Manufacturing container or tube from paper; or other manufacturi – With printing or photographic reproduction – And cutting – breaking – tearing – or abrading
Reexamination Certificate
1999-01-29
2001-07-24
Kim, Eugene (Department: 3721)
Manufacturing container or tube from paper; or other manufacturi
With printing or photographic reproduction
And cutting, breaking, tearing, or abrading
C493S363000, C493S364000, C083S127000, C083S146000
Reexamination Certificate
active
06264593
ABSTRACT:
BACKGROUND OF THE INVENTION
In electronic prepress systems, images to be printed by offset printing are scanned from photographic sources, digitized, assembled, and edited electronically at a workstation. The images are then transmitted to a raster image processor (RIP) for half-tone screening and image rasterization. The RIP image, or rasterized image, to be printed is then transmitted from the RIP to an imagesetter for photographic or film recording onto a medium such as paper, film, or a printing plate.
An imagesetter includes a supply of unexposed photosensitive media, a recording support surface, and an image exposing system for forming the image to be recorded according to the RIP image data. The image exposing system may employ a laser beam, a cathode ray tube (CRT), an LED emitter, or the like as a radiation source. The media passes either as single sheets or from a supply roll as a web to the recording support surface at which point the photosensitive media is exposed by the radiation source, forming a latent image on the media. Numerous images may be recorded on the web consecutively. The exposed web is then advanced for transfer to a media processor where chemical processing occurs.
Three inks, yellow, magenta, and cyan, are used to print color images. Often black ink is also used. The links are printed in small dots, sometimes overlaid, in varying amounts to create the desired colors when viewed. Thus, three or four black and white separation films must be imaged, one for each color.
In the printing process, the films are overlaid and must be aligned accurately to ensure a good quality image. Toward this end, registration openings or holes are punched in each film to serve as an alignment guide. The location of each pixel on each film is determined with respect to the registration openings.
In prior art punch assemblies, the leading edge of the media is fed into a punch assembly, also referred to as a head punch assembly, in the imagesetter. The punches are forced through the media and held while the media is imaged. After imaging, the punches are retracted from the media. In prior art punch assemblies, the punches arc biassed toward the retracted position by a spring mechanism. Upon release of the punching force, which must be sufficient to overcome the spring bias force, the spring mechanism causes the punch to retract. The spring mechanism, however, has been found to permit binding of the punches in the media.
SUMMARY OF THE INVENTION
The present invention provides a head punch assembly having a positive retraction mechanism which prevents binding of the punch in the media. The punch assembly includes a driving mechanism to provide a driving force on the punch and a positive retraction mechanism disposed to provide a retraction force on the punch operative sequentially following operation of the driving mechanism. The punch assembly is of a smaller size and more economical to manufacture and is particularly useful with an internal drum imagesetter of a prepress printing system. The punch assembly includes a punch which may be mounted in a cantilever maimer to punch the opening as close to the edge of the media as possible without interfering with the laser beam of the imaging assembly. In this manner, the area of media available for imaging may be maximized and media waste minimized.
Another feature of the present invention is the provision of a roller support mechanism for the shaft upon which punch actuating mechanisms for each punch are mounted. When the punches push into the media, an oppositely directed force is placed on the shaft. The roller support mechanism supports the shaft when it is so loaded by the punches, thereby allowing use of a smaller diameter shaft and minimizing deflection of the shaft.
In another aspect of the present invention, the take-up roller assembly which is used to advance the media from the imagesetter may be mounted to the punch assembly. Similarly, the cutter assembly which cuts sheets of the media may also be mounted to the punch assembly. The assembly thereby takes up less space.
REFERENCES:
patent: 4243314 (1981-01-01), Bowe et al.
patent: 5106017 (1992-04-01), Hicks
patent: 5291647 (1994-03-01), Fukasawa et al.
patent: 5487634 (1996-01-01), Vercillo
patent: 5628502 (1997-05-01), Amarakoon
patent: 5996206 (1999-12-01), Lynch et al.
Diramio Angelo
Newton, Jr. Arthur R.
Robinson Thomas E.
Agfa Corporation
Harmon Christopher
Hilton William
Kim Eugene
Sabourin Robert A.
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