Electrical visual element arrangement for a motor vehicle

Abstract

The invention relates to an electrical viewing element arrangement for a motor vehicle (2), in particular a window arrangement, wherein the viewing element arrangement (1) comprises at least one transparent viewing element (3) whose degree of transparency can be varied, as well as a control unit (4) which is designed to control the viewing element (3) to adjust its degree of transparency. It is proposed that the viewing element arrangement (1) comprise a transmission sensor (5) for measuring the degree of transparency of the viewing element (3), and that the control unit (4) controls the viewing element (3) depending on the measured degree of transparency.

Description

[0001] The present invention relates to an electrical visual element arrangement for a motor vehicle according to the preamble of claim 1 and to a method for operating an electrical visual element arrangement according to the preamble of claim 14.

[0002] The known prior art (DE 10 2012 013 558 A1), from which the invention is based, relates to a method for operating an electric viewing element arrangement. The motor vehicle in question has a viewing element arrangement with a viewing element in the form of a window arrangement, the degree of transparency of which can be changed by controlling it via a control unit. Such viewing elements are also referred to as smart glass. Such an adjustment of the degree of transparency can be used for a dimming function.

[0003] The known prior art (DE 10 2012 013 558 A1) proposes using a light sensor to determine the ambient brightness of the vehicle interior and controlling the viewing element via a control unit in such a way that the ambient brightness is adjusted to a target value. The ambient brightness also depends on the lighting conditions in the vehicle's surroundings.

[0004] The invention is based on the problem of designing and developing an electrical viewing element arrangement in such a way that a further optimization of the control of the viewing element is achieved.

[0005] The above problem is solved by the features of claim 1.

[0006] The invention is based on the finding that the temperature of the visible element affects the material properties, so that the control can be temperature-dependent and thus carried out in different ways at different temperatures to compensate for temperature effects. The fundamental idea is to measure the degree of transparency of the visible element, which is then used in the control.

[0007] In detail, it is proposed that the viewing element arrangement has a transmission sensor for measuring the degree of transparency of the viewing element and that the control unit controls the viewing element depending on the measured degree of transparency.

[0008] Preferably, in the embodiment according to claim 2, a temperature value of the visible element is determined on the basis of the measured degree of transparency, so that temperature effects can be easily taken into account in the control.

[0009] In particular, a temperature dependence can be clearly detected when a control voltage applied to the viewing element is changed, which is the subject matter of claims 3 and 4.

[0010] Particularly preferably, a measurement of the temporal change in the degree of transparency is carried out during a voltage jump or a voltage ramp according to claim 5, for example, during a switching of the viewing element. A temperature dependence can be particularly pronounced during a switching-off process, so that an optimal characterization of the viewing element can be achieved.

[0011] Since the switching time of the transparency level under a jump in the control voltage depends on the temperature, the switching behavior of the viewing element can be adjusted for different temperatures by modifying the control (claim 6). The vehicle operator is thus provided with the same operating principle of the viewing element regardless of the temperature.

[0012] Furthermore, by measuring the degree of transparency, a specific target degree of transparency can be reliably set (claim 7). In particular, by measuring the degree of transparency on the visible element itself, adjustment to the target degree of transparency is possible, so that, in principle, various intermediate states of the degree of transparency can be achieved.

[0013] The transmission sensor can preferably be integrated into the control unit with a light source and / or light sensor according to an embodiment of claim 8. The use of a light guide according to claim 9 can enable the control unit to be arranged at a distance from the viewing element. Likewise, the control unit can be mounted on the viewing element according to claim 11.

[0014] In the particularly preferred embodiment according to claim 10, a reflection element is provided for measuring the degree of transparency, whereby the light source and the light sensor can be arranged on the same side of the viewing element and in particular integrated in the control unit.

[0015] Claims 12 and 13 relate to a configuration with a module carrier and an adjustment arrangement, such as a window lifter arrangement, for the viewing element. By placing the transmission sensor in a section of the viewing element covered by a covering, the influence of stray light on the measurement is minimized.

[0016] According to a further teaching according to claim 14, which has independent significance, a method for operating an electrical viewing element arrangement is claimed. It is essential that the degree of transparency of the viewing element is measured by means of a transmission sensor of the viewing element arrangement, and that the control unit controls the viewing element depending on the measured degree of transparency. Reference is made to all statements regarding the proposed electrical viewing element arrangement.

[0017] In the following, the invention is explained in more detail with reference to a drawing which merely represents exemplary embodiments. In the drawing, Fig. 1 a) a motor vehicle with a proposed visual element arrangement and b) the visual element arrangement with a module carrier in respective side views, Fig. 2 the visible element arrangement in a schematic representation in cross section of the visible element and Fig. 3 exemplary temporal changes in the degree of transparency during a shutdown process at different temperatures.

[0018] The preferred embodiment illustrated in the figures relates to an electrical viewing element arrangement 1 for a motor vehicle 2. The viewing element arrangement 1 has at least one transparent viewing element 3 whose degree of transparency can be varied. The viewing element arrangement 1 is preferably designed as a window arrangement. The viewing element 3 can, in principle, be any window of a motor vehicle 2, in particular a rear side window or a roof window. The viewing element 3 can, in particular, be darkened or lightened, for example, by changing its opacity. Fig. 1 shows, by way of example, a motor vehicle 2 with a viewing element 3 in the form of a rear side window. As an alternative to a window, the viewing element 3 can also be a mirror.

[0019] The viewing element arrangement 1 has a control unit 4. The control unit 4 is configured to control the viewing element 3 to adjust its degree of transparency, in particular by the control unit 4 generating an electrical control voltage and applying it to the viewing element 3.

[0020] It is now essential that the viewing element arrangement 1 has a transmission sensor 5 for measuring the degree of transparency of the viewing element 3 and that the control unit 4 controls the viewing element 3 depending on the measured degree of transparency.

[0021] The transmission sensor 5 is part of the viewing element arrangement 1 and measures the degree of transparency directly or indirectly on the viewing element 3. In this context, measurement generally refers to any metrological determination, in particular also an indirect determination from measured variables. The degree of transparency is understood to be a quantitative measure of the light transmittance of the viewing element 3. For example, the degree of transparency is measured as a relationship between an intensity passing through the viewing element 3 and an intensity of light radiated onto the viewing element 3. The degree of transparency can be measured for one or more specific frequencies of radiation or for a predetermined spectrum of frequencies. In principle, the degree of transparency can be representative of the physical quantities of transmittance, reflectance, and / or dissipation of the viewing element 3.

[0022] In contrast to a measurement of the absolute intensity occurring in the interior of the motor vehicle 2, here and preferably an optical property of the viewing element 3 is determined as a relative quantity and used for control.

[0023] It is particularly preferred that the control unit 4 determines a temperature value of the visible element 3 on the basis of the measured degree of transparency and that the control unit 4 controls the visible element 3 depending on the determined temperature value.

[0024] The temperature value represents a measure of the temperature of the visible element 3. The temperature value can be specified based on comparative measurements on the visible element 3, for example, by measuring degrees of transparency on the visible element 3 for a set of temperatures. The temperature value can be used, in particular, to adjust the control and compensate for temperature effects. Preferably, the temporal progression, shape, magnitude, and / or frequency of the control voltage is / are adjusted depending on the determined temperature value.

[0025] Preferably, the viewing element 3 is designed as switchable smart glass, the degree of transparency of which can be adjusted by applying a control voltage. Specifically, it is preferably implemented as LC (liquid crystal) glass, in particular as PDLC (polymer dispersed liquid crystal) glass. Here, an alternating voltage with a voltage value preferably between 0V and 80V, more preferably between 30V and 70V, and more preferably between 40V and approximately 50V, is provided for control. An SPD (suspended particle device) glass can also be used, which can be controlled with an alternating voltage with a voltage value preferably between 0V and 200V, more preferably between 50V and 150V, and more preferably between 90V and 110V.

[0026] In a particularly preferred embodiment, the arrangement is such that a maximum degree of transparency can be achieved exclusively by applying a control voltage other than zero voltage to the viewing element 3. Further preferably, in the absence of a control voltage, a correspondingly reduced degree of transparency is achieved. The glass is then preferably self-darkening.

[0027] Furthermore, it is preferably provided here that the control unit 4 carries out the control on the basis of a temporal change in the measured degree of transparency under a change in a control voltage applied to the viewing element 3.

[0028] A change in the control voltage can be implemented by varying the timing, shape, magnitude, and / or frequency of the control voltage, thereby causing a change in the degree of transparency. The change in the degree of transparency can, in turn, depend on the material properties and, in particular, on temperature.

[0029] Accordingly, in a further embodiment, it can be provided that the control unit 4 determines a temperature value of the visible element 3 on the basis of a temporal change in the measured degree of transparency under a change in a control voltage applied to the visible element 3 and that the control unit 4 controls the visible element 3 depending on the determined temperature value.

[0030] It is preferred that the control unit 4 applies a voltage jump and / or a voltage ramp as a change in the control voltage to the viewing element 3 to effect the temporal change in the degree of transparency. A voltage jump can be understood as a switching of the magnitude of the control voltage between two different voltage values. A voltage ramp is understood as a continuous, for example, linear change in the magnitude of the control voltage between two different voltage values.

[0031] Preferably, the control unit 4 can reduce and, in particular, switch off the control voltage as a change starting from an operating value, for example, an amount of the control voltage used to achieve a maximum degree of transparency. The degree of transparency as a function of time t during such a switch-off process is shown, for example, in Fig. 3. Here, the degree of transparency is initially approximately constant at a constant alternating voltage. After the control voltage is switched off, the degree of transparency approaches a minimum value, in this case for a self-darkening glass. The exact progression of the degree of transparency depends on the temperature, which is Fig. 3 is indicated by the different line representations. Accordingly, the temperature value can be determined from the measurement of the degree of transparency and, in particular, the temporal progression.

[0032] In a further embodiment, it is provided that the control unit 4 controls the viewing element 3 as a function of the measured degree of transparency and in particular the temperature value in such a way that a switching time is adjusted to one another, in particular constant, when the degree of transparency changes for temperatures in a predetermined operating range.

[0033] For example, if a step-like increase in the control voltage is provided to switch the visible element 3 into a transparent state, the switch-on time—here the time from the previous state to the state to be achieved by the control—can depend on the temperature. To adjust the switch-on time, a ramp-like increase in the control voltage can be used instead of a step-like increase, depending on the temperature. In particular, the switch-on times at higher temperatures can be deliberately extended by the control in order to match them to the slower switch-on times at lower temperatures. The same applies to the switch-off time.

[0034] Furthermore, it is preferably provided here that a target degree of transparency to be achieved via the control is specified, and that the control unit 4 controls the viewing element 3 in such a way that the measured degree of transparency is adjusted to the target degree of transparency.

[0035] In a simple embodiment, the viewing element 3 is controlled by means of the control unit 4, for example with a predetermined voltage increase or voltage drop, until the desired degree of transparency is reached with a predetermined accuracy by the measured degree of transparency.

[0036] In a preferred embodiment, the control unit 4 regulates the measured degree of transparency to the desired degree of transparency by controlling the viewing element 3. The control unit 4 can contain a control loop that generates a control voltage as a controlled variable from a control deviation between the measured degree of transparency and the desired degree of transparency. In particular, the magnitude of an alternating voltage of the control voltage serves as the controlled variable.

[0037] With these advantageous embodiments, it is possible to achieve that the viewing element 3 can not only be switched between a minimum and maximum degree of transparency via a voltage jump or the like, but rather that intermediate states with different degrees of transparency can be reliably achieved. A temperature dependence of the precise control voltage for such intermediate states can be taken into account by specifically measuring the degree of transparency.

[0038] Fig. 2 shows a schematic representation of the viewing element arrangement 1 in cross-section to the viewing element 3. The transmission sensor 5 here has a light source 6 for emitting light and a light sensor 7 for detecting the light emitted by the light source 6. The light is preferably emitted by the light source 6 in a frequency-modulated manner, so that interference effects caused by scattered light, for example, can be suppressed during detection by the light sensor 7. The light sensor 7 and / or the light source 6 can be based on semiconductor elements, such as a photodiode, LED, or the like.

[0039] Particularly preferably, the light source 6 and / or the light sensor 7 is / are integrated into the control unit 4. Accordingly, the installation of additional electronic components for implementing the measurement of the degree of transparency can be avoided.

[0040] In particular, if the light source 6 and the light sensor 7 are integrated in the control unit 4, in deviation from Fig. 1b) and Fig. 2, it is not absolutely necessary for the control unit 4 to be arranged in the region of the viewing element 3. It can be provided that the transmission sensor 5 has at least one optical fiber that optically couples the light source 6 and / or the light sensor 7 to the viewing element 3 for measuring the degree of transparency. Accordingly, a spaced arrangement of the light source 6 and / or the light sensor 7 from the viewing element 3 is also possible.

[0041] As in Fig. 2, however, in a preferred embodiment, the light source 6 and the light sensor 7 are arranged on a first side of the viewing element 3. The light source 6 and the light sensor 7 are thus positioned on the same side of the viewing element 3 and can, in particular, be easily integrated into the control unit 4.

[0042] On a second side of the viewing element 3, opposite the first side, a reflection element 8 is arranged, which at least partially reflects the light emitted by the light source 6 onto the light sensor 7. The reflection element 8 can be a mirror element, a reflective film, or the like, which can also be attached to the viewing element 3. In addition to the joint arrangement of the light source 6 and the light sensor 7, the reflection on the reflection element 8 also allows a double transmission process to be used to measure the degree of transparency.

[0043] As an alternative to the aforementioned arrangement of the control unit 4 at a distance from the viewing element 3, Fig. 1b) and Fig. 2, the control unit 4 is mounted on the visible element 3. The control unit 4 can be glued to the visible element 3 and / or attached by fastening means, for example, locking means, thereby facilitating the assembly of the visible element arrangement 1.

[0044] It is preferably provided that the viewing element arrangement 1 has a module carrier 9 and an adjustment arrangement 10, by means of which the viewing element 3 can be adjusted relative to the module carrier 9 over an adjustment range.

[0045] The module carrier 9 is, for example, an assembly carrier for a window arrangement of the motor vehicle 2, on which, in addition to the adjustment arrangement 10, other components of a door or flap arrangement of the motor vehicle 2, such as a motor vehicle lock and / or a door control unit 11, can be arranged. The adjustment arrangement 10 can be a window lifter. For example, the viewing element 3, in the assembled state, is provided so that it can be retracted into a panel of the motor vehicle 2 via the adjustment arrangement 10.

[0046] Furthermore, it is preferably provided here that the transmission sensor 5 is arranged on a section of the viewing element 3 which, in the mounted state, is covered at least over part of the adjustment range by a panel, in particular a door panel or roof panel, of the motor vehicle 2.

[0047] In particular, the section of the visible element 3 is the one shown in Fig. 1b), which remains in the panel even when the visible element 3 is fully extended and serves, in particular, to connect it to the adjustment arrangement 10. The measurement of the degree of transparency can be carried out here independently of the position of the visible element 3.

[0048] According to a further teaching, a method is proposed for the operation of an electrical viewing element arrangement 1, in particular a window arrangement, of a motor vehicle 2, wherein the viewing element arrangement 1 has at least one transparent viewing element 3 whose degree of transparency can be changed, as well as a control unit 4 by means of which the viewing element 3 is controlled to adjust its degree of transparency.

[0049] It is provided that the degree of transparency of the visual element 3 is measured by means of a transmission sensor 5 of the visual element arrangement 1, and that the control unit 4 controls the visual element 3 depending on the measured degree of transparency. Reference is made to all explanations regarding the proposed electrical visual element arrangement 1. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2012 013 558 A1 [0002, 0003]

Claims

[1] Electrical viewing element arrangement for a motor vehicle (2), in particular a window arrangement, wherein the viewing element arrangement (1) has at least one transparent viewing element (3) whose degree of transparency can be changed, and a control unit (4) which is designed to control the viewing element (3) to adjust its degree of transparency, characterized by that the viewing element arrangement (1) has a transmission sensor (5) for measuring the degree of transparency of the viewing element (3) and that the control unit (4) controls the viewing element (3) depending on the measured degree of transparency. [2] Electrical visual element arrangement according to claim 1, characterized by that the control unit (4) determines a temperature value of the visible element (3) on the basis of the measured degree of transparency and that the control unit (4) controls the visible element (3) depending on the determined temperature value. [3] Electrical visual element arrangement according to claim 1 or 2, characterized by that the control unit (4) carries out the control on the basis of a temporal change in the measured degree of transparency under a change in a control voltage applied to the viewing element (3). [4] Electrical viewing element arrangement according to one of the preceding claims, characterized by that the control unit (4) determines a temperature value of the visible element (3) on the basis of a temporal change in the measured degree of transparency under a change in a control voltage applied to the visible element (3), and that the control unit (4) controls the visible element (3) depending on the determined temperature value. [5] Electrical visual element arrangement according to claim 3 or 4, characterized bythat the control unit (4) applies a voltage jump and / or a voltage ramp as a change in the control voltage to the viewing element (3) to effect the temporal change in the degree of transparency, preferably that the control unit (4) reduces the control voltage starting from an operating value, in particular switches it off, as a change. [6] Electrical visual element arrangement according to one of the preceding claims, characterized by that the control unit (4) controls the viewing element (3) in such a way as to depend on the measured degree of transparency and in particular on the temperature value that a switching time when the degree of transparency changes is adjusted to one another, in particular constant, for temperatures in a predetermined operating range. [7] Electrical visual element arrangement according to one of the preceding claims, characterized bythat a target degree of transparency to be achieved via the control is predetermined, and that the control unit (4) controls the viewing element (3) in such a way that the measured degree of transparency is adjusted to the target degree of transparency, preferably that the control unit (4) regulates the measured degree of transparency to the target degree of transparency by controlling the viewing element (3). [8] Electrical viewing element arrangement according to one of the preceding claims, characterized by that the transmission sensor (5) has a light source (6) for emitting, in particular frequency-modulated, light and a light sensor (7) for detecting the light emitted by means of the light source (6), preferably that the light source (6) and / or the light sensor (7) is / are integrated in the control unit (4). [9] Electrical visual element arrangement according to claim 8, characterized bythat the transmission sensor (5) has at least one light guide which optically couples the light source (6) and / or the light sensor (7) to the viewing element (3) for measuring the degree of transparency. [10] Electrical visual element arrangement according to claim 8 or 9, characterized by that the light source (6) and the light sensor (7) are arranged on a first side of the viewing element (3) and a reflection element (8) is arranged on a second side of the viewing element (3) opposite the first side, which reflection element (8) reflects the light emitted by the light source (6) onto the light sensor (7). [11] Electrical viewing element arrangement according to one of the preceding claims, characterized by that the control unit (4) is attached to the viewing element (3). [12] Electrical viewing element arrangement according to one of the preceding claims, characterized bythat the viewing element arrangement (1) has a module carrier (9) and an adjustment arrangement (10) by means of which the viewing element (3) can be adjusted relative to the module carrier (9) over an adjustment range. [13] Electrical visual element arrangement according to claim 12, characterized by that the transmission sensor (5) is arranged on a section of the viewing element (3) which, in the mounted state, is covered at least over part of the adjustment range by a panel, in particular a door panel or roof panel, of the motor vehicle (2). [14] Method for operating an electrical viewing element arrangement (1), in particular a window arrangement, of a motor vehicle (2), wherein the viewing element arrangement (1) has at least one transparent viewing element (3) whose degree of transparency can be changed, and a control unit (4) by means of which the viewing element (3) is controlled to adjust its degree of transparency, characterized bythat the degree of transparency of the visual element (3) is measured by means of a transmission sensor (5) of the visual element arrangement (1) and that the control of the visual element (3) is carried out by means of the control unit (4) as a function of the measured degree of transparency.

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