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US4455485A Expired / Lapsed US ⏱️ 0.0 years remaining

Laser beam scanning system

Assignee: Hitachi Ltd
•
Filing: 1981-11-25
•
Granted: 1984-06-19
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Expires: 2001-11-25
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Abstract

Abstract A laser beam scanning system for focusing a laser beam to a fine spot and for scanning precisely a large field includes an acousto-optical deflector enabled to deflect a laser beam in the direction of one axis or in the directions of two axes, while maintaining the fine spot diameter, to scan a small field, a relay lens for projecting said deflection point to the center of an objective lens, to effect the focusing of the beam to a fine spot, a high speed carriage enabled to move with high accuracy in biaxial directions, a precise position detector enabled to detect the position of the carriage, and a controller for organically controlling the aforementioned respective functions thereby to make it possible to precisely deflect the laser beam over a large field, whereby a scanning operation of a large field at a high speed and with a high accuracy is performed by the laser beam.

Inventors

  • 👤 Sumio Hosaka
  • 👤 Tatsuo Harada
  • 👤 Akihiro Takanashi

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-25 21:03
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/70; G03F7/70383; G03F7/704; G02; G02B; G02B26/00; G02B26/08; G02B26/10; G02B26/108; G02F; G02F1/00; G02F1/29; G02F1/33

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 127 words
A laser beam scanning system for scanning the surface of a specimen with a laser beam having a fine spot diamter, comprising: means for producing a finely-focused laser beam, an acousto-optical deflector for deflecting said laser beam at a high speed with a small field at a deflecting point; an objective lens for focusing the laser beam from said acousto-optical deflector to a spot having a fine diameter upon the surface of the specimen; a relay lens interposed between said acousto-optical deflector and said objective lens for projecting the laser beam deflecting point toward the center of said objective lens; and specimen positioning means including a specimen carriage for moving said specimen in the directions of two orthogonal axes in a parallel plane to said specimen surface.
Claim 2
Dependent Claim 127 words
A laser beam scanning system for scanning the surface of a specimen with a laser beam having a fine spot diamter, comprising: means for producing a finely-focused laser beam, an acousto-optical deflector for deflecting said laser beam at a high speed with a small field at a deflecting point; an objective lens for focusing the laser beam from said acousto-optical deflector to a spot having a fine diameter upon the surface of the specimen; a relay lens interposed between said acousto-optical deflector and said objective lens for projecting the laser beam deflecting point toward the center of said objective lens; and specimen positioning means including a specimen carriage for moving said specimen in the directions of two orthogonal axes in a parallel plane to said specimen surface.
Claim 3
Dependent Claim 33 words
A laser beam scanning system as set forth in claim 1, wherein said acousto-optical deflector includes means for deflecting the incident laser beam in the direction of one of said two orthogonal axes.
Claim 4
Dependent Claim 31 words
A laser beam scanning system as set forth in claim 1, wherein said acousto-optical deflector includes means for deflecting the incident laser beam in the directions of said two orthogonal axes.
Claim 5
Dependent Claim 32 words
A laser beam scanning system as set forth in claim 1, wherein said laser beam producing means includes an optical modulator for modulating the laser beam which incides upon said acousto-optical deflector.
Claim 6
Dependent Claim 49 words
A laser beam scanning system as set forth in claim 1, wherein said specimen positioning means includes a position deflector for detecting the position of said specimen carriage; and means for correcting the input signal to said acousto-optical deflector in response to the output signal of said position detector.

References Cited (Backward Citations)

US3514534A Cited
US3531184A Cited
US4390875A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1987-06-19 1987-12-19 1988-06-19 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1991-06-19 1991-12-19 1992-06-19 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1995-06-19 1995-12-19 1996-06-19 $7700.00 Window Closed / Lapsed

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