Controlling transitions in optically switchable devices

Electrochromic is a phenomenon where a material exhibits an optical property and a reversible electrochemical mediator change when placed in a different electronic state (usually by subjecting it to a voltage change). The optical properties are usually one or more of color, transmittance, absorptivity, and reflectivity. Electrochromic devices can be incorporated into many types of optical structures, including windows and mirrors. The optical state of these devices is switched by an electrochemical transformation.

A well-known electrochromic material is tungsten oxide (WO₃). Tungsten oxide is a cathodic electrochromic material in which a color transition (transparent to blue) occurs through electrochemical reduction.

Although electrochromic was discovered in the 1960s, electrochromic devices still unfortunately suffer from various problems and have not yet begun to realize their full commercial potential. Part of the difficulty is that the operating mode of electrochromic devices lacks universality. In addition, known control systems for electrochromic devices have limited functionality and cannot take into account certain unique features of electrochromic devices.

The various embodiments disclosed herein relate to controllers for windows with switchable optical devices and other optical components. It also discloses a method of switching the optical state in the optical component. An example of a switchable optical device is an electrochromic device. Other examples include liquid crystal devices and suspended particle devices.

In various instances, the controller or control method is designed or configured to operate without information about the current temperature of the device and/or the environment of the device. In addition, in some cases, the controller or control method is designed or configured to control the transition of an optical device to an intermediate state between two terminal states. For example, the controller can be configured to control a transition to a transmittance state between two ultimate transmittance states. In this case, the device has three or more stable transmittance states.

One aspect of the present invention relates to a method of causing one of the optical states in a switchable optical device to change. These methods can be characterized by the following operations: (a) controlling the current to the switchable optical device during an initial part of a transition from a first optical state to a second optical state; and (b) in the first optical state A later part of the transition from an optical state to the second optical state controls the voltage applied to the switchable optical device so that the magnitude of the voltage remains substantially at a predetermined level. The current control operation in (a) involves correcting the current to the switchable optical device when the magnitude of the current exceeds a safe current level defined by an upper limit or fails to meet a fast switching current level defined by a lower limit. In some embodiments, this is achieved by applying a voltage ramp to the switchable optical device and adjusting the voltage ramp if necessary to maintain the current at the safe current level defined by the upper limit and the fast current level defined by the lower limit. Switch between current levels to achieve. In other cases, this is achieved by applying an initial current to the switchable optical device and adjusting the initial current if necessary. In some cases, the methods include the following further operations: (c) after (b), the magnitude of the voltage applied to the switchable optical device is reduced to decrease the value in the switchable optical device One level of leakage current.

In a specific embodiment, the control of the current in (a) is performed for a period between about 2 minutes and 30 minutes. In addition, in certain specific embodiments, the safe current level defined by the upper limit is about 70 μA/cm²With 250 μA/cm²between. The fast switching current level defined by the lower limit can be between about 30 μA/cm²With 70 μA/cm²between. In a further specific embodiment, the control of the voltage in (b) is performed for a period between about 2 minutes and 30 minutes.

In many implementations , the temperature of the switchable optical device is not detected during at least the initial portion of the transition. In some embodiments, the switchable optical device is an electrochromic device. Although not so limited, the change in the optical state can be an intermediate optical state between the two ultimate optical states of the switchable optical device.

Another aspect of the present invention relates to a controller for controlling the change of one of the optical states in a switchable optical device. These controllers can be characterized by: (a) one or more interfaces that provide control commands, a driving voltage and/or a driving current to the switchable optical device; and (b) commands for Control the change of the optical state. The instructions may include: (i) controlling the current to the switchable optical device during an initial part of a transition from a first optical state to a second optical state, wherein the current is controlled by when the current When the magnitude exceeds the safe current level defined by an upper limit or fails to meet the fast switching current level defined by the lower limit, it is corrected to the current of the switchable optical device to achieve; and (ii) from the first optical state to A later part of the transition of the second optical state controls the voltage applied to the switchable optical device so that the magnitude of the voltage remains substantially at a predetermined level.

When the switchable optical device is an electrochromic device, the current and voltage levels specified in the instructions are defined for an electrochromic device. Other features of the controller may include instructions to implement one or more of the method operations described above. For example, the current and/or voltage levels specified in the instructions need not take into account the temperature of the switchable optical device during at least the initial portion of the transition. As another example, the instructions can specify a change from the optical state to an intermediate optical state between the two final optical states of the switchable optical device.

Another aspect of the invention relates to a method of causing a switchable optical device to transition to an intermediate optical state, the intermediate optical state being between the two ultimate states of the switchable optical device. These methods involve applying an oscillating voltage to the switchable optical device, wherein the oscillating voltage has an average voltage associated with the intermediate optical state, and wherein the oscillating voltage is substantially uniformly experienced over the surface of the switchable optical device Average voltage.

As an example, the oscillating voltage has a frequency of about 1 E3 Hz and 1E-5 Hz. As a further example, the oscillating voltage has an amplitude of about 0.01 volt to 1 volt.

In certain embodiments, the methods further include applying a voltage pulse to an operation of the switchable optical device prior to applying the oscillating voltage, wherein the voltage pulse has a substantially larger value than that associated with the intermediate optical state. A magnitude of the average voltage, and wherein the application of the voltage pulse substantially increases the speed at which the switchable optical device transitions to the intermediate optical state. In a specific example, the voltage pulse has a duration between about 5 minutes and 15 minutes. In a further specific example, wherein the voltage pulse has a magnitude between about 1 volt and 7 volts.

In some methods, there may be an additional operation of applying a second oscillating voltage to the switchable optical device, wherein the second oscillating voltage has a second average voltage associated with a second intermediate optical state, and Wherein applying the second oscillating voltage causes the device to transition to the second intermediate optical state.

Generally, the switchable optical device includes one or more bus bars for delivering voltage to the device, wherein the bus bars are located at one or more edges of the device and not in a central area of the device. Generally, the switchable optical device includes one or more transparent electrodes having a sheet resistance of at least about 5 ohms per square. In various embodiments, the switchable optical device is an electrochromic device.

Another aspect of the present invention relates to a controller for controlling a change in a switchable optical device to an intermediate optical state, wherein the controller is characterized by the following characteristics: (a) one or more interfaces, which It is used to provide a control command, a driving voltage and/or a driving current to the switchable optical device; and (b) a command which is used to control the change of the optical state. The instructions include applying an oscillating voltage to the switchable optical device, wherein the oscillating voltage has an average voltage associated with the intermediate optical state, and wherein the oscillating voltage is substantially uniformly experienced over the surface of the switchable optical device Average voltage.

As discussed in the above method embodiments, the switchable optical device controlled by the controller may include one or more bus bars for delivering voltage to the device, and the bus bars are located on one or more of the devices. At the edge and not in one of the central areas of the device. In addition, the switchable optical device may include one or more transparent electrodes having a sheet resistance of at least about 5 ohms per square.

When the switchable optical device is an electrochromic device, the characteristics of the oscillation specified in the instructions are defined for an electrochromic device. Other features of the controller may include instructions to implement one or more of the method operations just described above. For example, the instructions can specify that the oscillating voltage has a frequency of about 1 E3 Hz and 1E-5 Hz. In another example, the instructions may specify that the oscillating voltage has an amplitude of about 0.01 volt to 1 volt.

In yet another example, the instructions further include instructions for applying a voltage pulse to the switchable optical device before applying the oscillating voltage, wherein the voltage pulse has substantially greater than the average voltage associated with the intermediate optical state A magnitude, and wherein the application of the voltage pulse substantially increases the speed at which the switchable optical device transitions to the intermediate optical state. In some embodiments, the voltage pulse has a duration between about 5 minutes and 15 minutes. In some embodiments, the voltage pulse has a magnitude between about 1 volt and 7 volts.

Hereinafter, these and other features and advantages of the present invention will be described in more detail with reference to the associated drawings.

<i>Introduction and overview</i>

A switchable optical device, such as an electrochromic device, reversibly cycles between two or more optical states, such as a faded state and a colored state. Switching between these states is controlled by applying a predefined current and/or voltage to the device. The device controller usually includes a low-voltage power supply and can be configured to operate in conjunction with radiation and other environmental sensors, but these radiation and other environmental sensors are not required in various embodiments. The controller can also be configured to interface with an energy management system, such as the energy management system based on factors such as the time of the year, the time of the day, safety conditions and measured environmental conditions to control the electromotive force One of the color changing devices is a computer system. This energy management system can significantly reduce the energy consumption of a building.

FIG. 1 shows a current curve of an electrochromic window that uses a simple voltage control algorithm to cause an optical state of an electrochromic device to change (eg, color). In this curve, the ion current density (I) is expressed as a function of time. Many different types of electrochromic devices will have the drawn current curve. In one example, a cathode electrochromic material such as tungsten oxide is used in combination with a nickel tungsten oxide counter electrode. In these devices, negative current indicates the coloring of the device. The specific drawn curve is generated by ramping the voltage to a set level and then maintaining the voltage to maintain the optical state.

The current peak 101 is associated with changes in the optical state (ie, coloring and fading). In particular, these current peaks represent the delivery of charge required to color or fade the device. Mathematically, the shaded area below the peak represents the total change required to tint or fade the device. The portion of the curve after the initial current spike (section 103) represents the leakage current when the device is in the new optical state.

In this figure, a voltage curve 105 is superimposed on the current curve. The voltage curve is in the following sequence: negative ramp (107), negative hold (109), positive ramp (111), and positive hold (113). 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 107 drives the device to its new colored state and the voltage holding 109 maintains the device in the colored state until the voltage ramp 111 in the opposite direction drives the transition from the colored state to the faded state. In some switching algorithms, a current upper limit is imposed. That is, the current is not allowed to exceed a defined level in order to prevent damage to the device.

The speed of coloring is not only a function of applied voltage, but also a function of temperature and voltage ramp rate. Since both voltage and temperature affect lithium diffusion, the amount of charge transferred (and therefore the intensity of this current peak) increases with voltage and temperature, as indicated in FIG. 2. In addition, by definition, voltage and temperature are dependent, which means that a lower voltage can be used at a higher temperature to obtain the same switching speed as a higher voltage at a lower temperature. This temperature response can be used in a voltage-based switching algorithm, but the temperature needs to be actively monitored to change the applied voltage. Use temperature to determine which voltage to apply in order to achieve fast switching without damaging the device.

Figure 2 shows a series of Q vs. T (charge vs. temperature) curves for a specific voltage. More specifically, the figure shows the effect of temperature on how much charge is transferred to an electrochromic device after a fixed period of time has elapsed when a fixed temperature is applied. As the voltage increases, the amount of charge transferred increases for a given temperature. Therefore, for a desired amount of charge to be transferred, any voltage in a voltage range can be appropriate, as shown by the horizontal line 207 in FIG. 2. And it is clear that simply controlling the voltage will not guarantee that the change in the optical state will occur within a predefined period of time. The device temperature strongly affects the current at a specific voltage. Of course, if the temperature of the device is known, the applied voltage can be selected to drive the color change during the desired time period. However, in some cases, it is impossible to reliably determine the temperature of the electrochromic device. Although the device controller usually knows how much charge is needed to switch the device, it may not know the temperature.

If an excessively high voltage or current is applied to the temperature of the electrochromic device, the device may be damaged or degraded. On the other hand, if a too low voltage or current is applied to the temperature, the device will switch too slowly. Therefore, it would be desirable to have a controlled current and/or voltage early in the coloring state change. Keeping this idea in mind, a disclosed program controls charge (in the form of current) without being restricted to a specific voltage.

<i>Use of controlled current for initial phase transition</i>

Some of the control procedures described in this article can be implemented by imposing the following constraints on the device during an initial transition: (1) A defined amount of charge is transferred between the device electrodes to cause a complete optical transition; (2) The charge is transferred within a defined time frame; (3) the current does not exceed a maximum current; and (4) the voltage does not exceed a maximum voltage.

According to various embodiments described herein, a single algorithm is used to switch an electrochromic device regardless of temperature. In one example, a control algorithm involves: (i) controlling the current rather than the voltage during an initial switching period in which the ion current is significantly greater than the leakage current; (ii) during this initial period, using a current-time correlation Performance, so that the device can switch quickly enough at low temperatures without damaging the part at higher temperatures.

Therefore, during the transition from one optical state to another, a controller and associated control algorithm ensure that the switching speed is sufficiently fast and the current does not exceed a value that would damage the device to control the current to the device. In addition, in various embodiments, the controller and the control algorithm implement switching in two stages: a first stage, which controls the current until it reaches a defined point before the switching is completed; and a second stage, which After the first stage, the voltage applied to the device is controlled.

The various embodiments described herein can generally be characterized by the following three-type regime methodology.

1. Control the current to maintain it within a limited current range. This is only performed for a short period of time during the initial period of the change in the optical state. It is intended to protect the device from damage due to high current conditions, while ensuring that sufficient current is applied to permit rapid changes in state. Usually, the voltage during this stage stays within one of the maximum safe voltages of the device. In some embodiments using residential or architectural glass, this initial controlled current phase will last about 3 minutes to 4 minutes. During this phase, the current curve is relatively flat, and the change is not greater than (for example) about 10%.

2. After the initial controlled current phase is completed, transition to a controlled voltage phase in which the voltage remains at a substantially fixed value until the optical transition is completed, that is, until sufficient charge is delivered to complete the optical transition. Generally, the transition from state 1 to state 2 (controlled current to controlled voltage) is triggered by reaching a defined time from the start of the switching operation. However, in alternative embodiments, the transition is achieved by reaching a predefined voltage, a predefined amount of transferred charge, or some other criterion. During the controlled voltage phase, the voltage can be maintained at a level that does not vary more than about 0.2 V.

3. After completing the second phase, usually when the optical transition is completed, the voltage is reduced in order to minimize the leakage current while maintaining the new optical state. The transition to the third stage can be triggered by, for example, reaching a defined time from the start of the switching operation. In other examples, the transition is triggered by delivering a predefined amount of charge.

3A and 3B show current and voltage curves generated from a specific control method according to some embodiments. Figure 3C provides a flow chart associated with an initial part (controlled current part) of a control sequence. For discussion purposes, it is assumed that the negative current shown in these figures (as in Figure 1) drives the fade-to-color transition. Of course, this example is equally applicable to devices that operate the opposite way, that is, devices that use anode electrochromic electrodes.

In this particular instance, the following procedure was followed:

1. At time 0-the voltage is ramped up at a rate that is intended to correspond to a current level "I target" 301. See block 351 of Figure 3C. See also one of the voltage ramps 303 in FIG. 3A. I target can be set a priori for the device in question-independent of temperature. As mentioned, the control method described here can be beneficially implemented without knowing or inferring the temperature of the device. In an alternative embodiment, the temperature is detected and the temperature is considered when setting the current level. In some cases, the temperature can be inferred from the current-voltage response of the window.

In some examples, the ramp rate is between about 10 μV/s and 100 V/s. In more specific examples, the ramp rate is between about 1 mV/s_ and _500 mV/s.

2. Immediately after t0, usually within a few milliseconds, the controller determines the current level generated from the voltage application in operation 1 and compares it with the limit at the lower end by I slow and the upper end by I safe One of the limits is the acceptable current range. I safe is higher than the current level at which the device can be damaged or degraded. I slow is lower than the current level at which the device will switch at an unacceptably slow rate. As an example, the I target in the electrochromic window can be about 30 μA/cm²With 70 μA/cm²between. In addition, the range of a typical example of I slow is about 1 μA/cm²With 30 μA/cm²And the range of I safe instance is between about 70 μA/cm²With 250 μA/cm²between.

The voltage ramp is set and adjusted if necessary to control the current and usually produces a relatively consistent current level in the initial stage of the control sequence. This is illustrated by the flat current curve 301 as shown in FIGS. 3A and 3B. The flat current curve 301 is included between the levels I safe 307 and I slow 309.

3. Depending on the result of the comparison in step 2, the control method adopts one of the following operations (a) to (c). Note that the controller is not only immediately after t₀Then check the current level, and it is at t₀The current level is then frequently checked and adjustments are made, as explained here and as shown in Figure 3C.

a. The measured current is between I slow and I safe continue to apply a voltage that maintains the current between I slow and I safe. See the circles defined by boxes 353, 355, 359, 369, and 351 of Figure 3C.

b. The measured current is lower than I slow (usually because the device temperature is low) continue to ramp up the applied voltage so that the current is higher than I slow but lower than I safe. See the circles of boxes 353 and 351 in Figure 3C. If the current level is too low, it may be appropriate to increase the rate of increase of the voltage (that is, increase the steepness of the voltage ramp).

As indicated, the controller usually actively monitors the current and voltage to ensure that the applied current remains above I slow. In one example, the controller checks the current and/or voltage every few milliseconds. It can adjust the voltage on the same time scale. The controller can also ensure that the newly increased level of the applied voltage remains below V safe. V safe is the maximum applied voltage value, over which the device may be damaged or degraded.

c. The measured current is higher than I safe (usually because the device is operating at a high temperature) reduce the voltage (or the rate of increase of the voltage) so that the current is lower than I safe but higher than I slow. See blocks 355 and 357 of Figure 3C. As mentioned, the controller can actively monitor current and voltage. Therefore, the controller can quickly adjust the applied voltage to ensure that the current stays below I safe during the entire controlled current phase of the transition. Therefore, the current should not exceed I safe.

It should be understood that the voltage ramp 303 can be adjusted or even temporarily stopped when necessary to maintain the current between I slow and I safe. For example, when in a controlled current pattern, the voltage ramp can be stopped, reversed in direction, slowed down in rate, or increased in rate.

In other embodiments, the controller increases and/or decreases current instead of voltage when needed. Therefore, the above discussion should not be seen as limited to options for ramping up the voltage or otherwise controlling the voltage to maintain the current in the desired range. Regardless of hardware control of voltage or current (constant potential or constant current control), the algorithm obtains the desired result.

4. Maintain the current in the target range (between I slow and I safe) until a specified criterion is met. In one example, the criterion is to deliver current for a defined length of time t1, at which time the device reaches a defined voltage V1. After reaching this condition, the controller immediately changes from the controlled current to the controlled voltage. See blocks 359 and 361 in Figure 3C. Note that V1 is a function of temperature, but as mentioned, there is no need to monitor or even detect temperature according to various embodiments.

In some embodiments, t1 is about 1 minute to 30 minutes, and in some specific examples, t1 is about 2 minutes to 5 minutes. In addition, in some cases, the magnitude of V1 is about 1 volt to 7 volts, and more specifically, about 2.5 volts to 4 volts.

As mentioned, the controller continues in the controlled current phase until a specified condition is met, such as a defined period of time elapsed. In this example, a timer is used to trigger the transition. In other examples, the specified condition is to reach a defined voltage (for example, a maximum safe voltage) or to transfer a defined amount of charge.

Operations 1 to 4 correspond to the type 1-controlled current in the above general algorithm. The goal during this phase is to prevent the current from exceeding a safe level while ensuring a reasonably fast switching speed. It is possible that during this mode, the controller can supply the electrochromic device with a voltage exceeding the maximum safe voltage. In some embodiments, this problem is eliminated by using a control algorithm in which the maximum safety value is much larger than V1 across the operating temperature range. In some instances, I target and t1 are selected so that V1 is sufficiently below the maximum voltage at lower temperatures, while not degrading the window due to excessive current at higher temperatures. In some embodiments, the controller includes a safety feature that will alert the window before reaching the maximum safety voltage. In a typical example, the value of the maximum safe voltage of an electrochromic window is between about 5 volts and 9 volts.

5. Maintain the voltage at a defined level V2 until another specified condition is met, such as reaching a time t2. See voltage section 313 in FIG. 3A. Generally, time t2 or other specified conditions are selected so as to deliver a desired amount of charge sufficient to cause the desired change in coloration. In one example, the specified condition is to deliver a pre-specified amount of charge. During this phase, the current may gradually decrease, as illustrated by the current curve segment 315 in FIGS. 3A and 3B. In a specific embodiment, V2=V1, as shown in FIG. 3A.

This operation 5 corresponds to the above type 2-controlled voltage. One of the goals during this stage is to maintain the voltage at V1 for a sufficient length to ensure a desired coloring speed.

In some embodiments, t2 is about 2 minutes to 30 minutes, and in some specific examples, t2 is about 3 minutes to 10 minutes. In addition, in some cases, V2 is about 1 volt to 7 volts, and more specifically about 2.5 volts to 4 volts.

6. After the condition of step 5 is reached (ie, after sufficient charge has been delivered or a timer indicates that t2 has been reached), the voltage is reduced from V2 to one level V3. This reduces leakage current while maintaining the colored state. In a specific embodiment, the transition time t2 is predetermined and selected based on the time required for the center of the part (which is the slowest coloring) to achieve a certain percentage of transmittance. In some embodiments, t2 is between about 4 minutes and 6 minutes. This operation 6 corresponds to type 3 above.

The following table presents a specific example of the algorithm described above.

<img file="TW201248286A_D0001.tif" />

Definition of parameters:

I0-the target current value between I slow and I safe

V0-corresponds to the current I₀Voltage

T0-current = I0 time.

I1-The current at time t1. I1=I0

V1-Voltage at time t1. The voltage ramps from V0 to V1 between t0 and t1 and is a function of temperature.

t1- The time to maintain the current between I slow and I safe (for example, about 3 minutes to 4 minutes)

I2-Current at time t2. When the sustain voltage is at V1, the current decays from I1 to I2.

V2-The voltage at time t2. V1=V2.

t2-The time to maintain the voltage V1. It can be between about 4 minutes to 6 minutes from t1. After t2, the voltage drops from V2 to V3

The holding voltage between V3-t2 and t3.

I3-The current corresponding to the voltage V3.

t3-The time when the status change request is received.

<i>Intermediate state control using oscillation drive</i>

Another aspect of the invention relates to controlling the transition between optical states in a switchable optical device such as an electrochromic device to produce uniform coloration across the face of the device. It is particularly suitable for controlling the intermediate state between the high state and the low state. In other words, it is suitable for controlling a control device having at least three states (for example, an opaque state, a transparent state, and an intermediate optical state between opaque and transparent). For example, a single electrochromic device can be designed to have 4% transmittance (Tvis) in its opaque state, 62% transmittance in its faded state, and 40% transmittance in its intermediate state .

Before discussing the details of related control mechanisms, several challenges of switching between optical states will be discussed. One challenge involves the rapid transition between optical states. Another challenge involves the uneven transition over the area of the electrochromic device.

Large electrochromic devices (such as those on residential windows or architectural glass) can exhibit one of the effects sometimes referred to as "end effects." This is due to the relatively high sheet resistance of the thin electrochromic device film (including electrodes) coupled to the device design with the end (bus bar) located outside the visible area of the substrate (for example, only at the edge of the device/substrate) . In these devices, there is a considerable "ohmic" potential drop (and accompanying Leakage current). Therefore, not only does the central area of the device turn slower than the edge area near the end contacts, but the central area may never completely change. In other words, it can only be transformed to a limited extent compared to the edge. In addition, when the center of the device changes, it becomes slower than the edge of the device. In addition, once a transition state is reached in the center of the device, it can be difficult to maintain this state. These edge-to-center non-uniformities can be noticed and annoying by the user.

These challenges are especially significant when transitioning to an intermediate state. In the final state of the device (eg, completely opaque and completely faded), these challenges can be overcome at least in part by applying a terminal voltage that is significantly greater than the terminal voltage required to cause the transition to the optical terminal state at the terminal. In other words, the applied terminal voltage is of a sufficiently high magnitude such that the ohmic drop can be overcome and the voltage across the device surface is sufficiently large to permit a complete transition to the terminal state even at the center of the device. Unfortunately, this is not possible for an intermediate state, which may require a voltage in the middle of the voltage of the final state.

In some embodiments, these challenges can be overcome by applying an oscillating end voltage to the electrochromic device. The speed at which the device follows an oscillating drive voltage is much faster at the edge of the device (near the end (for example, the bus bar)) than at the center of the device (away from the bus bar). However, the average or average magnitude of the applied voltage will be the same or almost the same at the center and the edges of the device. Therefore, in certain embodiments in which the voltage applied at the end of the device (e.g., bus bar) oscillates, the amount of charge applied to achieve an optical transition is substantially the same at the center and the edges of the device.

Figure 4A graphically compares the voltage uniformity (or non-uniformity) across the surface of an electrochromic device for a non-oscillating drive voltage and an oscillating drive voltage applied to maintain an intermediate optical state. The horizontal axis represents the position on the surface of the electrochromic device, where points 401 and 401' represent the edge of the device where the electrical connector (for example, bus bar) is attached to the device. The position 403 represents the center of the device, that is, the position farthest from the connector. The vertical axis represents the local voltage experienced by the device and generated from an applied voltage at one of the connectors. Therefore, the voltage at positions 401 and 401' is actually the voltage applied by the connector. As can be seen, a voltage curve 407 associated with a non-oscillating drive potential drops to a relatively low value at the center of the device. As explained, this is due to the ohmic potential drop and leakage current across the cross-domain device. It causes one of the perceptible inhomogeneities in the coloration of the cross-domain device-even long after a stable state is established.

In contrast, a voltage curve 409 associated with an oscillating drive potential is substantially uniform across the device surface. Although the oscillation period of the optical density is significantly larger in the center of the device (see illustration 411) than at the edge (see illustration 413), the average voltage is substantially constant from the edge to the center. Therefore, although the time response is much slower at the center of the device, the voltage amplitudes at the center and edges are similar.

FIG. 4B shows modeled data of a device in which the applied voltage is repeatedly pulsed between coloring and fading to produce zero net optical density change. It can be seen that the optical density of the device can be controlled to an optical density of about 0.4 from about 400 seconds onwards. The associated voltage algorithm is shown in Figure 4C.

The frequency of oscillation will depend on various factors, including the leakage current of the device, the sheet resistance of the device electrode, the desired end state (eg,% Tvis), and the critical length of the component (ie, the distance between the bus bars). Generally, the voltage oscillation applied at the connector is between about 1 E3 Hz and 1E-6 Hz, more specifically between 1 Hz and 1E-5 Hz, and even more specifically between about 1E- Between 2 Hz and 1E-4 Hz. The amplitude of the oscillation will depend on many factors, including the desired level of the intermediate state. However, as a rough example, the amplitude of the applied oscillation is between about 0.01 volt and 1 volt, and in an example of a more specific range, it is between about 0.1 volt and 0.5 volt. In various embodiments, the oscillation has an asymmetric residence time for the colored and faded portions of a cycle (ie, the rising and falling portions of an oscillation are asymmetric). In a particular embodiment, the faded part of a cycle requires more time than the colored part of the same cycle. A controller as described herein can be designed or configured to apply a driving voltage that meets these needs.

This oscillation applied voltage control allows a device to operate in one or more intermediate states without any modification of device stacking or switching time. It simply requires the controller to be configured or designed to provide an oscillating driving voltage of an appropriate wave profile (including frequency, amplitude, duty cycle, average voltage, etc.). It should also be understood that this control bit allows any intermediate state within the range of the complete optical state between the two ultimate states to be generated. For example, a properly configured controller will provide a continuous transmittance (% Tvis) range that can be tuned to any value between the ultimate state.

This aspect of the present invention is particularly beneficial when used together with large-format buildings or residential windows on which electrochromic devices are made (especially when the sheet resistance of the device electrodes is about 1 ohm/square or greater (or about 3 ohm/ Square or more, or about 10 ohms/square or more). It is expected that the device benefiting from this control program will have a sheet resistance between about 1 ohm/square and 20 ohm/square. Of course, the critical dimension (the distance between the ends) will also strongly affect the need for the applied voltage for an oscillation. Devices with a critical dimension of at least about 50 cm will generally benefit from the control algorithm described.

In order to use the oscillating driving voltage to drive the device to an intermediate coloring state (as explained above), a controller can simply apply an appropriate intermediate voltage. However, it has been found that by doing so, the time to reach the intermediate colored state can be quite slow (at least compared to the time required to reach the final colored state). This is partly due to the fact that high voltage can be applied to reach the final state but not high voltage to reach an intermediate state.

One technique for increasing the speed at which the device reaches the intermediate state is to first apply a high voltage pulse suitable for full coloring (in an ultimate state) and then return to the oscillating intermediate state (explained just now). In other words, an initial low-frequency single pulse (lower than the frequency used to maintain the intermediate state) of one of the magnitude and duration selected for a given final state can be used to accelerate the transition. After this initial pulse, a higher frequency voltage oscillation can be used to make the intermediate state last for the desired time.

FIG. 4D shows an example of an applied voltage curve 421 for quickly transitioning to an intermediate state. As shown, first an initial voltage pulse 423 of substantially the same magnitude as the voltage pulse applied to reach a terminal state is applied. Thereafter, the applied voltage is reduced to a level 425 corresponding to the level of the desired intermediate state. In a specific embodiment, the applied voltage at this level is delivered in an oscillating manner, as described above. Although one of the oscillating voltages centered on the level 425 is indistinguishable from Figure D, it may exist. In various embodiments, the oscillation frequency can be much lower than the initial pulse frequency, for example, between 1 switch/minute and 1 switch/hour, depending on the size and the desired end state. As mentioned, the oscillation can be asymmetric.

In some cases, the total duration of the initial high-voltage pulse used to reach the intermediate state using this control sequence is usually between about 1 minute and 30 minutes, or more specifically, between about 3 minutes and 15 minutes. Time, or even more specifically between about 8 minutes and 11 minutes. Of course, the duration will depend on the desired final state (coloring level of the intermediate state), device size, leakage current, etc. In addition, in some cases, the magnitude of this initial pulse is (on average) about 1 volt to 7 volts, and more specifically about 1 volt to 4 volts. Of course, the coloring threshold, sheet resistance, coloring speed, and leakage current characteristics will vary from system to system, so these equivalent values and other characteristics are not intended to be limiting.

It has been observed that the intermediate state coloring time can be about 4x for a control sequence that does not use an initial high-voltage pulse, compared to a control sequence using this pulse.

It should be noted that a control algorithm (such as the one presented in Figure 4D) permits a relatively uniform edge-to-center optical transition between states. Higher voltage produces faster switching, but also enlarges the unevenness between the center and the edges. On the other hand, lower voltages produce slower switching, but more uniform transitions. By carefully choosing the magnitude of an initial applied voltage pulse, the optical transition in the electrochromic device achieves a balance between uniformity and speed.

In some applications, an initial voltage pulse may not allow sufficient control to achieve the desired intermediate state in a short time frame. As discussed above, when the applied voltage is high, the device will achieve higher coloration and faster switching time, and when the applied voltage is low, the device will achieve lower coloration (closer to the desired intermediate state), but It takes a much longer switching time. This is true for all types of electrochromic devices including devices in which the frequency of optical density changes at the center of the device is faster than, equal to, or slower than the edge of the device. However, by understanding the local efficiency of the device and the frequency at which the optical density changes at the positions of the highest optical density and the lowest optical density, it can be determined that the entire electrochromic device will be allowed to be much faster than it would be possible by applying a fixed voltage The ground reaches an intermediate state, the amplitude and frequency of the oscillating voltage.

<i>Controller for electrochromic device</i>

As indicated, the switchable optical device will have an associated controller, such as a microprocessor that controls and manages the device depending on the input. It is designed or configured (eg, programmed) to implement one of the types of control algorithms described above. In various embodiments, the controller detects the current level in the device and applies the voltage appropriately. The controller can also detect the voltage level to ensure that the optical device stays within a safe voltage level. In addition, the controller may have various additional features, such as a timer, a charge detector (for example, a coulomb counter), an oscillator, and so on.

In some embodiments, the controller is located outside the device and communicates with the device via a network. The communication can be direct or indirect (for example, via an intermediate node between a host controller and the device). This communication can be done via a wired or a wireless connection. Various configurations of external controllers are presented in the US patent application No. 13/049,756 filed on March 16, 2011 with Brown et al. as the inventor and titled "Multipurpose Controller for Multistate Windows". The full citation method is incorporated into this article.

In an embodiment, the controller is integrated with the optical device or housing. In a specific embodiment, the controller is integrated in a housing or an insulating glass unit (IGU) seal containing a switchable optical device. The various configurations of the integrated controller are presented in US Patent Application No. 13/049,750 filed on March 16, 2011 and titled "Onboard Controller for Multistate Windows", which is incorporated herein by reference in its entirety. middle.

In one embodiment, the controller includes various components as shown in FIG. 5. As shown, a controller 501 includes a power converter configured to convert a low voltage to the power requirements of an EC device of an EC pane of an IGU. This power is usually fed to the EC device via a driver circuit (power driver). In one embodiment, the controller 501 has a redundant electric drive, so that in the event of a failure, there is a backup and the controller does not need to be replaced or repaired.

The controller 501 also includes a communication circuit for receiving commands from a remote controller (shown as the "main controller" in FIG. "Communications"). The communication circuit is also used to receive input from a microcontroller and send input to the microcontroller. In one embodiment, power lines are also used (for example) to send and receive communications via protocols such as Ethernet. The microcontroller includes a logic for controlling at least one EC pane based at least in part on input received from one or more sensors. In this example, the sensors 1 to 3 are (for example) outside the controller 501, for example, in or close to the window frame. In one embodiment, the controller has at least one or more internal sensors. For example, the controller 501 may also have or alternatively have "onboard" sensors 4 and 5. In one embodiment, the controller (for example) uses the switchable optical device by using current-voltage (I/V) data obtained from sending one or more electrical pulses through the EC device and analyzing the feedback As a sensor.

In one embodiment, the controller includes a chip, a card, or a board, which includes logic for performing one or more control functions. The power and communication functions of the controller 501 can be combined in a single chip, for example, a programmable logic device (PLD) chip, field programmable gate array (FPGA), etc. These integrated circuits can combine logic, control, and power functions in a single programmable chip. In one embodiment where the electrochromic window (or IGU) has two electrochromic panes, the logic is configured to independently control each of the two electrochromic panes. In one embodiment, the function of each of the two electrochromic panes is controlled in a cooperatively enhanced manner, that is, so that each device is controlled to complement other devices. For example, the desired level of light transmission, thermal insulation effect, and/or other properties can be controlled through the combination of the states of each of the individual devices. For example, one electrochromic device can be placed in a colored state, while the other (for example) is used for resistive heating via a transparent electrode of the device. In another example, the optical states of the two electrochromic devices are controlled so that the combined transmittance is a desired result.

The controller 501 may also have wireless capabilities, such as control and power supply functions. For example, wireless controls such as Rf and/or IR and wireless communications such as Bluetooth, WiFi, Zigbee, EnOcean, etc. can be used to send commands to the microcontroller and for the microcontroller to send data out to (for example) Other window controllers and/or a building management system (BMS). Wireless communication can be used in the window controller for at least one of the following: programming and/or operating the electrochromic window, collecting data from the electrochromic window from the sensor, and using the electrochromic window for use It is a relay point of wireless communication. The data collected from the electrochromic window may also include count data, such as the number of times an electrochromic device has been activated (cycled), the efficiency of the electrochromic device over time, and so on.

In addition, the controller 501 may have wireless power capability. That is, the controller 501 may have one or more wireless power receivers, which receive transmissions from the one or more wireless power transmitters, and thus the controller 501 may supply power to the electrochromic window via wireless power transmission. Wireless power transmission includes, for example, but not limited to, inductance, resonance inductance, radio frequency power transmission, microwave power transmission, and laser power transmission. In one embodiment, power is transmitted to a receiver via radio frequency, and the receiver uses polarized waves (for example, circularly polarized waves, elliptically polarized waves, and/or dual-polarized waves) and/or various frequencies and vectors. Electricity is converted into electric current. In another embodiment, the power is transmitted wirelessly via the inductive coupling of the magnetic field. The exemplary wireless power function of the electrochromic window is described in the U.S. patent application filed on December 17, 2010, titled "Wireless Powered Electrochromic Windows" and serial number 12/971,576 with Robert Rozbicki as the inventor , The case is incorporated into this article by reference in its entirety.

The controller 501 may also include an RFID tag and/or memory, such as a solid-state serial memory (for example, I2C or SPI), which may be a programmable memory depending on the situation. Radio frequency identification (RFID) involves interrogators (or readers) and tags (or tags). RFID tags use communication via electromagnetic waves to exchange data between a terminal and an object (for example, for the purpose of identifying and tracking the object). Some RFID tags can be read from a few meters away from the line of sight of the reader and beyond the line of sight of the reader.

The RFID tag can contain at least two parts. One part is an integrated circuit for storing and processing information, modulating and demodulating a radio frequency (Rf) signal, and other specialized functions. The other part is an antenna used to receive and transmit the signal.

There are three types of RFID tags: passive RFID tags, which do not have a power source and require an external electromagnetic field to initiate a signal transmission; active RFID tags, which contain a battery and can transmit signals once a reader has been successfully identified; And battery-assisted passive (BAP) RFID tags, which require an external source to wake up, but have a significantly higher forward link capability that provides a larger range. RFID has many applications. For example, it is used in enterprise supply chain management to improve the efficiency of inventory tracking and management.

In one embodiment, the RFID tag or other memory is programmed with at least one of the following data: guarantee information, installation information, distributor information, batch/inventory information, EC device/IGU characteristics, EC device cycle information And consumer information. Examples of EC device and IGU characteristics include (for example) window voltage (V_W), window current (I_W), EC coating temperature (T_EC), glass visible transmission (%T_vis), %tint command (external analog input from BMS), digital input status and controller status. Each of these represents upstream information that can be provided from the controller. Examples of downstream data that can be provided to the controller include window drive configuration parameters, zone affiliation (for example, which zone this controller is part of),% tint value, digital output status, and digital control (tint) , Fade, auto, restart, etc.). Examples of window drive configuration parameters include fade to color transition ramp rate, fade to color transition voltage, initial color ramp rate, initial color voltage, initial color current limit, color retention voltage, color retention current limit, color to fade transition ramp rate , Color to fade transition voltage, initial fade ramp rate, initial fade voltage, initial fade current limit, fade retention voltage, fade retention current limit.

In one embodiment, a programmable memory is used in the controller described herein. This programmable memory can replace RFID technology or be used in combination with RFID technology. Programmable memory has the advantage of increased flexibility for storing data related to the controller and its matching IGU.

<i>Electrochromic device</i>

For the context, an example of electrochromic device design will now be explained. FIG. 6A schematically illustrates an electrochromic device 500 in a cross-sectional manner. The electrochromic device 500 includes a substrate 502, a first conductive layer (CL) 504, an electrochromic layer (EC) 506, an ion conductive layer (IC) 508, a counter electrode layer (CE) 510, and a Two conductive layers (CL) 514. The layers 504, 506, 508, 510, and 514 are collectively referred to as an electrochromic stack 520. A voltage source 516 is operable to apply a potential across the electrochromic stack 520 to effect the transition of the electrochromic device from, for example, a faded state to a colored state (shown). The order of the layers can be reversed with respect to the substrate.

The electrochromic device with dissimilar layers as described can be manufactured as a completely solid and/or completely inorganic device with a low defect rate. These devices and their manufacturing methods are described in more detail in the titled "Fabrication of Low-Defectivity Electrochromic Devices", which was filed on December 22, 2009, with the serial number of Mark Kozlowski et al. as the inventor of 12/645,111. The US patent application and the US patent application titled "Electrochromic Devices" filed on December 22, 2009 with the serial number 12/645,159 with Zhongchun Wang et al. as the inventor, these two applications were filed Incorporated by reference for all purposes. However, it should be understood that any one or more of the layers in the stack may contain a certain amount of organic material. The same can be said for liquid crystals that may be present in a small amount in one or more layers. It should also be understood that the solid-state material can be deposited or formed in other ways by processes using liquid crystal components (such as certain processes using sol-gel or chemical vapor deposition).

In addition, it should be understood that the reference frame for a transition between a faded state and a colored state is non-limiting and, inter alia, only shows an example of an electrochromic transition that can be implemented. Unless otherwise specified herein (including the foregoing discussion), whenever a fade-to-color transition is referred to, the corresponding device or procedure encompasses other optical state transitions, such as non-reflective-reflective, transparent-opaque, etc. In addition, the term "fading" refers to an optically neutral state, for example, non-colored, transparent or translucent. Furthermore, unless otherwise specified herein, the "color" of an electrochromic transition is not limited to any specific wavelength or range of wavelengths. As those familiar with this technology understand, the choice of appropriate electrochromic and counter electrode materials governs the associated optical transformations.

In the embodiments described herein, the electrochromic device reversibly cycles between a faded state and a colored state. In some cases, when the device is in a discolored state, a potential is applied to the electrochromic stack 520 so that the available ions in the stack mainly reside in the counter electrode 510. When the potential on the electrochromic stack is reversed, ions are transported across the ion conductive layer 508 to the electrochromic material 506 and cause the material to transition to a colored state.

Referring again to FIG. 6A, the voltage source 516 can be configured to operate in conjunction with radiation and other environmental sensors. As described herein, the voltage source 516 interfaces with a device controller (not shown in this figure). In addition, the voltage source 516 may interface with an energy management system that controls the electrochromic device according to various criteria such as the time of the year, the time of the day, and the measured environmental conditions. This energy management system combined with a large-area electrochromic device (for example, an electrochromic window) can significantly reduce the energy consumption of a building.

Any material having suitable optical, electrical, thermal, and mechanical properties can be used as the substrate 502. These substrates include, for example, glass, plastic, and mirror materials. Suitable glasses include clear or colored soda lime glass, including soda lime float glass. The glass can be tempered or untempered.

In many cases, the substrate is sized for one of the glass panes in residential glass applications. The size of this glass pane can vary widely depending on the specific needs of the residence. In other cases, the substrate is architectural glass. Architectural glass is usually used in commercial buildings, but can also be used in residential buildings, and usually (but not necessarily) separates an indoor environment from an outdoor environment. In some embodiments, the architectural glass is at least 20 inches×20 inches, and can be much larger, for example, about 80 inches×120 inches. Architectural glass is usually at least about 2 mm thick. Of course, the electrochromic device can be scaled according to a substrate that is smaller or larger than the architectural glass. In addition, the electrochromic device can be provided on a mirror of any size and shape.

The conductive layer 504 is on the top of the substrate 502. In some embodiments, one or both of conductive layers 504 and 514 are inorganic and/or solid. The conductive layers 504 and 514 can be made of several different materials, including conductive oxides, thin metal coatings, conductive metal nitrides, and composite conductors. Generally, the conductive layers 504 and 514 are transparent at least in the wavelength range in which the electrochromic layer exhibits electrochromic properties. Transparent conductive oxides include metal oxides and metal oxides doped with one or more metals. Examples of these metal oxides and doped metal oxides include indium oxide, indium tin oxide, doped indium oxide, tin oxide, doped tin oxide, zinc oxide, zinc aluminum oxide, doped zinc oxide, oxide Ruthenium, doped ruthenium oxide, etc. Since oxides are commonly used for these layers, they are sometimes referred to as "transparent conductive oxide" (TCO) layers. Thin metal coatings that are substantially transparent can also be used.

The function of the conductive layer is to expand a potential provided by the voltage source 516 above the surface of the electrochromic stack 520 to the inner region of the stack with a relatively small ohmic potential drop. The electric potential is transferred to the conductive layer via the electrical connection to the conductive layer. In some embodiments, bus bars (one in contact with conductive layer 504 and one in contact with conductive layer 514) provide electrical connection between voltage source 516 and conductive layers 504 and 514. The conductive layers 504 and 514 can also be connected to the voltage source 516 via other conventional components.

The overlying conductive layer 504 is an electrochromic layer 506. In some embodiments, the electrochromic layer 506 is inorganic and/or solid. The electrochromic layer may contain any one or more of several different electrochromic materials (including metal oxides). These metal oxides include tungsten oxide (WO₃), molybdenum oxide (MoO₃), niobium oxide (Nb₂O₅), titanium oxide (TiO₂), copper oxide (CuO), iridium oxide (Ir₂O₃), chromium oxide (Cr₂O₃), manganese oxide (Mn₂O₃), vanadium oxide (V₂O₅), nickel oxide (Ni₂O₃), cobalt oxide (Co₂O₃)Wait. During operation, the electrochromic layer 506 transmits ions to the counter electrode layer 510 and receives ions from the counter electrode layer 510 to cause optical conversion.

Generally, the coloration of electrochromic materials (or any change in optical properties-for example, absorptance, reflectance, and transmittance) is caused by reversible ion insertion (for example, addition) and a charge-balancing electron into the material One corresponds to the injection cause. Usually, a certain part of the ions responsible for the optical transformation is reversibly bound in the electrochromic material. Some or all of the reversibly bound ions are used to compensate for the "blind charge" in the material. In most electrochromic materials, suitable ions include lithium ion (Li⁺) And hydrogen ion (H⁺) (That is, protons). However, in some cases, other ions will be suitable. In various embodiments, lithium ions are used to generate electrochromic phenomena. The addition of lithium ions to tungsten oxide (WO_3-y(0&lt;y<img file="TW201248286A_D0002.tif" />~0.3)) Cause the tungsten oxide to change from transparent (faded state) to blue (colored state).

6A again, in the electrochromic stack 520, the ion conductive layer 508 is sandwiched between the electrochromic layer 506 and the counter electrode layer 510. In some embodiments, the counter electrode layer 510 is inorganic and/or solid. The counter electrode layer may include one or more of several different materials used as a reservoir of ions when the electrochromic device is in a discolored state. During an electrochromic transition initiated by (for example) the application of an appropriate potential, the counter electrode layer transfers some or all of the ions it holds to the electrochromic layer, thereby changing the electrochromic layer to Colored state. At the same time, in the case of NiWO, the counter electrode layer is colored due to the loss of ions.

In some embodiments, supplement WO₃Suitable materials for the counter electrode include nickel oxide (NiO), nickel tungsten oxide (NiWO), nickel vanadium oxide, nickel chromium oxide, nickel aluminum oxide, nickel manganese oxide, nickel magnesium oxide, chromium oxide (Cr₂O₃), manganese oxide (MnO₂), Prussian blue.

When a counter electrode 510 made of nickel tungsten oxide removes charge (ie, transfers ions from the counter electrode 510 to the electrochromic layer 506), the counter electrode layer will change from a transparent state to a colored state.

In the illustrated electrochromic device, there is an ion conductive layer 508 between the electrochromic layer 506 and the counter electrode layer 510. The ion conductive layer 508 serves as a medium for transporting ions (in the form of an electrolyte) through the electrochromic device when the electrochromic device transitions between the faded state and the colored state. Preferably, the ion-conducting layer 508 is highly conductive to the relevant ions of the electrochromic layer and the counter electrode layer, but has sufficiently low electronic conductivity such that the electron transfer that occurs during normal operation is negligible. A thin ion-conducting layer with high ion conductivity allows rapid ion conduction and therefore rapid switching of high-performance electrochromic devices. In some embodiments, the ion conductive layer 508 is inorganic and/or solid.

Examples of suitable ion-conducting layers (for electrochromic devices with a distinct IC layer) include silicate, silicon oxide, tungsten oxide, tantalum oxide, niobium oxide, and borate. Silicon oxide includes silicon aluminum oxide. These materials can be doped with different dopants, including lithium. The silicon oxide doped with lithium includes lithium silicon aluminum oxide. In some embodiments, the ion conductive layer includes a silicate-based structure. In some embodiments, silicon aluminum oxide (SiAlO) is used for the ion conductive layer 508.

The electrochromic device 500 may include one or more additional layers (not shown), such as one or more passive layers. A passive layer for improving certain optical properties may be included in the electrochromic device 500. A passive layer for providing moisture or scratch resistance can also be included in the electrochromic device 500. For example, the conductive layer can be treated with an anti-reflective or protective oxide or nitride layer. Other passive layers can be used to hermetically seal the electrochromic device 500.

6B is a schematic cross-sectional view of an electrochromic device in a faded state (or transitioned to a faded state). According to certain embodiments, an electrochromic device 600 includes a tungsten oxide electrochromic layer (EC) 606 and a nickel tungsten oxide counter electrode layer (CE) 610. The electrochromic device 600 also includes a substrate 602, a conductive layer (CL) 604, an ion conductive layer (IC) 608, and a conductive layer (CL) 614.

The power supply 616 is configured to apply a potential and/or current to the electrochromic stack 620 via suitable connections to the conductive layers 604 and 614 (for example, bus bars). In some embodiments, the power supply is configured to apply a potential of approximately 2 volts in order to drive the device to transition from one optical state to another optical state. The polarity of the potential as shown in FIG. 6A is such that ions (lithium ions in this example) mainly reside (as indicated by the dashed arrow) in the nickel tungsten oxide counter electrode layer 610.

6C is a schematic cross-sectional view of the electrochromic device 600 shown in FIG. 6B but in a colored state (or transitioning to a colored state). In FIG. 6C, the polarity of the voltage source 616 is reversed to make the electrochromic layer more negative to accept additional lithium ions, and thereby transition to a colored state. As indicated by the dashed arrow, lithium ions are transported across the ion conductive layer 608 to the tungsten oxide electrochromic layer 606. The tungsten oxide electrochromic layer 606 is shown in a colored state. The nickel tungsten oxide counter electrode 610 is also shown in a colored state. As explained, nickel tungsten oxide becomes increasingly opaque as it discards (de-adds) lithium ions. In this example, there is a synergistic strengthening effect in which the transition of both layers 606 and 610 to the colored state promotes reducing the amount of light transmitted through the stack and the substrate.

As explained above, an electrochromic device may include an electrochromic (EC) electrode layer and a counter electrode (CE) layer, which is composed of an ion conductive (IC) that is highly conductive to ions and highly resistant to electronic systems. Layer separation. As traditionally understood, the ion-conducting layer therefore prevents a short circuit between the electrochromic layer and the counter electrode layer. The ion conductive layer allows the electrochromic and counter electrode to maintain a charge and thereby maintain its faded or colored state. In electrochromic devices with dissimilar layers, the components form a stack that includes an ion conductive layer sandwiched between the electrochromic electrode layer and the counter electrode layer. The boundary between the three stacked components is defined by abrupt changes in composition and/or microstructure. Therefore, these devices have three distinct layers with two abrupt interfaces.

According to some embodiments, the counter electrodes and electrochromic electrodes are formed closely adjacent to each other, sometimes in direct contact, without separately depositing an ion conductive layer. In some embodiments, an electrochromic device having an interface area instead of a distinct IC layer is used with the controller described herein. These devices and their manufacturing methods are described in the respective U.S. patent applications filed on April 30, 2010 with serial numbers 12/772,055 and 12/772,075, and the serial numbers filed on June 11, 2010 are 12/814,277 and 12/814,279 U.S. patent applications-each of the four applications is titled "Electrochromic Devices", each with Zhongchun Wang et al. as the inventor, and each is quoted in its entirety The method is incorporated into this article.

FIG. 7 is a schematic cross-sectional view of an electrochromic device 700 in a colored state, in which the device has an interface region 708 that does not contain a different IC layer. The voltage source 616, the conductive layers 614 and 604, and the substrate 602 are basically the same as described with respect to FIGS. 6A and 6B. A region 710 is between the conductive layers 614 and 604, and the region 710 includes the counter electrode layer 610, the electrochromic layer 606, and an interface region 708 therebetween instead of a different IC layer. In this example, there is no obvious boundary between the counter electrode layer 610 and the interface region 708, and there is no obvious boundary between the electrochromic layer 606 and the interface region 708. Instead, there is a diffusion transition between the CE layer 610 and the interface region 708 and between the interface region 708 and the EC layer 606.

Although the foregoing invention has been described in a certain level of detail to facilitate understanding, the described embodiments should be regarded as illustrative and not restrictive. Those who are familiar with this technology will easily know that they can implement certain changes and modifications within the scope of the attached patent application.

<p>101Current peak value</p><p>Part 103</p><p>105Voltage curve</p><p>107Negative ramp/voltage ramp</p><p>109Negative hold/voltage hold</p><p>111positive ramp/voltage ramp</p><p>113 is keeping</p><p>207Horizontal Line</p><p>301Flat current curve</p><p>303Voltage ramp</p><p>307Level I safe</p><p>309Level I slow</p><p>313Voltage section</p><p>315Current curve segment</p><p>401'point/device edge/position</p><p>403Location</p><p>407Voltage curve</p><p>411Illustration</p><p>413Illustration</p><p>421Applied voltage curve</p><p>423Initial voltage pulse</p><p>425level</p><p>500Electrochromic device</p><p>501controller</p><p>502Substrate</p><p>504First conductive layer/layer/conductive layer</p><p>506Electrochromic layer/layer/Electrochromic material</p><p>508Ion conducting layer/layer</p><p>510Counter electrode layer/layer/counter electrode</p><p>514Second conductive layer/layer/conductive layer</p><p>516Voltage source</p><p>520Electrochromic stack</p><p>600Electrochromic device</p><p>602Substrate</p><p>604Conductive layer</p><p>606Tungsten oxide electrochromic layer/electrochromic layer/layer</p><p>608Ion conducting layer</p><p>610Nickel tungsten oxide counter electrode layer/counter electrode layer/layer</p><p>614Conductive layer</p><p>616Power/Voltage Source</p><p>620Electrochromic stack</p><p>700Electrochromic device</p><p>708Interface area</p><p>District 710</p>

Figure 1 shows a current curve of an electrochromic window that uses a simple voltage control algorithm to drive an optical state transition.

Figure 2 shows a series of Q vs. T (charge vs. temperature) curves for a specific voltage.

3A and 3B show current and voltage curves generated from a specific control method according to some embodiments.

FIG. 3C is a flowchart showing the control of current during an initial stage of an optical state transition.

Figure 4A compares the voltage non-uniformity across the surface of a device for an oscillating applied voltage and a non-oscillating applied voltage.

Figure 4B shows the center and edge modeling results generated from the applied voltage to generate a relatively uniform 0.4 OD intermediate state oscillation.

FIG. 4C is a voltage algorithm used to generate the result shown in FIG. 4B.

FIG. 4D shows a voltage curve used to quickly transition to an intermediate state.

Figure 5 is a schematic illustration of a controller that can be used to control a switchable optical device according to the method described herein.

Fig. 6A schematically illustrates one of an electrochromic device in a cross-sectional manner.

6B is a schematic cross-sectional view of an electrochromic device in a faded state (or transitioned to a faded state).

6C is a schematic cross-sectional view of the electrochromic device shown in FIG. 6B but in a colored state (or transitioning to a colored state).

FIG. 7 is a schematic cross-sectional view of an electrochromic device in a colored state, wherein the device has an interface region that does not contain a phase dissimilar ion conductor layer.

Control transitions in optical switchable devices