Backlight Module Sealant Frame for Force Touch Stability
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Solution Overview
Problem
The existing liquid crystal force touch apparatus experiences poor stability due to tolerances in the size and assembly of components, leading to a reduced capacitance variation when pressure is applied, which affects the accuracy of force touch detection.
Innovation Solution
A back light module with an optical film group, a sealant frame, and an annular support structure, where the conductive frame is electrically connected to a reference voltage and adhered to the sealant frame, creating a gap between the optical film group and the conductive frame to enhance the stability of force touch detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If tolerances exist between actual size and design size of films and assembly size, then the lower polarizer may sink into the inner groove of the sealant frame, narrowing the gap between the liquid crystal display panel and the optical film group, but this causes the variation in capacitance value to become less, resulting in poor stability of the force touch
Solution Approach 1:
The patent introduces an intermediary structure (the sealant frame with its inner groove and the polarizer positioning mechanism) that mediates between the liquid crystal display panel and the optical film group. This intermediary structure maintains a consistent gap despite manufacturing tolerances, preventing the polarizer from sinking into the sealant frame inner groove and ensuring stable capacitance variation for force touch detection.
2Volume of moving object
If the gap between the liquid crystal display panel and the optical film group is narrowed due to polarizer sinking, then the assembly size is reduced, but the capacitance variation decreases, causing poor force touch stability
Solution Approach 1:
The patent applies preliminary action by pre-positioning the lower polarizer relative to the sealant frame inner groove before assembly. The sealant frame's inner groove is designed in advance to accommodate the polarizer at a specific position, preventing sinking during assembly and maintaining the required gap for stable force touch detection while keeping the assembly size compact.
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 maintains a consistent gap between the force touch electrode and the conductive frame, improving the stability and accuracy of force touch signals by preventing the optical film group from sinking into the sealant frame, thus maintaining a stable capacitance variation under user pressure.
Implementation Method 1
the force touch function is realized by measuring the variation in the capacitance value of a capacitor C constituted by the two force touch electrodes
Implementation Method 2
The annular support structure is disposed between the optical film group and the conductive frame and extends along an edge of the optical film group
Implementation Method 3
The conductive frame is electrically connected to a reference voltage input terminal and adhered to a bottom surface of the sealant frame
Data Source
AI summary
A back light module and a liquid crystal display apparatus are provided A back light module has a conductive frame, connected electrically to a reference voltage input terminal; a sealant frame displaced inside the conductive frame, wherein the sealant frame has a bottom surface adhered to a top surface of the conductive frame; a support structure displaced above the top surface of the conductive frame along the inside edges of the sealant frame; and a plurality of optical films disposed over the conductive film and being supported by the support structure. The plurality of optical films includes an upper brightness enhancement film, a lower brightness enhancement film, a diffuser film, a light guide plate; and a reflector film.