Display Panel Driver Voltage Tuning for Variable-Frequency Luminance
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Solution Overview
Problem
Display apparatuses experience luminance differences and reduced display quality when switching between different driving frequencies due to changes in luminance during variable frequency driving.
Innovation Solution
The display apparatus includes a display panel with transistors and light emitting elements, where the first low voltage is increased during the blank period when the driving frequency is lowered, and a blank current is allowed to flow through the second transistor, reducing luminance differences and improving display quality by maintaining consistent luminance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the driving frequency is changed in variable frequency driving, then the display panel can adapt to different usage scenarios and reduce power consumption, but luminance differences occur and display quality deteriorates
Solution Approach 1:
The patent changes the voltage parameter (first low voltage level) based on the driving frequency. When the driving frequency changes, the first low voltage level is adjusted accordingly to compensate for luminance differences. This parameter change approach allows the display to maintain consistent luminance across different frequency operations while preserving the adaptability benefits of variable frequency driving.
2Illumination intensity
If the first low voltage is increased during blank period at lower driving frequency, then luminance differences are reduced and display quality improves, but the circuit operation complexity increases
Solution Approach 1:
The patent implements dynamic voltage adjustment where the first low voltage level is not fixed but changes based on the driving frequency. The voltage generator dynamically modifies the voltage level during blank periods when operating at lower frequencies, creating a adaptive system that automatically compensates for luminance variations without requiring complex external control circuits.
Solution Approach 2:
The display panel driver autonomously adjusts the first low voltage level based on the detected driving frequency without requiring external intervention. The system self-regulates the voltage to maintain luminance consistency, reducing the need for additional control complexity while achieving improved display quality.
3Illumination intensity
If a blank current is allowed to flow through the second transistor during blank period, then luminance differences are reduced, but energy consumption increases
Solution Approach 1:
The patent applies blank current in a periodic manner during blank periods rather than continuously. The blank current flows only during specific time intervals (blank periods) and is disabled during active periods, creating a periodic action pattern. This approach reduces luminance differences while minimizing overall energy consumption compared to continuous current application.
Data Source
AI summary
A display apparatus includes: a display panel including a pixel; and a display panel driver providing an active data voltage to the pixel through a data line in an active period, and applying a blank data voltage to the data line in a blank period, the pixel including: a light emitting element; a first transistor applying a driving current to the light emitting element; a second transistor applying the active data voltage to the first transistor based on a first gate signal; and a third transistor applying an initialization voltage to the light emitting element based on a second gate signal, wherein the first gate signal transitions between a first high voltage and a first low voltage and the second gate signal transitions between a second high voltage and a second low voltage, and wherein the first low voltage is changed based on a driving frequency of the display panel.