Pulse output circuit, shift register, and display device

摘要

An object is to suppress change of a threshold voltage of a transistor in a shift register and to prevent the transistor from malfunctioning during a non-selection period. A pulse output circuit provided in the shift register regularly supplies a potential to a gate electrode of a transistor which is in a floating state so that the gate electrode is turned on during a non-selection period when a pulse is not outputted. In addition, supply of a potential to the gate electrode of the transistor is performed by turning on or off another transistor regularly.

主权项

1. A pulse output circuit comprising:
third, fourth, fifth, eighth and ninth transistors; first, second, third and fourth input terminals; an output terminal; and third, fourth and fifth power supply lines, wherein a first electrode of the third transistor is electrically connected to the first input terminal and a second electrode of the third transistor is electrically connected to the output terminal, wherein a first electrode of the fourth transistor is electrically connected to the third power supply line and a second electrode of the fourth transistor is electrically connected to the output terminal, wherein a first electrode of the fifth transistor is electrically connected to the fourth power supply line, a second electrode of the fifth transistor is electrically connected to the gate electrode of the fourth transistor, and a gate electrode of the fifth transistor is electrically connected to the fourth input terminal, wherein a first electrode of the eighth transistor is electrically connected to the fifth power supply line, a second electrode of the eighth transistor is electrically connected to a second electrode of the ninth transistor, and a gate electrode of the eighth transistor is electrically connected to the second input terminal, and wherein a first electrode of the ninth transistor is electrically connected to the gate electrode of the fourth transistor, and a gate electrode of the ninth transistor is electrically connected to the third input terminal.