JPS5847576Y2 - Information signal reproducing element - Google Patents

Description

[Detailed description of the invention] In recent years, high-density recording and reproduction of various information signals has been developed using information recording media disks (hereinafter sometimes abbreviated as disks).
It is well known that research and development efforts have been actively conducted to improve the performance of information signals using discs, and many proposals have been made for high-density recording and reproduction of information signals using discs. Since then, we have been conducting research on high-density recording and reproducing methods for information signals using various types of disks.

As a result of considering the results of previous research, the applicant company has determined that the disc must be of a grooveless format so that the playback mode can be changed mutually during playback, and that the information signal from the disc must be of a grooveless type. detection)
Taking into account the fact that the capacitance change detection method is the best method and other conditions, we have developed a method for high-density recording and reproduction of information signals using non-groove disks (hereinafter referred to as non-groove disks). Promote development research and first,
Japanese Patent Application No. 51-38809
The original form was proposed in 1983 (IJGF 1983), and the subsequent practical research led to the publication of patent application No. 13322-1983 (IJGF
-98814) and many other proposals.

As clarified in the above-mentioned information signal recording, reproduction method, etc. proposed by the applicant company, the applicant company creates pits corresponding to main information signals in a spiral or concentric pattern on a flat surface. By arranging them, spiral or concentric recording traces (tracks) are spaced apart by a predetermined interval (track pitch) on a flat surface and correspond to the above-mentioned main information signals. Between adjacent tracks formed by the pit arrangement (hereinafter sometimes referred to as main information signal tracks), pits corresponding to tracking control signals are arranged continuously or intermittently. A spiral or concentric solid track (hereinafter sometimes abbreviated as a tracking control signal track) is formed by an arrangement of pits corresponding to this tracking control signal, and
A recording pattern is shown in which pits corresponding to the above-mentioned main information signals and pits corresponding to tracking control signals are arranged to overlap each other to some extent in the width direction of the pits, and , two signals having different frequency values are used as tracking control signals, and the two signals are alternately switched at a specific position (rotational phase) of the disk every rotation of the disk,
One of the two signals constitutes a grooveless disc in which a track is continuously or intermittently formed by an arrangement of pits corresponding to the tracking control signal, and the main information from the disc is The reproduction of the signal is
An electrode having an electrode width (during reproduction) that is approximately the same as the pit width of the pit corresponding to the main information signal in the disk (same as the track width of the track formed by the pit corresponding to the main information signal), and For example, Japanese Patent Application No. 51-13 discloses a device that can contact the surface of the disk with a contact width wider than the track pitch in the width direction of the track.
No. 7216 (% Kai No. 53-62501), patent application 1972
22764 (Japanese Unexamined Patent Publication No. 53-1084.13) etc., a plurality of information signals recorded on a disk using a reproducing needle (scanning needle) configured as shown in the above-mentioned electrode and disk Tracking control is performed by detecting changes in capacitance values between each information signal and the corresponding pit formed on the track, and during the above-mentioned reproduction, tracking control is performed on both sides of the main information signal track. We have proposed a method in which the signal obtained from the main information signal track is used as the tracking control signal, and the center of the electrode in the reproduction needle is always aligned with the center of the main information signal track by the operation of the tracking servo system.

When reproducing information signals from the above-mentioned grooveless disc, tracking is controlled by the operation of a tracking servo system so that the reproduction needle always accurately tracks the recording trace to be reproduced. Needless to say, the reproduction needle is driven and displaced by a tracking control 7 drive device in the tracking servo system.

In addition, disks are designed to be rotated accurately at a predetermined number of rotations when reproducing information signals, but disks are inevitably subject to mechanical deformation (distortion) due to various other causes during manufacturing. ), even if it is rotated at a constant number of revolutions during playback, the existence of the mechanical deformation described above causes a change in the relative speed between the recording trace and the playback needle, which causes The so-called time axis error (jitter) is rarely found in the reproduced signal.

For this reason, conventionally, a time axis error correction signal obtained by comparing a reference signal in the reproduction signal with a standard signal is applied to the drive device of the time axis error correction control circuit of the reproduction needle, thereby causing the reproduction needle to move. The driving displacement is performed in the direction in which the recording trace extends, so that no time axis error occurs in the reproduced signal.

Therefore, when reproducing information signals from a grooveless disc, there are two functions: time axis error correction control and tracking control.
It is necessary to drive and displace the reproducing needle two-dimensionally in both the extending direction of the recorded trace and the direction perpendicular thereto by two controls.

Therefore, the applicant company has conducted various researches to provide a playback needle 1 drive device that can drive and displace the playback needle two-dimensionally during playback of grooveless discs. The playback needle that reads information signals from the recording trace on the medium disk is driven and displaced in the direction of extension of the recording trace in accordance with the correction signal for the time axis error, and also in the direction of extension of the recording trace in accordance with the correction signal for tracking control. In a reproducing needle driving device for an information signal reproducing element, which is configured to drive and displace the information signal reproducing element in a direction orthogonal to the reproducing needle, at least three members are connected and fixed to a movable member supported so as to be freely displaceable integrally with the reproducing needle. or more coils, and at least three coils as described above are provided.
The coils are divided into a first coil group consisting of two specific coils and a second coil group consisting of the remaining coils, and the coils of the first coil group and the The coils of the second coil set are caused by the electromagnetic force generated between the current and the magnetic field generated by the DC magnetic field forming member when a current is applied to them, causing one coil set to move in the axial direction of the coil. 1 driven, and the other coil set includes the coil axis of each coil constituting the other coil set and is configured to rotate around an axis perpendicular to a plane parallel to the magnetic field. He completed a regenerated needle drive device, which was published in Japanese Patent Application No. 52-41151 (Japanese Unexamined Patent Publication No. 53-12).
A patent application was filed as No. 5817).

The present invention provides an information signal reproducing element equipped with a reproducing needle driving device capable of moving the reproducing needle two-dimensionally in one drive, such as the previously proposed reproducing needle driving device described above.
The pickup arm to which the regenerating needle is attached to the regenerating needle drive device can be easily attached and detached at its base end, and the regenerating needle and drive The distal end side of the device and the proximal end side of the pickup arm are well connected by an integral coupling mode, and the distal end side of the pickup arm can freely move in a direction perpendicular to the surface of the disk. The purpose of this invention is to provide an information signal reproducing element configured with such a coupling portion, and the specific contents thereof will be explained below with reference to the accompanying drawings.

FIG. 1 is an enlarged exploded perspective view of the main parts of the information signal reproducing element of the present invention, and for reference, part of the disk D and turntable TT are also shown. There is.

In FIG. 1, K is the overall code of the regeneration needle drive device, and the regeneration needle and drive device shown in FIG. Accordingly, the playback needle 15 attached to the pickup arm A is configured to be driven and displaced two-dimensionally in the extending direction of the recording trace of the disc D and in the direction perpendicular to the recording trace. There are
This regenerated needle drive device operates according to the drive principle described in the specification of Japanese Patent Application No. 52-41151 (Japanese Unexamined Patent Publication No. 53-125817), for which the applicant company previously filed a patent application. Such a configuration may also be used.

In FIG. 1, the regenerating needle and drive device are shown partially broken to make their structure clear; magnetic path bottom plate, 2a.

2b is a permanent magnet, 3 is a magnetic path front plate, and the magnetic path bottom plate 1, pole piece 1a, permanent magnets 2a, 2b, magnetic path front plate 3, etc. are bored in the magnetic path front plate 3. It operates as a DC magnetic field forming member to generate a predetermined DC magnetic field in the magnetic gap 3a formed between the hole and the outer periphery of the pole piece 1a.

For example, a 31mm coil is fixed to a mounting body 4 made of a non-magnetic material such as aluminum, which is attached to a plate spring 5 whose cross section in the plate thickness direction has a frame structure (rigid frame structure) with screws 6.7. However, among the above-mentioned 31-piece coils, the 21-piece coil is semi-cylindrical, and a part of each of these 21-piece coils is inside the magnetic gap 3a, and the rest is inside the pole. The other coil has a cylindrical shape and is arranged to exist in the magnetic gap 3a, and a current is passed through each of these coils. In this case, the electromagnetic force generated between the current in each coil and the DC magnetic field causes the mounting body 4 fixed to each coil to move integrally with each coil in the direction of the coil axis (arrow in Figure 1). A linear motion in the U direction) and a rotational motion (in the direction of the arrow R in FIG. 1) around an axis (direction ■ in FIG. 1) that includes the coil axis and is perpendicular to the plane parallel to the magnetic field. can be done.

That is, since the plate spring 5 to which the mounting body 4 is fixed is fixed on both sides to the side surface of the magnetic path front plate 3 by the screws 8, 8, the mounting body 4 driven by the coil is This allows smooth translation in the direction of the coil axis and rotation using the line connecting the screws 6.7 as the rotation axis.

Reference numeral 9 denotes a thin bar-shaped permanent magnet provided at the center of the end of the mounting body 4, and the permanent magnet 9 is arranged so that its longitudinal direction is perpendicular to the line connecting the screws 6.7. It is fixed to the end of the mounting body 4.

Reference numeral 10 denotes a plane bearing member provided on the front side of the permanent magnet 9, and this plane bearing member 10 is made of a hard non-magnetic material, and its surface is finished as a smooth surface. The plane bearing member 10 may be made of a thin plate of sapphire, for example.

Figures 2 to 7 are enlarged plan views of a part of the vicinity of the end of the mounting body 4 (Figure a in each figure) and
- a longitudinal side view at the X-ray position (view b of each figure);
Each of these figures shows rod-shaped permanent magnets 9, 9a provided near the end of the mounting body 4.

9b, the planar bearing member 10, etc., and the manner in which they are arranged and attached.

In Figures 2 to 7, L represents the length in the longitudinal direction of the part where the permanent magnet is present, and this length L is approximately the length of the coupling part of the ferromagnetic material provided in the pickup arm A, which will be described later. They are all treated equally.

'In the examples shown in FIGS. 2 to 7, a single thin rod-shaped permanent magnet 9 with a length L is used as the permanent magnet, and in the examples shown in FIGS. 2 to 7, A plurality of thin rod-shaped magnets 9a, 9 (two in the illustrated example, but may be three or more) are placed in the part where the permanent magnet is present.
b shows the case where the permanent magnets are provided near the end of the mounting body 4 in such a manner that the distance between the outer ends of the permanent magnets at both ends is L.

In the example shown in FIGS. 2 and 5, the permanent magnets 9, 9a9b are fixed on the surface of the mounting body 4, and the planar bearing member 10
is fixed to the mounting body 4 via a spacer 11.11 so that it is located in front of the permanent magnets 9.9a, 9b, and in the example shown in FIGS. 3 and 6, the surface of the mounting body 4 is grooves corresponding to the permanent magnets 9.9a, 9b are provided in the grooves, the permanent magnets 9.9a, 9b are fitted into the grooves, and the plane bearing member 10 is fixed to the surface of the mounting body 4. In the examples shown in FIGS. 4 and 7, permanent magnets 9.9a and 9b are inserted into holes 4a formed in the mounting body 4, and the planar bearing member 10 is fixed to the surface of the mounting body 4. ing.

Figures 8a and 8b illustrate the manner of magnetization in the permanent magnets 9.9a, 9b, etc. At the base end of the pickup arm A, there is a mounting body 4 in the above-mentioned regeneration needle drive device K. A coupling portion 12 made of a ferromagnetic material is provided which is magnetically attracted by the permanent magnets 9, 9a, 9b4 provided at the ends of the ferromagnetic material.

A hard ferromagnetic material is used for this coupling portion 12, and for example, so-called gauge steel may be used.

The coupling portion 12 made of a ferromagnetic material provided at the base end of the pickup arm A has a length approximately equal to the length L of the portion where the permanent magnet is provided on the mounting body 4 of the regeneration needle drive device K. It has a tip 12a having a length L.

Therefore, when the distal end portion 12a of the coupling portion 12 provided at the base end of the pickup arm A comes into contact with the flat bearing portion 10 at the end of the attachment portion 4 in the regeneration needle drive device K, the coupling portion 12 is attracted by the magnetic attraction force of the permanent magnets 9, 9a, 9b so that its tip gA12a is in a position exactly opposite to the position of the permanent magnets 9, 9a, 9b provided in the mounting portion 4.

9A to 9C are diagrams for illustrating and explaining that the above-described joint portion 12 can have various cross-sectional shapes as the tip 12a thereof, and FIG. 9A shows the tip 12a. 9C is a planar shape, FIG. 9C shows a case where the tip 12a has a convex curved shape, and FIG.
The case where 2a is formed into a so-called knife shape is shown.

10A and 10B are diagrams for illustrating and explaining that the joint portion 12 can have various planar shapes as the tip portion 12a thereof, and FIG. 10 shows a case where a portion 12a2 of the distal end portion 12a excluding the vicinity of both ends 12a1 is set back from the vicinity of both ends.

The above-described regeneration needle drive device and pickup arm A include permanent magnets 9.9a and 9b provided at the ends of the mounting body 4 in the regeneration needle 1 drive device K, and permanent magnets 9.9a and 9b provided at the base end of the pickup arm A. Coupling part 12 made of hard ferromagnetic material
By attracting each other by magnetic attraction,
The tip portion 12a of the coupling portion 12 is a permanent magnet 9.9a,
When the surface provided on the front surface of 9b is crimped to the surface of the plane bearing member 10 made of a hard non-magnetic material with a smooth surface, the tip end 12a of the joint portion 12 has both end portions attached to the permanent magnet 9.9a, The end portion 12a of the coupling portion 12 automatically slides on the surface of the flat bearing member 10 made of a hard non-magnetic material such as sapphire so as to coincide with both end portions of the existing portion of the permanent magnet 9b. Therefore, an accurate bonding relationship can be established in which the two correctly correspond to each other in the length direction.

When the regenerating needle 7 drive device operates, its support 4 is in the first position.
When performing two translational movements in the directions of arrows U and R in the figure, the pick-up arm A is integrated with the support body 4 and moves linearly in the directions of arrows U and H in Fig. 1.

In order to be able to rotate, the magnetic attractive force between the permanent magnets 9, 9a, 9b and the coupling portion 12 is stronger than the magnetic attraction force that acts on the pickup arm A when the pickup arm A makes two rotations in the linear motion. It is necessary to generate such a magnetic attraction force between the permanent magnet of the support body 4 in the reproduction needle drive device K and the coupling part 12 in the pickup arm A, although it is required to be sufficiently larger than the generated inertial force. This can be realized very easily, and at this time, the pickup arm A can freely rotate in the vertical direction using the joint point as a fulcrum.

Therefore, in the information signal reproducing element of the present invention, in order to displace the reproducing needle in two directions, that is, in the direction of extension of the recorded trace on the disk D and in the direction perpendicular thereto, the pickup arm A is moved by the reproducing needle driving device K. 2
The drive in the direction is performed with the support 4 and the pickup arm A in the regeneration needle drive device K being integrated, and the pickup arm A rotates in the vertical direction with extremely small rotational resistance. Therefore, desired sick control and tracking control can be carried out using the playback needle, and the playback needle can also operate while well following the surface runout of the disk.

In addition, in the information signal reproducing element of the present invention, the reproducing needle 1
Since the drive device and the pickup arm A are connected to each other by mutually attaching members made of a hard material with extremely small elastic deformation, the regeneration needle drive device K to the pickup arm A is The driving force transmission is
Sufficiently high frequency (about 10KHz or higher)
This can be done without any loss.

In FIG. 1, the pickup arm A includes a regenerating needle attachment rod 14 to which a regenerating needle 15 is fixed at the distal end, an arm body 13 connected and fixed to the regenerating needle attaching rod 14, and an arm body 13 attached to the proximal end. However, in implementing the present invention, the coupling portion 12 as described above is not provided at the base end of the pickup arm A. The configuration of the other parts may be arbitrary.

In the pickup arm A shown in the first diagram, the regeneration needle attachment rod 14 is, for example, a glass rod (glass fiber rod).
In addition, if the arm body is made of, for example, a thin aluminum plate, and the shape becomes gradually wider toward the base end, and both ends are bent, the frequency band required for operation can be achieved. Therefore, it is possible to easily provide a pickup arm A that does not cause unnecessary resonance or the like.

In addition, in FIG. 1, 13a is a hole bored in the arm body 13, and a stud 2 described later is inserted into this hole 13a.
8 (FIG. 11) is penetrated.

Further, 16 is a frame-shaped damper for making the playback needle 15 come into contact with the surface of the disc D with the required stylus pressure.
It may for example be made of a material such as rubber.

Further, 17 is a lead wire for connecting the electrode of the regeneration needle 15 and the center conductor of the semi-coaxial resonator, and the construction and operation of this part will be described later with reference to FIG.

FIG. 11 is a longitudinal sectional side view of a part of the reproducing apparatus showing a state in which an information signal is being reproduced from a disc D using the information signal reproducing element of the present invention described above. , 18 is a transfer body, which is transferred in the radial direction of the disk at a predetermined transfer speed by a transfer mechanism (not shown) during a reproduction operation.

Reference numeral 19 denotes a cover that can be expanded upward in the direction of arrow E around the shaft 20, and when the cover 19 is closed as shown in FIG.
is fixed to.

22 is a semi-coaxial resonator that constitutes a part of a device for converting the change in capacitance detected by the electrode of the regeneration needle 15 into an electrical signal, and 23 is the center of the semi-coaxial resonator. It is a conductor.

The above-mentioned cover 19 is provided with a guide member 25 which is rotatably supported by a shaft 24 so as to be able to rotate vertically within a small range. The other end of the spring 26, one end of which is attached to the cover 19, presses the upper surface of the spring 26, thereby biasing the lead wire 17 counterclockwise around the shaft 24, causing the leader wire 17 to resonate semi-coaxially. It is designed to be well connected to the tip of the center conductor 23 of the vessel 22.

Below the rear end of the guide member 25, the regenerating needle and the drive device K described above are fixed, and a pick-up The holding board 27 of arm A is fitted.

The pickup arm A is connected and supported by a frame-shaped damper 16 to the above-mentioned holding substrate 27 made of a material such as plastic, and is connected to the hole 1 of the arm body 13.
The position of the stud 28 is regulated by loosely penetrating the small diameter portion of the stud 28 protruding from the holding board 27 at 3a.

The state shown in FIG. 11 is a case where the pickup arm A and the playback needle drive device are coupled and fixed, and the playback needle 15 protrudes outward from the hole 18a of the transfer body 18 and slides on the surface of the disk D. being touched.

The operation of attaching and detaching the pickup arm A to the regenerating needle drive device K is performed as follows.

First, as shown in Figure 11, when removing the pickup arm A from the state where it is fixed to the regeneration needle drive device K, the screw 21 is removed and the cover 19 is rotated upward. Afterwards, while sliding the holding board 27 into the guide groove 25a of the guide member 25, it is pulled out from the front side.

As a result, the pickup arm A and the holding board 27 are removed from the transfer body 18.

At this time, the pickup arm A is prevented from falling downward due to the support by the frame damper 16 and the presence of the restraining plate 29 attached to the narrow diameter part of the stud 28 penetrating into the hole 13a of the arm body 13. Needless to say, it will be done.

Next, when attaching the pickup arm A to the transfer body 18, the both side edges of the holding board 27 to which the pickup arm A is attached are connected to the guide grooves in the guide member 25.
5a, and push the holding board 27 into the connecting part 1 attached to the base end of the pickup arm A.
When the distal end 12a of the joint 12 approaches the support 4 in the regenerating needle drive device K, the distal end 12a of the joint 12 is attracted by the magnetic attraction force of the permanent magnets 9, 9a, 9b provided on the fourth support. Thus, the tip end 12a of the coupling portion 12 and the plane bearing member 10 are reliably coupled at a predetermined position on the surface of the plane bearing member 10.

As is clear from the detailed explanation above, the information signal reproducing element of the present invention includes a pickup arm A to which a reproducing needle is attached, and a device for driving the reproducing needle in two directions for jitter correction and tracking correction. A so-called knife-shaped coupling portion 12 provided on the side of the pink-up arm A is magnetically attached to a predetermined position on the plane bearing member 10 provided on the side of the regeneration needle drive device. Since the pickup arm A is firmly connected by suction force, the pickup arm A can always be connected to the regeneration needle drive device K in the correct connection state, and the attachment and detachment of the pickup arm A is extremely easy. There is also a regeneration needle drive device and a pickup arm A.
There is no intervening member such as rubber in the connecting part, and the connecting part is made of hard materials, so the driving force from the regenerating needle drive device K to the pickup arm A is reduced. The information signal reproducing element of the present invention further includes a reproducing needle provided to drive the reproducing needle once in two directions for jitter correction and tracking correction; The driving in the two directions described above in the drive device K is performed integrally with the pickup arm A via the above-mentioned connecting portion, and the pickup arm A is freely pivotable in the vertical direction at the connecting portion. Therefore, it is possible to perform desired jitter control and tracking control using the playback needle, and the playback needle can also be made to follow the surface movement of the disk well.

[Brief explanation of the drawing]

Figure 1 is an exploded perspective view of the main parts of the information signal reproducing element of the present invention, Figures 2A to 7A are plan views of the vicinity of the plane bearing member (Figure A in each figure) and vertical cross-sectional views. (Fig. b of each figure), Fig. 8 a and b are perspective views of the permanent magnet, Fig. 9 a' = C are cross-sectional views of the tip of the joint, and Fig. 10 a and b are plane views of the same. FIG. 11 is a longitudinal sectional side view of a part of the reproducing apparatus. K...Regeneration needle drive device, A...Pickup arm, D...Disk, TT...Turn tip full, 4.
...Support body, 9t9a, 9b...Permanent magnet, 10...Plane bearing member, 12...Connection part, 13.
...Arm body, 15...Recycled needle, 16...Frame type damper, 17...Leader line, 19...Cover, 20, 24
... Shaft, 25 ... Guide member, 27 ... Holding board, 28 ... Stud, 29 ... Push-up plate.

Claims (1)

[Scope of utility model registration request] The playback needle that reads information signals from the recording traces on the information recording medium disk is driven and displaced in the direction of extension of the recording traces in accordance with the time axis error correction signal, and the recording traces are extended in accordance with the correction signals for tracking control. The pickup arm to which the regeneration needle is attached is detachable from the base end side of the regeneration needle drive device configured to drive and displace the regeneration needle in a direction perpendicular to the regeneration needle drive direction. Information signal reproduction configured such that the distal end side of the reproducing needle driving device and the proximal end side of the pickup arm can be combined in an integral manner with respect to the two drive displacement directions of the needle driving device. In the element, at least 11 fixed parts are arranged on the tip side of the reproduction needle drive device, in a plane parallel to the disk surface of the information recording medium disk, and with the longitudinal direction perpendicular to the pickup arm. A thin rod-shaped permanent magnet is fixed to the rod-shaped permanent magnet, and a flat bearing member with a smooth surface made of a hard non-magnetic material is provided on the front surface of the rod-shaped permanent magnet. An information signal reproducing element comprising a coupling part made of a hard ferromagnetic material and having a length approximately equal to the length in the longitudinal direction of a portion of a rod-shaped permanent magnet arranged and fixed to the reproducing needle drive device.