Electrically heatable pane with switch region

Abstract

An electrically heatable pane with a switch region is presented. The pane has a transparent substrate, with at least one transparent electrically conductive layer that is, at least partially, arranged on a surface of the pane. At least one separating line electrically divides the layer into a heating region and a switch region. At least two busbars are provided for connection to a voltage source. The busbars being connected to the heating region, form a current path between the busbars. A heating current can therefore flow through the current path. Furthermore, the switch region has at least one contact region, a feed line region, and a connection region, where the connection region can be connected to sensor electronics.

Claims

1. An electrically heatable pane with a switch region, comprising: a transparent substrate with a surface, at least one transparent and electrically conductive layer arranged on at least a part of the surface, at least one separating line that electrically divides the electrically conductive layer into a heating region and a switch region, and at least two busbars provided for connection to a voltage source that are connected to the heating region to form a current path for a heating current between the busbars, wherein: the switch region comprises at least one contact region, a feed line region, and a connection region, the at least one contact region, the feed line region, and the connection region are contiguous regions of the electrically conductive layer, the feed line region electrically connects the at least one contact region to the connection region, the connection region is adapted to be electrically connected to sensor electronics, and an area of the contact region is from 1 cm.sup.2 to 200 cm.sup.2 and/or a width of the at least one separating line is from 30 m to 200 m, and at least one additional separating line electrically divides the electrically conductive layer into a surrounding region that completely surrounds the switch region, and wherein the surrounding region has an additional connection region adapted to be connected to the sensor electronics.

2. The electrically heatable pane according to claim 1, wherein the feed line region has a length of 1 cm to 70 cm, and has a width of 0.5 mm to 10 mm.

3. The electrically heatable pane according to claim 1, wherein an angle a between the current path and a longitudinal direction of the feed line region is from 0 to 45.

4. The electrically heatable pane according to claim 1, wherein the connection region is arranged according to one of: a) at an edge of the pane, and b) adjacent to one of the busbars.

5. The electrically heatable pane according to claim 1, wherein the surrounding region has the same or a similar shape as the switch region and is implemented in a shape comprising one of: a) a circle, b) an ellipse, c) a drop, and d) a strip with rounded corners.

6. The electrically heatable pane according to claim 1, wherein the surface of the substrate is connected to a cover pane via a thermoplastic intermediate layer in a planar manner.

7. The electrically heatable pane according to claim 1, wherein at least one of the substrate and the cover pane contains one or a mixture of: a) glass, and b) polymers.

8. The electrically heatable pane according to claim 1, wherein the electrically conductive layer has a sheet resistance of 0.4 ohm/square to 10 ohm/square.

9. A pane arrangement comprising: the electrically heatable pane according to claim 6, and sensor electronics electrically connected to the connection region of the electrically heatable pane, wherein sensitivity of the sensor electronics is selected so as to output: i) a first switching signal when the at least one contact region of the electrically heatable pane is touched on the substrate by a human finger, and ii) no switching signal or a second switching signal, different from the first switching signal, when the at least one contact region is touched on the cover pane of the electrically heatable pane.

10. A pane arrangement comprising: the electrically heatable pane according to claim 6, and sensor electronics electrically connected to the connection region of the electrically heatable pane, wherein sensitivity of the sensor electronics is selected so as to output: i) a first switching signal when the at least one contact region is touched on at least one of the substrate and the cover pane by human finger, and ii) no switching signal or a second switching signal, different from the first switching signal, when the feed line region is touched on the substrate and/or the cover pane, wherein the connection region of the electrically heatable pane is connected to a flat conductor.

11. The electrically heatable pane according to claim 1, wherein the feed line region has a length of 1 cm to 8 cm and has a width of 0.5 mm to 2 mm.

12. The electrically heatable pane according to claim 2, wherein the feed line region has a shape of a rectangle, a strip, or a line.

13. The electrically heatable pane according to claim 1, wherein an angle a between the current path and a longitudinal direction of the feed line region is from 0 to 20.

14. The electrically heatable pane according to claim 1, wherein the feed line region has a length and a width, and wherein a ratio of the length to the width is less than or equal to 1:700.

15. The electrically heatable pane according to claim 4, wherein a distance from the connection region to one of a) and b) is less than, or equal to, 10 cm.

16. The electrically heatable pane according to one of claim 1, wherein the contact region has a shape according to one of: a) a circle, b) an ellipse, c) a drop, and d) rounded corners.

17. The electrically heatable pane according to claim 1, wherein a width of the at least one separating line is from 70 m to 140 m.

18. The electrically heatable pane according to claim 6, wherein the thermoplastic intermediate layer has a permittivity number from 2 to 4.

19. The electrically heatable pane according to claim 7, wherein a) comprises one or more of: a1) flat glass, a2) float glass, a3) quartz glass, a4) borosilicate glass, and a5) soda lime glass, and wherein b) comprises one or more of: b1) polyethylene, b2) polypropylene, b3) polycarbonate, and b4) polymethyl methacrylate.

20. The electrically heatable pane according to claim 1, wherein the electrically conductive layer has a sheet resistance of 0.5 ohm/square to 1 ohm/square.

21. The electrically heatable pane according to claim 2, wherein the electrically conductive layer comprises of one more of: a) silver (Ag), b) indium tin oxide (ITO), c) fluorine-doped tin oxide (SnO2:F), and d) aluminumdoped zinc oxide (ZnO:AI).

22. A pane arrangement comprising the electrically heatable pane according to claim 10, wherein the connection region of the electrically heatable pane is connected to a flat conductor, and wherein the flat conductor is guided out of the electrically heatable pane.

23. A method for producing the electrically heatable pane according to claim 1, the method comprising: applying a transparent electrically conductive layer on a surface of a transparent substrate; forming at least one separating line that electrically divides the transparent electrically conductive layer into at least one heating region and one switch region; and connecting at least two busbars to the transparent electrically conductive layer for connection to a voltage source, thereby forming a current path for a heating current between the at least two busbars.

Description

(1) In the following, the invention is explained in detail with reference to drawings and exemplary embodiments. The drawings are schematic depictions and not true to scale. The drawings in no way restrict the invention.

(2) They depict:

(3) FIG. 1A a top plan view of an embodiment of a pane arrangement according to the invention with a pane according to the invention,

(4) FIG. 1B an enlarged view of the detail Z of FIG. 1A,

(5) FIG. 1C a cross-sectional view along the cutting line A-A of FIG. 1A,

(6) FIG. 1D another view of the detail Z of FIG. 1A,

(7) FIG. 2A an alternative embodiment of a pane according to the invention in an enlarged view of the detail Z of FIG. 1A,

(8) FIG. 2B a cross-sectional view along the cutting line B-B of FIG. 2A,

(9) FIG. 3 another alternative embodiment of the pane according to the invention in an enlarged view of the detail Z of FIG. 1A,

(10) FIG. 4A a top plan view of an alternative embodiment of the pane according to the invention,

(11) FIG. 4B an enlarged view of the detail Z of FIG. 4A,

(12) FIG. 4C a cross-sectional view along the cutting line C-C of FIG. 4A,

(13) FIG. 5 a detailed flow chart of an embodiment of the method according to the invention.

(14) FIG. 1A depicts a top plan view of an exemplary embodiment of a pane arrangement 101 according to the invention with a pane 100 according to the invention. The pane 100 includes a substrate 1 and is made, for example, of soda lime glass. An electrically conductive layer 2 is applied on a surface III of the substrate 1. The electrically conductive layer 2 is a layer system, which includes, for example, three electrically conductive silver layers that are separated from each other by dielectric layers. When a current flows through the electrically conductive layer 2, it is heated as a result of its electrical resistance and Joule heat generation. Consequently, the electrically conductive layer 2 can be used for active heating of the pane 100. The dimensions of the pane 100 are, for example, 0.9 m1.5 m.

(15) The electrically conductive layer 2 is divided by a separating line 4.1 into a heating region 3 and a switch region 10. In other words, both the heating region 3 and the switch region 10 are made from the electrically conductive layer 2, but are electrically isolated from each other by the separating line 4.1. The separating line 4.1 has a width d.sub.1 of, for example, only 100 m and is, for example, introduced into the electrically conductive layer 2 by laser patterning. Separating lines 4.1 with such a small width are optically hardly perceptible and disrupt vision through the pane 100 only little, which is, especially for use in motor vehicles, of particular importance for driving safety.

(16) For the electrical contacting of the heating region 3, a first busbar 5.1 is arranged in the lower edge region and another second busbar 5.2 is arranged respectively in the upper edge region of the heating region 3. The busbars 5.1, 5.2 contain, for example, silver particles and were applied in the screenprinting method and subsequently fired. The length of the busbars 5.1, 5.2 corresponds approx. to the dimension of the electrically conductive layer 2. The two busbars 5.1, 5.2 run approx. parallel.

(17) FIG. 1B depicts an enlarged view of the detail Z of FIG. 1A. The switch region comprises a contact region 11, which is implemented approx. drop-shaped and transitions into a feed line region 12. Here, drop-shaped means that contact region 11 is substantially circular and tapers funnel-like on one side toward the feed line region 12. The width b.sub.B of the contact region 11 is, for example, 40 mm. The width b.sub.Z of the feed line region 12 is, for example, 1 mm. The ratio b.sub.Z:b.sub.B is thus roughly 1:40. The feed line region 12 is connected to a connection region 13. The connection region 13 has a square shape with rounded corners and a side length b.sub.A of, for example, 12 mm. The length l.sub.Z of the feed line region is roughly 48 mm.

(18) The connection region 13 is electrically conductively connected via an electrical line connection 20 to a foil conductor 17. The foil conductor 17 consists, for example, of a 50 m thick copper foil and is, for example, insulated outside the connection region 13 with a polyimide layer. Thus, the foil conductor 17 can be guided out beyond the busbar 5.2 over the upper edge of the pane 100 without an electrical short circuit. Of course the electrical connection of the connection region to the outside can also be guided outward via insulated wires or via a region, in which the busbar 5.2 is interrupted.

(19) Here, the foil conductor 17 is, for example, connected outside the pane 100 to capacitive sensor electronics that measure the capacitance changes of the switch region 10 against ground and, as a function of a threshold value, forwards a switch signal via the connection point 19, for example, to the CAN bus of a motor vehicle. Any functions in the motor vehicle, for example, even the voltage source 6 and, thus, the electrical heating of the pane 100 via the heating region 3, can be switched via the switch signal.

(20) FIG. 1C is a cross-sectional view along the cutting line A-A of FIG. 1A.

(21) Here, the pane 100 comprises, for example, a substrate 1 and a cover pane 9 that are bonded to each other via a thermoplastic intermediate layer 8. The pane 100 is, for example, a motor vehicle window and, in particular, the windshield of a passenger car. The substrate 1 is, for example, intended to face the interior in the installed position. In other words, the side IV of the substrate 1 is accessible from the interior out, whereas side I of the cover pane faces outward. Substrate 1 and cover pane 9 are made, for example, of soda lime glass. The thickness of the substrate 1 is, for example, 1.6 mm and the thickness of the cover pane 9 is 2.1 mm. Of course, the substrate 1 and the cover pane 9 can have any thicknesses and can, for example, even be implemented with the same thickness. The thermoplastic intermediate layer 8 is made of polyvinyl butyral (PVB) and has a thickness of 0.76 mm. The electrically conductive layer 2 is applied on the interior-side surface III of the substrate 1.

(22) The electrically conductive layer 2 extends, for example, over the entire surface III of the substrate 1 minus a circumferential frame-like uncoated region with a width of 8 mm. The uncoated region serves for electrical insulation between the voltage-carrying electrically conductive layer 2 and the motor vehicle body. The uncoated region is hermetically sealed by gluing to the intermediate layer 8 in order to protect the electrically conductive layer 2 against damage and corrosion.

(23) For the electrical contacting of the heating region 3 of the electrically conductive layer 2, a first busbar 5.1 is arranged in the lower edge region and an additional, second busbar 5.2 is arranged respectively in the upper edge region on the electrically conductive layer 2. The busbars 5.1, 5.2 contain, for example, silver particles and were applied by the screen printing method and subsequently fired. The length of the busbars 5.1, 5.2 corresponds approximately to the dimension of the heating region 3.

(24) When an electrical voltage is applied to the busbars 5.1 and 5.2, a uniform current flows through the electrically conductive layer 2 of the heating region 3 between the busbars 5.1,5.2. In roughly the center of each busbar 5.1,5.2, a foil conductor 17 is arranged. The foil conductor 17 is electrically conductively connected to the busbar 5.1,5.2 via a contact surface, for example, by means of a soldering compound, an electrically conductive adhesive, or by simple placement and contact pressure within pane 100. The foil conductor 17 contains, for example, a tinned copper foil with a width of 10 mm and a thickness of 0.3 mm. The busbars 5.1,5.2 are connected via the foil conductor 17 via feed lines 18 to a voltage source 6, which provides onboard voltage customary for motor vehicles, preferably from 12 V to 15 V and, for example, roughly 14 V. Alternatively, the voltage source 6 can also have higher voltages, for example, from 35 V to 45 V and, in particular, 42 V.

(25) The busbars 5.1,5.2 have, in the example depicted, a constant thickness of, for example, roughly 10 m and a constant specific resistance of, for example, 2.3 ohm.Math.cm.

(26) FIG. 1D depicts another view of the detail Z of FIG. 1A, in which the center current path 7 in the surrounding of the switch region 10 is depicted. The longitudinal direction of the feed line region 12 (depicted here by a parallel dash line 21) has an angle of, for example, 0.5 relative to the direction of the current path 7. Thus, the flow of current of the heating current upon application of a voltage to the busbars 5.1,5.2 is only slightly disrupted by the feed line region 12. The feed line region 12 can, consequently, be selected any length without the course of the heating current being appreciably disrupted and without local overheating areas, so-called hotspots, occurring on the pane 100.

(27) When the pane 100 is used, for example, as a windshield in a motor vehicle, the length of the feed line region 12 can be selected such that the driver of the motor vehicle or the front seat passenger can conveniently reach the contact region 11 of the switch region 10.

(28) FIG. 2A depicts an alternative embodiment of the pane 100 according to the invention in an enlarged view of the detail Z of FIG. 1A. The switch region 10 comprises a contact region 11, which is implemented approx. square, where the corners are implemented rounded and have a radius of curvature r of roughly 4 mm. The contact region 11 transitions into a feed line region 12. The width b.sub.B and the length l.sub.B of the contact region 11 is, for example, 40 mm. The width b.sub.Z of the feed line region 12 is, for example, 1 mm. The feed line region 12 is connected to a connection region 13. The connection region 13 has a square shape with rounded corners and a side length b.sub.A of, for example, 12 mm. The remaining structure of the pane 100 corresponds, for example, to the structure of the pane 100 of FIG. 1A.

(29) FIG. 2B depicts a cross-sectional view of the embodiment according to FIG. 2A along the cutting line B-B.

(30) FIG. 3 depicts another alternative embodiment of a pane 100 according to the invention in an enlarged view of the detail Z of FIG. 1A. The exemplary embodiment of the pane 100 corresponds to the pane of FIG. 1A, only with the width b.sub.Z of the contact region implemented wider and being, for example, 30 mm.

(31) FIG. 4A depicts an alternative embodiment of a pane arrangement 101 according to the invention with a top plan view of a pane 100 according to the invention, wherein the electrically conductive layer 2 has a switch region 10, a heating region 3, and a surrounding region 15. Otherwise, the pane 100 of this exemplary embodiment corresponds, for example, to the pane 100 of FIG. 1A.

(32) FIG. 4B depicts an enlarged view of the detail Z of FIG. 4A. The surrounding region 15 is formed by the region between the separating line 4.1 and another separating line 4.2 that electrically divides the surrounding region 15 from the heating region 3.

(33) FIG. 4C depicts a cross-sectional view along the cutting line C-C of FIG. 4B. The switch region 10, the surrounding region 15, and the heating region 3 are all regions of the electrically conductive layer 2 electrically isolated from each other.

(34) The separating lines 4.1,4.2 have a width of, for example, only 100 m and are introduced into the electrically conductive layer 2, for example, by laser patterning. Separating lines 4.1,4.2 with such a small width are hardly perceptible visually and disrupt vision through the pane 100 only little, which is, especially for use in motor vehicles, of particular importance for driving safety.

(35) The width c of the surrounding region 15 is, for example, 60 mm and completely surrounds the switch region 10. Such a surrounding region 15 is particularly advantageous since it increases the distance between the switch region 10 and the heating region 3 and thus enables precise measurement of the capacitance of the switch region 10. At the same time, because of it, the capacitance measurement is influenced less by the flow of current through the heating region 3.

(36) The surrounding region 15 can, as depicted here, have a connection point that is connected via an electrical line collection 20 to a foil conductor 17. This enables the connection of sensor electronics with two inputs, for example, for differential measurement of a capacitance change between the switch region 10 and the surrounding region 15. This is particularly advantageous for precise measurement of capacitance differences.

(37) FIG. 5 depicts a flowchart of an exemplary embodiment of the method according to the invention for producing an electrically heatable pane 100 with a switch region 10.

(38) The pane 100 according to the invention in accordance with FIGS. 1-4 has a switch region 10, which can, for example, be connected to capacitive sensor electronics 14. At the same time, the pane 100 has an electrically heatable heating region 3, wherein the heating function and heating power distribution is only slightly impaired or not all impaired by the switch region 10. Moreover, due to the small width of the separating lines 4.1,4.2, vision through the pane is only minimally impaired and satisfies, for example, the requirements for motor vehicle glazing.

(39) Particularly advantageous and surprising is a pane arrangement 101 with a composite pane in which the sensitivity of the sensor electronics 14 is coordinated with the geometry and the dimensions of the switch region 10 such that a selective triggering of the switching operation is only possible from one side of the pane 100.

(40) This result was unexpected and surprising for the person skilled in the art.

LIST OF REFERENCE CHARACTERS

(41) 1 substrate, transparent substrate

(42) 2 layer, transparent, electrically conductive layer

(43) 3 heating region

(44) 4.1,4.2 separating line

(45) 5.1,5.2 busbar

(46) 6 voltage source

(47) 7 current path

(48) 8 intermediate layer

(49) 9 cover pane, transparent cover pane

(50) 10 switch region

(51) 11 contact region

(52) 12 feed line region

(53) 13 connection region

(54) 14 sensor electronics, capacitive sensor electronics

(55) 15 surrounding region

(56) 16 additional connection region

(57) 17 foil conductor

(58) 18 feed line

(59) 19 connection point CAN bus

(60) 20 electrical line connection

(61) 21 direction of the feed line region 12

(62) angle between current direction 7 and direction of the feed line region 12

(63) c width of the surrounding region 15

(64) b.sub.A width of the connection region 13

(65) b.sub.B width of the contact region 11

(66) b.sub.Z width of the feed line region 12

(67) d.sub.1,d.sub.2 width of the separating line 4.1,4.2

(68) r radius of curvature

(69) l.sub.A length of the connection region 13

(70) l.sub.B length of the contact region 11

(71) l.sub.Z length of the feed line region 12

(72) A-A cutting line

(73) B-B cutting line

(74) C-C cutting line

(75) Z detail