• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    This optical device (2) is intended to form a light spot of predetermined shape on a target (20) forming part of a wavelength conversion device, from a light beam (F) emitted by a diode laser (4) and swept by a member (18) of scanning means. The laser diode (4) emits the beam (F) along an optical axis (X), a slow axis (Y) and a fast axis (Z), these axes being perpendicular two by two. It comprises optical means forming both a projection lens (6), in the plane containing the optical (X) and slow (Y) axes, and an anamorphic (8), in the plane containing the optical axes (X) and fast (Z).
    公开号:FR3023013A1
    申请号:FR1456118
    申请日:2014-06-30
    公开日:2016-01-01
    发明作者:Pierre Albou
    申请人:Valeo Vision SA；
    IPC主号:
    专利说明:

    [0001] The present invention relates to the technical field of optical devices for a motor vehicle. More particularly, the invention relates to an optical device for fire for a motor vehicle. A motor vehicle generally comprises several lights constituting lighting or signaling means fulfilling various functions. These functions are in particular fulfilled by the emission of a light beam whose properties vary from one function to another. When the light beam must have a high light intensity, it is known to use a high-luminance light source, for example a laser. It is then necessary, on the one hand, to modify the light spectrum of this beam by wavelength conversion means known per se, and, on the other hand, to collimate this beam so as to form a spot light of predetermined shape on a target formed by said converting means, by means of a scanning means member for scanning a light spot, formed on said member, on the wavelength converting means in order to produce a beam light emerging from the fire after projection by a projection member having the desired shape. However, these different means are subject to space constraints, especially at the front of the motor vehicle. Indeed, the front portion of a motor vehicle includes many organs whose maximum size should be limited. It will further be noted that the size of the spot formed by the beam on the target in the absence of scanning determines the resolution of the projected images and is constrained by the application (the largest dimension of the spot must be less than 1mm, preferably less than 0.3mm). To overcome this problem, a first solution consists in using a laser diode, which generally occupies less space than a conventional laser, and a scanning means member formed by one or more micro-mirrors, more commonly referred to as MEMS acronym for the Anglo-Saxon terms MicroElectroMechanical System. The intensity of the light beam emitted by a laser diode is certainly less than that emitted by a conventional laser of the same power, but it remains quite satisfactory. In practice, the laser diode (high power, greater than 1 W radiated) has an exit facet of the generally rectangular light beam and emits a light beam according to several propagation modes, which prohibits to consider as source the waist of the beam as is conventionally done for other lasers (we must consider the output facet): the beam is propagated along an optical axis, which corresponds to the direction of propagation of the energy carried by the beam, a slow axis and a fast axis, these three axes being perpendicular two by two. It is impossible to simply collimate the beam on the scanning means member with a single conventional lens when this member is located at a high distance from the collimation device (greater than 50 mm in particular), which is in practice the more often the case. Indeed, if a lens of small focal length is used, the size of the exit facet of the source along its large dimension causes an unacceptable divergence of the beam leading to a too large light spot on the conversion device. If a lens of large focal length is used, the divergence of the beam is small, but its large starting axis (on the exit surface of the lens) is too large compared to the desired spot size, because of the divergence 10 important of the beam of the diode along its fast axis (perpendicular to the long side of the output facet) .A simple collimation to operate imposes often unacceptable geometric constraints on the relative positions of the laser diode and the conversion device. A second solution is to focus the beam on the target. But the geometric constraints mentioned above lead to forming a stain extending beyond the contour of the scanning means member, so that a diaphragm must be used to avoid unnecessary illumination of surrounding elements. organ. This causes a significant decrease in the performance of the device, which is not acceptable. An object of the invention is to provide a device capable of forming a light spot of predetermined shape on the conversion device from a light beam emitted by a laser diode, the relative position of the laser diode with respect to the means of scanning means and the conversion device being determined. For this purpose, an optical device according to the invention is provided for forming a predetermined luminous spot on a target forming part of a wavelength conversion device, from a light beam emitted by a diode. laser and scanned by a means of scanning means, the laser diode emitting the beam along an optical axis, a slow axis and a fast axis, these axes being perpendicular in pairs, characterized in that it comprises optical means 30 forming both a projection lens, in the plane containing the optical and slow axes, and an anamorphic, in the plane containing the optical and fast axes. Thus, the optical means forming a projection lens in the first plane containing the optical and slow axes, the optical device simply focuses the source of large extent in this first plane on the conversion device. Given the small divergence of the beam along the slow axis, this makes it possible to ensure on the output face of the optical system a beam dimension close to the size of the scanning means member in the plane considered, of so that the beam converging towards the spot (image, smaller dimension) located on the conversion device passes in greater part at least on the means of scanning means located between the optical device and the conversion device . The optical means also forming an anamorphic in the second plane containing the optical and fast axes, the optical device makes it possible to shape the highly divergent beam in this second plane so that the dimension in this second plane of the formed light spot is contained in the scanning means member, while having as small a dimension as possible (less than or equal to the maximum spot size for the application) on the conversion device. A light spot of desired shape is thus well formed on the conversion device, passing through a scanning device of given size from a laser diode, the position of the laser diode with respect to the scanning means member and the conversion device being predetermined. According to a first embodiment of the invention, the objective and anamorphic means comprise three refractive curve diopters located downstream of the laser diode, considering the direction of propagation of the light beam, the diopter farthest from the diode, said dioptre distant, being divergent and the other two, said dioptres close, being convergent. Advantageously, each of the refractive curve diopters is formed by a lens having a planar light input surface and a curved light output surface, the light output surface of the lens furthest from the diode forming the remote diopter , and the light exit surfaces of the other two lenses forming the two adjacent diopters. The optical device is thus relatively simple, since it consists of three simple conventional lenses.
    [0002] It will be noted that the optical functions of the various refractive curve diopters can be distributed between the two surfaces of the lenses forming them, so that the "convex plane" and "concave plane" lenses described above can be replaced by lenses with the same transfer function, of the "biconvex" or "biconcave" type. Such a transformation is well known to those skilled in the art.
    [0003] According to a variant of the first embodiment of the invention, the two adjacent diopters are formed by respective light input and output surfaces of a convergent convex lens, and the remote diopter is formed by an output surface of light of a diverging concave lens, a light entry surface of the divergent concave lens being flat.
    [0004] The device is thus simpler to arrange, since arranging two lenses relative to each other, in particular to align their optical axes and to position them correctly according to their respective focal distances, is simpler. to arrange three lenses relative to each other. According to a second embodiment of the invention, the objective and anamorphic means comprise two refractive curve diopters located downstream of the laser diode, considering the direction of propagation of the light beam, the diopter farthest from the diode, said dioptre distant, being divergent, and the other dioptre, said diopter close, being convergent and having a curvature in the plane containing the optical axes and slow different from the curvature in the plane containing the optical axes and fast. Advantageously, the remote and near diopters are respectively formed by a light entry surface and a light exit surface of a lens, the light entry surface of this lens being astigmatic. The optical device is thus even simpler to arrange, since it is only necessary to place the lens correctly with respect to the laser diode, in a distance so that the focal points are placed properly, and in orientation to align its optical axis 15 with that of the laser diode. Preferably, the objective and anamorphic means are made at least in part of a material selected from silicone, polymethylmethacrylate and a glass. These materials are effective for transmitting a light beam whose light spectrum is included in the visible range. Preferably, the laser diode has an exit facet of the generally rectangular light beam, the length of each side of this output facet being at least two times greater than the wavelength of the light beam emitted by the diode, and the length of the largest side of this facet being at least twice that of the short side. Preferably, the wavelength of the light beam emitted by the laser diode is less than 455 nm. Thus, the length of each side of the output facet of the laser diode can be of the order of 1 μm or larger without the deleterious diffraction phenomena being too great. Also provided according to the invention is a motor vehicle lamp, comprising: a laser diode emitting a light beam along an optical axis, a slow axis and a fast axis, these axes being perpendicular in pairs, a conversion device wavelength sensor comprising a target, - a scanning means member for scanning the light beam on the target, and - an optical device for forming a predetermined shaped light spot on the target from the emitted light beam. by the laser diode, characterized in that the optical device is as defined above. Advantageously, the scanning means member comprises at least one micromirror. It is thus possible to scan the light spot, formed on the scanning means member, on a wavelength conversion device in order to emit a beam outside the light having a desired light spectrum, for example white . The invention will be better understood on reading the description which follows, given solely by way of example and with reference to the drawings in which: FIG. 1 is a schematic view of an optical device according to a first embodiment FIG. 2 is a longitudinal sectional view of the device illustrated in FIG. 1; FIG. 3 is a schematic view of an optical device according to a variant of the first embodiment of the invention; FIG. 4 illustrates the propagation of the light beam emitted by a laser diode through the device of FIG. 3; FIG. 5 is a view on a smaller scale of the device of FIG. 4; FIG. 6 is a side view. FIG. 7 illustrates the behavior of the two diopters close to the device of FIG. 6; FIG. 8 is a diagrammatic view of an optical device according to a second embodiment of the invention; - the figur e 9 illustrates the propagation of the light beam emitted by a laser diode through the device of FIG. 8, - FIG. 10 is a view on a smaller scale of the device of FIG. 9, - FIG. 11 illustrates the behavior of the diopter. close to the device of FIG. 10, FIG. 12 illustrates the light spot formed on a target of the conversion device by an optical device according to the invention from a laser diode, FIG. 13 illustrates the intensity distribution. 10 and 15 are views along the arrows XIV and XV of the lenses illustrated in FIG. optical device 2 according to a first embodiment of the invention. This optical device 2 is placed in line with a light source formed by a laser diode 4. This laser diode 4 emits a substantially monochromatic light beam F at a wavelength preferably less than 455 nm, for example of the order of 445 nm so that it emits a blue light. The laser diode 4 has an exit facet of the light beam (not shown for the sake of clarity of the figures) of generally rectangular shape, the length of each side of this output facet being at least twice the wavelength the light beam F emitted by the diode 4 and the length of the largest side of this facet being at least twice greater than that of the short side. The rectangular shape of the output facet of the light beam of the laser diode 4 implies that the laser diode 4 emits the beam along an optical axis X, a slow axis Y, parallel to the direction of the large dimension of the aperture. emission, and a fast axis Z, parallel to the direction of the small dimension of the emission aperture, these axes being perpendicular two by two. The exit facet is covered by a planar protective blade 5 of the laser diode 4. The optical device 2 comprises optical means forming both a projection lens 6, in the plane containing the optical axes X and slow Y, and an anamorphic 8, in the plane containing the optical axes X and fast Z. We will see in the following how these functions are performed. The means 6 forming and anamorphic 8 comprise three refracted curved diopters 10, 12 located downstream of the laser diode 4 by considering the direction of propagation of the light beam F, the diopter furthest from the diode 4, said remote dioptre 10, being divergent and the other two, said dioptres close 12, being convergent. Each of the curved refractive diopters 10, 12 is formed by a lens 14 having, for example, a planar surface of light entry 16 and a curved surface of light exit (biconvex, convex-plane, biconcave or concave-plane lenses can also be used), the light exit surface of the lens furthest from the diode forming the remote diopter 10, and the light exit surfaces of the other two lenses forming the two adjacent diopters 12. As a embodiment, the objective forming means 6 and anamorphic 8, that is to say the lenses 14, are manufactured at least partly in a material selected from silicone, polymethyl methacrylate and a glass. Preferably, all the lenses 14 are made of the same material. The protective blade 5 of the laser diode 4 is generally made of glass by the manufacturer of the component. A scanning means member 18 for scanning the light beam F on a wavelength conversion device comprising a target 20 is placed on the optical path of the beam F, downstream of the optical device 2 by considering the direction of propagation. This member 18 is formed by one or more micro-mirrors, more commonly referred to by the acronym MEMS for the Anglo-Saxon terms - MicroElectroMechanical System, but it may be provided that the member 18 is formed by a other means of scanning. The conversion device 20 is for example a body comprising phosphorescent or luminescent materials, for example rare earth-doped YAG (Yttrium Aluminum Carnet) crystals, ZnS, etc.
    [0005] We will now detail how to make the lenses 14 so that the optical device 2 can form a light spot of predetermined shape on the target 20 forming part of the conversion device from the light beam emitted by the laser diode 4 and scanned by the member 18 of scanning means. In the following reasonings, it is considered that the member 18 is removed from the path of the light beam F, and that the target 20 is moved so that it is confused with the image of the target by a rotation around the center of the member 18 moving the center of the target 20 on the optical axis X. It is said that we have "unfolded" the beam, since it is considered that it follows a substantially straight path. This makes it possible to simplify the calculations considerably, without however making them erroneous. The first lens 14a, that is to say the closest to the laser diode 4, is a lens of revolution about an axis which coincides with the optical axis X of the laser diode 4 when it is suitably placed, stigmatic between the center of the output facet of the light beam of the laser diode 4 and the intersection with the X axis of the target 20, if we consider the beam F "unfolded". This stigmatism takes into account the crossing of two parallel flat blades, perpendicular to the optical axis X. The first plane blade, real, corresponds to the protection blade 5, and the second flat plane, fictive, is made of the same material as the second and third lenses 14b, 14c and of thickness equal to the sum of the thicknesses in the center of the second and third lenses 14b, 14c. These blades are located, respectively, between the laser diode 4 and the first lens 14a and between the first lens 14a and the conversion device 20. Their precise position is indifferent. The focal length of the first lens 14a is chosen so that the magnification of a system consisting of the first lens 14a and the two plane blades is equal to the ratio of the dimension along the slow axis Y (long side) of the output facet of the laser diode 4 by the largest dimension desired for the spot to be formed on the target 20 perpendicular to the optical axis X. The second lens 14b is a cylindrical lens, of axis parallel to the slow axis Y of the laser diode 4, such that, in its cross section containing the optical axis X, all the rays R coming from the center of the laser diode 4, after passing through the protection blade 5 of the diode 4 and then the first and the second lens 14a, 14b, converge to a point Q (not shown in the figures) of the optical axis X located between the target - 8 - 20 and the input face 16 of the third lens. The third lens 14c is a cylindrical lens, of axis parallel to the slow axis Y of the laser diode 4, stigmatic, in cross section, between the intersection of the optical axis X and the conversion device 20 and the point Q. This lens 14c (or at least its input face 16 when the lens 14c is thick) is placed between this point Q and the exit face of the second lens 14b. The third lens 14c is therefore divergent. The positions of the point Q and the third lens 14c are chosen so that, in cross-section, the envelope of the beam calculated for the rays coming from the center of the source within a predetermined angular sector notably equal at the divergence of the beam along the fast axis (for example taken at 1 / e2) passes through the edges of the member 18, suitably inclined to take into account the incidence of the beam on this member 18, which can never be normal, because it forms scanning means and it is useless to reflect the beam F on the laser diode 4. The lenses 14 and the dioptres 10, 12 can be defined mathematically simply from the above, after having chosen the type lenses, their material, their thicknesses and their spacings. We give further details of the calculations of the following variant. FIGS. 3 to 7 illustrate an optical device 2 according to a variant of the first embodiment of the invention. This optical device 2 differs from the previous one in that the two adjacent diopters 12 are formed by respective light input and output surfaces of a convergent convex lens 14a ', and the remote diopter 10 is formed by a surface of light output of a divergent concave lens 14c, a light entry surface 16 of the divergent concave lens 14c being planar. The device thus comprises only two lenses 14a 'and 14c. The calculation of the convergent convex lens 14a 'is equivalent to the calculation of the first two lenses 14a, 14b of the three-lens optical device 2 described above. Indeed, if the first and second lenses 14a, 14b of the three-lens device are computed, by imposing that the first lens 14a is a "convex plane" type lens, with its flat face 16 facing towards the target 20 and that the second lens 14b is also of the "convex plane" type, but with its flat face 16 turned towards the laser diode 4, and in addition the thicknesses of these two lenses 14a, 14b are such that their flat faces 16 are in contact and that the two lenses 14a, 14b are made of refractive index materials identical to the wavelength of the laser diode 4 used, a single 'biconvex' type lens 14a 'may be used in place of of the two lenses 14a, 14b of the "convex plane" type, this single lens 14a 'having, for entry and exit faces, respectively, the convex faces of the first 14a and the second 14b lens of the embodiment at -9 - three lentils the. Calculations for defining lenses and dioptres are detailed in the following. The distance from the transmitter to the protection blade 5 is the distance of the blade 5 n, the refractive index of the material of the blade 5, the distance from the blade 5 to the input diopter 12 from the lens 14a 'and the thickness at the center of the lens 14a' t2 the distance between the lenses 14a 'and 14c (from the top of the exit diopter 12 of the lens 14a' to the flat input face 16 of the lens 14c) e2 the thickness at the center of the lens 14c n the refractive index of the lens material 14a 'and 14c (assumed to be identical) - the distance from the center of the exit surface 10 of the lens 14c to the intersection of the optical axis X and the target 20 (in the unfolded system) q the distance from the center of the exit surface 10 of the lens 14c to the point Q Rmi the half height along the fast axis Z of the scanning member 18 (Rmi depends on the angle of incidence of the beam F on the scanning member) Dmph the distance of the intersection with the optical axis X of the organ of ball 18 to 20 that (in the unfolded system) of the target 20 friend the half aperture at the top of the beam F of the diode 4 along the fast axis Z (for example at 1 / e2), 6, I, n1 and friend are imposed by the chosen source 4, n by the material selected for the production of the lenses 14a 'and 14c and the wavelength of the laser diode 4 used - and Rmis imposed by the application (implantation of the elements in a module illumination) el, t2 e2 are design parameters t1 is determined (see below) so as to obtain the desired spot size, so as not to lose light around the scanning member 18 poses: 7 = 6 + I + t1 (ballast the "draw" of the lens 14a ') E = e1 + e2 (E is the total thickness at the center of the lenses 14a' and 14c) = t2 + 4 (the physical parameters 4 and t2 appear in the calculation of the input surface 12 of the lens 14a 'only through, E1,) In the calculation of the diopters close 12 is considered a ray from the center of the source 4 (origin of the marker) making an angle with the optical axis X and y is called the angle of incidence of this ray on the target 20 (the ray meets the target 20 at its point of intersection with the optical axis X) considering the unfolded beam. F3 and E are termed two intermediate angles (angle of the radius, respectively, to 5 normal to the faces of the protection blade 5 where it passes through them, inside the material, and to the entry face 16 of the lens 14c, inside the material): n1 - sin fi = sin a and n - sin e = sin y (0) Let (x, z) be the coordinates of the point of the surface corresponding to the radius considered (current point sought ), Calculation of the input surface 12 of the lens 14a '(diopter 12 closest to the source 4): It is assumed in this calculation that the remote diopter 10 is plane (this amounts to working in section in the plane (O, X, Y)). Geometry: 15 z = 1 - tan fl + (x - 0 - tan a = A tan y + (E - (x - g)) - tan e (1) Constant optic path (stigmatism): 1 x - 1 ( E (x + = qtE (n1 - n1 + + n1) - 1 + n - E + A (2) cos / 3 cos cos cos (we call K the optical path: K = 7+ (n1 - 1) - 1 + n - EA) We eliminate x between (1) and (2), hence (1 nl) EA (tan a + tan e) + / cos a cos fi cos E cos y 1 n) (A - tan y + (7 + 0 tan E 1 - (tan a- tan fl)) (cos a cos E 20 (3) which is an equation in y (by (0)) that is soluble numerically, so y (a) from which we draw through (2) x (a) and then through (1) z (a) and thus the coordinates of the desired point as a function of a parameter (a) Determination of 7: 25 Paraxial approximation (a) , so f3, y and E tend to 0): (3) becomes (a + 0 (1 - n) 7 = (1 - n) (Ay + (7 + E) E + 1 (a - fl)) D where, as in this approximation, fi = and = Yin, a = 9 (4) paraxial magnification of the system, chosen equal to the ratio of the largest dimension of the spot on the target 20 at most If the laser diode 4 has a large size, Y 7-1 + -ni (4) is used as a function of the parameters. Calculation of the exit surface 12 of the lens 14a '(diopter 12 farthest from the source 4): Let (xs, zs) be the coordinates of the point of the surface corresponding to the radius 5 considered (desired current point), We know the point of entry of the previously calculated radius to the lens of coordinates (x (a), z (a)), and the corresponding angle E (a) (taken from y (a) from (0) ). The point Q is of coordinates (itE E + t2 q). 0 One writes the constancy of the optical path between the center of the exit facet of the diode 4 and the point Q. Let X be the length of the path of the ray in the lens 14a ', we have: / x - 1 ni cos / 3+ cos a + nil + (7+ E + t2 + q - xs) 2 = 7 + (n, - 1) 1 + n - el t2 e2 q (5) With (X = (X + TO COS z To sin E Substituting xs and zs in (5) according to (6) we obtain an equation in X as a function of the parameters and a 03 is a function of a, according to (0), from which we draw X (a) (by isolating the square root and then raising the two terms squared, one obtains a polynomial equation of the second degree in X) .From (6) one then has the position of the current point sought as a function of a Those skilled in the art will readily calculate the lens 14c, which can then be determined for a radius of angle α to the optical axis X from the center of the output facet of the laser diode 4 contained in FIG. plane (O, X, Z), its point of passage (xf (a), zf (a)) on the distant dioptre 10. That a part of If the energy of the beam F is not lost above or below the scanning member 18, then Zf (friend) <Rmi T + E +, 4-Xf (friend) DMPh Gold xf (a) ) and zf (a) depend on q and (7) can therefore be considered as a zf (friend) Rm, condition on q (we determine q by iteration so that T + E +, 4-Xf (friend) DMPh In a mode Advantageously, t2 = 0: the lenses 14a 'and 14c are then in contact, which allows easier mutual positioning. FIGS. 8 to 12 illustrate an optical device 2 according to a second embodiment of the invention. This optical device 2 differs from the previous ones in that the objective means 6 and anamorphic means 6 comprise two refracted curved diopters 10, 12 situated downstream of the laser diode 4, considering the sense of propagation of the light beam F, the diopter farthest from the laser diode 4, said remote diopter 10, being divergent, and the other diopter, said diopter close 12, being convergent and having a curvature in the plane containing the optical axes X and slow Y different from the curvature in the plane containing the optical axes X and fast Z. The remote diopters 10 and near 12 are respectively formed by a light entry surface and a light exit surface of a lens 14 " the light entry surface of this lens 14 "being astigmatic.
    [0006] The input face of this lens 14 "groups together the optical functions of the two surfaces of the first lens 14a 'of the two-lens embodiment or the first two lenses 14a, 14b of the three-lens embodiment. it is assumed that the exit surface of the lens 14 "is flat and the input face is calculated so that the lens 14" is stigmatic (taking into account the crossing of the protective blade 5 of the laser diode 4) between a point located in the center of the emission aperture and an arc centered on the intersection of the optical axis X and the target 20, contained in the plane parallel to the slow axis Y of the laser diode 4. We thus transform a spherical wave into a toric wave, a classic problem whose equation is made using Fermat's theorem.
    [0007] In a second step, a stigmatic lens is calculated between the preceding arc and the intersection of the optical axis X and the target 20 of the planar input face, coinciding with the fictitious plane output of the preceding calculation and zero thickness in the center. This "lens" is divergent because the toric wave is virtual. The calculation is similar to that of the input face, except for taking into account the crossing of the plane protective blade 5. The two fictitious plane faces, combined, being omitted, we obtain a single lens 14 ". The following calculations are made to define this lens Calculation of the near diopter 12: We consider a point = (xt, yt) of the circle corresponding to the toroidal wave when the minor radius vanishes. an angle u such that: (xt (7+ E + A - (A - q) cos u) Yt) - q) sin u Consider a radius of the toric wave passing through this point, defined by an angle v such that the direction of propagation of the ray is -i where C cos V cos il) COS v sin u sin v -13- The point through which the ray passes on the hypothetical plane exit face is xsp) A 'IE E Sp = (Ysp = tan u Zsp q)) tan vi cos u Let f> be the direction of the radius in matter: f> deduce from i by refraction on the plane dace (laws of Descartes). int current searched on the near diopter 12 and X the length of the path of the ray in the matter: xm) M = (Ym zm Sp M = (8) For the desired surface, the ray passing through the point M is derived from the origin of the marker.
    [0008] Let the angle be with the optical axis X: the crossing of the protection blade 5 of the laser diode 4 is described in the plane (0, OM, X) which contains the radius between the points M and O by 1 / tan fl + (xm - 0 tan a =, NI W4 + 44 nor sin fl = sin a In addition the stigma implies the constancy of the optical path between and the origin of the reference: i (+ q ) 7,11 xm- / = 'IE (ni-1) 1 + nE + q (10) cos cos cos cos cos 3 Replacing xM, ym and zm according to (8), {(9), ( 10)} constitutes a system of two equations with two unknowns (a and X (f3 is immediately eliminated in (9))), a function of the physical and geometrical parameters of the optical device 2 and the angles u and v; numerically From X we deduce M from (8) By varying u and v we describe the surface of the near diopter 12. 25 Calculation of the remote diopter 10: Let P be the current sought point and p the length of the path in the 14 "lens of the real beam (virtually of t): SpP = (11) Constant optical path (from point F of the conversion device): (9) -14- EF = 0 1 (A -3, + q) + np + PF = -q + 3 , (12) cosy cosu or PF2 = (SpF - SpP) - (SpF - SpP) = (SpF + p1) - (SpF + p1) = SpF2 + p2 + 2 (SpF - r) p So (12) is an equation in p (polynomial of the second degree by raising it squared after isolating PF).
    [0009] From p we deduce P from (11). By varying u and v, the surface of the remote diopter 10 is described. The two embodiments described above apply to a light for a motor vehicle, comprising: the laser diode 4 emitting the light beam F along the optical axis X , the slow axis Y 10 and the fast axis Z, these axes being perpendicular two by two, - the wavelength conversion device comprising the target 20, - the scanning means member 18, comprising at least a micro-mirror, for scanning the light beam F on the target 20, and - the optical device 2 for forming a light spot of predetermined shape on the target 20 from the light beam F emitted by the laser diode 4 by scanning formed by the member 18. FIG. 12 illustrates the light spot 22 formed on the target 20 thanks to the laser diode 4 and the optical device 2 according to any one of the embodiments described above. The spot is of rectangular general shape.
    [0010] FIG. 13 shows the light intensity distribution in the spot illustrated in FIG. 12, respectively along the slow axis Y by a first curve 24 and along the fast axis Z by a second curve 26. FIGS. 14 and 15 illustrate the two lenses 14a 'and 14c of the variant of the first embodiment, which are shown in FIGS. 3 to 6. FIGS. 14 and 15 also show extensions of the lenses 14a' and 14c forming fastening means 28 of these lenses on a conventional support. Of course, we can bring to the invention many changes without departing from the scope thereof. The lenses and the protective blade of the laser diode may comprise other materials than those described above. The laser diode may emit a light beam of wavelength different from that given by way of example above.
    权利要求:
    Claims (11)
    [0001]
    REVENDICATIONS1. An optical device (2) for forming a light spot of predetermined shape on a target (20) forming part of a wavelength conversion device, from a light beam (F) emitted by a laser diode (4) ) and scanned by a scanning means (18), the laser diode (4) emitting the beam (F) along an optical axis (X), a slow axis (Y) and a fast axis (Z), these axes being perpendicular two by two, characterized in that it comprises optical means forming both a projection lens (6), in the plane containing the optical axes (X) and slow (Y), and an anamorphic (8) , in the plane containing the optical (X) and fast (Z) axes.
    [0002]
    2. Device (2) according to claim 1, wherein the means forming objective (6) and anamorphic (8) comprise three refracted curved diopters (10, 12) located downstream of the laser diode (4) considering the direction propagation of the light beam (F), the diopter furthest from the diode, said remote dioptre (10), being divergent and the other two, said dioptres close (12), being convergent.
    [0003]
    3. Device (2) according to claim 2, wherein each of the curved refractive diopters (10, 12) is formed by a lens (14a-14c) having a planar light input surface (16) and a curved surface light output, the light output surface of the farthest lens (14c) of the diode (4) forming the remote diopter (10), and the light output surfaces of the other two lenses (14a, 14b) forming the two adjacent dioptres (12).
    [0004]
    4. Device (2) according to claim 2, wherein the two adjacent dioptres (12) are formed by respective input and output surfaces of light of a convergent convex lens (14a '), and the remote diopter ( 10) is formed by a light exit surface of a diverging concave lens (14c), a light entry surface (16) of the divergent concave lens (14c) being planar.
    [0005]
    5. Device (2) according to claim 1, wherein the means forming objective (6) and anamorphic (8) comprise two refracted curved diopters (10, 12) located downstream of the laser diode (4) considering the direction for propagating the light beam (F), the diopter farthest from the diode (4), said remote diopter (10), being divergent, and the other diopter, said near diopter (12), being convergent and having a curvature in the plane containing the optical (X) and slow (Y) axes different from the curvature in the plane containing the optical (X) and fast (Z) axes.
    [0006]
    6. Device (2) according to claim 5, wherein the remote dioptres (10) and near (12) are respectively formed by a light entry surface and a light exit surface of a lens (14 ") , the light entry surface of this lens (14 ") being astigmatic.
    [0007]
    7. Device (2) according to any one of the preceding claims, wherein the means forming objective (6) and anamorphic (8) are manufactured at least in part in a material selected from silicone, polymethyl methacrylate and a glass .
    [0008]
    8. Device (2) according to any one of the preceding claims, wherein the laser diode (4) has an exit facet of the generally rectangular light beam, the length of each side of this output facet being at least two times greater than the wavelength of the light beam (F) emitted by the diode (4), and the length of the largest side of this facet being at least twice greater than that of the short side.
    [0009]
    9. Device (2) according to any one of the preceding claims, wherein the wavelength of the light beam (F) emitted by the laser diode (4) is less than 450 nm.
    [0010]
    10. Fire for a motor vehicle, comprising: - a laser diode (4) emitting a light beam (F) along an optical axis (X), a slow axis (Y) and a fast axis (Z), these axes being perpendicular to two two, - a wavelength conversion device comprising a target (20), - a scanning means (18) for scanning the light beam (F) on the target (20), and - an optical device (2) for forming a light spot of predetermined shape on the target (20) from the light beam (F) emitted by the laser diode (4), characterized in that the optical device (2) is according to any one Claims 1 to 9.
    [0011]
    11. Fire according to the preceding claim, wherein the member (18) of scanning means comprises at least one micro-mirror.
    类似技术:
    公开号 | 公开日 | 专利标题
    FR3023013A1|2016-01-01|OPTICAL COLLIMATION DEVICE FOR LASER DIODE
    CA1134186A|1982-10-26|Optic fiber of which at least one end facehas a flat-convex microlens abutted by itsflat end to said end face
    EP0419320A1|1991-03-27|Automatic harmonizing device for an opto-electronic system
    FR2637741A1|1990-04-13|LASER RADIATION DEVICE WITH VARIABLE RADIATION ANGLE
    EP2703852A1|2014-03-05|Light guide sheet with input coupling and dioptre with Fresnel surface
    TWI616967B|2018-03-01|Generating an array of spots on inclined surfaces
    EP3203305A1|2017-08-09|Simple collimating lens for a coherent light source
    EP1712940A1|2006-10-18|Uniform illumination apparatus comprising a matrix of laser diodes
    WO2018138223A1|2018-08-02|Optical detector of particles
    EP3123076B1|2019-06-26|Optical collimator
    WO2013114022A1|2013-08-08|Optical system intended to measure brdf, bsdf and bdtf
    EP3376613A1|2018-09-19|Lighting device having mobile scanning means and optical fibre
    EP0995145B1|2001-09-19|Diffractive optics with synthetic aperture and variable focal length and laser cutting device incorporating such an optics
    FR3044743A1|2017-06-09|OPTICAL PROJECTION SYSTEM, LUMINOUS MODULE AND LIGHTING DEVICE FOR A MOTOR VEHICLE HAVING SUCH A SYSTEM
    WO2009053634A2|2009-04-30|Imaging system with wavefront modification and method of increasing the depth of field of an imaging system
    WO2004005897A1|2004-01-15|Method and device for measuring a light flux backscattered by a dispersed medium, unperturbed by interface reflections
    EP2232308B1|2012-11-28|Laser imaging system
    EP2002436B1|2009-11-11|Solid immersion lens with increased focusing capacity
    FR3095496A1|2020-10-30|Light module
    TWI637162B|2018-10-01|Radial polarized light surface plasma excitation device
    FR3017218A1|2015-08-07|METHODS AND DEVICES FOR CONTROLLING THE SIZE OF LARGE DIMENSIONAL BEAM BEAMS
    EP3329181B1|2019-07-17|Optical system for non-imaging collimation of maximum light intensity
    EP3598102A1|2020-01-22|Optical particle sensor
    EP2927577B1|2017-12-27|Lighting optic for biometric measurement device
    WO2021122860A1|2021-06-24|Optical part for a motor vehicle
    同族专利:
    公开号 | 公开日
    EP2963476A1|2016-01-06|
    FR3023013B1|2016-07-15|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US5159485A|1990-12-31|1992-10-27|Texas Instruments Incorporated|System and method for uniformity of illumination for tungsten light|
    EP1674914A1|2004-12-24|2006-06-28|Canon Kabushiki Kaisha|Optical scanning device and image display apparatus|
    US20080158524A1|2006-12-28|2008-07-03|Konica Minolta Opto, Inc.|Laser projection apparatus|
    US20120293775A1|2011-05-20|2012-11-22|Hiromi Kita|Scanning type projector|
    US20140029282A1|2012-07-27|2014-01-30|Valeo Vision|Adaptive lighting system for an automobile vehicle|
    FR3047294A1|2016-02-02|2017-08-04|Valeo Vision|OPTICAL SINGLE COLLIMATION FOR COHERENT LIGHT SOURCE|
    JP6791644B2|2016-03-24|2020-11-25|株式会社小糸製作所|Vehicle headlights|
    DE102016214513A1|2016-08-05|2018-02-08|Osram Gmbh|lighting device|
    FR3075925B1|2017-12-22|2019-11-29|Valeo Vision|SCANNING LIGHT MODULE, IN PARTICULAR FOR A MOTOR VEHICLE, EQUIPPED WITH A FOCUSING SYSTEM, AND LIGHT DEVICE OF A MOTOR VEHICLE COMPRISING SUCH A LUMINOUS MODULE|
    FR3075924B1|2017-12-22|2019-11-29|Valeo Vision|BRIGHT BEAM SCANNING LIGHT MODULE, IN PARTICULAR FOR A MOTOR VEHICLE, EQUIPPED WITH A TWO-LENS FOCUSING SYSTEM, AND A LIGHTING DEVICE FOR A MOTOR VEHICLE|
    FR3077117B1|2018-01-24|2021-01-29|Valeo Vision|LIGHTING MODULE FOR MOTOR VEHICLES, AND LIGHTING AND / OR SIGNALING DEVICE EQUIPPED WITH SUCH A MODULE|
    FR3095496B1|2019-04-26|2021-04-16|Valeo Vision|Light module|
    法律状态:
    2015-06-30| PLFP| Fee payment|Year of fee payment: 2 |
    2016-01-01| PLSC| Search report ready|Effective date: 20160101 |
    2016-07-08| PLFP| Fee payment|Year of fee payment: 3 |
    2017-06-30| PLFP| Fee payment|Year of fee payment: 4 |
    2018-06-27| PLFP| Fee payment|Year of fee payment: 5 |
    2019-06-28| PLFP| Fee payment|Year of fee payment: 6 |
    2021-03-12| ST| Notification of lapse|Effective date: 20210205 |
    优先权:
    申请号 | 申请日 | 专利标题
    FR1456118A|FR3023013B1|2014-06-30|2014-06-30|OPTICAL COLLIMATION DEVICE FOR LASER DIODE|FR1456118A| FR3023013B1|2014-06-30|2014-06-30|OPTICAL COLLIMATION DEVICE FOR LASER DIODE|
    EP15173843.2A| EP2963476A1|2014-06-30|2015-06-25|Optical device for laser diode|
    [返回顶部]