Pixel Driving Circuit With Memory Modulation for Luminance Control

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional LED and OLED displays face issues with controlling luminance due to leakage paths in capacitors, leading to ineffective current control and high power consumption.

Innovation Solution

A driving circuit incorporating a memory circuit, current source circuit, and modulation circuit to control a modulation current into the emissive pixel element, minimizing the impact of leakage currents and optimizing power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a capacitor is used to store the bit signal and control the operating current, then the pixel element can maintain a stable current, but leakage paths in the capacitor cause current changes and ineffective luminance control

Engineering Contradiction:

Improvecurrent control stabilityVSAvoidcapacitor leakage current

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The patent extracts the problematic capacitor component from the pixel element structure. By removing the capacitor that stores the bit signal, the leakage path is eliminated. The bit signal is instead transmitted directly through the transistor to control the operating current, avoiding the energy loss and instability caused by capacitor leakage.

Inventive Principle:

Principle #2Taking out (Extraction)

2Manufacturing precision

If the capacitor leakage changes the operating current, then the current control becomes ineffective, but maintaining effective current control requires additional circuit complexity

Engineering Contradiction:

Improveluminance control precisionVSAvoidcircuit structure complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent segments the control function by separating the bit signal transmission path from the operating current control path. The bit signal controls the transistor gate, which in turn controls the operating current through a dedicated current control mechanism. This segmentation allows precise luminance control without requiring complex compensation circuits to address capacitor leakage.

Inventive Principle:

Principle #1Segmentation

3Device complexity

If conventional capacitor-based current control is used, then the pixel element structure is simple, but power consumption increases due to leakage currents

Engineering Contradiction:

Improvepixel element structureVSAvoidpower consumption

Core Design Contradiction:

Device complexityVSUse of energy by moving object

Solution Approach 1:

The patent converts the harmful effect of capacitor leakage into a benefit by eliminating the capacitor entirely. The design uses the transistor's inherent current control capability to achieve both simple structure and low power consumption. The bit signal directly modulates the transistor to control current, turning the potential weakness of direct transistor control into a strength by avoiding capacitor-related energy losses.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Data Source

PatentUS12562111B2Driving circuit and pixel element

Publication Date: 2026.02.24 SILICON INTEGRATED SYSTEMS CORP

AI summary

A pixel element includes an emissive pixel element; and a driving circuit, coupled to the emissive pixel element, comprising: a memory circuit; a current source circuit; and a modulation circuit, coupled to the memory circuit, the current source circuit and the emissive pixel element, configured to control the current source circuit to inject a modulation current into the emissive pixel element according to modulation signals received from the memory circuit.