KR100626697B1 - An optical pick-up actuator - Google Patents

Abstract

The present invention discloses an optical pickup actuator in which the suspension wire can be maintained in a horizontal position (neutral position) without being inclined according to operating distances of different optical disks. The optical pick-up actuator of the present invention is provided with an operating distance adjusting device, wherein the operating distance adjusting device moves the wire holder according to the working distance of the different optical discs so that the blades are driven in a neutral position, that is, the position where the suspension wire is kept horizontal. To help. As described above, the present invention has the effect of lowering current consumption and improving stability against disturbance by allowing the blade to follow the track of the optical disk while the suspension wire is in the neutral position when recording / reproducing different optical disks.

Description

Optical pickup actuator {AN OPTICAL PICK-UP ACTUATOR}

      BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view for explaining the operation of a conventional optical pickup actuator including a BD-only objective lens and a CD / DVD common objective.

      Figure 2 is a perspective view showing the configuration of an optical pickup actuator according to the present invention.

      Figure 3 is a view for explaining the operation of the operating distance adjusting device in the optical pickup actuator according to the present invention.

      Figure 4 is a perspective view showing an example of the operation distance adjusting device in the optical pickup actuator according to the present invention.

      * Description of symbols on the main parts of the drawings *

      10: base 11, 12, 13, 14: magnet

      20: suspension wire 30: blade

      31: BD objective lens 32: CD / DVD objective lens

      33, 34: first coil 35, 36: second coil

      40: wire holder 50: operating distance adjusting device

      51 motor 53 screw shaft

      54: screw groove 60: control unit control

      The present invention relates to an optical pickup actuator, and more particularly, to an optical pickup actuator equipped with two different objective lenses so as to be compatible with different optical disks.

      An optical disc is a storage medium that records / reproduces data such as voice, images, documents, etc. by drilling a lot of pits on the surface thereof, and is typically a CD (Compact Disk) or a DVD (Digital Versatile Disk). Is equivalent to this. Recently, researches on high-density recording media with higher recording capacities as next-generation optical disks have been actively conducted. Such high-density recording media include BD (Blue-ray Disc) and AOD (Advanced Optical Disc). Such optical discs use laser light having different wavelengths and objective lenses having different numerical apertures depending on the amount of information to be stored. That is, CD uses near-infrared light with a wavelength of 780 nm and an objective lens of about 0.45, and DVD having a recording capacity of about 6 to 8 times compared with CD has an infrared light with a wavelength of 650 nm and an objective lens of about 0.65. BD, which has a recording capacity of about five times that of a DVD, records and reproduces information using a 405 nm wavelength blue violet laser light and an objective lens having a numerical aperture of about 0.85.

      The optical pickup device uses a semiconductor laser to provide information on the optical disc in a non-contact manner.

Refers to a device that records or plays back information stored on an optical disc. Ordinary

The optical pickup apparatus is provided with an optical pickup actuator which controls the position of the objective lens in the focusing direction, tracking direction and tilting direction so that the light can be focused on a desired track of the optical disk recording surface, thereby maintaining the focus of the optical spot. Control the light spot to follow the desired track.

      Recently, researches on optical pickup devices using two objective lenses have been actively conducted to be compatible with CDs, DVDs, and BDs. That is, CD, DVD, and BD are compatible by separately forming the optical system for BD and the optical system for CD / DVD, and using the objective lens for BD and the common objective lens for CD / DVD that can obtain the numerical aperture suitable for CD and DVD. It is to be able to adopt.

      BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view for explaining the operation of a conventional optical pickup actuator having a BD-only objective lens and a CD / DVD common objective. As shown in FIG. 1, the optical pickup actuator is equipped with a blade 1 that can be elastically flown by a plurality of suspension wires 4 equipped with a BD objective lens 2 and a CD / DVD common objective lens 3. ). In the case of driving in the focusing direction, the blade 1 moves in the vertical direction to maintain the focus of the light spot.

      However, each disc has a different working distance (BD: 0.55mm, CD: 0.75mm, DVD: 0.99mm, where operating distance means the distance between the optical disc and the objective lens during recording / playback of each optical disc). In view of this point, the two objective lenses 2 and 3 are mounted on the blade 1 to have different heights. Also, if the suspension wire 4 is in the neutral position (see FIG. 1A) when recording or playing a BD disc, the suspension wire 4 must be inclined upwardly than the neutral position in the case of a CD due to the difference in working distance. In the case of a DVD, the suspension wire 4 should be inclined downward from the neutral position (see FIGS. 1B and 1C). That is, the blade 1 follows the track of the CD or DVD with the suspension wire 4 tilted when recording or playing the CD or DVD.

      This inclination of the suspension wire 4 results in additional current consumption, less stability against disturbances, and tilt in the tilt direction compared to the case where the suspension wire 4 operates in a neutral position, i.e., in a horizontal state. It causes the problem of lowering the correction ability.

      In addition, in the related art, as the heights of the two objective lenses 2 and 3 are different from each other, the space occupied by the objective lens becomes large, and there is a problem in that the movable range in which the objective lens can move in the vertical direction is generated.

      SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object of the present invention is to provide an optical pickup actuator which can maintain a horizontal position (neutral position) without inclining the suspension wire according to the operating distances of different optical discs.

      Another object of the present invention is to provide an optical pickup actuator in which two objective lenses have the same height when two different objective lenses are mounted to be compatible with different optical discs.

      The optical pickup actuator according to the present invention for achieving the above object is a base, two blades are provided so that the two different objective lenses are elastically flowable on the base by a plurality of suspension wires, and the suspension wire It includes a wire holder for supporting, an operating distance adjusting device provided to move the wire holder in the vertical direction in accordance with the operating distance of the different optical disk, and an adjusting device controller for controlling the driving of the operating distance adjusting device. It features.

      The operation distance adjusting device includes a motor for providing power for the movement of the wire holder, and movement switching means for converting the rotational movement of the motor into a linear movement of the wire holder.

      When fixing the motor to the base in the lower portion of the wire holder, the movement switching means may be composed of a screw shaft rotated by the motor and a screw groove formed in the wire holder so that the screw shaft is inserted.

      Since the operation distance adjusting device moves the wire holder in the vertical direction in consideration of the operation distance according to each disk, the two different objective lenses may be mounted on the blade to have the same height.

      At this time, any one of the two different objective lenses may be a BD-only objective lens, the other objective lens may be a CD / DVD objective objective.

      Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in detail. 2 is a perspective view showing the configuration of an optical pickup actuator according to the present invention.

      As shown in FIG. 2, the optical pickup actuator according to the present invention is provided to be elastically flowable on the base 10 by a base 10 for supporting various components and a plurality of suspension wires 20. The blade 30 and the wire holder 40 for supporting the suspension wire 20 are provided.

      Two different objective lenses are mounted on the blade 30 so as to be compatible with different optical disks. In optical pickup devices compatible with CDs, DVDs, and BDs, an BD-only objective lens 31 and a CD / DVD objective lens 32 may be used, and the objective lenses 31 and 32 may be blades 30. Are placed side by side.

      The blades 30 are provided with first coils 33 and 34 wound in a vertical direction and second coils 35 and 36 wound in a horizontal direction. In addition, the base 10 is provided with magnets 11, 12, 13, 14, and the magnets interact with the coil as described above, so that the blade 30 is in the focusing direction (X-axis direction) or tracking direction (Y-axis). Direction). To this end, the magnets 11 and 12 are respectively installed to face the first coils 33 and 34, and the magnets 13 and 14 are respectively installed to face the second coils 35 and 36.

      The plurality of suspension wires 20 allow the blades 30 to be elastically supported on the base 10 while simultaneously providing passages for supplying current to the first coils 33, 34 and the second coils 35, 36. The role of the suspension wire 20 is fixed and supported by the wire holder 40. In FIG. 2, six suspension wires 20 are used, where a pair of wires supply current to the first coils 33 and 34, and a pair of wires are connected to the second coil 35. 36), and the last pair of wires is for supplying current in different directions to the second coils 35 and 36 for driving in the tilt direction (T direction).

      When a current in a predetermined direction is supplied to the first coils 33 and 34 in the optical pickup actuator, the blade 30 is driven in the tracking direction according to the left hand rule of flaming, and the second coils 35 and 36 are connected to the second coils 35 and 36. When a current in a constant direction is supplied, the blade 30 is driven in the focusing direction and follows the track of the optical disc. In addition, when current in different directions flows through the second coils 35 and 36, the blade 30 is driven in a tilt direction while being inclined by the forces in different directions on both sides.

      In addition, the optical pickup actuator according to the present invention is provided with an operating distance adjusting device 50 and a control device control unit 60 for driving the operating distance adjusting device 50 is provided to move the wire holder 40 in the vertical direction. Equipped. The working distance adjusting device 50 moves the wire holder 40 according to the working distance of different optical disks so that the blade 30 can be driven in a neutral position, that is, the position where the suspension wire 20 is kept horizontal. .

      3 is a view for explaining the operation of the operating distance adjusting device in the optical pickup actuator according to the present invention. As shown in FIG. 3A, in the case of recording / reproducing a BD, the adjusting device controller 60 adjusts the height of the wire holder 40 through the working distance adjusting device 50 in consideration of the working distance of the BD. Let the 20 stay in a neutral position. The blade 30 then drives in the focusing, tracking and tilt directions as the BD moves and follows the track.

      Similarly, when recording or playing a CD or DVD, the operation distance adjusting device 50 adjusts the position of the wire holder 40 in accordance with the operation distance of each optical disc (see FIGS. 3B and 3C), and then the blade ( 30) follows the movement of the CD or DVD.

      Figure 4 is a perspective view showing an example of the operation distance adjusting device in the optical pickup actuator according to the present invention. As shown in FIG. 4, the operation distance adjusting device 50 includes a motor 51 that provides power for the movement of the wire holder 40, and a linear movement of the wire holder 40 to rotate the motor 51. It is provided with a movement switching means for converting the movement. At this time, the motor may use a step motor.

      As shown in FIG. 4, the motor 51 may be fixed to the base 10 at the bottom of the wire holder 40, in which case the movement switching means is a screw shaft 53 coupled with the rotation shaft 52 of the motor 51. ) And a screw groove 54 formed in the wire holder 40 so that the screw shaft 53 can be inserted. The screw groove 54 is formed to have a predetermined depth from the bottom of the wire holder 40 to the inside of the wire holder 40. Therefore, when the screw shaft 53 inserted into the screw groove 54 is rotated by the motor 51, the wire holder 40 moves in the vertical direction. At this time, the guide member 55 is provided on the base 10 to prevent the wire holder 40 from rotating together with the motor 51 and to guide the movement of the wire holder 40.

      Since the example of the operating distance adjusting device described above is just one embodiment, various modifications may be made without departing from the spirit of the present invention.

      As described above, the present invention has the effect of lowering the current consumption and improving the stability against disturbance by allowing the blade to follow the track of the optical disk while the suspension wire is in the neutral position during recording / playback of different optical disks. have.

      In addition, the present invention has the effect that the movable range of the objective lens can be improved because the height can be matched without maintaining the assembly step of the two objective lenses in consideration of the operating distance of the different optical disk.

Claims (5)

      A base, two blades mounted with two different objective lenses to be elastically flowable on the base by a plurality of suspension wires, a wire holder for supporting the suspension wires, and a working distance of different optical discs. And an operating distance adjusting device provided to move the wire holder in the up and down direction, and an adjusting device control unit controlling the driving of the operating distance adjusting device.       The optical pickup actuator of claim 1, wherein the two different objective lenses are mounted on the blade to have the same height.       The optical pickup actuator of claim 1, wherein any one of the two different objective lenses is a BD-only objective lens, and the other objective lens is a CD / DVD common objective lens.       According to claim 1, wherein the operating distance adjusting device comprises a motor for providing power for the movement of the wire holder, and the movement switching means for converting the rotational movement of the motor into a linear movement of the wire holder. Optical pickup actuator.       The motor of claim 4, wherein the motor is fixed to the base at a lower portion of the wire holder, and the movement switching means includes a screw shaft rotated by the motor and a screw groove formed in the wire holder to insert the screw shaft. Optical pickup actuator, characterized in that the.

Images