Inverted LCD Structure for VR Light Recycling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Liquid Crystal Displays (LCDs) used in virtual reality, mixed reality, and augmented reality systems face limitations in achieving high resolution due to larger thin film transistor sizes and alignment errors between substrates, which reduce brightness and increase power consumption.
Innovation Solution
The LCD design includes a liquid crystal panel with a thin film transistor substrate and a color filter substrate, where the color filter substrate is closer to the backlight unit and features a reflective layer to recycle light, and the TFT substrate has a reflective layer to shield TFTs from light, eliminating the need for a black matrix and enhancing brightness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If larger TFT sizes are used for high speed electronic signal propagation, then signal propagation speed is improved, but aperture ratio is reduced and brightness is reduced
Solution Approach 1:
The patent converts the harmful light that would normally be absorbed by the black matrix into a beneficial resource by introducing a reflective layer. This reflective layer redirects the light back through the liquid crystal layer and color filter, allowing it to contribute to the final image brightness. This resolves the contradiction by making use of what would otherwise be wasted light, thereby improving brightness without requiring larger aperture ratios.
Solution Approach 2:
The patent recovers light that would normally be discarded or absorbed by the black matrix and TFT structures. The reflective layer captures light that would otherwise be lost and redirects it through the display stack, recovering its useful illumination function. This recovery mechanism allows the system to maintain high brightness while using smaller TFT apertures.
2Speed
If larger TFT sizes are used for high speed electronic signal propagation, then signal propagation speed is improved, but aperture ratio is reduced and power consumption is increased
Solution Approach 1:
The reflective layer converts the harmful absorption of light by the black matrix into a beneficial recycling mechanism. By redirecting light back through the liquid crystal and color filter, the system recovers illumination that would otherwise be wasted, reducing the total light output requirement from the backlight unit and thereby reducing power consumption.
Solution Approach 2:
The patent recovers light energy that would normally be discarded by the black matrix and TFT structures. The reflective layer captures and redirects this light through the display stack, recovering its illumination function and reducing the overall energy requirement for the backlight unit, thus lowering power consumption.
3Ease of manufacture
If alignment error between color filter substrate and TFT substrate is present, then manufacturing is simplified, but aperture ratio is reduced and brightness is reduced
Solution Approach 1:
The reflective layer compensates for alignment errors between the color filter substrate and TFT substrate by redirecting light through both substrates. This ensures that even when perfect alignment is not achieved, the light path is maintained and brightness is preserved, making the display less sensitive to manufacturing variations.
Solution Approach 2:
The reflective layer recovers light that would otherwise be lost due to misalignment between substrates. By redirecting light back through the liquid crystal and color filter, the system recovers illumination function even when perfect substrate alignment is not achieved, maintaining brightness while simplifying manufacturing tolerances.
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 increases the brightness of the LCD and reduces power consumption by recycling light and shielding TFTs from ambient light, thereby improving the display's efficiency and performance in high-resolution applications.
Implementation Method 1
The CF substrate may include a reflective layer in regions of the CF substrate between a plurality of pixels to reflect light from the BLU back towards the BLU to increase the brightness of the LCD
Implementation Method 2
The TFT substrate may include a reflective layer in regions of the TFT substrate covering a plurality of TFTs to shield the plurality of TFTs from light exiting the BLU
Data Source
AI summary
A liquid crystal display (LCD) is configured for use in a head mounted display (HMD) to increase the brightness and improve power consumption of the LCD by recycling light. The LCD includes a color filter (CF) substrate, a thin film transistor (TFT) substrate, and a backlight unit (BLU). The CF substrate is closer to the BLU than the TFT substrate. The CF substrate includes a first reflective layer in regions of the CF substrate between pixels to reflect light back towards the BLU to be recycled to increase the brightness of the LCD. The TFT substrate includes TFTs to drive the pixels and a second reflective layer covering TFTs to reflect light away from the TFTs.