Shift buffer capable of reducing frequency coupling effect and shift buffer unit

Abstract

The invention discloses a displacement buffer which can reduce a frequency coupling effect and a displacement buffer unit; wherein every level of the displacement buffer unit comprises at least a lifting driving module, a lifting module, at least a pull-down module and a pull down driving module; wherein, before a first frequency signal waveform or a second frequency signal waveform used by the lifting module forms an ascending edge, the pull-down driving module opens the conduction of the pull-down module for a particular period according to a first periodic signal; and / or before the first frequency signal waveform or the second frequency signal waveform used by the lifting module forms an descending edge, the pull-down driving module closes the conduction of the pull-down module for a particular period according to a second periodic signal; therefore, when the coupling effect of the frequency signal appears at that time, the pull-down module has enough ability to resist so as to improve the output waveform of the displacement buffer unit.

Description

technical field [0001] The invention relates to a shift register and a shift register unit, in particular to a shift register and a shift register unit capable of reducing frequency coupling effects. Background technique [0002] A conventional liquid crystal display (LCD) utilizes a driving module (Driving Circuit) to control the grayscale signals of a plurality of pixels (Pixels) on the panel of the liquid crystal display. The drive module includes a gate driver (GateDriver) electrically connected to several scan lines (or gate lines) to respectively output a gate pulse signal (Gate PulseSignal) to each corresponding pixel, and a source driver (Source Driver) is electrically connected to several data lines (or source lines) to respectively transmit the data signal (Data Signal) to each corresponding pixel, and the intersection of each scanning line and each data line is also connected to a corresponding The polarity terminals of the active element of the pixel (such as th...

AI Technical Summary

Problems solved by technology

like Figure 1A As shown, it is a circuit diagram of the Nth-stage shift register 210 disclosed in US Patent No. 7310402B2, which includes a boost transistor Q2 and pull-down modules 1 and 2 that both use a first frequency signal (CK1) as shown in the figure The ideal first frequency signal (CK1-ideal) waveform, but actually in operation, it is susceptible to a capacitance (Cgd) coupling effect ( Coupling Effect) impact, resulting in such as Figure 1B The shown waveform of the actual first frequency signal (CK1-real) rises slowly (such as the edge E1 of the curve), resulting in several periodic rising points B1 in the output waveform (Out) of the gate pulse signal; at the same time ,because Figure 1A The pull-down modules 1 and 2 are also driven by the delay of the first frequency signal (CK1), which jointly causes the level of the output node or input node (such as P2) of the boost module to not be pulled down in time, so that the pull-down effect is not good

In addition, although the pull-down module 2 uses the ideal second frequency signal (CK2-ideal), the actual second frequency signal (CK2-real) may also have the same coupling effect problem as the first frequency signal, so as Figure 1B The output waveform (Out) of the gate pulse signal shown also has several periodic downward sudden rise points B2

Images