Optical Touch Panel Pressure Sensing With Passive Stylus Input
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing touch-sensitive apparatuses rely on complex input devices with integrated sensors to detect touch pressure, limiting user choice and hindering the development of highly customizable and intuitive touch systems.
Innovation Solution
A touch-sensing apparatus that determines touch pressure by measuring the difference in received light as a panel deflects along its normal due to applied pressure, using emitters and detectors arranged along the perimeter to emit and receive light, allowing for passive touch objects without internal pressure sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If complex input devices with integrated sensors are used to detect touch pressure, then pressure detection capability is improved, but device complexity and cost increase
Solution Approach 1:
The patent replaces mechanical pressure sensors integrated into styluses with an optical measurement system. Emitters and detectors arranged along the panel perimeter use light reflection and attenuation to detect touch pressure indirectly through panel deflection, eliminating the need for complex mechanical sensors in the input device.
Solution Approach 2:
The touch panel itself is designed to serve multiple functions: it acts as both the display surface and the pressure sensing element. The panel's structural properties are utilized to convert pressure into measurable optical signals, making the panel a multi-functional component that eliminates the need for separate pressure sensing devices.
2Measurement precision
If complex input devices with integrated sensors are used to detect touch pressure, then pressure detection capability is improved, but user choice and customization are limited
Solution Approach 1:
By replacing mechanical sensors with an optical field-based system, the patent enables any object that can interact with light to become a potential input device. This includes passive styluses, fingers, or even transparent objects, greatly expanding user choice and customization options.
Solution Approach 2:
The patent uses optical reflection and light path modification to create a measurement system that doesn't require physical sensors in the input device. The panel itself becomes the sensing element, allowing any object that modifies light paths to be used as an input device, thereby increasing versatility.
3Ease of operation
If light paths extend across the panel above the touch surface, then touch interaction control is improved, but system complexity increases
Solution Approach 1:
The patent divides the light detection function into multiple discrete emitters and detectors arranged along the panel perimeter. Each emitter-detector pair creates independent scanlines, allowing the system to process touch information in segmented regions, which simplifies the overall system architecture while maintaining comprehensive coverage.
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
Facilitates intuitive and customizable touch interaction with a reduced system complexity and cost, enabling accurate pressure detection for enhanced user input and control, such as varying brush-like shapes and gestures.
Implementation Method 1
a set of optical emitters are arranged around the perimeter of a touch surface of a panel to emit light that is reflected to propagate across the touch surface
Implementation Method 2
An object that touches the touch surface will attenuate the light on one or more scanlines of the light and cause a change in the light received by one or more of the detectors
Implementation Method 3
determine a difference in the received detection light between deflection of the panel from a first position (p1) to a second position (p2) along a normal of the touch surface when a touch object deflects the panel
Data Source
AI summary
A touch sensing apparatus is disclosed for detecting touch pressure, comprising a panel that defines a touch surface, the panel having a perimeter, a plurality of emitters arranged along the perimeter, wherein the emitters emit light across the panel, a plurality of detectors arranged along the perimeter, whereby the detectors are arranged to receive at least part of said light as detection light, wherein the touch sensing apparatus is configured to determine, as a touch object deflects the panel along a normal of the touch surface, a difference in the received detection light between deflection of the panel from a first position (p1) to a second position (p2) along the normal, and determine a pressure of the touch object against the touch surface based on said difference.