Optical Trackpad Rotational Motion Detection via Segmented Sensor Array
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Solution Overview
Problem
Current optical trackpads are unable to detect rotational movements of a user's finger, mistakenly interpreting circular motions as vertical and horizontal movements, and are overwhelmed by the complexity of control options on handsets.
Innovation Solution
An optical trackpad module with a light source and a sensor array divided into sub-sections that detect translational movements, allowing for the detection of rotational motion by comparing signals from these sub-sections, enabling accurate interpretation of circular movements and reducing the need for additional control buttons.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a traditional optical trackpad is used to detect finger movements, then the device structure is simple and has no moving parts, but it cannot detect rotational movements and mistakenly interprets circular motions as vertical and horizontal movements
Solution Approach 1:
The sensor array is divided into multiple sub-sections (first, second, third, and fourth sub-sections) arranged in a specific pattern. Each sub-section independently detects light reflections from different aspects of the rotating object, enabling the system to distinguish rotational movements from translational movements by comparing signals across these segmented sensors.
2Adaptability or versatility
If multiple buttons or keys are added to the handset perimeter to provide more control options, then the device functionality increases, but the user becomes overwhelmed with the complexity of control options
Solution Approach 1:
The optical trackpad is designed to perform multiple functions: detecting translational movements (up, down, left, right), rotational movements (clockwise, counter-clockwise), and pressing actions. This multi-functional capability replaces the need for multiple separate buttons while maintaining comprehensive control options, thereby improving ease of operation without sacrificing adaptability.
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 detection of rotational movements, simplifying user interface controls and reducing the complexity of control options on handsets by integrating rotational motion detection into the trackpad, enhancing user experience and device usability.
Implementation Method 1
An infrared light source located below the trackpad emits infrared light towards the trackpad, and when a user places his finger on the trackpad, a sensor detects this event. The sensor detects the user's finger by receiving infrared light that has been reflected off the user's finger.
Data Source
AI summary
An optical trackpad module is described herein. The module includes a light source and a trackpad that is optically coupled to the light source such that light from the light source can reach the trackpad. The trackpad is configured to receive an input object. The module also includes a sensor array that receives at least some of the light from the light source that is reflected off the input object. The sensor array is divided into sub-sections, and each sub-section corresponds to a portion of the trackpad. In addition, each sub-section detects at least translational movement of the input object on the corresponding trackpad portions to enable detection of rotational motion of the input object on the trackpad.