Semiconductor device and display device

Abstract

A semiconductor device for individually controlling an element to be driven, such as an electroluminescence element, includes a switching TFT which operates when a selection signal is applied to its gate and which also captures a data signal, and an element-driving TFT in which its drain is connected with a drive power source, its source is connected with the element to be driven, gate receives a data signal supplied from the switching TFT, for controlling electric power supplied from the drive power source to the element to be driven. The semiconductor device further includes a storage capacitor having a first electrode connected with the switching TFT and with the gate of the element-driving TFT and a second electrode connected between the source of the element-driving TFT and the element to be driven, for holding the gate-source voltage of the element-driving TFT in accordance with the data signal, and a switching element for controlling the potential of the second electrode of the storage capacitor. With such a configuration, all the above-described switches can be formed by TFTs of the same conductivity type and reliable supply of electric power to the element to be driven can be assured.

Description

technical field [0001] The present invention relates to a circuit configuration for controlling driven elements such as electroluminescent display elements. Background technique [0002] An EL display device that uses a self-luminescence element (Electroluminescence: EL) element for each pixel as a light-emitting element is not only self-luminous, but also has the advantages of thinness and low power consumption. It is used as an alternative to liquid crystal Display devices such as display devices (LCDs) and CRTs have attracted attention, and research on them is still ongoing. [0003] In addition, an active matrix EL display device in which a switching element such as a thin film transistor (TFT) for individually controlling the EL element is provided in each pixel, and the EL element is controlled for each pixel is expected as a high-precision display device. . [0004] Figure 13 Circuit configuration of each pixel in an active matrix EL display device displaying m row...

AI Technical Summary

Problems solved by technology

In addition, in a region where the distance from the driving power supply Pvdd is long and the voltage drop due to the wiring resistance of the driving power supply line VL is significant, for example, in a pixel located far from the power supply, the voltage of the driving power supply line VL is low. And the luminance of each organic EL element 50 is lower than that of the elements close to the power source.

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