VA LCD Optical Alignment Resin Layer for Reflected Light Attenuation
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Solution Overview
Problem
The existing optical alignment treatment for VA mode LCDs is disturbed by light reflected from metal layers, leading to non-uniform anchoring forces and poor display quality due to the inability of existing methods to effectively attenuate the impact of reflected light on the alignment films.
Innovation Solution
A VA mode liquid crystal display device with a short wave absorbing resin layer between the metal layer and the optical alignment film, which attenuates the intensity of light reflected from the metal layer to 60% or less at the photosensitive wavelength, ensuring consistent anchoring force direction and alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If optical alignment treatment is performed on alignment films in VA mode LCDs, then pretilt directions can be defined for multi-domain structure, but light reflected from metal layers disturbs the alignment state causing non-uniform anchoring forces
Solution Approach 1:
A resin layer is introduced as an intermediary substance between the metal layer and the alignment film. This resin layer has optical properties that attenuate reflected light from the metal layer, preventing it from disturbing the optical alignment treatment of the alignment film. The resin layer acts as a buffer that blocks harmful reflected light while allowing the alignment treatment to proceed uniformly.
Solution Approach 2:
The reflected light from the metal layer, which was originally a harmful factor disturbing the alignment treatment, is converted into a beneficial situation by introducing the resin layer. The resin layer selectively attenuates the harmful reflected light at the photosensitive wavelength range (250-380 nm) while maintaining other necessary optical properties, thus transforming the problematic reflection into a controlled situation.
2Shape
If slits or ribs are used as alignment control structures, then multi-domain structure can be formed, but anchoring force becomes non-uniform and luminance decreases
Solution Approach 1:
The invention extracts and removes the problematic slits or ribs from the alignment control structure. Instead of using these physical structures that cause non-uniform anchoring forces and reduce luminance, the patent defines pretilt directions solely through alignment films treated with optical alignment treatment, eliminating the harmful elements while preserving the multi-domain functionality.
3Device complexity
If optical alignment treatment is used to define pretilt directions, then manufacturing complexity is reduced compared to rubbing treatment, but reflected light from metal layers causes alignment disturbance
Solution Approach 1:
The resin layer serves as a protective intermediary that enables the optical alignment treatment to proceed without disturbance from metal layer reflections. This maintains the simplicity of the optical alignment process while ensuring uniform alignment results, thus preserving both low complexity and high precision.
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 prevents disturbance of the alignment state during manufacturing, enhancing the display quality and reliability of VA mode LCDs with a multi-domain structure by maintaining uniform pretilt directions and luminance.
Implementation Method 1
a first resin layer arranged between the metal layer and the first alignment film, the first resin layer having an optical property that attenuates an intensity of light, which has been incident on the first resin layer and then reflected from the metal layer, to 60% or less at the photosensitive wavelength
Implementation Method 2
The first alignment film has been subjected to an optical alignment treatment by obliquely irradiating a first alignment film material, having a photosensitive wavelength within the wavelength range of 250 nm to 380 nm, with light including the photosensitive wavelength
Implementation Method 3
a vertical alignment liquid crystal layer in which liquid crystal molecules are aligned so as to have their axis form an angle of (i.e., have a pretilt angle of) approximately 85 degrees or more with respect to the surface of a vertical alignment film
Data Source
AI summary
A liquid crystal display device according to the present invention includes: a vertical alignment liquid crystal layer; first and second electrodes arranged on one surface of first and second substrates to face the liquid crystal layer; and first and second alignment films arranged on the first and second electrodes, respectively, in contact with the liquid crystal layer. The first alignment film has been subjected to an optical alignment treatment by obliquely irradiating a first alignment film material, having a photosensitive wavelength within the wavelength range of 250 nm to 380 nm, with light including the photosensitive wavelength. The device further includes: a metal layer arranged between the first alignment film and the first substrate; and a first resin layer arranged between the metal layer and the first alignment film. The first resin layer has an optical property that attenuates the intensity of light, which has been incident on the first resin layer and then reflected from the metal layer, to 60% or less at the photosensitive wavelength.