Liquid Crystal Transmitter Modulates Ambient Light

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Solution Overview

Problem

Conventional transmitters using light sources require three color light sources, making them structurally constrained and limited in flexibility.

Innovation Solution

A transmitter using a liquid crystal board with a control unit that switches transmittance to change the amount of outside light reflected and emitted, eliminating the need for multiple light sources by utilizing ambient light or light from other devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional light sources are used for visible light communication, then communication function is achieved, but structural constraints increase due to requiring three color light sources

Engineering Contradiction:
ImproveflexibilityVSAvoidstructural constraints
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent introduces a liquid crystal board as an intermediary component that modulates ambient light to carry communication signals. Instead of using multiple light sources directly, the system uses the liquid crystal board to control the transmission of existing light, thereby achieving communication functionality without adding complex light source structures.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention utilizes ambient light from the environment or other devices as the light source for communication. The liquid crystal board modulates this existing light to encode information, allowing the system to serve itself by using freely available light resources rather than requiring dedicated communication light sources.

Inventive Principle:
Principle #25Self-service

2Reliability

If multiple light sources are used for visible light communication, then communication coverage is improved, but power consumption increases

Engineering Contradiction:
Improvecommunication coverageVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system leverages ambient light from the environment or other devices as the illumination source, eliminating the need for dedicated high-power communication light sources. The liquid crystal board modulates this existing light to carry communication signals, significantly reducing power consumption while maintaining communication functionality.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The liquid crystal board changes its optical properties (transmittance) in response to received signals, dynamically controlling the modulation of ambient light. This parameter change approach allows the system to achieve reliable communication coverage by precisely controlling light transmission states without requiring multiple high-power light sources.

Inventive Principle:
Principle #35Parameter changes

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 flexible and efficient visible light communication without structural constraints, allowing for increased communication speed and reduced power consumption.

Implementation Method 1

a liquid crystal board, a control unit configured to, by switching transmittance of the liquid crystal board with respect to outside light between a first transmittance and a second transmittance through application, to the liquid crystal board, of a control voltage corresponding to a signal to be transmitted

Methodology Applied
Scientific EffectLiquid crystal transmittance control: Liquid Crystals

Implementation Method 2

change an amount of outside light reflected by the first board and emitted toward the receiver via the liquid crystal board

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP3110039B1Transmitter and transmitting method
Publication Date: 2020.09.30 PANASONIC INTELLECTUAL PROPERTY CORP OF AMERICA
  • EP3110039B1 patent drawingFigure 1
  • EP3110039B1 patent drawingFigure 2
  • EP3110039B1 patent drawingFigure 3(a)~3(b)

AI summary

A transmitter(100a) that is difficult to be affected by structural constraints includes: a liquid crystal board (103a); a first board (102a) having translucency; and a second board (104a); and a control unit (101a) that changes, by switching transmittance of the liquid crystal board (103a) with respect to outside light through application, to the liquid crystal board (103a), of a control voltage corresponding to a signal to be transmitted, an amount of light reflected by the first board (102a) and emitted toward the receiver via the liquid crystal board (103a), wherein the control unit (101a) maintains, when switching the transmittance of the liquid crystal board (103a) to a low transmittance, the transmittance of the liquid crystal board (103a) at the low transmittance until the outside light that passed through the liquid crystal board (103a) is reflected by the second board (104a) and reaches the liquid crystal board (103a).