EP0451106B1 - Dispositif d'analyse des bandes de contrôle d'impression - Google Patents

Dispositif d'analyse des bandes de contrôle d'impression Download PDF

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Publication number
EP0451106B1
EP0451106B1 EP91810226A EP91810226A EP0451106B1 EP 0451106 B1 EP0451106 B1 EP 0451106B1 EP 91810226 A EP91810226 A EP 91810226A EP 91810226 A EP91810226 A EP 91810226A EP 0451106 B1 EP0451106 B1 EP 0451106B1
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EP
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Prior art keywords
colour
tone
full
print control
density
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German (de)
English (en)
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EP0451106A1 (fr
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Hans Ott
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Gretag AG
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Gretag AG
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41F—PRINTING MACHINES OR PRESSES
    • B41F33/00—Indicating, counting, warning, control or safety devices
    • B41F33/0036—Devices for scanning or checking the printed matter for quality control

Definitions

  • the invention relates to a device for analyzing pressure control fields according to the preamble of the independent claims.
  • control of the printing process today mostly takes place on the basis of printed control fields, which are usually analyzed densitometrically or even colorimetrically in order to obtain control variables for the setting and control of the printing machine or other information of interest to the printer.
  • printed control fields which are usually analyzed densitometrically or even colorimetrically in order to obtain control variables for the setting and control of the printing machine or other information of interest to the printer.
  • offset printing in addition to various other control fields, in particular single-color solid-color fields and single-color halftone fields, often several nominal area covers are used simultaneously for all printing inks involved in the printing process, as well as two-color and sometimes three-color overprinting solid-color fields.
  • the parameters of interest are the layer thicknesses of the printing inks concerned, expressed by the respective densitometric color densities.
  • a characteristic of practical work with such hand densitometers is that the operator has to position the densitometer on the control field of interest and has to manually instruct the device via its operating elements which measurement variable is to be determined and displayed. Many of these devices are already able to determine the color of the control field, i.e. whether it is e.g. To deal with a cyan, magenta, yellow or black field automatically based on certain criteria and to indicate whether the color density or the area coverage or the color acceptance should be determined and displayed, the device must still be notified , the various functions of the device must therefore be selected by the operator.
  • a densitometer that automatically recognizes the type of control field just examined and automatically adjusts its measuring functions accordingly would significantly increase the ease of use of such a device.
  • EP-A-0 283 899 (corresponding to US Patent Application No. 30735 of March 25, 1987; US Patent No. 4947348) describes a handheld densitometer which is equipped with such an automatic operating mode or function switchover and capable of doing so is to automatically recognize and distinguish a limited set of control field types and to determine and display the quantities characteristic of the respective control field types.
  • the recognizable control field types include single-color solid fields, single-color grid fields and two-color overprint solid fields. Furthermore, it is also automatically recognized whether the current measurement is taking place at an unprinted point on the base.
  • the device determines the color densities in all available measuring channels (usually red, blue, green and visual corresponding to the color densities cyan, yellow, magenta and black) and determines which control field type it is by comparing it with fixed color density reference values deals what color is available etc. and then calculates the size assigned to the relevant control field type and displays it. For the calculation of certain more complex sizes, e.g. Color acceptance and area coverage are additional measured values from other control field types, e.g. Solid densities of the colors involved, required. In these cases, the device prompts the user to carry out the missing measurements and only shows these more complex sizes when all the necessary additional measurements have been carried out (in the correct order).
  • the present invention is now intended to remedy these shortcomings and to improve a densitometer of the type in question in such a way that it enables reliable automatic detection and differentiation of the most common types of pressure control field and the determination of more complex sizes, for which several individual measurements on different control field types are required simplified and more convenient for the user.
  • the densitometer according to the invention which meets these requirements, is characterized by the features of the independent claims. Preferred and particularly expedient and advantageous designs are described in the dependent claims.
  • FIG. 1 shows a sheet PS printed in an offset printing press, which, in addition to the actual print image, not shown, also contains a color measuring strip CMS, which is also printed, with a number of print control fields PCF of various types of the type mentioned at the outset.
  • the pressure control field PCF to be analyzed in each case is illuminated in a ring by light 11 emanating from a light source 10 contained in the densitometer 100 at an angle of incidence of 45 ° ⁇ 5 °.
  • the pressure control panel PCF at an angle of 0 ° ⁇ 5 °, i.e.
  • Light 12 radiated back perpendicular to the plane of the printing sheet passes via one of four measuring filters 14 arranged in a filter wheel 13 to an electro-optical receiver 15, which generates a corresponding electrical analog signal therefrom.
  • This is amplified in an amplifier 16 and converted in an A / D converter 17 into a corresponding digital signal and then fed to a microcomputer designated as a whole by 20.
  • This has a classic structure and contains the main components of a central unit 21, a program memory 22, a working memory 23 and various input / output interfaces 24-26, via which it communicates with an operating keyboard 27 and a display unit 28 and with the A / D Converter 17 is connected and also controls the light source 10 and a drive motor 18 for the filter wheel 13.
  • the fourth filter 14 is a spectral eye sensitivity, so-called visual filter.
  • all four filters 14 are swiveled into the beam path in sequence, so that four digital measuring signals are generated with each measuring process, from which four corresponding color density values are assigned in the microcomputer, which are assigned to the four colors cyan, yellow magenta and black of the printing inks normally used , which are the starting point for all subsequent calculations and displays.
  • the microcomputer 20 calculates a certain size from these four color density values, possibly from a number of them, or possibly in combination with the color density values measured at one or more other print control fields, according to its programming and the manually or automatically selected function, and possibly brings these together with suitable supplementary ones Information on the display unit 28 for display.
  • the densitometer according to the invention fully corresponds to the known manual densitometers of the type designations D183, D185 or D186 from the company Gretag Aktiengesellschaft, Regensdorf, Switzerland. The only exception is the possibility of automatic pressure control field recognition and function selection, which is explained in detail below, which is not available with these known manual densitometers.
  • the mechanical structure of the densitometer according to the invention also corresponds to the known hand densitometers D183, D185 and D186 and is e.g. in detail in US-A-4,645,350.
  • the densitometer system described in EP-A-0 283 899 has the same mechanical and electrical structure, so that no further explanation is necessary in this regard.
  • the principle of operation of the densitometer according to the invention can be seen from the flow chart shown in FIG. 2. It essentially only contains the function blocks or processes that are necessary for understanding the invention and that are new or different from the prior art; secondary functions, which are also present in known densitometers, for example various initialization processes, self-checks etc., are not shown for reasons of clarity. All functional sequences are controlled by the microcomputer 20, which has stored a corresponding program in its program memory 22.
  • the various functional sequences of the densitometer according to the invention are divided into two main program branches, namely the "Manual function selection” branch and the "Automatic function selection” branch. 2, these two program branches are separated by a dash-dotted line L, the program branch located to the left of line L corresponding to the "manual function selection".
  • This program branch contains all function and measurement options, such as those known handheld densitometers e.g. of the types D183, D185 and D186 from Gretag Aktiengesellschaft, Regensdorf, Switzerland are already provided, e.g. Determination of the solid density of solid fields, determination of the area coverage and / or the tonal value increase of raster fields, determination of the color acceptance of overpressure solid fields, automatic color detection etc. Only the function "solid density” is represented here by block 120 as representative of all these measurement functions. The remaining measurement functions are indicated symbolically by block 125. The manually selected measurement functions are essentially irrelevant for understanding the present invention and therefore do not require any detailed explanation.
  • the program branch "manual function selection” or the program branch “automatic function selection” is selected by the operator via the keyboard 27 (branch block 110).
  • "manual function selection” the user now makes a selection (branch block 115) on the keyboard 27 of the desired measurement function, and the associated function program is then called up.
  • the color F of the print control field is then determined from the color density values (function block 300).
  • the color is determined essentially the same as for the known densitometers D183, D185 and D186 or as in the "Manual function selection" program branch, but with the difference that in addition to the colors recognizable there, C, Y, M and K now the overprinting colors R, B and G can also be recognized. How this happens in detail is explained in more detail below.
  • the ink acceptance T of the second printing ink z involved on the first printing ink x involved is now calculated in program block 500 in a manner to be described in more detail and then the calculated ink acceptance T in program block 550 via the display unit 28 Color z of the second printing ink involved as well as the message that the displayed size is the ink acceptance T, the densitometer is currently in the (automatically selected) operating mode "ink acceptance determination", displayed and in the event of an error situation (explanation follows ) an appropriate error message is output.
  • the program then jumps back to its starting point (block 200 or, if the user has switched to "manual function selection", block 115) and is ready for the next measurement.
  • the program block 400 determines whether it is a solid tone field, a halftone field of a programmed first nominal area coverage FF1 (type 1) or a second nominal area coverage FF2 (type 2).
  • FF1 programmed first nominal area coverage
  • FF2 type 2
  • the distinction is not made on the basis of predefined, constant density reference values, but instead according to the invention on the basis of dynamic interface coverings FG1_2 and FG2_V, which are individually calculated on the basis of additional measured values, or alternatively limit densities DG1_2 and DG2_V. Details of this program block are explained in more detail below.
  • one of the program blocks 700, 800 or 900 is then called in branch block 450.
  • the program blocks 800 and 900 and the following program blocks 850 and 950 are functionally identical, they only process different numerical values.
  • the respective dot gain ZM is calculated in program blocks 800 and 900 in the manner described below in program block 850 or 950, via display unit 28, the display of the dot gain ZM and the color F of the print control measuring field as well as the output of a message that the displayed size is the dot gain for a type 1 or type 2 grid, where type 1 or 2 represents the previously entered (or possibly also preprogrammed) nominal film area coverage FF1 or FF2, for example 40% or 80%. In the event of an error situation, a corresponding error message is also output.
  • the program then returns to the starting point in exactly the same way as after the "Color acceptance determination" operating mode and is ready for the next measurement.
  • the full-color density DV is displayed in program block 700, i.e. in this case directly the measured color density value D (f) in the determined color F of the print control field, and the color F itself, and the output of a Message that the displayed size is a full-tone density, ie the device is currently in the "Full-tone density determination" operating mode.
  • a full-tone density memory (reserved memory area in the working memory 23) is then updated in the program block 750 in that the determined full-tone density DV (f) of the print control field PCF is stored therein.
  • the determined full-tone density DV (f) of the print control field PCF is stored therein.
  • this solid density memory will therefore contain the corresponding solid density for each color, which is continuously updated by replacing the stored value with the new value for each new measurement (a solid field of the corresponding color).
  • a secondary density memory (or corresponding variable) is updated in program block 770.
  • the secondary (full tone) densities of the current solid tone field i.e. the color density values DVN of the respective full-tone field of color F measured for the two other chromatic colors in each case are stored.
  • the values DVN (c, m) and DVN (c, y) are stored.
  • These values are also required for the calculation of the color acceptance T in program block 500.
  • the program blocks 700, 750 and 770 are also processed within the program branch "Manual function selection” if the (manual) operating function "Full tone density measurement” is selected. This ensures that the full-tone density memory and the secondary density memory are updated frequently and the additional measured values required for the functions of the automatic mode mentioned are practically always available in practical operation of the densitometer. If this should not be the case (e.g. when the device is started up for the first time), this is automatically recognized in program blocks 500 and 800 or 900 and a corresponding error message is issued.
  • program block 770 the program returns to its starting point, as already described, and is ready for the analysis of a further print control field PCF.
  • the program block 300 "automatic color recognition" is more detailed shown.
  • the blackening G exceeds a predetermined threshold value G_Limit, typically about 0.7, the color of the print control field is assessed as black (K). Otherwise the tonal value error H is examined. If H falls below a predetermined threshold value H_Limit, this is interpreted as an individual color, otherwise as an overpressure situation.
  • the color F of the print control field is recognized as C, M or Y, depending on whether f3 was c, m or y.
  • the color F is recognized as R, G or B, depending on whether f1 was c, m or y.
  • the corresponding values are finally assigned to the variables F and f and the automatic color recognition is thus completed.
  • the automatic color recognition therefore does not take place by comparison with fixed predetermined color density values, but only by relative comparisons of the measured color density values via the quantities of blackening and hue errors. This ensures color recognition over a much larger density range.
  • the automatic color detection is implemented in the same way as in the present invention. In the latter, however, the method is refined and expanded in that it also allows the overprinting colors R, B and G to be recognized, which is the case with the Densitometers D183, D185 and D186 are not the case. These only recognize the individual colors C, M, Y and K.
  • FIG. 4 shows the program part of FIG. 2 comprising the program blocks 400, 450, 700, 750, 770, 800, 850, 900 and 950 in greater detail, the individual program steps being combined somewhat differently into blocks. In total, these blocks result exactly in the program sequence defined by the program blocks of FIG. 2.
  • the two typical area coverings FT1 and FT2, and the two associated areas are first determined using the nominal film area coverage FF1 and FF2 entered via the keyboard and the preprogrammed typical dot gain function ZT Boundary coverages FG1_2 and FG2_V as well as the area coverage FS of the print control field are calculated with respect to the recognized color F (block 411). How this is done in detail is explained in more detail below.
  • a type 1 grid defined by the nominal film area FF1
  • a type 2 grid defined by the nominal film area FF2
  • a full-tone field nominal film area coverage 100%
  • program block 417 which corresponds to program block 700 in FIG. 2, the solid color density D (f) of the recognized color F, the color F itself and the functional mode are displayed as described in connection with FIG. 2.
  • the subsequent program block 418 brings about the updating of the full-tone density memory analogously to block 750 in FIG. 2 and in blocks 419-424 is finally as in FIG Block 770 in FIG. 2 updated the secondary density memory.
  • the associated solid color density DV (f) is also required. This is available in the full-tone density memory from previous measurements and is taken from it for the calculation. If the required solid color density is not available, a corresponding error message is issued, which draws the user's attention to this error situation.
  • FIG. 5 shows the course of the area coverage FT in printing (ordinate) typical of offset printing as a function of the area coverage FF in the underlying raster film (abscissa).
  • the graph 460 shown in full lines indicates the relationship between FT and FF
  • the graph 462 shown in broken lines shows the relationships if FT would always be the same for all FF.
  • the increase of the graph 460 compared to the graph 462, that is to say FT-FF, is the typical dot gain or dot gain ZT.
  • the arrow 464 shows the typical dot gain ZT50, that is to say the difference between the area coverage of a raster field, which is typically measured in pressure, the nominal area coverage of which in Film is 50%.
  • FT FF ⁇ (1 + 4 ⁇ ZT50 ⁇ (1-FF / 100) / 100) FT, FF, ZT50 in%
  • This typical functional relationship between FT and FF is stored in the program memory 22 of the microcomputer 20 and is used to calculate the boundary surface coverings FG1_2 and FG2_V or, alternatively, the boundary densities DG1_2 and DG2_V.
  • the nominal area coverage FF1 is that of a grid type 1 (here e.g. 50%), the nominal area coverage FF2 correspondingly that of a grid type 2 (here e.g. 80%).
  • the nominal area coverage FF3 100 is that of a solid field, the associated typical area coverage is designated FT3.
  • the nominal area coverage FF1 and FF2 are specified by the grid types in the print control strip and must be entered into the densitometer using the keyboard.
  • an analyzed print control field is a solid color field or a type 1 or type 2 grid
  • two interface covers FG1_2 and FG2_V are defined (block 411) and the measured area coverage FS is compared with these interface covers (blocks 412-414). If FS is below the first (lower) interface coverage FG1_2, the print control field is defined as a type 1 grid (block 412). If FS lies between the first and the second interface coverage, the print control field is regarded as a type 2 grid (block 413).
  • the pressure control field is recognized as a full tone field (block 414).
  • 5 shows five measured area coverings FS1, FS2, FS3, FS4 and FS5, for example.
  • the first two values therefore belong to a type 1 grid, the next two values FS3 and FS4 to a type 2 grid, and the last value FS5 to a solid field.
  • FG1_2 (FT2-FT1) / 2
  • FG2_V (FT3-FT2) / 2.
  • FG1_2 (FT2-FT1) / 2
  • FG2_V (FT3-FT2) / 2
  • the distinction between halftone and solid fields is not made on the basis of the measured color density values by direct comparison with fixed reference color density values (static), but dynamically by comparing boundary surface coverings with the surface coverage determined for the relevant print control field, the calculation of which also includes Full-tone density of the recognized color of the print control field concerned is received.
  • the current solid color density is therefore included in the differentiation criteria, and the differentiation of the different types of pressure control fields is much more reliable in this way.
  • FIG. 6, illustrates an alternative method based on the same principles according to the invention for distinguishing between solid and grid fields.
  • DRT -log (1- (1-10 -DV FT / 100)
  • This typical screen density is to be understood as the screen density value that is expected as a measured value due to the typical relationship between the area coverage in the film and the area coverage in the print, if the area coverage of the relevant print control field in the film has the value FF and the value FT in the print.
  • the formula thus transforms the area coverage area into a grid density space.
  • the typical area coverings FT1 and FT2 belonging to the two nominal area coverings FF1 and FF2 can be converted into the two typical grid densities DRT1 and DRT2:
  • DRT1 -log (1- (1-10 -DV FT1 / 100)
  • DRT2 -log (1- (1-10 -DV FT2 / 100)
  • DG1_2 -log (1- (1-10 -DV FG1_2 / 100)
  • DG2_V -log (1- (1-10 -DV FG2_V / 100)
  • these two limit densities into which the respective solid tone densities are included and which are therefore dynamic values, can be used to distinguish between solid tone and screen fields.
  • the program blocks 431 to 434 directly replace the corresponding program blocks 411-414 in FIG. 4.
  • the entered nominal area coverings FF1 and FF2 are converted into the two limit densities DG1_2 and DG2_V as well as the two boundary densities DG1_2 and DG2_V based on the typical relationship between nominal area coverage and the area coverage to be measured in printing and also taking into account the current full tone density in the full-tone density memory associated with the recognized color of the print control field measured color density value and the associated solid color density, the area coverage FS of the print control field is calculated.
  • blocks 432-434 there is a classification analogous to blocks 412-414 in FIG. 4.
  • the print control field is defined as a grid of type 1, a grid of type 2 or a solid field, depending on whether it is recognized in the Color measured color density value (ie the relevant screen density) lies below the first limit density, between the two limit densities or above the second limit density.
  • a branch to program blocks 415, 416 or 417 takes place again or a return to the program start point in accordance with FIG. 4.
  • FIG. 6 illustrates how the limit densities DG1_2 and DG2_V and the typical screen densities DRT1 and DRT2 and DRT3 change depending on the solid density DV over their characteristic variation range given by the physical layer thickness change of the printing ink in question.
  • the typical screen density DRT3 is that of a nominal 100% screen, i.e. a full tone screen.
  • the curves have a noticeable slope, in particular for higher nominal area coverings (DRT3, DG2_V, DRT2, DG1_2).
  • the limit densities DG1_2 and DG2_V which are decisive for the differentiation of the pressure control field types, are of different sizes for each solid density value. If, as is the case with the known system of EP-A-0 283 899, a fixedly specified, constant density reference value were used as a differentiation criterion, different results would be obtained depending on the current full-tone density, in particular at low values of the same. To illustrate this problem, an example of a constant density reference value KDR is entered in FIG. 6.
  • a print control field with a screen density DRB1 measured, for example, with an associated full tone density of ⁇ 1.0 would, however, already be defined as a screen field, whereas it would still be recognized as a full tone field according to the method according to the invention.
  • a print control field with a screen density DRB2 measured, for example, with an associated full tone density of ⁇ 1.5 would be assessed as a full tone field, whereas according to the invention it would be classified as a type 2 screen.
  • Constant density reference values are therefore at best only suitable as a differentiation criterion within a defined, relatively narrow, full-tone density value range.
  • the boundary coverings FG1_2 and FG2_V or the boundary densities DG1_2 and DG2_V can also be laid differently than described in connection with FIGS. 5 and 6.
  • FIG. 9 which is the same as FIG. 6
  • DG2_V (DRT2 + DRT3) / 2 applies.
  • DRT1 and DRT2 are calculated from the nominal area coverings FT1 and FT2 and from the associated full-tone density DV.
  • DRT3 is 100%.
  • the densitometer according to the invention distinguishes between solid tone fields and two types of grid fields. It goes without saying that, in exactly the same way, several types of grid fields with different nominal area coverage can be recognized. To do this, it is only necessary to define or calculate more surface coverings or boundary densities according to the same criteria and to compare the measured surface coverings or grid densities in an analogous manner. Conversely, it is of course also possible to restrict yourself to only a single type of grid or only to distinguish between the solid field and the grid itself. For example, as shown in FIG.
  • a print control field PCF is then regarded as a solid tone field if the measured area coverage FS lies above the interface area FGR_V, otherwise it is defined as a grid area per se, without reference to a specific nominal area coverage. (In this case, of course, there is no need to enter a nominal area coverage).
  • boundary density DGR_V is calculated analogously to the other boundary densities DG1_2 and DG2_V from the boundary surface coverage FGR_V.
  • An error variable is initialized in blocks 511-513 and the error variable is set in the event that the recognized color is black.
  • block 514 it is examined whether the recognized color is red. If positive, the color of the second printing ink z involved is determined (blocks 515, 516) and the color of the first printing ink x involved is determined (blocks 517, 518) or the error variable is also set again (block 519).
  • block 520 it is examined whether the recognized color is green and then again analogously determines the second printing ink z involved (blocks 521, 522) and the first printing ink x (blocks 523, 524) or the error variable is set (block 525).
  • D (z) mean the measured color density value which was measured using the measurement filter corresponding to the second printing ink involved (in the case of overpressure from yellow to magenta, for example, the measured yellow density), DV (z) the associated second color, the full-tone density in the full-tone density memory and DVN (x, z) the secondary absorption density associated with the two colors involved, which in the secondary density memory is also available from previous measurements on solid fields.
  • the (arbitrary) convention is based on the fact that the second color z should be the one whose associated solid color density is the most current, i.e. the color of the last or latest measured solid color field.
  • This convention corresponds to the usual and proven measurement sequence scheme for the manual determination of the color acceptance in the known densitometers D183, D185 and D186. Of course, another scheme is also possible.
  • FIGS. 2, 3, 4 and 7 The program blocks or functional sequences shown in FIGS. 2, 3, 4 and 7 are summarized below in the form of a program listing formulated in the programming language "PASCAL".
  • the program is stored in a suitably compiled form in the program memory 22 of the microcomputer 20. (Texts enclosed in curly brackets are explanatory comments.)

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  • Quality & Reliability (AREA)
  • Spectrometry And Color Measurement (AREA)
  • Inking, Control Or Cleaning Of Printing Machines (AREA)

Claims (17)

  1. Dispositif d'analyse des plages de contrôle de l'impression, notamment pour impression offset, comprenant
    - un dispositif de mesure électro-optique (10, 15, 16, 17, 200) destiné à déterminer une série de densités d'encrage des plages de contrôle,
    - un dispositif d'identification des couleurs (300), destiné à déterminer la couleur de la plage à partir des densités d'encrage,
    - un dispositif d'identification des types (400, 450), destiné à établir à partir des densités d'encrage que le type de la plage considérée est l'un des types d'une série prédéterminée,
    - un dispositif de détermination des grandeurs à mesurer (500, 700, 800, 900), destiné à déterminer à partir des densités d'encrage une grandeur afférente au type et à la couleur décelée sur la plage, et
    - un dispositif d'affichage (28, 550, 700, 850, 950) destiné à afficher les grandeurs affectées, la couleur de la plage et des informations guidant l'utilisateur,
       dispositif d'analyse, caractérisé en ce que
       le dispositif (400, 450) d'identification des types discrimine et identifie les plages à aplat d'une couleur simple et des plages tramées d'au moins deux taux de couverture différents, à partir de taux de couverture nominaux (FF1, FF2) mémorisés ou introduits manuellement et d'une caractéristique typique (FT) mémorisée du taux de couverture.
  2. Dispositif selon la revendication 1, caractérisé en ce que le dispositif (300) d'identification des couleurs établit à partir des densités d'encrage [D(c), D(m), D(y), D(k)] les grandeurs relatives noircissement (G) et erreur de teinte (H),ainsi que la couleur (F) de la plage à partir de ces grandeurs relatives.
  3. Dispositif selon la revendication 2, caractérisé en ce que le dispositif (300) d'identification des couleurs permet aussi d'identifier les couleurs de surimpression rouge, bleu et vert.
  4. Dispositif selon l'une des revendications 1 à 3, caractérisé en ce qu'il comporte, pour chacune des densités d'encrage de la série, une mémoire (DV) des densités d'aplat, dans laquelle les densités des aplats des couleurs simples concernées sont mémorisées en attente et sont actualisées à chaque nouvelle analyse d'une plage à aplat d'une couleur simple.
  5. Dispositif selon la revendication 4, caractérisé en ce qu'il comporte, pour chaque densité d'encrage avec une encre non noire de la série,une mémoire (DVN) de densités secondaires, dans laquelle les deux densités d'acceptation secondaires de la plage à aplat de la couleur correspondante sont enregistrées en attente et sont actualisées à chaque nouvelle analyse d'une plage à aplat d'une couleur simple.
  6. Dispositif selon la revendication 5, caractérisé en ce que le dispositif (500) de détermination des grandeurs à mesurer calcule comme grandeur l'acceptation d'encre (T), quand le dispositif (300) d'identification des couleurs a établi, à partir de la couleur de la plage de contrôle, qu'il s'agit d'une plage à surimpression de deux couleurs, ce dispositif (500) de détermination des grandeurs prélevant dans la mémoire des aplats (DV) et la mémoire (DVN) des densités secondaires les valeurs d'à-plats des encres qui participent à cette surimpression, valeurs nécessaires pour le calcul de l'acceptation d'encre.
  7. Dispositif selon l'une des revendications 1 à 6, caractérisé en ce qu'il est prévu un élément (400) de calcul des taux de couverture, qui détermine le taux de couverture (FS) de chacune des plages de contrôle (PCF) identifiée comme étant d'une couleur simple et en ce que le dispositif (450) d'identification des types compare ces taux de couverture à des taux limites (FG1_2 et FG2_V) qui sont fixés par les taux nominaux de couverture (FF1, FF2, FF3) et la caractéristique (FT) et en ce que le dispositif (450) d'identification des types identifie la plage de contrôle considérée comme étant un aplat d'une couleur simple ou une plage tramée d'une couleur simple, d'après le résultat de cette comparaison.
  8. Dispositif selon la revendication 7, caractérisé en ce que les valeurs limites (FG1_2 et FG2_V) du taux de couverture se trouvent sensiblement au milieu entre les valeurs typiques (FT1, FT2, FT3) de ce taux, découlant des taux de couverture nominaux (FF1, FF2, FF3) pour les plages tramées et les aplats et de la caractéristique typique (FT) mémorisée de taux de couverture.
  9. Dispositif selon l'une des revendications 1 à 8, caractérisé en ce que le dispositif d'identification des types discrimine et identifie les aplats de couleurs simples et les plages tramées de couleur simple par comparaison de la densité d'encrage (D(f)) mesurée de la couleur (F) constatée de la plage de contrôle concernée avec des densités limites (DG1_2 et DG2_V), lesquelles sont fixées par les taux nominaux (FF1, FF2, FF3) de couverture et par la caractéristique typique (FT) du taux de couverture.
  10. Dispositif selon les revendications 4 et 7, caractérisé en ce que l'élément (400) de calcul des taux de couverture calcule le taux de couverture (FS) de la plage de contrôle (PCF) en se rapportant à la densité actuelle d'un aplat de la couleur considérée, mémorisée en attente dans la mémoire des aplats (DV).
  11. Dispositif selon les revendications 4 et 9, caractérisé en ce que le dispositif d'identification des types calcule, à partir des taux nominaux (FF1, FF2, FF3) de couverture et de la caractéristique typique (FT) mémorisée, ainsi que de la densité actuelle d'un aplat de la couleur considérée mémorisé en attente dans la mémoire des aplats (DV), des taux limites FG1_2 et FG2_V à partir desquels il détermine les densités limites (DG1_2 et DG2_V) correspondantes.
  12. Dispositif selon les revendications 4 et 9, caractérisé en ce que le dispositif d'identification des types calcule à partir des taux nominaux (FF1, FF2, FF3) de couverture et de la caractéristique typique (FT) de taux, enregistrée, ainsi que de la densité actuelle d'un aplat de la couleur considérée, enregistrée dans la mémoire des aplats (DV), des densités de trame typiques (DRT1, DRT2, DRT3) de l'épreuve et détermine à partir de ces dernières les densités limites DG1_2 et DG2_V de façon que DRT1<DG1-2<DRT2<DG2_V<DRT3.
  13. Dispositif selon la revendication 12, caractérisé en ce que le dispositif d'identification des types fixe les densités limites (DG2_2, DG2_V) de façon que DG1_2=(DRT1+DRT2)/2 et DG2_V=(DRT2+DRT3)/2.
  14. Dispositif selon l'une des revendications 1 à 13, caractérisé en ce que le dispositif (800) de détermination des grandeurs à mesurer calcule comme grandeur l'augmentation d'intensité de couleur (ZM) lorsque le dispositif (450) d'identification des types a identifié la plage de contrôle (PCF) comme étant une plage tramée.
  15. Dispositif d'analyse des plages de contrôle de l'impression, notamment l'impression offset, comprenant
    - un dispositif électro-optique de mesure (10, 15, 16, 17, 200), destiné à déterminer une série de densités d'encrage des plages de contrôle,
    - un dispositif d'identification des couleurs (300), destiné à déterminer la couleur de la plage de contrôle à partir des densités d'encrage,
    - un dispositif d'identification des types (400, 450), destiné à établir, à partir des densités d'encrage, que la plage de contrôle est l'une de celles d'une série prédéterminée de types de plages,
    - un dispositif de détermination des grandeurs à mesurer (500, 700, 800, 900) destiné à déterminer à partir des taux d'encrage une grandeur affectée au type constaté et à la couleur constatée de la plage et
    - un dispositif d'affichage (28, 550, 700, 850, 950), destiné à afficher les grandeurs affectées, la couleur de la plage de contrôle et des informations guidant l'utilisateur,
       dispositif d'analyse caractérisé en ce que
       le dispositif (400, 450) d'identification des types discrimine et identifie les aplats d'une couleur simple et les plages tramées au moyen d'une caractéristique typique (FT) de taux de couverture, enregistrée, en comparant la densité D(f) mesurée de la plage de contrôle (PCF), ou bien le taux de couverture (FS) calculé à partir de cette densité, avec une densité limite (DRG_V) ou avec un taux limite (FGR_V) de couverture fixés grâce à la caractéristique typique (FT) de taux de couverture.
  16. Dispositif selon la revendication 15, caractérisé en ce que le dispositif d'affichage (28) affiche le taux de couverture (FS) lorsque le dispositif (400, 450) d'identification des types a identifié la plage de contrôle (PCF) comme étant une plage tramée.
  17. Dispositif selon l'une des revendications 1 à 14, caractérisé en ce qu'il est en outre doté des caractéristiques des revendications 15 et/ou 16.
EP91810226A 1990-04-06 1991-03-27 Dispositif d'analyse des bandes de contrôle d'impression Expired - Lifetime EP0451106B1 (fr)

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CH1170/90 1990-04-06
CH117090 1990-04-06

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EP0451106A1 EP0451106A1 (fr) 1991-10-09
EP0451106B1 true EP0451106B1 (fr) 1994-06-15

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EP (1) EP0451106B1 (fr)
JP (1) JP3028248B2 (fr)
DE (1) DE59101912D1 (fr)

Families Citing this family (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IL98453A (en) * 1991-06-11 1996-06-18 Scitex Corp Ltd Method and device for creating a control bar
US5841955A (en) * 1991-12-02 1998-11-24 Goss Graphic Systems, Inc. Control system for a printing press
DE4229267A1 (de) * 1992-09-02 1994-03-03 Roland Man Druckmasch Verfahren zur Steuerung des Druckprozesses auf einer autotypisch arbeitenden Druckmaschine, insbesondere Bogenoffsetdruckmaschine
US5412577A (en) * 1992-10-28 1995-05-02 Quad/Tech International Color registration system for a printing press
JP3324708B2 (ja) * 1993-01-11 2002-09-17 富士写真フイルム株式会社 カラー画像記録方法
US5357448A (en) * 1993-02-02 1994-10-18 Quad/Tech, Inc. Method and apparatus for controlling the printing of an image having a plurality of printed colors
DE4335350A1 (de) * 1993-10-16 1995-04-20 Heidelberger Druckmasch Ag Verfahren und Vorrichtung zur Ermittlung von Passerabweichungen bei mehrfarbigen, in einer Druckmaschine erstellten Druckprodukten
US6129015A (en) * 1993-11-23 2000-10-10 Quad/Tech, Inc. Method and apparatus for registering color in a printing press
DE4402784C2 (de) * 1994-01-31 2001-05-31 Wifag Maschf Messfeldgruppe und Verfahren zur Qualitätsdatenerfassung unter Verwendung der Messfeldgruppe
DE4402828C2 (de) * 1994-01-31 2001-07-12 Wifag Maschf Messfeldgruppe und Verfahren zur Qualitätsdatenerfassung unter Verwendung der Messfeldgruppe
US5812705A (en) * 1995-02-28 1998-09-22 Goss Graphic Systems, Inc. Device for automatically aligning a production copy image with a reference copy image in a printing press control system
US5767980A (en) 1995-06-20 1998-06-16 Goss Graphic Systems, Inc. Video based color sensing device for a printing press control system
US5805280A (en) * 1995-09-28 1998-09-08 Goss Graphic Systems, Inc. Control system for a printing press
US5903712A (en) * 1995-10-05 1999-05-11 Goss Graphic Systems, Inc. Ink separation device for printing press ink feed control
US6938550B2 (en) * 2002-10-31 2005-09-06 R. R. Donnelley & Sons, Co. System and method for print screen tonal control and compensation
US8532371B2 (en) * 2010-10-04 2013-09-10 Datacolor Holding Ag Method and apparatus for evaluating color in an image
US9076068B2 (en) 2010-10-04 2015-07-07 Datacolor Holding Ag Method and apparatus for evaluating color in an image
US10070118B2 (en) 2015-09-17 2018-09-04 Lumii, Inc. Multi-view displays and associated systems and methods
US11007772B2 (en) 2017-08-09 2021-05-18 Fathom Optics Inc. Manufacturing light field prints

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4947348A (en) * 1987-03-25 1990-08-07 Kollmorgen Corporation Densitometer method and system for identifying and analyzing printed targets

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EP0451106A1 (fr) 1991-10-09
DE59101912D1 (de) 1994-07-21
US5206707A (en) 1993-04-27
JP3028248B2 (ja) 2000-04-04
JPH04226360A (ja) 1992-08-17

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