EP2373125B1 - Appareil pour générer un signal de commande pour un dispositif de lampe et procédé de génération d'un signal de commande pour un dispositif de lampe - Google Patents

Appareil pour générer un signal de commande pour un dispositif de lampe et procédé de génération d'un signal de commande pour un dispositif de lampe Download PDF

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Publication number
EP2373125B1
EP2373125B1 EP10159003A EP10159003A EP2373125B1 EP 2373125 B1 EP2373125 B1 EP 2373125B1 EP 10159003 A EP10159003 A EP 10159003A EP 10159003 A EP10159003 A EP 10159003A EP 2373125 B1 EP2373125 B1 EP 2373125B1
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Prior art keywords
pulse
brightness
pulse train
pulses
train
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EP10159003A
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German (de)
English (en)
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EP2373125A1 (fr
Inventor
Walter Englert
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GLP German Light Products GmbH
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GLP German Light Products GmbH
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Priority to EP10159003A priority Critical patent/EP2373125B1/fr
Priority to PCT/EP2011/054446 priority patent/WO2011120855A1/fr
Priority to CN2011800180969A priority patent/CN102835188A/zh
Priority to JP2012553356A priority patent/JP2013519988A/ja
Publication of EP2373125A1 publication Critical patent/EP2373125A1/fr
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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
    • H05B45/30—Driver circuits
    • H05B45/32—Pulse-control circuits
    • H05B45/335—Pulse-frequency modulation [PFM]
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
    • H05B45/10—Controlling the intensity of the light

Definitions

  • the present invention relates to the field of generating drive signals, especially for lamp devices, such as LED spots.
  • the adjustment of the brightness of an LED (light emitting diode) lightning device, such as an LED spot (for example, with a plurality of LEDs) is realized by a fast off and on switching of the LEDs.
  • a modulation signal for the on/off switching of LEDs is typically based on pulse-width modulation (PWM).
  • PWM pulse-width modulation
  • an LED spot (for example, with a plurality of LEDs) shall be applicable for modern TV cameras, like HDTV cameras, it is desired to have a PWM frequency as high as possible. Furthermore, this PWM frequency should be an integer multiple of 50Hz and 60Hz, otherwise, the LED spot cannot be used world-wide.
  • the shutter time of a TV camera defines how long a shutter of the TV camera is opened to acquire one picture. If this mentioned shutter time is very short, then a very high PWM frequency is desired. It has been found that a PWM frequency of 600Hz is sufficient, but a PWM frequency of 1200Hz or 2400Hz offers a safety distance to obtain a picture without pulsing and jittering also in ambient lightning conditions.
  • a typical microcontroller with a typical instruction time of 100ns (which corresponds to a frequency of 10Mz), this time is much too short to output impulses of this length. Furthermore, one microcontroller should be used to control a plurality of LEDs to save costs and effort. Therefore, a typical microcontroller cannot be used for providing a signal to drive an LED or a plurality of LEDs of an LED spot, which fulfils all the above-mentioned requirements for modem HDTV cameras. One possibility would be to use high-sophisticated digital signal processing processors, but which would result in a dramatically increase of costs and effort.
  • US 2005/122065 A1 shows a dynamic colour emitting LED device that includes a plurality of light emitting diode units.
  • a controller supplies driving signals to each of the LED's individually.
  • the driving signals individually control relative intensity outputs of the LED's.
  • the average relative intensity of the different LED components is controlled by frequency modulating the individual driving signals provided to each respective LED.
  • the frequency modulation is effectuated by providing a fixed pulse width at variable frequency, to thereby control the duty cycle.
  • US 2007/0257869 A1 describes a backlight device including a light source having a plurality of light sources, a detecting circuit, a control unit and a pulse with modulation driving circuit.
  • the PWM driving circuit is used for generating a PWM signal for driving the light source module.
  • the PWM driving circuit adjusts the base frequency of the PWM signal according to a control signal without adjusting the duty cycle of the PWM signal to control the brightness of the light source.
  • US 2007/103086 A1 shows an apparatus for controlling a set of light emitting diodes comprising at least one current source f for powering the LED's; a main controller for receiving dimming and/or colour mixing information and for translating the information into LED control information and transmitting the LED control information to control the set of LED's.
  • the LED control information is based on ON- and OFF-Times.
  • US 7,598,683 B1 describes a method and a circuit to control the intensity of lights using pulses of a fixed duration and a fixed frequency. A total current flowing to a light source is controlled by varying the number of pulses in a control burst.
  • WO 2006/107199 A2 describes a method of driving, by means of a single power supply, a number of high power light emitting diodes, the number of LED's being divided into two or more groups, each group being separately energizable.
  • An object of the present invention is to provide a concept allowing to drive an LED or an LED spot for an HDTV camera with lower requirements to a drive signal generator for the LED or the LED spot than in the prior art.
  • a first drive signal for a first brightness for a lamp device differs from a second drive signal for a second brightness for the lamp device by a frequency or, in other words, by a number of pulses the drive signals contain in a certain amount of time. It has been found that by changing the frequency of the drive signals for a change in brightness, instead of keeping the frequency constant and changing the length of the pulses of the drive signals for changing the brightness, as this is done in PWM, the individual pulses of the drive signals can be made longer than in the conventional PWM.
  • a conventional microcontroller and especially a low-cost microcontroller can be used for generating a drive signal for a lamp device, such as an LED or an LED spot.
  • An advantage of the present invention is, therefore, that by changing the frequency to adjust the brightness of a light device, instead of changing the length of pulses and keeping the frequency constant, cheaper and easier devices for generating a drive signal for a lamp device or an LED or an LED spot can be used as this is known in the prior art.
  • Some embodiments of the present invention provide an apparatus for generating a drive signal for a lamp device.
  • the apparatus comprises a pulse generator for generating a first pulse train in response to a first brightness request for a first brightness and for generating a second pulse train in response to a second brightness request for a second brightness.
  • the first pulse train has a first frequency and the second pulse train has a second frequency, wherein the first frequency is different from the second frequency.
  • the second pulse train comprises two neighboring pulses of the first pulse train and a further pulse between the two neighboring pulses, the further pulse not being comprised in the first pulse train.
  • the pulse generator is configured to provide a pulse train such that a time between two rising edges of pulses of the pulse train is different for different subsequent following pulses of the pulse train.
  • the pulse generator may be configured to generate the first and the second pulse trains such that a pulse length of the two neighboring pulses and of the further pulse is identical.
  • the pulse generator may be configured to change a brightness of the lamp device by adding or removing pulses of an equidistant length.
  • the frequency of the drive signal is constant and a change of brightness is attained by changing the on/off ratio of the pulses.
  • different drive signals for different degrees of brightness differ only by the on/off ratio of the pulses (and therefore by the length of the pulses) and not by the frequency of the drive signal itself.
  • the second brightness may be brighter than the first brightness, for example, if a pulse is a current pulse provided to the lamp device.
  • the apparatus may further comprise a brightness request generator, which is configured to provide at least a first and a second brightness request to an input terminal of the pulse generator.
  • the pulse generator may, for example, receive the first and the second brightness request at the input terminal and may output a drive signal with a corresponding pulse train, for example, depending on an internal look-up table.
  • a pulse length may in the following also be called as a pulse time or as a temporal extension of the pulse.
  • Fig. 1a shows a block diagram of an apparatus 100 according to an embodiment of the present invention coupled to a lamp device 110.
  • the apparatus 100 for generating a drive signal 120 for the lamp device 110 comprises a pulse generator 130.
  • the pulse generator 130 is configured to generate a first pulse train 140 (shown in Fig. 1b ) and to generate a second pulse train 160 (shown in Fig. 1b ).
  • the first pulse train 140 and the second pulse train 160 may be provided at an output terminal 180 of the apparatus 100 and may as a continuous stream create the drive signal 120, wherein a drive signal 120 based on the first pulse train 140 would result in another brightness of the lamp device 110 than a drive signal 120 based on the second pulse train 160.
  • the pulse generator 130 is configured to generate the first pulse train 140 in response to a first brightness request for a first brightness and to generate the second pulse train 160 in response to a second brightness request for a second brightness.
  • the first pulse train 140 has a frequency f 140 , which is different to a frequency f 160 of the second pulse train 160. Therefore, the first brightness may be different from the second brightness, for example, the first brightness may be higher than the second brightness.
  • Fig. 1b shows a schematic diagram 150 of the first pulse train 140 and a schematic diagram 170 of the second pulse train 160
  • the first pulse train 140 comprises at least a first pulse 142a and a second pulse 142b.
  • the first pulse 142a and the second pulse 142b are neighboring pulses, which means the second pulse 142b follows the first pulse 142a in time and no other pulse is arranged between these two neighboring pulses 142a, 142b. Therefore, the period of the pulse train 140 may be a time t 140 between the first pulse 142a and the second pulse 142b.
  • the second pulse train 160 comprises the two neighboring pulses 142a, 142b of the first pulse train 140 and a further pulse 162a between the two neighboring pulses 142a and 142b.
  • the further pulse 162a is not comprised nor contained in the first pulse train 140. Because of the temporal arrangement of the further pulse 162a between the two neighboring pulses 142a, 142b a second time t 160 between two temporally-subsequent pulses of the second pulse train 160 is shorter than the first time t 140 (between the two neighboring pulses 142a, 142b) of the first pulse train 140.
  • a first time t 160 between a rising edge of the first neighboring pulse 142a and a rising edge of the temporally-following further pulse 162a is shorter than the first time t 140 between the rising edge of the first neighboring pulse 142a and the rising edge of the second neighboring pulse 142b of the first pulse train 140. Therefore, a frequency f 160 of the second pulse train 160 is higher than a frequency f 140 of the first pulse train 140.
  • the further pulse 162a is temporally arranged between the two neighboring pulses 142a, 142b such that a time between the rising edge of the first neighboring pulse 142a and the rising edge of the further pulse 162a is the same, like a time between the rising edge of the further pulse 162a and a rising edge of the second neighboring pulse 142b.
  • the further pulse 162a could also be arranged in a temporally-arbitrary position between the two neighboring pulses 142a, 142b.
  • the frequency f 160 of the second pulse train 160 is double the amount of the frequency f 140 of the first pulse train 140.
  • a brightness of the lamp device 110 may be higher when the second pulse train 160 is provided as the drive signal 120 to the lamp device 110 than when the first pulse train 140 is provided as a drive signal 120 to the lamp device 110.
  • An amplitude I pulse of the pulses of the first pulse train 140 and the second pulse train 160 may, for example, represent a current flowing through the lamp device 110.
  • the lamp device 110 is switched on more often at the same time (for example, the time t 140 ) than when the first pulse train 140 is applied as a drive signal 120. This leads to a longer on-time of the lamp device 110 per time unit and, therefore, to a brighter light impression for a human eye.
  • the time unit in which the lamp device 110 is switched on and off is chosen such that the human eye is not able to see the on/off switching of the lamp device 110.
  • a pulse length t pulse or of the two neighboring pulses 142a, 142b and the further pulse 162a may be identical.
  • the first time t 140 and the second time t 160 may be a multiple of the pulse length t pulse .
  • a temporal extension of the first pulse train 140 and a temporal extension of the second pulse train 160 may be identical, as is shown in Fig. 1b .
  • the temporal extension of the first pulse train 140 is the first time t 140 and a temporal extension of the second pulse train 160 is twice the second time t 160 , wherein the second time t 160 is half of the first time t 140 .
  • the drive signal 120 may comprise a plurality of first pulse trains 140 or second pulse trains 160.
  • the drive signal 120 would, for example, be a continuous stream of pulse trains 140 and for the second brightness, the drive signal 120 would be a continuous stream of the pulse trains 160.
  • a time between two rising edges of two temporally subsequent pulses would be the first time t 140 .
  • a time between two rising edges of two temporally subsequent pulses would be the second time t 160 .
  • a time between two rising edges of subsequent following pulses of a pulse train may vary within in the pulse train, therefore a time between two rising edges of pulses of the pulse train may be different for different subsequent following pulses of the pulse train.
  • the pulse generator 130 may be further configured to generate a plurality of pulse trains in response to a plurality of different brightness requests, such that a pulse train out of the plurality of pulse trains corresponds to a brightness request out of the plurality of brightness requests.
  • Different pulse trains may differ from each other by the number of pulses they comprise.
  • a temporal extension of the different pulse trains may be identical for all pulse trains.
  • the pulse train generator 130 may comprise a microcontroller, which is configured to provide the drive signal 120 or a plurality of drive signals 120 at an output terminal or at a plurality of output terminals.
  • An output terminal of the microcontroller may, for example, be an I/O pin of the microcontroller.
  • the I/O pin of the microcontroller may be coupled to the lamp device 110, by directly connecting the lamp device 110 to the I/O pin, or with a lamp device driver, which provides a drive current for the lamp device 110, between the I/O pin and the lamp device 110.
  • the lamp device 110 may comprise an LED or a plurality of LEDs or any other lightning devices.
  • a lamp device 110 comprising a plurality of lightning devices or LEDs may therefore comprise a plurality of input terminals for the plurality of drive signals 120, such that degrees of brightness of the different LEDs or lightning devices of the lamp device 110 can differ from each other.
  • the different LEDs or lightning devices of the lamp device 110 may comprise different colors, for example, an LED or a lightning device for red, an LED or a lightning device for green and an LED or a lightning device for blue.
  • the lamp device 110 may be an RGB lamp device.
  • Fig. 2 shows the schematic diagram 150 of the first pulse train 140 from Fig. 1 and a schematic diagram 210 of a corresponding PWM signal 220. Furthermore, Fig. 2 shows the schematic diagram 170 of the second pulse train 160 from Fig. 1b and a schematic diagram 230 of a corresponding PWM signal 240.
  • the first PWM signal 220 corresponds to the first pulse train 140, because a sum of pulse durations of pulses of the first PWM signal 220 in a given time interval (for example, the time interval t 140 ) is equal to the sum of pulse durations of pulses of the first pulse train 140 in the given time interval.
  • the second PWM signal 240 corresponds to the second pulse train 160, because the sum of pulse durations of pulses of the second PWM signal 240 in the given time interval is equal to a sum of pulse durations of pulses of the second pulses train 160 in the given time interval.
  • a first number of charge carriers flowing into the lamp device 110 in the time interval t 140 is the same when the drive signal 120 is based on the first pulse train 240 or on the second PWM signal 220 and a second number of charge carriers flowing into the lamp device 110 is the same when the drive signal 120 is based on the second pulse train 160 or on the second PWM signal 240. Therefore, the first brightness corresponding to the first pulse train 140 also corresponds to the first PWM signal 220 and the second brightness corresponding to the second pulse train 160 also corresponds to the second PWM signal 240.
  • the first PWM signal 210 comprises four pulses 222a, 222b, 222c, 222d in the time interval t 140 between the two neighboring pulses 142a and 142b of the first pulse train 140.
  • a time interval t PWM between two rising edges of neighboring pulses of the second PWM signal 220 is a quarter of t 140 (t 140 /4).
  • a frequency f PWM of the first PWM signal 220 is, therefore, four times higher than the frequency f 140 of the first pulse train 140.
  • a drawback of the conventional PWM is that the frequency for a conventional PWM drive signal stays constant for every brightness request.
  • a minimum pulse duration of a PWM signal has to be much shorter than in embodiments of the present invention, wherein drive signals 120 for different brightness requests differ by frequency.
  • a pulse length of the pulses 222a to 222d of the first PWM signal 220 is one-fourth of the pulse length t pulse of the pulses 142a, 142b of the first pulse train 140. Therefore, a pulse generator generating the second PWM signal 220 has to be at least four times faster than a pulse generator 130 for generating the first pulse train 140.
  • a low frequency of the first pulse train 140 compared to the second PWM signal 220 is not a problem, because TV cameras only react in a sensitive manner to low frequencies of the pulsing of the lamp device 110 with higher brightness (for example, half of the maximum brightness of the lamp device 110).
  • a brightness of the lamp device 110 is increased by raising the frequency of the drive signal 120, for example, a frequency of the drive signal 120 may be the highest when the TV camera is most sensitive to a pulsing of the lamp device 110.
  • the frequency of the drive signal 120 in a most sensitive region of a TV camera may be the same or even higher than a frequency of a corresponding PWM signal.
  • a brightness of the lamp device 110 is raised by raising the frequency of the drive signal 120. Therefore, the frequency f 160 of the second pulse train 160 is higher than the frequency f 140 of the first pulse train 140 and, therefore, the frequency of the drive signal 120 is higher when the drive signal 120 is based on the second pulse train 160 than on the first pulse train 140.
  • the second PWM signal 240 which corresponds to the second pulse train 160, has the same frequency f PWM as the first PWM signal 220.
  • a drawback of these conventional PWM signals is that, therefore, pulse lengths of the pulses of the conventional PWM signal have to be kept much shorter than in embodiments of the present invention, wherein different degrees of brightness correspond to different frequencies of the drive signal 120.
  • hatched lines in the pulses mark the changes from the first pulse train 140 to the second pulse train 160 and from the first PWM signal 220 to the second PWM signal 240.
  • the further pulse 162a between the two neighboring pulses 142a, 142b in the second pulse train 160 more charge carriers flow into the lamp device 110 when the drive signal 120 is based on the second pulse train 160 than on the first pulse train 140.
  • the length of the pulses of the PWM signal would be extended to obtain more charge carriers flowing into the lamp device. This is shown in Fig.
  • a pulse length of the pulses 242a to 242d is half the pulse length t pulse of the pulses 142a, 162a, 142b of the second pulse train 160.
  • the pulse length t pulse of the pulses of the second pulse train 160 is identical with the pulse length t pulse of the pulses of the first pulse train 140. Due to the shorter duration of the pulses of the second PWM signal 240, a pulse generator for the second PWM signal 240, for example, a microcontroller would still have to be at least double as fast as the pulse generator 130 for generating the second pulse train 160.
  • a further pulse may be added between the two neighboring pulses 142a, 142b, wherein with each increase of brightness of the lamp device 110, the frequency of the drive signal 120 would be increased, too. Therefore, a drive signal 120 generated by the pulse generator 130 may have the same or even a higher frequency than a corresponding PWM signal for the same brightness of the lamp device 110.
  • the pulse generator 130 may be configured such that a frequency of the drive signal 120 is the highest, when a sensitivity of a TV camera used in conjunction with a lamp device 110 is the highest in regards of a pulsing of the lamp device 110.
  • the pulse generator 130 may be a conventional microcontroller with a comparatively low instruction cycle time compared to a pulse generator needed for generating a drive signal based on a conventional PWM signal and fulfilling the requirements of a TV camera used in conjunction with the lamp device 110.
  • the pulse generator 130 for generating the first pulse train 140 and the second pulse train 160 may be four times slower than a pulse generator for generating the first PWM signal 220 and the second PWM signal 240.
  • the pulse generator 130 may be significantly cheaper and/or may be used to control a plurality of lamp devices 110 compared to the conventional pulse generator for generating the first PWM signal 220 and the second PWM signal 240.
  • Fig. 3a shows a schematic block diagram of an apparatus 300 for generating a drive signal 320 for a lamp device 110.
  • the apparatus 300 comprises a pulse generator 330 for generating a first pulse train 340 in response to a first brightness request for a first brightness and for generating a second pulse train 360 in response to a second brightness request for a second brightness.
  • the first pulse train 340 (shown in Fig. 3b ) has at least three individual pulses.
  • the second pulse train 360 (shown in Fig. 3b ) has at least three individual pulses, wherein less than all of the said at least three individual pulses have the same length. At least one of the at least three individual pulses of the second pulse train 360 has a different length compared to the corresponding individual pulse in the first pulse train 340.
  • the pulse generator may, for example, be a microcontroller (for example, directly connected or with a lamp driver in-between) coupled to the lamp device 110.
  • the drive signal 320 may be based on a continuous stream of first pulse trains 340 or on a continuous stream of second pulse trains 360, dependent on a brightness request.
  • a drive signal 320, which is based on the first pulse train 340 may lead to a different brightness of the lamp device 110 than a drive signal 320 based on the second pulse train 360.
  • a brightness of the lamp device 110 may be higher or larger when a drive signal 320 based on the second pulse train 360 is applied to the lamp device 110 than when a drive signal 320 based on the first pulse train 340 is applied to the lamp device 110. Therefore, the second brightness may be higher than the first brightness.
  • Fig. 3b shows a schematic diagram 350 of the first pulse train 340 and a schematic diagram 370 of the second pulse train 360.
  • the first pulse train 340 comprises a first pulse 342a, a second pulse 342b and a third pulse 342c.
  • a temporal extension t 342a of the first pulse train 342a is twice the temporal extension t pulse of the pulse 342b and the pulse 342c.
  • the three individual pulses 342a, 342b, 342c are individual, because the first pulse train 340 not comprises any pulses between two neighboring pulses of the three individual pulses 342a, 342b, 342c.
  • an amplitude of the three individual pulses 342, 342b, 342c is a current flowing into the lamp device 110 between the three individual pulses 342a, 342b, 342c, i.e. between a falling edge of one of the three individual pulses 342a, 342b, 342c and a rising edge of a temporally-following pulse of the three individual pulses 342a, 342b, 342c, no current flows into the lamp device 110.
  • the second pulse train 360 comprises three individual pulses 342a, 342b, 362c (from the first pulse train 340).
  • a temporal extension t 362c or a pulse length of the third pulse 362c of the three individual pulses 342a, 342b, 362a of the second pulse train 360 differs from the pulse length t pulse of its corresponding pulse 342c of the first pulse train 340.
  • the pulse length of the other two individual pulses 342a, 342b of the second pulse train 360 is identical to the pulse length of the corresponding individual pulses in the first pulse train 340.
  • the pulse length t 362c of the third pulse 362c of the second pulse train 360 is one pulse length interval t pulse longer than the pulse length t puke of the third pulse 342c of the first pulse train 340.
  • the time t pulse may be the smallest possible pulse length, wherein pulse lengths of all pulses of pulse trains generated by the pulse generator 330 may be at least the smallest pulse length t pulse or a multiple of the smallest pulse length t pulse .
  • the pulse length of a pulse of a pulse train may differ to a pulse length of another pulse of the same pulse train at maximum by the smallest pulse length t pulse .
  • the time between two rising edges of pulses of a pulse train may be a multiple of the smallest pulse length t pulse .
  • an increase in the brightness of the lamp device 110 can be obtained with a pulse generator 330 by extending a pulse length of a pulse of a pulse train generated by the pulse generator 330.
  • a frequency of different pulse trains corresponding to different degrees of brightness of the lamp device 110 may be the same for all pulse trains.
  • Fig. 4 shows the schematic diagram 350 of the first pulse train 340 from Fig. 3b and a schematic diagram 410 of a corresponding first PWM signal 420. Furthermore, Fig. 4b shows the schematic diagram 370 of the second pulse train 160 from Fig. 3b and a schematic diagram 430 of a corresponding second PWM signal 440.
  • the first PWM signal 420 corresponds to the first pulse train 340, because a sum of the length of all pulses of the first pulse train 340 is the same as the sum of the length of all pulses of the first PWM signal 420.
  • a drive signal 120 based on the first pulse train 340 would generate the same brightness at the lamp device 110 as a drive signal based on the first PWM signal 420.
  • the first PWM signal 420 comprises three identical individual pulses 422a, 422b, 422c.
  • a length or temporal extension of each pulse is t 422 , which is a third of the pulse length t pulse (t pulse /3).
  • t 422 is a third of the pulse length t pulse (t pulse /3).
  • a time t PWM between two following pulses of the first PWM signal 420 is the same, as the time t 340 between two following pulses of the first pulse train 340. Therefore, the first PWM signal 420 differs from the first pulse train 340 in the fact that all pulses 422a, 422b, 422c of the first PWM signal 420 have the same length.
  • the second PWM signal 440 corresponds to the second pulse train 360, because a brightness of the lamp device 110 generated by a drive signal 320 based on the second pulse train 360 is the same as the brightness generated by a drive signal based on the second PWM signal 440.
  • the second pulse train 360 differs from the first pulse train 340 by the pulse 362c, which length differs from its corresponding pulse 342c in the first pulse train 340.
  • the pulse 362c is compared to the pulse 342c extended by one pulse length t pulse .
  • the second PWM signal 440 differs from the first PWM signal 420 in the fact that all pulses 442a, 442b, 442c are longer than their corresponding pulses 422a, 422b, 422c of the first PWM signal 420.
  • An advantage of the pulse generator 330 for generating the first pulse train 340 and the second pulse train 360 compared to a conventional pulse generator for generating the first PWM signal 420 and the second PWM signal 440 is, that for a change of brightness, only a length of one pulse of a pulse train has to be changed by a certain time interval (for example, by the pulse length t pulse ) instead of changing the time of all pulses of the pulse train by a much smaller pulse length (t pulse/3 ).
  • a pulse generator 330 according to an embodiment of the present invention may, therefore, comprise a conventional microcontroller with a significantly lower instruction cycle time than a pulse generator for generating the conventional PWM signal. This leads to a significant cost reduction of the apparatus 300 compared to conventional apparatuses driving a lamp device with a conventional PWM signal.
  • the amplitude of the pulses of the pulse trains 140, 160 generated by the pulse generator 130 according to Fig. 1a are identical for the two pulse trains 140, 160
  • the amplitude of the pulses of the first pulse train 140 may be different from the amplitude of the pulses of the second pulse train 160. Therefore, the second pulse train 160 may differ from the first pulse train 140 generated by the first pulse generator 130 not only by the frequency of the pulse trains, but also by an amplitude of the pulses of the pulse trains.
  • the amplitude of the pulses of the first pulse train 140 may be lower than the amplitude of the pulses of the second pulse train 160.
  • this may also apply to the first pulse train 340 and the second pulse train 360 generated by the pulse generator 330 according to Fig. 3a .
  • the first pulse train 340 generated by the pulse generator 330 may, therefore, differ from the second pulse train 360 generated by the pulse generator 330 not only by a length of pulses of the pulse trains, but also by an amplitude of the pulses of the pulse trains.
  • an amplitude of the pulses of the first pulse train 340 generated by the pulse generator 330 may be lower than an amplitude of the pulses of the second pulse train 360 generated by the pulse generator 330.
  • Fig. 5 shows an apparatus 500 according to an embodiment of the present invention coupled to a lamp device 110.
  • the apparatus 500 may be the apparatus 100 according to Fig. 1a or the apparatus 300 according to Fig. 3a further comprising a brightness request generator 590 configured to provide at least the first brightness request and the second brightness request to an input terminal of a pulse generator 530 of the apparatus 500.
  • the pulse generator 530 may, for example, be the pulse generator 130 or the pulse generator 330.
  • the brightness request generator 590 may, for example, comprise a microcontroller or a control unit.
  • Fig. 6a shows schematic diagrams of pulse trains, for example, generated by the pulse generator 130 according to Fig. 1 as drive signals 120 for a lamp device 110.
  • Fig. 6a shows different pulse trains for different degrees of brightness of the lamp device 110 (plus one diagram with the value 0 for an off-state of the lamp device 110).
  • the value on the left side of the schematic diagrams designates the brightness which the corresponding pulse train generates at the lamp device 110, wherein a higher number corresponds to a higher brightness of the lamp device 110, and the value 16 corresponds to a maximum brightness of the lamp device 110.
  • the frequency factor on the right side of the schematic diagrams designates the frequency of the corresponding pulse train, wherein a higher number designates a higher frequency of the pulse train.
  • a pulse train shown in the second schematic diagram with a value 1 may, for example, be the first pulse train 140 and a pulse train shown in the second schematic diagram with a value 2 may, for example, be the second pulse train 160.
  • the different pulse trains only differ from each other by the number of pulses they contain, wherein for each increase in brightness, one pulse is added, which is marked with hatched lines. Therefore, with every brightness increase, a frequency of the pulse train and of the drive signal 120 is increased until a maximum frequency is achieved.
  • a maximum frequency is achieved at half of the brightness of the lamp device 110 (in the schematic diagram with the value 8), which is the brightness where TV cameras are most sensitive to the pulsing of the lamp device 110.
  • a pulse length of the pulses of the pulse trains is the same for every pulse.
  • An amplitude of the pulses in the schematic diagrams corresponds to a current, which flows through the lamp device 110 or an LED 110.
  • a frequency factor is reduced by the factor 8 which means a PWM signal corresponding to the first pulse train 140 would have 8 pulses in the one period shown in Fig. 6a , wherein a pulse length of the pulses would be one-eighth of t pulse . It has been shown that a frequency factor of 16 is a good compromise.
  • the concept shown is based on the fact that not one pulse with a variable length is used, like in the conventional PWM concept, but pulses are added based on the brightness.
  • a maximum frequency is not limited. The frequency is always dependent from the brightness, vice-versa, the brightness is always dependent on the frequency of a pulse train or the drive signal 120. A maximum frequency is achieved at half the brightness of the lamp device 110.
  • a frequency of the drive signal 120 may, at the half of the maximum brightness of the lamp device 110, be the same as the frequency of a corresponding conventional PWM signal.
  • a pulse generator 130 By choosing the frequency and by having longer pulse lengths than conventional PWM signals, a pulse generator 130 and, therefore, an apparatus 100 can be less sophisticated than a pulse generator needed for generating a conventional PWM signal for driving the lamp device 110 fulfilling the same requirements, like the pulse generator 130.
  • Fig. 6b shows the schematic diagrams of Fig. 6a , but wherein the different pulse trains for the different degrees of brightness not only differ by the number of pulses they contain, but also by the amplitude of the pulses thereof.
  • an amplitude of the pulses for example, a current flowing into the lamp device 110
  • the amplitude (the current amplitude) of all pulses may be increased linearly from 0% to 100% (for example, with every increase infrequency).
  • an amplitude of the pulses of the first pulse train may be one-sixteenth of the amplitude of the pulses of the 16 th pulse train (value 16).
  • This concept has the advantage that very small degrees of brightness can be adjusted soft and stepless (or at least nearly stepless or continuous).
  • drive signals based on the pulse trains with low frequencies have the lowest amplitudes and, therefore, very low degrees of brightness.
  • An amplitude of the pulses may be adjusted by a digital to analog converter of the pulse generator 130, wherein the pulse generator 130 may, for example, be a conventional microcontroller.
  • Fig. 6c shows schematic diagrams of drive signals with different pulse trains for different degrees of brightness for a lamp device 110.
  • the pulse trains shown in Fig. 6c differ from the pulse train shown in Fig. 6a in the fact that a maximum frequency of the pulse trains is limited (in the concrete embodiment shown in Fig. 6c to a frequency factor of 4) and when a maximum frequency of the pulse trains is reached, no further individual pulses are added, but a length of the pulses of the pulse trains is changed to further increase the brightness of the lamp device 110.
  • the pulse generator generating the pulse trains shown in Fig. 6c may, therefore, be a combination out of the pulse generator 130 according to Fig. 1a and the pulse generator 330 according to Fig. 3a .
  • Fig. 1a the pulse generator 330 according to Fig. 3a
  • the first four pulse trains (value 1 to value 4) differ by the number of pulses they contain. Beginning from the fifth pulse train, the pulse trains differ by the length of the pulses they contain. A length of the pulses is not extended continually. This means that the pulses are always extended by a pulse length t pulse of the pulse of the first pulse train with a value 1.
  • the first pulse train with the value 1 may, for example, be the first pulse train 140 according to Fig. 1b .
  • the second pulse train with the value 2 may, for example, be the second pulse train 160 according to Fig. 1b .
  • the fourth pulse train (value 4) may, for example, be the first pulse train 340 according to Fig. 3b .
  • the fifth pulse train (value 5) may, for example, be the second pulse train 360 according to Fig. 3b .
  • Fig. 6c reduces the frequency of the drive signal by a factor 2...256 compared to conventional PWM signals. For simplicity reasons, in Fig. 6c , a reduction of the frequency factor 4 is shown. As mentioned before, it has been shown that a frequency factor of 16 is a good compromise. The concept is based on this, that not one pulse with a variable length (PWM) is used, but instead several pulses are added, based on a required brightness. These pulses are added based on a binary method. As soon as, for example, sixteen pulses for a factor of 16 or four pulses for a factor of 4 are contained in a pulse train, for a further increase of the brightness, the length of the pulses are increased based on the same binary method.
  • PWM variable length
  • the frequency is raised, for example, until sixteen pulses or, in the concrete embodiment shown in Fig. 2c, four pulses for a period are provided. After this (beginning with the fifth pulse train with a value of 5), for a further brightness increase, the frequency is, furthermore, not raised. Instead, the pulse lengths from pulse-to-pulse are extended (which means the pulse lengths of the pulses contained in the pulse trains are extended). The pulse lengths of the pulses may not be continuously extended, but in steps of the length (t pulse ) of the first pulse of the first pulse train.
  • a first pulse of the first pulse train has a pulse length of 1ms
  • the first pulse is extended to 2ms (its pulse length is increased to 2ms). If then all sixteen pulses (in the concrete embodiment shown in Fig. 6c , after all four pulses) are extended to 2ms, then the first pulse is extended to 3ms and ongoing, until the drive signal is a continuous high signal (value 16 in Fig. 6c ).
  • Fig. 6d shows a schematic diagram from Fig. 6c with the difference that with a brightness increase, not only the frequency of the drive signal is raised or the length of the pulses is extended, but also an amplitude of the pulses of the pulse trains is changed. This is analog to Fig. 6b and offers the same advantages, as already described in Fig. 6d .
  • a conventional PWM signal has a constant frequency, wherein a pulse-pause ratio is changed (for example, continuously changed). Furthermore, an amplitude of the pulses of the PWM signal is constant.
  • a length of the pulses in a base period of the drive signal may be different at arbitrary places within the base period. Additionally, an amplitude of the pulses may be varied.
  • Fig. 7 shows a flow diagram of a method 700 for generating a drive signal for a lamp device.
  • the method 700 comprises a step 710 of generating a first pulse train in response to a first brightness request for a first brightness.
  • the first pulse train has a first frequency.
  • the method 700 comprises a step 720 of generating a second pulse train in response to a second brightness request for a second brightness.
  • the second pulse train has a second frequency, wherein the first frequency of the first pulse train is different from the second frequency of the second pulse train.
  • the second pulse train further comprises two neighboring pulses of the first pulse train and comprises a further pulse between the two neighboring pulses. The further pulse of the second pulse train is not comprised in the first pulse train.
  • the method 700 may comprise a step of receiving a first brightness request before the step 710 of generating the first pulse train. Furthermore, the method 700 may comprise a step of receiving the second brightness request before the step 720 of generating the second pulse train.
  • Fig. 8 shows a flow diagram of a method 800 for generating a drive signal for a lamp device.
  • the method 800 comprises a step 810 of generating a first pulse train in response to a first brightness request for a first brightness.
  • the first pulse train comprises at least three individual pulses.
  • the method 800 comprises a step 820 of generating a second pulse train for a second brightness.
  • the second pulse train comprises at least the three individual pulses of the first pulse train. Less than all of the at least three individual pulses of the second pulse train have the same length as in the first pulse train and at least one of the at least three individual pulses of the second pulse train has a different length compared to its corresponding individual pulse in the first pulse train.
  • the method 800 may comprise a step of receiving the first brightness request before the step 810 of generating the first pulse train. Furthermore, the method 800 may comprise a step of receiving the second brightness request before the step 820 of generating the second pulse train.
  • the methods 700 and 800 may be supplemented by any features or functions of the apparatus as described before.
  • the concept described herein of providing a drive signal for a lamp device has several advantageous features compared to conventional PWM concepts.
  • aspects have been described in the context of an apparatus, it is clear that these aspects also represent a description of the corresponding method, where a block or device corresponds to a method step or a feature of a method step. Analogously, aspects described in the context of a method step also represent a description of a corresponding block or item or feature of a corresponding apparatus.
  • embodiments of the invention can be implemented in hardware or in software.
  • the implementation can be performed using a digital storage medium, for example a floppy disk, a DVD, a Blue-Ray, a CD, a ROM, a PROM, an EPROM, an EEPROM or a FLASH memory, having electronically readable control signals stored thereon, which cooperate (or are capable of cooperating) with a programmable computer system such that the respective method is performed. Therefore, the digital storage medium may be computer readable.
  • Some embodiments according to the invention comprise a data carrier having electronically readable control signals, which are capable of cooperating with a programmable computer system, such that one of the methods described herein is performed.
  • embodiments of the present invention can be implemented as a computer program product with a program code, the program code being operative for performing one of the methods when the computer program product runs on a computer.
  • the program code may for example be stored on a machine readable carrier.
  • inventions comprise the computer program for performing one of the methods described herein, stored on a machine readable carrier.
  • an embodiment of the inventive method is, therefore, a computer program having a program code for performing one of the methods described herein, when the computer program runs on a computer.
  • a further embodiment of the inventive methods is, therefore, a data carrier (or a digital storage medium, or a computer-readable medium) comprising, recorded thereon, the computer program for performing one of the methods described herein.
  • a further embodiment of the inventive method is, therefore, a data stream or a sequence of signals representing the computer program for performing one of the methods described herein.
  • the data stream or the sequence of signals may for example be configured to be transferred via a data communication connection, for example via the Internet.
  • a further embodiment comprises a processing means, for example a computer, or a programmable logic device, configured to or adapted to perform one of the methods described herein.
  • a processing means for example a computer, or a programmable logic device, configured to or adapted to perform one of the methods described herein.
  • a further embodiment comprises a computer having installed thereon the computer program for performing one of the methods described herein.
  • a programmable logic device for example a field programmable gate array
  • a field programmable gate array may cooperate with a microprocessor in order to perform one of the methods described herein.
  • the methods are preferably performed by any hardware apparatus.

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  • Circuit Arrangement For Electric Light Sources In General (AREA)
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Claims (16)

  1. Appareil (100) pour générer un signal de commande (120) pour un dispositif de lampe LED (110), l'appareil (100) comprenant :
    un générateur d'impulsions (130) présentant une borne d'entrée ; et
    un générateur de demande de luminosité (590) configuré pour fournir une première demande de luminosité pour une première luminosité du dispositif de lampe LED (110), une deuxième demande de luminosité pour une deuxième luminosité du dispositif de lampe LED (110) et une troisième demande de luminosité pour une troisième luminosité du dispositif de lampe LED (110) à la borne d'entrée du générateur d'impulsions (130), où la deuxième luminosité est supérieure à la première luminosité, et où la troisième luminosité est supérieure à la deuxième luminosité;
    dans lequel le générateur d'impulsions (130) est configuré pour générer un premier train d'impulsions (140) comme signal de commande (120) en réponse à la première demande de luminosité pour la première luminosité, ledit premier train d'impulsions (140) ayant une première fréquence, pour générer un deuxième train d'impulsions (160) comme signal de commande (120) en réponse à la deuxième demande de luminosité pour la deuxième luminosité, ledit deuxième train d'impulsions (160) ayant une deuxième fréquence, où la première fréquence est différente de la deuxième fréquence, où le deuxième train d'impulsions (160) comprend deux impulsions voisines (142a, 142b) du premier train d'impulsions (140) et comprend une autre impulsion (162a) entre les deux impulsions voisines (142a, 142b), ladite autre impulsion (162a) n'étant pas comprise dans le premier train d'impulsions (140), où la deuxième fréquence est supérieure à la première fréquence,
    caractérisé par le fait que
    le générateur d'impulsions (130) est configuré pour générer le deuxième train d'impulsions (160) de sorte qu'un premier temps entre un flanc descendant d'une première impulsion (142a) des deux impulsions voisines (142a, 142b) et un flanc ascendant de l'autre impulsion (162a) soit identique à un deuxième temps entre un flanc descendant de l'autre impulsion (162a) et un flanc ascendant d'une deuxième impulsion (142b) des deux impulsions voisines (142a, 142b), et
    le générateur d'impulsions (130) est configuré pour fournir un troisième train d'impulsions avec une troisième fréquence comme signal de commande (120) en additionnant une autre impulsion au deuxième train d'impulsions en réponse à la troisième demande de luminosité pour la troisième luminosité, de sorte qu'un temps entre les flancs ascendants de deux impulsions successives du troisième train d'impulsions soit différent d'un temps entre les flancs ascendants de deux impulsions successives différentes du troisième train d'impulsions, où la troisième fréquence est supérieure à la deuxième fréquence.
  2. Appareil (100) selon la revendication 1, dans lequel le générateur d'impulsions (130) est configuré pour générer le premier train d'impulsions (140) et le deuxième train d'impulsions (160) de sorte qu'une longueur d'impulsion (tpulse) des deux impulsions voisines (142a, 142b) et de l'autre impulsion (162a) soit identique.
  3. Appareil (100) selon la revendication 1, dans lequel le générateur d'impulsions (130) est configuré pour générer le premier train d'impulsions (140) et le deuxième train d'impulsions (160) de sorte qu'une extension dans le temps du premier train d'impulsions (140) et une extension dans le temps du deuxième train d'impulsions (160) soient identiques.
  4. Appareil (100) selon la revendication 1, dans lequel le générateur d'impulsions (130) est configuré pour générer le deuxième train d'impulsions (160) de sorte qu'un temps entre un flanc descendant d'une première impulsion (142a) des deux impulsions voisines (142a, 142b) et un flanc ascendant de l'autre impulsion (162a) soit identique à une longueur d'impulsion de l'une des impulsions voisines (142a, 142b) ou de l'autre impulsion (162a), ou soit un multiple d'une longueur d'impulsion de l'une des impulsions voisines (142a, 142b) ou de l'autre impulsion (162a).
  5. Appareil (100) selon la revendication 1, dans lequel le générateur d'impulsions (130) est configuré pour générer le premier train d'impulsions (140) et le deuxième train d'impulsions (160) de sorte qu'une première amplitude des impulsions du premier train d'impulsions (140) soit identique, de sorte qu'une deuxième amplitude des impulsions du deuxième train d'impulsions (160) soit identique et de sorte que la première amplitude soit inférieure à la deuxième amplitude.
  6. Appareil (100) selon la revendication 1, dans lequel le générateur d'impulsions (130) est configuré pour générer une pluralité de trains d'impulsions différents en réponse à une pluralité de demandes de luminosité différentes, de sorte qu'un train d'impulsions parmi la pluralité de trains d'impulsions corresponde à une demande de luminosité parmi la pluralité de demandes de luminosité et de sorte que la pluralité de trains d'impulsions diffèrent l'un de l'autre par le nombre d'impulsions qu'ils comprennent.
  7. Appareil (100) selon la revendication 6, dans lequel le générateur d'impulsions (130) est configuré pour générer la pluralité de trains d'impulsions différents de sorte que la pluralité de trains d'impulsions différents diffèrent l'un de l'autre par ailleurs par une amplitude des impulsions qu'ils comprennent.
  8. Appareil (300) pour générer un signal de commande (320) pour un dispositif de lampe LED (110), l'appareil (300) comprenant:
    un générateur d'impulsions (330) présentant une borne d'entrée;
    un générateur de demande de luminosité (590) configuré pour fournir une première demande de luminosité pour une première luminosité du dispositif de lampe LED (110) et une deuxième demande de luminosité pour une deuxième luminosité du dispositif de lampe LED (110) à la borne d'entrée du générateur d'impulsions (330),
    caractérisé par le fait que
    le générateur d'impulsions (330) est configuré pour générer un premier train d'impulsions (340) comme signal de commande (320) en réponse à la première demande de luminosité pour la première luminosité, ledit premier train d'impulsions (340) comprenant au moins trois impulsions individuelles (342a, 342b, 342c); et
    pour générer un deuxième train d'impulsions (360) comme signal de commande (320) en réponse à la deuxième demande de luminosité pour la deuxième luminosité, ledit deuxième train d'impulsions (360) comprenant les au moins trois impulsions individuelles (342a, 342b, 362c); où moins de tous les au moins trois impulsions individuelles (342a, 342b, 362c) du deuxième train d'impulsions (360) ont la même longueur que dans le premier train d'impulsions (340) et au moins une impulsion (362c) des au moins trois impulsions individuelles (342a, 342b, 362c) du deuxième train d'impulsions (360) a une longueur différente, comparé à l'impulsion individuelle (342c) dans le premier train d'impulsions (340).
  9. Appareil (300) selon la revendication 8, dans lequel le générateur d'impulsions (330) est configuré pour générer le premier train d'impulsions (340) et le deuxième train d'impulsions (360) de sorte que la longueur des au moins trois impulsions individuelles (342a, 342b, 342c) du premier train d'impulsions (340) soit un multiple de la longueur d'impulsion (tpulse) la plus petite ou soit la longueur d'impulsion (tpulse) la plus petite et de sorte que l'au moins une impulsion (362c) des au moins trois impulsions individuelles (342a, 342b, 362c) du deuxième train d'impulsions (360), ayant la longueur différente, comparé à son impulsion individuelle (342c) correspondante dans le premier train d'impulsions (340), diffère de son impulsion individuelle (342c) correspondante dans le premier train d'impulsions (340) d'un multiple de la longueur d'impulsion (tpulse) la plus petite ou de la longueur d'impulsion (tpulse) la plus petite.
  10. Appareil (300) selon la revendication 8, dans lequel le générateur d'impulsions (330) est configuré pour générer le premier train d'impulsions (340) et le deuxième train d'impulsions (360) de sorte qu'une longueur des trois impulsions individuelles soit identique ou de sorte qu'une première longueur de l'une des trois impulsions individuelles diffère de la longueur d'impulsion la plus petite à une deuxième longueur des autres deux impulsions des trois impulsions individuelles.
  11. Appareil (300) selon la revendication 8, dans lequel le générateur d'impulsions (330) est configuré pour générer le premier train d'impulsions (340) et le deuxième train d'impulsions (360) de sorte qu'une première amplitude des impulsions du premier train d'impulsions (340) soit identique, de sorte qu'une deuxième amplitude des impulsions du deuxième train d'impulsions (360) soit identique et de sorte que la première amplitude soit inférieure à la deuxième amplitude.
  12. Appareil (300) selon la revendication 8, dans lequel le générateur d'impulsions (330) est configuré pour générer une pluralité de trains d'impulsions différents en réponse à une pluralité de demandes de luminosité différentes, de sorte qu'un train d'impulsions parmi la pluralité de trains d'impulsions corresponde à une demande de luminosité parmi la pluralité de demandes de luminosité et de sorte que la pluralité de trains d'impulsions diffèrent l'un de l'autre d'une longueur d'au moins une impulsion qu'ils comprennent.
  13. Appareil (300) selon la revendication 12, dans lequel le générateur d'impulsions (330) est configuré pour générer la pluralité de trains d'impulsions différents de sorte que la pluralité de trains d'impulsions différents diffèrent l'un de l'autre par ailleurs par une amplitude des impulsions qu'ils comprennent.
  14. Procédé (700) pour générer un signal de commande (120) pour un dispositif de lampe LED (110), comprenant les étapes suivantes consistant à:
    fournir une première demande de luminosité pour une première luminosité du dispositif de lampe LED (110), une deuxième demande de luminosité pour une deuxième luminosité du dispositif de lampe LED (110) et une troisième demande de luminosité pour une troisième luminosité du dispositif de lampe LED (110) par un générateur de demande de luminosité, où la deuxième luminosité est supérieure à la première luminosité, et où la troisième luminosité est supérieure à la deuxième luminosité;
    générer (710) un premier train d'impulsions (140) comme signal de commande (120) en réponse à la première demande de luminosité pour la première luminosité, ledit premier train d'impulsions (140) ayant une première fréquence;
    générer (720) un deuxième train d'impulsions (160) comme signal de commande (120) en réponse à la deuxième demande de luminosité pour la deuxième luminosité, ledit deuxième train d'impulsions (160) ayant une deuxième fréquence, où la première fréquence est différente de la deuxième fréquence et où le deuxième train d'impulsions (160) comprend deux impulsions voisines (142a, 142b) du premier train d'impulsions (140) et comprend une autre impulsion (162a) entre les deux impulsions voisines (142a, 142b), ladite autre impulsion (162a) n'étant pas comprise dans le premier train d'impulsions (140), où la deuxième fréquence est supérieure à la première fréquence,
    caractérisé par le fait que
    le deuxième train d'impulsions est généré de sorte qu'un premier temps entre un flanc descendant d'une première impulsion (142a) des deux impulsions voisines (142a, 142b) et un flanc ascendant de l'autre impulsion (162a) soit identique à un deuxième temps entre un flanc descendant de l'autre impulsion (162a) et un flanc ascendant d'une deuxième impulsion (142b) des deux impulsions voisines (142a, 142b), et
    un troisième train d'impulsions avec une troisième fréquence comme signal de commande (120) est fourni en additionnant une autre impulsion au deuxième train d'impulsions en réponse à la troisième demande de luminosité, de sorte qu'un temps entre les flancs ascendants de deux impulsions successives du troisième train d'impulsions soit différent d'un temps entre les flancs ascendants de deux impulsions successives différentes du troisième train d'impulsions, où la troisième fréquence est supérieure à la deuxième fréquence.
  15. Procédé (800) pour générer un signal de commande (320) pour un dispositif de lampe LED (110), comprenant les étapes suivantes consistant à:
    fournir une première demande de luminosité pour une première luminosité du dispositif de lampe LED (110) et une deuxième demande de luminosité pour une deuxième luminosité du dispositif de lampe LED (110) par un générateur de demande de luminosité (590);
    caractérisé par le fait de
    générer (810) un premier train d'impulsions (340) comme signal de commande (320) en réponse à la première demande de luminosité pour la première luminosité, ledit premier train d'impulsions (340) comprenant au moins trois impulsions individuelles (342a, 342b, 342c); et
    générer (820) un deuxième train d'impulsions (360) comme signal de commande (320) en réponse à la deuxième à la deuxième demande de luminosité pour la deuxième luminosité, ledit deuxième train d'impulsions (360) comprenant les au moins trois impulsions individuelles (342a, 342b, 362c); où moins de toutes les au moins trois impulsions individuelles (342a, 342b, 362c) du deuxième train d'impulsions (360) ont la même longueur que dans le premier train d'impulsions (340) et où au moins une (362c) des au moins trois impulsions individuelles (342a, 342b, 342c) du deuxième train d'impulsions (360) a une longueur différente, comparé à son impulsion individuelle (342c) correspondante dans le premier train d'impulsions (340).
  16. Support de mémoire numérique lisible par ordinateur présentant, y mémorisé, un programme d'ordinateur ayant un code de programme pour réaliser, lorsqu'il est exécuté sur un ordinateur, le procédé selon la revendication 14 ou le procédé selon la revendication 15.
EP10159003A 2010-04-01 2010-04-01 Appareil pour générer un signal de commande pour un dispositif de lampe et procédé de génération d'un signal de commande pour un dispositif de lampe Active EP2373125B1 (fr)

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EP10159003A EP2373125B1 (fr) 2010-04-01 2010-04-01 Appareil pour générer un signal de commande pour un dispositif de lampe et procédé de génération d'un signal de commande pour un dispositif de lampe
PCT/EP2011/054446 WO2011120855A1 (fr) 2010-04-01 2011-03-23 Appareil destiné à produire un signal d'attaque pour un dispositif à lampe, ainsi que procédé de production d'un signal d'attaque pour un dispositif à lampe
CN2011800180969A CN102835188A (zh) 2010-04-01 2011-03-23 用于产生灯装置的驱动信号的设备和用于产生灯装置的驱动信号的方法
JP2012553356A JP2013519988A (ja) 2010-04-01 2011-03-23 照明装置の駆動信号を生成する装置及び方法

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US8299987B2 (en) 2005-11-10 2012-10-30 Lumastream Canada Ulc Modulation method and apparatus for dimming and/or colour mixing utilizing LEDs
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