COMPOSITE PANE HAVING ELECTRICALLY CONTROLLABLE OPTICAL PROPERTIES

Abstract

A composite pane having electrically controllable optical properties, includes an outer pane and an inner pane, which are joined to one another via a thermoplastic intermediate layer, wherein an optoelectronic functional element having electrically controllable optical properties is embedded in the intermediate layer, which functional element comprises an active layer, with which transparent flat control electrodes are associated on both surfaces, between a first carrier film and a second carrier film, and wherein a capacitive contact switching element is arranged between the active layer and the thermoplastic intermediate layer.

Claims

1. A composite pane having electrically controllable optical properties, comprising an outer pane and an inner pane, which are joined to one another via a thermoplastic intermediate layer, wherein an optoelectronic functional element having electrically controllable optical properties is embedded in the thermoplastic intermediate layer, which optoelectronic functional element comprises an active layer, with which transparent flat control electrodes are associated on both surfaces, between a first carrier film and a second carrier film, and wherein a capacitive contact switching element is arranged between the active layer and the thermoplastic intermediate layer, in direct contact with the second carrier film facing in the direction of the inner pane.

2. The composite pane according to claim 1, wherein in the region of the capacitive contact switching element, a patterned conductive layer is arranged, which is arranged on a surface of the optoelectronic functional element associated with the inner pane.

3. The composite pane according to claim 2, wherein the patterned conductive layer has a contact switch structure that is formed by laser patterning of a conductive layer deposited in a vacuum-based coating method.

4. The composite pane according to claim 1, wherein the capacitive contact switching element is formed by a dedicated contact switch structure of the transparent flat control electrode of the optoelectronic functional element facing the inner pane.

5. The composite pane according to claim 1, wherein the optoelectronic functional element is a PDLC functional element, PNLC functional element, SPD functional element, or electrochromic functional element.

6. The composite pane according to claim 1, wherein the optoelectronic functional element is provided in a first subregion of the composite pane and the capacitive contact switching element is placed in a second subregion of the composite pane, which is included in the first subregion.

7. The composite pane according to claim 1, wherein the optoelectronic functional element has a control connector electrically connected to the capacitive contact switching element.

8. The composite pane according to claim 1, wherein the capacitive contact switching element has two parallel or concentric conductors that have a contact switch section spaced at a distance in the range between 0.3 and 1.5 cm from one another.

9. The composite pane according to claim 1, wherein the capacitive contact switching element has a plurality of conductors that are spaced apart from one another and are separately connected or connectable toward the outside of the optoelectronic functional element (1; S).

10. The composite pane according to claim 1, wherein a visual marking is associated with the capacitive contact switching element, which identifies its position for the user.

11. The composite pane according to claim 1, implemented as a windshield or roof glazing of a road vehicle or an aircraft or watercraft.

12. A composite pane assembly, comprising a composite pane according to claim 1, a control unit for controlling the optical properties of the optoelectronic functional element, and a switching control unit connected to the contact switching element for switching for manual control of the optoelectronic functional element.

13. The composite pane assembly according to claim 12, wherein the capacitive contact switching element has a plurality of conductors that are spaced apart from one another and are separately connected or connectable toward the outside of the optoelectronic functional element, and the switching control unit has a number of inputs corresponding to the number of separately connectable conductors of the capacitive contact switching element and in response to signal reception at the respective signal inputs, activates one of more than two control states of the optoelectronic functional element.

14. A road vehicle, comprising a composite pane assembly according to claim 12.

15. A method for producing a composite pane according to claim 1, wherein comprising providing an optoelectronic functional element, which comprises an active layer, with which transparent flat control electrodes are associated on both surfaces, between a first carrier film and a second carrier film, and a capacitive contact switching element, and laminating the optoelectronic functional element between an outer pane and an inner pane via a thermoplastic intermediate layer.

16. The composite pane according to claim 7, wherein the control connector has an MQS plug.

17. The composite pane according to claim 8, wherein the range is between 0.5 and 1 cm.

18. The composite pane according to claim 10, wherein the visual marking is a black print region.

19. The composite pane according to claim 11, wherein the road vehicle is a passenger car and the aircraft or watercraft is a boat or a passenger ship.

20. The composite pane assembly according to claim 12, wherein the switching control unit connected to the contact switching element is for ON/OFF switching or for contrast or brightness adjustment.

Description

[0037] The invention is explained in greater detail with reference to figures and exemplary embodiments. The drawings are schematic representations and not to scale. The figures in no way restrict the invention. They depict:

[0038] FIG. 1 a plan view of a first embodiment of the composite pane according to the invention as a windshield with an electrically controllable sun visor,

[0039] FIG. 2 a cross-section through the windshield of FIG. 1,

[0040] FIG. 3 an enlarged representation of the region Z of FIG. 2,

[0041] FIG. 4 a schematic perspective representation of an embodiment of the composite pane according to the invention,

[0042] FIG. 5 a schematic representation of an alternative implementation of the contact switching element in a composite pane according to the invention, and

[0043] FIG. 6 a schematic representation of an embodiment of the composite pane assembly according to the invention in the manner of a functional block diagram.

[0044] FIG. 1, FIG. 2, and FIG. 3 depict in each case a detail of a windshield W with an electrically controllable sun visor S, an exemplary embodiment of the composite pane according to the invention having electrically controllable optical properties. The windshield W comprises an outer pane 1 and an inner pane 2 joined to one another via an intermediate layer 3. The outer pane 1 has a thickness of 2.1 mm and is made of a green-colored soda lime glass. The inner pane 2 has a thickness of 1.6 mm and is made of a clear soda lime glass. The windshield has an upper edge D facing the roof in the installed position and a lower edge M facing the engine compartment in the installed position.

[0045] The windshield is equipped with an electrically controllable sun visor S in a region above the central field of vision B (as defined in ECE-R43). A contact switching element T for ON/OFF switching of the sun visor function and, optionally, (depending on the specific embodiment) also for manual adjustment of the degree of transmittance of the sun visor are provided in the upper edge region of the sun visor.

[0046] The sun visor S is formed by a commercially available PDLC multilayer film as a functional element 4, which is embedded in the intermediate layer 3. The intermediate layer 3 includes a total of three thermoplastic layers 3a, 3b, 3c, formed in each case by a thermoplastic film with a thickness of 0.38 mm made of PVB. The first thermoplastic layer 3a is bonded to the outer pane pane 1; the second thermoplastic layer 3b, to the inner pane 2. The third thermoplastic layer 3c interposed therebetween has a cutout, into which the cut-to-size PDLC multilayer film is inserted with a substantially precise fit, i.e., roughly flush on all sides. The third thermoplastic layer 3c thus forms, so to speak, a sort of passe-partout for the roughly 0.4-mm-thick functional element 4, which is thus encapsulated all around in thermoplastic material and is thus protected.

[0047] The first thermoplastic layer 3a has a tinted region 3a′ arranged between the functional element 4 and the outer pane 1. The light transmittance of the windshield is, as a result, additionally reduced in the region of the sun visor 4, and the milky appearance of the PDLC functional element 4 in the diffuse state is toned down. The aesthetics of the windshield are thus made significantly more appealing.

[0048] The controllable functional element 4 is a multilayer film, consisting of an active layer 5 between two flat electrodes 8, 9 and two carrier films 6, 7. The active layer 5 contains a polymer matrix with liquid crystals dispersed therein, which align themselves as a function of the electrical voltage applied to the flat electrodes, by which means the optical properties can be controlled. The carrier films 6, 7 are made of PET and have a thickness of, for example, 0.125 mm.

[0049] The carrier films 6, 7 are provided with a coating of ITO with a thickness of approx. 100 nm, on the surface facing the active layer 5, forming the flat electrodes 8, 9. The flat electrodes 8, 9 can be connected to the on-board electrical system by means of bus bars (not shown) (for example, formed by a silver-containing screen print) and connecting cables (likewise, not shown). To implement the present invention, the flat electrode 9 facing the inner pane 2 of the windshield W can be provided in a small subregion with a conductor pattern produced by laser processing, by means of which the contact switching element T (FIG. 1) is formed and connected, on the one hand, to the large-area ITO coating for realizing the sun visor function and, on the other, to the on-board electronics.

[0050] The windshield has, as is customary, a surrounding peripheral masking print 10 formed by an opaque enamel on the interior-side surface (facing the interior of the vehicle in the installed position) of the outer pane 1 and the inner pane 2. The distance of the functional element 4 from the upper edge D and the side edges of the windshield is less than the width of the masking print 10 such that the side edges of the functional element 4—with the exception of the side edge facing the central field of vision B—are concealed by the masking print 10. The electrical connections (not shown) are also expediently installed in the region of the masking print 10 and are thus hidden. The contact switching element T can also be placed in the region of the masking print, in particular when it is formed by a nontransparent conductor structure (see below).

[0051] FIG. 4 depicts an exemplary embodiment of the windshield W that has the structure depicted in FIG. 2 with a special configuration of the contact field element. The components of the windshield are identified with the same reference numbers also used in FIG. 2, and, here, the contact switching element has the reference number 11.

[0052] As can be seen in the figure, the contact field element 11 comprises two concentric circular conductors 11a, 11b that are connected to a dedicated connector 13 (for instance, in the form of an MQS (micro quadlock system) connector) for the external connection of the contact switching element. The connector 13 is arranged at a different side edge of the optoelectronic functional element 4 than the bus bars 14a, 14b that connect the functional element to an external control circuit (not shown here). The contact switching element 11 with the conductors 11a, 11b can—as noted above—be formed by laser patterning of one of the transparent surface elements 8, 9 of the optoelectronic functional element 4 using techniques and laser beam processing devices known per se.

[0053] FIG. 5a depicts a cross-section through a region having a contact switching element 11 that was created by laser patterning of a flat electrode 9 of the functional element 4. The electrically insulating regions 17 are created by laser treatment. FIG. 5b depicts an alternative implementation of the contact switching element 11, in which a separate conductive layer 12 is created on the optoelectronic functional element 4. Here, the contact switching element 11 is formed by patterning the additional conductive layer 12, while, here, the flat electrodes 8, 9 of the functional element 4 serve exclusively to implement its other functions.

[0054] This embodiment enables the use of intermediate layer laminates configured independently of the contact switching function and the subsequent implementation of the contact switching function as part of the functional element 4.

[0055] In a modification of the structure depicted in FIG. 5b, the conductive layer 12 can, in principle, also be provided on the inner surface of the inner pane of a windshield facing the functional element 4. The additional conductive layer 12 can, for example, be formed by a printing method known per se or also by sputtering.

[0056] FIG. 6 schematically depicts a composite pane assembly, comprising a windshield W designed according to the invention and associated control devices in a vehicle (not shown).

[0057] An optoelectronic functional element 4 is arranged in a subregion of the windshield W, and a contact switching element 11 is, in turn, provided in a subregion of the surface of the functional element 4. As already depicted in FIG. 5, two bus bars 14a, 14b are arranged at a first side edge of the functional element 4 for its connection in a manner known per se, and a special connector 13 placed on a different side edge of the functional element is associated with the contact switching element 11. Both instead of the bus bars 14a, 14b and also the connector 13 specified above as an MQS connector, other types of connectors can, in principle, be used, provided they are suitable for use in or with a composite pane of the type in question here.

[0058] Whereas the functional element 4 is controlled in a manner known per se by a control unit 15 for realizing its usual functions, the contact switching element 11 is connected via the connector 13 to a switching control unit 16, which controls, for example, the ON/OFF state of the functional element 4 or, optionally, even of subsections thereof or even certain parameters of the functional element 4 based on manual actuation by the driver. This can, for example, be a degree of transmittance or a contrast ratio or brightness or other parameters whose individual adjustment by the driver of the vehicle is useful or desirable as a function of the ambient conditions or according to the drivers preferences.

[0059] The figure illustrates the linkage of the functions of the control unit 15 and the switching control unit 16, merely schematically, using only a simple signal connection; however, the interaction of the two units can be designed in a more complex manner, and the two units 15, 16 can also be integrated with one another.

[0060] Overall, the implementation of the invention is not limited to the aspects highlighted above and examples described above, but is equally possible in a large number of variants that are within the scope of the appended claims.

REFERENCE CHARACTERS

[0061] 1 outer pane [0062] 2 inner pane [0063] 3 thermoplastic intermediate layer [0064] 3a first layer of the intermediate layer 3 [0065] 3a′ tinted region of the first layer 3a [0066] 3b second layer of the intermediate layer 3 [0067] 3c third layer of the intermediate layer 3 [0068] 4; S functional element having electrically controllable optical properties [0069] 5 active layer of the functional element 4 [0070] 6 first carrier film of the functional element 4 [0071] 7 second carrier film of the functional element 4 [0072] 8, 9 flat electrode of the functional element 4 [0073] 10 masking print [0074] 11; T contact switching element [0075] 11a, 11b conductor of the contact switching element [0076] 12 conductive layer [0077] 13 connector of the contact switching element [0078] 14a, 14b control connectors (bus bars) [0079] 15 control unit [0080] 16 switching control unit [0081] 17 electrically insulating region [0082] B field of vision of the windshield [0083] D upper edge of the windshield [0084] M lower edge of the windshield [0085] S sun visor [0086] W windshield [0087] X-X′ section line [0088] Z detail region of the windshield