Control device, system for changing the transparency of a window pane, window system and vehicle

Abstract

A control device (300) for controlling the change in the transparency of a window pane (500) for a vehicle (100), the transparency of which depends on an electric field in at least one region of the window pane (500), wherein the control device (300) is connectable to a voltage source and is designed to change a voltage supply of a device (400) for generating the electric field in response to a transparency change request, characterized in that the control device (300) is further designed to supply voltage to a heating device (600) for heating the at least one region of the window pane (500) in response to the transparency change request in order to reduce temperature differences between window regions of the window pane (500) and / or different window panes (500) of the vehicle (100),so that reaction times of the window areas of the window pane (500) and / or the different window panes (500) of the vehicle (100) are equalized.,

Description

[0001] The present invention relates to a control device for controlling the change in transparency of a window pane for a vehicle, a system for changing the transparency of a window pane, a window system and a vehicle.

[0002] Switchable glazing (suspended particle device, SPD), i.e. window panes whose transparency in at least one area of ​​the window pane depends on an electric field, is finding increasing use, not only, but especially in the automotive sector.

[0003] The Fig. 1 and Fig. 2 show an exemplary switchable glazing according to the prior art, wherein the Fig. 1 shows the state that occurs when an electric field is applied, and Fig. 2 shows the state that occurs when no electric field is applied.

[0004] In the example shown, the switchable glazing comprises electrically alignable particles 10 in a carrier liquid 20 in a matrix polymer 30, which is arranged between two transparent electrodes 40, 50. If no field is applied ( Fig. 2), the particles are disordered, resulting in low light transmission and thus a low degree of transparency. However, if an electric field is applied ( Fig. 1), the particles 10 in the carrier liquid 20 align themselves along the field lines, resulting in a higher light transmission and thus a higher degree of transparency.

[0005] To control the change in the transparency of the window pane, a control device can be used which can be connected to a voltage source and is designed to change a voltage supply of a device for generating an electric field on the window pane or a region thereof in response to a transparency change request.

[0006] For example, transparency can be changed from less than 1% to more than 40% by applying a 120V alternating electric field. Similarly, transparency can also be changed gradually by changing the field.

[0007] The window panes can form window systems, for example, in vehicles. An exemplary application in the automotive sector is described in DE 10 2013 001 334 A1. In this case, it is desirable for transparency changes to occur uniformly across all window panes. DE 10 2012 013 561 A1 addresses this and proposes individual control of the pane, adapted to the specific window. Further prior art is described in US 2008 / 0007086 A1 and DE 10 2008 024 870 A1.

[0008] US 7,009,156 B2 discloses a composite pane with an electroluminescent light element. A flat, heatable layer is associated with the electroluminescent light element, which allows the temperature of the electroluminescent light element to be increased at low ambient temperatures to the range for which its optical properties, for example, the color of the emitted light, are designed.

[0009] The invention is based on the object of further improving the homogeneity of transparency changes.

[0010] The inventors have observed a strong pane temperature dependence of the rate of transparency change and recognized the influence of this dependence on the homogeneity of the change in window systems.

[0011] In order to improve the homogeneity of transparency changes, the invention proposes a control device according to claim 1 for controlling the change in the transparency of a window pane for a vehicle.

[0012] The transparency of the window pane depends on an electric field in at least one region of the window pane. The control device is connectable to a voltage source and configured to change the voltage supply of a device for generating the electric field in response to a transparency change request.

[0013] The control device is further configured to supply voltage to a heating device for heating at least the area of ​​the window pane in response to the transparency change request.

[0014] Demand-dependent heating makes it possible to reduce temperature differences between windows or window areas and thus achieve more uniform response times.

[0015] In a preferred embodiment of the invention, it is provided that the control device is designed to supply the heating device with voltage as a function of a temperature measurement value and a comparison temperature value.

[0016] Temperature-dependent heating makes it possible to reduce temperature differences between windows even more effectively, thus achieving even more consistent response times.

[0017] The control device can be designed to change the voltage supply of the device for generating the electric field in response to the change in transparency only when the temperature measurement value corresponds to the or another comparison temperature value.

[0018] The delayed change of the field makes it possible to further reduce temperature differences between windows and thus achieve even more uniform response times.

[0019] The invention further proposes a system according to claim 4 for changing the transparency of a window pane for a vehicle. Transparency in at least one region of the window pane depends on an electric field. The system comprises a device for generating the electric field, a control device according to the invention that can supply voltage to the device for generating the electric field, and the heating device that can be supplied with voltage by the control device.

[0020] In a preferred embodiment of the invention, it is provided that the control device is designed according to one embodiment of the control device and the system further comprises a temperature sensor for detecting the temperature measurement value.

[0021] According to the invention, a window system according to claim 6 for a vehicle is further proposed. The system comprises: at least one window pane, the transparency of which depends on an electric field in at least one region of the window pane. The window system comprises a system according to the invention for each window pane, wherein the heating device and the device for generating the electric field are arranged with respect to the respective window pane such that the region of the respective window pane can be heated and the requested change in transparency can be effected at least in that region.

[0022] In a preferred embodiment of the invention, it is provided that the window system of each system is designed according to the embodiment and the temperature sensor is arranged with respect to the respective window pane such that a pane temperature can be measured at least in the area.

[0023] For each of the window panes, the comparison temperature value can be a predefined target temperature value.

[0024] This allows all panes to be heated to a target temperature before the transparency change is effected.

[0025] The control device can be designed according to the embodiment and the window system can comprise at least two window panes, wherein for each of the window panes the comparison temperature value can depend on the temperature measurement value of at least one of the other window panes.

[0026] This allows all panes to be adjusted to the same temperature before the change in transparency occurs.

[0027] Finally, according to the invention, a vehicle according to claim 10 with the window system according to the invention is proposed.

[0028] The control device can be configured to supply the heating device with voltage for a predetermined heating duration. The control device can be configured to supply the heating device with voltage such that a predetermined maximum temperature is not exceeded in the area of ​​the window pane. The control device can be configured to supply the device for generating the electric field with a voltage that depends on the measured temperature value and the comparison temperature value.

[0029] The vehicle may comprise a plurality of window systems whose control devices are coordinated with one another such that a same transparency change request in a same transparency state results in the same requested transparency change in the window panes of the window systems within response times that differ from one another by at most 10%, preferably at most 5%, even more preferably at most 2%.

[0030] Further preferred embodiments of the invention emerge from the remaining features mentioned in the subclaims.

[0031] The various embodiments of the invention mentioned in this application can be advantageously combined with one another, unless otherwise stated in the individual case.

[0032] The invention is explained below in exemplary embodiments with reference to the accompanying drawings. They show: Fig. 1 a switchable glazing according to the state of the art, if no electric field is applied, Fig. 2 a switchable glazing according to the state of the art when an electric field is applied, Fig. 3 an embodiment of a vehicle according to the invention, Fig. 4 an embodiment of a window system according to the invention and Fig. 5 shows a further embodiment of a window system according to the invention.

[0033] Fig. 3 shows a vehicle 100 with, for example, two window panes 500, each of which is part of a window system 200. Exemplary embodiments of window systems 200 are shown in the Fig. 4 and Fig.5. The window systems 200 each comprise a control device 300, at least one device 400 for applying an electric field to a window pane 500 of the window system 200, and a heating device 600 for heating the window pane 500. The exemplary embodiment additionally comprises an optional temperature sensor 700 for determining a temperature measurement value representative of the pane temperature of the window pane 500. The heating device 600 and / or the device 400 for applying an electric field can also each heat only specific portions of the window pane 500 and / or apply a field thereto. The window pane 500 is a switchable glazing whose transparency depends on the applied field.

[0034] The device 400 for applying an electric field may, for example, comprise a transformer that is supplied with an input voltage, for example 5 volts vehicle electrical system voltage, and transforms this into a higher output voltage, for example 120 volts.

[0035] For example, switchable glazing in the absence of an electric field (0 volts) exhibits a transparency of 1% or less, making the glazing appear dark blue, for example. In a field operated at 120 volts, however, the transparency is 40% or more, making the glazing appear transparent, for example. Transparency levels between minimum and maximum can be achieved using appropriate voltages between 0 volts and 120 volts.

[0036] The glazing in this example reacts to voltage changes at different speeds depending on the pane temperature. For example, the change from minimum transparency to maximum transparency (brightening time) at a maximum temperature of, for example, 85° Celsius occurs within less than 1 second after the maximum voltage is applied. Likewise, the change from maximum transparency to minimum transparency (darkening time) at the maximum temperature occurs within less than 1 second after the voltage is switched off. At -20° Celsius, however, the brightening time is 219 seconds and the darkening time is as much as 629 seconds. At 60° Celsius, the brightening and darkening times are each 0.6 - 0.7 seconds long. At 23° Celsius, the brightening time is 3 seconds and the darkening time is 6 seconds.

[0037] The control devices 300 are configured to supply voltage to the heating device 600 in response to a transparency change request, for example, by a user input, in order to heat the window pane 500 when the measured pane temperature (temperature measurement value) of the respective window pane 500 is lower than a comparison temperature value.

[0038] It is possible to design and / or operate the window system in such a way that heating does not cause the maximum operating temperature of the window pane to be exceeded.

[0039] In an exemplary embodiment, the comparison temperature value is a predetermined target value, for example, 23° Celsius. The voltage device 300 can then be configured to supply the heating device 600 with voltage for a predetermined heating period. Additionally, the control device 300 can be configured to supply the device 400 with the voltage changed according to the requested transparency change only after the heating period has elapsed.

[0040] It is also possible for the respective comparison temperature value to be another temperature measurement value from the sensor 700 of the respective other window pane 500, which can be exchanged between the control devices 300, for example, via a CAN bus 800. Or the respective comparison temperature value is another temperature measurement value from another sensor on the respective window pane. The respective control device 300 can then be designed to supply the heating device 600 with voltage until the respective temperature measurement value is at most a predetermined difference, for example, 1° Celsius, smaller than the respective further temperature measurement value.In addition, the respective control device 300 can be configured to supply the respective device 400 with the voltage changed according to the requested transparency change only when the respective temperature measurement value deviates from the respective further temperature measurement value by at most the difference.

[0041] Then, if the pane temperature difference is greater than the predetermined difference and the transparency change requirement is the same for both window systems, one of the two window systems 200 heats its window pane 500 until the pane temperature difference is less than the predetermined difference. Only then are the transparency changes effected in both panes, which then begin essentially synchronously and last the same length of time.

[0042] Or the heating device 600 heats only an area of ​​the window pane in which the temperature measurement value is detected, and the comparison temperature value is another temperature measurement value detected by another sensor outside the heatable area.

[0043] The control device 300 can then be configured to supply the heating device 600 with voltage until the respective temperature measurement value is at most the predetermined difference smaller than the further temperature measurement value. Additionally, the control device 300 can be configured to supply the respective device with the voltage changed according to the requested transparency change only when the heating process is completed.

[0044] Then, if the internal temperature difference within the pane 500 is greater than the predetermined difference, the window system 200 heats the area of ​​the window pane 500 until the internal temperature difference is less than the predetermined difference. Only then is the transparency change effected, which then lasts essentially the same length of time for the entire pane. This is particularly suitable, for example, for icy areas of vehicle windows.

[0045] In vehicles with more than two window systems, it is also possible for the comparison temperature value to be a respective maximum value of the further temperature measurement values ​​of some or all of the other window panes. The voltage device can then be designed to supply the respective heating device with voltage until the respective temperature measurement value is at most the predetermined difference smaller than the respective maximum value. In addition, the respective control device can be set up to only supply the respective device with the voltage changed according to the requested transparency change when the respective temperature measurement value is at most smaller than the respective maximum value by the difference and at most greater than a respective minimum value of the further temperature measurement values ​​by the difference.

[0046] Then, if the pane temperature difference between the window systems is greater than the predetermined difference and the same transparency change requirement applies to all window systems except for one window system with the highest pane temperature, all window systems heat their respective window panes until each pane temperature difference is less than the predetermined difference. Only then are the transparency changes initiated in all panes, which then begin essentially synchronously and last the same length of time.

[0047] A further exemplary embodiment of the present invention comprises a device for changing the transparency of a window pane for a vehicle, the transparency of which in at least one region of the window pane depends on an electric field applied to the window pane. The device comprises a control device connectable to a voltage source and designed to apply or deactivate the electric field to the window pane in response to a transparency change request. The device further comprises a heating device, which can be supplied with voltage by the control device and is designed to heat at least the region of the window pane. The control device is designed to supply voltage to the heating device in response to the transparency change request, such that at least the region of the window pane is heated to a predetermined target temperature.

[0048] Embodiments of the present invention can be used, for example, to preheat one of two windows with different icing tendencies in the event of icing or under another boundary condition, so that it then changes its degree of transparency synchronously with the other window.

[0049] This or other embodiments of the present invention can be used, for example, to preheat the window on the shaded side of the vehicle in the case of two windows, one of which is arranged on a shady side of the vehicle and the other on a sunny side of the vehicle, so that it then changes its degree of transparency synchronously with the other window.

[0050] Still other embodiments of the present invention may be usefully employed, for example, to preheat a lower window region adjacent to the window seal and earlier than the rest of the window during icing or under another boundary condition so that it subsequently changes its degree of transparency synchronously with the rest of the window. List of reference symbols 10 particles 20 Carrier fluid 30 matrix polymer 40 transparent electrode 50 transparent electrode 100 vehicles 200 window system 300 control device 400 Device for applying an electric field 500 window panes 600 heater 700 temperature sensor 800 CAN bus

Claims

[1] Control device (300) for controlling the change in the transparency of a window pane (500) for a vehicle (100), the transparency of which depends on an electric field in at least one area of ​​the window pane (500), wherein the control device (300) is connectable to a voltage source and is designed to change a voltage supply of a device (400) for generating the electric field in response to a transparency change request, characterized byin that the control device (300) is further designed to supply voltage to a heating device (600) for heating the at least one region of the window pane (500) in response to the transparency change request in order to reduce temperature differences between window regions of the window pane (500) and / or different window panes (500) of the vehicle (100), so that reaction times of the window regions of the window pane (500) and / or the different window panes (500) of the vehicle (100) are equalized. [2] Control device according to claim 1, characterized by that the control device (300) is designed to supply the heating device (600) with voltage as a function of a temperature measurement value and a comparison temperature value. [3] Control device according to claim 2, characterized bythat the control device (300) is designed to change the voltage supply of the device (400) for generating the electric field in response to the transparency change request only when the temperature measurement value corresponds to the or another comparison temperature value. [4] System for changing the transparency of a window pane (500) for a vehicle (100), the transparency of which depends on an electric field in at least one area of ​​the window pane (500), comprising a device (400) for generating the electric field, characterized by that the system comprises a control device (300) according to one of claims 1 to 3, which can supply voltage to the device (400) for generating the electric field, and the heating device (600) which can be supplied with voltage by the control device (300). [5] System according to claim 4, characterized bythat the control device (300) is designed according to claim 2 or 3 and the system further comprises a temperature sensor (700) for detecting the temperature measurement value. [6] Window system (200) for a vehicle (100), comprising: at least one window pane (500), the transparency of which depends on an electric field in at least one region of the window pane (500), characterized by that the window system (200) comprises for each window pane (500) a system according to claim 4 or 5, wherein the heating device (600) and the device (400) for generating the electric field are arranged with respect to the respective window pane (500) such that the area of ​​the respective window pane (500) can be heated and the requested change in transparency can be effected at least in the area. [7] Window system according to claim 6, characterized bythat each system is designed according to claim 5 and the temperature sensor (700) is arranged with respect to the respective window pane (500) such that a pane temperature can be measured at least in the area. [8] Window system according to claim 7, characterized by that for each of the window panes (500) the comparison temperature value is a predetermined target temperature value. [9] Window system according to claim 7, characterized by that the control device (300) is designed according to claim 2 or 3, and that the window system (200) comprises at least two window panes (500), wherein for each of the window panes (500) the comparison temperature value depends on the temperature measurement value of at least one of the other window panes (500). [10] Vehicle (100), characterized by at least one window system (200) according to at least one of claims 6 to 9.

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