Colour-management

Abstract

The invention presents a method for controlling the composition of an ink mixture ( 11, 31 ) for at least one printing press ( 2 ), in which actual optical values (I) of light ( 7 ) are obtained, whereas the light ( 7 ) has interacted at least with parts of the printing picture, which is generated by the printing press ( 2 ) on the printing substrate ( 6 ) using an ink mixture which is provided by an ink supply system, and in which, due to the deviation of the actual optical value from optical reference values (S), a corrective ink mixture ( 31 ) is created, which is added to the ink mixture ( 11 ) which is provided by said ink supply system and which changes the ratio of the amounts of ink pigments therein. The ink mixtures ( 11, 31 ) used in the method are provided by different ink mixing devices ( 16, 24 ).

1 . Method for controlling the composition of an ink mixture ( 11 ,  31 ) for at least one printing press ( 2 ),
 in which actual optical values (I) of light ( 7 ) are obtained, whereas the light ( 7 ) has interacted at least with parts of the printing picture, which is generated by the printing press ( 2 ) on the printing substrate ( 6 ) using an ink mixture which is provided by an ink supply system   and in which, due to the deviation of the actual, optical value from optical reference values (S), a corrective ink mixture ( 31 ) is created, which is added to the ink mixture ( 11 ) which is provided by said ink supply system and which changes the ratio of the amounts of ink pigments therein,   characterized in that   
       the ink mixtures ( 11 ,  31 ) used in the method are provided by different ink mixing devices ( 16 ,  24 ). 
     
     
         2 . Method according to the preceding claim wherein
 the first ink mixing device ( 16 ) is an ink kitchen ( 16 ), which is used for the supply of ink ( 11 ) for a first number (N) of printing presses ( 2 ),   the second ink mixing device ( 24 ) is a decentralized mixing device ( 24 ), which is used for the supply of ink ( 11 ) for a second number (M) of printing presses ( 2 ), and   the first number (N) of printing presses is greater than or equal to the second number (M) of printing presses ( 2 ).   
     
     
         3 . Process according to the preceding claim,
 wherein   the second decentralized mixing device, which is used for the supply of ink for the second number (M) of printing presses, is assigned to a single printing press.   
     
     
         4 . Process according to  claim 1 , wherein
 the composition of the ink mixture is controlled or closed loop controlled at least two printing presses ( 2 ) and   at least one of the ink mixing devices is moved between at least two printing presses for providing these printing presses with ink mixtures.   
     
     
         5 . Process according to the preceding claim, wherein
 the ink mixing device, which is moved between at least two printing presses ( 2 ) for providing these printing presses with ink mixtures, feeds different ink components to an ink supply system ( 61 ) of a colour deck ( 8 ) of the printing press ( 2 ) and   wherein these ink components mix up only within said ink supply system ( 61 ).   
     
     
         6 . Process according to  claim 1 , wherein
 at least one of the measurements, with which actual optical values (I) are obtained, is a densitometrical measurement, that takes measurements of the light intensity (L) only inside first selected wavelength ranges ( 51 ) which are part of the transparent parts (TB) of the respective ink mixture.   
     
     
         7 . Process according to  claim 1 , wherein
 estimated values with respect to the light intensities (L) in second selected wave length ranges ( 53 ) which differ from the first wavelength ranges ( 51 ) and in which the light intensity is not measured are deduced or extrapolated from the densitometric measurement.   
     
     
         8 . Process according to the preceding claim, wherein for said estimation the optical values ( 50 ) are taken into account, which have been the result of prior measurement of light that interacted with the used ink ( 11 ) or the used ink components. 
     
     
         9 . Process according to  claim 7 , wherein
 for said estimation at least parts of a curve ( 50 ) are taken into account, whereas the curve ( 50 ) reflects the spectral intensity (L) of the remitted light ( 7 ), that is the result of the interaction of light with the used ink ( 11 ) or with the used ink components in a wave length range.   
     
     
         10 . Process according to  claim 7 , wherein
 the densitometric measured values underlie the production of a correction mixture ( 31 ).   
     
     
         11 . Process according to  claim 7 , wherein
 at least one of the measurements to obtain actual optical values (I) is a spectral-photometrical measurement that comprises measurement of light intensities (L) in all wavelength ranges ( 51 ,  52 ) of the part of the transparent part of the respective ink mixture.   
     
     
         12 . Process according to the preceding claim, wherein the spectrophotometric measured values are the basis for the production of basic mixtures ( 21 ). 
     
     
         13 . Process according to  claim 11 , wherein
 the spectrophotometric measured values are taken as a basis for re-checking the quality of the densitometrical measurement and/or of said estimation.   
     
     
         14 . Process according to  claim 1  wherein
 for the supply of said correction mixture ( 31 ) less different kinds of basic inks ( 26 ) are used than for the production of the basic ink mixture ( 21 ). 
 
     
     
         15 . Process according to  claim 1  wherein
 at least at one of the following devices measurements of the mass of the ink and/or the volume of the ink are performed and wherein said measurements are taken into account at the creation of the ink mixture:
 at ink containers ( 18 ) of the centralized ink kitchen ( 16 ) 
 at ink repositories ( 10 ) of at least one printing press ( 2 ) 
 at ink repositories ( 25 ) of the decentralized mixing device. 
 
 
     
     
         16 . Mixing device for supplying of ink mixtures for at least one printing press ( 2 ), comprising at least two ink repositories and a dosing device,
 characterized in that   the mixing device further comprises means for movement—preferentially wheels.   
     
     
         17 . Mixing device according to the preceding claim, wherein
 a control and evaluation device ( 23 ) is provided.   
     
     
         18 . Mixing device ( 24 ) according to the preceding claim, wherein
 at least a part of said dosing device ( 13 ,  38 ,  28 ) of the mixing device is controllable by said control and evaluation device.   
     
     
         19 . Mixing device ( 24 ) according to the preceding claim, further comprising
 interfaces ( 30 ) to external control components ( 3 ,  19 ), which can be used to submit data relating to the ink mixtures ( 11 ,  31 ) which are needed by the at least one printing press ( 2 ).   
     
     
         20 . System ( 1 ) for controlling the composition of a ink mixture for at least one printing press ( 2 ),
 which comprises at least one optical measuring device, which can record actual optical values ( 1 ) of light, whereby the recordable light has interacted at least with parts of the printing picture ( 9 ), that is creatable on a printing substrate by at least one printing press ( 2 ) using an ink mixture which is provided by an ink supply system of said printing press, and   which comprises components, with which a corrective ink mixture is creatable on the basis of deviation of the actual optical values (I) from optical reference values (S), whereas said corrective ink mixture can be added to the ink mixture which is provided by the ink supply system ( 61 ) in order to change the ratio of the amounts of ink pigments therein ( 61 )   
       characterized in that 
       the system comprises at least two different ink mixing devices ( 16 ,  24 ), each usable to supply ink mixtures ( 11 ,  31 ). 
     
     
         21 . Printing press ( 2 ), comprising
 at least one ink supply system ( 61 ), with which ink can be transferred from an inlet point ( 10 ) to the printing substrate,   at least one optical measuring device ( 5 ,  8 ) for measuring actual optical values (I) of light, in which the actual optical values (I) are from light of selected wavelength ranges ( 51 ,  53 ) and in which the light has interacted with at least parts of the printing picture,   
       characterized in that 
       the printing press ( 2 ) further comprises
 an ink mass determination device for determining the weight of at least parts of the ink which is located within an ink supply system 
 a control and evaluation device ( 3 ) which can be provided with measured values from the optical measuring device and with measured values from the ink mass determination device and which can be used to determine the optical deviation that is the deviation of the actual optical values from the optical reference values (S), which are available a light intensity values (L) of selected wavelength ranges,
 and which control and evaluation device can be used to determine on the basis of the optical deviation and the values from the weighing devices ( 12 ), how much corrective ink having a determined composition is fed to the printing press ( 2 ) in order to approximate the actual optical values (I) to the optical reference values (S). 
 
 
     
     
         22 . Printing press ( 2 ) according to the preceding claim, wherein
 a device for measuring the viscosity of the ink contained in the ink supply system is provided.   
     
     
         23 . Printing press ( 2 ) according to the preceding claim, wherein
 a connection line for the transfer of measured values from said device for measuring the viscosity to the control and evaluation device ( 3 ) is provided.   
     
     
         24 . Printing press ( 2 ) according to  claim 1 , wherein
 with the control and evaluation device ( 3 ) the composition of the ink contained in said ink supply system after at least one ink correction process is computable on the basis of the values from said ink mass determination device and preferably from the device for measuring the viscosity of the ink as well as on the basis of the quantity and the composition of the corrective ink.   
     
     
         25 . Printing press ( 2 ) according to the preceding claim, wherein
 a memory device for recording the composition of the ink after at least one in correction process is provided.   
     
     
         26 . Printing press ( 2 ) according to  claim 1 , wherein
 with the control and evaluation device ( 3 ) the mass of the ink is estimated, which ink is contained in at least a part of that parts of said ink supply system, which is not available for measuring the mass of the ink by the ink mass determination device.   
     
     
         27 . Printing press ( 2 ) according to the preceding claim, wherein
 the volume of at least a part of ink supply system ( 61 ), in which no measurement of the mass of the ink by the ink mass determination device is possible, is known by the control and evaluation device and wherein said control and evaluation device performs said estimation on the basis of said volume.   
     
     
         28 . Printing press ( 2 ) according to  claim 1 , wherein
 an optical measuring device is provided for recording densitometrial measurements, which base on the measurement of the light intensity (L) in first selected wavelength ranges ( 51 ).   
     
     
         29 . Printing press ( 2 ) according to the preceding claim, wherein
 with the control and evaluation device ( 3 ) estimated values with respect to the light intensities (L) in second selected wavelength ranges ( 52 ) which differ from the first wavelength ranges ( 51 ) and in which the light intensity is not measured are deduced from the densitometric measurement ( 51 ).   
     
     
         30 . Printing press ( 2 ) according to the preceding claim, wherein
 optical values ( 50 ) are known by the control and evaluation device ( 3 ), wherein said values ( 50 ) result from an interaction of light with the used ink of the used ink components and   wherein these values can be taken into account for said estimation.   
     
     
         31 . Printing press ( 2 ) according to  claim 29 , wherein
 estimated values are considered by the control and computing device in order to compute the mass and the composition of the corrective ink.   
     
     
         32 . Printing press ( 2 ) according to  claim 29 , wherein
 the optical values, which can be taken into account by the control and evaluation device, comprising at least parts of a curve ( 50 ) which reflects the spectral intensity (L) of the remitted light ( 7 ) that is the result of the interaction of light with the printed colour or with the printed colour components in a wavelength range.   
     
     
         33 . Printing press ( 2 ) according to  claim 1 , wherein
 a memory device is provided which is adjusted to save optical measured values ( 50 ) and/or ink formulas and/or ink compositions and   a control and evaluation device ( 3 ) is provided which is adjusted to take into account said saved values during the execution of a later printing job.   
     
     
         34 . Method for the operation of a printing press ( 2 ), comprising the steps of:
 transferring ink from an inlet point ( 10 ) to the printing substrate ( 6 ) via at least one ink supply system ( 61 )   measuring actual optical values (I) of light by at least one optical measuring device wherein said actual optical values (I) are intensity values of light in selected wavelength range and wherein the light has undergone an interaction with at least parts of the print image   characterized in that   the method further comprises the steps of:
 measuring and/or estimating the mass of the ink contained in said at least one ink supply system by using an ink mass determination device 
 feeding the values from the optical measuring device ( 4 ,  54 ) and from the ink mass determination device to a control and evaluation device ( 3 ), 
 determining the optical deviation ΔK, that is the deviation of the actual optical values (I) from the optical reference values (S), which are also available as light intensity values (L) of selected wavelength ranges, by said 
 control and evaluation device ( 3 ) and 
   determination on the basis of the optical deviation and the values from the weighing devices ( 12 ), how much corrective ink having a determined composition is fed to the printing press ( 2 ) in order to approximate the actual optical values (I) to the optical reference values (S) by said control and computing device.   
     
     
         35 . Method according to the preceding claim,
 wherein different printing jobs are performed sequentially with said printing press ( 2 ), wherein an equal optical reference value (S) with regard to at least one colour underlies at least at two of said different printing jobs for at least one colour and   wherein measured values ( 50 ) and/or ink formulas of a former of said at least two different printing jobs are taken into account for supplying of the ink mixture for a later one of the at least two printing jobs.   
     
     
         36 . Method according to the preceding claim, wherein for supplying of said ink mixture for a later of the at least two printing jobs measured values ( 50 ) are taken into account and
 wherein one of these measured values ( 50 ) is the deviation (ΔK), which has resulted from the former of the at least two different printing job, when it was printed with an ink mixture, which was used for the attainment of the optical reference value (S).   
     
     
         37 . Method according to the preceding claim, wherein
 at least two measured values ( 50 ) are taken into account and   wherein said at least two measured values reflect at least one former (ΔK 1 ) and one later (ΔK 2 ) deviation, both (ΔK 1 , ΔK 2 ) having occurred at an adjustment of the reference value (S) of a printing ink ( 11 ) during a former printing job, when is was printed with a former ink mixture and with a later ink mixture, wherein said later ink mixture was corrected in comparison with the former ink mixture.   
     
     
         38 . Method according to  claim 1 , wherein
 the deviations (ΔK, ΔK 1 , ΔK 2 ) and the optical reference value (S) are determined in coordinates of a colour space,   wherein a difference chromaticity coordinate (D) is determined by subtract the deviation from the reference chromaticity coordinate (S) in a vectorial manner   and wherein a resulting ink formula is computed by the control and computing device on the basis of the difference chromaticity coordinate (D).   
     
     
         39 . Method according to  claim 1 , wherein
 in addition to the optical measured values ( 50 ) the composition and/or formulas of the ink mixtures, which led to the deviations (ΔK, ΔK 1 , ΔK 2 ) of said optical measured values (I) from the optical reference values (S), are taken into account.   
     
     
         40 . Method for controlling the composition of an ink mixture ( 11 ,  31 ) for at least one printing press ( 2 ),
 in which actual optical value (I) of light are obtained, whereat the light has interacted at least with parts of the printing picture, which is generated by the printing press on the printing substrate using an ink mixture which is provided by an ink supply system   and in which, due to the deviation of the actual optical value (I) from optical reference values (S), a corrective ink mixture is created, which is added to the ink mixture which is provided by the ink supply system and which changes the ratio of the amounts of ink pigments therein,   
       characterized in that
 first actual optical values are obtained inline, that is at running and just printed printing substrate, wherein these actual optical values are densitometrical values. 
 
     
     
         41 . Method according to the preceding claim, characterized in that
 estimated values with respect to the light intensities (L) in second selected wave length ranges ( 52 ) which differ from the first wave length intervals ( 51 ) and in which the light intensity is not measured are deduced from the densitometric measured values ( 51 ).   
     
     
         42 . Method according to the preceding claim, wherein for said estimation the optical values are taken into account, which have been the result of prior measurement of light that interacted with the used ink or the used ink components. 
     
     
         43 . Method according to  claim 41 , wherein
 for said estimation at least parts of a curve ( 50 ) are taken into account, whereas the curve ( 50 ) reflects the spectral intensity (L) of the remitted light ( 7 ), that is the result of the interaction of light with the used ink or with the used ink components in a wavelength range.   
     
     
         44 . Method according to  claim 41 , wherein
 also second actual optical values are obtained by a spectrophotometrical measurement, whereat the spectrophotometrical measurement bases on measured value of the light intensity (L) in all wavelength ranges ( 51 ,  52 ) of the part of transparent part of the respective ink mixture.   
     
     
         45 . Method according to the preceding claim, wherein the spectrophotometric measurements underlie the generation of basic mixtures ( 21 ). 
     
     
         46 . Method according to  claim 44 , wherein
 the spectrophotometric measurement are taken as a basis for re-checking the quality of the densitometrical measurement and/or of said estimation.   
     
     
         47 . Method according to  claim 1 , wherein
 the second actual spectrophotometrical measured value is acquired offline, that means at the printing substrate, which is located outside the printing process.   
     
     
         48 . System ( 1 ) for controlling the composition of a ink mixture for at least one printing press ( 2 ),
 in which ( 1 ) actual optical values (I) of light ( 7 ) are determinable with the aid of an optical measurement device and   in which due to the deviation of the actual optical values (I) from the optical reference value (S) at least one corrective ink mixture is creatable, which can be added to the ink mixture contained in the ink supply system ( 61 ) of the printing press ( 2 ), so that there the ratio of the quantities of the ink pigments can be changed   
       characterized in that 
       the first actual optical values (I) can be obtained inline, that is at running and just printed printing substrate, wherein these actual optical values (I) are densitometrical values. 
     
     
         49 . System ( 1 ) according to the preceding claim, wherein estimated values with respect to the light intensities (L) in second selected wave length intervals ( 52 ), which differ from the first wave length intervals ( 51 ) and in which the light intensity is not measured, can be deduced from the densitometric measured values ( 51 ). 
     
     
         50 . System according to  claim 1 , wherein
 the control device ( 3 ) of the at least one printing press ( 2 ) is adjusted so that it determines the composition of a corrective ink mixture and the basis of the actual optical values (I)   
     
     
         51 . System according to the preceding claim, wherein the control device ( 3 ) of said printing press is adjusted for the determination of the corrective ink mixture and
 wherein at least one ink mixing device ( 16 ,  24 ) is provided, which, on its part, is equipped with a control device ( 19 ,  23 ), that is adjusted for the determination of the basic ink mixture.   
     
     
         52 . System according to the preceding claim, wherein the at least one ink mixing device ( 16 ,  24 ) is the central ink mixing device ( 16 ). 
     
     
         53 . System according to  claim 1 , wherein
 the control device ( 3 ) is provided with interfaces ( 29 ), which permit the control device ( 3 ) to pass data about the composition of the ink mixture to a central and/or decentral ink mixing device ( 16 ,  24 ).   
     
     
         54 . System, device or machine according to  claim 1  which refer to a system, device or machine. 
     
     
         55 . Method or process according to  claim 1  which refer to a method or a process.