| 摘要 |
<P>PROBLEM TO BE SOLVED: To make high-quality image display possible in a pixel circuit by (n) channel TFTs. <P>SOLUTION: The pixel circuit comprises five N channel thin-film transistors (TFTs) each consisting of an organic EL element, a holding capacitor, a sampling transistor, a drive transistor, a switching transistor, and first and second detecting transistors. Further, the circuit has a holding capacitor bootstrap function to compensate the threshold voltage fluctuation of the drive transistor and the deterioration with lapse of time of the organic EL element, and compensates the change with lapse of time of the I-V characteristics of the organic EL element of a current drive type and the threshold voltage fluctuation of the drive transistor. The start timing and end timing of the threshold detection operation of the drive transistor for the bootstrap function are determined by on/off of the switching transistor T3 connecting the drain of the drive transistor and a power source potential. The occurrence of the gradation by the difference between the threshold detection operation periods is thereby averted. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
