Finger-Worn Accelerometer Pointing Apparatus for Portable Computers
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Solution Overview
Problem
Current pointing devices for portable computers, such as touch pads and track points, face limitations in mobility, accuracy, and the risk of misinput due to their size and design, particularly in portable computing environments where space is restricted and precise motion recognition is needed.
Innovation Solution
A pointing apparatus that uses a 2-axis accelerometer to measure finger motion, convert it into a pointing signal, and transmit this signal to a portable computer, distinguishing intentional pointing from unintentional motion by sensing micro-collisions and rising signals, and differentiating between pointing and typing operations without requiring additional sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a touch pad with a sensing membrane of predetermined size is used, then the pointing area is sufficient, but misinput caused by contact with a palm can occur during typewriting
Solution Approach 1:
The pointing function is segmented from the palm-rest area by placing the accelerometer on the finger tip, creating a separate pointing input zone that does not overlap with the keyboard input zone, thereby eliminating misinput during typewriting
Solution Approach 2:
The accelerometer acts as an intermediary sensor that detects finger motion independently of the palm contact area, allowing precise pointing detection without requiring the user to place their hand on a specific surface, thus preventing misinput
2Reliability
If a track point is installed in the center of a keyboard, then misinput during typewriting is prevented, but the responsivity and precision are less than the touch pad
Solution Approach 1:
The mechanical track point system (requiring physical contact with a pointing stick) is replaced by an accelerometer-based system that detects finger motion through acceleration forces, enabling higher precision and responsivity while maintaining the ability to prevent misinput during typewriting
Solution Approach 2:
The detection parameter is changed from mechanical displacement (track point) to acceleration force (accelerometer), allowing for more sensitive and precise motion detection while maintaining the benefit of preventing palm contact misinput
3Reliability
If a mouse is used, then stable 2D motion and orthogonality are achieved, but the device requires predetermined size and limits mobility
Solution Approach 1:
The pointing function is extracted from the traditional mouse form factor and integrated onto a finger-worn accelerometer device, eliminating the need for a separate handheld mouse while maintaining stable 2D motion detection capability
Solution Approach 2:
The pointing input is transferred from a 2D surface interaction (mouse on desk) to a 3D finger motion interaction (accelerometer on finger), enabling mobility while maintaining motion stability through accelerometer-based detection
4Area of stationary object
If a touch pad is used on a palm-rest area, then the pointing area is sufficient, but the device cannot be applied to small-sized devices such as PDA because of space restrictions
Solution Approach 1:
The pointing function is extracted from the device body and placed on the user's finger, completely eliminating the need for onboard pointing hardware in small devices like PDAs while maintaining full pointing functionality
Solution Approach 2:
The user's own finger serves as the pointing interface, eliminating the need for dedicated pointing hardware on the device, thereby enabling small-device portability without sacrificing pointing area or 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
The solution provides a portable, accurate, and efficient pointing method that maximizes mobility, reduces the risk of misinput, and does not occupy the palm-rest area, enabling precise 2D motion recognition with minimal power consumption and no need for extra sensors beyond a 2-axis accelerometer.
Implementation Method 1
adopts an accelerometer to measure the motion of a finger, to convert the motion into a pointing signal
Data Source
AI summary
Provided are a pointing apparatus and method. The apparatus, which inputs a pointing signal to a portable computer, includes an accelerometer outputting an acceleration signal in response to motion of the finger; and a signal processing unit sensing micro-collisions generated when the finger comes into contact with a predetermined contact surface and a rising signal generated when the finger is detached from the contact surface using the acceleration signal, sensing pointing motion of the finger lasting between the generation of the micro-collisions and the generation of the rising signal, and outputting the pointing signal.