Backlit Key Structure With Protrusion Layer for Precise Membrane Switching
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Solution Overview
Problem
Conventional control devices with light-transmissible key structures face challenges in precisely triggering membrane switches due to their hollow design, leading to difficulties in intuitive operation and increased fabrication and modification costs.
Innovation Solution
The control device incorporates a key structure comprising a light-transmissible keycap, an optical film layer, an elastic element, and a membrane switch with a protrusion structure, where the keycap's press action triggers the membrane switch by pushing the protrusion structure, allowing for adjustable travel distance and tactile feel, reducing fabrication costs and modification time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the key structure has a hollow portion to be light-transmissible, then the visualized button function is achieved, but the precision of triggering the membrane switch deteriorates
Solution Approach 1:
The key structure is divided into multiple functional layers: keycap layer, optical film layer, and membrane switch layer. The optical film layer is segmented with light-transmissible regions and light-shielding regions, allowing light to pass through while the protrusion structures provide precise mechanical triggering. This segmentation resolves the contradiction by separating the optical function from the mechanical triggering function.
Solution Approach 2:
The protrusion structures on the optical film layer serve as intermediary elements between the keycap and the membrane switch. When the keycap is pressed, the protrusion structures transmit the mechanical force precisely to the membrane switch's contact points, ensuring accurate triggering while maintaining the hollow, light-transmissible design of the key structure.
2Manufacturing precision
If the key structure has a special structural design to overcome hollow portion drawbacks, then the triggering precision is improved, but the device complexity increases
Solution Approach 1:
The optical film layer and the triggering mechanism are merged into a single integrated component. The protrusion structures are formed directly on the optical film layer, combining the light-guiding function and the mechanical triggering function in one element. This reduces device complexity while maintaining triggering precision.
Solution Approach 2:
The optical film layer serves multiple functions simultaneously: it guides light from the display panel to create the visualized button effect, provides structural support for the keycap, and incorporates protrusion structures for precise mechanical triggering of the membrane switch. This multi-functionality reduces the need for separate components, simplifying the overall structure.
3Adaptability or versatility
If the protrusion structure height is adjusted to meet different product specifications, then the adaptability is improved, but the manufacturing cost increases
Solution Approach 1:
The height of the protrusion structures can be adjusted as a design parameter to meet different product specifications for travel distance and tactile feel. By modifying this single parameter during the molding process, the same basic structure can be adapted to various applications without requiring completely different tooling, thereby controlling manufacturing costs while maintaining adaptability.
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
This design enhances the precision of triggering the membrane switch, meets various product specifications, and reduces fabrication costs and mold verification time by allowing adjustable protrusion height and tactile feedback.
Implementation Method 1
The elastic element includes a support part, a lateral wall and a lower part. The support part is connected with the keycap. When the keycap is pressed down, the keycap or the support part is moved downwardly to push the first protrusion structure.
Implementation Method 2
The keycap is light-transmissible. A light beam emitted by the display panel is transmitted upwardly through the at least one second opening, the at least one first opening and the keycap.
Data Source
AI summary
A control device is provided. A key structure of the control device includes a keycap, an optical film layer and a membrane switch. A protrusion structure is formed on the optical film layer or the membrane switch. When the keycap is pressed down by the user, the arrangement of the protrusion structure can facilitate the user to trigger the underlying membrane switch more precisely.