Display Control Apparatus for Low-Frequency Flicker Prevention

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Solution Overview

Problem

Display apparatuses driven at low frequencies experience flickering due to inconsistent threshold voltages of drive thin-film transistors between write and hold frames, resulting in varying brightness levels.

Innovation Solution

A display control apparatus that includes a first reset unit, a write unit, and an adjustment unit to output specific voltages to the drive thin-film transistor, adjusting its threshold voltage to maintain consistent brightness by applying positive and negative voltages during write and hold frames.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If display apparatus is driven at low frequency with data voltage written in write frame and maintained in hold frame, then power consumption is reduced, but brightness inconsistency and flickering occur due to threshold voltage variations of drive thin-film transistors

Engineering Contradiction:
Improvepower consumptionVSAvoidbrightness consistency
Core Design Contradiction:
Loss of energyVSIllumination intensity

Solution Approach 1:

The patent applies preliminary action by resetting the threshold voltage of drive thin-film transistors to a reference value at the beginning of each write frame through the first reset unit. This preliminary reset operation ensures that regardless of the threshold voltage state from previous hold frames, all transistors start with a consistent reference threshold voltage, preventing brightness inconsistency and flickering while maintaining low power consumption operation

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent utilizes parameter changes by dynamically adjusting the threshold voltage of drive thin-film transistors through voltage application. The first reset unit applies a first reset voltage to reset threshold voltages to a first reference value, while the adjustment unit applies adjustment voltages to set threshold voltages to a second reference value. This dynamic parameter adjustment ensures consistent brightness across write and hold frames in low-frequency driving mode

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If threshold voltage of drive thin-film transistor is not reset between write and hold frames, then circuit operation is simplified, but brightness varies due to threshold voltage drift

Engineering Contradiction:
Improvecircuit operation complexityVSAvoidbrightness stability
Core Design Contradiction:
Device complexityVSIllumination intensity

Solution Approach 1:

The patent implements preliminary action by resetting threshold voltages to a reference value at the start of each write frame. This preliminary reset ensures that threshold voltage drift from previous operations does not affect current frame brightness, maintaining brightness stability while keeping the hold frame operation simple without requiring continuous threshold voltage monitoring or adjustment

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent applies periodic action by resetting threshold voltages periodically at the beginning of each write frame through the first reset unit. This periodic reset operation synchronizes with the display refresh cycle, ensuring that threshold voltage drift is corrected regularly to maintain brightness stability without requiring continuous intervention during hold frames

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP4195189B1Display control apparatus, display apparatus, and electronic device
Publication Date: 2025.07.23 HONOR DEVICE CO LTD
  • EP4195189B1 patent drawingFigure 1~2
  • EP4195189B1 patent drawingFigure 3
  • EP4195189B1 patent drawingFigure 4

AI summary

This application discloses a display control apparatus, a display apparatus, and an electronic device, relates to the field of electronic circuit technologies, and aims to eliminate flickering of the display apparatus in a low-frequency driving mode. A specific solution is as follows. An adjustment unit in the display control apparatus outputs an adjustment voltage in a write frame to a control-end back channel of a drive thin-film transistor in a light-emitting drive unit, so that the influence of negative bias of a threshold voltage of the drive thin-film transistor caused by a negative voltage of a first reset voltage, and therefore a transfer characteristic curve of the drive thin-film transistor shifts forward in the write frame, that is, the threshold voltage of the drive thin-film transistor shifts forward, making it easier for the drive thin-film transistor to turn on in the write frame, and increasing the brightness of the drive thin-film transistor in the write frame. As a result, the light-emitting drive unit controls the light-emitting brightness of a light-emitting device in the write frame and a hold frame to avoid deviation, thereby preventing the display apparatus from flickering.