Method for designing a colorimeter having integral CIE color-matching filters

• US 7,420,680 B2
• Filed: 11/16/2005
• Issued: 09/02/2008
• Est. Priority Date: 11/16/2004
• Status: Expired due to Fees

• Current Assignee: Datacolor Holding AG
• Original Assignee: Datacolor Holding AG
• Inventors: Vrhel, Michael, Slocum, David, Shannon, Colman
• Primary Examiner(s): Punnoose; Roy M
• Application Number:
  US11/281,766
• Publication Number:
  US 20060103864A1
• Time in Patent Office: 1,021 Days
• Field of Search: 356/416, 356/418, 356/419
• US Class Current: 356/419
• CPC Class Codes: G01J 2003/467 Colour computing
• 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 3/465 taking into account the colour perception of the eye; using tristimulus detection
• CPC Class Codes: G01J 3/51 using colour filters
• CPC Class Codes: G01J 3/513 having fixed filter-detector pairs

Abstract

A method for determining the optimal colorant thicknesses for integral CIE color-matching filters is provided. According to a computational study, a four band filter of the present invention provides a best approximation to the CIE XYZ color-matching functions with the least cost.

Claims

1. A method for designing a colorimeter having integral CIE-like color-matching filters, comprising:

determining a set of channels from a plurality of channels;

determining a set of filters, each filter being permanently deposited on each of the channels, each filter being an absorptive filter, each filter having at least one layer, at least one channel having at least one filter with a double layer so that a linear combination of the set of channels matches a set of CIE-like target color-matching functions within a tolerance, each channel integrating at least one detector and at least one filter onto a single semiconductor substrate;

determining a colorant for each layer on each channel from a set of colorants; and

determining a thickness of each layer on each channel.

2. The method of claim 1, further comprising:

determining the linear combination of channels to approximate each of the CIE-like target color-matching functions in the set of CIE-like target color-matching functions.

3. The method of claim 1, wherein the channels are substantially identical prior to attachment of the filters.

4. The method of claim 1, wherein the selection of the colorant for each channel and the colorant thickness for each layer on each channel is performed by:

generating a set of potential solutions, the set of potential solutions including the set of colorants to be apportioned in colorant layers to comprise the filter for each channel, a particular number of colorant layers for each filter, and a thickness of each colorant layer for each channel.

5. The method of claim 4, further comprising:

selecting a solution from the set of potential solutions by minimizing the number of channels needed to match the CIE-like target color-matching functions within the tolerance, by minimizing the number of colorant layers per channel without increasing the number of channels needed to match the CIE-like target color-matching functions within the tolerance, and by minimizing deviations in performance under the influence of colorant layer thickness variations; and

providing the solution, the solution including the set of channels, the colorant for each layer of each channel, and the thickness of each layer needed to match the CIE-like target color-matching functions within the tolerance.

6. The method of claim 5, wherein selecting the solution further comprises:

optimizing colorant selection end layer thicknesses for a best match to the CIE-like target color-matching functions; and

optimizing channel coefficients for the best match to the CIE-like target color-matching functions.

7. The method of claim 5, wherein selecting the solution further comprises:

testing the potential solutions for layer thickness variation;

sorting the potential solutions by a figure of merit value;

selecting the solution from the potential solutions by configuration type and layer structure.

8. The method of claim 5, wherein matching the CIE-like target color-matching functions within the tolerance includes computing an error measure for a test monitor spectra.

9. The method of claim 5, further comprising:

comparing and storing results for the potential solutions.

10. The method of claim 5, further comprising:

providing a plot of the solution and the target color-matching functions.

11. The method of claim 5, further comprising:

providing quantitative color differences between the solution and the target color-matching functions.