GB2244457A - Print room control system - Google Patents

Abstract

A print room control system is proposed for a plurality of printing presses (1.1 - 1.n), the latter being connected to colour control systems (2.1 - 2.n) for ink feed control. The measurement data from the individual colour control systems (2.1 - 2.n) can be fed to a data-capture computer (4) via a master computer (3). The data-capture computer (4) is so devised as continuously to receive the current data obtained and convert the same to quality data. The quality data are displayed according to their information content on different zones of a monitor screen (5). The data-capture computer (4) continually updates the quality data display. Thus, the print room manager has available a tool by means of which he can supervise the quality situation of the printed products produced on the individual presses. In another aspect, provision is made to display not only the quality data of the individual presses but also the job progress for job progress control. <IMAGE>

Description

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17 This invention relates to a print room control system for a plurality of presses, which, for ink feed control, are connected to colour control systems and the measured data obtained at the individual colour control systems can be fed to a master computer.

Production planning systems are known from manufacturing industry and visualise production progress per unit of time. Graphic displays on a VDU enable the actual state of a production sequence to be displayed in comparison with the ideal plan. From a display of this kind, it is possible to determine whether the production is within the plan or whether it is lagging.

Quality control systems are also known in which the distribution of the quality of the products can be graphically displayed with reference to a desired quality agreed, for example, between the client and the manufacturer.

The use of the above-described systems is also known in the printing industry. Together with the delivered order, the client of a printing works may be given a certificate showing, for example, how the colour densities or colour locations of certain printed sheets, in accordance with which the press ink feed has been controlled, are distributed about the required colour densities or required colour locations. A disadvantage, however, is that such systems are accommodated either in a quality control department or in a department of the printing works organisation or administration.

Published German Patent Specification 3 829 342 Al discloses a printing works control system in the form of a computer network consisting of a master computer and a number of station computers. The station computers perform certain tasks in the various working zones of the printing works. For example, there are station computers for printing works administration, work preparation. operational data capture and for quality control. The colour measuring and control systems of the presses can be connected to the latter computer so that quality data for the print orders produced on the machines can be prepared from the measurement data obtained there (colorimetric values, colour density values).

The various station computers are interconnected via a data communications line so that the data captured by and stored in one station computer can also be available at other station computers, i.e. in other working areas.

The tasks of a print room manager include supervising the presses in the print room and the quality of the printed products produced on these machines. He must devote his attention particularly to the degree of press utilisation (press utilisation factor) in conjunction with the quality, which is important to the saleability of the printed products. If the print room manager finds that the quality of a printed product (e. g. the required colour tint in printing for packaging) is maintained only inadequately on one press, for example owing to a deviation, then he must immediately take or initiate appropriate action in order to prevent the printing of non-saleable spoilage. it is important to interrupt nonsaleable production at an early stage so that the planned timescale for progressing of a print order is not exceeded and so that there is no need to postpone subsequent runs. Exceeding the time allotted for a print run and the consequent delay in subsequent print runs reduces the press utilisation factor while, in addition, is specific orders tied to specific dates and requiring short-term execution cannot be completed within the due dates because of the necessary postponement of the order.

Since the known systems do not offer the print room manager any appreciable help in his activities as briefly outlined above, it is the object of this invention to give the print room manager a tool whereby he is at all times informed of all the current quality features and, more particularly, the production progress of the press in a print room per unit of time.

According to the present invention, there is provided a print room control system for a plurality of presses, which, for ink feed control, are connected to colour control systems and the measured data obtained at the individual colour control systems can be fed to a master computer, the system including a data-capture computer which is so connected to the master computer that the measured data obtained in the colour systems in respect of ink feed can be fed directly to the data-capture computer. the data- capture computer being so devised as to convert the measured data to quality data representing the quality of the printed products produced at the individual presses, a monitor adapted to display the quality data according to their information content. and wherein the display of the quality data can be directly updated by the data-capture computer as fresh measured data is obtained in respect of the ink feed control.

The advantage of the invention is that the measurement data obtained at the various printing presses or colour control systems are captured at the actual times when they occur and can immediately be displayed in a fully graphic form. The fully graphic display is a simple means of imparting information while, in addition, the real time capture and display of the quality data guarantees that the print room manager always has available the most up-to-date data concerning the presses in the print room and the products printed thereon, so that he can carry out his activities.

According to the invention, it is possible to display for the print room manager other data relevant to his tasks. This applies particularly if the print room control system of the invention is incorporated in a printing works control system of the type disclosed in German Patent Specification 3 829 342 Al.

-The invention will be explained in detail and by way of example with reference to the accompanying drawings in which:

Figure 1 is a diagram showing a print room control i i system.

Figure 2 is an example of one advantageous monitor design.

Referring to Figure 1, a number of presses 1.1 - 1.n in the print room of a printing works are connected to colour control systems 2.1 - 2.n. The colour control systems 2.1 - 2.n are used photoelectrically to scan the printed products produced on the presses 1.1 - 1.n and to convert to control data for ink feed. the measurement data obtained by photoelectric scanning. The ink feed is then controlled accordingly either manually (as a followup control by the control recommendations displayed) or is fully automatically (closed control loop). The presses 1.1 - 1.n may be sheet-fed and web-fed presses, more particularly offset presses.

As shown in Figure 1, the various presses 1.1 - 1.n have colour control systems 2.1 - 2.n operating in different ways. The printed sheet or the image printed on a web of paper can be scanned at measuring marks (colour measuring strips) or directly at printed image locations densitometrically or colorimetrically. The densitometers or colorimeters can be adjustable manually to test zones (e.g. as disclosed in German Patent Specification 3 829 342 Al) or automatically scan a measuring strip (e.g. a traversing densitometer as disclosed in German Patent Specification 2 728 738 A2). Also. a number of presses

1.1 - 1.n can be connected to a colour measuring and control system (e.g. as disclosed in European Patent Specification 0 096 238 B1). It is also known to determine colour density or colour location inside the press, for example on the moving web followed by colour control (e.g. as disclosed in East German Patent Specification 227 094 Al). The measured data thus obtained in different ways are evaluated in accordance with control strategies known from the prior art and accordingly converted to control data for the ink feed.

is At the present time. three basic types of colour control (measurement acquisition and evaluation) are used most frequently:

Solid tint and/or raster tint control; ink feed in this case is such that the colour densities of single-colour measurement fields are controlled to give ideal densities (obtained from_ standardisation of the printing process).

Grey balance; the colour densities of grey fields obtained by superimposed printing are determined and the ink feed is so controlled as to give a neutral-grey superimposed print as far as possible. One example of this is given by the Forga-Symposium Densitometrie oder Farbmessung in der Druckindustrie, "Bildbezogene MeB- und Regeltechnik - System Brunner PCPII, Felix Brunner, System Brunner AG.

Colorimetry; colour locations and colour distances are determined colorimetrically in respect of ideal colours (special colours or neutral grey) and the ink feed is so influenced as to minimise the colour distances (e.g. as disclosed in European Patent Specification 228 347 B1).

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1 The type of measurement technique or control strategy used depends more particularly on the printing works equipment and the nature of the print order in conjunction with specific client requirements.

As is known from German Patent Specification 3 829 342 Al, the colour control systems 2.1 - 2.n of the presses 1.1 - 1.n are connected to a master computer 3 in such manner that the measurement data obtained at the individual colour control systems 2.1 - 2.n can be transmitted thereto. Of course. other data from the colour control systems 2.1 - 2.n or from the presses 1.1 - 1.n can be transmitted to the computer 3. For example, press operational data (running time, machine material conditions, downtimes, printing speed), orderspecific data (number of sheets already printed or still to be printed) and so on. The colour control systems 2.1 - 2.n in such conditions usually themselves already have a computer together with display means (monitor) particularly if one or more of the colour control systems 2.1 - 2.n is integrated into the command technology of the presses 1.1 - 1.n, i.e. the entire press and the printing process can be monitored and operated centrally from one control console.

According to the invention, a data-capture computer 4 with a monitor 5, keyboard 6 and a control 7 (mouse. roller ball, joystick or the like) is connected to the master computer 3. The computer 4 with the latter components is readily available in the form of a personal computer and is connected to the master computer 3 via an appropriate data line. The connection between computers 3 and 4 is by way of data communications systems which are adequately known today. No further explanation is therefore necessary. In the data network just described, the master computer 3 acts as a "server" and additionally has data memories. for example in the form of drives (tape or disc). The most up-to-date, i.e. data already obtained in a colour control system 2.1 - 2.n, can now be continuously fed to the computer 4 via the master computer 3, the datacapture computer 4 acting accordingly on the master computer 3 via the data line so that master computer 3 is caused always to transmit the most up-to-date measurement data to the ink feed control. In the data- capture computer 3, the updated measurement data from the colour control systems 2.1 - 2.n are processed to form quality data and displayed on the monitor 5 graphically in a form varying with the is different measurement information. Thus, the print room manager can, via the monitor 5, monitor the most up-todate quality data of all the presses 1.1 - 1.n in the print room.

Figure 2 is an example of a graphic representation of quality data on the screen of monitor 5. In this example, the print room contains five presses 1.1 - 1.5. The monitor screen is divided up into five equal vertical partitions to correspond to the number of presses. The top lines in each partition show, for example, the order number, type of press and a menu line. If, for example, the menu line is activated (keyboard 6 or control 7), then other displays or functions can be selected. The quality data of the respective presses 1.1 - 1.5 are displayed in each partition in two superimposed windows according to the measurement information at any time.

The different types of display in the top row of windows indicate that the presses 1.1 - 1.5 are controlled in accordance with different control strategies, and that the colour control systems 1.1 - 1.5 operate with different data capture (type of photoelectric scanning) and data processing. Each window additionally contains a marking by means of which it can be zoomed up to the full screen size. This is again done, for example, via the control 7.

The top row of windows shows the quality data of the latest updated measurements and the bottom row of windows gives the display of the quality control for the run, i.e. for each inking unit of the presses 1.1 - 1.5, the trend of the colour densities, colour density deviations from required values and, in the case of colorimetric is measurement, the brightness and colour location deviations of the measurements taken in continuous printing.

In the example shown in Figure 2, the presses 1.1 and 1.5 are controlled to a grey balance in continuous printing. The "colour locations" of a grey raster field in the middle tint (three-colour superimposed print) and of a deep tint (three-colour solid-tint superimposed print) as determined by densitometric measurement are displayed in a hexagon. Such colour control and such display of "colour locations" is known. for example, from the brochure by MAN Roland Druckmaschinen AG, "Picture Contrast Technology PCT by the Brunner System - Roland Print Pilot - Roland Autopilot", 1988. The measurement and display of these "colour locations" is, in each case, effected for an image zone formed, for example, by combining a number of ink metering zones. The image zone displayed on the monitor 5. or its quality data, can be freely selected and also changed by selection of a menu i point. Thus. the quality data of whichever image zone is, for example, regarded as particularly critical and agreed between the client and the printing works can thus be displayed.

The hexagon display additionally shows a short-term trend over, for example, the last ten measurements. The large rectangles may denote the "colour locations" of the middle tints, and the small rectangles correspond to the "colour locations" of the deep tints. The latest updated measurements are marked. If this window is zoomed up to full screen size, then it is also possible to display data such as, for example, the order number, image zone number, middle "colour location",, dispersion of "colour location,' over the run and the average gradation (lightdark ratio).

The bottom windows of the quality data display for the presses 1.1 and 1. 5 show, for the run quality control, the dispersion per unit of time about the average value for the solid- tint densities (cyan, yellow, magenta, black) and the middle gradations. When this window is enlarged to full screen size, it is also possible to display the above-described data (numerical values) of the upper window.

According to the example in Figure 2, the presses 1.2 and 1.4 are controlled according to solid tint or raster tint. Assuming that the two presses 1.2 and 1.4 are four-colour presses, the upper window accordingly displays the standard deviations of the solid-tint and raster-tint densities of the inks in the form of four horizontal bars. This is an averaging of the density deviations (squares) over the entire print format width, i.e. over all the measured zones. In addition, the upper window displays for each ink the maximum absolute deviation (total) in the form of a vertical line. The average values of the densities over the current sheet and the associated standard deviations can also be displayed as numerical values in the zoomed window.

In the bottom window of the display for press 1.2, the curve of the standard deviation from the set-values over the run is displayed in the lower window of the display for press 1.2 for each inking unit. The display in the bottom window of the screen for press 1.4 will be explained more fully hereinafter (job progress control).

is In the example shown in Figure 2, press 1.3 is controlled colorimetrically. The upper window displays the colour locations of the last seven measurements in the LUV system for one image zone (this can be freely selected menu) (for example see: Graufeldmessung und Grauachse im Mehrfarben-Bilderdruckll, Papier und Druck 39, 1990, No.

3, pages 104 to 108).

These colorimetric colour locations are entered as rectangles and the last updated measurement is marked.

For better identification, the circle segments can be displayed in colours corresponding thereto. The centrepoint of this "colour clock" may be assumed to correspond to the required colour location of the image zone in question. In addition to the "colour clock", the brightness-deviation delta-L is shown as a black bar (too dark) or as a white bar (too light). The numericai values of the average and dispersion of the densitometrically determined ink black, the lightness deviation delta-L, and delta-E (colour distance) for the entire colour deviation can also he displayed in the zoomed window.

The bottom window of the display for press 1.3 gives the dispersion of the colour density of the ink black about the set-value, the average colour deviation delta-E (colour distance), the dispersion of the colour deviation sigma (delta-E). the average lightness deviation delta-L and the dispersion of the lightness deviation sigma (delta-L) for the run quality control over the run. Figure 2 marks the displays of these values as DB, AE, aAE, AL and aAL.

As in the bottom window of the display for press 1.4, the current occupation of each press 1.1 - 1.n for an order can be displayed for job progress control. All the orders of a shift on one press can then be seen simultaneously. The time input for an order, differentiated as to preparation (R) and continuous printing (F), is displayed as a pair of horizontal bars above the clock time. Two bars of equal length belong to each order. The top bar begins at the planned start and the bottom bar begins at the processing data that is actually possible at the current time. If an order is postponed through a longer processing time than planned, or if an order is interposed, then all the subsequent really possible dates are shifted accordingly. The total run (number of printed sheets) is indicated as a number, and the proportion already printed is marked graphically (K) in the top bar of the order already processed. The marking line (T) of the actual time extends over the entire window. A comparison of the proportion of an order already printed (graphic marking K) in the upper bar with the clock time marking line (T) shows how far 11 above or below the plan the job production is situated.

In a particularly advantageous aspect of the invention. all the bottom windows of the displays for the presses 1.1 - 1.5 show the press utilisation for an order as described above for order progress control. In a display of this kind, the respective upper windows then show the quality data of the products printed on the individual printing units 1.1 - 1.5 in conjunction with the order occupation at any time. It is thus now possible for the print room manager simultaneously to supervise all the presses 1.1 - 1.n in respect of the produced quality in conjunction with the utilisation factor on the associated press (set-values and actual-values). Since computer 4 always receives the most up-to-date measurement data from master computer 3 and the quality data are immediately updated in the monitor display, the print room manager can immediately recognise any change in the quality of a printed product. Appropriate action can be taken immediately and without delay.

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Claims (7)

1. A print room control system for a plurality of presses, which, for ink feed control, are connected to colour control systems and the measured data obtained at the individual colour control systems can be fed to a master computer. the system including a data-capture computer which is so connected to the master computer that the measured data obtained in the colour systems in respect of ink feed can be fed directly to the datacapture computer, the data-capture computer being so devised as to convert the measured data to quality data representing the quality of the printed products produced at the individual presses, a monitor adapted to display the quality data according to their information content, and wherein the display of the quality data can be directly updated by the data-capture computer as fresh measured data is obtained in respect of the ink feed control.

2. A print room control system according to Claim 1 wherein the display of the quality data of the individual colour control systems or of the presses is effected in each case in a separate area or window of the monitor screen.

3. A print room control system according to Claim 1 or 2 and including means for displaying, in addition to the actual quality data. in another zone or window of the screen the progress of all the quality data or measurements already obtained from the associated colour control systems.

4. A print room control system according to any one of 1 1 1 i i I i i i A - 15 the preceding claims and including means for displaying, in addition to the up-to-date quality data of the individual colour control systems and of the presses. data relating to job progress control of the associated press in the form of two horizontal bars, the same being differentiated by preparation and continuous printing, wherein a marking line denotes the current time in this display and wherein the proportion of an order already printed can be graphically indicated in the bar diagram.

5. A print room control system according to any one of the preceding claims wherein the data-capture computer. together with the monitor, is constructed as a personal computer with a keyboard and a positionsensitive control element.

6. A print room control system according to Claim 5 wherein the positionsensitive control element is a mouse, roller-ball or joystick.

7. A print room control system substantially as hereinbefore described with reference to the accompanying drawings.

Published 1991 at The Patent Office, Concept House, Cardiff Road, Newport, Gwent NP9 M. Further copies may be obtained from Sales Branch, Unit 6, Nine Mile Point Cwmfelinfach, Cross Keys. Newport. NP1 711Z. Printed by Multiplex techniques lid, St Mary Cray. Kent.