US3851230A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrostatic transfer-printing sheet stripping device
Assignee: Ricoh Co Ltd
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Filing: 1973-05-18
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Granted: 1974-11-26
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Expires: 1993-05-18
Abstract
Abstract A device wherein a transfer-printing sheet electrostatically adhering to the photosensitive surface of a photoreceptor after an electrostatic latent image has been formed thereon by transfer-printing from the photoreceptor is subjected to optical illumination to remove the residual charge from the photosensitive surface so as to permit the transfer-printing sheet to be easily peeled off the photoreceptor.
Inventors
- 👤 T Okamoto
- 👤 T Watanabe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:16
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/65; G03G15/6532; G03G15/14; G03G15/18
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
169 words
An electrostatic transfer-printing device of the type comprising: a. a photoreceptor having a photosensitive surface on which an electrostatic latent image is formed for transfer to a transfer-printing sheet; wherein the improvement comprises: b. means for bringing one surface of a transfer-printing sheet into pressing engagement with the photosensitive surface at a transfer-printing position and for applying a voltage to the other surface of said sheet, of opposite polarity from that of the electrostatic latent image charge, to transfer said image onto said transfer-printing sheet by transfer-printing from the photosensitive surface; and c. illumination means for throwing visible light rays onto the photosenitive surface adjacent the transfer-printing position after the transfer-printing sheet is brought into pressing contact with the photosensitive surface of the photoreceptor to illuminate the transfer-printing sheet on which the electrostatic latent image hAs been formed and the photosensitive surface of the photoreceptor on which there is a residual charge so as to remove said residual charge sufficiently to release said transfer-printing sheet from said photosensitive surface.
Claim 2
Dependent Claim
169 words
An electrostatic transfer-printing device of the type comprising: a. a photoreceptor having a photosensitive surface on which an electrostatic latent image is formed for transfer to a transfer-printing sheet; wherein the improvement comprises: b. means for bringing one surface of a transfer-printing sheet into pressing engagement with the photosensitive surface at a transfer-printing position and for applying a voltage to the other surface of said sheet, of opposite polarity from that of the electrostatic latent image charge, to transfer said image onto said transfer-printing sheet by transfer-printing from the photosensitive surface; and c. illumination means for throwing visible light rays onto the photosenitive surface adjacent the transfer-printing position after the transfer-printing sheet is brought into pressing contact with the photosensitive surface of the photoreceptor to illuminate the transfer-printing sheet on which the electrostatic latent image hAs been formed and the photosensitive surface of the photoreceptor on which there is a residual charge so as to remove said residual charge sufficiently to release said transfer-printing sheet from said photosensitive surface.
Claim 3
Dependent Claim
26 words
A device as in claim 1 wherein said illumination means comprises a light source and a reflector for directing said light rays onto said photosensitive surface.
Claim 4
Dependent Claim
29 words
A device as in claim 2 wherein said reflector has a reflecting surface of the shape which corresponds to one-half portion of an ellipse cut along its major axis.
Claim 5
Dependent Claim
28 words
A device as in claim 3 wherein the edge of said reflector remote from the transfer-printing position has an extension thereon for guiding said transfer-printing sheet after release.
Claim 6
Dependent Claim
21 words
A device as in claim 1 including guide means for guiding said transfer printing sheet after illumination by said illuminating means.
Claim 7
Independent Claim
123 words
A method for stripping a transfer-printing sheet from the photosensitive surface of a photoreceptor against which it has been pressed to transfer-print a latent electrostatic image on one surface thereof comprising the steps of applying a voltage of opposite polarity to that of the latent electrostatic image charge to the other surface of said sheet during the pressing and shining visible light rays onto the photosensitive surface of said photoreceptor adjacent the transfer-printing position after the transfer printing to illuminate the transfer-printing sheet on which the electrostatic latent image has been formed and the photosensitive surface of the photoreceptor on which there is a residual charge so as to remove said residual charge sufficiently to release said transfer-printing sheet from said photosensitive surface.
Claim 8
Independent Claim
123 words
A method for stripping a transfer-printing sheet from the photosensitive surface of a photoreceptor against which it has been pressed to transfer-print a latent electrostatic image on one surface thereof comprising the steps of applying a voltage of opposite polarity to that of the latent electrostatic image charge to the other surface of said sheet during the pressing and shining visible light rays onto the photosensitive surface of said photoreceptor adjacent the transfer-printing position after the transfer printing to illuminate the transfer-printing sheet on which the electrostatic latent image has been formed and the photosensitive surface of the photoreceptor on which there is a residual charge so as to remove said residual charge sufficiently to release said transfer-printing sheet from said photosensitive surface.
Claim 9
Dependent Claim
42 words
A method as in claim 6 wherein said light rays are shone by means of a light source and further comprising the step of disposing a reflector about said light source for directing and concentrating said light rays onto said photosensitive surface.
Claim 10
Dependent Claim
41 words
A method as in claim 7 wherein said reflector is formed by the step of bending a flat plate into a shape which is substantially in the form of a letter u in cross section and has a narrowed upper opening.
Claim 11
Dependent Claim
24 words
A method as in claim 6 wherein the transfer printing sheet is made of paper and its surface is treated with a dielectric material.
Claim 12
Dependent Claim
25 words
A method as in claim 6 including the step of providing a guide way for the transfer printing sheet after shining the light rays thereon.
References Cited (Backward Citations)
US3575502A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-25 | 1978-05-27 | 1978-11-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-25 | 1982-05-27 | 1982-11-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-25 | 1986-05-27 | 1986-11-26 | $7700.00 | Window Closed / Lapsed |