EP0115666A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Optical focus position control in optical disc apparatus
Assignee: Sharp Corp
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Filing: 1983-09-15
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Granted: —
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Expires: 2003-09-15
Abstract
Abstract Disclosed below is the essence of an optical focus position control device of an optical disc apparatus that records, plays back, and erases any information by irradiating optical beams such as the laser beams onto a recording media composed of magnetic film, wherein said optical focus position control device is characterized in that; it incorporates a focussing permanent magnet that makes up a closed magnetic circuit, a focussing yoke plate, a focussing yoke, and a focussing drive coil installed so that it crosses the focussing magnetic space existing between the focussing yoke plate and the focussing yoke so that the focussing magnetic space can be created in an area close to the recording media which is installed in the closed magnetic circuit. In addition, the optical focus position control device that executes both the tracking and focussing control operations for the optical disc apparatus also includes mechanism that drives the objective lens in the direction of dual axes, i.e., in the vertical (up/down) and horizontal (left/right) directions.
Inventors
- 👤 Yoshikazu Fujii
- 👤 Toshihisa Deguchi
- 👤 Tetsuya Inui
- 👤 Hideyoshi Yamaoka
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 18:45
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/08; G11B7/09; G11B7/0925; G11B7/093; G11B11/00; G11B11/10; G11B11/105; G11B11/10502; G11B11/10504; G11B11/1055; G11B11/10576
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
92 words
An optical focus position control device of an optical disc apparatus that records, plays back, and/or erases any information by irradiating optical beams such as the laser beams onto a recording media composed of magnetic film, wherein comprising; a focussing permanent magnet that makes up a closed magnetic circuit; a focussing yoke plate; a focussing yoke; and a focus drive coil installed so that it crosses the focussing magnetic space existing between said focussing yoke plate and focussing yoke at a position close to the recording media of said closed magnetic circuit.
Claim 2
Dependent Claim
92 words
An optical focus position control device of an optical disc apparatus that records, plays back, and/or erases any information by irradiating optical beams such as the laser beams onto a recording media composed of magnetic film, wherein comprising; a focussing permanent magnet that makes up a closed magnetic circuit; a focussing yoke plate; a focussing yoke; and a focus drive coil installed so that it crosses the focussing magnetic space existing between said focussing yoke plate and focussing yoke at a position close to the recording media of said closed magnetic circuit.
Claim 3
Dependent Claim
86 words
An optical trading position control device-of an optical disc apparatus that records, plays back, and/ or erases any information by irradiating optical beams such as the laser beams onto a recording media composed of magnetic film, wherein comprising; a tracking permanent magnet that makes up a closed magnetic circuit; a tracking yoke plate; a tracking yoke, and a radial drive coil installed so that it crosses the tracking magnetic space, while said tracking permanent magnet is provided in the center position of said closed magnetic circuit.
Claim 4
Dependent Claim
86 words
An optical trading position control device-of an optical disc apparatus that records, plays back, and/ or erases any information by irradiating optical beams such as the laser beams onto a recording media composed of magnetic film, wherein comprising; a tracking permanent magnet that makes up a closed magnetic circuit; a tracking yoke plate; a tracking yoke, and a radial drive coil installed so that it crosses the tracking magnetic space, while said tracking permanent magnet is provided in the center position of said closed magnetic circuit.
Claim 5
Dependent Claim
160 words
An optical focus position control device of an optical disc apparatus that records, plays back,and/or erases any information by irradiating optical beams such as the laser beams onto a recording media composed of magnetic film, wherein comprising; a focussing permanent magnet that makes up a closed magnetic circuit; a focussing yoke plate; a focussing yoke; a focussing controller provided with a focus drive coil installed so that it crosses the focussing magnetic space existing between said focussing yoke plate and focussing yoke; a tracking permanent magnet; a tracking yoke plate; a tracking yoke; a tracking controller that is provided with a radial drive coil being installed so that it crosses the tracking magnetic space existing between said tracking yoke plate and tracking yoke; and a construction wherein the magnetic poles of both the focussing and tracking controllers contain portions of the magnetic paths close to the recording media, where said magnetic paths exist in the position closest to both controllers.
Claim 6
Dependent Claim
160 words
An optical focus position control device of an optical disc apparatus that records, plays back,and/or erases any information by irradiating optical beams such as the laser beams onto a recording media composed of magnetic film, wherein comprising; a focussing permanent magnet that makes up a closed magnetic circuit; a focussing yoke plate; a focussing yoke; a focussing controller provided with a focus drive coil installed so that it crosses the focussing magnetic space existing between said focussing yoke plate and focussing yoke; a tracking permanent magnet; a tracking yoke plate; a tracking yoke; a tracking controller that is provided with a radial drive coil being installed so that it crosses the tracking magnetic space existing between said tracking yoke plate and tracking yoke; and a construction wherein the magnetic poles of both the focussing and tracking controllers contain portions of the magnetic paths close to the recording media, where said magnetic paths exist in the position closest to both controllers.
Claim 7
Dependent Claim
174 words
An optical focus position control device of an optical disc apparatus that records, plays back, and/or erases any information by irradiating optical beams such as the laser beams onto a recording media composed of magnetic film, wherein comprising; a focussing controller provided in a stationary holder; a tracking controller that drives said focussing controller in the direction of the tracking control; a construction wherein said focussing controller is provided with an interim holder, an objective lens mirror cylinder connected to said . interim holder via a parallel spring moving in the focussing direction, electromagnetic means for driving said objective lens mirror cylinder in the focussing direction; a construction wherein said tracking controller is provided with electromagnetic means for driving said focussing controller in the direction of the tracking control; and a construction wherein said focussing controller and a stationary holder are connected to each other via a parallel spring that moves in the direction of the disc radius, where said parallel spring is capable of moving in the direction of the tracking control; and
Claim 8
Dependent Claim
174 words
An optical focus position control device of an optical disc apparatus that records, plays back, and/or erases any information by irradiating optical beams such as the laser beams onto a recording media composed of magnetic film, wherein comprising; a focussing controller provided in a stationary holder; a tracking controller that drives said focussing controller in the direction of the tracking control; a construction wherein said focussing controller is provided with an interim holder, an objective lens mirror cylinder connected to said . interim holder via a parallel spring moving in the focussing direction, electromagnetic means for driving said objective lens mirror cylinder in the focussing direction; a construction wherein said tracking controller is provided with electromagnetic means for driving said focussing controller in the direction of the tracking control; and a construction wherein said focussing controller and a stationary holder are connected to each other via a parallel spring that moves in the direction of the disc radius, where said parallel spring is capable of moving in the direction of the tracking control; and
Claim 9
Dependent Claim
204 words
An optical focus position control device of an optical disc apparatus that records, plays back, and/or erases any information by irradiating optical beams such as the laser beams onto a recording media composed of magnetic film, wherein comprising; a focussing controller that drives an objective lens mirror cylinder in the direction of the optical axis of-the incident beams within the stationary holder; a tracking controller that drives said focussing controller in the direction of the disc radius; a construction wherein said focussing controller is provided with an interim holder, an objective lens mirror cylinder connected to said interim holder via the first parallel spring that only moves in the direction of the incident beam axis, and electromagnetic means that'drives said objective lens mirror cylinder in the direction of the disc radius, where said focussing controller is connected to said stationary holder via the second parallel spring that only moves in the direction of the disc radius; a construction wherein said tracking controller is provided with electromagnetic means that drives said focussing controller in the direction of the disc radius via said interim holder; and a construction wherein elastic material is used for bonding the first and/or second parallel spring(s) for improving the damping characteristics.
Claim 10
Dependent Claim
204 words
An optical focus position control device of an optical disc apparatus that records, plays back, and/or erases any information by irradiating optical beams such as the laser beams onto a recording media composed of magnetic film, wherein comprising; a focussing controller that drives an objective lens mirror cylinder in the direction of the optical axis of-the incident beams within the stationary holder; a tracking controller that drives said focussing controller in the direction of the disc radius; a construction wherein said focussing controller is provided with an interim holder, an objective lens mirror cylinder connected to said interim holder via the first parallel spring that only moves in the direction of the incident beam axis, and electromagnetic means that'drives said objective lens mirror cylinder in the direction of the disc radius, where said focussing controller is connected to said stationary holder via the second parallel spring that only moves in the direction of the disc radius; a construction wherein said tracking controller is provided with electromagnetic means that drives said focussing controller in the direction of the disc radius via said interim holder; and a construction wherein elastic material is used for bonding the first and/or second parallel spring(s) for improving the damping characteristics.
References Cited (Backward Citations)
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