Method and setup for performing a series of optical measurements with a 2D imaging system
A method for performing a series of optical measurements on an activated display, whether or not it has already been mounted in an actual display device, the activated display having an optical characteristic with a performance that changes during and/or between the measurements of the series of optical measurements that are configured as a sequence of measurements comprising a pair of identical 2D image measurements or a pair of identical spot measurements in combination with a 2D image measurement to determine at least one of luminance, color-point and spectral distribution of emitted light, and the distributions of luminance and color-point over the entire light-emitting area of the activated display with an improved accuracy. An optical measurement setup for performing the series of optical measurements in accordance with the method.
1. A method for performing a series of optical measurements with a 2D imaging system on an activated display that has an optical characteristic with a performance that changes during and/or between the measurements of the series of optical measurements, wherein an improved comparability is achieved for values for the optical characteristic that are determined based on measurement results for the optical characteristic that are obtained by performing the series of optical measurements, the method comprising the steps of:
configuring the 2D imaging system to perform each optical measurement of the series of optical measurements as a sequence of measurements to obtain for each optical measurement a respective set of measurement results for the optical characteristic; and
determining for each optical measurement of the series of optical measurements a respective value for the optical characteristic by performing time-averaging of the measurement results of the respective set of measurement results of the respective optical measurement,
wherein configuring the 2D imaging system to perform each optical measurement of the series of optical measurements as a sequence of measurements to obtain for each optical measurement a respective set of measurement results for the optical characteristic comprises:
determining a total time interval during which the series of optical measurements is performed by adding up the respective time intervals during which each respective optical measurement of the series of optical measurements is performed; and
configuring the sequence of measurements to comprise at least one pair of identical 2D image measurements, wherein a first 2D image measurement of a first pair of identical 2D image measurements is performed during a first time interval using a first optical filter of a first type to obtain a first measurement result of the set of measurement results, and a second 2D image measurement of the first pair of identical 2D image measurements is performed during a second time interval using said first optical filter of the first type to obtain a second measurement result of the set of measurement results, wherein the first time interval and the second time interval are non-overlapping and mirrored with respect to the center of the total time interval,
wherein the sequence of measurements is configured to comprise a second pair of identical 2D image measurements,
wherein a third 2D image measurement of the second pair of identical 2D image measurements is performed during a third time interval using a second optical filter of a second type to obtain a third measurement result of the set of measurement results, and a fourth 2D image measurement of the second pair of identical 2D image measurements is performed during a fourth time interval using said second optical filter of the second type to obtain a fourth measurement result of the set of measurement results,
wherein the third time interval and the fourth time interval of the second pair of identical 2D image measurements are non-overlapping neither with each other nor with the first time interval and the second time interval of the first pair of identical 2D image measurements, and
wherein the third time interval and the fourth time interval of the second pair of identical 2D image measurements are also mirrored with respect to the center of the total time interval.
2. The method according to claim 1 , wherein the sequence of measurements is configured to comprise a third pair of identical 2D image measurements, wherein a fifth 2D image measurement of the third pair of identical 2D image measurements is performed during a fifth time interval using a third optical filter of a third type to obtain a fifth measurement result of the set of measurement results, and a sixth 2D image measurement of the third pair of identical 2D image measurements is performed during a sixth time interval using said third optical filter of the third type to obtain a sixth measurement result of the set of measurement results, wherein the fifth time interval and the sixth time interval of the third pair of identical 2D image measurements are non-overlapping neither with each other nor with the first time interval and the second time interval of the first pair of identical 2D image measurements and the third time interval and the fourth time interval of the second pair of identical 2D image measurements, and wherein the fifth time interval and the sixth time interval of the third pair of identical 2D image measurements are also mirrored with respect to the center of the total time interval.
3. The method according to claim 1 , wherein the optical characteristic of the activated optical display is one of luminance, color-point and spectral distribution, and wherein using the values that are determined by performing time-averaging of the measurement results of the respective set of measurement results, x and y chromaticity coordinates in accordance with the CIE 1931 xy chromaticity diagram are determined for one of luminance, color-point and spectral distribution with an improved accuracy that is less than 0.002.
4. A method for performing a series of optical measurements with a 2D imaging system on an activated display that has an optical characteristic with a performance that changes during and/or between the measurements of the series of optical measurements, wherein an improved comparability is achieved for values for the optical characteristic that are determined based on measurement results for the optical characteristic that are obtained by performing the series of optical measurements, the method comprising the steps of:
configuring the 2D imaging system to perform each optical measurement of the series of optical measurements as a sequence of measurements to obtain for each optical measurement a respective set of measurement results for the optical characteristic; and
determining for each optical measurement of the series of optical measurements a respective value for the optical characteristic by performing time-averaging of the measurement results of the respective set of measurement results of the respective optical measurement,
wherein configuring the 2D imaging system to perform each optical measurement of the series of optical measurements as a sequence of measurements to obtain for each optical measurement a respective set of measurement results for the optical characteristic comprises:
configuring the sequence of measurements to comprise at least one pair of identical spot measurements and a first 2D image measurement, wherein a first spot measurement of a first pair of identical spot measurements is performed during a first time interval to obtain a first measurement result of the set of measurement results, a second spot measurement of the first pair of identical spot measurements is performed during a second time interval to obtain a second measurement result of the set of measurement results, and the first 2D image measurement is performed during a third time interval using a first optical filter of a first type to obtain a third measurement result of the set of measurement results, wherein the first time interval, the second time interval and the third time interval are non-overlapping and wherein the first time interval and the second time interval are mirrored with respect to the center of the third time interval,
wherein the sequence of measurements is configured to comprise a second pair of identical spot measurements and a second 2D image measurement, wherein a third spot measurement of the second pair of identical spot measurements is performed during a fourth time interval to obtain a fourth measurement result of the set of measurement results, a fourth spot measurement of the second pair of identical spot measurements is performed during a fifth time interval to obtain a fifth measurement result of the set of measurement results, and said second 2D image measurement is performed during a sixth time interval using a second optical filter of a second type to obtain a sixth measurement result of the set of measurement results, wherein the fourth time interval, the fifth time interval and the sixth time interval of the second pair of identical spot measurements and said second 2D image measurement, respectively are non-overlapping neither with each other nor with the first time interval, the second time interval and the third time interval of the first pair of identical spot measurements and said first 2D image measurement, respectively, and wherein the fourth time interval and the fifth time interval are mirrored with respect to the center of the sixth time interval.
5. The method according to claim 3 , wherein the sequence of measurements is configured to comprise a third pair of identical spot measurements and a third 2D image measurement, wherein a fifth spot measurement of the third pair of identical spot measurements is performed during a seventh time interval to obtain a seventh measurement result of the set of measurement results, a sixth spot measurement of the third pair of identical spot measurements is performed during an eighth time interval to obtain an eighth measurement result of the set of measurement results, and said third 2D image measurement is performed during a ninth time interval using a third optical filter of a third type to obtain a ninth measurement result of the set of measurement results, wherein the seventh time interval, the eighth time interval and the ninth time interval of the third pair of identical spot measurements and said third 2D image measurement, respectively are non-overlapping neither with each other nor with any one of the first time interval, the second time interval and the third time interval of the first pair of identical spot measurements and said first 2D image measurement, respectively, and the fourth time interval, the fifth time interval and the sixth time interval of the second pair of identical spot measurements and said second 2D image measurement, respectively, and wherein the seventh time interval and the eighth time interval are mirrored with respect to the center of the ninth time interval.
6. The method according to claim 4 , wherein the optical characteristic of the activated optical display is one of luminance, color-point and spectral distribution, and wherein using the values that are determined by performing time-averaging of the measurement results of the respective set of measurement results, x and y chromaticity coordinates in accordance with the CIE 1931 xy chromaticity diagram are determined for one of luminance, color-point and spectral distribution with an improved accuracy that is less than 0.002.
7. An optical measurement setup for performing a series of optical measurements on an activated display that has an optical characteristic with a performance that changes during and/or between the measurements of the series of optical measurements, wherein an improved accuracy is achieved for values for the optical characteristic that are determined based on measurement results for the optical characteristic that are obtained by performing the series of optical measurements, the optical measurement setup comprising:
a 2D imaging system that is configured and arranged to allow performing a series of optical 2D image measurements on the activated display;
a spot measurement system that is configured and arranged to allow performing a series of optical spot measurements on the activated display; and
a processing unit comprising a memory unit that is provided with computer instructions, the processing unit being operatively connected with at least one of the 2D imaging system and the spot measurement system for receiving the measurement results for the optical characteristic of the activated display in the memory unit, wherein the computer instructions, when being executed on said measurement results, perform the steps of
configuring the 2D imaging system to perform each optical measurement of the series of optical measurements as a sequence of measurements to obtain for each optical measurement a respective set of measurement results for the optical characteristic; and
determining for each optical measurement of the series of optical measurements a respective value for the optical characteristic by performing time-averaging of the measurement results of the respective set of measurement results of the respective optical measurement,
to determine based on said measurement results, values for the optical characteristic with the improved accuracy, and
wherein the 2D imaging system comprises a beam splitter that is configured and arranged to enable a spot measurement and a 2D image measurement to be performed simultaneously on the activated display.