Gate Driver Circuit Pulse Width Adjustment for Display Luminance Uniformity

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Solution Overview

Problem

Display panels face luminance non-uniformity due to position-specific driving voltage deviations and varying threshold voltage sampling times of driving transistors, leading to image quality degradation.

Innovation Solution

The solution involves adjusting the pulse widths of gate pulse signals to compensate for these deviations, ensuring that subpixels on different horizontal lines receive appropriate driving voltages by varying the threshold voltage sampling times of the driving transistors, thereby improving luminance uniformity across the display panel.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If the pulse width of gate pulse signals is adjusted to compensate for position-specific driving voltage deviations, then luminance uniformity is improved, but device complexity increases

Engineering Contradiction:
Improveluminance uniformityVSAvoiddevice complexity
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by adjusting the pulse width of gate pulse signals based on the position of horizontal lines in the display panel. Different pulse widths are applied to different horizontal lines to compensate for voltage drops, thereby improving luminance uniformity without requiring additional hardware components.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements dynamics by making the gate pulse signal parameters variable rather than fixed. The pulse width dynamically changes depending on the horizontal line position, allowing the system to adapt to position-specific voltage deviations and improve overall display uniformity.

Inventive Principle:
Principle #15Dynamics

2Illumination intensity

If threshold voltage sampling times of driving transistors are varied to compensate for voltage drops, then luminance uniformity is improved, but manufacturing precision requirements increase

Engineering Contradiction:
Improveluminance uniformityVSAvoidmanufacturing precision
Core Design Contradiction:
Illumination intensityVSManufacturing precision

Solution Approach 1:

The patent varies the threshold voltage sampling times of driving transistors based on their position in the display panel. This parameter change compensates for voltage drops across different horizontal lines, improving luminance uniformity while using existing transistor structures without requiring higher manufacturing precision.

Inventive Principle:
Principle #35Parameter changes

3Illumination intensity

If pulse widths of gate pulse signals are adjusted based on horizontal line positions, then luminance deviations are compensated, but ease of operation decreases

Engineering Contradiction:
Improveluminance uniformityVSAvoidease of operation
Core Design Contradiction:
Illumination intensityVSEase of operation

Solution Approach 1:

The patent implements self-service by enabling the display panel to automatically compensate for its own voltage drops through position-based pulse width adjustment. The system self-regulates the gate pulse signals based on horizontal line positions, eliminating the need for external manual calibration or adjustment mechanisms.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3343554B1Display device, display panel, driving method, and gate driver circuit
Publication Date: 2023.08.02 LG DISPLAY CO LTD
  • EP3343554B1 patent drawingFigure 1
  • EP3343554B1 patent drawingFigure 2
  • EP3343554B1 patent drawingFigure 3

AI summary

A display device (100), a display panel (110), a driving method, and a gate driver circuit (130). Threshold voltage sampling times of driving transistors (DRT) are changed by varying pulse widths (W1, W2) of gate clock signals (GCLK) depending on horizontal lines (HL1, HL2). Luminance uniformity of the display panel (110) is improved, even in the case in which horizontal line-specific driving voltages have different voltage drops.