Controlling transitions in optically switchable devices

Patent metadata

Field	Value
Publication number	US-11835834-B2
Application number	US-202218047839-A
Country	US
Kind code	B2
Filing date	Oct 19, 2022
Priority date	Jun 28, 2013
Publication date	Dec 5, 2023
Grant date	Dec 5, 2023

Abstract

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

First claim

What is claimed is:

1. An apparatus for operating an optically switchable device, the apparatus comprising a processor that executes instructions to:
operate the optically switchable device at a first operating parameter for a first time period;
generate a characterization parameter based at least in part on voltage and/or current measurements that are obtained during the first time period, wherein generating the characterization parameter comprises consideration of a leakage current of the optically switchable device; and
control the optically switchable device for a second time period based at least in part on the characterization parameter.

2. The apparatus of claim 1 , wherein generating the characterization parameter comprises measuring an open circuit voltage of the optically switchable device.

3. The apparatus of claim 2 , wherein generating the characterization parameter further comprises plotting the open circuit voltage.

4. The apparatus of claim 1 , wherein a threshold charge or threshold charge density for controlling the optically switchable device during the second time period is based at least in part on the leakage current.

5. The apparatus of claim 1 , wherein the apparatus is further configured to measure a voltage and/or current on the optically switchable device during the first time period.

6. The apparatus of claim 1 , wherein the apparatus is further configured to store the characterization parameter after generating the characterization parameter.

7. The apparatus of claim 1 , wherein the first operating parameter corresponds to a first optical state.

8. The apparatus of claim 7 , wherein the first optical state is an intermediate optical state.

9. The apparatus of claim 7 , wherein the apparatus is further configured to determine a temperature of the optically switchable device, and wherein a voltage applied to the optically switchable device to change the optically switchable device from the first optical state to a second optical state is based at least in part on the temperature of the optically switchable device.

10. The apparatus of claim 1 , wherein the apparatus if further configured to determine an optical state of the optically switchable device.

11. The apparatus of claim 10 , wherein the apparatus is configured to determine the optical state of the optically switchable device at least in part by integrating current over time.

12. The apparatus of claim 1 , wherein the apparatus is configured to update the characterization parameter based at least in part on voltage and/or current measurements obtained during the second time period, and to control the optically switchable device for a third time period based at least in part on the updated characterization parameter.

13. The apparatus of claim 1 , wherein the apparatus is configured to modify the characterization parameter based at least in part on an ambient temperature surrounding the optically switchable device.

14. The apparatus of claim 1 , wherein the first operating parameter corresponds to an intermediate optical state wherein the ionic current has stopped, or nearly stopped, decaying.

15. A method of operating an optically switchable device, the method comprising:
operating the optically switchable device at a first operating parameter for a first time period;
generating a characterization parameter based at least in part on voltage and/or current measurements that are obtained during the first time period, wherein generating the characterization parameter comprises consideration of a leakage current of the optically switchable device; and
controlling the optically switchable device for a second time period based at least in part on the characterization parameter.

16. The method of claim 15 , wherein generating the characterization parameter comprises measuring an open circuit voltage of the optically switchable device.

17. The method of claim 16 , wherein generating the characterization parameter further comprises plotting the open circuit voltage.

18. The method of claim 15 , wherein a threshold charge or threshold charge density for controlling the optically switchable device during the second time period is based at least in part on the leakage current.

19. The method of claim 15 , further comprising measuring a voltage and/or current on the optically switchable device during the first time period.

20. The method of claim 15 , further comprising storing the characterization parameter after generating the characterization parameter.

21. The method of claim 15 , wherein the first operating parameter corresponds to a first optical state.

22. The method of claim 21 , wherein the first optical state is an intermediate optical state.

23. The method of claim 21 , further comprising determining a temperature of the optically switchable device, wherein a voltage applied to the optically switchable device to change the optically switchable device from the first optical state to a second optical state is based at least in part on the temperature of the optically switchable device.

24. The method of claim 15 , further comprising determining an optical state of the optically switchable device.

25. The method of claim 24 , wherein determining the optical state of the optically switchable device comprises integrating current over time.

26. The method of claim 15 , further comprising updating the characterization parameter based at least in part on voltage and/or current measurements obtained during the second time period, and controlling the optically switchable device for a third time period based at least in part on the updated characterization parameter.

27. The method of claim 15 , further comprising modifying the characterization parameter based at least in part on an ambient temperature surrounding the optically switchable device.

28. The method of claim 15 , wherein the first operating parameter corresponds to an intermediate optical state wherein the ionic current has stopped, or nearly stopped, decaying.

Assignees

• View Inc

Inventors

• Jack Gordon
• Kailasam Sridhar K
• Brown Stephen C
• Pradhan Anshu A

Classifications

• G02F1/163 Primary

  Operation of electrochromic cells, e.g. electrodeposition cells; Circuit arrangements therefor · CPC title

• E06B3/6722

  with adjustable passage of light · CPC title

• E06B9/24

  Screens or other constructions affording protection against light, especially against sunshine; Similar screens for privacy or appearance; {Slat blinds}(operating, guiding or securing devices or arrangements for roll-type closures E06B9/56; free-hanging flexible screens A47H23/00) · CPC title

• G02F1/0121

  Operation of devices; Circuit arrangements, not otherwise provided for in this subclass · CPC title

• E06B2009/2464

  featuring transparency control by applying voltage, e.g. LCD, electrochromic panels · CPC title