US4270149A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Laser beam facsimile apparatus
Assignee: NEC Corp
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Filing: 1979-08-20
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Granted: 1981-05-26
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Expires: 1999-08-20
Abstract
Abstract A laser beam facsimile apparatus is disclosed. The apparatus utilizes a slit to define the light of a scan line. A laser beam is subjected to amplitude modulation and rapidly deflected toward the slit in a sub-scanning direction by an accousto-optic modulator (AOM) cell. An aperture of the slit is selected to be larger than the diameter of the deflected beam and smaller than the deflection scan in the sub-scanning direction. The light beam passed through the slit is focused on a light-sensitive medium by an optical system, whereby the optical intensity across the entire width of the scan line is constant without losing the sharpness at the edges of the scan line.
Inventors
- 👤 Yoshinori Ohta
- 👤 Keiichi Kubota
- 👤 Mitsuhito Sakaguchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 07:17
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/024; H04N1/032; H04N1/036
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
176 words
A laser beam facsimile apparatus comprising: a laser light source; an accousto-optic modulator cell disposed on the exit side of said laser light source for deflecting a laser beam emitted from said laser light source in a sub-scanning direction; an optical system disposed on the exit side of said accousto-optic modulator cell for collimating said laser light beam; a slit disposed on the exit side of said optical system and having an aperture larger than the diameter of the light beam deflected by said modulator cell in a predetermined direction; an optical system for focusing a light beam passed through said aperture on a photosensitive medium; means for scanning said deflected light beam on said photosensitive medium to produce a pattern of scan lines on said photosensitive medium; a sweep signal generator connected to said modulator cell for scanning a light beam across said slit so that the deflected light beam runs over said aperture; and said sweep signal having a frequency sufficiently higher than the maximum frequency of a signal for producing said scan lines.
Claim 2
Dependent Claim
176 words
A laser beam facsimile apparatus comprising: a laser light source; an accousto-optic modulator cell disposed on the exit side of said laser light source for deflecting a laser beam emitted from said laser light source in a sub-scanning direction; an optical system disposed on the exit side of said accousto-optic modulator cell for collimating said laser light beam; a slit disposed on the exit side of said optical system and having an aperture larger than the diameter of the light beam deflected by said modulator cell in a predetermined direction; an optical system for focusing a light beam passed through said aperture on a photosensitive medium; means for scanning said deflected light beam on said photosensitive medium to produce a pattern of scan lines on said photosensitive medium; a sweep signal generator connected to said modulator cell for scanning a light beam across said slit so that the deflected light beam runs over said aperture; and said sweep signal having a frequency sufficiently higher than the maximum frequency of a signal for producing said scan lines.
Claim 3
Dependent Claim
18 words
A light beam facsimile apparatus according to claim 1, wherein said scanning means is a drum scanning type.
Claim 4
Dependent Claim
18 words
A light beam facsimile apparatus according to claim 1, wherein said scanning means is a plane scanning type.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-05-25 | 1984-11-24 | 1985-05-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-05-25 | 1988-11-24 | 1989-05-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-05-25 | 1992-11-24 | 1993-05-26 | $7700.00 | Window Closed / Lapsed |