JP2006196072A - Objective lens actuator, optical head and optical disk device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the operation sound of an optical disk device, especially an operation sound caused by the vibration of the yoke of an objective lens actuator. <P>SOLUTION: A yoke part is held in an actuator holder by a bent plate spring in with freedom in at least two directions, and the actuator holder is bonded and connected to a head case. Alternatively, the yoke part is held in the head case by a coil spring or the like in the state of freedom in at least two directions, and the actuator holder is bonded and connected to the head case. Thus, the transmission of the vibration of the yoke to the head case is made difficult, and an operation sound caused by an objective lens actuator is reduced. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an objective lens actuator, an optical head, and an optical disc apparatus.

  As background art of this technical field, for example, there is JP-A-2003-187472. In this publication, there is a description as “Providing an optical disc apparatus that suppresses operation-generated sound from the objective lens driving unit of the optical pickup and that is low in noise”. Further, as a solving means, “the opposed surfaces of the coils 107 and 108, the magnet 109, and the yoke 110 are arranged at substantially symmetrical positions with respect to the optical axis 111 of the objective lens 103 in the non-energized state, and the yoke 110 and the unit base 117 are arranged. Are connected to each other via a spring member 118, and the unit base 117 is attached to the housing 120. Here, the spring member 118 is connected to the yoke 110 at a position 121 spaced forward from the objective lens 103, and at least the objective lens. 103. The casing 120 is provided with a unit base 117, a lens holder 106, a yoke 110, and a magnet 109, except for a surface facing the disc-shaped recording medium 104. It has a closed structure surrounding the space. "

JP 2003-187472 A

  Conventionally, various attempts have been made to improve the vibration characteristics of an objective lens actuator used in an optical disc apparatus. These contrivances have been made from the viewpoint of how accurately the light spot focused by the objective lens is positioned on the optical disk medium. However, in recent years, the optical disk apparatus is widely used as a video and audio recording apparatus as represented by a DVD-camera, and the problem of noise caused by the vibration of the objective lens actuator cannot be ignored.

  Here, it has been found that vibrations having little relation to the movement of the objective lens itself cause noise.

  FIGS. 3A and 3B are diagrams of an objective lens actuator proposed in, for example, Japanese Patent Application Laid-Open No. 2003-187472. 3A is a front view of the optical head, and FIG. 3B is a top view of the optical head.

  An optical head used in an optical disk device generally includes an optical system and an objective lens actuator. Here, the optical system condenses a light beam emitted from a laser light source (not shown) on an information recording surface of a disk-shaped recording medium via an optical element such as a prism or an objective lens, and the information recording surface. The light beam reflected by is incident on the photodetector through the optical element. In addition, the objective lens actuator holds the objective lens 1 and has a lens holder 2 having at least two sets of driving coils (not shown), and holds the lens holder 2 so as to be operable in the thickness direction and the radial direction of the disc-shaped recording medium. A plurality of suspensions 6, an actuator holder 7 that holds the other end of the suspension 6, a circuit board 8 joined to the actuator holder 7, a plurality of magnets 5, a yoke 3 that holds them and forms a magnetic circuit, and an inner yoke 4 Etc.

  The objective lens 1 is disposed in a magnetic circuit formed by the magnet 5, the yoke 3 and the inner yoke 4, and when a plurality of coils are energized, the objective lens 1 receives electromagnetic force from the circuit and receives the electromagnetic force from the circuit in the thickness direction and radial direction. To work. The plurality of coils are energized from the electric circuit of the optical disk device through the circuit board 8 and through the suspension 6 that also serves as a conducting wire. The suspension 6 and the actuator holder 7 are joined by, for example, the solder 9 to provide a holding and conducting action. The yoke 3 and the leaf spring 10 are joined by a method such as caulking, bonding, welding, and soldering at the portion A. On the other hand, the actuator holder 7 and the leaf spring 10 are joined mainly by bonding because the material of the actuator holder 7 is often plastic. The objective lens actuator is bonded to the head case 11 with, for example, an adhesive 12. In Japanese Patent Laid-Open No. 2003-187472, the yoke 3 vibrates as an action of the reaction force of the lens holder 2 and the resulting operating noise is reduced by joining the yoke 3 and the actuator holder 7 via the leaf spring 10. Yes. The patent document mentioned above is the content that the actuator holder 7 is also held in the head case 11 by an elastic body instead of the adhesive 12.

  By the way, as a new type of optical disk apparatus having a built-in microphone for recording external sound, for example, a general-purpose optical disk camera apparatus capable of shooting digital moving images and still image videos has been proposed. In an optical disk camera device, components such as an imaging system, a recording microphone, an optical disk device, and a signal processing circuit are mounted inside a housing, and a recording microphone is disposed in the vicinity of the optical disk device in order to reduce the size of the entire device. In some cases, the operation sound generated from the optical disc apparatus jumps into the recording microphone and the reproduction sound quality deteriorates. Further, since the optical disk camera device is often used near the face when photographing, the operation sound may leak, which may be annoying to use.

  One of the main causes of the generation of this operation sound is that the yoke 3 which is the structure of the objective lens actuator in the focus / tracking operation mode vibrates slightly, and this minute vibration causes the focus / tracking servo control system control circuit (illustrated). No.) to repeat the state of inputting as a disturbance to the objective lens driving unit constituted by the yoke 3, the inner yoke 4, the magnet 5, and the coil (not shown) held by the lens holder 2, It was found that minute vibrations are amplified and appear in the operation sound.

  Another factor is that the lens holder 2 that holds the objective lens 1 in the objective lens actuator tends to cause a slight rotational vibration due to manufacturing variations, and this slight rotational vibration causes the yoke 3 to vibrate. It was also found that it was amplified through a control circuit (not shown) of the focus and tracking servo control system and appeared in the operation sound.

  Further, as another factor, the above is described with respect to the vibration of the yoke 3 as a rigid body, but it has been found that the yoke 3 itself also undergoes deformation vibration such as bending and torsion.

  These vibrations are transmitted to the head case 11 of the optical head holding the objective lens actuator, and the circuit board 8 and various covers (not shown) attached to the entire head case 11 and the head case 11 are diaphragms. As a result, it was found that the operation sound (= noise) deteriorates the reproduction sound quality and becomes annoying noise in use. At this time, the frequency characteristics (response displacement, phase characteristics) of the focus and tracking servo control system do not cause any response disturbance that causes problems in servo control. Done. Based on this result, it can be said that the response of the objective lens 1 with respect to the disk, that is, the light spot on the disk surface, is not deteriorated. Conventionally, the optical disk apparatus has been used as a recording medium for video and audio, in particular, as an optical disk camera apparatus having a built-in microphone for recording external audio. In the frequency characteristics (gain and phase characteristics), there was no disturbance that would cause a problem in performing servo control, and the operation sound generated by the operation of the objective lens driving unit was hardly a problem.

  In consideration of the above-described factors, in the conventional technique described in Patent Document 1, the longitudinal component of the inner leaf spring 10 (the radial direction of the disk-shaped recording medium) of the deformation vibration of the yoke 3 and the inner yoke 4 causes the actuator holder 7 to move. It was found that it was transmitted to the head case 11. Therefore, the operation sound caused by the vibration in the radial direction of the disk-shaped recording medium is not reduced, and there is room for improvement that the operation sound jumps into the recording microphone and the reproduction sound quality is deteriorated.

  The present invention has been made in view of the above points, and in an optical disc apparatus, particularly an optical disc apparatus used in an optical disc camera apparatus having a built-in microphone for recording external sound, a yoke and an actuator holder can be freely moved in at least two directions. By connecting with an elastic member having a certain degree, an operation sound generated from an objective lens driving unit constituted by a yoke 3 of the optical head, an inner yoke 4, a magnet 5 and a coil (not shown) held by the lens holder 2 is generated. An object of the present invention is to provide a low-noise optical disk apparatus that is suppressed and that is compatible with the above-described portable use.

  Therefore, an object of the present invention is to improve the usability of an optical disc apparatus.

  The above object can be achieved by the invention described in the claims.

  According to the present invention, the usability of the optical disk apparatus is improved.

  In this embodiment, the deformation vibration of the yoke itself is hardly transmitted to the head case, and a more effective operation sound reduction is realized.

  This embodiment will be described with reference to FIG. Note that the description of the configuration that performs the same operation as in FIGS. 3-1 and 3-2 described above is omitted here. Further, B part is a joint part between the yoke 3 and the leaf spring 14 and is joined by a method such as caulking, adhesion, welding, soldering or the like.

  In this embodiment, the leaf spring 14 that connects the yoke 3 and the actuator holder 7 is formed into, for example, a substantially L shape as shown in the figure (or a configuration in which the other end of the actuator holder described later may be folded back), so that at least a disk shape is obtained. There are two degrees of freedom in the thickness direction and the radial direction of the recording medium, and vibrations in these two directions are hardly transmitted to the actuator holder 7. For this reason, both the phenomenon that the entire yoke 3 vibrates as a function of the reaction force of the lens holder 2 and the phenomenon that the yoke 3 and the inner yoke 4 themselves deform and vibrate are made difficult to be transmitted to the head case 11, and the operation sound is generated. Can be reduced. Further, the leaf spring 14 in the present embodiment is made of a member longer than that in FIG. 3, and by folding the other end of the actuator holder, the front side of the sheet perpendicular to the thickness direction and the radial direction is provided. It is also good against vibration in the back direction.

  Next, another embodiment of the present embodiment will be described with reference to FIG.

  In this embodiment, the yoke 3 is connected to the head case 11 through the elastic member 13. The elastic member 13 is formed of, for example, a coil spring or rubber-based resin, and makes it difficult for vibrations in at least two directions in the thickness direction and the radial direction of the disk-shaped recording medium to be transmitted to the head case 11. For this reason, both the phenomenon that the entire yoke 3 vibrates as a function of the reaction force of the lens holder 2 and the phenomenon that the yoke 3 and the inner yoke 4 themselves deform and vibrate are made difficult to be transmitted to the head case 11, and the operation sound is generated. Can be reduced. Here, in this embodiment, noise is reduced by the member 13 separated from the actuator holder 7. In the configuration in which the actuator holder 7 is also held by an elastic body, the objective lens actuator itself is tilted, which may adversely affect the recording and reproducing performance as the optical disc apparatus. According to the present embodiment, the actuator holder 7 is held so as not to be tilted, so that there is no adverse effect on the recording / reproducing performance.

  According to the above-described embodiment, in the optical disk camera device, the operation sound caused by the vibration in the radial direction of the disk-shaped recording medium is reduced, and it is possible to prevent the operation sound from jumping into the recording microphone and deteriorating the reproduction sound quality.

  Further, according to the above-described embodiment, it is possible to prevent the adverse effect on the recording and reproducing performance as the optical disk apparatus due to the inclination of the objective lens actuator itself, and the operation sound caused by the radial vibration of the disk-shaped recording medium in the optical disk camera apparatus. It is possible to prevent the reproduction sound quality from deteriorating due to the operation sound due to the reduction of the recording sound.

  The above-mentioned means makes it difficult for vibrations that move the entire yoke and deformation vibrations of the yoke to be transmitted to the head case. In the optical head, excitation occurs when the lens holder is driven by energization of the coil and the action of the magnetic field generated by the magnet and the yoke. Therefore, it is possible to significantly reduce the operation sound due to the generated vibration. As a result, it is possible to provide an optical disc apparatus with reduced motion generated sound.

Illustration of one embodiment Illustration of one embodiment Illustration of prior art

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Objective lens 2 ... Lens holder 3 ... Yoke 4 ... Inner yoke 5 ... Magnet 6 ... Suspension 7 ... Actuator holder 8 ... Circuit board 9 ... Solder 10 ... leaf spring 11 ... head base 12 ... adhesive 13 ... elastic member 14 ... leaf spring L

Claims (10)

A lens holder for holding the objective lens;
A spring member for movably holding the lens holder;
An actuator holder for holding the other end of the lens holder of the spring member;
A yoke holding a magnet for moving the lens;
A lens actuator comprising:
The actuator holder holding the yoke and the other end is connected by an elastic member having a degree of freedom in at least two directions.
Objective lens actuator. The yoke has a U-shape,
The elastic member is in contact with the yoke in a folded state;
The objective lens actuator according to claim 1.   An optical head having the objective lens actuator according to claim 1.   An optical disk apparatus having the optical head according to claim 3. A lens holder for holding the objective lens;
A spring member for movably holding the lens holder;
An actuator holder for holding the other end of the lens holder of the spring member;
A yoke holding a magnet for moving the lens;
An optical head comprising a head case that houses the lens holder, the spring member, the actuator holder, and the yoke,
The yoke is held by the head case by an elastic member,
Light head.   The optical head according to claim 5, wherein the elastic member is a spring member.   An optical disc apparatus having the optical head according to claim 5. A lens holder that holds the objective lens and a plurality of coils, a spring member that also serves as a conducting wire that movably holds the lens holder, and an actuator holder that holds the other end of the lens holder of the spring member, In the objective lens actuator composed of a magnet with a yoke arranged to face the plurality of coils,
The objective lens characterized in that the magnet with yoke and the actuator holder holding the other end are connected by an elastic member having degrees of freedom in at least two directions of the optical axis direction of the objective lens and the axial direction of the spring member. Actuator. A lens holder that holds the objective lens and a plurality of coils, a spring member that also serves as a conducting wire that movably holds the lens holder, and an actuator holder that holds the other end of the lens holder of the spring member, In the objective lens actuator composed of a magnet with a yoke arranged to face the plurality of coils,
The yoke-attached magnet is connected to the optical head case by an elastic member having degrees of freedom in at least two directions of the objective lens optical axis direction and the spring member axial direction, and the actuator holder holding the other end is connected to the optical head case. An optical head characterized by being held so as to be restrained.   An optical head comprising the objective lens actuator according to claim 8.

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