OBJECTIVE LENS DEVICE, OPTICAL PICKUP DEVICE, OPTICAL-DISC DRIVING DEVICE AND DRIVING METHOD OF OBJECTIVE LENS
First Claim
1. An objective lens device comprising:
- a first objective lens having a first numerical aperture, which can condense light into a disc-shaped first optical recording medium including a first cover layer of first thickness;
a second objective lens having a second numerical aperture which is smaller than said first numerical aperture, which can condense light into a disc-shaped second optical recording medium including a second cover layer of second thickness which is thicker than said first thickness;
a third objective lens having a third numerical aperture which is smaller than said second numerical aperture, which can condense light into a disc-shaped third optical recording medium including a third cover layer of third thickness which is thicker than said second thickness; and
a lens holder configured to integrally hold said first, second, and third objective lenses.
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Accused Products
Abstract
An objective lens device includes: a first objective lens having a first numerical aperture, which can condense light into a disc-shaped first optical recording medium including a first cover layer of first thickness; a second objective lens having a second numerical aperture which is smaller than the first numerical aperture, which can condense light into a disc-shaped second optical recording medium including a second cover layer of second thickness which is thicker than the first thickness; a third objective lens having a third numerical aperture which is smaller than the second numerical aperture, which can condense light into a disc-shaped third optical recording medium including a third cover layer of third thickness which is thicker than the second thickness; and a lens holder configured to integrally hold the first, second, and third objective lenses.
26 Citations
22 Claims
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1. An objective lens device comprising:
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a first objective lens having a first numerical aperture, which can condense light into a disc-shaped first optical recording medium including a first cover layer of first thickness; a second objective lens having a second numerical aperture which is smaller than said first numerical aperture, which can condense light into a disc-shaped second optical recording medium including a second cover layer of second thickness which is thicker than said first thickness; a third objective lens having a third numerical aperture which is smaller than said second numerical aperture, which can condense light into a disc-shaped third optical recording medium including a third cover layer of third thickness which is thicker than said second thickness; and a lens holder configured to integrally hold said first, second, and third objective lenses. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. An optical pickup device comprising:
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a light source configured to emit a first laser beam including a first wavelength, a second laser beam including a second wavelength which is longer than said first wavelength, and a third laser beam including a third wavelength which is longer than said second wavelength; a first objective lens having a first numerical aperture, which can condense said first laser beam into a disc-shaped first optical recording medium including a first cover layer of first thickness; a second objective lens having a second numerical aperture which is smaller than said first numerical aperture, which can condense said second laser beam into a disc-shaped second optical recording medium including a second cover layer of second thickness which is thicker than said first thickness; a third objective lens having a third numerical aperture which is smaller than said second numerical aperture, which can condense said third laser beam into a disc-shaped third optical recording medium including a third cover layer of third thickness which is thicker than said second thickness; a lens holder configured to integrally hold said first, second, and third objective lenses; and an actuator configured to drive said lens holder. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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21. An optical-disc driving device comprising:
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a rotational driving mechanism configured to rotationally drive a disc-shaped first optical recording medium including a first cover layer of first thickness, a disc-shaped second optical recording medium including a second cover layer of second thickness which is thicker than said first thickness, or a disc-shaped third optical recording medium including a third cover layer of third thickness which is thicker than said second thickness; a first objective lens including a first numerical aperture, which can condense light into said first optical medium; a second objective lens including a second numerical aperture which is smaller than said first numerical aperture, which can condense light into said second optical recording medium; a third objective lens including a third numerical aperture which is smaller than said second numerical aperture, which can condense light into said third optical recording medium; a lens holder configured to hold said first, second, and third objective lenses integrally; an actuator configured to drive said lens holder; and a recording/playback processing unit configured to record a signal in said first, second, or third optical recording medium which is rotationally driven by said rotational driving mechanism, or to play a signal recorded therefrom.
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22. An objective lens driving method comprising the steps of:
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condensing light into a disc-shaped optical recording medium including a first cover layer of first thickness using a first objective lens including a first numerical aperture; condensing light into a disc-shaped second optical recording medium including a second cover layer of second thickness which is thicker than said first thickness, using a second objective lens including a second numerical aperture which is smaller than said first numerical aperture; condensing light into a disc-shaped third optical recording medium including a third cover layer of third thickness which is thicker than said second thickness using a third objective lens having a third numerical aperture which is smaller than said second numerical aperture; and driving a lens holder configured to integrally hold said first, second, and third objective lenses to record or play a signal.
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Specification