Patent US2575258A successfully refreshed from Google Patents.
Patent US4006984A successfully refreshed from Google Patents.
US4006984A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for the manufacture of printing plates
Assignee: Hoechst AG
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Filing: 1975-11-05
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Granted: 1977-02-08
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Expires: 1995-11-05
Abstract
Abstract A method and apparatus for the manufacture of printing masters by electrophotographic means in which the unexposed printing masters are placed in the apparatus in a printing master holder and undergo electrostatic charging, image exposure, development, drying and discharging from the apparatus mechanically. The apparatus provides a charging device, a lighting device for indirect illumination of an original, an imaging device for projecting the image of the original in a preselected scale onto the printing master, and transportation, development, and drying means.
Inventors
- 👤 Ferdinand Friese
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:13
CPC Classifications
G; G03; G03B; G03B27/00; G03B27/32; G03B27/52; G03B27/54; G03B27/542; G03B27/34; G03B27/36; G03G; G03G15/00; G03G15/22; G03G15/26
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
168 words
An apparatus for the manufacture of printing masters by electrophotographic means comprising: a frame supporting an unexposed printing master holder and carriage means for removal of unexposed printing master from said holder by reduced pressure of a vacuum plate; an exposure platform communicating with said frame to receive said unexposed printing master from said carriage means and securely retain said printing master during charging and exposure thereof; charging means communicating with said frame for electrostatic charging of said printing master retained to said exposure platform; means communicating with said frame for holding an image containing original for illumination and projection onto said printing master; means communicating with said frame for illumination of said original by radiation sources capable of only indirect illumination of said original; means communicating with said illumination means for projection of image of said original onto said charged printing master; and means communicating with said frame for transportation, developing and drying of said printing master after exposure of said printing master to said projected image.
Claim 2
Independent Claim
168 words
An apparatus for the manufacture of printing masters by electrophotographic means comprising: a frame supporting an unexposed printing master holder and carriage means for removal of unexposed printing master from said holder by reduced pressure of a vacuum plate; an exposure platform communicating with said frame to receive said unexposed printing master from said carriage means and securely retain said printing master during charging and exposure thereof; charging means communicating with said frame for electrostatic charging of said printing master retained to said exposure platform; means communicating with said frame for holding an image containing original for illumination and projection onto said printing master; means communicating with said frame for illumination of said original by radiation sources capable of only indirect illumination of said original; means communicating with said illumination means for projection of image of said original onto said charged printing master; and means communicating with said frame for transportation, developing and drying of said printing master after exposure of said printing master to said projected image.
Claim 3
Dependent Claim
46 words
The apparatus according to claim 1, whereby said carriage runs on two guide rails and is driven by a motor mounted on its upper side, said motor being geared, over a gear, to a rack-and-pinion gear arranged parallel to the direction of movement of the carriage.
Claim 4
Dependent Claim
71 words
The apparatus according to claim 2, whereby after removing said printing plate from said plate holder, said carriage may be displaced from its position above said plate holder in the direction of said exposure platform; whereby, after depositing said printing plate on said exposure platform, said vacuum plate of said carriage switches on said charging means; whereby said carriage then returns to its initial position and switches off said charging means.
Claim 5
Dependent Claim
25 words
The apparatus according to claim 3, wherein said charging means is arranged at the front end of said carriage and extends over its longitudinal edge.
Claim 6
Dependent Claim
14 words
The apparatus according to claim 1, wherein said printing master is a printing plate.
Claim 7
Dependent Claim
37 words
The apparatus according to claim 5, whereby said plateholder is constructed as a withdrawable drawer equipped with a limit switch which blocks an automatic starter for the feed of said printing plate when said plateholder is empty.
Claim 8
Dependent Claim
34 words
The apparatus according to claim 5, wherein on the front end of said carriage, two or more pins are arranged which may be lowered by means of electromagnetic coils after termination of said exposure.
Claim 9
Dependent Claim
41 words
The apparatus according to claim 7, wherein grooves are provided in said exposure platform which extend in the direction of movement of said carriage and are engaged by said lowered pins during the movement of said carriage over said exposure platform.
Claim 10
Dependent Claim
50 words
The apparatus of claim 8, whereby after exposure of said printing plate, said carriage leaves its initial position and during this movement, said pins rest against the trailing edge of said printing plate and push said plate over a conveyor belt into a developing means and an adjacent drying means.
Claim 11
Dependent Claim
26 words
The apparatus according to claim 5, wherein said projection means comprises a movable optical system for selective variation of the scale of reproduction of said image.
Claim 12
Dependent Claim
30 words
The apparatus of claim 10, wherein said movable optical system comprises a toggle lever drive communicating with a bracket movable along a spindle and carrying a diaphragm and a shutter.
Claim 13
Dependent Claim
27 words
The apparatus of claim 11, wherein said toggle lever drive comprises two levers supported in a pivot bearing on said housing and stationary bearing on said frame.
Claim 14
Dependent Claim
50 words
The apparatus according to claim 12, wherein said two levers of said toggle lever drive are engaged in their pivotal point by a third lever whose length may be fixedly adjusted and the other end of which is attached to the foot of said movable bracket carrying said optical system.
Claim 15
Dependent Claim
19 words
The apparatus according to claim 10, wherein said radiation sources are separated from said original by a radiation screen.
Claim 16
Dependent Claim
51 words
The apparatus according to claim 14, wherein said illumination means comprises first and second reflectors which partially surround said radiation sources and are arranged between said screen and said radiation sources in such a manner that they direct the radiation received from said radiation sources onto said original by indirect reflection.
Claim 17
Dependent Claim
55 words
The apparatus according to claim 15, wherein each of said radiation sources is surrounded by a first, curved reflector which is positioned at a distance of not more than 3 cm from the surface of said radiation source and is open in the direction of longitudinal side walls of a housing of the illumination means.
Claim 18
Dependent Claim
33 words
The apparatus according to claim 16, wherein the planar sections of said second reflector are attached to said side walls and that said curved sections extend in the direction of said radiation sources.
Claim 19
Dependent Claim
30 words
The apparatus according to claim 17, wherein said side walls are reflecting and direct the incident radiation onto said original at an acute angle to the surface of said original.
Claim 20
Dependent Claim
31 words
The apparatus according to claim 18, wherein said radiation sources surround said original symmetrically to its edges and at a distance which is slightly less than the depth of said housing.
Claim 21
Dependent Claim
59 words
The apparatus according to claim 19, wherein said screen comprises an attachment which surrounds the entrance opening of a bellows at the wall of said housing opposite said original and having a rectangular cross-sectional area with a border strip arranged at right angles thereto, to avoid direct radiation of the said radiation sources in the direction of said original.
Claim 22
Dependent Claim
30 words
The apparatus according to claim 18, wherein said holder of said original is arranged at the back of said housing against a sealed glass cover communicating with a vacuum pump.
Claim 23
Dependent Claim
20 words
The apparatus according to claim 21, wherein a drop door communicates with said housing providing access to said glass cover.
Claim 24
Dependent Claim
20 words
The apparatus according to claim 22, wherein said drop door connects with said glass cover by way of cylindrical damper.
Claim 25
Dependent Claim
104 words
An electrophotographic method for the manufacture of printing masters comprising: arranging an image containing original in a holder, mechanically transferring an unexposed printing master by reduced pressure from a printing master holder to an exposure platform, electrostatically charging said unexposed printing master, exposing said printing master to said image of said original projected through a movable optical system by way of an indirect illumination of said original, mechanically transferring said exposed printing master to a developing device, developing and fixing the latent electrostatic image on said printing master, mechanically transferring said developed printing master to a drying device, and drying said developed printing master.
Claim 26
Dependent Claim
104 words
An electrophotographic method for the manufacture of printing masters comprising: arranging an image containing original in a holder, mechanically transferring an unexposed printing master by reduced pressure from a printing master holder to an exposure platform, electrostatically charging said unexposed printing master, exposing said printing master to said image of said original projected through a movable optical system by way of an indirect illumination of said original, mechanically transferring said exposed printing master to a developing device, developing and fixing the latent electrostatic image on said printing master, mechanically transferring said developed printing master to a drying device, and drying said developed printing master.
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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) | 1980-02-08 | 1980-08-09 | 1981-02-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-02-08 | 1984-08-09 | 1985-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-02-08 | 1988-08-09 | 1989-02-08 | $7700.00 | Window Closed / Lapsed |