Abstract: A method for the correction of measurement errors caused by surface effects induced by ink splitting during the color measurement of a printed sheet on a running printing device, includes scanning the printed sheet photoelectrically point by point and forming color and/or density measured values from scanning signals from the scanned points. Those scanned points which have a brightness exceeding a limiting value are identified, and the measured values are corrected by using the identified scanned points. In particular, during the formation of the color and/or density measured values, the scanning signals from the identified scanned points are not taken into account.

Abstract: A measuring system for photoelectrically scanning measurement points of a measurement object includes a lighting channel (21-24) for applying illuminating light to the measurement object (M) disposed in a measurement plane (MP) and a measuring channel (11-13) for capturing and photoelectrically converting the measurement light reflected by the measurement points of the measurement object M. The lighting channel and/or the measuring channel is configured so as to detect the reflection properties of the measurement points in several wavelength bands. The lighting channel (21-24) has a spatial light modulator controlled by an electronic control unit (40) for generating a spatial lighting pattern which causes illuminating light to be selectively applied to measurements points (25) of interest of the measurement object (M).

Abstract: Methods for measuring the colour of printed samples by measuring a first spectral proportion of the total spectral reflection factor of a sample by illuminating the sample with light having no UV element are provided. The methods calculate a spectral correction factor by making allowance for the characterisation data of the brightened substrate and the spectral properties of a selected type of illuminating light, adding the spectral correction factor to the first spectral proportion to obtain the total spectral reflection factor of the measured sample. The methods further evaluate the total spectral reflection factor on the basis of measurements taken with illuminating light with no UV element and with UV light only on a limited set of measurement samples, especially on the non-printed substrate only (paper whiteness).

Abstract: A scanner device includes a color measuring, a support surface for a measured object and a drive unit for moving the measuring head across the support surface and for adjusting the height of the measuring head in a direction perpendicular to the support surface. The measuring head is equipped with an illuminating channel and a collection channel. The illuminating channel has a light source and optical means for illuminating the measured object at a measurement site at a mean angle of incidence of 45°. The collection channel has optical means for capturing light emanating from the measured object at the measurement site at a mean collection angle of 0° and coupling it into a light guide, which directs the captured light to a wavelength-selective photoelectric transformer, which resolves it into a number of wavelength ranges and generates an electric measurement signal corresponding to each wavelength range.

Abstract: A scanner device for measuring the color properties of a measured object pixel by pixel has a support surface for the measured object, a color measuring head, a drive unit for moving the color measuring head above the support surface in at least one dimension thereof and for adjusting the height of the color measuring head in the direction perpendicular to the support surface, as well as a measurement and drive control unit which activates the drive unit and co-operates with the color measuring head. It is also equipped with an electronic distance control system which adjusts the distance of the color measuring head above the measurement point in the direction perpendicular to the support surface to a desired measuring distance for every measurement point by means of the drive unit. The electronic distance control system works with measurement values generated by the color measuring head and distance values computed from them.

Abstract: Image measurement values of a measurement object, in particular a printed sheet, measured by means of a photoelectric image measuring unit operating on the basis of pixels are corrected with respect to at least one influencing variable which influences the measurement result with a view to at least partially eliminating the effect of this influencing variable on the measuring process. The image measurement values measured by the image measuring unit are converted by correction parameters of a parameter-based correction model into corrected image measurement values which no longer contain the influencing variable affecting the measuring process. The correction parameters used for the parameter-based correction model are automatically calculated using reference measurement values measured at reference measurements points on preferably the same measurement object by means of a reference measuring unit and the image measuring unit.

Abstract: The measuring device comprises a lighting system, a photoelectric receiver unit and optical means. The lighting system applies light to image elements disposed in strip-shaped lighting regions (15) at a standardized angle of incidence range. The photoelectric receiver unit comprises several photoelectric line sensors (21) disposed parallel at a distance apart which are sensitized to different wavelength ranges by color filters (22) connected upstream. The optical means comprise linear optical arrays (31) which pick up the measurement light reflected by the image elements at a standardized range of angle of reflection and direct it to one of the respective line sensors (21). By means of optical screening and other structural features, cross-talk effects between adjacent image elements are largely reduced.

Abstract: A spectral photoelectric measurement transformer comprises an array (10) of photoelectric transformer elements and dielectric interference bandpass filters (22a, 22b) disposed on a common filter support (21) connected upstream of them for sensitizing the transformer elements to different wavelength ranges of the measurement light. The bandpass filters are divided into a number of filter groups, each of which contains the same different bandpass filters within the filter group. An optical deflector element (30) spectrally shifts the effective bandpass curves of the bandpass filters of all the filter groups except one so that the effective bandpass curves of all the bandpass filters have different spectral positions. As a result, a multiplication of the filter channels effectively made available can be achieved using only a few different bandpass filters. Due to the small number of different bandpass filters, the measurement transformer is inexpensive to manufacture.

Abstract: A scanning device for photoelectrically measuring a measurement object in the form of a printed sheet on the basis of image elements comprises a measuring table (MT) for supporting the measurement object, a measuring device which can be moved above the surface of the measuring tables for scanning image element lines of the measurement object, a drive system for moving the measuring device above the measurement object, a measurement and drive control system for the measuring device and drive system, and a processing unit, for processing and evaluating the measurement signals generated by the measuring device from the scanned image elements of the measurement object (S). The measuring device comprises a lighting system, a photoelectric receiver unit and optical means. The lighting system applies light to image elements disposed in strip-shaped lighting regions (15) at a standardized angle of incidence range.

Abstract: In a method for determining color and/or density values for use in monitoring and regulating a printing process in a printing apparatus, specifically in a sheet-fed offset printing press, measuring areas of a printed sheet are measured photoelectrically during the printing process, directly in or on the running printing apparatus. From the measured values obtained in the process, the color and/or density values for the relevant measuring areas are formed. From the measurement, measured value deviations caused directly in the printing process with respect to a measurement outside the printing process can be corrected computationally.

Abstract: A measuring system for photoelectrically scanning measurement points of a measurement object includes a lighting channel (21-24) for applying illuminating light to the measurement object (M) disposed in a measurement plane (MP) and a measuring channel (11-13) for capturing and photoelectrically converting the measurement light reflected by the measurement points of the measurement object M. The lighting channel and/or the measuring channel is configured so as to detect the reflection properties of the measurement points in several wavelength bands. The lighting channel (21-24) has a spatial light modulator controlled by an electronic control unit (40) for generating a spatial lighting pattern which causes illuminating light to be selectively applied to measurements points (25) of interest of the measurement object (M).

Abstract: To measure the colour of samples printed on a substrate containing brightener, a first spectral proportion of the total spectral reflection factor of the sample is measured by illuminating the sample with light having no UV element. From this first spectral proportion, a spectral correction factor is calculated making allowance for the characterisation data of the brightened substrate and the spectral properties of a selected type of illuminating light. The spectral correction factor is added to the first spectral proportion in order to obtain the total spectral reflection factor of the measured sample. The total spectral reflection factor is then evaluated for measuring and control purposes, in particular for calculating colour values of the sample. The characterising data of the substrate is determined on the basis of measurements taken with illuminating light with no UV element and with UV light only on a limited set of measurement samples, especially on the non-printed substrate only (paper whiteness).

Abstract: For the color measurement of samples printed on a substrate including a brightener, a raw spectral reflection factor of the sample is measured in a first measurement by illumination of the sample with light without UV portion. In a second measurement, a fluorescence spectrum of the sample is measured by illumination of the sample with only UV light. The measured fluorescence spectrum is recalculated as a corrected fluorescence spectrum by weighting with spectrally dependent correction factors and, finally, the measured raw spectral reflection factor and the corrected fluorescence spectrum are added to form a corrected spectral reflection factor from which the values characterizing the color of the sample are then calculated. The spectral correction factors are determined during the device manufacture for a certain set of light types and stored in the device.

Abstract: A color management system using distributed profiles includes a color printer adapted to print controlled color using a custom profile. The color printer system creates a custom profile by reading its initial characterization data, the profiles of the inks and the profile of the paper used in the printer. The color printing system includes a spectral measurement module adapted to generate spectral measurement of an output of the color printer. The printing system computes its initial characterization data by using the output of the color printer, measured by the spectral measurement module. The printing system updates the paper profile, the ink profile and/or the printer characterization data based on the measurement of the spectral measurement module.

Abstract: A method for the correction of measurement errors caused by surface effects induced by ink splitting during the color measurement of a printed sheet on a running printing device, includes scanning the printed sheet photoelectrically point by point and forming color and/or density measured values from scanning signals from the scanned points. Those scanned points which have a brightness exceeding a limiting value are identified, and the measured values are corrected by using the identified scanned points. In particular, during the formation of the color and/or density measured values, the scanning signals from the identified scanned points are not taken into account.

Abstract: A scanner device includes a support surface for the measured object and a drive unit for moving a color measuring head across the support surface in at least one dimension thereof and for adjusting the height of the color measuring head in the direction perpendicular to the support surface, as well as a measuring and drive control unit activating the drive unit and cooperating with the color measuring head (MH). The color measuring head (MH) is equipped with at least an illuminating channel (IC) and a collection channel (CC). The illuminating channel (IC) has a light source (10) and optical means (12-22) for illuminating the measured object (S) at a measurement site at a mean angle of incidence of 45 E.

Abstract: A scanner device for measuring the color properties of a measured object pixel by pixel has a support surface for the measured object, a color measuring head, a drive unit for moving the color measuring head above the support surface in at least one dimension thereof and for adjusting the height of the color measuring head in the direction perpendicular to the support surface, as well as a measurement and drive control unit which activates the drive unit and co-operates with the color measuring head. It is also equipped with an electronic distance control system which adjusts the distance of the color measuring head above the measurement point in the direction perpendicular to the support surface to a desired measuring distance for every measurement point by means of the drive unit. The electronic distance control system works with measurement values generated by the color measuring head and distance values computed from them.

Abstract: Spectral, densitometric, or color measured values are detected on sheet printing materials during the printing process in a sheet-fed printing press. The measured values are determined on sheets as they are moving through the printing press and the measured values are used in real-time by a computer to control parameters for controlling the printing process in the sheet-fed printing press.

Abstract: A spectral photoelectric measurement transformer comprises an array (10) of photoelectric transformer elements and dielectric interference bandpass filters (22a, 22b) disposed on a common filter support (21) connected upstream of them for sensitizing the transformer elements to different wavelength ranges of the measurement light. The bandpass filters are divided into a number of filter groups, each of which contains the same different bandpass filters within the filter group. An optical deflector element (30) spectrally shifts the effective bandpass curves of the bandpass filters of all the filter groups except one so that the effective bandpass curves of all the bandpass filters have different spectral positions. As a result, a multiplication of the filter channels effectively made available can be achieved using only a few different bandpass filters. Due to the small number of different bandpass filters, the measurement transformer is inexpensive to manufacture.

Abstract: A printing press for processing sheet printing materials includes at least one printing unit, a computer and a measuring device for monitoring printing quality during a printing process. The measuring device has a sensing device for measuring by color or spectrally to register the printing material. At least one sheet-guiding element leads the sheet printing material past the sensing device. A measuring device for monitoring printing quality during a printing process in a printing press for processing sheet printing materials, is also provided.