JPH06267098A - Apparatus for reproducing optical disc - Google Patents

Abstract

PURPOSE:To easily and efficiently clean an objective lens in touch with a cleaning member of a dummy disc by vibrating the objective lens by means of a tracking controlling mechanism in a direction to control tracking. CONSTITUTION:When a dummy disc having a felt or the like cleaning member attached to the surface thereof is loaded and a cleaning instruction is commanded, it is switched to a focus servo signal, thereby impressing a direct current bias signal from a bias power source 25 and shifting an objective lens upward by a constant amount via a driver 31. Then, it is changed to a tracking servo signal, and an alternative current 1-5Hz voltage is supplied from an oscillator 26. The objective lens is consequently vibrated via a driver 32 in a direction to control tracking. In this manner, the surface of the objective lens can be efficiently cleaned under the contact pressure not adversely influencing the supporting structure for the objective lens.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disc reproducing apparatus having a lens cleaning device for cleaning an objective lens of an optical head for optically reproducing recorded information on a disc.

[0002]

2. Description of the Related Art Recently, the spread of optical discs such as compact discs (CDs) has been remarkable. An optical disc device that optically reproduces recorded information on a disc of this type is basically an optical head in which an optical disc is supported on a turntable and rotated to face the disc surface at a predetermined distance. While moving the disc in the radial direction of the disc, laser light is emitted from the optical head, and the optical head receives the reflected light of the laser beam from the information recording surface of the disc to read and reproduce recorded information. To be done.

Generally, a disc is recorded by forming a spiral recording track on the disc surface with an array of pits indicating digitized information. The optical head is moved in the radial direction in synchronization with the rotation of the disk so as to trace the recording track and reproduce the recorded information. At this time, the objective lens of the optical head is moved in the direction of its optical axis for focusing control so as to focus the laser light on the recording track, and is moved in the direction intersecting the recording track for tracking control. .

The objective lens thus controlled for focusing and tracking is generally supported by the optical head main body through an elastic member so as to be movable in the optical axis direction and the direction orthogonal thereto. In particular, in order to enable control with good responsiveness by a light driving force, the objective lens is supported through an elastic member having a relatively weak elastic force, and the supporting structure thereof is very delicate.

[0005]

By the way, in a general usage environment of the optical disk reproducing apparatus, it is unavoidable that the surface of the objective lens is contaminated due to adhesion of dust or the like. Therefore, in order to maintain the characteristics of the optical head, it is desirable to regularly clean the surface of the objective lens.

However, as described above, the supporting structure of the objective lens is often very delicate. Therefore, if the lens surface is directly cleaned with fingers, an excessive load is applied to the supporting portion, and the elastic supporting characteristic of the objective lens by the elastic member may change. When such a change in the elastic support characteristic occurs, the characteristics of focusing control and tracking control are greatly changed, and high-precision control cannot be performed.

In this respect, Japanese Utility Model Laid-Open No. 62-57931 uses a dummy disk having a cleaning brush attached to the disk surface,
A technique is disclosed in which the dummy disk is mounted on an optical disk reproducing apparatus to clean the objective lens of the optical head. That is, in the technique disclosed in this publication, a dummy disc is loaded and a reproducing operation is performed, and a cleaning brush attached thereto is brought into contact with an objective lens while rotating the dummy disc to clean the surface thereof. .

However, in such a structure, it is necessary to rotate the dummy disk in order to clean the objective lens. When the cleaning brush is brought into contact with the objective lens while rotating the dummy disk in this way, the rotational force directly acts strongly on the objective lens from one direction, and the elastic support member for supporting the objective lens. May be damaged or the elastic support characteristics thereof may be deteriorated.

Further, the cleaning brush attached to the dummy disk needs to have a long bristle of a length that comes into contact with the objective lens facing the disk surface with a predetermined distance. Moreover, the dummy disk provided with the cleaning brush having long bristles has some problems such as poor handleability.

The present invention has been made in consideration of such circumstances, and an object thereof is a lens having a simple structure capable of effectively cleaning the objective lens thereof without impairing the characteristics of the optical head. An object is to provide an optical disc device including a cleaning device.

[0011]

SUMMARY OF THE INVENTION According to the present invention, an optical head is confronted with a disk which is supported by a turntable and is rotated, and the optical head is moved in the radial direction of the disk to optically record information on the disk. The present invention relates to an optical disc reproducing device for reproducing information, and particularly as a lens cleaning device driven when a dummy disc provided with a cleaning member on the disc surface is supported by a turntable, using the focus control mechanism of the optical head, Lens moving means for bringing the objective lens into contact with the cleaning member of the dummy disk, and vibrating means for vibrating the objective lens brought into contact with the cleaning member by the lens moving means in the tracking control direction using the tracking control mechanism of the optical head. And a lens cleaning device provided with.

The lens cleaning device can be operated only when the dummy disk is mounted and only when the rotation of the dummy disk is stopped.

[0013]

According to the apparatus of the present invention having such a configuration, the focus control mechanism for moving the objective lens of the optical head in the optical axis direction and the tracking control mechanism for moving the objective lens in the direction intersecting the optical axis are provided. When the dummy disc is mounted, the objective lens is brought into contact with the cleaning member provided on the dummy disc, and the objective lens is vibrated in the disc surface direction in this state, so that the objective lens is not applied with an extra load. The surface of the lens can be effectively cleaned.

Moreover, since the objective lens itself is moved to come into contact with the cleaning member and vibrates to clean the surface thereof, it is not necessary to bother to rotate the dummy disk to which the cleaning member is attached. Therefore, the objective lens is lightly contacted with the cleaning member within a range that does not impair the support characteristic of the objective lens by the elastic member, and in that state, the objective lens is vibrated along the disk surface, so that the cleaning is easy and It can be done effectively.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a schematic configuration of a main part of an apparatus of the embodiment, FIG. 2 is a block diagram of a control circuit section in the embodiment, and FIG.

In FIG. 1, 1 is a turntable,
Motor 3 fixed to chassis 2 of the optical pickup device
It is attached to the rotating shaft of. Compact disc (C
D) is placed on the turntable 1 and is fixed by being pressed from above by a clamper (not shown).
It is rotationally driven by the motor 3.

Then, the turntable 1 of the chassis 2
At the side position of the turntable 1
It is provided so as to be movable in the radial direction of the CD mounted on the CD. That is, the optical head 4 has its main body portion 4a movably supported by two linear guide rods 5 and 6 provided in parallel with the chassis 2, and the main body portion 4a of the optical head 4 is moved along the guide rods 5 and 6. The rack 7 provided on the side is engaged with the pinion 8 to
It is designed to move linearly by the rotation of 8. The pinion 8 is a control motor fixed to the chassis 2.
It is attached to the rotating shaft of 9 and is driven to rotate forward and backward.

By the way, the optical head 4 is a laser light emitter,
It is mainly composed of a light receiving element, an objective lens, a beam splitter, and the like, and the laser light emitted and output from the laser light emitting body is converged through the objective lens 11 to irradiate the disk surface of the CD, and the light reflected by the disk surface The light receiving element is configured to receive light via the objective lens 11. The beam splitter has a function of separating the emitted laser light and its reflected light and preventing their mutual interference.

However, the objective lens 11 is provided so as to be movable in the optical axis direction thereof so that the emitted laser light is converged on the disk surface of the CD by focusing adjustment.
Further, the objective lens 11 performs recording so that the laser beam emitted from the optical head 4 accurately follows the spiral recording track formed on the disk surface of the CD as the CD rotates and the optical head 4 moves. It is movably provided in a direction intersecting with the track (moving direction of the optical pickup device 4) and tracking control is performed.

Specifically, the objective lens 11 is attached to the upper end of a cylindrical lens holder 12. This lens holder 12 has one end fixed to the side wall 4b of the main body 4a.
It is fixed to the other end of the parallel rod spring 13 of the book, and is thereby supported movably in the optical axis direction (arrow X direction) and the direction orthogonal thereto (arrow Y direction).

Further, a U-shaped permanent magnet 14 is attached to the side of the lens holder 12 in the Z direction with its opening facing downward. A focusing coil 15 is provided in the main body portion 4a so as to surround a side portion forming one pole of the permanent magnet 14, and a tracking coil 16 is provided so as to pass through a central gap portion of the permanent magnet 14.

By controlling the energization (current amount) of the focusing coil 15, the lens holder 12 is moved up and down, the objective lens 11 is moved in the optical axis direction, and focusing is performed on the disk surface of the CD. Further, by controlling the energization (current amount) of the tracking coil 16, the lens holder 12 is moved left and right (in the Y direction), the horizontal position of the objective lens 11 is displaced, and tracking control for the recording track is performed.

Here, the lens holder 12 has a permanent magnet 14 attached thereto.
The focusing coil 15 and the tracking coil 16 corresponding thereto are provided in the main body 4a.
It goes without saying that 16 may be provided on the lens holder 12 side and the permanent magnet 14 may be provided on the main body portion 4a side.

Basically, an optical disk reproducing apparatus having the optical head 4 constructed as described above is characterized by this embodiment. For example, as shown in FIG. 3, a felt is formed on the disk surface. A dummy disk 22 having a cleaning member 21 attached thereto is mounted on the turntable 1 instead of a normal CD, and the optical head 4 is used to mechanically clean the surface of the objective lens 11 using the dummy disk 22. 2 is added to the control circuit unit of FIG.

That is, the focusing coil 15 for moving the objective lens 11 up and down in the optical axis direction is energized and driven by the focus coil driver 31, and the focus coil driver 31 operates by receiving the focus servo signal. The tracking coil 16 for moving the objective lens 11 in the disk radial direction is energized by a tracking coil driver 32, and the tracking coil driver 32 operates by receiving a tracking servo signal. In the control circuit portion of the optical head 4 having a characteristic configuration in this embodiment, the dummy disk 22 as described above is mounted on the turntable 1 for each of the drivers 31 and 32 described above, and a predetermined operation condition is satisfied. At this time, a means for applying a predetermined DC bias signal in place of the focus servo signal (bias power supply 25) is used as the lens moving means, and a means for applying an alternating signal of 1 to 5 Hz in place of the tracking servo signal (oscillator 26). Is provided as a vibrating means.

Incidentally, the DC bias signal applied from the bias power source 25 causes the driver 31 to move the objective lens 11 upward by a fixed amount in the optical axis direction beyond the range of movement by the normal focusing operation, and the driver 31 moves the focusing coil 15 accordingly. Is a signal that causes a certain amount of current to flow. By applying such a DC bias signal, the objective lens 11 is moved to a position where it comes into light contact with the cleaning member 21 attached to the disk surface of the dummy disk 22. Moreover, the alternating signal of 1 to 5 Hz applied from the oscillator 26 is an objective lens.
This is a signal for the driver 32 to periodically apply a predetermined amount of current to the focusing coil 15 in order to vibrate 11 along the disc surface in the tracking control direction (direction orthogonal to the optical axis).

If the focusing coil 15 and the tracking coil 16 are energized and controlled by using the DC bias signal and the alternating signal, the tip of the lens holder 12 movably supported via the four parallel bar springs 13. The objective lens 11 attached to the turntable 1 is oscillated to the left and right while being moved to a position where the dummy disk 22 mounted on the turntable 1 is in slight contact with the cleaning member 21. The surface of the lens 11 will be cleaned.

The conditions for cleaning the objective lens 11 in this manner are, for example, the dummy disk 22.
CD has been loaded. Confirm that the turntable 1 (dummy disc 22) has stopped rotating, and that a cleaning command has been given by operating the cleaning mode switch. Care should be taken to prevent the objective lens 11 from accidentally coming into contact with the disk surface of the CD in normal use.

Incidentally, since the absolute address information (TOC; Table of Contents) of the recorded information is recorded in the lead-in area set on the inner peripheral side of the disc surface of the CD, for example, the initial operation of disc reproduction is performed. Depending on whether TOC is detected or not, whether the disc mounted on the turntable 1 is a normal CD or a dummy disc
You may make it determine whether it is 22. Then, when it is determined that the dummy disk 22, the rotation of the turntable 1 is stopped, it is determined whether or not the signal issued by the cleaning command operation is given, and then the above-described cleaning operation is started. Just do it.

Needless to say, it is not necessary to operate the signal reproducing circuit or the like during this cleaning operation. In this case, of course, it is not necessary to move the optical head 4 in the radial direction of the disk, but rather the objective lens 11
It is desirable that the optical head 4 be fixedly positioned at a predetermined position facing the cleaning member 22.

Regarding the control of the cleaning operation described above,
Although various sensing elements and operation control elements may be used for discrete control, it is of course possible to control operation by software using a microprocessor.

As described above, according to the apparatus of the embodiment,
The objective lens 11 is lightly contacted with the cleaning member 21 attached to the disc surface of the dummy disc 22.
Since it is oscillated to the left and right, the surface of the objective lens 11 can be effectively cleaned under a preset contact pressure. Further, since the objective lens 11 can be easily cleaned without rotating the dummy disk 22, no extra load is applied to the support structure of the objective lens 11. Therefore, by applying an excessive load to the objective lens 11, the elastic support member
The effect that the support characteristics due to the (bar spring) are deteriorated and the controllability of focusing and tracking is impaired is not brought about.

Further, since the movement control mechanism of the objective lens 11 is used as it is for lens cleaning, the present apparatus can be realized by slightly changing the control circuit of the existing optical disk reproducing apparatus, and the structure is complicated. There is also an advantage that it is not caused.

The present invention is not limited to the above embodiment. For example, as the cleaning member 21 provided on the dummy disk 22, a soft paper material such as Japanese paper may be used in place of the felt material, and a cleaning liquid such as anhydrous alcohol may be impregnated therein. May be Further, the structure of the optical pickup device is not limited to the above-described embodiment, and the structure in which the lens holder is movably supported by the leaf springs combined in the directions orthogonal to each other can be similarly applied.

It is also possible to provide the cleaning control circuit with a function of timer-managing the cleaning operation time so that when the cleaning command is given, the cleaning operation is performed for a fixed time.
Of course, the cleaning operation time can be manually set. Furthermore, during the cleaning operation, the dummy disk 22
You may make it rotate at a very low speed slowly.

Further, the cleaning history is stored, and the objective lens is
It is also possible to sequentially change the position of the cleaning member 22 with which the 11 is brought into contact in the radial direction of the disc, and control the cleaning of the objective lens 11 at a clean portion of the cleaning member 22. In addition, a test signal recording area is provided at a predetermined position outside the attachment area of the cleaning member 21 of the dummy disk 22, and after the cleaning operation is completed, information reproduction of the test signal recording area is performed so that its optical characteristics are improved. You may make it judge.

In short, the present invention can be modified in various ways without departing from the scope of the invention, and can be applied to various types of optical disk reproducing apparatuses.

[0038]

According to the optical disc reproducing apparatus of the present invention, the objective lens is raised and brought into slight contact with the cleaning member of the dummy disc, and in that state the objective lens is vibrated to the left and right. Practical use, such as the surface of the objective lens can be easily and effectively cleaned under contact pressure that does not adversely affect the support structure that supports the lens movably, and its configuration is simple. Great effect can be achieved.

[Brief description of drawings]

FIG. 1 is a perspective view showing a schematic configuration of a main part of an optical disc reproducing apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a schematic configuration of a control circuit in an apparatus according to an embodiment of the present invention.

FIG. 3 is a perspective view showing a configuration example of a dummy disk used in an apparatus according to an embodiment of the present invention.

[Explanation of symbols]

1 ... Turntable, 4 ... Optical head, 1
1 ... Objective lens, 12 ... Lens holder, 13 ... Rod spring (elastic support member), 14 ... Permanent magnet, 15 ... Focusing coil, 16 ... Tracking coil, 21 ... Cleaning member, 22 ...
Dummy disk, 25 ... Bias power supply (lens moving means),
26 ... Oscillator (vibration means).

Claims (5)

[Claims] 1. An optical head (4) is opposed to a disk supported and rotated by a turntable (1), and the optical head is moved in the radial direction of the disk to optically record information on the disk. In an optical disc reproducing device for reproducing, a dummy disc (22) provided with a cleaning member (21) on the disc surface
Is equipped with a lens cleaning device that is driven when the optical head is supported by a turntable to bring the objective lens of the optical head into contact with the cleaning member for cleaning, and the lens cleaning device is a focus control mechanism for the optical head. And a lens moving means (25) for bringing the objective lens into contact with the cleaning member of the dummy disk by using, and the objective lens brought into contact with the cleaning member is vibrated in the tracking control direction using the tracking control mechanism of the optical head. An optical disk reproducing apparatus comprising a vibrating means (26). 2. The optical disc reproducing apparatus according to claim 1, wherein the lens cleaning device is allowed to operate only when the rotation of the dummy disc is stopped. 3. The lens cleaning device is allowed to operate only when it is confirmed from the recorded information in the lead-in area of the disc mounted on the turntable that the disc is a dummy disc. 1. The optical disk reproducing device according to 1. 4. The optical disk device according to claim 1, wherein the lens cleaning device is permitted to operate only when receiving a signal issued by a lens cleaning command operation. 5. The optical disk reproducing apparatus according to claim 1, wherein the lens moving means moves the objective lens to a position where the objective lens comes into contact with the cleaning member of the dummy disk beyond the moving range of the focusing operation.