Pretension Assembly for Foldable Display Flatness
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Solution Overview
Problem
Current foldable display devices suffer from irreversible plastic deformation and visible fold marks when bent multiple times due to stringent bending radius requirements and hinge design issues, leading to compromised screen flatness and user experience.
Innovation Solution
A display device incorporating a first and second folding frame, support plates, and a pretension assembly with elastic elements to provide pretension force to the flexible display screen, reducing the likelihood of fold marks and enhancing flatness by distributing stress evenly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If the bending radius of the OLED screen is reduced to achieve thinness and lightness designs, then the device becomes thinner and lighter, but local deformation in bending regions increases and irreversible plastic deformation occurs
Solution Approach 1:
The pretension assembly applies preliminary tension force to the flexible display screen before folding operations occur. This pre-tensioning prevents the screen material from entering the plastic deformation zone during bending by maintaining it in the elastic deformation range, thereby solving the problem of fold marks while enabling smaller bending radii for thinner and lighter devices
Solution Approach 2:
The patent changes the stress state parameter of the flexible display screen by introducing a pretension force. This parameter change transforms the stress distribution in the bending region, ensuring that the material remains within elastic deformation limits even under small bending radii, thus preventing irreversible plastic deformation while achieving thinness and lightness
2Adaptability or versatility
If the flexible display screen is bent multiple times during use, then the device is more flexible and usable, but irreversible plastic deformation accumulates and visible fold marks form
Solution Approach 1:
The pretension assembly applies preliminary tension force to the flexible display screen before folding operations occur. This pre-tensioning prevents the screen material from entering the plastic deformation zone during bending by maintaining it in the elastic deformation range, thereby solving the problem of fold marks while enabling smaller bending radii for thinner and lighter devices
Solution Approach 2:
The pretension assembly maintains continuous tension force on the flexible display screen throughout multiple folding and unfolding cycles. This continuous action ensures that the screen consistently returns to its original flat state without accumulating plastic deformation, thereby maintaining reliability and preventing fold marks over extended use
3Device complexity
If hinge designs are optimized for compact folding, then the device structure is improved, but motion tracks between middle frame structures and screens cause microscopic damage to OLED modules
Solution Approach 1:
The patent extracts the tensioning function from the hinge structure itself and implements it through a separate pretension assembly. This separation allows the hinge to maintain its compact design for optimized folding while the independent pretension assembly handles the protection of the OLED module from motion track damage, thereby resolving the contradiction between structural compactness and module protection
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 pretension assembly effectively reduces the formation of fold marks and improves the flatness of bending regions, enhancing the overall user experience by maintaining screen quality even after repeated bending.
Implementation Method 1
the at least one pretension assembly includes at least one elastic element, and the at least one elastic element generates the pretension force
Data Source
AI summary
A display device is provided, which includes a first folding frame, a second folding frame, a first support plate, a second support plate, a pretension assembly, and a flexible display screen. The second folding frame rotates relative to the first folding frame. The first support plate is disposed on the first folding frame and the second folding frame and includes a bending structure. The bending structure is connected to the first folding frame and the second folding frame. The second support plate is disposed on at least one side of the first support plate. The pretension assembly is connected to the second support plate. The flexible display screen is disposed on the first support plate and the at least one second support plate and is connected to the second support plate. The pretension assembly is configured to provide a pretension force to the flexible display screen.