Display Device Frame Frequency Luminance Flicker Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing organic EL display devices experience display flicker when frame frequency is switched, due to changes in luminance caused by variations in charge release time and data voltage levels.
Innovation Solution
A display device with a gradation conversion circuit that adjusts data voltage levels and charging periods based on frame frequency, ensuring consistent luminance by performing gradation conversion on video signals and controlling the timing of control signals to match the frame frequency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the frame frequency is switched from 60 Hz to 90 Hz, then the moving image quality is improved, but the average luminance increases causing display flicker
Solution Approach 1:
The patent adjusts the data voltage level according to the frame frequency. When switching from 60 Hz to 90 Hz, the data voltage is reduced to compensate for the increased average luminance, thereby preventing display flicker while maintaining improved moving image quality
Solution Approach 2:
The patent preemptively adjusts the data voltage level before frame frequency switching occurs. By calculating the required voltage adjustment based on the target frame frequency, the system prevents luminance fluctuations and display flicker from occurring during the transition
2Use of energy by stationary object
If the frame frequency is switched from 60 Hz to 30 Hz, then the power consumption is reduced, but the average luminance decreases causing display flicker
Solution Approach 1:
The patent adjusts the data voltage level according to the frame frequency. When switching from 60 Hz to 30 Hz, the data voltage is increased to compensate for the decreased average luminance, thereby preventing display flicker while maintaining reduced power consumption
Solution Approach 2:
The patent preemptively adjusts the data voltage level before frame frequency switching occurs. By calculating the required voltage adjustment based on the target frame frequency, the system prevents luminance fluctuations and display flicker from occurring during the transition
3Device complexity
If the data voltage is kept constant during frame frequency switching, then the circuit design is simplified, but the luminance changes causing display flicker
Solution Approach 1:
The patent implements a dynamic data voltage adjustment mechanism that automatically adapts the voltage level according to the current frame frequency. This dynamic adjustment prevents display flicker while maintaining relatively simple circuit design through automated control
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Prevents display flicker by maintaining consistent luminance during frame frequency changes, ensuring smooth and flicker-free visuals.
Implementation Method 1
an organic electroluminescence (hereinafter referred to as EL) display device provided with a pixel circuit including an organic EL element as a light-emitting element
Data Source
AI summary
A display device is provided with: a display portion including a plurality of scanning lines, a plurality of data lines, and a plurality of pixel circuits; a scanning line drive circuit; and a data line drive circuit. The level of a data voltage applied to the data line decreases when a frame frequency is switched higher, and increases when the frame frequency is switched lower. This can prevent a display flicker when the frame frequency is switched. The level of the data voltage may change when the frame frequency is switched, and may return to its initial level over a plurality of frame periods. The timing of the control signal used to drive the display portion may change in accordance with the frame frequency to cause the length of the charging period of the pixel circuit to change in accordance with the frame frequency.