Abstract
TFT-LCD (thin film transistor liquid crystal display) industry is one of the most important industries in Taiwan. Light-on test is one of the visual inspection tasks in TFT-LCD panels manufacturing. The operators of the light-on test inspection are working in a high luminance ratio (low ambient illumination and highly local illumination) environment. The purpose of this study was to examine the effects of different local illumination and work-rest schedule on inspectors' visual fatigue and task performance. A total of 9 well-trained female operators participated in this experiment. The experiment involved four levels of local illumination: (1) 2600 lx (with original lamp); (2) 6000 lx (with new lamp); (3) 2600 lx (with new lamp plus polarizer panel), and (4) 1900 lx (with new lamp plus polarizer panel and lamp half-covered). The work-rest schedule had two different conditions: (1) working 29 minutes and resting 1 minute, then repeat once, and (2) working 58 minutes and resting 2 minutes. At the beginning and the end of each experiment combination, the subjects took critical fusion flicker (CFF) tests to measure their visual fatigue. The results showed that the local illumination effect was significant on task performance. Using new lamp (6000 lx) and new lamp plus polarizer panel (2600 lx) had lower miss rate than the original lamp (2600 lx). It seems that increasing local illumination to 6000 lx, and using polarizer panel to reduce high contract can enhance the inspection performance. The results also showed that the local illumination and work-rest schedule did not show significant influence on visual fatigue. This might due to the operators were adapted to the work environment. A further study is necessary to involve more environmental illumination factors in evaluating the light-on test inspection. © 2013 Taylor & Francis Group.