Pixel Current Source Circuit for Uniform Display Brightness

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Solution Overview

Problem

Current display modules suffer from uneven display brightness due to uncontrollable current values in data signals, leading to potential deviations and interference, which affects the expected brightness of light-emitting elements.

Innovation Solution

The implementation of a pixel circuit with a controllable current value data signal through a data writing module, combined with a current source circuit that adjusts the current value to maintain expected potential and enhance stability against interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If data signal current value is not controlled, then device complexity is reduced, but display brightness uniformity deteriorates

Engineering Contradiction:

Improvedata signal control circuit complexityVSAvoiddisplay brightness uniformity

Core Design Contradiction:

Device complexityVSIllumination intensity

Solution Approach 1:

The pixel circuit autonomously measures the voltage drop across the data signal line and self-adjusts the data signal current value to compensate for the voltage drop, eliminating the need for external complex control circuits while ensuring uniform display brightness

Inventive Principle:

Principle #25Self-service

2Illumination intensity

If data signal current value is controlled to compensate voltage drop, then display brightness uniformity is improved, but device complexity increases

Engineering Contradiction:

Improvedisplay brightness uniformityVSAvoidpixel circuit complexity

Core Design Contradiction:

Illumination intensityVSDevice complexity

Solution Approach 1:

The voltage drop measurement function and data signal adjustment function are merged into a single integrated pixel circuit structure, where the same circuit nodes and components serve multiple purposes, avoiding additional complex control circuits

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The pixel circuit dynamically adjusts the data signal current value parameter based on the measured voltage drop, changing the electrical parameter to compensate for line losses and ensure uniform brightness across the display

Inventive Principle:

Principle #35Parameter changes

3Ease of operation

If data signal line voltage drop is not compensated, then ease of operation is maintained, but display quality deteriorates

Engineering Contradiction:

Improvesignal line design simplicityVSAvoidlight-emitting element brightness

Core Design Contradiction:

Ease of operationVSIllumination intensity

Solution Approach 1:

The pixel circuit automatically performs voltage drop compensation by measuring and adjusting the data signal current, eliminating the need for complex external voltage regulation while ensuring expected brightness

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS12494159B2Pixel circuit, current source circuit and display module

Publication Date: 2025.12.09 SHANGHAI TIANMA MICRO ELECTRONICS CO LTD

AI summary

Pixel circuit, current source circuit and display module are provided. The pixel circuit includes a first driving branch and a data writing module. The first driving branch, connected to a light-emitting element, includes a first driving module. A control end of the first driving module is electrically connected to a first node, a first end of the first driving module is electrically connected to a voltage signal line of a first power supply, and a second end of the first driving module is electrically connected to a first electrode of a light-emitting element. A control end of the data writing module is electrically connected to a first scanning signal line, a first end of the data writing module is electrically connected to a data signal line, and a second end of the data writing module is electrically connected to the first node.