JPS5925299B2 - Information signal reproducing element drive device - Google Patents

Description

[Detailed Description of the Invention] In recent years, there has been research and development into high-density recording and reproduction of various information signals using information recording medium disks (hereinafter sometimes abbreviated as disks). Practical research is progressing, and high-density recording and reproducing systems for information signals using many types of disks have been announced.

The applicant's company is also promoting development research and practical research on high-density recording and reproducing methods for information signals using grooveless disks, which offer various advantages, and is promoting the development and practical research of information signal readout (detection) methods. Many proposals have been made regarding detection methods using changes in capacitance, recording and reproducing methods using magnetic heads, and optical reproducing methods (for example,
Publication No. 2-123205, Japanese Patent Application No. 13322-1983 (
(Refer to Japanese Patent Application Laid-Open No. 1983-98814), Japanese Patent Application No. 1982-9
No. 5346 (see Japanese Patent Application Laid-Open No. 54-29617), Japanese Patent Application No. 35483-1983 (see Japanese Patent Application Laid-open No. 128303-1983), and many others).

By the way, when reproducing information signals from a non-grooved disc, a tracking control means is required to ensure that the information signal reproducing element (reproducing element) always accurately follows the recording trace on the disc. Needless to say,
The reproducing element is driven and displaced in the width direction of the recorded trace by a driving device of a tracking control system.

Furthermore, although disks are designed to be rotated accurately at a predetermined number of rotations when reproducing information signals, disks are inevitably subject to mechanical deformation due to various other causes during manufacturing. (distortion), even if the disk is rotated at a constant number of revolutions during playback, the mechanical deformation that exists in the disk will cause a gap between the recording trace and the playback element. This causes a change in the relative velocity of the signal, and as a result, a so-called time axis error (jitter) is included in the reproduced signal. For this reason, conventionally, a time axis error correction signal obtained by comparing a reference signal in a disc playback signal with a standard signal is applied to one drive device of the time axis error correction control circuit of the playback element. By driving and displacing the reproducing element in the direction in which the recording trace extends, a time axis error is prevented from occurring in the reproduced signal.

Therefore, when reproducing information signals from a non-grooved disc, two types of control, namely time axis error correction control and tracking control, are used to move the reproducing element in the direction in which the recording trace extends and the recording trace. It is necessary to drive and displace the reproducing element two-dimensionally in both the width direction and the width direction of the disc.
We have been conducting various research on drive devices for information signal reproducing elements that can be driven and displaced dimensionally, and have already achieved many results (for example,
No. 2-35501 (see JP-A-53-121610), Japanese Patent Application No. 52-35502 (see JP-A-53-121)
611), Japanese Patent Application No. 52-41151 (see Japanese Patent Application Laid-Open No. 53-125817), Japanese Patent Application No. 11999
No. 9, Japanese Patent Application No. 52-12230 (Japanese Unexamined Patent Publication No. 53-974)
70), Utility Model Application No. 52-90270 (see Utility Model Application No. 54-18222), etc.). The present invention further improves the previously proposed drive device for an information signal reproducing element that can drive and displace the reproducing element two-dimensionally when reproducing an information signal from a grooveless disk, thereby eliminating unnecessary vibration modes. The occurrence of is suppressed, and
The purpose of this invention is to provide a drive device for an information signal reproducing element that does not cause crosstalk due to a difference in drive sensitivity in two directions, and has excellent characteristics such as easy maintenance and long life. And below,
The specific contents of the information signal reproducing element driving device of the present invention will be explained in detail with reference to the accompanying drawings.

1 and 2 are perspective views of the main parts of the previously proposed drive device for an information signal reproducing element, respectively. In these figures, A is the overall symbol of the movable part, and B is the general symbol of the DC magnetic field generator. In addition, in FIGS. 1 and 2, the movable part A is composed of a plurality of coils 1, 2, . . . fixed to a support plate 3, and 3 are rubber rods 4a and 4b in the configuration shown in the first figure.
In addition, in the configuration shown in the second figure, the movable part A has a connecting member 13 made of an elastic body (for example, rubber) in the central longitudinal part of the support plate 3.
For example, the thickness is 0.15m1! A rotation fulcrum member 12 is connected and fixed to a central vertical portion of a support member 10 made of an elastic plate such as a Norin bronze plate.
(a plurality of plates are provided at intervals in the vertical direction), the support plate 3 of the movable part A is properly pressed against the apex of the rotation fulcrum member 12, and a rotation fulcrum is provided to the movable part A. It will be done.
Note that the bottom portion of the rotation fulcrum member 12 is fixed to the support member 10. Further, the support member 10 has a support body 1 whose both ends are made of a material such as hard rubber.
1a and 11b, the support member 1
0 can be easily bent in the front-rear direction, but not deformed in other directions. Therefore, displacement in the front-rear direction in the movable part A is easily performed by the support member 10, and
The rotation movement of the movable part A is easily performed with the straight line position connecting the apexes of the rotation fulcrum member 12 serving as the rotation axis, and movement in other directions is suppressed. This is superior to the one shown in Figure 1 in this respect.
Now, pivot receivers 9a and 9b are provided on the horizontal center line of the support plate 3 of the movable part A, and each leg of a two-pronged pick-up arm (cantilever one) can be mounted on the pivot receivers 9a and 9b, for example. The press-contact portion at the tip on the proximal end side can be freely brought into contact with and separated from it through the operation of the magnetic coupling means.

In FIG. 2, the pivot receivers 9a and 9b attached to the support plate 3 have through holes 10a and 9b drilled in the support member 10, respectively.
10b and protrudes forward.

The DC magnetic field generator B consists of an external magnetic path 5 (case 5), a pole piece 6, permanent magnets 7, 8, etc. The tip of the pole piece 6 is divided into two parts 6a and 16b, and the above-mentioned movable The coil 1 of part A is loosely fitted into the pole piece 6a so that one side thereof is present in the magnetic gap formed between the permanent magnet 7 and the pole piece 6a, and
The coil 2 of the movable part A described above is loosely fitted into the pole piece 6b so that one side thereof exists in the magnetic gap formed between the permanent magnet 8 and the pole piece 6b.

The permanent magnets 7 and 8 generate a magnetic field in the magnetic gap between each of them and the opposing pole pieces 6a and 6b,
Further, the pole pieces 6a and 6b are magnetized so as to constitute a DC magnetic field generator that does not generate a magnetic field.

The related structure of the coil of the movable part A and the DC magnetic field generator B described above is similar to that of the coil of the movable part A and the DC magnetic field generator in the embodiment of the information signal reproducing element drive device of the present invention, which will be described later. It is also adopted as a related configuration aspect. In the drive mechanism device as described above, the coils 1 and 2 of the movable part A are coiled by the electromagnetic force generated between the current supplied to them and the magnetic field of the magnetic gap in the DC magnetic field generator. The coils 1 and 2 are driven and displaced in the axial direction (Y direction), but each coil 1 and 2 is driven in the same direction with the same driving force. On the other hand, when a current is supplied, the movable part A displaces the information signal reproducing element attached to the pick-up arm in the direction of extension of the recorded trace on the disk (Y direction), that is, in the direction of correcting the time axis error, Also, each coil 1 is driven in the same direction and oppositely with the same driving force.
, 2, the movable part A moves to Z
Since the information signal reproducing element attached to the pick-up arm is rotated about the shaft as the rotation axis and is displaced in the width direction (X direction) of the recorded trace on the disk, the information signal is supplied to the coils 1 and 2 of the movable part A. If the magnitude and direction of the current are appropriate, the information signal reproducing element attached to the pick-up arm by the movable part A will be able to move in the direction Y of the recording trace on the data star and in the direction orthogonal thereto. The correction current from the drive circuit for correcting the time axis error for the coils 1 and 2, and the tracking control current from the drive circuit 1 in the tracking control circuit are applied to the coils 1 and 2. By applying a correction current of (For the drive circuit for each correction current, refer to, for example, Japanese Patent Application No. 52-35502 (see Japanese Patent Laid-Open No. 53-121611)).

Now, among the previously proposed drive devices described above, the one shown in FIG. Since it does not include any mechanical contact parts, it has the advantage of long life, but on the other hand, it includes rubber rods 4a and 4b to which the support plate 3 of the movable part A is fixed. In the vibration system, for example, the displacement of the reproducing element in the X direction is not only given by the rotational movement of the movable part A;
This vibration system is designed to allow vibrations in different vibration modes to coexist, such as the deformation in the rubber rods 4a, 4b0X direction that occurs in the rubber rods 4a, 4b during the rotational movement of the movable part A. Then, the transfer characteristic is curve G in Figure 3.
2, it shows unnecessary resonance peaks at high frequency FOs, and therefore its phase lag characteristics also become
1 at the frequency FOs as shown by the curve φ2 in the figure.
Therefore, if a vibration system with such characteristics is included in a tracking control system, time axis, or error correction control system, sufficient improvement can be achieved in a stable state. It is difficult to construct an automatic control system that achieves this.

Furthermore, in the drive device shown in FIG. 1, rotational movement around the X-axis occurs due to unbalanced tension between the two rubber rods 4a and 4b, and a linear movement mode in the Z-axis direction occurs. Unnecessary vibration modes such as oscillation modes are likely to occur, which poses problems such as giving unnecessary displacements and changes in contact pressure to the reproducing element. Furthermore, in the previously proposed drive device having the configuration shown in the second figure, the transmission of the linear motion of the movable part A and the transmission of the rotational motion of the movable part A are performed by independent support mechanisms. to be done,
The drive device shown in the second diagram does not have the same drawbacks as the above-mentioned one drive device shown in the first diagram, and the vibration system of the drive device shown in the second diagram has its transmission characteristics and phase delay characteristics. As shown by curves Gl and φ in FIG. 3, there are no unnecessary peaks in the transfer characteristics, and
In addition, it has good second-order phase delay characteristics,
An automatic control system that can obtain a sufficient degree of improvement in a stable state can be easily constructed.

That is, in the single drive device shown in the second figure, the linear movement of the movable part A is performed by the supports 11a made of hard rubber material, etc.
The rotation movement of the movable part A is easily performed by the arcuate deformation of the support member 10 made of phosphor bronze plate whose both ends are supported by the support plate 3 and the support member 10. This is easily accomplished by rotating the support plate 3 of the movable portion A about a line connecting the vertices (knife-edge-shaped vertices) of the plurality of rotation fulcrum members 12 provided as the rotation axis.

A connecting member 1 made of rubber is provided to sandwich the rotational fulcrum member 12 in a crimped state between the support plate 3 and the support member 10.
3 is made of, for example, butyl rubber with a hardness of H4O, and when the support plate 3 of the movable part A performs a rotational movement, the displacement in the X-axis direction from the support plate 3 to the connecting member 13 is:
Since most of it is absorbed by the displacement of the connecting member 13 itself, the displacement does not cause the support member 10 to bend in an S-shape, and the movable parts A are arranged in a plurality of sections as described above. A good rotational movement can be performed using the line connecting the vertices of the rotational fulcrum member 12 as the rotational axis. As described above, the previously proposed drive device having the configuration as shown in the second figure has superior characteristics compared to the previously proposed drive device having the configuration as shown in the first figure. Rotating fulcrum member 12 with a knife edge-like mechanical contact point therein
Because of this, it is difficult to maintain a long life, and maintenance is troublesome and expensive.

In other words, if even a slight play occurs at the apex of the rotation fulcrum member 12, the presence of that play will seriously impede the tracking control operation, which should be performed with an accuracy of 1 μm or less, for example. It is difficult to obtain a highly reliable drive device with the previously proposed drive device shown in FIG. FIG. 4 is a perspective view of an embodiment of a driving device for an information signal reproducing element according to the present invention, and in FIG. 4, components corresponding to those in the driving device shown in FIG. The same drawing numerals as those used in FIG. 2 are given to .

In FIG. 4, A is the overall code of the movable part, B is the overall code of the DC magnetic field generator, and a plurality of coils 1, 2.
. . . are fixed to the support plate 3 at one end thereof. The thickness of the support plate 3 is, for example, 0.2 m77! This support plate 3 has pivot holders 9a19b at symmetrical positions on its center line.
is fixed. The tip portion (pivot) of a bifurcated pick-up arm is pressed against these pivot receivers 9a, 9b, thereby transmitting vibrations of the movable portion A in the drive device to the reproducing element. For example, case 5 has a hardness of H.
One end of supports 11a, 11b made of 5O butyl rubber is fixed, and grooves 11a1, 11b1 provided in these supports 11a, 11b have grooves 11a1, 11b1 with a thickness of, for example, 0.12 mm.
Both ends of the support member 10 made of a phosphor bronze plate are fitted and fixed. The horizontal length of the support member 10 described above is equal to the length of the grooves 11 provided in the supports 11a and 11b described above.
a,, 11b1 is made slightly longer than the distance l (FIG. 5) between the bottoms of the supports 11a, 11b.
The support member 10, whose both ends are fitted into the grooves 11a1 and 11b, is connected to the supports 11a and 11 by its both ends.
Since the parts 11a2 and 11b2 between the bottom of the groove b and the case 5 are stably supported by the two supports 11a and 11b in a compressed state, the support member 10 is hardly displaced in the left-right direction. First, it is designed so that it can be easily deformed into an arcuate shape in the front-rear direction. For example, in the grooves of supports 11a and 11b made of butyl rubber with hardness H5O, where the distance between the groove bottom of grooves 11a1 and 11b1 and case 5 is 2.2 mm,
Both ends of the supporting member 10 made of a phosphor bronze plate with a thickness of 0.12 mm are fitted, and the distance between the groove bottoms of the grooves 11a1 and 11b1 in the supports 11a and 11b and the case 5 is 2 m.
77! When the support member 10 is supported by the two supports 11a and 11b in such a state, when the same force is applied to the support member 10 in the X direction and the Y direction, the support member When the amount of displacement occurring in the X direction and the Y direction of 10 was compared, the amount of displacement occurring in the Y direction was approximately 300 times the amount of displacement occurring in the X direction.

This means that the support member 10 supported in the above manner is in an extremely well damped state in the X direction, and even if the support member 10 is excited in the X direction, the vibration will be reduced. This means that the size is extremely small, and therefore the support member 10 is
It can be considered that it does not displace in the Y direction, but easily bends into an arch shape in the Y direction. The support member 10 has a through hole 10 through which the pivot receivers 9a and 9b fixed to the support plate 3 are passed.
a, 10b are drilled. Both the support member 10 and the support plate 3 of the movable part A, which are arranged parallel to each other, are integrally connected to each other in a state where their center lines in the left-right direction substantially coincide with each other.

In the embodiment shown in the fourth figure, in a state where the support plate 3 and the support member 10 interpose the columnar connecting body K, the support plate 3 and the support member 10 An example is shown in which the support plate 3 and the support member 10 are integrally connected to each other in a state in which the support plate 3 and the support member 10 substantially coincide with each other. The support plate 3 and the support member 10 are integrally connected to each other in a state where their center lines in the left and right direction substantially coincide without using a connecting body K that is separate from the member 10. It is also possible to do so.

Further, at this time, the connecting portion of one or both of the support plate 3 and the support member 10 may be processed and deformed, for example, into a convex shape to connect the two. If the dimension of the support plate 3 in the X direction (horizontal direction) is much smaller than the dimension of the support member 10 in the X direction (horizontal direction), the support plate 3 and the support member 10 may be With the center lines substantially aligned, the entire surface of the support plate 3 can be fixed to the support member 10 to integrally connect the two.

When a connecting body K is used between the support plate 3 and the support member 10 as in the embodiment shown in the fourth figure, the connecting body K may be made of a material that is light and has high rigidity. desirable.

Incidentally, as the connecting body K, an aluminum columnar body can also be used. In the drive device for the information signal reproducing element of the present invention, when the drive force from the movable part A is a direct force in the Y direction, the support member 10 is deformed into a bow shape as shown in FIG. 6a. In response to the linear motion of the movable part A,
When the driving force from the movable part A is a rotational movement around the Z-axis, the movable part A rotates about the center line 0 in the left-right direction of the support member 10, and at this time the support member 10 It bends and deforms into an S-shape as shown in FIG. 6b.

That is, as mentioned above, the support member 10 is firmly supported at both ends by the supports 11a and 11b so as not to be displaced in the X direction, and the movable part 3 and the support Since the members 10 are integrally connected to each other in a state in which their center lines in the left and right directions substantially coincide with each other, the rotation fulcrum (rotation center) when the movable part A performs rotation movement is , becomes the center line in the left-right direction of the support member 10, and this pivot point is always kept stable.

As described above, since the support member 10 does not undergo displacement in the X direction, the gain characteristics and phase characteristics with respect to frequency between the drive current applied to each coil in the movable part A and the vibration generated in the vibration system. is the curve Gl, φ in Figure 4.
It will be in good condition like 1.

Therefore, when an automatic control system is configured using the information signal reproducing element drive device of the present invention, it has been demonstrated through experiments that an improvement of about 70 dB can be stably obtained. Ta.

Now, as is clear from FIGS. 6A and 6B, the state of deformation of the support member 10 when the movable part A performs a linear motion, and the state of deformation when the movable part A performs a rotational motion. Comparing the state of deformation of the support member 10, the radius of curvature of the support member 10 when the movable part A performs a rotational motion is greater than the radius of curvature of the support member 10 when the movable part A performs a linear motion. It is smaller than the radius of curvature of member 10.

However, when considering the relationship between the displacement amount of the support plate 3 and the displacement amount of the reproducing element, when the movable part A is performing linear motion, the displacement amount of the support plate 3 is the same as that of the reproducing element. The amount of displacement is in the extension direction of the trace, whereas when the movable part A is rotating, the rotation of the support plate 3 causes the reproducing element to be displaced in the width direction of the recorded trace. The amount is
It is enlarged according to the length of the pick-up arm (cantilever).

By the way, the displacement amount by which the reproducing element should be displaced by one drive in the width direction of the recorded trace for tracking control, and the displacement amount by which the reproducing element should be driven and displaced in the extending direction of the recorded trace for jitter correction are as follows. Usually, they are of the same degree, so if the rotational movement of the movable part A is performed with the same magnitude as the 9 drive current for the linear motion of the movable part A, the rotation angle is small. If it is possible to successfully balance out the fact that In a state where the same magnitude of drive current is supplied to each coil in the movable part A, the amount of displacement of the reproducing element in the extension direction of the recorded trace and the amount of displacement of the reproducing element in the width direction of the recorded trace are It is possible to balance it.

However, in the previously proposed device shown in the second figure, since the movable part A is configured to easily rotate using the apex of the rotation fulcrum member 12 as a rotation fulcrum, the amount of force applied to each coil of the movable part A is When the drive currents are the same, the amount of displacement of the reproducing element caused by the rotation angle due to the rotational movement of the movable part A is greater than the amount of displacement of the reproducing element caused by the linear motion of the movable part A. Therefore, in the previously proposed device shown in the second figure, in order to displace the reproducing element by the same amount of displacement in the extension direction of the recorded trace and the width direction of the recorded trace, it is necessary to The magnitude of the coil and drive current when moving A in a linear manner must be different from the magnitude of the coil drive current when rotating movable part A.

For example, the length of the pick-up arm (one cantilever) is 35m77! The connecting member 13 is made of butyl rubber with a hardness of H4O (length in the X direction: 4 m1, length in the Y direction: 2.2 mm).
It is made with a length of 11m0 in the Z direction, and the support member 10 has a thickness of 0.15m7! In the drive device of the already proposed configuration shown in the second figure, which is made of a hard phosphor bronze plate of L and has a rotation fulcrum member 12 between the support plate 3 and the support member 10, If the magnitude of the coil drive current for rotating the movable part A is about 10% of the magnitude of the coil and drive current for causing the movable part A to move in a linear motion, the reproduction element X, It is known that the amount of displacement in both Y directions cannot be made the same.

Therefore, when performing tracking control and time axis error correction control on the reproducing element using the previously proposed drive device shown in the second figure as described above, it is necessary to control the coil for time axis error correction. Unless the current to be supplied is 10 times the current to be supplied to the coil for tracking control, it is not possible to cause the reproducing element to produce the same amount of displacement in the X direction and the Y direction. be.

Additionally, if there is an imbalance between the left and right sides of movable part A in the driving force generated between the coil of movable part A and the magnetic field, crosstalk around the Z axis will occur when movable part A drives in the Y direction. Assume that the amount of crosstalk in the drive device is 10%, and in order to drive the movable part A in the Y direction (time axis error correction direction) as in the example above, If the drive current value is 10 times the drive current value for driving the movable part A8X direction (correction direction for tracking control), the amount of crosstalk during actual operation of this drive device is It becomes 100%.

However, the two drive currents for driving the drive device are respectively supplied from a tracking control circuit and a control circuit for time axis error correction, and each of the automatic control circuits It is natural that the amount of crosstalk mentioned above has been greatly improved since the system is in a state where automatic control is performed individually. If there is a 10 times difference in sensitivity between the X and Y directions,
It can be easily inferred that the tracking control is greatly disturbed by the control for correcting the time axis error that is performed simultaneously.

However, in the information signal reproducing element drive device of the present invention, since the support plate 3 and the support member 10 are integrally coupled, a large mechanical impedance is exhibited with respect to rotational movement around the Z axis. Therefore, it is possible to easily reduce the crosstalk as described above by bringing the sensitivity in the X direction and the Y direction closer together in one drive device.

That is, in the information signal reproducing element driving device of the present invention, the balance of sensitivity in both the X and Y directions can be easily achieved by changing the manner of coupling between the support plate 3 and the support member 10 in the movable part A. For example, the fourth
As in the illustrated embodiment, the support plate 3 and the support member 1
0 is performed with the connecting body K interposed between the two, the balance of sensitivity in both the X and Y directions of the drive device can be adjusted by changing the shape and structure of the connecting body K. You can do that by changing.

To explain this specifically, for example, if a long dimension in the X direction is used as the connecting body K, the connecting body K
The length of the freely bendable portion of the support member 10 becomes smaller depending on the width in the X direction at The mechanical impedance becomes high for the mode. Further, the above adjustment may be made by changing the material used for the connecting body K. For example, the present invention can be carried out even if hard rubber with high hardness is used as the connecting body K.

The support plate 3 and the support member 1 can be connected without using a separate connecting body K.
The above-mentioned adjustment in the case where the drive device of the present invention is implemented as a configuration in which 0 and This can be easily done by changing the ratio of the lengths of the support plate 3 and the support member 10 in the left-right direction.

In the drive device of the present invention described with respect to the embodiment shown in FIG.
Although the supports 1a and 11b are made of hard rubber, rigid bodies can also be used as the supports 11a and 11b in carrying out the present invention.

However, the support form of both ends of the support member 10 in this case is different from the support form that is close to free support when rubber is used as the supports 11a and 11b.
Since it is a fixed support, the mechanical impedance of the support member increases with respect to both linear and rotational movements, and the damping effect obtained when a rubber support is used is also lost. In this case, as the supporting member 10 is bent, the case 5 deforms to absorb the effect of the bending. In this manner, in the information signal reproducing element drive device of the present invention, the support plate 3 of the movable part A and the support member 10 are integrally coupled in a state in which the center lines of the two in the left-right direction substantially coincide with each other. By doing so, the support member 10 is deformed into an arcuate shape when the movable part A moves in a linear motion, and the pivot point when the movable part A rotates is fixed, and the support member 10 is Vibration modes other than rotational and linear vibration modes are well suppressed, and automatic control systems using this drive device can stably,
Moreover, it is possible to perform control operations that provide a sufficient degree of improvement.

Further, in the drive device of the present invention, it is easy to balance the ratio (sensitivity) between the displacement amount in the two directions in which the reproducing element is to be displaced and the 1 drive current, and crosstalk can be easily balanced in both directions. Furthermore, since a mechanical fulcrum such as a forced fulcrum using a knife edge is not used as a rotation fulcrum,
Advantages such as long service life and easy maintenance are achieved.

FIGS. 7 to 9 show an example of an information signal reproducing device from a disk using the information signal reproducing element driving device of the present invention, in which the reproducing element reads an information signal from the disk based on the capacitance value. This figure shows a case in which a regeneration needle is provided with an electrode for detecting changes. In each figure, D is a disk, and S is a disk.
is a regenerated needle, P is a bifurcated pick-up arm (cantilever one), G is a guide base, C is a cartridge base, E
is a transporter.

Note that FIG. 8 shows a state in which the pick-up arm P and the drive device are separated, and FIG. 9 shows a state in which the pick-up arm P and the drive device are coupled. Disc D rotates 1 at a predetermined number of rotations in the direction of the lost mark R.
The transporting body E is being driven and rotated, and the transporting body E is being transported in the radial direction of the disk D at a predetermined transporting speed, and the regeneration needle S provided at the tip of the pick-up arm P is slid onto the disc D with a predetermined needle pressure. The information signal of the disk D is read as a change in capacitance value, and connected to the connection terminal 1 of the center conductor of the semi-coaxial resonator of the high frequency oscillator (not shown) via the connection line 14.
Give to 5.

How to attach and detach the cartridge base, how the pick-up arm P and the cartridge base are configured, and how the pick-up arm P
Pivot 16 at the tip of
, 9b, the mode of connection and detachment, and the appropriate needle pressure are regenerated needle S.
Regarding the means for providing
Please refer to the specification of No. 2230 (see Japanese Unexamined Patent Publication No. 54-55401). The track pitch of the main information signals on disk D is 2.2 μm.
The electrode width (X direction) appearing on the sliding surface of the regenerating needle S with the disk D is 1.2 μm (the electrode is made of a thermally and chemically stable metal such as hafnium, For example, if the thickness is 2000A0), the reproduction needle S has an accuracy of ±0.5 μm with respect to the recorded trace on the disk D. If the information is not followed, adjacent recorded information will be played back at the same time, causing bead interference in the playback signal.

Now, if the deviation of the playback needle S from the recorded trace is ±300 μm when tracking control is not performed, the playback needle S can be made to follow the recorded trace with an accuracy of ±0.5 μm using tracking control. requires an improvement of 56 dB by the tracking control system.

Since the amount of displacement of the reproducing needle S from the recorded trace due to the above-mentioned control is less than 1 μm, the drive device is required to faithfully perform extremely minute displacements in accordance with the drive current from the control system. . In addition, the drive device performs tracking control as well as control to correct time axis errors.
A displacement of about 300 μm in the Y direction is also required, and the control system for correcting time axis errors requires, for example, a displacement of about 300 μm.
An improvement of 0 dB is required.

In this way, in order to stably achieve the above-mentioned improvement required for each control system in each control system, it is necessary to exhibit a straightforward phase delay characteristic over the required frequency band. At the same time, the drive device is required to have no steep peak response at frequencies other than the fundamental resonant frequency, and as mentioned above, the drive device of the present invention has a transmission characteristic of 3. This is shown by curve G1 in the figure, and the phase delay characteristic is as shown by curve φ in FIG. The control system for the correction of both can achieve the required degree of improvement under stable operating conditions.

As described above, according to the drive device for an information signal reproducing element of the present invention, all the problems of the previously proposed devices described above can be satisfactorily solved. 1 drive device can be easily provided.

[Brief explanation of the drawing]

1 and 2 are perspective views of the previously proposed drive device, FIG. 3 is a curve diagram for explaining characteristics, and FIG. 4 is an embodiment of the drive device for an information signal reproducing element of the present invention. 5 is a partial cross-sectional plan view of the same as above, FIGS. 6A and 6B are partial plan views for explaining the operation, and FIG. The perspective view and FIGS. 8 and 9 are partially vertical side views of the same as above. 1, 2... Coil, 3... Support plate, 5
...Magnetic path (case), 9a, 9b...
Pivot receiver, 10... Support member, 11a, 11
b...Support body, 12...Rotation fulcrum member, 13...Connection member, A...Movable part,
B: DC magnetic field generator, C: Cartridge base, D: Disk, K:
...Connection body, P...Pickup arm.

Claims (1)

[Claims] 1. Width of a recording trace for tracking control of an information signal reproducing element that slides into sliding contact with a predetermined pressure contact force on the surface of an information recording medium in order to read an information signal from a spiral or concentric recording trace on an information recording medium disk. drive in the direction and drive in the direction of extension of the recording trace for correction of time axis errors are performed by driving displacement of a plurality of coils movably disposed in the energizing magnetic field. Further, there is provided a driving device for an information signal reproducing element, which is configured to be detachably connected to a support plate to which one end of each of the plurality of coils is fixed. A support plate to which each end is fixed, and a support member disposed parallel to the above-mentioned support plate and whose both ends are supported by a support body in the left-right direction of both of them. By being integrally connected with their centers substantially coincident, when the support plate is moved in the coil axial direction by drive displacement of the plurality of coils, the support member is bent and deformed in an arch shape, and A drive device for an information signal reproducing element, wherein the support member is bent and deformed in an S shape when the support plate is rotated by drive displacement of the plurality of coils.