| 摘要 |
PURPOSE:To uniformize the luminance on both surfaces, by respectively providing an upper and lower electrodes on the upper and lower ends of counter electrodes and respectively applying an AC voltage of a prescribed amplitude and a prescribed DC voltage across one end and the other end of the counter electrodes. CONSTITUTION:Since an upper electrode 72 is connected with a connecting point P1, a voltage of 0Vp-p is always applied across the electrode 72 and, since a lower electrode 73 is connected with a connecting point P2 at the time of an odd field and another connecting point P3 at the time of an even field, a voltage of 4Vp-p in amplitude is applied across the electrode 73. Therefore, the voltage is divided in a transparent electrode 71 by means of equivalent resistances in a column direction and a voltage gradient is produced in the electrode 71 and, as a result, voltage waveforms of different amplitudes are applied across at every row. Therefore, even when the potential across the counter electrodes fluctuates while the voltage waveform impressed upon a liquid crystal cell 1 is maintained, the mean values of the effective values of voltages VP1, VP2,...VPN applied across the liquid crystal cell 1 of each row become almost equal to each other in the column direction and the luminance at the lower sections of both surfaces is not reduced, since the amplitude of the counter electrodes is made larger as going to lower rows. Therefore, the luminance on both surfaces becomes uniform.
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