Asymmetric Backlight Module for Automotive Viewing Angle Control
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Solution Overview
Problem
Conventional backlight modules for automotive displays face challenges in achieving the required wide viewing angle without causing light reflection from car windows, particularly when applied to displays in front of the driver's or co-driver's seat.
Innovation Solution
A backlight module comprising a surface light source, optical film, and light control film with asymmetrical optical structures that deflect light to one side, suppressing emission on the other side, using a combination of optical and light control films to achieve asymmetric light distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a wide viewing angle is used in automotive display devices, then passengers on both sides can see the displayed content, but light may be reflected by car windows and affect the driver
Solution Approach 1:
The patent applies asymmetry by using a light control film with asymmetric microstructures that have different inclinations on opposite sides. The first inclination angle on the first side is different from the second inclination angle on the second side, creating asymmetric light deflection. This allows the display to have different light emission characteristics in different directions, enabling wide viewing angles for passengers while redirecting light away from the driver's position to minimize window reflection interference.
Solution Approach 2:
The patent implements local quality by varying the inclination angles of microstructures at different locations on the light control film. Specifically, the inclination angle on the first side (facing the driver) is set differently from the inclination angle on the second side (facing passengers). This localized variation in structural properties enables differential light control - restricting light emission toward the driver while maintaining wide viewing angles for passengers, thus resolving the contradiction between wide viewing angle and light reflection interference.
2Adaptability or versatility
If conventional backlight module structures are used, then the display can be implemented, but the specific viewing angle requirements of automotive display devices cannot be met
Solution Approach 1:
The patent applies parameter changes by modifying the inclination angles of the microstructures in the light control film. The inclination angles are specifically designed with different values on opposite sides (first inclination angle ≠ second inclination angle), and these angular parameters are optimized to control light emission directions. By changing these geometric parameters, the backlight module achieves precise control over viewing angles, meeting the specific requirements of automotive displays while preventing harmful light emission in unwanted directions.
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 directs light to one side, reducing reflections from windows and ensuring clear visibility for drivers and passengers by minimizing light emission from the opposite side.
Implementation Method 1
the transmittance of the light of the optical film is at least 50%
Implementation Method 2
the light emitted by the surface light source is entered the light control film and deflects in the direction away from the first optical surface of at least one of said first optical structures after passing the light control film
Implementation Method 3
The first optical surface and the first reference surface form a first included angle θ1, the second optical surface and the first reference surface form a second included angle θ2, the first included angle θ1 is an acute angle, and the first included angle θ1 is smaller than the second included angle θ2
Data Source
AI summary
A backlight module includes a light source, an optical film, and a light control film. The light control film has a first reference surface and a plurality of first optical structures disposed on the first reference surface. Each of the first optical structures has a first optical surface and a second optical surface. A first included angle is formed between the first optical surface and the first reference surface. A second included angle is formed between the second optical surface and the first reference surface. The first included angle is an acute angle and is smaller than the second included angle. Thereby, the light can be deflected to one side and the light output of the other side can be suppressed. This invention also provides a display device including the backlight module.