US4469430A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Light beam printer
Assignee: Hitachi Ltd
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Filing: 1982-11-30
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Granted: 1984-09-04
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Expires: 2002-11-30
Abstract
Abstract In a laser beam printer for scanning a surface of a uniformly charged photoconductive photosensitive drum by a laser beam to form an electrostatic latent image and developing the electrostatic latent image by fine particles of toner, a dust-proof box is provided at a laser beam emitting port of an exposure optical system to prevent the toner from entering into the exposure optical system and contaminating the same.
Inventors
- 👤 Isamu Terashima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 03:40
CPC Classifications
G; G06; G06K; G06K15/00; G06K15/02; G06K15/12; G06K15/1295; G06K15/1204
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
119 words
A light beam printer comprising: an electrostatic recording unit for selectively discharging charges on a surface of a uniformly charged photoconductive photosensitive body to form an electrostatic latent image and developing the electrostatic image by fine particles of toner; an exposure optical system isolated from said electrostatic recording unit and having a light beam path for deflecting a light beam to scan the surface of said photoconductive photosensitive body by said light beam to selectively discharge said charges; and a dust-proof box disposed at a light beam emitting port of said exposure optical system and including a wall having a slit forming a light path for said light beam and a dust sink system formed inside of said wall.
Claim 2
Dependent Claim
119 words
A light beam printer comprising: an electrostatic recording unit for selectively discharging charges on a surface of a uniformly charged photoconductive photosensitive body to form an electrostatic latent image and developing the electrostatic image by fine particles of toner; an exposure optical system isolated from said electrostatic recording unit and having a light beam path for deflecting a light beam to scan the surface of said photoconductive photosensitive body by said light beam to selectively discharge said charges; and a dust-proof box disposed at a light beam emitting port of said exposure optical system and including a wall having a slit forming a light path for said light beam and a dust sink system formed inside of said wall.
Claim 3
Dependent Claim
17 words
A light beam printer according to claim 1 wherein said dust-proof box is made of conductive material.
Claim 4
Dependent Claim
21 words
A light beam printer according to claim 2 wherein needle electrodes are arranged on an inner wall of said dust-proof box.
Claim 5
Dependent Claim
17 words
A light beam printer according to claim 1 wherein a magnet is arranged in said dust-proof box.
Claim 6
Dependent Claim
39 words
A light beam printer according to claim 1 wherein said light beam emitting port has a deflection mirror facet error correction optical system and said dust-proof box is disposed at an end of said facet error correction optical system.
Claim 7
Dependent Claim
120 words
A light beam printer comprising: an electrostatic recording unit for selectively discharging charges on a surface of a uniformly charged photoconductive photosensitive body to form an electrostatic latent image and developing the electrostatic image by fine particles of toner; an exposure optical system insolated from said electrostatic recording unit and having a light beam path for deflecting a light beam to scan the surface of said photoconauctive photosensitive body by said light beam to selectively discharge said charges; and a dust-proof box disposed at a light beam emitting port of said exposure optical system and including a plurality of walls each having a slit forming a light path for said light beam and dust sink spaces formed among said walls.
Claim 8
Dependent Claim
120 words
A light beam printer comprising: an electrostatic recording unit for selectively discharging charges on a surface of a uniformly charged photoconductive photosensitive body to form an electrostatic latent image and developing the electrostatic image by fine particles of toner; an exposure optical system insolated from said electrostatic recording unit and having a light beam path for deflecting a light beam to scan the surface of said photoconauctive photosensitive body by said light beam to selectively discharge said charges; and a dust-proof box disposed at a light beam emitting port of said exposure optical system and including a plurality of walls each having a slit forming a light path for said light beam and dust sink spaces formed among said walls.
Claim 9
Dependent Claim
30 words
A light beam printer according to claim 6 wherein said dust-proof box is made of conductive material and needle electrodes are arranged on an inner wall of said dust-proof box.
Claim 10
Dependent Claim
177 words
A light beam printer comprising: an electrostatic recording unit for selectively discharging charges on a surface of a uniformly charged photoconductive photosensitive body to form an electrostatic latent image and developing the electrostatic image by fine particle toner; an exposure optical system isolated from said electrostatic recording unit and having a light beam path for deflecting a light beam to scan the surface of said photoconductive photosensitive body by said light beam to selectively discharge said charges; a dust-proof box disposed at a light beam emitting port of said exposure optical system and including a wall having a slit forming a light path for said light beam and a dust sink space formed inside of said wall; light detection means for detecting an intensity of the light beam emitted from said light beam emitting port to said dust sink space; and means for comprising an intensity of the light beam emitted from said light source with the intensity of the light beam detected by said light detection means to monitor the contamination of said exposure optical system.
Claim 11
Dependent Claim
177 words
A light beam printer comprising: an electrostatic recording unit for selectively discharging charges on a surface of a uniformly charged photoconductive photosensitive body to form an electrostatic latent image and developing the electrostatic image by fine particle toner; an exposure optical system isolated from said electrostatic recording unit and having a light beam path for deflecting a light beam to scan the surface of said photoconductive photosensitive body by said light beam to selectively discharge said charges; a dust-proof box disposed at a light beam emitting port of said exposure optical system and including a wall having a slit forming a light path for said light beam and a dust sink space formed inside of said wall; light detection means for detecting an intensity of the light beam emitted from said light beam emitting port to said dust sink space; and means for comprising an intensity of the light beam emitted from said light source with the intensity of the light beam detected by said light detection means to monitor the contamination of said exposure optical system.
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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) | 1987-09-04 | 1988-03-05 | 1988-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-09-04 | 1992-03-05 | 1992-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-09-04 | 1996-03-05 | 1996-09-04 | $7700.00 | Window Closed / Lapsed |