BR102012032526A2 - LIGHTING SYSTEM FOR A FRONT HEADLIGHT FOR A MOTORIZED VEHICLE - Google Patents

Abstract

LIGHTING SYSTEM FOR A FRONT HEADLIGHT, IN PARTICULAR FOR AN ENGINE VEHICLE. A lighting system for a motor vehicle, capable of producing a complex profile cut-out beam comprising: first and second lighting devices (1,2) configured to generate a first beam producing at least partially respectively a first and second portion of the section profile, a lens (10) having two parts (11,12), each being dedicated to output from the exit lens (10) of one of a first beam or a second beam comprising a upstream face (13) and one downstream face (14), the two parts (11,12) being connected together on the upstream face (13) by an upstream junction (19) and on the downstream face ( 14) by a downstream junction (20), at least one of which is tangentially formed; a reflector (6) receiving the rays at the output of the first beam and producing reflected rays towards the lens (10), the reflector (6) and the lens (10) such that the first beam is parallel to the optical axis ( x).

Description

"LIGHTING SYSTEM FOR A FRONT HEADLIGHT FOR A MOTORIZED VEHICLE"

The present invention notably relates to a headlamp lighting system, particularly applicable in the automotive industry. More particularly, the invention may be used to produce light beams.

performing a function known as "low beam". The invention also relates to a method of manufacturing an optical device that can be implemented in the lighting system.

In the latter field, lighting modules or headlights are known, among which conventionally they are essentially found:

- low beam headlamps, with a road lane of around 70 meters, which are used essentially at night and whose beam of light is distributed in such a way that it cannot overshadow the driver of an approaching vehicle. Typically, this beam has a top section with a horizontal portion, preferably around 0.57 degrees.

below the horizon so as not to illuminate the area within which the driver of a vehicle arriving in the opposite direction should be located,

- long-range, high beam headlamps, the range of which may reach 600 meters on the road and which must be switched off when encountering or following another vehicle so as not to obscure its driver,

- fog lights.

More recently, partial lighting modes have been developed consisting of the formation of a selective beam showing dark areas where vehicles or persons not to be dazzled are at least potentially located. Road lighting is improved over conventional low beam headlamps alone, while at the same time avoiding the discomfort of excessive light for drivers encountered or followed, whose discomfort would be generated by, for example, front headlights. conventional high beam. Such selective lighting function is alternatively referred to as ADB (Adaptive Steering Beam). Such selective beams have a cutting profile, in other terms, a

line, a plane perpendicular to the optical geometrical axis, connecting the illuminated surface area and the erased surface area. Lighting devices, whose cutting profile is complex, have recently been developed in order to better adapt the projected beam to the desired lighting distribution. Thus, there is notably the Z-shaped cut having two changes of cutting direction or even two more angles. There are also cuts with a single change of direction (a single angle), for example in the form of a 'V'. This type of cut beam is currently, in the case of headlights using LEDs, most of the time generated by the juxtaposition of two lighting modules. One of them produces a beam that is substantially flat, with a straight cut parallel to the horizon and sweeping a relatively wide angular sector.

The other module creates a narrower beam around the optical geometry axis and with a specific orientation cut, such as a V or a 'Z', having at least one change of direction. Simultaneous application of the two beams described above generates a global beam with a complex cut, having a substantially horizontal part.

Such a technique is, however, complex and its means are voluminous. The unaesthetic aspect produced by the headlight thus designed must also be noted, notably by the non-unitary nature of its front face.

The object of the present invention is to overcome all or part of the above mentioned drawbacks.

For this purpose, the present invention relates to a headlight illumination system notably of a motor vehicle, this system being capable of producing an output beam oriented along an optical geometrical axis and having a section whose profile comprises at least two portions in different instructions, the system comprising:

a first device emitting rays of light configured to generate a first beam forming a portion of the output beam and producing at least partially a

first of at least two portions of the section profile,

a second device emitting rays of light configured to generate a second beam forming a portion of the output beam and producing at least partially a second of at least two portions of the section profile,

characterized by understanding: i. an output lens with two lens parts, each dedicated to the output

from the output lens of a different one from the first beam or the second beam, comprising an upstream face and a downstream face in the direction of light beam travel of the first and second emission devices, the two lens parts being connected together on the upstream face by an upstream joint and on the downstream face by a downstream joint, at least one of or an upstream joint or a downstream joint being formed tangentially;

ii. an intermediate reflector configured to receive light rays from the first emitting device and configured to produce reflected light rays toward the portion of the output lens dedicated to the first beam output, the intermediate reflector and the output lens being configured so that the first beam is substantially parallel to the optical geometric axis of the system.

An advantage of such a system is that it offers a combination and cooperation of the optical means employed in beam output. Although fully separate modules are currently used for each of the two beams, the invention makes the lens portion of the common optical output device. Such an inventive approach is contrary to what a technician would be inclined to do because the appropriate optical interface for one of the light-emitting devices is usually inadequately adapted to be used for the second device. The invention overcomes this obstacle by means of an intermediate reflector allowing, together with other components located in the light ray path of the first device, a substantially stigmatic assembly to be produced, the output of which is a beam substantially parallel to the optical geometrical axis. It is possible that one of the junctions upstream or downstream is formed

tangentially without the other junction being formed tangentially.

Preferably, the lens thus implemented produces surface continuity between its portions without using any connecting surfaces that are optically inactive, never illuminated, and potential sources of spurious light, each being dedicated to one of the two beams forming the beam. global output. The appearance is consequently improved.

The lens can furthermore be manufactured as a single solid part, notably by injection, which reduces the number of parts required.

Other options of the invention corresponding to non-limiting embodiments of the invention are introduced below:

- the upstream and downstream junctions are formed tangentially;

- the first device is configured to generate a first beam producing a cut with a V-shaped profile or a 'Z';

- the second device is configured to generate a second beam producing a section with a substantially straight and horizontal profile;

- the downstream face of the lens is a fully derivable surface for the first

order;

- the upstream face has, on a first lens portion dedicated to the first device, a first input portion being configured to form a

portion of the lens extending outwardly from the upstream junction to the edge of the upstream face where the first portion is situated;

- the upstream face has, on a first lens portion dedicated to the first device, a first inlet portion configured to form a lens portion having, from the upstream joint to the edge of the upstream face, where the first

part is situated a profile with a shape of the Gaussian curve;

- the first device comprises at least one light source, a reflector arranged to generate a reflected light beam from the light rays of the light source and to direct said reflected beam towards the intermediate reflector and a mask having an edge located in the path of the reflected light beam and configured to form at least partially the first of at least two portions of the section profile;

- the second device comprises at least one light source, a reflector arranged to generate a reflected light beam from said light source and to direct

the reflected light beam towards the upstream face of the exit lens and a mask having an edge located in the path of said reflected light beam and configured to at least partially form the second of at least two portions of the cut profile;

the portion of the output lens dedicated to the second device is configured to form an infinity image of the second device's mask edge on a

two-dimensional construction in each plane perpendicular to the edge of the mask.

The invention also relates to a vehicle equipped with at least one system of the present invention and advantageously two systems, each producing a beam towards the front of the vehicle and laterally spaced. The invention further relates to a method of manufacturing a lens for a

lighting system.

Other features, objects and advantages of the present invention will become apparent upon reading the following detailed description and with reference to the accompanying drawings given by way of non-limiting examples and in which: Figure 1 separately shows various system constituents of the present invention.

invention in a first embodiment.

Figure 2 illustrates in perspective the path of light rays in the embodiment of Figure 1.

Figure 3 is a top view of the embodiment in Figures 1 and 2.

Figure 4 is a front view from a point opposite the exit region of the

output beam in the embodiment in figures 1 to 3.

Figures 5 to 8 show a second embodiment of the invention, with views, respectively, similar to those of figures 1 to 4.

The terms "vertical" and "horizontal", which may be used in the present description to denote directions, notably the directions of a beam cut, in an orientation perpendicular to the horizon plane for the term "vertical", and according to with an orientation parallel to the horizon plane for the term "horizontal". They must be considered under the operating conditions of the device in a vehicle. The use of these terms does not mean that slight variations around the vertical and horizontal directions are excluded from the invention. For example, an inclination with respect to these directions in the region around 10 ° is considered here as a slight variation around these two special directions. As previously indicated, the system of the invention advantageously combines two light beam generating means which, when combined at the output, can produce a complex output beam, for example, capable of serving a low beam function.

In a preferred embodiment, one of the emission devices used in the system of the invention produces a beam with a two-direction cut, generally with a sudden change of direction and notably an angular sector between the two directions. less than 90 °. This part of the exit beam, forming a first portion of the cut, may be relatively spatially compact and form a light concentration with an accurate dark to light profile near the horizon. The system of the invention advantageously uses a second emission device 2.

having the function of forming another part of the output beam, this time more spatially spread out noticeably in a horizontal direction and constituting a second portion of the cut which is substantially straight and horizontal. It will be readily understood that the combination of device 1 and device 2 allows the formation of a complex output beam, where two beams overlap each other in order to produce either a V or Z complex cut or any another type of complex profile, and a horizontal section, with significant beam diffusion in this section direction.

Exemplary preferred embodiments of each of the 1.2 light-emitting devices will be presented below in the description. Referring to Figure 1, the above mentioned devices 1, 2 are

shown, together with an intermediate reflector 6 and an output lens 10. It will be noted that despite the use of two light-emitting devices 1, 2, here a single lens 10 is formed. In order to allow the single output lens 10 to provide the optical output interface function for the two beams respectively generated by the emitting device 1 and the emitting device 2, the intermediate reflector 6 is employed.

More particularly, with reference to FIG. 2, a light ray channel is illustrated from a source 3 integrated in the emitting device 1 towards the downstream face 14 of the output lens 10 which may for example be the front face of a motor vehicle headlamp.

It can be seen from figure 2 that the rays emitted by the emission device

1 impact the intermediate reflector 6 so that they are reflected towards the upstream face 13 of the exit lens 10. Then the rays entering the exit lens 10 follow a deflected path allowing light rays to form a beam of the type low beam are obtained at the exit of the lens 10 over its downstream face 14 with a V-shaped or Z-shaped cut. In particular, all rays passing through the second focal point of the emitting device 1 emerge from the lens 10 on its downstream face 14 parallel to one another and substantially parallel to the optical geometric axis of the complete system. The optical geometrical axis χ is more particularly illustrated in Figure 3, this figure further showing a top view of the system according to the invention.

More particularly, it can be seen here that the exit lens 10 comprises a complex configuration associating, according to a lateral orientation (substantially perpendicular to the optical axis x), two parts, namely a more specifically dedicated first part 11. the transmission of light rays from the first device 1, and a second part 12, more particularly devoted to the transmission of light rays from the second device 2. Although the exit lens 10 is advantageously comprised of a single piece and, advantageously, formed by a one-piece injection, for example made of a PMMA (poly (methyl methacrylate)) type polymer material, a region where the junction is formed between the first part 11 and the second part 12 is shown in the figure 3, by two parallel rectilinear lines. More particularly, on the upstream face 13 of the exit lens 10, an upstream junction 19 is formed. Preferably, there is no discontinuity in the vector director about the

upstream face surface 13 of lens 10 at upstream junction 19, thus there is a surface here that is fully derivable for the first order.

Advantageously, similarly, the downstream junction 20 situated on the downstream face 14 forms a surface continuity between the first part 11 and the second part 12 of the exit lens 10. It should be noted that on the downstream face 14, this allows a complete front face of the system to be formed with a continuous appearance.

Both the upstream junction 19 and the downstream junction 20 allow the two lens parts to be advantageously connected together to form a smooth transition, in other words, without abrupt variation in lens thickness or shape at these locations. The joint being formed tangentially is meant that the tangents of the two parts 11, 12 are thus common at these locations (or at least one of the two joints) such that their bonding is continuous and progressive.

As previously mentioned, the light emitting device 2 can be configured to produce a horizontally cut emission with a relatively wide lateral spatial distribution. In order to achieve this, an exemplary embodiment of the sending device 2 is presented below.

In this example corresponding to various figures 1 to 8, the emitting device 2 comprises at least one light source 4, for example composed of at least one light emitting diode. In addition, the emitting device 1 comprises a reflector 7 advantageously configured to connect a cavity around the source 4 to reflect the rays emitted by the source 4 towards an upstream facing region 13 of the source. exit lens 10 on the second part 12 of lens 10. A reflector 7 as a part of a substantially ellipsoidal shaped revolution element may notably be used whose cross-sectional shape in a horizontal plane consists of an ellipse whose main geometrical axis passes through the center of the light source 4. This configuration is not, however, limited and a reflector 7, a mask 9 and a first lens part 12, according to the teachings of FR2872257, may preferably be used. . In this case the surface 18 is a part of a torus and in particular a cylinder.

Figure 4 shows a rear view of the device 2, and the shape of the reflector 7, to connect an internal space for the source location. Advantageously, as shown, the reflector 7 is concave and equipped with a light source 4 within its cavity so as to illuminate at least downwards. The reflector 7 is associated with a flat, preferably horizontal, plate represented by the mask 9. The plane of the mask 9 advantageously passes through the center of the light source 4. The mask 9 is especially formed by a flat element located in the region. where the rays reflected by the reflector 7 exit, in order to prevent the output of part of them. Advantageously, the mask 9 performs a return function and itself consists of a reflective surface so as to reflect the return rays it receives towards the exit through another direction.

The shape of the edge 22 of mask 09 may vary according to the desired cutting profile for this portion of the output beam. By way of example, the edge 22 may be straight or slightly convex, as is the case in the figures, for example being an arc of a circle.

In summary, when generated by source 4, the light rays are directed, in part, directly towards the output of device 2 and impact the upstream face 13 of lens 10 on the second part 12. Another part of the rays reflected by the reflector 7 is intercepted by mask 9 and edge 22 of mask 9 determines a cut profile.

Turning to Fig. 2, an exemplary embodiment of the emitting device allowing another portion of the output beam to be formed is now described. In this figure, device 1 comprises at least one light source 3, which may, like source 4, consist of at least one light emitting diode. Quite similar to device 2, device 1 preferably comprises a reflector 5 in the form of a semi-ellipsoid whose inner surface connects a cavity for propagation of light rays and forms a reflective surface capable of reflecting light rays. generated by source 3 towards an output portion of device 1. Advantageously, source 3 is situated at a first focal point of the elliptical cross-section of the reflector 5. In this way, the rays emitted by the source are substantially reflected here in the region of the source. second reflector geometric focal point 5. At this second focal point, a mask 8 having an edge 21 with a particular profile is implemented to produce a predetermined shape cut in the beam. As in the case of mask 9, mask 8 may have a reflective surface to reflect the rays it receives and thus perform a return function. Similarly to device 2, it will be readily understood that part of the rays emitted by source 3 is reflected by the reflector 5 and directly sent to the output of device 1. Another part of the rays emitted by source 3 is first reflected by the reflector then intercepts the Mask surface 8.

In view of the complex shape of the section profile to be obtained with the beam generated by the first device 1, the edge shape 21 of the mask 8 is designed to produce such a profile. Whether they are directly reflected by reflector 5 or intercepted by mask 8, the emerging rays from device 1 are received on an intermediate reflector 6. In the case shown, the reflector is shaped like a sheet with a reflective surface. Any type of mirror can be used for the intermediate reflector 6. It should be noted that the shape of the reflection surface of the intermediate reflector 6 is designed so that the rays from the second focal geometric point of the reflector 5 once reflected, impacts the upstream face 13 of the lens 10 in its first part 11. This light path is illustrated in Figure 2, wherein the rays entering the lens 10 are subsequently propagated within the lens and exit via the downstream face 14, in the form of a beam of parallel rays substantially oriented along the optical axis x.

It should be noted that the combination of the geometric shapes chosen for the border

21 of the mask 8, the intermediate reflector 6 and the lens shape 10 allow the desired result to be obtained, namely a complex cut beam existing parallel to the optical axis x.

Figures 1 to 4, which were used to substantiate the foregoing description, show an emitting device 1 below the lens 10 and the intermediate reflector 6. The term "below" means that the device 1 is at a level with a height that is smaller in the Z direction, which may be vertical.

In another embodiment, device 1 may be easily located above lens 10 and intermediate reflector 6. This case is not illustrated. The embodiment shown in figures 5 to 8 shows an alternative to this

A configuration wherein the emitter 1 is laterally positioned relative to the lens 10, with a y-offset, which may be the horizontal direction.

Any other orientation of device 1 and any other location of this device with respect to the rest of the system is within the scope of the present invention. Comparison of the shapes of the output lenses 10 between the embodiment in the

Figures 1 to 4 and the embodiment in Figures 5 to 8, however, reveals that the location of the device 1 may influence the shape of the lens 10, especially in its first part 11. Thus, while the embodiment in Figures 1 4 shows a first inlet portion 17 of the upstream face 13 of lens 10, with a profile in the form of a torus portion with a cross-section as an arc of a circle, the first inlet portion 17 illustrated in the embodiment. 5 to 8 is enlarged outwardly from the upstream junction to the free side edge of the first inlet portion 17, in other words, that situated near the emitting device 1. The downstream face 14 may have the shape of a bell.

Before going into details of examples of determining the format of the inventive system components, some general parameters are data which may be employed and which are satisfactory:

lens width 10 in the y direction, for example shown in figure 20: 50mm;

total lens height 10 in z-orientation, for example shown in figure 15: 40 mm;

- minimum lens thickness 10: 2 mm;

- separation between edge 22 and second inlet portion 10: 35 mm;

- distance between the surface of the intermediate reflector 6 and the first outlet 15 of the downstream face 15: 70 mm.

These parameters are given by way of example only and, for example, with an output lens 10 having an index of 1.49 corresponding to PMMA.

The system is arranged such that the focal point of the assembly formed by the intermediate reflector 6, the first inlet portion 17 and the first outlet portion 15 corresponds to the second focal point of the first reflector 5. In the embodiment illustrated in FIGS. 1 to 4, using the parameters given above, this, for example, gives the position of this second focal point at the following point (coordinates in millimeters): '-39,7343 ^

F =

0

-24

In the embodiment shown in figures 5 to 8, a possible positioning of this second focal point F is:

'-39,7343 ^

F =

-29 0

all being always indicated in the reference frame x, y, z, having as the origin of the reference frame the middle of the downstream face part 14, in the middle of its height and in the middle of its width.

A possible implementation method of the system of the invention is set forth below.

In general, the following steps can be implemented:

1a.) Determining the optical and geometric parameters of the second lens part 12 to provide the output beam portion corresponding to the horizontal section produced by the device 2. For this purpose, a lens design known as a toric lens may be appropriate;

2nd ) Downstream face definition 14: The shape of the downstream face 14 can be adjusted to adapt the lens to produce the output beam portion corresponding to device 1 (with a complex cut). However, it is advantageous for a uniform appearance of the front face of the system to implement a downstream face 14 similar to the first part 11 and the second lens part 10. Thus, as shown in figures 3 and 7, the system is arranged such that the first outlet portion 15 is simply the continuity (without variation along x) of the second portion 16. The profile in the ζ direction of the downstream face 14 is also similar between the first portion 15 and the second portion 16. , notably following a convex line. This definition of the first outlet portion 15 of the downstream face 14 gives the restrictions to be imposed on the first inlet face portion 17 of the upstream face 13 and the shape of the intermediate reflector 6. Since the first portion 11 of the lens 10 cannot be stigmatic, the intermediate reflector 6 / first input portion 17 / first output portion 15 combination is arranged to form a stigmatic array for light rays exiting device 1, edge 21 of mask 8 being placed at the focal point object of this set.

3a.) Determination of a first inlet portion 17 / intermediate reflector 6 pair:

For this step, an inverse return principle can be put into practice: using two radii oriented along the optical geometric axis χ and coming from infinity at the downstream face input 14 of the first part 11 of lens 10, the geometric characteristics of the first input portion 17 and intermediate reflector 6 are determined such that these rays converge to a single point (F), the focal point object of the first part 11 assembly of lens 10 / intermediate reflector 6. This point F is also the second focal point of reflector 5.

4a.) Optimization of edge profile 21 of mask 8 and portion 17

If sharp cutting is desired, the shape of the 8 edge of the mask 8 and the lens (in the first inlet portion 17) is optimized to limit the deflections of certain radii around the cut line, notably those passing through points laterally distant from the focal point of the 6 + 11 set. Similarly, the shape of the portion 17 can simultaneously be optimized within certain reasonable limits (eg center thickness) and under certain constraints (continuities of the first and second 10

15

20

25

order along the junction line with the second part 12, required in order to obtain smooth faces. Symmetry is optional, but desirable with respect to plane zx) to optimize cutting sharpness. In the exemplary embodiment detailed hereinafter, it is assumed that the smallest radius of the entry face of the upstream face 13 is considered to be very large. In this case, the upstream face 13 is cylindrical with a vertical axis, and the continuity conditions between the front face 13 and the portion 17 in three dimensions can be ensured by making the portion 17 also cylindrical and ensuring the continuity conditions ( first and second order), in two dimensions between the straight sections of the two cylinders at the point where they meet. Optimization of the portion 17 and edge of the mask thus passes for simultaneous optimization (with the aim of obtaining the best cutting edge when moving away from the optical geometry axis) of two curves. A known solution is to optimize such problems by modeling each curve with a polynomial function of a previously chosen degree or with a Bezier curve passing through a number of points with arbitrary abscissa values and searching for values of the coefficients of the polynomials or point ordinates that optimize the chosen cost function (in this case, the deflection of the rays passing through the edge of the mask in relation to the cut after reflection in the intermediate reflector 6 and passing through the lens).

These general considerations regarding the possible method for determining system elements are illustrated by the following calculations, which refer to the example presented for the invention with reference to Figures 1 to 4:

Figure 9 shows schematically the profile of the downstream face 14 of lens 10. It can be determined to satisfy the projection of the beam produced by the second device 2, with a distance T between the edge 22 of the mask 9 and the inlet. from lens 10 of thickness E to a cylindrical face 11 with a vertical geometrical axis and a parallel straight cross section at 9 at distance Τ. The origin 0 (0, 0, 0) of the reference frame is chosen to be in the middle of the lens 10 in the direction of its height (z direction) and in the middle of the part 15 in the y direction and set to 15.

The following calculations allow any point P of the downstream face 14 to be determined with the dimensional parameters illustrated in Figure 10. Parameter "n" represents the refractive index of lens 10.

sin i -.

VR2 + H2

H

sin i dh sin r = - = -

- => dh = 1

Oh

η l

nylT2 + h 10

15

20

λ / τ2 + h2 + nl + (E-dx) = Τ + ηΕ => nl - dx = T - λ / Τ2 + h2 + (η-1) Ε

/-.il-, .- V I = T-ylT2 + h2 + (η-1) Ε

I

η1 {Τ1 + hz)

from which l (h, e) is extracted

from which dx (h, E) and dh (h, E) are extracted; or dx (hmaXlE) = emin from which E is extracted

where emln is the minimum lens thickness at cross section 10 (an important physical parameter for practical object formation imposed by molding limitations)

giving P =

'dx -E ^

y

h + dh

ν

= P (h, y)

The downstream face 14 is thus defined.

2nd ) In order to determine the shape of the first input portion 17 of lens 10, Figure 11 shows that the curve with the function χ = q (y) is defined in the (x, y) plane, corresponding to the lens thickness variation. 10 in your first part 1.

Figure 12 shows the location of any point Q of the first input portion 17 in the plane (x, z).

Any point Q on the surface of the first input portion 17 corresponds to a point P of the reverse return output face of a radius originating at infinity on the optical axis x:

f iiy)

Q = y

h + dh + {q (y) -dx + E) tg (r) j

It is advantageous for the upstream face 13 to be cylindrical with a z-oriented generator.

With this assumption, in point Q, the following can be written:

- for the tangent T in the plane (x, y) for the profile of the first input portion 17:

'dxΛ

T =

dy vl /

Voon

- for normal in Q, in this same plane x, y:

N = Ur (J)

With the inverse return method, let iq be the vector director of the incident radius

in Q (corresponding to a parallel radius ax incident on the output surface 15 refracted toward Q), Nq is the normal Q vector for the lens surface and rq is the ray vector director pictured in Q (in reverse) , the following can be written: 1

N =

9 Vi + q, 2 (y)

r -cosr ^

q '(y)

THE

1C =

ν "bELL

\, Nq =

cos r

Vi + 2 '(y)

10

15

7q = n (Tq - (Tq · Nq) Nq) + ^ -n \\ - (Tq-Nqy) Nq

where η is the refractive index of the lens material.

r ^ thus gives the radius deflection at the upstream face exit 13 in the method

inverse.

3.) Taking into account the calculations of the preceding point 2), the equation of a reflector 6 is sought which, for any point Q of the input portion 17, reflects back the radii calculated above on a single point F, according to the inverse return method.

This equation is that which defines any point M of reflector 6 such that M = Q + λΓρ

The following can be written (Fermat's theorem, that is, constant optical path of a flat wave surface perpendicular to χ and tangent at 15 to the point F): E-dx + ηΡΟ + λ + MF = K

MF = K-E + dx-nPQ

* -ν- '- Â - K - A

k

MF2 = Jt2 - 2 U + A2 = (ÕF - X7qj = QF2 + λ2-2 AQF ^ q

2Á (ÕF.rq-k) = QF2-k2 from which AeM are extracted

K (optical path) can be determined by setting xM (h = 0; y = 0) = - D0 (system depth being limited to optical surfaces),

'χκίΚνΫ

where it was proposed that M (h, y) = yM (h, y) (This is an equation in K) 10

15

20

25

If q (0) = - E0 and q '(0) = 0, K = D0 + (n-1) E0 +

FM0 where M0 =

'-D, ^ 0 0

In the general case, this value is a good starting point for the numerical solution of the equation in K.

It should be noted that K is determined using the geometric characteristics.

Further, depending on the profile of the first inlet portion 17 chosen, particular points can easily be deduced and additional constraints attached. For example, in the embodiment in Figures 1 to 4 at junction 19:

q =

'-'- Ϊ

= -E

= tga where L is the width of the lens and α is the angle of the upstream junction

19 with respect to y.

Optionally can also be placed:

v2,

q (0) = -E0

. (L) q 2

= -E2 (thickness at free end of part 11)

(thickness in center of bell-shaped profile) = tga2 (where a2 is the free-end inclination of part 11)

30

q '(0) = tga0 (slope in center of concave profile)

Moreover, if the component in the y direction of the downstream face 14 of the first part 11 is rectilinear and in the y direction, α = 0. This is the hypothesis formulated in the preceding calculations and is a non-limiting assumption.

4th ) The shape of the mask 8 for improved cutting sharpness can be optimized. To this end, a method may be applied for determining the direction when it emerges from the first output portion 15 of a radius from any given point S and reaching the intermediate reflector 6 at an M point. For each radius in question, The difference is calculated between the desired and the calculated cut.

If S is over edge 21, this difference is ideally zero. It is then sought to minimize these differences by varying the parameters of the equation q previously given and two of the coordinates of S (one of the coordinates is fixed). By repeating this method for multiple points S, q is optimized while at the same time optimizing edge 21.

Generally, the edge 21 of the mask 8 thus determined has a complex profile designed to generate a specific cut. In the embodiment in Figures 1 to 4, this profile is three-dimensional with a point on the main axis a of the reflector elliptical profile 5 forming a support (which may be substantially in the middle) between two curved lines, one projecting sideways. opposite from reflector 5, the other most reflective of said reflector 5.

The case of Figures 5 to 8 also illustrates a border 21 with a complex profile in three dimensions. In both situations, the cross-section along a perpendicular to the main axis "a" has an 'Z' shaped global envelope with two parallel and more or less straight end regions at different heights and a more connecting region. or less complex (from a straight line with a wavy profile) between the two end regions, these three regions forming an elbow angle assembly, producing the complex cut.

In use, devices 1 and 2 are advantageously activated simultaneously in order to

generate the two specific parts of the output beam.

The invention is not limited to the described embodiments and covers all embodiments according to their spirit.

15

20

25

30

35

REFERENCES

1. First device

2. Second device

3. First source

4. Second Source

5. First reflector

6. Intermediate Reflector

7. Third reflector

8. First mask

9. Second Mask

10. Exit Lens

11. Part One

12. Second Part

13. Upstream

14. Downstream

15. First out portion

16. Second Outing Portion

17. First Portion

18. Second Portion

19. Upstream join

20. Downstream Junction

21. Mask Edge

22. Mask Edge

23. Large portion 24. Gaussian curve portion x: Optical geometry axis a: Main geometry axis

Claims (11)

1. Headlight lighting system, notably for a motor vehicle, this system being capable of producing an output beam oriented along an optical geometrical axis (x) and having a section whose profile comprises at least two portions with different directions. the system comprising: - a first device (1) emitting rays of light configured to generate a first beam forming a portion of the output beam and producing at least partially a first of at least two portions of the section profile, - a second device (2) emitting rays of light configured to generate a second beam forming a portion of the output beam and producing at least partially a second of at least two portions of the section profile, characterized in that it comprises: i. An exit lens ( 10) having two lens parts (11,12), each being dedicated to the output from the output lens (10) of a different one from the first beam or of the second beam, comprising an upstream face (13) and a downstream face (14) in the direction of travel of light rays from the first and second emission devices (1,2), the two lens parts (11) 12) being connected together on the upstream face (13) by an upstream joint (19) and on the downstream face (14) by a downstream joint (20), at least one or upstream joint ( 19) or a downstream junction (20) being formed tangentially; ii. an intermediate reflector (6) configured to receive light rays from the first emission device (1) and configured to produce reflected light rays towards the portion of the output lens (10) dedicated to the output of the first beam, the intermediate reflector (6) and the output lens (10) being configured such that the first beam is substantially parallel to the optical geometrical axis (x) of the system. System according to Claim 1, characterized in that the exit lens (10) consists of a single integral part. System according to either of the preceding two claims, characterized in that the upstream junction (19) and the downstream junction (20) are formed tangentially. System according to one of the preceding claims, characterized in that the first device (1) is configured to generate a first beam producing a cut with a 'V' or 'Z' shaped profile. System according to one of the preceding claims, characterized in that the second device (2) is configured to generate a second beam producing a section with a substantially rectilinear and horizontal profile. System according to one of the preceding claims, characterized in that the downstream face (14) of the lens is a fully derivable surface for the first order. System according to one of the preceding claims, characterized in that the upstream face (13) has, in a first lens portion (11) dedicated to the first device (1), a first inlet portion (17) being configured to form a portion of the lens extending outwardly from the upstream junction (19) to the edge of the upstream face (1) where the first part (11) is situated. System according to one of Claims 1 to 6, characterized in that the upstream face (13) has a first input portion in a first lens portion (11) dedicated to the first device (1). (17) configured to form a portion of the lens having, from the upstream junction (19) to the edge of the upstream face (13), where the first part is situated, a profile having a Gaussian curve shape. System according to one of the preceding claims, characterized in that the first device (1) comprises: - at least one light source (3); a reflector (5) arranged to generate a reflected light beam from the light rays of the light source (3) and to direct said reflected beam towards the intermediate reflector (6); a mask (8) having an edge (21) located in the path of the reflected light beam and configured to form at least partially the first of at least two portions of the cut profile. System according to one of the preceding claims, characterized in that the second device (2) comprises: - at least one light source (4); a reflector (7) arranged to generate a reflected light beam from said light source (4) and to direct said reflected light beam toward the upstream face (13) of the output lens (10); a mask (9) having an edge (22) located in the path of said reflected light beam and configured to at least partially form the second of at least two portions of the cut profile. System according to the preceding claim, characterized in that the portion of the output lens dedicated to the second device (2) is configured to form an infinity image of the edge (22) of the mask (9) of the second device (2) in a two-dimensional construction, in each plane perpendicular to the edge of the mask (9).