# Patent

## Title
Multi-pane dynamic window and method for making same

## Abstract

A window assembly comprises a plurality of dynamic electrochromic zones formed on a single transparent substrate in which at least two electrochromic zones are independently controllable. In one exemplary embodiment, the window assembly comprises an Insulated Glass Unit (IGU), and at least one transparent substrate comprises a lite. In another exemplary embodiment, the IGU comprises at least two lites in which at least one lite comprises a plurality of independently controllable dynamic zones.

## Background
BACKGROUND
The subject matter disclosed herein relates to dynamic windows, such as smart windows. More particularly, the subject matter disclosed herein relates to dynamic multi-pane Insulated Glass Units (IGUs) in which at least one pane comprises a plurality of independently controllable dynamic zones.



BRIEF DESCRIPTION OF THE DRAWINGS
The subject matter disclosed herein is illustrated by way of example and not by limitation in the accompanying figures in which like reference numerals indicate similar elements and in which:
FIGS. 1A and 1B depict a conventional dynamic IGU that utilizes a dynamic coating in a well-known manner to change the visible transmittance through the IGU;
FIG. 2 depicts one exemplary embodiment of a multi-pane IGU having multiple dynamic zones according to the subject matter disclosed herein;
FIG. 3 depicts a cross-sectional view A-A′ (shown in FIG. 2) of a portion of multi-pane IGU according to the subject matter disclosed herein; and
FIG. 4 depicts a sectional view of a first exemplary embodiment of a solid-state electrochromic device that is suitable for a dynamic zone according to the subject matter disclosed herein.



DETAILED DESCRIPTION
The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any embodiment described herein as “exemplary” is not to be construed as necessarily preferred or advantageous over other embodiments.
The subject matter disclosed herein relates to multi-pane Insulated Glass Units (IGUs) comprising at least one pane, or lite, having a dynamic (i.e., a variable visible transmittance (Tvis) and/or variable Solar Heat Gain Coefficient (SHGC)) coating on a surface of the pane that provides at least two, independently controllable dynamic zones.
FIGS. 1A and 1B depict a conventional dynamic IGU 100 that utilizes a dynamic coating in a well-known manner to change the visible transmittance through the IGU. In particular, FIG. 1A depicts conventional dynamic IGU 100 in a clear state, and FIG. 1B depicts conventional dynamic IGU 100 in a darkened state.
Masking has been one conventional approach that has been tried for making a dynamic IGU that has multiple independently controllable zones. Masking, nevertheless, includes the problems of producing short circuits that require elimination and of producing visual defects in the isolation area between two independently controlled dynamic zones. Other techniques that have been tried include difficult manufacturing techniques that significantly increase the production costs associated with such IGUs. Thus, conventional practical sealed IGUs have been restricted to a either a single dynamic zone or several separately glazed IGUs, each having a single dynamic zone, formed together into a single IGU assembly.
Multi-zone, dynamic windows according to the subject matter disclosed herein provide many advantages over conventional dynamic IGUs, such as permitting optimized harvesting of natural daylight through one or more dynamic zones, while being able to maximize solar-control advantages in the other dynamic zones of the window. Different dynamic zones can be created at any arbitrary distance from the edge of a window in order to satisfy diverse design goals and requirements.
FIG. 2 depicts one exemplary embodiment of a multi-pane IGU 200 having multiple dynamic zones according to the subject matter disclosed herein. IGU 200 comprises an IGU frame 201, a seal 202, at least two window panes (or lites) 203. IGU frame 201 holds and supports each window pane 203 in a well-known manner. The space between window panes 203 is sealed by seal 202 in a well-known manner so that the space can be filled in a well-known manner with air and/or an inert gas, such as argon, krypton and/or xenon. Alternatively, the space between the window panes can be evacuated so that the space contains a partial vacuum.
At least one window pane 203 of IGU 200 comprises a first dynamic zone 204 and a second dynamic zone 205. In one exemplary embodiment dynamic zones 204 and 205 are electrochromic dynamic zones. In another exemplary embodiment, at least one dynamic zone could be a photochromic or a thermochromic dynamic zone. Bus bars 206 are coupled to each dynamic zone in a well-known manner in order to independently apply control voltages to each respective dynamic zone. Bus bars 206 are made electrically available at the outside edge of frame 201. Each respective dynamic zone can be independently controlled in a well-known manner based on, for example, internal and/or external light levels, internal and/or external weather conditions, the time of day, the time of year, etc.
FIG. 3 depicts a cross-sectional view A-A′ (shown in FIG. 2) of a portion of multi-pane IGU 200 according to the subject matter disclosed herein. As shown in FIG. 3, multi-pane IGU 200 comprises a first lite 203a, a second lite 203b, a spacer 211, a first seal 212, and a second seal 213. (Frame 201 is not depicted in FIG. 3.) First and second lites 203a and 203b can be formed from, for example, glass, acrylic and/or polycarbonate. One or both lites 203a and 203b can be transparent or be translucent. Alternatively, a portion of one or both lites 203a and 203b can be transparent or be translucent. Spacer 211 is positioned in a well-known manner between first lite 203a and second lite 203b to form space 214. In one exemplary embodiment, spacer 211 forms a gap (or space) between first lite 203a and second lite 203b of about 12 mm to about 20 mm. First seal 212, such as a silicon-based seal, and second seal 213, such as a butyl-based seal, form seal 202 (FIG. 2) and hermetically seals space 214 in a well-known manner. Other sealing materials can alternatively or additionally be used. A desiccant (not shown) can, for example, be placed within spacer 211 in a well-known manner for preventing condensation and improving insulating performance of IGU 200.
FIG. 3 also depicts a bus bar 206 and dynamic coating 220 that have been formed on lite 203b. In one exemplary embodiment, dynamic coating 220 is an electrochromic-based coating that forms a dynamic zone. According to the subject matter disclosed herein, both bus bar 206 and dynamic coating 220 are formed across a desired area on lite 203b. A laser scribing and/or ablation process is then used to form very thin, highly isolating lines between desired dynamic zones. The bus bars that are coupled to each respective dynamic zone are made electrically available in a well-known manner through the frame of the IGU. Because each dynamic zone is isolated from other dynamic zones of the IGU, each dynamic zone can be independently controlled to vary the transmittance through the zone.
Several exemplary techniques for forming the layers of an electrochromic dynamic zone in a well-known manner generally comprise physical vapor deposition, sputtering, pyrolytic-coating techniques, wet-chemical techniques, such as a sol gel process, spin-coating techniques, and vacuum-coating techniques.
Bus bars 206 can be formed on substrate 201 prior to forming any dynamic coatings. Alternatively, bus bars 206 can be ultrasonically soldered on to substrate 201 following deposition of the dynamic zones or at an intermediate time during the deposition process. The bus bars are arranged on substrate 201 using form factors that are based on the size and shape of the desired dynamic zones. When the bus bars are formed separately for each dynamic zone, and the dynamic zone is formed as one large zone, laser ablation can be used for separating and isolating one dynamic zone from another dynamic zone. Alternatively, the bus bars may be created along the entire length of an IGU, such as depicted in FIG. 2. For this alternative technique, the laser would be used to ablate and isolate both the dynamic coating zones and the bus bars into distinct dynamic zones. When using this alternative technique, care must be taken for the removal of bus bar material ejected during ablation. Separation lines formed by laser ablation, in general, have a desired narrow width (i.e., between about 10 μm and 100 μm), have a clean edge that provides excellent electrical isolation characteristics between dynamic zones and between bus bars. Alternatively, ablation lines have a width greater than 100 μm can also be used. Lasers that are suitable for producing the ablation lines include solid-state lasers, such as Nd:YAG at a wavelength of 1064 nm, and excimer lasers, such as ArF and KrF excimer lasers respectively emitting at 248 nm and 193 nm. Other solid-state and excimer lasers are also suitable.
FIG. 4 depicts a sectional view of a first exemplary embodiment of a solid-state electrochromic device 400 that is suitable for a dynamic zone according to the subject matter disclosed herein. Electrochromic device 400 comprises a substrate layer 401 (i.e., lite 203) and a solid-state electrochromic cell 402. Electrochromic cell 402 comprises a transparent conductive layer 403, a counter electrode (CE) layer 404 (anode), an ion conductor (IC) layer 405, an electrochromic (EC) layer 406 (cathode), and a transparent conductive layer 407. Voltage V1 is applied between conductive layer 403 and conductive layer 407 to control the transmittance of cell 402 in a well-known manner. Different voltages can be independently applied to the different cells for the different dynamic zones of an IGU.
Cell 402 can be vacuum deposited in a continuous fashion onto substrate 401. Any deposition method may be used, i.e., electron beam, AC sputtering, DC sputtering or CVD for deposition of the various layers of cell 402. Another exemplary solid-state electrochromic device that is suitable for a dynamic zone is a multi-cell solid-state electrochromic device that is disclosed in U.S. patent application Ser. No. 12/145,846, entitled “Multi-cell Solid-state Electrochromic Device, invented by Roger Phillips, the disclosure of which is incorporated by reference herein.
Photochromic and thermochromic materials could be used one or more dynamic zones. Suitable photochromic materials include, but are not limited to, triarylmethanes, stilbenes, azastilbenes, nitrones, fulgides, spriropyrans, naphthopyrans, sprio-oxazines, and quinones. Suitable thermochromic materials include, but are not limited to, liquid crystals and leuco dyes. Both photochromic and thermochromic materials can be formed on substrate 201 (FIG. 2) in a well-known manner. No bus bars would be needed for photochromic or thermochromic dynamic zones because light and heat respectively modulate the properties of the materials. One exemplary embodiment using photochromic and/or thermochromic dynamic zones could be a window having at least one electrochromic dynamic zone towards the top of the window that is actively controlled for daylighting and at least one photochromic dynamic zone towards the bottom of the window that self darkens when under direct light.
While only two dynamic zones 204 and 205 are depicted in FIG. 2, it should be understood that any number of dynamic zones can be used. Moreover, while dynamic zones 204 and 205 are depicted as having a generally rectangular shape, the subject matter disclosed herein provides that a plurality of dynamic zones, each having a selected shape, can be used. Further still, while multi-pane IGU 200 is depicted as having a generally rectangular shape, the subject matter disclosed herein provides that a multi-pane IGU of any selected size and shape can be used.
Further, it should be understood that one exemplary embodiment of the subject matter disclosed herein can comprise a window having a single pane, or lite, that comprises a plurality of independently controlled dynamic zones. Another exemplary embodiment of the subject matter disclosed herein comprises an IGU comprising multiple zones of electrochromic window on one pane and clear glass on the other pane. Yet another exemplary embodiment of the subject matter disclosed herein comprises an IGU comprising multiple zones of electrochromic window on one pane and a low-E, tinted, or reflective glass on the other pane. Still another exemplary embodiment of the subject matter disclosed herein comprises an IGU comprising multiple zones of electrochromic window on one pane of the IGU and a patterned or special glass on the other pane in which the patterning or features may match, compliment, and/or contrast the areas of dynamic zones on the first pane. It should be understood that the foregoing exemplary embodiments can be configured so that the lite comprising the plurality of dynamic zones is a clear lite, a low-E lite, a reflective, and/or partially reflective lite.
Moreover, patterning of a lite and/or the characteristics of the lite can accentuate the functions of each dynamic zone in a window. For example, silk screening and/or added scattering features can be added on the opposite pane (i.e., not the pane comprising dynamic zones) corresponding to at least one dynamic zone, for example, for light harvesting in order to improve the effects of daylighting and/or for reducing glare issues. Yet other exemplary embodiments of the subject matter disclosed herein include a window pane comprising a plurality of independently controllable dynamic zones that has been glazed in a frame in a sash or a curtain wall.
Although the foregoing disclosed subject matter has been described in some detail for purposes of clarity of understanding, it will be apparent that certain changes and modifications may be practiced that are within the scope of the appended claims. Accordingly, the present embodiments are to be considered as illustrative and not restrictive, and the subject matter disclosed herein is not to be limited to the details given herein, but may be modified within the scope and equivalents of the appended claims.

## Claims

1. A method, comprising:
providing a substrate through which light can pass;
forming a single electrochromic coating and associated bus bars on the substrate; and
forming a plurality of electrochromic zones on the substrate using a laser scribing process to remove portions of the single electrochromic coating and the associated bus bars to electrically isolate the plurality of electrochromic zones.

2. The method according to claim 1, wherein forming the single electrochromic coating comprises:
forming a first transparent conductive layer on the substrate through which light can pass;
forming a counter electrode layer in contact with the first transparent conductive layer;
forming an ion conductor layer in contact with the counter electrode layer;
forming an electrochromic layer in contact with the ion conductor layer; and
forming a second transparent conductive layer in contact with the electrochromic layer.

3. The method according to claim 1, wherein at least two of the plurality of electrochromic zones are independently controllable.

4. The method according to claim 1, wherein the removed portions of the single electrochromic coating form an area between two adjacent electrochromic zones isolating the two adjacent electrochromic zones.

5. The method according to claim 1, wherein at least one zone of the plurality of electrochromic zones includes at least one of a photochromic material and a thermochromic material formed on the single substrate.

6. The method according to claim 1, wherein at least one zone of the plurality of electrochromic zones includes a photochromic material selected from the group consisting of triarylmethanes, stilbenes, azastilbenes, nitrones, fulgides, spriropyrans, naphthopyrans, sprio-oxazines, and quinones.

7. The method according to claim 1, wherein at least one zone of the plurality of electrochromic zones includes a thermochromic material selected from the group consisting of liquid crystals and leuco dyes.

8. The method according to claim 1, wherein the single substrate through which light can pass comprises one of glass, acrylic and polycarbonate.