Patent Application
20250106952
This invention relates to a glazing suitable for a sensor, a method of manufacturing the same and use of the same. The glazing is a vehicle window having a sensor bracket.
Glazings for a sensor comprising a glass sheet and a bracket on the glass sheet for mounting the sensor are known. A heating element for defogging or defrosting a heated region on the glazing, allows the sensor to receive electromagnetic radiation such as visible light or radio frequencies through the heated region. The heated region heats faster than the rest of the glazing so useful data from the sensor is available sooner. Autonomous vehicles and vehicles with advanced driver assistance systems rely on camera data so these vehicles are typically fitted with glazing for a camera with an electric heating element on the glazing.
WO2006077149A1 (Baranski) describes a retaining socket for detachable fixing of a built-in part, for example a rain sensor, to a glass pane. The built-in part is supplied with energy via supply lines on the glass pane. Energy supply on the glass surface to a heating element is provided by a permanent connecting technique, such as soldering.
Prior art glazings having electrical connections, such as solder connections or adhesive tape patches, are expensive to manufacture. Difficulties of accurately positioning components of the electrical connections result in slow cycle times for assembly of the bracket on the glass sheet.
A first need is for an alternative glazing comprising a bracket and a heating element with improved electrical connection which is a solution to a problem of easy, fast, and accurate positioning of the electrical connection. Such a glazing would overcome the shortfalls of the prior art, providing an electrical connection accurately positioned relative to the bracket and the heating element.
According to a first aspect of the present invention there is provided a glazing for a sensor, an inner glass sheet for facing the sensor, a print layer on a surface of the glazing, an opening in the print layer for the sensor to sense via the glazing, a contact pad on the inner glass sheet, a heating element for heating the opening electrically connected to the contact pad, an adhesive layer bonded to a part of the inner glass sheet, a bracket for the sensor bonded to the adhesive layer, a sensor hole in the bracket for positioning the sensor, a spring contact biased against the contact pad by the adhesive layer and attached to a connector for supplying electrical power from a power source wherein the spring contact and/or the connector is moulded in, or clipped to, the bracket.
The invention is greatly advantageous because a glazing having a spring contact biased against a contact pad and attached to a connector moulded in, or clipped to, a bracket replaces a conventional soldered connection. The invention eliminates the risks of failure in service of a lead-free solder connection.
Supplying electrical power via a connector attached to the bracket results in an unexpected synergy that the bracket also protects a spring contact attached to the connector. As a result, the invention provides a reliable electrical connection at lower cost than conventional solder connections or adhesive tape patches.
Preferably, the glazing further comprises an outer glass sheet bonded to the inner glass sheet by a ply of interlayer material.
Preferably, the sensor hole at least partly overlaps the opening in the print layer.
Preferably, the heating element at least partly overlaps the opening in the print layer.
Preferably, the connector at least partly overlaps the adhesive layer.
Preferably, the glazing further comprises a spring contact hole in the bracket for positioning the spring contact.
Preferably, the glazing further comprises a cap for covering the spring contact hole.
Preferably, the glazing further comprises a clip for clipping the spring contact to the bracket.
Preferably, the bracket has thickness 6 mm or less, more preferably 4 mm or less, most preferably 2 mm or less. Reduced thickness of the bracket is advantageous to save cost and to allow flexing of the bracket during assembly of the bracket on the glass sheet.
Preferably, the heating element is selected from a conductive coating, conductive tracks, conductive wires, or a combination thereof.
Preferably, the heating element is conductive tracks comprising silver print, silver nanowires, carbon nanotubes, graphene, silver powder, silver spheres, graphite powder, graphite rods, carbon nanotubes or glass flakes having a conductive coating or is printed using sprayed particles or is shaped as strip or braid comprising copper. More preferably, the heating element is conductive wires comprising copper, tungsten, or silver.
Preferably, a power density in the heating element is in a range from 100 to 3,000 W/m2, more preferably from 200 to 1,000 W/m2, most preferably from 300 to 600 W/m2.
A second need is for a corresponding method of manufacturing which is simple and has reduced cycle time for assembly of the bracket on the glass sheet.
According to a second aspect of the present invention, there is provided a method for manufacturing a glazing for a sensor, according to the first aspect of the present invention, comprising steps: providing an inner glass sheet for facing the sensor, printing a print layer on a surface of the glazing, forming an opening in the print layer for the sensor to sense via the glazing, printing a contact pad on the inner glass sheet, forming a heating element for heating the opening electrically connected to the contact pad, bonding an adhesive layer to a part of the inner glass sheet, bonding a bracket for the sensor to the adhesive layer, forming a sensor hole in the bracket for positioning the sensor, providing a spring contact biased against the contact pad by the adhesive layer and attached to a connector for supplying electrical power from a power source wherein the spring contact and/or the connector is moulded in, or clipped to, the bracket.
The connector moulded in, or clipped to, the bracket surprisingly makes accurate positioning of the spring contact on the contact pad easier and faster. Cycle time for assembly of the bracket on the glass sheet is thus reduced.
Preferably, the step of bonding the bracket for the sensor to the adhesive layer and the step of providing the spring contact biased against the contact pad by the adhesive layer occur simultaneously. By simultaneously bonding the bracket to the adhesive layer and providing the spring contact biased against the contact pad by the adhesive layer, cycle time for assembly of the bracket on the glass sheet is further reduced.
A third need is that the alternative glazing should meet test requirements for defogging or defrosting a vehicle window in a sensor system for faster availability of useful data from the sensor mounted on the bracket.
According to a third aspect of the present invention, there is provided use of the glazing, according to the first aspect of the present invention, as a windshield, a rear window, a side window, or a roof window of a motor vehicle, for a sensor system to enable an autonomous vehicle or a vehicle with an advanced driver assistance system.
A result of the invention is that the glazing meets industrial test requirements for defogging and defrosting, for example of a vehicle window having a camera. The invention also meets test requirements for a glazing serving as a vehicle windshield in a camera system to enable an autonomous vehicle or a vehicle with an advanced driver assistance system. The improved electrical connection according to the present invention has lower resistance than conventional electrical connections, so more electrical power is available to the heating element. Defogging and defrosting is thereby faster, so useful data from the sensor is available sooner.
The invention will now be further disclosed by non-limiting drawings.
The inner glass sheet (1) and the outer glass sheet (12) are preferably soda lime silica glass, manufactured using the float process. Glass thickness is preferably in a range from 2 to 12 mm. The inner glass sheet (1) or the outer glass sheet (12) may be toughened glass with surface stress greater than 65 MPa, or heat strengthened glass with surface stress in a range from 40 to 55 MPa, or semi-toughened with surface stress in a range from 20 to 25 MPa, or annealed glass. The interlayer material (11) is any thermoplastic resin, preferably polyvinyl butyral (PVB).
A print layer (2) is printed on an inner surface (S2) of the outer sheet (12) and/or on an inner surface (S4) of the inner glass sheet (1).
The print layer (2) may comprise a black enamel deposited by screen printing black ink in a selected region on the inner glass sheet (1) or the outer glass sheet (12). The inner glass sheet (1) or the outer glass sheet (12) is then baked at a predetermined temperature to make the printed ink into a hard enamel. Advantageously, the print layer (2) extends around a periphery of the glazing (10) to mask an adhesive material, such as polyurethane (PU), used to bond the glazing (10) to a vehicle body (not shown).
An opening (2a) is arranged in the print layer (2) for the sensor to sense via the glazing (10). The sensor may be a camera, an RFID tag, or any electronic device to transmit and receive electromagnetic radiation, such as visible light or radio frequencies. For example, vehicle windows allow data acquisition for toll collection, or for Advanced Driver Assistance Systems (ADAS) to assist drivers in driving and parking functions. The sensor is mounted on a bracket (5) on a surface of the inner glass sheet (1). Optionally, a larger opening (2b) is formed in the print layer (2) for example as a vision area for a driver of a vehicle.
A contact pad (3) is provided on the inner glass sheet (1). The contact pad (3) is typically printed using a silver-containing ink. The contact pad (3) may be printed on the print layer (2) adjacent the opening (2a) as shown. Advantageously, the print layer (2) masks the contact pad (3) from view.
A heating element (3a) for heating the opening (2a) is provided on a first surface of the inner glass sheet (1) and is electrically connected to the contact pad (3). The heating element (3a) is typically conductive lines comprising silver print. The contact pad (3) and the heating element (3a) may comprise the same material and may be printed simultaneously. The heating element (3a) extends adjacent to or in the opening (2a).
An adhesive layer (4) is bonded to a part of the inner glass sheet (1). The adhesive layer (4) may be applied to the inner glass sheet (1), or to a bracket (5). The bracket (5) is then pressed towards the inner glass sheet (1). A plurality of adhesive layers (4) may bond the bracket (5) to the inner glass sheet (1), for example two adhesive layers (4) as shown. The plurality of adhesive layers (4) may form a dashed line. The adhesive layer (4) may be polyurethane (PU).
The bracket (5) for the sensor is bonded to the adhesive layer (4) and allows the sensor to be mounted securely on the inner glass sheet (1). A sensor hole (5a) formed in the bracket (5) is for positioning the sensor for example concentric with the opening (2a) in the print layer (2). The bracket (5) may be made of a metal such as steel or aluminium, or a plastic such as polybutylene terephthalate (PBT), optionally blended with polycarbonate (PC), acrylonitrile styrene acrylate (ASA), acrylonitrile styrene (SAN), polyamide (PA) or any combination thereof, or polyetherimide (PEI). The plastic is preferably a thermoplastic material suitable for injection moulding.
A spring contact (6) is biased against the contact pad (3) by the adhesive layer (4) and attached to a connector (7) for suppling electrical power from a power source.
Optionally, the inner glass sheet (1) and an outer glass sheet (12) are bonded together by a ply of interlayer material (11) as shown.
| Number | Date | Country | Kind |
|---|---|---|---|
| 22425002.7 | Jan 2022 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/GB2023/050179 | 1/26/2023 | WO |
