Shift Register Forward Backward Scanning Circuit Segmentation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing shift registers experience poor reliability during backward scanning due to changes in current directions of input and reset signals, leading to issues at high temperatures, especially after prolonged forward scanning.

Innovation Solution

The shift register design incorporates separate forward and backward scanning input and reset sub-circuits, ensuring that input and reset signals are directed through different circuits during each scanning mode, maintaining consistent current directions and improving reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single scanning input circuit is used for both forward and backward scanning, then the device complexity is reduced, but the reliability deteriorates due to current direction changes

Engineering Contradiction:

Improvecircuit structureVSAvoidscanning reliability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent divides the scanning input circuit into separate forward scanning input circuit and backward scanning input circuit. Each circuit is dedicated to a specific scanning direction, preventing current direction changes that cause reliability issues. This segmentation resolves the contradiction by prioritizing reliability over circuit simplicity.

Inventive Principle:

Principle #1Segmentation

2Reliability

If separate forward and backward scanning input circuits are used, then the reliability is improved by maintaining consistent current directions, but the device complexity increases

Engineering Contradiction:

Improvescanning reliabilityVSAvoidcircuit structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements separate forward and backward scanning input circuits, each handling only one scanning direction. This segmentation ensures consistent current flow direction in each circuit, improving reliability while accepting increased circuit complexity as a necessary trade-off.

Inventive Principle:

Principle #1Segmentation

3Device complexity

If a single reset circuit is used for both scanning directions, then the device complexity is reduced, but the reliability deteriorates under high temperature conditions

Engineering Contradiction:

Improvecircuit structureVSAvoidhigh temperature reliability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent divides the reset circuit into separate forward scanning reset circuit and backward scanning reset circuit. Each reset circuit is dedicated to a specific scanning direction, preventing interference and reliability issues under high temperature conditions. This segmentation resolves the contradiction by prioritizing reliability over circuit simplicity.

Inventive Principle:

Principle #1Segmentation

4Reliability

If separate reset circuits for forward and backward scanning are used, then the reliability under high temperature conditions is improved, but the device complexity increases

Engineering Contradiction:

Improvehigh temperature reliabilityVSAvoidcircuit structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements separate reset circuits for forward and backward scanning operations. Each reset circuit is optimized for its specific scanning direction, improving reliability under high temperature conditions while accepting the necessary increase in circuit complexity.

Inventive Principle:

Principle #1Segmentation

5Productivity

If integrated gate driving circuit is formed on the panel, then the productivity is improved by reducing packaging processes, but the device complexity increases due to integration requirements

Engineering Contradiction:

Improveproduction efficiencyVSAvoidintegration complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent integrates the gate driving circuit directly onto the display panel, eliminating the need for separate packaging processes (COF or COG). This merging of functions improves productivity by streamlining manufacturing, while the internal circuit segmentation manages the integration complexity.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS11308853B2Shift register and driving method thereof, gate driving circuit and display apparatus

Publication Date: 2022.04.19 BEIJING BOE OPTOELECTRONCIS TECH CO LTD

AI summary

There are provided in the present disclosure a shift register and a driving method thereof, a gate driving circuit and a display apparatus. The shift register of the present disclosure includes: a forward scanning input sub-circuit for pre-charging a potential of a pull-up node by an operation level signal under control of a forward input signal and a forward scanning signal upon scanning forwards; a backward scanning input sub-circuit for pre-charging the potential of the pull-up node by an operation level signal under control of a backward input signal and a backward scanning signal upon scanning backwards; an output sub-circuit for outputting a clock signal through a signal output terminal under control of the potential of the pull-up node; wherein the pull-up node is a connection node of the forward scanning input sub-circuit, the backward scanning input sub-circuit and the output sub-circuit.