Pixel Circuit Time Control for Micro LED Flicker Reduction

Solution Overview

Problem

Micro LED and Mini LED display devices face challenges in achieving optimal gray scale display and reducing power consumption while minimizing flicker phenomena, as existing pixel circuits rely on continuous light emission for low gray scales, leading to inefficient power usage and visible flicker.

Innovation Solution

A pixel circuit with a time control circuit that adjusts light-emitting durations based on control signals, allowing for intermittent light emission during low gray scale displays, utilizing a frequency of 3000 Hz for the third control signal to extend perceived light-emitting duration and reduce dark states, thereby enhancing display effectiveness and user experience.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If continuous light emission is used for low gray scale display, then display uniformity is improved, but power consumption increases and flicker becomes visible

Engineering Contradiction:

Improvedisplay uniformityVSAvoidpower consumption

Core Design Contradiction:

Stability of the object's compositionVSUse of energy by moving object

Solution Approach 1:

The patent implements periodic light emission by dividing the light-emitting phase into multiple sub-phases with different durations. For low gray scales, the light-emitting circuit performs intermittent emission with multiple on-off cycles within one frame period, while for high gray scales, continuous emission is maintained. This periodic action reduces power consumption and eliminates flicker by ensuring the emission frequency remains above the human visual perception threshold.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The patent dynamically adjusts the light-emitting duration based on the gray scale value. The time control circuit modifies the duration of the light-emitting phase in real-time according to the displayed gray scale: using longer continuous emission for high gray scales and shorter intermittent emission for low gray scales. This dynamic adjustment optimizes both power consumption and display uniformity across different brightness levels.

Inventive Principle:

Principle #15Dynamics

2Stability of the object's composition

If continuous light emission is used for low gray scale display, then display uniformity is improved, but flicker visibility increases

Engineering Contradiction:

Improvedisplay uniformityVSAvoidflicker visibility

Core Design Contradiction:

Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The patent implements periodic light emission by dividing the light-emitting phase into multiple sub-phases with different durations. For low gray scales, the light-emitting circuit performs intermittent emission with multiple on-off cycles within one frame period, while for high gray scales, continuous emission is maintained. This periodic action reduces power consumption and eliminates flicker by ensuring the emission frequency remains above the human visual perception threshold.

Inventive Principle:

Principle #19Periodic action

3Use of energy by moving object

If intermittent light emission is used for low gray scale display, then power consumption is reduced, but perceived light-emitting duration decreases

Engineering Contradiction:

Improvepower consumptionVSAvoidlight-emitting duration

Core Design Contradiction:

Use of energy by moving objectVSDuration of action of moving object

Solution Approach 1:

The patent dynamically adjusts the light-emitting duration based on the gray scale value. The time control circuit modifies the duration of the light-emitting phase in real-time according to the displayed gray scale: using longer continuous emission for high gray scales and shorter intermittent emission for low gray scales. This dynamic adjustment optimizes both power consumption and display uniformity across different brightness levels.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the temporal parameters of light emission by introducing multiple duration settings (first duration and second duration) within the same frame period. The system switches between these parameter configurations based on the gray scale being displayed, thereby optimizing the balance between power consumption and perceived brightness without requiring continuous emission.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS11694600B2Pixel circuit and method for controlling the same, and display device

Publication Date: 2023.07.04 BOE TECHNOLOGY GROUP CO LTD

AI summary

A pixel circuit includes an input circuit and a time control circuit. The input circuit is configured to output a driving signal to an element to be driven. The time control circuit is configured to control a light-emitting duration of the element in a light-emitting phase to be a first duration by controlling the input circuit coupled thereto in response to a first control signal from a first control signal terminal, and control the light-emitting duration in another light-emitting phase to be a second duration by controlling the input circuit in response to a second control signal from a second control signal terminal and a third control signal from a third control signal terminal. The second duration is less than the first duration. The second duration includes interval time periods. The third control signal has a frequency multiple times that of the first control signal or the second control signal.