Display Light Source Modulation for Device Communication

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Solution Overview

Problem

Conventional methods for home electric appliance communication are limited to devices with three color light sources and do not effectively enable communication between devices other than lighting units, such as those with insufficient computational performance or without a communication function due to cost constraints.

Innovation Solution

A transmitting method that uses luminance change patterns to modulate visible light signals, allowing communication by switching multiple light sources in a display, including turning on specific light sources only during designated periods to transmit signals, enabling communication between various devices, including those without traditional lighting functions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional optical spatial transmission methods are used, then communication can be established between lighting devices, but the method is limited to devices with three color light sources and cannot be applied to displays or other devices

Engineering Contradiction:
Improvedevice compatibilityVSAvoidlight source configuration
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies universality by enabling display devices to perform visible light communication functions. The display device uses its existing light sources (RGB subpixels) for both display purposes and communication purposes, making the communication technology universally applicable to displays without requiring separate communication hardware. This resolves the limitation of conventional methods being restricted to lighting devices with specific three-color configurations.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent segments the light source control into two independent control mechanisms: a common switch that controls all light sources simultaneously for communication timing, and individual pixel switches that control specific light sources for data encoding. This segmentation allows the display to maintain its display function while enabling communication functionality using the same physical light sources.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If existing communication protocols are implemented in home electric appliances, then communication capability is achieved, but computational performance requirements and cost increase

Engineering Contradiction:
Improvecommunication capabilityVSAvoidcomputational requirements
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent enables displays to perform communication functions using their own existing infrastructure (light sources and control circuits) without requiring additional communication hardware or complex processing units. The display itself generates and transmits communication signals through luminance modulation, making the system self-sufficient and eliminating the need for separate communication modules in low-performance devices.

Inventive Principle:
Principle #25Self-service

3Productivity

If luminance change patterns are used for signal transmission, then communication can be achieved using display light sources, but the signal transmission period must be synchronized with pixel switching timing

Engineering Contradiction:
Improvecommunication efficiencyVSAvoidcontrol synchronization
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent uses preliminary action by setting the common switch control signal to activate all light sources before the pixel switching operation begins. This ensures that when individual pixels are switched to encode communication data, the light sources are already in the appropriate state for modulation. The timing is pre-coordinated so that communication signals can be transmitted during the pixel switching periods without requiring complex real-time synchronization.

Inventive Principle:
Principle #10Preliminary action

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 method allows for effective communication between diverse devices, including those without traditional lighting functions, by utilizing luminance changes in displays with multiple light sources, enhancing communication capabilities without altering the display structure significantly.

Implementation Method 1

transmitting a visible light signal by way of luminance change; determining a luminance change pattern by modulating the visible light signal

Methodology Applied
Scientific EffectLuminance change: Light

Data Source

PatentEP3236598B1Transmission method, transmission device and program
Publication Date: 2021.05.26 PANASONIC INTELLECTUAL PROPERTY CORP OF AMERICA
  • EP3236598B1 patent drawingFigure 1
  • EP3236598B1 patent drawingFigure 2
  • EP3236598B1 patent drawingFigure 3

AI summary

Provided is a transmitting method that enables communication between various devices including devices other than lightings. The transmitting method includes determining a luminance change pattern by modulating a visible light signal (SC11), switching a common switch according to the luminance change pattern, the common switch being for turning ON a plurality of light sources in common, the plurality of light sources being included in a light source group of a display and each being for representing a pixel in an image (SC12), and turning ON a first pixel switch for turning ON a first light source, to cause the first light source to be ON only for a period in which the common switch is ON and the first pixel switch is ON, to transmit the visible light signal, the first light source being one of the plurality of light sources included in the light source group (SC13).