Backlight Module Grid Reflective Element Crosstalk Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current backlight modules with local dimming features using Mini-LEDs suffer from optical crosstalk between adjacent dimming zones, leading to light leakage and halo effects on display screens.
Innovation Solution
A backlight module design incorporating a reflective element with a grid portion and an optical element with light guide portions of varying thicknesses, which are strategically positioned to reduce optical crosstalk and improve light uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If local dimming zones are used to improve brightness and contrast, then display performance is improved, but optical crosstalk between adjacent zones occurs causing light leakage and halo effects
Solution Approach 1:
A light shielding structure is introduced as an intermediary component between adjacent light-emitting elements. This structure includes a light shielding portion that extends from the light-emitting element toward the display panel, creating a physical barrier that blocks light from spreading into adjacent dimming zones. The light shielding structure acts as a mediator that prevents direct optical interaction between neighboring zones, thereby eliminating crosstalk while preserving the local dimming effect.
2Length of moving object
If the light guide portion is made thinner to reduce module thickness, then compactness is improved, but light guiding efficiency deteriorates
Solution Approach 1:
The light guide portion is designed with non-uniform thickness, creating different optical path lengths in different regions. The thickness varies from a first thickness in one region to a second thickness in another region. This local variation in thickness allows the light guide to maintain compact overall dimensions while providing sufficient optical path length in specific areas to ensure efficient light guiding and extraction.
Solution Approach 2:
Instead of uniformly reducing thickness in one dimension, the design varies the thickness dimension locally to optimize light guiding. By creating a thickness gradient or stepped structure, the patent transforms a one-dimensional thickness parameter into a two-dimensional spatial variation, allowing simultaneous achievement of compactness and light guiding efficiency through strategic thickness distribution.
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 proposed design effectively reduces optical crosstalk between adjacent dimming zones, minimizing light leakage and halo effects, thereby enhancing the display quality of local dimming display devices.
Implementation Method 1
The optical element has a light guide portion composed of non-light diffusing material
Implementation Method 2
The reflective element is disposed on the circuit board and located between the optical element and the circuit board
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A backlight module (10, 10A, 10B, 10C, 10D, 10E) includes a circuit board (110), light-emitting elements (120), an optical element (140) and a reflective element (130). The light emitting elements (120) are disposed on the circuit board (110). The light emitting elements (120) are disposed between the optical element (140) and the circuit board (110). There is no other optical component between the optical element (140) and the light-emitting elements (120). The optical element (140) has a light guide portion composed of a non-light diffusing material. The reflective element (130) is disposed on the circuit board (110) and is located between the optical element (140) and the circuit board (110). The reflective element (130) includes a grid portion (132). The grid portion (132) separates the light emitting elements (120). The grid portion (132) has openings (132o), and the light-emitting elements (120) are respectively disposed in the openings (132o). A top surface (132t) of the grid portion (132) is higher than the light-emitting elements (120) in a first direction (z), and a gap (AG) is between the grid portion (132) and the optical element (140).