CONTROL DEVICE FOR A LIGHT SOURCE MATRIX FOR INTERIOR LIGHTING OF A MOTOR VEHICLE'S PASSENGER COMPARTMENT

Abstract

The invention provides a control device for a matrix of light sources in a lighting module for illuminating the interior of a motor vehicle. It comprises a central unit configured to receive an activation instruction for one of several predetermined interior lighting functions, functionally connected to a plurality of control devices, each configured to control the activation of a group of light sources in the matrix. The central unit is configured to select a plurality of light sources in the matrix to be activated to perform said lighting function, and to transmit instructions to the control devices to activate the selected light sources. (See Figure 1 for abbreviations.)

Description

Title of the invention: DEVICE FOR CONTROLLING A MATRIX OF LIGHT SOURCES FOR THE INTERIOR LIGHTING OF THE PASSENGER COMPARTMENT OF A VEHICLE CAR

[0001] The invention relates to lighting systems for motor vehicles. The invention relates in particular to a system for lighting the interior of a passenger compartment of a motor vehicle.

[0002] A light-emitting diode, LED, is an electronic component capable of emitting light when an electric current flows through it. The light intensity emitted by an LED is generally dependent on the intensity of the electric current flowing through it. Among other things, an LED is characterized by a current intensity threshold value. This maximum forward current generally decreases with increasing temperature. Similarly, when an LED emits light, a voltage drop equal to its forward voltage is observed across its terminals. In the automotive field, LED technology is increasingly being used for various light signaling solutions. LEDs are used to provide lighting functions such as daytime running lights, signaling lights, etc. It has also been proposed to use LED technology to produce lighting systems for the passenger compartment of a motor vehicle.Such systems comprise, in a known manner, a ceiling light and reading lights. Typically, in the case of the ceiling light, it is for example possible to activate lighting illuminating towards the driver's side and, separately, lighting illuminating the passenger side. In order to reduce the number of lighting devices necessary to achieve all the required lighting functions, it has been proposed to use at least one matrix comprising LEDs. The matrix is ​​configured to achieve, depending on its operating mode, a plurality of functions including the reading light function, left / right ceiling light and so on. This makes it possible to potentially use a single lighting device, instead of using a specific device per function.

[0003] However, given the large number of light sources involved in such a matrix and the large number of lighting functions which may be required inside the passenger compartment of a motor vehicle, the control of the light sources and the management of their electrical power supply become complex electronic systems, the maintenance of which may in particular prove to be complicated.

[0004] The invention aims to overcome at least one of the problems posed by the prior art. More specifically, the invention aims to facilitate the control of a matrix of light sources which is used to perform a plurality of heterogeneous lighting functions within the passenger compartment of a motor vehicle.

[0005] The subject of the invention is a device for controlling a matrix of light sources of a light module for lighting the interior of the passenger compartment of a motor vehicle. The control device is remarkable in that it comprises a central unit configured to receive an instruction to activate one of several predetermined lighting functions of the passenger compartment. The central unit is functionally connected to a plurality of control devices, each being configured to control the activation of a group of light sources of said matrix. The central unit is configured to select a plurality of light sources of the matrix to be activated to perform said lighting function, and to transmit instructions to the control devices to control the activation of the selected light sources.

[0006] Preferably, the central unit may comprise a microcontroller element and means for receiving and transmitting data.

[0007] The central unit may preferably comprise a memory element comprising structured data, which associates each instruction for activating a lighting function with a predetermined group of light sources of the matrix to be activated to carry out said lighting function.

[0008] Alternatively or in addition, the central unit may preferably be configured to determine a group of light sources of the matrix to be activated to perform said lighting function.

[0009] The activation instruction may preferably comprise a color or color temperature instruction for the light to be emitted, a plurality of coordinates, and / or a light intensity instruction. The coordinates may advantageously correspond to an upper left corner and a lower right corner delimiting a group of light sources to be switched on.

[0010] Preferably, the central unit can be arranged to select, upon receipt of an activation instruction, one or more of the plurality of control devices to be activated as a function of this activation instruction, and to transmit to each selected control device a current instruction to be supplied to the groups of light sources that this device controls as a function of this instruction.

[0011] The central unit may preferably be arranged to calculate said setpoint from the instruction received and as a function of one or more of the following parameters: - the position of the light sources selected in the passenger compartment; - the area intended to be illuminated by the selected light sources; - the position of the light segments projected from the light emitted by the light sources selected in the lighting function performed by the light module (for example, the central unit can calculate a first intensity setpoint intended for one or more light sources associated with first segments, and in particular the segments at the center of the function and a second intensity setpoint intended for one or more light sources associated with second segments, and in particular the segments at the edges of this function, so as to compensate for the inequalities in optical efficiency of an optical system associated with the matrix of light sources to obtain a light beam of homogeneous light intensity at the output of such an optical system), - the intrinsic characteristics of the selected light sources, for example their BIN information (color and / or flux), and - the characteristics of the optical means coupled to the selected light sources, for example the optical efficiency of these optical means.

[0012] Preferably, each control device can be connected to a power supply line and can be configured to receive a current setpoint to be supplied to the group of light sources that it controls and to modulate and transmit said power supply to this group as a function of said current setpoint.

[0013] The central unit may preferably be configured to receive data on a CAN (“Controller Area Network”) or LIN (“Local Interconnect Network”) type bus of a motor vehicle.

[0014] Preferably, each of the control devices may comprise an electrical voltage converter circuit and / or an electrical current regulator circuit. Alternatively, only the central unit comprises an electrical voltage converter circuit.

[0015] Each of the control devices may preferably comprise a microcontroller element operatively connected to the converter circuit.

[0016] Preferably, each control device can be configured to control the electrical current activation of a group among the light sources of the matrix.

[0017] Said groups may preferably be disjoint groups. Alternatively, the groups may be non-disjoint, so that one or more of the light sources of the matrix belong to a plurality of groups.

[0018] Preferably, each group may comprise the light sources of a row or a column of the matrix. Alternatively, each group may comprise a single light source, or a plurality of light sources distributed over different rows and / or columns of the matrix.

[0019] Each light source of the matrix may preferably comprise at least two elementary light sources with different luminous properties.

[0020] Where appropriate, each group may comprise only one of the elementary light sources of the light sources of this group, or alternatively, one of the elementary light sources of one or more of the light sources of this group and the other of the elementary light sources of one or more other of the light sources, or alternatively both elementary light sources of the light sources of this group.

[0021] One of the elementary light sources of each light source can preferably emit light of a first predetermined color, and the other of the elementary light sources can emit light of a second predetermined color, when the sources are supplied with electric current.

[0022] Preferably, the first color may be warm white and the second color is cool white. Cool white may correspond to a color temperature between 4500 and 6000 K. Warm white may correspond to a color temperature between 2700 and 3000 K.

[0023] Each of the elementary sources can preferably be controlled separately and independently of the other elementary sources of the light source by the control devices associated therewith.

[0024] Preferably, each elementary source may comprise a light ray emitting face of an electroluminescent semiconductor element.

[0025] The light sources of the matrix can preferably be arranged on at least two separate physical supports. These are preferably two printed circuits installed in two different locations in the passenger compartment of a motor vehicle.

[0026] The dimensions of the matrix may preferably accommodate at least five rows / columns comprising at least six light sources each.

[0027] The invention also relates to a light module for lighting the interior of the passenger compartment of a motor vehicle. The module comprises at least one matrix of light sources, and it is remarkable in that it comprises a device for controlling said matrix, the control device being in accordance with the invention.

[0028] The light module may preferably comprise optical means, each light source being coupled to an optical means, the optical means being arranged to project, from the light emitted by the light source coupled thereto, a light segment into a specific area of ​​the passenger compartment.

[0029] Preferably, the optical means may be arranged so that each light segment covers at least a portion of another adjacent light segment.

[0030] The optical means may preferably comprise at least one optical lens or a light guide.

[0031] By using the measures proposed by the present invention, it becomes possible to control a plurality of light sources, for example of the light-emitting diode, LED, type, controlled and driven by several control devices, using a central control unit. In the case of application to the lighting of the passenger compartment of a motor vehicle, the proposed architecture makes it possible in particular to receive a high-level setpoint threshold from a control member of the vehicle at the central control unit. The high-level setpoint is used to identify the required lighting function. The central control unit is configured so as to translate the high-level setpoint thus received into low-level setpoints, indicating for example a precise current intensity, to the plurality of control devices involved in powering the LED matrix.The proposed approach therefore allows the scaling of LED matrix systems for the realization of multiple lighting functions (dim light, reading light, directional ambient light, etc.), without requiring changes to the LED control and piloting devices.

[0032] Other features and advantages of the present invention will be better understood with the aid of the exemplary description and the drawings among which: - [Fig.l] is a schematic illustration of a control device according to the invention in a preferred embodiment; - [Fig.2] is an illustration of a central unit of a control device according to the invention in a preferred embodiment.

[0033] Unless specifically indicated otherwise, technical features described in detail for a given embodiment may be combined with the technical features described in the context of other embodiments described by way of example and not limitation. Similar reference numerals will be used to describe similar concepts across different embodiments of the invention. For example, references 110 and 210 designate a central unit of a control device according to the invention, in two described embodiments.

[0034] [Fig.l] shows a control device 100 according to a preferred embodiment of the invention. The device 100 is used to control a matrix 10 which groups together light sources 14 inside the passenger compartment of a motor vehicle. The light sources 14 are used to perform a plurality of lighting functions in the passenger compartment. This is, without limitation, a reading light, standby, welcome lighting function or others.

[0035] The diagram in [Fig.l] shows the light sources 14 by indicating their light ray emitting faces. The matrix arrangement of the sources is apparent. Preferably, the light sources 14 are light emitting diodes, LEDs. By using LEDs having varied characteristics to populate the matrix 10, it becomes possible to achieve a plurality of lighting functions by deciding to power subsets of these light sources.

[0036] For example, a single matrix 10 may bring together light sources of a first type which emit light of a first color (for example warm white) when they are supplied with electric current, and light sources of a second type, which emit light of a second color (for example cold white). A single electronic component bringing together two or more electroluminescent semiconductor elements with different electrical and / or luminous characteristics may also be used.

[0037] In [Fig.l], the light sources of the two different types are indicated by the presence and absence of a hatched pattern, respectively. The arrangement of the matrix is ​​such that the light sources are physically close together, so that two sources are not visibly distinguishable by a passenger of the vehicle equipped with the matrix. Depending on the number, type of sources, their position in the matrix, and the light intensity emitted by the light sources switched on at a given time, the matrix 10 is therefore capable of performing a plurality of different light functions.

[0038] A key aspect for the realization of these multiple light functions is the control of the electric current supply of each of the sources. By way of example and not limitation, the light sources of a row 12 of the matrix 10 are powered by one of the control devices 120. Each of the control devices 120 is capable of converting a direct input voltage V1N, generally supplied by a source internal to the motor vehicle equipped with the device 10, into a charging voltage which is adapted to the power supply of the light sources 12 associated therewith. The operation of such devices for controlling or controlling the electric power supply will not be described in detail within the scope of the present invention, since it is known in the art.Thus, the control devices generally involve at least one conversion circuit of the voltage step-down ("buck"), voltage step-up ("boost") or SEPIC ("Single-Ended Primary Inductance Converter") type. In addition, the average intensity of the charging current can be influenced in a known manner by a pulse width modulation signal, PWM ("Pulse Width Modulation"). Since the average intensity of the charging current has a direct impact on the light intensity emitted by the powered LEDs, it becomes apparent that by controlling the control devices 120 in a centralized and concerted manner, a selection of the LEDs 14 of the matrix can be caused to emit light of a predetermined intensity and color temperature.

[0039] The control devices 120 preferably comprise at least one voltage converter circuit capable of converting said input voltage Vin into said input voltage load and a current regulator circuit capable of generating a PWM type signal in accordance with a current setpoint 114 intended for the light sources 12 associated with it. Preferably, the control devices 120 also comprise reception means which make it possible to receive such a current setpoint 114.

[0040] The current setpoints 114 are transmitted centrally to the various control devices 120 by a central unit 110. While [Fig.l] shows a direct connection between the central unit 110 and each of the control devices 120, a serial connection of the control devices is conceivable in an equivalent manner and without departing from the scope of the present invention. The central unit 110 is configured to determine, on the basis of an activation instruction 112 received by an external member indicating a lighting function, which of the light sources 14 of the matrix 10 are to be supplied and with what current intensity, in order to carry out the required lighting function. Then, a current setpoint 114 is transmitted to the control devices 120 which are responsible for supplying the set current intensity 114 to the selected light sources.

[0041] [Fig. 2] shows a schematic illustration of the central unit 210 according to a preferred embodiment of the invention. An activation indication 212 is received, for example on a CAN or LIN bus of a motor vehicle, using data reception means 213. The activation indication 212 comprises, by way of example and not limitation, a color instruction, coordinates (for example indicating an upper left corner and a lower right corner of a rectangular group of sources 14 of the matrix 10), and / or a light intensity instruction. A microcontroller element 216 programmed for this purpose interprets the received indication 212 to determine all the instructions 214. The instructions 214 are transmitted to each of the control devices 120 using transmission means 215.

[0042] The central unit may preferably be arranged to calculate said setpoint from the instruction received and as a function of one or more of the following parameters: - the position of the light sources selected in the passenger compartment; - the area intended to be illuminated by the selected light sources; - the position of the light segments projected from the light emitted by the light sources selected in the lighting function performed by the light module (less intensity for the segments in the center of the function than for the segments at the edges of this function), - the intrinsic characteristics of the selected light sources, for example their BIN information, and - the characteristics of the optical means coupled to the selected light sources data, for example the optical efficiency of these optical means.

[0043] The central unit 210 preferably comprises a memory element 218 to which the microcontroller element 216 has read access. This memory element is preloaded with the data necessary for determining said setpoint 214. This is, for example, data relating to the location of the sources 14 in the passenger compartment, the intrinsic characteristics of the light sources 14, etc.

[0044] In another embodiment, the memory element 218 is a structured memory element, such as a table. The table is preloaded with predetermined configurations, which relate an activation indication 212 to a setpoint 214 for each of the control devices. In this way, a simple table consultation operation makes it possible to configure all of the control devices, to cause them to activate the preselected light sources. Using the functional and structural description just given, a person skilled in the art will be able to program a microcontroller so that it can carry out the functions of the microcontroller element 216, using this general computer knowledge.

[0045] The control device according to the invention finds its particular application in a light module for lighting the interior of the passenger compartment of a motor vehicle. In such a module, each light source of the matrix is ​​coupled to an optical means such as an optical lens or a light guide. The optical means makes it possible to project, from the light emitted by the light source coupled thereto, a light segment into a specific area of ​​the passenger compartment. This arrangement allows lighting by beams, segments, bands or even by pixels of the different elements of the matrix. Ideally, each light segment covers at least a part of another adjacent light segment, in order to produce continuous light areas when several adjacent light segments are lit.

Claims

[Claim 1] Claims Light module for lighting the interior of the passenger compartment of a motor vehicle, the module comprising at least one matrix of light sources (10) of the light-emitting diode (LED) type, characterized in that the light module comprises a control device (100) for said matrix, the control device comprising: a central unit (110, 210) configured to receive an activation instruction (112, 212) of one of several predetermined lighting functions of the passenger compartment, functionally connected to a plurality of control devices (120), each being configured to control the activation of a group (12) of light sources (14) of said matrix (10), the central unit (110, 210) being configured to select a plurality of light sources of the matrix to be activated to perform said lighting function,and to transmit instructions (114) to the control devices (120) to control the activation of the selected light sources., characterized in that the module comprises optical means, each light source being coupled to an optical means, the optical means being arranged to project, from the light emitted by the light source coupled thereto, a light segment into a specific area of ​​the passenger compartment, characterized in that the optical means are arranged so that each light segment covers at least part of another adjacent light segment.

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