Display Device Black Data Voltage Control for Variable-Frequency Driving

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Solution Overview

Problem

In display devices supporting variable frequency driving, the increase in time where data voltage is not written in one frame leads to increased current leakage through sub-pixel switching transistors, causing luminance differences.

Innovation Solution

The display device adjusts the black data voltage based on driving frequency, dimming level, and temperature, using a driving controller to determine offset voltages and set optimal black data voltages to minimize current leakage and luminance differences.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If variable frequency driving is supported, then adaptability is improved, but current leakage increases causing luminance differences

Engineering Contradiction:

Improvevariable frequency driving supportVSAvoidcurrent leakage through switching transistor

Core Design Contradiction:

Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The patent applies parameter changes by dynamically adjusting the black data voltage level based on the driving frequency. When the driving frequency changes, the black data voltage is modified to compensate for the increased current leakage at higher frequencies, thereby maintaining consistent luminance across different operating conditions.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent implements a feedback mechanism where the driving controller monitors the driving frequency and automatically adjusts the black data voltage accordingly. This closed-loop control ensures that the display maintains uniform luminance by compensating for frequency-dependent current leakage variations.

Inventive Principle:

Principle #23Feedback

2Manufacturing precision

If black data voltage is adjusted dynamically, then luminance uniformity is improved, but device complexity increases

Engineering Contradiction:

Improveluminance uniformityVSAvoidvoltage adjustment mechanism

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent achieves luminance uniformity by integrating the black data voltage adjustment function into the existing driving controller, which already manages gamma reference voltages and data driving signals. This multi-functional approach allows the controller to handle both standard display operations and frequency-dependent voltage compensation without requiring a separate dedicated circuit.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS12456409B2Display device, method of driving the same, and electronic device including the same

Publication Date: 2025.10.28 SAMSUNG DISPLAY CO LTD

AI summary

A display device includes a display panel including a sub-pixel, a gate driver which provides a gate signal to the sub-pixel, a data driver which provides a data voltage to the sub-pixel, a driving voltage generator which provides a gamma reference voltage including a black data voltage to the data driver, and a driving controller which determines an offset voltage of the black data voltage based on at least one selected from a driving frequency, a dimming level, and a temperature.