| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a dimming element that can reduce a ratio of a non-operating state to an operating state of a polymer dispersed liquid crystal, in comparison with a direct application of AC voltage from a commercial power supply to a transparent electrode, and that can achieve high degree of transparency. <P>SOLUTION: A liquid crystal dimmer comprises: a liquid crystal dimming element 10 including a pair of transparent electrodes 2 which faces each other and respectively disposed on a pair of insulating substrates 1, and a liquid crystal layer 3 of polymer dispersed liquid crystal, which is sandwiched between the pair of insulating substrates 1 and formed by dispersing liquid crystal into a polymer matrix; and a waveform conversion unit 20 for converting a voltage supplied from a power supply 200 into an AC voltage which has a crest value higher than a threshold voltage V<SB POS="POST">th</SB>and whose polarity is alternately inverted at zero-cross point, and for applying the AC voltage to the pair of transparent electrodes 2. The ratio of a time period when the AC voltage is equal to or higher than the threshold voltage V<SB POS="POST">th</SB>in a half-period of the AC voltage to the half-period, is greater than the ratio a time period when a voltage of a commercial power supply 201 is equal to or higher than the threshold voltage V<SB POS="POST">th</SB>in a half-period of the commercial power supply to the half-period. <P>COPYRIGHT: (C)2013,JPO&INPIT |
