Mini LED Backlight Driving Circuit for Current Pulse Reduction
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Solution Overview
Problem
The mini LED backlight module experiences high current pulses when all rows of LEDs are simultaneously illuminated, leading to reduced OLED lifetime and electromagnetic interference.
Innovation Solution
A driving method and circuit that sequentially scans and illuminates rows of light emitting units across multiple backlight sections, using a gate driver to provide scan signals and a source driver to input data signals based on luminance information, allowing all units to work together during each frame time while controlling the time period for illumination to achieve desired grayscale.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If all rows of LEDs are simultaneously illuminated in a frame period, then the backlight module achieves uniform illumination and high brightness, but the current pulse becomes huge which reduces OLED lifetime and causes electromagnetic interference
Solution Approach 1:
The patent divides the backlight module into multiple independently controllable backlight sections (e.g., left and right sections). Each section can be illuminated separately with controlled current, avoiding the simultaneous illumination of all rows which causes huge current pulses. This segmentation allows the system to maintain uniform backlight effect while reducing peak current and electromagnetic interference.
2Reliability
If all rows of LEDs are simultaneously illuminated, then the display achieves high contrast and delicate dynamic distribution, but the power consumption increases and OLED lifetime is reduced
Solution Approach 1:
By dividing the backlight into multiple sections that can be independently controlled, the system can illuminate only the necessary sections at any given time. This reduces overall power consumption and decreases the stress on individual OLEDs, thereby extending their lifetime while maintaining the ability to achieve high contrast and delicate dynamic distribution in the displayed image.
Solution Approach 2:
The patent employs periodic scanning of rows within each backlight section rather than continuous simultaneous illumination. This periodic action reduces the duty cycle for each OLED, decreasing power consumption and heat generation, which helps extend OLED lifetime while still achieving the desired display quality through controlled timing.
3Area of stationary object
If multiple backlight sections are driven simultaneously, then the backlight coverage is complete, but the current pulse amplitude increases causing noise and electromagnetic interference
Solution Approach 1:
The backlight module is divided into multiple independently controllable sections that can be illuminated in a staggered manner. This segmentation allows complete backlight coverage to be achieved while controlling the current pulse amplitude in each section, thereby reducing noise and electromagnetic interference compared to simultaneous illumination of all sections.
Solution Approach 2:
The patent uses periodic scanning and staggered illumination of different backlight sections. By activating sections sequentially rather than simultaneously, the system maintains complete coverage over time while reducing peak current amplitude, which minimizes noise and electromagnetic interference generated by the backlight system.
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
This approach reduces the amplitude and pulse of the backlight current, alleviating the issues of OLED degradation and electromagnetic interference by ensuring that each row of LEDs is illuminated in a controlled and staggered manner.
Implementation Method 1
Each of the backlight sections comprises light emitting units arranged in an m*n array
Implementation Method 2
Each of the backlight plates have organic LEDs (OLEDs) arranged in an array
Data Source
AI summary
A mini LED backlight module, a driving circuit and a display device are provided. Emitting units of the same row in the mini LED backlight module are divided into multiple sections that could be illuminated differently. This could avoid the issue of a high backlight current pulse when each row of light emitting units in different backlight sections is simultaneously illuminated and thus alleviate the issue of reducing the lifetime of light emitting units.