Electro-optic element buss

Abstract

An electro-optic element is provided that includes: a first transparent substrate having a first surface and a second surface; a first transparent conductive layer on the second surface; a second transparent substrate having a third surface and a fourth surface, wherein the first and second substrates are arranged substantially parallel in a middle viewing area with a cell spacing, the first and second substrates are separated in perimeter area at a distance greater than the cell spacing; a second transparent conductive layer on the third surface; an electro-optic medium between the conductive layers in the middle area; a first buss disposed on the second surface within the perimeter area in contact with the first conductive layer; and a second buss disposed on the third surface within the perimeter area in contact with the second conductive layer, wherein a combined thickness of the first and second busses exceeds the cell spacing.

Description

Atty. Docket No. AUTO 05174T (GEN010 FP1395AWO)ELECTRO-OPTIC ELEMENT BUSSCROSS REFERENCE TO RELATED APPLICATION

[0001] This application claims priority under 35 U.S.C. §119(e) upon U.S. Provisional Patent Application No. 63 / 679,842, entitled "ELECTRO-OPTIC ELEMENT BUSS" filed on August 6, 2025, by Matthew A. Koppey et al., the entire disclosure of which is incorporated herein by reference.SUMMARY

[0002] According to one aspect of the present disclosure, an electro-optic element is provided that includes: a first transparent substrate having a first surface, and a second surface opposite the first surface; a first transparent electrically conductive layer disposed on the second surface; a second transparent substrate having a third surface, and a fourth surface opposite the third surface, wherein the first and second transparent substrates are arranged such that the second and third surfaces are substantially parallel in a middle viewing area with a substantially constant cell spacing, the first and second transparent substrates being bowed out around a perimeter area outside of the middle viewing area such that the first and second transparent substrates are separated from one another in the perimeter area at a distance greater than the cell spacing; a second transparent electrically conductive layer disposed on the third surface; an electro-optic medium disposed between the first and second electrically conductive layers in the middle viewing area; a first buss disposed on the second surface within the perimeter area in electrical contact with the first transparent electrically conductive layer; and a second buss disposed on the third surface within the perimeter area in electrical contact with the second transparent electrically conductive layer, wherein a combined thickness of the first and second electrical busses exceeds the cell spacing in the middle viewing area.

[0003] In another aspect of the present disclosure, an electro-optic element is provided that includes: a first transparent substrate having a first surface, and a second surface opposite the first surface; a first transparent electrically conductive layer disposed on the second surface; a second transparent substrate having a third surface, and a fourth surface opposite the third surface, wherein the first and second transparent substratesare arranged such that the second and third surfaces are substantially parallel in a middle viewing area with a substantially constant cell spacing, the first and second transparent substrates being bowed out around a perimeter area outside of the middle viewing area such that the first and second transparent substrates are separated from one another in the perimeter area at a distance of about 240 pm, wherein the cell spacing is about 25 pm; a second transparent electrically conductive layer disposed on the third surface; an electro-optic medium disposed between the first and second electrically conductive layers in the middle viewing area; a first buss disposed on the second surface within the perimeter area in electrical contact with the first transparent electrically conductive layer; and a second buss disposed on the third surface within the perimeter area in electrical contact with the second transparent electrically conductive layer, wherein a thickness of each the first and second busses exceeds the cell spacing in the middle viewing area.

[0004] These and other features, advantages, and objects of the present disclosure will be further understood and appreciated by those skilled in the art by reference to the following specification, claims, and appended drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0005] The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:

[0006] FIG. 1A is a perspective view of an automobile that incorporates at least one electro-optic element, in accordance with an aspect of the present disclosure;

[0007] FIG. IB is a perspective view of an airplane that incorporates at least one electrooptic element, in accordance with an aspect of the present disclosure;

[0008] FIG. 1C is a perspective view of a building that incorporates at least one electrooptic element, in accordance with an aspect of the present disclosure;

[0009] FIG. 2 is a front view of an assembled electro-optic element;

[0010] FIG. 3 is a partial side view of the electro-optic element shown in FIG. 4; and

[0011] FIG. 4 is a partial side view of a conventional electrochromic element.DETAILED DESCRIPTION

[0012] The present illustrated embodiments reside primarily in combinations of method steps and apparatus components related to an electro-optic element. Accordingly, the apparatus components and method steps have been represented, where appropriate, by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present disclosure so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein. Further, like numerals in the description and drawings represent like elements.

[0013] In this document, relational terms, such as first and second, top and bottom, and the like, are used solely to distinguish one entity or action from another entity or action, without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0014] Large area devices (LADs) such as windows and sunroofs for land vehicles, windows for airplanes, or architectural windows for buildings have incorporated electrooptic elements that may be selectively darkened to enhance privacy and to reduce the brightness of light passing therethrough. As shown in FIG. 4, some LADs 100 have been made in the past using a solution-phase electrochromic medium 130 between two glass substrates 112 and 114 having indium tin oxide (ITO) coatings 124 and 126. These LADs 100 were relatively thick having a cell spacing between the substrates of about 420 pm. With this large a cell spacing, busses 132 and 134 made of silver ink were provided along one or more perimeters of the inner surfaces of each of coated glass substrates 112 and 114 with a nonconductive seal 150 provided therebetween and conductive tabs 133 and 135 extending outward for electrical connection to the busses. The busses could be made relatively thick given the cell spacing of the device.

[0015] In a move to make LADs thinner and lighter, a thin film electro-optic material is proposed between two polymer substrates. Such a device has a cell spacing of about 25 pm, which is much smaller than the prior device with its 420 pm cell spacing. However, inthe proposed device, the ITO layers on the polymer substrates exhibit a noticeably higher sheet resistance than the same ITO layers when on glass substrates. Further, the cell spacing is so much smaller that the busses are too thick to fit within the cell spacing. Although some LADs address this by offsetting the substrates and then applying the bus to the offset side(s), this approach does not allow a buss to contact the electrode layers around their full perimeter, which leads to reduced performance. The present disclosure addresses these technical problems and provides for improved electro-optic elements that are thinner, exhibit improved response times, more uniform coloration, and are capable of being more easily manufactured at reduced cost.

[0016] As discussed further below, the present disclosure pertains to an electro-optic element 10. With reference now to FIGS. 1A-1C, the electro-optic element 10 may be incorporated with one or more structures 36A-36C. For example, FIG. 1A illustrates a vehicle 36A employing the electro-optic element 10. All or some components of the electro-optic element 10 may be located within, or at least partially form, a vehicle mirror 38 or a vehicle window or sunroof 40. The vehicle 36A may include a commercial vehicle, an emergency vehicle, a residential vehicle, a train, or the like. FIG. IB illustrates an airplane 36B employing the electro-optic element 10. The electro-optic element 10 may be located within, or at least partially form, an airplane window 42. FIG. 1C illustrates a building 36C employing the electro-optic element 10. The electro-optic element 10 may be located within, or at least partially form, a building window 44. Generally speaking, the electro-optic element 10 may be incorporated into any environment wherein changing transmittance and / or reflectivity is beneficial.

[0017] As shown in FIGS. 2 and 3, the electro-optic element 10 may include a first substrate 12 having a first surface 12a and a second surface 12b opposite the first surface 12a, and a second substrate 14 having a third surface 14a and a fourth surface 14b opposite the third surface 14a. As shown in FIG. 3, the first and second substrates 12 and 14 are arranged such that the second and third surfaces 12b and 14a are substantially parallel in a middle viewing area 16 with a substantially constant cell spacing, the first and second transparent substrates 12 and 14 being bowed out around a perimeter area 18 outside of the middle viewing area 16 such that the first and second transparent substrates 12 and 14 are separated from one another in the perimeter area 18 at a distance greater than the cell spacing. As used herein, "the middle viewing area" is thatarea of the element through which light may be attenuated whereas "the perimeter area" surrounds the middle viewing area and is an area that is generally obscured from view by a frame or other structure.

[0018] The electro-optic element 10 further includes a first transparent electrically conductive layer 24 disposed on the second surface 12b and a second transparent electrically conductive layer 26 disposed on the third surface 14a. An electro-optic medium 30 is disposed in the middle viewing area between the first and second electrically conductive layers 24 and 26.

[0019] A first buss 32 is disposed on the second surface 12b within the perimeter area 18 in electrical contact with the first transparent electrically conductive layer 24. A second buss 34 is disposed on the third surface 14a within the perimeter area 18 in electrical contact with the second transparent electrically conductive layer 26. The first and second electrical busses 32 and 34 may thus have a thickness that exceeds the cell spacing in the middle viewing area 16. The cell spacing in the middle viewing area 16 may be around 25 pm whereas the first and second electrical busses 32 and 34 may each have a thickness of about 120 pm, which would include a conductive portion 32a and 34a and an insulating portion 32b and 34b. It should be noted that these thicknesses are provided for example only and the thicknesses may vary.

[0020] The first and second busses 32 and 34 may be a conductive tape or other preformed conductive material or may be a conductive material that is formed as it is applied to the outer surfaces 12a and 14b of the substrates 12 and 14, respectively, such as a silver ink.

[0021] In addition, as shown in FIG. 2, the first and second busses 32 and 34 may extend around the entire perimeter of the first and second substrates 12 and 14. By providing electrical connection of the busses 32 and 34 to the respective first and second transparent electrically conductive layers 24 and 26 around the entire perimeter of the element 10, the negative impact of a higher sheet resistance of the electrically conductive layers 24 and 26 over a large area may be mitigated. Moreover, the initial inrush current is higher and the element 10 colors both faster, and more uniformly.

[0022] The first and second transparent substrates 12 and 14 may be made of a polymer such as polyethylene terephthalate (PET), one or more plastics, or multi-plastic stacks, for example, and may have a thickness of about 125 pm. Alternatively, the transparentsubstrates 12 and 14 may be made of a flexible glass or a hybrid glass / polymer material. The first transparent electrically conductive layer 24 and the second transparent electrically conductive layer 26 may be formed by electrically conductive transparent materials, including, but not limited to, a transparent conducting film (e.g., indium tin oxide (ITO), F:SnO2, ZnO, IZO), insulator-metal-insulator ("IMI") structures, carbon (graphene and / or graphite) and / or a conductive metal mesh (e.g., nanowires).

[0023] The electro-optic medium 30 may be a solid-state thin film electro-optic medium. A seal is optional for such a thin film electro-optic medium. The thin film may include cathodic materials, anodic materials, and electrolyte materials. The electro-optic medium 30 may be selected such that it exhibits a memory so as to retain a colored state or a non-colored state without application of a voltage.

[0024] By using a thin film electro-optic medium and polymer or hybrid polymer / glass substrates, the electro-optic elements 10 may be manufactured by rolling sheets of the materials together or otherwise laminating the components and then subsequently cutting the rolled sheets to the desired size. The first and second transparent substrates 12 and 14 may then be subjected to bending to widen the spacing therebetween in the perimeter area 18. The busses 32 and 34 and conductive tabs 33 and 35 may then be applied to the respective transparent electrically conductive layers 24 and 26.

[0025] In this document, relational terms, such as "first," "second," and the like, are used solely to distinguish one entity or action from another entity or action, without necessarily requiring or implying any actual such relationship or order between such entities or actions.

[0026] As used herein, the term "and / or," when used in a list of two or more items, means that any one of the listed items can be employed by itself, or any combination of two or more of the listed items can be employed. For example, if a composition is described as containing components A, B, and / or C, the composition can contain A alone; B alone; C alone; A and B in combination; A and C in combination; B and C in combination; or A, B, and C in combination.

[0027] For purposes of this disclosure, the term "associated" generally means the joining of two components (electrical or mechanical) directly or indirectly to one another. Such joining may be stationary in nature or movable in nature. Such joining may be achieved with the two components (electrical or mechanical) and any additional intermediatemembers being integrally formed as a single unitary body with one another or with the two components. Such joining may be permanent in nature or may be removable or releasable in nature unless otherwise stated.

[0028] The term "substantially," and variations thereof, will be understood by persons of ordinary skill in the art as describing a feature that is equal or approximately equal to a value or description. For example, a "substantially planar" surface is intended to denote a surface that is planar or approximately planar. Moreover, "substantially" is intended to denote that two values are equal or approximately equal. If there are uses of the term which are not clear to persons of ordinary skill in the art, given the context in which it is used, "substantially" may denote values within 10% of each other, such as within 5% of each other, or within 2% of each other.

[0029] The term "transparent" is applied in the relative sense. "Transparent" refers to an optical element or material that is substantially transmissive of at wavelengths in question and thus generally allows light at such wavelengths to pass therethrough. The wavelengths in question will vary based on the context. However, in the event the wavelengths in question are not readily apparent, the wavelengths in question shall generally refer to visible light.

[0030] It should be appreciated by those skilled in the art that the above-described components may be combined in additional or alternative ways not explicitly described herein. Modifications of the various implementations of the disclosure will occur to those skilled in the art and to those who apply the teachings of the disclosure. Therefore, it is understood that the embodiments shown in the drawings and described above are merely for illustrative purposes and not intended to limit the scope of the disclosure, which is defined by the following claims as interpreted according to the principles of patent law, including the doctrine of equivalents.

Claims

CLAIMSWhat is claimed is:

1. An electro-optic element comprising: a first transparent substrate having a first surface, and a second surface opposite the first surface; a first transparent electrically conductive layer disposed on the second surface; a second transparent substrate having a third surface, and a fourth surface opposite the third surface, wherein the first and second transparent substrates are arranged such that the second and third surfaces are substantially parallel in a middle viewing area with a substantially constant cell spacing, the first and second transparent substrates being bowed out around a perimeter area outside of the middle viewing area such that the first and second transparent substrates are separated from one another in the perimeter area at a distance greater than the cell spacing; a second transparent electrically conductive layer disposed on the third surface; an electro-optic medium disposed between the first and second electrically conductive layers in the middle viewing area; a first buss disposed on the second surface within the perimeter area in electrical contact with the first transparent electrically conductive layer; and a second buss disposed on the third surface within the perimeter area in electrical contact with the second transparent electrically conductive layer, wherein a combined thickness of the first and second busses exceeds the cell spacing in the middle viewing area.

2. The electro-optic element of claim 1, wherein the first and second busses extend around the entire perimeter of the respective first and second transparent substrates and make electrical contact with the respective first and second transparent substrates around the entire perimeter.

3. The electro-optic element of any one of claims 1 and 2, wherein the electro-optic medium is a thin film electro-optic medium.

4. The electro-optic element of any one of claims 1-3, wherein the first and second transparent substrates comprise a polymer.

5. The electro-optic element of claim 4, wherein the polymer is polyethylene terephthalate.

6. The electro-optic element of any one of claims 1-5, wherein the first and second electrical busses each have a thickness that exceeds the cell spacing in the middle viewing area.

7. The electro-optic element of any one of claims 1-6, wherein the first and second electrical busses each have a thickness of at least about 120 pm.

8. The electro-optic element of any one of claims 1-7, wherein the cell spacing in the middle viewing area is about 25 pm.

9. The electro-optic element of any one of claims 1-8, wherein the first and second substrates each have a thickness of at least about 125 pm.

10. The electro-optic element of any one of claims 1-9, wherein the first and second electrical busses each have a conductive portion and an insulating portion, wherein the conductive portion faces and contacts the respective first and second transparent electrically conductive layers and the insulating portions prevent electrical contact between the first and second electrical busses.

11. An electro-optic element comprising: a first transparent substrate having a first surface, and a second surface opposite the first surface; a first transparent electrically conductive layer disposed on the second surface; a second transparent substrate having a third surface, and a fourth surface opposite the third surface, wherein the first and second transparent substrates arearranged such that the second and third surfaces are substantially parallel in a middle viewing area with a substantially constant cell spacing, the first and second transparent substrates being bowed out around a perimeter area outside of the middle viewing area such that the first and second transparent substrates are separated from one another in the perimeter area at a distance of about 240 pm, wherein the cell spacing is about 25 pm; a second transparent electrically conductive layer disposed on the third surface; an electro-optic medium disposed between the first and second electrically conductive layers in the middle viewing area; a first buss disposed on the second surface within the perimeter area in electrical contact with the first transparent electrically conductive layer; and a second buss disposed on the third surface within the perimeter area in electrical contact with the second transparent electrically conductive layer, wherein a thickness of each the first and second busses exceeds the cell spacing in the middle viewing area.

12. The electro-optic element of claim 11, wherein the first and second busses extend around the entire perimeter of the respective first and second transparent substrates and make electrical contact with the respective first and second transparent substrates around the entire perimeter.

13. The electro-optic element of any one of claims 11 and 12, wherein the electrooptic medium is a thin film electro-optic medium.

14. The electro-optic element of any one of claims 11-13, wherein the first and second transparent substrates comprise a polymer.

15. The electro-optic element of claim 14, wherein the polymer is polyethylene terephthalate.

17. The electro-optic element of any one of claims 11-16, wherein the first and second electrical busses each have a thickness of at least about 120 pm.

19. The electro-optic element of any one of claims 11-18, wherein the first and second substrates each have a thickness of at least about 125 pm.

20. The electro-optic element of any one of claims 11-19, wherein the first and second electrical busses each have a conductive portion and an insulating portion, wherein the conductive portion faces and contacts the respective first and second transparent electrically conductive layers and the insulating portions prevent electrical contact between the first and second electrical busses.

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