JPS6424524U

JPS6424524U -

Info

Publication number: JPS6424524U
Application number: JP11791587U
Authority: JP
Priority date: 1987-07-31
Filing date: 1987-07-31
Publication date: 1989-02-09

Description

[Brief explanation of the drawing]

第１図は本考案に係る対物レンズ駆動装置を示
す斜視図であり、第２図は本考案を構成するヨー
ク及びマグネツトを示す斜視図であり、第３図は
上記ヨークにマグネツトを取付けた状態を示す斜
視図であり、第４図はトラツキング用バツクヨー
ク片周辺における磁束の状態を示す概略平面図で
あり、第５図はフオーカス用バツクヨーク片周辺
における磁束の状態を示す概略側面図であり、第
６図は支持棒の振動振幅及び位相の変動特性を示
す特性図である。第７図は従来の対物レンズ駆動
装置を示す斜視図であり、第８図はマグネツトか
らの磁束の状態を示す概略側面図であり、第９図
はマグネツトからの磁束の状態を示す概略平面図
であり、第１０図はトラツキング方向に対物レン
ズを駆動変位させたときにおけるボビンに加わる
力の状態を示すボビンの側面図である。１……対物レンズ、５ａ，５ｂ及び５ｃ，５ｄ
……支持棒、６……フオーカス制御用コイル、７
……トラツキング制御用コイル、８，９……マグ
ネツト、１５，１６……ヨーク、１８，１９……
フオーカス用バツクヨーク片、２０，２１……ト
ラツキング用バツクヨーク片。 Fig. 1 is a perspective view showing the objective lens drive device according to the present invention, Fig. 2 is a perspective view showing the yoke and magnet that constitute the present invention, and Fig. 3 is a state in which the magnet is attached to the yoke. FIG. 4 is a schematic plan view showing the state of magnetic flux around the back yoke piece for tracking, FIG. 5 is a schematic side view showing the state of magnetic flux around the back yoke piece for focusing, and FIG. FIG. 6 is a characteristic diagram showing the vibration amplitude and phase variation characteristics of the support rod. FIG. 7 is a perspective view showing a conventional objective lens driving device, FIG. 8 is a schematic side view showing the state of magnetic flux from the magnet, and FIG. 9 is a schematic plan view showing the state of magnetic flux from the magnet. FIG. 10 is a side view of the bobbin showing the state of the force applied to the bobbin when the objective lens is driven and displaced in the tracking direction. 1...Objective lens, 5a, 5b and 5c, 5d
...Support rod, 6...Focus control coil, 7
...Tracking control coil, 8, 9... Magnet, 15, 16... Yoke, 18, 19...
Back yoke pieces for focusing, 20, 21... Back yoke pieces for tracking.

Claims

[Claims for Utility Model Registration] An objective lens supported movably in a predetermined direction via a support member having a predetermined spring constant, and an object for driving the objective lens movably disposed integrally with the objective lens. A drive coil, a magnet disposed opposite to the drive coil via a magnet support plate, and a yoke disposed on the outer periphery of the magnet not facing the drive coil to form a leakage magnetic flux and a closed magnetic path. Objective lens drive device.