US-12619118-B2 - Controlling transitions in optically switchable devices

US12619118B2US 12619118 B2US12619118 B2US 12619118B2US-12619118-B2

Abstract

Aspects of this disclosure concern controllers and control methods for applying a drive voltage to bus bars of optically switchable devices such as electrochromic devices. Such devices are often provided on windows such as architectural glass. In certain embodiments, the applied drive voltage is controlled in a manner that efficiently drives an optical transition over the entire surface of the electrochromic device. The drive voltage is controlled to account for differences in effective voltage experienced in regions between the bus bars and regions proximate the bus bars. Regions near the bus bars experience the highest effective voltage. In some cases, feedback may be used to monitor an optical transition. In these or other cases, a group of optically switchable devices may transition together over a particular duration to achieve approximately uniform tint states over time during the transition.

Inventors

Gordon E. Jack
Sridhar Karthik Kailasam
Stephen Clark Brown
Anshu A. Pradhan
Jose Vigano
Dhairya Shrivastava
Mark David Mendenhall

Assignees

VIEW, INC.

Dates

Publication Date: 20260505
Application Date: 20220413

Claims (20)

1 . A controller for optically switchable devices, the controller being configured to: apply a plurality of electrical drive signals to a corresponding plurality of optically switchable devices; and stagger application of the electrical drive signals.
2 . The controller of claim 1 , further configured to determine the electrical drive signals for each of the plurality of optically switchable devices.
3 . The controller of claim 2 , wherein the controller is configured to determine the electrical drive signals for each of the plurality of optically switchable devices by: applying an electrical sensing pulse to each of the plurality of optically switchable devices, analyzing a response of each of the plurality of optically switchable devices to the electrical sensing pulse, and determining the electrical drive signals for each of the plurality of optically switchable devices based at least in part on the response of each of the plurality of optically switchable devices to the electrical sensing pulse.
4 . The controller of claim 3 , wherein applying the electrical sensing pulse to each of the plurality of optically switchable devices comprises at least one technique selected from the group consisting of (1) applying a probe voltage to each of the plurality of optically switchable devices, (2) applying a probe current to each of the plurality of optically switchable devices, and/or (3) applying open circuit conditions to each of the plurality of optically switchable devices.
5 . The controller of claim 4 , wherein analyzing the response of each of the plurality of optically switchable devices to the electrical sensing pulse comprises at least one technique selected from the group consisting of (1) analyzing a current response to the probe voltage, (2) analyzing a voltage response to the probe current, and/or (3) analyzing an open circuit voltage in response to the open circuit conditions.
6 . The controller of claim 2 , wherein the controller is configured to apply updated electrical drive signals for an ongoing optical transition for each of the plurality of optically switchable devices by: applying an electrical sensing pulse to each of the plurality of optically switchable devices at a first time, analyzing a response of each of the plurality of optically switchable devices to the electrical sensing pulse, determining one or more electrical characteristics of each the plurality of optically switchable devices at the first time, comparing the one or more electrical characteristics of each of the plurality of optically switchable devices at the first time with one or more electrical characteristics of each of the plurality of optically switchable devices at a second time, determining whether a change in the one or more electrical characteristics of each of the plurality of optically switchable devices between the first time and the second time reaches a threshold amount, and applying the updated electrical drive signals when the change in the one or more electrical characteristics of each of the plurality of optically switchable devices between the first time and the second time reaches the threshold amount.
7 . The controller of claim 1 , wherein staggering the application of the electrical drive signals comprises sequentially applying two or more of the plurality of electrical drive signals.
8 . The controller of claim 7 , wherein staggering the application of the electrical drive signals comprises sequentially applying each of the plurality of electrical drive signals.
9 . The controller of claim 1 , wherein the controller is capable of applying the electrical drive signals to each of the optically switchable devices within a group of optically switchable devices simultaneously.
10 . The controller of claim 1 , wherein the stagger of the application of the electrical drive signals minimizes a peak power draw of the plurality of optically switchable devices.
11 . The controller of claim 1 , wherein the stagger of the application of the electrical drive signals causes a peak power draw of each optically switchable device to occur at a different time.
12 . A system of optically switchable devices, the system comprising: a first optically switchable device comprising a first optically switchable material; a second optically switchable device comprising a second optically switchable material; and a controller configured to provide a first electrical drive signal to the first optically switchable device and a second electrical drive signal to the second optically switchable device, wherein the controller is configured to temporally stagger application of the first electrical drive signal and the second electrical drive signal.
13 . The system of claim 12 , wherein the controller is configured to temporally stagger application of the first electrical drive signal and the second electrical drive signal by applying the second electrical drive signal after applying the first electrical drive signal.
14 . The system of claim 12 , wherein the controller is configured to: characterize one or more electrical properties of each of the first and second optically switchable devices; establish the first electrical drive signal and the second electrical drive signal based on the characterized one or more electrical properties of each of the first and second optically switchable devices; and temporally stagger the application of the first and second electrical drive signals based on one or more characteristics of the first and second electrical drive signals.
15 . The system of claim 12 , further comprising: a third optically switchable device comprising a third optically switchable material; and a fourth optically switchable device comprising a fourth optically switchable material, wherein the controller is configured to provide a third electrical drive signal to the third optically switchable device and to provide a fourth electrical drive signal to the fourth optically switchable device, and wherein the controller is configured to temporally stagger application of each of the first, second, third, and fourth electrical drive signals relative to one another such that none of the first, second, third, or fourth electrical drive signals are applied simultaneously with any other of the first, second, third, or fourth electrical drive signals.
16 . The system of claim 12 , wherein: the first and second optically switchable devices are part of a plurality of optically switchable devices; and the controller is configured to: establish, for each of the plurality of optically switchable devices, a corresponding electrical drive signal and provide the electrical drive signal to the corresponding optically switchable device; determine which of the plurality of electrical drive signals can be applied simultaneously with one another without causing one or more electrical characteristics to exceed a predetermine threshold; and if two of the plurality of electrical drive signals, when applied simultaneously with one another, would cause the one or more electrical characteristics to exceed the predetermined threshold, temporally stagger the two electrical drive signals relative to one another.
17 . The system of claim 12 , wherein the controller is configured to apply updated electrical drive signals for an ongoing optical transition for each of the first and second optically switchable devices by: applying an electrical sensing pulse to each of the first and second optically switchable devices at a first time, analyzing a response of each of the first and second optically switchable devices to the electrical sensing pulse, determining one or more electrical characteristics of each the first and second optically switchable devices at the first time, comparing the one or more electrical characteristics of the first and second optically switchable devices at the first time with one or more electrical characteristics of the first and second optically switchable devices at a second time, determining whether a change in the one or more electrical characteristics of the first and second optically switchable devices between the first time and the second time reaches a threshold amount, and applying the updated electrical drive signals when the change in the one or more electrical characteristics of first and second optically switchable devices between the first time and the second time reaches the threshold amount.
18 . A controller for an optically switchable device, the controller being configured to: apply an applied signal to the optically switchable device in a ramp to drive period during which the applied signal changes with a first slope; following the ramp to drive period, apply the applied signal that changes with a second slope having an absolute value higher than that of the first slope; analyze a response of the optically switchable device after the applied signal is applied with the second slope; and determine a subsequent applied signal to apply to the optically switchable device based at least in part on the response of the optically switchable device.
19 . The controller of claim 18 , wherein the applied signal is an applied voltage.
20 . The controller of claim 19 , wherein the controller is configured to analyze the response of the optically switchable device to the applied voltage by analyzing a current response to applied voltage.

Description

INCORPORATION BY REFERENCE An Application Data Sheet is filed concurrently with this specification as part of the present application. Each application that the present application claims benefit of or priority to as identified in the concurrently filed Application Data Sheet is incorporated by reference herein in their entireties and for all purposes. BACKGROUND Electrochromic (EC) devices are typically multilayer stacks including (a) at least one layer of electrochromic material, that changes its optical properties in response to the application of an electrical potential, (b) an ion conductor (IC) layer that allows ions, such as lithium ions, to move through it, into and out from the electrochromic material to cause the optical property change, while preventing electrical shorting, and (c) transparent conductor layers, such as transparent conducting oxides or TCOs, over which an electrical potential is applied to the electrochromic layer. In some cases, the electric potential is applied from opposing edges of an electrochromic device and across the viewable area of the device. The transparent conductor layers are designed to have relatively high electronic conductances. Electrochromic devices may have more than the above-described layers such as ion storage or counter electrode layers that optionally change optical states. Due to the physics of the device operation, proper function of the electrochromic device depends upon many factors such as ion movement through the material layers, the electrical potential required to move the ions, the sheet resistance of the transparent conductor layers, and other factors. The size of the electrochromic device plays an important role in the transition of the device from a starting optical state to an ending optical state (e.g., from tinted to clear or clear to tinted). The conditions applied to drive such transitions can have quite different requirements for different sized devices. What are needed are improved methods for driving optical transitions in electrochromic devices. SUMMARY Aspects of this disclosure concern controllers and control methods for applying a drive voltage to bus bars of optically switchable devices such as electrochromic devices. Such devices are often provided on windows such as architectural glass. In certain embodiments, the applied drive voltage is controlled in a manner that efficiently drives an optical transition over the entire surface of the optically switchable device. The drive voltage is controlled to account for differences in effective voltage experienced in regions between the bus bars and regions proximate the bus bars. Regions near the bus bars experience the highest effective voltage. In some embodiments, a first optical transition may be interrupted by a command to undergo a second optical transition, for example having a different ending optical state than the first optical transition. In certain embodiments, a group of optically switchable devices may undergo a simultaneous optical transition. Some optically switchable devices in the group may transition faster than other optically switchable devices. In some such embodiments, the transition on the faster optically switchable device may be broken into smaller transitions that are separated in time. This may allow the slowest and faster optically switchable devices in the group to transition over approximately the same switching time, with the various optically switchable devices displaying approximately matching optical states over the course of the overall transition. In one aspect of the disclosed embodiments, a method of controlling a first optical transition and a second optical transition of an optically switchable device is provided, the method including: (a) receiving a command to undergo the first optical transition from a starting optical state to a first ending optical state; (b) applying a first drive parameter to bus bars of the optically switchable device and driving the first optical transition for a first duration; (c) before the optically switchable device reaches the first ending optical state: (i) receiving a second command to undergo the second optical transition to a second ending optical state, and (ii) applying a second drive parameter to the bus bars of the optically switchable device and driving the second optical transition for a second duration, where the second drive parameter is different from the first drive parameter, where the second drive parameter is determined based, at least in part, on the second ending optical state and an amount of charge delivered to the optically switchable device during the first optical transition toward the first ending optical state, and where the second optical transition is controlled without considering an open circuit voltage of the optically switchable device. In some embodiments, the method may further include monitoring an amount of charge delivered to the optically switchable device during the second opt