Touch Pad Key Input Function LED Placement
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Solution Overview
Problem
Conventional touch pads with key input functions require additional sensing compensation processes due to the position relationships between LED light-emitting elements and the touch sensing layer, increasing complexity and cost.
Innovation Solution
The touch pad design includes a circuit board with LED light-emitting elements arranged between touch sensing units, where the LED terminals are installed in blank regions to avoid influencing the capacitive sensing effect, allowing for a simplified structure that eliminates the need for additional sensing compensation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If LED light-emitting elements are arranged beside the light guide plate to provide backlight illumination, then the touch pad can display numbers and symbols through light-transmissible patterns, but the position relationship between LED elements and touch sensing layer requires additional sensing compensation processes
Solution Approach 1:
The patent extracts the LED light-emitting elements from the conventional position beside the light guide plate and relocates them onto the circuit board in blank regions of the touch sensing layer. This separation removes the interfering element (LED) from the sensing area, eliminating the need for sensing compensation processes while maintaining the backlight illumination function through the light guide plate and diffusion layer
2Device complexity
If LED light-emitting elements are installed on the circuit board in blank regions of touch sensing units, then the capacitive sensing effect is not influenced and additional sensing compensation is eliminated, but the arrangement requires precise positioning in blank regions
Solution Approach 1:
The patent performs preliminary action by designing the circuit board layout with predetermined blank regions in the touch sensing units before LED installation. These blank regions are specifically allocated for LED terminal placement, ensuring that LEDs are installed in positions that do not interfere with sensing circuit regions and driving circuit regions, thereby eliminating the need for sensing compensation while simplifying manufacturing positioning requirements
3Ease of manufacture
If the touch pad structure is simplified by eliminating sensing compensation processes, then manufacturing cost and process complexity are reduced, but the position relationship between LED elements and touch sensing layer must be precisely controlled
Solution Approach 1:
The patent segments the touch sensing unit into distinct functional regions: sensing circuit regions, driving circuit regions, and blank regions. By allocating LED terminals to specific blank regions, the design creates clear spatial separation between illumination components and sensing components. This segmentation simplifies manufacturing by providing predetermined installation positions while ensuring no interference with sensing functions, thus reducing both manufacturing cost and precision requirements
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 enables effective and accurate touch control operations without the need for additional sensing compensation, reducing complexity and cost while maintaining the key input function.
Implementation Method 1
The plural LED light-emitting elements 13 are installed on an edge of the touch sensing layer 11. In addition, the plural LED light-emitting elements 13 are arranged beside the light guide plate 12, which is located over the touch sensing layer 11. The plural LED light-emitting elements 13 emit plural light beams.
Implementation Method 2
The diffusion layer 142 is located over the mask layer 141 in order to diffuse and homogenize the light beams.
Implementation Method 3
After the plural light beams are introduced into the light guide plate 12 through a light input surface 121 of the light guide plate 12, the light beams are guided by the light guide plate 12 and diffused to the overlying region.
Data Source
AI summary
A touch pad includes a circuit board, plural LED light-emitting elements, a light guide plate and a light-transmissible touch structure. A touch sensing layer is formed on a top surface of the circuit board. The touch sensing layer includes plural touch sensing units. The plural LED light-emitting elements are arranged between the plural touch sensing units. The light guide plate is located over the touch sensing layer and arranged beside the plural LED light-emitting elements. The light-transmissible touch structure includes plural light-transmissible patterns. The light-transmissible touch structure is located over the plural LED light-emitting elements and the light guide plate. A touch control operation is performed on the light-transmissible touch structure by the user. The two terminals of each LED light-emitting element are respectively installed on blank regions of two corresponding sensing circuit regions.