Systems and methods for controlling the state of two or more liquid crystal based switchable elements

Abstract

The invention proposes a method for controlling the state of two or more liquid crystal based switchable elements (10), wherein the switchable elements (10) are configured as a smart window (2) and / or as a switchable subunit (4) of a smart window (2). The method comprises a first step a) wherein at least two keyframes are defined, wherein each keyframe comprises a set value defining an intended state of a group of switchable elements (10). The group can be a selection of one or more specific switchable elements (10) or all available switchable elements (10). In a subsequent step b) a calculated display frame is generated based on at least one of the defined keyframes, wherein the display frame comprises a set value for the state of the group of switchable elements (10). After the calculated display frame is generated, in a subsequent step c) of the method the state of each switchable element (10) of the group of switchable elements (10) is set as defined by the set value of the calculated display frame. Further methods relate to a master controller (20) for the method and a system (1) implementing the method.

Description

Technical Field

[0001] This invention relates to a method for controlling the state of two or more liquid crystal-based switchable elements configured as smart windows and / or switchable sub-units of smart windows. Other aspects relate to a main controller used in conjunction with the method and a system for implementing the method. Background Technology

[0002] A liquid crystal-based smart window allows for the control of light transmission through the window via a drive signal that controls the state of the smart window. Such smart windows are known in the prior art.

[0003] The review article "Properties, requirements and possibilities of smart windows for dynamic daylight and solar energy control in buildings: A state-of-the-art review", *Solar Energy Materials & Solar Cells* 94 (2010), pp. 87-105, by R. Baetens et al., describes colorable smart windows. Smart windows can utilize various techniques to modulate light transmittance, such as electrochromic devices, liquid crystal devices, and electrophoretic or suspended particle devices. Liquid crystal-based devices utilize the change in the orientation of liquid crystal molecules between two conductive electrodes by applying an electric field, thereby causing a change in their transmittance.

[0004] Liquid crystal-based devices typically include a first substrate, a switchable layer, and a second substrate in this order. The switchable layer comprises at least one liquid crystal material. Both substrates are coated with transparent electrodes to allow the switchable layer to be controlled by means of an electric field.

[0005] In smart windows, devices for modulating light transmittance (hereinafter referred to as switchable optics) are typically laminated to another sheet or carrier glass or between two other substrates or carrier glass substrates to protect the switchable optics and provide mechanical rigidity. In this lamination process, the glass sheet is bonded to the substrate of the switchable optics by means of a thermoplastic interlayer. In the lamination process, the interlayer is disposed between one or more carrier glass sheets and at least one switchable optics. In subsequent processing, which typically involves applying heat and / or high pressure or low pressure, at least one sheet, the interlayer, and the switchable optics are bonded together.

[0006] Smart windows may include additional panes that form the glass units for insulated windows. Furthermore, smart windows may include additional components, such as frames for mechanically mounting switchable optics and / or other panes.

[0007] The state of at least one switchable optics of the smart window, or more specifically, the smart window, is controlled by providing a drive signal applied to electrodes of the switchable element. Changes in the drive signal cause changes in the state of the switchable optics.

[0008] Smart windows can be arranged in a pattern on the facade of a building, for example, or a single smart window can contain multiple independently switchable sub-units arranged in a pattern. Setting the state of each smart window and / or each sub-unit in such an arrangement of multiple smart windows and / or multiple switchable sub-units can be cumbersome. Therefore, it is desirable to provide users with a system and method to help them set the desired state of each smart window and / or each switchable sub-unit in an arrangement including multiple smart windows and / or switchable sub-units.

[0009] A smart window that can be used as an electronic curtain is known from WO2016010186A1. The smart window includes a switchable polymer-dispersed liquid crystal layer, and the light transmission state of the switchable layer can be controlled by means of an electric field applied using electrodes. The smart window has segmented electrodes divided into stripe or grid patterns for controlling the state of the window. A controller provides voltage to the segmented electrodes in response to a signal received from a portable communication device. The portable communication device may include a touch screen for defining the transmissive area of ​​the polymer-dispersed liquid crystal panel.

[0010] DE102014220818 discloses a system and method for reducing glare from sunlight in a room. The system includes a tintable panel arranged in window glass, the tintable panel comprising a plurality of cells that can be tinted independently of each other. The system further includes an optical sensor that acquires an image of the room and an occupant present in the room, and controls the tinting of the individual cells based on the acquired image, such that shadows are cast onto the occupants. The system implements an interactive procedure in which changes in the cast shadows are assigned to corresponding cells of the panel. A synchronization signal can be applied to the panel to synchronize the components of the system (particularly the optical sensor and the panel), taking into account signal transmission and time delays in the individual components.

[0011] The known systems and methods in the prior art cannot assist users in defining and activating complex patterns of facilities that include multiple switchable windows and / or multiple switchable sub-units. Summary of the Invention

[0012] A method is proposed for controlling the state of two or more liquid crystal-based switchable elements, wherein the switchable elements are configured as smart windows and / or switchable subunits of smart windows.

[0013] The method includes a first step a), wherein at least two keyframes are defined, each keyframe including a setting that defines the expected state of a group of switchable elements. This group may be a selection of one or more specific switchable elements or all available switchable elements.

[0014] In subsequent step b), at least one of the keyframes defined is used to compute a display frame, wherein the display frame includes a setting value for the state of the switchable element group.

[0015] After the display frame is computed, in a subsequent step c) of the method, the state of each switchable element in the switchable element group is set to the setting value defined by the computed display frame.

[0016] The switchable element includes a liquid crystal-based switchable optics device capable of controlling the transmittance of light. The liquid crystal-based switchable optics device typically includes a first substrate, a switchable layer, and a second substrate in this order. The switchable layer includes at least one liquid crystal medium. Each of the two substrates is coated with a transparent electrode to allow control of the switchable layer by means of an electric field. The liquid crystal medium may include other components, such as spacers, to ensure a uniform thickness of the liquid crystal-based switchable layer.

[0017] The switchable layer of the liquid crystal-based switchable optics includes a liquid crystal medium. A liquid crystal medium is defined as a substance exhibiting liquid crystal properties. A typical liquid crystal medium contains at least one component having elongated rod-shaped molecules. The liquid crystal medium used in conjunction with this invention has at least two states and may have intermediate states. The state of the liquid crystal medium is controlled using an electric field generated by an AC driving voltage applied between two transparent electrodes. To provide a driving signal to the two transparent electrodes, the switchable element can be connected to a controller.

[0018] Preferably, the switchable optics are liquid crystal (LC) based devices selected from modes of LC-based dye mixtures / dye-free LC and modes of geometry of twisted nematic, super-twisted nematic, planar or vertical ECB nematic, Heilmeier, vertical alignment, twisted vertical alignment, highly twisted nematic, polymer-stabilized cholesteric texture (PSCT), polymer network liquid crystal (PNLC), or polymer dispersed liquid crystal (PDLC). The switchable optics may include other functional layers, for example, color filters, alignment layers, and / or polarizers. Optionally, two or more such switchable optics may be stacked in a switchable element.

[0019] Preferably, the liquid crystal-based switchable optics additionally includes an alignment film located on a first substrate layer and / or a second substrate layer. The alignment film is preferably disposed on the side facing the switchable layer. If electrodes are also located on the respective substrate layers, the alignment film is preferably disposed on a conductive electrode layer, such that the alignment film is in direct contact with the switchable layer. The alignment film can be rubbed in the alignment direction.

[0020] Two substrate layers and a liquid crystal medium are arranged in a cell, wherein the liquid crystal medium is placed in a gap formed by the two electrode layers. The size of the gap is preferably from 1 µm to 300 µm, more preferably from 3 µm to 100 µm, and even more preferably from 5 µm to 100 µm, and most preferably from 10 µm to 50 µm. The cell is typically sealed by means of adhesive lines located at or near the edges.

[0021] The optical state of switchable optics and therefore switchable elements can be controlled by applying an electrical drive signal in the form of an AC voltage to the electrodes. Typical switching times between two states can be, for example, in the range of about 0.1 seconds to 5 seconds, preferably 0.2 seconds to 2 seconds, and more preferably 0.5 seconds to 1 second. For example, a typical liquid crystal-based switchable element takes about 0.5 seconds to switch from a dimmed state to a transparent state across its entire range, and about 0.8 seconds to switch from a transparent state to a dimmed state across its entire range. The full switching range is typically defined as a step size between 10% and 90% of the maximum range. That is, since the last 10% (on either side) is typically reached gradually, it is less visually significant.

[0022] Preferably, the setting values ​​define the desired optical state of the switchable element in the form of numbers selected from the minimum value corresponding to the minimum level of the state and the maximum value corresponding to the maximum level of the state. The setting values ​​can be provided in the form of fixed-point, floating-point, or integer values. For example, the setting values ​​can be provided in the form of integers from 0 to 255. The keyframes defined in step a) and the display frames calculated in step b) include setting values ​​for defining the optical state of the individual switchable elements in the group.

[0023] Preferably, the setting of the state for each switchable element in the switchable element group according to step c) includes: step d), deriving a drive signal for each switchable element based on the corresponding setting value defined by the display frame and the configuration value defining the relationship between the drive signal and the setting value of each switchable element; and step e), applying the derived drive signal to each switchable element.

[0024] For example, the drive signal can be a DC drive signal or an AC drive signal with a defined drive voltage or a defined drive current. For example, the state of a switchable element (especially a liquid crystal-based switchable element) is defined by setting an appropriate drive voltage. For example, the drive voltage of the drive signal can be defined via the relationship between the drive voltage and the set value of the corresponding switchable element.

[0025] A driver configured to generate a drive signal (particularly an AC drive signal) based on a derived voltage can be used to apply the calculated drive voltage to individual switchable elements. The driver can receive parameters from a connected controller for setting the drive signal, particularly a setpoint or the derived voltage of the drive signal. Alternatively, the controller and one or more drivers can be configured as a single device. A single driver can be configured to provide a drive signal to one or more switchable elements. Preferably, the driver is configured to provide a drive signal to more than one switchable element, for example, two to twelve switchable elements, particularly eight switchable elements.

[0026] Preferably, the setpoint is provided to the driver as a digital signal. The configuration value can be used to translate the digital signal into a drive signal.

[0027] Preferably, configuration data containing configuration values ​​is assigned to each switchable element. Configuration values ​​can be set individually for each switchable element, or they can be set uniformly for a group of switchable elements with the same or similar properties.

[0028] Preferably, the configuration data assigned to the switchable elements includes addressing information for identifying the drivers used to drive each switchable element, and this addressing information is used to transmit setpoints or derived drive signals to the identified drivers. The addressing information may further include information for identifying the controller to which a particular driver is connected, so as to identify the complete communication path for communicating with the driver. Furthermore, if the driver includes more than one channel for generating drive signals and is therefore connected to multiple switchable elements, the addressing information may additionally include information for identifying specific channels.

[0029] The use of addressing information allows for large setups requiring multiple controllers and / or drivers to supply drive signals to individual switchable elements. Controllers can be configured identically or in the form of a hierarchical network. Controllers can be directly connected to each other or connected to a communication network for communication, particularly for receiving setpoints or parameters, such as drive voltages. In this arrangement, the addressing information preferably includes an indication of the controller to which the driver for driving a particular one of the switchable elements is connected. In the case of a hierarchical network of controllers, the addressing information may include indications of all controllers forming communication paths to communicate with the driver to which a particular one of the switchable elements is connected.

[0030] Preferably, a communication network is arranged between a main controller configured to calculate a display frame according to step b) and a driver for driving the switchable elements, wherein the communication network includes at least one sub-controller. Preferably, the main controller and the at least one sub-controller have assigned instructions that can be used as part of addressing information for relaying information to a specific driver to which one of the switchable elements is connected.

[0031] In this arrangement, the controllers are in a hierarchical configuration, wherein the main controller is preferably configured to store keyframes defined according to step a) and display frames calculated according to step b), the display frames including setting values ​​for each switchable element. Furthermore, the main controller is configured to identify the sub-controllers to which each switchable element is connected based on addressing information, and to send the setting values ​​of the calculated display frames to the sub-controllers.

[0032] In this hierarchical configuration, the system spans all windows on the building facade, covering multiple floors. For each floor, a driver for generating drive signals can be positioned close to a switchable element, and one or more sub-controllers for relaying information to the driver can be positioned close to the driver in an electronic cabinet on that floor. The sub-controllers then connect to a main controller located in one of the electronic cabinets.

[0033] This hierarchical configuration allows for setups with a large number of switchable elements (e.g., up to 1,000 or more preferably up to 5,000 switchable elements). Therefore, the method can be used to consistently control the state of all smart windows throughout a building.

[0034] Sub-controllers and one or more drivers can be integrated into a single device. This integrated device is preferably configured to communicate directly with the main controller. Furthermore, it is conceivable to allow other external driver devices to connect to this integrated sub-controller / driver device. External driver devices may also be provided as integrated sub-controller / driver devices with the sub-controller functionality disabled.

[0035] Furthermore, integrated controller devices are available that implement the functions of both a main controller and one of the sub-controllers within a single integrated device. Such integrated main controller / sub-controller devices allow for the connection of one or more external sub-controllers to expand the setup. External sub-controller devices can be provided as integrated main controller / sub-controller devices with the main controller function disabled. Additionally, external sub-controller devices can be provided as integrated sub-controller / driver devices.

[0036] Preferably, the sub-controller is configured to store current setting values ​​of switchable elements assigned to at least one sub-controller. In this configuration, the sub-controller preferably includes storage memory for storing the current setting values. The current setting values ​​represent the current state of each switchable element. The sub-controller is preferably configured to receive updates of the stored setting values ​​from the main controller. Furthermore, the sub-controller is preferably configured to control one or more drivers for generating drive signals for connected switchable elements based on the stored setting values.

[0037] Preferably, at least one sub-controller is further configured to store pending updates of setpoints of switchable elements assigned to the at least one sub-controller, and to update the current setpoints in a coordinated manner in response to a trigger signal or trigger command received from the main controller.

[0038] In this configuration, the sub-controller preferably includes two stores for setting values: one for the current setting value and one for pending updates. Upon receiving a trigger signal or trigger command, the stored update is applied to replace the previous current setting value, and then the new value is assigned to the connected drive. Alternatively, the sub-controller may include a single store for setting values ​​and flags indicating pending updates for each setting value. Upon receiving a trigger signal or trigger command, the new setting value with the set flag is assigned to the connected drive, and the flag is cleared.

[0039] The storage for pending updates allows the main controller to first distribute setpoint updates one by one to all sub-controllers, and after each sub-controller has received all pending updates for the setpoint, the setpoint is applied in a coordinated manner by transmitting a trigger signal or trigger command. This has the advantage that the new setpoints based on the new display frame calculated according to step b) take effect substantially simultaneously for each switchable element, regardless of the speed of the connection between each sub-controller and the main controller, or the total number of switchable elements and / or sub-controllers. This is particularly important in large setups where a large number of sub-controllers are used, and the process of sending new setpoints to the sub-controllers is typically a timing process where each transmission takes a specific amount of time. The transmission of the trigger command is only a single command for each sub-controller, which can be transmitted only within a fraction of the time required to transmit the command used to update the setpoints. This allows for a uniform appearance of the switchable elements, as they change their state in a coordinated manner as the new display frame is calculated and the corresponding setpoints are applied to the switchable elements.

[0040] Preferably, the clocks of at least one sub-controller are synchronized with the clock of the main controller, and the current setting value is updated by at least one sub-controller at a predetermined time after being triggered by the main controller. This allows the new setting value to be applied in a coordinated manner to each switchable element, even if the trigger signal may not be received simultaneously by all sub-controllers.

[0041] Preferably, at least one sub-controller is configured to communicate with the main controller using a first protocol and to communicate with at least one driver using a second protocol.

[0042] A first communication protocol is preferably chosen to allow for large distances between the master controller and the sub-controllers. This facilitates the setup of large hierarchical networks, where, for example, sub-controllers are distributed across several floors of a building and a single master controller is connected to each sub-controller. Furthermore, the first communication protocol preferably has a higher bandwidth than the second communication protocol.

[0043] For example, the first communication protocol can be selected from local area network (LAN) protocols, such as Ethernet or WiFi, LON, CANopen, Ethernet / IP, Powerlink, DeviceNet, Profinet, and EtherCat.

[0044] The second communication protocol is preferably used to traverse shorter distances than the first communication protocol, such as the distance between two devices in the same electronic cabinet. In a hierarchical configuration, the second communication protocol is used at a lower level in the hierarchy, requiring less bandwidth than the first communication protocol, thus allowing for the use of a more cost-effective communication protocol.

[0045] For example, the second communication protocol can be selected from RS485, RS232, or an internal communication protocol of the device or circuit (e.g., I²C).

[0046] When the sub-controller and one or more drivers are configured as a single integrated device, the integrated device is preferably configured to use a first communication protocol for communication with the main controller. Additionally, the integrated device can utilize a second communication protocol for internal device communication between the unit implementing the functions of the sub-controller and the unit implementing the functions of one or more drivers. Furthermore, the interface can be exposed to the second communication protocol, thereby allowing other external driver devices to connect to this integrated sub-controller / driver device.

[0047] Preferably, the operation of displaying the frame according to step b) is performed by responding to user input, sensor input, and / or selecting one of the defined key frames as the set point according to predefined rules.

[0048] For example, user input can be provided by means of buttons, toggles, or other input devices. These input devices for providing user input can be connected to a controller, particularly a main controller, configured to process display frames according to step b) of the method. Alternatively, the input devices can be connected to other components that can then communicate with the controller, such as a building management system.

[0049] The input device can be connected via a communication bus (such as KNX bus, BACnet, Dali, Modbus, eBus, Profibus) or any other wireless or wired communication device.

[0050] For example, the user input device can be selected from a group including buttons, toggles (such as on / off toggles or dimming toggles), and smart devices (such as smartphones and laptops). Such a user input device can be used to allow the user to manually input preferred conditions considered when calculating the display frame.

[0051] For example, sensor input can be provided directly via a connected sensor or indirectly via a rule depending on a particular sensor input. Sensors are preferably configured to detect light, temperature, or presence. For example, a light sensor can be configured as an internal or external light sensor. For example, a temperature sensor can be configured as an internal or external thermometer. For example, a presence sensor can be configured as a motion detector, radar sensor, IR sensor, or noise sensor. Other suitable sensors may include, for example, sensors for power consumption sensors or bird detection devices.

[0052] Internal and / or external light sensors can be used to respond to the actual lighting conditions in the room and thus provide appropriate signals that can be considered when calculating display frames for the smart window assigned to this room. Similarly, internal and / or external temperature sensors can be used when calculating display frames for the smart window to maintain the desired temperature in the room. For example, if the temperature in the room is lower than the desired temperature, the smart window assigned to this room can be set to a bright state to allow more light and therefore more heat to enter the room, and if the temperature in the room is higher than the desired temperature, the smart window can be set to a dark state to block light and heat from entering the room.

[0053] Noise sensors can be used to respond to sounds and / or noise detected in a room. For example, a smart window assigned to a room could switch based on the bass beat of the sound detected using a noise sensor, providing a disco-like lighting effect.

[0054] Room occupancy sensors (such as radar sensors, IR sensors, or motion detectors) can be used to detect the presence of people inside a room. Furthermore, noise sensors can detect noise caused by people entering or leaving the room.

[0055] Power consumption sensors can be used to detect a building's current power consumption. For example, if a building's power consumption exceeds a preset limit, certain functions can be suspended, such as providing a uniform appearance for the building facade. Limiting a building's peak power consumption can also be useful in order to receive lower pricing from the utility that supplies the electricity.

[0056] Information about historical climate data can, for example, be used to provide information on the expected heat input due to solar radiation on a given day and to control the transmission of smart windows accordingly.

[0057] In one implementation, shadows and shadow patterns are taken into account throughout the day and, particularly, throughout the year, which includes seasonal variations. Shadows cast on a window at any given time inherently reduce light and heat input. Therefore, it can be useful to adjust the window's transmittance setting when the window is in shadow or partially in shadow. In this regard, the position and relative movement of the sun, the position and orientation of individual windows and facades, the time of day and which day of the year, the geographical location of the building or facility and the shape and location of surrounding buildings, and other structures in the environment (e.g., trees) can be considered to generate shadow data, particularly shadow data covering the entire calendar year. The time interval for the shadow values ​​of individual windows can be suitably selected, for example, down to a few minutes or even seconds, preferably with shorter intervals, especially during the transition period between full exposure and full shadow. Depending on the annual shadow pattern data, the window transmittance can be adjusted accordingly, particularly by appropriately limiting the switchable tinting or dimming range, for example, by adding an offset and shortening the output range or applying a proportional adjustment factor to the output range and adding an offset value.

[0058] The sensor can be directly connected to a controller configured to calculate the display frame according to step b). Alternatively, the sensor can be connected, for example, to a control unit that communicates with the controller configured to calculate the display frame, such as a building management system. The sensor can be connected using a communication bus (e.g., a KNX bus) or via any other wireless or wired communication device.

[0059] Other suitable input devices include, in particular, user devices such as computers or smart devices, such as smartphones, smartwatches, and laptops. With the aid of a suitable software application (“app”), the smart device can be configured to connect to the main controller. The app can provide virtual input devices (such as virtual dimming buttons) to provide user input to the main controller. Furthermore, other user interface devices, such as sliders, can be used. The computer or smart device can communicate directly with the main controller via, for example, a local area network connection (such as Ethernet or Wi-Fi). Alternatively, the computer or smart device can communicate with the main controller via an Internet connection. In such a configuration, the main controller also has an Internet connection, and both the main controller and the user device are connected to a server or cloud service for relaying commands.

[0060] The calculation of the display frame may depend on rules that can be processed by the controller or by another component (such as a building management system). Furthermore, these rules may be processed by a cloud service that provides computing resources and is connected to the controller. The rules may depend on data sources such as sensors, user input devices, and / or other data sources, for example, clocks, calendars, connections to communication devices, and historical climate databases. Optionally, data regarding the shading pattern may also be included.

[0061] Preferably, the state of the switchable element defines the shading and / or haze level of the corresponding switchable element.

[0062] For example, a first (shading) type switchable element can, for instance, control the shading or transmission of light passing through the smart window, and a second (scattering) type switchable element can, for instance, control the haze of the smart window. The smart window may include a single switchable element or any combination of two or more switchable elements of the shading and scattering types. In particular, the smart window may include a stack of both shading-type and scattering-type switchable elements, enabling control over both transmission and haze.

[0063] Preferably, at least two keyframes are assigned to the animation. This animation can describe the transition of one or more switchable elements from one state to another, where other keyframes define intermediate states of the transition. One or more animations can be defined, each with two or more keyframes.

[0064] Preferably, the animation is configured as an animation of the curtains closing horizontally or vertically.

[0065] It can take advantage of the fast switching time of liquid crystal-based switchable elements to provide a smooth transition between state and aesthetic animation.

[0066] For example, a smart window in a room may include multiple switchable elements arranged in an array with multiple rows and configured to control shading. A first keyframe defines the state of all switchable elements of this smart window as maximum transparency, and a last keyframe defines the state of all switchable elements of this smart window as minimum transparency. Then, intermediate frames can continuously define states in which the rows of the smart window become increasingly opaque, creating the effect of curtains moving downwards, starting from the top row.

[0067] In another example, a smart window for a room may include multiple switchable elements arranged in an array with multiple columns and configured to control shading. A first keyframe defines the state of all switchable elements of this smart window as maximum transparency, and a final keyframe defines the state of all switchable elements of this smart window as minimum transparency. Intermediate frames can then progressively define states in which the columns of the smart window become increasingly opaque, creating the effect of curtains moving laterally, starting with the first column on one side.

[0068] Any pattern can be defined as animated. For example, animation can be used to display moving patterns using a switchable array of elements. In particular, animation can be defined as making a building facade used to display moving text or images, where each smart window on the facade acts as a pixel. This is especially useful when the smart windows are arranged in a grid pattern.

[0069] Preferably, each keyframe is assigned a time code. This time code can be given in any unit or as a standard unit (e.g., seconds) and can be used to define the rate at which transitions occur between the states of the switchable element.

[0070] Preferably, by means of a filtering function that depends on at least one of the keyframes of the animation and the current time, the animation defined by the assigned keyframes is played from the current time to a specific time point according to the assigned timecode by calculating the display frames according to step b) and setting the state of the switchable element according to step c) until the animation playback is completed, and the current time advances according to the predefined playback frame rate after each execution of step b).

[0071] The playback frame rate defines the number of display frames processed per second. The frame rate is preferably selected in the range of 0.5 to 15 frames per second, more preferably in the range of 1 to 10 frames per second, and for example, 5 frames per second.

[0072] For example, the filtering function could be a nearest neighbor filter, which is configured to select the keyframe of the animation whose timecode is closest to the current playback time for a given current playback time.

[0073] Alternatively, the filtering function can be a linear, polynomial, or nonlinear interpolation function that depends on two or more keyframes of the animation. For example, the filtering function can be a linear interpolation, where the display frame's setpoint is calculated based on a first setpoint defined by a first keyframe, a second setpoint defined by a second keyframe, and a weighting factor that depends on the timecode of the first and second keyframes and the current playback time.

[0074] Preferably, in response to user input, sensor input, or predetermined rules, a specific time point of the animation is selected as the setpoint, and the animation is played from the current time to the setpoint. Furthermore, more than one animation can be defined so that a specific animation and a specific time point of the selected animation can be defined as the setpoint.

[0075] Animation defines the transition of a switchable element from one state to another, where a specific point in time within the animation defines an intermediate state within the animation. Therefore, a setpoint, set by the user or dependent on sensor input and / or rules, can be considered as defining the desired state of each switchable element. After setting the setpoint, the method modifies the state of each switchable element by playing the animation from the current time to the specific point in time defined by the setpoint. Once the setpoint is reached, playback ends. The switchable element then resides in the state defined by the animation for the corresponding point in time.

[0076] Preferably, a step size is assigned to the animation, wherein the step size is given relative to the timecode assigned to the keyframe assigned to the animation, and a specific time point of the animation is set as a setpoint by receiving step or step-down commands as user input, sensor input, and / or in response to predefined rules.

[0077] Assigning a step size to an animation allows a setpoint to be defined by issuing step or step-down commands. For example, a step command can be used to increase the translucency of a switchable element, and a step-down command can be used to decrease it, with a step size of, for example, 10% in the animation. The first keyframe of the animation defines the maximum transparency setting, and the last keyframe defines the minimum transparency setting. The step size can be selected, for example, as 1 / 10 of the animation's duration. For example, user-operable up / down buttons can be used to issue step and step-down commands.

[0078] Preferably, the calculation of the display frame according to step b) further includes: adjusting the set value defined by the keyframe by applying a function that responds to user input, sensor input, or predetermined rules. For example, the function may be to apply a gain value by multiplication and / or to apply an offset value by addition.

[0079] For example, if you don't intend to use the full dynamic range of a toggleable element, you can adjust the scaling to reduce the animation's opacity from 0% to 100% to 20% to 80%. With such scaling values, there's no need to redefine the animation's keyframes. Instead, you only need to adjust the scaling values.

[0080] For example, adjustment can be defined using gain and offset values. For instance, if the setting is represented by an integer value in the range of 0 to 255, a gain of 1 and an offset of 0 will allow the use of the full range of settings. A gain of 0.5 and an offset of 100 will limit the range to values ​​between 100 and 228.

[0081] Adaptation can be used based on user / sensor input signals and / or rules. For example, a rule could be defined that allows a full range of values ​​from 0 to 255 in cloudy conditions but only a limited range from 0 to 150 in bright conditions. In this example, a higher setting results in higher transparency, thus ensuring that there is always some level of sunlight dimming.

[0082] The proposed method allows for the automatic adjustment of individual settings of various switchable elements to changing conditions, relying on inputs such as user interaction (e.g., pressing a button) or from rules or sensors. The settings can be complex, such as an animation of closing curtains, using animations comprising at least two keyframes. This animation must be defined only once. Subsequent changes to the desired state of the smart window, including the switchable elements, can then be easily performed by selecting appropriate points in the animation as setpoints. For example, depending on sensor input, the setpoint can be limited to 0.5 times the range, while user input (e.g., step / step commands) will still cause the animation to run to the desired setpoint within the animation. Furthermore, the method allows defining the step size of the animation so that the timing of the animation can be easily set by providing step and step commands. In this way, automatic adjustment to changing lighting conditions can be easily achieved while still respecting user preferences.

[0083] Furthermore, the system can be configured to respond to specific inputs in a predefined manner. For example, the system can connect to a fire detection system or a burglar detection system. Through this connection, an alarm can be triggered. Depending on the configuration rules, this can replace the currently running animation with a specified alarm animation. In response to such an alarm animation, privacy windows, where settings define a fog level, can switch to their transparent state, allowing firefighters to see inside the room. To create awareness of evacuating the building, solar windows, where settings define a tinting level, can display a dark / light checkerboard pattern by alternating between dark and light windows.

[0084] Advantageously, the proposed method allows for a smooth transition between the current state and the desired state defined by a setpoint by playing the animation at a high frame rate, typically 5 frames per second or higher. Furthermore, the method allows for smooth transitions using interpolation between two or more keyframes. Therefore, the method allows for aesthetically pleasing transition effects from one state to another of one or more switchable elements. This dynamic effect can be used to attract the user's attention and convey information.

[0085] Furthermore, the method provides synchronization between multiple controllers so that transitions between states are consistent across all involved switchable elements.

[0086] Another aspect of the invention relates to a main controller for controlling the state of two or more liquid crystal-based switchable elements. The main controller is configured for use with one of the methods described herein. In particular, the main controller is configured to store keyframes defined according to step a) of the method and to compute display frames according to step b) of the method.

[0087] Furthermore, an object of the present invention is to provide a system for controlling the state of two or more liquid crystal-based switchable elements in one of the methods described herein. The system includes a main controller and at least one driver for driving at least one switchable element.

[0088] Preferably, the system includes a communication network arranged between the main controller and at least one driver. Preferably, the communication network includes at least one sub-controller configured to store current settings of switchable elements assigned to the at least one sub-controller.

[0089] The main controller and / or system can be configured to provide connectivity for establishing system configuration (particularly the main controller configuration). For example, the system can provide a network connection to allow main controller configuration. This could be a local area network (LAN) connection or an internet connection. With a LAN connection, a computer running configuration software can be connected to perform, for example, initial setup of the main controller. With an internet connection, the main controller and / or system can be configured to connect to a remote configuration service to configure the main controller. Specifically, the connection can allow initial setup of the main controller, including the definition of animations and their keyframes. This remote configuration service can be cloud-based.

[0090] In addition, the main controller and / or system may be configured to provide diagnostic connectivity for transmitting status messages and / or error messages. Attached Figure Description

[0091] Figure 1 A first embodiment of a system for controlling the state of two or more liquid crystal-based switchable elements. Figure 2 A second embodiment of a system for controlling the state of two or more liquid crystal-based switchable elements. Figure 3 For the building facade, Figure 4 Animations a through 4d depict the vertical movement of the curtains, and Figure 5 Animations a through 5c depict the moving diagonal curtains. Detailed Implementation

[0092] Figure 1A first embodiment of a system 1 for controlling the state of two or more liquid crystal-based switchable elements 10 is schematically shown. For example, the switchable elements 10 may be configured to control the transmission of solar radiation through a smart window 2 including the switchable elements 10.

[0093] exist Figure 1 In the example shown, system 1 controls twelve switchable elements 10 arranged in twelve smart windows 2. The liquid crystal-based switchable elements 10 can change their optical state from transparent to dark depending on an AC drive signal. System 1 includes a driver 40 for providing drive signals to the switchable elements 10. Figure 1 In the configuration shown, each driver 40 is configured to generate drive signals for both switchable elements 10. Therefore, Figure 1 The system shown includes six drives 40.

[0094] To coordinate the setting of the state of the switchable elements 10, system 1 includes a main controller 20. The main controller 20 is configured to store at least two keyframes, each keyframe including a setting value that defines the expected state of each switchable element 10 in a group of switchable elements 10 for a given condition. This group can be a selection of one or more specific switchable elements 10 or all available switchable elements 10. For example, the group could include all twelve switchable optical elements 10 that can be arranged in a grid pattern with two rows and six columns.

[0095] Keyframes can, for example, define the animation of a horizontally moving curtain. The first keyframe can define the state of all switchable elements 10 as fully transparent, and the last keyframe can define the state of all switchable elements as having minimum transparency. The second keyframe can define only the first column as having minimum transparency and the other rows as having maximum transparency, with subsequent keyframes setting the other columns to have minimum transparency. Furthermore, each keyframe is assigned a timecode.

[0096] Furthermore, the main controller 20 is configured to operate on at least one display frame based on defined keyframes. This display frame includes settings that define the optical states of the various switchable elements 10 to be set using drive signals generated by the driver 40.

[0097] The main controller 20 includes a connection to a control bus 36 for receiving sensor input and / or user input. For example, the control bus 36 may be configured as a KNX bus. Figure 1 In the example implementation depicted, control bus 36 is connected to switch 62 and sensor 64. Switch 62 may be configured, for example, as a dimming switch, and sensor 64 may be configured, for example, as an internal light sensor for determining the light level in a room.

[0098] The main controller 20 can calculate the display frame based on user input provided by the switch 62 and sensor input provided by the sensor 64.

[0099] A drive signal is generated for the switchable element 10 based on the set value defined by the calculated display frame. Figure 1 In the implementation described herein, multiple drivers 40 are used, which are connected to the main controller 20 via a hierarchical network including sub-controllers 30. Figure 1 In the implementation shown, the main controller 20 communicates with the sub-controller 30 using a communication device 34 (which may be an Ethernet local area network), and the sub-controller 30 communicates with multiple drivers 40 using a serial communication line 32 (particularly an RS485 bus).

[0100] In an alternative implementation, the functionality of the sub-controllers 30 and the drivers 40 connected to each sub-controller 30 can be integrated into a single device. In other words, the drivers 40 will be equipped with an interface for the communication device 34 and can be directly connected to the main controller 20. In this case, a second protocol (e.g., serial communication line 32) can be used for intra-device communication within the combined sub-controller / driver device.

[0101] Users can easily set the desired state of the twelve switchable elements 10 using a dimming switcher. Depending on the position of the dimming switcher, a certain point in time of the animation of the horizontally moving curtains is set as a setpoint. The main controller 20 then plays the defined animation by calculating appropriate display frames until a certain point in time of the animation defined by the setpoint is reached.

[0102] Alternatively or additionally, the desired state of the twelve switchable elements 10 can be set relying on sensor input provided by sensor 64. For example, initially, the twelve switchable elements are in the state defined by the first frame of the animation and therefore in the state of maximum transparency. If the light level in the room rises above a predetermined threshold, the timecode of the animation representing the last frame can be selected as the set point. The system then produces an aesthetic transition of the twelve switchable elements 10 from the state of maximum transparency defined by the corresponding keyframe of the animation to the state of minimum transparency defined by the corresponding keyframe of the animation.

[0103] In one implementation scheme, such as regarding Figure 1The described system 1 further includes a building management system 50, which is connected to the main controller 20 and serves as another data source for computing display frames. For example, the building management system 50 may be configured to provide a time-dependent signal to the main controller 20 that causes it to select a specific point in time as a setpoint for the animation. For example, the system 1 including the building management system 50 may be configured to set the switchable element 10 to a state of minimum transparency, and otherwise to a state of maximum transparency, during a time span in which a room including a smart window 2 with a switchable element 10 is exposed to direct sunlight. In various cases, the system 1 will provide aesthetic transitions between states by playing an animation sequence defined by keyframes.

[0104] Figure 2 A schematic diagram showing a second embodiment of a system 1 for controlling the state of two or more liquid crystal-based switchable elements 10.

[0105] Similar to System 1 in the first implementation scheme, in Figure 2 In the example, system 1 includes twelve switchable elements 10 arranged in twelve smart windows 2. The liquid crystal-based switchable elements 10 can change their optical state from a transparent state to a dark state depending on an AC drive signal provided by a driver 40. Figure 2 In the embodiment shown, each driver 40 provides AC drive signals to two of the switchable elements 10. Therefore, Figure 2 The system shown includes six drivers 40. The six drivers 40 are connected to a sub-controller 30. The sub-controller 30 provides signals to the drivers 40 that cause them to generate corresponding drive signals. The sub-controller 30 can communicate with the drivers 40 via a bus (e.g., an RS485 bus).

[0106] System 1 includes a main controller 20, as per [reference needed] Figure 1 As described, the main controller 20 is configured to store at least two keyframes, each keyframe including a setpoint defining the expected state of each switchable element 10 in a group of switchable elements 10. This group may be a selection of one or more specific switchable elements 10 or all available switchable elements 10. The main controller 20 is further configured to compute a display frame including setpoints defining the desired state of the switchable element 10. This display frame is computed based on input signals that may be provided in the form of user input, sensor signals, and / or rules.

[0107] To provide sensor input and user input, such as Figure 2The system shown includes a control bus interface 60 connected to, for example, an input control bus 66 configured as a KNX bus for connecting switch 62 and sensor 64. For rule processing, the system may include a building management system 50.

[0108] and Figure 1 Compared to the configuration of System 1, the main controller 20, bus interface 60, building management system 50, and sub-controller 30 are interconnected using a network switch 80 via a star-shaped network connection 82. For example, network connection 82 can be configured as an Ethernet link allowing communication between devices on the input control bus 66 and the main controller 20 (marked with an arrow with reference numeral 100). Furthermore, System 1 allows communication between the main controller 20 and the building management system 50 (marked with an arrow with reference numeral 110), and communication between the main controller 20 and the sub-controller 30 (marked with an arrow with reference numeral 120). Therefore, Figure 2 System 1 has a different network topology, but can be compared with... Figure 1 The implementation scheme operates in essentially the same way as described.

[0109] like Figure 2 The system 1 described herein further includes Internet connectivity, which is depicted as a network connection 82 to Internet connectivity service 70. For example, Internet connectivity service 70 may include remote configuration service 72 and remote monitoring service 74.

[0110] The remote configuration service 72 can communicate with the main controller 20 (as indicated by the arrow with reference numeral 130), and in particular, can allow the service agent to configure the main controller 20. For example, the initial setup of the main controller 20, including the definitions of animations and their keyframes, can be performed via the service agent through the remote configuration service 72.

[0111] The remote monitoring service 74 can communicate with the main controller 20 (as indicated by the arrow with reference numeral 140). The main controller 20 can be configured to transmit the current status of system 1 and possible error messages to the remote monitoring service 74. If an abnormal operation or error is transmitted to the remote monitoring service 74, the service agent can use the remote configuration service 72 to make changes to the configuration of system 1 or, if necessary, dispatch a service team to provide maintenance.

[0112] although Figure 2A network with a star-shaped topology network connection 82 is depicted, but not all possible interactions between the connecting devices are used. Since the main controller 20 maintains the animation (represented by at least two reference frames), it is the only device communicating with the driver 40 (via the sub-controller 30). All other devices (specifically the building management system 50, switch 62, and sensor 64) interact only with the main controller 20. In this way, the main controller 20 is the central control point. In other embodiments, other network topologies, such as chains or rings, may also be used. For example, if the network covers multiple floors of a building, each floor may have a network switch 80, where the network switches 80 on each floor are interconnected.

[0113] Figure 3 A schematic depiction of the facade 8 of a building 6 having multiple smart windows 2 arranged in a grid pattern. (As per...) Figure 1 and Figure 2 The described system 1 can be used to control the state of all smart windows 2 of a building 6, or at least all smart windows 2 on the facade of a building 6. In particular, this allows for coordinated and synchronized operation of all smart windows 2 and can be used to provide aesthetic transitions between two states of the smart windows 2.

[0114] Figure 4 a to Figure 4 d depicts four different keyframes of an animation of vertically moving curtains that can be used to control the level of light in a room. Figure 4 a to Figure 4 In the example depicted in d, the room has a wall 7 with 25 switchable elements 10 configured as individual smart windows 2. The smart windows 2 on the wall 7 are arranged in a 5×5 matrix. However, it is also envisioned that four keyframes are used to define the state of a single smart window 2, including the 25 switchable elements 10 arranged in a 5×5 matrix and configured as switchable sub-units. Each switchable element 10 can be switched independently.

[0115] exist Figure 4 In the first keyframe depicted in section a, where the assigned timecode is "0", the first row of switchable elements 10 is assigned 60% transparency and the second row of switchable elements 10 is assigned 80% transparency. The remaining three rows are each assigned 100% transparency as a set value.

[0116] exist Figure 4 In the second keyframe depicted in b, with the assigned timecode "33", the first row of switchable elements 10 is assigned 40% transparency, and the second row of switchable elements 10 is assigned 60% transparency. The third row has an assigned transparency of 80%. The remaining two rows are each assigned 100% transparency as a set value.

[0117] exist Figure 4In the third keyframe depicted in c, with the assigned timecode "67", the first row of switchable element 10 is assigned 20% transparency, and the second row of switchable element 10 is assigned 40% transparency. The third row has an assigned transparency of 60%, and the fourth row has an assigned transparency of 80%. The last row has an assigned transparency of 100% as the set value.

[0118] exist Figure 4 The timecode for the assignment depicted in d is "100". In the fourth and last keyframes, the first two rows of switchable elements 10 have 20% assignment transparency, and the third row of switchable elements 10 has 40% assignment transparency. The fourth row has 60% assignment transparency. The last row has 80% assignment transparency as the set value.

[0119] When the animation starts Figure 4 The first keyframe of a plays to Figure 4 In the last keyframe of d, the wall 7, including the switchable element 10, darkens from top to bottom to simulate the vertical closing of the curtains.

[0120] For example, a user can select any intermediate state by choosing a time point between time codes 0 and 100 as the setpoint. This selection can be performed, for example, by using a dimming switch, where a position of the switch is assigned to a time code. Alternatively, a step size of, for example, 10 can be defined, and a specific time point can be selected by issuing a step / decrease command that increments / decrements a time point by a step size defined by the step size.

[0121] Figure 5 a to Figure 5 c depicts three different keyframes of the animation of the moving diagonal curtain as another instance of animation. Figure 5 a to Figure 5 In example c, wall 7 has 30 switchable elements 10 arranged in a 6×5 matrix, configured as smart windows 2. However, the same keyframes can also be used to define the state of a single smart window 2 with 30 switchable sub-units arranged in a 6×5 matrix as switchable elements 10. In the depicted keyframes, gradients are shown, where the lower left switchable element 10 is always set to maximum opacity and the upper right switchable element 10 is always set to minimum opacity. The 50% opacity point is further moved to the left by shifting the opacity value of each switchable element 10 towards the left of each consecutive keyframe in each row. As the animation moves from... Figure 5 The first keyframe of a plays to Figure 5 This creates the illusion of the diagonal curtains moving from right to left on the last keyframe of c.

[0122] List of reference numerals

[0123] 1: System

[0124] 2: Smart Window / Switchable Window

[0125] 6: Buildings

[0126] 7: Walls

[0127] 8: Facade

[0128] 10: Switchable components

[0129] 20: Main Controller

[0130] 30: Sub-controller

[0131] 32: Serial communication line

[0132] 34: Communication device

[0133] 36: Control Bus

[0134] 40: Driver

[0135] 50: Building Management System

[0136] 60: Control bus interface

[0137] 62: Switcher

[0138] 64: Sensors

[0139] 66: Input control bus

[0140] 70: Internet connectivity services

[0141] 72: Remote Configuration Service

[0142] 74: Remote Monitoring Service

[0143] 80: Network Switch

[0144] 82: Network Connection

[0145] 100: Communication from user input and / or sensor input

[0146] 110: Communication with the building management system

[0147] 120: Communication with switchable elements

[0148] 130: Communication with remote configuration

[0149] 140: Communication with remote monitoring

Claims

1. A method for controlling the state of two or more liquid crystal-based switchable elements (10), said switchable elements (10) configured as smart windows (2) and / or switchable subunits of smart windows (2), said method comprising a) Define at least two keyframes, each keyframe including a setting value that defines the expected state of a group of switchable elements (10), said group being the selection of one or more specific switchable elements (10) or all available switchable elements (10). b) Display a computational frame based on at least one of the defined keyframes, the display frame including a setting value for the state of a group of switchable elements (10). c) Set the state of each switchable element (10) in the group of switchable elements (10) to the setting value defined by the calculated display frame. Its features are, At least two keyframes are assigned to the animation, each keyframe being assigned a timecode. The display frames are calculated by means of a filtering function that depends on at least one of the keyframes of the animation and the current time. The animation defined by the assigned keyframes is played from the current time to a specific time point according to the assigned timecode. Steps b) and c) are repeated until the animation is completed, and the current time is advanced according to a predefined playback frame rate after each execution of step b).

2. The method according to claim 1, characterized in that, According to step c), setting the state for each switchable element (10) in the group of switchable elements (10) includes the following steps: d) Based on the configuration values ​​defined by the display frame and the relationship between the AC drive signal and the set values ​​of each switchable element (10), derive the AC drive signal for each switchable element (10), and e) Apply the derived AC drive signal to each switchable element (10).

3. The method according to claim 1, characterized in that, A communication network is arranged between a main controller (20) configured to calculate the display frame according to step b) and a driver (40) for driving the switchable element (10), wherein the communication network includes at least one sub-controller (30).

4. The method according to claim 3, characterized in that, The sub-controller (30) is configured to store the current settings of the switchable element (10) assigned to at least one sub-controller (30).

5. The method according to claim 4, characterized in that, The at least one sub-controller (30) is further configured to store pending updates of the set values ​​of the switchable elements (10) assigned to the at least one sub-controller (30), and to update the current set values ​​in a coordinated manner in response to a trigger signal or trigger command received from the main controller (20).

6. The method according to claim 5, characterized in that, The clocks of the at least one sub-controller (30) and the main controller (20) are synchronized, and the update of the current set value is performed by the at least one sub-controller (30) at a predetermined time after being triggered by the main controller (20).

7. The method according to claim 3, characterized in that, The at least one sub-controller (30) is configured to communicate with the main controller (20) using a first protocol and to communicate with at least one driver (40) using a second protocol.

8. The method according to claim 1, characterized in that, The configuration data assigned to the switchable element (10) includes addressing information for identifying the driver (40) for driving each switchable element (10), and the addressing information is used to transmit the set value or derived drive signal to the identified driver (40).

9. The method according to claim 1, characterized in that, The operation of step b) displays the frame by selecting one of the defined key frames as the setpoint in response to user input, sensor input, and / or depending on predefined rules.

10. The method of claim 1, wherein the state of the switchable element (10) defines the level of shading and / or haze of the corresponding switchable element (10).

11. The method of claim 1, wherein the animation is configured as an animation of closing the curtains horizontally or vertically.

12. The method of claim 1, wherein a specific time point of the animation is selected as a set point in response to user input, sensor input, or a predetermined rule, and the animation is played from the current time to the set point.

13. The method of claim 12, wherein a step size is assigned to the animation, wherein the step size is given with respect to the timecode assigned to the keyframes assigned to the animation, and a specific time point of the animation is set as a setpoint by receiving a stepping or step-down command as user input, sensor input, or in response to a predefined rule.

14. The method according to claim 1, characterized in that, The operation of the display frame according to step b) further includes: adjusting the set values ​​defined by the keyframe by applying a function that responds to user input, sensor input, or predetermined rules.

15. A system (1) for controlling the state of two or more liquid crystal-based switchable elements (10) according to the method of any one of claims 1 to 14, comprising a main controller (20) for controlling the state of two or more liquid crystal-based switchable elements (10) according to the method of any one of claims 1 to 14, wherein the main controller (20) is configured to store key frames defined according to step a) of the method and to compute display frames according to step b) of the method, and at least one driver (40) for driving at least one switchable element (10), the at least one driver (40) being configured to generate an AC drive signal.

16. The system (1) according to claim 15, characterized in that, The communication network arranged between the main controller (20) and the at least one driver (40) includes at least one sub-controller (30), which is configured to store the current settings of the switchable elements (10) assigned to the at least one sub-controller (30).

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