KR19980058061A - Shaft coupling structure of actuator for DVD - Google Patents

Abstract

The present invention relates to a shaft coupling structure of the actuator for the DVD, the objective lens (L1) for the DVD by the shaft 11 of the yoke plate 20 is inserted through the shaft insertion hole (1) of the lens holder 10 and In the shaft coupling structure of the axial perturbation DVD actuator for guiding the lifting and the left and right movement of the lens holder 10 having the objective lens L2 for a compact disc, the center of the lens holder 10 On the inner circumferential surface of the formed shaft insertion hole (1) is attached a magnetic (2) having a cylindrical shape and inserted into the shaft insertion hole (1) of the lens holder 10 to support the lens holder 10 ( The outer circumferential surface of 11) has a structure in which a magnetic 12 having the same polarity as that of the magnetic 2 of the shaft insertion hole 1 is attached to the shaft. From 11) Is configured's movement of the holder 10 is made so smooth.

Description

Shaft coupling structure of actuator for DVD

The present invention relates to a sliding actuator for a DVD, a magnetic having a cylindrical shape is attached to the inner circumferential surface of the shaft insertion hole of the lens holder having the objective for DVD and the objective for the compact disc, combined with the lens holder and the lens The outer peripheral surface of the shaft to support the holder is attached to the magnetic having the same polarity as the magnetic of the shaft insertion hole is configured to facilitate the movement of the lens holder from the shaft by the magnetic bearing effect according to the repulsive force between the magnetic.

In general, a player that uses an optical disc as a recording medium such as a compact disc, a laser disc, or a mini disc is installed perpendicular to the disc to linearly move in the radial direction of the disc to detect a desired track position on the disc. A hologram element is provided for converting the reflected light of the laser beam incident on the pit of the disc into an electrical signal to reproduce the recorded contents on the disc. The hologram element ensures that the laser beam is accurately focused on a predetermined pit of the disc, In order for the reflected light of the laser beam reflected from the pit of the disk to be accurately incident on the hologram element, the optical system constituting the optical pickup is moved horizontally in parallel with the vertical axis movement of the optical pickup by the actuator. The micro-movement of the optical system performs vertical and horizontal movement of the optical system by selectively applying current to the focus coil wound on the side of the lens holder and the tracking coils respectively attached to both sides of the focus coil.

However, in recent years, a digital video disk (DVD) is used to reproduce a video signal along with a voice signal by recording a video by video compression technology together with the audio signal according to the above process. In order to increase the recording density by recording the video signal together with the audio signal in the area, the pitch between the tracks is made smaller than that of a normal optical disc such as a compact disc, and the size of each pit is finely formed. And compact discs show a great deal of difference in specifications and specifications such as the wavelength of the laser beam irradiated during reproduction, the linear velocity of the disc, and the focal length of the objective lens.

Therefore, the DVD has a dedicated optical system and a separate optical system for reproducing voice-only optical discs such as ordinary compact discs to provide compatibility with compact discs and mini discs. The optical system for reproducing voice-only optical discs is generally positioned in a symmetrical direction with the optical system for DVDs. Move in the direction to act selectively.

On the other hand, as shown in Fig. 1, the actuator for the DVD having the objective lens for the compact disc together with the objective lens for the compact disc to selectively apply the objective lens according to the type of the disc has a rectangular shape as shown in FIG. In the center of the lens holder 60 having the shape of the shaft insertion hole 61 is formed so that the shaft 71 of the upper portion of the yoke plate 70 is inserted, respectively formed in the same radius from the shaft insertion hole 61 The lens insertion holes 63 and 65 are provided with the objective lens L1 for the DVD and the objective lens L2 for the compact disc, respectively, and the tracking magnetics 72 and 73 attached to the yoke plate 70 on the side and the bottom thereof. Tracking coils 66 and 67 are attached to rotate the lens holder 60 in the horizontal direction in combination with the above, and the focus of each objective lens L1 and L2 is increased by lifting from the shaft 71. Adjust Will wind the focus coil 68 on the outer circumferential surface of the circular projection 60A.

The axial perturbation DVD actuator 80 detects the focus and tracking states of the disc's recording feet from a photo detector and generates an error in focus and tracking, thereby correcting the focus and tracking. If necessary, the current is applied to the focus coil 68 or the tracking coils 66 and 67 from the outside via the flexible PC 81 and the coil PC 82 from the outside, and the lens holder 60 is driven by the current. The objective lens according to the type of the disc is moved by moving in the vertical and horizontal directions from the shaft 71 by the combination of the tracking magnetics 72 and 73 and the focus magnetics 75 and 76 provided in the yoke plate 70. The selection of L1 and L2 and the focusing and tracking of each of the selected objective lenses L1 and L2 are adjusted according to the above process.

However, as described above, in the axial perturbation DVD actuator 80 in which all operations of the lens holder 60 are supported by the support of the shaft 71, the shaft insertion hole of the shaft 71 or the lens holder 60 ( If an error occurs in the accuracy of 61), an error occurs during the reproduction process of the DVD or compact disc, so that the shaft 71, including the shaft insertion hole 61 of the lens holder 60, is processed to an accurate dimension and shape, The surface of the shaft 71 has an extremely low coefficient of friction, such as Teflon, to minimize the friction of the contact surface between the shaft insertion hole 61 and the shaft 71 to facilitate the movement of the lens holder 60 from the shaft 71. It will be coated as a material.

However, in the conventional DVD actuator 80 as described above, the contact area between the shaft insertion hole 61 of the lens holder 60 and the shaft 71 is excessive, so that the objective lenses L1 and L2 are selected. The Teflon-coated surface coated on the surface of the shaft 71 by the friction generated by the contact between the shaft 71 and the lens holder 60 during the operation or the focus and tracking adjustment process of the objective lens (L1, L2) described above. Peeling from the 71 causes the friction force between the shaft insertion hole 61 formed in the lens holder 60 and the shaft 71 to be sharply increased, thereby causing a disturbance in the movement of the lens holder 60 from the shaft 71. As the shaft insertion hole 61 of the lens holder 60 is expanded, a flow occurs in the lens holder 60, and thus, many problems, such as an error, occur in the disc regeneration process.

The technical problem of the present invention is to attach a magnetic having a cylindrical shape to the inner circumferential surface of the shaft insertion hole of the lens holder having the objective lens (L1) for DVD and the objective lens (L2) for compact disc, and combined with the lens holder By attaching a magnetic having the same polarity as that of the shaft insertion hole on the outer peripheral surface of the shaft to support the lens holder, the lens holder can be moved smoothly from the shaft by the magnetic bearing effect according to the repulsive force between the magnetics. It is to provide a means for increasing the reliability of the operation of the actuator.

The technical problem as described above is the lifting and the left-right direction of the lens holder having the objective lens L1 for DVD and the objective lens L2 for compact disc by the shaft of the yoke plate inserted through the shaft insertion hole of the lens holder. In the shaft coupling structure of the axial perturbation type actuator for guiding movement to the lens, a magnetic having a cylindrical shape is attached to the inner circumferential surface of the shaft insertion hole formed in the center of the lens holder, the shaft insertion hole of the lens holder The outer peripheral surface of the shaft inserted to support the lens holder is achieved by providing a shaft coupling structure of the actuator for the DVD, characterized in that consisting of a structure attached to the magnetic having the same polarity as the magnetic of the shaft insertion hole.

1 is an exploded perspective view showing an actuator for a DVD having a conventional structure. 2 is an exploded perspective view of the present invention.

Figure 3 is a detailed view of the main portion showing the combined state of the present invention.

4 is an exemplary view showing an operating state of the present invention.

<Explanation of symbols for main parts of drawing>

1: shaft insertion hole 2,12: magnetic

5: shaft insertion hole 10: lens holder

11: shaft 20: yoke plate

L1, L2: Objective Lens

2 is an exploded perspective view of the present invention, Figure 3 is a detailed view of the main portion showing the combined state of the present invention, the shaft coupling structure 30 of the actuator for the DVD according to the present invention, the upper portion of the yoke plate 20 The objective L1 and the compact lens for the DVD are formed by the interaction between the tracking coils 66 and 67 which are supported by the shaft 11 protruding perpendicularly from the current and the tracking magnetics 72 and 73 attached to the yoke. Selective application of the disk objective lens L2 and tracking of the objective lenses L1 and L2 are adjusted while the current is applied to the focus coil 68 so that the focus adjustment of the objective lenses L1 and L2 is made. A cylindrical magnetic body 2 is attached to the inside of the shaft insertion hole 1 of the lens holder 10 constituting the axial actuator type DVD actuator 50, and the shaft insertion of the lens holder 10 is performed. Inserted into the ball (1) to support the lens holder (10) On the outer circumferential surface of the shaft 11, a magnetic 12 having the same polarity as that of the magnetic 2 attached to the shaft insertion hole 1 is attached to the magnetic bearing effect according to the repulsive force between the magnetics 2 and 12. Therefore, the shaft 11 and the lens holder 10 are prevented from directly contacting each other so that the lifting of the lens holder 10 from the shaft 11 and the rotation in the left and right directions can be performed smoothly.

Then, the magnetic 12 to be attached to the outer peripheral surface of the shaft 11 has a diameter smaller than the inner diameter of the magnetic 2 attached to the lens holder 10 and the lifting and lowering of the lens holder 10 from the shaft 11 and Prevents direct contact of each magnetic (2, 12) during rotation to enable a smooth movement, in particular, each magnetic (2, 12) is a small change in the position of the lens holder 10 due to the excessive repulsive force To prevent it.

Referring to the operation of the present invention as described above, the shaft coupling structure 30 of the actuator for DVD according to the present invention, the magnetic (2) inside the shaft insertion hole (1) formed in the center of the lens holder 10 12 is attached to the outer peripheral surface of the shaft 11 coupled to the inner circumferential surface of the magnetic (2, 12), the magnetic pole 12 of the same polarity as the magnetic (2) of the lens holder 10 is attached The shaft 11 is inserted, and when the shaft 11 is coupled to the inside of the magnetic 2 coupled to the shaft insertion hole 1 of the lens holder 10, the magnetic of the lens holder 10 2) and the magnetic 12 of the shaft 11 in contact with the same polarity, the magnetic 12 attached to the shaft 11 according to the repulsive force between the magnetic (2, 12) is the magnetic attached to the lens holder 10 Each magnet by being located in the internal space with a constant distance from (2) Since direct contact between the ticks 1 and 12 is prevented, and the magnetic bearing effect due to the repulsive force is prevented, the selective action of the objective lenses L1 and L2 according to the type of the disc and the objective lens for the pit of the disc ( The fine movement of the lens holder 10 from the shaft 11 during the fine adjustment for focusing and tracking adjustment of the L1 and L2 is performed smoothly.

The shaft coupling structure 30 of the actuator for DVD according to the present invention is provided on the inner circumferential surface of the shaft insertion hole 1 of the lens holder 10 having the objective lens L1 for the DVD and the objective lens L2 for the compact disc. Magnetic (2) of the shaft insertion hole (1) is attached to the outer peripheral surface of the shaft (11) attached to the magnetic holder having a cylindrical shape and coupled to the lens holder (10) to support the lens holder (10) By attaching a magnetic (12) having the same polarity as that of the Teflon coating, without the expensive process, such as without the costly process between the magnetic (2, 12) according to the repulsion between the shaft 11, the lens holder 10 is smoothly moved Meanwhile, the shaft 11 and the lens holder 10 may be prevented from directly contacting each other, thereby preventing damage to the coupling part between the components due to friction, thereby improving reliability of the operation of the DVD actuator 50. Many Can achieve the effect.

Claims (1)

A lens holder having an objective lens L1 for a DVD and an objective lens L2 for a compact disc by the shaft 11 of the yoke plate 20 inserted through the shaft insertion hole 1 of the lens holder 10 ( In the shaft coupling structure of the axial perturbation DVD actuator for guiding the lifting and moving in the left and right directions of 10), the inner peripheral surface of the shaft insertion hole (1) formed in the center of the lens holder 10 has a cylindrical shape The magnetic part of the shaft insertion hole 1 is attached to the outer circumferential surface of the shaft 11 to which the magnetic 2 is attached and inserted into the shaft insertion hole 1 of the lens holder 10 to support the lens holder 10. A shaft coupling structure of a actuator for a DVD, comprising a structure in which a magnetic 12 having the same polarity as in (2) is attached.