LED Diode Luminaire and Interior Lighting System with High-Fidelity Control of Luminous Flux

Abstract

The LED luminaire comprises a digital interface (Pi / o) receiving a digital light control (CNL) and means for converting this control into a digital current control (CC). The luminaire has a light-producing channel (CN) controlled by the digital current control and comprising a series-connected diode array (GD), digital-to-analog conversion means (CFC, CDA, RN) receiving the digital current control and producing an analog current control (C_ID), and a DC current generator (GC) supplying the diode array with a DC supply current (ID) whose intensity is a function of the analog current control. According to the invention, the digital-to-analog conversion means produce the analog current control with a quantization step that increases as the digital current control increases. Figure 5

Description

Title of the invention: LED LUMINAIRE AND INTERIOR LIGHTING SYSTEM WITH HIGH-FIDELITY CONTROL OF LIGHT FLUID

[0001] The present invention relates generally to interior building lighting. More particularly, the invention relates to a light-emitting diode (LED) luminaire equipped with high-fidelity control means for the luminous flux. The invention also relates to a dynamic interior lighting system comprising at least one LED luminaire as mentioned above. The invention finds a preferred, but not exclusive, application in interior lighting systems that deliver a luminous flux mimicking daylight.

[0002] In recent years, the field of lighting has seen significant technological advances with the emergence of LED lighting devices, which are less energy-intensive than traditional lighting devices and provide higher-quality artificial light. LED luminaires are capable of providing light with spectral characteristics close to those of natural white light, and offer users unprecedented satisfaction in terms of visual comfort.

[0003] Natural light is an essential contributing factor to visual comfort. It plays a crucial role in our health and well-being, notably by helping to regulate our biological clock, stimulate vitamin production, and improve our mood and energy. Thus, the daylight factor, or "DF," is a widely used indicator, particularly among the scientific community and architects, and is taken into account by various standardization and labeling systems.

[0004] LEDs are characterized by a luminous flux that is substantially proportional to the current flowing through them. The arrangement of LEDs connected in series and carrying the same current is common in LED luminaires. Such an arrangement offers the advantage of simple and simultaneous current control of a plurality of LEDs. LEDs with similar characteristics are connected and, when powered by the same current, provide a uniform luminous flux.

[0005] In the prior art, pulse width modulation, or "PWM" (for "Pulse Width Modulation"), has become the standard for controlling the average current in LEDs. This switching control technique allows for adjustment of the average current and a Regulation is achieved by controlling the duty cycle of a pulse train. Current control via pulse-width modulation (PWM) is frequently used for dimming the light intensity emitted by LED luminaires.

[0006] The inventive entity considers that interior lighting systems with high-fidelity control of luminous flux are expected to develop in the coming years. The provision of robust and economically accessible technology is an essential condition for the successful adoption of these systems.

[0007] An interior lighting system with high-fidelity control of the luminous flux is a system capable of reproducing daylight in its spectral components, brightness, and dynamics. Such a system creates the illusion of a more transparent space, with more windows. The illuminated space then appears to have a perceived daylight factor that is higher than the actual daylight factor of that space.

[0008] The human eye has a wide dynamic range of sensitivity to light, with a ratio of 1 / 106, adapting equally well to sunlight of 100,000 lux in summer and moonlight of 0.1 lux. For the illusion of natural light to work, daylight must be faithfully reproduced by the lighting system. The reproduction of daylight variability due to the daily cycle, as well as to passing clouds or other factors, is important. With insufficient dynamic range, the eye perceives jumps in brightness, and the user experience is unsatisfactory. The color of the light must also be faithfully reproduced. To achieve this, luminous fluxes from different light sources must be precisely measured to obtain the appropriate color mixture, given that the human eye has a sensitivity of up to 0.5 MK-1 in its color perception.

[0009] In digital technology, to linearly cover a dynamic range from 0.1 lux to 100,000 lux, with an accuracy of, for example, 0.1 lux, at least 10⁶ different numerical values ​​are required. In binary, 20 bits allow for the 2²⁰ = 1,048,576 different numerical values. At least 20 bits are necessary in this example to represent the aforementioned dynamic range.

[0010] The PWM modulation control solutions known in the field of lighting generally offer 8-bit digital control, i.e., 2⁸ = 256 discrete values ​​available for control. In the field of home automation, 16-bit PWM controls are known, i.e., 2¹⁶ = 65,536 discrete values ​​available. These earlier techniques based on PWM modulation are limited in terms of accuracy over a wide dynamic range and are not suitable for the need expressed above. Furthermore, the frequency of the PWM pulse train The switching frequency becomes less than 20 kHz with 16-bit control, which can cause interference in the audible band and / or with the pixel scan frequencies used in video displays. Electromagnetic interference with switching power supplies and electromagnetic compatibility (EMC) issues can also occur with PWM modulation. Excessive switching frequencies can lead to a loss of linearity in LEDs, particularly due to their turn-on time, and degraded response of other semiconductor components in the circuits. Furthermore, LEDs are subjected to increased stresses during switching, including thermal stresses, which reduce their lifespan.

[0011] Analog current control in an LED diode has the advantage of not having the aforementioned disadvantages.

[0012] In his technical article entitled “Hybrid Wide Dimming Ratio Linear LED Current Controller Using LT8614 & LT3083 / LT6015” and published on October 17, 2016 in the “Resource Library” of the American company ANALOG DEVICE®, Thomas Mosteller disclosed an electronic circuit for analog current control in an LED. This circuit implements a DC-DC voltage converter, an operational amplifier, and a MOSFET transistor, and allows for precise analog control of the current in the LED.

[0013] A digital-to-analog converter, called a "DAC" (from "Digital-Analog") A digital-to-analog converter (DAC) is necessary to control a series of LEDs in a luminaire using analog current from a digital interface. As mentioned above, to linearly cover the entire daylight spectrum with high accuracy, a very large number of different digital values ​​are required. A 24-bit DAC would be necessary for high-fidelity control of an indoor lighting system reproducing daylight. The price of a DAC depends on its bit depth. Integrating a 24-bit DAC into an LED luminaire significantly increases the overall cost.

[0014] The present invention aims to provide a technical solution to the problems detailed above and proposes a new approach enabling the design at an optimal cost of "LED" diode luminaires and interior lighting systems capable of delivering a luminous flux copying daylight.

[0015] According to a first aspect, the invention relates to a light-emitting diode luminaire, known as "LED", of the type having a digital interface receiving a digital light control and means for converting the The luminaire comprises a digital light control system with at least one digital current control, the luminaire having at least one light-producing channel controlled by the digital current control, and the light-producing channel comprising a series-connected array of LEDs, digital-to-analog conversion means receiving the digital current control and producing in response a corresponding analog current control, and DC current generation means supplying the LED array with a DC supply current whose intensity is a function of the analog current control. According to the invention, the digital-to-analog conversion means are arranged to produce the analog current control with a quantization step that increases as the value of the digital current control increases.

[0016] According to a particular embodiment of the luminaire according to the invention comprising at least two light-producing channels, the digital light control includes brightness and color information, and the digital light control conversion means convert it into at least two digital current commands which are supplied respectively to the two light-producing channels for the control thereof.

[0017] According to a particular feature of the invention, in a light-producing channel, the digital-to-analog conversion means comprise binary format reduction means, a linear-type digital-to-analog converter, and analog-level restoration means, the binary format reduction means having at least two ranges jointly covering a full dynamic range of values ​​of the digital current control, a first range and a second range being associated respectively with low and high values ​​of the digital current control, and the range of values ​​covered by the second range being wider than that of the first range, and, in each of the ranges, the digital current control being represented by a calibrated digital current information and a range indication information,and the calibrated digital current information having a specific number of bits equal to that of the digital-to-analog converter and less than the number of bits of the digital current control.

[0018] According to another particular feature, the binary format reduction means comprise three calibers.

[0019] According to yet another particular characteristic, the digital-to-analog converter is a 16-bit converter.

[0020] According to yet another particular feature, the analog level restoration means comprise a switchable voltage divider resistive bridge which is controlled in switching by the range indication information so as to establish a voltage division ratio which corresponds to an applied range indicated by the range indication information.

[0021] According to yet another particular feature, in the light production channel, the means for generating direct current include a direct-direct type voltage converter and a voltage-controlled current generation circuit.

[0022] According to yet another particular characteristic, the voltage-controlled current generation circuit is of the so-called "current well" type and includes an operational amplifier and a transistor of the so-called "MOSFET" type.

[0023] According to another particular embodiment of the invention, in the light production channel, the digital-to-analog conversion means include a logarithmic type digital-to-analog converter.

[0024] The invention also relates to an interior lighting installation comprising at least one luminaire, as briefly described above, installed in a building, a light sensor installed outside the building and exposed to daylight, wired and / or wireless information transmission links and control means, the control means being in communication, via the links, with the sensor and the luminaires and controlling them from light information provided by the sensor and control information transmitted by a user via a human-machine communication means.

[0025] Other advantages and features of the present invention will become more apparent upon reading the detailed description below of several particular embodiments of the invention, with reference to the accompanying drawings, in which:

[0026] The [Fig. 1] is a curve showing the brightness perceived by a human eye in relation to the measured brightness.

[0027] Fig. 2 is a general diagram showing a first architecture for controlling a group of LED diodes in a luminaire according to the invention.

[0028] Fig. 3 is a general diagram showing another architecture for controlling a group of LED diodes in a luminaire according to the invention.

[0029] Fig. 4 is a diagram illustrating, using a theoretical example, the operating principle of controlling a group of LED diodes in the architecture of Fig. 3.

[0030] Fig. 5 is a simplified electronic diagram of a luminaire according to the invention designed with the architecture of Fig. 3 and having a single light production channel.

[0031] Fig. 6 is a simplified electronic diagram of a luminaire according to the invention designed with the architecture of Fig. 3 and having two light production channels.

[0032] Fig. 7 is a simplified block diagram of an interior lighting system according to the invention designed to provide daylight-copying lighting.

[0033] Fig. 8 schematically shows an example of deployment of the system of Fig. 7 in a residential building.

[0034] In general, the invention takes advantage of the fact that the perception of brightness by the human eye is not linear with respect to the brightness level, as illustrated by the curve in [Fig. 1] showing perceived brightness (LP) as a function of measured brightness (LR). The sensitivity of the human eye is logarithmic and decreases significantly at high brightness levels. Thus, for example, the human eye will easily distinguish a brightness variation from 0.2 lux to 0.4 lux, but will have more difficulty distinguishing a brightness variation from 200 lux to 210 lux. The inventing entity has deduced from this that it is not necessary to maintain a constant resolution across the entire brightness range of the reproduced light to provide the user with a fully satisfactory natural light experience.With this approach, it becomes possible in a luminaire of the invention to use a digital-to-analog converter with a reduced number of bits to control the LED diodes with analog current from a digital interface of the luminaire.

[0035] In general, in the various examples and embodiments described below, components and information with similar references are components and information with similar characteristics and / or functionalities and will not be systematically specified.

[0036] Fig. 2 schematically shows a luminaire of the invention LUI having a first control means architecture MCI for controlling a direct current generator GC providing the power supply to a group GD of LED diodes connected in series.

[0037] The MCI control means here essentially comprise two functional blocks, CLC and CNAL0G. The functional blocks CLC and CNAL0G jointly perform a conversion of a digital light control signal CNL into an analog current control signal C_ID, which is applied to a control input of the current generator GC. The C_ID signal applied to the input of the current generator GC results in a continuous supply current ID flowing through the diode group GD, this current ID having an intensity proportional to the value of the C_ID signal.

[0038] The CLC function block receives the CNL digital light command as input and translates it into a DC digital current command, using a calibration function. This calibration function, typically obtained through prior measurements, is stored in the CLC function block and provides information, via the delivered DC digital command, on the intensity of the current ID to be supplied to the group of GD diodes to obtain the production of light having the brightness in lux requested by the CNL control.

[0039] In this architecture, the CNAL0G functional block is a logarithmic digital-to-analog converter. The CNAL0G converter receives the digital current control signal CC as input and outputs the analog current control signal C_ID, which is supplied to the current generator GC. The CNAL0G converter operates with a quantization step that increases as the value applied to its digital input increases, resulting in a reduction of the resolution of the corresponding value supplied to its analog output. This operation of the CNAL0G converter allows for a reduction in its number of bits compared to that which would be required with a linear digital-to-analog converter. Thus, for example, considering a digital light control signal CNL represented on 24 bits, an 18-bit CNAL0G converter may suffice to obtain the analog current control signal C_ID.

[0040] Figure 3 schematically shows a luminaire of the invention LU2 having an alternative control means architecture MC2 for controlling the current generator GC which supplies power to the diode group GD. This alternative architecture is described below with reference also to Figure 4, which illustrates the operating principle through a theoretical example.

[0041] As can be seen in [Fig.3], the MC2 control means here essentially comprise the aforementioned CLC functional block, a CF_CNA functional block and an RN analog level recovery circuit which together perform the conversion of the CNL digital light control into the C_ID analog current control.

[0042] The CF_CNA function block receives as input the DC digital current command delivered by the CLC function block, corresponding to the CNL digital light command. The CF_CNA function block outputs a current command comprising an ICa calibrated analog current command and a CL calibrated indication signal. The CF_CNA function block essentially comprises a CFC binary format reduction function and a CDA digital-to-analog converter.

[0043] The binary format reduction function CFC reduces the binary format of the command by introducing ranges and using the same reduced number of bits to represent the value in each range. The range used is determined by the CFC function according to the value of the CC command. Each range corresponds to a specific quantization step and therefore a specific resolution, as will become clearer later. The CFC function outputs A CNC digital current controller includes a calibrated digital current information IC and the corresponding range indication information CL, which indicates the active range. The calibrated digital current information IC has a significantly lower number of bits than the CNL and CC digital controllers. The IC information is provided as input to the DAC. The range indication information CL is provided to a switching control input of the analog level recovery circuit RN. The CFC format reduction function is typically performed by calculation and / or with the aid of mapping.

[0044] The DAC is a linear type, typically a commercially available DAC compatible with the target cost of the LU2 luminaire. The DAC delivers the calibrated analog current control ICa in response to the digital information IC supplied as input. The DAC has a number of bits equal to that of the digital information IC delivered by the binary format reduction function CFC. The analog control ICa is supplied as input to the analog level recovery circuit RN.

[0045] The analog level restoration circuit RN is formed from a switchable resistive voltage divider bridge. Electronic switches controlled by the CO and Cl bits of the CL range indication information allow setting a voltage division ratio of the RN circuit. The analog current control C_ID is produced in the RN circuit by adjusting the level of the analog control ICa using a level adjustment factor FA. The value of the applied adjustment factor FA is determined by the voltage division ratio selected in the RN circuit. The value of the adjustment factor FA therefore corresponds to the range indicated by the CL range indication information and applied by the binary format reduction function CFC.

[0046] In the theoretical example considered here and illustrated in [Fig.4]:

[0047] The CNL digital light control provides a 24-bit setpoint from 0 to 105 lux, which is translated into a 24-bit DC digital current control from 0 to 3500 mA by the CLC function block.

[0048] CAO, CAI, and CA2 ranges are used by the CFC binary format reduction function. The CAO, CAI, and CA2 ranges are defined from 0 to 20 mA, 20 to 300 mA, and 300 to 3500 mA, and correspond to the luminance ranges of 0 to 571 lux, 571 to 8571 lux, and 8571 lux to 105 lux. The values ​​"10", "01", and "00" are assigned to the range indication information CL=(C0, Cl) and represent the CAO, CAI, and CA2 ranges, respectively, with "10" corresponding to C0= "1" and Cl= "0", "01" to C0= "0" and Cl= "1", and "00" to C0= "0" and Cl= "0".

[0049] The calibrated current digital information IC is represented on 16 bits and can therefore take 216=65536 different values, with IC having a minimum value Vmin = 0 and a maximum value Vmax=65535 in this theoretical example.

[0050] Thus, for the CAO range from 0 to 20 mA, it results in a quantization step PQ0 = 20 mA / 65536 = 0.3 pA, for the CAI range from 20 to 300 mA, a quantization step PQ1 = 280 mA / 65536 = 4.27 pA and for the CA2 range from 300 to 3500 mA, a quantization step PQ2 = 3200 mA / 65536 = 48.83 pA. These quantification steps PQ0, PQ1 and PQ2, which increase with increasing brightness of natural light, induce a decreasing resolution of the brightness of the restored light, with an applied accuracy of PL0 = 571 lux / 65536 = 0.0087 lux, of PL0 = (8571-571) lux / 65536 = 0.12 lux and of PL2 = (105-8571) lux / 65536 = 1.39 lux for respectively the CAO, CAI and CA2 calibers.

[0051] In this theoretical example, the DAC is a 16-bit linear converter. It provides the calibrated analog current control ICa corresponding to the calibrated digital current information IC. In the RN circuit, the range indication information CL selects an adjustment factor FA = F0, FA = Fl = 15.F0, or FA = F2 = 175.F0. These values ​​F0, Fl, and F2 of the adjustment factor FA are applied to the analog control ICa for the ranges CAO from 0 to 20 mA, CAI from 20 to 300 mA, and CA2 from 300 to 3500 mA, respectively. The analog current control C_ID = ICa.FA is then derived and enables the control of the current generator GC.

[0052] Thus, generally speaking, as is clear from the theoretical example above, considering a first and a second range, for example CA and CA1, or CA1 and CA2, which correspond respectively to low and high values ​​of the DC digital current control, these cover value ranges with different extents, with the range of values ​​covered by the second range being wider than that of the first range. In each of the first and second ranges, the DC digital current control is represented by a calibrated current digital information IC having the same fixed number of bits. This results in different qualification steps for the first and second ranges, with a quantization step for the first range that is smaller than that of the second range.The accuracy associated with the first caliber (the one for lower values) is therefore greater than that associated with the second caliber (the one for higher values).

[0053] With particular reference to [Fig. 5], a form is now described practical implementation L0 of a luminaire according to the invention having an architecture of the same type as that described above with reference to [Fig.3] and [Fig.4]. The LO luminaire includes a single light production channel to produce white light whose brightness can be controlled through a digital interface.

[0054] As shown schematically in [Fig.5], the LO luminaire comprises a group of LED diodes, identified as GD, which is supplied with current by a DR control circuit, designated "driver" in English by those skilled in the art.

[0055] The grouping GD comprises a plurality of LED diodes connected in series, of the same specifications, for example white LED diodes.

[0056] The DR control circuit is powered by a switched-mode power supply unit ALIM connected to an AC power supply network REac. The ALIM unit is typically integrated into the luminaire L0 and provides a DC voltage Vs and one or more other voltages required to power the various components of the luminaire L0.

[0057] The DR control circuit essentially comprises a microcontroller MCUL0, a digital-to-analog converter DAC, an analog level recovery circuit RN and a voltage-controlled current generator GC.

[0058] The MCUlo microcontroller is coupled to a Pi / o digital control interface for the luminaire L0, typically a serial interface. The MCUlo microcontroller hosts, in internal memory (MEM), embedded software responsible for the functional management of the luminaire L0. The embedded software includes, in particular, a first software module implementing the CLC function block, which processes the digital light control (CNL) and provides the DC digital current control. The embedded software also includes a second software module implementing the CFC function, which processes the DC digital current control and provides the CNC digital current control. The CNC control includes the calibrated digital current information (IC) and the range indication information (CL).

[0059] The DAC receives the digital information IC and outputs the calibrated analog current control ICa. The DAC here is typically a 16-bit converter, preferably of the type known to those skilled in the art as "rail-to-rail", with excellent linearity and low offset.

[0060] In this embodiment, the software module implementing the CFC function and the DAC converter collaborate to perform the functions of the CF_DAC block mentioned above with reference to [Fig.3].

[0061] The analog level restoration circuit RN here essentially comprises four resistors RI to R4 in series and two electronic switches T0 and T1 in the form of two MOSFET-type transistors. The resistors RI to R4 are connected in series in the order RI to R2, R2 to R3, and R3 to R4, with connection points P1, P2, and P3 respectively between RI and R2, R2 and R3, and R3 and R4. The Resistor RI is at the circuit input and is connected to the output of the DAC to receive a voltage representative of the control signal ICa. Resistor R4 is connected to ground. Switches TO and Tl are connected between connection point P2 and ground and between connection point P3 and ground, respectively. The voltage present at connection point PI is the current control signal C_ID, which is supplied as input to the voltage-controlled current generator GC.

[0062] Three different voltage division ratios, one of which is selected by the range indication information CL controlling the TO, Tl switches, are provided by the RN circuit. The selected voltage division ratio determines the adjustment factor FA applied to the ICa control to obtain the C_ID control.

[0063] As shown in [Fig. 5], the invention provides for a calibration step of the luminaire and dedicated means E1, E2, and E3, to compensate for a disparity in the ohmic values ​​of the resistors RI to R4 of the RN circuit and to obtain the required accuracy. The calibration performed allows the use of lower-class resistors, which benefits the cost optimization of a luminaire according to the invention. Thus, in accordance with this feature of the invention, the calibration values ​​(CAO, CAI, and CA2 in this embodiment) are precisely determined at the end of the luminaire manufacturing process, during this calibration step. This calibration step is preferably performed using a software routine embedded in the MCUL0 microcontroller.Under the control of this routine, a reference voltage is applied to the input of the RN circuit, and the voltage present at point PI is precisely measured using a laboratory multimeter by an operator for each voltage division ratio. The voltage division ratio being measured is selected by the routine by appropriately controlling the TO and TL switches. The measured voltage values ​​are then entered into the MCUlo microcontroller, and the routine calculates the ranges that correspond precisely to the measured values, defining limit values ​​for these ranges that are close to the theoretical values ​​(20 mA, 300 mA, and 3500 mA in this example implementation). The calculated values ​​defining the ranges are provided by the routine to the CFC function.

[0064] The means E1, E2 and E3 for the implementation of this calibration step include herein in particular conductive contact points for measurement sampling integrated into the electronics of the luminaire, the aforementioned laboratory multimeter, the aforementioned on-board routine, human-machine communication means and others.

[0065] The voltage-controlled current generator GC essentially comprises a DC-DC type voltage converter DC, and a voltage-controlled DC current generation circuit SC. The DC voltage converter (CDC) is powered by the DC voltage Vs supplied by the power supply unit (ALIM) and provides a highly stable DC voltage Vdc. The CDC converter supplies an anode of the diode group GD, one cathode of which is connected to the SC circuit. The SC circuit is a current-sink type and forces the current ID to flow through the diode group GD.

[0066] The SC circuit includes, in particular, an operational amplifier AO, a MOSFET-type transistor TR, and resistors R5 and R6. The operational amplifier AO and the transistor TR operate in linear mode. Resistors R5 and R6 provide the amplifier AO with setpoint-following negative feedback. This circuit determines a current in the diode group GD that is approximately equal to ID = C_ID / R5.

[0067] With particular reference to [Fig. 6], another practical embodiment L1 of a luminaire according to the invention is now described, having an architecture of the same type as that described above with reference to [Fig. 3] and [Fig. 4]. This embodiment of the luminaire of the invention is designed to reproduce the brightness and color of a light.

[0068] As schematically shown in [Fig. 6], the luminaire L1 comprises two groups of white LEDs, labeled GDI and GD2, which are powered respectively by driver circuits PG1 and PG2. Group GDI comprises LEDs emitting cool white light. Group GD2 comprises LEDs emitting warm white light. Thus, the luminaire L1 comprises two light-producing channels, CN1 and CN2, so as to produce light that is composed of a mixture of the luminous flux supplied by group GDI and that supplied by group GD2.

[0069] The control circuits PG1 and PG2 have the same architecture and each comprise a DAC converter, an RN circuit, and a current generator GC. In this luminaire L1, these DAC, RN, and GC components are analogous to those described above with reference to [Fig. 3], [Fig. 4], and [Fig. 5] and will not be detailed again here.

[0070] The PG1 and PG2 circuits receive CNC1 and CNC2 digital current commands as input and deliver corresponding currents ID1 and ID2 as outputs which power the diode groups GDI and GD2, respectively.

[0071] The CNC1 and CNC2 commands are similar to the CNC command described above and include information ICI, CL1, and IC2, CL2 respectively. The information ICI, IC2, and CL1, CL2 is similar to the calibrated current digital information IC and the range indication information CL described above.

[0072] In this embodiment, an MCULi microcontroller controls the two light-producing channels CN1 and CN2 from a digital control of CNLO light. The CNLO digital light control is received in the luminaire L1 via an SP radio transmission module, for example of the "LoRa®" type, and is provided to the MCULi microcontroller via its Pi / o interface.

[0073] The CNLO command includes brightness information and color information. Digital current commands CCI and CC2 are calculated from the aforementioned information contained in the CNLO command. The CCI and CC2 commands are then processed to produce the CNC1 and CNC2 commands, which are supplied to the inputs of the PG1 and PG2 circuits, respectively.

[0074] The MCUli microcontroller contains in its MEM memory a CLCO software module and CFC1 and CFC2 software modules. The CLCO module is responsible for calculating the CCI and CC2 commands from the information contained in the CNLO command. The CCI and CC2 commands are then processed respectively by the CFC1 and CFC2 modules. The CFC1 and CFC2 modules perform binary format reductions on the CCI and CC2 commands to obtain the CNC1 and CNC2 commands. The binary format reductions performed are similar to those described above, particularly with reference to [Fig. 4]. The CNC1 and CNC2 commands are then supplied to the PG1 and PG2 circuits and processed by their various functional components, as described previously, to produce the ID1 and ID2 currents and power the GDI and GD2 diode groups.

[0075] Although not shown in [Fig. 6], for reasons of readability, it should be noted that the luminaire L1 includes the means necessary for its calibration at the end of manufacturing, as described for the luminaire L0 with reference to [Fig. 5]. During this calibration, the gauges used in each of the light production channels CN1, CN2, are precisely defined.

[0076] With reference now more particularly to [Fig. 7] and [Fig. 8], a particular embodiment IEI of an interior lighting system according to the invention, designed to deliver a luminous flux mimicking daylight, is described below. The interior lighting system IEI here takes the form of a daylight lighting installation in a residential building BA.

[0077] The IEI interior lighting system comprises a plurality of luminaires of the invention, L1, ... Ln, L(n+1), ... LN, which are distributed in one or more rooms of building BA. The luminaires L1 to LN are of the type described with reference to [Fig. 6] and are equipped with LoRa® radio transmission modules. The luminaires L1 to LN receive their respective digital light commands, CNL1, ... CNLn, ... CNLN, via a LoRa® wireless data communication network that covers the entire building BA, or even several buildings in the case of a multi-site installation, for example.

[0078] A control unit BC including an MCUS microcontroller is also provided herein to monitor the operation of the IEI system. The MCUS microcontroller hosts embedded application software (not shown) that monitors the overall operation of the lighting system. The MCUS microcontroller receives, via an IE communication interface and a human-machine interface (HMI), light measurement information from one or more external CE light sensors and commands from a user UR. The MCUS microcontroller processes this information and these commands and generates the appropriate commands CNL1 to CNLN for the various luminaires L1 to LN.

[0079] The external sensor CE is, for example, mounted on the roof or facade of building BA and is connected to the control unit BC via a wireless link, or wired in another installation configuration. In all cases, the external sensor CE is positioned so as to be illuminated by daylight. It produces the light measurement information for the operation of the IEI system, and other information that may be required by the considered embodiment of the invention, such as sensor location information or other data.

[0080] The user UR interacts with the IEI system, for example, via a dedicated software application installed on a computing device DI, such as a tablet, computer, smartphone, or other device, or via a remote control unit. The user UR can thus configure the IEI interior lighting system, which may include different lighting modes, and control its overall operation.

[0081] The invention is not limited to the particular embodiments described herein by way of example. Generally, a person skilled in the art, depending on the applications of the invention, may make various modifications and variations falling within the scope of protection of the invention.

Claims

Demands

1. Light-emitting diode luminaire, referred to as "LED", of the type having a digital interface (Pi / o) receiving a digital light control (CNL) and means for converting said digital light control (CNL) into at least one digital current control (DC), said luminaire having at least one light-producing channel (CN) controlled by said digital current control (DC), and said light-producing channel (CN) comprising a group of light-emitting diodes (GD) connected in series, digital-to-analog conversion means (CFC, CDA, RN) receiving said digital current control (DC) and producing in response a corresponding analog current control (C_ID), and means for generating direct current (GC) supplying said group of light-emitting diodes (GD) with a direct supply current (ID) the intensity of which is a function of said analog current control (C_ID),characterized in that said digital-to-analog conversion means (CFC, CDA, RN) are arranged so as to produce said analog current control (C_ID) with a quantization step that increases as the value of said digital current control (CC) increases.

2. Luminaire according to claim 1, comprising at least two said light production channels (CN1, CN2), characterized in that said digital light control (CNLO) includes brightness and colour information, and in that said conversion means (CLCO) of said digital light control (CNLO) convert it into at least two said digital current controls (CCI, CC2) which are supplied respectively to the two said light production channels (CN1, CN2) for the control thereof.

3. Luminaire according to claim 1 or 2, characterized in that, in said light-producing channel (CN; CN1, CN2), said digital-to-analog conversion means (CFC, CDA, RN) comprise binary format reduction means (CFC), a linear-type digital-to-analog converter (CDA), and analog level restoration means (RN), said binary format reduction means (CFC) comprising at least two ranges (CAO, CAI, CA2) jointly covering a full dynamic range of values ​​of said digital current (DC) control, a first said range (CAO; CAI) and a second said range (CAI; CA2) being associated respectively with low values ​​and high values ​​of said digital current (DC) control, and the range of values ​​covered by said second range (CAI; CA2) being more extensive than that of the first range (CAO; CAI) and, in each of said ranges (CAO, CAI, CA2), said digital current (DC) control being represented by a calibrated digital current information (IC) and a range indication information (CL), and said calibrated digital current information (IC) having a determined number of bits equal to that of said digital-to-analog converter (DAC) and less than the number of bits of said digital current (DC) control.

4. Luminaire according to claim 3, characterized in that said binary format reduction means (CFC) comprise three gauges (CAO, CAI, CA2).

5. Luminaire according to claim 3 or 4, characterized in that said digital-to-analog converter (DAC) is a 16-bit converter.

6. Luminaire according to any one of claims 3 to 5, characterized in that said analog level restoration means (RN) comprise a switchable voltage divider resistive bridge (RI to R4, TO, T1) which is controlled in switching by said range indication information (CL, CO, Cl) so as to establish a voltage division ratio which corresponds to an applied range (CAO, CAI, CA2) indicated by said range indication information (CL).

7. Luminaire according to any one of claims 1 to 6, characterized in that, in a said light production channel (CN; CN1, CN2), said direct current generation means (GC) comprise a DC-DC voltage converter (CDC) and a voltage-controlled current generation circuit (GC).

8. Luminaire according to claim 7, characterized in that said voltage-controlled current generation (GC) circuit is of the so-called "current well" type and comprises an operational amplifier (AO) and a transistor (TR) of the so-called "MOSFET" type.

9. Luminaire according to claim 1 or 2, characterized in that, in a said light production channel, said digital-to-analog conversion means comprise a logarithmic type digital-to-analog converter (CNAL0G).

10. An interior lighting installation, characterized in that it comprises at least one luminaire (L1 to LN) according to any one of claims 1 to 9 installed in a building (BA), a light sensor (CE) installed outside said building (BA) and exposed to daylight, wired and / or wireless (SF) information transmission links and control means (BC, MCUS), said control means (BC, MCUS) being in communication, via said links, with said sensor (CE) and said at least one luminaire (L1 to LN) and controlling said at least one luminaire (L1 to LN) from light information provided by said sensor and control information transmitted by a user (UR) to said control means (BC, MCUS) via a human-machine communication (DI, IHM) means.

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