Light-emitting component with a light source and an integrated circuit

Abstract

A light-emitting device (100) with a light source (112) and an integrated circuit (114). The integrated circuit (114) is configured to receive a serial data stream in which brightness values ​​for a plurality of series-connected light-emitting devices are encoded, to extract a brightness value for the light source (112) from the serial data stream, and to determine a switching point for controlling the light source (112) to the brightness value based on the received serial data stream. Finally, the integrated circuit (114) is configured to set the light source (112) to the brightness value at the determined switching point.

Description

[0001] The present invention relates to a light-emitting component comprising at least one illuminant and an integrated circuit, as well as a method for controlling the same. Furthermore, the present invention relates to a transparent display comprising a plurality of such light-emitting components.

[0002] Transparent displays with a multitude of light-emitting components are generally known. For example, the structure of such a transparent display is described in EP 2 879 120 A1. The light-emitting components are applied to a transparent substrate, e.g., a glass pane, and made contactable by means of a transparent and electrically conductive coating. The coating is structured on the transparent substrate in such a way that the light-emitting components can be supplied with both power and control signals.

[0003] Common transparent and electrically conductive coatings on glass panes or plastic films have a high sheet resistance, which can range from 1 to 6 ohms per unit area (ohm / sq). In comparison, a copper layer on a circuit board has a sheet resistance of 0.5 mOhm / sq. The high sheet resistance of common coatings means that electrical energy can only be transported to the light-emitting components with high losses. Furthermore, control signals cannot be easily transmitted like with a conventional circuit board.

[0004] As shown in EP 2 879 120 A1, the control signals for the light-emitting components can be transmitted via individual supply and return lines, which are patterned into the electrically conductive coating with a laser. However, lasering a large number of conductor tracks is complex and leads to increasing production costs. Furthermore, many closely spaced structures are visible upon close inspection and are undesirable for a transparent display. Furthermore, the numerous supply and return lines require complex connection technology at the edge of the transparent display.

[0005] DE 10 2018 107 309 A1 addresses these problems and proposes, on the one hand, a special structuring of the coating and, on the other hand, the use of active light-emitting components. Active light-emitting components are characterized by the fact that, in a common housing, they integrate a control circuit, usually in the form of one or more LEDs, along with a light source capable of processing a digital data signal and, based on this, controlling the light source to a defined brightness value. Active light-emitting components, also known as smart LEDs or pixel LEDs, can be connected in series, with each element being individually addressable by a central controller.The use of active light-emitting components in series can significantly simplify the wiring effort and connection technology, enabling simpler and more effective structuring of the transparent conductive coating.

[0006] For active light-emitting components, the actual power consumption can fluctuate significantly depending on the set brightness. Due to the individual control of the active light-emitting components, combined with the high lead resistances, the voltage drop across the individual light-emitting components is subject to significant fluctuations. Typically, active light-emitting components are operated with a constant voltage, e.g., 5V or 12V, which is provided by a common, equally constant voltage supply on the transparent substrate.However, the constant voltage supply of the transparent substrate, the high lead resistances of the transparent and conductive coating, and the variable power consumption of the active light-emitting components can result in the actual operating voltage applied to the components being outside the permissible specifications of the active light-emitting components, potentially leading to undefined behavior of the light-emitting component. Likewise, the fluctuating voltage levels mean that common reference potentials cannot be used during data transmission, which can lead to transmission errors. Commercially available active light-emitting components cannot therefore simply be used for transparent displays of this type.

[0007] DE 10 2018 107 309 A1 proposes, on the one hand, connecting a Zener diode in parallel to the supply terminals of the light-emitting component and, on the other hand, decoupling the data line between any two adjacent components using a coupling capacitor. The Zener diode ensures that a constant voltage is always applied to the light-emitting component, regardless of the respective brightness. This means that when the light-emitting component is set to bright, most of the energy flows into the component, while when the component is set to dark, the energy is dissipated in the form of heat via the Zener diode. In this way, active light-emitting components can be operated with a constant voltage within their specifications, albeit with low energy efficiency. The coupling capacitor isolates the data line between the components.On one side, the voltage level of the transmitting component is established, and on the other side, the voltage level of the receiving component. The latter can be achieved using a pull-down resistor or a diode. Decoupling improves data transmission between the components because defined voltage levels are established. According to the measures presented in DE 10 2018 107 309 A1, commercially available active light-emitting components can, in principle, be used for large-area transparent displays.

[0008] However, if very bright light-emitting components with high power consumption are required for certain applications, for example because the transparent displays are to be operated outdoors even in daylight or if energy efficiency is a priority, the measures described in DE 10 2018 107 309 A1 are not sufficient to enable efficient, error-free operation.

[0009] US Patent No. 8,492,983 B1 describes a system for serially controlling LEDs, in which each LED or group of LEDs is connected to a main controller via a microcontroller and a serial data bus. The bus controller sends data packets containing the address and commands for the LEDs. Each LED controller modifies the address fields of the packets and forwards them to the next unit, allowing the LEDs to be controlled without predefined addresses. The architecture enables simultaneous control of the LEDs and reduces latency through instantaneous packet forwarding. Overload conditions are avoided by monitoring the current and temperature of the LED units, with the main controller implementing additional safety measures.

[0010] Against this background, it is an object of the present disclosure to provide an improved light-emitting component comprising a luminous source and an integrated circuit that enables efficient operation of transparent displays requiring bright luminous sources. In particular, it is an object to enable energy-efficient operation and to minimize errors in the control of the light-emitting component due to transmission errors in the control signals.

[0011] According to one aspect of the present disclosure, this object is achieved by a light-emitting component having a lamp and an integrated circuit, wherein the integrated circuit is configured to receive a serial data stream in which brightness values ​​for a plurality of series-connected light-emitting components are encoded, to extract a brightness value for the lamp from the serial data stream, to determine a switching time for controlling the lamp to the brightness value based on a length of the received serial data stream, and to set the lamp to the brightness value at the determined switching time.

[0012] According to a further aspect, this object is achieved by a method for controlling a light-emitting component with a luminous means and an integrated circuit, comprising the steps: - receiving a serial data stream encoding brightness values ​​for a plurality of series-connected light-emitting components; - Extracting a brightness value for the lamp from the serial data stream; - Determining a switching time for controlling the lamp to the brightness value based on a length of the received serial data stream; and - Adjusting the lamp to the brightness value at the specific switching time.

[0013] It is therefore an idea of ​​the present invention to design an active light-emitting component in such a way that it can determine a switching time from a control signal at which the lamp is to be set to the desired brightness value. The active light-emitting component can then only set the lamp to the brightness value read from the data stream at the determined switching time. This configuration of the individual light-emitting component makes it possible for several such components connected in series to determine a common switching time at which they simultaneously set their respective lamps to the values ​​taken from the control signal. In other words, in this way several components connected in series can be synchronized so that they switch almost simultaneously and change their current consumption at a specific time.

[0014] Synchronization enables a defined temporal behavior of all series-connected light-emitting components, to which both the individual components and the central controller can be coordinated. This allows, for example, data transmission or power supply to be better coordinated to operate the light-emitting components more efficiently or ensure reliable communication between them and a controller. This also allows light-emitting components with high power requirements to be operated on structures not designed for such high power transmission, such as transparent displays, in which a large number of light-emitting components are arranged on a transparent substrate and connected with a semi-transparent, conductive coating.

[0015] In a further embodiment, the integrated circuit can be configured to delay the adjustment of the illuminant to the brightness value until the switching time.

[0016] According to this embodiment, the switching time can be configured as an offset. For example, the switching time can be configured as a delay relative to the reception of the data signal or a specific marker in the data signal, which makes synchronization easy to implement.

[0017] In a further embodiment, the integrated circuit can be configured to temporarily store the brightness value for the illuminant until the switching time.

[0018] According to this design, the brightness value can be buffered by the integrated circuit. This allows the control of the light source to be independent of the reception of the data signal, allowing synchronized switching even with series-connected light-emitting components that receive a data signal sequentially.

[0019] In a further embodiment, the integrated circuit can be configured to block the adjustment of the brightness value of the illuminant for a defined switching time. In particular, the integrated circuit can be configured to temporarily block an input via which the serial data stream is received, in particular for the switching time, for a defined switching time.

[0020] According to this embodiment, the integrated circuit can prevent a brightness change from occurring during a defined period of time. For example, the integrated circuit can deactivate an input at which the data signal is received for the specified period of time or ignore a received data signal. This prevents data from being received during a switching phase or the lighting device from being set to incorrectly received brightness values. The design thus advantageously contributes to robust and error-free operation.

[0021] In a further embodiment, the length of the received serial data stream can be defined by a number of received bits from the reception of the brightness value up to a code word concluding the serial data stream.

[0022] According to this embodiment, the integrated circuit determines the switching time based on the length of the signal arriving at the light-emitting component. This makes it possible to dispense with a special data element or code word within the serial data stream, which is used to communicate the switching time to the light-emitting component. Another advantage is that known serial protocols can be used without having to introduce new data elements. This makes transmitting a common switching time particularly easy to implement.

[0023] In a further embodiment, the integrated circuit can be configured to forward the serial data stream to a number N of further light-emitting components and to determine the number N from the length of the serial data stream. In particular, the integrated circuit can be configured to determine the switching time by multiplying the number N by a defined latency t latenz of the light-emitting component, whereby the multiplication of the number N with the defined latency time t latenz of the light-emitting component defines a time offset and the switching time is defined by the time offset with respect to a signal input of the serial data stream at the light-emitting component or with respect to the reception of a code word contained in the serial data stream.

[0024] According to this design, the switching time can be determined particularly easily and effectively from the serial data signal without the need for additional information that must be separately transmitted to the light-emitting component. The latency time t ıatenz can advantageously be a parameter that is specific to a particular type of light-emitting component and the same for all light-emitting components of that type. Using the number of components thus determined, it is then easy to determine when the last component in the series circuit has received the data signal and is ready to change brightness. The light-emitting component that determined the time must wait at least as long as it takes to switch with all components simultaneously.

[0025] In a further embodiment, the integrated circuit can be designed to extract the brightness value for the luminous means from the serial data stream and to delete it from it.

[0026] According to this embodiment, a single component can easily modify the serial data stream in such a way that subsequent components can derive a parameter for determining the switching time from the modified data stream. This embodiment preferably allows known transmission protocols to continue to be used for communication, and no changes to the transmission protocols are required to implement time synchronization.

[0027] In a further embodiment, the light-emitting component can have a voltage regulator, in particular a DC-DC converter, which provides a constant operating voltage for the light-emitting component. In particular, the voltage regulator can be designed to adjust the operating voltage depending on a current through the light-emitting component.

[0028] A voltage regulator can provide a constant voltage to the light-emitting component, which compensates for fluctuating supply voltage. Compared to a passive element, a voltage regulator can set a desired voltage with lower losses and thus more efficiently. Furthermore, a voltage regulator can be selected so that a uniform current consumption is achieved with moderate fluctuations at the input. This avoids a strongly pulsed current sink, which on average causes higher energy consumption in the lead resistance than a uniform current drain. It is advantageous if the voltage regulator can raise or lower its output voltage depending on the brightness of the LED, i.e. depending on the current flowing through the LED.This also enables a less pulsed control of the light-emitting component by dimming the lamp with a low current instead of a more pulsed control.

[0029] In a further embodiment, the illuminant may comprise two or more, in particular three, light-emitting diodes, and the received brightness value includes a separate brightness value for each of the two or more light-emitting diodes.

[0030] According to this embodiment, the luminous device can generate a multitude of colors from colored light-emitting diodes by operating light-emitting diodes in different primary colors at different brightness levels. In this case, the received brightness value can contain several individual brightness values ​​for the plurality of light-emitting diodes, which are read by the component and used to control the light-emitting diodes. Temporal synchronization of a plurality of such light-emitting components can also be achieved here using the method described above.

[0031] In a further embodiment, the illuminant and the integrated circuit can be powered by a common power supply. In particular, the illuminant and the integrated circuit can be arranged in a common housing, for example, a 5050 housing, which has four external connections.

[0032] This design has the advantage that the light-emitting component can be made particularly small and space-saving, making it particularly suitable for use on a transparent substrate. The smaller the component, the less surface area it occupies and covers on the transparent substrate.

[0033] It is understood that the features mentioned above and those to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the present invention.

[0034] Embodiments of the invention are illustrated in the drawings and explained in more detail in the following description. They show: Fig. 1 a transparent display according to an embodiment of the present disclosure, Fig. 2 a first variant of the Fig. 1 shown transparent displays, Fig. 3 a second variant of the Fig. 1 shown transparent displays, Fig. 4 shows a single light-emitting component according to an embodiment of the present disclosure in a schematic representation, and Fig. 5 shows a functional structure of an integrated circuit of a light-emitting device according to an embodiment of the present disclosure in a schematic representation.

[0035] Fig. Figure 1 shows a transparent display according to an embodiment of the present disclosure. The transparent display is designated herein as a whole by reference numeral 10.

[0036] The transparent display 10 has an at least partially transparent substrate 12, for example, a glass pane or a laminated glass pane. The transparent substrate 12 extends flatly in the xy plane shown here. The thickness of the substrate in the z direction is many times smaller than the respective dimensions in the x and y directions. A plurality of light-emitting components 100 arranged in series are arranged on the transparent substrate 12 as electrical consumers. The light-emitting components 100 are, as will be explained below, designed in particular for a series connection and can preferably be controlled individually to display different colors and / or brightnesses.

[0037] The light-emitting components 100 generally require a constant supply voltage, which can be applied to the respective light-emitting component 100 via a first terminal 102 and a second terminal 104. The first and second terminals 102, 104 are also referred to below as supply terminals. A third terminal 106 of the light-emitting component is an input terminal via which a data signal can be received. The light-emitting component 100 can output a data signal via a fourth terminal 108 as an output terminal. The light-emitting components 100 are connected in series by connecting the input and output terminals in series.

[0038] The connection between the input and output terminals, as well as the connection of the supply terminals to the respective supply potentials, is established via an electrically conductive and partially transparent coating 14 on the transparent substrate 12. The coating can be produced, for example, using a wet-chemical process and can comprise, for example, a composite of ZnO - SnO2, ZnO - In2O3, ZnO - Ga2O3, and Ga2O3 - Sb2O5. Partially transparent in this context means that the layer is at least 50% transparent.

[0039] The partially transparent and electrically conductive coating 14 is applied to a surface of the transparent substrate 12, on which the plurality of light-emitting components can also be arranged. The coating 14 can be structured similarly to a copper coating of a circuit board with conductive tracks. The structuring can be achieved, for example, by lasering the coating 14. Since the coating 14 is transparent, the transparent display 10 also remains largely transparent. Furthermore, in addition to the transparent substrate 12 and the electrically conductive coating 14, the transparent display 10 can have further layers, for example a final transparent cover layer, which covers the light-emitting components 100 on their light exit side, so that the light-emitting components 100 are enclosed between the transparent substrate 12 and the cover layer.The transparent display 10 can thus be a multi-layer laminated glass.

[0040] In contrast to a copper coating, the specific surface resistance of the semi-transparent, electrically conductive coating 14 is approximately 2,000 to 10,000 times higher than the surface resistance of a conventional copper coating on a printed circuit board. Known connection techniques using an opaque coating on a carrier material, such as in a rigid or flexible printed circuit board with a metal coating, cannot therefore be readily applied. Instead, the leads to the light-emitting components must be specially structured to enable effective operation of the light-emitting components.

[0041] As in Fig. 1, the supply lines to the light-emitting components 100 are not designed as conductor tracks, but as flat segments of the partially transparent and conductive coating 14. A first segment 16 and a second segment 18 connect the light-emitting components 100 to a first supply terminal 20 and a second supply terminal 22, to which a constant supply voltage can be applied. For a uniform voltage drop across the light-emitting components 100, the first segment 16 and the second segment 18 can be designed, as shown here, such that they taper from the supply terminals 20, 22 along the series circuit. However, other structures are also conceivable if they promote a uniform voltage supply to the individual light-emitting components 100. The present disclosure is not limited to a specific embodiment.

[0042] A third segment 24 forms the data line between the individual light-emitting elements and can be formed from a plurality of individual segment sections 26, which are schematically indicated by arrows in the drawing. The third segment 24 is several times smaller than the first and second segments 16, 18, since less power needs to be transmitted for data transmission. Nevertheless, data transmission is also influenced by the low conductivity of the partially transparent and conductive coating 14, which, however, cannot be significantly improved by structuring the segment.

[0043] The segment sections 26 connect the light-emitting components 100 in a series circuit and to at least one signal terminal 28 of the transparent substrate 12. A data signal present at the signal terminal 28 is transmitted to the light-emitting components 100 via the third segment 24.

[0044] Fig. 2 and Fig. 3 show variants of the Fig. 1 shown transparent displays 10. The same reference numerals here denote the same elements as previously in Fig. 1 and a separate description is omitted below.

[0045] The embodiments according to Fig. 2 and Fig. 3 differ from Fig. 1 by the arrangement of the light-emitting elements 100 in a matrix arrangement 30 and by a correspondingly modified structuring of the connection segments (first and second segments 16, 18).

[0046] The matrix arrangement 30 according to Fig. 2 and Fig. 3 comprises, for example, 4 rows and 8 columns with a total of 32 light-emitting components 100. The light-emitting components 100 are arranged in each row, as previously described with reference to Fig. 1, are connected in series via a plurality of segment sections 26. Additionally, a segment section 32 at the beginning and end of each row connects the individual rows. This results in a continuous series connection of all light-emitting components 100 of the matrix arrangement 30.

[0047] As already mentioned in Fig. As shown in Figure 1, the first segment 16 connects all light-emitting components 100 to a first supply terminal 20, and the second segment 18 connects all light-emitting components 100 to a second supply terminal 22. The first segment 16 and the second segment 18 are comb-shaped and each have a segment section 34 per row. The segment sections 34 extend along the rows and alternately interlock.

[0048] The statements according to Fig. 2 and Fig. 3 differ in the design of the first and second segments 16, 18. In Fig. 2, the segment sections 34 of each row are each block-shaped and cover the largest possible area. Fig. 3 are the segment sections 34, similar to the design according to Fig. 1, are designed in a serrated shape and taper along the row. It goes without saying that the two configurations shown are only examples. Depending on the desired electrical properties of the supply line, a different structure for the first and second segments 16, 18 and their segment section 34 can also be selected.

[0049] The transparent displays 10 according to the Fig. 1 to 3 can be connected to a controller (not shown here) via signal connection 28. The controller reads display information and prepares it for display on the transparent display 10. The controller can be implemented as a microcontroller, FPGA, ASIC, DSP, or as a system on chip (SoC). In various embodiments, the controller can be implemented, for example, in the form of a Raspberry Pi or an Arduino. However, the present disclosure is not limited to any specific embodiment.

[0050] The controller can read in image information and use it to determine brightness values ​​for the individual light-emitting components 100. The controller then encodes the brightness values ​​into a serial data stream and transmits this as a data signal to the light-emitting components 100. In one embodiment, the brightness values ​​for all light-emitting components 100 can be written sequentially into the serial data stream according to the arrangement of the light-emitting components 100 in the series circuit. Each light-emitting component 100 can extract and display its own determined brightness value from the data stream. In this way, the image read in by the controller can be displayed on the transparent display 10. It goes without saying that moving images can also be displayed by repeatedly performing this process.

[0051] The transmission of the brightness values ​​and their extraction from the data stream will be explained in more detail below. However, first, with reference to Fig. 4 a single light-emitting component 100 is explained in more detail.

[0052] Fig. Figure 4 shows a schematic representation of a single light-emitting component according to an embodiment of the present disclosure. The light-emitting component is designated in its entirety by reference numeral 100.

[0053] The light-emitting component 100 is composed of individual components that can be arranged in a common housing 110. The individual components can be connected to one another, for example, on a common circuit board. The light-emitting component 100 has the four connections 102, 104, 106, 108 already described, via which the components arranged in the housing 110 can be contacted from the outside. The four connections include the two supply connections 102, 104, via which a supply voltage can be applied to the light-emitting component 100, and the signal connections 106, 108, via which a data signal can be received or output.

[0054] The light-emitting component 100 further comprises at least one light-emitting device 112 and an integrated circuit 114. The light-emitting device 112 can comprise one or more controllable light-emitting diodes, the brightness of which can be controlled via the integrated circuit 114. In one embodiment, the light-emitting device 112 can comprise three light-emitting diodes, each representing a primary color. By controlling the three light-emitting diodes 112 to different brightness values, the primary colors can be mixed to display different colors.

[0055] The integrated circuit 114 controls the light source 112 and sets it to different brightness values. The integrated circuit 114 obtains the brightness values ​​from a data signal received at the signal terminal 106. The data signal can be a digital signal in which a bit sequence represents a brightness value for an individual LED. The integrated circuit 114 reads the brightness values ​​for all LEDs of the light source 112 and controls the LEDs accordingly so that they display the transmitted brightness values.

[0056] The light-emitting component 110 can further comprise a voltage regulator 116, which stabilizes an electrical voltage provided at the supply terminals 102, 104. The light-emitting component 112 and the integrated circuit 114 can be operated with the stabilized supply voltage. Voltage regulators are known in various variants, which can be based on different principles. The selection of a suitable voltage regulator can be crucial for error-free operation and can significantly influence energy efficiency. For example, a simple cross-regulator in the form of a Zener diode connected in parallel with the supply terminals 102, 104 can set a constant operating voltage at the loads, i.e., at the light source 112 and the integrated circuit 114, while simultaneously enabling a constant power consumption, since any current not required by the loads is diverted via the diode.However, since the discharged current is converted into heat, such voltage regulation is not very energy efficient.

[0057] Other voltage regulators, such as active DC-DC converters, can provide a constant supply voltage much more efficiently, but not at all, or only to a limited extent, with constant power consumption. While irregular power consumption, for example in the form of a pulsed current sink, may be unproblematic with a normal power supply, irregular power consumption with high lead resistances, as occurs in the transparent displays 10 described above, can be less efficient overall than constant power consumption, where excess power is converted into heat. Furthermore, fluctuating power consumption can also negatively impact data transmission between the light-emitting components and lead to transmission errors.

[0058] In order to still be able to operate the light-emitting components 100 with efficient voltage regulators, the integrated circuit 114 can be configured to control the illuminant 112 in a defined manner and to enable a brightness change at a defined time. It has been shown that power fluctuations occur particularly when a illuminant changes from one brightness value to another. Because the integrated circuit 114 can determine a defined time for the brightness change and the integrated circuit 114 brings about the brightness change at the specific time, synchronization of a plurality of light-emitting components 100 configured in this way can be achieved, and power fluctuations can be limited to a defined period of time.

[0059] In various embodiments, the integrated circuit 114 can be configured to receive a serial data stream in which brightness values ​​for a plurality of series-connected light-emitting components 100 are encoded, and to extract a brightness value for the illuminant 112 from the serial data stream. Based on the received serial data stream, the integrated circuit 114 can determine a switching time for controlling the illuminant 112 with the brightness value and set the illuminant 112 to the brightness value at the determined switching time. The process is described in detail with reference to the Fig. 5 is explained in more detail.

[0060] Fig. 5 shows a schematic representation of a functional structure 200 of an integrated circuit 114 of a light-emitting device 100 according to an embodiment of the present disclosure.

[0061] The integrated circuit 114 is not limited to a particular form and may be, for example, a microcontroller, an ASIC, a DSP, an FPGA, or the like.

[0062] The functional structure 200 is composed of several functional units which together implement the functions previously described with reference to Fig. 4 can be implemented. In the example shown here, the functional units comprise an input unit 202, an output unit 204, an error detection unit 206, a decoding unit 208, and a number of pulse width modulation units 210 corresponding to the number of LEDs 212 to be controlled.

[0063] The input unit 202 is coupled to the signal terminal 106 of the light-emitting component 100 and can be configured as one or more serial interfaces. The input unit 202 receives the data signal present at the signal terminal 106. The data signal can be an electrical signal in which defined signal levels correspond to discrete values. The data signal can be a binary data stream. The input unit 202 can, as shown here, have two redundant interfaces, wherein one interface is configured as a fallback interface and is alternatively switched on when no signal is received at the primary interface.

[0064] The error detection unit 206 checks the data stream for errors and enables further processing if the data stream was received correctly. Further processing is performed by the decoding unit 208, which decodes the data stream and extracts the brightness information intended for the light-emitting component 100 from the data stream, for example, three brightness values ​​with a length of 8 bits. The LEDs 212 are then controlled by the pulse-width modulation units 210, which convert the received brightness values ​​into a pulse-width modulated signal and apply it to the LEDs 212.

[0065] Finally, the data signal is output via the output unit 204 and made available to a subsequent light-emitting component 100.

[0066] The functional units described above have already been implemented in this or a similar manner in known active light-emitting components, such as the Smart Pixel marketed under the designation WS2812B. The light-emitting component 100 according to the present disclosure differs from this, among other things, by a delay unit 214 and a delay time calculation unit 216.

[0067] The delay unit 214 is configured to delay the brightness setting of the LEDs 212 for a defined period of time, for example, by preventing the transmission of new brightness values ​​to the pulse-width modulation units 210 until a defined point in time. The pulse-width modulation units 210 thus provide the previous pulse-width modulated signal until the defined period of time has elapsed, even if new brightness information has already been transmitted to the light-emitting component 100. The delay unit 214 can have a timer and a buffer. The brightness values ​​for the defined period of time can be stored in the buffer. The timer can initiate further processing of the buffered values ​​at an adjustable point in time.

[0068] The delay time calculation unit 216 is configured to determine the defined time period and provide a corresponding value, for example, to the timer. In other words, the delay time calculation unit 216 is configured to determine a switching time at which the light-emitting component 100 performs the brightness change of the illuminant 212. The calculation is performed based on the received data stream, for example, based on a value contained therein or advantageously also based on a length of the received data stream.

[0069] When calculating based on the length of the received data stream, the calculation is advantageously not tied to decoding the data stream. For example, the number of subsequent light-emitting components can be determined based on the length of the data stream, and the determined number can be used to estimate when the last light-emitting component in the series circuit has received the data stream and is thus ready to switch the brightness values. Using this information, it can be individually determined for each light-emitting component 100 when it must switch so that all light-emitting components 100 make the brightness change simultaneously. The estimation can be made based on a known transmission delay of a light-emitting component 100 and under the assumption that the transmission delay is the same for all components or changes in a defined manner over time.

[0070] Using the length of the data stream to determine the switching time also has the advantage that existing transmission protocols can be reused, since no additional data needs to be transmitted. Furthermore, common transmission protocols favor this method because the data is transmitted in a manner that facilitates estimation of the number of subsequent components. For example, common protocols first transmit the brightness information of the first light-emitting component and then that of the subsequent ones in descending order. Finally, the data stream is terminated by a defined code word as a stop mark, e.g., a zero signal lasting a few microseconds.

[0071] The fact that a light-emitting component 100 not only reads out its associated brightness information, but also removes it from the data stream and forwards the modified data stream to the subsequent components, not only simplifies the reading of the data stream, since each component only has to read out the first information block of the data stream, but also the determination of an individual switching time, since the length of the data stream is individual at each component and corresponds to the actual length from the beginning of the data stream to the stop mark.

[0072] From the length of the applied data stream, the delay time calculation unit 216 can directly determine the number of subsequent components by dividing the length by the fixed length of a single brightness information block (e.g., 24 bits). The number can then be multiplied by a predefined time period t Latenzto calculate the individual delay time and thus the switching time at which the light-emitting component must switch in order to switch simultaneously with all other light-emitting components in the series circuit. The predefined time period t Latenz can be, for example, a transmission delay of the light-emitting component, which is preferably the same for all light-emitting components in the series circuit.

[0073] As already explained, undefined states can occur during a switching phase because the power consumption of the individual light-emitting components 100 changes, and this change is not compensated for or is compensated for only slowly when using energy-efficient DC-DC converters, as indicated here by reference numeral 218. Such an undefined state can lead to transmission errors and thus to faulty control of the light-emitting components 100.

[0074] To prevent this, a blocking unit 220 can be provided, which blocks the digital inputs for the duration of the switching phase. The duration of the switching phase can be determined from an empirically determined value or derived from the previously determined number of light-emitting components 100 in the series circuit. With this arrangement, during a defined switching phase, no brightness information is read from the input unit 202, or the read value is discarded to prevent falsified brightness values.

[0075] Transmission errors can thus be effectively and efficiently avoided due to the known switching times. At the same time, energy efficiency can be improved because uneven power consumption of the individual light-emitting components 100 can be tolerated up to a defined degree, thus enabling the use of energy-efficient DC-DC converters 218 to stabilize the voltage supply to the individual light-emitting components 100.

[0076] It should be noted that the above embodiments are merely exemplary, and further variants of individual components are possible to realize embodiments of the following claims. The scope of the present invention is determined by the following claims and is not limited by the features explained in the description or illustrated in the figures.

Claims

[1] Light-emitting component (100) comprising a luminous means (112) and an integrated circuit (114), wherein the integrated circuit (114) is configured to - to receive a serial data stream in which brightness values for a plurality of light-emitting components connected in series are coded, - to take a brightness value for the lamp (112) from the serial data stream, - to determine a switching time for controlling the illuminant (112) to the brightness value based on a length of the received serial data stream, and - to set the light source (112) to the brightness value at the specific switching time. [2] Light-emitting component according to claim 1, wherein the integrated circuit (114) is configured to delay the setting of the illuminant (112) to the brightness value until the switching time. [3] Light-emitting component according to claim 1 or 2, wherein the integrated circuit (114) is configured to temporarily store the brightness value for the luminous means (112) until the switching time. [4] Light-emitting component according to one of claims 1 to 3, wherein the integrated circuit (114) is configured to block the adjustment of the illuminant to the brightness value during a defined switching time. [5] Light-emitting component according to one of claims 1 to 4, wherein the integrated circuit (114) is configured to temporarily block an input via which the serial data stream is received, in particular around the switching time for a defined switching time. [6] A light-emitting component according to any one of claims 1 to 5, wherein the length of the received serial data stream is defined by a number of received bits from a reception of the brightness value to a code word terminating the serial data stream. [7] Light-emitting component according to one of claims 1 to 6, wherein the integrated circuit (114) is arranged to forward the serial data stream to a number N of further light-emitting components and to determine the number N from the length of the serial data stream. [8] Light-emitting component according to claim 7, wherein the integrated circuit (114) is arranged to determine the switching time by multiplying the number N by a defined latency time t latenz of the light-emitting component. [9] Light-emitting component according to claim 8, wherein the multiplication of the number N with the defined latency time tlatenz of the light-emitting component defines a time offset and the switching time is defined by the time offset with respect to a signal input of the serial data stream at the light-emitting component or with respect to a reception of a code word contained in the serial data stream. [10] Light-emitting component according to one of claims 1 to 9, wherein the integrated circuit (114) is configured to extract the brightness value for the illuminant (112) from the serial data stream and to delete it therefrom. [11] Light-emitting component according to one of claims 1 to 10, wherein the light-emitting component has a voltage regulator (116), in particular a DC-DC converter, which provides a constant operating voltage for the light-emitting component (100). [12] Light-emitting component according to claim 11, wherein the voltage regulator (116) is arranged to adjust the operating voltage as a function of a current through the illuminant (112). [13] Light-emitting component according to one of claims 1 to 12, wherein the illuminating means (112) comprises two or more, in particular three, light-emitting diodes, and the received brightness value includes a separate brightness value for each of the two or more light-emitting diodes. [14] Light-emitting component according to one of claims 1 to 13, wherein the luminous means (112) and the integrated circuit (114) are powered from a common power supply. [15] Light-emitting component according to one of claims 1 to 14, wherein the illuminant (112) and the integrated circuit (114) are arranged in a common housing (110), in particular a 5050 housing, which has four external terminals (102, 104, 106, 108). [16] Transparent display (10), comprising: a glass element (12); a partially transparent and electrically conductive coating (14) structured on the glass element (12); and a plurality of light-emitting components (100) according to one of claims 1 to 15, which are arranged on the glass element (12) and can be electrically contacted via the partially transparent and electrically conductive coating (14). [17] Transparent display according to claim 16, wherein the partially transparent and electrically conductive coating (14) comprises a first continuous segment (16) and a second continuous segment (18), wherein the first continuous segment (16) is connected to a first terminal (102) of each of the plurality of light-emitting components (100), and wherein the second continuous segment (18) is connected to a second terminal (104) of each of the plurality of light-emitting components (100) and is electrically insulated from the first continuous segment (16). [18] Transparent display according to claim 16 or 17, wherein the partially transparent and electrically conductive coating (14) has a third segment (24) which is composed of a plurality of segment sections (26) and connects the plurality of light-emitting components (100) in series. [19] Method for controlling a light-emitting component (100) with a luminous means (112) and an integrated circuit (114), comprising the steps: - receiving a serial data stream in which brightness values for a plurality of series-connected light-emitting components (100) are encoded; - Extracting a brightness value for the illuminant (112) from the serial data stream; - determining a switching time for controlling the illuminant (112) to the brightness value based on a length of the received serial data stream; and - Setting the lamp (112) to the brightness value at the specific switching time.

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