Lighting device and lighting system comprising the lighting device

Abstract

A lighting device including an LED light source, wherein the LED light source includes a first LED strand for generating a first light with a first correlated color temperature and a second LED strand for generating a second light with a second color temperature different from the first color temperature. The lighting device further comprises control electronics with a controllable LED driver for driving the LED light source, wherein the control electronics comprise a switch for switching between the first LED strand and the second LED strand so that either the first LED strand or the second LED strand is activated depending on the switch position. A lighting system comprising the lighting device is further disclosed.

Claims

1. A lighting device comprising: an LED light source, the LED light source comprising a first LED strand for generating a first light having a first correlated color temperature and a second LED strand for generating a second light having a second correlated color temperature which is different from the first correlated color temperature; and control electronics comprising a controllable LED driver for driving the LED light source, wherein the control electronics comprise a switch for switching between the first LED strand and the second LED strand so that either the first LED strand or the second LED strand is activated depending on the switch position, wherein the lighting device comprises a third LED strand for generating a third light with a third correlated color temperature different from the first color temperature and the second correlated color temperature, wherein the third LED strand is drivable by the LED driver independently of the switch position.

2. The lighting device of claim 1, wherein the third LED strand is connected in parallel to the first LED strand and the second LED strand.

3. The lighting device of claim 1, wherein the control electronics are configured to detect an actuation of a switching device and to flip the switch based on the detected actuation of the switching device.

4. The lighting device of claim 3, wherein the control electronics are designed to detect an actuation of a switching device designed as a light switch or as a dimmer and to flip the switch based on the detected actuation of the switching device.

5. The lighting device of claim 1, wherein the LED driver is designed as a dimmable LED driver.

6. The lighting device of claim 1, wherein the first correlated color temperature is in the range between 3500 K and 6500 K, the second correlated color temperature is in the range between 2700 K and 5000 K, and the third correlated color temperature is in the range between 1500 K and 3000 K.

7. The lighting device of claim 1 further comprising at least one controller for separately driving at least one of the three LED strands.

8. The lighting device of claim 7, wherein the controller has a feedback input for detecting a feedback signal and is configured to drive the third LED strand based on a feedback signal from the first LED strand and the second LED strand.

9. The lighting device of claim 1, wherein at least one of the LED strands comprises at least one passive electrical component.

10. The lighting device of claim 1 wherein the LED strands are configured such that a maximum luminous flux of the light generated by the first LED strand and a maximum luminous flux of the light generated by the second LED strand are higher than a maximum luminous flux of the light generated by the third LED strand.

11. A lighting system comprising: the lighting device of claim 1; and a switching device for actuating the light device, wherein the control electronics are adapted to detect an actuation of the switching device of the light device and to flip the switch based on the detected actuation of the switching device.

12. The lighting system of claim 11, wherein the switching device is designed as a dimmer, wherein the control electronics of the lighting device are designed to detect an actuation of the dimmer and to control the LED strands of the lighting device.

13. The lighting system of claim 12, wherein the dimmer comprises a communication interface for wireless communication and is configured to be controlled by a control signal from a controller via the communication interface.

14. The lighting system of claim 13, wherein the dimmer is configured as a smart phase cut dimmer that can be controlled with a mobile application of a mobile control device.

15. The lighting system of claim 13, wherein the dimmer control signal is time-dependent, date-dependent, and/or location-dependent.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 illustrates a schematic view of an electrical circuit of a lighting device in accordance with an embodiment of the present disclosure.

(2) FIG. 2 illustrates a schematic view of an electrical circuit of a lighting device in accordance with another embodiment of the present disclosure.

(3) FIG. 3 illustrates a schematic view of an electrical circuit of a lighting device in accordance with a further embodiment of the present disclosure.

(4) FIG. 4 illustrates dependencies between luminous flux and color temperature for a lighting device in accordance with an embodiment of the present disclosure.

(5) FIG. 5 illustrates a lighting system with a lighting device in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE DRAWINGS

(6) FIG. 1 illustrates a schematic view of an electrical circuit of a lighting device in accordance with an embodiment of the present disclosure. The electrical circuit of the lighting device 100 may include a controllable LED light source with a first LED strand 1, a second LED strand 2, and a third LED strand 3. The lighting device 100 may further include control electronics with an LED driver 4, a switch 5 and a switch controller 6.

(7) The LED driver 4 may be designed to supply electrical current to the LEDs in the first LED strand 1, the second LED strand 2, and the third LED strand 3. In accordance with the embodiment of FIG. 1, the LED driver 4 may be designed as a dimmable LED driver, which may be controlled with a dimmer, particularly with a phase-cut dimmer. FIG. 1 shows a dimmer 7 to which the LED driver 4 may be electrically connected. The dimmer 7 may be designed as a phase-cut dimmer by which the LED driver 4 may be controlled so that the light generated by the lighting device 100 may be dimmed or brightened by means of the dimmer 7.

(8) The first LED strand 1, the second LED strand 2, and the third LED strand 3 may each have one or more LEDs. In particular, the LED strands 1, 2, and 3 may each have series-connected LEDs, parallel-connected LEDs, or a combination of series-connected and parallel-connected LEDs. The first LED strand 1 may be designed to generate a white light with a first correlated color temperature CCT1 of about 6000 K. The second LED strand 2 may be designed to generate a white light with a second correlated color temperature CCT2 in the range from about 4000 K to about 6000 K. The third LED strand may be designed to generate a white light with a third correlated color temperature CCT3 of about 2000 K.

(9) The switch 5 may be adapted to switch between the first LED strand 1 and the second LED strand 2, such that either the first LED strand 1 or the second LED strand 2 may be deactivated depending on the switch position or switch setting. The switch 5 may be controlled by the switch controller 6, which may adapted to detect an actuation of the dimmer 7 and may flip the switch 5 if the detected actuation of the dimmer 7 is taken by the switch controller 6 as a command to flip the switch 5. Thus, the first LED strand 1 or the second LED strand 2 may be activated or deactivated by the user as required.

(10) The switch controller 6 may be electrically connected to the LED driver 4 on the input side and to the switch 5 on the output side. The switch controller 6 may be designed such that an actuation of the dimmer 7 may be detected by the switch controller 6, in particular to recognize so-called “fast clicks,” for example if two or more clicks occur within a short time (e.g., 2 s) at the dimmer 7. The detected fast clicks may then be interpreted by the switch controller 6 as a command to flip the switch 5, whereupon the switch controller 6 may control the switch 5 such that the switching position of the switch 5 may be flipped. Thus, a fast click may be used to switch between the first LED strand 1 and the second LED strand 2 to change the lighting behavior of the lighting device.

(11) The differences (e.g., intrinsic differences) in electrical characteristics, such as impedance forward voltages, etc., of the individual LED strands 1, 2 and 3, may create the condition that when the lighting device 100 is dimmed, for example by means of a phase-cut dimmer, glow dim effect may occur as a system intrinsic property or as an integral functionality of the circuit, such that when the lighting device is brightened or the luminous flux of the generated light is increased, the color temperature of the generated light may also increase.

(12) Accordingly, the color temperature of the light produced may be reduced when the light fixture is dimmed.

(13) FIG. 2 illustrates a schematic view of an electrical circuit of an electrical device in accordance with another embodiment of the present disclosure. The electrical circuit shown in FIG. 2 is similar to the electrical circuit of FIG. 1 and additionally may include a controller 8. The controller 8 may be connected in series with the LEDs in the third LED strand 3 and may be designed to control the third LED strand 3 separately from the other LED strands 1 and 2. The controller 8 may include a feedback input 9 for detecting a feedback signal from the first LED strand 1 or from the second LED strand 2. The controller 8 may be designed to control the third LED strand 3, taking into account the feedback signal from the LED strands 1 and 2, respectively, in such a way as to achieve a predetermined or desired color temperature of the overall light generated by the lighting device 100.

(14) FIG. 3 illustrates a schematic view of an electrical circuit of an electrical device in accordance with a further embodiment of the present disclosure. The circuit of FIG. 3 is similar to the circuit shown in FIG. 2 and additionally may include a series resistor 10, which may connected in series with the LEDs in the third LED strand 3 and the controller 8.

(15) In some embodiments, one or more resistors (e.g., series resistors) and/or other passive electronic components may be connected in one or more LED strands 1, 2 and 3. By means of the series resistors and/or by means of the other passive electrical components, characteristics of LED strands 1, 2 and 3, influenced by different forward voltages of different LEDs, may be influenced such that the luminous behavior or light characteristic of the lighting device may be specifically influenced.

(16) As an example, the third LED strand 3 may have a lower forward voltage than the first LED strand 1 or the second LED strand 2, especially with the same number of LEDs. The third LED strand 3 may then draw a disproportionately high current from the LED driver 4, particularly at low electrical voltages, and accordingly light up more intensely relative to the other two LED strands 1 or 2. This may lead to the suppression of the illumination of the first and second LED strands 1 and 2, respectively, especially when dimming or at low dimming levels of the lighting device 100.

(17) By flipping the switch 5 (e.g., by actuating or fast-clicking the dimmer) the lighting behavior or lighting characteristics of the lighting device 100 may be influenced during operation. For example, if the switch 5 is flipped such that the second LED strand 2 is deactivated, only the first LED strand 1 and the third LED strand 3 may contribute to light generation. The resulting light or white light may in this instance have a CCT in the range between 2000 K and 6000 K. Alternatively, if the switch 5 is flipped such that the first LED strand 1 is disabled, only the first LED strand 2 and the third LED strand 3 may contribute to light generation. The resulting light may then have a CCT in the range between 2000 K and 4000 K. Compared to the constellation when the second LED strand 2 is deactivated, the overall color spectrum of the resulting light will be shifted to the “warmer” spectral range.

(18) The lighting device 100 may enable click-dim control, whereby two different color temperature luminous flux dimming (CCT & Flux-Dim) curves are realized. Depending on which of the two LED strands 1 or 2 is activated, different dim-to-warm curves may be achieved. Dim-to-warm curves are dependencies between the luminous flux and the color temperature, where the dimming (i.e., the decrease of the luminous flux) may be accompanied by the decrease of the color temperature. This may cause, among other things, a so-called “dimming glow effect,” such that when the lighting device 100 is dimmed down, the color temperature of the light may shift in the warm white direction, similar to incandescent bulbs.

(19) Switching between the two dependency curves may thereby be performed by switching between the first LED strand 1 and the second LED strand 2 by the switch 5 in the manner described above. In doing so, the switch controller 6 may detect an actuation (e.g., successive ON/OFF events) at the dimmer 7 and may flip the switch 5 if necessary.

(20) FIG. 4 illustrates dependencies between luminous flux and color temperature for a lighting device in accordance with an embodiment of the present disclosure. Two dependency curves 101 and 102 are shown in FIG. 4. The dependency curves 101 and 102 correspond to two different operating states or different switching positions of the switch 5. Such or similar curves may be generated when dimming or brightening a lighting device 100 according to FIG. 1, 2 or 3.

(21) The first dependency curve 101 shows the dependency between luminous flux and the color temperature of the light generated by the lighting device 100 in the operating condition when the second LED strand 2 is deactivated, such that only the first LED strand 1 and the third LED strand 3 contribute to light generation.

(22) The second dependency curve 102 shows the dependency between luminous flux and the color temperature of the light generated by the lighting device 100 in the operating condition when the first LED strand 1 is deactivated and is contributed to light generation only by the second LED strand 2 and the third LED strand 3.

(23) The two dependency curves 101 and 102 cover essentially the same luminous flux range between a minimum luminous flux of about 50 lm and a maximum luminous flux of about 800 lm, although the color temperature ranges of the two curves may differ significantly. The color temperature range of curve 101 may extend to a maximum value of about 4800 K, while the color temperature range of curve 102 may extend to about 3800 K. The minimum value of the color temperature for both curves may be about 2400 K. A characteristic of both curves 101 and 102 may be monotonic increase in color temperature or CCT with increasing luminous flux. The color temperature may increase as the luminous device 100 is brightened, and the color temperature may decrease as the luminous device 100 is dimmed. This luminous behavior of the luminous device 100 corresponds to the glow-dim effect similar to incandescent bulbs.

(24) Compared to the dependency curve 102, the dependency curve 101 is shifted overall to higher color temperatures, with the color temperature increasing steeper when the luminous flux is brightened or increased. This lighting behavior of the lighting device 100 may promote concentration and alertness in humans, and therefore may also be referred to as an active operating mode or “active mode.”

(25) In dependency curve 102, the color temperature increases slower with the increasing luminous flux, essentially linearly smooth. The slow increase of the color temperature with the luminous flux as well as the overall lower color temperature range of the dependency curve 102 provides for a pleasant, relaxed and cozy atmosphere, which is why this operating mode of the lighting device 100 may also be referred to as “relax mode”.

(26) FIG. 5 illustrates a lighting system with a lighting device in accordance with an embodiment of the present disclosure. The lighting system 200 may include a lighting device 100, wherein the lighting device 100 is shown as an LED lamp in FIG. 5.

(27) The lighting system 200 may include a dimmer 7 having a communication interface (not shown) for wireless control of the dimmer 7. The communication interface may be formed as a standardized communication interface for controlling the dimmer 7 using a standard protocol, such as ZigBee®, WiFi®, or BLE®, such that the lighting device 100 may be remotely controlled by a control device via the dimmer 7. The dimmer 7 may be electrically connected to the lighting device 100 by electrical lines 201 and 202. The dimmer 7 may be configured as a smart phase-cut dimmer and may include a controller (not shown) configured to process signals received via the communication interface and to send corresponding control signals to the lighting device 100 via the lines 201 and 202. FIG. 5 also shows a control device 301 for remotely controlling the dimmer 7. The control device 301 may be in the form of a smartphone that can be operated by a user 302 (symbolically shown) via a smartphone application.

(28) The control device 301 or smartphone application may provide an input interface, such as a touch screen input interface, for receiving user commands, and may be configured to send the user commands via one of the standardized communication interfaces to the remotely controlled dimmer 7 for controlling the lighting device 100. The input of the user commands and the control of the dimmer 7 by the smartphone 301 is symbolically represented by the wide arrows in FIG. 5.

(29) The remote-controlled dimmer 7 may be designed to convert the user commands from the control unit 301 via the communication interface of the dimmer 7 into control signals understandable to the control electronics of the lighting device 100 and to transmit these control signals to the lighting device 100 via the electrical lines 201 and 202. The control signals may have the same or compatible format as the control signals of a conventional phase-cut dimmer, such that the control electronics of the lighting device 100 may interpret them as the actuation of a conventional dimmer and control the LED strands 1, 2, and 3 of the lighting device 100 accordingly.

(30) If the user enters the command to switch between two operating modes, for example from “active” to “relax”, this may be received by the dimmer controller via the dimmer communication interface. The dimmer controller may then convert these commands into electrical signals, for example by disconnecting and reconnecting the electrical connection to the lighting device 100 through the lines 201 and 202. The control electronics of the lighting device 100 may take this disconnection and reconnection of the electrical connection as an “ON/OFF” event or as a fast-click and may switch the lighting device 100 from one operating mode to another operating mode by flipping the switch 5. The control device 301, or the application stored therein, may also generate time-dependent control signals that may cause the smart phase-cut dimmer to change phase cut angles. Based on the change in phase-cut angle, the control electronics of the lighting device 100 may drive the LED strands 1, 2, and 3 such that the CCT and luminous flux of the generated light are on one of the CCT&Flux dim curves intrinsic to the lighting device 100.

(31) The control device 301 or mobile application may be configured to mimic natural daylight or provide HCL lighting by controlling the remote dimmer 7. In this regard, the illumination of the lighting device 100 may be dimmed depending on the time of day. The time dependency of the lighting behavior may be stored in the memory of the control device 301 or the smartphone and/or the dimmer 7, in particular for imitating natural daylight (HCL curve). Additionally, further HCL curves may be downloaded from the cloud via wireless communication of the control device 301 and/or the dimmer 7 and stored in the memory of the control device 301 and/or the dimmer 7. HCL curves for special purposes, such as relaxation or to promote work concentration, may also be used.

(32) Although at least one exemplary embodiment has been shown in the foregoing description, various changes and modifications may be made. The aforementioned embodiments are examples only and are not intended to limit the scope, applicability, or configuration of the present disclosure in any way. Rather, the foregoing description provides the person skilled in the art with a plan for implementing at least one exemplary embodiment, wherein numerous changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of protection of the appended claims and their legal equivalents.