Patent ID: 6873319

Claim:
A driving circuit of a liquid crystal device for driving a plurality of pixels, having pixel electrodes, a counter electrode opposing the pixel electrodes and to which a constant reference voltage is applied, so as to be turned on or off according to tone data, and a liquid crystal interposed between the pixel electrodes and the counter electrode, the pixels being disposed at intersections between a plurality of data lines and a plurality of scanning lines, said driving circuit comprising: a data converting circuit that generates a binary signal indicating that a given pixel is turned on or off in each of a plurality of sub-fields divided from each field corresponding to a non-linear relationship between an effective voltage applied to the liquid crystal and a relative transmittance or reflectance, a period of each sub-field relative to one field being set to achieve the effective voltage corresponding to the tone data, the data converting circuit generating the binary signal from the tone data in each sub-field per pixel so that the proportion of the period during which the pixel is turned on to the period during which the pixel is turned off within one field corresponds to the proportion according to the tone data; and a data line driving circuit that applies a voltage to turn on or off the pixel to the data lines according to the binary signal from said data converting circuit, and, when the pixel is turned on, switches any one of a first voltage which is higher than the constant reference voltage and a second voltage which is lower than the constant reference voltage at a predetermined time interval to apply it to the data line to which the pixel is connected; each of the plurality of scanning lines includes a first scanning line and a second scanning line, said driving circuit further comprising a scanning line driving circuit for supplying a first scanning signal to the first scanning line and a second scanning signal, having a signal polarity opposite to the first scanning signal, to the second scanning line, the pixels being connected to the data lines via complementary switching elements connected to the first scanning line and the second scanning line; and the voltage level at which the first scanning signal allows the switching element connected to the first scanning line to be turned on and the voltage level of the first voltage are the same, and the voltage level at which the second scanning signal allows the switching element connected to the second scanning line to be turned on and the voltage level of the second voltage are the same.