Backlight Module Quasi-U-Shaped Lamp Configuration
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Solution Overview
Problem
Conventional backlight modules for liquid crystal displays face challenges in maintaining uniform luminance due to temperature differences among lamps, leading to variations in electric current and luminance across the display.
Innovation Solution
The solution involves connecting pairs of elongated lamps in a quasi-U-shape configuration, with each pair comprising a lamp at a higher position and a lamp at a lower position, and using two alternating-current power sources to power odd- and even-numbered lamps, respectively, to balance temperature differences and maintain consistent electric current flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If lamps are connected in adjacent pairs to form quasi-U-shape, then device complexity is reduced, but luminance uniformity deteriorates due to temperature differences
Solution Approach 1:
The backlight module is divided into multiple lamp groups, where each group consists of two lamps connected in series. Within each group, one lamp is positioned at a higher location and the other at a lower location, creating segmented temperature zones that can be compensated independently.
Solution Approach 2:
The lamp pairs are configured asymmetrically in terms of position (one higher, one lower) to intentionally create temperature differences that can be compensated. The asymmetric positioning allows the system to address temperature non-uniformity through strategic placement rather than assuming uniform temperature distribution.
2Ease of operation
If power lines are extended to reach all lamps, then ease of operation is improved, but leakage current increases
Solution Approach 1:
The power distribution system is segmented into multiple localized inverter units, each serving a specific lamp group. This segmentation allows power lines to remain short and localized, reducing leakage current while maintaining ease of operation through distributed power delivery.
Solution Approach 2:
Local inverters act as intermediary components between the main power source and the lamps. These intermediaries receive power and distribute it to nearby lamps, reducing the length of power lines and minimizing leakage current while maintaining operational ease.
3Device complexity
If all lamps are powered by a single power source, then device complexity is reduced, but luminance uniformity deteriorates due to temperature variations
Solution Approach 1:
The single power source is segmented into multiple independent inverter units, each responsible for powering a specific lamp group. This segmentation allows independent control and compensation of temperature variations in different lamp regions, improving luminance uniformity while maintaining manageable system complexity.
Solution Approach 2:
Each inverter unit provides localized power control tailored to the specific thermal conditions of its associated lamp group. This local quality approach allows optimization of power delivery for each region's temperature characteristics, improving overall luminance uniformity.
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 configuration ensures high luminance uniformity across the display, reduces leakage current by keeping power lines short, and effectively compensates for temperature variations among lamps, resulting in a more consistent and efficient backlight module.
Implementation Method 1
The backlight module includes elongated fluorescent lamps that are powered by the inverter
Implementation Method 2
ballast capacitors positioned at two ends of each CCFL
Data Source
AI summary
A display includes a backlight module having elongated lamps. At least a pair of the lamps has a first lamp and a second lamp that are electrically connected in series. The first lamp and the second lamp are spaced apart with at least a third lamp positioned between the first and second lamps.