Heated inlaid glass panel

Abstract

The present invention relates to a sandwich-type electrically heated embedded glass panel, comprising: (i) a first outer substrate and a second inner substrate (1) having an inner surface and an outer surface, the first outer substrate and the second inner substrate being sandwiched to each other via at least one polymer-enclosed interlayer; (ii) a coating (2) comprising at least one heatable conductive layer disposed between the outer substrate and the inner substrate, the coating (2) being divided into at least one heatable coating region (31) and at least one non-heatable coating region (42, 43), the first heatable region (31) being defined by at least two region boundaries (6, 7) insulated by coating-eliminated regions; and (iii) at least a first conductive busbar and a second conductive busbar (21, 22), each of the spaced first busbar and second busbar (21, 22) being adapted to supply voltage across the at least one electrically heated coating region (31). According to the invention, when current flows through the first busbar and the second busbar (21, 22), only the at least one electrically heated coating region (31) is heated, and wherein the conductive path is defined between these busbars (21, 22).

Description

Technical Field

[0001] This invention relates to an electrically heatable embedded glass panel. Background Technology

[0002] In the case of a heatable mounted glass panel comprising a conductive coating and being of a substantially regular shape (e.g., rectangular), current is carried to the conductive coating through, for example, metal busbars that are substantially parallel to each other. In this particular case, the distance between the busbars along their entire length remains substantially the same. Therefore, the resistance of the current path along the length of these busbars is substantially the same. When such a mounted glass panel is subjected to a given voltage, the amount of heat generated will be substantially uniform across the entire surface of the mounted glass panel covered with the conductive coating.

[0003] In the case of significantly irregularly shaped heated glass panels (e.g., those used in the automotive, railroad, or aerospace industries), busbars that branch off at intervals along at least a portion of their length can be used. Consequently, the distance between the busbars changes, and therefore the resistance of the current path also changes. Therefore, when such a heated glass panel is subjected to a given voltage, the amount of heat generated will vary along the length of the busbars, creating a risk of localized overheating that could damage or destroy the conductive coating. Furthermore, when such heated glass panels are used for defogging or de-icing purposes, some areas may defog or de-ic than others. This can create visibility problems for observers looking through such glass panels.

[0004] Heated windows are known in the art. Conventional heated windows for vehicles typically include a first and a second conductive busbar in electrical contact with a conductive coating (which includes a conductive layer). Typically, the first busbar is located at the top of the window, and the second busbar is located at the bottom. When current flows through the conductive layer located between these busbars, the conductive layer generates heat. In this way, snow and ice can be melted from vehicle windows (such as windshields, rear windows, side windows, etc.). This method can also be used to defog windows.

[0005] In recent years, laminated rear window glass and large windshields that extend to the sunroof to form a "one-piece" have become ideal choices for vehicles such as cars, trucks, and SUVs.

[0006] Unfortunately, it is often difficult to heat the glass mount evenly and efficiently in its usual locations, including the busbars and defrosting / defogging areas, especially in the main area of ​​the glass mount corresponding to the visible area observed by an observer through the glass mount panel. If the shape of the upper busbar in a conventional heated windshield is simply modified to heat the glass mount panel more efficiently, hot spots tend to form at the corners / bends of the upper busbar when the windshield is heated (i.e., the current is not distributed roughly evenly).

[0007] In view of the above, it will be apparent to those skilled in the art that there is a need in the art for a heatable window design that allows the current to be distributed approximately evenly, thereby reducing the possibility of overheating and enabling efficient heating of the window. Summary of the Invention

[0008] According to one aspect, the present invention provides a heatable fitted glass panel as claimed in claim 1. The other claims define alternative and / or preferred aspects of the invention.

[0009] The purpose of this invention is to provide a heatable vehicle window, the heatable vehicle window comprising a laminated electrically heatable inlaid glass panel, the laminated electrically heatable inlaid glass panel comprising:

[0010] - A first outer substrate and a second inner substrate having an inner surface and an outer surface, respectively, the first outer substrate and the second inner substrate being laminated to each other via at least one polymer-enclosed intermediate layer;

[0011] - A coating comprising at least one heatable conductive layer disposed between the outer substrate and the inner substrate, the coating being divided into at least one heatable coating region and at least one non-heatable coating region, the first heatable region being defined by at least two region boundaries insulated by coating-eliminated areas.

[0012] - At least a first conductive bus and a second conductive bus, each of the busbars spaced between the first bus and the second bus being adapted to supply voltage across the at least one electrically heatable coating region.

[0013] According to the invention, when current flows through the first busbar and the second busbar, only the at least one electrically heatable coating area is heated, and wherein the conductive path is defined between these busbars.

[0014] Another object of the present invention is to provide a heatable window design that is less likely to overheat and is able to heat uniformly in the at least first heatable zone.

[0015] Another object of the present invention is to accomplish one or more of the objects listed above.

[0016] When voltage is applied across the busbars of these intervals, the heat generated can be substantially uniform across the entire surface of the mounted glass panel. In one embodiment, the mounted glass panel can thus be de-iced or defogged substantially uniformly.

[0017] Advantageously, at least a portion of the conductive path extends substantially from the lower edge of the mounted glass panel to the upper edge of the mounted glass panel. In this embodiment, heat can be generated substantially simultaneously at both the upper and lower edges of the mounted glass panel, thereby providing uniform heating at both edges of the mounted glass panel.

[0018] According to embodiments of the invention, at least a portion of the conductive path extends substantially from a side edge of the inlaid glass panel to the opposite side edge and the lower edge of the inlaid glass panel. This is particularly true for large windshields of automobiles, such as those extending to sunroofs to form a single piece of glass (also called a roof) formed by the windshield and the sunroof. This type of inlaid glass offers visual advantages but is difficult to heat uniformly without generating hot spots, and therefore may cause damage to the inlaid glass.

[0019] Therefore, one object of the present invention is to provide a solution for uniformly, rapidly, and efficiently heating the visible area observed by an observer through such an inlaid glass panel. This may be attributed to defining the area to be heated rapidly and efficiently by removing the coating.

[0020] Preferably, the mounting glass panel is substantially covered with a conductive coating; for example, the coating may cover at least 60%, 70%, 75%, 80%, 85%, 90%, or 95% of the mounting glass panel. This can provide a mounting glass panel having substantially the same optical properties (e.g., reflection, reflected color, total visible light transmittance, total energy transmittance) in each zone and preferably substantially the same across the entire visible surface of the mounting glass.

[0021] Preferably, the glass panel according to the invention is an automotive glass panel, and more specifically a windshield or laminated rear window glass.

[0022] Arranging the conductive paths of the electrically heatable regions according to the invention to uniformly and efficiently heat at least the desired areas within the conductive coating allows the surface of the conductive paths to be designed independently of the size, shape, or configuration of the mounting glass panel. This allows for selection of the resistance of the conductive paths at different portions of the mounting glass panel without directly limiting the height, shape, or configuration of the mounting glass panel at the portions in question. In some embodiments, this can be used to achieve substantially uniform heating across the entire surface of the mounting glass panel, particularly when substantially the same voltage is applied across each conductive heatable region.

[0023] Advantageously, these busbars are positioned along the length of the same edge of the fitted glass panel, for example, along the lower edge of the fitted glass panel; this can help to conceal the busbars from being seen, for example by covering them with enamel or other masking agents, or by arranging them in a way that they are hidden in use, for example, by being hidden by part of the vehicle body.

[0024] The electrically heated zone is defined by at least two insulated zone boundaries. As used herein, "insulated" means a zone boundary that is less conductive than the coating or substantially does not conduct current.

[0025] Zone boundaries can be provided by patterning a material less conductive than the conductive coating onto the conductive coating. Preferably, the zone boundaries are provided by one or more uncoated portions of the mounted glass panel. These one or more uncoated portions may have resistance such that when a voltage is applied between the busbars, substantially no current flows, and therefore they may be substantially non-conductive. One or more uncoated portions can be provided by patterning a masking agent onto the substrate before depositing the conductive layer and then removing the masking agent covering the coating. Alternatively, one or more uncoated portions can be provided by removing the conductive coating after deposition. Advantageously, the coating can be removed using a laser, such as a laser diode. These zone boundaries can be substantially invisible to the naked eye, especially when formed by removing a portion of the coating using a laser. Advantageously, the width of the zone boundaries is equal to or greater than 300 μm. Zone boundaries can define or substantially define one electrically heatable zone from another electrically heatable zone.

[0026] These busbars can be formed by depositing precious metal paste (such as silver paste) or by depositing metal strips.

[0027] Applying a conductive coating, which is intended to serve as a solar control coating, allows the function of preventing excessive solar energy transmission through the mounting glass to be combined with the heatability of the mounting glass panel. The term "solar control" here refers to a coating that increases the selectivity of the substrate, i.e., increases the ratio of incident visible light transmitted through the substrate to incident solar energy transmitted through the substrate. Alternatively, the conductive coating can be a low-emissivity coating.

[0028] The conductive coating can be deposited using vacuum deposition techniques (e.g., by magnetron sputtering) or formed pyrolytically, for example, by chemical vapor deposition. Preferably, the coating is applied to the entire surface of the substrate or to a large portion of the surface.

[0029] In a preferred embodiment of the invention, the coating film includes at least one metallic infrared reflective layer. The coating film may include a series of layers: dielectric layer / silver / dielectric layer or dielectric layer / silver / dielectric layer / silver / dielectric layer. These dielectric layers may include, for example, tin oxide, zinc oxide, silicon nitride, titanium oxide, aluminum oxide, or one or more mixtures thereof.

[0030] The conductive coating preferably has a resistance between 0.5 ohms / square and 100 ohms / square, more preferably between 0.5 ohms / square and 25 ohms / square (e.g., 0.8 ohms / square, 2 ohms / square, 5 ohms / square or 10 ohms / square).

[0031] In the inlaid glass panel according to the invention, the substrate can be glass, such as a flat glass sheet, soda-lime glass sheet, or float glass sheet, particularly a glass sheet intended for subsequent use as or incorporated into an architectural or vehicle inlaid glass panel. It can be subjected to heat toughening or bending treatment before or after a coating has been deposited on at least a portion of its surface. Alternatively, the substrate can be a rigid or flexible plastic sheet material, which can also be intended for subsequent use as or incorporated into an architectural or vehicle inlaid glass panel.

[0032] The conductive coating can be applied directly to the surface of the substrate, or alternatively, it can be applied using a film, such as PET or other plastic sheet materials bonded to an embedded glass panel.

[0033] The embedded glass panel can be the windshield or rear window of a vehicle or train, the windshield of an aircraft, or an embedded glass panel with applications in the marine field.

[0034] The embedded glass panel can be adapted to have a voltage applied across the busbar between 10 and 100 volts, preferably between 30 and 55 volts. For automotive applications, a voltage of 32 volts, more preferably 36 volts, and most preferably 42 volts is applied. Alternatively, the embedded glass panel can be adapted to have a voltage applied across the busbar between 10 and 14 volts, for example, about 12 volts. The heat generated by the electrically heated area preferably includes between 250 watts / m² and 1500 watts / m². Attached Figure Description

[0035] Figure 1 This is a top view of a heated rear window glass of a vehicle according to another exemplary embodiment of the present invention. Detailed Implementation

[0036] The invention will now be described by way of example only, with reference to... Figure 1 It is a schematic representation of a glass panel.

[0037] Some embodiments of the present invention relate to a heatable vehicle window, and more specifically to a rear window glass comprising at least a first heating zone. Initially, a heatable coating (comprising one or more layers, at least one of which is conductive and heatable) is applied to a substrate of the window. The initial coating is partially removed to divide it into at least two distinct, spaced-apart heatable coating portions and a heating zone. First and second spaced-apart conductive busbars are disposed on the heatable coating portions, wherein these two busbars are electrically connected to each of the at least two distinct heatable coating portions. Using these two busbars, current is allowed to flow through at least one heating zone, the spaced-apart heatable coating portions (but not connected to these busbars), to uniformly and efficiently heat the main area corresponding to the visible area observed by an observer through this fitted glass panel, thereby heating the window.

[0038] Because the coating is divided into at least two distinct coating sections, a roughly uniform current distribution is achieved along the top busbar, thereby reducing the likelihood of overheating when the window is heated.

[0039] Reference Figure 1 The rear window glass of the vehicle includes a coating sandwiched between a first glass substrate and a second glass substrate. In some embodiments of the invention, the coating may be a single-layer coating (e.g., conductive Ag or ITO), or alternatively, in other embodiments of the invention, it may be a multi-layer low-E coating. The coating is at least partially removed via an elimination line to divide the coating into at least two distinct, spaced-apart heatable coating portions: a first heatable coating portion and a second or / or third intermediate coating portion not specifically designed for heating. This removal of the initial coating may be accomplished via laser removal, sandblasting removal, removal grinding wheels or discs, or any other suitable coating removal technique / equipment.

[0040] The heatable coating portion is separated from the unheated portion by an insulating area formed by the removal of the coating (i.e., see the removal / insulation area between the heatable coating portion and the removal / insulation area).

[0041] Because the coating is removed via elimination lines, the first heatable area and the other coated portion are electrically insulated from each other (completely or at least partially). For illustrative purposes only, the insulating / elimination area may be formed in the shape of a fine line (e.g., providing a gap of approximately 0.5 mm or less). Alternatively, in some embodiments, the coating may also be eliminated along at least one edge of the window (e.g., see coating elimination area 4c along the edges(multiple) of the window) to accommodate busbar leads, extensions(multiple) etc.

[0042] See still Figure 1For conventional interlayer purposes, a polyvinyl butyral (PVB) encapsulated interlayer (not shown) is disposed between substrates. According to certain embodiments of the invention, a coating is disposed on the inner surface of one of the substrates such that the coating is disposed on a second or third surface conventionally referred to as a rear window or windshield. Figure 1 A laminated glass panel (10) in the form of a rear window glass for an automobile is shown; a substantially transparent conductive coating (2) covering essentially the entire surface of the glass panel; busbars (21, 22); and insulating zone boundaries (6), (7) defining an electrically heated zone (31). The electrically heated zone (31) is the visible area observed by an observer through this glass panel. Two adjacent zones (42, 43) with an electrocoated coating are not heated because they are not electrically connected to the busbars (21, 22). Each busbar is formed by screen printing an exemplary 40 μm thick and 15 mm wide layer of silver paste.

[0043] The busbar is placed in a laminated glass that is in contact with a heatable conductive coating.

[0044] In this embodiment, spaced busbars 21 and 22 are disposed in the upper edge 35 and lower edge 36 of the embedded glass. In this embodiment, busbars 21 and 22 extend partially along the side edges of the embedded glass. An insulating zone boundary 7 (which preferably has the form of a line) defines the zone 31 to be heated.

[0045] The busbar can be made of copper and then glued to the mounting glass using adhesive.

[0046] The conductive path of the first electrically heated zone 31 is defined between busbars 21 and 22, which are suitable for applying voltage across the electrically heated zone.

[0047] The boundaries of the insulating zones 6 and 7 are created by removing the coating. The coating is removed substantially perpendicular to the upper and lower edges 35 and 36 of the mounting glass.

[0048] Advantageously, the coating can be removed using a laser, such as a laser diode. These zone boundaries can be substantially invisible to the naked eye, especially when formed by removing a portion of the coating using a laser. Advantageously, the width of the zone boundaries is equal to or greater than 300 μm. The zone boundaries can define or substantially define one electrically heatable zone from another electrically heatable zone.

[0049] These busbars can be concealed in use by hiding the lower and side edges of the embedded glass panel within the vehicle body to which the embedded glass panel is adapted for installation.

[0050] According to another embodiment of the invention, the embedded glass panel 10 may be an automotive roof (i.e., a windshield extending into a sunroof and comprising laminated embedded glass); a substantially transparent conductive coating covering essentially the entire surface of the embedded glass; busbars; and an insulating boundary defining an electrically heated area. This electrically heated area is the visible area observed by an observer through such an embedded glass panel. Two areas adjacent to the first heated area, with an electrically coated portion, are not heated because they are not electrically connected to the busbars. Each busbar is formed by screen printing an exemplary 40 μm thick and 15 mm wide layer of silver paste.

[0051] The busbar is placed in a laminated glass that is in contact with a heatable conductive coating.

[0052] In this embodiment, the spaced busbars are laterally spaced near the side edges of the glazing and in the lower edge of the glazing in contact with the heatable conductive coating. In this particular embodiment, the busbars are made as a single piece. The busbars can be made of copper and then adhered to the glazing using adhesive. In this particular embodiment, a first boundary is located in the lower portion of the glazing and a second boundary is located in the upper portion of the glazing, more specifically, in the "windshield section," to define the visible area viewed by an observer through this glazing panel. In this case, the canopy is not heated by the application of current. The busbars can be made as a single piece.

[0053] The busbar can be made of copper and then glued to the mounting glass using adhesive.

Claims

1. A sandwiched electrically heatable glazing panel (10) comprising: - a first outer substrate and a second inner substrate (1) each having an inner face and an outer face, the first outer substrate and the second inner substrate being laminated to each other via at least one polymeric containment interlayer; - a coating (2) comprising at least one heatable electrically conductive layer disposed between the outer substrate and the inner substrate, the coating (2) being divided into at least one heatable coating zone (31) and at least one non-heatable coating zone (42, 43), the at least one heatable coating zone (31) being delimited by at least two zone boundaries (6, 7) insulated by a coating elimination area, - at least a first busbar and a second busbar (21, 22) electrically unconnected to the at least one non-heatable coating zone (42, 43), each of the spaced first and second busbars (21, 22) being adapted to supply a voltage across the at least one heatable coating zone (31), and wherein, when an electric current flows through the first and second busbars (21, 22), only the at least one heatable coating zone (31) is heated, and wherein an electrically conductive path is defined between these busbars (21, 22), - wherein the glazing panel has an irregular shape, - one busbar is disposed at an upper edge of the glazing, the other busbar is disposed at a lower edge of the glazing, - the busbars (21, 22) are parallel to each other, - the heatable coating zone (31) is a visible zone for an observer looking through such glazing panel.

2. The electrically heatable glazing panel (10) according to claim 1, wherein At least a portion of the electrically conductive path extends substantially from the lower edge (35) of the glazing panel to the upper edge (36) of the glazing panel.

3. The electrically heatable glazing panel (10) according to claim 1 or 2, wherein The at least one heatable coating zone (31) is a main surface of the glazing.

4. The electrically heatable glazing panel (10) according to claim 2, wherein The first and second busbars (21, 22) are disposed along the length of the lower edge (35) and the upper edge (36) of the glazing panel.

5. The electrically heatable glazing panel (10) according to claim 1 or 2, wherein The heatable coating zone (31) is delimited by at least two zone boundaries (6, 7) insulated by uncoated portions of the glazing panel.

6. The electrically heatable glazing panel (10) according to claim 1 or 2, wherein One of the first and second busbars (21, 22) extends along the at least one heatable coating zone (31).

7. The electrically heatable glazing panel (10) according to claim 1 or 2, wherein The at least two zone boundaries (6, 7) have a width of 300 pm or more.

8. The electrically heatable glazing panel (10) according to claim 1 or 2, wherein The coating (2) is a solar control coating.

9. The electrically heatable glazing panel (10) according to claim 1 or 2, wherein The coating (2) has an electrical resistance ranging between 2 ohm / square and 25 ohm / square.

10. The electrically heatable glazing panel (10) according to claim 1 or 2, wherein The second inner substrate (1) is a glass sheet.

11. The electrically heatable glazing panel (10) according to claim 1 or 2, wherein The coating elimination area comprises a first and a second linear coating elimination area delimiting the at least one heatable coating zone (31).

12. The electrically heatable glazing panel (10) according to claim 1 or 2, wherein The glazing panel is an automotive windshield.

13. The electrically heatable glazing panel (10) according to claim 1 or 2, wherein The glazing panel is an automotive glazing formed on a windshield sheet extending to a sunroof.

14. The electrically heatable glazing panel (10) according to claim 2, wherein The glazing panel is a rear window, wherein the coating elimination area is perpendicular to the upper and lower edges (36, 35) of the glazing in plan view.

15. The electrically heatable glazing panel (10) according to claim 1 or 2, wherein The at least one heatable coating zone (31) extends over the field of view of a passenger of the vehicle.

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