System for distributing and controlling color reproduction at multiple sites

• US 8,917,394 B2
• Filed: 03/15/2013
• Issued: 12/23/2014
• Est. Priority Date: 08/25/1997
• Status: Expired due to Fees

• Current Assignee: RAH Color Technologies LLC
• Original Assignee: RAH Color Technologies LLC
• Inventors: Holub, Richard A.
• Primary Examiner(s): Geisel, Kara E
• Application Number:
  US13/843,355
• Publication Number:
  US 20130314701A1
• Time in Patent Office: 648 Days
• Field of Search: 356405-406
• US Class Current: 356/405
• CPC Class Codes: G01B 11/002 for measuring two or more coordinates
• CPC Class Codes: G01J 2003/283 computer-interfaced
• CPC Class Codes: G01J 2003/2866 Markers; Calibrating of scan
• CPC Class Codes: G01J 3/02 Details
• CPC Class Codes: G01J 3/0218 using optical fibers
• CPC Class Codes: G01J 3/0224 using polarising or depolarising elements
• CPC Class Codes: G01J 3/0262 Constructional arrangements for removing stray light
• CPC Class Codes: G01J 3/0291 Housings; Spectrometer accessories; Spatial arrangement of elements, e.g. folded path arrangements
• CPC Class Codes: G01J 3/1838 Holographic gratings
• CPC Class Codes: G01J 3/28 Investigating the spectrum using colour filters G01J3/51
• CPC Class Codes: G01J 3/2823 Imaging spectrometer
• CPC Class Codes: G01J 3/46 Measurement of colour; Colour measuring devices, e.g. colorimeters measuring colour temperature G01J5/60
• CPC Class Codes: G01J 3/462 Computing operations in or between colour spaces; Colour management systems
• CPC Class Codes: G01J 3/463 Colour matching
• CPC Class Codes: G01J 3/465 taking into account the colour perception of the eye; using tristimulus detection
• CPC Class Codes: G01J 3/505 measuring the colour produced by lighting fixtures other than screens, monitors, displays or CRTs
• CPC Class Codes: G01J 3/51 using colour filters
• CPC Class Codes: G01J 3/524 Calibration of colorimeters
• CPC Class Codes: G03F 7/70058 Mask illumination systems
• CPC Class Codes: G06T 5/40 using histogram techniques
• CPC Class Codes: G06T 5/77 : Retouching; Inpainting; Scratch removal
• CPC Class Codes: G06T 7/90 : Determination of colour characteristics
• CPC Class Codes: G09G 2320/0276 : for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction
• CPC Class Codes: G09G 2320/043 : Preventing or counteracting the effects of ageing
• CPC Class Codes: G09G 2320/0606 : Manual adjustment
• CPC Class Codes: G09G 2320/0626 : for control of overall brightness
• CPC Class Codes: G09G 2320/066 : for control of contrast
• CPC Class Codes: G09G 2320/0666 : for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 2320/0693 : Calibration of display systems
• CPC Class Codes: G09G 2320/08 : Arrangements within a display terminal for setting, manually or automatically, display parameters of the display terminal
• CPC Class Codes: G09G 5/02 : characterised by the way in which colour is displayed details of colour display specific for CRTs G09G1/28; specific for flat matrix panels other than liquid crystal displays G09G3/2003; specific for liquid crystal displays G09G3/3607
• CPC Class Codes: H04N 1/6055 : using test pattern analysis
• CPC Class Codes: H04N 1/6058 : Reduction of colour to a range of reproducible colours, e.g. to ink- reproducible colour gamut
• CPC Class Codes: H04N 17/02 : for colour television signals
• CPC Class Codes: H04N 9/643 : Hue control means, e.g. flesh tone control
• CPC Class Codes: H04N 9/646 : for image enhancement, e.g. vertical detail restoration, cross-colour elimination, contour correction, chrominance trapping filters
• CPC Class Codes: H04N 9/69 : for modifying the colour signals by gamma correction controlling camera response for colour signals H04N23/83

Abstract

In a color imaging system, multiple rendering devices are provided at different nodes along a network. Each rendering device has a color measurement instrument for calibrating the color presented by the rendering device. A rendering device may be a printer in which the measuring of color samples on a sheet rendered by the printer is provided by a sensor coupled to a transport mechanism which moves the sensor and sheet relative to each other, where the sensor provides light from the samples to a spectrograph. A rendering device may also be a display having a member supporting a color measuring instrument for receiving light from an area of the screen. The color measuring instruments provide for non-contact measurements of color samples rendered on a display or a sheet, and are self-calibrating by the use of calibration references.

Claims

1. A quality control system comprising:

optics for collecting reflected, transmitted or emitted light from a surface or object;

a measurement module comprising an array of sensor elements and one of spectrally selective filters or light spectral dispersion element, wherein said measurement module receives said light collected by said optics and converts electrical signals of said sensor elements to data representative of the spectral distribution of said light, at least said measurement module is calibrated to enable CIE colorimetry traceable to a standard, and wherein said data represents one or more measurements;

one or more interfaces to an external computer;

one or more processors to control the conversion of said electrical signals and to communicate with said external computer;

a calibration reference associated with said measurement module enabling a user to verify the calibration of said system; and

software executable by at least one of said one or more processors or said external computer comprising;

one or more programs for producing a representation of said one or more measurements in terms of one or more CIE variables utilized in calculation of measures of variation with respect to one or more reference colors for the purpose of quality control and for performing said calculation of measures of variation;

a program that enables communication of at least one of said one or more measurements and said representation of said one or more measurements through at least one of said interfaces to said external computer;

one or more programs operable for storing a file having information in a plurality of fields and identifiers for said fields, said information comprising at least one of said representation of said one or more measurements, said one or more measurments, and results of said calculation of measures of variation; and

a program for storing at least part of said information in a database along with the times of said one or more measurements.

2. The system according to claim 1 wherein said computer system communicates, through a network interface, with one or more product prototyping nodes, wherein said system records color quality of production in relation to design specifications.

3. The system according to claim 1 further comprising a graphical user interface operable by said external computer that enables a user to configure processing of said one or more measurements or said representation of said one or more measurements by assembling graphical elements representing configured processes on a display, wherein said information further comprises results of said processing.

4. The system according to claim 3 wherein said measures of variation comprise color errors with respect to aim values of color of said surface or object and said computer system provides said information of color errors to controls of a production system.

5. The system according to claim 3 wherein access to said information is restricted in accordance with security settings in said software.

6. The system according to claim 3 further comprising a program for accessing said file, and a program that enables a user to visualize a rendering of color represented by said one or more measurements on a color rendering device.

7. The system according to claim 6 wherein said information further comprises the grayness of a color.

8. The system according to claim 6 wherein said rendering on said color rendering device is performed with the aid of a color profile.

9. The system according to claim 6 further comprising a program that displays an annotation upon said rendering.

10. The system according to claim 3 wherein at least said optics are mechanically moveable to measure said surface or object.

11. The system according to claim 10 wherein said surface or object moves with respect to said system enabling measurement of color of said surface or object in at least two spatial dimensions.

12. The system according to claim 1 wherein said software further comprises one or more programs executable by said external computer to enable one or more color output devices to render a representation of measured colors in accordance with a transformation from device independent coordinates to coordinates useable in rendering to said one or more color output devices, wherein said one or more color output devices comprise at least a printer.

13. The system according to claim 12 wherein said transformation is part of a color profile.

14. The system according to claim 13 wherein said color profile further comprises at least one of a gamut filter or a chromatic adaptation transform.

15. The system according to claim 1 further comprising a graphical user interface operable by said external computer, wherein said graphical user interface enables a user to visualize said representation of said one or more measurements in a three-dimensional coordinate system.

16. The system according to claim 15 wherein said graphical user interface further provides tutorial assistance for operating said system.

17. The system according to claim 15 further comprising a xenon illumination source and a reference spectral sensor to monitor variations in said xenon illumination.

18. A quality control system comprising:

optics for collecting reflected, transmitted or emitted light from a surface or object;

a measurement module comprising an array of sensor elements and one of spectrally selective filters or a light spectral dispersion element, wherein said measurement module receives said light collected by said optics and converts electrical signals of said sensor elements to data representative of the spectral distribution of said light, at least said measurement module is calibrated to a device independent standard, and said data represents one or more measurements;

one or more interfaces to an external computer;

one or more processors to control the conversion of said electrical signals and to communicate with said external computer;

a calibration reference associated with said measurement module enabling a user to verify the calibration of said system; and

software executable by at least one of said one or more processors or said external computer comprising;

one or more programs for producing a representation of said one or more measurements in accordance with the calibration of said system and in terms of at least one variable employed in calculation of measures of variation with respect to one or more references, and performing said calculation of said measures of variation, said measures of variation being used for quality control;

a program that enables communication of at least one of said one or more measurements and said representation of said one or more measurements through at least one of said interfaces to said external computer;

one or more programs operable for storing a file having information in a plurality of fields and identifiers for said fields, said information comprising at least one of said representation of said one or more measurments, said one or more measurements, and results of said calculation of measures of variation; and

a program for storing at least part of said information in a database along with the times of said one or more measurements.

19. The system according to claim 18 wherein said surface or object is scanned by said system to record rasters of image data.

20. The system according to claim 18 wherein said measurement module captures an image of at least part of said surface or object.

21. The system according to claim 20 wherein said array of sensor elements is a two-dimensional area array in which one dimension encodes spatial position along a line through an image of said surface or object and the other dimension encodes the spectrum of light energy at pixels along said line.

22. The system according to claim 21 wherein at least one of said two-dimensional area array and said surface or object move relative to the other to enable capture of multiple lines of image data.

23. The system according to claim 20 wherein said image is based upon said representation of said one or more measurements in terms of at least one variable employed in calculation of measures of variation and said system further comprises a program for preparing said image to be rendered on an output device.

24. The system according to claim 20 further comprising one or more programs for determining when values of said at least one variable are out of tolerance with respect to a reference for measurements and for providing information to a user concerning the variations of measurements with respect to one another or said reference for measurements.

25. The system according to claim 24 wherein said one or more programs for determining when values of said at least one variable are out of tolerance compare at least one histogram representing the distribution of said at least one variable in said image of at least part of said surface or object to a corresponding at least one histogram representing said reference for measurements.

26. The system according to claim 18 further comprising a graphical user interface operable by said external computer that enables a user to configure processing of said one or more measurements or said representation of said one or more measurements by assembling graphical elements representing configured processes on a display, wherein said information further comprises results of said processing.

27. The system according to claim 26 wherein at least said optics are mechanically moveable to measure said surface or object.

28. The system according to claim 27 wherein said surface or object moves with respect to said system enabling measurement of said surface or object in at least two dimensions.

29. The system according to claim 26 wherein said system provides information of said variations of measurements with respect to said one or more references for use by controls of a production system.