Patent US5387789A successfully refreshed from Google Patents.
US5387789A
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US
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Converging light beam focus detector using two equally and oppositely offset light beam spot size detectors
Assignee: Fujifilm Business Innovation Corp
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Filing: 1994-03-17
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Granted: 1995-02-07
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Expires: 2014-03-17
Abstract
Abstract Two spot size detecting elements are disposed on both sides of an effective scanning area on a scanning surface and spaced from the scanning surface perpendicularly in opposite directions by the same distance, and detect diameters of scanning laser beam. A comparison circuit compares the beam diameters as detected by the two spot size detecting elements. An electrostrictive element attached to a light source deformed in accordance with a comparison result to move the light source so as to correct a converging position of the scanning laser beam.
Inventors
- 👤 Akira Ota
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 12:36
CPC Classifications
G; G06; G06K; G06K15/00; G06K15/02; G06K15/12; G06K15/1204; G06K15/1219
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
107 words
A converging position detecting apparatus in a scanning optical apparatus which scans a scanning surface by a light beam emitted from a light source and converged onto the scanning surface in a regular state, comprising: two spot size detecting means disposed on both sides of an effective scanning area of the scanning surface and spaced from the scanning surface perpendicularly in opposite directions by substantially the same distance, for detecting beam diameters of the light beam; and means for correcting a converging position of the light beam based on the detected beam diameters so that the converging position is located on or close to the scanning surface.
Claim 2
Dependent Claim
107 words
A converging position detecting apparatus in a scanning optical apparatus which scans a scanning surface by a light beam emitted from a light source and converged onto the scanning surface in a regular state, comprising: two spot size detecting means disposed on both sides of an effective scanning area of the scanning surface and spaced from the scanning surface perpendicularly in opposite directions by substantially the same distance, for detecting beam diameters of the light beam; and means for correcting a converging position of the light beam based on the detected beam diameters so that the converging position is located on or close to the scanning surface.
Claim 3
Dependent Claim
47 words
The converging position detecting apparatus of claim 1, further comprising an electrostrictive element attached to the light source, wherein the correcting means corrects the converging position by moving the light source in its light emitting direction by deforming the electrostrictive element based on the detected beam diameters.
Claim 4
Dependent Claim
52 words
The converging position detecting apparatus of claim 1, further comprising a collimating lens for collimating the light beam as emitted from the light source, wherein the correcting means corrects the converging position by moving the collimating lens in a light emitting direction of the light source based on the detected beam diameters.
Claim 5
Dependent Claim
33 words
The converging position detecting means of claim 1, wherein the correcting means corrects the converging position so that the beam diameters as detected by the two spot size detecting means become substantially identical.
References Cited (Backward Citations)
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JPH01237614A
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US5231280A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-02-06 | 1998-08-08 | 1999-02-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-02-06 | 2002-08-08 | 2003-02-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-02-06 | 2006-08-08 | 2007-02-07 | $7700.00 | Window Closed / Lapsed |