Pressure-Sensing Touch System Using Optical Interference
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Solution Overview
Problem
Current touch input devices, particularly those based on capacitive sensors, are ineffective in detecting pressure applied during touch operations, necessitating an alternative method to recognize touch events through pressure sensing.
Innovation Solution
A pressure-sensing touch system utilizing a light guide plate, light output plate with through-openings, interference plates, and detectors to detect changes in light intensity distribution caused by pressure-induced bending, allowing for recognition of touch events and pressure levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional capacitive touch sensors are used, then position and track sensing is achieved, but pressure detection capability is lost
Solution Approach 1:
The patent replaces traditional mechanical pressure sensors with an optical measurement system. Light sources illuminate the light guide plate, and detectors measure changes in light intensity distribution caused by pressure-induced bending, thereby detecting pressure without mechanical contact
Solution Approach 2:
The system detects pressure by measuring changes in light intensity distribution parameters. When pressure is applied, the light guide plate bends, altering the path and intensity of light, which is detected and converted into pressure information
2Measurement precision
If pressure sensors are used for touch input, then pressure detection is effective, but device complexity increases
Solution Approach 1:
The light guide plate serves multiple functions: it guides light from the light source to the display area and simultaneously acts as the pressure-sensing element. Its bending under pressure changes the light intensity distribution, allowing one component to perform both optical guidance and pressure detection
Solution Approach 2:
The system uses its own display components (light guide plate, light sources, detectors) for dual purposes. The detectors that monitor light intensity for display purposes also detect pressure-induced changes, eliminating the need for separate pressure sensing hardware
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
Enables accurate recognition of touch events and pressure levels by analyzing changes in light intensity distribution, providing a more effective alternative to traditional capacitive touch sensors.
Implementation Method 1
at least part of the output light exiting from the respective first through-opening passes through the two second through-openings to interfere with each other
Implementation Method 2
The light guide plate and the light output plate are bendable upon application of the pressure at the touch position
Data Source
AI summary
A pressure-sensing touch system for recognition of a touch event caused by a pressure applied at a touch position is disclosed which includes a light guide plate, a light output plate, a light source subsystem, a plurality of interference plates, a plurality of detectors and a controller. Upon application of the pressure at the touch position, a change in an intensity distribution of output light exiting from two through-openings of the interference plate occurs. The plurality of detectors are configured to detect the change. The controller is configured to recognize the touch event based on the detecting by the plurality of detectors. Also disclosed are a pressure-sensing touch method and a display system.