Dual-Mode LCD Panel Switching Viewing Angles
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Solution Overview
Problem
Liquid crystal display devices either have a narrow viewing angle range, which is undesirable in certain applications, or a wide viewing angle range, which may not be suitable for tasks requiring focused viewing, such as in banking or insurance work.
Innovation Solution
A liquid crystal display device with a first panel operating in In-Plane Switching mode for wide viewing angles and a second panel operating in Electrically Controlled Birefringence mode, allowing for selective application of horizontal and vertical electric fields to switch between wide and narrow viewing angle modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a vertical electric field type LCD device is used, then high aperture ratio can be easily provided, but the viewing angle range is narrowed to about 90°
Solution Approach 1:
The invention divides the single LCD panel into multiple regions (first region and second region) with different liquid crystal alignment characteristics. The first region has liquid crystal molecules aligned substantially perpendicular to the substrate, providing high aperture ratio. The second region has liquid crystal molecules aligned substantially parallel to the substrate, providing wide viewing angle. This segmentation allows both high aperture ratio and wide viewing angle to coexist in the same display device.
2Adaptability or versatility
If a horizontal electric field type LCD device (IPS mode) is used, then a wide viewing angle range of about 160° is achieved, but the aperture ratio is reduced
Solution Approach 1:
The invention divides the single LCD panel into multiple regions (first region and second region) with different liquid crystal alignment characteristics. The first region has liquid crystal molecules aligned substantially perpendicular to the substrate, providing high aperture ratio. The second region has liquid crystal molecules aligned substantially parallel to the substrate, providing wide viewing angle. This segmentation allows both high aperture ratio and wide viewing angle to coexist in the same display device.
3Reliability
If a single viewing angle mode is selected, then the display is optimized for specific applications, but it cannot adapt to different work environments
Solution Approach 1:
The invention makes the LCD panel multi-functional by incorporating both first and second regions with different viewing angle characteristics in the same display device. Users can selectively view the first region for narrow viewing angle applications (such as banking or insurance work requiring focused viewing) and the second region for wide viewing angle applications. This universality allows a single display device to adapt to different work environments and application 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
Enables easy switching between wide and narrow viewing angle modes, improving usability in different work environments by maintaining image clarity and contrast across varying viewing angles.
Implementation Method 1
a liquid crystal display device displays image by controlling optical transmittance of liquid crystal materials. This is done by injecting liquid crystal materials between two substrates (one has common electrode and the other has pixel electrode) and applying an electric field to the liquid crystal through electrodes facing each other with the liquid crystal therebetween.
Implementation Method 2
A liquid crystal display device according to the direction of the electric field applied to the liquid crystal layer, can be categorized into a vertical electric field type and a horizontal electric field type.
Implementation Method 3
The horizontal electric field type LCD device is so-called In-Plane-Switching mode (IPS) LCD device. The IPS LCD device is driven by a horizontal electric field (horizontal direction to an LCD panel surface) between the pixel electrode and the common electrode arrayed on the lower substrate. In this mode, there is hardly a movement in the vertical direction as the liquid crystal is driven in the horizontal direction mainly. Therefore, the device has an advantage of having a wide viewing angle range of about 160°.
Implementation Method 4
The vertical electric field type LCD device drives the liquid crystal layer between a pixel electrode and a common electrode through a vertical electric field (vertical to an LCD panel surface). However, a disadvantage of this type LCD device is that a viewing angle range is narrowed to about 90°. This results from the movement of the liquid crystal which affects the light passing through the substrate in an oblique direction as the liquid crystal moves in the vertical direction to the substrate due to vertical electric field.
Data Source
AI summary
A liquid crystal display device and a method for driving the same are provided. The liquid crystal display device includes a first liquid crystal layer selectively driven by a first electric field in a first direction; and a second liquid crystal layer selectively driven a second electric field in a second direction, the second direction being different from the first direction.