Shift Register Circuit Discharging First Node Before Output Terminal

Solution Overview

Problem

Conventional shift register circuits in flat panel displays, such as LCDs, face high dynamic power consumption due to low carrier mobility materials, which restrict their application ranges and require large thin-film transistors, leading to increased parasitic capacitance.

Innovation Solution

A shift register circuit design that includes a pull-up circuit, first and second driving circuits, and a discharging circuit with transistors, where the discharging circuit discharges the first node before the output terminal, preventing constant reference voltage from charging the output terminal, thereby reducing dynamic power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If thin-film transistors with large size are used to drive gate lines due to low carrier mobility, then the gate lines can be effectively driven, but parasitic capacitance increases and dynamic power consumption increases

Engineering Contradiction:

Improvegate line driving capabilityVSAvoiddynamic power consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The discharging circuit performs preliminary discharge action on the first node before the output terminal needs to be charged, preventing unnecessary charging cycles. By proactively discharging the first node to ground potential before subsequent charging operations, the circuit avoids parasitic charging of the output terminal, thereby reducing dynamic power consumption while maintaining reliable gate line driving capability

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The discharging circuit extracts and removes excess charge from the first node through a dedicated discharge path to ground. By separating the discharge function from the charging function and providing an independent discharge path, the circuit prevents charge accumulation that would otherwise lead to parasitic charging of the output terminal and reduced power efficiency

Inventive Principle:

Principle #2Taking out (Extraction)

2Reliability

If thin-film transistors with large size are used to drive gate lines due to low carrier mobility, then the gate lines can be effectively driven, but parasitic capacitance effect increases

Engineering Contradiction:

Improvegate line driving capabilityVSAvoidparasitic capacitance effect

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The discharging circuit performs preliminary discharge action on the first node before the output terminal needs to be charged, preventing unnecessary charging cycles. By proactively discharging the first node to ground potential before subsequent charging operations, the circuit avoids parasitic charging of the output terminal, thereby reducing dynamic power consumption while maintaining reliable gate line driving capability

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The discharging circuit extracts and removes excess charge from the first node through a dedicated discharge path to ground. By separating the discharge function from the charging function and providing an independent discharge path, the circuit prevents charge accumulation that would otherwise lead to parasitic charging of the output terminal and reduced power efficiency

Inventive Principle:

Principle #2Taking out (Extraction)

Data Source

PatentUS8515000B2Shift register circuit

Publication Date: 2013.08.20 AU OPTRONICS CORP

AI summary

A shift register circuit includes a plurality of shift registers. Each of the shift registers is configured for outputting a corresponding start-pulse signal and a corresponding driving-pulse signal. Each of the shift registers includes a pull-up circuit, a first driving circuit, a second driving circuit and a discharging circuit. The pull-up circuit is configured for charging a first node. The first driving circuit is configured for generating the corresponding start-pulse signal, and the second driving circuit is configured for generating the corresponding driving-pulse signal. The discharging circuit firstly discharges the first node before discharging an output terminal of the second driving circuit.