US4355860A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Double pass scanning system
Assignee: Xerox Corp
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Filing: 1980-09-29
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Granted: 1982-10-26
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Expires: 2000-09-29
Abstract
Abstract A raster scanner with laser for generating a scanning beam and compact, folded optical system for transmitting the beam to the object to be scanned. The optical system includes a first mirror for guiding the laser beam forward along a downwardly inclined slope to the modulator, a second mirror below the modulator for intercepting the beam from the modulator and folding the intercepted beam to guide the beam backwards along a horizontal plane to a third mirror which folds the beam and guides the beam forward along an upwardly inclined slope against the mirrored facets of a rotating polygon, the polygon scanning the beam through a preset scan arc and returning the beam via a focusing lens to the third mirror, the third mirror folding the scan beam and guiding the scan beam forward, and a fourth mirror for intercepting the scan beam and guiding the beam to the object to be scanned.
Inventors
- 👤 Pierre A. Lavallee
- 👤 Sidney W. Marshall
- 👤 Ronald L. Antos
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:41
CPC Classifications
G; G02; G02B; G02B26/00; G02B26/08; G02B26/10; G02B26/12; G02B26/127
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
125 words
A symmetrical optical system for a raster scanner which minimizes the need for cross scan corrections and avoids the use of a toroidal type lens, comprising: a plurality of reflective surfaces cooperable to form an optical path for causing a beam of light to impinge on the object to be scanned, said reflective surfaces including a rotatable deflector for scanning said beam through a preset scan arc, and at least one mirror for guiding said beam to said deflector so that said beam strikes said deflector once, said deflector reflecting said beam directly back to said mirror whereby to provide a dual pass optical path between said deflector and said mirror, said mirror reflecting the beam from said deflector toward the object to be scanned.
Claim 2
Dependent Claim
125 words
A symmetrical optical system for a raster scanner which minimizes the need for cross scan corrections and avoids the use of a toroidal type lens, comprising: a plurality of reflective surfaces cooperable to form an optical path for causing a beam of light to impinge on the object to be scanned, said reflective surfaces including a rotatable deflector for scanning said beam through a preset scan arc, and at least one mirror for guiding said beam to said deflector so that said beam strikes said deflector once, said deflector reflecting said beam directly back to said mirror whereby to provide a dual pass optical path between said deflector and said mirror, said mirror reflecting the beam from said deflector toward the object to be scanned.
Claim 3
Dependent Claim
14 words
The optical system according to claim 1 in which said deflector comprises a polygon.
Claim 4
Dependent Claim
47 words
The optical system according to claim 1 in which said reflective surfaces cooperate to form one input and one output optical path to and from said deflector, said input and output paths being tangentially offset from one another to avoid interference between said input and output paths.
Claim 5
Dependent Claim
185 words
In a raster scanner, the combination of: a source of a high intensity beam of light; mirror means forming a compact folded optical path between said light source and the object to be scanned; said mirror means including a rotatable polygon having a plurality of mirror-like facets for scanning a beam input thereto through an arc as said polygon rotates; and plural mirrors for guiding said light beam to said polygon facets and for guiding the scanning beam output by said polygon to the object to be scanned; said mirrors guiding said beam so that said beam strikes said polygon once, said mirror means folding said beam so that the light beam input to said polygon projects along an axis tangent to the axis of said scanning beam output by said polygon and at least two light responsive detectors in the path of said scanning beam for generating start of scan and end of scan signals as said scanning beam sweeps thereacross; said mirror means including pickoff mirrors for guiding said scanning beam to said detectors, said detectors cooperating to provide a predetermined scan arc.
Claim 6
Dependent Claim
185 words
In a raster scanner, the combination of: a source of a high intensity beam of light; mirror means forming a compact folded optical path between said light source and the object to be scanned; said mirror means including a rotatable polygon having a plurality of mirror-like facets for scanning a beam input thereto through an arc as said polygon rotates; and plural mirrors for guiding said light beam to said polygon facets and for guiding the scanning beam output by said polygon to the object to be scanned; said mirrors guiding said beam so that said beam strikes said polygon once, said mirror means folding said beam so that the light beam input to said polygon projects along an axis tangent to the axis of said scanning beam output by said polygon and at least two light responsive detectors in the path of said scanning beam for generating start of scan and end of scan signals as said scanning beam sweeps thereacross; said mirror means including pickoff mirrors for guiding said scanning beam to said detectors, said detectors cooperating to provide a predetermined scan arc.
Claim 7
Dependent Claim
20 words
The raster scanner according to claim 4 in which said beam is folded at least twice by said mirror means.
Claim 8
Dependent Claim
22 words
The raster scanner according to claims 4 or 5 including lens means for focusing said beam onto the object to be scanned.
References Cited (Backward Citations)
US3752558A
Cited
USRE29067E
Cited
US3898627A
Cited
US4058828A
Cited
US4054361A
Cited
US4054928A
Cited
US4179183A
Cited
US4274703A
Cited
US4213157A
Cited
US4284994A
Cited
US4232964A
Cited
US4258395A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-10-25 | 1986-04-26 | 1986-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-10-25 | 1990-04-26 | 1990-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-10-25 | 1994-04-26 | 1994-10-26 | $7700.00 | Window Closed / Lapsed |