LCD Backlight Frame Shielding Case for Light Source Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional liquid crystal display devices face issues with maintaining the optical axis stability of the light source element due to repulsive forces caused by internal stress in the flexible wiring substrate, leading to reduced brightness and potential damage from assembly jigs, especially in thinner and lighter portable devices.
Innovation Solution
A liquid crystal display device design where an electromagnetic shielding case is attached to the flexible wiring substrate to cover the electronic component and securely fix it within a housing concave portion on the frame, preventing displacement of the light source element and reducing repulsive forces, while also providing electromagnetic interference shielding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the flexible wiring substrate is bent to place the light source element and electronic component in housing concave portions, then the back surface becomes flat and device thickness is reduced, but repulsive forces from internal stress cause displacement of the light source element and reduce brightness
Solution Approach 1:
The device is divided into functional modules: the flexible wiring substrate is segmented from the frame structure, allowing independent optimization. The light source element and electronic component are mounted on separate regions of the flexible substrate, enabling differential stress management and positioning strategies for each component.
Solution Approach 2:
The patent introduces intermediary elements including adhesive layers between the flexible substrate and frame, and positioning structures within the housing concave portions. These intermediaries absorb and distribute the repulsive forces generated by substrate bending, preventing direct transmission of stress to the light source element and maintaining its optical alignment.
2Manufacturing precision
If assembly jigs are used to form permanent bends in the flexible wiring substrate, then the substrate can be positioned accurately, but the circuits formed in the substrate may be broken by the jigs
Solution Approach 1:
The flexible wiring substrate is pre-formed with the required bends and circuit patterns before assembly. This preliminary formation allows the substrate to be prepared in a controlled environment where circuits can be verified for integrity before the substrate is subjected to assembly operations, preventing damage during final assembly.
Solution Approach 2:
Instead of forming bends during assembly using jigs that may damage circuits, the patent inverts the process sequence: the flexible substrate with pre-formed bends and circuits is assembled into the housing, and then the housing structure itself is used to maintain and refine the positioning. This reverses the traditional approach and protects circuit integrity.
3Volume of moving object
If the flexible wiring substrate is bent with a reduced bending diameter to reduce device size, then portability is improved, but repulsive forces increase causing greater displacement and potential damage
Solution Approach 1:
The patent employs the flexible wiring substrate as a thin film structure that can be bent to small diameters. By utilizing the inherent flexibility and thinness of the substrate, the design achieves compact device size while the distributed nature of the thin film structure helps manage the repulsive forces generated during bending, preventing concentration of stress that would cause displacement or damage.
Data Source
AI summary
A backlight unit for a liquid crystal display device includes a light source element, a light guide plate for guiding the output light from the light source element, and a frame for housing the light guide plate. The light source element is mounted on a flexible wiring substrate fixed to the liquid crystal display panel at one end thereof, together with an electronic component. The light source element and the electronic component are attached to the frame in such a way that each of the light source element and the electronic component is placed in a housing concave portion formed on the back surface side of the frame, by bending the flexible wiring substrate. A case is fixedly attached to the flexible wiring substrate to cover the electronic component. Then, the case is fixed to the inside of the housing concave portion.