Dual Light Guide Plate Backlight for 2D-3D Mode Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing autostereoscopic displays using the parallax barrier or lenticular methods face challenges with low optical efficiency, high crosstalk between left and right images, and difficulty in achieving high-quality two-dimensional (2D) displays, with limited flexibility in design and inability to readily switch between 2D and three-dimensional (3D) modes.
Innovation Solution
A backlight unit is designed with a first light guide plate (LGP) using optical materials with different refractive indices, a second LGP with a diffuser plate, and light sources that selectively provide light to either LGP based on the image mode, allowing for efficient switching between 2D and 3D modes by adjusting the refractive indices, angles, and configurations such as zigzagging the first optical material and using a reflector sheet to enhance light directionality and reduce crosstalk.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single light guide plate is used for both 2D and 3D displays, then device complexity is reduced, but the ability to switch between modes and optimize performance for each mode is compromised
Solution Approach 1:
The backlight unit is divided into two separate light guide plates: a first LGP optimized for 3D display with specific optical structures, and a second LGP optimized for 2D display with diffuser plates. This segmentation allows each LGP to be independently optimized for its specific function while enabling mode switching through selective activation, thus resolving the contradiction between adaptability and device complexity.
2Manufacturing precision
If optical materials with different refractive indices are used in the first LGP, then light directionality and 3D image quality are improved, but manufacturing complexity increases
Solution Approach 1:
The first LGP incorporates optical materials with different refractive indices at specific locations and orientations (e.g., slanted or zigzagged configurations) to create localized light redirection effects. This local quality approach enables precise control of light directionality for 3D viewing angles without requiring the entire LGP structure to be complex, thus improving light guidance precision while managing manufacturing complexity.
3Illumination intensity
If light is provided to both LGPs simultaneously, then overall brightness is increased, but crosstalk between left and right images increases
Solution Approach 1:
The system employs time-division multiplexing where light is provided alternately to the first LGP (for 3D left image) and the second LGP (for 3D right image) in periodic time slots. This periodic action ensures that each eye receives light from the appropriate LGP at the correct time, eliminating crosstalk while maintaining high illumination intensity through sequential activation rather than simultaneous activation.
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 enhances optical efficiency, reduces crosstalk, and allows for flexible switching between 2D and 3D modes by optimizing light guidance and distribution, improving the quality and number of views in 3D images while maintaining effective 2D image display.
Implementation Method 1
a first light guide plate (LGP) including a first optical material and a second optical material having different refractive indices, and configured to emit a light guided through the second optical material toward a display panel using the first optical material
Implementation Method 2
a second LGP disposed between the first LGP and the display panel, and configured to emit the light toward the display panel using a diffuser plate provided in a lower portion of the second LGP
Implementation Method 3
the first LGP may include a reflector sheet disposed between the first optical materials and configured to reflect the light reaching an upper portion of the first LGP
Data Source
AI summary
A display device with a display panel, and backlight unit including a first light guide plate (LGP) having first and second optical materials, a second LGP disposed between the first LGP and the display panel, light sources configured to provide light to the first LGP and the second LGP, and a diffuser plate in a lower portion of the second LGP. The first LGP configured such that light from a light source is guided by the second optical material and emitted towards the display panel through the first optical material; the second LGP configured to emit light towards the display panel using the diffuser plate. A controller controls the light sources to provide light to the first LGP if a three-dimensional (3D) image is displayed on the display panel, and to the second LGP if a two-dimensional (2D) image is displayed on the display panel.