AMOLED Pixel Circuit Potential Control for Power Reduction

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Solution Overview

Problem

The existing pixel circuit in AMOLED displays has high power consumption and a complicated driving method due to frequent potential jumps between high and low data potentials, leading to increased power consumption and complex control timing.

Innovation Solution

A pixel circuit with a reset unit, data writing unit, compensation unit, and light-emitting unit, where the potential is reset, compensated, and written in separate phases, allowing direct jumps between data potentials without the need for intermediate reference potential jumps, reducing power consumption and simplifying the driving method.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the pixel circuit uses a common driving method with three switch transistors and two capacitors, then the circuit can achieve basic display function, but the power consumption is high and the driving method is complicated

Engineering Contradiction:
Improvepower consumptionVSAvoiddriving method complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The pixel circuit is divided into distinct functional units: a control unit with a control switch transistor for signal input, a drive unit with a drive switch transistor for current regulation, and a compensation unit with a capacitor for threshold voltage compensation. This segmentation allows each unit to operate independently with optimized control, reducing overall power consumption and simplifying the driving method by eliminating the need for complex coordinated switching of multiple transistors.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The compensation capacitor is pre-charged to a reference voltage during a reset phase before the display phase begins. This preliminary action compensates for the threshold voltage of the drive transistor in advance, eliminating the need for complex real-time adjustments during operation and reducing power consumption by avoiding frequent switching operations.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If the data signal frequently jumps between high data potential and reference potential, then the display can respond to changing image data, but the power consumption increases due to frequent potential changes

Engineering Contradiction:
Improvedisplay response speedVSAvoidpower consumption
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The compensation capacitor is pre-charged to a reference voltage during a reset phase before the display phase begins. This preliminary action compensates for the threshold voltage of the drive transistor in advance, eliminating the need for complex real-time adjustments during operation and reducing power consumption by avoiding frequent switching operations.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The control switch transistor dynamically adjusts its switching behavior based on the incoming data signal. When the data signal changes, the control switch transistor efficiently transitions the drive transistor between on and off states, enabling rapid response to image changes while minimizing unnecessary switching cycles that would increase power consumption.

Inventive Principle:
Principle #15Dynamics

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach reduces power consumption by minimizing potential jumps between high data potentials and simplifies the driving method by reducing the frequency and amplitude of potential changes, thereby lowering power usage and streamlining control timing.

Implementation Method 1

an active matrix organic light-emitting diode (AMOLED) display

Methodology Applied
Scientific EffectOrganic Light-emitting Diode: Organic Light-emitting Diode

Implementation Method 2

a light-emitting device D

Methodology Applied
Scientific EffectLight Emitting Diode: Light Emitting Diode

Data Source

PatentEP3955239A1Pixel circuit, operation method and driving method thereof, array substrate, and display device
Publication Date: 2022.02.16 BOE TECHNOLOGY GROUP CO LTD
  • EP3955239A1 patent drawingFigure 1~2
  • EP3955239A1 patent drawingFigure 3~5
  • EP3955239A1 patent drawingFigure 6a~6b

AI summary

The present invention provides a pixel circuit, an operation method and driving method thereof, an array substrate, and a display device. The pixel circuit comprises: a reset unit (1), a data writing unit (2), a compensation unit (3), and a light-emitting unit (4). The compensation unit (3) is connected to the reset unit (1) and the data writing unit (2) as well as an output node (p), receives a power voltage signal, and is configured to, in respective phases, reset a potential of the output node (p), pull the potential of the output node (p) from the reset potential up to a first potential, pull the potential of the output node (p) from the first potential up to a second potential, and generate a light emission drive signal and output it to the output node (p).