Controlling a plurality of lighting units

Abstract

A lighting system includes a plurality of lighting units. Each lighting unit includes a unit control circuit and a lighting element. The unit control circuit is disposed to store at least one lighting scenario. The lighting scenario comprises a succession of settings of intensity and/or color of the lighting element. A system control circuit is disposed to transmit an execute signal to one or more of the lighting units. The unit control circuit is disposed to control, upon reception of the execute signal, the lighting element according to the lighting scenario. The lighting units are connected to a common electrical power supply via two conductors. The execute signal is transmitted from the system control circuit to the lighting units wirelessly or via the two conductors.

Claims

1. A lighting system, comprising: a plurality of lighting units, each of the plurality of lighting units comprising a unit control circuit and a lighting element, each unit control circuit comprising a memory that stores at least one lighting scenario, each of the at least one lighting scenario comprising a succession of settings of at least one of intensity of the lighting element and color of the lighting element; and a system control circuit comprising a transmitter configured to transmit an execute signal to the plurality of lighting units that includes an indication of one or more of the plurality of lighting units that is to operate the lighting element according to the at least one lighting scenario, wherein the plurality of lighting units are electrically connected in parallel to a common electrical power supply via two conductors, wherein the execute signal is transmitted at least one of wirelessly and via the two conductors from the system control circuit to the plurality of lighting units.

2. The lighting system according to claim 1, wherein a programming device is provided to transmit scenario data for the lighting scenario to at least one of the plurality of lighting units, wherein each unit control circuit is disposed to receive and store the scenario data, and the scenario data being transmitted at least one of wirelessly or via the two conductors.

3. The lighting system according to claim 2, wherein the programming device is disposed to transmit a programming signal sequence to one or more of the plurality lighting units, and each unit control circuit is disposed to receive and store the scenario data upon reception of the programming signal sequence.

4. The lighting system according to claim 2, wherein at least one of the execute signal and the scenario data are transmitted by transmitter means comprising at least one light source disposed to transmit at least one of the scenario data and the execute signal by modulated light, and wherein the plurality of lighting units comprise a light sensor, each unit control circuit being disposed to process a signal received from the light sensor upon reception of the modulated light to receive at least one of the scenario data and the execute signal.

5. The lighting system according to claim 4, wherein each lighting elements of the plurality of lighting units comprise at least one LED element, and the at least one LED element is used as the light sensor.

6. The lighting system according to claim 2, wherein at least one of the execute signal and the scenario data are transmitted by modulating means disposed to modulate electrical power supplied from the electrical power supply to the two conductors, and each unit control circuit being connected to the two conductors and disposed to process a modulated electrical signal at the conductors to receive at least one of the execute signal and the scenario data.

7. The lighting system according to claim 6, wherein the modulating means are disposed to modulate the electrical power using at least a first voltage level sufficient for operation of each unit control circuit but not sufficient for operation of each lighting element.

8. The lighting unit according to claim 7, wherein the modulating means are disposed to modulate the electrical power using a second voltage level sufficient for operation of each lighting element.

9. The lighting system according to claim 1, wherein each unit control circuit is disposed to store a plurality of lighting scenarios, and upon reception of an execute signal associated with one of the plurality of stored lighting scenarios operate each lighting element according to the lighting scenario.

10. The lighting system according to claim 1, wherein each of the at least one lighting scenarios comprises a plurality of settings, and wherein each of the plurality of settings comprise at least one of an intensity of light and a color of light to emitted from each of the plurality of lighting units, and a display time during which each of the plurality of lighting units is operated according to said setting.

11. The lighting system according to claim 1, wherein each of the plurality of lighting units are arranged in a string configuration, wherein each of the plurality of lighting units are arranged spaced along a line and connected by the two conductors.

12. A method of operating a lighting system, including a plurality of lighting units, each of the plurality of lighting units including a unit control circuit and a lighting element, each of the plurality of lighting units being electrically connected in parallel to a common electrical power supply via two conductors, the method comprising: storing at least one lighting scenario within each of the plurality of lighting units, the at least one lighting scenario comprising a succession of settings of at least one of an intensity of the lighting element and a color of the lighting element; transmitting an execute signal to one or more of the ouch of the plurality of lighting units, the execute signal being transmitted at least one of wirelessly or via the two conductors; and in response to receiving the execute signal by each of the plurality of lighting units, controlling each lighting element according to the lighting scenario.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.

(2) In the drawings:

(3) FIG. 1 is a schematic diagram of a lighting unit;

(4) FIG. 2 is a timing diagram as an example of a lighting scenario;

(5) FIG. 3 is a schematic diagram of a first embodiment of a lighting system with multiple lighting units and a modulation means;

(6) FIG. 4 is a schematic diagram of a second embodiment of a lighting system with multiple lighting units and a modulated light source;

(7) FIGS. 5 and 6 are diagrams showing examples of display patterns;

(8) FIG. 7 shows a fourth example of a lighting system with a programming light source;

(9) FIGS. 8A-8C show diagrams of modulation sequences.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(10) FIG. 1 shows a schematic diagram of a lighting unit 10, which is connected between a first electrical conductor 12 and a second electrical conductor 14. The lighting unit 10 comprises a lighting element 16 and a unit control circuit 18. The lighting element 16 is a multicolor LED comprising individually operable LED elements for red, green and blue light.

(11) The unit control circuit 18 is an integrated circuit including a microcontroller. Unit control circuit 18 further comprises memory for storing an operating software, the function of which will be described below. Further, the unit control circuit 18 comprises memory to store data, namely lighting scenario data, as will be further described below.

(12) The unit control circuit 18 is connected to both electrical conductors 12, 14 to be supplied with operating electrical power. It further comprises circuitry (not shown) to determine a voltage level of an operating voltage V between the conductors.

(13) The lighting element 16 is connected to the unit control circuit 18 such that its operating current I is controlled by the unit control circuit 18. In the preferred embodiment, the unit control circuit 18 can turn the operating current I on and off, which enables control by PWM. While in FIG. 1 only one connection is shown, the unit control circuit 18 is connected to the lighting element 16 to control operation of each individual LED separately.

(14) In operation of the lighting unit 10, operating voltage V of a magnitude sufficient to operate the lighting element 16, e. g. 7.5 V, is supplied between the electrical conductors 12, 14. The unit control circuit 18 controls the lighting element 16 according to a pre-stored lighting scenario. A lighting scenario is stored as scenario data in the internal memory of the unit control circuit 18 describing a sequence of operation of the lighting element 16, i. e. time-dependent settings for intensity and color.

(15) FIG. 2 shows a timing diagram of an example of a lighting scenario 20. The individual current values IR, IG, IB for the red, green and blue LEDs are shown over time t. As shown, the LEDs of the lighting element 16 are turned on or off at specified times and for specified durations, or may be operated in a dimmed manner by pulse width modulation. The resulting light output of the lighting element 16 operated according to the lighting scenario 20 is consequently of varying color and intensity over time t. It should be understood that the scenario 20 is merely an example demonstrating the nature of scenario data, whereas in practical embodiments different scenarios may be used, both of constant and/or varying color.

(16) FIG. 3 shows a first embodiment of a lighting system 22 with a number of lighting units 10a-10d, each configured as described above for lighting unit 10, electrically connected in parallel between the conductors 12, 14. The lighting units 10a-10d are arranged in a string configuration, i. e. spaced along a line and connected by the conductors 12, 14.

(17) An operating voltage V is applied to the conductors 12, 14 by a power source 24. The power source 24 thus supplies electrical operating power to the lighting units 10a-10d for operation of the unit control circuits 18 and of the lighting elements 16. While it may be possible to implement linear control of the current in each lighting unit, this could lead to increased losses. Therefore, it is preferred to provide control of the total current supplied by the power source 24 to the lighting units 10a-10d in each instant according to the presently required total current.

(18) In addition to supplying electrical operating power, the power source 24 is in the present example also used to communicate with the lighting units 10a-10d. A system control circuit 34 controls the power source 24 to modulate the operating voltage V. By way of modulation of the operating voltage V, data may be transmitted from the system control circuit 34 to the lighting units 10a-10d.

(19) One type of data to be transmitted from the system control circuit 34 is an execute signal, causing one or more of the lighting units 10a, 10d to execute a pre-stored scenario 20, i. e. to operate the lighting elements 16 according to the stored sequence of settings corresponding to the scenario data. The execute command may include an address of one or more of the lighting units 10a-10d to specify which lighting unit is supposed to apply the pre-stored scenario. If multiple lighting scenarios are stored in the unit control circuit 18, the execute command may select which of the pre-stored lighting scenarios should be executed by the addressed lighting units 10a-10d.

(20) FIG. 5 shows a first example of a display pattern that may be achieved by using pre-stored scenarios. In the example eight lighting units 10a-10h are provided in a string configuration. In the diagram of FIG. 5, the lighting units 10a-10h are shown over time t from top to bottom. Activated lighting units, i. e. with lighting elements 16 emitting light, are shown hatched.

(21) At first, all lighting units 10a-10h are deactivated (first row in FIG. 5). Progressing over time t, first the two lighting units 10g, 10h to the right are activated, then three lighting units 10f, 10g, 10h, then four lighting units 10e, 10f, 10g, 10h, etc. The resulting display pattern progresses from right to left over time t. Lighting units 10a-10h may e.g. constitute a turn signal unit for a motor vehicle. The display pattern may then constitute a progressive turn signal showing the direction of a planned turn (to the left in the example of FIG. 5).

(22) The display pattern illustrated in FIG. 5 is the result of eight individual lighting scenarios stored in the lighting units 10a-10h. An example of a lighting scenario 20 is shown for the first lighting unit 10a which is deactivated during the first seven cycles and activated only in the last cycle. In contrast, the lighting unit 10h is deactivated only in the first cycle and activated in all remaining cycles.

(23) Display of the pattern illustrated in FIG. 5 may thus be achieved by pre-storing the individual scenarios in the lighting units 10a-10h and sending a common execute signal, causing each lighting unit to execute its pre-stored scenario over the seven cycles shown.

(24) FIG. 6 shows a second example of a display pattern, which could for example also be used for a turn signal light of a motor vehicle, or alternatively for another signal light of a motor vehicle, e.g. a daytime running light DRL or a position light. The sequence shown may e.g. be a welcome light shown as the motor vehicle is unlocked. Again, individual lighting scenarios 20 pre-stored in the lighting units 10a-10h are executed by sending an execute signal to all lighting units 10a-10h to show the display pattern of FIG. 6.

(25) It should be noted that, as the individual lighting scenarios 20 are pre-stored in the lighting units 10a-10h and only one common execute signal needs to be transmitted from the system control circuit 34 to the lighting units, the required bandwidth is very low.

(26) FIG. 4 shows a second embodiment of a lighting system 32 with multiple lighting units 10a-10d. The second embodiment of a lighting system 32 corresponds in many elements to the first embodiment of a lighting system 22. Like reference numbers refer to like parts. In the following, only differences will be further explained.

(27) In the lighting system 32, the system control circuit 34 is connected to a light source 36 which may be controlled to emit modulated light. In this embodiment, the LEDs of the lighting element 16 in the lighting unit 10a-10d are operated as light sensors by the unit control circuits 18. In this way, data, such as an execute signal, is transmitted from the system control circuit 34 to the lighting units 10a-10d.

(28) There are different possible ways to set up the lighting systems 22, 32 for operation as described above. For programming the scenario data in the local storage of each lighting unit, the data may be transmitted from a programming device. For example, the lighting units may be provided with individual addresses, so that datae.g. as modulated light or through modulation of the supply voltage Vmay be transferred individually to the lighting units to be stored as scenario data.

(29) Individual addresses of the lighting units 10a-10d may e.g. be achieved by hardware coding, e.g. by providing coding resistors. Further, it is possible to use a laser to connect, disconnect and/or change a coding element on each of the lighting units 10a-10d which is then read out by the unit control circuit 18 to establish an address.

(30) Preferably, addressing may be provided by in-circuit programming using modulated light. FIG. 7 shows a fourth embodiment of a lighting system 42 with four lighting units 10a-10d connected to an electrical power supply 24. A programming light source 44 may be placed above the strip of lighting units 10a-10d. The programming light source 44 has individually controllable lighting elements 46a-46d, each associated with and placed adjacent to one of the lighting units 10a-10d. Programming signal 50 may be send as a modulated supply voltage V to set the lighting units 10a-10d into a programming mode. A sequence of modulated light 52 may then be sent by the lighting elements 46a-46d of the programming light source 44 to be received by the lighting elements 16 of the lighting units 10a-10d acting as sensors to receive scenario data. The scenario data is stored in the local storage of the unit control circuit 18.

(31) For communication, both by a programming device and by a system control circuit with the lighting units 10a-10d via modulation of the voltage V, different modulation schemes may be used. Preferred embodiments of modulation sequences are shown in FIGS. 8A-8C.

(32) FIG. 8A shows an example using three different voltage levels V0, V1 and V2. The voltage level V2 may correspond to a logic high and be sufficient of the lighting element 16 in each lighting unit 10 to operate. For example, the voltage level V2 may be 7.5 V. The voltage level V1, e.g. corresponding to a logical low, is lower than the voltage level V2, but still sufficient for the unit control circuit 18 to operate, e. g. at 3 V.

(33) Data may then be encoded by a modulation as shown in the example by the supply voltage V varying between voltage levels V1 and V2, rendering the unit control circuits 18 of all connected lighting units operational throughout the entire time t to decode the sequence. This type of communication may both be used for transmission of an execute signal and for programming of scenario data. A specific sequence of variations between the voltage levels may e.g. include encoded data, for example to identify one of several pre-stored scenarios to execute.

(34) In alternative communication schemes, further different voltage levels both above and below V1 and V2 may be used for encoding and transmitting data, e.g. as a learning signal to announce scenario data to store, or as execute signal to start a specific pre-stored scenario.

(35) If communication needs to occur while the lighting units 10 remain activated, modulation may be effected as shown in the example of FIG. 8B, i. e. by keeping the supply voltage at the voltage level V2 required for operation of the lighting element 16 with only very short interruptions during which the voltage V is reduced to level V1, still sufficient to keep the unit control circuit 18 operational. If interruptions are short enough, they will not be visible to the human eye.

(36) FIGS. 8A-8C show an example of a fallback solution, e. g. to cause the lighting system to emit an emergency flash, where all lighting units are directly activated. This may e.g. be achieved by switching on directly to the voltage level V2, skipping the intermediate voltage V1.

(37) While the invention has thus been illustrated and described in detail in the drawings and the foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments.

(38) For example, the number and special configuration of the lighting units 10 in the lighting system may be chosen as required for a given requirement. Instead of RGB multicolor LEDs as described, the lighting units may have LEDs of a single color, or other color configurations such as e.g. RGBW (red, green, blue, and converted white). Further, other types of light sources emitting e.g. infrared or ultraviolet light may be used. Also, the type of modulation used may be freely chosen without being limited by the given examples. While the unit control circuit 18 has been described as an integrated circuit it is alternatively possible to use an electrical circuit of discrete components fulfilling the described function.

(39) Further variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure and the dependent claims. In the claims, the word comprising does not exclude other elements and steps, and the indefinite article (a or an) does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims or different embodiments does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.