Patents Assigned to Gretag Aktiengesellschaft
  • Patent number: 6084693
    Abstract: The invention relates to the use of a spectrophotometer connected with a computer to measure and store a solid color atlas in the computer. The halftone percentage values necessary for the adjustment of a given color are calculated by determining the desired color coordinates of the color involved and entered into the computer. The latter calculates from them, using the stored color atlas and a regression method, the halftone percentage values sought. In the process, with the aid of printing characteristics, stored color adaptations to prevailing printing conditions can be brought up to date without the need for the preparation of a new solid color atlas.
    Type: Grant
    Filed: January 25, 1996
    Date of Patent: July 4, 2000
    Assignee: Gretag Aktiengesellschaft
    Inventors: Bruno Zimmermann, Hans Ott, Thomas Senn
  • Patent number: 5987396
    Abstract: A computer-controlled device for detecting optical transmission and/or remittance properties of a measuring object has a measuring unit for illuminating the measuring object and for receiving the light transmitted by the measuring object and/or reflected from the measuring object. Furthermore, it has an input unit for selecting the type of measurement and the like, as well as a display unit for displaying the values measured. Moreover, it comprises a first non-volatile memory in which the measuring functions of the device are stored, as well as a control unit for controlling all procedures in the device. In a second non-volatile memory are stored release codes assigned to the individual measuring functions and, with the help of which, the control unit accesses the measuring functions in the first non-volatile memory.
    Type: Grant
    Filed: August 22, 1995
    Date of Patent: November 16, 1999
    Assignee: Gretag Aktiengesellschaft
    Inventors: Markus Berner, Thomas Senn
  • Patent number: 5530563
    Abstract: The invention relates to the use of a spectrophotometer connected with a computer to measure and store a solid color atlas in the computer. The halftone percentage values necessary for the adjustment of a given color are calculated by determining the desired color coordinates of the color involved and entered into the computer. The latter calculates from them, using the stored color atlas and a regression method, the halftone percentage values sought. In the process, with the aid of printing characteristics, stored color adaptations to prevailing printing conditions can be brought up to date without the need for the preparation of a new solid color atlas.
    Type: Grant
    Filed: July 22, 1992
    Date of Patent: June 25, 1996
    Assignee: Gretag Aktiengesellschaft
    Inventors: Bruno Zimmermann, Hans Ott, Thomas Senn
  • Patent number: 5519210
    Abstract: An apparatus for recording photometric data that is positioned in succession or in adjacent fashion on a page-like or strip-like print is equipped with at least one reflectance measuring unit with a reflectance measuring lens for measuring opaque prints (for example, paper test strips for examining the paper developing baths or for control of the basic printer setting). Wavelength dispersion elements positioned in the light path of the reflected light permit the analysis of the measuring fields according to wavelengths and preferably in the three primary colors of red, green, and blue. The apparatus can be equipped with an automatic transport device for the page-like or strip-like prints; the transport device is positioned behind the measuring lens. The prints are inserted into the device through an intake slot which is designed to accommodate prints of different width. On at least one side of the intake slot there is at least one stop for the prints.
    Type: Grant
    Filed: April 28, 1994
    Date of Patent: May 21, 1996
    Assignee: Gretag Aktiengesellschaft
    Inventor: Markus Berner
  • Patent number: 5426508
    Abstract: A manual densitometer for measuring the color composition of an original has a housing which includes a unit for measuring the original, a unit for controlling the measuring, as well as an evaluating electronics and display unit which displays selected variables and parameters. In addition, it has a control unit with a manually-operated dial, which can be rotated from outside the housing, whereby the measuring, the measurement variables, and the parameters for the measurement can be selected by rotating the dial.
    Type: Grant
    Filed: December 22, 1993
    Date of Patent: June 20, 1995
    Assignee: Gretag Aktiengesellschaft
    Inventor: Fortunat Schrammli
  • Patent number: 5267178
    Abstract: A computer controlled spectrophotometer is equipped with a serial interface to which a bar code reader can be connected. Using the bar code reader, calibration and configuration data or functional commands for the spectrophotometer may be read from a data carrier and transmitted to the computer in the spectrophotometer.
    Type: Grant
    Filed: July 13, 1992
    Date of Patent: November 30, 1993
    Assignee: Gretag Aktiengesellschaft
    Inventor: Markus Berner
  • Patent number: 5206707
    Abstract: A microcomputer controlled manual densitometer for the analysis of print control fields has a manual and an automatic operating mode. In the manual mode the measuring functions desired are selected by the operator, while in the automatic mode the measuring function is selected automatically on the basis of the type of the print control field measured. The densitometer is able to recognize the color of the print control field including overprint situations, and to distinguish between solid-tone fields including overprint situations, and to distinguish between full-tone fields and half-tone fields with two different nominal dot areas. For solid-tone fields the color and the solid-tone density, for overprint fields the ink trap and the overprint color and for half-tone fields the dot gain, the color and the nominal dot area, are detected and displayed. The color recognition is based on the relative variables of grayness and color hue error.
    Type: Grant
    Filed: April 1, 1991
    Date of Patent: April 27, 1993
    Assignee: Gretag Aktiengesellschaft
    Inventor: Hans Ott
  • Patent number: 5113258
    Abstract: In a compensation circuit for the correction of image defects of an image projection system according to the control layer principle, in particular of an eidophor projector, a compensation signal is produced from signals associated with three adjacent lines, using an adder followed by a coefficient multiplier in order to produce a compensation signal. The amplitude of the compensation signal assumes a maximum value for low values of an intermediate image point in a single column image matrix of a video signal and a minimum value for high levels of the intermediate image point.
    Type: Grant
    Filed: April 9, 1990
    Date of Patent: May 12, 1992
    Assignee: Gretag Aktiengesellschaft
    Inventor: Philippe Roth
  • Patent number: 5068810
    Abstract: In a process for the evaluation of the quality of prints and for the color control or ink regulation of a printing machine, half tone fields, preferably gray balance fields, are scanned by a densitometer. The half tone density differences obtained by comparative measurements are transformed by an experimentally determined transform matrix into colorimetric measure differences of a color space uniformly graduated relative to perception, so that on the one hand the advantages resulting from quality evaluations in a true colorimetric system instead of a densitometric measure system may be utilized, and on the other, the use of regulation strategies requiring a colorimetric measuring system, such as for example the L*a*b* system or the LUV system, becomes possible. The transform matrix system is determined experimentally by producing a reference calibrating print and several addition calibrating prints, each containing one gray balance field and three full tone fields.
    Type: Grant
    Filed: July 9, 1990
    Date of Patent: November 26, 1991
    Assignee: Gretag Aktiengesellschaft
    Inventor: Hans Ott
  • Patent number: 5020106
    Abstract: In a process for the cryptographic processing of data in a cryptographic system, processing takes place in two parts. In the first part the data transmission routines within a data entity and a coded text entity are detected. The clear text and the cryptographic are separately processed cryptographically in the second part and then recombined in the first part with the data transmission routines.
    Type: Grant
    Filed: February 8, 1990
    Date of Patent: May 28, 1991
    Assignee: Gretag Aktiengesellschaft
    Inventors: Peter Rabold, Hans-Jorg Klemenz, Paul J. Schobi
  • Patent number: 5015088
    Abstract: In an illuminating apparatus for projection purposes, in particular a film projector or television image projector by the eidophor system, four condensers are located around a source of light in a cube-shaped housing, the condensers reproducing via the use of deflecting mirrors, an image of the light source on several, spatially adjacent imaging mirror segments, which in turn reproduce the condenser images superimposed upon one another, via an output mirror, on an image aperture of the projection optics.
    Type: Grant
    Filed: August 30, 1990
    Date of Patent: May 14, 1991
    Assignee: Gretag Aktiengesellschaft
    Inventors: Bruno Rhomberg, Beat Frick
  • Patent number: 4975862
    Abstract: A three-color offset printing machine produces, during the printing of sheets, color measuring strips with several color measuring fields. A gray half-tone field produced by the overprinting of three colors serves as the reference field. The color location of the reference field is compared in a color deviation computer with the color location of a correlated desired reference field. From the color deviation, a layer thickness variation computer calculates a layer thickness variation control vector by means of a sensitivity matrix calculated on the basis of a linear model by a matrix computer. The matrix computer evaluates a series of secondary fields comprising three single color half-tone fields, three single color full-tone fields, three two-color full-tone fields, and a three-color full-tone field.
    Type: Grant
    Filed: January 5, 1989
    Date of Patent: December 4, 1990
    Assignees: Gretag Aktiengesellschaft, Heidelberger Druckmaschinen AG
    Inventors: Guido Keller, Helmut Kipphan
  • Patent number: 4969188
    Abstract: Each encryption device of a communication network is divided into a base part and a security module in credit card form. The security module contains the functional stages required for the coding/decoding of the keys of lower hierarchical levels under keys of higher hierarchical levels and thus the secret elements of the network. The base parts contain no secret elements. The secret elements are stored in the security module preferably in a cryptologically secured form. A password also provided therein secures it against unauthorized use.
    Type: Grant
    Filed: February 4, 1988
    Date of Patent: November 6, 1990
    Assignee: GRETAG Aktiengesellschaft
    Inventor: Paul J. Schobi
  • Patent number: 4968140
    Abstract: A manual device for the detection of photometric values on a printed product comprises a measuring head extruding from a housing into a measuring position. The measuring head is mounted together with its optical components on a measuring carriage, which may be displaced along the bottom of the housing by means of a drive motor between a rest position and a measuring position. The drive motor drives via a gear, a drive pulley and a grid axle for a monochromator. A sliding gear and a locking device are coordinated with the drive pulley, with the locking device immobilizing the measuring carriage precisely in the measuring position. The drive motor serves to displace the measuring carriage until the locking process essentially begins; and after this process, serves to rotate the grid axle.
    Type: Grant
    Filed: January 24, 1989
    Date of Patent: November 6, 1990
    Assignee: Gretag Aktiengesellschaft
    Inventors: Markus Berner, Fortunat Schrammli, Lido Feri, Wilhelm H. Koch
  • Patent number: 4967379
    Abstract: In a process for the ink control or regulation of a printing machine the actual color coordinates of measuring fields are compared with the desired color location. If the desired color location is found outside the correction color space defined by the boundary values of the full tone densities of the printing inks, as a substitute for the given desirable color locations, attainable desired color locations are determined on the surface of the correction color space by finding the point on the surface of the color correction space that is nearest to the given desired color location. The search for the nearest point may also be carried out in a manner such that the nearest point on the surface of the correction color space is sought in the direction of the brightness axis of the color space.
    Type: Grant
    Filed: December 5, 1988
    Date of Patent: October 30, 1990
    Assignee: GRETAG Aktiengesellschaft
    Inventor: Hans Ott
  • Patent number: 4961646
    Abstract: A manual device for the detection of photometric data which includes a measuring head to illuminate a measuring surface and to detect the light reflected. The measuring light captured by the measuring head is spectrally decomposed by a monochromator containing a diffraction grating. The intensity of the light exiting through an outlet diaphragm is detected by a photodetector. The spectral position of the measuring light is set by a drive motor rotating a grating shaft connected with the holder of the diffraction grating. From the spectra detected, densitometric and colorimetric data are calculated by a computer, which together with the spectra determined, may be displayed on a display field.
    Type: Grant
    Filed: January 24, 1989
    Date of Patent: October 9, 1990
    Assignee: Gretag Aktiengesellschaft
    Inventors: Fortunat Schrammli, Markus Berner, Hans Ott
  • Patent number: 4929084
    Abstract: A measuring head, in particular a manual device for the determination of photometric data, includes an optical illuminating device with an aspherical mirror having a groove which extends in an annular manner around an axis of rotational symmetry of the groove, and which, in cross-section, has the configuration of an elliptical segment. The measuring optics to detect the light reflected from a measuring spot forms a round measuring spot on an ellipse at the inlet slit of a monochromator, for which a spherical/cylindrical lens, a first glass rod and a second glass rod are used, the glass rods being provided with cylindrical surfaces, the associated cylinder axes of which are crossed with each other.
    Type: Grant
    Filed: January 24, 1989
    Date of Patent: May 29, 1990
    Assignee: GRETAG Aktiengesellschaft
    Inventors: Fred Mast, Jean A. Knus
  • Patent number: 4893786
    Abstract: In a scanning densitometer the mobile head is connected by means of an optical fiber cable with stationary parts of the apparatus. The optical fiber cable is looped around a cable drum and guided by it. The cable drum is suspended by means of two supporting cord layouts looped around it in opposing directions in a rotating manner parallel to the linear path of motion of the measuring head. The supporting cord layouts are mounted stationarily on the apparatus and one of them contains an equalizing spring. This type of a cable conduit is highly protective and therefore particularly suitable for mechanically sensitive parts, such as for example, optical fiber cables.
    Type: Grant
    Filed: November 30, 1988
    Date of Patent: January 16, 1990
    Assignee: GRETAG Aktiengesellschaft
    Inventor: Ernst Huber
  • Patent number: 4865456
    Abstract: A measuring head for the determination of the optical reflectance properties of color measuring fields co-printed with color sheets includes an optical illuminating device having two Mangin mirrors and an aplanar system located in alignment with the Mangin mirrors in a central opening. The light emitted by a light source and reflected by the measuring area arrives in a glass rod and is fed through an optical measuring device into a light waveguide, through which the reflected light is fed into a spectrometer for spectral analysis.
    Type: Grant
    Filed: August 31, 1988
    Date of Patent: September 12, 1989
    Assignee: Gretag Aktiengesellschaft
    Inventors: Fred Mast, Jean A. Knus
  • Patent number: D357695
    Type: Grant
    Filed: March 7, 1994
    Date of Patent: April 25, 1995
    Assignee: Gretag Aktiengesellschaft
    Inventor: Hans Ott