System and apparatus for improved low reflectance color measurement
AssigneeDatacolor Inc.
InventorZhiling Xu
Life of this patent
Estimating the term…
Abstract
An apparatus and system for providing a solution that enables technicians or other technical professionals obtain an accurate color value for a sample regardless of the reflectance properties. The present invention allows for the generation of high precision reflectance information using improved composite measurements.
Claims18
An apparatus for measuring the color or reflectance of a sample comprising:
- a plurality of reference targets of known reflectance value, each reference target having a reflective surface, wherein, at all of a selected set of measurement wavelengths, at least one reference target reflects a greater fraction of light projected on its surface than at least one of the other reference targets;
- an activated variable intensity light source having a light output, configured to project light in the direction of one of the plurality of targets and the sample having a color characteristic to be measured;
- at least one color sensor positioned as a sample channel so as to receive light reflected from one of the plurality of targets and sample and output a measured color value;
- at least one reflectance sensor positioned as a reference channel so as to receive light reflected from a light division device prior to contact with one of the target or sample and output a reference value;
- and
- a processor configured to compare the output from the sample channel to the output of the reference channel and generate a computed measurement value that is substantially free of variations of the activated light source;
- the processor further configured to compare the known reflectance value of each of the plurality targets to the computed measurement value obtained from at least one of the reference targets and generate an adjustment value;
- the processor further configured to generate a computed measurement value of a sample and adjust the computed measurement value of the sample by the adjustment value and output the result.
A computer-implemented method for utilizing a particular connection with an electronic device in combining different illumination intensities to achieve a reflectance value of a sample using a spectrometer device having a plurality of known reference value targets, a processor, a memory, an input device, an output device;
- and a compensation application stored in the memory and executable by the processor, the method comprising:
- generating a sample channel value from a color sensor related to the surface characteristics possessed by at least one of the plurality of reference targets and generating a reference channel value from a reference sensor wherein the reference channel value is related to the variation in the light projected onto the reference target;
- generating a target measurement value based on the comparison of the sample channel value with the reference channel value using the processor by executing the compensation application so as to identify a component of the sample channel value due to intensity variations;
- comparing the target measurement value to the known reflectance value of the target to obtain a calibration value;
- obtaining a sample channel value from a color sensor related to the surface characteristics possessed by the sample and obtaining a reference channel value from a reference sensor wherein the reference channel value is related to the variation in the light projected onto the sample;
- comparing the sample channel value with the reference channel value using the processor by executing the compensation application so as to identify a component of the sample channel value due to intensity variations to obtain a sample measurement value;
- generating a calibrated measurement value by adjusting the sample measurement value with the calibration value;
- and
- outputting the calibrated measurement value as a visual indicator on a display device.
Dependencies are inferred from the claim text.