CONTROLLER CONFIGURED FOR AN ELECTRO-OPTIC DEVICE AND METHOD THEREOF

• US 20130258440A1
• Filed: 03/14/2013
• Published: 10/03/2013
• Est. Priority Date: 03/30/2012
• Status: Active Grant

• Current Assignee: Gentex Corporation
• Original Assignee: Gentex Corporation
• Inventors: Eaton, David L., Guarr, Thomas F., Ash, Kevin L., Theiste, David A.
• Granted Patent: US 9,405,165 B2
• Time in Patent Office: Days
• US Class Current: 359/275
• CPC Class Codes: G02F 1/163 Operation of electrochromic cells, e.g. electrodeposition cells; Circuit arrangements therefor

Abstract

A controller system configured to control an electrochromic device and method thereof are provided, wherein the controller system includes an electrochromic device having a first substantially transparent substrate, a second substantially transparent substrate approximately parallel to the first substantially transparent substrate such that a chamber is defined by the first and second substantially transparent substrates, and an electrochromic medium between the first and second substantially transparent substrates, and a controller in communication with the electrochromic device, wherein the controller is configured to monitor electrical power supplied to the electrochromic device and adjust the electrical power supplied to the electrochromic device to maintain the electrochromic device in an approximately minimum transmission state.

Claims

1. A controller system configured to control an electro-optic device, said controller system comprising:

an electro-optic device comprising;

a first substantially transparent substrate;

a second substantially transparent substrate approximately parallel to said first substantially transparent substrate such that a chamber is defined by said first and second substantially transparent substrates; and

an electro-optic medium between said first and second substantially transparent substrates; and

a controller in communication with said electro-optic device, wherein said controller is configured to monitor electrical power supplied to said electro-optic device and adjust said electrical power supplied, such that approximately a minimum potential is applied to said electro-optic device to maintain said electro-optic device in an approximately minimum transmission state.

2. The controller system of claim 1, wherein said controller is further configured to maintain said electro-optic device in said approximately minimum transmission state independent of a measurement of temperature of said electro-optic device.

3. The controller system of claim 1, wherein electrical power needed to maintain said electro-optic device at said approximate minimum transmission state varies based upon temperature of said electro-optic device, such that said controller is configured to electrical power to be supplied to said electro-optic device is determined by said controller without receiving an input from a temperature sensor.

4. The controller system of claim 1, wherein said controller is further configured calculate a first derivative and a second derivative of electrical current across said electro-optic device and determine an approximate maxima and minima of said first and second derivatives, such that said electrical power to be supplied to maintain said approximately minimum transmission state can be determined based upon said maxima and minima

5. The controller system of claim 1, wherein said controller is further configured for reverse potential monitoring and reverse potential control.

6. The controller system of claim 5, wherein said reverse potential monitoring and reverse potential control comprises said electro-optic device operating as an open circuit, such that an open circuit voltage potential that a non-equilibrium state of said electro-optic device produces is monitored.

7. The controller system of claim 6, wherein said controller is configured to use a magnitude of said open circuit voltage potential to determine a counter-potential that is applied in order to clear the electro-optic device.

8. The controller system of claim 1, wherein said controller is further configured for current monitoring and reverse potential control.

9. The controller system of claim 8, wherein said current monitoring and reverse potential comprises applying a reverse potential to said electro-optic device while reducing a current to reverse direction that would otherwise cause reverse coloring.

10. The controller system of claim 1, wherein said controller is further configured to monitor reverse current and dynamically adjust a potential to maintain a substantially maximized current magnitude and reduce current flow that otherwise results in reverse coloring.

11. The controller system of claim 1, wherein said controller is further configured to control said electro-optic device transitions from a substantially clear state to a substantially dark state without substantially pulsing.

12. The controller system of claim 1, wherein said controller is further configured to control said electro-optic device, such that a transmittance of said electro-optic device monitonically increases.

13. The controller system of claim 1, wherein said controller is further configured to increase a transmittance of said electro-optic device devoid of any periodic reduction in transmission being less than about 0.5% of the current transmission.

14. The controller system of claim 1, wherein said controller is further configured to increase a transmittance of said electro-optic device, such that there are less about two periodic reductions in transmission per minute.

15. A method for maintaining an electro-optic device at a substantially dark state, said method comprising the steps of:

supplying electrical power to said electro-optic device; and

adjusting said supplied electrical power to maintain said electro-optic device in an approximately minimum transmission state independent of a measurement of temperature of said electro-optic device.

16. The method of claim 15 further comprising the steps of:

calculating a first derivative of electrical current across said electro-optic device;

calculating a second derivative of electrical current across said electro-optic device; and

determining an approximate maxima and minima of said first and second derivatives.

17. The method of claim 15 further comprising the step of:

transitioning said electro-optic device from a substantially clear state to a substantially dark state without substantially pulsing.

18. A non-transitory computer readable medium having stored thereon software instructions that, when executed by a processor, cause the processor to generate control signals to control an electro-optic device, by executing the steps comprising:

supplying electrical power to said electro-optic device; and

adjusting said supplied electrical power to maintain said electro-optic device in an approximately minimum transmission state independent of a measurement of temperature of said electro-optic device.

19. The non-transitory computer readable medium of claim 18 further executing the steps comprising:

calculating a first derivative of electrical current across said electro-optic device;

calculating a second derivative of electrical current across said electro-optic device; and

determining an approximate maxima and minima of said first and second derivatives.

20. The non-transitory computer readable medium of claim 18 further executing the steps comprising:

monitonically increasing a transmittance of said electro-optic device.