Reflective Polarizing Module with Diffusion Pattern for Backlight Units
Solution Overview
Problem
The existing reflective polarizing modules in liquid crystal displays suffer from reduced light-condensing efficiency and visual defects such as moire phenomena and color shifts due to bonding issues between the reflective polarizing sheet and light-condensing sheets, which lead to a deterioration in screen quality and brightness.
Innovation Solution
A reflective polarizing module with a coating layer having a diffusing pattern on the reflective polarizing sheet to diffuse light and prevent bonding line generation, combined with a bonding layer on the lower surface to minimize the elimination of the upper end of the prism and enhance bonding strength, thereby preventing brightness reduction and optical interference effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the light-condensing sheet is bonded to the reflective polarizing sheet, then bonding stability is improved, but light-condensing efficiency deteriorates due to elimination of the upper end portion of the prism
Solution Approach 1:
The light-condensing sheet is divided into multiple prisms, with only the lower portions bonded to the reflective polarizing sheet while the upper end portions remain unbonded to maintain light-condensing functionality. This segmentation allows simultaneous achievement of bonding stability and light-condensing efficiency.
Solution Approach 2:
Different regions of the light-condensing sheet have different bonding states: the lower portions are bonded to ensure stability, while the upper end portions remain unbonded to preserve light-condensing efficiency. This local differentiation resolves the contradiction between bonding stability and light-condensing efficiency.
2Reliability
If bonding is performed between the reflective polarizing sheet and light-condensing sheet, then bonding stability is improved, but visual quality deteriorates due to bonding surface lines and color shifts
Solution Approach 1:
The bonding is segmented to occur only at the lower portions of the prisms rather than across the entire surface, which reduces the visibility of bonding surface lines and minimizes optical interference effects that cause color shifts.
Solution Approach 2:
A diffusion pattern is introduced as an intermediary element between the bonding interface and the viewer, which diffuses light to mask bonding surface lines and reduce the visibility of color shifts caused by optical interference.
3Reliability
If the upper end portion of the prism is eliminated for bonding, then bonding stability is improved, but brightness deteriorates due to reduced light-condensing efficiency
Solution Approach 1:
The prism structure is segmented such that only the lower portions are eliminated for bonding purposes, while the upper end portions are preserved to maintain light-condensing efficiency and prevent brightness deterioration.
Solution Approach 2:
The elimination of prism portions is localized to specific bonding regions rather than affecting the entire light-condensing sheet, thereby maintaining overall light-condensing efficiency and preventing significant brightness loss.
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 effectively reduces moire phenomena and color shifts, maintains light-condensing efficiency, and prevents brightness reduction by diffusing light through the diffusing pattern and enhancing bonding stability between the reflective polarizing sheet and light-condensing sheets.
Implementation Method 1
a coating layer having a separate diffusion pattern is provided on the reflective polarizing sheet so as to diffuse light transmitted through the reflective polarizing sheet
Implementation Method 2
a separate reflective polarizing sheet is provided on the upper portion of the light-condensing sheet to transmit only the light of a specific polarization upwardly
Implementation Method 3
the light guide plate is provided with a reflector on a lower surface thereof so as to transmit a light emitted from the light source upwardly
Data Source
AI summary
A reflective polarizing module is provided which includes a reflective polarizing sheet to selectively transmit light; a light-condensing sheet having continuously repeating light-condensing bodies, wherein each of the light-condensing bodies has a gradually decreasing transverse cross-sectional area from the lower portion to the upper portion of the reflective polarizing sheet, and the upper end of the first unit light-condensing body is bonded to the lower portion of the reflective polarizing sheet so as to have a first transverse width; and a coating layer on the upper surface of the reflective polarizing sheet and having a diffusion pattern to diffuse light transmitted through the reflective polarizing sheet, the diffusion pattern being constituted by a plurality of diffusion protrusions protruding from the upper surface of the coating layer, wherein at least some of the plurality of diffusion protrusions are formed to have a transverse width relatively smaller than the first transverse width.