EP1972184B1 - Method for the operation of a light source with the aid of a lamp operating device, and lamp operating device therefor - Google Patents

Abstract

According to the invention, a lamp operating device (1), which adjusts the brightness of a light source (LA) in accordance with brightness commands when the light source is operated (LA) with the aid of the lamp operating device (1), continuously or gradually adjusts the brightness of the light source (LA) from the current brightness to the new brightness within a dimming period (T) after receiving a new brightness command. The inventive operating device (1) automatically determines an adequate dimming period (T) based on the points in time (t1, t2) when the current brightness command and previous brightness commands is/were received.

Description

The present invention relates to a method for operating a light source according to the preamble of claim 1, wherein the brightness of the light source is set in dependence on external brightness commands with the aid of a lamp operating device. In addition, the present invention relates to a suitable for performing the corresponding method lamp operating device.

In order to be able to carry out a comfortable lighting control, lamp operating devices of modern design usually have the option of transmitting to them external control commands, which are taken into account in the control of the light source associated with the lamp operating device. In particular, it is possible here to specify brightness values with the aid of digital commands, which are converted by the lamp operating device in a corresponding manner.

WO 99/60804 A shows a network-based electrical control system with distributed sensors and control, which is designed for lighting purposes. In this case, a local area network discloses a communication network for information exchange and a plurality of electrical components connected to the communication network. Each of the electrical components is configured to perform a particular function whereby information may be received by one or more other electrical components connected to the communications network. The electrical components work together, which distributes component functions and shares information. The electrical components are sensors, transceivers, switches, dimmers and control units.

JP 08 148284 A discloses a method of controlling a light dimmer, and a light dimmer control apparatus. In this case, the deviation of a dimming coefficient is reduced depending on a frequency, even if the dimming coefficient is small.

JP 07 320879 A shows an illumination control apparatus which prevents unnatural flicker of the lamp by means of a bit correction unit, even if the values of the light control information have been blurred by noise.

US 2005/174067 A1 relates to a method for operating a lamp and an electronic ballast (ECG), for example for operating a gas discharge lamp. In this case, an internal timer of the ECG is corrected by means of time information received by external signals.

US-A-5,477,111 shows a dimmer for use in a lighting control, which includes a triac loop, which allows both the control of light bulb systems and low-voltage lighting systems. The triac loop includes a microcontroller that adjusts the duration of the gate triggering pulse based on the desired intensity of the load.

Modern lighting systems often work in accordance with the so-called DALI (Digital Addressable Lighting Interface) standard, which represents an interface definition for the transmission of digital commands for the lighting control. Developed by leading lighting industry representatives, the DALI standard opens up the possibility of digitally controlling distributed light sources in a simple way. The central element of the DALI standard is the ability to transmit luminaire commands individually or in groups, in order to set the corresponding light sources to the desired brightness levels. Other lighting systems in which distributed lamp operating devices are transmitted from a center of brightness commands are known.

If a lamp operating device operating in accordance with the DALI standard receives a new brightness command, it usually does not immediately control the light source assigned to it with the new brightness. Instead, since such brightness jumps would be annoying for an observer, the brightness is increased or reduced continuously or in several small steps to the new brightness value, wherein in the case of the stepwise change, the individual steps are selected such that a nearly continuous transition for a viewer results. Such a brightness change is much more pleasant for the viewer than the sudden change. The various lamp operating devices each have a specific dimming speed, which specifies within which dimming period the brightness is changed from the initial value to the new final value. For example, it is known to specify a dimming period of 500 ms. After receiving a new brightness command, the light source is raised or lowered to the new brightness within 0.5s.

It has now been shown that a default of 500 ms for the brightness change in situations in which the brightness is changed only very rarely, is completely sufficient. On the other hand, however, there may well be cases in which new brightness commands are repeatedly transmitted for specific applications within a short period of time. If the time interval between the transmission of two new brightness commands is shorter than the predetermined dimming period of, for example, 500 ms, this has the consequence that the final or target brightness value just received has not yet been set before a new target value has already been transmitted again. Ultimately, this means that the light sources are never driven in the desired brightness. If, however, the time interval of the transmission of successive brightness commands is slightly above the predetermined dimming period, the result is a brightness curve that is also very unattractive to a viewer, since the brightness remains constant for a short period of time and is then changed again, which is very similar to a flickering of the luminaire is. Although the DALI standard certainly allows the dimming speed to be readjusted with the aid of control commands transmitted specifically for this purpose, this is associated with an increased outlay in the data transmission and, accordingly, is advantageous only in applications in which the time interval between the data transmission Transmission of brightness commands is essentially consistent.

The present invention is accordingly an object of the invention to provide a novel solution in the brightness control of light sources, in which the disadvantages described above do not occur or are at least significantly reduced.

The object is achieved by a method for operating a light source according to claim 1 and by a lamp operating device according to claim 12. Advantageous developments of the invention are the subject of the dependent claims.

The solution according to the invention is based on the idea of making the dimming speed of the lamp operating devices variable. In contrast to the previous solution according to the DALI standard, however, in which the dimming speed was set in each case by correspondingly transmitted control commands, it is now provided according to the invention that the operating devices themselves are capable of setting a suitable speed for the brightness change. In particular, the operating devices take into account the times when current and previous brightness commands were received.

According to the present invention, therefore, a method for operating a light source with the aid of a lamp operating device is proposed, which lamp operating device adjusts the brightness of the light sources in response to brightness commands, the operating device after receiving a new brightness command, the brightness of the light source within a dimming period continuously or step by step the current brightness sets to the new brightness, and wherein it is provided according to the invention that the operating device independently determines the dimming period on the basis of the times at which the current and previous brightness command was received.

In addition, a lamp operating device for operating at least one light source is proposed, wherein the lamp operating device has a receiving unit for receiving external brightness commands and a control circuit, which adjusts the brightness of the light sources in response to the received brightness commands, and wherein the control circuit is adapted, after receiving a new brightness command to adjust the brightness of the light source within a dimming period continuously or in stages from the current brightness to the new brightness. According to the invention, it is provided that the control circuit determines the dimming period on the basis of the times at which the current and previous brightness command were received.

By being able to independently set a suitable dimming speed, the devices can respond flexibly to received control command sequences. In particular, they can adjust their dimming speed or the dimming period required to adjust the brightness such that the new brightness is very likely to be reached precisely at the time when a new brightness command is transmitted. This results in a very pleasant continuous or almost continuous brightness curve for a viewer, in which the desired brightness is set without flickering.

According to a particularly preferred embodiment of the present invention, it is provided that the duration between the reception of the last brightness command and the reception of the current brightness command is set as the dimming period. In this approach, the lamp operating device is thus assumed that at least over a certain period of time, the brightness commands are transmitted in almost uniform intervals. However, the time interval changed by the control panel, the lamp operating device automatically adjusts to this new situation.

Preferably, it is provided that the independent determination of the dimming period is carried out in a so-called adaptive mode of the operating device, wherein this adaptive mode can either be activated or deactivated by an external control command or the operating device automatically activates the mode in certain situations. In this case, it can be provided, in particular, that the adaptive mode is activated by the operating device if the duration between the receipt of the last brightness command and the reception of the current brightness command has fallen below a predetermined reference period. If, on the other hand, brightness commands are transmitted only at large time intervals, then this is interpreted by the lamp operating device as meaning that no specific brightness sequences are to be set, but instead only one-time brightness changes are provided. In this case, it is preferable to resort to a fixed predetermined dimming speed of, for example, 500 ms.

The brightness commands are preferably transmitted as digital control commands, which can be done within the scope of all conceivable options for command transmission. It would be conceivable, for example, the use of separate bus systems, as provided in particular according to the DALI standard. In addition to the wired ones, the wireless transmission (wireless) of brightness commands or the use of power line carrier (PLC) data transmission techniques is also possible.

As light sources, which are assigned to the operating device, in particular LEDs come into question, since there the dynamic light control plays a special role.

Fig. 1

schematisch die Ausgestaltung eines erfindungsgemäßen Lampenbetriebsgeräts zum Betreiben einer Lichtquelle;

Fig. 2

den Helligkeitsverlauf bei Übermittlung einer bestimmten Helligkeitssequenz und sehr langsamer Dimmgeschwindigkeit;

Fig. 3

den Helligkeitsverlauf bei einer sehr hohen Dimmgeschwindigkeit und

Fig. 4

den Helligkeitsverlauf bei adaptiver Dimmgeschwindigkeit gemäß der vorliegenden Erfindung.

The invention will be explained in more detail with reference to the accompanying drawings. Show it:

Fig. 1

schematically the embodiment of a lamp operating device according to the invention for operating a light source;

Fig. 2

the brightness curve when transmitting a specific brightness sequence and very slow dimming speed;

Fig. 3

the brightness curve at a very high dimming speed and

Fig. 4

the brightness curve at adaptive dimming speed according to the present invention.

The invention will be explained with reference to an embodiment of an electronic ballast for operating a gas discharge lamp. It should be noted, however, that the concept of adaptive dimming speed is by no means limited to such lamp operating devices and light sources. Instead, the present invention can basically be applied to all types of Lämpenbetriebsgeräten which are able to adjust the light sources associated with them in their brightness. The light sources may be LEDs in particular.

This in Fig. 1 generally illustrated by the reference numeral 1 lamp has as a central component to a control circuit 2, which is responsible for the operation of the ballast 1 and takes over the control of all other components. The operation of the ballast 1 is carried out in particular on the basis of control commands, which are the wired ballast 1 and / or wirelessly (radio) transmitted from a central command generator 22. For this purpose, the ballast 1 to a transmitting and receiving unit or an interface 3, via which a data exchange takes place. The interface 3 is in the illustrated embodiment via a bus line system 21, to which other ballasts can be connected, connected to the central command generator 22. Commands received by the interface 3 via the bus line system 21 are then forwarded to the control unit 2, which regulates the operation of the ballast 1 in a suitable manner.

It should be noted that other solutions for the transmission of the control commands can be provided. In particular, it would also be possible to provide wireless command transmission. The use of the lines of the power supply network 20 for the command transmission would be conceivable, in which case so-called powerline carrier techniques are used. In the illustrated embodiment, the use of a separate bus line 21, the command transmission is preferably carried out according to the DALI standard, although any other way of digital command transmission can be provided.

The brightness setting of the gas discharge lamp connected there to the ballast 1 is effected in that the power supplied to the lamp LA in is set appropriately. For this purpose, the ballast 1 internally initially has a rectifier 4 connected to the power supply network 20, whose rectified input voltage is fed to a DC link circuit 5. This serves on the one hand the harmonic filtering and on the other hand generates an intermediate circuit voltage, which is converted by an inverter 6 into a high-frequency AC voltage. This in turn is supplied to the output-side load circuit 7, which has output terminals for the lamp LA. In known manner, the lamp power can now be changed by changing the frequency of the alternating voltage generated by the inverter 6. Since the load circuit 7 has a series resonant circuit consisting of an inductance and a capacitance, the power can be changed by changing the operating frequency with respect to the series resonant frequency of the load circuit. Depending on the type of the type of light source connected to the lamp operating device, however, other concepts for power or brightness control can also be used.

If the lamp operating device 1 now receives a new brightness command for the lamp LA via the bus line 21, the control circuit 2 changes the power supplied to the lamp LA such that it is finally operated with the new desired brightness. However, the transition from the output brightness to the new final brightness does not take place abruptly, but continuously or in smaller steps, in order to produce a more pleasant brightness transition. This so-called dimming speed is usually determined by the specification of a dimming period, which indicates within which time the brightness is raised or lowered from the initial brightness to the final brightness.

For example, a standard dimming period is 500ms, which means the new brightness will be triggered within half a second. This speed is sufficient for such cases, in which only at long time intervals in each case a new brightness value is given. On the other hand, quite special applications are conceivable in which the brightness value should be changed more quickly, since new brightness commands are transmitted in short time intervals. If the dimming speed is too slow for this, this means that the final value is not reached at all before a new brightness value is transmitted again.

Fig. 2 shows an example of a brightness curve, in which at the times t1, t2 and t3, ie at a time interval of 100ms alternately brightness values of 20% and 80% are transmitted. Since at a fixed predetermined Dimming speed of 500ms for the brightness change the period for setting the new brightness value is greater than the time sequence of the transmission of the individual commands, this has - as shown - the consequence that at any time the desired final brightness is achieved. Instead, the brightness varies between values of about 65% and 35%, which does not correspond to the desired brightness curve.

If, instead, a significantly higher dimming speed is displayed, the result is a brightness progression, as it is, for example, in Fig. 3 is shown. Although in this case the desired final brightness is achieved before the transmission of a new brightness command, this results in an ultimately very ugly brightness curve, since there are phases in which the brightness is changed, and on the other hand the brightness remains constant at high or low in short periods of time Brightness value remains. This leads to an unsightly flicker.

To circumvent these disadvantages, it is now proposed according to the invention that the lamp operating device sets the dimming speed, more precisely the dimming period independently. In particular, it is provided here that the operating device recognizes the sequence from the previous command sequences and subsequently adapts the future behavior in the brightness adjustment in order to produce the most continuous possible brightness curve.

In the embodiment according to Fig. 4 For this purpose, it is provided that the dimming period T, ie the period in which, after receiving a new brightness command, the lamp brightness is changed from the initial value to the new final value, corresponds to the time interval between the transmission of the last brightness command and the current brightness command. At the in Fig. 4 As shown, this means that the lamp operating device at the time t2, at which a new brightness command was obtained, determines that before 100 ms, ie at the time t1, the previous last brightness command was transmitted. This time interval τ is recorded in an internal memory 8 of the control circuit 2 and now serves as a dimming period T for the subsequent adjustment of the brightness. After expiration of the period T, the new brightness of 80% is reached. If the transmission of the control commands occurs almost at constant time intervals, this means that the new final brightness is reached precisely at the time t3 at which a new brightness command is also received. The brightness is thus changed almost continuously, resulting in a very pleasant brightness.

It should be noted that in the case of Fig. 4 of course, the time interval for the transmission of the brightness commands could be changed from time to time, which would mean that in such a transition then the final brightness is not achieved exactly at the time at which the new brightness command was transmitted. In the subsequent sequences, however, then the lamp operating device adapts itself again to the new time intervals, without the need for a corresponding command transmission would be required. This ensures that predominantly a continuous brightness profile is achieved.

This so-called adaptive mode of the lamp operating device is therefore obviously advantageous if a multiple and rapid change in the lamp brightness is provided. An application for this would be, for example, the control of LEDs. On the other hand, if a new brightness command is only occasionally transmitted, a corresponding adjustment of the dimming speed is not absolutely necessary or even disadvantageous, which is why it is preferably provided that this adaptive mode is used only in those cases in which it brings about the advantages described above , For this purpose, on the one hand, it may be provided that the adaptive mode is explicitly activated or deactivated by means of corresponding digital commands. On the other hand, it can also be provided that the lamp operating device automatically activates the adaptive mode if the transmission of the brightness commands indicates that a specific command sequence is now to be expected. For example, in the event that the time interval between two consecutive brightness commands falls below a reference value or possibly an externally presettable value, the lamp operating device can automatically switch to adaptive mode. In the case of manual activation or deactivation of the adaptive mode, it is preferably provided that in this case the corresponding instruction set of the DALI standard is extended in order to integrate the solution according to the invention into this standard.

In addition, it should be noted that the estimation or adjustment of the dimming speed in other ways than with regard to Fig. 4 described can be done. In particular, several past times of the brightness command transmission could also be taken into account, in which case a suitable dimming speed is estimated on the basis of corresponding statistics or the like. The consideration of the current time of the command transmission and the time of the last command transmission draws However, it is characterized by its simplicity, which is why this is a particularly preferred approach.

Overall, therefore, the solution according to the invention provides an improvement in the control of light sources, by means of which, in particular in the repeated and rapid transmission of different brightness commands, a particularly pleasant brightness progression is achieved. At the same time it is also ensured that in each case the desired final brightness value is reliably achieved.

Claims (22)

1. Method for operating a light source (LA) with the aid of a lamp operating device (1), which adjusts the brightness of the light source (LA) as a function of brightness commands supplied externally via an interface, the operating device (1), having received a new external brightness command, adjusting the brightness of the light source (LA) from the present brightness to the new brightness continuously or stepwise at a dimming speed within a dimming time period (T), characterized in that the operating device (1) adjusts the dimming speed automatically and adaptively on the basis of the times (t₁, t₂) at which the present and earlier brightness commands were received.
2. Method according to Claim 1, characterized in that the duration (τ) between the reception of the last brightness command and the reception of the present brightness command is selected as the dimming time period (T).
3. Method according to Claim 1 or 2, characterized in that the automatic determination of the dimming time period is performed in an adaptive mode of the operating device (1).
4. Method according to Claim 3, characterized in that the adaptive mode is activated or deactivated by an external control command.
5. Method according to Claim 3, characterized in that the adaptive mode is activated automatically by the operating device (1).
6. Method according to Claim 5, characterized in that the adaptive mode is activated by the operating device (1) if the duration (τ) between the reception of the last brightness command and the reception of the present brightness command has fallen below a predetermined reference time period.
7. Method according to Claim 6, characterized in that the reference time period can be predetermined by an external control command.
8. Method according to one of the preceding claims, characterized in that the brightness commands are communicated in the form of digital control commands.
9. Method according to Claim 8, characterized in that the communication of the brightness commands is performed corresponding to the DALI standard.
10. Method according to one of the preceding claims, characterized in that the brightness commands are communicated in a wireless and/or wired manner.
11. Method according to one of the preceding claims, characterized in that the light source is at least one light-emitting diode.
12. Lamp operating device (1) for operating at least one light source (LA), the lamp operating device (1) having:

    a reception unit (3) for receiving external brightness commands, and

    a control circuit (2), which adjusts the brightness of the light source (LA) as a function of the received brightness commands,

    and the control circuit (2) being designed such that it adjusts, continuously or stepwise, the present brightness of the light source (LA), in accordance with a received new brightness command, to the new brightness at a dimming speed within a dimming time period, characterized in that the control circuit (2) is designed to automatically and adaptively adjust the dimming speed on the basis of the times (t₁, t₂) at which the present and earlier brightness commands were received.
13. Lamp operating device according to Claim 12, characterized in that the control circuit determines, as the dimming time period (T), the duration (τ) between the reception of the last brightness command and the reception of the present brightness command.
14. Lamp operating device according to Claim 12 or 13, characterized in that the automatic determination of the dimming time period is performed in an adaptive mode of the operating device (1).
15. Lamp operating device according to Claim 14, characterized in that the adaptive mode can be activated or deactivated by an external control command.
16. Lamp operating device according to Claim 14, characterized in that the adaptive mode is activated automatically by the control circuit (2).
17. Lamp operating device according to Claim 16, characterized in that the adaptive mode is activated by the control circuit (2) if the duration (τ) between the reception of the last brightness command and the reception of the present brightness command has fallen below a predetermined reference time period.
18. Lamp operating device according to Claim 17, characterized in that the reference time period can be predetermined by an external control command.
19. Lamp operating device according to one of Claims 12 to 18, characterized in that the brightness commands are digital control commands.
20. Lamp operating device according to Claim 19, characterized in that the communication of the brightness commands is performed corresponding to the DALI standard.
21. Lamp operating device according to one of Claims 12 to 20, characterized in that the device is set up to receive wired and/or wireless brightness commands.
22. Lamp operating device according to one of Claims 12 to 21, characterized in that the light source is at least one light-emitting diode.

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