JP2005276379A - Optical pickup unit and optical disk drive - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make a user hardly insert his or her finger or the like into a grooved opening part of a chassis used also as a cover member. <P>SOLUTION: Both side parts 15a of the grooved opening part 15 of the chassis 2 is also used as a stopper wall part 14 regulating upward movement quantity of a chassis 2 of an objective lens 7 at the time of focusing drive of the objective lens 7 of an optical pickup 6, and the conventional two axis actuator cover is not needed any more, and groove width W12 of this grooved opening part 15 is reduced to size being slightly larger than the diameter ψ of the objective lens 7. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical pickup unit and an optical disk drive apparatus that are most suitable for application to an optical disk drive apparatus that reproduces optical disks such as CDs and DVDs and a magneto-optical disk drive apparatus that records and reproduces magneto-optical disks such as MO In particular, it covers the outside of the thread for transferring the mounted optical pickup in the radial direction of a disk-shaped recording medium such as an optical disk or a magneto-optical disk, and transfers the objective lens of the optical pickup along the groove-shaped opening. It relates to the cover member.

  Conventionally, as shown in FIGS. 6 and 8, a chassis 2 that also serves as a cover member of an optical pickup unit 1 used in an open type optical disk drive device such as a portable CD player or DVD player has high strength. It is molded into a horizontally long, nearly box shape with the bottom side open using engineering plastic, which is a synthetic resin. A spindle motor 3 is vertically mounted outside the one end side of the chassis 2, and a turntable 3 a is coaxially provided at the upper end of the spindle motor 3. A sled 4 and a sled transfer mechanism 5 are mounted horizontally inside the chassis 2, and an optical pickup 6 is mounted on the sled 4. The sled transfer mechanism 5 includes a lead screw 5b that also serves as a guide main shaft and a guide countershaft 5c that are driven to rotate forward and backward by a motor 5a. The optical pickup 6 includes an objective lens 7, a biaxial actuator 8, and the like. The objective lens 7 is transferred along a groove-shaped opening 11 formed along substantially the center of the upper wall 2a of the chassis 2. It is configured to be.

  Then, an optical disk D, which is a disk-shaped recording medium such as a CD or DVD, is horizontally chucked on the turntable 3a, rotated by a spindle motor 3, and light such as a laser beam is output by an objective lens 7 of an optical pickup 6. In a state where the beam is converged on the optical disk D from below through the groove-shaped opening 11 of the chassis 2, the thread 4 is transported in the transport direction a which is the radial direction of the optical disk D by the thread transport mechanism 5. By driving the objective lens 7 in the focusing direction b and the tracking direction c with respect to the optical disc 7 by the biaxial actuator 8 while seeking the objective lens 7 (= light beam) in the radial direction of the optical disc D, Focusing drive and tracking drive Data of the optical disk D performs is configured to perform the reproduction of the (information) (e.g., Patent Document 1).

  In the conventional optical pickup unit 1, when the objective lens 7 of the optical pickup 6 is driven to focus in the focusing direction b by the biaxial actuator 8, the objective lens 7 is moved outward from the groove-shaped opening 11 of the chassis 2. A stopper wall for restricting the amount of movement L of the objective lens 7 in the direction of the arrow b1 which is the outer side of the chassis 2 for the purpose of preventing the optical disk D from jumping out upward (in the focusing direction). A substantially box-shaped biaxial actuator cover 12 that also serves as a part is fixed on the thread 4 to cover the outer periphery of the objective lens 7.

That is, the horizontal top plate portion 12a of the biaxial actuator cover 12 is formed on the stopper wall portion, and the top plate portion 12a is formed in a substantially short shape. A through hole 2b that is sufficiently larger than the diameter φ (= 5.5 mm) of the objective lens 7 is formed in the substantially central portion of the top plate portion 12a. The objective lens 7 is loosely fitted in the through hole 12b with a gap that can move in the focusing direction b and the tracking direction c. Then, as shown by a one-dot chain line in FIG. 8, the coil bobbin in which the objective lens 7 is mounted on the upper end when the focusing 8 of the objective lens 7 is driven by the biaxial actuator 8 in the arrow b1 direction on the upper side. A pair of small protrusions 8b provided at the upper end of 8a collide with the top plate portion 12a of the biaxial actuator cover 12 from below, whereby the movement amount T1 of the objective lens 7 to the upper side of the chassis 2 (arrow b1 direction). Was regulated. Incidentally, this movement amount T1 is configured to be about 1.25 mm. The top plate portion 12 a of the biaxial actuator cover 12 is configured to be transferred in the transfer direction “a” along the groove-shaped opening 11 of the chassis 2 together with the thread 4.
JP 2002-230883 A

  The problem to be solved is that a substantially box-shaped biaxial actuator cover 12 also serving as a stopper wall portion is fixed on the thread 4 and the top plate portion 12a constituting the stopper wall portion of the biaxial actuator cover 12 is fixed. When the structure in which the objective lens 7 is loosely fitted in the through hole 12b is adopted, the lateral width W1 (about 13.5 mm) of the top plate portion 12a of the biaxial actuator cover 12 that is considerably larger than the diameter φ (5.5 mm) of the objective lens 7. ) Restricts the groove width W2 of the groove-shaped opening 11 of the chassis 2, so that the groove width W2 of the groove-shaped opening 11 is at least about 15.0 mm, which is about twice the diameter φ of the objective lens. It had to be configured with a considerably large width.

  Moreover, in this way, when the groove width W2 of the groove-shaped opening 11 is large (wide), particularly in an open type optical disk drive device, the user can easily and mistakenly put a finger or the like into the groove-shaped opening 11. Easy to insert. Then, a finger or the like inserted into the groove-shaped opening 11 touches a live part in the optical pickup 6 to cause an electrostatic breakdown of the optical pickup 6 or other foreign matters are transferred from the groove-shaped opening 11 to the chassis 2. The optical pickup 6 is likely to be seriously damaged due to being inserted therein. In addition, since the biaxial actuator cover 12 must be processed separately from the chassis 2 and assembled to the thread 4, the number of parts and assembly man-hours increase, resulting in a problem of increased costs.

  In the optical pickup unit of the present invention, an optical pickup is mounted on a sled that is transported in the radial direction of a disk-shaped recording medium, and an objective lens that is driven for focusing and tracking by a biaxial actuator of the optical pick-up is transferred to the sled transport path. In the optical pickup unit that moves along the groove-shaped opening of the cover member that covers the outside of the cover member, the amount of movement of the objective lens to the outside of the cover member during the focusing drive of the objective lens by the biaxial actuator is regulated The groove wall of the groove-shaped opening is configured to be small by using the stopper wall portion to be used on both sides of the groove-shaped opening of the cover member.

  The optical disk drive apparatus of the present invention includes a spindle motor that rotationally drives a disk-shaped recording medium, an optical pickup that is mounted on a sled and is transported in the radial direction of the disk-shaped recording medium, and a thread transfer path. And an objective lens that has a groove-shaped opening formed along the radial direction of the disk-shaped recording medium and is driven for focusing and tracking by a biaxial actuator of the optical pickup. And a cover member that is moved along the inside of the optical disc drive device. A stopper that restricts the amount of movement of the objective lens to the outside of the cover member when the objective lens is driven for focusing by the biaxial actuator. The wall is used on both sides of the groove opening of the cover member. By, is obtained by slightly configure the groove width of the groove-like opening.

  In the optical pickup unit and the optical disk drive device of the present invention, the groove width of the groove-shaped opening of the cover member to which the objective lens of the optical pickup is transferred can be configured to be small, so that, for example, an open type optical disk drive device In this case, the user accidentally inserts a finger into the groove-shaped opening and touches the optical pickup, or inserts another foreign object into the groove-shaped opening. Therefore, safety can be remarkably improved. The stopper wall that regulates the amount of movement of the objective lens to the outside of the cover member can also be used as the cover member, eliminating the need for the biaxial actuator cover that was required in the past and reducing the number of parts and the number of assembly steps Can run down.

It is preferable that the groove width of the groove-shaped opening of the cover member is set to the minimum diameter of the objective lens + 2 mm.
The cover member is formed such that at least the inner surface of the outer wall in which the groove-shaped opening is formed is parallel to the thread transfer direction, and the outer surface of the outer wall advances toward the outer periphery of the disk-shaped recording medium. It is preferable that the disc-shaped recording medium is inclined so as to be gradually separated from the medium, and has a relief structure against surface deflection during the rotational driving of the disk-shaped recording medium.
On the outer wall of the cover member, the outer surface of the outer wall of the cover member in which at least the groove-shaped opening is formed is inclined so as to be gradually separated from the disk-shaped recording medium as it moves away from both sides of the groove-shaped opening. By letting dust or the like adhering to the outside of the groove-like opening escape, the dust or the like can be prevented from dropping from the groove-like opening onto the internal optical pickup and adhering to the objective lens.
Since the cover member is also used as a sled transfer mechanism and / or a chassis on which a spindle motor is mounted, the number of parts and the number of assembling steps can be reduced.

First, a first embodiment of an optical disk drive device provided with an optical pickup unit to which the present invention is applied will be described with reference to FIGS.
In addition, about the same structure part demonstrated in FIG.6 and FIG.8, the same code | symbol is attached | subjected and description of the same structure part is abbreviate | omitted.

  As shown in FIG. 2, a chassis 2 that also serves as a cover member for the optical pickup unit 1 is mounted on a main chassis 22 of an optical disk drive device 21 such as an open type that is an optical disk drive device or a magneto-optical disk drive device. Yes. At this time, as shown in FIGS. 1, 2 and 4, a plurality of (for example, three) buffer means holding portions 23 integrally formed on the outer periphery of the chassis 2 are molded by an elastic member such as rubber. (For example, three) buffer means (insulators) 24 are mounted. The optical pickup unit 1 is inserted into an opening 25 formed in the main chassis 22, and the chassis 2 is elastically placed on the main chassis 22 via a plurality of buffer means 24. The center portion of the buffer means 24 is screwed onto the main chassis 22 with a set screw 26. Thus, the external vibration applied to the main chassis 22 can be buffered by the plurality of buffer means 24.

  Next, a groove-shaped opening 15 having a very small groove width W12 is formed in the upper side wall 2a, which is the outer wall of the chassis 2 that also serves as a cover member of the optical pickup unit 1, as will be described later. A pair that regulates the amount of movement T1 of the objective lens 7 in the direction of the arrow b1 on the outer side of the chassis (cover member) on the focusing drive shaft, which is the driving of the objective lens 7 in the focus direction b by the biaxial actuator 8. The stopper wall portion 14 is also used as both side portions 15 a of the groove-shaped opening 15.

  In other words, in the optical pickup unit 1 of the present invention, the objective lens 7 is moved by omitting the biaxial actuator cover 12 also serving as the stopper wall portion used in the conventional example shown in FIGS. The groove-like opening 15 is formed by using the stopper wall 14 that restricts the amount of movement T1 of the objective lens 7 in the direction of the arrow b1 at both sides 15a of the groove-like opening 15 of the chassis (cover member) 2. The groove width W12 is greatly reduced from about 15.0 mm of the conventional example to about 7.7 mm, which is slightly larger than the diameter of the objective lens 7.

  Incidentally, as an example of the biaxial actuator 8 of the optical pickup 6, the length of the groove-shaped opening 15 of the coil bobbin 8a in which the biaxial actuator base 8c is mounted on the sled 4 and the objective lens 7 is horizontally mounted on the upper end. Elastically to the support base 8e on the biaxial actuator base 8c via a pair of spring mechanisms 8d using a pair of upper and lower parallel springs in a direction orthogonal to the length direction of the groove-shaped opening 15 on both sides in the direction. A total of 8 coils 8f, 4 focusing driving coils and 4 tracking driving coils, are fixed to both sides of the coil bobbin 8a in the width direction of the groove-shaped opening 15 on both sides of the coil bobbin 8a. A pair of magnets 8g and a yoke 8b mounted vertically on the actuator base 8c are arranged in the width direction of the groove-shaped opening 15. Structure with inserted in a state having a play to the outer and the inner coil bobbin 8a is employed.

  Then, by energizing the four focusing driving coils in the eight coils 8f in total, the objective lens 7 is integrated with the coil bobbin 8a in parallel with the vertical focusing direction b against the spring force of the spring mechanism 8d. Drive to move. Further, by energizing the other four tracking driving coils in the eight coils 8f in total, the objective lens 7 is integrated with the coil bobbin 8a in the tracking direction which is the horizontal direction against the spring force of the spring mechanism 8d. It is comprised so that it may drive so that it may translate.

  As in the prior art, a pair of small protrusions 8b are provided at the upper end of the coil bobbin 8a of the biaxial actuator 8, and an arrow on the upper side of the objective lens 7 as shown by a one-dot chain line in FIG. At the time of focusing drive in the b1 direction, the pair of small protrusions 8b collide with the lower surfaces of the pair of stopper wall portions 14 that are also used on both side portions 15a of the groove-shaped opening 15 of the chassis (cover member) 2 from below. Thus, the amount of movement T1 (about 1.25 mm) of the objective lens 7 to the upper side of the chassis 2 (in the direction of the arrow b1) is regulated.

  As a result, the substantially box-shaped biaxial actuator 12 which has been conventionally required is not required, and the groove width W12 of the groove-like opening 15 of the chassis 2 is slightly larger than the diameter φ (= 5.5 mm) of the objective lens 7. For example, it could be reduced to about 7.7 mm.

  Thus, the optical pickup unit 1 of the present invention reduces the groove width W12 of the groove-shaped opening 15 of the chassis 2 from about 15.0 mm, which is the conventional groove width W2, to about 7.7 mm to about ½. As a result, in particular, in the open type optical disk drive device 21, it becomes impossible or difficult for the user to carelessly insert a finger or other foreign material into the groove-shaped opening 15. As a result, the user may inadvertently insert a finger or other foreign object deep into the groove-shaped opening 15 and touch the live part of the optical pickup 6 to cause electrostatic breakdown of the optical pickup 6. Further, it is possible to prevent a scandal such as mechanical damage to the optical pickup 6, and the safety is greatly improved.

  Further, the optical pickup unit 1 of the present invention has a stopper wall portion 14 for restricting the amount of movement of the objective lens 7 in the direction of the arrow b1 on the outer side of the chassis by the biaxial actuator 8 in the groove-shaped opening 15 of the chassis 2. Since the both side portions 15a are also used, the two-axis actuator cover 12 serving as a stopper wall that has been processed separately from the chassis 2 and attached to the thread 4 can be used as the chassis 2 itself. As a result, in the optical pickup unit 1 of the present invention, the biaxial actuator cover 12 that also serves as a stopper wall, which has been necessary in the past, is not required, and the number of parts and assembly man-hours of the optical pickup unit 1 are reduced. Can perform a significant cost reduction.

  On the other hand, in the optical pickup unit 1 of the present invention, as shown in FIG. 4, the inner surface 2 b that is the lower surface of the upper side wall 2 a that is the outer wall in which the groove-shaped opening 15 of the chassis 2 is formed is the transfer direction of the thread 4. It is formed on a horizontal plane 16 which is a plane parallel to a. On the other hand, the upper surface 2c which is the outer surface of the upper side wall 2a is an inclined surface (tapered surface which is an example of an inclined shape) 17 which is gradually separated downward from the optical disc D as it advances from the inner peripheral side to the outer peripheral side of the optical disc D. Is formed.

  As a result, as shown by a one-dot chain line in FIG. 4, even if a surface runout in the vertical direction d occurs on the outer peripheral side of the optical disc D during the rotation of the optical disc D by the spindle motor 3, the outer peripheral end of the optical disc D It is possible to avoid accidental contact of the Da side with the upper surface 2c (= inclined surface 17) of the upper side wall 2a of the chassis 2, and high safety can be ensured.

  Incidentally, the thickness t11 of the inner peripheral end 2a1 of the optical disc D on the upper side wall 2a of the chassis 2 is formed to be about 0.75 mm, and the thickness t12 of the outer peripheral end 2a2 of the optical disc D on the upper side wall 2a. Is formed to be approximately 0.45 mm, and the upper surface 2c of the upper side wall 2a is gradually lowered from the horizontal reference plane P1 at an angle θ1 as it advances from the inner peripheral end 2a1 to the outer peripheral end 2a2. A surface (tapered surface) 17 is formed.

  On the other hand, recently, in order to secure the stroke of the objective lens 7 of the optical pickup 6, particularly in the focusing direction b, thin processing (thin design) is required to reduce the thickness t of the upper side wall 2 a of the chassis 2. Yes. However, if the wall thickness t of the upper side wall 2a is reduced, it greatly affects the appearance surface such as sink marks and welds, and warpage of the upper side wall 2a is likely to occur. However, the inclined surface (tapered surface) is gradually separated downward from the optical disk D as the upper surface (outer surface) 2c of both side portions 15a of the groove-shaped opening 15 of the chassis 2 is advanced from the inner peripheral side to the outer peripheral side of the optical disc D. 17), even if the upper surface (outer surface) 2c is warped upward, the risk of the optical disc D coming into contact with the upper surface (outer surface) 2c can be avoided. Safety can be secured.

Next, a second embodiment of the optical disk drive device provided with the optical pickup unit to which the present invention is applied will be described with reference to FIG.
In the second embodiment, the upper surface (outer surface) 2c of the upper side wall (outer wall) 2 in which the groove-shaped opening 15 of the chassis 2 also serving as the cover member of the first embodiment is formed as the groove-shaped opening 15. It is formed on an inclined surface (tapered surface) 18 formed in an inclined shape so as to be gradually separated downward from the optical disc D as it moves away from both sides.
That is, in the direction e perpendicular to the length direction (radial direction a) of the groove-shaped opening 15 of the chassis 2, the angle from the horizontal reference plane P1 increases as the upper surface 2c of the upper side wall 2a moves away from the groove-shaped opening 15 in the left-right direction. It is formed on an inclined surface (tapered surface) 18 that gradually descends with θ2.

  As a result, the dust adhering to the upper surface 2c of the upper side wall 2a of the chassis 2 can escape to the left and right sides outside the groove-shaped opening 15 by the inclined surface 18 as shown by the arrow e. An effect is obtained that can be prevented from being dropped from the opening 15 onto the optical pickup 6 inside the chassis 2 and attached to the objective lens 7.

Although the embodiments of the present invention have been described above, various modifications can be made based on the technical idea of the present invention.
For example, the inclined shape indicating the inclined surface 17 of the first embodiment or the inclined surface 18 of the second embodiment of the upper surface (outer surface) 2c of the chassis 2 also serving as a cover member may be stepped. In addition, the inclined surface 17 of the first embodiment and the inclined surface 18 of the second embodiment may be formed on the chassis 2 alone, but may be formed by combining these inclined surfaces 17 and 18.
Further, the present invention can be applied to an optical pickup unit of various optical disk drive devices using an optical disk or a magneto-optical disk.

It is a perspective view explaining Example 1 of the optical pick-up unit of the optical disc drive apparatus to which this invention is applied. It is a top view of the state which mounted the optical pick-up unit of FIG. 1 on the chassis. It is an expanded sectional view by the AA arrow of FIG. It is a partially cutaway expanded sectional view by the BB arrow of FIG. FIG. 6 is a cross-sectional view similar to FIG. 3 for explaining an optical pickup unit 2 of an optical disk drive device to which the present invention is applied. It is a perspective view of the conventional optical pick-up unit. It is a top view of the conventional optical pick-up unit. It is an expanded sectional view in the CC arrow of FIG. 7 of the conventional optical pick-up unit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical pick-up unit 2 Chassis which also serves as a cover member 2a Upper side wall which is an outer wall of the chassis 2b Lower surface which is an inner surface of the upper side wall of the chassis 2c Upper surface which is an outer surface of the upper side wall of the chassis 3 Spindle motor 4 Thread 5 Thread transfer mechanism 6 Optical pickup 7 Objective lens 8 Biaxial actuator 14 Stopper wall portion 15 Groove opening portion 15a Both side portions also serving as stopper walls of the groove opening portion 16 Horizontal surface 17 Inclined surface which is an inclined surface 18 Inclined surface which is an inclined surface Surface 21 Main chassis 23 Buffer means holding part 24 Buffer means D Optical disk as a disk-shaped recording medium φ Diameter of objective lens W12 Groove width of groove-shaped opening

Claims (12)

An optical pickup is mounted on the sled transported in the radial direction of the disk-shaped recording medium,
In the optical pickup unit for transferring the objective lens that is driven to focus and track by the biaxial actuator of the optical pickup along the groove-shaped opening of the cover member that covers the outside of the transfer path of the thread,
Stopper walls that restrict the amount of movement of the objective lens to the outer side of the cover member when the objective lens is driven for focusing by the biaxial actuator are also used on both sides of the groove-shaped opening of the cover member. Thus, the groove width of the groove-shaped opening is configured to be small. 2. The optical pickup unit according to claim 1, wherein a groove width of the groove-shaped opening is set to a minimum diameter of the objective lens + 2 mm. The inner surface of the outer wall in which at least the groove-shaped opening of the cover member is formed is formed in a plane parallel to the thread transfer direction;
The outer surface of the outer wall is formed in an inclined shape so as to be gradually separated from the disc-shaped recording medium as it advances from the inner circumference side to the outer circumference side of the disc-shaped recording medium. Optical pickup unit. The outer surface of the outer wall on which the groove-shaped opening of the cover member is formed is formed so as to be gradually separated from the disk-shaped recording medium as it moves away from both sides of the groove-shaped opening. The optical pickup unit according to claim 1. The optical pickup unit according to claim 1, wherein the cover member is also used as a chassis on which at least the thread transfer mechanism is mounted. 2. The optical pickup unit according to claim 1, wherein the cover member is also used as a chassis on which at least the thread transfer mechanism and a spindle motor that rotationally drives the disk-shaped recording medium are mounted. A spindle motor that rotates and drives a disk-shaped recording medium;
An optical pickup mounted on a sled and transported in the radial direction of the disc-shaped recording medium;
An objective lens that covers the outside of the thread transfer path and has a groove-shaped opening formed along the radial direction of the disk-shaped recording medium, and is driven for focusing and tracking by the biaxial actuator of the optical pickup. An optical disk drive device comprising a cover member that is transported along the groove-shaped opening,
Stopper walls that restrict the amount of movement of the objective lens toward the outer side of the cover member when the objective lens is driven to focus by the biaxial actuator are also used at both sides of the groove-shaped opening of the cover member. Thus, the groove width of the groove opening is configured to be small. 8. The optical disk drive device according to claim 7, wherein the groove width of the groove-shaped opening is set to the minimum diameter of the objective lens + 2 mm. The inner surface of the outer wall in which at least the groove-shaped opening of the cover member is formed is formed in a plane parallel to the thread transfer direction;
8. The outer surface of the outer wall is formed in an inclined shape so as to be gradually separated from the disc-shaped recording medium as it advances from the inner circumference side to the outer circumference side of the disc-shaped recording medium. Optical disk drive device. The outer surface of the outer wall on which the groove-shaped opening of the cover member is formed is formed so as to be gradually separated from the disk-shaped recording medium as it moves away from both sides of the groove-shaped opening. The optical disk drive device according to claim 7. 8. The optical disk drive device according to claim 7, wherein the cover member is also used as a chassis on which at least the thread transfer mechanism is mounted. 8. The optical disk drive device according to claim 7, wherein the cover member is also used as a chassis on which at least the thread transfer mechanism and a spindle motor that rotationally drives the disk-shaped recording medium are mounted.

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