DRIVER FOR ELECTROCHROMIC ELEMENT, METHOD FOR DRIVING ELECTROCHROMIC ELEMENT, OPTICAL FILTER, IMAGING DEVICE, LENS UNIT, AND WINDOW COMPONENT

• US 20140362430A1
• Filed: 06/04/2014
• Published: 12/11/2014
• Est. Priority Date: 06/07/2013
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Yamamoto, Jun, Okada, Shinjiro
• Granted Patent: US 9,933,681 B2
• Time in Patent Office: Days
• US Class Current: 359/275
• CPC Class Codes: G02F 1/1503 caused by oxidation-reduction reactions in organic liquid solutions, e.g. viologen solutions
• CPC Class Codes: G02F 1/163 Operation of electrochromic cells, e.g. electrodeposition cells; Circuit arrangements therefor
• CPC Class Codes: G09G 3/19 using electrochromic devices

Abstract

A driver for an electrochromic element is configured to adjust the transmittance of a solution-type electrochromic element to allow the element to display a tone. The element has a pair of electrodes and at least one organic electrochromic material mixed between the electrodes. The driver has an adjusting controller configured to adjust the transmittance of the element. The adjusting controller has controller A and controller B. Controller A is configured to saturate a change in the transmittance of the element to an initial state by applying the voltage which resets the element to the initial state. Controller B is configured to control the tone of the element by applying the voltage which adjusts the transmittance of the element following controller A.

Claims

1. A driver for an electrochromic element, the driver configured to adjust transmittance of a solution-type electrochromic element to allow the element to display a tone, the element having a pair of electrodes and at least one organic electrochromic material mixed between the electrodes, the driver comprising:

an adjusting controller configured to adjust the transmittance of the element, the adjusting controller having controller A and controller B, controller A configured to saturate a change in the transmittance of the element to an initial state by applying the voltage which resets the element to the initial state, controller B configured to control the tone of the element by applying the voltage which adjusts the transmittance of the element following controller A.

2. The driver for an electrochromic element according to claim 1, wherein:

controller A applies voltage V1 to saturate the change in the transmittance of the element to reset the element to the initial state;

controller B, following controller A, applies voltage V2 higher than the voltage V1 and not lower than an oxidation voltage if the voltage V1 is equal to or lower than a back reduction voltage, or applies voltage V2 lower than the voltage V1 and not higher than the back reduction voltage if the voltage V1 is equal to or higher than the oxidation voltage,

connects a resistor R1 in series in a closed circuit including the element for a duration T1, and

connects a resistor R2 of higher resistivity than the resistor R1 in series in the closed circuit including the element for a duration T2 to reduce circuit current; and

controller B continuously alternates connecting the resistor R1 for the duration T1 and connecting the resistor R2 for the duration T2 while in operation.

3. The driver for an electrochromic element according to claim 1, wherein:

controller A applies voltage V1 to saturate the change in the transmittance of the element to reset the element to the initial state;

controller B, following controller A, applies voltage V2 higher than the voltage V1 and not lower than a reduction voltage if the voltage V1 is equal to or lower than a back oxidation voltage, or applies voltage V2 lower than the voltage V1 and not higher than the back oxidation voltage if the voltage V1 is equal to or higher than the reduction voltage,

connects a resistor R1 in series in a closed circuit including the element for a duration T1, and

connects a resistor R2 of higher resistivity than the resistor R1 in series in the closed circuit including the element for a duration T2 to reduce circuit current; and

controller B continuously alternates connecting the resistor R1 for the duration T1 and connecting the resistor R2 for the duration T2 while in operation.

4. The driver for an electrochromic element according to claim 2, wherein controller B is configured to adjust the transmittance of the element by changing T1 with a total duration T1+T2 constant.

5. The driver for an electrochromic element according to claim 2, wherein the duration T1+T2 is 100 milliseconds or less.

6. The driver for an electrochromic element according to claim 2, wherein the at least one organic electrochromic material is a plurality of organic electrochromic materials, and the voltage V1 and V2 are voltages equal to or higher than a highest oxidation voltage of or equal to or lower than a lowest back reduction voltage of oxidation and back reduction voltages of the organic electrochromic materials.

7. The driver for an electrochromic element according to claim 6, wherein at least one of the plurality of organic electrochromic materials has an optical absorption peak different from an optical absorption peak of the other organic electrochromic materials.

8. The driver for an electrochromic element according to claim 6, wherein at least one of the plurality of organic electrochromic materials has an optical absorption peak in a wavelength range from 440 nm to 490 nm or a wavelength range from 540 nm to 630 nm.

9. The driver for an electrochromic element according to claim 6, wherein at least one of the organic electrochromic material is selected from compounds (1) to (4) represented by the following structural formulae.

14. An optical filter comprising an electrochromic element and the driver for an electrochromic element according to claim 1.

15. An imaging device comprising the optical filter according to claim 14 and a light-receiving element configured to receive light after the light has passed the optical filter.

16. A lens unit comprising an optical system and the optical filter according to claim 14, the optical system including a plurality of lenses, arrangement being such that light should pass through the optical system after passing through the optical filter.

17. A lens unit comprising an optical system and the optical filter according to claim 14, the optical system including a plurality of lenses, arrangement being such that light should pass through the optical filter after passing through the optical system.

18. A window component comprising the driver for an electrochromic element according to claim 1 and a circuit configured to supply the driver with driving voltage.

10. A method for driving an electrochromic element, the method designed to adjust transmittance of a solution-type electrochromic element to allow the element to display a tone, the element having a pair of electrodes and at least one organic electrochromic material mixed between the electrodes, the method comprising:

adjusting the transmittance of the element, the adjustment including saturating a change in the transmittance of the element to reset the element to an initial state and then controlling the transmittance.

11. The method for driving an electrochromic element according to claim 10, wherein:

the saturation includes applying voltage V1 to saturate the change in the transmittance of the element to reset the element to the initial state;

the control, following the saturation, includes applying voltage V2 higher than the voltage V1 and not lower than an oxidation voltage if the voltage V1 is equal to or lower than a back reduction voltage, or applying voltage V2 lower than the voltage V1 and not higher than the back reduction voltage if the voltage V1 is equal to or higher than the oxidation voltage,

connecting a resistor R1 in series in a closed circuit including the element for a duration T1, and

connecting a resistor R2 of higher resistivity than the resistor R1 in series in the closed circuit including the element for a duration T2 to reduce circuit current; and

connecting the resistor R1 for the duration T1 and connecting the resistor R2 for the duration of T1 continuously alternate while the control proceeds.

12. The method for driving an electrochromic element according to claim 10, wherein:

the saturation includes applying voltage V1 to saturate the change in the transmittance of the element to reset the element to the initial state;

the control, following the saturation, includes applying voltage V2 higher than the voltage V1 and not lower than a reduction voltage if the voltage V1 is equal to or lower than a back oxidation voltage, or applying voltage V2 lower than the voltage V1 and not higher than the back oxidation voltage if the voltage V1 is equal to or higher than the reduction voltage,

connecting a resistor R1 in series in a closed circuit including the element for a duration T1, and

connecting a resistor R2 of higher resistivity than the resistor R1 in series in the closed circuit including the element for a duration T2 to reduce circuit current; and

connecting the resistor R1 for the duration T1 and connecting the resistor R2 for the duration of T1 continuously alternate while the control proceeds.

13. The method for driving an electrochromic element according to claim 11, wherein the control includes adjusting the transmittance of the element by changing T1 with a total duration T1+T2 constant, where T1 is the duration for which the resistor R1 is in the connected state and T2 is the duration for which the resistor R2 is in the connected state.