JP4188575B2 - Optical pickup device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical pickup device used for reading or writing data recorded on a recording medium such as a CD (compact disc) or a DVD (digital versatile disc).
[0002]
[Prior art]
In the optical pickup device, an objective lens is held by a lens holder, and the lens holder is supported by an elastic member such as a wire suspension so as to be finely movable. Correction driving means for operating the lens holder in the focus direction and the tracking direction is provided.
[0003]
Since recent disk devices are required to be thin, the working distance WD between the objective lens and the disk is often set to about 1 mm or less than 1 mm. On the other hand, the correction range for moving the lens holder in the focusing direction is secured to a certain extent depending on the surface runout when the disc rotates, the runout of the turntable, the height error during assembly of the pickup device and the turntable, etc. It is necessary to.
[0004]
Accordingly, when the disk is loaded in the disk device and the reproduction operation is stopped and the focus servo by the correction drive means is in the OFF state, when the external vibration is applied, the lens holder moves in the focus direction and the objective is moved. The lens may hit the disc and scratch the disc. In particular, in an in-vehicle disk device, the probability that the lens holder moves due to vehicle body vibration increases, and the disk is easily damaged.
[0005]
In the conventional optical pickup device, as a means for preventing contact between the objective lens and the disk, a cover for covering the lens holder is provided, and the lens holder is applied to the cover when the lens holder is moved by external vibration. There is something.
[0006]
Alternatively, a lens holder made of a synthetic resin material is provided with a protrusion that protrudes from the surface of the objective lens, and when the lens holder is moved by external vibration, the protrusion is preferentially applied to the disk. Some discs prevent the disc from being damaged.
[0007]
[Problems to be solved by the invention]
However, in the structure in which the cover for covering the lens holder is provided as described above, the cover is positioned between the lens holder and the disk, and as a result, thinning of the disk device is hindered.
[0008]
Further, in the structure in which the lens holder is provided with the protrusion, the frequency with which the protrusion hits the disk is high, which is not optimal in terms of protection of the disk surface. Also, if no means for restricting the movement of the lens holder is provided, when the lens holder is tilted in the rolling direction due to external vibration or the like, the projection does not hit the disk, and the corner of the lens holder hits the disk, or A coil terminal provided on the side of the lens holder or solder attached to the coil terminal may hit the disk and damage the disk.
[0009]
The present invention is made to solve the conventional problems described above, the lens holder is possible and thinning can reduce the probability of hitting the recording medium, that is the outer edge portion of the further lens holder prevents effectively that hits the disk An object of the present invention is to provide a possible optical pickup device.
[0010]
[Means for Solving the Problems]
The present invention relates to a chassis, a support provided on the chassis, a lens holder supported by an elastic member extending from the support, and an object that is held by the lens holder and faces a recording medium positioned above the lens holder. And a correction driving means for operating the lens holder in a focusing direction F along the optical axis direction Oc of the objective lens and a tracking direction T orthogonal to both the extending direction of the elastic member and the optical axis direction Oc. In the provided optical pickup device,
When a center line passing through the center of the objective lens and extending in a direction perpendicular to the tracking direction is a tangential direction center line Or-Or,
The lens holder includes a protruding portion that protrudes from both sides sandwiching the tangential center line Or-Or and to which the tip of the elastic member is fixed, and is below the surface of the objective lens and the tangential center line. Abutting portions are provided on both sides of the Or-Or and projecting at positions different from the projecting portion, and stoppers are provided on both sides of the tangential center line Or-Or in portions other than the lens holder. And
The stopper does not protrude upward from the surface of the objective lens, and is opposed to the abutting portion with an interval upward without facing the protruding portion ,
The stopper is provided with a tracking restricting portion that is opposed to the contact portion with an interval in the tracking direction T, and the tracking restricting portion restricts the amount of movement of the lens holder in the tracking direction. it is characterized in that there.
[0011]
Preferably, when the lens holder is in a neutral position of a focus correction operation range, the stopper does not protrude upward from the surface of the objective lens and faces the contact portion with an interval upward. It is provided in the position to do.
[0012]
In the present invention, when the lens holder is moved by vibration, the contact portion hits the stopper, so that the probability that the lens holder hits the recording medium can be reduced. Further, since the contact portion and the stopper are formed at positions that do not protrude upward from the objective lens, the disk device can be thinned.
[0014]
In addition, the lens holder can be prevented from tilting in the rolling direction and hitting the recording medium, and the corner of the lens holder and the coil terminal protruding from the lens holder or the solder attached to the coil terminal can be prevented from hitting the recording medium. It becomes easy to prevent damage.
[0016]
By the lens holder for restricting the movement of larger in the tracking direction, damage to the lens holder, damage of the coils of the correction drive means, or the like deterioration of the elastic member can be prevented.
[0017]
The chassis is made of a sheet metal material. When the stopper extends integrally from the chassis, the chassis can be configured with a minimum number of parts. The stopper may be formed as a separate part from the chassis and fixed to the chassis, or the stopper may be provided on a fixed side other than the chassis, except for the lens holder or the movable part. Also good.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a plan view of an optical pickup device of the present invention, FIG. 2 is a side view showing a state in which the optical pickup device faces a disk as a recording medium, and FIG. 3 shows a state in which the optical pickup device also faces the disk. It is sectional drawing of the III-III line of FIG.
[0019]
The chassis 1 of this optical pickup device is configured by pressing one sheet metal material. The chassis 1 is mounted on a pickup base (not shown). The pickup base is equipped with a laser light emitting element, a rising mirror that applies laser light to the objective lens, a light receiving element, and the like, and the chassis 1 can adjust an installation angle (skew angle) with respect to the pickup base. Installed as follows.
[0020]
The chassis 1 includes left and right side plates 1a and 1b, a base support plate 1c that connects the side plates 1a and 1b on the base side, and a front support plate 1d that connects the side plates 1a and 1b on the front side. have. A part of the base support plate 1c is bent upward at a substantially right angle to integrally form a base yoke plate 1e, and the front support plate 1d is also bent at a substantially right angle to a front yoke plate. If is integrally formed.
[0021]
On both side plates 1a and 1b of the chassis 1, there are formed stoppers 2 and 3 extending upward from the sheet metal material. As shown in FIG. 3, the stoppers 2 and 3 are provided with focus restricting portions 2a and 3a bent inward from the upper ends thereof, and tracking restricting portions 2b and 3b extending upward on the same plane as the side plates 1a and 1b. Is formed.
[0022]
A support 5 made of a synthetic resin material is fixed to the upper surface of the base support plate 1c of the chassis 1, and an elastic formed by a printed circuit board made of glass epoxy or the like on the back of the support 5 is fixed. The central part of the deformable support plate 6 is fixed. One of the elastic arm portions 6a, 6a at the left and right ends of the support plate 6 is soldered to the base end portion of the wire suspension 7, 7 as an elastic member, and the other is the base end portion of the wire suspension 8, 8 to the solder. 9 and 9 are fixed.
[0023]
The wire suspensions 7, 7 and 8, 8 extend forward through the through holes 5 a, 5 a formed in the support 5, and are made of synthetic resin by the wire suspensions 7, 7, 8, 8. A lens holder 11 is supported. An objective lens 15 is held at the center of the lens holder 11.
[0024]
The wire suspensions 7 and 7 are parallel to each other, and the wire suspensions 8 and 8 are also parallel to each other. Two metal coil terminals 12 and 12 are fixed to one side of the lens holder 11 and two coil terminals 13 and 13 are fixed to the other side. The tip portions of the wire suspensions 7 and 7 are fixed to the coil terminals 12 and 12, and the wire suspensions 8 and 8 are fixed to the coil terminals 13 and 13 by fixing means capable of electrical conduction such as soldering. Has been.
[0025]
A focus coil Fc is wound around the lens holder 11. Two tracking coils Tc are fixed to the front and rear end faces of the lens holder 11 respectively.
[0026]
The terminal of the coil wire of the focus coil Fc is soldered to one of the coil terminals 12 and 12 and the coil terminals 13 and 13, and the terminal of the coil wire of the tracking coil Tc is also connected to the other coil terminal. Soldered. Therefore, a correction current can be supplied from the wire suspensions 7, 7 and 8, 8 to the focus coil Fc and the tracking coil Tc.
[0027]
Magnets M, M are fixed to the base yoke plate 1e and the front yoke plate 1f, and the magnets M, M are opposed to the focus coil Fc and the tracking coil Tc. The focus coil Fc, the tracking coil Tc, and the magnets M and M constitute correction driving means.
[0028]
Projections are integrally formed on both side portions of the lens holder 11, and the projections are contact portions 16 and 17. The focus restricting portions 2 a and 3 a of the stoppers 2 and 3 are opposed to the upper portions of the contact portions 16 and 17. 2 and 3 show a state in which the lens holder 11 is in a neutral position in the correction operation range in the focus direction F. FIG. When the lens holder 11 is in the neutral position, an interval δf in the focus direction is between the upper surface of the contact portion 16 and the focus restricting portion 2a and between the upper surface of the contact portion 17 and the focus restricting portion 3a. Opened.
[0029]
Further, when the lens holder 11 is in the neutral position in the correction operation range in the tracking direction T, between the contact portion 17 and the tracking restriction portion 2b and between the contact portion 17 and the tracking restriction portion 3b. The interval δt in the tracking direction is opened.
[0030]
The interval δf is necessary for focus correction in consideration of surface runout during rotation of the disk D, which is the recording medium, surface runout of the turntable on which the disk D is installed, and errors during assembly of the optical pickup device and the turntable. The objective lens 15 is set to approximately ½ of the operating range in the focus direction F. Similarly, the interval δt is set to approximately ½ of the correction operation range of the objective lens 15 in the tracking direction T.
[0031]
As shown in FIG. 3, the upper ends of the contact portions 16 and 17 and the stoppers 2 and 3 are lower than the surface of the objective lens 15 when the lens holder 11 is in the focus correction neutral position (disc Located on the side away from the As described above, the contact portions 16 and 17 and the stoppers 2 and 3 are located inside the thickness dimension of the lens holder 11, and the stoppers 2 and 3 are located between the lens holder 11 and the disk D. Therefore, it is possible to reduce the thickness of the entire optical pickup device.
[0032]
When the lens holder 11 is in the neutral position of the focus correction operation range, the working distance WD between the objective lens 15 and the disk D is set to 1 mm or less than 1 mm.
[0033]
In this embodiment, protective projections 19 are formed at the four corners of the upper surface of the lens holder 11 so as to extend slightly above the surface of the objective lens 15. The protective projections 19 are integrally formed of the same resin material as the lens holder 11, and the surface of each protective projection 19 has a curved shape, preferably a spherical shape. Further, the protective projection 19 may be formed of a material different from the lens holder 11, for example, a resin material or an elastomer softer than the lens holder 11 and fixed to the lens holder 11.
[0034]
In the optical pickup device, the lens holder 11 is corrected and driven in the focus direction F by the focus correction signal given to the focus coil Fc, and the lens holder 11 is corrected and driven in the tracking direction T by the tracking correction signal given to the tracking coil Tc. .
[0035]
When the supply of the focus correction signal and the tracking correction signal is cut off, external vibration such as vehicle body vibration is applied, and when acceleration is applied to the lens holder 11 in the direction of the disk D, the lens holder 11 moves upward. At this time, the contact portions 16 and 17 hit the focus restricting portions 2a and 3a located above the contact portions 16 and 17, so that the lens holder 11 does not approach the disk D any more. Therefore, even if the disk D is loaded in the disk device at this time, it is difficult for the surface of the objective lens 15 to directly contact the surface of the disk D.
[0036]
Further, the contact portions 16, 17 and the stoppers 2, 3 are parallel to the tangential centerline Or-Or shown in FIG. 1 (in parallel with the direction in which the wire suspensions 7, 7 and 8, 8 extend through the center of the objective lens). Because the lens holder 11 is located on both sides of the center line), even if the lens holder 11 is tilted around the tangential center line Or-Or (rolling direction), the contact portions 16 and 17 are the focus restricting portions. By hitting 2a and 3a, it is possible to prevent the lens holder 11 from hitting the disk D in an inclined state.
[0037]
Therefore, it is possible to prevent the left and right corner portions 11a and 11a of the lens holder 11 from hitting the disk D, or the coil terminals 12 and 13 or the solder attached to the coil terminals 12 and 13 from hitting the disk D.
[0038]
In order to prevent the lens holder 11 from inclining in the rolling direction and hitting the disk D, the contact portions 16 and 17 and the stoppers 2 and 3 are arranged on both sides of the tangential center line Or-Or. It is necessary to be. Furthermore, in the illustrated embodiment, the contact portions 16 and 17 protrude from both side portions of the lens holder 11, and the contact points between the contact portions 16 and 17 and the focus restricting portions 2a and 3a are the coils. Since the terminals 12 and 13 are located on the left and right outer sides of the soldering portion of the coil wire terminal, even if a tilting force in the rolling direction acts on the lens holder 11, the corner portions 11a and 11a and further the coil terminals The soldered parts 12 and 13 do not hit the disk D.
[0039]
In addition, since the surface deflection or the like during rotation of the disk D is large, as a result, even if the upper surface of the lens holder 11 hits the disk D, the protective protrusion 19 on the upper surface of the lens holder 11 contacts the disk D. The objective lens 15 does not directly hit the disk D. Further, the lens holder 11 moves upward until the contact portions 16 and 17 and the focus restricting portions 2a and 3a contact each other. At this time, even if the lens holder 11 hits the disk D, the lens holder 11 does not tilt. Hits the disk D in a state parallel to the disk D. Therefore, the four protective projections 19 come into contact with the disk D at the same time, and the possibility of scratching the disk D becomes extremely low.
[0040]
Further, even if a force in the tracking direction T acts on the lens holder 11 due to the external vibration, the lens holder 11 does not largely shake in the tracking direction by the contact portions 16 and 17 hitting the tracking restriction portions 2b and 3b. . Therefore, problems such as the coil terminals 12 and 13 being damaged, the coil wires being disconnected, or the wire suspensions 7, 7 and 8, 8 being deteriorated can be prevented.
[0041]
【The invention's effect】
As described above, according to the present invention, it is possible to prevent inconveniences such as the objective lens hitting the disc and damaging the disc when external vibration is applied. Further, since the stopper or the like does not protrude upward from the objective lens, the optical pickup device can be made thin.
[Brief description of the drawings]
FIG. 1 is a plan view of an optical pickup device of the present invention,
FIG. 2 is a side view showing a state where the optical pickup device is opposed to a disk;
3 is a cross-sectional view taken along line III-III in FIG. 1, showing a state in which the optical pickup device faces the disk;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Chassis 2, 3 Stopper 2a, 3a Focus control part 2b, 3b Tracking control part 5 Support body 7, 8 Wire suspension (elastic member)
DESCRIPTION OF SYMBOLS 11 Lens holder 12, 13 Coil terminal 15 Objective lens 16, 17 Contact part 19 Protection protrusion

Claims (3)

A chassis, a support provided on the chassis, a lens holder supported by an elastic member extending from the support, an objective lens facing the recording medium held by the lens holder and positioned above the lens holder, Light provided with a correction driving means for operating the lens holder in a focusing direction F along the optical axis direction Oc of the objective lens and in a tracking direction T orthogonal to both the extending direction of the elastic member and the optical axis direction Oc. In the pickup device,
When a center line passing through the center of the objective lens and extending in a direction perpendicular to the tracking direction is a tangential direction center line Or-Or,
The lens holder includes a protruding portion that protrudes from both sides sandwiching the tangential center line Or-Or and to which the tip of the elastic member is fixed, and is below the surface of the objective lens and the tangential center line. Abutting portions are provided on both sides of the Or-Or and projecting at positions different from the projecting portion, and stoppers are provided on both sides of the tangential center line Or-Or in portions other than the lens holder. And
The stopper does not protrude upward from the surface of the objective lens, and is opposed to the abutting portion with an interval upward without facing the protruding portion ,
The stopper is provided with a tracking restricting portion that is opposed to the contact portion with an interval in the tracking direction T, and the tracking restricting portion restricts the amount of movement of the lens holder in the tracking direction. optical pickup device characterized by there.   The stopper is provided at a position facing the abutting portion with an interval upward without protruding upward from the surface of the objective lens when the lens holder is in the neutral position of the focus correction operation range. The optical pickup device according to claim 1. The chassis is formed of sheet metal material, the stopper optical pickup apparatus according to claim 1 or 2, wherein extending integrally from said chassis.

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