Hitachi Media Electronics Co., Ltd.

Hitachi Consumer Electronics Co., Ltd.

Jun Hato

Katsuhiko Kimura

Hidenao Saito

Ryuichiro Mizuno

Yoshihiro Sato

Seiichi Kato

Takahiro Yamaguchi

Yoshihiro Satou

Kazuhiro Todori

Daisuke Tomita

Seiichi Katou

Manabu Ochi

Akio Yabe

Kazumi Takahashi

Yasushi Kinoshita

Akiko Mizushima

Souichirou Yamada

Masayuki Okamura

Yoshitaka Kusano

Zhi Yan Gao

Zhiyan Gao

High-performance and reliable objective lens driving apparatus and optical pickup wherein the tilt of an objective lens relative to an optical disc is suppressed are provided. The optical pickup is equipped with a semiconductor laser, an electro-optic component, and the objective lens driving apparatus. In this optical pickup, the objective lens driving apparatus is comprised of: a moving part including an objective lens, a holder that holds the objective lens, a focusing coil, and a tracking coil; a holding member for elastic support members that couples together multiple elastic support members providing elastic support on a fixed part and the moving part and is mounted on the moving part; the elastic support members that elastically support the moving part from the fixed part; and the fixed part. The holding member for elastic support members mounted on the moving part and the holder that holds the objective lens are joined together by fitting together a concavity and a convexity.

Objective lens driving apparatus, optical pickup

In an optical pickup equipped with a semiconductor laser, electro-optical components such as a lens, and an objective lens drive device, the objective lens drive device includes objective lenses, a holder holding the objective lenses, a focusing coil, and tracking coils. The focusing coil is wound in parallel to the optical surface of the objective lens, and formed in a parallelogram shape having inclined portions provided near the tracking coils. The two tracking coils are placed on diagonal portions of the lens holder.

Objective lens drive device and optical pickup

An optical pickup includes a lens moving mechanism constructed of a lens, a lens holder holding the lens, a guide member guiding the lens holder, a lead screw including a thread groove, a motor rotating the lead screw, and a rack gear including a body fixed to the lens holder and claws fitted into the thread groove of the lead screw, in which an arm connecting the body and the claws of the rack gear is formed so that the shape of a cross section perpendicular to the rotational axis direction of the lead screw is a convex shape, a recess shape or a wave-shape.

Optical pickup

An optical pickup which excels in assembly workability and which can increase the drive force generated in a focusing coil is provided. The optical pickup has an objective lens, a lens holder holding the objective lens, and a first and a second focusing coil wound around the lens holder. The first focusing coil includes an upper part wound about a central axis extending in parallel with an optical axis of the objective lens and a lower part connected to the upper part. The second focusing coil includes an upper part wound, in a wiring system separate from the first focusing coil, about a central axis extending in parallel with the optical axis of the objective lens and a lower part connected to the upper part.

An optical pickup whose thickness is small and power consumption is low is provided, in which these advantages are achieved by increasing the driving force generated in the tilt coil in an objective lens driving apparatus and by making the thickness of the objective lens driving apparatus to be small. In an optical pickup including: an objective lens for condensing light onto an optical disc; a lens holder to which the objective lens has been attached; a focusing coli, a tracking coil, and a tilt coil, which have been attached to the lens holder; and a reflection mirror for reflecting light toward the optical axis of the objective lens, the tilt coil is made to have a shape in which the tilt coil is not brought into contact with the side of the reflection mirror, the side being near to the objective lens.

In an optical pickup for use in an optical disc device, wire rods are wound directly around a lens-coil holder to make tracking coils and focus coils. The lens-coil holder is divided into three holders, one of which holds an optical lens thereon and has on its sides wire-winding protrusions for wiring wire rods therearound to make tracking coils. The remaining holders have focus coils that are wound therearound. Alternatively, the lens-coil holder is divided into two holders, one of which has on its sides wire-winding protrusions for wiring wire rods therearound to make tracking coils. The remaining holder holds an optical lens thereon and has focus coils that are wound therearound. The lens-coil holder has a cavity for letting pass through a laser beam emitted in parallel to an optical disc surface.

An optical pickup includes an objective lens, a lens holder which holds the objective lens, a focusing coil attached to the lens holder having the winding axis directed at the optical axis of the objective lens, and a magnet provided opposite the side surface of the lens holder. A protruding portion is attached to the side surface of the lens holder at a side apart from the objective lens with respect to the optical axis direction of the objective lens farther than the focusing coil.

An objective lens actuator, for driving an objective lensfor focusing lights upon a recoding surface of an optical disc, comprises a moving part, which comprises the objective lensand a coil; a magnet, which is fixed on a yoke and drives the moving part; a plural number of elastic support parts, each of which supports the moving partat an end thereof; a first fixing portionand a second fixing portion, which fix other ends of the plural number of elastic support partsand are disposed opposite to each other in a focus direction; and a moving mechanism, which is provided on the first and second fixing portionand, so that the first and second fixing portionsandcan move in the focus direction, relatively, and thereby providing the objective lens actuatorenabling to reduce the dynamic relative tilt between the optical disc and the objective lens(i.e., reducing the tilt of the objective lensin the tangential direction when operating), as well as, an optical pickup and an optical disc drive.

Objective lens actuator for enabling to reduce the dynamic tilt between optical disc and objective lens

There is provided a low-cost and reliable optical pickup device, wherein an objective lens is in contact with an adhesive at least one or more portions and fixed to the adhesive and also the height of the adhesive for fixing the objective lens is higher than the surface of the objective lens or the end of the objective lens, thereby a sufficient adhesive strength is secured between the objective lens and a member to which the objective lens is adhered and further this adhesive serves also as a disc protector.

Optical pickup device having disc protector

An optical pickup in which the position of a magnet can be adjusted with respect to a yoke is provided. The optical pickup has an objective lens, a lens holder that holds the objective lens, a magnet disposed opposite to a side surface of the lens holder, and a yoke to the inside of which the magnet is attached. The yoke has an opening at least near the bottom of the magnet, through which the magnet can be visually observed from the outside of the yoke, the bottom being on the side of the yoke that is farther from an optical disc and the top being on the side of the yoke that is closer to the optical disc along the optical axis of the objective lens.

In an optical pick-up used in common with DVD/CD and BD, when the thickness is intended to be reduced by mounting a total reflection mirror, a cavity for passing through a laser light is necessary and, since this decreases the degree of freedom for arranging tracking coils and magnets and secondary resonance caused by a magnetic thrust in the tracking direction tends to be generated, an improvement therefor is necessary. In a lens coil holder of the optical pick-up having an objective lens and tracking coil mounted thereon each of the coils is arranged such that the thrust relative to the vertical center of the suspension wires that support the lens coil holder is well balanced. For example, most of the portion of the tracking coils is situated at one height relative to the suspension wire and the tilt coil is situated at the other remaining height.

Optical pick-up

This invention aims at reducing a rolling moment generated in coils mounted to lens holder side face without losing drive forces in a focusing direction and tracking direction in an objective lens drive of an optical pickup device. By shifting a coil line portion near the objective lens of two coil line portions substantially parallel to the tracking direction of the first coil in a direction departing from a lens optical axis, increase and decrease in drive forces generated in right and left first coils when the lens holder is moved in the tracking direction cancel each other so as to eliminate imbalance between the right and left drive forces.

Optical pickup device

The present invention provides an object lens actuator, an optical pickup, and an optical disk drive, which can increase the size of the object lens actuator driving a lens holder in the tangential tilt direction, and drive and control the lens holder with a small amount of drive current. An object lens actuator comprising a lens holder having an object lens and a first coil; a first magnet fixed to a yoke; plural elastic support parts for supporting said lens holder with a first fulcrum; a moving part for supporting said elastic support parts with a second fulcrum different from said first fulcrum, and a fixed part having a moving mechanism for moving said moving part, wherein said first coil and said first magnet constitute a first magnetic circuit, said first magnetic circuit makes said lens holder movable in a focusing direction, a tracking direction and a radial tilt direction of an optical disk for read/write, and said moving mechanism makes said moving part movable.

Object lens actuator, optical pickup and optical disk drive

An optical pickup that can incline an objective lens in the same direction as that of a bend of an optical disc is provided. The optical pickup includes a lens holder that holds an objective lens, focusing coils attached to the lens holder, a yoke to which magnets are attached, and inner yokes disposed opposite to the magnets via the focusing coils, and the optical pickup is structured so that a cross-sectional area of the inner yoke disposed toward the outer periphery of the optical disc is greater than a cross-sectional area of the inner yoke disposed on the inner periphery of the optical disc.

An object lens drive unit in which an undesired displacement or inclination of an object lens with respect to an optical disc is reduced. The position at which a lens holder for the object lens is supported by a pair of rod-shaped elastic support members in the focusing direction substantially coincides with the center of the tracking coil in the focusing direction.

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Fujisawa, Japan

Jun Hato