Web material alignment apparatus and method

Winding – tensioning – or guiding – Convolute winding of material – With coiled supply

Reexamination Certificate

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

C033S286000, C033S623000, C033SDIG002, C242S533700, C242S534100, C242S563100

Reexamination Certificate

active

06595460

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to the field of large format printing, and more particularly to an apparatus and method for aligning an image receiving substrate material on the web handling assembly of a large format printer.
2. Technical Background
There are several systems commercially available today that employ a plurality of piezoelectric print heads to transfer ink to a large scale image receiving substrate or web material to produce graphic products with multicolored or enhanced graphic images for signs, large banners, billboards, and the like. The web material used in such systems is typically supplied in a roll and is typically constructed of vinyl, some other polymeric material, or specialty paper. Generally speaking a computer system is employed to format a selected graphic target image such that it can be reproduced in the desired enlarged size and location on the web material by the piezoelectric print heads as the web material is advanced through a plurality of rollers in the printer. A carriage housing the piezoelectric print heads is typically moved across the web material at a controlled rate of speed while ink is delivered from the heads to the web material. Generally speaking the ink is typically delivered during a number of passes across the web material so that the graphic image created on the web material resembles the target image entered in the computer as closely as possible.
Printing with such commercially available systems is extremely difficult and time consuming. Because such systems generally deliver only four colors of ink, preferably, cyan, magenta, yellow, and black, reproducing an acceptable likeness of the target image requires precise synchronization of the web advancement and ink delivery. Any misalignment of the web material, change in the advancement rate of the web material, clogging of the print heads, misfires of the ink jet nozzles, improper impact of the ink droplets on the web material, or other misstep in the process can result in poor color quality, improper shading, an effect commonly known in the art as “banding”, poor resolution, or other defect in the graphic image transferred to the web material. Moreover, because the graphic image transferred to the web material occupies such a large surface area, small mistakes in the process are magnified and are generally readily apparent to the naked eye.
An important aspect of large format printing is the alignment of the web material with respect to the print heads. If the web material, which is generally supplied in a roll having a diameter of up to approximately 16 inches, is not properly loaded into the printer, any initial misalignment, however small, will result in a significant shift in alignment of the web material as the web material approaches the end of the roll. This phenomena, known as “walking” will significantly impact printing quality, and if severe enough, can inhibit printing altogether. In most commercially available large format printers, loading of the web material is still a manual process and requires an operator to advance the web material several meters in a dry run to determine if the web material walks. Others have attempted to position reference marks on the web material rollers to facilitate proper alignment during loading, but this approach has had little success as the web material cores often cover the reference marks or the reference marks become inadvertently covered with ink so that they are no longer visible after a relatively short period of time. As a result, determining whether the web material is loaded square or straight in the printer has been a difficult task.
What is needed therefore, but currently unavailable in the art, is an improved large format printer incorporating an alignment apparatus and method for facilitating proper loading of web material onto the web handling assembly rollers of the printer. The apparatus and method should be easy to maintain, provide quick and accurate web material alignment, and facilitate proper incremental advancement of the web material during printing operations. Moreover, such a device should facilitate efficient loading and unloading of web material rolls and provide large format graphic images of higher resolution and clarity than other large format printers known in the art, while at the same time increasing print speeds. The alignment apparatus should also be inexpensive to manufacture and maintain and should be efficient in operation. It is to the provision of such an apparatus and method that the present invention is primarily directed.
SUMMARY OF THE INVENTION
Accordingly, one aspect of the present invention relates to a method of aligning the edge of an elongated printable media on the web handling assembly of a printer. The method includes the steps of projecting an alignment marker onto at least a portion of the web handling assembly, passing the elongated printable media through the web handling assembly, and aligning the edge of the elongated printable media with the alignment marker so that the edge is substantially co-linear with the alignment marker.
In another aspect of the present invention is directed to an elongated printable media alignment apparatus for aligning the elongated printable media on the web handling assembly of a printer. The apparatus includes a light source constructed and arranged to project a substantially linear alignment marker onto at least a portion of the web handling assembly, and an adjustable support structure for securing a light source to the printer such that the light source is sufficiently remote from the printer.
An additional aspect of the present invention relates to a method of aligning an edge of an elongated printable media on a printer web handling assembly incorporating a supply roller and take-up roller. The method includes the steps of loading a roll of elongated printable media onto the supply roller, projecting an alignment marker onto at least a portion of the web handling assembly, and moving the roll of elongated printable media toward the alignment marker to align the edge of the media with the alignment marker. The elongated printable media is extracted from the roll to pass the elongated printable media through the web handling assembly, and the edge of the elongated printable media is aligned with the alignment marker as the elongated printable media is brought into engagement with the take-up roller. Once the edge of the elongated printable media is aligned with the alignment marker, the elongated printable media is secured to the take-up roller.
The web material alignment apparatus and method of the present invention results in a number of advantages over other grand format printers and methods of printing large scale graphics commonly known in the art. For example, the web material alignment apparatus of the present invention significantly reduces web material misalignments during web material loading. In addition, the present invention obviates the need for complex and inaccurate web material and alignment procedures and facilitates the rapid loading and unloading of web material rolls.
In addition to the advantages set forth above, the web material alignment apparatus and method of the present invention significantly reduces the occurrence of web material wrinkling during web advancement and printing operations. Moreover, web material “walking” on the take-up roller during web advancement and printing is substantially prevented. As a result, far less time is spent repeating the same print job using the improved grand format printer of the present invention.
Additional features and advantages of the present invention will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from the description or recognized by practicing the invention as described herein.


REFERENCES:
patent: 3232547 (1966-02-01), Theide et al.
patent: 4021031 (1977-05-01), Meihofer et al.
patent: 4077579 (1978-03-01), Seleski et al.
pa

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Web material alignment apparatus and method does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Web material alignment apparatus and method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Web material alignment apparatus and method will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-3071355

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.