and hollow rotating magnetic recording medium that can be effectively used in the above-mentioned image capturing and recording apparatus. A signal recording surface is formed on either or both of the outer circumferential surface and inner circumferential surface of the substrate, which is processed to have an outer shape of a truncated right circular cone (such as that obtained from a right circular cone with extremely small angles). An example of a hollow recording medium is one formed on an outer circumferential side surface that is made highly smooth by injection molding of, for example, a synthetic resin material.

By depositing a magnetic layer or film by applying electroless plating or other deposition means.

There is a cylindrical rotating magnetic recording medium, which is used for recording and reproducing information signals such as recording TV video signals on the above-mentioned rotating magnetic recording medium and reproducing video signals from the rotating magnetic recording medium. The applicant company has proposed many devices in the past.

(Means for Solving the Problems) Now, the magnetic recording medium used for magnetically recording and reproducing information signals is a cylindrical rotating magnetic recording medium having the above-mentioned constituent layers. Or, even if it is a flat rotating magnetic recording medium that has been commonly used in the past.

2. Description of the Related Art A magnetic recording medium capable of recording information signals at high density is required to have a magnetic layer made of a magnetic material having high coercive force.

By the way, when the magnetic recording/reproducing device is put into the recording mode, it is necessary to erase the recorded contents recorded on the rotating magnetic recording medium up to that point before starting new recording. As mentioned above, in a rotating magnetic recording medium configured to enable high-density recording and reproduction, a magnetic material with high coercive force is used as the magnetic layer. A powerful erasing head capable of generating a strong magnetic field must be used to erase the information signals present.

As an erase head for advance erasing,
Conventionally, a magnetic head that combines a recording/reproducing head with a recording/reproducing function and an erasing head with an erasing function has been used, or an erasing head separate from the recording/reproducing head has been used. Composite magnetic heads are difficult to manufacture, and they also suffer from magnetic gaps in the recording/reproducing head section.
There is a problem in that it is difficult to bring both the magnetic gap in the erasing head portion into good contact with the rotating magnetic recording medium. A contact adjustment mechanism is provided between the recording/reproducing head and the erasing head so that the magnetic gaps of the recording/reproducing head and the erasing head are brought into good contact with the rotating magnetic recording medium. The problem is that each adjustment mechanism must be separately provided for both and adjusted separately.

(Means for Solving the Problems) The present invention provides a magnetic head that is attached to one end of a magnetic head that slides into sliding contact with a magnetic recording medium for recording and reproducing information signals, and that the other end of the magnetic head is attached to a predetermined position. a magnetic head transporting means connected via a contact pressure applying means and configured to transport the magnetic head in a predetermined direction; At a position that is ahead of the position of the magnetic head in the direction of movement, the erasing permanent magnet piece fixed to one end of the support member of the erasing head is applied to the rotating magnetic recording medium with a predetermined low contact pressure. For sliding contact,
The other end of the supporting member of the erasing head is connected to the transporting means of the magnetic head through a contact pressure applying means, and an electromagnetic force can be generated between the supporting member and the permanent magnet piece for erasing. An erasing head displacement driving means is provided near the erasing permanent magnet piece, and in the recording mode, the erasing permanent magnet piece is moved to a predetermined low position on the rotating magnetic recording medium by the erasing head displacement driving means. The present invention provides a advance erasing device for a rotating magnetic recording medium, which is equipped with means for controlling sliding contact by contact pressure.

(Example) Hereinafter, specific contents of the advance erasing device for a rotating magnetic recording medium of the present invention will be explained in detail with reference to the accompanying drawings.

1 and 2 are perspective views showing the schematic configurations of different embodiments of the advance erasing device for a rotating magnetic recording medium of the present invention, and FIG. 3 is an explanation of the operation of the erasing head displacement driving means. Cross-sectional view for.

FIG. 4 is a sectional view of an example configuration of the erasing head.

FIG. 1 shows an embodiment in which a cylindrical magnetic recording medium is used as the rotating magnetic recording medium.

Further, FIG. 2 shows an embodiment in which a flat magnetic recording medium is used as the rotating magnetic recording medium.

In FIG. 1, reference numeral 1 denotes a substrate of a mechanism section in a magnetic recording/reproducing device, and 2 denotes a motor housing that houses and fixes a motor 3 for driving a rotating magnetic recording medium. It is fixed to the substrate 1 described above by .

The above-mentioned rotating magnetic recording medium can be rotated integrally with the rotating shaft 5 by the clamper 6 after being engaged with an engaging portion (not shown) fixed to the rotating shaft 5 of the drive motor 3. It is fixed like this.

7 is a motor for driving the magnetic head transfer mechanism.

The driving motor 7 of this transfer mechanism is fixed to the substrate 1 described above.

8 is a speed reducer that reduces the rotational force of the drive motor 7 of the transfer mechanism, and 9 is a feed screw connected to the output shaft of the speed reducer 8.

This feed screw 9 is threaded into a screw hole 11 provided in a transport body (carriage) 10, and a guide rod 13 is loosely fitted into a hole 12 bored in the transport body 10. ing. Therefore, when the drive motor 7 of the transfer mechanism rotates, the above-mentioned transfer body 10 moves as shown by the arrow W in FIG.
is transported in the direction of

The transport body 10 includes an actuator ACT used for displacing and driving the recording/reproducing magnetic head Hrp in a predetermined direction in accordance with a control signal, and an erasing head He composed of a strong permanent magnet piece. A displacement drive mechanism DDM is fixedly attached thereto for bringing the device into contact with the rotating magnetic recording medium or separating it from the rotating magnetic recording medium.

Although the configuration of the actuator ACT is not shown in FIG. 1, the actuator ACT may have the same configuration as the actuator ACT shown in FIG. 2, for example. The actuator ACT shown in FIG. The actuator ACT is configured to drive and displace the recording/reproducing magnetic head Hrp in two directions, one perpendicular to the other.

In this actuator ACT, A is the overall symbol of the movable part of the actuator, B is the overall symbol of the DC magnetic field generating part of the actuator, and the movable part A is the entire symbol of the movable part of the actuator.
4.15... are fixed to the center vertical portion of the support plate 16 via a connecting member 17 made of an elastic body (for example, rubber).

For example, it is connected and fixed to a central vertical portion of a support member 18 made of an elastic plate such as a phosphor bronze plate.

A rotation fulcrum is set by a rotation fulcrum member 19 (a plurality of rotation fulcrum members 19 are provided at intervals in one vertical direction).

Both ends of the support member 18 described above are sandwiched between rubber-like supports 20a and 20b, and the support member 18 can be easily bent in the front-rear direction, but does not deform in other directions. ,therefore.

Displacement of the movable part A in the front-rear direction is easily performed by the support member 18, and the rotational movement of the movable part A is easily performed because the straight line position connecting the apexes of the rotation fulcrum member 19 serves as the rotation axis. movement in other directions is suppressed at 18a in Figure 0.

18b is a through hole in the support member.

The thickness of the connecting member 17 in the front-rear direction is slightly smaller than the length of the one-turn fulcrum member 19 in the front-rear direction, so that the support plate 16 and the support member 18 of the movable part A are
After connecting and fixing them by the connecting member 17, the rotation fulcrum member 19 is inserted into the gap between the support plate 16 and the support member 18.
If you insert .

The connecting member 17 is in an extended state, and its contractile force presses the support plate 16 well to the apex portion of the rotation fulcrum member 19.

25 is a connecting rod 26 fixed to the support member 16 described above;
This is a mounting member fixed to the tip of the mounting member 27, and two pivots 28 and 29 are implanted in the mounting member 25, and a permanent magnet 31 is fixed to the mounting member 25.

The recording/reproducing magnetic head Hrp is a recording/reproducing head support member (
Cantilever) 30 is fixed to the tip.

The support member 30 for the recording/reproducing head described above is provided with holes 33 and 34 for receiving pivots corresponding to the two pivots 28 and 29 in the mounting member 25, respectively, at its rear end. The mounting member 25 described above
A biasing force is generated to mechanically connect the magnetic head support member 30 to the magnetic head support member 30, and a contact pressure is generated to bring the recording/reproducing magnetic head Hrp into contact with the rotating magnetic recording medium at a predetermined contact pressure. A permanent magnet 32 is fixedly attached thereto.

That is, the permanent magnet 32 is used to mechanically connect the mounting member 25 and the support member 30 of the recording/reproducing head by the magnetic force acting between the permanent magnet 31 provided on the mounting member 25. It is used to generate biasing force and contact pressure for bringing the recording/reproducing magnetic head Hrp into contact with the rotating magnetic recording medium with a predetermined contact pressure. The support member 30 for the recording/reproducing head described above may be made by bending a thin metal plate, for example.

The mounting member 25 and the recording/playback head support member 30 are arranged so that the two conical pivots 28 and 29 of the mounting member 25 are bored at the rear end of the recording/playback head support member 30. Through hole 33, 3 for receiving the pivot
4 by inserting it into the conical pivot 28.
The vicinity of the tip at 29 is the support member 30 of the recording/reproducing head.
The mounting member 25 and the support member 30 of the recording/playback head are connected in a state in which the mounting member 25 is engaged with the edges of the pivot receiving through holes 33 and 34 formed in the A permanent magnet 32 provided on the support member 30 of the recording/reproducing head, and a permanent magnet 31 provided on the mounting member 25.
The mounting member 25 and the recording/reproducing head support member 30 are magnetically attracted to each other through a gap.
This means that the end portion of the support member 30 of the recording/playback head is rotated and mechanically suspended around the engagement portion between the pivot 28, 29 and the pivot receiving through hole 33, 34 as the center of rotation. It is integrally connected to the

The support member 30 of the recording/playback head in a state in which the support member 30 of the recording/playback head and the mounting member 25 are integrated is connected to the magnetism acting between the permanent magnet 31 and the permanent magnet 32 described above. By pulling it forward against a strong suction force, the recording/reproducing head support member 30 and the mounting member 25 can be easily separated.

By the way, the DC magnetic field generating section B in the actuator ACT described above is composed of an outer magnetic path 21, a pole piece 22, permanent magnets 23 and 24, and the like.

The pole piece 22 has two tips 22a and 22b.
The coil 14 of the above-mentioned movable part A is loosely fitted into the pole piece 22a so that one side thereof is present in the magnetic gap formed between the permanent magnet 23 and the pole piece 22a, Also.

The coil 15 of the movable part A described above is loosely fitted into the pole piece 22b so that one side thereof exists in the magnetic gap formed between the permanent magnet 24 and the pole piece 22b.

Permanent magnets 23,24 create a magnetic field in the magnetic air gap between each and the opposing pole piece 22a, 22b, and also the pole piece 22a.

22b constitutes a direct current magnetic field generating section B that does not generate a magnetic field, and is magnetized so as to hang.

The coils 14 and 15 of the movable part A in the actuator ACT having the above-mentioned configuration are moved around the coil axis by the electromagnetic force generated between the current supplied to them and the magnetic field of the magnetic gap in the DC magnetic field generating part B. The coils 14 and 15 are both driven in the same direction (X direction) and displaced with the same driving force.
When current is supplied to each of the coils 14 and 15, the movable part A moves the recording/reproducing magnetic head Hrp attached to the recording/reproducing head support member 30 to the recording trace on the rotating magnetic recording medium. in the extension direction (X direction), that is, 1
When a current is supplied to each coil 14.15 so that the coil 14.15 is displaced in the direction of correcting the time axis error, and the coils 14.15 described above are driven in the same direction and in opposite directions with the same driving force. In this case, the movable part A rotates about the Z axis as a rotation axis, and rotates the recording/reproducing magnetic head Hrp attached to the recording/reproducing head support member 30 once in the direction of extension of the recording trace on the magnetic recording medium. (Y direction), that is, in the tracking error correction direction.

In Fig. 1, a displacement drive mechanism is used to bring the erasing head He, which is composed of a strong permanent magnet piece, into contact with the rotating magnetic recording medium or to separate it from the rotating magnetic recording medium. The DDM includes a yoke 35 fixed to the transfer body 10, a center pole 36,
An excitation winding 37 wound around the center pole 36, a suspension 38 made of an elastic material whose one end is fixed to the yoke 35, and a ferromagnetic material fixed to the suspension 38. Movable piece 39 made of
A damper 40 made of an elastic material is fixed to the movable piece 39.

The other end of an erasing head support member 41 having an erasing head He fixed to one end is inserted into the damper 40 . The damper 40 described above is a displacement drive for bringing the erasing head He, which is composed of a strong permanent magnet piece, into contact with the rotating magnetic recording medium or separating it from the rotating magnetic recording medium. Machine 41DDM
When the erasing head He is brought into sliding contact with the rotating magnetic recording medium by the operation of The erasing head He has the function of applying

The above-described displacement drive mechanism DDM of the erase head He is driven by the elasticity of the suspension 38 made of an elastic material whose one end is fixed to the yoke 35 when no current is supplied to the excitation winding 37 thereof. A movable piece 39 made of a ferromagnetic material fixed to the suspension tube 38 is separated from the center ball 36, thereby maintaining the erasing head He separated from the rotating magnetic recording medium. This state is shown in FIG. 3(a).

Next, a current is supplied to the excitation winding 37 in the displacement drive mechanism DDM of the erase head He.

A movable piece 39 made of a ferromagnetic material is magnetically attracted to the center ball 36 against the elasticity of a suspension 38 made of an elastic material whose one end is fixed to the yoke 35, and the erasing head He performs rotational magnetic recording. It is brought into sliding contact with the media. FIG. 3(b) shows such a state.

E in FIG. 3(b) is a power supply, and SW is a switch, which is turned on when the recording/reproducing apparatus is put into the recording mode, and is turned on to connect the above-mentioned erasing head He. A current is supplied to the excitation winding 37 in the displacement drive mechanism DDM.

The above-mentioned erasing head Ha is composed of a strong permanent magnet, but it is designed to prevent damage to the recording layer of the rotating magnetic recording medium when it comes into sliding contact with the rotating magnetic recording medium. For example, as shown in FIG. 4, it is a preferred embodiment to coat its tip with a thin film 5471 of a material with good lubricity, such as a thin film 47 of Teflon. In addition, as a strong permanent magnet piece used as an erasing head, it is magnetized with a magnetization pattern in which N poles and S poles are sequentially arranged alternately in the direction of movement relative to the magnetic recording medium. If a permanent magnetic erase head is used, erasing similar to alternating current erasing can be performed.

Next, in the embodiment shown in FIG. 2, a flat rotating magnetic recording medium is used as the one-rotation magnetic recording medium, and the configuration of the erasing head displacement drive mechanism DDM is different from that described above. This embodiment differs only from the embodiment shown in FIG. Note that, in the embodiment shown in the second Wi, detailed illustration of the magnetic head transport mechanism is omitted.

In the embodiment shown in the second figure, the erasing head Ha is fixed to one end of the erasing head support member 41, and the other end of the erasing head support member 41 is connected to the fixed part 43 by a damper 42. has been done. The damper 42 described above supports the erasing head H"Q and supports the erasing head support member 41.
is biased in a direction to separate it from the rotating magnetic recording medium.

An electromagnet made of a magnetic core 44 made of a soft magnetic material and a winding 45 wound around a magnetic core 44 is installed above the erasing head He made of a strong permanent magnet. When the winding 45 of the electromagnet is not excited, the permanent magnet constituting the erasing magnet is attracted to the magnetic core 44 of the electromagnet installed above it. When the switch SW is turned on and current is supplied from the power supply E to the winding 45 of the electromagnet, a magnetic repulsion is generated between the electromagnet and the permanent magnet that constitutes the erasing head, causing erasure. The head He is brought into contact with the rotating magnetic recording medium at a predetermined low contact pressure.

(Effects) As is clear from the above detailed explanation, the advance erasing device for the rotating magnetic recording medium of the present invention has a magnetic head attached to one end of the rotating magnetic recording medium for recording and reproducing information signals in sliding contact with the rotating magnetic recording medium. The other end of the supporting member of the magnetic head is connected via a predetermined contact pressure applying means, and the magnetic head is configured to be able to move the magnetic head in a predetermined direction. and an erasing permanent fixed to one end of the support member of the erasing head at a position preceding the position of the magnetic head transported by the magnetic head transport means in the direction of movement of the magnetic head. connecting the other end of the supporting member of the erasing head to the magnetic head transporting means via a contact pressure applying means so that the magnet piece can slide into contact with the rotating magnetic recording medium with a predetermined low contact pressure; Further, an erasing head displacement driving means capable of generating an electromagnetic force between the erasing permanent magnet piece is provided near the erasing permanent magnet piece, and the erasing head is moved in the recording mode. This advance erasing device for a rotating magnetic recording medium is equipped with means for controlling the above-mentioned erasing permanent magnet piece to come into sliding contact with the rotating magnetic recording medium with a predetermined low contact pressure by means of a displacement drive means. In the present invention, the strong magnetic field required to erase the information signal recorded on the magnetic layer is generated by an erasing head using a strong permanent magnet piece, so it has a high coercive force. The recorded contents magnetically recorded on the recording layer made of magnetic material can be erased well, and the recording/reproducing magnetic head and the erasing head can each contact the rotating recording medium with low contact pressure. The erase head is enabled only when the magnetic recording/reproducing device is put into recording mode.

Since the permanent magnet piece for erasing is automatically brought into sliding contact with the rotating magnetic recording medium at a predetermined low contact pressure by the displacement drive mechanism of the erasing head, there is no need for adjustment. For example, all of the problems with the conventional musical score mentioned above are solved satisfactorily.

[Brief explanation of drawings]

1 and 2 are perspective views showing the schematic configurations of different embodiments of the advance erasing device for a rotating magnetic recording medium of the present invention, and FIG. 3 is a sectional view for explaining the operation of the displacement driving means of the erasing head. , Figure 4 is erased. FIG. 3 is a cross-sectional view of an example configuration of a removal head. 1... A substrate of a mechanism section in a magnetic north recording/reproducing device. 2...Motor housing housing and fixing the motor 3 for driving the rotating magnetic recording medium, 4...Screw, D...
Rotating magnetic recording medium, 3... drive motor. 5... Rotating shaft, 6... Clamper, 7... Drive motor for the magnetic head transfer mechanism, 8... Drive motor for the transfer mechanism, 9... Connected to the output shaft of the deceleration et8. feeding screw, 10... transport body (carriage), 11...
・Screw hole, 12...hole, 13...guide rod, He・
・Erasing head consisting of a strong permanent magnet piece, H
rp...Magnetic head for recording/reproduction, ACT...Actuator, DMM...Erasing head He is brought into contact with the rotating magnetic recording medium or separated from the rotating magnetic recording medium. Displacement drive mechanism for
...Overall code of the DC magnetic field generating part of the actuator, 1
4.15...Coil, 16...Support plate, 17...
Connection member, 18...Support member, 19...Rotation fulcrum member, 20a, 20b--Support body, 18g, 1
8b...Through hole of support member, 25...Mounting member, 26
, 27... Connecting rod, 28.29... Pivot, 23
, 24° 31.32... Permanent magnet, 30... Recording/reproduction head support member (cantilever), 33.34...
Pivot receiver, river hole, 21...outer magnetic path, 22...pole piece, 35...yoke, 36...center ball, 37...excitation winding wound around center ball 36 line. 38...An elasticity whose one end is fixed to the yoke 35. Suspension made of material j), 39... Movable piece made of ferromagnetic material fixed to suspension 38, 40.
... Damper made of elastic material, 41 ... Erasing head support member, 45 ... Winding wire, 47 ... Thin film of material with good lubricity,

Claims (1)

[Claims] A magnetic head for recording and reproducing information signals by slidingly contacting a rotating magnetic recording medium is attached to one end of the magnetic head, and the other end of the support member of the magnetic head is connected via a predetermined contact pressure applying means, and , a magnetic head transporting means configured to be able to transport the magnetic head in a predetermined direction; and a magnetic head transporting means configured to transport the magnetic head in a predetermined direction; The supporting member of the erasing head is adjusted so that the erasing permanent magnet piece fixed to one end of the supporting member of the erasing head can slide into contact with the rotating magnetic recording medium with a predetermined low contact pressure. An erasing head displacement driving means whose other end is connected to the above-described magnetic head transfer means via a contact pressure applying means, and which can generate electromagnetic force between it and the above-mentioned erasing permanent magnet piece. is provided in the vicinity of the permanent magnet piece for erasing, so that the permanent magnet piece for erasing is brought into sliding contact with the rotating magnetic recording medium with a predetermined low contact pressure by the displacement driving means of the erasing head during the recording mode. A pre-erasing device for a rotating magnetic recording medium, comprising means for controlling the