Backlight Gesture Detection Using Ambient Light Sensors
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Solution Overview
Problem
Conventional input interfaces, such as mice, are impractical for handheld devices like tablets and mobile phones due to the need for a flat surface and the potential for finger obstructions and smudges on touch-sensitive screens.
Innovation Solution
A system utilizing three or more ambient light sensors (ALSs) arranged in a triangular pattern beneath the screen to detect gestures by measuring changes in ambient light intensity, allowing for touch-less gesture detection and identification of gestures like swipes and hovers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If capacitive touch sensors are used for navigation, then user interaction is enabled, but the screen is obstructed and fingerprint smudges occur
Solution Approach 1:
The patent introduces an intermediary system consisting of light sources and light sensors that detect hand gestures without requiring direct contact with the screen. This intermediary optical detection system allows users to interact with the device through hand movements in the air, eliminating the need for finger contact and thus preventing screen obstruction and fingerprint smudges while maintaining ease of operation
Solution Approach 2:
The patent replaces the mechanical capacitive touch sensing system with an optical detection system using light sources and light sensors. This substitution enables gesture recognition through light reflection and absorption patterns, allowing contactless interaction that avoids the harmful effects of direct finger contact while preserving user interaction capabilities
2Measurement precision
If mice are used for input, then precise control is achieved, but a flat stable surface is required
Solution Approach 1:
The patent replaces the mechanical mouse system with an optical gesture recognition system using light sources and sensors. This substitution eliminates the requirement for a flat stable surface by detecting hand gestures in three-dimensional space through light reflection patterns, thereby maintaining control precision while significantly improving adaptability to different usage environments including handheld devices
3Ease of operation
If ambient light sensors are added for gesture detection, then touchless interaction is enabled, but device complexity increases
Solution Approach 1:
The patent implements a multi-functional system where the light sources serve dual purposes: as backlight for the display and as illumination for gesture detection. The light sensors similarly serve multiple functions including ambient light sensing and gesture detection. This multi-functionality approach enables touchless interaction while minimizing the increase in device complexity by reusing existing components
Solution Approach 2:
The patent merges the backlight system with the gesture detection illumination system, and combines ambient light sensing with gesture detection functionality. By integrating these functions into unified systems rather than separate components, the patent enables touchless interaction while reducing overall device complexity through component consolidation
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 and practical gesture detection on handheld devices without physical contact, enhancing user interaction by allowing gestures to be recognized in various ambient lighting conditions.
Implementation Method 1
When an object is approaching the display panel, the display device detects a shadow of the object, which is cast over the display panel in such a manner that ambient light is blocked by the object, using the photo sensors.
Implementation Method 2
When an object is approaching the display panel, the display device detects a shadow of the object, which is cast over the display panel
Data Source
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AI summary
A device and method to detect a gesture performed by an object in touchless communication with the device are described. The device includes two or more ambient light sensors arranged at respective first surface locations of the device, each of the two or more ambient light sensors sensing light intensity at the respective first surface location. The device also includes one or more processors to operate one or more light sources at respective second surface locations of the device based on the light intensity sensed by the two or more ambient light sensors, and detect the gesture based on the light intensity sensed by each of the two or more ambient light sensors.