Method of controlling a light emitting diode lighting device and light emitting diode, LED, based lighting device

Abstract

A method for controlling a multicolor LED lighting device is disclosed. The LED lighting device includes at least two LED light sources connected in series, each having different color metric values ​​and supplied with current, and each LED light source is controlled by a corresponding switch operating according to a duty cycle. The method adjusts the operating current amplitude supplied to the multicolor LED lighting device based on a color point desired by the user. The method includes the steps of: receiving a specified color metric value for the LED lighting device; determining the operating current amplitude for the LED lighting device based on a current profile within the color metric value range and the specified color metric value; and setting the current supplied to the LED light source to the determined operating current amplitude.

Description

Technical Field

[0001] This disclosure generally relates to the field of lighting equipment control, and more specifically to methods for controlling lighting equipment based on multicolor light-emitting diodes (LEDs) and LED lighting equipment. Background Technology

[0002] Multicolor LED lights typically consist of multiple LED light sources of different colors. Each LED light source can be controlled independently by a separate switch, allowing the LED light sources to operate independently of each other to produce different output lighting colors. Alternatively, light from two or more LED light sources can be mixed to give a desired output lighting color.

[0003] In many multi-color LED lights, pulse width modulation (PWM) is used to control the color and intensity of the LED light source. PWM allows for maximum control over the color of the LED light. Alternative control methods, such as current control, may suffer from color inconsistencies. Therefore, PWM, where the current is fixed, is the primary architecture used for color control of LED lights.

[0004] The issue of PWM-controlled LED lights involves the conflicting requirements between the LED's power output and the current supplied to the LED light source, which are determined by the lamp's flux output.

[0005] For LEDs controlled by PWM, the current is constant across all color points, which can be expressed, for example, by correlated color temperature (CCT). Therefore, there is a trade-off due to the different requirements at different color points. At a certain white point (e.g., 4000K), efficiency needs to be optimal, which requires the lowest possible current. On the other hand, at other color points, for cost reasons and sometimes size reasons, flux output may need to be as high as possible with a minimum number of LEDs. Conversely, high flux output may require relatively high current, unlike the low current required for high efficiency.

[0006] Due to the aforementioned facts, trade-offs often have to be made, which may not only reduce throughput capacity but also reduce the effectiveness of the corresponding LED lights.

[0007] Therefore, what is truly needed is a method for controlling LED lights that helps ensure and achieve improved performance of multicolor LED lights with higher throughput and higher efficiency. Summary of the Invention

[0008] In a first aspect of this disclosure, a method for controlling a light-emitting diode (LED) lighting device is presented, the LED lighting device comprising at least two LED light sources connected in series and having different color metric values ​​and supplied with current, each LED light source being controlled by a corresponding switch coupled in parallel to the respective LED light source and operating according to a duty cycle, the method being executed by a controller and comprising the following steps:

[0009] - Receive specified color measurement values ​​for LED lighting devices;

[0010] - The operating current amplitude for LED lighting equipment is determined based on the current profile within the color metric range and the specified color metric value, and

[0011] - Set the current supplied to the LED light source to the determined operating current range.

[0012] This disclosure is based on the insight that adjusting the operating current amplitude of LED lighting devices that include LED light sources with different color metrics, such as color temperature representing color points, allows the LED lighting devices to be optimized in terms of their power and flux output without making a trade-off between power and flux output.

[0013] Optimization is achieved through a method according to a first aspect of this disclosure. According to this method, a specified color metric value is first received, which determines the color appearance of the LED lighting device. Then, the method refers to a current profile designed for a range of color metric values ​​and determines the operating current amplitude for the LED lighting device based on the specified color metric value. The current supplied to the LED light source is then set to the determined operating current amplitude.

[0014] The current profile is designed to allow the flux output of LED lighting equipment to be increased for color points other than, for example, 4000K (which often requires the minimum current), without compromising the overall efficiency of the LED lighting equipment. As a result, the operating current amplitude for the LED lighting equipment is determined based on the current profile designed for a range of color metrics and the specified or desired color metric, allowing the LED lighting equipment to have maximum flux output for color points other than, for example, 4000K.

[0015] Specifically, at a color temperature of 4000K, the operating current amplitude can be kept low to achieve optimal flux output. On the other hand, for other color temperatures, the operating current amplitude can be increased to achieve higher flux at those temperatures. The increase in operating current amplitude must be kept within the specified power level of the LED lighting device.

[0016] The LED lighting device thus simultaneously achieves high or optimal flux output at a first color temperature and high or optimal power efficiency at a second color temperature. Preferably, the current amplitude is lower at the color metric value with high flux than at the color metric value with low flux. This color metric value can be the color temperature at which optimal power efficiency is achieved, for example, at 4000K.

[0017] The inventors' insight is that at a specific color metric value, a user perceives a higher light output, or flux, at a given power level than at the same power level at different color metric values. This means that the effectiveness of an LED lighting device differs at different color metric values. For example, a user perceives the highest flux per power at 4000K. The inventors have learned that at this color metric value, the power can be at its lowest, allowing the user to still perceive sufficient light output. At this lower power level, the current is lower, resulting in higher effectiveness.

[0018] In one embodiment of this disclosure, the specified color metric includes a set of color coordinates or a color temperature value.

[0019] Color temperature values ​​can be, for example, CCT values. Alternatively, color metrics can be a set of CIE xy coordinates. This value can be generated based on, for example, a color selected by the user via a remote control of the LED lighting device.

[0020] In one embodiment of this disclosure, a specified color metric value is received from a user.

[0021] This allows users to control the color appearance of LED lighting devices as needed and according to their preferences, which helps to provide a better user experience.

[0022] For example, a color metric can be represented by a color that can be selected by the user via a control panel or remote control. The control panel can offer various color options, allowing users to select and set different colors as needed.

[0023] Those skilled in the art can imagine that users can also customize colors based on their needs or moods.

[0024] In one embodiment of this disclosure, the current profile is a lookup table or current conversion function that converts color metrics into operating current amplitudes, and the determination step includes converting a specified color metric into an operating current amplitude based on the lookup table or current conversion function.

[0025] The current profile can be designed as a lookup table and made available to the controller, for example, by storing it in the controller's internal memory. The lookup table can be easily used to support the conversion of color temperature to the operating current amplitude of LED lighting devices. Therefore, the determination process is straightforward and easy to implement, thus incurring negligible additional resources for the controller.

[0026] Alternatively, the current profile can be designed as a current transformation function that takes a specified current as input and generates an appropriate operating current amplitude as output. Therefore, the determination steps can obtain the operating current amplitude from the transformation function.

[0027] In one embodiment of this disclosure, the operating current amplitude for the LED lighting device is also determined based on at least one of the reference current of the LED lighting device and the reference flux output.

[0028] Those skilled in the art will envision that the operating current range must be within a reference current (such as the nominal current of the LED lighting device itself). A reference flux output can also be considered when determining the operating current range of the LED lighting device, thereby allowing the lighting device to simultaneously achieve improved efficiency and flux output.

[0029] In one embodiment of this disclosure, the method further includes the step of determining the duty cycle of each switch used to control the corresponding LED light source.

[0030] This method allows for the independent determination of the duty cycle required for each LED light source. Consequently, the dimming and color appearance of each LED light source remain individually controlled, allowing the LED light source to maintain high power efficiency.

[0031] Specifically, in one embodiment of this disclosure, the duty cycle is determined based on at least one of the determined operating current amplitude and the reference flux output of the LED lighting device.

[0032] This also allows for a more refined tuning of the color appearance of LED lighting devices.

[0033] In a second aspect of this disclosure, a light-emitting diode (LED) lighting device is presented, comprising at least two LED light sources connected in series and having different color metric values ​​and supplied with current, each LED light source being controlled by a corresponding switch operating according to a duty cycle, the LED lighting device further comprising a processor for controlling the LED lighting device, the processor comprising:

[0034] - A receiving module, which is arranged to receive specified color measurement values ​​for LED lighting devices;

[0035] - A determination module, which is configured to determine the operating current amplitude for LED lighting equipment based on a current profile within a colorimetric range and a specified colorimetric value, and

[0036] - A setting module is arranged to set the current supplied to the LED light source to a determined operating current amplitude.

[0037] The operating current amplitude of the LED lighting device is determined based on a specified color temperature, and the LED is controlled by a processor that operates according to the method of controlling the LED lighting device, thereby providing the LED lighting device with optimized output flux and optimized efficiency.

[0038] The processor's functional modules can be operated to perform the corresponding control functions as described in the method according to the first aspect of this disclosure.

[0039] Those skilled in the art will envision that the processor can be integrated into the internal control section of an LED lighting device. Alternatively, the processor can be a separate processor located, for example, within a remote control or control panel used to control the LED lighting device.

[0040] In a third aspect of this disclosure, a computer program product is provided, comprising a computer-readable storage medium storing instructions that, when executed on at least one processor, cause at least one processor to perform the method according to a first aspect of this disclosure.

[0041] The above and other features and advantages of this disclosure will be best understood from the following description with reference to the accompanying drawings. In the drawings, similar reference numerals denote the same parts or parts that perform the same or equivalent functions or operations. Attached Figure Description

[0042] Figure 1 A schematic diagram of a series-connected light-emitting diode (LED) light source in a multi-color LED lighting device is shown.

[0043] Figure 2 It is a graph that schematically shows the relationship between the generated flux and the current of the LED lighting device.

[0044] Figure 3 A flowchart-type diagram illustrates a method for controlling an LED lighting device according to an embodiment of the present disclosure.

[0045] Figure 4 A current conversion profile designed as a conversion function from CCT value to LED current is schematically shown.

[0046] Figure 5 It is a graph that schematically shows a comparison between flux curves obtained using a fixed current and a variable current.

[0047] Figure 6 A controller for controlling LED lighting equipment according to the present disclosure is shown schematically.

[0048] Figure 7 An LED lighting device including a controller according to the present disclosure is illustrated schematically. Detailed Implementation

[0049] Embodiments contemplated by this disclosure will now be described in more detail with reference to the accompanying drawings. The subject matter disclosed should not be construed as limited to the embodiments set forth herein. Rather, the illustrated embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art.

[0050] Figure 1 Figure 10 schematically illustrates a series-connected light-emitting diode (LED) light source for a multi-color LED lighting device. In Figure 10, five LEDs, labeled 11 to 15 respectively, are shown. These five LEDs 11 to 15 can each have colors such as red, green, blue, warm white, and cool white. LEDs 11 to 15 are connected in a single string and driven by a fixed current (not shown). Pulse-width modulation (PWM) signals are provided to switches 110 to 150, which control LEDs 11 to 15 by opening or closing the switches, thereby controlling the color and output flux of the lighting device including LEDs 11 to 15. Preferably, the switches are placed in parallel with the LEDs.

[0051] Regarding LED lighting equipment, maximum efficiency is typically required around the color point where the output flux of the LED lighting equipment is highest, either due to regulatory considerations or due to power limitations related to the maximum heat that the LED lighting equipment can withstand. Figure 2 This is a graph schematically illustrating the relationship between the generated flux output and the current of the LED lighting device. From Figure 2 It can be seen that at higher currents, more flux output can be generated at extreme correlated color temperature (CCT) points such as 2200K and 6500K or in the corners of the color gamut.

[0052] On the other hand, the efficiency of LED lights decreases at higher peak currents. Consequently, a trade-off is often made between the efficiency and flux output of LED lights, which reduces both flux capability and efficiency. This applies to some LED light sources.

[0053] This disclosure presents a method and controller for controlling an LED lighting device comprising multiple LED light sources, which can help achieve optimized lighting performance, namely, higher throughput and higher efficiency of the LED lighting device.

[0054] Figure 3A flowchart-type diagram illustrates a method 30 for controlling an LED lighting device according to an embodiment of the present disclosure.

[0055] Method 30 can be performed by a processor or controller for controlling an LED lighting device comprising at least two LED light sources. The at least two LED light sources are connected in series and supplied with current. Each of the at least two LED light sources is controlled, for example, by a pulse width module (PWM) signal via a corresponding switch, so that the LED light source can be turned on and off according to a desired light color scheme.

[0056] The controller can be an integrated module of the LED lighting equipment or a separate control device. As an example, the controller can be the processor of the LED lighting equipment.

[0057] Each LED light source can have a color appearance represented by color metrics, such as color temperature expressed as correlated color temperature (CCT) or International Commission on Illumination (CIE) xy coordinates.

[0058] At step 31, “Receive specified color metric value for LED lighting device”, the processor receives the color metric value of the desired color. As an example, a user can press a button on the remote control of the LED lighting device to select a specific color, which generates a signal to the processor. The selected color can be converted into a color temperature or CIExy coordinate set for the processor, which will be used to control the LED lighting device accordingly.

[0059] In step 32, “Determine the operating current amplitude for the LED lighting device based on the current profile and specified color metric value”. The controller can determine the operating current amplitude for the LED lighting device based on the current profile and specified color metric value, that is, the current used to drive each LED light source of the LED lighting device.

[0060] Current profiles can be designed within the range of xy coordinates or CCT values. Figure 4 A current conversion profile, designed as a conversion function from CCT value to LED current, is schematically illustrated. This is achieved through methods such as... Figure 4 The conversion function shown allows the controller to easily determine the appropriate operating current amplitude.

[0061] Figure 4 The currents shown for different CCT values ​​are relative currents in arbitrary units. If based on... Figure 4 The conversion function shown changes the current supplied to the LED light source, thus increasing the lamp flux output for color points other than 4000K. It can be seen that at the highest flux output, the current amplitude is lowest to meet efficiency requirements.

[0062] Alternatively, the current profile can be designed as a lookup table that can be used to convert the received specified color metric value into a suitable operating current amplitude for LED lighting equipment.

[0063] In determining the operating current amplitude, other factors may also be considered, such as a reference current or a reference flux output, or a combination of both. The reference current could be, for example, the nominal current used in LED lighting equipment. The reference flux output could be a flux that complies with regulations and specifications.

[0064] Next, at step 33, “the current supplied to the LED light source is set to the determined operating current amplitude”, the processor sets the current supplied to the LED lighting device (i.e., the current driving each LED light source) to the operating current amplitude determined at step 32.

[0065] The determined operating current amplitude allows LED lighting equipment to have optimal flux output, for example, at a specified color temperature. Figure 5 Graph 50 schematically illustrates the flux output curves obtained using fixed and variable currents. Figure 5 In the diagram, curve 51 is the flux output curve obtained for an LED lighting device with a current controlled according to the method described above, and curve 52 is the flux output curve obtained for an LED lighting device with a fixed current. Flux output is in arbitrary units.

[0066] from Figure 5 It can be seen that when the operating current supplied to the LED lighting equipment varies according to, for example, a color metric value specified by the user, the flux output of the LED lighting equipment increases for color points other than 4000K. This optimizes the flux output of the LED lighting equipment.

[0067] At step 34, the processor can also determine the desired PWM settings related to the operating current amplitude for a specified color metric. As an example, the controller can determine the duty cycle of each PWM signal used to control the corresponding LED light source. In determining the PWM settings, the method can also consider a reference flux.

[0068] This allows the efficiency of the corresponding LED light source to be optimized based on the determined operating current amplitude.

[0069] Therefore, this method allows for the control of LED lighting devices in a manner that simultaneously achieves optimized power efficiency and optimized flux output.

[0070] Figure 6 A schematic diagram illustrates a controller 60 for controlling LED lighting equipment according to the present disclosure.

[0071] The controller 60 may include a receiving module 61, a determining module 62, and a setting module 63.

[0072] The receiving module 61 is arranged to receive a specified color metric value for an LED lighting device, for example, as referenced above. Figure 3 As described in step 31.

[0073] The determining module 62 is configured to determine the operating current amplitude for LED lighting equipment based on a current profile within a color metric range and a specified color metric value, for example, as referenced above. Figure 3 Step 32 is described. The determining module 62 can also be arranged to determine the operating current amplitude using other factors such as reference current and / or reference flux.

[0074] The setting module 63 is configured to set the current supplied to the LED light source to a predetermined operating current amplitude, for example, as referenced above. Figure 3 Step 34 is described.

[0075] The determination module 62 can also be arranged to determine the PWM settings related to the operating current amplitude at the specified color point.

[0076] Figure 7 An LED lighting device 70 including a controller according to the present disclosure is shown schematically.

[0077] The LED lighting device 70 may include a control section or control device 710 and a load, such as a lighting fixture or lighting device 720 including a lighting module 721, and the lighting module 721 may be an LED lighting module including multiple LED light sources. The control device 710 may, for example, control the operation of the lighting module 721 according to the methods of this disclosure. The control device 710 may include reference... Figure 6 The aforementioned controller.

[0078] The control device 710 operates a communication interface 71, which may be a network adapter or transceiver Tx / Rx module. This network adapter or transceiver Tx / Rx module is configured to exchange messages or data packets wirelessly 72 or wiredly 73 with another LED lighting device in a network, for example. The communication interface 71 can also be used as a receiving module for the controller 60 used to control the LED lighting device.

[0079] Network protocols used for exchanging data through networked devices or nodes may include: ZigBee-based protocols for wireless networks. TM ,Bluetooth TM And WiFi protocols, and such as DALI TMWired bus networks including (Digital Addressable Lighting Interface), DSI (Digital Serial Interface), DMX (Digital Multiplexing), and KNX (or KNX-based systems), as well as other proprietary protocols.

[0080] The control device 710 also includes at least one microprocessor μP or controller 75, and at least one data library or storage device or memory 76, which, among other things, is used to store, for example, the current profile described above.

[0081] At least one microprocessor or controller 75 interacts communicatively with communication interface 71 and at least one data storage library or storage device 76 via internal data communication and control bus 79 of control device 710, and controls communication interface 71 and at least one data storage library or storage device 76. The at least one microprocessor or controller 75 can run one or more algorithms or applications and execute methods for controlling LED lighting device 720.

[0082] The at least one microprocessor or controller 75 can be used as a determination module and a setting module for the controller 60 used to control LED lighting equipment.

[0083] The lighting fixture or lighting device 720 is connected to at least one microprocessor or controller 710 via a connection link 74 and is controlled by at least one microprocessor or controller 710 from a data communication and control bus 79.

[0084] This disclosure is not limited to the examples disclosed above, and can be modified and enhanced by those skilled in the art beyond the scope of this disclosure as disclosed in the appended claims, without necessarily applying inventive skills and in any data communication, data exchange and data processing environment, system or network.

Claims

1. A method for controlling a light-emitting diode (LED) lighting device, the LED lighting device comprising at least two LED light sources connected in series and having different color metric values ​​and supplied with current, each LED light source being controlled by a corresponding switch coupled in parallel to the respective LED light source and operating according to a duty cycle, the method being executed by a processor and comprising the following steps: - Receive (31) a specified color metric value for the LED lighting device; -The operating current amplitude for the LED lighting device is determined based on the current profile within the color metric range and the specified color metric value, and (32) - The current supplied to the LED light source is set (33) to the determined operating current amplitude. At the first color metric value and the first flux, the operating current amplitude is lower than at the second color metric value and the second flux, wherein the first flux is higher than the second flux. The specified color metric includes a set of color coordinates or a color temperature value.

2. The method of claim 1, wherein the specified color metric value is received from the user, and At a given power, the LED is adapted to emit light at the first color metric value, the light having a light output, i.e., flux, as perceived by the user, which is higher than the light output at the second color metric value at the same power.

3. The method according to any one of the preceding claims, wherein the current profile is a lookup table or current conversion function for converting color measurement values ​​into operating current amplitudes, and the determining step includes converting the specified color measurement value into the operating current amplitude based on the lookup table or the current conversion function.

4. The method according to any one of the preceding claims further includes the step of determining the duty cycle of each switch for controlling the corresponding LED light source.

5. The method of claim 4, wherein the duty cycle is determined based on at least one of the determined operating current amplitude and the reference flux output of the LED lighting device.

6. A light-emitting diode (LED) lighting device, comprising: - At least two LED light sources connected in series, each having different color metric values ​​and supplied with current; - At least two switches, each LED light source is controlled by a corresponding switch connected in parallel with the LED light source, which operates according to the duty cycle; as well as - A processor (60) for controlling the LED lighting device, the processor comprising: - A receiving module (61) is arranged to receive a specified color measurement value for the LED lighting device; - A determining module (62) is configured to determine the operating current amplitude for the LED lighting device based on a current profile within a color metric range and the specified color metric value, and - A setting module (63) is arranged to set the current supplied to the LED light source to the determined operating current amplitude. At the first color metric value and the first flux, the operating current amplitude is lower than at the second color metric value and the second flux, wherein the first flux is higher than the second flux. The specified color metric value includes a set of color coordinates or a color temperature value. The current profile is a lookup table or current conversion function that converts color measurement values ​​into operating current amplitudes, and the determining module is configured to convert the specified color measurement value into the operating current amplitude based on the lookup table or the current conversion function.

7. The LED lighting device according to claim 6, wherein the receiving module is arranged to receive the specified color measurement value from the user.

8. The LED lighting device according to any one of claims 6 or 7, wherein the determining module is further arranged to determine the duty cycle of each switch for controlling the corresponding LED light source.

9. The LED lighting device of claim 8, wherein the determining module is arranged to determine the duty cycle based on at least one of the determined operating current amplitude and the reference flux output of the LED lighting device.

10. A computer program product comprising a computer-readable storage medium storing instructions that, when executed on at least one processor, cause the at least one processor to perform the method according to any one of claims 1-5.

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