JP2939125B2 - Optical disk drive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for recording, reproducing and erasing information on an optical disk by irradiating a laser beam with an optical pickup having an objective lens guard for preventing collision between the disk and an objective lens. It concerns the device.

[0002]

2. Description of the Related Art FIGS. 6A and 6B are schematic explanatory views of an optical disk cartridge and an optical disk drive, wherein FIG. 6A is a top view of the optical disk cartridge, FIG. 6B is a side view of the optical disk cartridge, and FIG. FIG. 3 is a cross-sectional view taken along the line XY, showing a state during recording and reproduction of the device. The optical disk 1 is housed in a cartridge case 12 to form an optical disk cartridge 11.

In FIG. 6C, an optical disk 1 is positioned on a shaft 4 of a spindle motor 3 by a center hub 2. The center hub 2 is adjusted so that the track on the optical disc 1 is concentric with the hole 5 of the center hub 2 and is fixed to the optical disc 1 by bonding. The center hub 2 is partially or entirely made of a magnetic material. The center hub 2 is attracted by a chucking magnet 6 fixed to the spindle motor 3, and the optical disc 1 is pressed against the turntable surface 7 of the spindle motor 3. And rotates with the spindle motor 3. On the other hand, the optical pickup 8 has a laser light source and the objective lens 9
As a result, a spot is formed on the track of the optical disc 1. Further, a permanent magnet 10 for generating an auxiliary magnetic field is provided on the opposite side of the optical disc 1 from the optical pickup 8.
A magnetic field is generated on the optical disc 1 in a direction indicated by an arrow 100. With such a configuration, information is recorded on the disk according to the level of the laser power. The above is the description of the normal operation of the optical disk device such as the recording / reproduction or erasing. Next, loading of the optical disk cartridge will be described.

FIG. 7 is a schematic explanatory view showing the operation of the apparatus at the time of loading, and shows the relationship among an optical disk cartridge, a spindle motor, and an optical pickup inside the apparatus. The optical disk cartridge 11 is shown in FIG.
As shown in (a), it is inserted horizontally from outside the device. At this time, the optical disk 1 is placed on the cartridge case 12 by gravity.
Located at the bottom inside. In this state, FIG.
When the optical disk 1 comes directly above the spindle motor 3 as shown in (b), the cartridge 11 is lowered by a guide mechanism (not shown), and the optical disk 1 is loaded on the spindle motor 3 in the state shown in FIG. You. At this time, the optical disk 1 escapes from the state of contact with the cartridge case 12 and becomes freely rotatable by the spindle motor 3.

In an apparatus employing the loading method as shown in FIG. 7, since the cartridge 11 moves up and down, a dead space expressed by the product of the projected area of the cartridge and the vertical movement distance is large, which is disadvantageous for miniaturization of the apparatus. there were. For this reason, in many cases, a method of loading an optical disk onto a spindle motor by moving a spindle motor having a small projected area up and down without moving the cartridge up and down is used. FIG. 8 is a schematic view for explaining a loading method for moving the spindle motor up and down.
2 shows the relationship among an optical disk cartridge, a spindle motor, and an optical pickup inside the apparatus. FIG.
2A, the optical disk cartridge 11 is inserted horizontally from outside the apparatus along a cartridge guide mechanism 13 indicated by a broken line. At this time, the optical disk 1 is located at the lowest position inside the cartridge case 12 due to gravity. In this state, as shown in FIG. 8B, when the optical disk 1 comes directly above the spindle motor 3, the spindle motor 3 is raised by a motor guide mechanism (not shown).
The optical disc 11 is loaded on the spindle motor 3 in the state shown in FIG. At this time, the optical disc 1
The spindle motor 3 escapes from the contact state with the cartridge case 12 and becomes freely rotatable by the spindle motor 3.

[0006]

In order to reduce the size of the entire apparatus, it is desirable to adopt a loading system in which the spindle motor is moved up and down as described above. Further, in order to further reduce the size, it is necessary to reduce the working distance of the objective lens. Because the numerical aperture of the objective lens is fixed, when the working distance is reduced, the objective lens itself is also reduced, so the objective lens driving device for moving the objective lens is also reduced, and further, the light beam diameter inside the optical pickup is reduced. Because.

However, in an apparatus employing a loading system in which the spindle motor is moved up and down, if the working distance of the objective lens is reduced, the neutral position of the objective lens approaches the disk, and therefore, as shown in FIG. If the optical disc 1 is inserted in a tilted state, the optical disc 1 catches the objective lens 9 and there is a problem that the pickup is damaged. Here, the neutral position refers to the position of the objective lens in a state where power is not supplied. Normally, since the objective lens is supported by an elastic body, a balance of force is obtained at the neutral position.

[0008] A method of lowering the objective lens by applying a current to the objective lens driving device when a disc is inserted as in Japanese Patent Application Laid-Open No. 3-52123 is also conceivable. is there.

[0009]

Means for Solving the Problems] To solve the above problems, an optical disk device of the present invention includes a spindle motor for rotating the optical disk, recording of information on an optical disc, reproduction, laser light source and erasing An optical pickup having an objective lens for focusing a laser beam, and after inserting a cartridge holding the optical disk therein through an insertion slot, setting the cartridge at a predetermined position, and loading the optical disk by moving the spindle motor up and down In the optical disk device, a projection provided on the insertion port side of the objective lens of the optical pickup, projecting from the objective lens, and installed at a height between the optical disk and the objective lens. An optical pickup having an objective lens guard capable of height adjustment is provided. Further, the objective lens guard is characterized in that the shape of the objective lens guard is low on the side of the insertion opening of the optical disc and high on the side of the objective lens, and the objective lens guard is made of a buffer material.

The objective lens guard is a head of a screw having a tapered shape. The screw is screwed into a housing of the optical pickup via a compression spring, and the height of the objective lens guard is adjusted by turning the screw. Is performed.

[0011] Further, an objective lens guard is provided on a cover for driving the objective lens in the focus direction and the radial direction with respect to the optical disk and protecting the entire objective lens driving device. Further, the cover is screw-fixed to the housing of the optical pickup at two places, the cover has a narrow portion near the fixed portion, and the narrow portion is deformed by an adjusting screw and a spring provided at another position, The height of the objective lens guard can be adjusted by tilting the entire cover. In addition, together with the cover is secured to the housing of the optical pickup,
The cover has a deformable movable portion including the objective lens guard connected by a fixed portion and a narrow portion, and the deformable movable portion is tilted by an adjusting screw provided on the deformable movable portion, and the height of the objective lens guard is reduced. It can be adjusted.

The screw hole of the housing of the optical pickup into which the adjusting screw is screwed for adjusting the height of the objective lens guard is penetrated, and the set screw is brought into contact with the adjusting screw from the side opposite to the adjusting screw. The adjustment screw is fixed by screwing.

[0013]

With the above arrangement, in the optical disk apparatus of the present invention, when a cartridge is inserted in a loading system in which the spindle motor is moved up and down, the disk does not hit the objective lens regardless of the position of the disk in the cartridge case. The objective lens does not hurt because it rides on the objective lens guard first.

Further, since the height of the objective lens guard can be adjusted, the objective lens guard can be accurately arranged in the gap even if the difference in height between the disk and the objective lens becomes small.

[0015]

1 to 4 show an embodiment of the present invention. Members having the same functions as the members shown in the drawings of the conventional example are denoted by the same reference numerals.

FIG. 1 shows one embodiment of the present invention. FIG. 1 (a) is a plan view of an optical pickup having an objective lens guard of the present invention, and FIG. 1 (b) is FIG. 1 (a). A-
It is B sectional drawing. 1B, the objective lens 9 is held by an objective lens holder 14, and the objective lens holder 14 is supported by a leaf spring (not shown). The objective lens guard 15 is a screw having a tapered head 16 and is screwed to a housing 18 of the optical pickup 8 via a coil spring 17. By turning the objective lens guard 15, the height of the tip 19 can be adjusted between the neutral position of the objective lens and the disk. The coil spring 17 eliminates a gap between the threaded portions by its elastic force, so that adjustment can be stably performed. The screw portion 32 of the housing 18 is penetrated, and the set screw 40 is screwed from the bottom of the housing 18 until it hits the objective lens guard 15, thereby fixing the objective lens guard 15. Alternatively, without using the set screw 40, the objective lens guard 1 may be provided with an adhesive.
5 may be fixed. The tapered head 16 is desirably made or covered with a cushioning material such as plastic so that the disk is not damaged when colliding with the disk 1.

FIG. 2 shows another embodiment of the present invention. FIG. 2 (a) is a plan view of an optical pickup having an objective lens guard of the present invention, and FIGS. 2 (b) and 2 (c). () Is a cross-sectional view taken along a line AB in FIG. In FIG. 2B, the objective lens 9 is held by an objective lens holder 14 and supported by a leaf spring (not shown). The objective lens 9 and the objective lens holder 14 are integrally driven by a voice coil motor (not shown).
The objective lens driving device comprises the objective lens support mechanism and the voice coil motor. A cover 20 covering the entire objective lens driving device is fixed to the housing 18 by fixing screws 21 at two screw fixing portions. In addition, the cover 20 has an adjusting portion for adjusting the height of the protrusion formed by the adjusting screw 22 and the coil spring 23 at a position other than on a straight line formed by connecting the two fixing portions 21, 21.
The adjusting screw 22 is screwed to the housing 18 via a screw hole 24 of the cover 20 and a coil spring 23. By rotating the adjusting screw 22, the screw hole 24 moves up and down. At this time, the narrow portion 25 provided in the vicinity of the fixing portion of the cover 20 is twisted and deformed, so that the screw hole portion 24 can easily move up and down. The cover 20 can be tilted in the direction of the arrow 26 about the narrow portion 25 by the adjustment mechanism as described above. The cover 20 is provided on the insertion port side with respect to the objective lens 9 with a projection 27 having such a shape that the end on the objective lens side is the highest and becomes lower as approaching the spindle motor side. The height of the tip of the projection 27 changes. When the adjustment is completed, the through screw hole 32 into which the adjustment screw 22 is screwed.
Can be fixed by screwing the set screw 40 from the opposite side to the adjustment screw 22. Note that the set screw 40 may not be used but fixed with an adhesive.

FIG. 2C shows an embodiment in which the coil spring 23 in FIG. 2B is omitted. When the cover 20 is fixed with the fixing screws 21, the screw hole 24 is positioned upward. It is molded so that an upward force always acts on the head of the adjusting screw 22 in the horizontal position. FIG. 5 shows the cover 20 formed so that the screw hole 24 is located upward. As shown in FIG. 5, the fixing portion 31 of the fixing screw has an inclination, and when the fixing portion 31 is fixed with the fixing screw, the screw hole portion 24 is floated from the horizontal position, so that the screw hole portion 24 is adjusted. If the screw is fixed, an upward force always acts on the adjusting screw.

When the adjustment is completed, the set screw 40 can be fixed by screwing the set screw 40 from the opposite side of the through screw hole 32 into which the adjustment screw 22 is screwed until the set screw 40 hits the adjustment screw 22. In addition, set screw 40
Instead of using it, it may be fixed with an adhesive. The objective lens guard is configured with the above structure.

FIG. 3 shows a state where an optical disk 1 is inserted into an optical disk apparatus using the second embodiment of the present invention. The optical disc 1 inserted horizontally from the outside of the apparatus was located at a height that could collide with the objective lens 9, but was supported by an objective lens guard 27 provided on the insertion port side of the objective lens 9, By being pushed upward, collision with the objective lens is avoided.

FIG. 4 shows another embodiment of the present invention. FIG. 4 (a) is a plan view of an optical pickup having an objective lens guard of the present invention, and FIGS. 4 (b) and 4 (c). 4) is a cross-sectional view taken along a line AB in FIG. In FIG. 4B, the objective lens 9 is held by an objective lens holder 14 and supported by a leaf spring (not shown). The objective lens 9 and the objective lens holder 14 are integrally driven by a voice coil motor (not shown).
The objective lens driving device is composed of the objective lens supporting mechanism, the voice coil motor and the objective lens driving mechanism. A cover 20 covering the entire objective lens driving device is fixed to the housing 18 by bonding, fitting, screws or the like. The cover 20 has narrow portions 25, 25 formed by providing the notches 28, 29, and is transformed into a part of the cover 20 with the notches 28, 29 and the narrow portions 25, 25 as boundaries. The movable part 30 is formed. The deformable portion 30 includes a projection 27, a screw hole 24, and a narrow portion 25. When the adjusting screw 22 is rotated, the narrow portion 25 is elastically deformed. As a result, the height of the screw hole 24 is reduced. Instead, the protrusion 27
Height can be adjusted. The projection 27 is provided closer to the insertion port than the objective lens, as in the case shown in FIG. 2, and the portion near the objective lens is the highest, and is lower in the radial direction. FIG. 4B shows a case where the adjustment screw 22 is screwed into the housing 18 via the screw hole 24 and the coil spring 23, and the coil spring 2
By 3, the backlash of the screw is eliminated and stable adjustment is realized. After the adjustment, the set screw 40 is screwed into the through screw hole 3 into which the adjustment screw 22 is screwed.
The screw 2 is screwed from the opposite side to the adjustment screw 22 so as to be fixed. The set screw 40
May be fixed by using an adhesive without using the adhesive. The objective lens guard is configured with the above structure.

FIG. 4 (c) shows an embodiment in which the coil spring in FIG. 4 (b) is omitted. When the cover 20 is fixed to the housing, the screw hole 24 is formed so as to be located upward, and the horizontal position is obtained. In this state, an upward force always acts on the head of the adjusting screw 22. When the adjustment is completed, the adjustment screw 22 can be fixed by screwing the set screw 40 from the opposite side of the through screw hole 32 into which the adjustment screw 22 is screwed until the set screw 40 hits the adjustment screw 22. Note that the set screw 40 may not be used but fixed with an adhesive. In the embodiment shown in FIGS. 2 and 4, it is desirable that the protrusion 27 is made or covered with a buffer material such as plastic so that the disk is not damaged when the disk collides with the disk.

[0023]

When the cartridge is inserted in the loading method in which the spindle motor is moved up and down, the objective lens guard collides with the disk before the objective lens regardless of the position of the disk in the cartridge case. The disk does not hit the lens directly. For this reason, it is easy to adopt a loading method in which the spindle motor is moved up and down, which is effective in reducing the thickness of the apparatus.

The height of the objective lens guard can be adjusted. Even if the height difference between the objective lens and the turntable becomes very small, the objective lens guard can be brought into the gap between the objective lens and the turntable. Sometimes the objective lens guard does not hit the disc. Since the objective lens guard can be accurately positioned, an objective lens having a smaller working distance can be used. The fact that the working distance of the objective lens can be reduced can reduce the light beam diameter of the optical system in the pickup, which is advantageous for miniaturization of the pickup.
Further, since the numerical aperture is fixed, if the working distance is reduced, the objective lens itself is also reduced, so that the objective lens driving device can be reduced, which is advantageous in miniaturizing the optical pickup and, consequently, miniaturizing the entire device. .

Further, by fixing the adjusting screw with the set screw, the height position of the objective lens guard can be kept stable against aging and vibration, and the reliability of the apparatus can be improved.

[Brief description of the drawings]

FIG. 1 is a view showing an objective lens guard of the present invention.

FIG. 2 is a view showing another embodiment of the objective lens guard of the present invention.

FIG. 3 is a schematic diagram showing the operation of the objective lens guard of the present invention when an optical disc is inserted.

FIG. 4 is a view showing another embodiment of the objective lens guard of the present invention.

FIG. 5 is a view showing a cover used in FIGS. 2 and 3;

FIG. 6 is a schematic diagram of an optical disk cartridge and an optical disk drive.

FIG. 7 is a schematic diagram showing an operation at the time of loading of a conventional optical disc device.

FIG. 8 is a schematic diagram showing an operation at the time of loading of a conventional optical disc device.

FIG. 9 is a schematic diagram for explaining inconvenience in a conventional optical disk device.

[Explanation of symbols]

 Reference Signs List 1 optical disk 3 spindle motor 8 optical pickup 9 objective lens 11 optical disk cartridge 12 cartridge case 14 objective lens holder 15 objective lens guard 18 housing 20 cover 21 fixing screw 22 adjusting screw 23 coil spring 24 screw hole 25 narrow portion 27 projection 30 Deformable moving part 40 Set screw

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-3-152733 (JP, A) JP-A-4-129039 (JP, A) (58) Fields investigated (Int.Cl. ⁶ , DB name) G11B 7/08 G11B 7/09 G11B 7/095 G11B 7/12

Claims (8)

(57) [Claims] A spindle motor for rotating 1. A optical disc, recording information on the optical disc, reproduction, and an optical pickup having an objective lens for focusing the laser light source and a laser light erasing, inside the optical disc Retention
After the cartridge to be inserted is inserted from the insertion port, the optical disk device is installed at a predetermined position and loads the optical disk by moving the spindle motor up and down, provided on the insertion port side of the objective lens of the optical pickup. A projection protruding from the objective lens, installed at a height between the optical disc and the objective lens, and
An optical disk device comprising an optical pickup having an objective lens guard whose height can be adjusted in the meantime. 2. The optical disk apparatus according to claim 1, wherein the shape of the objective lens guard is such that the insertion opening side of the optical disk is low and the objective lens side has a high gradient. 3. The optical disk device according to claim 2, wherein the objective lens guard is made of a buffer material. 4. The objective lens guard is a head of a screw having a tapered shape. The screw is screwed to a housing of the optical pickup via a compression spring, and the height of the objective lens guard is increased by turning the screw. 4. The optical disk device according to claim 3, wherein the adjustment is performed. 5. The optical disk according to claim 3, wherein an objective lens guard is provided on a cover that protects the entire objective lens driving device and drives the objective lens in a focus direction and a radial direction with respect to the optical disk. apparatus. 6. The cover is screw-fixed to the housing of the optical pickup at two places, the cover has a narrow portion near the fixed portion, and the narrow portion is adjusted by an adjusting screw and a spring provided at another place. 6. The optical disk device according to claim 5, wherein the height of the objective lens guard can be adjusted by deforming and tilting the entire cover. 7. The deformable movable portion including the objective lens guard, wherein the cover is fixed to the housing of the optical pickup, and the cover is connected to a fixed portion and a narrow portion. allowed tilt the deformable movable portion by providing the adjusting screw, an optical disk apparatus according to claim 5, characterized in that to adjust the <br/> height of the objective lens guard. 8. The one of the claims 4, 6 and 7 1
In the optical disc device described in the paragraph, the screw hole of the housing of the optical pickup to which the adjustment screw is screwed is penetrated, and the set screw is screwed from the side opposite to the adjustment screw until the set screw hits the adjustment screw. An optical disk device to which an adjustment screw is fixed.