| 摘要 |
<p>PURPOSE:To obtain the effective inspecting method and quality criterion for securing high reliability principally in the high-temperature operation of an LCD from variation in the mean potential of a counter electrode about the means potential of picture element electrodes when the optical response ampli tude of the driving frequency component of liquid crystal is nearly the minimum. CONSTITUTION:An LCD panel 4 is held in a thermostatic chamber 1 and driven by a panel driver 12. Light passed through the LCD panel 4 is detected by a photomultiplier 5, the optical response of the liquid crystal is monitored on an oscilloscope 6, and its mean brightness is read on a digital voltmeter 7. Under the control of a computer 11, the counter electrode potential VCO which nearly minimizes the optical response amplitude of the driving frequency compo nent of the liquid crystal at temperature TL is measured. Then, the VCO is measured similarly at estimated temperature TH as an actual use limit. Then it is judged that the quality is normal when the difference between VCO corre sponding to the temperature TL and that corresponding to the temperature TH is <=2V and abnormal, when not. In general, TL=20 deg.C and TH=60 deg.C are proper values.</p> |
