Patent US1035249A successfully refreshed from Google Patents.
Patent US4297422A successfully refreshed from Google Patents.
US4297422A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrophotographic process for printing a plurality of copies
Assignee: Olympus Corp
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Filing: 1978-07-18
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Granted: 1981-10-27
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Expires: 1998-07-18
Abstract
Abstract An electrophotographic process for printing a number of copies from a single electrostatic charge latent image once formed on a photosensitive member by projecting an optical image of a document to be copied comprises the following successive steps; (a) a step for effecting a uniform primary electrification with one polarity for the photosensitive member; (b) a step for forming on the uniformly charged photosensitive member, a primary electrostatic latent image corresponding to the image of the document by projecting the document image to the photosensitive member; (c) a step for developing the primary latent image with opaque toner particles having charged in the other polarity to form on the photosensitive member a toned image; (d) a step for placing a transfer member over a surface of the photosensitive member on which surface the toned image has been formed; (e) a step for effecting a secondary electrification with the one polarity from a side of the transfer member and for effecting a secondary exposure also from the side of the transfer member with light which is substantially absorbed by the toners, while the transfer member being placed over the photosensitive member, to form on the photosensitive member a secondary electrostatic latent image corresponding to the primary latent image; and (f) a step for separating the transfer member from the photosensitive member to transfer the toner image onto the transfer member. After the above steps have been completed the steps (c) to (f) are repeated successively for the secondary electrostatic charge latent image repeatedly formed on the photosensitive member so as to form a number of duplicated copies.
Inventors
- 👤 Eiichi Sato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 13:00
CPC Classifications
G; G03; G03G; G03G13/00; G03G13/22
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
351 words
An electrophotosensitive process for printing a plurality of copies with a single imagewise exposure of a document to be duplicated comprising (a) a step for effecting a uniform primary electrification with one polarity for a photosensitive member; (b) a step for forming on the uniformly charged photosensitive member a primary electrostatic latent image corresponding to an image of the document by effecting the imagewise exposure; (c) a step for developing the primary latent image with toner developer having charged in the other polarity to form on the photosensitive member a toner image; (d) a step for placing a transparent or translucent transfer member over a surface of the photosensitive member on which surface the toned image has been formed; (e) a step for effecting a secondary electrification with the one polarity by applying a transferring electric field from the side of the transfer member in such a manner that a potential at an imagewise dark portion on the photosensitive member on which portion the toner has been applied will assume a substantially same potential as that of the primary electrostatic latent image after a transfer and for effecting a secondary exposure with light having a wavelength which is substantially absorbed by the toner developer also from the side of the transfer member in such a manner that undesired charge applied at an imagewise bright portion on the photosensitive member is decayed, but the charge on the imagewise dark portion is not decayed due to the presence of the light impermeable toner so as to be able to form on the photosensitive member a secondary electrostatic latent image having an image information substantially corresponding to the primary latent image after the transfer, said secondary electrification and secondary exposure being simultaneously or successively effected, while the transfer member is placed over the photosensitive member; and (f) a step for separating the transfer member from the photosensitive member to transfer the toner image onto the transfer member; whereby the steps (c) to (f) are repeated successively for the secondary latent image repeatedly formed on the photosensitive member to form a number of duplicated copies.
Claim 2
Dependent Claim
351 words
An electrophotosensitive process for printing a plurality of copies with a single imagewise exposure of a document to be duplicated comprising (a) a step for effecting a uniform primary electrification with one polarity for a photosensitive member; (b) a step for forming on the uniformly charged photosensitive member a primary electrostatic latent image corresponding to an image of the document by effecting the imagewise exposure; (c) a step for developing the primary latent image with toner developer having charged in the other polarity to form on the photosensitive member a toner image; (d) a step for placing a transparent or translucent transfer member over a surface of the photosensitive member on which surface the toned image has been formed; (e) a step for effecting a secondary electrification with the one polarity by applying a transferring electric field from the side of the transfer member in such a manner that a potential at an imagewise dark portion on the photosensitive member on which portion the toner has been applied will assume a substantially same potential as that of the primary electrostatic latent image after a transfer and for effecting a secondary exposure with light having a wavelength which is substantially absorbed by the toner developer also from the side of the transfer member in such a manner that undesired charge applied at an imagewise bright portion on the photosensitive member is decayed, but the charge on the imagewise dark portion is not decayed due to the presence of the light impermeable toner so as to be able to form on the photosensitive member a secondary electrostatic latent image having an image information substantially corresponding to the primary latent image after the transfer, said secondary electrification and secondary exposure being simultaneously or successively effected, while the transfer member is placed over the photosensitive member; and (f) a step for separating the transfer member from the photosensitive member to transfer the toner image onto the transfer member; whereby the steps (c) to (f) are repeated successively for the secondary latent image repeatedly formed on the photosensitive member to form a number of duplicated copies.
Claim 3
Dependent Claim
39 words
An electrophotosensitive process according to claim 1, wherein the exposure in the step (e) is uniformly effected to form the secondary electrostatic latent image which includes image information completely corresponding to the toned image formed in the step (c).
Claim 4
Dependent Claim
48 words
An electrophotographic process according to claim 1, wherein the exposure in the step (e) is effected in an imagewise manner corresponding to another document to form the secondary electrostatic latent image which corresponds to a superimposed image of the toned image and the image of said another document.
Claim 5
Dependent Claim
19 words
An electrophotographic process according to claim 1, wherein said electrification and exposure in the step (e) are effected simultaneously.
Claim 6
Dependent Claim
22 words
An electrophotographic process according to claim 1, wherein the electrification and exposure in the step (e) are effected successively in this order.
Claim 7
Dependent Claim
13 words
An electrophotographic process according to claim 1, wherein said transfer member is transparent.
Claim 8
Dependent Claim
13 words
An electrophotographic process according to claim 1, wherein said transfer member is translucent.
Claim 9
Dependent Claim
33 words
An electrophotographic process according to claim 6, wherein said transparent transfer member is an endless sheet and the toned image formed on the endless transfer sheet is further transferred to a record medium.
Claim 10
Dependent Claim
28 words
An electrophotographic process according to claim 8, further comprising a step for cleaning the endless transfer sheet after the toned image has been transferred to the record medium.
Claim 11
Dependent Claim
17 words
An electrophotographic process according to claim 7, wherein said translucent transfer member is a plain paper sheet.
Claim 12
Dependent Claim
31 words
An electrophotographic process according to claim 1, wherein said uniform primary electrification in the step (a) and the secondary electrification in the step (e) are effected by the same charging device.
Claim 13
Dependent Claim
31 words
An electrophotographic process accordng to claim 1, wherein the uniform primary electrification in the step (a) and the secondary electrification in the step (e) are carried out by separate charging devices.
Claim 14
Dependent Claim
37 words
An electrophotographic process according to claim 1, wherein the secondary electrification is effected to such an extent that the secondary electrostatic latent image has substantially same amount of charge as that of the primary electrostatic latent image.
Claim 15
Dependent Claim
66 words
An electrophotographic process according to claim 1, wherein as the photosensitive member use is made of a photosensitive drum comprising a rotatable drum body made of electrically conductive material and a photosensitive layer applied on a circumferential surface of the drum and the transfer member is travelled with being in contact with the photosensitive drum over a given arc of the circumferential passage of the drum.
References Cited (Backward Citations)
US2951443A
Cited
DE2151283A1
Cited
US3764207A
Cited
US3954463A
Cited
US3918971A
Cited
US3877934A
Cited
US3941592A
Cited
US4014605A
Cited
US3992557A
Cited
US3961951A
Cited
US4141728A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-10-26 | 1985-04-27 | 1985-10-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-10-26 | 1989-04-27 | 1989-10-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-10-26 | 1993-04-27 | 1993-10-27 | $7700.00 | Window Closed / Lapsed |