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 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. 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.The scanning device enables the entire printed sheet to be scanned at high speed and is relatively uncomplicated in terms of its construction. It combines the advantages of technologies known from imaging technologies but without their intrinsic disadvantages. It is suitable for quality control applications in the graphics industry and for the calorimetric control of printing processes.
Abstract:
A system and method are provided for producing a color palette including a multitude of color patterns for a predetermined coloring process with a multitude of defined base colors and for a predetermined substrate. The individual color patterns are systematically, especially equidistantly, defined in a mathematically defined color space by the way of color coordinates describing the color space. The spectrum of the color pattern is synthesized by calculation for each color pattern in the color space by way of a color mixing model representing the predetermined coloring process and the predetermined substrate, whereby that spectrum is selected having the highest color constancy. The spectra synthesized by calculation are stored in relation to the color coordinates of the underlying color patterns. Through use of a mathematical/physical basis (such as the CIE-system), it is possible to define a visually equidistant color space and assign a spectral curve to individual points having the best color constancy.
Abstract:
An electronic projector (beamer) is equipped with a profiling device (100) internally or externally connected thereto through standard interfaces. The profiling device includes all functionalities required for the color management (color measurement, calibration, profile generation, etc.) and corresponds with the projector (200) by way of a simple text based protocol. The latter can be implemented relatively easily by way of software in the projector, so that no changes to the fundamental concept of the projector are required. The profiling device can therefore on the one hand be easily integrated at the factory into existing projectors and on the other hand used as external complement to available projectors. The profiling device can however also be an independent device for the profiling of other electronic display devices (for example monitors) as well as for other, for example metrological tasks.
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 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). The control unit (40) may be equipped with image processing functions and be configured to identify measurement points (25) suitable for the application purpose from image data of the measurement object (M) and to calculate corresponding lighting patterns for selectively illuminating the measurement points.
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 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. The scanner device is suitable for running high-precision measurements on even the smallest measurement fields without contact and no separate measurement sensor is needed for the distance control system.
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:
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.