KR960015206B1 - Slim type optical pick-up - Google Patents

Abstract

a base member (10) an object lens (21); suspensions (23) for supporting a lens fixing member (20); thin film type magnets (24) installed at both ends of the lens fixing member (20); and electro magnetic coils (voice coils) (15) for positioning by magnetic reaction with the film type magnets (24). The actuator reduces size and capacity of the optical pick-up not requiring great driving force for tracking or focusing and provides a quick respondence to input signal.

Description

Slim Optical Pickup Actuator

1 is a diagram for explaining a configuration of a general optical pickup device.

2 is a view illustrating a slim optical pickup actuator according to the present invention.

FIG. 3 is a side view illustrating the relationship between the lenghing part and the base member shown in FIG.

* Explanation of symbols for main parts of the drawings

1: objective lens 2: objective lens holder

3: yoke 4: wire suspension

5 base member 6 coil

7: permanent magnet 10: base member

11 PCB body 12 optical lens system

14: groove 15: electromagnet coil (boy coil)

20: lens fixing member 21: objective lens

22: yoke 23: wire suspension

24: thin film magnet

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slim type optical pickup actuator, and more particularly, a plurality of voice coils (Voice) as driving means of an optical pickup actuator for driving an objective lens so that a laser beam radiated from a laser light source is accurately focused on a surface of an information recording medium. It relates to a slim optical pickup actuator in which the optical pickup actuator has a slim structure using a coil and a thin film magnet.

For example, an optical pickup apparatus employed for irradiating a laser beam to an information recording medium in a disc form in which audio information and / or video information is recorded on an information recording surface and reading out audio information or video information recorded on the information recording surface is generally used. A laser beam source emitting a laser beam and a collimated lens converting the laser beam emitted from the laser beam into a parallel beam, and collecting the laser beam converted into parallel light by the collimator lens on the information recording surface of the information recording medium. An optical pickup actuator for positioning the objective lens to focus and track the objective lens, the laser beam focused by the objective lens, on the information recording surface of the information recording medium, and reflected on the information recording surface of the information recording medium Beam splits forming an optical lens system that reflects emitted light Or right-angle prism is a beam splitter or a right angle to receive the reflected light reflected on a prism configuration equipped with a light-receiving element that outputs an electrical signal for a focusing signal and a tracking signal and the information.

FIG. 1 is a view showing a schematic configuration of the above-described general optical pickup device. In such an optical pickup device, the objective lens 1 is typically an objective lens in which a laser light source is disposed below the inside, as shown in FIG. The day member 5 housed in the holder 2 and including the objective lens holder 2 is suspended by a plurality of wire suspensions 4 each of which is fixed to both sides of the optical pickup case 8. It is installed in the form.

Further, the objective lens holder 2 is disposed on the optical pickup base member 5, and the laser beam radiated from the laser light source around the base member 5 is accurately focused and tracked on the information recording surface of the information recording medium. A plurality of coils 6 and permanent magnets 7 which are arranged to face each other by forming an optical pickup actuator are arranged.

Therefore, according to the optical pickup device shown in FIG. 1, in the case of focusing and tracking the information recording surface of the information recording medium, the interaction between the coil 6 and the permanent magnet 7 which acts as an electromagnet upon application of current is applied. As a result, the objective lens 2 is moved in the vertical direction and the horizontal direction, thereby adjusting focusing and tracking. That is, according to the amount of current flowing through the focusing and tracking coil 6 for focusing or tracking the information recording surface of the information recording medium, the liquid flows in the vertical direction during the focusing adjustment, while the laser light source flows in the horizontal direction during the tracking adjustment. The laser beam emitted from is positioned to ensure precise focusing and tracking with respect to the information recording surface of the information recording medium.

However, according to the conventional optical pickup apparatus shown in FIG. 1, in order to perform focusing and tracking on the recording surface of the information recording medium, an electromagnet for adjusting the focusing or tracking of the information recording surface of the information recording medium while constructing the optical pickup actuator A plurality of magnets for accurately positioning the objective lens 1 on the information recording surface of the information recording medium of the information recording medium by the magnetizing action of the focusing and tracking coil 6 acting as Since (7) must be provided, the overall weight of the optical pickup apparatus is significant or the size thereof becomes large.

Due to the large weight and size of the optical pickup device, a larger driving force is required in the information processing apparatus that reads and processes the information recorded on the information recording medium, and is required for focusing and tracking input on the information recording surface of the information recording medium. As a result, the quick response is degraded, so that the optical pickup device cannot meet the requirements for light weight, miniaturization and thinning.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is characterized in that the magnetic levitation effect and magnetic force acting between the lightweight voice coil mounted on the optical pickup base member and a magnet having a thin film type provided around the objective lens. It is an object of the present invention to provide a slim optical pickup actuator in which the overall weight and dimensions of the optical pickup apparatus are reduced by focusing and tracking the objective lens using movement.

In order to achieve the above object, according to the present invention, a laser light source accommodated in a base member to emit a laser beam with respect to the information recording surface of the information recording medium and a laser beam emitted from the laser light source on the information recording surface of the information recording medium. An optical pickup apparatus comprising an objective lens for condensing on a plurality of objects, the optical pickup apparatus comprising: a plurality of thin film magnets mounted at both ends of a lens fixing member having the objective lens fixed at a center thereof and supported at both ends by a plurality of suspensions; And a plurality of electromagnet coils, which are housed in a plurality of grooves formed on the base member corresponding to the position where the thin film magnet is installed, and which adjust the position for focusing and tracking of the objective lens by magnetic action with the thin film magnet. A slim optical pickup actuator is provided.

Preferably, the electromagnet coil is composed of a plurality of voice coils for adjusting the vertical movement by the magnetic levitation of the objective lens and the horizontal movement by the phase change of the current on the base member. The thickness of the magnets provided at both ends of the lens is equal to or smaller than the thickness of the objective lens.

According to the slim optical pick-up actuator according to the present invention configured as described above, a voice coil is installed on a thin film type permanent magnet provided at both ends of an objective lens and a base member at a position corresponding to the permanent magnet, Focusing is performed by using the floating effect, while the optical pickup actuator is realized in a slim type by changing the phase of the current flowing through the voice coil to move the objective lens in the lateral direction to perform tracking.

Hereinafter, with reference to the accompanying drawings, the present invention will be described in detail.

That is, FIG. 2 is a view showing the slim optical pickup actuator according to the present invention, and FIG. 3 is a side view illustrating the relationship between the lens fixing member and the base member constituting the slim optical pickup actuator according to the present invention shown in FIG. In the structure of the present invention, a laser light source bonded to the reference 10 PCB substrate 11 and generating a laser beam at a central portion thereof and a laser beam generated from the laser light source are information recording surfaces of the disc-shaped information recording medium. An optical lens system 12, such as a beam puller or a right angle prism, which focuses reflected light reflected from an information recording surface of a disk-shaped information recording medium or a light receiving element that receives the reflected light and outputs an electrical signal, is provided. The internal pickup and the bottom of the optical pickup apparatus in which the groove 13 is formed to provide the optical path of the laser beam in the upper center. It shows a switch member.

Here, on the base member 10, a plurality of grooves 14 are formed at regular intervals on both sides of the grooves 12 formed in the upper center thereof to provide an optical path, and each groove 14 has an electromagnet upon application of current. The electromagnet coil 15, which acts as a part, is partially received as shown in FIG. The electromagnet coil 15 is preferably composed of a voice coil acting as an electromagnet by a PWN current signal from a control device (not shown).

Reference numeral 20 denotes an objective lens 21 for condensing a laser beam generated from a laser light source stored in the base member 10 and radiating from the optical lens system 12 onto an information recording surface of a disc-shaped information recording medium. The lens fixing member 20 is fixed to the bar, the lens fixing member 20 is supported in a form in which both ends are suspended by a wire suspension 23 fastened to the yoke 22.

Here, the thin film magnet 24 is installed at both ends of the lens fixing member 20 at a position corresponding to the electromagnet by the plurality of voice coils 15 provided on the base member 10, the thin film magnet ( The total thickness of the lens fixing member 20 on which the 24 is installed is preferably formed thinner than the thickness of the objective lens 21.

Further, the thin film magnet 24 records information by the attraction force or repulsion force of the electromagnetic field from the voice coil 15 generated in accordance with the amount of current applied to the voice coil 15 and the direction of the current, that is, magnetic levitation force. It is possible to adjust the position in the focusing direction with respect to the medium, and fix the lens to which the objective lens 21 is fixed by controlling the phase of the current flowing through the voice coil 15 in consideration of the polarity of the thin film magnet 24. The member 20 is moved in the horizontal direction to enable tracking.

Next, the operation of the slip type optical pickup actuator according to the present invention configured as described above will be described.

First, the focusing operation of the objective lens 21 with respect to the information recording medium will be described. The fixed lens is suspended by the wire suspension 23 in the plurality of voice coils 15 provided on the base member 10. Each voice coil 15 is supplied with a PWM current from a control device (not shown) so that the same or the opposite polarity as that of the thin film magnet 24 provided at both ends of the member 20 is generated, thereby acting as an electromagnet. The object of the lens holding member 20 is raised or lowered by the magnetic levitation effect by the suction force or the repulsive force between the thin film magnet 24 provided at both ends of the lens fixing member 20, so that the objective The lens 21 ensures an elaborate focusing state on the information recording medium.

On the other hand, during the tracking operation of the objective lens 21 with respect to the information recording medium, if the phase of the current applied to the plurality of voice coils 15 provided on the base member 10 is appropriately changed, the lens The objective lens 21 moves in the tracking direction of the information recording medium by magnetic action with the thin film magnets 24 provided at both ends of the fixing member 20. That is, when the phase of the current is sequentially applied to the voice coil 15 to have a magnet opposite to that of the thin film magnet 24 attached to the lens fixing member 15, the thin film magnet 24 and the The lens holding member 20 including the objective lens 21 is moved in the tracking direction by the suction force acting between the voice coils 15, so that the tricking operation on the information recording medium of the laser beam emitted from the laser light source is performed. Will be performed.

As described above, according to the slim type optical pickup actuator according to the present invention, the focusing and the thin film magnets installed around the objective lens and the voice coil acting as an electromagnet according to the current direction on the optical pickup base member are focused. By enabling the tracking operation, the optical pickup device can be made smaller and lighter, and as a result of the miniaturization and lighter weight, large driving force is not required for tracking and focusing, and fast response to the input signal can be guaranteed. Will have

Claims (3)

The objective lens 21 accommodated in the base member 10 and acting to cause the laser light source radiating the laser beam to the information recording surface of the information recording medium and the laser beam emitted from the laser light source to be focused on the information recording surface of the information recording medium. In the optical pickup device comprising a plurality of thin-film magnets are provided at both ends of the lens fixing member 20, the objective lens 21 is fixed in the center and both ends are supported by floating by a plurality of suspensions (23) (24) and a plurality of grooves (14) formed on the base member (10) corresponding to the position where the thin film magnets (24) are installed, and are housed in a magnetic action with the thin film magnets (24). A slim optical pickup actuator, comprising: a plurality of electromagnet coils 15 for position adjustment for focusing and tracking of (21). The slim type light beam according to claim 1, wherein the electromagnet coil (15) comprises a voice coil (15) which moves on the base member (10) in the vertical direction and the horizontal direction of the objective lens (21). Pickup actuator. The slim optical pickup actuator according to claim 1, wherein a thickness of the thin film magnet (24) provided at both ends of the lens fixing member (20) is equal to or smaller than that of the objective lens (21).