Retrofit automotive LED lamp

Abstract

A lamp (10) that can be used, for example, for retrofitting lamps of an H7 type for motor vehicles, comprises a lamp body (12, 161, 162, 20), which extends in a longitudinal direction (X10), the lamp body having a rear base part (10a) and a front part (10b) and including a support member (12). Solid-state light sources (141, 142) are arranged on said support member (12) in the front part (10b) of the lamp body (12, 161, 162, 20), with driving circuitry (301, 302) for driving the light sources (141, 142) set in the rear part (10a) of the lamp body (12, 161, 162, 20). The driving circuitry (301, 302) for the light sources (141, 142) comprises a switching converter operating at a switching frequency of between 500 kHz and 1000 kHz, optionally approximately 790 kHz.

Description

[0001] RETROFIT AUTOMOTIVE LED LAMP

[0002] Technical field

[0003] The present disclosure relates to lamps .

[0004] One or more embodiments may be applied to lamps that use solid-state generators or light sources , for example LED sources .

[0005] One or more embodiments may find advantageous application in the automotive sector, for example , as retrofit lamps for motor vehicles .

[0006] Technological background

[0007] Lamps that use solid-state light generators , for example LED light generators , are used ever increasingly in place of traditional incandescent or fluorescent 1 amp s .

[0008] This applies , in particular, to the automotive sector .

[0009] LED lamps for vehicles are able to provide characteristics of luminous flux and distribution of light that are compatible with the requirements of use in lights for motor vehicles , where the characteristics of intensity and distribution of the luminous flux assume particular importance .

[0010] The fact of wishing to reproduce as faithfully as possible the performance of a traditional lamp, such as a halogen lamp, both in terms of si ze , and in terms of performance ( for example , flux, expressed in lumen) leads to taking into account the high temperature that may be reached by a solid-state source , such as a LED source , and studying solutions for improvement at the level of heat dissipation .

[0011] The above aspect may assume particular importance in the automotive sector, for example for providing an H-type lamp that can be used in place of conventional lamps , such as halogen lamps , whether at a retrofit level or at the level of initial installation .

[0012] The relevant prior art is rather extensive , as documented by EP 3 828 463 Bl and by the extensive review of prior documents contained therein (US 9 677 753 B2 ; US 10 415 787 B2 ; US 9 470 391 B2 - corresponding to which is US 2014 / 328079 Al ; US 8 118 462 B2 ; US 8 066 414 B2 ; US 7 144 140 B2 ; US 2015 / 0146447 Al ; US 2011 / 0025211 Al ; US 2010 / 0165632 Al ; US 2010 / 0027270 Al ; EP 3 647 649 Al , IT 102019000010188 Al ; CN 109 140 373 A; CN 106 594 627 , CN 207 334 634 U) and by the Italian patent 102022000010499 .

[0013] The document EP 3 828 463 Bl describes a lamp that can be used for retrofitting lamps of an H7 type for motor vehicles , comprising a lamp body that extends in a longitudinal direction between a rear base part and a front part . The lamp body includes a support member, arranged on which in the front part of the lamp body are solid-state light sources , for example LED sources . Present in the rear base part of the lamp body is circuitry for driving the light sources with ventilation openings configured to favour a flow of air for ventilating the driving circuitry through the rear base part of the lamp body, between a first side and a second side opposite to one another of the rear part of the lamp body . The path of flow of ventilation air extends from an air inlet to an air outlet . Provided in the rear part of the lamp body, on the support member, is an airmoving element . This element is located along the path of flow of ventilation air from the air inlet to the air outlet and can be activated to produce a forced flow of ventilation air through the rear part of the lamp body .

[0014] The solutions described in the aforesaid prior-art document facilitate production of LED lamps that , when activated, are able to emit at least 1200 lumen, being in compliance with the dimensions speci fied in the ECE regulation, in particular with the text known as Addendum 36: Regulation No. 37, pp . 35-38. To the aforesaid ECE text for H7 lamps there correspond in the United States the specifications SAE 9004 or 9007.

[0015] It has been noted that the intent to produce retrofit lamps (for example, for lights such as drivingbeam headlights, dipped headlights, foglamps, and direction lights) , thus fully meeting - with solutions that can be qualified as "street legal" - specifications like the ECE specifications, may prove difficult to combine with the intent to preserve the dimensions of the socket for H7 halogen lamps.

[0016] In that respect, reference can be made, by way of example, to document US 2010 / 213809 Al, which discloses a headlamp having a cap and a light output which is predetermined by international standardization with respect to the distance and position with respect to a reference plane of the cap, wherein the light output is provided by one or more semiconductor light sources with drive circuitry including an inductor step-down DC / DC voltage converter.

[0017] Using high-frequency switching converters in the field of LED drivers is otherwise known as witnessed, for instance by the synchronous step-down LED driver SGM3770 PWM Control Linear Dimming LED Driver with 1:500 Twinkle Free Dynamic Range (see www.sg- micro.com / product / SGM3770) where a fixed 790kHz switching frequency is used.

[0018] Incorporating such a component to an automotive solid-state lamp for vehicles, while complying with the related specifications, is however far from easy.

[0019] For instance, a distribution of light emitted fully compliant with the ECE specifications can be obtained by resorting to three-chip LEDs; these LEDs may, however, require heatsinks of quite a considerable size, which proves di f ficult to combine with maintenance o f the dimensions of the socket for traditional H7 halogen 1 amp s .

[0020] Other solutions (using four-chip LEDs , for instance ) can provide an even higher luminous flux, but the resulting light distribution does not comply with ECE R112 spci f ications and create glare . Also , the luminous flux may vary appreciably with the input voltage and ambient temperature .

[0021] Obj ect and summary

[0022] The obj ect of one or more embodiments is to provide improved solutions that will be able to overcome the di f ficulties highlighted previously .

[0023] According to one or more embodiments , the above obj ect may be achieved thanks to a lamp having the characteristics recalled speci fically in the ensuing claims .

[0024] The claims form an integral part of the technical teachings provided herein in relation to the embodiments .

[0025] Solutions like the ones described herein envisage using, for supplying the sources of light radiation, a switching converter operating in a frequency range between 500 kHz and 1000 kHz .

[0026] Such a converter may be implemented with integrated circuits that are more compact than those of conventional switching converters for the automotive sector that operate at frequencies in the region of 100- 150 kHz .

[0027] Solutions like the ones described herein prove compatible with the dimensions of traditional lamps , and at the same time facilitate complete reproduction o f the optical performance thereof using LED sources ( for instance , 3x1 LED sources can be positioned with respect to the longitudinal axis and the reference plane of the lamp in such a way as to comply with ECE R122 speci fications ) , driven via a high- frequency converter (with reduced si ze and high ef ficiency) , while also facilitating adequate thermal diss ipation ( for instance with a copper support board and / or a fan that provides an air flow impinging on the heat-generating components of the lamp ) .

[0028] Solutions like the ones described herein prove compatible with the dimensions of traditional H7 lamps , and at the same time facilitate complete reproduction of the optical performance thereof using LED sources .

[0029] Solutions like the ones described herein are suited to being used in the so-called aftermarket for drivingbeam headlights , dipped headlights , foglamps , and direction lights , without requiring any adaptors , with reduced complexity, and with consequent extension of the range of compatibility .

[0030] Brief description of the drawings

[0031] One or more embodiments will now be described, purely by way of non-limiting example , with reference to the annexed drawings , wherein :

[0032] Figure 1 , which is drawn from speci fications of the automotive sector, and is hence to be deemed in itsel f known, exempli fies characteristics of overall dimensions that can be applied to lamps according to some embodiments ;

[0033] Figure 2 is a view in side elevation of a lamp according to some embodiments ;

[0034] Figure 3 is a view in side elevation of a lamp according to some embodiments from a viewpoint opposite to that of Figure 2 and with some parts removed for clarity of representation;

[0035] Figure 4 is an exploded perspective view of a lamp according to some embodiments ;

[0036] Figure 5 illustrates a possible distribution of components in solutions like the ones described herein; and

[0037] Figures 6 , 7 , 8 , and 9 illustrate advantageous embodiments of solutions like the ones described herein .

[0038] Detailed description of embodiments

[0039] In the ensuing description one or more speci fic details are illustrated, aimed at enabling an in-depth understanding of examples of embodiments . The embodiments may be obtained without one or more of the speci fic details , or with other methods , components , materials , etc . In other cases , known structures , materials , or operations are not illustrated or described in detail so that certain aspects of the embodiments will not be obscured .

[0040] Reference to "an embodiment" or "one embodiment" in the framework of the present description is understood as indicating that a particular configuration, structure , or characteristic described in relation to the embodiment is comprised in at least one embodiment . Hence , phrases such as " in an embodiment" or " in one embodiment" that may be present in one or more points of the present description do not necessarily refer to a speci fic embodiment . Moreover, particular conformations , structures , or characteristics may be combined in any adequate way in one or more embodiments .

[0041] The references used herein are provided merely for convenience and hence do not define the sphere of protection or the scope of the embodiments .

[0042] In all of the annexed figures , unless the context indicates otherwise , parts or elements that are similar are designated by similar ref erences / numbers , and the corresponding description will not be repeated for reasons of brevity .

[0043] Figure 1 of the annexed drawings is drawn from the ECE regulation, which aims at dictating speci fications for lamps that can be used in the automotive sector, and in particular is drawn from the text known as Addendum 36 : Regulation No . 37 , pp . 35-38 , with the indication of relevant dimensional parameters for H7-type lamps that a LED lamp that can be used for retrofitting an incandescent H7 lamp is expected to meet . To the aforesaid ECE text for H7 lamps there correspond in the United States the speci fications SAE 9004 or 9007 .

[0044] The space without shading in Figure 1 represents the spatial envelope of the socket into which the retrofit ( LED) lamp along with its components should be inserted .

[0045] In this context , it has been noted that two dimensional data of importance may be represented by : the distance commonly defined as light centre length ( LCL ) , equal to 25 mm, between the reference plane and the centre of the light source CLS , this distance being measured in an axial direction with respect to the lamp, i . e . , along the reference axis ; and the (maximum) length of the lamp, equal to 44 mm, measured starting from the reference plane .

[0046] One or more embodiments are such as to : be altogether compatible with the dimensions speci fied in the ECE Regulation, as indicated in the figure reproduced herein; and dissipate in an adequate way the heat generated during operation by LED sources that are able to meet fully - at a " street legal" level - the speci fications of emission expressed by the ECE regulation, for example in relation to a luminous flux of ( at least ) 1500 Im .

[0047] In Figure 2 and in the subsequent figures , the reference number 10 designates as a whole a lamp that can be used, for example , for retrofitting ( and also for initial equipping) a light ( for example , a headlight ) of a vehicle , such as a motor vehicle .

[0048] Of the above vehicle (which is not visible as a whole in the figures ) , partially represented in Figure 2 is part of a dish P of one of the lights ( for example , a front headlight ) .

[0049] The lamp 10 may be , for example ( and as has already been seen) , an automotive solid-state lamp that can be used, for example , as retrofit lamp, in place of a conventional homologous H-type lamp, such as a halogen lamp .

[0050] In one or more embodiments as exempli fied herein, the lamp 10 may comprise a lamp body having an elongated shape , mounted on which are , in corresponding positions on opposite sides of the body itsel f , solid-state light sources .

[0051] In one or more embodiments , such sources comprise two linear arrays of LEDs ( each, for example , of three LEDs ) 141 , 142 that extend in the direction of a longitudinal axis X10 of the lamp 10 .

[0052] In the example provided herein (which - it is emphasi zed - is purely an example ) , the linear arrays of LEDs 141 , 142 are arranged in such a way that their light-emitting area ( LEA) is aligned with the longitudinal axis X10 of the lamp .

[0053] A mounting element 20 , for example having the shape of a flanged cup, can enable mounting of the lamp 10 on a support member P, such as precisely a dish of a light of a motor vehicle .

[0054] As has been said, the profile of such a dish body is indicated partially with a dashed line in j ust Figure 2 , where on the other hand it is assumed, by way of example , that the lamp 10 is mounted with a first side and a second side facing in opposite directions .

[0055] Possible advantages of such a mounting position are linked to the possible setting-up of a ( forced) flow of ventilation air through openings 101a and 101b made in the body of the lamp 10 . For instance, it is possible to use an air-moving element (for example, a motorized blower or fan 102) , causing the air to be drawn in starting from the front part of the lamp 10.

[0056] In this way, it is possible to take into account the fact that it may be difficult to draw in air from the rear part of the lamp on account of the presence of plastic or rubber plugs used for sealing the light (e.g., headlight or rear light) in which the lamp is mounted.

[0057] The solution represented herein is on the other hand just one of various possible solutions for mounting the lamp 10 on a support member such as the dish of a light of a motor vehicle, for example with coupling mechanisms substantially of the type of quarter-turn coupling mechanisms .

[0058] As discussed more extensively in what follows, the annular element 20 (possibly constituted by two complementary parts 201 and 202) in general exemplifies an element configured for mounting the lamp on a vehicle, with this element comprising, in a position corresponding to the rear part of the lamp body, at least one reference formation (such as an annular flange 200a) that is able to define a reference plane transverse with respect to the longitudinal axis X10.

[0059] In one or more embodiments as exemplified herein, the lamp 10 may present, in the direction of the longitudinal axis X10: a (rear) base part 10a, where the mounting element 20 is provided, that can be mounted - for example inserted - into the support member P; and a front part 10b, starting from which, in use, light radiation is emitted.

[0060] In one or more embodiments as exemplified herein (see, for example, the exploded perspective view of Figure 4) , the lamp 10 may comprise a laminar element 12 (with characteristics that are similar to a printed circuit board - PCB ) having two mutually opposite surfaces on which the LED light generators 141 , 142 are arranged .

[0061] In one or more embodiments as exempli fied herein ( see once again the exploded perspective view of Figure 4 ) the laminar element 12 may be set between two complementary pieces 161 , 162 , having, for example , a shell shape , made of pressed metal or moulded plastic .

[0062] The pieces 161 , 162 with the laminar element 12 provided between them may be held together in the rear part 10a and in the front part 10b via screws 18 passing through holes provided in the pieces 161 , 162 themselves .

[0063] Advantageously, as illustrated here , the annular element 20 may be constituted by two semicircular ( or C- shaped) parts 201 and 202 , each of which is made of a single piece ( for example , by moulding a plastic material that is a good conductor of heat or by pressing light metal ) with one of the shells 161 , 162 .

[0064] The arrangement of the LED light generators 141 , 142 on the surfaces of the laminar element 12 is such that the generators 141 , 142 themselves proj ect light away from the laminar element 12 in a direction as a whole radial with respect to the axis X10 .

[0065] The pieces or shells 161 , 162 are consequently provided, in a position corresponding to the LED light generators 141 , 142 , with portions permeable to light , such as openings or transparent portions . Such openings or transparent portions are located at the bottom of two recessed portions 221 , 222 , which, in the assembled lamp body, form two insets that are ( specularly) symmetrical with respect to an ideal diametral plane of the lamp body . This diametral plane may be substantially identi fied with the plane of lie of the laminar element 12 . In one or more embodiments , the elements 12 , 161 and 162 and the mounting element 20 , possibly formed by complementary parts 201 , 202 made of a single piece with the shells 161 , 162 can be engaged with one another, with the possibility of mounting the lamp 10 on the support member P ( see Figure 2 ) with the aforesaid diametral plane , i . e . , with the laminar element 12 oriented in the vertical direction, in the plane of the sheet of Figures 2 and 3 , the axis X10 being oriented in a direction that is at least approximately hori zontal .

[0066] In one or more embodiments , the light generators 141 , 142 may be located in a position substantially corresponding to the ( distal ) front part 10b of the lamp 10 .

[0067] The light generators 141 , 142 may advantageously be constituted by three-chip LEDs like the ones available under the brand name OSRAM OSLON® Compact PL KW3 .

[0068] Such sources may present a light-emitting area ( LEA) of approximately 3 mm2capable of facilitating an adequate distribution of the luminous flux, for example in headlamps of a motor vehicle .

[0069] The aforesaid LED light generators 141 , 142 can be supplied and driven via circuitry organi zed ( as described further hereinafter ) in two sections designated, respectively, by 301 and 302 , housed, in general , in the rear part 10a of the lamp 10 and coming under contacts 20a, for example of a lamellar type , which are such as to provide a live contact and a ground contact for the light generators 141 , 142 .

[0070] As has been said in the introductory part of the present description, the fact of wishing to reproduce as faithfully as possible - with a lamp 10 of the type exempli fied herein - the performance of a traditional lamp ( for example , a halogen lamp ) leads to taking into account the high temperature that may be reached during operation by a solid-state source, such as the LED light generators 141, 142, with the consequent problems of dissipation of heat. This applies also to the corresponding driving circuitry, i.e., the circuitry 301, 302, in the lamp 10 exemplified here.

[0071] One or more embodiments may for the above purpose envisage that the rear part 10a of the lamp 10 may present an open-work structure (so to speak, a cage-like structure) with openings 101a and 101b for enabling flow of ventilation air through the rear base part 10a of the lamp body.

[0072] In one or more embodiments, the aforesaid openings may be arranged in two arrays of arched slits, located on opposite sides with respect to the ideal diametral plane mentioned previously, passing through the laminar element 12, for example, the one array being made in the piece 161 and the other array being made in the piece 162.

[0073] In one or more embodiments, the aforesaid two arrays of arched openings may be specularly symmetrical with respect to the aforesaid diametral plane.

[0074] In one or more embodiments, the lamp body (for example, the pieces 161, 162 in the lamp 10 as exemplified herein) may have, at least in the rear part 10a, an at least approximately circular cross section (i.e., a section transverse to the longitudinal axis X10) , optionally wider than the cross section of the front part 10b.

[0075] In one or more embodiments, the openings (slits) 101a, 101b for passage of the ventilation air may present an arched profile, i.e., a C-shaped profile, extending according to rounded (for example, circular) paths, which lie in planes transverse with respect to the axis X10, optionally according to paths orthogonal to, and / or paths centred with respect to, the axis X10. With the lamp mounted on the support member P in the conditions described previously - the axis X10 approximately horizontal and the diametral plane passing through the laminar supporting element 12 approximately vertical - the openings 101a, 101b can thus define paths of flow of ventilation air through the rear part 10a of the lamp 10 . This ventilation air is able to lap the portion of circuitry 302 performing an action of removal of heat therefrom .

[0076] The heat developed by the solid-state light generators 141 , 142 during operation can in this way be at least in part dissipated as a result of the aforesaid flow of ventilation air , this also taking into account the fact that the shells 161 , 162 can be made , as already mentioned and in a way in itself known, of metal or plastic material with good characteristics of heat conduction ( for example , pressed metal material or moulded plastic material ) .

[0077] The aforesaid flow of air (basically a convective flow) may be a forced flow imposed by an air-moving element 102 ( a blower, such as an electrically powered fan) , which is advantageously mounted ( according to a solution already proposed in the document EP 3 838 463 Al , cited previously) on the laminar support 12 in the rear part 10a of the lamp 10 , with two branches or portions 12a of the laminar supporting element 12 that have the blower 102 therebetween .

[0078] This solution ( integration of the element 102 in the support 12 ) proves advantageous for various reasons .

[0079] The blower ( air-moving element ) 102 is in ef fect integrated in the laminar support 12 , without envisaging any connector, thus avoiding the presence of external wires along the body of the lamp 10 , with the heat produced by the LEDs 141 , 142 during operation of the device impinged upon directly by the flow of ventilation air .

[0080] The distance (measured in the longitudinal direction identified by the axis X10) that separates the reference plane identified by the flange 200a of the mounting element 20 (from the centre) of the light source 141, 142 may be rendered approximately equal to 25 mm (taking into account the production and measurement tolerances) .

[0081] Likewise, the length (once again measured in the longitudinal direction identified by the axis X10) of the part of lamp that extends from the reference plane up to the extreme margin of the front part 10b may be kept within the value of 44 mm.

[0082] In solutions like the ones described here, such dimensional values may be achieved, so as to match completely with the dimensions of a socket of an H7 type and, in particular, so as to comply completely with the characteristics of emission contemplated by the ECE specifications, by envisaging that the circuitry for power-supply / driving of the sources 141, 142 comprises a driving function with a DC-DC converter of a switching type (for example, a buck converter) operating at high frequency, i.e., in a frequency range comprised between 500 kHz and 1000 kHz (for example, at a frequency of approximately 790 kHz) .

[0083] Such a solution is suited to being implemented with integrated circuits that are more compact than those of conventional switching converters in the automotive sector that operate at frequencies in the region of 100- 150 kHz.

[0084] The use of converters operating at high frequency is documented in various sectors of the art, such as, power electronics (power transformers, electrical lines, and other applications that require high voltages and currents) , telecommunications (optical-fibre communications, wireless communications, and other applications) , industrial applications of various nature (including electromagnetic compatibility and high- precision measurement testing) , and the medical sector (x-rays, nuclear magnetic resonance, tomography) .

[0085] Proposing high-frequency applications of such a nature in an automotive context as considered herein involves taking into account various factors.

[0086] One of these factors is, for example, electromagnetic interference (EMI) : the level of interference generated by a switching converter is proportional to the square of the switching frequency; hence, if the switching frequency doubles, the level of EMI can increase by four times.

[0087] Again, use in an automotive context as considered herein draws advantage from the presence of possible additional functions, such as an anti-flash function, to facilitate conversion to LED sources, overcoming problems linked to the use in a CAN (Controller Area Network) -bus context and problems linked to stability, as well as a CLC (Cold Lamp Check) function.

[0088] The latter function envisages "cold" diagnostic testing, with generation of a pulsed current and an antiflash function to verify integrity with the lamp off (i.e. not powered) .

[0089] Solutions like the ones described herein facilitate providing driving circuitry capable of supplying sources 141, 142 of the type mentioned previously by implementing a DC-DC conversion starting from the electrical wiring system of a motor vehicle such as a car (12-V battery rated voltage) via a high-frequency converter meeting in an ideal way the characteristics of the LED sources 141, 142 recalled above, namely: range of operating voltages: 10.5 to 18 V;

[0090] LED current constant from 10.5 to 18 V; luminous flux constant from 10 . 5 to 18 V; power : > 15 W; compliance with the ECE RI O speci fication on homologation for electrical wiring systems of vehicles ; mechanical dimensions in compliance with the ECE 37 speci fication; class 3 in accordance with the CISPR 25 standard for measurement of radio disturbance for the protection of receivers on board vehicles ; possibility of protection against reverse polarity and thermal derating ( or thermal foldback : reduction of power output as a function of the environmental conditions , for example as protection from high temperatures and for preventing failures ) .

[0091] According to the solutions proposed herein, this result is achieved by paying attention to the layout of the driver circuit and to the distribution of the components , it being thus possible to obtain integration thereof in a lamp 10 that : is altogether compliant with the dimensions speci fied in the ECE Regulation, as indicated in Figure 1 seen previously; and is able to dissipate in an adequate way the heat generated during operation by LED sources capable of fully meeting - at a street-legal level - the speci fications of emission expressed by the ECE regulation, for example in relation to a luminous flux of ( at least ) 1500 Im .

[0092] A lamp 10 like the one described herein can draw advantage from the use of solutions of LED driving circuitry as described in a PCT application filed by the present applicant and claiming the same priority date of the present application .

[0093] The reader is consequently referred to the aforesaid parallel application for a complete description of the structure and of operation o f the aforementioned circuitry solutions , which substantially comprise : an input stage configured to generate a voltage signal ( a bus voltage signal , Vbus ) starting from a control signal coming, for example , from a BCM (Body Control Module ) ; an electrical dummy load; a driver module ( integrated circuit or IC ) for driving light sources that is configured to supply at least one solid-state light source ; a comparator, which is coupled to the input stage and is configured to make a comparison between the aforesaid voltage signal and a lower threshold level ; and a block for enabling the electrical dummy load and the light-source driver module , the enable block being coupled to the comparator and being configured for counting a time-out time .

[0094] According to the solution described in the parallel application, the enable block is configured to : i ) in response to the aforesaid voltage signal , enable the electrical dummy load with the light-source driver module disabled, and activate counting of the time-out time ; and ii ) in response to elapsing of the time-out time , disable the dummy load, conditioning enabling of the light-source driver module to the outcome of the comparison between the aforesaid voltage signal and the lower threshold level of the comparator .

[0095] The solution described in the parallel application facilitates execution of CLC ( Cold Lamp Check) tests , countering any undesired flashing phenomena, with the capacity to handle a PWM ( Pulse-Width Modulation) operation and a function of thermal derating ( or thermal foldback) .

[0096] Figures 5 to 9 illustrate a possible distribution of the components of such a circuitry for driving the LEDs 141, 142 organized in two sections 301, 302 that can be housed: as regards the part or section 301, on an approximately disk-shaped support, designated by 400, set transverse to the axis X10 between the "proximal" end of the rear base part 10a of the body of the lamp 10 (from which the contacts 20a project) , with the possible interposition of a heatsink 400a; and as regards the part or section 302, on the same support 12 that houses the LEDs 141, 142 and the blower 102.

[0097] The support 400 may advantageously be made of a composite of glass-fibre-reinforced epoxy resin, for example of ER (Flame Retardant) material compliant with the UL94V-0 specifications on flammability of plastic materials .

[0098] The heatsink 400a can be provided as "cooling plate", i.e., as a small additional heatsink that has the function of facilitating cooling of the components mounted thereon, such as the diode bridge designated by 401 in Figure 6, which will be described hereinafter.

[0099] The heatsink 400a may advantageously be obtained as a base plate made of metal (for example, aluminium) having a thickness of 1 mm to 1.2 mm, with applied thereto a thermal pad made of TIM (Thermal Interface Material) that facilitates transfer of heat to the plate.

[0100] The support 12 may advantageously be obtained as a copper-based printed circuit board (Cu-PCB) comprising two branches 12a sidewise of the blower 102, thus facilitating electrical connection between the sections of circuitry 301 and 302.

[0101] Figure 5 illustrates a possible distribution of components that basically envisages providing : on the support 400 , a first section 301 of circuitry that is entrusted, for example , with the functions of generation of the PWM signal and thermal derating ( or foldback) and with part of the CLC and anti- flash functions ; on the support 12 , a second section 302 of circuitry that is entrusted, for example , with the remaining part of the CLC and anti- flash functions , the function of conversion proper ( for example , the integrated circuit SGM3700™) and radiofrequency (RF) filtering aimed at containing the EMI phenomena .

[0102] In particular, as illustrated in Figures 6 and 7 , on the support 400 there may be mounted, for example : on a first face of the support 400 , a bridge recti fier 401 ( for polarity management ) with associated thereto a circuit for suppression of voltage transients 402 and a capacitor 403 of a bus that is to trans fer a voltage Vbus to a circuit or module for driving in current the LEDs 141 , 142 ( this circuit being designated by 503 and being described hereinafter ) ; and on a second face of the support 400 , the control part of the circuitry for the CLC function 404 , antiflash circuitry 405 , a generator 406 for generation of the PWM signal that drives switching operation of the converter, circuitry 407 for thermal derating, and a possible further part of the capacitance of the bus 408 .

[0103] These are circuit parts that during operation do not develop heat to an extent such as to require being exposed to the flow of ventilating air by the blower 102 , which can thus be mounted on the support 12 .

[0104] As illustrated in Figures 8 and 9 , on the support 12 where the blower 102 is integrated there may be mounted, for example : on a first face of the support 12 , the power part 501 of the circuitry for the CLC function, a shunt 502 for detection of the current of the LEDs, and a power inductor 503 of the converter (for example, a buck converter) ; and on a second face of the support 12, a circuit or module 504 for driving in current the LEDs 141, 142 (for example, the integrated circuit SGM3770™) , i.e., basically, the driver operating at high frequency (500 kHz to 1000 kHz, for example 790 kHz) , and, in the proximity of the high-frequency driver 504, an RE filter 505 (for suppression of the radiofrequency disturbance) .

[0105] These are, in particular in the case of the driver 504, circuit parts that, just as the LEDs 141, 142, may develop, during operation, heat to an extent such as to benefit from being exposed to the induced flow of ventilation air of the blower 102 (air-moving element) that is integrated in the support 12 on a path of flow of ventilation air through the openings 101a 101b, with this flow of ventilation air being able to lap the high- frequency driver 504.

[0106] The driver itself 504, which is a source of radiofrequency disturbance, draws benefit from the vicinity of the RE filter 505, advantageously mounted on the same face of the support 12.

[0107] Without prejudice to the underlying principles, the details of construction and the embodiments may vary, even significantly, with respect to what has been described herein purely by way of non-limiting example, without thereby departing from the sphere of protection, as this is specified in the annexed claims. LIST OF REFERENCE SIGNS

[0108] Lamp 10 Rear part 10a Front part 10b Longitudinal axis X10 Dish P Support member 12 Branches of support member 12a Air inlet 101a Air outlet 101b Air-moving element 102 Light sources (LEDs) 141, 142 Pieces (half-shells) 161, 162 Screws 18 Mounting element 20; 201, 202 Flange for mounting element 200a Lamellar contacts 20a Insets 221, 222 Circuitry 301, 302 Supporting element 400 Spacer 400a Bridge rectifier 401 Circuit for suppression of voltage-transients 402 Bus capacitance 403 CLC circuitry (1st part) 404 Anti-flash circuitry 405 PWM generator 406 Thermal-derating circuitry 407 Bus capacitance 408 CLC circuitry (2nd part) 501 Shunt 502 Power inductor 503 Driving integrated circuit 504 RF filter 505

Claims

CLAIMS1. An automotive solid-state lamp (10) for vehicles, comprising: a lamp body (12, 161, 162, 20) extending in a longitudinal direction (X10) between a rear base portion (10a) and a front portion (10b) , the lamp body including a support member (12) , solid-state light sources (141, 142) arranged on said support member (12) at the front portion (10b) of the lamp body (12, 161, 162, 20) , and drive circuitry (301, 302) of the light sources (141, 142) arranged at the rear portion (10a) of the lamp body (12, 161, 162, 20) , wherein : the drive circuitry (301, 302) of the light sources (141, 142) includes a switching converter (504) operating at a switching frequency between 500 e 1000 kHz , the drive circuitry (301, 302) of the light sources (141, 142) comprises a control section (301) and a power section (302) , wherein the power section includes the switching converter (504) and is arranged together with the solid-state light sources (141, 142) on said support body ( 12 ) , and the lamp (10) comprises, arranged on said support body (12) in the rear portion of the lamp body (12, 161, 162, 20) , an air-moving element (102) configured to produce a ventilation air flow (101a, 101b) in the lamp body (12, 161, 162, 20) , wherein the power section (302) of the drive circuitry (301, 302) of the light sources (141, 142) is arranged on said support body (12) intermediate the solid-state light sources (141, 142) and said air-moving element (102) .

2. The lamp (10) of claim 1, wherein the drive circuitry (301, 302) of the light sources (141, 142)includes a switching converter (504) operating at a switching frequency of about 790 kHz.

3. The lamp (10) of claim 1 or claim 2, wherein the support member (12) comprises a copper-based board.

4. The lamp (10) of any of the previous claims, wherein the support member (12) is a laminar support body having opposed faces.

5. The lamp (10) of any of the previous claims, comprising a radiofrequency filter (505) arranged adjacent said switching converter (504) .

6. The lamp (10) of claim 4 and claim 5, wherein the switching converter (504) and the radiofrequency filter (505) are arranged on a same face of the laminar support body.

7. The lamp (10) of any of the previous claims, wherein the support member (12) comprises two branches (12a) having the air-moving element (102) therebetween.

8. The lamp (10) of any of the previous claims, wherein the lamp fits a spatial envelope according to Figure 2 of Addendum 36 of ECE Regulation 37 for H7 lamps (SAE 9004 or 9007) .

9. The lamp (10) of any of the previous claims, wherein the solid-state light sources (141, 142) comprise LED light sources arranged aligned with the longitudinal direction (X10) of the lamp (10) .

10. The lamp (10) of claim 9, wherein the solid- state light sources comprise a linear array of three LED light sources arranged aligned with the longitudinal direction (X10) of the lamp (10) .

11. The lamp (10) of any of the previous claims, wherein the solid-state light sources (141, 142) when activated, emit a luminous flux of at least 1500 Im.

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