Image analysis – Applications – Document or print quality inspection
Patent
1996-04-15
1998-03-03
Lee, Thomas D.
Image analysis
Applications
Document or print quality inspection
25022711, 25055901, G06K 900
Patent
active
057244375
DESCRIPTION:
BRIEF SUMMARY
The invention relates to a device for image inspection and colour measurement on at least one printed product produced in a printing press with at least one printing unit.
Known from EP 0 324 718 A1 are a process and a device for the inking control of a printing press. On the basis of the spectral measured values of a colour-control strip, if an actual colour locus deviates from a setpoint colour locus, the required film-thickness changes in the individual ink zones of the individual printing units are calculated through the intermediary of a special computing process (linear model). Since a colorimetric closed-loop control simulates a closed-loop control with regard to the colour sensation received by the human eye from a printed product, it is possible to achieve a high-grade print quality. The colorimetric control process for a printing press described in EP 0 324 718 A1 is to be viewed as an advantageous embodiment of colorimetric closed-loop control and as an integral constituent part of the present patent application.
A device for the implementation of a comprehensive quality control on printed sheets is described in EP 0 410 253 A2. The image data of a printed product are captured by a video camera disposed above a colour-matching table. The data are stored in a memory for digital image data. Provided parallel to the video camera is a light source both for the representation of data and also as a guiding apparatus for the measuring apparatuses. Provided between video camera and light source are one or more systems for image evaluation, particularly for pattern recognition, which use the data of the memory for the image data. In particular, colour-measuring devices and register-measuring devices enter into consideration as measuring apparatuses.
The object of the present invention is to create a device that makes in possible for the quality and colour of printed products to be evaluated simultaneously.
The object of the invention is achieved in that the device consists of at least one image-capturing apparatus, supplying image data (:=position-correlated measured data) from the printed product, and of a computing apparatus, the computing apparatus, on the one hand, determining all image data of the printed product for the purpose of image inspection and, on the other hand, determining from the image data of at least one measuring point (pixel) of the printed product a measured variable for a colour assessment. The image data for image inspection and colour assessment may come either from one or also from various printed products.
Proposed for the first time herewith is a device that simultaneously satisfies two requirements that are decisive with regard to a high-grade print quality. Firstly, an evaluation with regard to print quality is carried out on the basis of the entire image-data set of the printed product (printed product:=sheet and/or printed image). A comparison of actual and setpoint values is used in order to detect, for example, hickies, insufficient damping-solution supply, ghosting, register errors, geometrical position errors of the printed image on the sheet and imperfections in the sheet as well as mis-fed sheets. In addition, measured variables for a colour assessment are determined on the basis of the image data of certain regions, yet of at least one pixel of the printed product.
According to advantageous further developments of the device according to the invention, it is provided that either said measured values are visualized on a display means, such as a monitor, and/or the measured values are used to derive a controlled variable for inking control in the individual printing units.
According to advantageous further developments of the device according to the invention, it is provided that the image-capturing apparatus is used both in-line and also off-line, it being disposed, in the latter case, above a deposition device for printed products. Such a deposition device is described, for example, in the hereinbefore cited EP 0 410 253 A2.
If the device according to the invention
REFERENCES:
patent: 3660594 (1972-05-01), Marsh
patent: 4197584 (1980-04-01), Blazek
patent: 4426074 (1984-01-01), Fischer
patent: 4439038 (1984-03-01), Mactaggert
patent: 4660159 (1987-04-01), Ott
patent: 4685139 (1987-08-01), Masuda et al.
patent: 4748680 (1988-05-01), Margolin
patent: 4827526 (1989-05-01), Matsumoto
patent: 4963895 (1990-10-01), Harada et al.
patent: 4975862 (1990-12-01), Keller et al.
patent: 5050994 (1991-09-01), Kipphan et al.
patent: 5142139 (1992-08-01), Hayashi et al.
patent: 5163012 (1992-11-01), Wuhrl et al.
patent: 5223918 (1993-06-01), Berthold et al.
patent: 5300767 (1994-04-01), Steinle et al.
patent: 5537229 (1996-07-01), Brandestini et al.
Publ. Applied Optics, vol. 30, No. 32, Nov. 1991, (Simpson et al.), pp.4666-4670, "Imaging colorimetry". . .
Xerox Disclosure Journal, vol. 18, No. 2 (Edmunds et al),Mar./Apr. 1993, pp.203-210, "Adaptive exposure ". . .
Publ. Fogra-Symposium, Apr. 1988 (Kleinmeier), pp.1-14, "Der heutige Stand der Bilderfassung bei der . . .".
Publ. Der Polygraph 11-92 (Zankel), pp.42-43, "Digital-isierte Steuerungen fuer Bogen-und Rollenmaschinen . . . ".
Publ. Deutscher Drucker No.43, 21-11-91, pp.41-43, "Neues fuer den Flexodrucker: Rasterwalzen, Klischees". . .
Publ. Feingeraetetechnik No.38, 1989 (Geschke et al.) pp. 10-13, "Digitale Bildverarbeitung zur Kontrolle . . . ".
Bucher Harald
Fischer Gerhard
Geissler Wolfgang
Huber Werner
Kipphan Helmut
Greenberg Laurene A.
Heidelberger Druckmaschinen AG
Lee Thomas D.
Lerner Herbert L.
Patel Jayanti K.
LandOfFree
Device for parallel image inspection and inking control on a pri does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Device for parallel image inspection and inking control on a pri, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Device for parallel image inspection and inking control on a pri will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2256404