Backlight Module Privacy Control via Dual Light Source Segmentation
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Solution Overview
Problem
Existing display panel backlight systems fail to provide effective privacy protection due to reduced contrast ratio when viewed from left and right angles, as they do not adequately control light distribution to limit the viewing angle.
Innovation Solution
A backlight module comprising a transparent substrate with first and second light emitting units, a light guide plate, and a reflective material, where the first units emit light with a narrow beam angle and the second units emit light from both surfaces, allowing for adjustable light intensity modes to achieve a narrow viewing angle for privacy protection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single light source is used in the backlight module, then the device complexity is reduced, but the ability to adjust light distribution and control viewing angle is insufficient
Solution Approach 1:
The backlight module is segmented into two distinct light source groups: first light sources positioned at the top surface of the transparent substrate and second light sources positioned at the bottom surface. This segmentation allows independent control of light distribution patterns, enabling the system to switch between wide viewing angle mode (both sources active) and narrow viewing angle mode (first sources dominant), thereby resolving the contradiction between adaptability and device complexity.
Solution Approach 2:
The system implements dynamic control by independently adjusting the light intensity of the first and second light sources based on different operating modes. In normal mode, both sources operate at higher intensity for wide viewing angle; in privacy protection mode, the first light sources are intensified while second light sources are dimmed or turned off, creating a narrow viewing angle. This dynamic adjustment capability provides adaptability without requiring permanent complex structural modifications.
2Adaptability or versatility
If microstructures are designed on the light guide plate for privacy protection, then the manufacturing complexity increases, but the light distribution control is improved
Solution Approach 1:
Instead of modifying the physical structure of the light guide plate with complex microstructures, the patent achieves viewing angle control by changing the operational parameters of the light sources. By adjusting the intensity ratios between first and second light sources and controlling their emission patterns, the system achieves narrow or wide viewing angles without any structural modifications to the light guide plate, thereby maintaining ease of manufacture while improving adaptability.
3Object-affected harmful factors
If the beam angle of light emitting units is reduced to achieve narrow viewing angle, then the privacy protection is improved, but the illumination coverage area is reduced
Solution Approach 1:
The patent merges the functions of two different light source groups positioned at opposite surfaces of the transparent substrate. The first light sources (top surface) provide narrow beam angles for privacy protection, while the second light sources (bottom surface) provide broader illumination coverage. When both operate together in normal mode, their combined light distribution achieves both adequate coverage area and acceptable privacy protection. When the first sources are intensified in privacy mode, they maintain narrow angles while the overall system coverage is sustained through the coordinated operation of both source groups.
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
The solution effectively enhances privacy protection by allowing for adjustable light intensity modes that provide a narrow viewing angle while maintaining a wide viewing angle in normal conditions, improving contrast ratio and light distribution.
Implementation Method 1
The first light emitting units are disposed on the top surface of the transparent substrate. A beam angle of the first light emitting units is greater than or equal to 30 degrees and less than or equal to 45 degrees.
Implementation Method 2
The light guide plate is disposed on the bottom surface of the transparent substrate. The light guide plate includes multiple holes corresponding to the second light emitting units respectively, and each of the second light emitting units is disposed in the respective hole.
Implementation Method 3
a diffuser is disposed above the top surface of the transparent substrate. The first light emitting units are disposed between the diffuser and the transparent substrate.
Data Source
AI summary
The backlight module includes the following units. Multiple first light emitting units are disposed on a top surface of a transparent substrate. A beam angle of the first light emitting units is greater than or equal to 30 degrees and less than or equal to 45 degrees. Multiple second light emitting units and a light guide plate are disposed on a bottom surface of the transparent substrate. Each second light emitting unit is disposed in a respective hole of the light guide plate. A light intensity of the first light emitting units in a first mode is smaller than that in a second mode. A light intensity of the second light emitting units in the first mode is greater than that in the second mode. In this way, the purpose of privacy protection can be achieved.