Display Backlight Position Encoding for Interactive Pen Input
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional pen sensor technology requires integration into display devices at manufacture, making it difficult and costly to add interactive functionality post-manufacture, and aftermarket solutions are unsightly and inconvenient.
Innovation Solution
A display device controller programs LED backlights to emit unique light patterns that are undetectable to humans but can be decoded by a pen device with light sensors, allowing interaction without hardware additions, using backlight modulation to encode position and orientation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional pen sensor technology is integrated into display devices at manufacture, then interactive functionality is achieved, but device complexity and manufacturing cost increase
Solution Approach 1:
The display device's existing LED backlight serves dual purposes: providing illumination and encoding position information through modulation patterns. The pen device uses light sensors to detect these patterns, enabling the display to interactively recognize pen position without additional sensor hardware in the display itself.
Solution Approach 2:
The LED backlight is made multi-functional by having it perform both its primary role of providing illumination and a secondary role of encoding spatial position information through unique modulation patterns for different display regions, eliminating the need for separate sensor components.
2Adaptability or versatility
If pen sensor technology is added after manufacture, then interactive functionality is achieved, but installation difficulty and alignment precision deteriorate
Solution Approach 1:
The display device encodes position information within its existing LED backlight structure, eliminating the need for separate aftermarket sensor components that would require precise alignment and installation procedures.
3Measurement precision
If visible light patterns are emitted for position encoding, then position recognition is achieved, but user visibility and display quality deteriorate
Solution Approach 1:
The LED backlight emits light in periodic pulse patterns with unique temporal modulations for different display regions. These rapid on-off cycles encode position information in the time domain rather than amplitude, making the encoded patterns imperceptible to human vision while allowing precise position detection by the pen's light sensor.
Solution Approach 2:
The position encoding is performed in the temporal domain through pre-planned pulse patterns, separating the information encoding function from the visual display function, so that position data can be extracted without affecting the perceived display image quality.
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 interactive display functionality without hardware modifications, supporting pen-based interactions with high accuracy and low power consumption, suitable for various user inputs and applications.
Implementation Method 1
capturing, by the light receiving device, light transmitted by the display
Implementation Method 2
an array of light-emitting diodes (LEDs) that provide a backlight or visual content
Implementation Method 3
different regions of the array of LEDs emit different patterns of pulses
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
In general, the subject matter described in this disclosure can be embodied in methods, systems, and program products for determining a position of a display at which a light receiving device is oriented. The method includes capturing, by the light receiving device, light transmitted by the display, wherein the display is configured to emit a plurality of different codes from a respective plurality of different regions of the display, such that each region of the plurality of different regions emits a unique code from among the plurality of different codes. The method includes identifying, by a computing system, a first code encoded within the light transmitted by the display and captured by the light receiving device. The method includes determining, by the computing system, a first region of the display that corresponds to the first code from among the plurality of different regions of the display.