JPS6353768A - Optical disk record reproducer - Google Patents

Abstract

PURPOSE:To control a pickup with high accuracy by providing a speed detector that has a magnetic circuit to generate a magnetic flux crossing the magnetic flux generated by the magnetic circuit of a linear motor approximately orthogonally. CONSTITUTION:On a main chassis 10, the optical pickup 40 is disposed via a guide shift 41. At one end of the main chassis 10, a linear motor 42 is disposed, and a speed detector 43 is disposed at the other end. Driving coils 42d and 43d are disposed corresponding to permanent magnets 42b and 43b attached on the side wall parts of yoke members 42a and 43a that are respectively magnetized in the direction of width. And bobbins 42c and 43c are fixed to the pickup 40. The linear motor 42 and the speed detector 43 are so disposed on the main chassis 10 that the magnetized surfaces of their yoke members 42a and 43a cross each other approximately orthogonally. As a result, the flux of the linear motor 42 can be prevented from influencing the flux of the speed detector 43, and the pickup 40 can be controlled with a high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION [Objective of the Invention (Industrial Application Field) The present invention relates to an optical disc record playback device suitable for, for example, an optical DAD (digital audio disc) system or an optical disc file system.

(Prior Art) Recently, in the field of audio equipment, digital recording and reproducing systems using PCM (pulse code modulation) technology are becoming popular in order to achieve high-fidelity reproduction as much as possible. This is called digital audio, and it has been established in principle that the audio characteristics are far superior to conventional analog systems without depending on the characteristics of the recording medium. A system that uses a disk as a recording medium is called a DAD system, and there are optical, electrostatic, mechanical, etc. playback methods.

For example, among the optical playback methods, an optical disc record playback device that uses the CD (compact disc) method uses a transparent disc with a diameter of 12 mm and a thickness of 1.2 mm.
A disk on which a metal film with bits corresponding to CM) data is formed is processed using the CLV (constant linear velocity) method for approx.
Rotate at variable rotation speed from 00 to 200 rpm.

At the same time, the digitized data is reproduced from the disk using an optical pickup containing a semiconductor laser and an optical conversion element in a linear tracking manner from the inner circumferential side to the outer circumferential side.

The pitch of this disc is 1.6p, and a huge amount of information is recorded on one side of the disc, allowing for approximately one hour of stereo playback, for example.

The next requirement for the above-mentioned optical disc record playback device is to ensure compactness with a simple and efficient configuration, and to ensure reliable operation.

A specific target of such a request is a pickup transport mechanism that transports an optical pickup in the radial direction of an optical disc. That is, FIG. 12 shows such a conventional pickup feeding mechanism, in which 1 indicates arrow E through a guide shaft 2.

This is an optical pickup that is movably arranged in the F direction. A linear motor 3 for transport driving is disposed at one end of the pickup 1, and a speed detector 4 for controlling the pickup speed is disposed at the other end. These linear motors 3 and speed detectors 4 similarly include permanent magnets 3b on the sides of yoke members 3a and 4a magnetized in the thickness direction, for example.
4b are attached to form magnetic circuits, and drive coils 3d, 4 having wires wound around bobbins 3c, 4c are attached to yoke members 3a, 4a facing the permanent magnets 3b, 4b.
d are attached so as to be movable in the directions of arrows E and F, respectively.

When current is supplied to the drive coil 3d of the linear motor 3, the magnetic flux B of the magnetic circuit changes, and the pickup 1 is moved in the directions of arrows E and F together with the drive coil 3d. At the same time, the speed detector 4 detects the back electromotive force caused by moving its drive coil 4d in the same direction as the yoke member 4a, and controls the linear motor 1 in response to the detection. .

However, in the pickup feeding mechanism configured as described above, due to its configuration, the drive coil 3d of the linear motor 3
As shown in FIG. 13(a), the magnetic flux B generated at
, y, z in substantially the same way.

When these vectors x, y, and z are decomposed, different components X', ', and z' exist in the thickness direction, and the magnetic flux B causes the magnetic flux B' of the speed detector 4 to
This will have an effect as shown in Figure (b). According to this, the drive control of the linear motor 3 is performed by the drive coil 3 of the linear motor 3.
Since this is done by adjusting the amount and direction of the current supplied to d, the magnetic flux B constantly changes, so the influence on the magnetic flux B' of the speed detector 4 constantly changes, making it possible to control it accurately. This will cause problems.

(Problems to be Solved by the Invention) This invention was made in order to solve the problems that occur when controlling the linear motor described above. An object of the present invention is to provide an optical disc record playback device that can realize the following.

[Structure of the Invention] (Means and Effects for Solving the Problems) The present invention provides an optical disc record playback device having a linear motor for moving an optical pickup in the radial direction of an optical disc. The linear motor is controlled by detecting a back electromotive force generated in conjunction with the linear motor, and includes a speed detector provided with a magnetic circuit that generates a magnetic flux substantially orthogonal to the magnetic flux generated in the magnetic circuit of the linear motor. This feature is characterized in that the speed detector is prevented from being adversely affected by the magnetic flux from the linear motor, thereby enabling highly accurate control of the pickup.

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

FIGS. 1 and 2 show the front and back sides of an optical disc record playback device according to an embodiment of the present invention, and numeral 10 in the figures shows the inside of a casing 11 (not shown in FIG. 2). This is the main chassis housed in the main chassis. A turntable 12 constituting a disk drive section is disposed approximately in the center of the main chassis 10 so as to be movable in the axial direction (directions of arrows A and B). As this turntable 12 moves in the direction of arrow A, an engaging portion penetrates into the interior through the through hole 13a of the disk case 13 and is fitted into a clamper (not shown) through the hole 14a of the disk 14 so that the disk can be driven. 1
2a, and a drive section 17 consisting of a stator 15 and a rotor 16 is connected to a shaft 12b on the back side of the main chassis 10, as shown in FIG. This drive unit 1
One end of a lifting lever 18 is engaged with the rotor 16 of No. 7. The intermediate portion of the lift lever 18 is rotatably supported by the main chassis 10 via a shaft 18a, and a spring member 19 is attached to the shaft 18a to apply its spring force to the turntable 12.
is engaged to bias it in the direction of arrow B. The other end of the lift lever 18 is engaged with a cam 21 for holding and driving a disk formed on one side of a cam gear 20, and this cam 21 has a switch drive section 21a connected to the main chassis 10.
(See FIG. 4). The cam gear 20 is rotatably supported by the main chassis 10, and a worm gear 25, which is fitted to the rotating shaft of a drive motor 24 via an intermediate gear 23, is meshed with the gear portion 20a of the cam gear 20. Further, on the other side of the cam gear 20, an engagement protrusion 26 for disengaging the disc case is formed corresponding to the cam 21, and one end of the ejection slider 27 corresponds to the engagement protrusion 26. This ejection slider 27 is connected to the main chassis 1 as shown in FIG.
0 so as to be movable in the directions of arrows C and D, and a spring member 28 is engaged at the intermediate portion thereof so as to apply its spring force in the direction of arrow C. A switch drive section 27a is formed in the middle portion of the ejection slider 27, and a position detection switch 29 disposed on the main chassis 10 corresponds to this switch drive section 27a. An engaging portion 27b is formed at the other end of the ejection slider 27, and an engaging pin 3 formed at one end of the first ejecting lever 30 is attached to the engaging portion 27b.
0a is supported. The first ejection lever 30 has an intermediate portion rotatably supported by the main chassis 10 via a rotation shaft 30b, and a spring member 31 is provided between one end of the first ejection lever 30 and the main chassis 10 to apply the spring force. It is attached so as to be applied in the counterclockwise direction in Fig. 5. An intermediate portion of a second ejection lever 32 is rotatably supported at the other end of the first ejection lever 30 via a rotation shaft 32a. The second ejection lever 32 has one end formed with a release part 33 that is inclined downward in the ejection direction (direction of arrow C) facing the end of the disc case 13 (see FIG. 6), and the other end of the second ejection lever 32. A discharge section 34 is formed opposite the end of the disc case 13. An engaging portion 32b is formed at one end of the second ejection lever 32 so as to correspond to the protrusion 10a implanted at a predetermined position on the main chassis 10.

Further, the main chassis IO is provided with a case accommodating portion 35 corresponding to the case insertion hole 11a of the housing 11 (
(See Figure 1). Disk case guide portions 36.36 are formed on both sides of the case storage portion 35, and the disk case 13 is guided in and out of the guide portions 36.36 in the directions of arrows C and D. A pair of sliding guide receivers 37 and 37 are provided on the lower surface of the disc accommodating portion 35 near the insertion hole at one end of the turntable 10, and a pair of positioning pins 37 and 37 are provided at the other end of the turntable 10. Pins 38, 38 (only one side is shown in FIG. 1) are provided corresponding to the positioning holes 13b, 13b of the disk case 13.

Holding springs 39, 39 for positioning are provided on the upper surface of the guide portion 36, 36, corresponding to the upper surface of the disk case. They are arranged at predetermined intervals.

Further, in the other part of the main chassis 10, for example, an optical pickup 40 for recording and reproducing a disc is disposed so as to be movable in the directions of arrows C and D via a guide shaft 41, and in a stopped state, the optical pickup 40 is controlled to move most in the direction of the arrow. be done. A linear motor 42 is disposed at one end of the pickup 40, and a speed detector 43 is disposed at the other end. Similarly, the linear motor 42 and the speed detector 43 have permanent magnets 42b and 43b attached to the side walls of yoke members 42a and 43a, respectively, which are magnetized in the thickness direction.
2b, 43b, each yoke member 42a, 43a has a drive coil 42 wound around a bobbin 42c, 43c.
d and 43d are arranged movably in the direction of arrow C2D.

Bobbins 42c and 43c of these drive coils 42d and 43d
are each accompanied by a pickup 40. The linear motor 42 and the speed detector 43 are arranged on the main chassis 10 so that the magnetized surfaces of the yoke members 42a and 43a are substantially perpendicular to each other.

Further, a holding member 44 for holding the pickup is rotatably disposed on the main chassis 10 via a rotation shaft 44a. This holding member 44 is in a state in which the guide portion 36.36 is biased counterclockwise in FIG. A driving portion 44b that comes into contact with the disk case 13 is formed at one end of the driving portion 44b (see FIG. 7). A locking portion 44 is provided at the other end of this holding member 44.
c is formed corresponding to the pickup 40. This holding member 44 is rotationally controlled in conjunction with the insertion and removal of the disc case 13, and in the inserted state, the locking portion 44c is separated from the pickup 40 located furthest in the direction of the arrow (see FIG. The side portion of the pickup 40 is locked in the extended state (see FIG. 4(a)).

Furthermore, one end of a disk case locking locking member 45 is rotatably supported by the main chassis 10 in correspondence with the case accommodating portion 35 .

As shown in FIGS. 8 and 9, a spring member 46 is engaged with the middle portion of this lock member 45 so as to apply its spring force in the clockwise direction in the drawings, and the other end portion is provided with a lock portion 45a.
is formed corresponding to the recess 13c formed in the disk case 13. A switch driving section 45b is formed at the other end of the locking member 45 in correspondence with a lock detection switch 47 for disk case lock detection disposed on the main chassis 10. When the disc case 13 is inserted into the case accommodating portion 35 to a predetermined position, the lock member 45 locks the spring member 46 by the disc case 13.
The switch drive unit 45b is rotated in the counterclockwise direction in the figure against the spring force, and the lock detection switch 47 is turned off once, see FIGS. 9(a) and 9(b). ),
After that, when the lock part 45a is locked to the four parts of the disc case, the switch drive part 45b again operates the lock detection switch 47 to turn it on (see FIG. 9(C)). Further, a case detection switch 48 for detecting a disk case is provided in the main chassis 10 in correspondence with the case housing section. This case detection switch 48 is turned on by the disk case 13 when the disk case 13 is accommodated in the case accommodating portion 35 (see FIG. 8(C)).
.

The main chassis 10 also includes an accidental erasure prevention lever 4.
9 is rotatably disposed via a rotation shaft 49a. A detection section 49b corresponding to the erroneous erasure prevention claw 50 formed on the disk case 13 is formed at one end of this erroneous erasure prevention lever 49, and a detection switch 51 is formed at the other end to connect the drive section 49C to the disk drive section. corresponds to. The erroneous erasure prevention lever 49 is biased clockwise in FIG. 1 via a spring member (not shown). When the disc case 13 is attached to the case accommodating portion 35, this erroneous erasure prevention lever 49 is activated by a spring member (not shown) depending on the presence or absence of the erroneous erasure prevention claw 50 of the disc case 13. The detection switch 5 is rotated by the spring force of
1 is turned off to stop the disc drive and prevent disc recording.

Now, the optical disc record reproducing apparatus configured as described above operates as described below.

That is, when the playback or recording operator is operated and the disc case 13 containing the disc 14 is inserted from the insertion hole 11a of the housing 11 in the direction of the arrow, the disc case 13 is moved by the holding spring 39 of the guide portion 36. .39 and the receiver are guided by the pin 37°37 in the process of moving (
(see FIGS. 5(a) and (b)), and the holding member 4 is
The driving portion 44b of No. 4 is rotated clockwise in FIG. 7 against the spring force of the spring member (not shown), and the locking portion 44c is rotated clockwise in FIG.
is separated from the pickup 40 (see FIG. 7). When the disk case 13 is inserted to a predetermined position, the disk case 13 is inserted at a time T as shown in FIG.
At time T2, the locking member 45 is urged to rotate against the spring force of the spring member 46, and the lock detection switch 47 is turned off (see FIG. 9(b)), and then at time T2, the positioning hole 13b of the disk case 13, The positioning pins 38 and 38 of the main chassis 10 are engaged with the positioning pins 13b, and the case detection switch 48 is turned on at the tip thereof. Next, the disc case 13 locks the locking member 45 into the recess 13c at time T3.
The lock portion 45a is locked, and the lock detection switch 47 is turned on (see FIG. 9(C)). Then, the drive motor 24 is driven as shown in FIG. 5(C), and the cam gear 20 is driven to rotate.
The cam 21 of No. 0 rotates the lift lever 18 against the spring force of the spring member 19 to move the turntable 12 in the direction of arrow A. As a result, the engaging portion 12a of the turntable 12 passes through the through hole 13a of the disk case 13 and is drivably fitted into the clamper (not shown) via the hole 14a of the disk 14 (see FIG. 3). b)). At this time, the cam gear 20 is activated by the switch drive section 21a of the cam 21 turning on the mode detection switch 22 and driving the drive motor 24.
(See Figure 5(d)). Here, the drive section 17 of the turn tape 12 is driven, and the pickup 40 is drive-controlled via the linear motor 42 and speed detector 43 to perform disk reproduction or recording.

Note that when recording the disc, the disc case 13
When the disk case 13 is housed in the case accommodating section 35 at time T3 as described above, the detection section 49a of the erroneous erasure prevention lever 49 detects the presence or absence of the erroneous erasure prevention claw 50 on the disk case 13. As a result, the erroneous erasure prevention lever 49 turns off the detection switch 51 in a state where the erroneous erasure prevention claw 50 of the disc case 13 is not detected, and stops the drive of the disk drive section, thereby preventing erroneous erasure due to re-recording.

Next, when the disk reproduction or recording is completed and a stop operation member (not shown) is operated, first, the drive of the linear motor 42 is stopped and the turntable 12 is stopped. At this time, the drive motor 24 is driven again, and the cam gear 20 is rotationally driven (see FIG. 5(e)). Then, as the cam gear 20 rotates, the cam 21 first reverses the elevator lever 18 and urges the turntable 12 to move in the direction of arrow B as shown in FIG. 1) and spaced apart from the disc case 13, and then one end of the ejection slider 27 is engaged with the engagement protrusion 26. Then, when the cam gear 20 is further driven to rotate, the engagement protrusion 26 urges the discharge slider 27 to move in the direction of the arrow against the spring force of the spring member 28, turning off the position detection switch 29, and turning off the position detection switch 29. , the ejection slider 2
7 of the engaging portion 27a of the first ejection lever 30.
0a and urges the first ejection lever 30 to rotate clockwise in the figure. As a result, the first ejection lever 30
are shown in Figures 6(a) and (b).

As shown in (C), the second ejection lever 32 is rotated and biased, and the detachment portion 33 of the second ejection lever 32 lifts one end of the disk case 13 to the positioning hole 1.
The positioning bins 38 and 38 are removed from 3b and 13b. Then, when the ejection slider 27 is further moved in the direction indicated by the arrow, the first ejection lever 30 is rotated in the same direction, and the engaging portion 32b of the second ejection lever 32 is moved toward the main chassis 10. It is brought into contact with the protrusion 10a.

As a result, the second ejection lever 32 moves to the ejection slider 27.
When it is further moved in the direction of the arrow, it is reversed counterclockwise in the figure about the rotation shaft 32a with respect to the first ejecting lever 30, and the ejecting section 34 moves the disk case 13 into the case housing section. 35 (see FIG. 5(f)).

Then, one end of the ejection slider 27 that engages with the engagement protrusion 25 of the cam gear 20 is disengaged, and the ejection slider 27 is returned to its original position by the spring force of the spring member 28. On the other hand, the first and second unloading levers 30, 32 are each reversed by the spring force of the spring member 31 and returned to their original positions (see FIG. 5(g)). At the same time, the discharge slider 27 turns on the position detection switch 29 using its switch drive section 27a, and stops the drive motor 24.

At step 22, when the disk case 13 is pulled out in the direction of arrow C and removed from the case housing portion 35, the holding member 44 is moved by the spring force of the spring member (not shown) as shown in FIG. 7(a). The side of the pickup 40 is rotated counterclockwise in the figure, and the locking portion 44c holds the side of the pickup 40 on the turntable 12.
It is regulated so that it is held in a state located at the outermost part of the periphery.

In this manner, the optical disk record reproducing apparatus is configured such that the magnetized surface of the yoke member 42a of the linear motor 42 and the magnetized surface of the yoke member 43a of the speed detector 43 are arranged substantially perpendicular to each other. As shown in FIG. 11, the magnetic flux B of the linear motor 42 is reliably prevented from influencing the magnetic flux B' of the speed detector 43, making it possible to control the pickup 40 with as high precision as possible.

Further, in the above embodiment, the yoke member 43 of the speed detector 43
The magnetized surface of the yoke member 42a of the linear motor 42 was configured to face the main chassis 10 and be substantially perpendicular to the magnetized surface of the yoke member 42a of the linear motor 42. A similar effect can be expected even if it is configured to face the chassis 10.

Further, in the above embodiment, the case is explained in which the disc 14 is applied to a so-called cassette type device in which the disc 14 is housed in the disc case 13, but the present invention is not limited to this, and the invention is not limited to this, but it is applicable to a type in which the disc is directly attached to the turntable. It is also applicable to Therefore, it goes without saying that the present invention is not limited to the above-mentioned embodiments, and that various modifications can be made without departing from the spirit of the invention.

[Effects of the Invention] As described in detail above, according to the present invention, it is possible to provide an optical disc record reproducing device that has a simple configuration and can realize highly accurate control of an optical pickup.

[Brief explanation of the drawing]

1 and 2 are configuration explanatory diagrams showing an optical disc record playback device according to an embodiment of the present invention, FIGS. 3 and 4 are sectional views and perspective views showing the main parts of FIG. 2, Figure 5 is a diagram showing the operating states of Figures 1 and 2, and Figure 6 is a diagram showing the operating states of Figures 1 and 2.
Figure 7 shows the main parts of the discharge mechanism in Figure 1 and Figure 2.
8 and 9 are diagrams showing the locking mechanism of the disc case, FIG. 10 is a timing chart shown to explain the operation of FIG. 9, and FIG. 11 is a diagram showing the pickup holding mechanism shown in FIG. FIGS. 1 and 2 are diagrams showing operating states of a linear motor and a speed detector, and FIGS. 12 and 13 are diagrams shown to explain a conventional pickup feeding mechanism, respectively. 10... Main shard, 11... Housing, 11a.
...Insertion hole, 12...Turntable, 13...Disk case, 13a...Through hole, 14...Disk, 14a...Hole, 12a...Engaging part, 12b...
Shaft, 15... Stator, 16... Rotor, 17...
・Drive unit, 18... Lifting lever, 18a... Axis, 1
9... Spring member, 20... Cam gear, 21... Cam, 21a... Switch drive unit, 22... Mode detection switch, 20a... Gear unit, 23... Intermediate gear, 24... Drive motor, 25... Worm gear, 2
6... Engaging protrusion, 27... Ejection slider, 28...
...Spring member, 27a...Switch drive section, 29...
・Position detection switch, 27b...engaging portion, 30...
First ejection lever, 30a...Engagement pin, 30b...
- Rotating shaft, 31... Spring member, 32... Second ejection lever, 32a... Rotating shaft, 33... Detachment part, 34
...Discharge part, 32b...Engaging part, 10a...Protrusion part, 35...Case housing part, 36...Guiding part, 37
...Receiving pin, 38...Positioning pin, 13b...
Positioning hole, 39... Holding spring, 40... Pick up, 41-... Guide shaft, 42... Linear motor, 4
3... Speed detector, 42a. 43a... Yoke member, 42b, 43b... Permanent magnet, 42c, 43C-bobbin, 42d, 43d,... Drive coil, 44... Holding member, 44a... Rotating shaft,
44c...Locking part, 45...Lock part, 13c...
- Recessed portion, 45b...Switch drive unit, 47...Lock detection switch, 48...Case detection switch, 49
... Erroneous erasure prevention lever, 49a... Rotation shaft, 50.
... Erroneous erasure prevention claw, 49b... detection section, 49c...
Drive unit, 51... detection switch. Applicant's agent Patent attorney Takehiko Suzue DC (a) (b) Ueki 7 M (a) (C) t! PJS diagram (a) Figure 13

Claims (1)

[Claims] An optical disc record playback device having a linear motor that transports an optical pickup in the radial direction of the optical disc, in which the linear motor is controlled by detecting a back electromotive force generated in conjunction with the movement of the pickup. An optical disk record reproducing apparatus, characterized in that it comprises a speed detector provided with a magnetic circuit that generates a magnetic flux substantially orthogonal to the magnetic flux generated in the magnetic circuit of the linear motor.