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US5663944A Expired / Lapsed US ⏱️ 0.0 years remaining

Vertical cavity laser light beam monitored by reflection of a half mirror, with application in optical pick-up

Assignee: Qiang Technologies LLC
•
Filing: 1995-12-29
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Granted: 1997-09-02
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Expires: 2015-12-29
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Abstract

Abstract There is provided a device for monitoring the light output of a VCSEL and a recording and reproducing optical pick-up adopting the device. The device for monitoring the light output of a VCSEL has a half mirror positioned in front of a VCSEL, for reflecting a portion of the light emitted from the VCSEL, and a monitoring optical detector positioned behind the VCSEL, for detecting the light reflected from the half mirror. The recording and reproducing optical pick-up employing the device includes a VCSEL having a light-emitting surface for emitting light vertically from the light-emitting surface, a light output monitor for monitoring the light output of the VCSEL, an objective lens for concentrating incident light on an optical recording medium to form an optical spot thereon, a light path changer for changing a path of the light reflected from the optical recording medium, and a first optical detector for receiving the reflected light and detecting an error signal and an information signal. The light output monitor comprises a half mirror positioned in front of the VCSEL, for reflecting a portion of the light emitted from the VCSEL, and a second monitoring optical detector positioned behind the VCSEL, for detecting the light reflected from the half mirror.

Inventors

  • 👤 Jong-kuk Mun

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-03 12:44
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/12; G11B7/125; G11B7/126; G11B7/123; G11B7/135; G11B7/1353; H; H01; H01S; H01S5/00; H01S5/02; H01S5/026; H01S5/0262; H01S5/0264; G11B7/13; H01S5/022; H01S5/0225; H01S5/02257; H01S5/10; H01S5/18; H01S5/183

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 81 words
A device for monitoring the light output of a vertical cavity surface emitting laser (VCSEL) comprising a VCSEL having a light-emitting surface for emitting light vertically from said light-emitting surface, and means for monitoring light output of said VCSEL; wherein said monitoring means comprises a half mirror positioned in front of said VCSEL, for reflecting a part of the light emitted from said VCSEL, and a monitoring optical detector positioned behind said VCSEL, for detecting light reflected from said half mirror.
Claim 2
Independent Claim 81 words
A device for monitoring the light output of a vertical cavity surface emitting laser (VCSEL) comprising a VCSEL having a light-emitting surface for emitting light vertically from said light-emitting surface, and means for monitoring light output of said VCSEL; wherein said monitoring means comprises a half mirror positioned in front of said VCSEL, for reflecting a part of the light emitted from said VCSEL, and a monitoring optical detector positioned behind said VCSEL, for detecting light reflected from said half mirror.
Claim 3
Dependent Claim 141 words
A recording/reproducing optical pick-up employing a device for monitoring the light output of a vertical cavity surface emitting laser (VCSEL), said optical pick-up comprising a VCSEL having a light-emitting surface for emitting light vertically from said light-emitting surface, means for monitoring light output of said VCSEL, an objective lens for concentrating the light on an optical recording medium to form an optical spot thereon, means for changing a path of the light reflected from said optical recording medium, and a first optical detector for receiving said reflected light and detecting an error signal and an information signal; wherein said monitoring means comprises a half mirror positioned in front of said VCSEL, for reflecting a part of the light emitted from said VCSEL, and a monitoring second optical detector positioned behind said VCSEL, for detecting the light reflected from said half mirror.
Claim 4
Dependent Claim 141 words
A recording/reproducing optical pick-up employing a device for monitoring the light output of a vertical cavity surface emitting laser (VCSEL), said optical pick-up comprising a VCSEL having a light-emitting surface for emitting light vertically from said light-emitting surface, means for monitoring light output of said VCSEL, an objective lens for concentrating the light on an optical recording medium to form an optical spot thereon, means for changing a path of the light reflected from said optical recording medium, and a first optical detector for receiving said reflected light and detecting an error signal and an information signal; wherein said monitoring means comprises a half mirror positioned in front of said VCSEL, for reflecting a part of the light emitted from said VCSEL, and a monitoring second optical detector positioned behind said VCSEL, for detecting the light reflected from said half mirror.
Claim 5
Dependent Claim 39 words
A recording/reproducing optical pick-up as claimed in claim 2, wherein said changing means is a hologram device positioned between said VCSEL and said objective lens, for diffracting light reflected from said optical recording medium toward said first optical detector.
Claim 6
Dependent Claim 56 words
A recording/reproducing optical pick-up as claimed in claim 2, wherein said changing means is a hologram device positioned between said VCSEL and said objective lens, for diffracting light reflected from said optical recording medium toward said first optical detector, said changing means having said half mirror formed on a surface thereof by a reflective material coating.

References Cited (Backward Citations)

US5136603A Cited
US5132982A Cited
US5285466A Cited
US5295147A Cited
US5475701A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2000-09-01 2001-03-03 2001-09-02 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2004-09-01 2005-03-03 2005-09-02 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2008-09-01 2009-03-03 2009-09-02 $7700.00 Window Closed / Lapsed

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