TY - JOUR
T1 - A method for evaluating luminance non-uniformity of displays by use of a commercially available digital camera
AU - Kawamoto, Keishin
AU - Tokurei, Shogo
AU - Morishita, Junji
N1 - Funding Information:
The authors are grateful to Yongsu Yoon, M.Sc., Yusuke Matsunobu, M.Sc., Yoichiro Shimizu, M.Sc., Shun Tsubaki, M.Sc., and Hitomi Nakamura, B.Sc., for useful discussions. We also thank Noriyuki Hashimoto (EIZO Corporation, Ishikawa, Japan) for helpful discussions. We are grateful to the editorial assistant of this journal, Mrs. Lanzl, for providing initial and final polishing of our manuscript to improve the readability and English expressions, and the reviewers for giving us useful comments and suggestions for improving our manuscript. J Morishita received technical support from the EIZO Corporation (Ishikawa, Japan).
Publisher Copyright:
© 2017, Japanese Society of Radiological Technology and Japan Society of Medical Physics.
PY - 2017/12/1
Y1 - 2017/12/1
N2 - The luminance uniformity of liquid–crystal displays (LCDs) deteriorates with their prolonged use. In this paper, we present a method for evaluating the degree of luminance non-uniformity of LCDs with the use of a commercially available digital camera. In this study, seven monochrome LCDs, which were used during various operating times ranging from 5000 to 25,000 h, were evaluated with use of a camera. The maximum luminance deviation (MLD) was measured on the two-dimensional (2D) images obtained with the camera. In addition, an index of the luminance non-uniformity was calculated as the ratio of the area exhibiting luminance non-uniformity to the area of the entire LCD screen. We determined the area with the luminance non-uniformity by setting the allowable luminance deviation as the judgment criterion to evaluate the degree of luminance non-uniformity. The MLD values were less than 20% for all conditions, and they varied depending on the locations of the luminance measurement. The area ratios of the luminance non-uniformity based on 2D luminance distributions tended to increase with the duration of use of LCDs, and they indicated the degree of luminance non-uniformity of the LCDs regardless of the measurement locations. Our approach of using a commercially available digital camera showed its potential usefulness for providing more detailed and consistent evaluations of the degree of luminance non-uniformity of LCDs based on the 2D luminance distributions.
AB - The luminance uniformity of liquid–crystal displays (LCDs) deteriorates with their prolonged use. In this paper, we present a method for evaluating the degree of luminance non-uniformity of LCDs with the use of a commercially available digital camera. In this study, seven monochrome LCDs, which were used during various operating times ranging from 5000 to 25,000 h, were evaluated with use of a camera. The maximum luminance deviation (MLD) was measured on the two-dimensional (2D) images obtained with the camera. In addition, an index of the luminance non-uniformity was calculated as the ratio of the area exhibiting luminance non-uniformity to the area of the entire LCD screen. We determined the area with the luminance non-uniformity by setting the allowable luminance deviation as the judgment criterion to evaluate the degree of luminance non-uniformity. The MLD values were less than 20% for all conditions, and they varied depending on the locations of the luminance measurement. The area ratios of the luminance non-uniformity based on 2D luminance distributions tended to increase with the duration of use of LCDs, and they indicated the degree of luminance non-uniformity of the LCDs regardless of the measurement locations. Our approach of using a commercially available digital camera showed its potential usefulness for providing more detailed and consistent evaluations of the degree of luminance non-uniformity of LCDs based on the 2D luminance distributions.
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U2 - 10.1007/s12194-017-0412-7
DO - 10.1007/s12194-017-0412-7
M3 - Article
C2 - 28815467
AN - SCOPUS:85027489301
SN - 1865-0333
VL - 10
SP - 409
EP - 414
JO - Radiological physics and technology
JF - Radiological physics and technology
IS - 4
ER -