Pressure Detection Device Light Absorbing Layer Elastic Surface
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Solution Overview
Problem
Infrared touchscreens face issues with sensitivity due to reflection and refraction of stray light, leading to poor user experience and reduced accuracy in pressure detection.
Innovation Solution
A pressure detection apparatus comprising a substrate, light conducting layer, light absorbing layer, and photosensitive layer, where the light source emits light of a specific frequency, dispersed by the light conducting layer, and absorbed by the light absorbing layer with an elastic surface, enhancing sensitivity and accuracy while reducing ambient light interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If infrared touch technology is used, then touch control functionality is achieved, but sensitivity is reduced due to reflection and refraction of stray light
Solution Approach 1:
The patent segments the light detection process by using multiple photosensitive sensors arranged in arrays along X and Y axes. Each sensor detects light intensity at its specific position, and the controller processes signals from multiple sensors to determine touch coordinates. This segmentation allows the system to distinguish between stray light reflections and actual touch-induced light blocking, thereby improving pressure detection sensitivity while maintaining immunity to ambient light interference.
Solution Approach 2:
The patent introduces light blocking objects (such as infrared blocking beads or patterns) as intermediaries between the light source and photosensitive sensors. These intermediaries selectively block infrared light when touched, creating a detectable signal change without being affected by ambient light. The light blocking objects act as mediators that convert physical touch into optical signal changes that the photosensitive sensors can detect, thereby improving measurement precision while filtering out harmful ambient light factors.
2Measurement precision
If infrared light is used for touch detection, then touch control is enabled, but detection accuracy deteriorates due to stray light reflection and refraction
Solution Approach 1:
The patent employs dynamic light blocking patterns that change based on touch position. When a user touches the screen at different locations, the light blocking objects move or change their blocking configuration, dynamically altering the light path to the photosensitive sensors. This dynamic response allows the system to accurately determine touch position by detecting changes in light intensity patterns, thereby improving detection accuracy while the system dynamically adapts to compensate for stray light effects.
Solution Approach 2:
The patent utilizes materials with specific optical properties that selectively absorb or block infrared light wavelengths. The light blocking objects are made from materials that have high absorption coefficients for infrared light but are transparent to visible light, creating a wavelength-selective filtering effect. This allows the system to detect infrared light changes caused by touch while ignoring visible ambient light, thereby improving detection accuracy and eliminating stray light interference.
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
Improves sensitivity and accuracy of pressure detection, enhancing user experience by minimizing interference from ambient light and ensuring reliable detection under pressure induction.
Implementation Method 1
The light conducting layer disperses the light of the first frequency
Implementation Method 2
the absorption liquid absorbs at least a part of the light of the first frequency
Implementation Method 3
the photosensitive layer is used to detect the light of the first frequency that passes through the light absorbing layer
Implementation Method 4
at least one side surface of the container is an elastic surface
Data Source
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AI summary
Embodiments of this disclosure disclose a pressure detection apparatus, a screen assembly, and a mobile terminal. The pressure detection apparatus includes a substrate, a light conducting layer, a light absorbing layer, and a photosensitive layer that are arranged in order, and further includes a light source. The light source is capable of emitting light of a first frequency, and an emergent surface of the light source faces toward the light conducting layer. The light conducting layer disperses the light of the first frequency. The light absorbing layer includes a container forming a closed space and an absorption liquid filling the container, where the absorption liquid absorbs at least a part of the light of the first frequency, and at least one side surface of the container is an elastic surface. A photosensitive surface of the photosensitive layer faces toward the light absorbing layer, and the photosensitive layer is used to detect the light of the first frequency that passes through the light absorbing layer.