| 摘要 |
PROBLEM TO BE SOLVED: To provide a light emitting device which solves a problem in which luminance unevenness due to variation in threshold values of TFTs for supplying electric current to light emitting elements among pixels hampers improvement in image quality of the light emitting devices.SOLUTION: In a light emitting device, a voltage equal to a threshold value of a TFT is held in capacitor means. When a video signal is input from a source signal line, the voltage held in the capacitor means is added to the video signal and applied to a gate electrode of the TFT. Even when the threshold values are varied for each pixel, respective threshold values are held in the capacitor means for each pixel, so that influence of variation in the threshold values can be cancelled. Furthermore, the threshold values are stored only in the capacitor means, thus a voltage between two electrodes is not changed when the video signal is written, so that the video signal is not affected by the variation in the capacitance values.SELECTED DRAWING: Figure 15 |
