Light Valve and Reflective Polarizer for Display Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing display systems struggle to effectively hide the contrast between a display device and its surrounding frame when in a power-off state, as conventional diffusers may still transmit light and illuminate, leading to an unsightly appearance.
Innovation Solution
A display system incorporating a light valve, a reflective polarizer, and a diffusing layer, where the light valve is operable in pass and block modes, and the diffusing layer can switch between transparent and opaque states, combined with a controller to manage these states, ensuring minimal light transmission when the device is off.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a conventional diffuser is used to hide the display screen, then the display screen can be hidden in opaque state, but the diffuser may still be light transmissive when in diffusive state, making one diffuser layer insufficient to hide the contrast
Solution Approach 1:
The patent combines a first diffuser layer and a second diffuser layer to form a composite diffusing system. The first diffuser layer is arranged between the display screen and the second diffuser layer, with each layer having different optical properties. This merging of multiple diffuser layers achieves better light blocking performance than a single layer could provide, resolving the contradiction between hiding light transmission and avoiding increased device complexity.
Solution Approach 2:
The patent employs composite material structure by using multiple diffuser layers with different optical characteristics. The first diffuser layer and second diffuser layer are configured with different optical densities and scattering properties, creating a composite optical system that effectively blocks light transmission while maintaining a uniform appearance. This composite approach solves the problem of insufficient light blocking with a single diffuser layer.
2Object-affected harmful factors
If the diffuser is controlled to be in opaque state to hide the display screen, then the contrast is hidden, but it is not desirable to illuminate the diffuser in the opaque or off state
Solution Approach 1:
The patent implements a self-service mechanism where the display screen's own backlight serves as the illumination source for the diffuser system. When the display is on, the backlight automatically illuminates the diffuser layers, eliminating the need for a separate illumination system. This resolves the contradiction by making the system energy-efficient while maintaining the ability to hide contrast when needed.
Solution Approach 2:
The patent makes the display backlight serve multiple functions: it provides the primary display illumination and simultaneously serves as the illumination source for the diffuser system when the display is on. This multi-functionality eliminates the need for dedicated diffuser illumination, reducing energy consumption while maintaining the capability to control contrast visibility.
3Object-affected harmful factors
If a cover of similar color as the frame is used on the display, then the contrast may be partially hidden, but the display is very hard to blend with the frame and the whole device
Solution Approach 1:
The patent applies local quality by using diffuser layers with spatially varying optical properties. The diffuser layers are configured to have different optical densities and scattering characteristics in different regions, allowing the display to blend seamlessly with the frame in both on and off states. This local variation in optical properties resolves the contradiction between hiding color contrast and achieving uniform appearance.
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 significantly reduces color contrast between active and non-active display areas, providing a uniform appearance when the device is off, improving the aesthetic appeal of devices like smart phones and AI terminals.
Implementation Method 1
The reflective polarizer is configured to substantially transmit light having a first polarization state and substantially reflect light having an orthogonal second polarization state
Implementation Method 2
The diffusing layer is disposed on the reflective polarizer opposite to the light valve
Implementation Method 3
The light valve includes a liquid crystal light valve (LCLV)
Data Source
AI summary
An article for a display device having an output surface. The article includes a light valve, a reflective polarizer, and a diffusing layer. The light valve is configured to be disposed on the output surface of the display device. The light valve is operable in a pass mode and a block mode. The reflective polarizer is disposed on the light valve opposite to the display device. The reflective polarizer is configured to substantially transmit light having a first polarization state and substantially reflect light having an orthogonal second polarization state. The diffusing layer is disposed on the reflective polarizer opposite to the light valve.