EP0092997A2
Expired / Lapsed
EP
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An optical pickup
Assignee: Toshiba Corp
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Filing: 1983-04-22
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Granted: —
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Expires: 2003-04-22
Abstract
Abstract An optical pickup for reading data from a high density record medium has an electro magnetically adjustable focus and tracking mechanism. A magnetic yoke 132 has resilient support members 142 connected to it through a plate 138 and magnet 140. Support members 142 carry a plate 146 on which is a magnetic member 148, to which are attached resilient support members 182. The sets of support members 142 and 182 are flexible in mutually perpendicular directions. The support members 182 carry a magnetic member 172 to which is attached an objective lens 167. A magnet 150 is mounted opposite the magnetic member 148 and an electromagnet 152 is mounted on the magnet 150. An electromagnet 162 is mounted on the plate 138. The permanent magnets 140 and 150 normally keep the respective magnetic plates 170 and 146 in a substantially fixed relative position and the lens 167 is thus both resiliently and magnetically supported. Variation in the magnetic field applied by either electromagnet 162 or 152 will alter the effective magnetic field applied by magnetic member 170 or 146 respectively. This variation in magnetic field will cause movement of either the flexible support members 142 and the rest of the assembly, including the lens 167, in a direction parallel to the optical access of the lens or movement of the flexible members 182 and the parts attached thereto in a direction perpendicular to this axis. These directions corespond respectively to the focusing and tracking directions of the pickup and therefore focusing and tracking can be controlled by varying current supply to the electromagnets 162 and 152.
Inventors
- 👤 Fusayoshi C/O Patent Division Kido
- 👤 Atsushi C/O Patent Division Takahashi
- 👤 Shitta C/O Patent Division Shingu
- 👤 Yoshinori C/O Patent Division Higuchi
- 👤 Akira C/O Patent Division Yamada
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 18:32
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/08; G11B7/09; G11B7/0925; G11B7/0932
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
103 words
An optical pickup comprising: a base member (132); an objective lens (167); means (142, 182) for flexibly connecting said object lens (167) to said base (132) to permit said objective lens (167) to move in first and second mutually perpendicularly directions; first electromagnetic means (152) for moving said objective lens (167) in said first direction; second electromagnetic means (162) for moving said objective lens in said second direction; light source means (188), fixed with respect to said base (132), for providing light to said objective lens (167); and means for generating an electrical signal related to light received from said objective lens (167).
Claim 2
Dependent Claim
103 words
An optical pickup comprising: a base member (132); an objective lens (167); means (142, 182) for flexibly connecting said object lens (167) to said base (132) to permit said objective lens (167) to move in first and second mutually perpendicularly directions; first electromagnetic means (152) for moving said objective lens (167) in said first direction; second electromagnetic means (162) for moving said objective lens in said second direction; light source means (188), fixed with respect to said base (132), for providing light to said objective lens (167); and means for generating an electrical signal related to light received from said objective lens (167).
Claim 3
Dependent Claim
197 words
An optical pickup for reading data from a high density record medium, comprising: a base member (132); an objective lens (167); a light source (188) arranged to provide light to the objective lens (167); a focusing lens (168) arranged to receive light from the objective lens (167); a photo-detector arranged to receive light from the focusing lens (168); at least one first and at least one second resilient support member (142, 182), the first support member (142) connected to the base (132) and flexible in a first direction, and the second support member (182) connected with the first support member (142), flexible in a second direction perpendicular to the first and connected to support the objective lens (167); means (140, 150) for producing first and second magnetic fields which interact respectively with a first and a second magnetically susceptible material (148, 170), and the interacting combinations arranged to at least assist in maintaining, respectively the positions of the first and second flexible support members (142, 182) and first and second electromagnet means (152, 162) for altering the first and second magnetic fields, respectively, so as to move the objective lens (167) in the first and second directions.
Claim 4
Dependent Claim
197 words
An optical pickup for reading data from a high density record medium, comprising: a base member (132); an objective lens (167); a light source (188) arranged to provide light to the objective lens (167); a focusing lens (168) arranged to receive light from the objective lens (167); a photo-detector arranged to receive light from the focusing lens (168); at least one first and at least one second resilient support member (142, 182), the first support member (142) connected to the base (132) and flexible in a first direction, and the second support member (182) connected with the first support member (142), flexible in a second direction perpendicular to the first and connected to support the objective lens (167); means (140, 150) for producing first and second magnetic fields which interact respectively with a first and a second magnetically susceptible material (148, 170), and the interacting combinations arranged to at least assist in maintaining, respectively the positions of the first and second flexible support members (142, 182) and first and second electromagnet means (152, 162) for altering the first and second magnetic fields, respectively, so as to move the objective lens (167) in the first and second directions.
Claim 5
Dependent Claim
32 words
An optical pickup as claimed in claim 2 wherein the first direction in which the first support member (142) is flexible is parallel to the optical axis of the objective lens (167).
Claim 6
Dependent Claim
61 words
An optical pickup as claimed in claim 2 or 3 wherein at least one of the first and second magnetic field means (140, 150) is provided on the base member (132) and the corresponding of the first and second magnetically susceptible material is in the form of a magnetic member (148, 170) connectd with the first or second support member, respectively.
Claim 7
Dependent Claim
29 words
An optical pickup as claimed in claim 2, 3 or 4 wherein at least one of the first and second magnetic field means is a permanent magnet (140, 150).
Claim 8
Dependent Claim
45 words
An optical pickup as claimed in any one of claims 2 to 5 wherein the base member is a magnetic yoke (132) and the first support member (142) is connected with one of two walls (134, 136) defining a magnetic gap of the yoke (132).
Claim 9
Dependent Claim
39 words
An optical pickup as claimed in any one of claims 2 to 6 wherein at least one of the first and second electromagnet means (152, 162) is mounted on or adjacent to the respective magnetic field means (150, 160).
Claim 10
Dependent Claim
56 words
An optical pickup as claimed in any one of claims 2 to 7 wherein at least one of the first and second electromagnet means (152, 162) has two pole pieces (154, 156) arranged in line with the respective first or second direction and each of the pole pieces has a coil (158, 160) wound round it.
Claim 11
Dependent Claim
32 words
An optical pickup as claimed in claim 8 wherein the coils (158, 160) on the pole pieces of the first and/or the second electromagnet means (153, 162), are wound in opposite senses.
Claim 12
Dependent Claim
23 words
An optical pickup as claimed in any preceding claim wherein the light source (188) is fixed with respect to the base member (132).
Claim 13
Dependent Claim
25 words
An optical pickup as claimed in any preceding claim wherein the focusing lens (168) and photo detector are fixed with respect to objective lens (167).
Claim 14
Dependent Claim
259 words
An optical pickup comprising: a magnet yoke (132) having first and second portions facing each other (134, 136), defining a magnetic gap therebetween; a plurality of first flexible supporting members (142) each having first and second ends, each of the first ends being fixed to a first portion of said yoke (132), and the first flexible supporting members (142) being flexible in a first direction; a movable member (146) attached to said second ends of said first flexible supporting members; a plurality of second flexible supporting members (182) having first and second ends, the first ends being fixed to the movable member (146), and the second flexible supporting members (182) being flexible in a second direction perpendicular to the first direction; a lens assembly including an object lens (167), a focusing lens (168), a photo-detector and a first magnetic member (170), the objective lens (167) having an optical axis parallel to the first direction, and the object lens (167), the focusing lens (168) and the photo-detector being connected to the first magnetic member (170), the first magnetic member (170) being fixed to the second ends of the second flexible members (182); a first permanent magnet attached to the first portion of the yoke (132); a first electromagnet (162) attached to the first permanent magnet; a second magnetic member (148) provided on the movable member; a second permanent magnet (150) provided on the second portion of the yoke (132); a second electromagnet (152) provided on the second permanent magnet (150); and a light source (188) fixed to the yoke (132).
Claim 15
Dependent Claim
259 words
An optical pickup comprising: a magnet yoke (132) having first and second portions facing each other (134, 136), defining a magnetic gap therebetween; a plurality of first flexible supporting members (142) each having first and second ends, each of the first ends being fixed to a first portion of said yoke (132), and the first flexible supporting members (142) being flexible in a first direction; a movable member (146) attached to said second ends of said first flexible supporting members; a plurality of second flexible supporting members (182) having first and second ends, the first ends being fixed to the movable member (146), and the second flexible supporting members (182) being flexible in a second direction perpendicular to the first direction; a lens assembly including an object lens (167), a focusing lens (168), a photo-detector and a first magnetic member (170), the objective lens (167) having an optical axis parallel to the first direction, and the object lens (167), the focusing lens (168) and the photo-detector being connected to the first magnetic member (170), the first magnetic member (170) being fixed to the second ends of the second flexible members (182); a first permanent magnet attached to the first portion of the yoke (132); a first electromagnet (162) attached to the first permanent magnet; a second magnetic member (148) provided on the movable member; a second permanent magnet (150) provided on the second portion of the yoke (132); a second electromagnet (152) provided on the second permanent magnet (150); and a light source (188) fixed to the yoke (132).
References Cited (Backward Citations)
No citation records indexed.
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