Facsimile and static presentation processing – Static presentation processing – Attribute control
Reexamination Certificate
1997-02-13
2001-04-17
Lee, Thomas D. (Department: 2624)
Facsimile and static presentation processing
Static presentation processing
Attribute control
C358S451000, C358S406000, C355S051000, C355S072000
Reexamination Certificate
active
06219154
ABSTRACT:
A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by any one of the patent disclosure, as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyright rights whatsoever.
1. Technical Field
The present invention relates to digital platesetting and imagesetting. More particularly, the present invention relates to the establishment and monitoring of the proper exposure setting of an image recording device.
2. Background Art
Modern electronic digital platesetters and imagesetters write or record images for subsequent reproduction at a predefined resolution rate. Such systems may write or record images on various media including, photo or thermal sensitive paper or polymer films, photo or thermal sensitive coatings, erasable imaging materials or ink receptive media mounted onto an image recording surface, polymer film or aluminum based printing plate materials, all used in image reproduction. Such media are mounted onto a recording surface which may be planar or curved.
Conventional digital imagesetters include a raster image processor (RIP) which receives signals representing an image to be recorded on the applicable media and converts the signals into instructions to a scanner which scans the recording media to produce the desired image. It is the function of the RIP to process the received signals representing the image into an instruction set corresponding thereto which will be understood by the scanner.
In an article entitled “How to Calibrate and Linearize an Imagesetter Using the Digital UGRA/FOGRA Wedge” (Franz Sigg and David Romano, Society for Imaging Science and Technology, Proceedings of the Fourth Technical Symposium on Prepress Proofing and Printing, October, 1995, pp. 88-92), which was co-authored by David Romano who is also a co-inventor of the invention described herein, the need for imagesetter predictability and repeatability is discussed. As noted therein, most modern imagesetters require adjustment so that a prespecified solid density associated with the media to be imaged is produced. In most cases, it is required that the imagesetter be adjusted until a solid density within a range of 1.0 to 4.0 or more is obtained on the medium being recorded. A densitometer can be utilized to measure the density of a recorded image to ensure correspondence with the pre-specified density.
In practice, the scanner intensity is often adjusted to change the density of a recorded image. However, because the intensity adjustment does not guarantee that desired dot areas will actually be recorded on the medium, it has been proposed that linearization curves be utilized to further adjust the imagesetter to offset the dot gain on the medium recorded by the imagesetter which is typically experienced as the intensity of the scanner is increased. In this way, the size or number of dots within an image are modified so that the desired dot areas will actually be recorded on the imaged medium. However, utilizing linearization curves does not ensure proper exposure. Although the use of linearization curves, may result in proper dot areas, the adjustments made to obtain the desired density may also result in undesirable dot fringe or fog between the dots on the recorded medium.
In the above referenced article, it is proposed that half-tone patterns formed of one-by-one, two-by-two and four-by-four pixel checkerboards be compared with a 50% half-tone patch to calibrate the imagesetter. More particularly, it was disclosed that the proper imagesetter exposure occurs when the three checkerboards and a 50% half-tone patch have the same darkness or tint and hence the same visual density.
In non-digital platemaking, it is well known to form continuous grey tone wedges with a plurality of continuous tone density patches on a separate sheet of medium to compare with a test or registration patch formed on the recorded medium to initially set the exposure of the platemaker and/or to confirm that each individual sheet of recorded medium includes a test patch which matches the selected patch on the wedge. Such a wedge is depicted in prior art FIG.
1
.
As shown in
FIG. 1
, the wedge
10
includes various continuous tone density patches
20
which are numbered 1-13 on the wedge. The densities of the respective patches vary from 0 to 100%. Other fields, which are not relevant for purposes of the present disclosure, are also included on the wedge
10
. The patches
20
are formed on a medium
30
which is preferably of a material substantially similar to the medium to be production imaged and on which the test patch is to be recorded. The platemaker operator is instructed which of the particular step(s) on the wedge
10
, and therefore which of the specific patch or patches within the continuous tone density patches
20
the test patch recorded on each piece of production medium must correspond to in order to be acceptable.
In a typical operational setting, a range of steps, e.g.
4
,
5
and
6
, might be designated for use in initially establishing the exposure setting for the platemaker or in monitoring the acceptability of recorded media and hence the repeatability of the platemaker. The wedge
10
provides a simple way in which to initially set the platemaker exposure and to monitor the quality of recorded media in non-digital platemakers. Although providing a rough indicator for initially establishing an acceptable platemaker exposure setting and for monitoring platemaker repeatability by ensuring that all recorded media is exposed at approximately the same level, the wedge
10
cannot ensure that the recorded test patch actually corresponds to a desired density. In any event, many of the operators now operating digital platesetters and imagesetters were trained on non-digital platemakers and are familiar with the use of the
FIG. 1
wedge for quality control.
OBJECTIVES OF THE INVENTION
In view of the above, it is an objective of the present invention to provide an improved technique for calibrating digital platesetters and imagesetters.
It is a further object of the present invention to provide a technique which allows digital platesetter and imagesetter operators to simply and precisely establish the correct exposure for the platesetter or imagesetter prior to production recording of desired images on a medium.
It is a further object of the present invention to provide a technique which allows digital platesetter and imagesetter operators to simply and precisely monitor repeatability of the platesetter or imagesetter using an aid similar to that used in non-digital platemaking.
It is an additional objective of the present invention to provide a technique which allows platesetter and imagesetter operators to visually determine whether or not exposure has been optimally adjusted.
It is still another objective of the present invention to provide a technique which facilitates a precise determination of how close the digital platesetter or imagesetter exposure is to its optimum exposure.
It is yet another objective of the present invention to provide a user friendly technique which allows digital platesetter or imagesetter operators to visually determine the acceptability of characters to be printed on a medium at an exposure level during production operations.
Still a further objective of the present invention is to provide a digital platesetter or imagesetter system with automated exposure monitoring and/or control.
Additional objects, advantages, novel features of the present invention will become apparent to those skilled in the art from this disclosure, including the following detailed description, as well as by practice of the invention. While the invention is described below with reference to preferred embodiment(s), it should be understood that the invention is not limited thereto. Those of ordinary skill in the art having access to the teachings herein will recognize additional implementations, modifications, and embod
Alterio Brian P.
Romano David J.
Kelley Edward L.
Lee Thomas D.
Stadnicki Alfred A.
LandOfFree
Exposure control technique for imagesetting applications does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Exposure control technique for imagesetting applications, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Exposure control technique for imagesetting applications will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2474103