Shift Register Voltage Shifting Inverting Modules

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Solution Overview

Problem

Conventional shift registers fail to simultaneously provide a low voltage output for the GATE and RESET signals and a high voltage output for the EMISSION signal, which is required in Active Matrix Organic Light-Emitting Diode (AMOLED) pixel structures with a compensation function.

Innovation Solution

A shift register design incorporating a voltage shifting module, a voltage inverting module, a voltage complementing module, and a voltage shifting control module, which delays and inversely outputs a startup voltage, allowing for simultaneous output of both delayed and inverse voltage signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If a conventional shift register uses N-type TFTs, then it outputs a high voltage Vgh in the operating period, but it cannot output a low voltage simultaneously

Engineering Contradiction:
Improveoutput voltage levelVSAvoidvoltage output capability
Core Design Contradiction:
PowerVSAdaptability or versatility

Solution Approach 1:

The shift register is divided into multiple stages, with each stage containing independent switching elements (first and second switching elements) that can be controlled separately. This segmentation allows different output terminals to provide different voltage levels simultaneously, resolving the contradiction between fixed output voltage and versatile voltage output capability

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The shift register stage is designed to perform multiple functions: it can output high voltage Vgh from one terminal while simultaneously outputting low voltage Vgl from another terminal. The circuit structure enables it to serve as both a high-voltage source and a low-voltage source, achieving multi-functionality that satisfies diverse voltage requirements in AMOLED pixel structures

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Power

If a shift register provides high voltage output for EMISSION signal, then it cannot provide low voltage output for GATE and RESET signals simultaneously

Engineering Contradiction:
Improveemission signal voltageVSAvoidsignal provisioning capability
Core Design Contradiction:
PowerVSEase of operation

Solution Approach 1:

The output stage is segmented into multiple output terminals with independent voltage control. The first output terminal can provide high voltage Vgh for the EMISSION signal while the second output terminal provides low voltage Vgl for GATE and RESET signals simultaneously, enabling ease of operation for multiple signal types

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different output terminals are assigned different voltage characteristics based on local requirements. The terminal driving the EMISSION signal is configured for high voltage output, while terminals driving GATE and RESET signals are configured for low voltage output, achieving local optimization of voltage quality for each signal type

Inventive Principle:
Principle #3Local quality

3Adaptability or versatility

If a pixel structure requires both high voltage and low voltage startup signals, then the circuit complexity increases to five driving signals

Engineering Contradiction:
Improvestartup voltage requirementVSAvoidnumber of driving signals
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The shift register stage is designed as a universal module that can generate both high voltage Vgh and low voltage Vgl outputs simultaneously from the same circuit structure. This multi-functional design reduces the need for separate voltage generation circuits, thereby reducing overall device complexity while meeting diverse startup voltage requirements

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The circuit merges the high-voltage generation and low-voltage generation functions into a single integrated stage. By combining these functions in one module, the patent reduces the total number of separate driving signals and circuits needed, simplifying the overall pixel structure while maintaining adaptability to different voltage requirements

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP2835802B1Shift register, drive circuit and display device
Publication Date: 2017.02.22 BOE TECHNOLOGY GROUP CO LTD
  • EP2835802B1 patent drawingFigure 1~2
  • EP2835802B1 patent drawingFigure 3~4
  • EP2835802B1 patent drawingFigure 5

AI summary

The present disclosure provides a shift register for delaying and outputting a received startup voltage and meanwhile outputting a voltage inverse to the delayed startup voltage. The shift register including: a voltage shifting module for outputting from the second output terminal a voltage non-inverted to the startup voltage under the control of a second startup voltage signal; a voltage inverting module for outputting from the first output terminal a voltage inverse to the startup voltage under the control of the voltage outputted from the voltage shifting module, and outputting from the first output terminal the voltage non-inverted to the startup voltage under the control of the first startup voltage signal or a third startup voltage signal; a voltage complementing module for outputting from the second output terminal the voltage inverse to the startup voltage under the control of the voltage outputted from the voltage inverting module; and a voltage shifting control module for controlling to turn off the voltage shifting module under the control of the third startup voltage signal. The present disclosure further provides a display apparatus adopting the above shift register and a corresponding method.