# US 8,570,498 B2 · Filters, illuminants, and customized spectral profiles for reducing perceptible changes in appearance > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,570,498 B2 - Document ID: US8570498B2 - Status: Granted - Kind: B2 - Application number: 12/780,546 - Filed: 2010-05-14 - Published: 2010-11-18 - Granted: 2013-10-29 - Earliest claimed: 2009-05-15 - Assignees: Board of Regents, The University of Texas System - Applicants: Carl W. Dirk - Inventors: Carl W. Dirk - Web page: https://patentgrep.com/patent/US8570498B2 ## CPC - G01J 3/46: Measurement of colour; Colour measuring devices, e.g. colorimeters (measuring colour temperature G01J5/60) - G01N 21/255: {Details, e.g. use of specially adapted sources, lighting or optical systems} - G01N 21/29: using visual detection (G01N21/31 takes precedence) - G01J 2001/0276: {Protection} - G01J 2003/1282: {Spectrum tailoring} - G01J: MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY (light sources F21, H01J, H01K, H05B; investigating properties of materials by optical means G01N) - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) ## Abstract Customized spectral profiles, and filters and illuminants having a customized spectral profile, optimized to reduce light in one or more wavelength regions for which one or more pigments are relatively more susceptible to perceptible changes in appearance. ## Claims ### Claim 1 A method of generating a customized spectral profile, the method comprising: determining for one or more pigments one or more wavelength regions for which the one or more pigments are relatively more susceptible to perceptible changes in color than for one or more other less-susceptible wavelength regions; optimizing a spectral profile to generate a customized spectral profile such that an illuminant or filter configured to have the customized spectral profile will reduce light in the one or more more-susceptible wavelength regions. ### Claim 2 (depends on 1) The method of claim 1, where optimizing further includes optimizing the spectral profile to generate a customized spectral profile such that an illuminant or filter configured to have the customized spectral profile will reduce light to a lesser degree in the one or more less-susceptible wavelength regions than in the one or more more-susceptible wavelength regions. ### Claim 3 (depends on 2) The method of claim 2, where at least one less-susceptible wavelength region is less susceptible to photochemical damage than at least one more-susceptible wavelength region. ### Claim 4 (depends on 1) The method of claim 1, where the step of optimizing further comprises optimizing the custom spectral profile such that an illuminant or filter configured to have the customized spectral profile will also have a color rendering index (CRI) of at least 85 for the one or more pigments relative to an unfiltered reference illuminant. ### Claim 5 (depends on 4) The method of claim 4, where the step of optimizing further comprises optimizing the custom spectral profile such that an illuminant or filter configured to have the customized spectral profile will also have a color rendering index (CRI) of at least 90 for the one or more pigments relative to an unfiltered reference illuminant. ### Claim 6 (depends on 5) The method of claim 5, where the step of optimizing further comprises optimizing the custom spectral profile such that that an illuminant or filter configured to have the customized spectral profile will also have a color rendering index (CRI) of at least 95 for the one or more pigments relative to an unfiltered reference illuminant. ### Claim 7 (depends on 4) The method of claim 4, where the unfiltered reference illuminant is an incandescent lamp having a color temperature of about 3000K. ### Claim 8 (depends on 1) The method of claim 1, where the step of determining comprises: obtaining a reflection spectrum for the one or more pigments; and determining color change susceptibility (CCS) of the one or more pigments across the reflection spectrum. ### Claim 9 (depends on 8) The method of claim 8, where the step of optimizing comprises: identifying one or more peaks or shoulders of CCS across the reflection spectrum for the one or more pigments, the peaks or shoulders each corresponding to a wavelength region in which the pigment is relatively more susceptible to damage causing perceptible changes in appearance; and modifying the customized spectral profile to reduce light in the one or more wavelength regions. ### Claim 10 (depends on 8) The method of claim 8, where the step of determining CCS comprises calculating a color change or change in color rendering per unit change in reflectance across the reflection spectrum for the pigment. ### Claim 11 (depends on 8) The method of claim 8, where the step of obtaining a reflection spectrum comprises imaging the reflection spectrum with a spectral imaging camera or other spectral imaging device controlled by suitably programmed software. ### Claim 12 (depends on 1) The method of claim 1, where the step of determining comprises determining two or more wavelength regions in which the one or more pigments are relatively more susceptible to damage causing perceptible changes in appearance, and where modifying comprises modifying the customized spectral profile to reduce light in each of the two or more wavelength regions. ### Claim 13 (depends on 12) The method of claim 12, further comprising: coupling one or more filter layers to a substrate such that the substrate and filter layers are configured to have the customized spectral profile. ### Claim 14 (depends on 12) The method of claim 12, further comprising: coupling one or more filter layers to an illuminant such that, if the illuminant is energized, the filter layers are configured to filter light from the illuminant according to the customized spectral profile. ### Claim 15 A method of generating a customized spectral profile, the method comprising: determining for an image a plurality of wavelength regions in which one or more pigments of the image are relatively more susceptible to damage causing perceptible changes in appearance; optimizing a custom spectral profile for a filter or illuminant to reduce light in each of the wavelength regions. ### Claim 16 An apparatus comprising: an illuminant configured to emit light if the illuminant is energized; a plurality of filter layers coupled to the illuminant; where the apparatus is configured such that, if the illuminant is energized and emits light, the filter layers will: (a) block a portion of the light having wavelengths in one or more selected wavelength regions in which one or more pigments are relatively more susceptible to damage causing perceptible changes in appearance, and (b) transmit a portion of the light such that the transmitted light has a color rendering index of at least 85 for the one or more pigments relative to the illuminant without filter layers. ### Claim 17 (depends on 16) The apparatus of claim 16, where the filter layers are physically coupled to the illuminant. ### Claim 18 (depends on 17) The apparatus of claim 17, where one or more of the filter layers are in direct contact with the illuminant.