Switchable Glass Drive Circuit Using Adjustable AC Dimming

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Solution Overview

Problem

Current dimming glass technologies face challenges in adjusting light transmittance efficiently due to polarization issues with dye liquid crystal molecules, particularly when using DC voltage signals, which limits the ability to control brightness and color effectively.

Innovation Solution

A drive circuit comprising a controller and a voltage adjustment circuit that generates an alternating current signal with adjustable amplitude, controlling the degree of deflection of liquid crystal molecules to adjust light transmittance, thereby improving the dimming glass's brightness and color control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If DC voltage signals are used to control dimming glass, then the control is simple, but polarization issues occur that limit brightness and color control

Engineering Contradiction:
Improvecontrol simplicityVSAvoidbrightness and color control effectiveness
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent changes the voltage signal parameter from DC to AC with adjustable amplitude. The AC voltage signal's amplitude can be varied to control the degree of liquid crystal molecule deflection, thereby adjusting light transmittance, brightness, and color without causing polarization issues that limit control effectiveness.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs periodic AC voltage signals instead of continuous DC signals. The periodic nature of the AC signal allows for dynamic control of liquid crystal orientation through varying amplitude levels, enabling effective brightness and color adjustment while avoiding the polarization problems associated with DC signals.

Inventive Principle:
Principle #19Periodic action

2Illumination intensity

If the liquid crystal molecules are neatly arranged, then light penetration is free and the glass is transparent, but the control over light transmittance is limited

Engineering Contradiction:
Improvelight penetrationVSAvoidlight transmittance control flexibility
Core Design Contradiction:
Illumination intensityVSAdaptability or versatility

Solution Approach 1:

The patent introduces dynamic control through adjustable amplitude AC voltage signals. By varying the amplitude of the AC signal, the degree of liquid crystal molecule deflection can be dynamically adjusted, allowing continuous control over light transmittance from fully transparent to various dimming levels, thereby enhancing adaptability while maintaining light penetration capability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent utilizes parameter changes in the AC voltage signal amplitude to control light transmittance. Different amplitude levels correspond to different degrees of liquid crystal orientation, enabling versatile control over the glass's transparency state while preserving the ability to achieve full light penetration when needed.

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

The drive circuit enables adjustable light transmittance and brightness control, enhancing the market competitiveness of dimming glass by avoiding polarization and allowing for flexible light management in various applications.

Implementation Method 1

the output voltage signal adjusts light transmittance of the dimming glass by controlling a degree of deflection of liquid crystal molecules in the dimming glass

Methodology Applied
Scientific EffectLiquid crystal deflection: Liquid Crystals

Implementation Method 2

the absorption of light by the liquid crystal molecules along a molecular axis and the absorption of light by the liquid crystal molecules along a direction perpendicular to the molecular axis are different

Methodology Applied
Scientific EffectElectro-optic effect: Electro-Optic Effects

Implementation Method 3

A dye is a substance that absorbs light of a specific wavelength and can enable the light reflected from the dye or transmitted through the dye appear colored

Methodology Applied
Scientific EffectLight absorption: Absorption (EM radiation)

Implementation Method 4

the dye molecules dissolved in the liquid crystal can show different colors with different orientations of the liquid crystal molecules under the action of an electric field

Methodology Applied
Scientific EffectElectric field orientation: Electric Field

Data Source

PatentEP3920174B1Drive circuit and drive method for switchable glass, and switchable glass apparatus
Publication Date: 2024.03.06 BOE TECHNOLOGY GROUP CO LTD
  • EP3920174B1 patent drawingFigure 1~2
  • EP3920174B1 patent drawingFigure 3~4A
  • EP3920174B1 patent drawingFigure 4B~5

AI summary

A drive circuit (100) for a switchable glass (200), a switchable glass apparatus (10), and a drive method. The drive circuit (100) for the switchable glass (200). The drive circuit comprises: a controller (110) of which an input end (INT11) receives a control instruction, the controller (110) being configured to output a voltage control signal at an output end (OUT2) of the controller according to the control instruction; and a voltage regulator circuit (120) of which a control input end (INT12) is connected to the output end (OUT2) of the controller (110) and a power source input end (INT13) is connected to a first power source (130) and a voltage output end (OUT1) is connected to a voltage input end (INT1) of the switchable glass (200), the voltage regulator circuit being configured to generate an output voltage signal (S1) at the voltage output end (OUT1) of the voltage regulator circuit according to a voltage control signal. The output voltage signal (S1) adjusts the transmittance of the switchable glass (200) by controlling the degree of deflection of liquid crystal molecules in the switchable glass (200). The drive circuit (100) can adjust the transmittance of the switchable glass (200) so as to achieve the adjustment of the brightness of the switchable glass (200).