JP2002319164A - Optical head device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical head device in which adhesion of dust incoming from the outside to the components of a magnetic driving mechanism to drive a lens holder supporting an objective lens is prevented with a simple structure without increasing the number of components. SOLUTION: An objective lens driving mechanism 3 provided with a magnetic driving mechanism is mounted on the device frame 2 of the optical head device 1, and a lens holder 32 holding an objective lens 31 is driven in a tracking direction and a focusing direction. The magnetic driving mechanism is provided with a drive coil attached to the circumferential surface of the lens holder 32 and a drive magnet attached to the portions 336 and 337 of the circumferential plate of a cup-shaped yoke plate 33 attached to the device frame 2. Notched parts 334 and 335 formed at the portions 336 and 337 of the circumferential plate of the yoke plate 33 are blocked by using the extended portion 712 formed by extending part of a flexible printed circuit board 6 for supplying electric power to the drive coil from the outside. Thereby, the adhesion of the dust incoming from the outside through the notched parts 334 and 335 to the components of the magnetic driving mechanism can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compact disc (CD) and a digital versatile disc (DVD).
The present invention relates to an optical head device used for reproduction of an optical recording disk such as the above. More specifically, the present invention relates to an optical head device in which a dustproof mechanism for various optical components mounted on an apparatus frame is formed using a flexible printed circuit board.

[0002]

2. Description of the Related Art In an optical head device used for reproducing an optical recording disk such as a CD or a DVD, a laser beam is applied to the optical recording disk by driving a lens holder holding an objective lens in a tracking direction and a focusing direction. It converges to a target position and reads information recorded there. The driving of the lens holder movably supported in the tracking direction and the focusing direction is generally performed by a magnetic drive mechanism. The magnetic drive mechanism includes a drive coil mounted on a lens holder and a drive magnet mounted on a yoke plate supported by the device frame.

[0003] The yoke plate has an arc shape so as to surround the outer peripheral surface of the lens holder, and its upper end opening is closed by a resin dust cover so as to cover the upper part of the lens holder. The use of the yoke plate and the dust-proof cover prevents dust that may cause a malfunction from adhering to the components of the magnetic drive mechanism.

On the other hand, various optical components are mounted on the device frame from the back side through a back surface opening. The back opening is closed by a back cover attached thereto so that dust and the like do not adhere to the optical components.

[0005]

Here, power is supplied to the drive coil attached to the lens holder which is the movable side.
This is performed by a flexible printed circuit board. in this case,
A cutout portion is formed in the yoke plate so that the wiring pattern of the flexible printed circuit board can be soldered to the drive coil constituting the magnetic drive mechanism. In addition, a cutout portion having a width that includes a moving range of the objective lens mounted on the lens holder in the tracking direction is formed on the yoke plate.

Due to the presence of such a notch, the conventional optical head device cannot reliably prevent dust from adhering to components of the magnetic drive mechanism.

Also, if the back opening attached to the back opening of the apparatus frame cannot be completely closed by the back cover attached thereto, dust and dirt enter through these gaps and adhere to optical components and the like. It is not preferable.

[0008] In view of the above, an object of the present invention is to provide:
An object of the present invention is to provide an optical head device capable of preventing dust and dirt from adhering to components of a magnetic drive mechanism with a simple configuration without increasing the number of components.

Another object of the present invention is to provide an optical head device capable of preventing dust and dirt from adhering to an optical component or the like mounted on an apparatus frame with a simple configuration without increasing the number of components. It is in.

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an apparatus frame, a lens holder supported on the apparatus frame so as to be movable in a tracking direction and a focusing direction, and While being disposed on the device frame and the lens holder,
An optical head device having a flexible printed circuit board for power supply bridged between them, a cover wall surrounding at least a part of the lens holder, and a cutout formed in the cover wall. In the above, the flexible printed circuit board has an extended portion not used as a wiring portion formed by extending a portion thereof, and the extended portion blocks at least a part of the cutout portion. I have.

Here, there is provided a magnetic drive mechanism for driving the lens holder in the tracking direction and the focusing direction. The magnetic drive mechanism includes a drive coil attached to an outer peripheral surface of the lens holder, and a drive coil attached to the drive coil. When a drive magnet is provided so as to face the yoke plate disposed on the apparatus frame, the yoke plate functions as the covering wall portion that covers the outer peripheral surface of the lens holder. The notch portion necessary for soldering the wiring pattern of the flexible printed board to the drive coil of the magnetic drive mechanism is formed in the yoke plate. Therefore, the notch may be closed by the extension of the flexible printed circuit board.

With this configuration, it is possible to prevent dust and dirt from adhering to the drive coil and the drive magnet through the cutout portion of the yoke plate without attaching another dustproof member.

In this case, the notch portion of the yoke plate has a notch portion for moving the lens having a width including a moving range of the objective lens held by the lens holder in the tracking direction. Is formed. In order to prevent dust and dirt from adhering to the components of the magnetic drive mechanism, the rising mirror and the collimator lens located below the objective lens through such a notch for moving the lens, It is preferable that the notch portion is also closed by the extension portion of the flexible printed circuit board.

Here, in order to reinforce such an extended portion, a dummy wiring pattern may be formed.

Next, the present invention provides an apparatus frame, a lens holder supported on the apparatus frame so as to be movable in a tracking direction and a focusing direction,
A power supply flexible printed circuit board disposed between the device frame and the lens holder and extending between the device frame and the lens holder, and an optical element mounted on the device frame from an opening on the back surface of the device frame. In the optical head device, the flexible printed circuit board has an extension portion that is not used as a wiring portion formed by extending a portion of the extension portion, and the extension portion covers the optical element mounted on the device frame. In addition, at least a part of the back surface opening is closed.

By using a part of the flexible printed circuit board as described above, the opening on the rear surface of the apparatus frame can be closed, and dust and dirt adhere to the optical elements and the like mounted on the apparatus frame. Can be prevented.

In the case where the flexible printed circuit board has a light receiving element mounted on the device frame from the back surface opening, the flexible printed circuit board has a soldered portion for connection to the light receiving element. . In this case, if the extension portion is an extension portion formed by expanding the soldering portion in the front-rear and left-right directions, smoke or the like generated at the time of soldering is mounted in the device frame from the opening on the back surface and the optical element Is preferable since it can be prevented from wrapping around and adhering to them.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of an optical head device to which the present invention is applied will be described below with reference to the drawings.

(Overall Configuration) FIG. 1 is a schematic configuration diagram showing an optical system of an optical head device. Referring to FIG. 1, an optical head device 1 of the present embodiment performs information recording and information reproduction on an optical recording disk 5 such as a CD or a DVD, and is made of a metal or resin device frame such as aluminum. 2 and an objective lens driving mechanism 3 mounted on the front surface 21a. Objective lens drive mechanism 3
Is an objective lens 31 that causes light emitted from a laser light source 41 mounted on the apparatus frame 2 to converge on the optical recording disk 5.
Is moved in the focusing direction F along the support shaft 35 and is rotated in the tracking direction T.

At both ends of the device frame 2, a main shaft guide hole 22 formed of a round hole and a sub shaft guide groove 23 projecting in a U-shape are formed. Each of the guide hole 22 and the guide groove 23 is formed. Along a main axis and a sub-axis (not shown) of the recording / reproducing apparatus main body passed through the optical head device 1.
Can move in the radial direction of the optical recording disk 5.

The apparatus frame 2 includes a surface plate portion 21 and an outer peripheral wall portion 2 extending perpendicularly downward from the outer peripheral edge portion.
6 and a back surface opening 24 is formed on the back surface side. The back opening 24 is closed by a back cover 25. Inside the device frame 2, a laser light source 41,
A half mirror 42 as a beam splitter that reflects the laser light emitted from the laser light source 41, and a rising mirror 43 that raises the laser light are mounted.
A light receiving element 45 for receiving return light reflected by the optical recording disk 5 is also provided. A collimator lens 44 for collimating outgoing light raised toward the objective lens 31 is provided in an opening 21b opened in the apparatus frame surface plate portion 21.
Is attached.

FIGS. 2A, 2B and 2C are a plan view, a side view and a rear view, respectively, showing the optical head device of FIG. The configuration of the objective lens driving mechanism 3 will be described with reference to FIGS.

The objective lens driving mechanism 3 includes an objective lens 31
Lens holder 32 for holding
, And a magnetic drive mechanism 30 for moving the objective lens 31 in the tracking direction T and the focusing direction F. The magnetic drive mechanism 30
A cup-shaped yoke 33 having an open upper part;
3, an upper cover 34 closing the upper opening, focusing driving magnets 51 and 52 and tracking driving magnets 53 and 54 attached to the inner peripheral side surface of the yoke 33, and these driving magnets 51 to 54.
And focusing drive coils 55 and 56 and tracking drive coils 57 and 58 attached to the outer peripheral side surface of the lens holder 32 so as to face the lens. In FIG. 2, the top cover 34 is omitted for easy understanding of the configuration of the objective lens driving mechanism 3.

Here, the yoke 33 is connected to the bottom plate portion 331 attached to the surface plate portion 21 of the apparatus frame 2.
And an outer peripheral plate portion 332 formed by raising the outer peripheral edge portion of the bottom plate portion 331 at a right angle. The support shaft 35 stands upright at the center of the bottom plate portion 331. Therefore, the outer peripheral plate portion 332 has an arc shape centered on the support shaft 35. As can be seen from FIG. 2A, the outer peripheral plate portion 332 has a shape symmetrical with respect to a line passing through the center of the objective lens 31 and the center of the support shaft 35. That is, a notch portion 333 formed in the outer peripheral plate portion 332 with a width including the moving range of the objective lens 31 in the tracking direction T, and the notch portion 33
A pair of left and right cutout portions 334 and 335 formed on the opposite side in the diametric direction with respect to 3 form a pair of arc-shaped outer peripheral plate portions 336 and 337 and an outer periphery for relaying a flexible printed circuit board located therebetween. A plate portion 338 is formed.

(Flexible Printed Circuit Board) Here, the objective lens driving mechanism 3 mounted on the apparatus frame 2 and the laser light source 41 mounted inside the apparatus frame 2 are externally supplied with power by the flexible printed circuit board 6. Through this, a detection signal from the light receiving element 45 is taken out to the outside.

FIG. 3 is a plan view showing a state in which the flexible printed circuit board 6 is developed on a plane. Referring to FIG. 2 and FIG.
Is bent in a U-shape so as to go from the front surface 21a of the device frame 2 to the back surface 24a via the side surface 26a, and has a surface routing portion 61 disposed on the front surface 21a of the device frame 21 and a side surface 26a. It has a side running part 62 arranged and a back side running part 63 arranged on the back surface 24a.

A connection terminal 611 for connecting an external power supply is attached to the surface routing portion 61, and a control IC including a signal processing circuit for processing a signal from the light receiving element 45 and the like is mounted to the side routing portion 62. A chip 621 is mounted. Further, the rear surface routing portion 63 is arranged along the inner surface of the back cover 25 of the device frame 2.

The surface routing portion 61 includes a first connection portion 71 for supplying power to drive coils 55 to 58 attached to the lens holder 32 and a surface 21 of the device frame 2.
a and a second connecting portion 72 for supplying power to an optical component attached to the side surface of the device frame 2, and the rear surface routing portion 63 for supplying power to an optical element disposed inside the device frame 2. It has a third connection portion 73.

Here, the first connecting portion 71 of the surface routing portion 61 includes a wiring portion 711 on which a wiring pattern for supplying power to the drive coils 55 to 58 is formed, and a wiring portion 7.
An extension 712 is formed by further extending the tip of the extension 11. This extension 712 has no wiring pattern formed at the portion on the wiring portion 711 side, but has a reinforcing wiring pattern 71
2a is formed.

The second connecting portion 72 includes a wiring portion 721 on which a wiring pattern for supplying power to the optical parts mounted on the front surface 21a of the device frame 2 and the side surface of the device frame 2 is formed. To the first connection portion 711
And an extension 722 formed by extending toward the side (the objective lens driving mechanism 3 side). The extension portion 722 has no wiring pattern formed on the side portion of the wiring portion 721, but has a reinforcing wiring pattern 722a formed on the tip side portion. Therefore, the extension 7
22 is a broken line 72 indicated by a two-dot chain line with the wiring portion 721.
By bending at 3, it can be raised from the second connection portion 72.

The third connecting portion of the rear surface routing portion 63 is
A wiring portion 731 on which a wiring pattern for supplying power to the optical element disposed inside the device frame 2 is formed, and an extension portion formed by expanding the soldering portion 732b of the optical element of the wiring portion 731 in the front, rear, left, and right directions. 732. The extension portion 732 has no wiring pattern formed on the portion on the side of the wiring portion 731, but has a reinforcing wiring pattern 732 a formed on the tip side portion.

FIGS. 4 to 6 show first to third connection portions 7 of the flexible printed circuit board 6, respectively.
It is an expansion perspective view which shows 1,72,73. In these figures, the top cover 34 is omitted.

First, as shown in FIG. 4, the first connecting portion 71 is formed by a pair of arc-shaped outer peripheral plate portions 336 of the yoke 33,
It is routed along the outer periphery of 337, and is adhesively fixed to a flexible printed circuit board relay outer peripheral plate portion 338 located therebetween. The first connecting portion 71 is provided with left and right cutout portions 334, 33 of the outer peripheral plate portion 338.
5 is routed from the right cut-out portion 335 side, the right cut-out portion 335 is closed by the wiring portion 711, and the left cut-out portion 334 is closed by the extension 712 formed at the end of the wiring portion 711. are doing. Therefore, it is possible to prevent dust and dirt from adhering to the drive coil and the drive magnet through the cutout portions 334 and 335 of the yoke plate.

The distal end of the extension 712 is fixed between the left arc-shaped outer peripheral portion 336 formed with the left cutout portion 334 therebetween and the drive magnet 53 attached to the outer peripheral portion 336. Just do it.

Next, as shown in FIG.
2 is attached to the surface 21a of the device frame 2 on the side where the objective lens 31 supported by the lens holder 32 is arranged. The second connecting portion 72 has a notch for moving the objective lens formed between the arc-shaped outer peripheral plate portions 336 and 337 of the yoke 33 on the objective lens 31 side when the extension portion 722 is raised from the wiring portion 721. The part 333 is closed. Accordingly, dust and dirt are removed from the components of the magnetic drive mechanism and the objective lens 3 through the lens moving cutout portion 333.
1 can be prevented from adhering to the rising mirror 43, the collimator lens 44, and the like located below. The rising portion of the extension 722 is reinforced by a dummy wiring pattern 722a.

The third connecting portion 73 is, as shown in FIG.
It is arranged along the inside of the back cover 25 attached to the back opening 24 of the device frame 2 with screws 25a. The third connecting portion 73 closes the back surface opening 24 with the extension 732. Therefore, it is possible to prevent dust and dirt from adhering to the optical element and the like mounted on the apparatus frame 2 from the rear opening 24.

The extension portion 732 is connected to the wiring portion 731.
Is formed by expanding the soldering portion 732b of the optical element in the front, rear, left and right directions, so that smoke generated when soldering to an optical component such as the light receiving element 45 is mounted in the apparatus frame 2 from the rear opening 24. It can also be prevented from wrapping around the optical element such as the rising mirror 43 and adhering to them.

As described above, in the optical head device 1, the flexible printed circuit board 6 includes the wiring portions 711, 721, 73
It has extensions 712, 722, 732 that extend from 1. With these extensions 712, 722, 732,
Notch portions 333, 334, 335 formed in yoke 33 covering lens holder 32, and device frame 2
Can be covered with the rear opening 24. Therefore, it is possible to take measures against dust in the optical head device 1 without adding new components.

[0039]

As described above, the optical head device of the present invention utilizes the flexible printed circuit board to cut out the notch formed in the covering wall covering the outer peripheral surface of the lens holder and the device. The opening on the back of the frame is closed.

Therefore, according to the present invention, using the flexible printed circuit board, dust or dirt entering from outside through these notched portions or the back surface opening moves the lens holder in the tracking direction and the focusing direction. To the components of the magnetic drive mechanism and the optical components mounted on the device frame. Therefore, it is possible to easily take measures against dust in the optical head device without increasing the number of components.

Further, by using a part of the flexible printed circuit board as a dust-proof cover, there is an advantage that repair and disassembly can be facilitated as compared with a case where dust-proof measures are performed by covering with metal or resin.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an optical system of an optical head device to which the present invention has been applied.

FIGS. 2 (a), (b) and (c) respectively show FIGS.
FIG. 3 is a plan view, a side view, and a rear view showing the optical head device of FIG.

FIG. 3 is a development view showing a state in which the flexible printed circuit board of FIG. 2 is developed.

4 is an enlarged perspective view of a portion where a first connection portion is located on the flexible printed circuit board of FIG. 2 attached to the optical head device.

FIG. 5 is an enlarged perspective view of a portion where a second connection portion is located in the flexible printed circuit board of FIG. 2 attached to the optical head device.

FIG. 6 is an enlarged perspective view of a portion where a third connection portion is located on the flexible printed circuit board of FIG. 2 attached to the optical head device.

[Explanation of symbols]

 Reference Signs List 1 optical head device 2 device frame 3 objective lens driving mechanism 5 optical recording disk (optical recording medium) 6 flexible printed circuit board 21 surface plate portion 21a surface 21b opening 26 outer peripheral wall 26a side surface 24 back opening 24a back surface 25 back cover 30 Magnetic drive mechanism 31 Objective lens 32 Lens holder 33 Yoke 34 Top cover 35 Support shaft 41 Laser light source 42 Half mirror 43 Start-up mirror 44 Collimator lens 45 Light receiving element 51, 52 Focusing drive magnet 53, 54 Tracking drive magnet 55, 56 Focusing drive coil 57, 58 Tracking drive coil 61 Front surface routing portion 62 Side surface routing portion 63 Back surface routing portion 71 First connection portion 72 Second connection portion 73 Third connection portion 331 Bottom plate portion 332 Peripheral plate portion 333, 334, 335 Notched portion 336, 337 Arc-shaped peripheral plate portion 338 Peripheral plate portion for flexible printed circuit board relay 711, 721, 731 Wiring portion 712, 722, 732 Extension portion 712a, 722a, 732a Reinforcement Wiring pattern 732b Soldering part

Claims (6)

[Claims] 1. An apparatus frame, a lens holder supported by the apparatus frame in a movable state in a tracking direction and a focusing direction, and disposed on the apparatus frame and the lens holder, and between the apparatus frame and the lens holder. An optical head device having a flexible printed circuit board for feeding power, a covering wall surrounding at least a part of the lens holder, and a cutout formed in the covering wall; An optical head device, wherein the printed circuit board has an extension portion that is not used as a wiring portion formed by extending a portion of the extension portion, and the extension portion blocks at least a part of the cutout portion. . 2. The device according to claim 1, further comprising a magnetic drive mechanism for driving the lens holder in a tracking direction and a focusing direction, wherein the magnetic drive mechanism includes a drive coil attached to an outer peripheral surface of the lens holder; A drive magnet attached to a yoke plate disposed on the device frame so as to face the drive coil, wherein the yoke plate functions as the covering wall portion that covers an outer peripheral surface of the lens holder. An optical head device, wherein a part of the cutout portion formed in the yoke plate is closed by the extended portion of the flexible printed circuit board. 3. The notch portion of claim 2, wherein the notch portion of the yoke plate includes a notch portion for moving a lens having a width including a moving range in a tracking direction of an objective lens held by the lens holder. An optical head device, wherein the extended portion of the flexible printed board includes a blocking portion for blocking a part of the cutout portion for moving the lens. 4. The optical head device according to claim 3, wherein a reinforcing wiring pattern is formed in the closed portion. 5. An apparatus frame, a lens holder supported by the apparatus frame in a movable state in a tracking direction and a focusing direction, and disposed on the apparatus frame and the lens holder, and between the apparatus frame and the lens holder. In an optical head device having a flexible printed circuit board for power supply that is bridged and an optical element mounted on the device frame from the opening on the back surface of the device frame, the flexible printed circuit board is formed by extending a part thereof. An extension not used as a formed wiring portion is provided, and the extension closes at least a part of the back surface opening to cover the optical element mounted on the device frame. Optical head device. 6. The light-receiving device according to claim 5, further comprising a light-receiving element mounted on the device frame through the back surface opening, wherein the flexible printed circuit board includes a soldering portion for connecting to the light-receiving element. The optical head device is characterized in that the extension portion is an extension portion formed by expanding the soldered portion in front, rear, left and right.