Micro-LED Global Dimming Using Combined GPWM and DPWM Signals
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Micro-LED displays face challenges in implementing global dimming due to limited pixel circuit space, making it difficult to adjust brightness and luminance efficiently, especially with shrinking pixel sizes and increasing resolution and frame rates.
Innovation Solution
A micro-LED display system that incorporates a frame buffer, bitplane generator, and dimming module to generate combined pulse width modulation signals at multiple resolutions, allowing for efficient brightness and luminance control through a combined FPWM signal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If additional circuitry is added to adjust brightness and luminance of each pixel, then brightness control capability is improved, but pixel circuit space is exceeded
Solution Approach 1:
The patent extracts the global dimming control function from individual pixel circuits and places it at the display panel level. A dimming control circuit is provided outside the pixel array, receiving grayscale voltage and generating dimming control signals that are applied globally to all pixels through scan lines, thereby removing the brightness control burden from individual pixel circuits.
Solution Approach 2:
The patent combines global dimming control with the existing scan line structure. The same scan lines used for pixel row selection are also utilized to transmit dimming control signals to corresponding pixel rows, merging two functions into a single signal path and eliminating dedicated dimming circuitry within pixels.
2Manufacturing precision
If pixel size is reduced for higher resolution, then image quality is improved, but pixel circuit space becomes more limited
Solution Approach 1:
The patent extracts brightness control functionality from the shrinking pixel circuits and relocates it to external dimming control circuits. This extraction allows pixel circuits to be minimized for high resolution while maintaining full brightness control capability through the separate dimming control system that operates at the panel level.
3Productivity
If frame rate is increased for better video quality, then video performance is improved, but power consumption increases
Solution Approach 1:
The patent implements dimming control through periodic pulse width modulation (PWM) signals. The dimming control circuit generates PWM signals with varying duty cycles to control pixel row brightness, allowing efficient power management by switching LEDs on and off at high frequency rather than using continuous analog dimming, thereby reducing power consumption while maintaining video quality.
Solution Approach 2:
The patent changes the voltage parameter dynamically through the dimming control circuit. The circuit receives grayscale voltage and combines it with dimming control signals to produce varied output voltages that control pixel brightness levels, enabling power consumption adjustment without affecting the underlying video signal integrity or frame rate performance.
Data Source
AI summary
A micro-LED display, including a display panel with pixel circuits, wherein each pixel circuit includes at least one LED, a frame buffer configured to store display data of the display panel, a first gate driver configured to select a row of the display panel, a bit plane generator configured to and generate a plurality of bitplanes and write the display data to each pixel circuit in the row of the display panel, wherein each bitplane corresponds to a bit of the display data, where the plurality of bitplanes generates a GPWM signal for each pixel circuit of the display panel, a second gate driver configured to output a DPWM signal to each row of the display panel based on the dimming value, where each pixel circuit of the display panel is configured to merge the GPWM and DPWM signals into an FPWM to adjust a brightness of the pixel circuit.