Backlight Module Brightness Uniformity via Feedback Control
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Solution Overview
Problem
Conventional micro/mini light-emitting diode (MLED) backlight modules experience uneven brightness and darkness due to IR drop and manufacturing process variations, leading to suboptimal display performance.
Innovation Solution
A backlight module comprising multiple light-emitting units, driving chips with control terminals, signal acquisition units, and control units with feedback nodes, along with an adjustment module that adjusts brightness based on collected feedback voltages to ensure uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If multiple MLEDs share the same positive terminal and are driven by different driving chips with PWM control, then local dimming function is achieved with high contrast ratio, but uneven brightness and darkness occur due to IR drop and manufacturing process variations
Solution Approach 1:
The patent implements a feedback mechanism where each control unit includes a feedback node that detects the actual current flowing through each MLED. The signal acquisition unit collects these feedback voltages, and the adjustment module uses this information to dynamically adjust the driving current for each MLED, compensating for brightness inconsistencies caused by manufacturing variations and IR drop.
Solution Approach 2:
The patent dynamically changes the driving parameters (current) for each MLED based on detected feedback. The adjustment module modifies the current flowing through each MLED individually according to the collected feedback voltages, thereby compensating for manufacturing process variations and achieving uniform brightness across all MLEDs.
2Illumination intensity
If feedback nodes and signal acquisition units are added to each control unit, then brightness uniformity is improved through current detection and adjustment, but device complexity increases
Solution Approach 1:
The patent merges the feedback node, signal acquisition unit, and adjustment module into an integrated driving chip structure. By combining these functions within the same chip that already controls the MLEDs, the patent reduces the need for separate external components and minimizes the increase in overall device complexity while achieving brightness uniformity.
Data Source
AI summary
The present application provides a backlight module and a display device. The backlight module includes multiple light-emitting units, at least one driving chip, and an adjustment module. In the driving chip, control units are used to control the respective corresponding light-emitting unit to emit light based on control signals. Each control unit has a feedback node. A signal acquisition unit is connected to the feedback nodes to collect feedback voltages of the feedback nodes. An adjustment module is connected to the at least one driving chip and is used to adjust light-emission brightness of the light-emitting units according to the feedback voltages.