Optical unit, in particular for a motor vehicle

Abstract

An optical unit, in particular for an optical module, comprising: at least one first and one second mutually distant luminous sources, at least one convergent multifocal lens, comprising at least one undulated face, the undulated face comprising at least three distinct portions, two of these portions being focused substantially on the first luminous source and the other portion being positioned between these two portions and being focused substantially on the second luminous source.

Claims

1. An optical unit for an optical module, comprising: at least one first and one second mutually distant luminous sources, at least one convergent multifocal lens, comprising at least one undulated face, said at least one undulated face comprising at least three distinct portions, a first portion and a second portion being substantially focused on said at least one first luminous source and a third portion being positioned between said first portion and said second portion and being focused substantially on said second mutually distant luminous source; wherein said at least one undulated face is formed by sweeping a generating curve along a director curve; wherein said luminous sources each exhibit an emission axis (X1,X2) and said director curve of said at least one undulated face is contained in a plane generally parallel to a plane (P) defined by said emission axes (X1,X2).

2. The optical unit as claimed in claim 1, wherein said at least three distinct portions are mutually adjoining pairwise by at least one part of their outline.

3. The optical unit as claimed in claim 1, wherein said at least three distinct portions together cover the whole of said at least one undulated face.

4. The optical unit as claimed in claim 1, wherein said first and second portions focused on said at least one first luminous source are alternated with said third portion focused on said second mutually distant luminous source.

5. The optical unit as claimed in claim 1, wherein said at least one undulated face is an entry face for the light emitted by said luminous sources in said lens.

6. The optical unit as claimed in claim 1, wherein said lens comprises a second face, said second face being formed by sweeping a generating curve along a director curve.

7. The optical unit as claimed in claim 6, wherein said director curve of said second face is contained in a plane perpendicular to a plane (P) defined by the emission axes of the luminous sources.

8. An optical module for a lighting and/or signaling device, comprising at least one optical unit as claimed in claim 1.

9. The optical module as claimed in claim 8, wherein said optical module comprises at least two optical units, exit faces for egress of the light from said optical units being adjoining pairwise.

10. The optical module as claimed in claim 8 wherein together, exit faces for egress of the light from said optical units exhibit a continuous appearance.

11. The optical module as claimed in claim 8, wherein said optical module is capable of creating a first light beam on the basis of the light rays emitted by said at least one first luminous sources, said first light beam achieving at least one part of a first predetermined regulatory photometric function.

12. The optical module as claimed in claim 11, wherein said optical module is capable of creating a first light beam on the basis of the light rays emitted by said at least one first luminous sources, said first light beam achieving the entirety of a first predetermined regulatory photometric function.

13. The optical module as claimed in claim 11, wherein said optical module is capable of creating a second light beam on the basis of the light rays emitted by said at least one second mutually distant luminous sources, said second light beam achieving at least one part of a second predetermined regulatory photometric function.

14. The optical module as claimed in claim 13, wherein said optical module is capable of creating a second light beam on the basis of the light rays emitted by said at least one second mutually distant luminous sources, said second light beam achieving the entirety of a second predetermined regulatory photometric function.

15. A lighting and/or signaling device for an automotive vehicle, comprising at least one optical module as claimed in claim 8.

16. The optical module as claimed in claim 8 wherein together, exit faces for egress of the light from said optical units exhibit a continuous appearance.

17. A convergent multifocal lens for an optical unit as claimed in claim 1, wherein said optical unit comprises at least one undulated face, said at least one undulated face comprising at least three distinct portions, said at least three distinct portions comprising a first portion and a second portion focused on a first focusing zone and a third portion positioned between said first portion and said second portion and being focused substantially on a second focusing zone, said first and second focusing zones being distinct or overlapping only partially.

Description

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

(1) The invention will be better understood on reading the detailed description which follows, of nonlimiting examples of implementation of the invention, and on examining the appended drawing in which:

(2) FIG. 1 illustrates, schematically and partially, in a view from behind, an optical unit according to an exemplary implementation of the invention;

(3) FIG. 2 represents, schematically and partially, a cross-section of the optical unit of FIG. 1;

(4) FIGS. 3 to 6 represent, schematically and partially, a cross-section of an optical unit according to various examples of implementation of the invention;

(5) FIGS. 7A-9B represent, schematically and partially, a cross-section of an optical unit according to various examples of implementation of the invention;

(6) FIGS. 10 and 11 represent, schematically and partially, respectively in a view from behind and in an end-on view, an optical module according to an exemplary implementation of the invention using several optical units; and

(7) FIGS. 12 and 13 represent, schematically and partially, an example of the evolution of the focusing points of the undulated face along the director of the lens.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(8) Represented in FIG. 1 is an optical unit 1 comprising a lens 2 and two light-emitting diodes 3 and 4 mounted respectively on their electronic card.

(9) The lens 2 comprises an undulated entry face 5 for the light and an exit face 6 for the light.

(10) The undulated entry face 5 is cylindrical and exhibits a straight generating line 10 and a director curve 11.

(11) The director curve 11 is an undulated curve contained in a plane parallel to the plane P containing the respective emission axes X1 and X2 of the light-emitting diodes 3 and 4.

(12) The director curve 11 is globally curved.

(13) The amplitudes of the undulations of the director curve 11 decrease steadily as these undulations get further away from the diodes 3 and 4.

(14) The undulated entry face 5 comprises a plurality of striations 7 whose profile corresponds to the director curve 11.

(15) The striations 7 overlap the entirety of the undulated entry face 5, these striations 7 being arranged periodically the whole way along the undulated entry face 5.

(16) The striations 7 extend over the whole of the height of the undulated entry face 5.

(17) Each striation 7 comprises two portions 8 and 9, these portions meeting at the top of the striation.

(18) This top is illustrated on two striations as dashed lines (FIG. 2) between the portions 8 and 9. For the sake of clarity, it has been represented on only two striations.

(19) Consequently, the portions 8 alternate with the portions 9 the whole way along the undulated entry face 5.

(20) The portions 8 are focused on the light-emitting diode 3 and the portions 9 are focused on the light-emitting diode 4.

(21) The exit face 6 is cylindrical and exhibits a straight generating line 12 and a director curve 13.

(22) The director curve 13 of the exit face 6 is contained in a plane perpendicular to the plane P.

(23) The light-emitting diodes 3 and 4 emit in the direction of the lens 2 respectively white colored light and amber colored light.

(24) Represented in FIG. 2 is a part of a cross-section through a plane parallel to the plane P of the lens 2 of FIG. 1.

(25) The lens 2 exhibits an undulated entry face 5 exhibiting striations 7, an exit face 6 for the light and an optical axis O1.

(26) The striations 7 each comprise two portions 8 and 9 meeting at the top of the striation.

(27) The portions 8 are focused on the light-emitting diode 3 and the portions 9 are focused on the light-emitting diode 4.

(28) Light rays 14 of white color emitted by the diode 3 in the direction of the lens 2 reach one of the portions 8 of the striations 7 and are refracted successively by these portions 8 and then parallel to the optical axis O1 by the exit face 6.

(29) The light beam produced by the optical unit 1 on the basis of these rays 14 achieves a part of a daytime light.

(30) Light rays 15 of amber color emitted by the diode 4 in the direction of the lens 2 reach one of the portions 9 of the striations 7 and are refracted successively by these portions 9 and then parallel to the optical axis O1 by the exit face 6.

(31) The light beam produced by the optical unit 1 on the basis of these rays 15 achieves a part of a direction indicator.

(32) The optical unit 1 is therefore capable of producing two beams exhibiting a different photometry but according to one and the same optical axis on the basis of two distinct light sources.

(33) Represented in FIGS. 3 to 6 are other portions of the lens 2 of FIG. 1 according to various examples of implementation of the invention.

(34) In FIG. 3, a portion 16 focused predominantly on the light-emitting diode 3 has been represented.

(35) That is to say at least 50% of the focusing zone 17, representing the set of focusing points of the portion 16, is positioned on the light-emitting diode 3.

(36) Moreover, the portion 16 is focused symmetrically around the center of the light-emitting diode 3.

(37) That is to say the focusing zone or portion 16 extends symmetrically on either side of the center M of the diode 3.

(38) In FIG. 4, two portions 18 and 19 forming a striation 20 have been represented.

(39) The portion 18 is focused predominantly on the light-emitting diode 3 without being focused on the light-emitting diode 4.

(40) The portion 19 is focused predominantly on the light-emitting diode 4 without being focused on the light-emitting diode 3.

(41) Thus, the focusing zone 21 of the portion 18 is distant from the light-emitting diode 4 while the focusing zone 22 of the portion 19 is distant from the light-emitting diode 3.

(42) Represented in FIG. 5 are two portions 23 and 24 similar to the portions 18 and 19 of FIG. 4 with the exception of the fact that the respective focusing zones 25 and 26 of the portions 23 and 24 overlap one another.

(43) Two portions 27 and 28 of a striation 29 have been represented in FIG. 6.

(44) The focusing zone 30 of the portion 27 is focused only on the light-emitting diode 3.

(45) The focusing zone 31 of the portion 28 is focused only on the light-emitting diode 4.

(46) Thus, the entirety of the focusing points forming the zones or portions 27 and 28 are respectively positioned on the light-emitting diodes 3 and 4.

(47) Represented in FIGS. 7A-9B are two cross-sections of a lens 32 respectively through a plane P parallel to the plane containing the emission axes of the luminous sources and through a plane P perpendicular to P according to three exemplary embodiments.

(48) In FIGS. 7A-7B, the lens 32 comprises an undulated entry face 33 for the light and an exit face 34 for the light.

(49) The undulated entry face 33 is cylindrical and is formed by the extrusion of a straight generating line 38 along a so-called director curve 35.

(50) The director curve 35 of the undulated entry face 33 exhibits a globally circular arc-like shape. The director curve 35 comprises undulations whose amplitude is determined by a carrier 36.

(51) The undulations of the director curve 35 form the profile of the striations of the lens 32 when the straight generating line 38 is translated along this director curve 35.

(52) The exit face 34 for the light is also cylindrical and is formed by the extrusion of a straight generating line 37 along a director curve 39.

(53) The director curve 39 of the exit face 34 is an elliptic arc portion devoid of undulation so as to form an exit face 34 exhibiting a smooth profile.

(54) In FIGS. 8A-8B, the lens 32 comprises an undulated entry face 33 for the light and an exit face 34 for the light 34.

(55) The undulated entry face 33 is formed by sweeping a generating curve 40 along a director curve 41.

(56) The director curve 41 of the undulated entry face 33 is a globally curved undulated curve.

(57) The amplitude of the undulations of the director curve 41 is constant and is determined by a carrier 42.

(58) The generator 40 of the undulated entry face 33 is a portion of circle devoid of undulation.

(59) The exit face 34 for the light is cylindrical and is formed by the extrusion of a straight generating line 43 along a director curve 44.

(60) The director curve 44 of the exit face 34 is a portion of ellipse devoid of undulation.

(61) In FIGS. 9A-9B, the lens 32 comprises an undulated entry face 33 for the light and an exit face 34 for the light.

(62) The undulated entry face 33 is formed by sweeping a generating curve 45 along a director curve 46.

(63) The director curve 46 of the undulated entry face 33 is a globally curved undulated curve.

(64) The amplitude of the undulations of the director curve 46 is determined by a carrier 47, these undulations meeting at cusp points.

(65) The generator 45 is a smooth ellipse portion.

(66) The exit face 34 for the light is cylindrical and is formed by the extrusion of a straight generating line 48 along a director curve 49.

(67) The director curve 49 is a portion of ellipse devoid of undulation.

(68) An optical module 50 according to one embodiment of the invention has been represented in FIGS. 10 and 11, in an end-on view and a view from behind.

(69) This optical module 50 comprises eight optical units 51.

(70) These optical units 51 each comprise a lens 52, such as described in FIG. 1, and two photoemissive elements of one and the same light-emitting diode 53, the lenses 52 being focused alternately on these two photoemissive elements.

(71) The set of exit faces of the lenses 52 exhibits a continuous and smooth visual appearance.

(72) The optical module 50 is capable of emitting, in the direction 54, a daytime light, and in the direction 55, a direction indicator.

(73) A part of a cross-section in a plane P of the optical unit of FIG. 1 has been represented in FIG. 12. Observed, in this FIG. 12, are two portions 56 and 57 of the undulated light entry face of the lens, an exit face 59 for the light and two luminous sources 58.

(74) The portion 56 corresponds to the slope of a first striation and the portion 57 corresponds to the slope of a second striation, these two striations meeting at a point with abscissa x3.

(75) The portion 56 extends between the top of the first striation with abscissa x1 and the point with abscissa x3.

(76) The portion 56 exhibits a point of inflection with abscissa x2.

(77) The portion 57 extends between the top of the second striation with abscissa x5 and the point with abscissa x3.

(78) The portion 57 exhibits a point of inflection with abscissa x4.

(79) Represented in FIG. 13 is the curve of the positioning of focusing points, that is to say the points from which a light ray would be emitted and would be refracted, parallel to the optical axis of the lens, by the lens, portions 56 and 57 on an axis F passing through the centers F1 and F2 of the luminous sources 58, as a function of the position of a point M along the portions 56 and 57, more particularly as a function of the abscissa x of this point M.

(80) As illustrated in FIGS. 12 and 13, the focusing point of the point x1 is situated between the two light sources 58, at the point with abscissa O on the axis F.

(81) When the point M progresses over the portion 56 from the point x1 to the point x2, the focusing point progresses from the point O to the point dFMAX1.

(82) So doing, it successively encounters a first edge dFLED1 of the source 58 with center F1, the center F1 of the source and a second edge dFLED2 of the source 58 with center F1.

(83) When the point M progresses from the point x2 to the point x3, the focusing point progresses from the point dFMAX1 to the point O.

(84) So doing, it successively encounters the second edge dFLED2 of the source 58 with center F1, the center F1 of the source and the first edge dFLED1 of the source 58 with center F1.

(85) When the point M passes beyond the point x3, this point M progresses over the portion 57 and the focusing is done around the source 58 with center F2.

(86) When the point M progresses over the portion 57 from the point x3 to the point x4, the focusing point progresses from the point O to the point dFMAX2.

(87) When the point M progresses over the portion 57 from the point x4 to the point x5, the focusing point progresses from the point dfMAX2 to the point O.

(88) When the point M passes beyond the point x5, this point M progresses over the following portion and the focusing is done around the source 58 with center F1, in the same manner as described above for the portion 56.

(89) While the system, apparatus, process and method herein described constitute preferred embodiments of this invention, it is to be understood that the invention is not limited to this precise system, apparatus, process and method, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.