US-12617186-B2 - Method for electrically controlling a functional element embedded in a glazing unit

US12617186B2US 12617186 B2US12617186 B2US 12617186B2US-12617186-B2

Abstract

A method for controlling a glazing unit having electrically controllable optical properties, wherein the glazing unit includes a composite pane having an outer pane and an inner pane which are connected to one another via a thermoplastic intermediate layer, a functional element is arranged between the outer pane and the inner pane and has an active layer having electrically controllable optical properties between a first planar electrode and a second planar electrode, the optical properties are controlled by a control unit, wherein the control unit is connected to at least two transparent planar electrodes of the functional element, an electrical voltage is applied between the planar electrodes by the control unit, and an inverse function is used to determine a magnitude of the electrical voltage.

Inventors

Richard STELZER
Bastian KLAUSS
DOANE SHELBY CRAIG

Assignees

SAINT-GOBAIN GLASS FRANCE

Dates

Publication Date: 20260505
Application Date: 20220413
Priority Date: 20210419

Claims (20)

1 . A method for controlling a glazing unit having electrically controllable optical properties, wherein the glazing unit comprises a composite pane having an outer pane and an inner pane which are connected to one another via a thermoplastic intermediate layer, a functional element is arranged between the outer pane and the inner pane and has an active layer having electrically controllable optical properties between a first planar electrode and a second planar electrode, the method comprising controlling the optical properties by means of a control unit, wherein the control unit is connected to at least two transparent planar electrodes of the functional element, and applying an electrical voltage between the at least two transparent planar electrodes by means of the control unit, wherein an inverse function is used to determine a magnitude of the electrical voltage, and wherein an impedance of the active layer is determined by means of the control unit.
2 . The method according to claim 1 , wherein the inverse function is used as a temperature-dependent linearization function, wherein the temperature-dependent linearization function is the inverse function of a calibration function of the functional element.
3 . The method according to claim 1 , wherein a temperature of the functional element is ascertained by the control unit and a magnitude of the electrical voltage between the at least two transparent planar electrodes is determined as a function of the temperature of the functional element by means of the control unit and applied.
4 . The method according to claim 1 , wherein the temperature of the functional element and/or composite pane is determined by means of the impedance.
5 . The method according to claim 4 , wherein the impedance is determined from a ratio of the electrical voltage to a current of the functional element.
6 . The method according to claim 1 , wherein a current consumption of the functional element is ascertained.
7 . The method according to claim 1 , wherein the at least two transparent planar electrodes are free of insulation lines.
8 . The method according to claim 1 , wherein the electrical voltage applied between the at least two transparent planar electrodes is a DC voltage or an AC voltage.
9 . The method according to claim 1 , wherein the temperature of the functional element or of the composite pane is from 30° C. to 80° C.
10 . The method according to claim 9 , wherein the temperature of the functional element or of the composite pane is from 40° C. to 60° C.
11 . A glazing unit having electrically controllable optical properties, comprising a composite pane having an outer pane and an inner pane which are connected to one another via a thermoplastic intermediate layer, an electrically controllable functional element which is arranged between the outer pane and the inner pane and has an active layer having electrically controllable optical properties between a first planar electrode and a second planar electrode, a control unit for controlling the optical properties of the functional element, wherein the control unit is provided to carry out a method according to claim 1 .
12 . The glazing unit according to claim 11 , wherein the functional element is a PDLC functional element, an SPD functional element or an electrochromic functional element.
13 . The glazing unit according to claim 11 , wherein the control unit comprises a DC-DC converter and/or an inverter.
14 . The glazing unit according to claim 11 , wherein the control unit is provided for ascertaining a temperature of the functional element and, depending on the temperature, for determining a magnitude of the electrical voltage applied between the first and second planar electrodes.
15 . The glazing unit according to claim 11 , wherein the control unit is provided for determining the impedance of the active layer and, depending on the impedance, for ascertaining the temperature of the functional element.
16 . A vehicle with a glazing unit according to claim 11 .
17 . The vehicle according to claim 16 , wherein the vehicle is a passenger car.
18 . A method for controlling a glazing unit having electrically controllable optical properties, wherein the glazing unit comprises a composite pane having an outer pane and an inner pane which are connected to one another via a thermoplastic intermediate layer, a functional element is arranged between the outer pane and the inner pane and has an active layer having electrically controllable optical properties between a first planar electrode and a second planar electrode, the method comprising controlling the optical properties by means of a control unit, wherein the control unit is connected to at least two transparent planar electrodes of the functional element, and applying an electrical voltage between the at least two transparent planar electrodes by means of the control unit, wherein an inverse function is used to determine a magnitude of the electrical voltage, and wherein the inverse function is used as a temperature-dependent linearization function, wherein the temperature-dependent linearization function is the inverse function of a calibration function of the functional element.
19 . The method according to claim 18 , wherein a temperature of the functional element is ascertained by the control unit and a magnitude of the electrical voltage between the at least two transparent planar electrodes is determined as a function of the temperature of the functional element by means of the control unit and applied.
20 . The method according to claim 18 , wherein a current consumption of the functional element is ascertained.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is the U.S. National Stage of PCT/EP2022/059911, filed Apr. 13, 2022, which in turn claims priority to European patent application number 21183015.3 filed Jul. 1, 2021 and European patent application number 21169057.3 filed Apr. 19, 2021. The content of these applications are incorporated herein by reference in their entireties. The invention relates to a method for controlling a glazing unit having electrically controllable optical properties, to a glazing unit, and to a use of the glazing unit. Functional elements having electrically controllable optical properties are used in the industrial production of glazing units. Such glazing units are frequently composite panes in which a functional element is embedded. The composite panes consist of at least one outer pane, an inner pane and an adhesive intermediate layer, which connects the outer pane to the inner pane in a planar manner. Typical intermediate layers are polyvinyl butyral films which, in addition to their adhesive properties, have high toughness and a high acoustic damping effect. The intermediate layer prevents the disintegration of the composite pane when damaged. The composite pane does crack but remains inherently stable. Composite panes having electrically controllable optical properties are known from the prior art. Such composite panes contain a functional element, which typically contains an active layer between two planar electrodes. The optical properties, in particular the transmission of visible light, of the active layer can be changed by a voltage applied to the planar electrodes. An example of this are electrochromic functional elements known, for example, from US 20120026573 A1 and WO 2012007334 A1. Another example is suspended particle device (SPD) functional elements or polymer dispersed liquid crystal (PDLC) functional elements known, for example, from EP 0876608 B1 and WO 2011033313 A1. By applying voltage, the transmission of visible light can be controlled by electrochromic SPD/PDLC functional elements. SPD and PDLC functional elements are commercially available as multilayer films. The planar electrodes required for applying a voltage are arranged between two PET carrier films. During the manufacture of the glazing unit, the functional element is cut to the desired size and shape from the multilayer film and embedded between the films of an intermediate layer. Via flat conductors, the planar electrodes are electrically conductively connected outside the composite pane to a control module (ECU). The control module is designed to apply an electrical voltage between the planar electrodes. Windshields have been proposed in which an electrically controllable sun shield is realized by a functional element in order to replace the mechanically foldable sun visor in motor vehicles. WO 2019/011891 A1 discloses a device for operating a functional element having electrically controllable optical properties. However, a glazing unit with such a functional element has a temperature dependence of its transmission or also transparency. In many cases, the switchable functional elements have a characteristic curve which deviates significantly from a straight line and makes reproducible switching behavior difficult. The object of the present invention is to provide an improved method in which the switching behavior of the transparency is improved. The object of the present invention is achieved according to the invention by a method according to independent claim 1. Preferred embodiments of the invention emerge from the dependent claims. The object is achieved according to the invention by a method for controlling a glazing unit having electrically controllable optical properties, wherein the glazing unit comprises a composite pane having an outer pane and an inner pane which are connected to one another via a thermoplastic intermediate layer. Furthermore, a functional element is arranged between the outer pane and the inner pane and has an active layer having electrically controllable optical properties between a first planar electrode and a second planar electrode, the optical properties being controlled by means of a control unit. For this purpose, the control unit is connected to the at least two transparent planar electrodes of the functional element so that an electrical voltage can be applied between the planar electrodes by means of the control unit. Since a nonlinear coherence is present between the electrical voltage and a transparency of the functional element, an inverse function is used to determine a magnitude of the electrical voltage. The inverse function can in particular be the inverse function of the characteristic of the adjustment of the transparency (also referred to as light transmittance) of the functional element. The invention is based on the finding that the switching behavior of electrically switchable functional elements is temperature-dependent. An electrica