Viewing-angle adjustable liquid crystal display with sidelight unit
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Solution Overview
Problem
Existing liquid crystal display technologies face challenges in providing adjustable viewing angles without compromising luminance and contrast, particularly in offering narrow viewing-angle modes for users beyond the front view, and often require additional external structures that complicate usage.
Innovation Solution
A liquid crystal display system comprising a backlight module, a light valve, and a sidelight unit, where the sidelight unit includes a light guide plate and sidelight sources, allowing for direct or scattered light distribution based on viewing-angle mode requirements, with the backlight and sidelight units powered accordingly to achieve desired viewing angles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a shutter structure is added to adjust viewing angle, then viewing angle control is improved, but device complexity and luminance loss increase
Solution Approach 1:
The patent extracts the viewing angle control function from the main display structure by using a separate light scattering device layer that can be independently controlled. This allows the shutter structure to be removed and the viewing angle adjustment function to be achieved through optical property modulation of a dedicated layer, thereby reducing overall device complexity while maintaining viewing angle control capability.
Solution Approach 2:
The light scattering device serves multiple functions: it acts as a viewing angle control mechanism, a light diffusion element, and a selectable optical path modifier. By integrating this multi-functional component, the patent eliminates the need for separate shutter structures while achieving the same viewing angle control objectives, thus reducing device complexity.
2Adaptability or versatility
If a shutter structure is used to control viewing angle, then viewing angle restriction is improved, but luminance decreases
Solution Approach 1:
The patent changes the optical parameters of the light scattering device by applying different voltages to switch between scattering and non-scattering states. This parameter-based control allows the system to adjust viewing angle and luminance characteristics electrically without physically blocking light, thereby maintaining high luminance while achieving viewing angle control.
Solution Approach 2:
The patent replaces the mechanical shutter structure with an electrically controlled light scattering device. Instead of using physical shutters to block light paths, the system uses voltage-controlled optical property changes in the scattering device to achieve viewing angle control, eliminating mechanical components and associated luminance losses from light absorption.
3Adaptability or versatility
If a light scattering device is used to provide wide viewing angle, then viewing angle flexibility is improved, but luminance is reduced due to light reflection
Solution Approach 1:
The patent implements a dynamic light scattering device that can switch between scattering and non-scattering states based on applied voltage. This dynamic control allows the system to optimize between wide viewing angle mode (scattering state) and high luminance mode (non-scattering state), providing adaptability while minimizing luminance loss through intelligent state selection.
4Adaptability or versatility
If additional alignment layers are added to control viewing angle, then viewing angle adjustment is improved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent extracts the viewing angle control function from the alignment layer structure and places it in a separate, controllable light scattering device layer. This separation allows standard alignment layers to be used without additional rubbing direction adjustments, significantly simplifying the manufacturing process while maintaining viewing angle control capability through electrical actuation of the scattering device.
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
Enables adjustable viewing angles with maintained luminance by selectively powering the backlight and sidelight units, allowing users to see images from various angles without significant luminance differences between modes, effectively addressing the limitations of previous technologies.
Implementation Method 1
the backlight Lb is scattered to form the scattering light Ls and enter the liquid crystal layer 200 so that the observers at every viewing angle can see the displayed images
Implementation Method 2
The sidelight unit, disposed under the display panel, includes a light guide plate and a first sidelight source
Data Source
AI summary
A viewing-angle adjustable liquid crystal display includes a display panel, a backlight unit, and a sidelight unit. The backlight unit is located under the sidelight unit, and the sidelight unit is disposed under the display panel. The sidelight unit includes a first sidelight source and a light-guide plate. The first sidelight source is disposed at one end of the light-guide plate. The displaying method includes providing direct light to the display panel in response to the narrow-viewing-angle-mode signal; and providing scattering light to the display panel in response to the wide-viewing-angel-mode signal.