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US4639072A Expired / Lapsed US ⏱️ 0.0 years remaining

Optical beam scanning apparatus including a cylindrical lens having its opposite ends closer to the scanned plane than its medial portion

Assignee: Konica Minolta Inc
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Filing: 1984-11-29
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Granted: 1987-01-27
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Expires: 2004-11-29
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Abstract

Abstract An optical beam scanning apparatus wherein a beam shaping device for forming a flat light beam which has a large width in the scanning direction and which is substantially parallel with the direction of the optical axis is disposed between a light source and rotary polygonal mirror, and a cylindrical lens bent to have both ends in the longitudinal direction thereof approaching to the scanned plane is disposed between a condensing lens for condensing the light beam reflected by the rotary polygonal mirror and a scanned plane in the vicinity of the latter. The rotary polygonal mirror and the scanned plane are arranged to have a conjugate relation with each other from geometrical optics. The light beam is converged so as to generate the beam waist near the scanned plane.

Inventors

  • 👤 Toyotsugu Itoh
  • 👤 Toshio Muramatsu

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 22:25
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/0025; G02B27/0031; G02B26/00; G02B26/08; G02B26/10; G02B26/12; G02B26/124

Claims Analysis

Total Claims: 15
Claim 1
Independent Claim 69 words
In an optical beam scanning apparatus wherein a light beam from a light source is reflected by a rotary polygonal mirror and then radiated to a scanned plane through a condensing lens for scanning of the beam, the improvement in that a cylindrical lens bent to have both ends in the longitudinal direction thereof approaching to said scanned plane is disposed between said condensing lens and said scanned plane.
Claim 2
Dependent Claim 69 words
In an optical beam scanning apparatus wherein a light beam from a light source is reflected by a rotary polygonal mirror and then radiated to a scanned plane through a condensing lens for scanning of the beam, the improvement in that a cylindrical lens bent to have both ends in the longitudinal direction thereof approaching to said scanned plane is disposed between said condensing lens and said scanned plane.
Claim 3
Dependent Claim 19 words
An optical beam scanning apparatus according to claim 1 wherein said cylindrical lens is disposed near said scanned plane.
Claim 4
Dependent Claim 26 words
An optical beam scanning apparatus according to claim 2, wherein said light beam is converged so as to generate the beam waist near said scanned plane.
Claim 5
Dependent Claim 43 words
An optical beam scanning apparatus according to claim 1, wherein the reflection surfaces of said rotary polygonal mirror and said scanned plane are arranged to have a conjugate relation with each other from geometrical optics in the direction perpendicular to the scanning direction.
Claim 6
Dependent Claim 26 words
An optical beam scanning apparatus according to claim 1, wherein said light beam is converged so as to generate the beam waist near said scanned plane.
Claim 7
Dependent Claim 17 words
An optical beam scanning apparatus according to claim 1, wherein said light beam is a laser beam.
Claim 8
Dependent Claim 80 words
In an optical beam scanning apparatus wherein a light beam from a light source is reflected by a rotary polygonal mirror and then radiated to a scanned plane through a condensing lens for scanning of the beam, the improvement in that a flexible cylindrical lens and a constraining member adapted to forcibly bend said cylindrical lens to have both ends in the longitudinal direction thereof approaching to said scanned plane are disposed between said condensing lens and said scanned plane.
Claim 9
Dependent Claim 80 words
In an optical beam scanning apparatus wherein a light beam from a light source is reflected by a rotary polygonal mirror and then radiated to a scanned plane through a condensing lens for scanning of the beam, the improvement in that a flexible cylindrical lens and a constraining member adapted to forcibly bend said cylindrical lens to have both ends in the longitudinal direction thereof approaching to said scanned plane are disposed between said condensing lens and said scanned plane.
Claim 10
Dependent Claim 19 words
An optical beam scanning apparatus according to claim 7 wherein said cylindrical lens is disposed near said scanned plane.
Claim 11
Dependent Claim 19 words
An optical beam scanning apparatus according to claim 7, wherein a guide member is used as said constraining member.
Claim 12
Dependent Claim 43 words
An optical beam scanning apparatus according to claim 7, wherein the reflection surface of said rotary polygonal mirror and said scanned plane are arranged to have a conjugate relation with each other from geometrical optics in the direction perpendicular to the scanning direction.
Claim 13
Dependent Claim 26 words
An optical beam scanning apparatus according to claim 10, wherein said light beam is converged so as to generate the beam waist near said scanned plane.
Claim 14
Dependent Claim 26 words
An optical beam scanning apparatus according to claim 7, wherein said light beam is converged so as to generate the beam waist near said scanned plane.
Claim 15
Dependent Claim 17 words
An optical beam scanning apparatus according to claim 7, wherein said light beam is a laser beam.

References Cited (Backward Citations)

US4496209A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1990-01-26 1990-07-28 1991-01-27 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1994-01-26 1994-07-28 1995-01-27 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1998-01-26 1998-07-28 1999-01-27 $7700.00 Window Closed / Lapsed

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