Touch Pad Light Guide Structure for Clear Pattern Display
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Solution Overview
Problem
Existing touch display systems in household and industrial appliances suffer from erroneous function determination in bright environments, high cost, complex drive control, and high requirements on chip performance due to SPI communication, and deep mounting grooves.
Innovation Solution
A touch pad structure with a capacitive or resistive touch module, LED lamps, and light guide plates, where the touch assembly is connected to a PCB, and light guide plates with inclined surfaces and film paper reduce optical crosstalk, allowing independent control of touch patterns without additional driver chips.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a traditional display screen with resolution and active pattern display is configured, then pattern display capability is improved, but cost and drive control complexity increase
Solution Approach 1:
The patent uses a preset pattern film instead of a high-resolution display screen. The pattern film is a simple, low-cost component that displays patterns passively when backlit, eliminating the need for complex display drivers and controllers. This resolves the contradiction by sacrificing active display capability for significantly reduced complexity and cost.
Solution Approach 2:
The patent extracts the display function from a complex display screen and implements it through a simple pattern film combined with LED backlight control. By separating the pattern display function from the lighting function and using independent LED control, the system achieves pattern display capability without requiring a high-resolution screen and its associated complex drive circuitry.
2Ease of manufacture
If a preset pattern film system is used, then cost is reduced, but pattern recognition accuracy in bright environments deteriorates
Solution Approach 1:
The patent applies local quality by making each touch key area independently controllable through individual LED backlighting. When a specific key is touched, only that local area is illuminated, creating high contrast against the dark background. This local illumination approach maintains cost-effectiveness while dramatically improving pattern recognition accuracy in bright environments by focusing light only where needed.
Solution Approach 2:
The patent uses flashing LED lamps to create periodic illumination action. When a touch is detected, the corresponding LED flashes or illuminates periodically, drawing user attention to the specific touched area. This periodic action enhances visibility and recognition accuracy in bright environments while maintaining the low-cost pattern film approach.
3Ease of operation
If SPI communication is used for data interaction, then communication capability is achieved, but requirements on chip performance increase
Solution Approach 1:
The patent replaces SPI communication with a simpler parallel I/O interface. Instead of requiring high-performance chips with SPI capability, the system uses basic microcontroller I/O ports to control individual LEDs and read touch inputs. This dramatically reduces chip performance requirements while maintaining full communication and control capability.
4Stability of the object's composition
If deep mounting grooves are used for display modules, then module stability is improved, but device thickness increases
Solution Approach 1:
The patent merges the display module and touch module into a single integrated structure. The pattern film serves both as the display medium and the touch sensing surface, eliminating the need for separate mounting grooves for distinct display and touch modules. This integration maintains module stability while significantly reducing overall device thickness.
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 touch pad structure provides clear pattern recognition in bright environments, reduces optical crosstalk, and is cost-effective without requiring additional driver chips, achieving thinner designs and simpler control.
Implementation Method 1
Light emitting diode (LED) lamps are arranged on the top surface of the PCB, the LED lamps are electrically connected to an internal circuit of the PCB
Implementation Method 2
the surface, facing the adjacent light guide plate, of each light guide plate is an inclined surface, and the inclined surface gradually narrows towards the direction of the touch assembly
Implementation Method 3
When a spacing between two adjacent light guide plates is less than or equal to preset optical crosstalk spacing, the surface, facing the adjacent light guide plate, of each light guide plate is an inclined surface
Implementation Method 4
the touch assembly is of a capacitive touch module or a resistive touch module
Implementation Method 5
the touch assembly is of a capacitive touch module or a resistive touch module
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
Provided is a touch pad structure capable of displaying patterns. A touch assembly is arranged on a top surface of a printed circuit board (PCB), and light emitting diode (LED) lamps are arranged on the top surface of the PCB; two sets of LED lamps are arranged at a first end and a second end of the touch assembly respectively; light guide plates are arranged between the two sets of LED lamps, the light guide plates are arranged on an upper side of the touch assembly, and two sets of LED lamps have light emitting surfaces and performing forward lighting or side lighting; and when a spacing between two adjacent light guide plates is less than or equal to preset optical crosstalk spacing, the surface, facing the adjacent light guide plate, of each light guide plate is inclined, and film paper is mounted on the light guide plate.