Spectrophotometer with digital camera

• US 20050134853A1
• Filed: 12/17/2004
• Published: 06/23/2005
• Est. Priority Date: 12/19/2003
• Status: Active Grant

• Current Assignee: Datacolor AG Europe (Datacolor AG)
• Original Assignee: Applied Color Systems Inc
• Inventors: Slocum, David, Brill, Michael H., Ingleson, Alan
• Granted Patent: US 7,230,707 B2
• Time in Patent Office: Days
• US Class Current: 356/402
• CPC Class Codes: G01J 3/0251 Colorimeters making use of an integrating sphere
• CPC Class Codes: G01J 3/0262 Constructional arrangements for removing stray light
• CPC Class Codes: G01J 3/0264 Electrical interface; User interface
• CPC Class Codes: G01J 3/50 using electric radiation detectors
• CPC Class Codes: G01N 21/255 Details, e.g. use of specially adapted sources, lighting or optical systems
• CPC Class Codes: G01N 21/274 Calibration, base line adjustment, drift correction
• CPC Class Codes: G01N 21/57 Measuring gloss
• CPC Class Codes: G01N 2201/0642 Light traps; baffles
• CPC Class Codes: G01N 2201/065 Integrating spheres
• CPC Class Codes: G06T 7/90 Determination of colour characteristics

Abstract

Systems, methodologies, media, and other embodiments associated with color measuring are described. One exemplary system embodiment includes a spectrophotometer, one or more light sources for illuminating an interior of the spectrophotometer, and a digital camera configured at a port of the spectrophotometer and being configured to measure light components from a sample. In the present invention, segmentation logic is provided for the spectrophotometer that is configured to employ computational image segmentation to characterize specular reflection from a sample and to characterize a selected patch or portion from the test sample, such as a selected color in a multicolor pattern. In accordance with the present invention, the spectrophotometer and the included digital camera may be color-characterized in situ.

Claims

1. A method for color measuring, comprising:

collecting light signals from an illuminated sample using a multi-segmented detector;

dividing a total signal received by said detector into groups of one or more of said segments; and

determining respective color information for one or more of said divided groups.

2. The method of claim 1, wherein said multi-segmented detector comprises a digital camera.

3. The method of claim 2, wherein said segments comprise pixels.

4. The method of claim 1, wherein said groups are formed by segments receiving signals having similar color properties.

5. The method of claim 1, further comprising color-characterizing said multi-segmented detector with standard test samples.

6. An apparatus for color measuring, comprising:

a spectrophotometer;

at least one light source for illuminating an interior of the spectrophotometer and at least one sample; and

a multi-segmented detector configured at a port of the spectrophotometer and being adapted to measure light components from said at least one sample.

7. The apparatus of claim 6, wherein said spectrophotometer comprises an integrating-sphere.

8. The apparatus of claim 6, wherein said multi-segmented detector comprises a digital camera.

9. The apparatus of claim 6, further comprising at least one photometer for measuring light components from standard test samples for use in color-characterizing at least one of said multi-segmented detector and said spectrophotometer.

10. The apparatus of claim 6, wherein one of said at least one light sources is configured to directly illuminate the at least one sample, and the at least one sample and the multi-segmented detector are apposed to a direction of the light from said one of said at least one light source to form a specular path connecting the light, the sample, and the multi-segmented detector.

11. The apparatus of claim 10, wherein said one of said at least one light sources comprises a light projector that projects an illuminated grid image onto the sample which is captured by the multi-segmented detector.

12. The apparatus of claim 11, wherein said captured illuminated grid image is used to determine if a sample port of said spectrophotometer is opened or closed, and if open, the size of the opening.

13. The apparatus in claim 6, wherein one of said at least one light sources is configured to diffusely illuminate the sample, and the multi-segmented detector is configured to capture spatial variations in the color of the sample.

14. A computer-readable medium configured to provide processor executable instructions operable to perform a method, the method comprising:

illuminating a test sample within an integrating sphere;

measuring optical signals received from the test sample; and

color-characterizing a digital camera based on the optical signals received where the digital camera is operably connected to the integrating sphere.

15. A computer-readable medium configured to provide processor executable instructions operable to perform a method, the method comprising:

receiving an image generated from measured light signals from a color sample;

selecting a region of interest from within the image; and

determining color information for the selected region of interest independently from other areas of the image.

16. The computer-readable medium of claim 15 where the processor executable instructions are embodied as a graphical user interface.

17. A color measuring system, comprising:

a spectrophotometer for providing and directing light signals from a sample;

at least one light source for illuminating an interior of said spectrophotometer and said sample; and

a digital camera configured in a port of the spectrophotometer and being configured to measure the light signals from the sample;

selection logic configured to enable a region of interest to be selected from the measured light signals; and

analysis logic adapted to determine color information from the region of interest separately from other measured light signals.

18. The color measuring system of claim 17, further comprising:

calibration logic configured to calibrate or characterize the digital camera using the measured light signals and known color values for the sample.

19. The color measuring system of claim 17, further comprising:

logic configured to determine a size of an aperture of a sample port using the measured light signals from the digital camera.

20. The color measuring system of claim 17, wherein said digital camera is adapted to measure optical radiation from the sample and generate image data of the sample and to communicate the image data to a computing device using wireless communication.

21. The color measuring system of claim 17, wherein said color measuring system comprises a plurality of modes of operation including at least a spectrophotometer mode, a mode used to characterize the specular-reflected component of a material, a mode used to image a variegated sample and a mode used to perform shape measurement of a three-dimensional sample.

22. The color measuring system of claim 21, wherein said at least one light source comprises at least two light sources and a light projector that projects an illuminated grid image onto the sample and wherein said color measuring system switches between modes of operation by activating and deactivating specific ones of said light sources.