Patent ID: 7492342
Filing Date: 2009-02-17
Classification: G09G

Abstract:
1. A driving circuit of an electro-optical device, the electro-optical device including a plurality of pixels which are provided to correspond to intersections of a plurality of scanning lines and a plurality of data lines and which display the gray-scale levels corresponding to data signals sampled to the data lines when the scanning lines and the data lines are selected; a scanning line driving circuit which selects the scanning lines; shift registers which generate pulse signals for selecting the data lines for a period of time when the scanning lines are selected; a logical circuit which restricts the pulse signals respectively generated by the shift registers to the pulse width of an enable pulse to output them as sampling signals; and a sampling circuit which samples the data signals to the data lines according to the sampling signals, the driving circuit comprising: a phase difference detecting circuit which detects the phase difference between a monitoring signal supplied in synchronization with the data signal and a reference pulse supplied in synchronization with the enable pulse and which outputs the detected result as a phase difference signal; a first phase adjusting circuit which roughly adjusts, in a retrace period in which neither the scanning lines nor the data lines are selected, the phase of the enable pulse supplied to the logical circuit; a second phase adjusting circuit which minutely adjusts, in an effective display period in which either the scanning lines or the data lines are selected, the phase of the enable pulse supplied to the logical circuit with higher precision than the first phase adjusting circuit; and an adjustment control circuit which, when the phase difference signal indicates that the phase of the monitoring signal is delayed with respect to the reference pulse, controls the first phase adjusting circuit to advance the phase of the enable pulse and then controls the second phase adjusting circuit to minutely adjust the phase of the enable pulse such that the phase difference indicated by the phase difference signal is minimum, and which, when the phase difference signal indicates that the phase of the monitor signal precedes that of the reference pulse, controls the first phase adjusting circuit to delay the phase of the enable pulse and then controls the second phase adjusting circuit to minutely adjust the phase of the enable pulse such that the phase difference indicated by the phase difference signal is minimum.