US Patent No. 10,714,203

SHIFT REGISTER AND DISPLAY APPARATUS


Patent No. 10,714,203
Issue Date July 14, 2020
Title Shift Register And Display Apparatus
Inventorship Chien-Ting Chan, Tainan (TW)
Assignee HannStar Display (Nanjing) Corporation, Nanjing (CN) HannStar Display Corp...

Claim of US Patent No. 10,714,203

1. A shift register, comprising:a pre-charge unit configured to receive a first input signal and a second input signal and to output a pre-charge signal via a first node based on the first input signal and the second input signal, wherein the pre-charge unit comprises:
a first transistor, wherein a gate of the first transistor is configured to receive a starting signal, a first source/drain of the first transistor is configured to receive a forward input signal, and a second source/drain of the first transistor is configured to output the pre-charge signal; and
a second transistor, wherein a gate and a first source/drain of the second transistor are configured to receive a scan signal outputted by a next four stage shift register, and a second source/drain of the second transistor is coupled to the second source/drain of the first transistor;
a pull-up unit coupled to the pre-charge unit, the pull-up unit configured to receive the pre-charge signal and a clock signal and to output a scan signal via a second node based on the pre-charge signal and the clock signal;
a first pull-down unit coupled to the pre-charge unit and the pull-up unit, the first pull-down unit configured to receive the pre-charge signal, a first pull-down control signal and a second pull-down control signal and to control whether to pull down the scan signal to a first reference voltage level based on the pre-charge signal, the first pull-down control signal and the second pull-down control signal; and
a second pull-down unit coupled to the pre-charge unit and the pull-up unit, the second pull-down unit configured to receive the pre-charge signal, the first pull-down control signal and the second pull-down control signal and to control whether to keep the scan signal at the first reference voltage level based on the pre-charge signal, the first pull-down control signal and the second pull-down control signal;
wherein a duty cycle of the clock signal is less than 50 percent.