Light Control Film for Narrow Viewing Angle LCD
Solution Overview
Problem
Liquid crystal display apparatuses struggle to effectively switch between wide and narrow viewing angles, particularly in scenarios where a narrower viewing angle is required for privacy and information management, and existing solutions do not adequately address the need for further narrowing of the viewing angle during narrow viewing angle display.
Innovation Solution
A light control film comprising a first and second transparent substrate, a light control layer with a liquid crystal compound that switches between transmitting and scattering states based on applied voltage, and a surface light source device emitting linearly polarized light, which, when integrated with a liquid crystal panel and polarizing plates, allows for adjustable viewing angles while maintaining high brightness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a light control film with conventional transparent substrates is used, then the viewing angle can be switched between wide and narrow, but the viewing angle cannot be sufficiently narrowed for privacy protection
Solution Approach 1:
The patent applies parameter changes by controlling the liquid crystal layer's optical properties through voltage application. The liquid crystal molecules reorient in response to electric fields, changing the light scattering characteristics from wide-angle to narrow-angle transmission, thereby dynamically adjusting the viewing angle parameter to meet different privacy protection requirements
Solution Approach 2:
The patent implements dynamics by using a controllable light control film with liquid crystal material that can dynamically switch between different optical states. The viewing angle is not fixed but can be adjusted in real-time through voltage control, allowing the display to adapt between wide viewing angle for collaboration and narrow viewing angle for privacy protection
2Object-affected harmful factors
If the viewing angle is narrowed for privacy protection, then privacy is improved, but the brightness and visibility of the display decrease
Solution Approach 1:
The patent applies local quality by creating different optical characteristics in different viewing directions. The light control film is designed to transmit light with high intensity in the forward direction while scattering or blocking oblique light, thereby maintaining bright visibility for authorized viewers while providing privacy protection from side angles simultaneously
3Object-affected harmful factors
If a light control film with low transmittance is used to narrow viewing angle, then privacy protection is improved, but the overall brightness and visibility of the display are reduced
Solution Approach 1:
The patent implements dynamics by using a voltage-controlled light control film that can dynamically adjust its optical state. In the off-state, the liquid crystal layer maintains high transmittance for bright display; in the on-state, it creates strong light scattering to narrow the viewing angle and protect privacy, thereby dynamically optimizing both brightness and privacy protection based on operational requirements
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 enables a liquid crystal display apparatus to switch between wide and narrow viewing angles while achieving a narrower viewing angle during narrow viewing angle display, maintaining high brightness and visibility, and effectively reducing oblique brightness to enhance privacy.
Implementation Method 1
a light control layer which contains a liquid crystal compound, and which enables switching between a light transmitting state and a light scattering state in accordance with a voltage to be applied
Implementation Method 2
a surface light source device configured to emit, from a light emitting surface opposed to the light control film, light having directivity in an approximately normal direction of the light emitting surface
Implementation Method 3
the first transparent substrate has a front retardation of 50 nm or less, wherein the second transparent substrate has a front retardation of 50 nm or less
Data Source
AI summary
The present invention provides a light control film, including: a first transparent substrate; a first transparent electrode layer; a light control layer which contains a liquid crystal compound, and which enables switching between a light transmitting state and a light scattering state in accordance with a voltage to be applied; a second transparent electrode layer; and a second transparent substrate in the stated order, wherein the first transparent substrate has a front retardation of 50 nm or less, wherein the second transparent substrate has a front retardation of 50 nm or less, and wherein the light control film has a total light transmittance of from 85% to 99% in the light transmitting state.