JP2003036547A - Feed mechanism for optical pickup in optical disk record reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a feed mechanism, which can prevent tooth skipping that a tooth part is slipped from the thread groove of a lead crew and therewith the load applied to a motor can be reduced by minimizing the pressing force of a feed member to the lead screw. SOLUTION: In order to connect between an optical pickup 30 and a lead screw 40 and then slide and move an optical pickup 30 by the rotation of the lead screw 40, a holding part 54 fixed with the optical pickup is formed at an end, and the feed member 52 is arranged at the other end, on which a tooth part 56 fitted in the thread groove of the lead screw 40 and a latch 60 placed at a side facing to a side where the tooth part 56 of the lead screw 40 is fitted so that the fitting of the tooth part 56 and the thread groove is not slipped, are formed.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a CD, a CD-R,
Of an optical disk recording / reproducing apparatus for reproducing and / or recording information on an optical disk such as a CD-RW or a DVD,
The present invention relates to a feed mechanism of an optical pickup.

[0002]

2. Description of the Related Art An optical disc recording / reproducing apparatus for reproducing optical discs such as CDs, CD-Rs, CD-RWs and DVDs and / or recording data on the optical discs is provided with a feed for moving an optical pickup in the tracking direction of the optical discs. A mechanism is provided. Below, as an example of the feeding mechanism, an optical pickup is provided so as to slide on the thread axis passed in the tracking direction by the rotation of the lead screw.
A description will be given based on FIGS. 3 and 4.

The optical pickup 10 is slidably supported on the thread axis lines 12 and 13 by two thread shafts 12 and 13 arranged along the tracking direction (arrow A) of the optical disk. Reference numeral 15 is a lead screw. The lead screw 15 is a so-called threaded rod in which a thread groove is formed in a spiral shape on the outer peripheral surface, and is arranged so that its axis extends in the tracking direction A. The lead screw 15 is rotatably installed around the axis. The rotation of the lead screw 15 is performed by the motor 16.

The optical pickup 10 has a tooth portion 18 which is fitted into the thread groove of the lead screw 15 to be fitted therein.
Is provided with a feed member 20. Feeding member 20
Is a synthetic resin member extending from the optical pickup 10 in the direction of the lead screw 15, one end of which is fixed to a predetermined position of the optical pickup 10 and the other end of which is provided with the tooth portion 18 described above. Has been done. The other end of the feed member 20 is disposed above the lead screw 15, and the tooth portion 18 provided at the other end is provided so as to project downward.

The thread axis 12 of the optical pickup 10,
The motor 16 moves the lead screw 15
It is done by rotating. That is, the motor 16
When the lead screw 15 is rotated by driving, the tooth portion 18 of the feed member 20 moves along the spiral thread groove,
The feed member 20 moves the optical pickup 10 along the axis of the lead screw 15. In addition to the simple tooth portion 18, a nut shape may be considered as a shape for screwing the lead screw 15 and the feeding member 20 (not shown). However, since the nut-shaped one completely covers the periphery of the lead screw 15, the contact portion with the screw groove is increased and friction is large, so that it is not suitable for high speed rotation, and the load on the motor during driving is large. It was not adopted because it exists. Further, the structure such as the tooth portion 18 can also simplify the parts and reduce the weight,
It was adopted because it was considered suitable for use in the feed mechanism of an optical pickup.

The feeding member 20 is pressed in such a direction that the other end of the feeding member 20 is pressed against the lead screw so that the tooth portion 18 does not fall out of the thread groove (direction of arrow B in FIG. 4, that is, from top to bottom). It is attached with force.
That is, when the lead screw 15 is rotated,
There is a possibility that the tooth portion 18 receives a force from the side wall of the thread groove of the lead screw 18, and this causes the tooth portion 18 to be disengaged from the thread groove, and the screwing of the feed member 20 and the lead screw 15 may be released. This is because. In order to prevent the tooth portion 18 from coming off from the thread groove (this phenomenon is also referred to as tooth jump in this specification), the tooth portion 18 is pressed against the thread groove and fed. The member 20 is attached.

[0007]

In the above-mentioned feeding mechanism of the optical pickup, the feeding member is applied with a force to press the side where the tooth portion is provided so that the tooth portion does not come off from the thread groove of the lead screw. Was attached.
However, when the lead screw rotates at a high speed during a long jump, etc., the teeth are likely to come off no matter how much the feed member is pressed against the lead screw. However, there is a problem that it is an obstacle to speeding up reading and / or writing of the optical disk.

On the other hand, in order to realize the high-speed rotation of the lead screw and to reliably prevent the tooth portion from jumping, it is necessary to further increase the pressing force of the tooth portion of the feeding means. However, when the pressing force is increased, the load applied to the lead screw is increased, and the motor for rotating the lead screw also needs a large rotational torque. Therefore, there is a problem that the motor must be upsized.

Therefore, the present invention has been made to solve the above problems, and an object of the present invention is to prevent tooth jumping in which a tooth portion comes off a thread groove of a lead screw and to press a feeding member against a lead screw. It is an object of the present invention to provide an optical pickup feed mechanism capable of reducing the load on the motor by reducing the force as much as possible.

[0010]

That is, according to the feeding mechanism of the optical pickup in the optical disc recording / reproducing apparatus of the present invention, the feeding mechanism for sliding the optical pickup in the optical disc recording / reproducing apparatus in the tracking direction of the optical disc. An optical pickup, a threaded shaft that slidably supports the optical pickup in the tracking direction, a lead screw having an axis parallel to the tracking direction, and a screw groove spirally formed on the outer peripheral surface, and the lead screw. A fixed motor fixed to the optical pickup at one end for connecting the optical pickup to the lead screw and rotating the lead screw to slide the optical pickup by rotation of the lead screw. Part is formed and the other end is Prevention of disengagement provided on the side opposite to the side where the tooth portion of the lead screw is fitted so that the tooth portion fitted in the thread groove of the lead screw and the fitting of the tooth portion and the screw groove do not come off. And a feed member formed with a piece. By adopting this configuration, even when the lead screw is rotated at a high speed and the teeth are about to come off,
It is possible to press the feed member so that the disengagement prevention piece provided by sandwiching the lead screw contacts the lead screw and the tooth portion does not come off.

Since there is a gap formed between the disengagement prevention piece and the lead screw, the gap being narrower than the depth of fitting of the tooth portion and the screw groove, the lead screw is normally formed. Sometimes the disengagement prevention piece does not contact, so it does not hinder the rotation operation of the lead screw, but if the tooth part is about to come off, the disengagement prevention piece will contact the lead screw and cause good tooth skipping. Can be prevented.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a plan view of a feed mechanism of the optical pickup according to the present embodiment, and FIG. 2 is a sectional view of a feed member portion of the feed mechanism of the optical pickup shown in FIG. The optical pickup 30 is supported by two thread shafts 32 and 34. Both thread shafts 3
Reference numerals 2 and 34 are cylindrical rod members, which are arranged parallel to the tracking direction A of the optical disc (not shown).
For this reason, the optical pickup 30 includes both thread shafts 32,
It is slidable along 34 (ie in the tracking direction).

One of the two thread shafts 32 and 34 is the main thread shaft 32 and is inserted into the insertion hole 36 (see FIG. 2) of the guide portion 37 formed on the side surface of the optical pickup 30. The optical pickup 30 is supported. The other of the thread shafts is a sub thread shaft 34 provided on the side surface opposite to the main thread shaft 32 with the optical pickup 30 interposed therebetween. The sub thread shaft 34 has an auxiliary role of the main thread shaft 32. Secondary thread shaft 34
Are housed in a guide portion 39 provided on the side surface of the optical pickup 30 and having an open U-shaped cross section.

The lead screw 40 is a threaded rod in which a thread groove is spirally formed on the outer surface. The lead screw 40 is arranged parallel to the tracking direction A. Further, the lead screw 40 is axially supported by bearings (not shown) at both ends 41, 41 in the longitudinal direction so as to be rotatable about the axis.

The rotation driving mechanism of the lead screw will be described. The lead screw 40 is rotated by driving the motor 42. The motor 42 is fixed to a mechanical chassis (not shown) by a bracket 44. A drive gear 46 is attached to the rotary shaft 43 of the motor 42. The drive gear 46 is a drive gear 48 attached to the lead screw 40 via a drive gear 47.
The driving force of the motor 42 is transmitted to.

An encoder 49 is attached to the rotary shaft 43 of the motor 42 and rotates with the rotation of the rotary shaft 43. The bracket 44 is provided with an optical sensor 50 that detects the rotation of the encoder 49 with the encoder 49 interposed therebetween. The rotation of the motor 42 detected by the optical sensor 50 is
The motor 42 is input to a control unit (not shown) such as a CPU.
The rotation of is controlled by the controller.

The feeding member will be described. Reference numeral 52 is a feeding member. The feed member 52 is a member for moving the optical pickup 30 in the tracking direction by the rotation of the lead screw 40, and is made of synthetic resin in this embodiment. The feed member 52 is configured as a fixing portion 54 having one end fixed to the optical pickup 30, and the other end has a bifurcated tip end, which leads to the lead screw 40.
It is provided so as to sandwich. At the other end of the feed member 52, a tooth portion 56 fitted in the thread groove of the lead screw 40 is provided on the upper piece 57 located above the lead screw 40. The tooth portion 56 is a projecting portion formed to have a size that fits into the thread groove of the lead screw 40.

Below the lead screw 40, there are teeth 5
A disengagement prevention piece 60 for preventing tooth jumping of No. 6 is formed. The detachment prevention piece 60 is arranged so as to leave a gap of a predetermined distance k with respect to the lead screw 40. Here, the gap k between the detachment prevention piece 60 and the lead screw 40 is provided so as to be at least a value smaller than the fitting depth h between the tooth portion 56 and the thread groove.

The feed member will be further described. First,
The fixing portion 54 of the feeding member 52 is attached to the optical pickup 30 so that the other end of the feeding member 52 is pressed toward the lead screw 40 (in the direction of arrow B) so that the tooth portion 56 does not come out of the thread groove. . However, the feeding member 52
In this case, since the disengagement prevention piece 60 is provided for preventing tooth jumping, this pressing force can be minimized. Normally, the tooth portion 56 of the feeding member 52 is fitted to the lead screw 40, and the optical pickup 30 is moved by the rotation of the lead screw 40. Also, the lead screw 40
Since the detachment prevention piece 60 located on the lower side of the lead screw 40 does not contact the lead screw 40 in a normal state, no load is applied to the lead screw 40.

When the lead screw 40 is rotated at a high speed, the tooth portion 56, which receives a force in the tracking direction from the side surface of the thread groove, tends to move in the direction away from the thread groove (upward in FIG. 2). Then, the detachment prevention piece 60 also moves upward and comes into contact with the lead screw 40. At this time, the tooth portion 56 moves upward only by the gap k that the disengagement prevention piece 60 has, and the disengagement prevention piece 60 does not move even if the disengagement prevention piece 60 is disengaged.
Is in contact with the lead screw 40 and cannot move any further, so it will not come off from the thread groove. In this way, the disengagement prevention piece 60 can prevent tooth skipping.

In some cases, the lead screw 40 may continue to rotate even if the feed member 52 hits the end of the lead screw 40 due to poor control of the control unit or the like. In such a case, the position of the optical pickup 30 is already in a position where it cannot be moved anymore, so the tooth portion 5
If 6 does not come out of the thread groove and the teeth do not jump, the feed member 52 may be damaged. Therefore, when a certain force or more is applied to the feed member 52 in this way,
It is preferable that the detachment prevention piece 60 that comes into contact with the lead screw 40 is deformed to raise the other end 57 of the feeding member 52 and remove the tooth portion 56 from the thread groove. That is, at least the detachment prevention piece 60 of the feed member 52 is formed of a material that deforms when a predetermined force is applied. As described above, it is preferable that the detachment preventing piece 60 is formed of synthetic resin or the like that is capable of being deformed to some extent when a force of a certain amount or more is applied, because damage to the feeding member can be prevented.

The optical disk recording / reproducing apparatus to which the present invention is applied may be an apparatus having a function of only reproducing an optical disk, or an apparatus capable of both recording and reproducing.

Although the present invention has been variously described with reference to the preferred embodiments, the present invention is not limited to these embodiments, and many modifications can be made without departing from the spirit of the invention. Of course.

[0024]

According to the feeding mechanism of the optical pickup in the optical disk recording / reproducing apparatus of the present invention, even if the tooth portion is about to come off due to the high speed rotation of the lead screw, the detachment provided by sandwiching the lead screw is provided. The feed member can be pressed so that the preventive piece comes into contact with the lead screw and the tooth portion does not come off.

If a gap is formed between the disengagement prevention piece and the lead screw, the gap being narrower than the depth at which the teeth are fitted in the thread groove, the disengagement prevention piece is normally provided. Since it does not contact the lead screw,
Although it does not hinder the rotation operation of the lead screw, when the tooth portion is about to come off, the detachment prevention piece comes into contact with the lead screw, and tooth jump can be prevented satisfactorily.

[Brief description of drawings]

FIG. 1 is a plan view of a feeding mechanism of an optical pickup in an optical disc recording / reproducing apparatus according to the present invention.

FIG. 2 is a cross-sectional view of a feeding mechanism of an optical pickup in the optical disc recording / reproducing apparatus according to the present invention.

FIG. 3 is a plan view of a feeding mechanism of an optical pickup in a conventional optical disc recording / reproducing apparatus.

FIG. 4 is a sectional view of a feed mechanism of an optical pickup in a conventional optical disc recording / reproducing apparatus.

[Explanation of symbols]

30 optical pickup 32 Main thread axis 34 Secondary thread axis 36 insertion hole 37, 39 Guide part 40 lead screw 41 Edge 42 motor 43 rotation axis 44 bracket 46,47,48 drive gear 49 encoder 50 optical sensor 52 Feeding member 54 Fixed part 56 teeth 57 Upper piece 60 Disengagement prevention piece

Claims (2)

[Claims] 1. A feed mechanism for slidingly moving an optical pickup in an optical disc recording / reproducing apparatus in a tracking direction of an optical disc, the optical pickup, a sled shaft for slidably supporting the optical pickup in the tracking direction, and an axis line tracking A lead screw having a thread groove formed spirally on the outer peripheral surface, provided parallel to the direction, a motor for rotating the lead screw about an axis, and connecting the optical pickup and the lead screw. In order to slide and move the optical pickup by rotation of the lead screw, a fixing portion fixed to the optical pickup is formed at one end, and a tooth portion fitted in the thread groove of the lead screw at the other end, Make sure that the fitting between the teeth and the thread groove does not come off. Feeding mechanism of the optical pickup in the optical disc recording and reproducing apparatus characterized by comprising a feed member and de screw toothing mated side and out preventing piece that is provided on opposite sides of are formed. 2. A gap is formed between the disengagement prevention piece and the lead screw, the gap being narrower than the fitting depth of the tooth portion and the screw groove. An optical pickup feeding mechanism in the optical disc recording / reproducing apparatus according to 1.