Color measurement instrument with modulated illumination
First Claim
Patent Images
1. A method for measuring optical properties of a sample comprising:
- illuminating the sample including driving a plurality of light sources each having a unique spectral energy distribution and each modulated at a continuous frequency, said illuminating step further including providing servo control of each light source;
detecting composite light including modulated sample light reflected by the sample from the modulated light sources; and
filtering the composite light to separate the sample light at each of the continuous modulated frequencies from the composite light.
12 Assignments
0 Petitions
Accused Products
Abstract
An instrument and method for measuring light or color using modulated illumination. The system includes an LED illuminator modulated at a specific frequency for illuminating the sample, and a sensor capable of differentiating between the modulated light from the sample and unmodulated ambient light. The instrument is therefore capable of “seeing” only light from the sample, while ignoring ambient light. In a second embodiment, the system includes multiple illuminators of different colors each modulated at a unique frequency so that the sample can be measured at multiple at each of the different frequencies.
-
Citations
28 Claims
-
1. A method for measuring optical properties of a sample comprising:
-
illuminating the sample including driving a plurality of light sources each having a unique spectral energy distribution and each modulated at a continuous frequency, said illuminating step further including providing servo control of each light source;
detecting composite light including modulated sample light reflected by the sample from the modulated light sources; and
filtering the composite light to separate the sample light at each of the continuous modulated frequencies from the composite light. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A method for measuring optical properties of a sample comprising:
-
illuminating the sample including driving a plurality of illumitlators outputting different colors each at a continuous modulated frequency, said illuminating step further including providing closed loop control of the driving step to compensate for nonlinearity of the illuminators;
detecting composite light including modulated sample light reflected by the sample from the illuminators; and
filtering the composite light including filtering at each continuous modulated frequency to discriminate between sample light and other light within the composite light. - View Dependent Claims (9, 10, 11, 12, 13, 14)
-
-
15. An instrument for measuring optical properties of a sample comprising:
-
illumination means for illuminating the sample, said illumination means including a plurality of spectrally unique light sources each modulated at a continuous frequency, said illumination means further including servo means for providing servo control for each of said light sources;
detector means for detecting composite light including light of interest reflected by the sample from said illuminators, the composite light also including light not of interest reflected by the sample from other light sources; and
filter means for filtering the composite light to separate the light of interest at each frequency from the light not of interest. - View Dependent Claims (16, 17, 18, 19, 20, 21)
-
-
22. An instrument for measuring optical properties of a sample comprising:
-
illumination means for illuminating the sample with a plurality of light colors each modulated at a continuous frequency, said illumination means including illuminator for each of the light colors, said illumination means further including control means for providing closed loop control of said illuminators to compensate for the nonlinearity of said illuminators;
detector means for detecting composite light including (a) sample light of interest reflected by the sample from said illumination means and (b) sample light not of interest reflected by the sample from other light sources; and
filtering means for filtering the composite light at the continuous frequency of each light color to separate the sample light of interest from the sample light not of interest. - View Dependent Claims (23, 24, 25, 26, 27, 28)
-
Specification