Pixilated Light-Turning Layer Optical Touch Screen
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Solution Overview
Problem
Conventional touch screen technologies face challenges in accurately detecting touch events without causing image degradation and often require complex electrode patterns, which can be costly and difficult to manufacture.
Innovation Solution
An optical touch screen apparatus featuring a light guide, a light source, a light sensor, and a pixilated light-turning layer that redirects scattered light from a touch event to correlated locations on the light sensor, allowing for precise detection of touch positions without the need for electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional touch screen technologies use electrode patterns for touch detection, then touch events can be detected, but image degradation occurs and manufacturing complexity increases
Solution Approach 1:
The patent replaces the conventional electrode-based electrical detection system with an optical detection system using light guides, light sources, and light sensors. This substitution eliminates the need for transparent electrodes that cause image degradation, while maintaining touch detection capability through optical scattering measurements.
Solution Approach 2:
The patent introduces a light guide as an intermediary component between the touch surface and the detection system. The light guide distributes light across the touch surface and collects scattered light from touch events, enabling indirect optical detection without requiring direct electrical contact or transparent electrodes that degrade image quality.
2Measurement precision
If conventional touch screens use intricate electrode patterns for accurate touch detection, then touch precision is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent replaces complex electrode patterns with a simpler optical system consisting of light guides and light sensors. The light guide can be manufactured as a single integrated component using conventional optical manufacturing techniques, eliminating the need for complex transparent electrode patterning processes.
Solution Approach 2:
The patent divides the light guide into multiple light guide portions, each associated with specific light sensors for detecting touch events in different regions. This segmentation enables precise localization of touch events while using simpler, modular light guide components that are easier to manufacture than intricate electrode patterns.
3Measurement precision
If conventional touch screens use multiple separate components for light guiding and sensing, then detection functionality is achieved, but part count and manufacturing cost increase
Solution Approach 1:
The patent merges the light guiding function and the touch detection function into an integrated optical system. The light guide serves dual purposes: distributing light from light sources across the touch surface and collecting scattered light from touch events to deliver to light sensors. This consolidation reduces the number of separate components while maintaining detection functionality.
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 solution enables accurate detection of touch events with reduced image degradation and simpler manufacturing, as it eliminates the need for intricate electrode patterns, while integrating the light guide with a display to reduce parts and costs.
Implementation Method 1
a light guide configured to propagate light from the light source
Implementation Method 2
Each of the pixels is configured to selectively redirect scattered light from the light source to one or more correlated light receiving locations of the light sensor. The scattered light can correspond to light emitted by the light source that is scattered by an object upon the object contacting the major surface.
Data Source
AI summary
This disclosure provides systems, methods and apparatus for a touch screens configured to determine a position of a touch event by selectively redirecting light to correlated locations on a light sensor. In one aspect, the touch screen apparatus can include a light guide forming a touch interface, a light source for injecting light into the light guide, a light sensor for detecting the injected light, and a pixilated light-turning layer. The pixilated light-turning layer can include a plurality of light-turning features forming pixels. The pixels can receive incident light corresponding to the emitted light scattered by an object contacting the light guide. The pixels can redirect the incident scattered light towards the light sensor such that light selectively propagates to one or more correlated light receiving locations. A processor can map the light receiving location to an area contacted by the object, thereby determining a position of a touch event.