US3715156A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Imaging device having a pivoting pressure pad for engaging and disengaging a web medium
Assignee: Varian Medical Systems Inc
•
Filing: 1971-03-22
•
Granted: 1973-02-06
•
Expires: 1991-03-22
Abstract
Abstract The recording web in an electrophotographic apparatus is pressed into engagement with the photoconductive plate by a flexible, resilient, pivoting pressure pad. Due to the positioning of the axis of the pressure pad with respect to the plane of the photoconductive plate, the end of the pressure pad closest to the pivot axis initially contact the web. The area of engagement then increases as the pressure pad is further pivoted against the plate. This progressive engagement action smooths out wrinkles in the web and squeeges or displaces air from between the web and the plate. After full engagement is established, an exposureimaging cycle is initiated which causes a charge image to be formed on the web. The charge image establishes electrostatic forces which further engage the web to the photoconductive plate. After exposure, the web is disengaged from the plate by pivoting the pressure pad away from the plate. The web is peeled off of the surface of the plate during this disengagement causing the area of engagement to progressively decrease as the pressure pad is pivoted. The pivoting-peeling action requires less disengagement force to overcome the electrostatic engagement force than would be required if the web were disengaged over the entire area of engagement simultaneously. Further minimization of the disengagement force is obtained because the force of disengagement established by the pivoting pressure pad is applied generally perpendicular to the plane of the web-plate engagement. The present minimal disengagement forces remain uniformly minimal throughout the disengagement cycle. Timers and limit switches are employed to automate the pressure pad pivoting, exposure-charge cycle, and web transport cycle.
Inventors
- 👤 R Levy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 01:47
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/14; G03G15/18
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
260 words
An electrophotographic recording device employing a recording medium which is periodically engaged and disengaged from a recording structure, the combination comprising: a transparent plate for displaying an image of an original to be copied; a resilient flexible pressure pad having a generally planar surface pivotally mounted with respect to the transparent plate for engaging and disengaging a recording medium in an area between the plate and the pad, said pressure pad being pivotal about an axis located outside of said area of engagement and in a plane other than the plane of the area of engagement for causing the pressure pad when pivoted to initially engage said plate with a recording medium therebetween at a portion thereof close to the pivot axis and for causing the area of engagement to gradually increase as the pivoting of said pad is increased and to extend toward a portion of the pressure pad remote from the pivot axis, and upon disengagement of the pad from said plate with a recording medium therebetween the pivoting relationship causes the area of engagement to gradually decrease toward the portion of the pressure pad close to the pivot axis; recording medium holding means affixed to the pressure pad at the end thereof remote from the initially engaged portion between a recording medium and the plate and the pressure pad for retaining a recording medium during disengagement causing a recording medium to peel away from the plate as the area of engagement decreases; and means for causing the pressure pad to pivot with respect to the transparent plate.
Claim 2
Dependent Claim
260 words
An electrophotographic recording device employing a recording medium which is periodically engaged and disengaged from a recording structure, the combination comprising: a transparent plate for displaying an image of an original to be copied; a resilient flexible pressure pad having a generally planar surface pivotally mounted with respect to the transparent plate for engaging and disengaging a recording medium in an area between the plate and the pad, said pressure pad being pivotal about an axis located outside of said area of engagement and in a plane other than the plane of the area of engagement for causing the pressure pad when pivoted to initially engage said plate with a recording medium therebetween at a portion thereof close to the pivot axis and for causing the area of engagement to gradually increase as the pivoting of said pad is increased and to extend toward a portion of the pressure pad remote from the pivot axis, and upon disengagement of the pad from said plate with a recording medium therebetween the pivoting relationship causes the area of engagement to gradually decrease toward the portion of the pressure pad close to the pivot axis; recording medium holding means affixed to the pressure pad at the end thereof remote from the initially engaged portion between a recording medium and the plate and the pressure pad for retaining a recording medium during disengagement causing a recording medium to peel away from the plate as the area of engagement decreases; and means for causing the pressure pad to pivot with respect to the transparent plate.
Claim 3
Dependent Claim
260 words
An electrophotographic recording device employing a recording medium which is periodically engaged and disengaged from a recording structure, the combination comprising: a transparent plate for displaying an image of an original to be copied; a resilient flexible pressure pad having a generally planar surface pivotally mounted with respect to the transparent plate for engaging and disengaging a recording medium in an area between the plate and the pad, said pressure pad being pivotal about an axis located outside of said area of engagement and in a plane other than the plane of the area of engagement for causing the pressure pad when pivoted to initially engage said plate with a recording medium therebetween at a portion thereof close to the pivot axis and for causing the area of engagement to gradually increase as the pivoting of said pad is increased and to extend toward a portion of the pressure pad remote from the pivot axis, and upon disengagement of the pad from said plate with a recording medium therebetween the pivoting relationship causes the area of engagement to gradually decrease toward the portion of the pressure pad close to the pivot axis; recording medium holding means affixed to the pressure pad at the end thereof remote from the initially engaged portion between a recording medium and the plate and the pressure pad for retaining a recording medium during disengagement causing a recording medium to peel away from the plate as the area of engagement decreases; and means for causing the pressure pad to pivot with respect to the transparent plate.
Claim 4
Dependent Claim
260 words
An electrophotographic recording device employing a recording medium which is periodically engaged and disengaged from a recording structure, the combination comprising: a transparent plate for displaying an image of an original to be copied; a resilient flexible pressure pad having a generally planar surface pivotally mounted with respect to the transparent plate for engaging and disengaging a recording medium in an area between the plate and the pad, said pressure pad being pivotal about an axis located outside of said area of engagement and in a plane other than the plane of the area of engagement for causing the pressure pad when pivoted to initially engage said plate with a recording medium therebetween at a portion thereof close to the pivot axis and for causing the area of engagement to gradually increase as the pivoting of said pad is increased and to extend toward a portion of the pressure pad remote from the pivot axis, and upon disengagement of the pad from said plate with a recording medium therebetween the pivoting relationship causes the area of engagement to gradually decrease toward the portion of the pressure pad close to the pivot axis; recording medium holding means affixed to the pressure pad at the end thereof remote from the initially engaged portion between a recording medium and the plate and the pressure pad for retaining a recording medium during disengagement causing a recording medium to peel away from the plate as the area of engagement decreases; and means for causing the pressure pad to pivot with respect to the transparent plate.
Claim 5
Dependent Claim
104 words
The device as specified in claim 1 employing a dielectric coated recording medium, wherein: a photoconductive layer is provided on the transparent plate adjacent to a recording medium; an electrode means is provided between the photoconductive layer and the transparent plate; the pressure pad is electrically conductive; a voltage source is provided for establishing an electric field between the electrode means and the pressure pad which passes through the photoconductive layer and a dielectric coated recording medium; and an imaging means is provided to illuminate the photoconductive layer with an image which results in a corresponding charge image on a dielectric coated recording medium.
Claim 6
Dependent Claim
35 words
The device as specified in claim 2, wherein a dielectric coated recording medium is normally slightly spaced from the photoconductive layer and is forced into engagement therewith by the pivoting action of the pressure pad.
Claim 7
Dependent Claim
55 words
The device as specified in claim 3, wherein drive means are provided for pulling a recording medium into a position slightly spaced from the photoconductive layer; and switching means are provided responsive to the pivoting of the pressure pad for automating the positioning and engagement of a recording medium and activation of the imaging means.
Claim 8
Dependent Claim
40 words
The device as specified in claim 2, wherein the electric field is maintained between the electrode means and the pressure pad during the imaging process and the subsequent disengagement of the pad from the plate with the recording medium therebetween
Claim 9
Dependent Claim
29 words
The device as specified in claim 2, wherein the pressure pad is bowed across the dimension thereof which is perpendicular to the direction of increasing and decreasing engagement area.
Claim 10
Dependent Claim
38 words
The device as specified in claim 2, wherein a hinged top housing is provided containing the pressure pad and the means for pivoting the pressure pad are mounted in the housing in a position over the photoconductive layer.
References Cited (Backward Citations)
US3288047A
Cited
US3510217A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-02-06 | 1976-08-07 | 1977-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-06 | 1980-08-07 | 1981-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-06 | 1984-08-07 | 1985-02-06 | $7700.00 | Window Closed / Lapsed |