Electrochromic Driver Tone Control via Reset Pulse
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Solution Overview
Problem
The control of tone in organic electrochromic elements is challenging due to variations in absorption spectra between radical species and assemblies during coloring and erasing, and when using multiple materials, different oxidation and back reduction voltages lead to uneven absorption ratios during coloring and back reduction.
Innovation Solution
A driver for electrochromic elements with a pair of electrodes and organic electrochromic materials, featuring an adjusting controller with controllers A and B to reset the element to an initial state and control tone by adjusting transmittance, using resistors with different resistivities to manage voltage and current durations, ensuring consistent absorption spectra during both coloring and erasing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple organic electrochromic materials are used to achieve desired color tone, then the color tone control is improved, but the absorption spectrum shape changes during coloring and erasing due to different oxidation and back reduction voltages
Solution Approach 1:
The patent applies a reset voltage pulse before tone control to preliminarily restore all electrochromic materials to their initial colorless state. This preliminary action ensures that all materials start from the same baseline, eliminating the problem of different oxidation and back reduction voltages causing spectrum shape changes during normal operation.
Solution Approach 2:
The patent changes the voltage parameter by applying a specific reset voltage (V1) that is sufficient to reduce all oxidized materials regardless of their individual back reduction voltages. This parameter change ensures uniform restoration of all materials, maintaining consistent absorption spectrum shape while still allowing tone control through subsequent voltage adjustments.
2Ease of operation
If PWM driving method is used to control tone through voltage pulse duration, then the tone control is achieved, but the absorption spectrum shape varies because radical species and assemblies exhibit different absorption behaviors
Solution Approach 1:
The reset voltage pulse is applied before tone control to preliminarily restore all electrochromic materials to their initial colorless state. This preliminary action ensures that all materials start from the same baseline, eliminating the problem of different oxidation and back reduction voltages causing spectrum shape changes during normal operation.
Solution Approach 2:
The patent uses periodic voltage pulses with specific patterns: a reset pulse followed by tone control pulses. This periodic action with defined intervals allows the electrochromic materials to respond uniformly, maintaining consistent absorption spectrum shape while achieving tone control through the duration and intensity of the control pulses.
3Reliability
If materials forming assemblies are used, then the electrochromic effect is enhanced, but the absorption spectrum shape changes because the electronic state of assemblies differs from radical species
Solution Approach 1:
The reset voltage pulse is applied before tone control to preliminarily restore all electrochromic materials to their initial colorless state. This preliminary action ensures that all materials start from the same baseline, eliminating the problem of different oxidation and back reduction voltages causing spectrum shape changes during normal operation.
Solution Approach 2:
The patent changes the voltage parameter by applying a specific reset voltage (V1) that is sufficient to reduce all oxidized materials regardless of their individual back reduction voltages. This parameter change ensures uniform restoration of all materials, maintaining consistent absorption spectrum shape while still allowing tone control through subsequent voltage adjustments.
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 driver effectively maintains the desired tone with no change in absorption spectrum shape, even with materials forming assemblies or having different redox potentials, by resetting and controlling the element's transmittance using fixed voltages and resistor switching.
Implementation Method 1
Electrochromism (EC) is a phenomenon in which a reversible electrochemical reaction (oxidation or reduction) induced upon application of voltage changes the optical absorption range of a substance and thereby makes the substance colored or colorless.
Implementation Method 2
a reversible electrochemical reaction (oxidation or reduction) induced upon application of voltage changes the optical absorption range
Implementation Method 3
a reversible electrochemical reaction (oxidation or reduction) induced upon application of voltage changes the optical absorption range
Data Source
AI summary
A driver for an electrochromic element is configured to adjust the transmittance of a solution-type electrochromic element to allow the element to display a tone. The element has a pair of electrodes and at least one organic electrochromic material mixed between the electrodes. The driver has an adjusting controller configured to adjust the transmittance of the element. The adjusting controller has controller A and controller B. Controller A is configured to saturate a change in the transmittance of the element to an initial state by applying the voltage which resets the element to the initial state. Controller B is configured to control the tone of the element by applying the voltage which adjusts the transmittance of the element following controller A.