US4592643A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Copying machine having reduced image memory
Assignee: Kyocera Mita Industrial Co Ltd
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Filing: 1985-03-28
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Granted: 1986-06-03
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Expires: 2005-03-28
Abstract
Abstract In a copying machine comprising a photosensitive drum having an amorphous silicon type photoconductive layer, if an image of an original is focussed on the photoconductive layer with a light having a wavelength shorter than 600 nm, the light fatigue of the amorphous silicon photoconductive layer is prevented, and the image memory phenomenon owing to the light fatigue is effectively obviated.
Inventors
- 👤 Teruaki Higashiguchi
- 👤 Nobuhiro Miyakawa
- 👤 Koji Yano
- 👤 Kazuo Yamamoto
- 👤 Yoshinobu Kawakami
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 21:01
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/04; G03G15/043; G03G15/0435
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
93 words
A copying machine having a photosensitive drum comprising an amorphous silicon type photoconductive layer formed on an electroconductive substrate and a light exposure mechanism in which an original placed on a transparent contact glass is irradiated with light and an image of the original is focussed on the photoconductive layer uniformly charged with a predetermined polarity through a predetermined optical system to form an electrostatic latent image, wherein the light for focussing the image of the original on the photoconductive layer is adjusted so as to have a wavelength shorter than 600 nm.
Claim 2
Dependent Claim
93 words
A copying machine having a photosensitive drum comprising an amorphous silicon type photoconductive layer formed on an electroconductive substrate and a light exposure mechanism in which an original placed on a transparent contact glass is irradiated with light and an image of the original is focussed on the photoconductive layer uniformly charged with a predetermined polarity through a predetermined optical system to form an electrostatic latent image, wherein the light for focussing the image of the original on the photoconductive layer is adjusted so as to have a wavelength shorter than 600 nm.
Claim 3
Dependent Claim
45 words
A copying machine as set forth in claim 1, wherein a multilayer film of a dielectric material is formed on at least one of mirrors constituting the optical system, whereby the focussing light is adjusted so as to have a wavelength shorter than 600 nm.
Claim 4
Dependent Claim
45 words
A copying machine as set forth in claim 1, wherein a multilayer film of a dielectric material is formed on at least one of lenses constituting the optical system, whereby the focusing light is adjusted so as to have a wavelength shorter than 600 nm.
Claim 5
Dependent Claim
19 words
A copying machine as set forth in claim 2 or 3, wherein the dielectric material is ZnS-MgF 2 .
Claim 6
Dependent Claim
40 words
A copying machine as set forth in claim 1, wherein an interference filter for blocking up rays having a wavelength of at least 600 nm is disposed in an optical path extending from the light source to the photoconductive layer.
Claim 7
Dependent Claim
22 words
A copying machine as set forth in claim 1, wherein the light source having an emission spectrum below 600 nm is used.
Claim 8
Dependent Claim
43 words
A copying machine as set forth in claim 1, wherein a color glass blocking up red rays and near infrared rays is used as the contact glass, whereby the focussing light is adjusted so as to have a wavelength shorter than 600 nm.
Claim 9
Dependent Claim
69 words
A copying machine as set forth in any one of claims 1 through 7, wherein the amorphous silicon type photoconductive layer has a spectral sensitivity characteristic on the short wavelength side, which satisfies the requirement represented by the following formula: Smin/S600>0.07 wherein S600 represents the photosensitivity to a ray having wavelength of 600 nm and Smin represents the minium photosensitivity to rays having a wavelength shorter than 500 nm.
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) | 1989-06-02 | 1989-12-02 | 1990-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-06-02 | 1993-12-02 | 1994-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-06-02 | 1997-12-02 | 1998-06-03 | $7700.00 | Window Closed / Lapsed |