CN117836710A

CN117836710A - Method for improving appearance-level aesthetics of dynamic glass

Info

Publication number: CN117836710A
Application number: CN202280057013.5A
Authority: CN
Inventors: I·库纳迪安; D·波普拉夫斯基; S·K·凯拉萨姆
Original assignee: View Inc
Current assignee: View Inc
Priority date: 2021-07-27
Filing date: 2022-07-27
Publication date: 2024-04-05

Abstract

Aspects of the present disclosure relate to a controller and control method for transitioning a set of optically switchable devices. Such devices are typically disposed over fenestrations such as architectural glass. In certain embodiments, the method transitions to a plurality of optically switchable devices positioned in proximity as a set. The method applies different drive voltages to different devices in the group. In these or other cases, a set of optically switchable devices may be transitioned together over a particular duration to achieve an approximately uniform hue state over time during the transition without slowing down the transition of the faster optically switchable devices in the set of optically switchable devices.

Description

Method for improving appearance-level aesthetics of dynamic glass

Cross Reference to Related Applications

The application data sheet is filed concurrently with the present specification as part of the present application. Each application requiring its identified rights or priority in the concurrently filed application data sheet is hereby incorporated by reference in its entirety for all purposes.

Background

Electrochromic (EC) devices are typically multi-layer stacks comprising (a) at least one layer of electrochromic material that changes its optical properties in response to application of an electrical potential, (b) an Ion Conductor (IC) layer that allows, for example, lithium ion plasma to pass therethrough into and out of the electrochromic material to cause the optical properties to change while preventing electrical shorting, and (c) a transparent conductor layer, such as a transparent conductive oxide or TCO, upon which an electrical potential is applied to the electrochromic layer. In some cases, the potential is applied from opposite edges of the electrochromic device and across the viewable area of the device. The transparent conductor layer is designed to have relatively high electron conductivity. Electrochromic devices may have more than the above layers, such as an ion storage layer or a counter electrode layer that optionally alters the optical state.

Due to the physical characteristics of the device operation, the proper functioning of electrochromic devices depends on many factors, such as ion movement through the material layer, the potential required to move the ions, the sheet resistance of the transparent conductor layer, 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 colored to transparent or from transparent to colored). The conditions used to drive this transition may have quite different requirements for different sized devices.

What is needed is an improved method for driving optical transitions in electrochromic devices.

Disclosure of Invention

Aspects of the present disclosure relate to a controller and a control method for applying a driving voltage to a bus bar of an optically switchable device, such as an electrochromic device. Such devices are typically disposed over fenestrations such as architectural glass (also known as dynamic glass). In certain implementations, the applied drive voltage is controlled in a manner that effectively drives the optical transition across the surface of the optically switchable device. The driving voltage is controlled to take into account the difference in effective voltage experienced in the region between the bus bars and the region near the bus bars. Some aspects of the present disclosure relate to controlling two or more optically switchable devices in proximity in a group, thereby providing improved uniformity of coloration of the devices during tone transition.

One aspect of the present disclosure relates to a method of transitioning a set of optically switchable devices. In some implementations, the method includes: (a) Receiving a command to transition the set of optically switchable devices to an ending optical state, wherein the set of optically switchable devices includes a slowest optically switchable device and a faster optically switchable device, and wherein when the same drive voltage is applied to each optically switchable device in the set of optically switchable devices, the slowest optically switchable device transitions at a slower or equal transition speed than any other optically switchable device in the set; (b) Transitioning the slowest optically switchable device to the ending optical state by applying a first drive voltage to the slowest optically switchable device; and (c) transitioning the faster optically switchable device to the ending optical state by applying a second drive voltage to the faster optically switchable device during (b), wherein the first drive voltage has a magnitude greater than the second drive voltage. In some implementations, (b) and (c) occur in about the same time period.

In some implementations, the average transition speed of the faster optically switchable device and the average transition speed of the slowest optically switchable device are about the same during a period of time that begins when the command is received and ends when all optically switchable devices of the group reach the end optical state.

In some implementations, the faster and the slowest optical switchable devices take approximately the same amount of time to transition to an intermediate optical state having an optical density between that of the starting optical state and that of the ending optical state before transitioning to the ending optical state.

In some implementations, the second drive voltage generates a current having a signal-to-noise ratio greater than a specified standard.

In some implementations, the transitioning of (b) further includes, prior to applying the first drive voltage, applying a first ramp to the drive voltage to the slowest optically switchable device; (c) Before applying the second drive voltage, applying a second ramp to the faster optically switchable device; and the first ramp to drive voltage has a faster ramp rate than the second ramp to drive voltage.

In some implementations, determining that the transition of the slowest optically switchable device to the ending optical state is to be completed when the open circuit voltage of the slowest optically switchable device reaches a first target open circuit voltage; determining that the transition of the faster optically switchable device to the ending optical state is to be completed when the open circuit voltage of the faster optically switchable device reaches a second target open circuit voltage; and

The first target open circuit voltage is closer to zero than the second target open circuit voltage.

In some implementations, the slowest optically switchable device has a larger surface area than the faster optically switchable device.

In some implementations, the method further includes: information of the set of optically switchable devices is received and driving voltage data of the set of optically switchable devices is obtained.

In some implementations, the Bus Bar Distance (BBD) of the slowest optically switchable device is greater than the BBD of the faster optically switchable device. In some implementations, the Diagonal Bus Bar Distance (DBBD) of the slowest optically switchable device is greater than the DBBD of the faster optically switchable device.

In some implementations, the transition of the slowest optically switchable device is monitored using feedback obtained during the transition of the slowest optically switchable device.

In some implementations, the feedback obtained during the transition of the slowest optically switchable device includes one or more parameters selected from the group consisting of: an open circuit voltage, a current measured in response to the applied voltage, and a charge or charge density delivered to the slowest optically switchable device.

In some implementations, the feedback obtained during the transition of the slowest optically switchable device includes the open circuit voltage and the charge or charge density delivered to the slowest optically switchable device.

In some implementations, the transition of the faster optically switchable device is monitored using feedback obtained during the transition of the faster optically switchable device.

In some implementations, the feedback obtained during the transition of the faster optically switchable device includes one or more parameters selected from the group consisting of: open circuit voltage, current measured in response to the applied voltage, and charge or charge density delivered to the faster optically switchable device.

In some implementations, the feedback obtained during the transition of the faster optically switchable device includes the charge or charge density delivered to the faster optically switchable device, and does not include the open circuit voltage nor the current measured in response to the applied voltage.

In some implementations, the method further includes applying a holding voltage to each device in the set of optically switchable devices when each device reaches the ending optical state.

In some implementations, the method further includes: in response to receiving a command to transition the set of optically switchable devices to a second ending optical state before the set of optically switchable devices reaches the ending optical state, the slowest optically switchable device and the faster optically switchable device are transitioned to the second ending optical state without any suspension.

In some implementations, the faster optically switchable device transitions to the ending optical state without pausing.

In some implementations, the method further includes determining a starting optical state of each optically switchable device in the set of optically switchable devices using feedback obtained from each optically switchable device before each optically switchable device begins to transition.

In some implementations, the feedback obtained from each optically switchable device before each optically switchable device begins to transition includes one or more parameters selected from the group consisting of: open circuit voltage, current measured in response to an applied voltage, and charge or charge density.

In some implementations, the first drive voltage and the second drive voltage are selected based at least in part on the starting optical state.

In some implementations, the set of optically switchable devices includes a third optically switchable device, and the third optically switchable device transitions faster than the faster optically switchable device when the same driving voltage is applied to the set of optically switchable devices. The method further comprises the steps of: during (b), transitioning the third optically switchable device to the ending optical state by applying a third drive voltage to the third optically switchable device, wherein the second drive voltage has a magnitude greater than the third drive voltage. In some implementations, the BBD of the slowest optically switchable device is greater than the BBD of the faster optically switchable device, and the BBD of the faster optically switchable device is greater than the BBD of the third optically switchable device. In some implementations, the DBBD of the slowest optically switchable device is greater than the DBBD of the faster optically switchable device, and the DBBD of the faster optically switchable device is greater than the DBBD of the third optically switchable device.

In some implementations, the method further includes: (d) Receiving a command to transition a second group of optically switchable devices to the ending optical state, wherein the second group comprises a second group of slowest optically switchable devices and a second group of faster optically switchable devices, wherein when the same driving voltage is applied to each of the optically switchable devices in the second group, the second group of slowest optically switchable devices transitions at a slower or equal transition speed than any other optically switchable device in the second group; (e) Transitioning the second set of slowest optically switchable devices to the ending optical state by applying a third drive voltage to the second set of slowest optically switchable devices during (b); and (f) transitioning the second set of faster optically switchable devices to the ending optical state during (b) by applying a fourth drive voltage to the second set of faster optically switchable devices, wherein the third drive voltage has a magnitude greater than the fourth drive voltage. In some implementations, the faster optical switchable device, the slowest optical switchable device, the second set of faster optical switchable devices, and the second set of slowest optical switchable devices reach the ending optical state at substantially the same time.

Another aspect of the disclosure relates to a control system comprising one or more processors and a memory storing instructions that, when executed by the one or more processors, cause the control system to implement any of the above methods. In some implementations, the control system includes one or more processors and a memory storing instructions that, when executed by the one or more processors, cause the control system to: (a) Receiving a command to transition a group of optically switchable devices to an ending optical state, wherein the group of optically switchable devices includes a slowest optically switchable device and a faster optically switchable device, and wherein the slowest optically switchable device does not transition faster than any other optically switchable device in the group when the same drive voltage is applied to the group of optically switchable devices; (b) Transitioning the slowest optically switchable device to the ending optical state by applying a first drive voltage to the slowest optically switchable device; and (c) transitioning the faster optically switchable device to the ending optical state by applying a second drive voltage to the faster optically switchable device during (b), wherein the first drive voltage has a magnitude greater than the second drive voltage.

Another aspect of the disclosure relates to a computer program product comprising one or more non-transitory storage media having instructions stored thereon, which when executed by one or more processors of a control system, cause the control system to perform any of the above methods. In some implementations, such a computer program product includes one or more non-transitory storage media having instructions stored thereon that, when executed by one or more processors of a control system, cause the control system to control a set of optically switchable devices, the instructions comprising: (a) Receiving a command to transition the set of optically switchable devices to an ending optical state, wherein the set of optically switchable devices includes a slowest optically switchable device and a faster optically switchable device, and wherein the slowest optically switchable device does not transition faster than any other optically switchable device in the set when the same drive voltage is applied to the set of optically switchable devices; (b) Transitioning the slowest optically switchable device to the ending optical state by applying a first drive voltage to the slowest optically switchable device; and (c) transitioning the faster optically switchable device to the ending optical state by applying a second drive voltage to the faster optically switchable device during (b), wherein the first drive voltage has a magnitude greater than the second drive voltage.

These and other features are described in more detail below with reference to the associated drawings.

Drawings

Fig. 1A schematically depicts a planar busbar arrangement.

Fig. 1B presents a simplified graph of local voltage values on each transparent conductive layer as a function of position on the layer.

FIG. 1C presents V _{Effective and effective} Simplified graph as a function of position on the device.

Fig. 2 is a graph depicting voltage and current distribution associated with driving an electrochromic device from transparent to tinted or vice versa.

Fig. 3 is a graph depicting certain voltage and current distributions associated with driving an electrochromic device from transparent to tinting.

FIG. 4A is a graph depicting an optical transition in which the applied voltage is varied from V _{Driving of} Down to V _Holding Resulting in a net current flow indicating that the optical transition has progressed far enough to allow the applied voltage to remain at V for the duration of the ending optical state _Holding 。

FIG. 4B is a graph depicting an optical transition in which the applied voltage is varied from V _{Driving of} Initially drop to V _Holding Resulting in a net current flow, indicating that the optical transition has not progressed far enough to allow the applied voltage to remain at V for the duration of the ending optical state _Holding . Thus, the applied voltage returns to V _{Driving of} For another period of time and then fall again to V _Holding The resulting current at this point indicates that the optical transition has progressed far enough to allow the applied voltage to remain at V for the duration of the ending optical state _{Protection device} Holding the steel.

Fig. 5A is a flow chart depicting a process for detecting the progress of an optical transition and determining when the transition is completed.

Fig. 5B is a flow chart depicting a process for detecting the progress of an optical transition and accelerating the transition if the transition does not progress fast enough.

Fig. 5C-5F are flowcharts depicting alternative processes for detecting the progress of an optical transition and determining when the transition is complete.

Fig. 5G and 5H are flowcharts illustrating methods for controlling optical transitions using various types of feedback modes.

Fig. 5I depicts various graphs depicting a plurality of parameters related to optical transitions over time.

Fig. 5J is a flow chart depicting another method for controlling an optical transition and determining when the transition is completed.

Fig. 5K-5M present a flow chart of a method of controlling optical transitions on multiple sets of optically switchable devices having different switching rates.

Fig. 6A and 6B show graphs depicting total charge delivered over time during an electrochromic transition versus applied voltage over time when the progress of the transition is detected and monitored using the method of fig. 5E at room temperature (fig. 6A) and at reduced temperature (fig. 6B).

Fig. 6C illustrates an electrochromic window having a pair of voltage sensors on a transparent conductive oxide layer, according to one embodiment.

Fig. 7A and 7B present cross-sectional views of an exemplary electrochromic device in operation.

Fig. 8 and 9 are representations of the aperture control and associated components.

Fig. 10 shows a set of optically switchable devices comprising one large device and several smaller devices.

Fig. 11A-11C present experimental data related to the method described in fig. 5K.

Fig. 12 is a flow chart depicting a process for modifying a drive voltage, in accordance with some embodiments.

Fig. 13A is a flow chart depicting a process for modifying a drive voltage based at least in part on an open circuit voltage, in accordance with some embodiments.

Fig. 13B is a flow chart depicting a process for modifying a drive voltage based at least in part on transferred charge, in accordance with some embodiments.

FIG. 14 is a flow diagram depicting a process for modifying a drive voltage based at least in part on historical parameters, in accordance with some embodiments.

Fig. 15 illustrates a flow diagram of a process 1500 for transitioning a set of optically switchable devices to an ending optical state, according to some implementations.

Fig. 16A illustrates a process 1600 for transitioning a set of optically switchable devices to an ending optical state, according to some implementations.

Fig. 16B illustrates two voltage distributions that may be used in accordance with some implementations of process 1600.

Fig. 17 illustrates a process 1700 for transitioning a set of optically switchable devices to an ending optical state, according to some implementations.

Detailed Description

Definition of the definition

An "optically switchable device" is a thin device that changes optical state in response to an electrical input. It may be reversibly cycled between two or more optical states. The switching between these states is controlled by applying a predefined current and/or voltage to the device. The device typically includes two thin conductive sheets that span at least one optically active layer. An electrical input driving the optical state change is applied to the thin conductive sheet. In certain embodiments, the input is provided by a bus bar in electrical communication with the conductive sheet.

Although the present disclosure emphasizes electrochromic devices as examples of light switchable devices, the present disclosure is not limited thereto. Examples of other types of light switchable devices include certain electrophoretic devices, liquid crystal devices, and the like. The light switchable device may be provided on a variety of light switchable products, such as light switchable windows. However, embodiments disclosed herein are not limited to switchable windows. Examples of other types of light switchable products include mirrors, displays, and the like. In the context of the present disclosure, these products are typically provided in a non-pixelated version.

An "optical transition" is a change in any one or more optical properties of an optically switchable device. The changed optical properties may be, for example, hue, reflectivity, refractive index, color, etc. In certain implementations, the optical transition will have a defined starting optical state and a defined ending optical state. For example, the starting optical state may be 80% transmittance and the ending optical state may be 50% transmittance. The optical transition is typically driven by applying an appropriate potential across the two thin conductive plates of the optically switchable device.

The "starting optical state" is the optical state of the optically switchable device immediately before the optical transition starts. The initial optical state is generally defined as the magnitude of the optical state, which may be hue, reflectivity, refractive index, color, etc. The starting optical state may be a maximum or minimum optical state of the optically switchable device; for example, a transmittance of 90% or 4%. Alternatively, the starting optical state may be an intermediate optical state having a value between the maximum and minimum optical states of the optically switchable device; for example, 50% transmittance.

An "ending optical state" is an optical state of the light-switchable device immediately following a complete optical transition from the starting optical state. A complete transition occurs when the optical state changes in a manner understood to be complete for a particular application. For example, the complete coloration may be considered as a transition from 75% transmittance to 10% transmittance. The ending optical state may be a maximum or minimum optical state of the optically switchable device; for example, a transmittance of 90% or 4%. Alternatively, the ending optical state may be an intermediate optical state having a value between the maximum and minimum optical states of the optically switchable device. For example, 50% transmittance.

"bus bar" refers to a conductive bar attached to a conductive layer, such as a transparent conductive electrode that spans an area of an optically switchable device. The bus bar delivers potential and current from an external lead to the conductive layer. The optically switchable device includes two or more bus bars, each bus bar connected to a single conductive layer of the device. In various embodiments, the bus bar forms an elongate line that spans a majority of the length or width of the device. Typically, the bus bars are located near the edges of the device.

"applied Voltage" or V _{Application of} Refers to the difference in potential applied to two opposite polarity bus bars on an electrochromic device. Each bus bar is electronically connected to a separate transparent conductive layer. The applied voltages may be of different magnitudes or functions, such as driving an optical transition or maintaining an optical state. Sandwiching optically switchable device material between transparent conductive layers, e.g.Electrochromic materials. Each of the transparent conductive layers undergoes a potential drop between a location where the bus bar is connected thereto and a location remote from the bus bar. In general, the greater the distance from the bus bar, the greater the potential drop in the transparent conductive layer. The local potential of the transparent conductive layer is generally referred to herein as V _TCL . The bus bars of opposite polarity may be laterally separated from each other on the surface of the optically switchable device.

"effective voltage" or V _{Effective and effective} Refers to the potential between the positive transparent conductive layer and the negative transparent conductive layer at any particular location on the optically switchable device. In Cartesian space, the effective voltage is defined for a particular x, y coordinate on the device. In measurement V _{Effective and effective} The two transparent conductive layers are separated in the z-direction (by the device material) but share the same x, y coordinates.

"holding voltage" refers to the applied voltage required to hold the device in the end optical state indefinitely. In some cases, the electrochromic window returns to its natural tint state without the application of a hold voltage. In other words, maintaining the desired tone state requires application of a holding voltage.

"drive voltage" refers to an applied voltage provided during at least a portion of an optical transition. The drive voltage may be considered to "drive" at least a portion of the optical transition. The magnitude of which is different from the magnitude of the applied voltage immediately before the start of the optical transition. In certain implementations, the magnitude of the drive voltage is greater than the magnitude of the hold voltage. An exemplary application of the drive voltage and the hold voltage is depicted in fig. 3.

The words "about," "approximately," "substantially" are used to modify quantities in the present disclosure. As such modifiers, they are meant to include ranges that are 5%, 10%, 15%, 20%, or 25% higher or lower than the modified amount in various implementations. If a portion of a range is not defined, they refer to the defined portion. For example, in various implementations, "about 100" refers to the following ranges: 95-105, 90-110, 85-115, 80-120, 75-125. When they are used to modify a quantitative adjective, they refer to a range of amounts that include the adjective, which in various implementations is 5%, 10%, 15%, 20%, or 25% higher or lower than the range. If a portion of a range is not defined, they refer to the defined portion. For example, in various implementations, "substantially all/whole" refers to 95%, 90%, 85%, 80%, or 75% all/whole. For example, "about the same time period" or "two substantially overlapping time periods" refers to when two time periods overlap within 95%, 90%, 85%, 80%, or 75% of the two time periods. For example, "substantially constant" refers to 5%, 10%, 15%, 20%, or 25% lower and higher than the indicated constant amount, e.g., in various implementations, the coefficient of variation is 0.05, 0.1, 0.15, 0.2, or 0.25. For example, "about the same" refers to less than or greater than 5%, 10%, 15%, 20%, or 25% of the indicated same amount, e.g., where in various implementations the difference between the two amounts divided by the lesser of the two amounts is less than 5%, 10%, 15%, 20%, or 25%.

As used herein, the phrase "at about/approximately/substantially the same time" refers to times less than 1, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 180, 240, or 300 seconds apart. In some implementations, the phrase sometimes refers to times less than 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 25, or 30 minutes apart.

The conjunctions "or" and/or "are used interchangeably herein to function as" comprising or "unless otherwise indicated. Thus, the expression "a or B" and "a and/or B" means A, B, or both a and B.

Background and overview

The disclosed embodiments utilize electrical detection and monitoring to evaluate an unknown optical state (e.g., a hue state or other optical characteristic) of an optically switchable device and/or to determine when an optical transition between a first optical state and a second optical state of the optically switchable device has progressed to a degree that may be sufficient to terminate application of a drive voltage. For example, electrical detection allows for a shorter time to apply the drive voltage than previously thought possible, as the particular device is driven in real time based on electrical detection of its actual optical transition progress. Further, real-time monitoring may help ensure that the optical transition progresses to a desired state. The electrical detection and monitoring techniques described herein may also be used to monitor/control optical transitions that begin during the course of a previously performed optical transition. A number of different control techniques are available, some of which are particularly suited to accomplishing different types of tasks, as described further below.

In various embodiments, terminating the drive voltage is achieved by reducing the applied voltage to a hold voltage. This approach takes advantage of what is generally considered to be an undesirable optical transition-the tendency of thin optically switchable devices to transition non-uniformly between optical states. In particular, many optically switchable devices initially transition at a location near the bus bar and only later transition at a region remote from the bus bar (e.g., near the center of the device). Surprisingly, this non-uniformity can be exploited to detect optical transitions. By allowing transitions to be detected in the manner described herein, the optically switchable device avoids the need for custom characterization and associated pre-programming of device control algorithms that specify the length of time that the drive voltage is applied, as well as eliminating the need to consider "universal" fixed time period drive parameters that span temperature variations, device structure variability, etc. of many devices. Furthermore, detection techniques may also be used to determine the optical state (e.g., hue state) of an optically switchable device having an unknown optical state, making such techniques useful both before and during optical transitions. Before describing the detection and monitoring techniques in more detail, some background will be provided regarding optical transitions in electrochromic devices.

Driving the transition in a typical electrochromic device is achieved by applying a defined voltage to two separate bus bars on the device. In such an arrangement, it is convenient to position the bus bar perpendicular to the smaller dimension of the rectangular aperture (see fig. 1A). This is because the transparent conductive layer used to deliver the applied voltage on the surface of the thin film device has an associated sheet resistance, and the bus bar arrangement allows the shortest span that the current must travel to cover the entire area of the device, thus shortening the time it takes for the conductor layer to fully charge on its respective area, and thus shortening the time it takes for the device to transition.

When the voltage V is applied _{Application of} When supplied across the bus bar, substantially all regions of the device experience a lower local effective voltage (V due to the sheet resistance of the transparent conductive layer and the current draw of the device _{Effective and effective} ). The center of the device (intermediate position between the two bus bars) typically has the lowest V _{Effective and effective} Values. This may result in unacceptably small optical switching ranges and/or unacceptably slow switching times at the center of the device. These problems may not exist at the edges of the device, closer to the bus bars. This is explained in more detail below with reference to fig. 1B and 1C.

Fig. 1A shows a top view of an electrochromic lighting zone 100 including bus bars having a planar configuration. The electrochromic lighting zone 100 includes a first bus bar 105 disposed on a first conductive layer 110 and a second bus bar 115 disposed on a second conductive layer 120. An electrochromic stack (not shown) is sandwiched between the first conductive layer 110 and the second conductive layer 120. As shown, the first bus bar 105 may extend substantially across one side of the first conductive layer 110. The second bus bar 115 may extend substantially across a side of the second conductive layer 120 opposite to a side of the electrochromic lighting zone 100 where the first bus bar 105 is disposed. Some devices may have additional bus bars, for example, on all four edges, but this complicates manufacturing. Further discussion of bus bar configurations including planar configured bus bars is found in U.S. patent application No. 13/452,032, filed on 4/2012, the entire contents of which are incorporated herein by reference.

Fig. 1B is a graph showing, for example, a plot of the local voltage in the first transparent conductive layer 110 and the voltage in the second transparent conductive layer 120, which drives the transition of the electrochromic lighting zone 100 from the transparent state to the colored state. Curve 125 shows the voltage V in the first transparent conductive layer 110 _TCL Is used to determine the local value of (1). As shown, due to sheet resistance and current flow through the first conductive layer 110, voltage is applied from the left-hand side (e.gThe first bus bar 105 is disposed on the first conductive layer 110 and a position where a voltage is applied) is lowered to the right-hand side of the first conductive layer 110. Curve 130 also shows the local voltage V in the second conductive layer 120 _TCL . As shown, the voltage increases (decreases in magnitude) from the right-hand side (e.g., where the second bus bar 115 is disposed on the second conductive layer 120 and the voltage is applied) to the left-hand side of the second conductive layer 120 due to the sheet resistance of the second conductive layer 120. In this example, the value V of the applied voltage _{Application of} Is the voltage difference between the right end of the potential curve 130 and the left end of the potential curve 125. Effective voltage V at any position between bus bars _{Effective and effective} Is the difference in the values of curves 130 and 125 at the position on the x-axis corresponding to the position of interest.

Fig. 1C is a view showing V on an electrochromic device between the first conductive layer 110 and the second conductive layer 120 of the electrochromic lighting zone 100 _{Effective and effective} Is a graph of the curve of (2). As explained, the effective voltage is the local voltage difference between the first conductive layer 110 and the second conductive layer 120. The regions of the electrochromic device that are subjected to the higher effective voltage transition between optical states faster than the regions that are subjected to the lower effective voltage. As shown, the effective voltage is lowest at the center of the electrochromic lighting zone 100 and highest at the edges of the electrochromic lighting zone 100. The voltage drop across the device is due to ohmic losses as current passes through the device. By disposing additional bus bars within the viewing area of the aperture, the voltage drop across the large electrochromic aperture can be reduced, effectively dividing a large optical aperture into multiple smaller electrochromic apertures that can be driven in series or in parallel. However, this approach may be aesthetically unattractive due to the contrast between the bus bars in the visible region and the visible region. That is, without any discrete bus bars in the viewable area, it may be more pleasing to have a monolithic electrochromic device.

As described above, as the aperture size increases, the resistance of the current flowing through the thin face of the TC layer also increases. May be located at a point closest to the bus bar (referred to as the edge of the device in the following description) and a point furthest from the bus bar (inReferred to as the center of the device in the following description). When current passes through the TCL, the voltage drops on the TCL plane, which reduces the effective voltage at the center of the device. This effect is exacerbated by the fact that the leakage current density of the aperture remains constant but the total leakage current increases due to the increased area, typically as the aperture area increases. Thus, with both effects, the effective voltage at the center of the electrochromic window drops significantly, and for electrochromic windows greater than, for example, about 30 inches wide, poor performance may be observed. By using a higher V _{Application of} So that the center of the device reaches a proper effective voltage to solve the problem.

Typically, the safe operating range of solid state electrochromic devices is between about 0.5V and 4V, or more typically between about 0.8V and about 3V, for example between 0.9V and 1.8V. These are V _{Effective and effective} Is used to determine the local value of (1). In one embodiment, an electrochromic device controller or control algorithm provides a drive profile, where V _{Effective and effective} Always below 3V, in another embodiment, the controller controls V _{Effective and effective} To be always below 2.5V, in another embodiment, the controller controls V _{Effective and effective} So that it is always below 1.8V. The voltage value refers to a time-averaged voltage (where the average time is about the time required for a small optical response, e.g., a few seconds to a few minutes).

An added complexity of electrochromic apertures is that the current drawn through the aperture is not fixed for the duration of the optical transition. In contrast, during the initial portion of the transition, when the optical transition is complete or near complete, the current through the device is much greater (up to 100 times) than in the end state. During this initial transition period, the problem of chromatic aberration of the device center is further exacerbated because of the value V at the center _{Effective and effective} Significantly lower than the value at the end of the transition period.

In the case of electrochromic devices with planar bus bars, it can be shown that V on devices with planar bus bars _{Effective and effective} Generally given by:

wherein:

V _{application of} Is a voltage difference applied to the bus bar to drive the electrochromic window;

DeltaV (0) is V at the bus bar connected to the first transparent conductive layer _{Effective and effective} (in the examples below, TEC type TCO);

DeltaV (L) is V on DeltaV (L) connected to the second transparent conductive layer _{Effective and effective} (in the examples below, an ITO-type TCO);

DeltaV (L/2) is V at the center of the device _{Effective and effective} An intermediate position between the two planar bus bars;

r = transparent conductive layer sheet resistance;

j = instantaneous average current density; and

l=distance between bus bars of electrochromic device.

It is assumed that the transparent conductive layer has a sheet resistance substantially similar to (if not identical to) the calculation. However, those of ordinary skill in the art will appreciate that even though the transparent conductive layers have different sheet resistances, the applicable physical characteristics of ohmic voltage drop and local effective voltage are still applicable.

As described above, certain embodiments relate to controllers and control algorithms for driving optical transitions in devices having planar bus bars. In such devices, substantially linear bus bars of opposite polarity are disposed on opposite sides of a rectangular or other polygonal electrochromic device. In some embodiments, devices with non-planar bus bars may be employed. Such devices may employ angled bus bars, for example, disposed at the apex of the device. In such devices, the bus bar effective separation distance L is determined based on the geometry of the device and the bus bar. Discussion of Bus Bar geometry and separation distance can be found in U.S. patent application No. 13/452,032 entitled "Angled Bus Bar," filed on 4/2012, which is incorporated herein by reference in its entirety.

With increasing R, J or L, V on the device _{Effective and effective} Reducing, thereby slowing or reducing device coloration during transition, even in the final optical state. Referring to equation 1, V on the aperture _{Effective and effective} At least ratio V _{Application of} Low RJL ² /2. It has been found that as the resistive voltage drop increases (due to increased aperture size, current draw, etc.), some losses can be reduced by increasing V _{Application of} To counteract, but the increase V _{Application of} Only to V at the edge of the device _{Effective and effective} A value below a threshold at which reliability degradation may occur is maintained.

In summary, it has been realized that both transparent conductive layers experience an ohmic drop and that this drop increases with distance from the associated bus bar, thus V for both transparent conductive layers _TCL Decreasing with distance from the bus bar. As a result, V _{Effective and effective} Reduced in the removed position from both bus bars.

To accelerate along an optical transition, the applied voltage is first provided at a magnitude greater than that required to hold the device in equilibrium in a particular optical state. This method is illustrated in fig. 2 and 3.

Fig. 2 shows the complete current and voltage distribution for an electrochromic device employing a simple voltage control algorithm to cause a cycling of the optical state transition of the electrochromic device (coloring followed by transparency). In the graph, the total current density (I) is expressed as a function of time. As mentioned, the total current density is a combination of the ion current density associated with electrochromic transitions and the electron leakage current between the electrochemically active electrodes. Many different types of electrochromic devices will have the current distribution depicted. In one example, a cathodic electrochromic material such as tungsten oxide is used in combination with an anodic electrochromic material such as nickel tungsten oxide for the counter electrode. In such devices, a negative current indicates the staining/coloring of the device. In one example, lithium ions flow from nickel tungsten oxide anodically coloring an electrochromic electrode into tungsten oxide cathodically coloring an electrochromic electrode. Correspondingly, electrons flow into the tungsten oxide electrode to compensate for positively charged incoming lithium ions. Thus, the voltage and current are shown as having negative values.

The depicted curve is obtained by ramping up the voltage to a set level and then holding the voltage to maintain the optical state. The current peak 201 is associated with a change in optical state (i.e., coloration and transparency). In particular, the current peaks represent the delivery of ionic charges required to color or clear the device. Mathematically, the shaded area under the peak represents the total charge required to color or clear the device. The portion of the curve after the initial current spike (portion 203) represents the leakage current when the device is in a new optical state.

In the figure, a voltage distribution 205 is superimposed on the current curve. The voltage profile follows the following sequence: negative ramp (207), negative hold (209), positive ramp (211), and positive hold (213). Note that the voltage remains constant after reaching its maximum magnitude and during the length of time the device remains in its defined optical state. The voltage ramp 207 drives the device to its new colored state and the voltage hold 209 maintains the device in the colored state until the voltage ramp 211 in the opposite direction drives the transition from the colored state to the transparent state. In some switching algorithms, an upper current limit is applied. That is, the current is not permitted to exceed a defined level in order to prevent damage to the device (e.g., driving ions through the material layer too fast may physically damage the material layer). The coloring speed depends not only on the applied voltage but also on the temperature and the voltage ramp rate.

Fig. 3 illustrates a voltage control profile according to certain embodiments. In the depicted embodiment, a voltage control profile is employed to drive the transition from the transparent state to the colored state (or to an intermediate state). To drive the electrochromic device in the opposite direction from the colored state to the transparent state (or from the more colored state to the less colored state), a similar but inverted distribution is used. In some implementations, the voltage control profile for coloring to transparency is a mirror image of the voltage control profile depicted in fig. 3.

The voltage values depicted in fig. 3 represent the applied voltage (V _{Application of} ) Values. The applied voltage profile is shown by the dashed line. Instead, the current density in the device is shown by the solid line. In the depicted distribution, V _{Application of} Comprising four partsThe amount is as follows: drive ramp component 303 to initiate transition, V to continue drive transition _{Driving of} Component 313, hold ramp component 315 and V _Holding A component 317. The ramp assembly is implemented as V _{Application of} And V is a variation of _{Driving of} And V _Holding The components providing a constant or substantially constant V _{Application of} Magnitude.

The driving ramp component is characterized by a ramp rate (increasing magnitude) and V _{Driving of} Is a magnitude of (2). When the magnitude of the applied voltage reaches V _{Driving of} At this time, the driving of the slowly varying component is completed. V (V) _{Driving of} The components being characterised by the use of V _{Driving of} The value of (2) and V _{Driving of} Is not shown, is not shown. As described above, V can be selected _{Driving of} To maintain a V with a safe but effective range over the entire face of the electrochromic device _{Effective and effective} 。

The hold ramp component is characterized by a voltage ramp rate (reduced magnitude) and V _Holding Of (or alternatively V) _{Driving of} And V _Holding Difference between them). V (V) _{Application of} According to the slope rate, until V is reached _Holding Values. V (V) _Holding The components being characterised by V _Holding The magnitude of (V) and V _Holding Is not shown, is not shown. In practice, V _Holding The duration of (2) is typically determined by the length of time the device remains in a colored state (or conversely in a transparent state). And driving slope, V _{Driving of} Unlike the ramp to hold component, V _Holding The components have arbitrary lengths, irrespective of the physical properties of the optical transitions of the device.

Each type of electrochromic device will have its own voltage distribution characteristic component for driving the optical transition. For example, a relatively large device and/or a device with more resistive conductive layers would require a higher V _{Driving of} And may require driving a higher ramp rate in the ramp component. U.S. patent application No. 13/449,251, filed 4/17/2012 and incorporated herein by reference, discloses a controller and associated algorithm for driving optical transitions under a wide range of conditions. As explained therein, each fraction of the applied voltage distribution can be independently controlled Quantity (here, ramp to drive, V _{Driving of} Ramp to hold and V _Holding ) To address real-time conditions such as current temperature, current transmittance level, etc. In some implementations, the value of each component of the applied voltage profile is set for a particular electrochromic device (with its own bus bar spacing, resistivity, etc.), and does not vary based on current conditions. In other words, in such implementations, the voltage profile does not take into account feedback such as temperature, current density, etc.

As indicated, all voltage values shown in the voltage transition profile of fig. 3 correspond to V described above _{Application of} Values. Which does not correspond to V described above _{Effective and effective} Values. In other words, the voltage values depicted in fig. 3 represent the voltage differences between the bus bars of opposite polarity on the electrochromic device.

In certain embodiments, the ramp-to-drive component of the voltage profile is selected to safely but rapidly cause ionic current to flow between the electrochromic electrode and the counter electrode. As shown in fig. 3, the current in the device follows the distribution of the drive voltage ramp components until the drive ramp portion of the distribution ends and V _{Driving of} Part is started. See current component 301 in fig. 3. The safe level of current and voltage may be determined empirically or based on other feedback. Us patent No. 8,254,013, filed on 3/16 2011, issued 8/28 2012 and incorporated herein by reference, presents an example of an algorithm for maintaining a safe current level during electrochromic device transitions.

In certain embodiments, V is selected based on the considerations described above _{Driving of} Is a value of (2). In particular, the values are chosen such that V over the entire surface of the electrochromic device _{Effective and effective} The values remain within the range of effectively and safely transitioning a large electrochromic device. V may be selected based on various considerations _{Driving of} Is not shown, is not shown. One of which ensures that the drive potential remains for a sufficient period to cause significant coloration of the device. For this purpose V _{Driving of} The duration of (2) may be empirically determined by _{Driving of} Time length held in place monitors the light of the deviceDensity is determined. In some embodiments, V _{Driving of} Is set to a specified time period. In another embodiment, V _{Driving of} The duration of which is set to correspond to the amount of ion and/or electron charge passed. As shown, V _{Driving of} During which the current ramps down. See current section 307.

Another consideration is the reduction of current density in the device because the ion current decays during the optical transition due to the available lithium ions completing the journey from the anode to the cathode (or counter) electrode. When the transition is complete, the only current flowing through the device is the leakage current through the ion conducting layer. As a result, the ohmic drop of the potential on the device surface is reduced, and V _{Effective and effective} Is increased. If the applied voltage is not reduced, these increased V _{Effective and effective} Values may damage or degrade the performance of the device. Thus, V is determined _{Driving of} Another consideration of the duration of (2) is to reduce the V associated with leakage current _{Effective and effective} Is set to a level of (2). By applying a voltage from V _{Driving of} Reduced to V _Holding Not only V on the surface of the device _{Effective and effective} Reduced, and leakage current reduced. As shown in fig. 3, the device current transitions in section 305 during the ramp to hold component. At V _Holding During this time, the current stabilizes to a steady leakage current 309.

_{Driving of} Controlling V using feedback from optical transitions

Since it may be difficult to predict V _{Driving of} And/or how long the applied drive voltage should be applied before transitioning to the hold voltage, thus presenting challenges. Devices of different sizes, and more particularly devices having bus bars spaced a certain distance apart, require different optimal driving voltages and different lengths of time for applying the driving voltages. Furthermore, the process used to fabricate optically switchable devices (e.g., electrochromic devices) may vary subtly from batch to batch or from process modification to process modification. Subtle process variations translate into optimal driving electricity that must be applied to the device used in operation for the driving voltage Potentially different requirements for pressure and length of time. Furthermore, the environmental conditions (and in particular the temperature) may influence the length of time the applied voltage should be applied to drive the transition.

To account for all of these variables, the current art may define a number of different control algorithms having different time periods for applying a defined drive voltage for each of a number of different aperture sizes or device features. The reason for this is to ensure that the drive voltage is applied for a sufficient period, regardless of the device size and type, to ensure that the optical transition is complete. Many different sizes of electrochromic window apertures are currently being fabricated. While the appropriate drive voltage time may be predetermined for each different type of aperture, this can be a cumbersome, expensive, and time consuming process. The improved method described herein is to determine the length of time that the drive voltage should be applied during operation.

Furthermore, it may be desirable to have the transition between two defined optical states occur within a defined duration regardless of the size of the optically switchable device, the process of manufacturing the device, and the environmental conditions under which the device operates at the time of the transition. This can be achieved by monitoring the transition process and adjusting the drive voltage as needed to ensure that the transition is completed within a defined time. Adjusting the magnitude of the drive voltage is one way to achieve this goal.

In various embodiments, detection techniques may be used to evaluate the optical state of the optically switchable device. Typically, the optical state relates to the hue state of the device, but other optical properties may be detected in some implementations. The optical state of the device may be known or may be unknown prior to initiation of the optical transition. In some cases, the controller may have information about the current optical state of the device. In other cases, the controller may not have any such information available. Thus, to determine the appropriate driving algorithm, it may be beneficial to probe the device in a manner that allows the current optical state of the device to be determined before any new driving algorithm is started. For example, if the device is in a fully colored state, transmitting various voltages and/or polarities through the device may damage the device. By knowing the current state of the device, the risk of sending any such damaging voltages and/or polarities through the device can be minimized, and appropriate driving algorithms can be employed.

In various embodiments, the unknown optical state may be determined by applying an open circuit condition to the optically switchable device and monitoring the open circuit voltage (V _oc ) To determine. The technique is particularly useful for determining the hue status of electrochromic devices, although it may also be used in some situations where different optical properties are determined and/or where different types of optically switchable devices are used. In many embodiments, the optical state of the optically switchable device is V _oc Is defined by a function of (a). Thus, V can be measured _oc To determine the optical state of the device. This determination allows the driving algorithm to be tailored for the particular optical transition that is to occur (e.g., from the determined starting optical state to the desired ending optical state). This technique is particularly useful and accurate when the device has been stationary (i.e., not actively transitioning) for a period of time (e.g., about 1-30 minutes or more) before the measurement occurs. In some cases, when based on the measured V _oc To determine the optical state of the device, temperature may also be considered. However, in various embodiments, the optical states and V _oc The relationship between these changes little with temperature and is therefore based on the measured V _oc The temperature may be ignored in determining the optical state.

Certain disclosed embodiments apply detection techniques to evaluate the progress of an optical transition during which the device is in transition. As shown in fig. 3, there are typically different ramp-to-drive and drive voltage maintenance phases of the optical transition. The detection technique may be applied at any of these stages. In many embodiments, the detection technique is applied during the drive voltage maintenance portion of the algorithm.

In certain embodiments, the detection technique involves pulsing the current or voltage applied to drive the transition and then monitoring the current or voltage response to detect an overdrive condition in the vicinity of the bus bar. When the local effective voltage is greater than the local optical transition At the required voltage, an overdrive condition occurs. For example, if when V _{Effective and effective} When 2V is reached, the optical transition to the transparent state is considered complete, and V in the vicinity of the bus bar _{Effective and effective} Is 2.2V, then the location near the bus bar can be characterized as being in an overdrive condition.

One example of a probing technique involves pulsing the applied drive voltage by reducing it to the level of the hold voltage (or the hold voltage modified by an appropriate offset) and monitoring the current response to determine the direction of the current response. In this example, when the current response reaches a defined threshold, the device control system determines that it is now time to transition from the drive voltage to the hold voltage. Another example of the detection technique described above involves applying an open circuit condition to the device and monitoring the open circuit voltage V _oc . This may be done to determine the optical state of the optical device and/or to monitor/control the optical transitions. Furthermore, in many cases, the amount of charge transferred to the optically switchable device (or, in relation, the delivered charge or charge density) can be monitored and used to control the optical transition.

FIG. 4A is a graph depicting an optical transition in which the applied voltage is varied from V _{Driving of} Down to V _Holding Resulting in a net current flow indicating that the optical transition has progressed far enough to allow the applied voltage to remain at V for the duration of the ending optical state _Holding . This is achieved by V _{Application of} From V _{Driving of} To V _Holding Is illustrated by voltage drop 411. At V _{Application of} Voltage drop 411 may otherwise be limited to be performed during the period that remains in the drive phase shown in fig. 3. As shown in current segment 307, when the applied voltage initially ceases to increase (becomes more negative) and at V _{Driving of} When settling is reached, the current flowing between the bus bars begins to drop (become less negative). However, when the applied voltage now drops at 411, the current begins to decrease more easily, as shown by current segment 415. According to some embodiments, the current level is measured after a defined period of time has elapsed after the voltage drop 411. If the current is below a certain threshold, the optical transition is considered complete, andthe applied voltage can be maintained at V _Holding (or if it is below V _{Driving of} To V _Holding ). In the particular example of fig. 4A, the current threshold is exceeded as shown. Thus V _{Application of} Remain at V for the duration of ending the optical state _Holding . End optical state selection V that may be provided for it _Holding . This ending optical state may be the maximum, minimum, or intermediate optical state of the optical device undergoing transition.

In the case that the current does not reach the threshold value during measurement, V is set _{Application of} Return to V _{Driving of} May be appropriate. This is shown in fig. 4B. FIG. 4B is a graph depicting an optical transition in which the applied voltage is varied from V _{Driving of} Initially drop to V _Holding (see 411) results in a net current flow, indicating that the optical transition has not progressed far enough to allow the applied voltage to remain at V for the duration of the ending optical state _Holding . It should be noted that when detected at 419, the current segment 415 having the trajectory created by the voltage drop 411 does not reach the threshold. Thus, the applied voltage returns to V _{Driving of} For another period of time while the current is restored at 417 and then falls again to V _Holding (421) The resulting current (423) at this point indicates that the optical transition has progressed far enough to allow the applied voltage to remain at V for the duration of the ending optical state _Holding . As explained, the ending optical state may be the maximum, minimum, or intermediate optical state of the optical device undergoing transition.

As explained, the holding voltage is the voltage that will maintain the optical device in balance at a particular optical density or other optical condition. Which produces a steady state result by generating a current that counteracts the leakage current in the end optical state. The application of a driving voltage to accelerate the transition to the point where the application of a holding voltage will result in a time-invariant desired optical state.

Certain detection techniques described herein may be understood in terms of the physical mechanisms associated with optical transitions driven from bus bars at the edges of the device. Basically, such techniques rely on optically switchable devicesDifferential values of effective voltages experienced across the surface of the device, especially V from the center of the device to the edge of the device _{Effective and effective} Is a variation of (c). Local changes in the potential on the transparent conductive layer result in V on the device surface _{Effective and effective} The values are different. V experienced by optically switchable devices in the vicinity of bus bars _{Effective and effective} The value is much greater than V at the center of the device _{Effective and effective} Values. As a result, the local charge accumulation in the region beside the bus bar is significantly greater than the charge accumulation in the center of the device.

At some point during the optical transition, V at the device edge near the bus bar _{Effective and effective} The value is sufficient to exceed the end optical state required for optical transition, while in the center of the device, V _{Effective and effective} Is insufficient to reach the end state. The end state may be an optical density value associated with an endpoint in the optical transition. In this intermediate stage of the optical transition, if the drive voltage drops to the hold voltage, the portion of the electrochromic device near the bus bar will effectively attempt to transition back to its starting state. However, since the device state at the center of the device has not reached the end state of the optical transition, the center portion of the device will continue to transition in the direction required for the optical transition when the holding voltage is applied.

When a device in this intermediate stage of transition experiences a change in applied voltage from a drive voltage to a hold voltage (or some other suitable lower magnitude voltage), the portion of the device located near the bus bar where the device is effectively overdrive generates a current that flows in a direction opposite to that required to drive the transition. Instead, the region of the device in the center that has not yet fully transitioned to the final state continues to facilitate current flow in the direction required to drive the transition.

During the optical transition, and when the device is experiencing an applied drive voltage, the drive force is gradually increased to reverse the current flow when the device is experiencing a sudden drop in the applied voltage. By monitoring the flow of current in response to a disturbance away from the drive voltage, it can be determined that the transition from the first state to the second state is far enough that the transition from the drive voltage to the hold voltage is at the point where it is appropriate. By "proper" is meant that the optical transition is sufficiently complete from the edge of the device to the center of the device. This transformation can be defined in a number of ways depending on the specifications of the product and its application. In one embodiment, the transition from the first state to the second state is assumed to be at least about 80% intact or at least about 95% intact. The change in optical density from the first state to the second state is fully reflected. The desired level of integrity may correspond to a threshold current level, as depicted in the examples of fig. 4A and 4B.

There are many possible variations of the detection scheme. Such variations may include certain pulse protocols defined in terms of the length of time from the beginning of the transition to the first pulse, the duration of the pulse, the size of the pulse, and the frequency of the pulse.

In one embodiment, the pulse sequence is initiated immediately after the application of the drive voltage or drive ramp voltage that initiates the transition between the first optical state and the second optical state. In other words, there will be no lag time between the onset of the transition and the application of the pulse. In some embodiments, the detection duration is short enough (e.g., about 1 second or less) that for the entire transition is at V _{Driving of} And V _Holding The back and forth detection has no significant adverse effect on the switching time. However, in some embodiments, it is not necessary to immediately begin probing. In some cases, the handoff is initiated after about 50% of the anticipated or nominal handoff period is completed, or after about 75% of this period is completed. Typically, the distance between the bus bars is known or may be read using a suitably configured controller. With a known distance, a conservative lower limit for initial probing may be achieved based on approximately known switching times. As an example, the controller may be configured to initiate probing after about 50-75% of the expected switching duration is completed.

In some embodiments, the detection begins about 30 seconds after the optical transition is initiated. Relatively early detection may be particularly useful in the event that an interrupt command is received. The interrupt command is a command that instructs the device to switch to the third light transmission state when the device is already in the process of changing from the first light transmission state to the second light transmission state. In this case, early detection may help determine the direction of the transition (i.e., whether the interrupt command requires the aperture to become brighter or darker than when the command was received). In some embodiments, detection begins about 120 minutes (e.g., or about 30 minutes, about 60 minutes, or about 90 minutes) after initiating the optical transition. Relatively late detection may be more useful where larger fenestrations are used, as well as where transitions occur from equilibrium. For architectural glass, detection may begin about 30 seconds to 30 minutes, in some cases about 1-5 minutes, such as about 1-3 minutes, or about 10-30 minutes, or about 20-30 minutes, after initiating the optical transition. In some embodiments, detection begins about 1-5 minutes (e.g., about 1-3 minutes, about 2 minutes in a particular example) after initiation of an optical transition by an interrupt command, while detection begins about 10-30 minutes (e.g., about 20-30 minutes) after initiation of an optical transition from a given initial command when the electrochromic device is in an equilibrium state.

In the examples of fig. 4A and 4B, the size of the pulse is between the drive voltage value and the hold voltage value. This may be for convenience. Other pulse magnitudes are also possible. For example, the magnitude of the pulse may be about +/-500mV of the hold voltage or about +/-200mV of the hold voltage. For context, electrochromic devices on a window aperture, such as a building window aperture, may have a drive voltage of about 0 volts to +/-20 volts (e.g., about +/-2 volts to +/-10 volts) and a hold voltage of about 0 volts to +/-4 volts (e.g., about +/-1 volt to +/-2 volts).

In various embodiments, the controller determines when the polarity of the detected current is opposite to the polarity of the bias voltage due to the transition proceeding to a significant extent during the optical transition. In other words, if the optical transition is still in progress, the current flowing to the bus bar flows in the opposite direction to that expected.

By taking the magnitude of the applied voltage from V _{Driving of} Down to V _Holding To detect provides a convenient and widely applicable mechanism for monitoring transitions to determine when the detected current first reverses polarity. By dropping the voltage to V _Holding An amount other than the amount of (2)The detection of the value may involve characterization of the aperture performance. Appear to be from V _{Driving of} To V _Holding The first time the post-detection current reverses the transition, even very large windows (e.g., about 60 ") substantially complete their optical transition.

In some cases, by making the applied voltage magnitude from V _{Driving of} Down to V _{Detection of} To detect, where V _{Detection of} Is a detection voltage other than the holding voltage. For example, V _{Detection of} May be V modified by offset _Holding . Although when from V _{Driving of} To V _Holding When the detected current first reverses the transition, many windows are able to substantially complete their optical transition, but some windows may benefit from pulsing voltages slightly offset from the holding voltage. In general, as the aperture size increases, and the temperature of the aperture decreases, the offset becomes increasingly beneficial. In some cases, the offset is between about 0-1V, and V _{Detection of} The ratio of magnitude V _Holding Is about 0-1V higher in magnitude. For example, the offset may be between about 0-0.4V. In these or other embodiments, the offset may be at least about 0.025V, or at least about 0.05V, or at least about 0.1V. The offset may cause the transition to have a longer duration than originally. The longer duration helps to ensure that the optical transition is fully completed. Techniques for selecting an appropriate offset relative to the hold voltage are discussed further below in the context of a target open circuit voltage.

In some embodiments, the controller informs the user or the aperture network master how far (e.g., percent) the optical transition has progressed. This may indicate what transmission level the aperture center is currently at. Feedback regarding the transition may be provided to a user interface in the mobile device or other computing apparatus. See, for example, PCT patent application number US2013/036456 filed on date 12, 4, 2013, which is incorporated herein by reference in its entirety.

The frequency of the probe pulses may be between about 10 seconds and 500 seconds. As used in this context, "frequency" means when the separation between the midpoints of adjacent pulses in a sequence of two or more pulsesAnd (3) the room(s). Typically, the frequency of the pulses is between about 10 seconds and 120 seconds. In certain embodiments, the frequency of the pulses is between about 20 seconds and 30 seconds. In certain embodiments, the detection frequency is affected by the size of the electrochromic device or the spacing between bus bars in the device. In certain embodiments, the detection frequency is selected as a function of the expected duration of the optical transition. For example, the frequency may be set to about 1/5 to about 1/50 (or about 1/10 to about 1/30) of the expected duration of the transition time. It should be noted that the transition time may correspond to V _{Application of} ＝V _{Driving of} Is a function of the expected duration of time of the (c). It should also be noted that the expected duration of the transition may be a function of the size of the electrochromic device (or the spacing of the bus bars). In one example, the duration of the 14 "fenestration is-2.5 minutes, while the duration of the 60" fenestration is-40 minutes. In one example, the detection frequency is every 6.5 seconds for a 14 "window and every 2 minutes for a 60" window.

In various embodiments, each pulse has a duration of about 1x10 ^-5 And between 20 seconds. In some embodiments, the duration of the pulse is between about 0.1 and 20 seconds, such as between about 0.5 and 5 seconds.

As indicated, in certain embodiments, an advantage of the detection techniques disclosed herein is that very little information needs to be preset with the controller responsible for controlling the aperture transition. Typically, this information contains only the holding voltage (and voltage offset, if applicable) associated with each optical end state. In addition, the controller may specify a voltage difference between the holding voltage and the driving voltage, or alternatively, V _{Driving of} The value of itself. Thus, for any selected ending optical state, the controller will know V _Holding 、V _{Offset of} And V _{Driving of} Is a magnitude of (2). The duration of the drive voltage is determined using the detection algorithm described herein. In other words, the controller determines how to apply the driving voltage appropriately as a result of actively detecting the degree of transition in real time.

Fig. 5A presents a flowchart 501 of a process for monitoring and controlling optical transitions in accordance with certain disclosed embodiments. As shown, the method begins with an operation, indicated by reference numeral 503, in which a controller or other control logic receives instructions directing optical transitions. As explained, the optical transition may be an optical transition between a colored state and a more transparent state of the electrochromic device. Instructions for directing the optical transition may be provided to the controller based on a preprogrammed schedule, algorithms that react to external conditions, manual inputs from a user, and the like. Regardless of how the instructions are initiated, the controller acts on the optically switchable devices by applying a drive voltage to their bus bars. See the operation indicated by reference numeral 505.

As described above, in conventional embodiments, the drive voltage is applied to the bus bar for a defined period of time, after which the optical transition is assumed to be sufficiently complete so that the applied voltage can drop to the holding voltage. In such implementations, the holding voltage is then maintained for the duration of the pending optical state. In contrast, according to embodiments disclosed herein, the transition from the starting optical state to the ending optical state is controlled by detecting the condition of the optically switchable device one or more times during the transition. This process is reflected in operation 507 of fig. 5A, etc.

In operation 507, after allowing the optical transition to proceed for an incremental period of time, the magnitude of the applied voltage decreases. The duration of this incremental transition is significantly less than the total duration required to complete the optical transition. After reducing the magnitude of the applied voltage, the controller measures the response of the current flowing to the bus bar. See operation 509. The associated controller logic may then determine whether the current response indicates that the optical transition is near completion. See decision 511. As described above, the determination of whether the optical transition is near completion may be accomplished in various ways. For example, it may be determined by the current reaching a certain threshold. Assuming that the current response does not indicate that the optical transition is near completion, process control is directed to the operation indicated by reference numeral 513. In this operation, the applied voltage returns to the magnitude of the drive voltage. Process control then loops back to operation 507 where the optical transition is allowed to proceed another increment and then again decrease to the magnitude of the applied voltage of the bus bar.

At some point in the process 501, decision operation 511 determines that the current response indicates that the optical transition is in fact near completion. At this time, the process control proceeds to an operation indicated by reference numeral 515, in which the applied voltage is converted to or maintained at the holding voltage for the duration of the ending optical state. At this point, the process is complete.

Separately, in some embodiments, the method or controller may specify the total duration of the transition. In such embodiments, the controller may be programmed to monitor the progress of the transition from the start state to the end state using a modified detection algorithm. Progress may be monitored, for example, using the detection techniques described above, by periodically reading the current value in response to a decrease in the magnitude of the applied voltage. The detection technique may also be implemented using a drop in applied current (e.g., measuring an open circuit voltage), as explained below. The current or voltage response indicates the extent to which the optical transition has been nearly completed. In some cases, the response is compared to a threshold current or voltage at a particular time (e.g., the time that has elapsed since the start of the optical transition). In some embodiments, the comparison is made using sequential pulses or checks for progression of the current or voltage response. The steepness of the progress may indicate when it is possible to reach the final state. This linear extension of the threshold current may be used to predict when the transition is complete, or more precisely when it is sufficiently complete, it is appropriate to reduce the drive voltage to the hold voltage.

With respect to algorithms for ensuring that an optical transition from a first state to a second state occurs within a defined time frame, the controller may be configured or designed to appropriately increase the drive voltage to accelerate the transition when the interpretation of the impulse response indicates that the transition is not fast enough to meet the desired transition speed. In certain embodiments, when it is determined that the transition is not proceeding fast enough, the transition switches to its mode of being driven by the applied current. The current is large enough to increase the transition speed but not so large that it can degrade or damage the electrochromic device. In some embodiments, the maximum appropriate safe current may be referred to as I _Secure 。I _Secure May be about 5. Mu.A/cm ² And 250. Mu.A/cm ² Between them. In the current-controlled drive mode, the applied voltage is allowed to float during the optical transition. Then, during this current controlled driving step, the controller may periodically detect by, for example, dropping to the holding voltage, and check the integrity of the transition in the same manner as when using a constant driving voltage.

In general, detection techniques can determine whether an optical transition is performed as expected. If the technique determines that the optical transition is proceeding too slowly, steps may be taken to accelerate the transition. For example, it may increase the driving voltage. Similarly, the techniques may determine that the optical transition is proceeding too fast and there is a risk of damaging the device. When such a determination is made, the probing technique may take steps to slow down the transition. As an example, the controller may decrease the driving voltage.

In some applications, the window group is set to match the transition rate. The apertures in the set may or may not start from the same starting optical state and may or may not end at the same ending optical state. In certain embodiments, the fenestrations will start from the same first optical state and transition to the same second transition state. In one embodiment, matching is accomplished by adjusting the voltage and/or drive current based on feedback (via pulse or open circuit measurements) obtained during probing as described herein. In implementations in which the transitions are controlled by monitoring the current responses, the magnitude of the current responses and/or the accumulation of charge delivered to the optically switchable device may be compared from controller to controller (for each of the aperture sets) to determine how to scale the drive potential or drive current of each aperture in the set. The rate of change of the open circuit voltage can be used in the same way. In another embodiment, the faster transition aperture may utilize one or more pauses in order to switch for the same duration as the slower switching aperture, as described below with respect to fig. 5K. The pauses may or may not correspond to preset tone states.

Fig. 5B presents a flowchart 521 depicting an exemplary process for ensuring that an optical transition occurs fast enough, e.g., within a defined period of time. The first four depicted operations in flowchart 521 correspond to the first four operations in flowchart 501. In other words, operations 523, 525, 527, and 529 of flowchart 521 correspond to operations 503, 505, 507, and 509 of flowchart 501. Briefly, in operation 523, a controller or other suitable logic receives an instruction to undergo an optical transition. Then, at operation 525, the controller applies a driving voltage to the bus bar. After allowing the optical transition to proceed incrementally, the controller reduces to the magnitude of the applied voltage of the bus bar. See operation 527. The magnitude of the lower voltage is typically (although not necessarily) the holding voltage. As mentioned above, the lower voltage may also be a holding voltage modified by an offset (the offset typically falls between about 0-1V, for example between about 0-0.4V in many cases). Next, the controller measures the current response to the applied voltage drop. See operation 529.

The controller next determines whether the current response indicates that the optical transition is proceeding too slowly. See decision 531. As explained, the current response may be analyzed in various ways to determine whether the transition is proceeding at a sufficient speed. For example, the magnitude of the current response may be considered, or the progress of the multiple current responses to multiple voltage pulses may be analyzed to make this determination.

Assuming operation 531 determines that the optical transition is taking place fast enough, the controller then increases the applied voltage back to the drive voltage. See operation 533. Thereafter, the controller then determines whether the optical transition is sufficiently complete that no further progress checking is required. See operation 535. In certain embodiments, the determination in operation 535 is made by considering the magnitude of the current response as discussed in the context of fig. 5A. Assuming that the optical transition has not been completed, process control returns to operation 527 where the controller allows the optical transition to be further incremented before again reducing the magnitude of the applied voltage.

Assuming that the execution of operation 531 indicates that the optical transition is proceeding too slowly, process control points to operation 537, where the controller increases the magnitude of the applied voltage to a level greater than the drive voltage. This drives the transition and hopefully accelerates it to a level that meets specifications. After increasing the applied voltage to this level, process control points to operation 527 where the optical transition continues another increment before the magnitude of the applied voltage drops. The entire process then proceeds through operations 529, 531, etc., as described above. At some point, the answer to decision 535 is affirmative and the process is complete. In other words, no further progress checking is required. The optical transition is then completed, for example, as shown in flow chart 501.

Another application of the detection techniques disclosed herein involves the immediate modification of optical transitions of different end states. In some cases, it may be necessary to change the end state after the transition begins. Examples of reasons for such modification include a user manually overriding a previously specified ending hue status and a widespread power shortage or interruption. In this case, the initially set end state may be transmittance=40%, and the modified end state may be transmittance=5%.

In the event of a final state modification during an optical transition, the detection techniques disclosed herein may adapt and move directly to a new final state, rather than first completing the transition to the initial final state.

In some implementations, the transition controller/method uses voltage/current sensing as disclosed herein to detect the current state of the aperture and then immediately moves to a new drive voltage. The new drive voltage may be determined based on the new end state and optionally the time allotted for completing the transition. If desired, the drive voltage is increased significantly to accelerate the transition or drive a larger transition of the optical state. The appropriate modification is completed without waiting for the transition initially defined to complete. The detection techniques disclosed herein provide a method of detecting the position of a device in transition and adjusting therefrom.

It should be appreciated that the detection techniques presented herein are not necessarily limited to measuring the magnitude of the current of the device in response to a voltage drop (pulse). Various alternatives exist to measure the magnitude of the current response to the voltage pulse as an indication of how far the optical transition has progressed. In one example, the curve of the current transient provides useful information. In another example, the open circuit voltage of the measurement device may provide the necessary information. In such embodiments, pulsing involves simply not applying a voltage to the device, and then measuring the voltage applied by the open circuit device. Furthermore, it should be understood that current and voltage based algorithms are equivalent. In current-based algorithms, probing is accomplished by discarding the applied current and monitoring the device response. The response may be a measured voltage change. For example, the device may be maintained in an open circuit condition to measure the voltage between the bus bars.

Fig. 5C presents a flow chart 541 of a method for monitoring and controlling optical transitions in accordance with certain disclosed embodiments. In this case, the detected process condition is an open circuit voltage, as described in the previous paragraph. The first two depicted operations in flowchart 541 correspond to the first two operations in flowcharts 501 and 521. In other words, operations 543 and 545 of flowchart 541 correspond to operations 503 and 505 of flowchart 501. Briefly, in operation 543, a controller or other suitable logic receives instructions to undergo an optical transition. Then, at operation 545, the controller applies a driving voltage to the bus bar. After allowing the optical transition to proceed incrementally, the controller applies an open circuit condition to the electrochromic device in operation 547. Next, the controller measures an open circuit voltage response at operation 549.

As in the case described above, the controller may measure the electronic response (in this case, the open circuit voltage) after a defined period has elapsed after the open circuit condition was applied. After an open circuit condition is applied, the voltage typically experiences an initial drop related to ohmic losses in the external components connected to the electrochromic device. Such external components may be, for example, conductors and connections to devices. After this initial drop, the voltage undergoes a first relaxation and stabilizes at a first plateau voltage. The first relaxation involves internal ohmic losses, for example at the electrode/electrolyte interface within the electrochromic device. The voltage at the first plateau corresponds to the voltage of the battery, having both a balanced voltage and an overvoltage for each electrode. After the first voltage plateau, the voltage undergoes a second relaxation to an equilibrium voltage. The second relaxation is much slower, e.g. on the order of a few hours. In some cases, it is desirable to measure the open circuit voltage during the first plateau when the voltage is relatively constant over a short period of time. This technique may be beneficial in providing particularly reliable open circuit voltage readings. In other cases, the open circuit voltage is measured at some point during the second relaxation. This technique may be advantageous to provide a sufficiently reliable open circuit reading while using less expensive and rapidly operating power/control equipment.

In some embodiments, the open circuit voltage is measured after a set period of time after the open circuit condition is applied. The optimal time period for measuring the open circuit voltage depends on the distance between the bus bars. The set time period may relate to the time that the voltage of a typical or specific device is within the first platform region described above. In such embodiments, the set time period may be on the order of milliseconds (e.g., a few milliseconds in some examples). In other cases, the set time period may relate to the time that the voltage of a typical or particular device experiences the second relaxation described above. Here, in some cases, the set time period may be on the order of about 1 second to several seconds. Shorter times may also be used depending on the available power source and controller. As described above, longer times (e.g., where the open circuit voltage is measured during the second relaxation) may be beneficial because they still provide useful open circuit voltage information without requiring high-end devices that can operate accurately in very short time frames.

In certain embodiments, the open circuit voltage is measured/recorded after a time frame that depends on the behavior of the open circuit voltage. In other words, the open circuit voltage may be measured over time after the open circuit condition is applied, and the voltage for analysis may be selected based on the voltage versus time behavior. As described above, after the open circuit condition is applied, the voltage undergoes an initial drop followed by a first relaxation, a first plateau and a second relaxation. Each of these periods may be identified on a voltage versus time graph based on the slope of the curve. For example, the first plateau region will relate to the plot in which dV _oc The magnitude of/dt is relatively low. This may correspond to the ion current having stopped(or almost stop) decay conditions. Thus, in certain embodiments, the open circuit voltage used in the feedback/analysis is at dV _oc The voltage measured when the magnitude of/dt falls below a certain threshold.

Returning to fig. 5C, after the open circuit voltage response is measured, it may be compared to a target open circuit voltage at operation 551. The target open circuit voltage may correspond to a holding voltage. In some cases, discussed further below, the target open circuit voltage corresponds to a hold voltage modified by the offset. Techniques for selecting an appropriate offset relative to the hold voltage are discussed further below. In the event that the open circuit voltage response indicates that the optical transition has not been complete (i.e., the open circuit voltage has not reached the target open circuit voltage), the method continues at operation 553, wherein the applied voltage is increased to the drive voltage for an additional period of time. After the additional period of time has elapsed, the method may repeat from operation 547, wherein the open circuit condition is again applied to the device. At some point in method 541, it will be determined in operation 551 that the open circuit voltage response indicates that the optical transition is near completion (i.e., where the open circuit voltage response has reached the target open circuit voltage). In this case, the method continues at operation 555, where the applied voltage transitions to or is maintained at the holding voltage for the duration of the ending optical state.

Method 541 of fig. 5C is very similar to method 501 of fig. 5A. The main difference is that in fig. 5C, the measured related variable is the open circuit voltage, while in fig. 5A, the measured related variable is the current response when a reduced voltage is applied. In another embodiment, the method 521 of fig. 5B is modified in the same manner. In other words, the method 521 may be altered such that detection is performed by placing the device in an open circuit condition and measuring the open circuit voltage rather than the current response.

In another embodiment, the process for monitoring and controlling the optical transition takes into account the total amount of charge delivered to the electrochromic device per unit area of the device during the transition. This amount may be referred to as the delivered charge or charge density or the total delivered charge or charge density. Thus, additional criteria such as total charge delivered or charge density may be used to ensure that the device transitions completely under all conditions.

The total delivered charge or charge density may be compared to a threshold charge or threshold charge density (also referred to as a target charge or charge density) to determine whether the optical transition is near completion. The threshold charge or threshold charge density may be selected based on the minimum charge or charge density required to complete or nearly complete the optical transition under the possible operating conditions. In various cases, the threshold charge or threshold charge density may be selected/estimated based on the charge or charge density required to complete or nearly complete the optical transition at a defined temperature (e.g., at about-40 ℃, about-30 ℃, about-20 ℃, about-10 ℃, about 0 ℃, about 10 ℃, about 20 ℃, about 25 ℃, about 30 ℃, about 40 ℃, about 60 ℃, etc.).

The appropriate threshold charge or threshold charge density may also be affected by the leakage current of the electrochromic device. Devices with higher leakage currents should have higher threshold charge densities. In some embodiments, the appropriate threshold charge or threshold charge density may be empirically determined for the individual aperture or aperture design. In other cases, the appropriate threshold may be calculated/selected based on characteristics of the aperture such as size, bus bar spacing distance, leakage current, start and end optical states, and the like. Exemplary threshold charge densities range from about 1 x 10 ^-5 C/cm ² And about 5C/cm ² Between, for example, about 1X 10 ^-4 And about 0.5C/cm ² Between, or about 0.005-0.05C/cm ² Between, or about 0.01-0.04C/cm ² Between, or in many cases between about 0.01 and 0.02. A smaller threshold charge density may be used for a partial transition (e.g., fully transparent to 25% coloration), and a larger threshold charge density may be used for a full transition. A first threshold charge or charge density may be used for bleaching/transparency transitions and a second threshold charge or charge density may be used for dyeing/tinting transitions. In certain embodiments, the threshold charge or charge density is higher for a colored transition than for a transparent transition. In particular examples, the threshold charge density of the coloration is between about 0.013 and 0.017C/cm ² And a transparent threshold charge density of about 0.016 to about 0.020C/cm ² Between them. Can be at the window holeIn the case of transitions between more than two states, additional threshold charge densities may be appropriate. For example, if the device is in four different optical states: A. b, C and D, a different threshold charge or charge density (e.g., a-B, A-C, A-D, B-a, etc.) may be used for each transition.

In some embodiments, the threshold charge or threshold charge density is empirically determined. For example, the amount of charge required to achieve a particular transition between desired end states may be characterized for different sized devices. A curve may be fitted for each transition to relate the bus bar separation distance to the desired charge or charge density. This information may be used to determine the minimum threshold charge or threshold charge density required for a particular transition on a given aperture. In some cases, the information gathered in such empirical determination is used to calculate the amount of charge or charge density that corresponds to a particular level of change (increase or decrease) in optical density.

Fig. 5D presents a flowchart of a method 561 for monitoring and controlling optical transitions in an electrochromic device. The method begins with operations 563 and 565, which correspond to operations 503 and 505 of fig. 5A. At 563, a controller or other suitable logic receives the instruction to undergo an optical transition. Then, at operation 565, the controller applies a driving voltage to the bus bar. After allowing the optical transition to proceed incrementally, at operation 567 the magnitude of the voltage applied to the bus bar is reduced to the detection voltage (in some cases the holding voltage, and in other cases the holding voltage modified by the offset). Next, at operation 569, a current response to the reduced applied voltage is measured.

Up to now, the method 561 of fig. 5D is identical to the method 501 of fig. 5A. However, the two methods differ in this point in the process, method 561 continues at operation 570, where the total delivered charge or charge density is determined. The total delivered charge or charge density may be calculated based on the current delivered to the device integrated over time during the optical transition. At operation 571, the associated controller logic may determine whether the current response and the total delivered charge or charge density each indicate that the optical transition is near completion. As described above, the determination of whether the optical transition is near completion may be accomplished in various ways. For example, it may be determined by the current reaching a particular threshold and by delivering a charge or charge density reaching a particular threshold. Both the current response and the total delivered charge or charge density must indicate that the transition is near completion before the method can continue at operation 575, where the applied voltage transitions or remains at the holding voltage for the duration of the ending optical state. Assuming that at least one of the current response and the total delivered charge or charge density indicates that the optical transition has not been nearly completed at operation 571, then process control is directed to the operation represented by reference numeral 573. In this operation, the applied voltage returns to the magnitude of the drive voltage. Process control then loops back to operation 567 where the optical transition is allowed to proceed another increment and then again decrease to the magnitude of the applied voltage of the bus bar.

Fig. 5E presents an alternative method 581 for monitoring and controlling optical transitions in an electrochromic device. The method begins with operations 583 and 585, which correspond to operations 503 and 505 of fig. 5A. At 583, a controller or other suitable logic receives an instruction to undergo an optical transition. Then, at operation 585, the controller applies a driving voltage to the bus bar. After allowing the optical transition to proceed incrementally, an open circuit condition is applied to the device at operation 587. Next, at operation 589, the open circuit voltage of the device is measured.

Up to now, method 581 of fig. 5E is the same as method 541 of fig. 5C. However, the two methods differ in this point in the process, method 581 continues at operation 590, where the total delivered charge or charge density is determined. The total delivered charge or charge density may be calculated based on the current delivered to the device integrated over time during the optical transition. At operation 591, the associated controller logic may determine whether both the open circuit voltage and the total delivered charge or charge density indicate that the optical transition is near completion. Both the open circuit voltage response and the total delivered charge or charge density must indicate that the transition is near completion before the method can continue at operation 595, where the applied voltage transitions to or remains at the holding voltage for the duration of the ending optical state. Assuming that at least one of the open circuit voltage response and the total delivered charge or charge density indicates that the optical transition has not been nearly completed at operation 591, process control is directed to the operation represented by reference numeral 593. In this operation, the applied voltage returns to the magnitude of the drive voltage. Process control then loops back to operation 587 where the optical transition is allowed to proceed another increment before the open circuit condition is again applied to the device. The method 581 of fig. 5E is very similar to the method 561 of fig. 5D. The main difference between the two embodiments is that in fig. 5D the applied voltage drops and the current response is measured, whereas in fig. 5E an open circuit condition is applied and the open circuit voltage is measured.

Fig. 5F shows a flow chart of a related method 508 for controlling optical transitions in an electrochromic device. Method 508 of fig. 5F is similar to method 581 of fig. 5E. The method 508 begins at operation 510, where the controller turns on. Next, at operation 512, the open circuit voltage (V _oc ) And the device waits for an initial command. As described above, by measuring V _oc The current optical state of the device may be determined. Because this optical state is the starting optical state for the transition to the next state, it may be beneficial to characterize this state before a new command is sent to the device, thereby minimizing the risk of damaging the device. An initial command is received at operation 514 indicating that the aperture should switch to a different optical state. After receiving the command, an open circuit condition is applied and the open circuit voltage is measured at operation 516. The amount of charge delivered (Q) may also be read at block 516. These parameters determine the direction of the transition (whether the aperture should be more tinted or more transparent) and influence the optimal driving parameters. An appropriate driving parameter (e.g., driving voltage) is selected at operation 516. This operation may also involve modifying the target charge count and the target open circuit voltage, particularly in the event an interrupt command is received, as discussed further below.

After reading the open circuit voltage at operation 516, the electrochromic device is driven for a period of time. In some cases, the drive duration may be based on the bus bar separation distance. In other cases, a fixed drive duration may be used, for example, about 30 seconds. This driving operation may involve applying a driving voltage or current to the device. Operation 518 may also involve modifying the drive parameters based on the sensed open circuit voltage and/or charge count. Next, at operation 520, it is determined whether the total time of transition (so far) is less than a threshold time. Exemplary threshold times may be about 1 hour, about 2 hours, about 3 hours, about 4 hours, and any range between these examples, although other time periods may be used as appropriate. If it is determined that the total time of the transition is not less than the threshold time (e.g., the transition has taken at least 2 hours and has not completed), the controller may indicate that it is in a fault state at operation 530. This may indicate that something is wrong in the transition. Otherwise, in the event that it is determined that the total time of the transition is less than the threshold time, the method continues at operation 522. Here, the open circuit condition is applied again, and the open circuit voltage is measured. At operation 524, it is determined whether the measured open circuit voltage is greater than or equal to the target voltage (in terms of magnitude). If so, the method continues at operation 526 where it is determined whether the charge count (Q) is greater than or equal to the target charge count. If the answer in either operation 524 or 526 is no, the method returns to block 518 where the electrochromic device transitions are driven for additional drive durations. In the event that the answer is yes in both operations 524 and 526, the method continues at operation 528 where a hold voltage is applied to maintain the electrochromic device in the desired hue state. Typically, the hold voltage continues to be applied until a new command is received, or until a timeout is experienced.

When a new command is received after the transition is complete, the method may return to operation 516. Another event that may cause the method to return to operation 516 is the receipt of an interrupt command, as shown in operation 532. After the initial command is received at operation 514 and before the transition is substantially completed at operation 528, an interrupt command may be received at any point in the method. The controller should be able to receive multiple interrupt commands during the transition. One example interrupt command involves a user indicating that the aperture has changed from a first shade state (e.g., fully transparent) to a second shade state (e.g., fully colored) and then interrupting the transition to indicate that the aperture has changed to a third shade state (e.g., half colored) instead of the second shade state before the second shade state is reached. After receiving the new command or interrupt command, the method returns to block 516, as indicated above. Here, an open circuit condition is applied and the open circuit voltage and charge count are read. Based on the open circuit voltage and charge count readings and the desired third/final tone state, the controller can determine appropriate driving conditions (e.g., driving voltage, target charge count, etc.) to achieve the third tone state. For example, an open circuit voltage/charge count may be used to indicate in which direction a transition should occur. The charge count and charge target may also be reset after receiving a new command or interrupt command. The updated charge count may relate to the charge delivered to move from the hue state when a new/interrupt command to the desired third hue state is received. Since the new command/interrupt command will change the start and end points of the transition, it may be necessary to modify the target open circuit voltage and target charge count. This is indicated as an optional part of operation 516 and is particularly valuable when a new or interrupt command is received.

Fig. 5G and 5H together describe an embodiment in which a plurality of different modes are used to control an optically switchable device, depending on the type of task the device is performing. Three different modes of operation will be discussed with reference to these figures. In a first mode, a controller associated with the aperture measures V _oc But does not monitor the amount of charge delivered to the device. In the second mode, the controller associated with the aperture measures V _oc And the amount of charge delivered to the device is monitored. In a third mode, the controller associated with the aperture monitors the amount of charge delivered to the device, but does not measure V _oc . The first mode is particularly useful for controlling transitions from an unknown state (e.g., after a power loss, first start-up) to a known end state. In some cases, the optically switchable device may default to this mode of operation after a loss of power or in any case when the initial state of the aperture is unknown. The second mode is particularly useful for controlling transitions between a known starting optical state and a known ending optical state. The mode being transitionable between two known states in which there is no interruptionIs used at any time. The third mode of operation may be particularly useful for controlling optical transitions that begin during a previously made optical transition (e.g., when an interrupt command is received). When an ongoing transition is interrupted in this way, the third mode may provide superior control of the transition as compared to the other modes.

Returning to fig. 5G and 5H, it should be noted that fig. 5H presents operation 552 of fig. 5G in more detail. The method 540 begins with operation 542 where an initial command is received. The initial command instructs the device to change to a particular ending optical state, referred to as ending state 1 in fig. 5G. Next, an open circuit condition is applied and an open circuit voltage (V is measured in operation 544 _oc ). Measurement of V _oc Allowing the optical state of the device to be determined. The optical state corresponds to a starting optical state of the optical transition. During operation 544, the fenestration operates in the first mode described above. Next, initial drive parameters are determined in operation 546. The drive parameters may be determined based at least in part on the end state 1 and the starting optical state determined in operation 544. In general, the drive parameters relate to the voltage or current applied to the device, sometimes referred to as the drive voltage and drive current, respectively. At operation 548, the drive parameters are applied to the device for a period of time and the optical transition begins.

Next, it is determined whether an interrupt command has been received in operation 550. In some cases, this may be actively checked, while in other cases such a determination may be made passively (e.g., the aperture/controller may not actively check whether a command has been received, but rather the aperture/controller may take action with respect to the interrupt command when such command has been received, that is, the controller/aperture may automatically respond to the interrupt command). The interrupt command is a command received while the previous optical transition is in progress, and instructs the device to undergo transition to a state other than the end state 1. An interrupt command may be used to cause the device to transition to a different end optical state, referred to as end state 2. The final state 2 may be more or less colored than the final state 1 (e.g., where the optically switchable device is an electrochromic device). In a simple case, the end state 2 may be the starting optical state, in which case the interrupt command essentially cancels the ongoing transition and causes the device to return to its starting optical state.

In the example of fig. 5G and 5H, the previous transition is a transition from the starting optical state to the ending state 1 determined in operation 544. The interrupt command indicates that the device instead undergoes a second transition, this time to end state 2. In the event that an interrupt command has been received, the method 540 continues with operation 552, where the device transitions to end state 2. Operation 552 is explained in further detail in fig. 5H.

In the case where no interrupt command is received in operation 550, the method 540 continues at operation 554. Here, the device can be probed to evaluate how far the optical transition has progressed. In this example, operation 554 involves applying an open circuit condition and measuring an open circuit voltage (V _oc ). The operation also involves monitoring the amount of charge delivered to the device, referred to as Q _Counting . In some cases, the total delivered charge or charge density may be monitored. At operation 556, V is determined _oc Whether or not V has been reached _{Target object} . This generally involves placing V _oc The magnitude of (V) is equal to V _{Target object} Is compared with the magnitude of (c). Depending on the transition, V _oc The value of (c) may increase or decrease over time. Thus, the term "reach" (e.g., as opposed to V _oc Reach V _{Target object} Used) can mean V _oc The magnitude of (2) should be equal to or greater than V _{Target object} Or V _oc The magnitude of (2) should be equal to or less than V _{Target object} Is a value of the magnitude of (2). Those of ordinary skill in the art understand how to determine which conditions to use based on the transition that is occurring. If V is _oc If the magnitude of (a) reaches the magnitude of the target voltage, then the method continues with operation 558, where the charge (Q) to be delivered to the device _Counting ) With target charge count (Q) _{Target object} ) A comparison is made. If the amount of charge delivered to the device reaches or exceeds Q _{Target object} The optical transition is complete and the device has reached final state 1, at which point a holding voltage may be applied, as shown in operation 560.

In which V in operation 556 _oc Has not yet reached V _{Target object} And/or where Q in operation 558 _Counting Not yet reach Q _{Target object} Instead, the method continues at operation 548, wherein a driving parameter is applied to the device to drive the optical transition for an additional duration. During operations 546, 548, 550, 554, 556 and 558 (particularly 554, 556 and 558), the fenestration/controller may be understood to operate in the second mode described above (where V is considered) _oc And charge count).

Turning to fig. 5H, operation 552 (transition of the device to end state 2) may be performed using a number of steps, as shown. At operation 562, when transitioning to end state 1, an interrupt command is received indicating that the device should instead transition to end state 2. Based on this command, the aperture/controller can switch to a particular mode of operation, such as the third mode described above, wherein the feedback for controlling the transition is based primarily on the amount of charge delivered to the device. At operation 576, a determination is made as to how much charge has been delivered to the device (Q) during the transition from the start state toward the end state 1 _Counting ). The Q is _Counting Indicating how far the first transition has been made and also providing an indication/estimate of what the current optical state of the aperture may be. Next, at operation 564, a second Q is determined based on the end state 2 _{Target object} . The second Q _{Target object} May be related to the amount of charge that would be suitable for delivery to the device to cause the device to transition from the starting optical state (prior to the transition toward end state 1) to end state 2. In such cases, Q _Counting The transitions from the beginning of the first transition towards end state 1 through to end state 2 may be counted cumulatively. In a similar embodiment, a second Q _{Target object} May be related to the amount of charge that would be suitable for delivery to a device to cause the device to transition from its transient optical state (e.g., the optical state at the point in time when the interrupt command was received in operation 562) to end state 2. In these cases, Q may be reset upon receipt of an interrupt command _Counting . In some such cases, Q delivered upon transition towards end state 1 may be based on _Counting To infer the instantaneous optical state of the deviceA state. For the purpose of fig. 5H, it is assumed that the first method is used and Q is measured cumulatively from the beginning of the first transition towards the end state 1 _Counting 。

Next, at operation 566, updated drive parameters for driving the device toward end state 2 are determined. In particular, the polarity and magnitude of the drive parameter, such as the drive voltage or drive current, may be determined. The updated driving parameters may be based on the second Q _{Target object} And Q delivered during transition from start state towards end state 1 _Counting To determine. In other words, the updated drive parameters are determined based on the new target optical state (end state 2) and how far the first transition has progressed before it is interrupted. These determinations are further described with reference to fig. 5I, as follows. At operation 568, updated drive parameters are applied to the device for a period of time and the optical transition toward end state 2 is driven. During this operation, the amount of charge (Q) delivered to the device may be continuously or periodically monitored _Counting ). At operation 572, a determination of Q _Counting Whether or not the second Q has been reached _{Target object} . This determination depends, at least in part, on whether the optical transition changes direction due to the interrupt command, as further explained with respect to fig. 5I. At Q _Counting Not yet reach the second Q _{Target object} In the event that the method returns to operation 568 wherein the drive parameters are applied for an additional duration and the device is driven toward end state 2. Once Q is _Counting Reaching the second Q _{Target object} The second optical transition is complete and a hold voltage may be applied to maintain end state 2.

The various steps presented in fig. 5G and 5H (and other flowcharts herein) may be performed at different points in time than those shown in the figures. This is especially true when several measurements and/or determinations are made at a time. In such cases, the related operations may be performed in any order that is useful.

Fig. 5I presents a number of graphs depicting aspects of several optical transitions (including transitions occurring due to interrupt commands) for a single optically switchable device. The uppermost curve depicts electrochromic at the center of the device over timeThe% transmission of the aperture. Four different optical states Tint ₁ -Tint ₄ Marked on the x-axis, each corresponding to a different hue level. Tint ₁ Is the least colored state and Tint ₄ Is the most colored state. The second curve depicts Q over time _Counting And Q _{Target object} . The third curve depicts V over time _oc And V _{Target object} (target open circuit voltage). The fourth and bottom curves depict the set point voltage over time.

At time T ₁ At which a command to undergo a first optical transition is received and the device begins to transition to the end state. In this example, the electrochromic device is at time T ₁ Where has an initial optical state Tint ₁ . Further, at time T ₁ The command received at it indicates the device to change to the end state 1, which corresponds to Tint ₄ . Responsive to at time T ₁ A command received thereat, the aperture/controller determining that it is appropriate to transition from a start state to an end state 1 (from Tint ₁ Transition to Tint ₄ ) Q of (2) _{Target object} And V _{Target object} . The transition may be detected and monitored as described herein, e.g., by applying an open circuit condition, measuring V _oc And with V _{Target object} Compare, and determine the charge (Q) delivered to the device by monitoring _Counting ) And combine it with Q _{Target object} A comparison is made. However, before the optical transition is completed, at time T ₂ A second command is received. At T ₂ The command received at this point indicates that the aperture experiences a different end state (end state 2, which corresponds to Tint ₃ ) Is referred to herein as a second optical transition). In other words, at time T ₂ At this point, it is determined that transition is not made to the end state 1 (Tint ₄ ) Instead the aperture should be shifted to a lesser degree of coloration (to end state 2, tint ₃ )。

At the time T when the command is made ₂ Where the device is in a transient optical state Tint ₂ . Because the window hole is at time T ₂ The instantaneous optical state at (between the initial optical state and the end state 2 (at Tint) ₁ With Tint ₃ Between) so that the optical transition will continue in the same direction (that is, the polarity of the drive parameter will be the same as in the direction of Tint ₄ The polarity of the driving parameters used during the transition at end state 1 is the same). Also at time T ₂ At the target open circuit voltage (V _{Target object} ) At Tint ₃ The duration of the optical transition at end state 2 becomes irrelevant. The target open circuit voltage is no longer considered because at this point the aperture/controller operates in the third mode described above, which primarily considers the charge delivered to the device rather than the open circuit voltage. FIG. 5I shows at time T ₂ The target open circuit voltage at return to 0, but it should be appreciated that V is not considered at all during the subsequent time period _oc And V _{Target object} (i.e. until at time T ₃ A new command is received).

As explained with respect to operation 564 in fig. 5H, at time T ₂ Determining a second Q _{Target object} Wherein the second Q _{Target object} Is adapted to change from a starting optical state (Tint ₁ ) Transition to end state 2 (Tint ₃ ) Is a charge amount of (a). Q as in FIG. 5I&Q _{Target object} Shown in the graph of time, a second Q _{Target object} Is significantly lower than the first Q _{Target object} Because when the end state 2 (Tint ₃ ) At the time, the end state 1 (Tint ₄ ) The device is not fully transitioned. The optical transition then proceeds until Q _Counting Reaching the second Q _{Target object} At this point the second optical transition is complete and a holding voltage can be applied to maintain the device in end state 2 (Tint ₃ )。

Next, at time T ₃ Where a command is received indicating that the device undergoes another optical transition (referred to herein as a third optical transition). The command instructs the aperture to switch to a new end state, end state 3 (at Tint ₁ At) a location. Drive parameters and target open circuit voltage (V _{Target object} ) And target charge count (Q) _{Target object} ) Can be determined as described herein, e.g., based on the initial optical state (Tint ₃ ) And an ending optical state of the device, ending state 3 (Tint ₁ ). Can be as described hereinDetects/monitors the transition as such, e.g. by measuring V _oc And is connected with V _{Target object} Compare and by monitoring Q _Counting And with Q _{Target object} A comparison is made. The third optical transition is completed without receiving any interrupt command. Thus, once V _oc Reach V _{Target object} And once Q _Counting Reach Q _{Target object} This transition is considered complete.

Then, at time T ₄ Where a new command is received indicating that the device undergoes another optical transition (referred to herein as a fourth optical transition). For this transition, the initial optical state is Tint ₁ And ending the optical state (ending state 4) at Tint ₄ Where it is located. Because the transition is between the same start and end states as the first optical transition, the same drive parameter V can be used _{Target object} And Q _{Target object} . The optical transition may be detected/monitored as described herein, e.g., by monitoring V _oc And is connected with V _{Target object} Compare and by monitoring Q _Counting And with Q _{Target object} A comparison is made.

Before the fourth optical transition is completed, at time T ₅ Is received to indicate that the device experiences a different ending state (ending state 5, tint ₃ At) a different optical transition (referred to herein as a fifth optical transition). And at time T ₂ As with the command received at time T ₅ The command received at that point is an interrupt command (because it indicates that the device has undergone a different optical transition while the previous optical transition is still occurring). Based on T ₅ The new command at which the new Q can be determined as described above _{Target object} . Similarly, V may be ignored for the duration of the fifth optical transition _{Target object} And may not measure V _oc As described above with reference to the second optical transition.

And at T ₂ At T, compared to the interrupt command received at ₅ The interrupt command received at this point affects the control method slightly differently, since the fourth optical transition is at time T ₅ At a time T compared with the second optical transition ₂ Substantially farther away. At time T ₅ Where the device has passed through end state 5 (Tint ₃ ). In other words, when the interrupt command is received, the instantaneous optical state of the device is not in the initial optical state (Tint ₁ ) And a new expected end state, end state 5 (Tint ₃ ) Between them. Although the transition is at time T ₂ Which are kept in the same direction (so that the polarity of the driving parameters is the same when comparing the first transition and the second transition), but at time T ₅ The situation is reversed (so that the polarity of the driving parameters is different when comparing the fourth transition and the fifth transition). As shown in the lowest graph depicting the set point voltage, V _{Set point} At time T ₅ The point is changed from negative to positive. In contrast, at time T ₂ V at _{Set point} But the polarity remains negative. Similarly, at time T ₅ At this point, the charge delivered to the device switches direction on the graph, upward toward 0. This switching occurs because current flows within the device in a direction opposite to that which occurs during the fourth optical transition.

Because the interrupt command causes switching in direction/polarity between the fourth optical transition and the fifth optical transition, the charge (Q) delivered to the device is made somewhat differently _Counting ) Whether or not Q has been reached _{Target object} Is determined by the above-described method. And when Q _Counting Is greater than or equal to Q _{Target object} At the magnitude of (2), the second optical transition is considered to be complete when Q _Counting Is less than or equal to Q _{Target object} At the magnitude of (2), the fifth optical transition is considered to be complete. Thus, as used herein, the term "reach" (e.g., as with respect to determining Q _Counting Whether or not Q has been reached _{Target object} Used) can mean Q _Counting The magnitude of (1) should reach a ratio Q _{Target object} Or Q _Counting The magnitude of (1) should reach a ratio Q _{Target object} Is small in magnitude. One of ordinary skill in the art can determine which condition should be used based on whether the instantaneous optical state of the device at the time the interrupt command is received is between the start optical state and the new desired end state.

Fig. 5J provides a flow chart of an alternative method 580 for controlling optical transitions. The method presented in fig. 5J facilitates faster switching times while ensuring that the device operates within safe limits. Briefly, the method of fig. 5J implements a dynamic drive voltage that is selected based on the open circuit voltage and a comparison of the open circuit voltage to the maximum effective safe voltage of the device. Many current driving algorithms use preset voltage drives that are low enough to avoid damaging the device. Such damage typically occurs due to the edges of the overdrive. The effective voltage on the device increases over time based on the selected drive voltage and the ramp rate for transitioning to the drive voltage. Most of the time, the device is well below the safe voltage limit of operation. However, these current driving algorithms result in a slower than optimal switching speed. Faster switching can be achieved by driving the device with a drive voltage closer to the safe voltage limit during a larger proportion of the switching time. However, for such methods, care should be taken to ensure that the drive voltage does not exceed the safety limits of the device.

Improved switching speed may be achieved by using method 580 shown in fig. 5J. In this method, the open circuit voltage (V _oc ) Essentially as maximum safe effective voltage (V _Secure ) Is representative of (c). At a known V _Secure In the case of (e.g., through empirical testing or other methods available to those skilled in the art), the drive voltage may be periodically increased up to V _oc Near or reach V _Secure . By being equal to or close to V _Secure V of the upper limit of (2) _oc In operation, the speed of optical transition can be maximized while ensuring safe operation. One result of this approach is that the magnitude of the applied voltage is initially high and decreases over time.

The method 580 begins at operation 582, wherein a drive voltage is applied to a bus bar of an optically switchable device. The drive voltage may be determined based on a starting optical state and an ending optical state of the optical transition. Next, at operation 584, an open circuit condition is applied and an open circuit voltage (V _oc ). Next, at operation 586, V is determined _oc Whether or not V has been reached _{Target object} 。V _{Target object} To a target open circuit voltage as described herein. Assuming that the strip is satisfiedThe method continues at operation 588, where the amount of charge delivered to the device is determined (Q _Counting ) Whether the target charge count (Q) of the transition has been reached _{Target object} ). Q can be determined as described herein _{Target object} . Assuming this condition is met, in operation 598 the transition is complete and a hold voltage may be applied to maintain the ending optical state. If it is determined that V _oc Has not yet reached V _{Target object} Or Q _Counting Not yet reach Q _{Target object} The transition has not completed and the method continues at operation 594. Here, V is _oc The magnitude of (V) is equal to V _Secure Is compared with the magnitude of (c). If V is _oc Is greater than V _Secure The method continues at operation 596 where the drive voltage is reduced to prevent damage to the device. If V is _oc Is smaller than V _Secure The method continues at operation 597 where the drive voltage is increased. In either case, when the method returns to operation 582, a drive voltage is applied for an additional duration. In some implementations of method 580, for V _Secure The values of (2) may include a buffer as described herein to ensure that the drive voltage never exceeds a value that may cause damage to the device.

Fig. 5K shows a flow chart of a method of transitioning a plurality of optically switchable devices, and will be explained in the context of a set of optically switchable devices shown in fig. 10. The method described in fig. 5K is particularly useful when it is desired that each of the optically switchable devices in a set of optically switchable devices transition over approximately the same duration and that their hue states visually approximate each other within the transition period.

In general, smaller optically switchable devices (e.g., devices with smaller bus bar spacing distances) transition faster than larger optically switchable devices. As used herein, the terms "small", "large" and similar descriptors used with respect to the dimensions of the optically switchable device refer to the distance between the bus bars. In this regard, a 14 "x 120" device having a bus bar spacing distance of about 14 "is considered to be smaller than a 20" x 20 "device having a bus bar spacing distance of about 20", even though the 20 "x 20" device has a larger area.

This difference in switching time is due to sheet resistance in the transparent conductor layer within the device. Given the same transparent conductor layer with a given sheet resistance, a larger aperture will take more time to switch than a smaller aperture. In another example, some of the apertures may have a modified transparent conductor layer, e.g., have a lower sheet resistance than other apertures in the set. The methods described herein provide approximate tone state (optical density) matching during transitions of aperture sets having different switching speeds among the aperture sets. That is, the slower switching fenestrations in the set may not necessarily be larger fenestrations. For the purposes of this discussion, an example is provided in which all of the fenestrations in a group have the same optical device characteristics, and thus the larger fenestrations in the group switch slower than the smaller fenestrations.

Referring to fig. 10, a small optically switchable device 1090 is expected to transition faster than a large optically switchable device 1091. Thus, when a set of differently sized apertures transition together, using a similar switching algorithm (e.g., similar I/V parameters), the smaller device completes the transition first, while the larger device spends additional time transitioning. In some implementations, this difference in switching times may be undesirable.

The method 1000 of fig. 5K begins at operation 1002, where a command to transition a set of optically switchable devices to an ending optical state is received. In this example, the group includes a relatively slow-transitioning large (e.g., 60 ") optically switchable device 1091 and a relatively fast-transitioning number of smaller (e.g., 15") optically switchable devices 1090. In this embodiment, it is desirable that all optically switchable devices 1090 and 1091 transition within the same period of time for aesthetic purposes. Since larger fenestrations take the most time to switch, the switching time of a fenestration group will be based on the slowest transition fenestration in the group. Thus, operation 1004 involves determining a switching time of a slowest transition optically switchable device in the group. Typically, this is the device with the greatest bus bar separation distance. The optical transitions of the faster transition devices 1090 may be tailored to match the switching time of the slowest transition device 1091. Operation 1004 may be accomplished as long as a group or region of optically switchable devices is defined, where it is expected that the group or region of optically switchable devices will transition together as a group.

In operation 1005, the slowest optically switchable device 1091 is transitioned to the ending optical state. The transition may be monitored using any of the methods described herein. In some cases, operation 1005 involves repeatedly detecting the slowest optically switchable device 1091 during the transition of the slowest optically switchable device (e.g., using a particular V _{Application of} And measuring the current response, or applying an open circuit condition and measuring V _oc And/or measuring/monitoring the amount or density of charge delivered to the optically switchable device) to determine when the slowest optically switchable device 1091 has reached or is approaching the ending optical state.

Operation 1006 involves transitioning the faster optically switchable device 1090 toward the ending optical state in order to approach the tonal state of the slower aperture during the transition. Operations 1005 and 1006 typically begin at the same time (or nearly the same time). At operation 1008, the optical transition of the faster optically switchable device 1090 is suspended for a duration before the faster optically switchable device 1090 reaches the end optical state. This pause increases the time it takes for the faster optically switchable device 1090 to reach the end optical state. The duration of the pause may be based on the difference in switching time between the faster optically switchable device 1090 and the slowest optically switchable device 1091. The tone states of the faster switching aperture and the slower switching aperture approximately match during the transition. The pause allows the slower switching aperture to catch up with the faster switching aperture, for example, or the pause is timed and selected to have a sufficient duration such that the tonal states of the slower (in this example, large) and faster (in this example, small) apertures appear to exhibit approximately the same optical density throughout the transition.

After the pause in operation 1008, the method continues with operation 1010 in which the optical transition on the faster optically switchable device 1090 is resumed such that the faster optically switchable device 1090 continues to transition toward the ending optical state. Operations 1008 and 1010 may be repeated any number of times (e.g., 0<n <. Infinity). In general, the use of a larger number of pauses will result in a transition in which the different optically switchable devices more closely match each other (in terms of optical density at a given time). However, over a certain number of pauses, any additional tone matching benefits between the faster switching device and the slower switching device become negligible and little or no benefit is included in the additional pauses. In certain implementations, a faster switching optically switchable device may pause 1, 2, 3, 4, 5, or 10 times during an optical transition in order to match the switching speed of a slower transition optically switchable device. In some cases, a faster switching optically switchable device may be paused at least two times or at least three times during its transition. In these or other cases, the faster switching optically switchable device may be paused up to about 20 times, or up to about 10 times, during its transition. The number, duration, and timing of pauses may be automatically determined each time a set of optically switchable devices is defined, and/or each time a set of optically switchable devices is instructed to simultaneously undergo a particular transition. The calculation may be based on characteristics of the optically switchable devices in the group, such as switching time (no pause) for each device in the group, differences in switching time for different devices in the group, number of devices in the group, starting and ending optical states of transitions, peak power available to the devices in the group, etc. In certain implementations, a lookup table may be used to determine the number, duration, and/or timing of pauses based on one or more of these criteria.

In one example where the slowest optically switchable device 1091 switches within about 35 minutes, the faster optically switchable device 1090 switches within about 5 minutes, and a single pause is used, operation 1006 may involve transitioning the faster optically switchable device 1090 for a duration of about 2.5 minutes (e.g., half of the expected transition time of the faster optically switchable device 1090), operation 1008 may involve suspending the optical transition of the faster optically switchable device 1090 for a duration of about 30 minutes, and operation 1010 may involve continuing to transition the faster optically switchable device 1090 for a duration of about 2.5 minutes. Thus, the total transition time of the slowest optically switchable device 1091 and the faster optically switchable device 1090 is 35 minutes. Typically, more pauses are used to approximate the tonal state of the larger aperture throughout the transition of the larger aperture.

In another example where the slowest optically switchable device 1091 switches in about 35 minutes, the faster optically switchable device 1090 switches in about 5 minutes, and four pauses (e.g., n=4) are used during transitions of the faster optically switchable device 1090, each iteration of operations 1006 and 1010 may involve driving optical transitions on the faster optically switchable device 1090 for a duration of 1 minute, and each iteration of operation 1008 may involve pausing such transitions for a duration of about 7.5 minutes. After five transition periods of 1 minute each and four pauses of 7.5 minutes each, the total transition time for each optically switchable aperture was 35 minutes.

As described in operation 1005 with respect to the slowest optically switchable device 1091, any of the methods described herein may be used to monitor optical transitions on the faster optically switchable device 1090. For example, operations 1006 and/or 1010 may involve repeatedly detecting faster optically switchable device 1090 (e.g., using a particular V _{Application of} And measuring the current response, or applying an open circuit condition and measuring V _oc And/or measuring/monitoring the amount or density of charge delivered to the optically switchable device) to determine whether the faster optically switchable device 1090 has reached or is approaching the ending optical state. In some embodiments, the method for monitoring optical transitions on the slowest optically switchable device 1091 is the same as the method for monitoring optical transitions on the one or more faster optically switchable devices 1090. In some embodiments, the method for monitoring optical transitions on the slowest optically switchable device 1091 is different from the method for monitoring optical transitions on the one or more faster optically switchable devices 1090.

Regardless of or how the different optical transitions are monitored, the method continues with operation 1012 where a holding voltage is applied to each optically switchable device. The hold voltage may be applied in response to determining that the associated optically switchable device has reached or approached the ending optical state. In other cases, the hold voltage may be applied based on a known switching time for a particular aperture or group of apertures, without regard to any feedback measured during the transition. A holding voltage may be applied to each optically switchable device as it reaches or approaches the ending optical state. The holding voltage may be applied to each optically switchable device simultaneously or over a relatively short period of time (e.g., within about 1 minute, or within about 5 minutes).

A specific example in which feedback is used to monitor the optical transitions and determine when to apply a holding voltage to each optically switchable device is shown in fig. 5L. The method 1020 is explained in the context of the aperture set shown in fig. 10, which includes a large optically switchable device 1091 (which is the slowest transitioning device in the set) and several small optically switchable devices 1090 (which are faster transitioning devices in the set). The method 1020 of fig. 5L shares many common features/operations with the method 1000 of fig. 5K. The method 1020 begins at operation 1002, where a command to transition a set of optically switchable devices to an ending optical state is received. Next, at operation 1004, a switching time of the slowest optically switchable device 1091 in the group is determined. The switching time will be the target switching time for all optically switchable devices in the group.

At operation 1005, the slowest optically switchable device 1091 is transitioned to the ending optical state. In this embodiment, operation 1005 involves specific steps for monitoring the optical transition on the slowest optically switchable device 1091. These steps are presented within a dashed box labeled 1005. Specifically, in operation 1005a, after the slowest optically switchable device 1091 transitions for a period of time (e.g., after applying V _{Driving of} After a certain duration of time), an open circuit condition is applied to the slowest optically switchable device 1091 and the open circuit voltage V of the slowest optically switchable device 1091 is measured _oc . Operation 1005a is similar to, for example, operations 587 and 589 of fig. 5E. In operation 1005b, the charge (or, in relation, the charge density) delivered to the slowest optically switchable device 1091 during the optical transition is determined. Operation 1005b is similar to operation 590 in fig. 5E. In operation 1005c, V is determined _oc And the charge delivered to the slowest optically switchable device during the transition (orCharge density) indicates that the optical transition is almost complete. Operation 1005c is similar to operation 591 in fig. 5E. Determination of the V that can be measured by comparison _oc Is of the magnitude of (2) and the target V _oc (sometimes the target is referred to as V _{Target object} ) And by comparing the delivered charge or charge density with a target charge or target charge density. At V _oc And the delivered charge (or charge density) indicate that the optical transition on the maximum optically switchable device 1091 is complete or nearly complete, the method continues with operation 1012 in which a holding voltage is applied to the maximum optically switchable device 1091. If V is _oc Or the charge/charge density indicates that the transition has not been nearly completed, the method continues with operation 1005d in which the applied voltage on the maximum optically switchable device 1091 is increased back to the driving voltage and the transition on the maximum optically switchable device 1091 continues for an additional duration. Operations 1005a-1005d may be repeated as many times as desired.

When the maximum/slowest optically switchable device 1091 is transitioning positive in operation 1005, the faster optically switchable device 1090 is also transitioning. Specifically, in operation 1006, the faster optically switchable device 1090 is transitioned toward the ending optical state. However, in operation 1008, the transition on the faster optically switchable device 1090 is suspended for a duration before the faster optically switchable device 1090 reaches the end optical state. As described above, pauses extend the switching time of the smaller/faster optically switchable devices 1090 such that they can match the switching time of the larger/slower optically switchable devices 1091.

Next, in operation 1010, the faster optically switchable device 1090 continues to transition toward the ending optical state. In this example, operation 1010 involves specific steps for monitoring transitions on the faster optically switchable device 1090. These steps are presented within a dashed box labeled 1010. In particular, operation 1010a involves determining the charge (or charge density) delivered to each faster optically switchable device 1090 during the transition. In operation 1010b, a determination is made as to whether the delivered charge (or charge density) indicates that the optical transition on each faster optically switchable device 1090 is complete or nearly complete. This may involve comparing the charge (or charge density) delivered to each of the faster optically switchable devices 1090 to a target charge or target charge density. Advantageously, suspending the transition as described herein does not substantially affect the target charge or charge density. Thus, the target charge and charge density for a particular transition configuration or calibration need not be modified to accommodate pauses. Similarly, the drive voltage (and other switching parameters such as ramp-to-drive rate and ramp-to-hold rate) need not be modified in order to accommodate the pause. In operation 1010b, each of the faster optically switchable devices 1090 may be considered separately. In the case where the delivered charge or charge density indicates that the relevant optical transition has not completed or is nearly completed, the method proceeds to operation 1010c, where the application of the drive voltage to the faster optically switchable device 1090 continues. Operation 1010c may be performed on an individual basis. In other words, the drive voltage may continue to be applied to any optically switchable device that still requires the application of an additional drive voltage. Operations 1008 and 1010 may be repeated any number of times. The duration of the pauses and the number of pauses can be tailored such that all optically switchable devices in a group transition over approximately the same total time period and display approximately the same hue state during the transition.

When the delivered charge (or charge density) indicates that the transition on a particular faster optically switchable device 1090 is complete or nearly complete, a hold voltage may be applied to the associated faster optically switchable device 1090 in operation 1012. The holding voltage may be applied to each optically switchable device individually, regardless of whether the holding voltage is being applied to other optically switchable devices in the group. Typically, the duration and number of pauses used during the transition of the faster optically switchable device 1090 may be selected such that the holding voltage is applied to each optically switchable device at approximately the same time or within a short period of time. This ensures that the switching time of all fenestrations in the group is substantially the same, resulting in a visually attractive transition. In some embodiments, the duration of one or more pauses (in some cases all pauses) can be at least about 30 seconds, at least about 1 minute, at least about 3 minutes, at least about 5 minutes, or at least about 10 minutes. In general, as the number of pauses increases (for a given set of optically switchable devices), a shorter pause may be used.

Fig. 5M illustrates another method 1030 for transitioning a group of optically switchable devices, wherein the group includes at least one relatively larger/slower device and at least one relatively smaller/faster device. Similar to the methods described in fig. 5K and 5L, the method of fig. 5M is described in the context of the set of optically switchable devices shown in fig. 10. The method 1030 begins with operation 1031 in which a command to transition a set of optically switchable devices to an ending optical state is received. In this example, the ending optical state is referred to as Tint ₄ . At operation 1033, it is determined which device in the group has the slowest switching time (in fig. 10, this will be device 1091). The device will determine the switching time of a set of optically switchable devices. At operation 1034, the slowest optically switchable device 1091 in the group is transitioned to the ending optical state (Tint ₄ ). In operation 1035, when the slowest optically switchable device 1091 is toward the ending optical state (Tint ₄ ) Upon transition, the faster optically switchable device 1090 transitions to a first intermediate optical state (Tint ₂ ). Next, at operation 1037, the faster optically switchable device 1090 is maintained in a first intermediate optical state (Tint ₂ ) For a duration of time. Next, in operation 1039, the faster optically switchable device 1090 is transitioned to a second intermediate optical state (Tint ₃ ) And in operation 1041, maintaining the second intermediate optical state (Tint ₃ ) For a duration of time. Then, in operation 1043, the faster optically switchable device 1090 is transitioned to an ending optical state (Tint ₄ ). At operation 1045, a holding voltage is applied to each optically switchable device as it reaches or approaches the ending optical state. Typically, the duration of maintaining the intermediate optical state may be selected to ensure that all optically switchable devices reach the end optical state at about the same time (e.g., in each case, within about 1 minute, or within about 2 minutes, or within about 5 minutes, or within about 10 minutes, or within about 15 minutes). Each of which The precise timing of when the individual optically switchable devices reach the ending optical state may not be as important as ensuring that the optical states of the different optically switchable devices in the group approximately match each other throughout the transition. In some implementations, all optically switchable devices in a group can display approximately the same optical state/hue level throughout the transition. In some implementations, at all points in time during the transition, the optical density of the slowest optically switchable device may be within about 0.1, 0.2, 0.3, 0.4, or 0.5 of the optical density of the faster optically switchable devices in the group. In other words, at all points in time during the transition, the optical density difference between the slowest and faster optically switchable devices in the group may be about 0.5 or less, 0.4 or less, 0.3 or less, 0.2 or less, or 0.1 or less. In some embodiments, the maximum optical density difference between the slowest optical switchable device and the faster optical switchable device in the group may be between about 0.1-0.5, or between about 0.1-0.4, or between about 0.2-0.3 throughout the transition. The optical density referred to herein refers to the optical density at the center of each optically switchable device at a given point in time.

Although the method 1030 of fig. 5M describes three active transition periods (operations 1035, 1039, and 1043) resulting in two intermediate optical states of the faster optically switchable device 1090, any number of transition periods and intermediate optical states can be used. While operations 1037 and 1041 are described in terms of maintaining the faster optically switchable device in a particular intermediate optical state, it should be understood that the optical state of the faster optically switchable device may change slowly during these operations. Further details are provided below.

Any of the methods described herein may be used to monitor any of the transitions described in fig. 5M (e.g., during operations 1034, 1035, 1039, and 1043). In one embodiment, the method of fig. 5E may be used to monitor one or more of these transitions. In general, method 1030 of FIG. 5M is similar to methods 1000 and 1020 of FIGS. 5K and 5L. The pause period described with respect to fig. 5K and 5L is similar to the period in fig. 5M in which the intermediate optical state is maintained.

One difference between these methods may be the manner in which the optical transitions are defined and monitored. For example, in some implementations of fig. 5K or 5L, a determination of when to apply a holding voltage to each of the faster optically switchable devices may be made based on data related to a complete optical transition from a starting optical state (e.g., at operation 1002) to an ending optical state. In contrast, in some embodiments of fig. 5M, the optical state may be based on the optical state that is measured from the last intermediate optical state (e.g., tint in fig. 5M ₃ ) To end the optical state (e.g., tint in FIG. 5M ₄ ) To make a determination of when to apply a holding voltage to each of the faster optically switchable devices.

Relatedly, in some implementations of fig. 5M, each individual transition on the faster optically switchable device (e.g., from the initial optical state→tint ₂ 、Tint ₂ →Tint ₃ And Tint ₃ →Tint ₄ ) The monitoring may be based on data related to the specific starting and ending optical states of each individual transition. In the methods of fig. 5K and 5L, it may not be necessary to actively monitor all individual parts of the transition. In various embodiments of fig. 5K and 5L, the transition may be monitored only during the final transition period (e.g., the transition period after the final pause). The end point of the earlier (non-final) portion of the transition may be determined based solely on timing (which may be selected based on the factors described above) without regard to feedback.

In various embodiments, the optically switchable devices may be disposed together on a network. In some cases, a communication network may be used to control various optically switchable devices. In one example, the master controller may be in communication with one or more network controllers, which may each be in communication with one or more aperture controllers. Each aperture controller may control one or more individual optically switchable devices. An exemplary communication network including different types of controllers is described in U.S. provisional patent application No. 62/248,181 filed on 10/29 2015 and entitled "controller for optically switchable devices (CONTROLLERS FOR OPTICALLY-SWITCHABLE DEVICES)", which is incorporated herein by reference in its entirety. The methods described herein may be implemented on a fenestration controller, a network controller, and/or a master controller, as desired for a particular application. In some implementations, the master controller and/or network controller may be used to evaluate parameters/switching characteristics of all optically switchable devices in a group or zone in order to determine, for example, which optically switchable device transitions slowest and the target switching time of the group. The master controller and/or network controller may determine switching parameters (e.g., ramp to drive rate, drive voltage, ramp to hold rate, hold voltage, number of pauses, duration of pauses, intermediate optical state, etc.) that should be used for each optically switchable device in the group. The master controller and/or the network controller may then provide these switching parameters (or some subset thereof) to the aperture controller, which may then effect the transition on each optically switchable device as appropriate.

Although the method described in fig. 5K-5M is presented in the context of fig. 10, in which a large optically switchable device 1091 is surrounded by a plurality of equally sized smaller optically switchable devices 1090, the method is not limited thereto. In general, the methods described in fig. 5K-5M are useful whenever there is a set of optically switchable devices that transition at two or more different rates/transition times, where each optically switchable device in the set is expected to transition in substantially the same period of time.

In many cases, a set of optically switchable devices will include at least one optically switchable device that is relatively small and transitions faster, and at least one optically switchable device that is relatively large and transitions slower. The total switching time is selected as the switching time of the slowest optically switchable device in the approximation set. The group may comprise optically switchable devices having a plurality of different sizes/switching times. The number and duration of pauses for each aperture can be independently selected as described herein to ensure that all optically switchable devices reach the end optical state at about the same time. For example, in one embodiment, a set of optically switchable devices includes two 60 "devices, two 30" devices, four 14 "devices, and one 12" device. In this example, the largest/slowest optically switchable device (which will determine the total switching time of the group) is two 60 "devices that can be transitioned without any pauses. Two 30 "devices may each transition using a single pause (n=1), four 14" devices may each transition using two pauses (n=2), and 12 "devices may transition using three pauses (n=3). The number and duration of pauses may be the same or different for the various optically switchable devices in the group.

The different optically switchable devices in a group may or may not start at the same starting optical state and may or may not end at the same ending optical state. Although the method is particularly useful in situations where it is desirable to substantially match the hue state on different devices during a transition, the method may also be used in situations where the absolute hue state of each device is not important. In some such cases, it may be desirable to match shading times across different devices, even though it is not important to match shading states across different devices.

In some implementations, it is desirable to interleave active transitions/pauses between different optically switchable devices so that peak power provided to a set of optically switchable devices is minimized. This minimization of peak power maximizes the number of optically switchable devices that can be disposed along a particular portion of the power distribution network for routing power to the optically switchable devices and may avoid the need to use higher-level (e.g., class 1, as compared to class 2) hardware (e.g., power supplies, cables, etc.) that may be more expensive.

For example, if all faster optically switchable devices actively transition and pause their optical transitions at the same time, the power drawn by the set of devices will be significantly reduced during the pause. When the pause is over, the power drawn by the set of devices will increase significantly (as all devices are driven simultaneously). Conversely, if the active transitions and pauses are staggered in time such that some faster optically switchable devices continue to actively transition while others pause, this significant increase in power may be avoided and the power delivered to a set of optically switchable devices may be more uniform over time. Interleaving may be achieved by dividing the faster optically switchable devices into subsets. Within a subset, the optically switchable devices may together actively transition/pause. Between different subsets, the optically switchable device can be actively transitioned/suspended at different times. The sub-groups may be as small as the individual optically switchable devices.

In the context of fig. 10, for example, the faster optically switchable devices 1090 may be divided into three subgroups (e.g., left, upper, and right). Devices in the left group may be first paused, devices in the upper group may be second paused, and devices in the right group may be third paused. Staggered pauses and active transitions may be cycled as desired. The pauses (and/or active transitions) may or may not overlap, depending on the transition and device involved and the number/duration of pauses selected.

In some implementations, different modes may be used for different types of transitions, with different switching behavior for each mode. In one example, the first mode may be used in the case of normal optical transitions. The optical transition may be from a known starting optical state to a known ending optical state. In the case where an interrupt command is received to transition the device to a different ending optical state, a second mode may be used. In other words, this mode may be used in situations where an ongoing optical transition on a given device is interrupted by a command to transition the device to a different ending optical state. In the first mode, the optically switchable device can be transitioned according to the method 1000 of fig. 5K. In the second mode, after receiving the interrupt command, the optically switchable device may make the transition using a different method, such as a method that does not involve suspending any transition. In the second mode, all optically switchable devices can transition to the new ending optical state as soon as possible.

In some cases, other methods for ensuring uniform transition times for a set of optically switchable devices including at least one relatively smaller/faster device and at least one relatively larger/slower device may be used. For example, transitions on faster optically switchable devices may be slowed by using lower ramp-to-drive rates and/or by using lower drive voltages. Ramp to drive rate and drive voltage are further discussed with respect to fig. 2 and 3. In many cases, smaller ramp-to-drive rates and/or smaller drive voltages have been used to drive smaller/faster devices than larger/slower devices, at least in part because larger/slower devices are able to withstand larger applied voltages without damage. Further reduction of the ramp to drive rate and/or drive voltage may slow down the transition of the faster optically switchable device. However, certain problems may occur with these approaches. For example, these methods may result in a slow-to-start transition on a faster optically switchable device. By comparison, transitions on larger/slower optically switchable devices are perceived visually earlier. The result is that toward the beginning of the transition, it appears that the large/slow device is beginning to transition, while the smaller/faster device appears to be unresponsive. While the various devices may reach the end optical state at approximately the same time, differences in visual appearance between the different devices near the beginning of the transition are undesirable.

Another possible problem with low ramp-to-drive and low drive voltage approaches is that under these conditions it may become difficult to monitor optical transitions on smaller/faster devices. This is particularly important in cases where monitoring the transition involves determining the amount or density of charge delivered to the device. Difficulties may arise because the current supplied to the device in these embodiments is relatively low (due to low ramp-to-drive rate and/or low drive voltage), and errors associated with measuring such current may be relatively high (e.g., depending on the controller used). Because the error may be large compared to the measured value, monitoring transitions on a fast optically switchable device becomes difficult or impossible. Thus, the ramp-to-drive rate and how low the drive voltage can be is limited, while still maintaining good control over the various optical transitions. The method described in fig. 5K-5M overcomes this problem by suspending transitions on the faster optically switchable device (fig. 5K and 5L) or by breaking down transitions on the faster optically switchable device into multiple smaller individual transitions separated by a suspension (fig. 5M).

A number of different options are available in terms of what is happening to the faster optically switchable device when transitions on such devices are suspended (as described with respect to fig. 5K and 5L) and/or when such devices maintain an intermediate optical state (as described with respect to fig. 5M). For brevity, both of these techniques will be referred to as pauses. In one example, an open circuit condition is applied during a pause. In this embodiment, during the pause, the current delivered to the device will drop to zero. The optical state of the device may remain substantially unchanged during the duration of the pause (except for any center-to-edge differences in the hue state of the device, which may be minimized during the pause). In some cases, the optical state of the device may relax back toward the starting optical state during the pause.

In another example, the applied voltage may be provided to the device during a pause. In one embodiment, an open circuit condition is applied to the device and V is measured shortly before suspension _oc . The applied voltage during the pause may correspond to the last measured V on the device _oc . In this embodiment, the current delivered to the device drops substantially during the pause, but does not stop completely. The device will continue to transition at a lower rate during the pause. In another embodiment, the applied voltage during the pause may be predetermined. Different pauses may have different predetermined applied voltages. For example, in one example, the faster optically switchable device transitions within three active transition periods separated by two pause periods. During the first pause, the applied voltage may be about-0.5V, and during the second pause, the applied voltage may be about-1.0V. The applied voltage may be determined based on the voltage applied before the transition, the hold voltage applied at the end of the transition, and the number of pauses. For example, if a single pause is used, the applied voltage during the pause may be selected to be approximately midway between the applied voltage before the transition and the hold voltage applied at the end of the transition. In another example where two pauses are used, the applied voltage during the first pause may be selected to be the voltage applied before the transition and the hold voltage applied at the end of the transition About 1/3 of the path between, and the applied voltage during the second pause may be selected to be about 2/3 of the path between the voltage applied before the transition and the hold voltage applied at the end of the transition. This example may be generalized to include any number of pauses. Other methods for specifying the applied voltage during each pause may also be used. In implementations where a predetermined voltage is applied during a pause, the current delivered to the device may drop substantially during the pause, but may not stop completely. The device may continue to transition at a lower rate during the pause.

Fig. 11A and 11B present experimental results related to the method described in fig. 5K. Each graph shows optical density at the center of certain optically switchable devices versus time during one or more optical transitions on the optically switchable device. FIG. 11A relates to the transition from a relatively transparent state (Tint ₁ ) To a relatively dark state (Tint) ₄ ) And FIG. 11B involves a transition from a relatively dark state (Tint ₄ ) To a relatively transparent state (Tint) ₁ ) Is a function of the optical transition of (a). Fig. 11A and 11B each show 58 "one optical transition on the optically switchable device (no pause) and 14" two different optical transitions on the optically switchable device, one of which involves a pause and the other of which involves no pause. Referring to fig. 11A, line 1102 relates to transitions on a 14 "device where no pauses are used, line 1104 relates to transitions on a 14" device where two pauses are used, and line 1106 relates to transitions on a 58 "device. Referring to FIG. 11B, line 1112 relates to transitions on a 14 "device where no pauses are used, line 1114 relates to transitions on a 14" device where two pauses are used, and line 1116 relates to transitions on a 58 "device. Pauses are associated with periods in which the optical density on the 14 "device changes much less than non-pause (e.g., active transition) periods.

As can be seen in fig. 11A and 11B, if no pause is used, the 14 "device will reach the end optical state faster than the 58" device. Visually, this means that the 14 "device is not colored (or is un-colored) synchronously with the 58" device, and there is a significant mismatch between the optical states on the different sized devices at any given time. In contrast, when the 14 "device uses a pause to make the transition, the transition time of the device is more similar. The visual result is that there is substantially less mismatch between the optical states of different sized devices at any given time.

Fig. 11C is a schematic diagram showing two optical transitions (Tint ₁ →Tint ₄ And then Tint ₄ →Tint ₁ ) A plot of optical density versus time in the process of (a) wherein no pause is used (line 1120), a single pause is used under open circuit conditions (line 1122), or wherein a single pause is used at a particular voltage (line 1124). The figure shows what the optical state of the device is occurring during different types of pauses. In the event that the transition is suspended under open circuit conditions (line 1122), the optical density is rapidly uniform and remains substantially the same during the suspension. In the event that the transition is suspended at a particular applied voltage (e.g., the last measured open circuit voltage or a preset voltage), the optical density continues to change, but at a slower rate.

In some embodiments, the rate of change of the open circuit voltage (dV) may be monitored in addition to the open circuit voltage itself _oc /dt). Additional steps may be provided in which dV is to be taken _oc The magnitude of/dt is compared with a maximum to ensure that V _oc The drive voltage is modified in a way that does not change too quickly. This additional step may be utilized herein as V _oc Any method of measurement is used.

In certain embodiments, the method involves using a static offset for the holding voltage. This offset hold voltage may be used to probe the device and elicit a current response, for example, as described with respect to fig. 5A, 5B, and 5D. The offset hold voltage may also be used as the target open circuit voltage as described with respect to fig. 5C, and fig. 5E, 5G, and 5J. In some cases, particularly for fenestrations having a large spacing (e.g., at least about 25 ") between bus bars, the offset may be beneficial to ensure that the optical transition proceeds to completion across the fenestrations.

In many cases, a suitable offset is between about 0-0.5V (e.g., about 0.1-0.4V, or about 0.1-0.2V). Typically, the appropriate offsetThe magnitude of (a) increases with the size of the window aperture. An offset of about 0.2V may be suitable for an aperture of about 14 inches and an offset of about 0.4V may be suitable for an aperture of about 60 inches. These values are merely examples and are not intended to be limiting. In some embodiments, the aperture controller is programmed to use V _Holding Is used to determine the static offset of the (c). The magnitude and in some cases the direction of the static offset may be based on device characteristics such as the size of the device and the distance between the bus bars, the drive voltage for a particular transition, the leakage current of the device, the peak current density, the capacitance of the device, and so on. In various embodiments, the static offset is empirically determined. In some designs, it is dynamically calculated upon the installation of the device or upon the installation and operation of the device based on monitored electrical and/or optical parameters or other feedback.

In other embodiments, the aperture controller may be programmed to dynamically calculate to V _Holding Is set in the above-described range (a). In one embodiment, the aperture controller is based on a current optical state (OD) of the device, a current (I) delivered to the device, a rate of change (dI/dt) of the current delivered to the device, an open circuit voltage (V) of the device _oc ) And the rate of change of the open circuit voltage (dV) of the device _oc /dt) to dynamically calculate V _Holding Is set in the above-described range (a). This embodiment is particularly useful because it does not require any additional sensors to control the transition. Instead, all feedback is generated by pulsing the electronic conditions and measuring the electronic response of the device. The feedback, along with the device characteristics described above, can be used to calculate the optimal offset for the particular transition that occurs at that time. In other embodiments, the aperture controller may dynamically calculate V based on certain additional parameters _Holding Is set in the above-described range (a). These additional parameters may include the temperature of the device, the ambient temperature, and the signals collected by the photo-optical sensor over the aperture. These additional parameters may help to achieve uniform optical transitions under different conditions. However, the use of these additional parameters also increases manufacturing costs due to the need for additional sensors.

Due to the effective voltage V applied across the device _{Effective and effective} Is of non-uniform qualityThe amount, offset may be beneficial in various situations. For example, as described above, a non-uniform V is shown in FIG. 2 _{Effective and effective} . Due to this non-uniformity, the optical transition does not occur in a uniform manner. In particular, the area near the bus bar experiences the greatest V _{Effective and effective} And rapidly transition while the region removed from the bus bar (e.g., the center of the aperture) experiences the lowest V _{Effective and effective} And transition slower. The offset may help ensure that the optical transition is completed at the center of the device where the change is slowest.

Fig. 6A and 6B show graphs depicting total charge delivered over time and applied voltage over time during two different electrochromic coloring transitions. The fenestrations in each case were approximately 24x24 inches. The total charge delivered is referred to as the tone charge count and is measured in coulombs (C). The total charge delivered is presented on the left hand y-axis of each graph and the applied voltage is presented on the right hand y-axis of each graph. In each figure, line 602 corresponds to the total charge delivered and line 604 corresponds to the voltage applied. Further, line 606 in each graph corresponds to a threshold charge (threshold charge density multiplied by the area of the aperture), and line 608 corresponds to a target open circuit voltage. The threshold charge and target open circuit voltage are used in the method shown in fig. 5E to monitor/control the optical transition.

The voltage curves 604 in fig. 6A and 6B each begin with a ramp to drive component where the magnitude of the voltage ramps up to a drive voltage of about-2.5V. After an initial period of applying the driving voltage, the voltage starts to spike upward at regular intervals. These voltage spikes occur when detecting electrochromic devices. As shown in fig. 5E, detection is performed by applying an open circuit condition to the device. The open circuit condition results in an open circuit voltage that corresponds to the voltage spike seen in the graph. Between each detection/open circuit voltage, there is an additional period in which the applied voltage is the drive voltage. In other words, the electrochromic device is driving the transition and periodically probing the device to test the open circuit voltage to monitor the transition. The target open circuit voltage represented by line 608 is selected to be about-1.4V for each case. The holding voltage in each case was approximately-1.2V. Thus, the target open circuit voltage is offset from the holding voltage by about 0.2V.

In the transition of fig. 6A, the magnitude of the open circuit voltage exceeds the magnitude of the target open circuit voltage at about 1500 seconds. Since the relevant voltage in this example is negative, it is shown in the graph as the point where the open circuit voltage spike first drops below the target open circuit voltage. In the transition of fig. 6B, the magnitude of the open circuit voltage exceeds the magnitude of the target open circuit voltage earlier than in fig. 6A, at about 1250 seconds.

The total delivered charge count curves 602 in fig. 6A and 6B each begin at 0 and monotonically rise. In the transition of fig. 6A, the delivered charge reaches the threshold charge at about 1500 seconds, which is very close to the time to meet the target open circuit voltage. Once both conditions are met, the voltage is switched from the drive voltage to the hold voltage for about 1500 seconds. In the transition of fig. 6B, the total delivered charge takes about 2100 seconds to reach the charge threshold, which is about 14 minutes longer than the time it takes for the voltage to reach the target voltage for this transition. After both the target voltage and the threshold charge are satisfied, the voltage is switched to the holding voltage. The additional requirement of the total charge delivered results in the case of fig. 6B driving the transition with the drive voltage for a longer time than would otherwise be possible. This helps ensure complete and uniform transition across many fenestration designs under various environmental conditions.

In another embodiment, the optical transition is monitored by a voltage sensing pad positioned directly on the Transparent Conductive Layer (TCL). This allows direct measurement of V at the center of the device between the bus bars _{Effective and effective} Wherein V is _{Effective and effective} At a minimum. In this case, V measured at the center of the device _{Effective and effective} When a target voltage, such as a hold voltage, is reached, the controller indicates that the optical transition is complete. In various embodiments, the use of a sensor may reduce or eliminate the benefit of using a target voltage that is offset from the holding voltage. In other words, no offset may be required and the target voltage may be equal to the holding voltage when a sensor is present. In the case of voltage sensors, there should be at least one sensor per TCL. The voltage sensor may be placed in the middle between the bus barsIs typically offset from one side of the device (near the edge) so that they do not affect (or minimally affect) the viewing area. In some cases, the voltage sensor may be hidden from view by placing the voltage sensor near an isolator/divider and/or frame that obscures the view of the sensor.

Fig. 6C shows an embodiment of an EC aperture 690 that utilizes a sensor to directly measure the effective voltage at the center of the device. The EC aperture 690 includes a top bus bar 691 and a bottom bus bar 692 that are connected to a controller (not shown) by wires 693. Voltage sensor 696 is placed on top TCL and voltage sensor 697 is placed on bottom TCL. The sensors 696 and 697 are placed at a distance midway between the bus bars 691 and 692, but offset from the sides of the device. In some cases, the voltage sensors may be positioned such that they are located within the frame of the aperture. This placement helps to hide the sensor and promote optimal viewing conditions. The voltage sensors 696 and 697 are connected to the controller by wires 698. Wires 693 and 698 may pass under or through the spacer/separator between panes placed and sealed in the fenestration. The fenestration 690 shown in fig. 6C may utilize any of the methods described herein to control optical transitions.

In some implementations, the voltage sensing pad may be a conductive tape pad. In some embodiments, the pad may be as small as about 1mm ² . In these or other cases, the pad may be about 10mm ² Or smaller. A four-wire system may be used in embodiments utilizing such voltage sensing pads.

In some implementations, the drive voltage of the optically switchable device is modified from an initial and/or preset magnitude. For example, the drive voltage may be modified during the tone transition to control the speed of the tone transition. In one example, the drive voltage may be increased during the tone transition to accelerate the tone transition. In another example, the drive voltage may be reduced during the tone transition to slow down the tone transition. In some implementations, the drive voltage can be modified such that the speed of the tone transition of the optically switchable device matches the speed of the tone transition of the other optically switchable devices. For example, the drive voltage of a particular optically switchable device may be modified such that the speed of the hue transition of the optically switchable device matches the speed of other proximate optically switchable devices (e.g., adjacent to and/or within the same region as the optically switchable device). In some implementations, the drive voltage may be modified such that the speed of the tone transition of a particular optically switchable device matches or conforms to a typical or expected tone transition speed. The typical or expected hue shift speed may be the hue shift speed of a normally operating optically switchable device having the same or similar material properties.

In some implementations, a determination to maintain a drive voltage applied to the optically switchable device or to modify the drive voltage is made based at least in part on a parameter indicative of a state of a hue transition (e.g., from an initial optical state toward a target optical state). For example, parameters indicative of the state of the tone transition may include Voc (e.g., an open circuit voltage measured during an applied open circuit condition) and/or an amount of charge (Q) that has been transferred or delivered during the tone transition. In some implementations, the determination of whether to maintain or modify the drive voltage may be made by comparing a parameter indicative of the state of the tone transition to one or more parameters indicative of a target duration for the optically switchable device to complete the tone transition.

In one example, the one or more parameters indicative of a target duration for the optically switchable device to complete the tone transition include typical Voc information and/or typical Q information. For example, the representative Voc information may include a representative Voc curve that indicates a change in Voc as a function of time (e.g., for a given applied voltage) for a normal operating optical switchable device having similar or identical material properties as the optical switchable device for which determination is being made. As another example, the typical Q information may include a typical amount of charge (e.g., for a given applied voltage) expected to be transferred as a function of time for a normally functioning optical switchable device having similar or identical material properties as the optical switchable device for which determination is being made. In one example, in cases where the measured Voc value during a tone transition is lower than the Voc value of a typical Voc curve and/or where the curve formed by the measured Voc value during a tone transition is shallower (e.g., less) than the slope of a typical Voc curve (thus indicating that the optically switchable device is transitioning at a slower speed or rate than expected), the drive voltage may be modified to be greater in magnitude than a preset magnitude, thereby causing the speed or rate of the tone transition to increase. Conversely, in cases where the measured Voc value is higher than the Voc value of the typical Voc curve and/or where the curve formed by the measured Voc values during the tone transition is steeper (e.g., greater) than the slope of the typical Voc curve (thus indicating that the optically switchable device is transitioning at a faster speed or rate than expected), the drive voltage may be modified to be smaller in magnitude than the preset magnitude, thereby causing the speed or rate of the tone transition to decrease.

In some implementations, the magnitude of the drive voltage is modified based at least in part on the measured Voc value and/or the degree to which the measured Q value differs from the typical Voc value and/or the typical Q value. For example, the drive voltage may be modified by a greater amount (e.g., increased by a greater amount and/or decreased by a greater amount) than in the case where the measured value differs from the typical value by a lesser amount. In some implementations, the magnitude of the drive voltage is modified according to safety standards. For example, the change in the magnitude of the drive voltage may be constrained by a threshold. In one example, the drive voltage may be constrained to not increase by more than 20mV, not increase by more than 40mV, not increase by more than 60mV, etc. In some implementations, there may be a constraint to increasing the drive voltage and no constraint to decreasing the drive voltage.

In some embodiments, the initial drive voltage is initially set for a particular optically switchable device, e.g., configured as a factory setting. In some implementations, the initial drive voltage may be modified to a modified drive voltage in response to determining that the drive voltage has been modified more than a predetermined number of times during the tone transition. For example, in the case where the initial drive voltage for a particular optically switchable device is initially preset to vinit_drive and where the initial drive voltage is modified to vmod_drive more than a predetermined number of times (e.g., more than two times, more than five times, more than ten times, etc.) during a tone transition (e.g., based on a comparison of measured Voc and/or measured Q to a typical Voc value and/or a typical Q value), the preset drive voltage may be modified to the modified drive voltage. By exceeding the preset drive voltage, modifications to the drive voltage determined based on the actual performance of the optically switchable device during the tone transition may be incorporated.

Fig. 12 illustrates an example of a process 1200 for modifying a drive voltage during a tone transition according to some embodiments. The blocks of process 1200 may be performed in a different order than that shown in fig. 12. In some implementations, two or more blocks of process 1200 may be performed substantially in parallel. In some implementations, one or more blocks of process 1200 may be omitted.

Process 1200 begins at 1202 by applying a drive voltage to an optically switchable device. The driving voltage may be preset. The drive voltage is applied during a tone transition from the first optical state to the second optical state. At 1204, process 1200 measures Voc. Voc is measured by applying an open circuit condition to the optically switchable device (e.g., by suspending application of a drive voltage). At 1206, process 1200 determines whether the measured Voc has reached a V-target. In some embodiments, vbatt may correspond to and/or be related to a holding voltage (which may be preset). If at 1206, process 1200 determines that the measured Voc has not reached the V-target ("no" at 1206), process 1200 proceeds to block 1214 and determines whether to modify the drive voltage. Conversely, if at 1206, the process 1200 determines that the measured Voc has reached V-target ("yes" at 1206), then the process 1200 proceeds to block 1208 and may determine whether the measured transferred charge (sometimes referred to herein as Q-count) has reached a target transferred charge amount (sometimes referred to herein as Q-target). If at 1208, process 1200 determines that the Q count has reached the Q target ("yes" at 1208), then process 1210 proceeds to 1210 and a hold voltage is applied because the tone transition has been completed. Conversely, if at 1208, process 1200 determines that the Q count has not reached the Q target (no at 1208), then process 1200 proceeds to block 1214 and determines whether to modify the drive voltage. In other words, the determination of whether to modify the drive voltage may be made during a mode in which Voc is measured (e.g., before the measured Voc reaches the V-target, i.e., in response to "no" at block 1206) and/or during a mode in which Voc is not measured and Q is measured to determine whether the tone transition is complete (e.g., in response to "no" at block 1208).

At 1214, process 1200 determines whether to modify the drive voltage based at least in part on a comparison of the measured Voc value to the representative Voc value and/or the measured Q value to the representative Q value. It should be noted that in some embodiments, the comparison may be formed based on multiple measured Voc values and/or multiple measured Q values. For example, in some embodiments, multiple measurements may be combined and/or aggregated (e.g., by taking a mean, weighted average, median, etc.). As another example, a curve may be formed by aggregating a plurality of measurements, each corresponding to a different point in time. In some implementations, the process 1200 may determine that the drive voltage is to be modified in response to determining that the measured Voc value is higher or lower than the typical Voc value by a threshold amount. In some implementations, the process 1200 may determine that the drive voltage is to be modified in response to determining that a slope of a curve formed from a plurality of measured Voc values differs from a slope of a curve of typical Voc values by more than a threshold amount. In some implementations, the process 1200 may determine that the drive voltage is to be modified in response to determining that the measured Q value is higher or lower than the typical Q value by a threshold amount. In some implementations, the process 1200 may determine that the drive voltage is to be modified in response to determining that the slope of the curve formed by the plurality of Q values differs from the slope of the curve of typical Q values by more than a threshold amount. If at 1214, process 1200 determines that the drive voltage is not to be modified ("no" at 1214), then process 1200 may proceed to block 1216 and the drive voltage may be maintained. Conversely, if at 1214, process 1200 determines that the drive voltage is to be modified (yes at 1214), then process 1200 may proceed to block 1218 and the drive voltage may be modified. The driving voltage may be increased or decreased. The drive voltage may be modified according to any constraint (e.g., safety constraints). Process 1200 then loops back to 1202 and applies a drive voltage. The drive voltage may be an original drive voltage (e.g., responsive to "no" at 1214) or a modified drive voltage (e.g., responsive to "yes" at 1214).

In some implementations, the drive voltage applied to the optically switchable device in conjunction with the tone transition is modified during the tone transition based at least in part on a comparison of the one or more measured Voc values with the Voc values indicated in the typical Voc curve. A typical Voc curve may indicate an expected Voc value (e.g., for a particular applied drive voltage) as a function of time. In some implementations, the typical Voc curve may be based at least in part on measurements from one or more other optically switchable devices (e.g., in addition to the optically switchable device for which a determination is being made whether to modify the drive voltage). In some implementations, one or more other optically switchable devices may be similar to the optically switchable device for which a determination is made with respect to material properties (e.g., size, dimension, volume, surface area, bus bar dimensions, number of completed transition cycles, etc.). In some implementations, one or more optically switchable devices may be similar to the optically switchable device for which the determination of relative position is made. In one example, one or more optically switchable devices can be located within the same area of a building. By utilizing a typical Voc curve corresponding to an optically switchable device within the same zone of a building, the tone transition time of an optically switchable device that deviates from the typical tone transition speeds of other optically switchable devices in that zone can be modified to provide uniformity of tone transition.

Fig. 13A illustrates an example of a process 1300 for modifying a drive voltage based at least in part on Voc values measured during tone transition of an optically switchable device, according to some embodiments. The blocks of process 1300 may be performed in a sequence not shown in fig. 13A. In some implementations, two or more blocks of process 1300 may be performed substantially in parallel. In some implementations, one or more blocks of process 1300 may be omitted. Process 1300 begins at 1302 by obtaining a typical Voc curve. A typical Voc curve may indicate normal and/or expected Voc measurements of an applied drive voltage as a function of time. A typical Voc curve may be obtained based on data and/or measurements for an optically switchable device similar in characteristics (e.g., material properties, location, etc.) to the optically switchable device that performs the tone transition. At 1304, process 1300 applies a drive voltage to the optically switchable device. A driving voltage is applied in conjunction with a tone transition (e.g., from a first optical state to a second optical state). At 1306, process 1300 measures Voc for an optically switchable device. For example, voc is measured across the bus bar of an optically switchable device during the application of an open circuit condition (e.g., during a pause in the provision of a drive voltage). At 1308, process 1300 compares the measured Voc to a typical Voc curve. In one example, the process 1300 compares the measured Voc at the point in time of the measured Voc during the tone transition with the Voc of the typical Voc curve at the corresponding point in time. For example, in the case where Voc is measured 5 seconds after starting to apply the driving voltage, the measured Voc is compared with the Voc value of a typical Voc curve at t=5 seconds. In another example, the process 1300 compares a plurality of measured Voc values with a typical Voc curve. For example, the process 1300 may compare an average of a plurality of measured Voc values (e.g., an average of the last N measurements) to the Voc values from a typical Voc curve. As another example, the process 1300 may compare the slope of a curve generated from a plurality of measured Voc values to the slope of a typical Voc curve. At 1310, process 1300 makes a determination of whether to modify the drive voltage based at least in part on the comparison. For example, process 1300 may determine that the drive voltage is to be modified in response to determining that one measured Voc value and/or a plurality of measured Voc values differ from a typical Voc value at a corresponding point in time by more than a threshold amount. As another example, process 1300 may determine that the drive voltage is to be modified in response to determining that the slope of the curve formed by the measured Voc values differs from the slope of a typical Voc curve by more than a threshold amount. If at 1310, the process 1300 determines that the drive voltage is not to be modified ("no" at 1310), the process 1300 proceeds to block 1312 and maintains the drive voltage at the current magnitude. Conversely, if at 1310, the process 1300 determines that the drive voltage is to be modified (yes at 1310), the process 1300 proceeds to block 1314 and modifies the drive voltage. The driving voltage may be increased or decreased. In some implementations, the magnitude of the increase or decrease may be determined based at least in part on the degree to which the measured Voc value differs from the expected Voc value indicated in the typical Voc curve. In some implementations, the drive voltage may be modified according to any suitable constraint. For example, the amount of increase in the drive voltage may be set to an upper limit (e.g., at 20mV, 40mV, 60mV, etc.).

In some implementations, the drive voltage applied to the optically switchable device in conjunction with the tone transition is modified during the tone transition based at least in part on a comparison of the measured amount of transferred charge (sometimes referred to herein as a Q count) to typical charge (Q) information. The typical Q information may indicate the amount of charge expected to be transferred as a function of the time of application of a particular drive voltage. In some implementations, the representative Q information may be based at least in part on measurements from one or more other optically switchable devices (e.g., in addition to the optically switchable device for which a determination is being made whether to modify the drive voltage). In some implementations, one or more other optically switchable devices may be similar to the optically switchable device for which a determination is made as to whether to modify the drive voltage relative to the material properties (e.g., size, dimension, volume, surface area, bus bar dimension, number of cycles, etc.). In some implementations, one or more optically switchable devices may be similar to the optically switchable device for which the determination of relative position is made. In one example, one or more optically switchable devices can be located within the same area of a building. By utilizing the typical Q information of an optically switchable device within the same zone of a building, the tone transition time of an optically switchable device that deviates from the typical tone transition speeds of other optically switchable devices in that zone can be modified to provide uniformity of tone transition. In some implementations, the drive voltage modification based on the measured Q value may be performed during an operating mode in which Voc has reached the Voc target. In some implementations, the drive voltage modification based on the measured Q value may be performed in response to determining that the Voc measurement has settled or stabilized (e.g., in response to determining that consecutive Voc measurements differ by less than a threshold amount).

Fig. 13B illustrates an example of a process 1320 for modifying a drive voltage applied to an optically switchable device during a tone transition based at least in part on a measured transferred charge (Q-count), according to some embodiments. The blocks of process 1320 may be performed in a different order than that shown in fig. 13B. In some implementations, two or more blocks of process 1300 may be performed substantially in parallel. In some implementations, one or more blocks of process 1300 may be omitted. Process 1320 begins at 1322 by obtaining typical Q information. The typical Q information may indicate the amount of expected charge to be transferred as a function of time for a particular applied drive voltage. Typical Q information may relate to an optically switchable device similar to the optically switchable device associated with the native tone transition with respect to at least one characteristic. The similarity characteristics may include material properties and/or location of the optically switchable device (e.g., location within a facility). At 1324, process 1320 applies a drive voltage. The driving voltage may be a preset driving voltage. The drive voltage may be associated with a tone transition (e.g., from a first optical state to a second optical state). At 1326, process 1320 measures the amount of charge transferred to the optically switchable device (Q count). At 1328, process 1320 compares the Q count to typical Q information. At 1330, process 1320 determines whether to modify the drive voltage based at least in part on the comparison. For example, process 1320 may determine whether the Q count differs from an expected Q at a current point in time (e.g., a current duration after an initial application of the drive voltage) as indicated in the typical Q information by more than a threshold amount. As another example, process 1300 may determine whether the slope of a curve formed from a plurality of Q count values differs from the slope of a curve associated with typical Q information by more than a threshold amount. If at 1330, process 1320 determines that the drive voltage is not to be modified ("no" at 1330), process 1300 proceeds to 1332 and maintains the drive voltage at the current magnitude. Conversely, if at 1330, process 1320 determines that the drive voltage is to be modified (yes at 1330), process 1300 proceeds to 1334 and the drive voltage is modified. The driving voltage may be increased or decreased. In some implementations, the magnitude of the increase or decrease may be determined based at least in part on the degree to which the measured Q value differs from the expected Q value indicated in the typical Q information. In some implementations, the drive voltage may be modified according to any suitable constraint. For example, the amount of increase in the drive voltage may be set to an upper limit (e.g., at 20mV, 40mV, 60mV, etc.). In some implementations, the drive voltage of the optically switchable device is modified based at least in part on the historical parameters. In some implementations, the historical parameter may relate to an optically switchable device. For example, the history parameter may indicate a speed of a tone transition of the optically switchable device during a previous tone transition, a previous modification of the drive voltage during a previous tone transition (e.g., based on a comparison of the measured delivered Voc and/or the measured delivered Q to a typical Voc value and/or a typical Q value), and so forth. In some implementations, the historical parameters may relate to one or more optically switchable devices other than the optically switchable device. For example, one or more other optically switchable devices can be other optically switchable devices that are similar in material properties (e.g., size, surface area, volume, bus bar dimensions, number of cycles, etc.). As another example, the one or more optically switchable devices may be other optically switchable devices similar in location to the optically switchable devices. In one example, one or more other optically switchable devices may be arranged in the same area of the facility as the optically switchable device for which the drive voltage is modified. In some implementations, historical parameters of one or more optically switchable devices can be retrieved from a database. For example, the database may be queried for information associated with an optically switchable device having a particular property, an optically switchable device located in a particular zone, or the like. By modifying the drive voltage of a particular optically switchable device based on historical parameters of similar optically switchable devices, the tone transition of the optically switchable device can be aligned and/or consistent with the similar optically switchable devices. For example, although different drive voltages are required to account for differences between devices, this may result in a group of optically switchable devices positioned close to each other having similar (e.g., visually similar) hue transitions. In one example, a slower optically switchable device may be caused to transition faster according to other optically switchable devices in proximity to the slower optically switchable device.

In some embodiments, the determination of whether to modify the initial drive voltage value of the optically switchable device is made based on a comparison of the performance of the optically switchable device with other similar optically switchable devices as indicated in the obtained historical parameters. For example, the history parameter may indicate that a particular optically switchable device completed a tone transition slower than other similar optically switchable devices. Continuing with this example, the following determination may be made: the initial drive voltage of the optically switchable device will be increased to accelerate the tone transition to align with the speed of the tone transition of the other optically switchable devices. It should be noted that in some embodiments, the following determination may be made: the initial drive voltage will be reduced to slow down the tone transition of a particular optically switchable device to align with the speed of the tone transition of other optically switchable devices. In some implementations, the determination that the initial drive voltage is to be modified may be made in response to determining that the speed of the tone transition is at the tail end of the distribution of the history parameters associated with the set of optically switchable devices (e.g., in the 5 th percentile, in the 10 th percentile, in the 90 th percentile, in the 95 th percentile, etc.).

Fig. 14 illustrates an exemplary process 1400 for modifying an initial drive voltage of an optically switchable device based at least in part on historical parameters. The blocks of process 1400 may be performed in an order different from that shown in fig. 14. In some implementations, two or more blocks of process 1400 may be performed substantially in parallel. In some implementations, one or more blocks of process 1400 may be omitted. Process 1400 begins at 1402 by obtaining historical parameters of an optically switchable device and/or a set of optically switchable devices. In cases where historical parameters of a set of optically switchable devices are obtained, the set of optically switchable devices may be similar with respect to material properties and/or location. At 1404, process 1400 obtains an initial drive voltage value for the optically switchable device. The initial driving voltage value may be a preset value set, for example, as part of a factory setting. At 1406, process 1400 determines whether to modify the initial drive voltage value based at least in part on the historical parameters. For example, process 1400 may compare the performance of an optically switchable device to a set of optically switchable devices associated with historical parameters. In one example, process 1400 may determine that the initial drive voltage is to be modified in response to determining that the hue transition time associated with the optically switchable device is at the end of the distribution of hue transition times for a set of optically switchable devices as indicated in the history parameter. If at 1406, it is determined that the initial drive voltage is not to be modified ("no" at 1408), process 1400 proceeds to 1408 and maintains the initial drive voltage. Conversely, if at 1406 it is determined that the initial drive voltage is to be modified (yes at 1406), then process 1400 proceeds to 1408 and the initial drive voltage is modified. The initial driving voltage may be increased or decreased. The initial drive voltage may be modified according to constraints (e.g., safety constraints). For example, the initial driving voltage may increase by no more than a threshold amount.

It should be noted that although fig. 12, 13A, 13B, and 14 describe modifying the drive voltage of a single optically switchable device, in some embodiments, techniques may be used to modify the drive voltages of multiple optically switchable devices. In some embodiments, multiple optically switchable devices can be controlled by a single aperture controller and operatively coupled to the same power source. In some such implementations, voc may be measured independently for each of a plurality of optically switchable devices during tone transition. In some implementations, the drive voltages can be independently modified for each optically switchable device such that optically switchable devices operatively coupled to the same aperture controller operate at different drive voltages and/or have drive voltages that are independently modified during parallel tone transitions.

Controlling multiple sets of optically switchable devices

As shown in fig. 10, a plurality of optically switchable devices are sometimes positioned in close proximity. In this case, the user typically desires to simultaneously transition a plurality of devices in the group to the target ending optical state. It is preferred to achieve uniformity or substantial uniformity across the different devices in the group at different times of the transition period so that the different devices in the group appear to transition together. This may improve the aesthetics of the aperture set. In other words, it is desirable for different devices in a span to have similar transition speeds and/or transition times because by causing different devices in the span to have such similar hue transition speeds and/or transition times during a transition period, the devices are caused to have similar hue appearances during the transition period. The term "device" in the following discussion refers to an optically switchable device, unless otherwise indicated.

As described above, one method for achieving uniform coloration across different devices in a set of optically switchable devices includes pausing one optically switchable device in the set having a faster tone transition speed during a tone transition rather than another optically switchable device having a slower tone transition speed. This will allow a slower transition device (also referred to herein as a slower device) to catch up with a faster transition device (also referred to herein as a faster device). However, in some implementations, the method may slow down the tone transition of the entire group, thereby limiting the transition speed to an optically switchable device that is not faster than the slowest transition in the group.

In various applications and environments, the transition speed of an optically switchable device may be affected by many factors, such as drive voltage, device size, device lifetime, ambient temperature, start optical state, end optical state, and transient optical state, among others. When transitioning multiple optically switchable devices, their transition speeds may be different due to any of these factors. When referring to two or more optically switchable devices, the present disclosure in many cases marks or identifies the device using the relative transition speed during a reference transition of two or more optically switchable devices in a group. The reference transformation process provides a frame of reference for quantifying and correspondingly marking the device. Such marking or identification assumes that the same driving voltage is applied to two or more optically switchable devices during a reference transition. It is further assumed that two or more optically switchable devices have the same starting optical state and the same ending optical state during a reference transition. Other factors affecting the speed of the transition may be the same or different between two or more optically switchable devices in a group. The relative transition speed refers to the average transition speed during the reference transition. For example, in some cases, a set of optically switchable devices includes a slowest optically switchable device (also referred to herein as a slowest transition optically switchable device) and one or more faster optically switchable devices (also referred to herein as faster transition optically switchable devices). This assumes that the same drive voltage is applied to a set of optically switchable devices during the reference transition. It is also assumed that during the reference transition the device starts from the same starting optical state and ends with the same ending optical state. The slowest optical transition means has the slowest average transition speed of the group. One or more of the faster optically switchable devices have a faster average transition speed than the slowest optically switchable device.

It is generally preferred to be able to switch the entire set of optically switchable devices to the target optical state as quickly as possible. Some implementations of the present disclosure provide alternative methods for achieving daylighting-by-daylighting-area, cross-device uniformity for tinting two or more optically switchable devices (such as electrochromic fenestrations described herein) to a target or ending optical state. Some of these implementations apply a higher drive voltage to the slower optically switchable device and a lower drive voltage to the faster optically switchable device. Here, the "higher" and "lower" drive voltages are relative to each other such that, for example, the drive voltage applied to the slower-transitioning optically switchable device is "higher" than the drive voltage applied to the faster-transitioning optically switchable device, and similarly, the drive voltage applied to the faster-transitioning optically switchable device is "lower" than the drive voltage applied to the slower-transitioning optically switchable device. Furthermore, as described above, the optically switchable devices of the "faster transition" and the "slower transition" are relative to each other. Some additional or alternative implementations apply a ramp having a faster ramp rate to the drive voltage to a slower-transitioning optically switchable device and apply a ramp having a slower ramp rate to the drive voltage to a faster-transitioning optically switchable device. Here, the ramp rates of "faster" and "slower" are relative to each other such that, for example, the ramp-to-drive voltage ramp rate applied to the slower-transitioning optically switchable device is "faster" than the ramp-to-drive voltage ramp rate applied to the faster-transitioning optically switchable device, and similarly, the ramp-to-drive voltage ramp rate applied to the faster-transitioning optically switchable device is "slower" than the ramp-to-drive voltage ramp rate applied to the slower-transitioning optically switchable device.

Because these implementations use a larger drive voltage and/or a faster ramp rate to transition the slower transition device than the faster transition device, these implementations advantageously accelerate the transition of the slower device. Thus, the entire set of devices may transition to the ending optical state faster than methods of suspending faster transitioning devices. It should also be noted that in implementations herein, the drive voltage applied to each optically switchable device is less than the burn-in voltage of the device. The burn-in voltage of a device is the maximum voltage that the device is expected to perform its intended function while meeting performance criteria. Contemplated functions include changing and maintaining optical density, changing and maintaining color, insulating heat, maintaining visual characteristics, and the like. Performance metrics include speed, reliability, consistency, uniformity, etc. The burn-in voltage of a device may be empirically determined for the device or similar device. It may also be modeled based on various relevant parameters of the device, such as material, thickness, dimensions, etc.

As mentioned above, in some implementations, applying different drive voltages to different optically switchable devices of a set of optically switchable devices may reach an ending optical state for the different optically switchable devices at the same or substantially the same time. However, in some such cases, this may still result in coloration non-uniformities between two or more optically switchable devices during the transition period itself. In other words, during a tone transition of a group of optically switchable devices to a target optical state (i.e., tone state), the optical state of one optically switchable device may be different from another optically switchable device in the group. Some implementations below address this problem by adjusting the drive voltages of the different optically switchable devices such that the optical state (i.e., hue level) of each optically switchable device in the group reaches the ending optical state at the same or substantially the same time and reaches one or more intermediate optical states at the same or substantially the same time. Some implementations address this by adjusting the ramp rate of the ramp applied prior to the drive voltage.

In some implementations, as mentioned above, when a low drive voltage is applied to an optically switchable device, the signal-to-noise ratio of the feedback signal measured for monitoring the device may be too small to be reliable. This problem can be solved by adjusting the drive voltage towards a higher range such that the signal-to-noise ratio of the feedback signal exceeds a minimum threshold, thereby ensuring reliable monitoring of the state of the device.

Fig. 15 illustrates a flow diagram of a process 1500 for transitioning a set of optically switchable devices to an ending optical state, according to some implementations. Process 1500 begins by receiving a command to transition a set of optically switchable devices to an ending optical state. See block 1502. One group of optically switchable devices includes the slowest optically switchable device and the faster optically switchable device. When the same drive voltage is applied to each optically switchable device in a group of optically switchable devices, the slowest optically switchable device transitions at a slower or equal transition speed than any other optically switchable device in the group. In other words, when the same driving voltage is applied to each optically switchable device in the group, the slowest optically switchable device does not transition faster than any other optically switchable device in the group. For example, in some implementations, a group may include a single slowest optically switchable device. In other implementations, a group may include two or more of the slowest optically switchable devices that all transition at or about the same slowest transition speed in the group.

As described above, the terms "slowest" and "faster" are used herein with reference to the relative transition speeds of the optically switchable devices in a group in the process of applying the same drive voltage to each of the optically switchable devices in the group, the process including the same starting optical state and the same ending optical state for each of the optically switchable devices. The "same drive voltage" is provided in the context of the same transition conditions (such as ambient temperature, aging conditions, etc.). Various factors of the device may affect the speed of the transition, such as material, size, bus bar distance, aspect ratio, etc.

In various implementations, the transition speed of the optically switchable device is affected by the Bus Bar Distance (BBD), the size of the device, the aspect ratio, the Diagonal Bus Bar Distance (DBBD), or a combination thereof. For two parallel bus bars, the BBD distance is the distance between two intersections of the two bus bars through a line perpendicular to the bus bars. For two non-parallel bus bars, in some implementations, the BBD distance is calculated as an average of two or more lines each intersecting two bus bars. In some implementations, DBBD of two bus bars is measured as the distance between one end of one bus bar and the diagonally opposite end of the other bus bar. In some implementations, DBBD of two bus bars is measured as an average of two diagonal connections of four ends of the two bus bars. Other measurements of the BBD and DBBD reflecting the distance between two bus bars may also be used in other implementations.

In some implementations, the slowest optically switchable device in the group has a larger surface area than the faster optically switchable device to be transitioned in a group of optically switchable devices. "larger" may include a larger surface area and/or a larger dimension (such as a length or width) herein. In some implementations, the BBD of the slowest optically switchable device is greater than the BBD of the faster optically switchable device. In some such cases, the slowest optically switchable device may also have a smaller measurement (such as its surface area or height) than the other optically switchable device. For example, the slowest optically switchable device in a group may have a BBD of 1m, a width of 1.25m parallel to the BBD, and a length of 0.5m, while another faster optically switchable device in a group has a BBD of 0.5m, a width of 0.75m, and a length of 2 m. In some implementations, the DBBD of the slowest optically switchable device is larger than the DBBD of the faster optically switchable device.

Fig. 10 may show optically switchable devices of different sizes in the same group. Here in fig. 10, all optically switchable devices 1090 and 1091 may be part of a group. The BBD and size of the optically switchable device 1090 is less than the BBD and size of the optically switchable device 1091. Thus, when the same driving voltage is applied to the optically switchable devices 1090 and 1091, the optically switchable device 1090 transitions to the ending optical state faster than the optically switchable device 1091 transitions to the same ending optical state. This may result in undesirable non-uniformities between optically switchable devices 1090 and 1091 during transition and/or in order to reach an end optical state. Using the techniques provided herein, such non-uniformities can be reduced or eliminated by using drive voltages of different magnitudes applied to the different sized optically switchable devices 1090 and 1091, respectively, wherein the faster optically switchable device 1090 is at a lower drive voltage than the slowest optically switchable device 1091. As provided above, some additional or alternative implementations use different ramp rates for the ramp-to-drive voltages applied to optically switchable devices 1090 and 1091.

The process 1500 also involves transitioning the slowest optically switchable device to the ending optical state by applying a first drive voltage to the slowest optically switchable device. See block 1504. The process 1500 also involves transitioning the faster optically switchable device to an ending optical state by applying a second drive voltage. The first driving voltage has a larger magnitude than the second driving voltage. See block 1506. In some implementations, the operation 1504 of transitioning the slowest optical switchable device and the operation 1506 of transitioning the faster optical switchable device occur within about the same time period, or the operations may overlap in time, including, for example, substantially overlapping. In some implementations, the average transition speed of the faster optical switchable device and the average transition speed of the slowest optical switchable device are about the same during a period of time that begins when a command is received and ends when all of the optical switchable devices of the set of optical switchable devices reach an end optical state. In some implementations, the faster and slowest optically switchable devices take about the same amount of time to transition to the ending optical state.

In some implementations, the first drive voltage and the second drive voltage are applied for approximately the same amount of time. In some implementations, the amounts of time for the first drive voltage and the second drive voltage are obtained from a memory of the control device or from a server over a network.

In some implementations, the process 1500 involves optionally obtaining information for a set of optically switchable devices and/or obtaining drive voltage data for a set of optically switchable devices before applying the first drive voltage in block 1504 and after block 1502. This operation is not shown in fig. 15, as it is optional. In some implementations, information of a device group and drive voltage data of the device group are obtained from a memory of a control device. In other implementations, information and drive voltage data is obtained from a server over a network. In some embodiments, the information may include drive parameters, such as drive voltage values for each optically switchable device in the group for transitioning to the plurality of optical states. For example, this may include a first drive voltage and a second drive voltage that respectively result in transitioning the slowest and faster optically switchable devices to the same ending optical state. As provided above, in some implementations, these first and second drive voltages may cause the slowest and faster optically switchable devices to have similar color tone transitions and/or to reach the same end optical state substantially simultaneously. In some implementations, the first drive voltage and the second drive voltage may cause the slowest optically switchable device and the faster optically switchable device to transition from the starting optical state to the ending optical state for the same or about the same duration. This information, including the drive parameters, may also include a target open circuit voltage (Voc) value and/or a target charge (or Q) value for each optically switchable device. These target values are associated with the target optical density of each optically switchable device and can be used to determine when the corresponding optically switchable device reaches a desired optical state.

Some implementations select a drive voltage that achieves uniform coloration across the device at one or more different points in time during a hue or optical state transition. In some implementations, the faster and slowest optically switchable devices take approximately the same first amount of time to transition to the intermediate optical state before transitioning to the ending optical state. The intermediate optical state has an optical density between that of the starting optical state and that of the ending optical state. The initial optical state is the optical state at the beginning of the transition. In some implementations, the faster and slowest optically switchable devices take approximately the same second amount of time to transition to the second intermediate optical state before transitioning to the ending optical state.

In some implementations, the second drive voltage generates a current having a signal-to-noise ratio greater than a specified standard. This may be achieved by setting the second voltage or its associated current to be above a threshold, resulting in a signal to noise ratio of the current that is greater than a specified criterion. This helps to improve the reliability of monitoring the current or the charge associated with the current or the open circuit voltage. This allows for a more reliable measurement of the monitoring signal for determining the optical state of the device.

In some implementations, the faster optically switchable device transitions to the ending optical state without pausing. In some cases, this may require faster optically switchable device transitions without slowing or stopping, and/or the slowest optically switchable device transitions faster by applying a larger drive voltage thereto. One or both of these may achieve uniform coloring of the device without sacrificing the transition speed of the entire device group.

Process 1500 also involves applying a holding voltage to each optically switchable device. See block 1512. In various implementations, the hold voltage has a smaller magnitude than the drive voltage. For example, these holding voltages may be any of those described herein, such as those described with respect to fig. 2-5H, 5J-5M, and 12-14.

Fig. 15 shows a process for controlling a set of optically switchable devices, but the process may also be implemented to control more than one set of optically switchable devices. In such implementations, the method further includes receiving a command to transition the second set of optically switchable devices to an ending optical state (the same ending optical state as the ending optical state of the first set) (in addition to the command to transition the above set (also referred to as the second set hereinafter)). The method may be used to dynamically control multiple sets of optically switchable devices. The second group includes a second group of slowest optically switchable devices and a second group of faster optically switchable devices. When the same drive voltage is applied to each optically switchable device in the second group, the slowest optically switchable device of the second group transitions at a slower or equal transition speed than any other optically switchable device in the second group. The method includes transitioning the second group of slowest optically switchable devices to the same ending optical state by applying a third drive voltage to the second group of slowest optically switchable devices during the transition of the slowest optically switchable devices in the first group to the ending optical state. The method includes transitioning the second set of faster optically switchable devices to the ending optical state by applying a fourth drive voltage to the second set of faster optically switchable devices during transition of the slowest optically switchable device in the first set to the ending optical state. The third driving voltage has a larger magnitude than the fourth driving voltage. In some implementations, the faster optical switchable device, the slowest optical switchable device, the second set of faster optical switchable devices, and the second set of slowest optical switchable devices reach the ending optical state at substantially the same time. In other words, some such implementations cause the first and second groups to reach the same or substantially the same ending optical state at the same or substantially the same time by: while applying a first drive voltage to the slowest optically switchable device in the first group, applying a second drive voltage to the faster optically switchable device in the first group, applying a third drive voltage to the second slowest optically switchable device in the second group during application of the first drive voltage of the first group, and applying a fourth drive voltage to the faster optically switchable device in the second group during application of the first drive voltage of the first group.

In effect, the method transitions the first set of optically switchable devices and the second set of optically switchable devices to the ending optical state in parallel and in synchronization. In some implementations, the transitioning of the two optically switchable devices in the first group and the transitioning of the two optically switchable devices in the second group occur in substantially the same time period. In some implementations, the average transition speeds of the four devices during the same period of time during the transition are about the same. In some implementations, four optically switchable devices take about the same amount of time to transition to the ending optical state.

In some implementations not shown in fig. 15, the process may be interrupted by a new command to switch to a second ending optical state before a set of optically switchable devices reaches the ending optical state before completing the transition to the ending optical state. In some implementations, the method further includes transitioning the slowest and faster optically switchable devices to the second ending optical state without any pauses in response to receiving a command to transition to the second ending optical state. This may be achieved by a process similar to that shown in fig. 5H and further explained below in fig. 17. Briefly, in some implementations, a method may include determining, for each optically switchable device, one or more current parameter values (e.g., voc or Q) and one or more target parameter values (e.g., voc or Q) associated with a second optical state when a new command to switch to the second ending optical state is received. The method further includes determining one or more updated drive parameters (e.g., drive voltage magnitude and drive voltage polarity) for each optically switchable device for transitioning to the second optical state using the one or more current parameter values and the one or more target parameter values. For example, the process described in FIG. 5H may be used to determine current parameter values and/or target parameter values. The method also includes applying a third drive voltage to the slowest optically switchable device and applying a fourth drive voltage to the faster optically switchable device. For example, the magnitude of the third driving voltage may be greater than the fourth driving voltage.

Fig. 15 provides a set of optically switchable devices comprising two devices. The methods disclosed herein may also be implemented to include three or more optically switchable devices. In some implementations, the method includes transitioning the three or more optically switchable devices by applying three or more drive voltages to the three or more optically switchable devices, respectively, during the same time period. In some implementations, the magnitudes of the three or more drive voltages decrease with the transition speed in response to an increase in the same drive voltage. In other words, the faster the device transitions, the smaller the voltage magnitude of the device. In some implementations, the magnitudes of the three or more drive voltages increase as the BBD increases. In some implementations, the magnitudes of the three or more drive voltages increase as DBBD increases.

For example, some implementations may include one or more slowest optically switchable devices, one or more second optically switchable devices, and one or more third optically switchable devices, and with the same drive voltage applied, the slowest optically switchable device transitions to an ending optical state slower than the one or more second optically switchable devices and the one or more third optically switchable devices, and the one or more second optically switchable devices transitions to the same ending state slower than the one or more third optically switchable devices. During the same or substantially the same period of time, a first drive voltage may be applied to one or more slowest optically switchable devices, a second drive voltage may be applied to one or more second optically switchable devices, and a third drive voltage may be applied to one or more third optically switchable devices, wherein the first drive voltage has a magnitude greater than the second drive voltage and the third drive voltage, and the second drive voltage has a magnitude less than the third drive voltage.

In some implementations, a group of optically switchable devices includes a third optically switchable device in addition to the slowest optically switchable device and the faster optically switchable device. When the same driving voltage is applied to a set of optically switchable devices, the third optically switchable device transitions faster than the fast optically switchable device. The process of transitioning a set of optically switchable devices further includes: the third optically switchable device is transitioned to the ending optical state by applying a third drive voltage to the third optically switchable device while transitioning the slowest or faster optically switchable device to the ending optical state. The second drive voltage applied to the faster optically switchable device has a greater magnitude than the third drive voltage. In some implementations, the BBD of the slowest optically switchable device is greater than the BBD of the faster optically switchable device, and the BBD of the faster optically switchable device is greater than the BBD of the third optically switchable device. In some implementations, the DBBD of the slowest optically switchable device is greater than the DBBD of the faster optically switchable device, and the DBBD of the faster optically switchable device is greater than the DBBD of the third optically switchable device.

Fig. 16A illustrates a process 1600 for transitioning a set of optically switchable devices to an ending optical state, wherein a ramp is applied to the drive voltage prior to the drive voltage, according to some implementations. Process 1600 is similar to process 1500 except that a ramp is applied to the drive voltage prior to applying the drive voltage to the device. Process 1600 begins with receiving a command to transition a group of optically switchable devices to an ending optical state, the group comprising a slowest optically switchable device and a faster optically switchable device. See block 1602. Process 1600 also involves applying a first ramp to the slowest optically switchable device to a drive voltage. See block 1604. Process 1600 also involves applying a first drive voltage to the slowest optically switchable device to transition it to the ending optical state. See block 1608. While applying the voltage to the slowest optically switchable device, the process 1600 applies a second ramp to the drive voltage to the faster optically switchable device in parallel. The first ramp to drive voltage has a faster ramp rate than the second ramp to drive voltage. See block 1606. Process 1600 also involves applying a second drive voltage to the faster optically switchable device. The first driving voltage has a larger magnitude than the second driving voltage. See block 1610.

In some implementations, the operation 1604 of applying the first ramp to the drive voltage to the slowest optically switchable device and the operation 1606 of applying the second ramp to the drive voltage to the faster optically switchable device occur within about the same first time period, or the operations may overlap in time, including, for example, substantially overlapping. In some implementations, the operation 1608 of applying the first drive voltage to the slowest optically switchable device and the operation 1610 of applying the second drive voltage to the faster optically switchable device occur within about the same second time period, or the operations may overlap in time, including, for example, substantially overlapping.

In some implementations, the average transition speed of the faster optically switchable device in response to the first drive voltage and the average transition speed of the slowest optically switchable device in response to the second drive voltage are about the same in the time period between the beginning of the transition and the reaching of the ending optical state. In some implementations, the faster and slow optical switchable devices take about the same amount of time to transition to the ending optical state.

The ramp-to-drive voltage and the drive voltage applied to each optically switchable device are implemented as segments of a voltage profile for driving transitions of the optically switchable device, such as voltage segment 303 and segment 313 in fig. 3.

Process 1600 also involves applying a holding voltage to each optically switchable device in the group. See block 1612. In some implementations, the same or substantially the same holding voltage is applied to each optically switchable device in the group. In other implementations, the holding voltage applied to one optically switchable device in a group may be different from one or more other optically switchable devices in the group.

In some implementations not shown in fig. 16, process 1600 optionally involves applying a ramp to the holding voltage to each device in the group after applying the driving voltage to each device and before applying the holding voltage to each device. For example, the ramp to hold voltage may be implemented as voltage segment 315 in the voltage profile in fig. 3.

Fig. 16B illustrates two voltage distributions that may be used in some implementations of the process 1600 of fig. 16A. More specifically, the process applies voltage profile 1620, shown in dashed lines, to the slowest optical switchable device in the set of optically switchable devices and voltage profile 1630, shown in solid lines, to the faster optical switchable devices in the set. Voltage distribution 1620 and voltage distribution 1630 are similar to the applied voltages in fig. 3. The voltage profile 1620 of the slowest optically switchable device includes ramp to drive voltage 1622 (corresponding to the first ramp to drive voltage of operation 1604 of process 1600), drive voltage 1624 (corresponding to the first drive voltage of operation 1608), ramp to hold voltage 1626, and hold voltage 1628 (corresponding to the hold voltage of operation 1612).

The voltage profile 1630 of the faster optically switchable device includes a ramp to drive voltage 1632 (corresponding to the second ramp to drive voltage of operation 1606), a drive voltage 1634 (corresponding to the second drive voltage of operation 1610), a ramp to hold voltage 1636, and a hold voltage 1638 (corresponding to the hold voltage of operation 1612).

The ramp-to-drive voltage 1622 of the slowest optically switchable device has a faster ramp rate than the ramp-to-drive voltage 1632 of the faster optically switchable device. Also, the drive voltage 1624 of the slowest optically switchable device has a greater magnitude than the drive voltage 1634 of the fast optically switchable device. These help to speed up the transition of the slowest optically switchable device, providing uniform coloration across both devices during the hue transition.

Fig. 16B illustrates that the ramp-to-drive voltage 1622 and the ramp-to-drive voltage 1632 occur in the same or substantially the same "ramp-to-drive" period as according to some implementations. In other implementations, the ramp-to-drive voltage 1622 and the ramp-to-drive voltage 1632 may occur in overlapping or substantially overlapping time periods. In some implementations, the ramp to drive voltage 1622 and the ramp to drive voltage 1632 may occur in non-overlapping time periods.

FIG. 16B further illustrates that the driving voltage 1624 and the driving voltage 1634 appear at the same or substantially the same V as according to some implementations _{Driving of} In a time period of. In other implementations, the driving voltage 1624 and the driving voltage 1634 may occur in overlapping or substantially overlapping time periods.

Fig. 16B illustrates that the ramp-to-hold voltage 1626 and the ramp-to-hold voltage 1636 occur in the same or substantially the same "ramp-to-hold" period as according to some implementations. In other implementations, the ramp to hold voltage 1626 and the ramp to hold voltage 1636 may occur in overlapping or substantially overlapping time periods. In other implementations, the ramp to hold voltage 1626 and the ramp to hold voltage 1636 may occur in non-overlapping time periods.

Fig. 16B illustrates that the magnitude of the holding voltage 1628 is the same or substantially the same as the magnitude of the holding voltage 1638, as according to some implementations. In other implementations, the magnitude of the holding voltage 1628 is different, statistically significantly different, or substantially different from the magnitude of the holding voltage 1638.

Fig. 17 illustrates a process 1700 for transitioning a set of optically switchable devices to an ending optical state, according to some implementations. Process 1700 is similar to process 1500, but it also includes operations for determining a starting optical state of the optically switchable device, determining drive parameters based on the starting optical state, and iteratively determining when to complete a transition.

Process 1700 begins with receiving a command to transition a group of optically switchable devices to an ending optical state, the group comprising a slowest optically switchable device and a faster optically switchable device. See block 1702. Process 1700 also includes determining a starting optical state of a set of optically switchable devices. See block 1704. The starting optical state is an optical state of the one or more optically switchable devices when a command to transition to the ending optical state is received. In some implementations, the starting optical state is one optical density or one transmittance of two or more devices in the group. However, the present disclosure is also applicable to implementations in which the starting optical state includes different optical densities or transmittances for two or more devices, e.g., one device having a first optical density or first transmittance and a second device having a second optical density or second transmittance that is different from the first optical density or first transmittance. Conversely, for two or more devices in a group, the ending optical state is typically, but not always, the same optical density or transmittance. In some implementations, the starting optical state of a set of optically switchable devices has been previously determined and stored in a memory of the control device or the server.

In some additional or alternative implementations, the process obtains one or more feedback signals from one or more devices in a set of optically switchable devices and determines a starting optical state of the one or more devices based on the obtained feedback signals. This may include obtaining signals from some or all of the devices in the group and determining a starting optical state of some or all of the devices in the group. As explained above, the various feedback signals feed back signals to determine the optical state. In some implementations, the feedback signal can be, for example, an open circuit voltage, a current measured in response to an applied voltage, and a charge or charge density. For example, the feedback signal may be compared to a typical open circuit voltage (Voc) or a typical charge or charge density to determine the optical state as described above. The starting optical state of the device may be used to determine the direction, magnitude or duration of the drive parameter. It can also be used to determine whether the driving voltage should not be applied or should be applied at a smaller magnitude, thereby avoiding damaging the device. Furthermore, it can be used to determine a charge target or an open circuit voltage target, which can be used to control the transition process.

Process 1700 also involves determining one or more drive parameters for a set of optically switchable devices. See block 1706. The driving parameters include a driving voltage of each device. As provided herein, this may include obtaining a drive voltage for one or more devices in the group that has a different magnitude than drive voltages for one or more other devices in the group. For example, a first drive voltage for the slowest optically switchable device in the group and a smaller second drive voltage for the faster optically switchable device. This may also include ramp rates that may be different between devices in a group to a drive voltage, e.g., a first ramp rate of a slowest optically switchable device in a group to a drive voltage and a second, slower ramp rate of a faster optically switchable device to a drive voltage. In some implementations, the drive parameters also include a drive duration of a drive voltage for each of the devices. In some implementations, the drive voltage of each of the devices depends on the starting optical state of each device. For example, if the starting optical state is less colored than the ending optical state, a negative drive voltage may be required. Conversely, if the starting optical state is more colored than the ending optical state, a positive drive voltage may be required. Similarly, the drive duration of the device may also be different depending on the hue difference between the starting optical state and the ending optical state.

In some implementations, the drive parameters may also include a target open circuit voltage (Voc) value and/or a target charge (or Q) value for each optically switchable device. These target values are associated with the end or target optical density of each optically switchable device and can be used to determine when the corresponding optically switchable device reaches a desired optical state. For example, voc and Q for each optically switchable device in a group may be obtained for a target optical state, and such instantaneous parameter values may be monitored during transitions of devices in the group, as described below with respect to blocks 1718 and 1716. As provided herein, in some implementations, the drive voltage of each optically switchable device can be associated with a corresponding Voc and/or charge target to achieve an ending, target optical state. These obtained drive parameters (such as Voc and/or charge targets corresponding to drive voltages for which an ending optical state is desired) may be used to monitor transitions and completions for each device, including when each device has reached the ending optical state.

The process 1700 also involves applying a first drive voltage to the slowest optically switchable device for a first duration to transition the device. See block 1708. Process 1700 also involves obtaining feedback from the slowest optically switchable device during the transition of the slowest optically switchable device. See block 1712. In some implementations, the feedback obtained from the slowest optically switchable device includes, for example, one or more of: open circuit voltage, current measured in response to the applied voltage, and charge or charge density delivered to the slowest optically switchable device. The process 1700 also involves determining whether the transition to the ending optical state is complete based on the obtained feedback, such as by comparing the obtained feedback to a target value, such as a target open circuit voltage, a target current response, or a target charge/charge density. See block 1716. In some implementations, when the open circuit voltage of the slowest optically switchable device reaches the first target open circuit voltage, a determination is made that the transition of the slowest optically switchable device to the ending optical state is to be completed. If it is determined that the transition is complete or near complete, then process 1700 involves applying a hold voltage to the slowest optically switchable device. See block 1720. If the transition is not complete, the process 1700 loops back to operation 1708 to apply the first drive voltage to the slowest optically switchable device for the first duration.

The process 1700 also applies a second drive voltage to the faster optically switchable device for a second duration. The first driving voltage has a larger magnitude than the second driving voltage. See block 1710. The first duration of the first driving voltage applied in operation 1708 may have the same length as the second duration of the second driving voltage applied in operation 1710 or a different length. In some implementations, the initial iteration of operation 1708 occurs in the same time period or substantially the same time period as the initial iteration of operation 1710. In some implementations, each iteration of operation 1708 occurs in the same time period or substantially the same time period as each iteration of operation 1710. In some implementations, each iteration other than the last iteration of operation 1708 occurs in the same time period or substantially the same time period as each iteration other than the last iteration of operation 1710.

In some implementations, the first time period consisting of all iterations of operation 1708 and the second time period consisting of all iterations of operation 1720 overlap entirely in time (both time periods are the same) or substantially in time. This may lead to the following behavior: the two optically switchable devices simultaneously or about simultaneously begin the tone transition and simultaneously or about simultaneously reach the end optical state. This behavior may be achieved even when one or more iterations of operation 1708 do not overlap with any iterations of operation 1710, so long as the first and second time periods completely or substantially overlap in time.

Process 1700 also involves obtaining feedback from the faster optically switchable device during a transition of the faster optically switchable device. See block 1714. In some implementations, the obtained feedback includes parameters such as an open circuit voltage, a current measured in response to the applied voltage, and a charge or charge density delivered to the faster optically switchable device. In some implementations, the feedback obtained during the transition of the faster optically switchable device includes the charge or charge density delivered to the faster optically switchable device and does not include an open circuit voltage or a current measured in response to an applied voltage.

Process 1700 also involves using the obtained feedback to determine whether the transition of the faster optically switchable device is complete. See block 1718. In some implementations, it is determined that the transition of the faster optically switchable device to the ending optical state is to be completed when the open circuit voltage of the faster optically switchable device reaches the second target open circuit voltage. As described above, when the open circuit voltage of the slowest optically switchable device reaches the first target open circuit voltage, it is determined that the transition of the slowest optically switchable device to the ending optical state will be completed. See block 1716. In some implementations, the first target open circuit voltage of the slowest optically switchable device is closer to zero than the second target open circuit voltage of the faster optically switchable device. If it is determined that the transition of the faster optically switchable device is complete, process 1700 applies a hold voltage to the faster optically switchable device. See block 1722. If the transition is not complete for the faster optically switchable device, the process 1700 loops back to operation 1710 to apply a second drive voltage to the faster optically switchable device for a second duration.

As mentioned above with reference to operation 1704, the process 1700 involves determining a starting optical state of a set of optically switchable devices. This determination is particularly useful when an interrupt command is received during a transition to a first ending optical state, which interrupt command requires a transition to a second ending optical state. Operation 1704 may be used to determine a transient state of the device during the transition to the first ending optical state, which may be used to determine a drive parameter for transitioning to the second ending optical state. In some implementations, the process 1700 involves receiving a command to transition a set of optically switchable devices to a second ending optical state before the set of optically switchable devices reaches the first ending optical state. The process involves transitioning the slowest and faster optically switchable devices to the second ending optical state without pausing. The interrupt command is similar to the interrupt command shown with reference to operations 550 and 552 in fig. 5G. The transition to the second ending optical state may be accomplished in a process similar to process 552 shown in fig. 5H, while applying different drive voltages to different devices as in fig. 17. Thus, although not shown in fig. 17, upon transitioning to the second ending optical state, the process 1700 may loop back to operation 1704 to determine the starting optical state of the group using feedback obtained from the device.

Electrochromic device and controller-examples

Examples of electrochromic device structure and fabrication will now be presented. Fig. 7A and 7B are schematic cross-sections of electrochromic device 700, showing the common structural motifs of such devices. Electrochromic device 700 includes a substrate 702, a Conductive Layer (CL) 704, an electrochromic layer (EC) 706, an optional ion conductive (electronic resistance) layer (IC) 708, a counter electrode layer (CE) 710, and another Conductive Layer (CL) 712. Elements 704, 706, 708, 710, and 712 are collectively referred to as electrochromic stack 714. In many embodiments, the stack does not include the ion conductive layer 708, or at least is not a discrete or separately fabricated layer. A voltage source 716 operable to apply a potential across the electrochromic stack 712 effects a transition of the electrochromic device from, for example, a transparent state (see fig. 7A) to a colored state (see fig. 7B).

The order of the layers may be reversed relative to the substrate. That is, the layers may be in the following order: a substrate, a conductive layer, a counter electrode layer, an ion conductive layer, an electrochromic material layer, and a conductive layer. The counter electrode layer may comprise electrochromic or non-electrochromic materials. If both electrochromic and counter electrode layers are employed electrochromic materials, one of them should be a cathodic coloring material and the other should be an anodic coloring material. For example, the electrochromic layer may employ a cathode coloring material and the counter electrode layer may employ an anode coloring material. This is the case when the electrochromic layer is tungsten oxide and the counter electrode layer is nickel tungstate.

The conductive layers typically comprise transparent conductive materials such as metal oxides, alloy oxides, and doped forms thereof, and are commonly referred to as "TCO" layers because they are made of transparent conductive oxides. In general, however, the transparent layer may be made of any transparent electronically conductive material compatible with electrochromic device stacks. Some glass substrates have a thin transparent conductive oxide layer, such as fluorinated tin oxide, sometimes referred to as "FTO".

The apparatus 700 is intended for illustrative purposes to understand the context of the embodiments described herein. The methods and apparatus described herein are used to identify and reduce defects in electrochromic devices regardless of the structural arrangement of the electrochromic devices.

During normal operation, an electrochromic device (such as device 700) reversibly cycles between a transparent state and a colored state. As depicted in fig. 7A, in the transparent state, a potential is applied across the electrodes of electrochromic stack 714 (transparent conductor layers 704 and 712) to cause available ions (e.g., lithium ions) in the stack to reside primarily in counter electrode 710. If electrochromic layer 706 contains a cathodically coloring material, the device is in a transparent state. In some electrochromic devices, the counter electrode layer 710 may be considered an ion storage layer when loaded with available ions.

Referring to fig. 7B, when the potential on the electrochromic stack is reversed, ions are transported across the ion conducting layer 708 to the electrochromic layer 706 and cause the material to enter a colored state. Again, this assumes that the light reversible material in the electrochromic device is a cathodically coloring electrochromic material. In certain embodiments, loss of ions from the counter electrode material also contributes to its coloration as depicted in the figures. In other words, the counter electrode material is an anodically coloring electrochromic material. Thus, layer 706 and layer 710 combine to reduce the amount of light transmitted through the stack. When a reverse voltage is applied to the device 700, ions travel from the electrochromic layer 706, through the ion conducting layer 708, and back into the counter electrode layer 710. Thus, the device is transparent.

Some relevant examples of electrochromic devices are given in the following U.S. patent applications, each of which is incorporated herein by reference in its entirety: U.S. patent application Ser. No. 12/645,111, filed 12/22/2009; U.S. patent application Ser. No. 12/772,055, filed 4/30/2010; U.S. patent application Ser. No. 12/645,159, filed 12/22/2009; U.S. patent application Ser. No. 12/814,279, filed 6/11/2010; U.S. patent application Ser. No. 13/462,725 filed on 5/2/2012 and U.S. patent application Ser. No. 13/763,505 filed on 8/2/2013.

For example, electrochromic devices (such as those described with respect to fig. 7A and 7B) are used in electrochromic windows. For example, the substrate 702 may be architectural glass on which electrochromic devices are fabricated. Architectural glass is glass used as a building material. Architectural glass is typically used in commercial buildings, but may also be used in residential buildings, and typically, but not necessarily, separates an indoor environment from an outdoor environment. In certain embodiments, the architectural glass is at least 20 inches by 20 inches, and may be larger, for example, up to about 72 inches by 120 inches.

In some embodiments, the electrochromic glazing is integrated into an Insulating Glass Unit (IGU). Insulating glass units include a plurality of glass panes assembled into a unit, typically intended to maximize the insulating properties of the gases contained in the space formed by the unit, while providing clear vision through the unit. The insulating glass unit incorporating electrochromic glass is similar to insulating glass units currently known in the art, except for the electrical terminals for connecting the electrochromic glass to a voltage source.

The optical transition drive logic may be implemented in many different controller configurations and coupled with other control logic. Various examples of suitable controller designs and operations are provided in the following patent applications, each of which is incorporated herein by reference in its entirety: U.S. patent application Ser. No. 13/049,623, filed 3/16/2011; U.S. patent application Ser. No. 13/049,756, filed 3/16/2011; us patent application number 8,213,074 filed 3/16/2011; U.S. patent application Ser. No. 13/449,235, filed 4/17/2012; U.S. patent application Ser. No. 13/449,248, filed 4/17/2012; U.S. patent application Ser. No. 13/449,251, filed on 4/17/2012; U.S. patent application Ser. No. 13/326,168, filed 12/14/2011; U.S. patent application Ser. No. 13/682,618, filed 11/20/2012; and U.S. patent application Ser. No. 13/772,969 filed on 21/2/2013. The following description and the associated figures (fig. 8 and 9) present certain non-limiting controller design options suitable for implementing the drive profiles described herein.

Fig. 8 shows a cross-sectional isometric view of an embodiment of an IGU 102 including two fenestration panes or areas 216 and a controller 250. In various embodiments, IGU 102 can include one, two, or more substantially transparent (e.g., in the absence of an applied voltage) lighting region 216 and a frame 218 supporting lighting region 216. For example, IGU 102 shown in FIG. 9 is configured as a double-pane window. The one or more lighting areas 216 may themselves be a laminate of two, three or more layers or lighting areas (e.g., similar to shatter-resistant glass of an automobile windshield). In IGU 102, at least one of the light-up regions 216 includes an electrochromic device or stack 220 disposed on at least one of an inner surface 222 or an outer surface 224 thereof; for example, the inner surface 222 of the outer lighting zone 216.

In a multi-pane configuration, each adjacent group of lighting zones 216 may have an interior volume 226 disposed therebetween. Generally, each of the lighting area 216 and IGU 102 as a whole is rectangular and forms a rectangular solid. However, in other embodiments, other shapes (e.g., circular, elliptical, triangular, curvilinear, convex, concave) may be desirable. In some embodiments, the volume 226 between the lighting areas 116 is evacuated of air. In some embodiments, IGU 102 is hermetically sealed. In addition, the volume 226 may be filled (to an appropriate pressure) with one or more gases such as argon (Ar), krypton (Kr), or Xenon (XN). Filling the volume 226 with a gas such as Ar, kr, or Xn may reduce conductive heat transfer through the IGU 102 because of the low thermal conductivity of these gases. The latter two gases can also improve the sound insulation effect by increasing the weight.

In some embodiments, the frame 218 is constructed from one or more workpieces. For example, frame 218 may be constructed of one or more materials such as vinyl, PVC, aluminum (Al), steel, or fiberglass. The frame 218 may also include or retain one or more foam or other material pieces that work in conjunction with the frame 218 to separate the light zones 216 and hermetically seal the volume 226 between the light zones 216. For example, in typical IGU implementations, a spacer is positioned between adjacent light-collecting areas 216 and forms a hermetic seal with the pane in conjunction with an adhesive sealant that may be deposited therebetween. This is known as the primary seal around which a secondary seal, typically an additional adhesive sealant, may be made. In some such embodiments, the frame 218 may be a separate structure supporting the IGU construction.

Each lighting area 216 includes a substantially transparent or translucent substrate 228. Generally, the substrate 228 has a first (e.g., inner) surface 222 and a second (e.g., outer) surface 224 opposite the first surface 222. In some embodiments, the substrate 228 may be a glass substrate. For example, the substrate 228 may be conventional silicon oxide (SO-based _x ) Such as soda lime glass or float glass, is made of, for example, about 75% silica (SiO ₂ ) Adding Na to ₂ O, caO and several minor additives. However, any material having suitable optical, electrical, thermal, and mechanical properties may be used as the substrate 228. Such substrates may also include, for example, other glass materials, plastics and thermoplastics (e.g., poly (methyl methacrylate), polystyrene, polycarbonate, allyl diglycol carbonate, SAN (styrene acrylonitrile copolymer), poly (4-methyl-1-pentene), polyesters, polyamides), or mirror materials. If the substrate is formed of, for example, glass, the substrate 228 may be strengthened, for example, by tempering, heating, or chemical strengthening. In other embodiments, the substrate 228 is not further strengthened, e.g., the substrate is not tempered.

In some embodiments, the substrate 228 is a glass pane sized for residential or commercial fenestration applications. The size of such glass panes can vary widely depending on the particular needs of the residential or commercial business. In some embodiments, the substrate 228 may be formed of architectural glass. Architectural glass is commonly used in commercial buildings, but also in residential buildings, and typically (although not necessarily) separates an indoor environment from an outdoor environment. In certain embodiments, a suitable architectural glass substrate may be at least about 20 inches by about 20 inches, and may be larger, such as about 80 inches by about 120 inches, or larger. Architectural glass is typically at least about 2 millimeters (mm) thick, and may be as thick as 6mm or more. Of course, electrochromic device 220 may be scalable with respect to substrates 228 that are larger or smaller than architectural glass, including in any or all of the corresponding length, width, or thickness dimensions. In some embodiments, the thickness of the substrate 228 is in the range of about 1mm to about 10 mm. In some embodiments, the substrate 228 may be very thin and flexible, such as Gorilla Or Willow ^TM Glasses, each available from Corning corporation of Corning, new york, may be less than 1mm thick, as thin as 0.3mm thick.

Electrochromic device 220 is disposed over an inner surface 222 of a substrate 228, such as outer pane 216 (a pane adjacent to the external environment). In some other embodiments, such as in colder climates or applications where IGU 102 receives a greater amount of direct sunlight (e.g., perpendicular to the surface of electrochromic device 220), it may be advantageous to place electrochromic device 220 on, for example, the inner surface of the inner pane adjacent the interior environment (the surface bordering volume 226). In some embodiments, electrochromic device 220 includes a first Conductive Layer (CL) 230 (generally transparent), an electrochromic layer (EC) 232, an ion conductive layer (IC) 234, a counter electrode layer (CE) 236, and a second Conductive Layer (CL) 238 (generally transparent). Likewise, layers 230, 232, 234, 236, and 238 are also collectively referred to as electrochromic stack 220.

The power supply 240 is operable to supply a potential (V _{Application of} ) Applied to the device and creates a V across the thickness of electrochromic stack 220 _{Effective and effective} And drive the transition of electrochromic device 220 from, for example, a transparent or lighter state (e.g., a transparent, translucent, or light transmissive state) to a colored or darker state (e.g., a colored, less transparent, or less light transmissive state). In some other embodiments, the order of the layers 230, 232, 234, 236, and 238 may be reversed or otherwise reordered or rearranged relative to the substrate 238.

In some embodiments, one or both of the first conductive layer 230 and the second conductive layer 238 are formed of inorganic and solid materials. For example, the first conductive layer 230 and the second conductive layer 238 may be made of a number of different materials, including conductive oxides, thin metal coatings, conductive metal nitrides, and composite conductors, as well as other suitable materials. In some embodiments, conductive layers 230 and 238 are substantially transparent at least in the wavelength range where electrochromic layer 232 exhibits electrochromic. Transparent conductive oxides include metal oxides and metal oxides doped with one or more metals. For example, metal oxides and doped metal oxides suitable for use as the first conductive layer 230 or the second conductive layer 238 may include indium oxide, indium Tin Oxide (ITO), doped indium oxide, tin oxide, doped tin oxide, zinc aluminum oxide, doped zinc oxide, ruthenium oxide, doped ruthenium oxide, and the like. As indicated above, the first conductive layer 230 and the second conductive layer 238 are sometimes referred to as "transparent conductive oxide" (TCO) layers.

In some embodiments, a commercially available substrate, such as a glass substrate, already contains a transparent conductive layer coating at the time of purchase. In some implementations, this product can be used uniformly for both the substrate 238 and the conductive layer 230. Examples of such Glass substrates include those sold under the trademark TEC Glass by Pickington, tolyo, ohio ^TM Sold under the trademark SUNGATE by PPG Industries, inc. of Pittsburgh, pa ^TM 300 and SUNGATE ^TM 500. Specifically, TEC Glass ^TM For example, glass coated with a fluorinated tin oxide conductive layer.

In some embodiments, the first conductive layer 230 or the second conductive layer 238 may each be deposited by a physical vapor deposition process including, for example, sputtering. In some embodiments, the first conductive layer 230 and the second conductive layer 238 may each have a thickness in the range of about 0.01 μm to about 1 μm. In some embodiments, it may be generally desirable for the thicknesses of the first and second conductive layers 230, 238, as well as the thickness of any or all of the other layers described below, to be uniform with respect to a given layer alone; that is, the thickness of a given layer is uniform and the surface of the layer is smooth and substantially free of defects or other ion traps.

The primary function of the first and second conductive layers 230, 238 is to diffuse the electrical potential provided by a power source 240 (such as a voltage or current source) over the surface of the electrochromic stack 220 from the outer surface area of the stack to the inner surface area of the stack. As mentioned, the voltage applied to the electrochromic device experiences some ohmic potential drop from the outer region to the inner region due to the sheet resistance of the first conductive layer 230 and the second conductive layer 238. In the depicted embodiment, bus bars 242 and 244 are provided such that bus bar 242 is in contact with conductive layer 230 and bus bar 244 is in contact with conductive layer 238 to provide an electrical connection between voltage or current source 240 and conductive layers 230 and 238. For example, bus bar 242 may be electrically coupled to a first (e.g., positive) terminal 246 of power supply 240, while bus bar 244 may be electrically coupled to a second (e.g., negative) terminal 248 of power supply 240.

In some embodiments, IGU 102 includes plug-in component 250. In some embodiments, the insert component 250 includes a first electrical input 252 (e.g., a pin, socket, or other electrical connector or conductor) that is electrically coupled with the power terminal 246 via, for example, one or more wires or other electrical connections, components, or devices. Similarly, the insert component 250 may include a second electrical input 254 that is electrically coupled with the power terminal 248 via, for example, one or more wires or other electrical connections, components, or devices. In some embodiments, first electrical input 252 may be electrically coupled with bus bar 242 and from there with first conductive layer 230, while second electrical input 254 may be coupled with bus bar 244 and from there with second conductive layer 238. The conductive layers 230 and 238 may also be connected to the power supply 240 using other conventional components as well as other components described below with respect to the aperture controller. For example, as described below with reference to fig. 9, the first electrical input 252 may be connected to a first power line, while the second electrical input 254 may be connected to a second power line. Additionally, in some embodiments, the third electrical input 256 may be coupled to a device, system, or building floor. Further, in some embodiments, fourth and fifth electrical input/outputs 258 and 260, respectively, may be used for communication between, for example, a fenestration controller or a microcontroller and a network controller.

In some embodiments, electrical input 252 and electrical input 254 receive, carry, or transmit complementary power signals. In some embodiments, the electrical input 252 and its supplemental electrical input 254 may be directly connected to the bus bars 242 and 244, respectively, and on the other side to an external power source that provides a variable DC voltage (e.g., sign and magnitude). The external power source may be the aperture controller itself (see element 114 of fig. 9), or power from the building that is transmitted to the aperture controller or otherwise coupled to the electrical inputs 252 and 254. In such implementations, the electrical signals transmitted through electrical input/outputs 258 and 260 may be directly connected to the memory device to allow communication between the aperture controller and the memory device. Further, in such embodiments, the electrical signal input to electrical input 256 may be internally connected or coupled (within IGU 102) to electrical input 252 or 254 or to bus bars 242 or 244 in such a way as to enable the remote measurement (sensing) of the electrical potential of one or more of those elements. This may allow the aperture controller to compensate for the voltage drop on the connection line from the aperture controller to the electrochromic device 220.

In some implementations, the fenestration controller may be immediately attached (e.g., external to the IGU 102 but not detachable by the user) or integrated within the IGU 102. For example, U.S. patent application Ser. No. 13/049,750 (attorney docket No. SLDMP 008), filed by Brown et al as inventor at 2011, 3/16, and entitled "on-board controller for Multi-State fenestrations (ONBOARD CONTROLLER FOR MULTISTATE WINDOWS)", which is incorporated herein by reference in its entirety, describes various embodiments of an "on-board" controller in detail. In such embodiments, the electrical input 252 may be connected to a positive output of an external DC power source. Similarly, the electrical input 254 may be connected to a negative output of a DC power supply. However, as described below, the electrical inputs 252 and 254 may alternatively be connected to the output of an external low voltage AC power source (e.g., a typical 24VAC transformer common to the HVAC industry). In such embodiments, electrical input/outputs 258 and 260 may be connected to a communication bus between the aperture controller and the network controller. In this embodiment, the electrical input/output 256 may ultimately be connected (e.g., at a power source) to a ground (e.g., a protective ground or in european PE) terminal of the system.

While the applied voltage may be provided as a DC voltage, in some implementations, the voltage actually supplied by the external power source is an AC voltage signal. In some other embodiments, the supplied voltage signal is converted to a pulse width modulated voltage signal. However, the voltage actually "seen" or applied to the bus bars 242 and 244 is actually a DC voltage. Typically, the voltage oscillations applied at terminals 246 and 248 are in the range of about 1Hz to 1MHz, and in a particular embodiment, about 100kHz. In various implementations, the oscillation has asymmetric dwell times for darkened (e.g., colored) and lightened (e.g., transparent) portions of a certain period. For example, in some implementations, it takes more time to transition from a first, less transparent state to a second, more transparent state than would otherwise be the case; i.e. from a more transparent second state to a less transparent first state. As described below, the controller may be designed or configured to apply a drive voltage that meets these requirements.

The oscillation-applied voltage control allows electrochromic device 220 to operate in one or more states and transition to and from one or more states without any necessary modification to electrochromic device stack 220 or transition time. Rather, the aperture controller may be configured or designed to provide an oscillating drive voltage of an appropriate waveform in consideration of factors such as frequency, duty cycle, average voltage, magnitude, and other possible suitable or appropriate factors. In addition, this level of control allows transition to any state throughout the optical state range between the two end states. For example, a properly configured controller may provide a continuous range of transmittance (%t) that may be tuned to any value between end states (e.g., opaque and transparent end states).

To drive the device to an intermediate state using an oscillating drive voltage, the controller may simply apply the appropriate intermediate voltage. However, there may be a more efficient way to reach intermediate optical states. This is in part because a high drive voltage may be applied to reach the end state, but traditionally no high drive voltage is applied to reach the intermediate state. One technique for increasing the rate at which electrochromic device 220 reaches the desired intermediate state is to first apply a high voltage pulse suitable for full transition (to the end state) and then back-off to the voltage oscillating the intermediate state (just described). In other words, the transition may be accelerated with an initial low frequency single pulse (low compared to the frequency used to maintain the intermediate state) of a magnitude and duration selected for the intended final state. After this initial pulse, a higher frequency voltage oscillation may be employed to maintain the intermediate state for a desired period of time.

In some embodiments, each IGU 102 includes a component 250 that is "insertable" or easily removable (e.g., easily repaired, manufactured, or replaced) from IGU 102. In some particular embodiments, each insert member 250 itself includes a fenestration controller. That is, in some such embodiments, each electrochromic device 220 is controlled by its own respective local aperture controller located within the insert member 250. In some other embodiments, the aperture controller is integrated with another portion of the frame 218, between glass panes of the secondary sealing region or within the volume 226. In some other embodiments, the fenestration controller may be located external to the IGU 102. In various embodiments, each aperture controller may communicate with its controlling and driving IGU 102, as well as with other aperture controllers, network controllers, BMS, or other servers, systems, or devices (e.g., sensors) via one or more wired (e.g., ethernet) networks or wireless (e.g., wiFi) networks, such as via wired (e.g., ethernet) interface 263 or wireless (WiFi) interface 265. See fig. 9. Embodiments with ethernet or Wi-Fi capability are also well suited for use in residential and other smaller scale non-commercial applications. In addition, the communication may be direct or indirect, e.g., via an intermediate node between a master controller, such as network controller 112, and IGU 102.

Fig. 9 depicts a fenestration controller 114, which may be deployed as, for example, a component 250. In some embodiments, the aperture controller 114 communicates with the network controller via a communication bus 262. For example, the communication bus 262 may be designed according to a Controller Area Network (CAN) vehicle bus standard. In such embodiments, the first electrical input 252 may be connected to a first power line 264 and the second electrical input 254 may be connected to a second power line 266. In some embodiments, as described above, the power signals sent on power lines 264 and 266 are complementary; that is, they collectively represent a differential signal (e.g., a differential voltage signal). In some embodiments, line 268 is coupled to the system or building ground (e.g., ground). In such embodiments, communication over the CAN bus 262 (e.g., between the microcontroller 274 and the network controller 112) may proceed along the first and second communication lines 270 and 272, respectively, transmitted via the electrical input/outputs 258 and 260, respectively, according to the CANopen communication protocol or other suitable open, proprietary, or superimposed communication protocol. In some embodiments, the communication signals sent over communication lines 270 and 272 are complementary; that is, they collectively represent a differential signal (e.g., a differential voltage signal).

In some embodiments, the component 250 couples the CAN communication bus 262 into the aperture controller 114 and, in particular embodiments, into the microcontroller 274. In some such embodiments, the microcontroller 274 is further configured to implement a CANopen communication protocol. The microcontroller 274 is also designed or configured (e.g., programmed) to implement one or more drive control algorithms in conjunction with a pulse width modulated amplifier or Pulse Width Modulator (PWM) 276, intelligent logic 278, and signal conditioner 280. In some embodiments, the microcontroller 274 is configured to generate the command signal V, for example in the form of a voltage signal _Command Which is then transmitted to PWM 276.PWM (pulse Width modulation)276 are then based on V _Command Generating a pulse width modulated power signal comprising a first (e.g., positive) component V _PW1 And a second (e.g., negative) component V _PW2 . Then, the power signal V _PW1 And V _PW2 To IGU 102, or more specifically to bus bars 242 and 244, through, for example, interface 288, to create a desired optical transition in electrochromic device 220. In some embodiments, PWM 276 is configured to modify the duty cycle of the pulse width modulated signal such that signal V _PW1 And V _PW2 The duration of the pulses in (a) is not equal: for example, PWM 276 causes V to be _PW1 Pulsing at first 60% duty cycle and pulsing V _PW2 For the second 40% duty cycle pulse. The duration of the first duty cycle and the duration of the second duty cycle together represent the duration t of each power cycle _PWM . In some embodiments, PWM 276 may additionally or alternatively modify signal pulse V _PW1 And V _PW2 Is a magnitude of (2).

In some embodiments, the microcontroller 274 is configured to respond to one or more factors or signals (e.g., any signals received over the CAN bus 262 and the voltage or current feedback signal V generated by the PWM 276, respectively) _FB And I _FB ) Generating V _Command . In some embodiments, the microcontrollers 274 are each based on the feedback signal I _FB Or V _FB Determining a current or voltage level in electrochromic device 220 and adjusting V according to one or more rules or algorithms described above _Command To achieve a relative pulse duration (e.g. relative durations of first and second duty cycles) or power signal V _PW1 And V _PW2 To produce a voltage profile as described above. Additionally or alternatively, the microcontroller 274 may also adjust V in response to signals received from the intelligent logic 278 or the signal conditioner 280 _Command . For example, the signal conditioner 280 may be responsive to signals from one or more networked or non-networked devices or sensors (e.g., an external photosensor or photodetector 282, an internal photosensor or photodetector 284, a thermal or temperature sensor 286, or a hue command signal V _TC ) Generates the regulation signal V by feedback of (a) _{Regulation of} . For example, signal conditioner 280 and V _{Regulation of} Additional embodiments of (c) are also described in U.S. patent application Ser. No. 13/449,235, filed 4/17/2012, and previously incorporated by reference.

In certain embodiments, V _TC An analog voltage signal, which may be between 0V and 10V, that may be used or adjusted by a user (such as a resident or a staff member) to dynamically adjust the hue of IGU 102 (e.g., a user may use a controller in a room or area of building 104 similar to a thermostat to fine tune or modify the hue of IGU 102 in the room or area), thereby introducing dynamic user input into the determination of V _Command Logic within microcontroller 274. For example, when set in the range of 0 to 2.5V, V _TC Can be used to cause a transition to 5%T state, and when set in the range of 2.51 to 5V, V _TC May be used to facilitate the transition to the 20% t state and is similar for other ranges such as 5.1 to 7.5V and 7.51 to 10V, as well as other ranges and voltage examples. In some embodiments, the signal conditioner 280 receives the above signals or other signals through a communication bus or interface 290. In some embodiments, PWM 276 is also based on signal V received from intelligent logic 278 _SMART Generating V _Command . In some embodiments, intelligent logic 278 is implemented by, for example, an internal integrated circuit (I ² C) Communication bus transmission V of multi-host serial single-ended computer bus _SMART . In some other implementations, the intelligent logic 278 communicates with the memory device 292 via a 1-WIRE device communication bus system protocol (developed by Dallas Semiconductor company of dallas, texas).

In some embodiments, the microcontroller 274 comprises a processor, chip, card, or board, or a combination of these, including logic for performing one or more control functions. The power and communication functions of the microcontroller 274 may be combined in a single chip, such as a Programmable Logic Device (PLD) chip or a Field Programmable Gate Array (FPGA) or similar logic. Such integrated circuits may combine logic functions, control functions, and power functions in a single programmable chip. In one embodiment, where one pane 216 has two electrochromic devices 220 (e.g., on opposite surfaces) or IGU 102 includes two or more panes 216 each including electrochromic devices 220, logic may be configured to control each of the two electrochromic devices 220 independently of each other. However, in one embodiment, the function of each of the two electrochromic devices 220 is controlled in a coordinated manner, e.g., such that each device is controlled to supplement the other device. For example, a desired light transmission level, thermal insulation effect, or other property may be controlled via a combination of states of each of the individual electrochromic devices 220. For example, one electrochromic device may be placed in a colored state while the other is used for resistive heating, e.g., via the transparent electrode of the device. In another example, the optical states of the two electrochromic devices are controlled such that the combined transmittance is the desired result.

In general, the logic for controlling the electrochromic device transitions may be designed or configured in hardware and/or software. In other words, the instructions for controlling the drive circuitry may be hard coded or provided as software. The instructions may be said to be provided by "programming". This programming is understood to include any form of logic, including hard-coded logic in a digital signal processor and other devices having specific algorithms implemented as hardware. Programming is also understood to include software or firmware instructions that may be executed on a general purpose processor. In some implementations, instructions for controlling the application of voltages to the bus bars are stored on a memory device associated with the controller or provided over a network. Examples of suitable memory devices include semiconductor memory, magnetic memory, optical memory, and the like. The computer program code for controlling the applied voltages may be written in any conventional computer readable programming language, such as assembly language, C, C ++, pascal, fortran, and the like. The compiled object code or script is executed by the processor to perform the tasks identified in the program.

As described above, in some embodiments, the microcontroller 274 or aperture controller 114 may also generally have wireless capabilities, such as wireless control and power supply capabilities. For example, instructions may be sent to the microcontroller 274 using wireless control signals such as Radio Frequency (RF) signals or Infrared (IR) signals, as well as wireless communication protocols such as WiFi (as described above), bluetooth, zigbee, enOcean, etc., and the microcontroller 274 sends data to, for example, other aperture controllers, the network controller 112, or directly to the BMS110. In various embodiments, wireless communication may be used to at least one of program or operate electrochromic device 220, collect data or generally receive input from electrochromic device 220 or IGU 102, collect data or receive input from a sensor, and use fenestration controller 114 as a relay point for other wireless communications. The data collected from IGU 102 can also include count data, such as the number of times electrochromic device 220 has been activated (cycled), the efficiency of electrochromic device 220 over time, and other useful data or performance metrics.

The aperture controller 114 may also have wireless power capability. For example, the aperture controller may have one or more wireless power receivers that receive transmissions from one or more wireless power transmitters; and one or more wireless power transmitters that transmit power transmissions such that the aperture controller 114 is capable of wirelessly receiving power and wirelessly distributing power to the electrochromic device 220. Wireless power transfer includes, for example, induction, resonant induction, RF power transfer, microwave power transfer, and laser power transfer. For example, U.S. patent application Ser. No. 12/971,576[ SLDMP003], entitled "Wireless Power electrochromic Condition (WIRELESS POWERED ELECTROCHROMIC WINDOWS)" filed by the inventor and on 12 months 17 of 2010, incorporated herein by reference, details various embodiments of wireless power capability.

To achieve the desired optical transition, a pulse width modulated power signal is generated such that the positive component V is injected during a first portion of the power cycle _PW1 Supplied to, for example, bus bar 244, with negative component V _PW2 During a second portion of the power cycle, to, for example, bus bar 242.

In some cases, depending on the frequency (or conversely the duration) of the pulse width modulated signalBetween) which may result in bus 244 being substantially at V _PW1 Is floating by a fraction of the magnitude of the first duty cycle, which is determined by the duration of the first duty cycle and the total duration t of the power cycle _PWM Is given by the ratio of (2). Similarly, this may result in bus bar 242 being substantially at V _PW2 Is floating by a fraction of the magnitude of the second duty cycle, which fraction is determined by the duration of the second duty cycle and the total duration t of the power cycle _PWM Is given by the ratio of (2). In this way, in some embodiments, the pulse width modulated signal component V _PW1 And V _PW2 Is twice the effective DC voltage across terminals 246 and 248 and thus across electrochromic device 220. In other words, in some embodiments, V applied to bus bar 244 _PW1 Score (determined by the relative duration of the first duty cycle) and V applied to bus bar 242 _PW2 The difference between the fractions (determined by the relative duration of the second duty cycle) of (a) is the effective DC voltage V applied to the electrochromic device 220 _{Effective and effective} . Current I through load (electromagnetic device 220) _{Effective and effective} Substantially equal to the effective voltage V _{Effective and effective} Divided by the effective resistance (represented by resistor 316) or impedance of the load.

Those of ordinary skill in the art will also appreciate that this description applies to various types of drive mechanisms, including fixed voltage (fixed DC), fixed polarity (time-varying DC), or reversed polarity (AC, MF, RF power, etc. with DC bias).

The controller may be configured to monitor the voltage and/or current from the optically switchable device. In some embodiments, the controller is configured to calculate the current by measuring a voltage across a known resistor in the drive circuit. Other modes of measuring or calculating current may be employed. These modes may be digital or analog.

Other embodiments

Although the foregoing embodiments have been described in some detail for purposes of clarity of understanding, the described embodiments should be considered illustrative and not restrictive. It will be apparent to those of ordinary skill in the art that certain changes and modifications may be practiced within the scope of the appended claims. For example, while the drive profiles have been described with reference to electrochromic devices having planar bus bars, they are applicable to any bus bar orientation in which bus bars of opposite polarity are separated by a distance large enough to cause a significant ohmic voltage drop in the transparent conductor layer from one bus bar to another. Furthermore, although the drive profiles have been described with reference to electrochromic devices, they are applicable to other devices in which bus bars of opposite polarity are provided at opposite sides of the device.

Claims

1. A method of transitioning a set of optically switchable devices, the method comprising:

(a) Receiving a command to transition the set of optically switchable devices to an ending optical state, wherein the set of optically switchable devices includes a slowest optically switchable device and a faster optically switchable device, and wherein when the same drive voltage is applied to each optically switchable device in the set of optically switchable devices, the slowest optically switchable device transitions at a slower or equal transition speed than any other optically switchable device in the set of optically switchable devices;

(b) Transitioning the slowest optically switchable device to the ending optical state by applying a first drive voltage to the slowest optically switchable device; and

(c) During (b), transitioning the faster optically switchable device to the ending optical state by applying a second drive voltage to the faster optically switchable device, wherein the first drive voltage has a greater magnitude than the second drive voltage.

2. The method of claim 1, wherein the average transition speed of the faster optically switchable device and the average transition speed of the slowest optically switchable device are about the same during a period of time that begins when the command is received and ends when all optically switchable devices of the set of optically switchable devices reach the ending optical state.

3. The method of any of the preceding claims, wherein the faster and slowest optically switchable devices take approximately the same amount of time to transition to an intermediate optical state having an optical density between that of a starting optical state and that of the ending optical state before transitioning to the ending optical state.

4. A method according to any one of the preceding claims, wherein the second drive voltage generates a current having a signal to noise ratio greater than a specified standard.

5. The method of any of the preceding claims, wherein:

(b) And (c) applying a first ramp to the drive voltage to the slowest optically switchable device prior to applying the first drive voltage,

(c) Also included in the transition of (a) is applying a second ramp to the drive voltage to the faster optically switchable device prior to applying the second drive voltage, and

the first ramp to drive voltage has a faster ramp rate than the second ramp to drive voltage.

6. The method of any of the preceding claims, wherein:

When the open circuit voltage of the slowest optically switchable device reaches a first target open circuit voltage, determining that a transition of the slowest optically switchable device to the ending optical state is to be completed,

when the open circuit voltage of the faster optically switchable device reaches a second target open circuit voltage, determining that a transition of the faster optically switchable device to the ending optical state is to be completed, and

7. The method of any one of the preceding claims, wherein the slowest optically switchable device has a larger surface area than the faster optically switchable device.

8. The method of any one of the preceding claims, wherein (b) and (c) occur in about the same time period.

9. The method of any of the preceding claims, further comprising: information of the set of optically switchable devices is received and drive voltage data of the set of optically switchable devices is obtained.

10. The method of any one of the preceding claims, wherein a Bus Bar Distance (BBD) of the slowest optically switchable device is greater than a BBD of the faster optically switchable device.

11. The method of any of the preceding claims, wherein a Diagonal Bus Bar Distance (DBBD) of the slowest optically switchable device is greater than a DBBD of the faster optically switchable device.

12. The method of any one of claims 1-9, wherein the set of optically switchable devices includes a third optically switchable device, and wherein the third optically switchable device transitions faster than the faster optically switchable device when the same drive voltage is applied to the set of optically switchable devices, the method further comprising: during (b), transitioning the third optically switchable device to the ending optical state by applying a third drive voltage to the third optically switchable device, wherein the second drive voltage has a magnitude greater than the third drive voltage.

13. The method of claim 12, wherein a BBD of the slowest optically switchable device is greater than a BBD of the faster optically switchable device and the BBD of the faster optically switchable device is greater than a BBD of the third optically switchable device.

14. The method of claim 12, wherein the DBBD of the slowest optically switchable device is greater than the DBBD of the faster optically switchable device and the DBBD of the faster optically switchable device is greater than the DBBD of the third optically switchable device.

15. The method of any of the preceding claims, further comprising:

(d) A command to transition a second set of optically switchable devices to the ending optical state is received,

wherein the second group comprises a second group of slowest optically switchable devices and a second group of faster optically switchable devices, wherein when the same drive voltage is applied to each optically switchable device in the second group, the second group of slowest optically switchable devices transitions at a slower or equal transition speed than any other optically switchable device in the second group;

(e) Transitioning the second set of slowest optically switchable devices to the ending optical state by applying a third drive voltage to the second set of slowest optically switchable devices during (b); and

(f) During (b), transitioning the second set of faster optically switchable devices to the ending optical state by applying a fourth drive voltage to the second set of faster optically switchable devices, wherein the third drive voltage has a magnitude greater than the fourth drive voltage.

16. The method of claim 15, wherein the faster optical switchable device, the slowest optical switchable device, the second set of faster optical switchable devices, and the second set of slowest optical switchable devices reach the ending optical state at substantially the same time.

17. The method of any of the preceding claims, wherein the transition of the slowest optically switchable device is monitored using feedback obtained during the transition of the slowest optically switchable device.

18. The method of claim 17, wherein the feedback obtained during the transition of the slowest optically switchable device comprises one or more parameters selected from the group consisting of: an open circuit voltage, a current measured in response to the applied voltage, and a charge or charge density delivered to the slowest optically switchable device.

19. The method of claim 18, wherein the feedback obtained during the transition of the slowest optically switchable device comprises the open circuit voltage and the charge or charge density delivered to the slowest optically switchable device.

20. The method of claim 19, wherein the transition of the faster optically switchable device is monitored using feedback obtained during a transition of the faster optically switchable device.

21. The method of claim 20, wherein the feedback obtained during the transition of the faster optically switchable device comprises one or more parameters selected from the group consisting of: an open circuit voltage, a current measured in response to an applied voltage, and a charge or charge density delivered to the faster optically switchable device.

22. The method of claim 21, wherein the feedback obtained during the transition of the faster optically switchable device includes the charge or charge density delivered to the faster optically switchable device and does not include the open circuit voltage nor the current measured in response to an applied voltage.

23. The method of any of the preceding claims, further comprising applying a holding voltage to each device of the set of optically switchable devices when each device reaches the ending optical state.

24. The method of any of the preceding claims, further comprising:

in response to receiving a command to transition the set of optically switchable devices to a second ending optical state before the set of optically switchable devices reaches the ending optical state, the slowest optically switchable device and the faster optically switchable device are transitioned to the second ending optical state without any pauses.

25. The method of any of the preceding claims, wherein the faster optically switchable device transitions to the ending optical state without pausing.

26. The method of any of the preceding claims, further comprising determining a starting optical state of each optically switchable device of the set of optically switchable devices using feedback obtained from each optically switchable device before each optically switchable device begins to transition.

27. The method of claim 26, wherein the feedback obtained from each optically switchable device before each optically switchable device begins a transition comprises one or more parameters selected from the group consisting of: open circuit voltage, current measured in response to an applied voltage, and charge or charge density.

28. The method of claim 1, wherein the first drive voltage and the second drive voltage are selected based at least in part on the starting optical state.

29. A control system comprising one or more processors and a memory storing instructions that, when executed by the one or more processors, cause the control system to implement the method of any of the preceding claims.

30. A control system comprising one or more processors and a memory storing instructions that, when executed by the one or more processors, cause the control system to:

(a) Receiving a command to transition a set of optically switchable devices to an ending optical state, wherein the set of optically switchable devices includes a slowest optically switchable device and a faster optically switchable device, and wherein the slowest optically switchable device does not transition faster than any other optically switchable device in the set of optically switchable devices when the same drive voltage is applied to the set of optically switchable devices;

31. A computer program product comprising one or more non-transitory storage media having instructions stored thereon that, when executed by one or more processors of a control system, cause the control system to perform the method of any of claims 1-28.

32. A computer program product comprising one or more non-transitory storage media having instructions stored thereon, which when executed by one or more processors of a control system cause the control system to control a set of optically switchable devices, the instructions comprising:

(a) Receiving a command to transition the set of optically switchable devices to an ending optical state, wherein the set of optically switchable devices includes a slowest optically switchable device and a faster optically switchable device, and wherein the slowest optically switchable device does not transition faster than any other optically switchable device in the set of optically switchable devices when the same drive voltage is applied to the set of optically switchable devices;

(c) Transitioning the faster optically switchable device to the ending optical state during (b) by applying a second drive voltage to the faster optically switchable device, wherein

The first driving voltage has a magnitude greater than the second driving voltage.