Optical device comprising a primary lens and a zoom mechanism

Abstract

Primary optics (12), comprising a mechanical retaining portion (21) and an optical mixing portion (22), the optical mixing portion (22) being configured to ensure color mixing of light from a light source (3) located at a point on an axis of the primary optics (12), the mechanical retaining portion (21) being configured to be removably fixed to a mechanical interface (13). Figure 2

Description

Title of the invention: Optical device comprising a primary optic and a zoom device

[0001] The present invention relates to the field of optics, and in particular to assemblies comprising a color mixer and a zoom device.

[0002] It is known to use a four-chip high-power LED: red, green, blue, white (RGBW). This type of LED has become widespread in the event lighting market (concerts, shows, etc.) and in the architectural lighting market (facade lighting). An example of this type of LED is the Ostar Stage, manufactured by OSRAM.

[0003] It is also known to use collimating optics specifically designed for this type of LED, which allow for good color mixing while preserving the geometric extent of the light beam (RGBW optics). Thus, it is known to use uncompromising optics that are both very intensive and very homogeneous. These optics make it possible to obtain fixed light beams; that is, the exit angle is predetermined by the optics and by the LED and cannot be adjusted afterward.

[0004] Furthermore, it is known to use variable beam optics (zoom optics), which allow the output angle to be adjusted dynamically by moving a movable optical component. Unfortunately, these zoom optics are not as efficient as fixed beam optics. Thus, the beam set at a given zoom position is slightly wider, slightly less intense, and significantly less color-homogeneous than its fixed beam equivalent. Therefore, irreducible colorimetric defects remain in the projected light. While these defects were acceptable 12 years ago for the events market, they are no longer acceptable in today's architectural market, where requirements have increased considerably over time.

[0005] It is therefore necessary to develop a new optical concept, adapted to RGBW LEDs, allowing the generation of a variable light beam, without compromise, which combines the performance of fixed beam RGBW optics and the performance of classic zoom optics.

[0006] More specifically, an RGBW LED has four separate chips, respectively red, green, blue, and white. With an existing, unsuitable optic, a visible separation of the four colors is observed in the projected light; this is due to the fact that the existing optic forms a partially distorted image of the LED chips.

[0007] The invention therefore aims to provide a solution to all or part of these problems.

[0008] To this end, the present invention relates to a primary optic, comprising a mechanical retaining part and an optical mixing part, the optical mixing part being configured to ensure a mixing of the colours of a light coming from a light source placed at a point on an axis of the primary optic, the mechanical retaining part being configured to be removably fixed on a mechanical interface.

[0009] According to one embodiment, the invention comprises one or more of the following features, alone or in a technically acceptable combination.

[0010] According to one embodiment, the mechanical retaining part and the optical mixing part, i.e. the primary optics, form a single piece.

[0011] According to one embodiment, the primary optics are made of a transparent plastic material so that the primary optics can be manufactured by plastic injection into a mold.

[0012] According to one embodiment, the plastic material is polycarbonate.

[0013] According to these provisions, the mechanical resistance and thermal resistance of the material are adapted as needed.

[0014] According to one embodiment, the mechanical retaining part includes at least one first fixing member, for example a bayonet-type fixing notch, the at least one first fixing member being configured to receive a first complementary fixing member disposed on the mechanical interface.

[0015] According to these provisions, at least a first fixing element allows the position of the primary optics to be locked in relation to the mechanical interface and to a collimator mounted on the mechanical interface.

[0016] According to one embodiment, the mechanical retaining part further comprises at least one second fixing element, for example standardized screw holes, configured to fix the primary optics on a support of the light source.

[0017] According to one embodiment, the mechanical retaining part further comprises at least one opening, for example kidney-shaped, configured to dissipate heat.

[0018] According to one embodiment, the mechanical retaining part has a transverse extension to the axis of the primary optic, with a cup shape, a lower part of the cup being closer to a light source than an upper part of the cup, the optical mixing part being positioned on the lower part of the cup.

[0019] According to these provisions, the optical mixing part is thus brought closer to the light source.

[0020] According to one embodiment, the optical mixing portion comprises at least two microlens arrays, each arranged on a hemisphere centered on the point of the axis of the primary optics on which the light source is placed, a microlens of one microlens array among the at least two arrays corresponding to a corresponding microlens of another microlens array among the at least two arrays, the microlens array defining a hemispherical face of the optical mixing part and forming a partition of said hemispherical face, without free space between two adjacent microlenses, and the other corresponding microlens array defining another hemispherical face of the optical mixing part, and forming a partition of said other hemispherical face without free space between two adjacent corresponding microlenses.

[0021] According to one embodiment, the microlens array, or the corresponding other microlens array, comprises at least a first part and a second part, the first part comprising the microlenses, or the corresponding microlenses, positioned on the hemispherical face, or the other hemispherical face, of the optical mixing portion, along successive concentric rings drawn on the hemispherical face, or the other hemispherical face, around the axis of the primary optics, up to a first parallel drawn on the hemispherical face, or the other hemispherical face, around the axis of the primary optics, the second part comprising the microlenses, or the corresponding microlenses, positioned on the hemispherical face, or the other hemispherical face, of the optical mixing portion,along successive concentric rings drawn on the hemispherical face, respectively on the other hemispherical face, around the axis of the primary optics, between the first parallel and a second parallel drawn on the hemispherical face, respectively on the other hemispherical face, around the axis of the primary optics, a number of microlenses, respectively a number of corresponding microlenses, positioned on each successive concentric ring being adjusted so that a contour of a surface of a microlens projected onto the hemispherical face, respectively a contour of a surface of a corresponding microlens projected onto the other hemispherical face, is substantially symmetrical about an axis passing through a center of the microlens and through a center of the corresponding microlens.

[0022] A contour of a surface is said to be substantially symmetrical about an axis if: - the point symmetrical with respect to the axis of any point on the contour is positioned on said contour, or if - the point symmetric with respect to the axis of any point on the contour is at a distance from the contour less than 10% of a distance to the axis of said point.

[0023] According to one embodiment, the microlens array, or the corresponding other microlens array, comprises a third part comprising the microlenses, respectively the corresponding microlenses, positioned on the hemispherical face, respectively on the other hemispherical face, of the optical mixing part, along successive concentric rings drawn on the hemispherical face, respectively on the other hemispherical face, around the axis of the primary optics, between the second parallel and a third parallel of the optical mixing part, the third parallel being coincident with a base of the hemispherical face, respectively of the other hemispherical face.

[0024] According to one embodiment, the microlenses, respectively the corresponding microlenses, of the first part have a first form and in which a distance between two adjacent microlenses, respectively between two adjacent corresponding microlenses, of the first part, comprises a curvilinear distance between two adjacent microlenses, respectively between two adjacent corresponding microlenses, which belong to two successive rings of the first part, and another curvilinear distance between two adjacent microlenses, respectively between two adjacent corresponding microlenses, of the same ring of the first part, the other curvilinear distance being equal to the curvilinear distance rounded to an integer value so that a number of adjacent microlenses, respectively a number of adjacent corresponding microlenses, of said same ring of the first part, is an integer.

[0025] According to one embodiment, the first shape is substantially hexagonal.

[0026] According to one embodiment, the microlenses, respectively the microlenses corresponding, of the second part have a second form, and in which a number of microlenses, respectively a number of corresponding microlenses, adjacent along a ring of the second part, is a multiple of 4.

[0027] According to one embodiment, the second shape is substantially hexagonal or substantially rectangular.

[0028] A substantially hexagonal shape is a regular hexagon, i.e. one which includes 6 vertices and whose two sides associated with each vertex form an angle of 120 degrees, or an irregular hexagon, i.e. one which includes 6 vertices and whose two sides associated with each vertex form an angle between 110 degrees and 130 degrees.

[0029] A substantially rectangular shape is a perfect rectangle, i.e. a quadrilateral comprising a right angle at each vertex, or a quadrilateral whose sides form, at each vertex, an angle between 80 degrees and 100 degrees.

[0030] According to one embodiment, the microlenses, respectively the corresponding microlenses, of the third part have a third shape, and in which a number of the microlenses, respectively a number of the corresponding microlenses, is constant from one ring to the next.

[0031] According to one embodiment, the third shape is substantially rectangular.

[0032] According to these provisions the contours of the projected surfaces of the microlenses and the corresponding microlenses have an axial symmetry with respect to an axis defined by a microlens and the corresponding microlens.

[0033] According to these provisions, the light from a microlens is entirely collected by the corresponding microlens, so as to avoid the formation of light artifacts.

[0034] According to these provisions, the optical device makes it possible to generate a variable light beam, which combines the performance of fixed-beam RGBW optics, which allow for color mixing with an intense and homogeneous light beam, and the performance of conventional zoom optics. In particular, the primary optic makes it possible to obtain: • A light output greater than 75% • An excellent mix of colors,

[0035] regardless of the zoom setting, used in combination and at the output of the primary lens, said zoom being able to range from 10° to 50°

[0036] According to one embodiment, a microlens of the microlens array, located along the axis of the primary optics, recovers an incident light beam from the light source and projects it towards a corresponding microlens of the other microlens array also located along the axis of the primary optics, so that the microlens projects an image of the light source onto the corresponding microlens, which projects a collimated and homogeneous emergent light beam, so that the corresponding microlens projects an image of the microlens at infinity.

[0037] According to one embodiment, a dimension of the microlens of the microlens array is adjusted to a dimension of the corresponding microlens of the other microlens array so that a geometric extent of the incident light beam is conserved and corresponds to a geometric extent of the emergent light beam.

[0038] According to one embodiment, at least one of the following is determined as a function of a distance separating the light source and the microlens: a radius of curvature of the microlens, a radius of curvature of the corresponding microlens, a distance separating the microlens from the corresponding microlens, a useful optical diameter of the microlens, a useful optical diameter of the corresponding microlens, is determined as a function of a distance separating the light source and the microlens.

[0039] According to one embodiment, the distance separating the light source and the microlens is defined so that a field angle of the incident beam is less than 20 degrees on either side of the axis of the primary optics, i.e. 40 degrees field angle in total.

[0040] According to one embodiment, one edge of the microlens corresponds to another edge of a corresponding microlens adjacent to the corresponding microlens, and in which one edge of the corresponding microlens corresponds to another edge of a corresponding microlens adjacent to the corresponding microlens, so that step by step a useful diameter of each microlens of the microlens array and a useful diameter of the corresponding microlens of the other microlens array are determined.

[0041] According to one aspect, the invention also relates to an optical device comprising a primary optic according to one of the embodiments described above, and a mechanical interface, the optical device further comprising a collimator, the primary optic being removably mounted on the mechanical interface, the collimator also being mounted on the mechanical interface, so that the light from the light source passes through the primary optic and then the collimator.

[0042] According to these provisions, the optical device has the advantage of being modular since it can be standardized and thus any mechanically compatible collimator can be attached to the primary optics. The mechanical interface ensures coplanarity for the alignment of the collimator and the primary optics.

[0043] According to one embodiment, the invention comprises one or more of the following features, alone or in a technically acceptable combination.

[0044] According to one embodiment, the collimator comprises a collimating optic and a collimating window, the collimating window of the collimator being movable in rotation relative to the mechanical interface around an axis of the primary optic, the collimator being configured to provide a variable zoom function as a function of a rotation angle of the collimating window.

[0045] According to one embodiment, the rotation angle of the collimation window is between 10 degrees and 15 degrees.

[0046] For better understanding, an embodiment and / or implementation of the invention is described with reference to the accompanying drawings, which represent, by way of non-limiting example, an embodiment or implementation of a device and / or method according to the invention. The same reference numerals in the drawings designate similar elements or elements with similar functions.

[0047] [Fig. 1] is a perspective and cross-sectional view of an optical device according to an embodiment of the invention.

[0048] [Fig.2] is a perspective view of a primary optic of an optical device according to an embodiment of the invention

[0049] [Fig.3] is a simplified two-dimensional representation, in a cross-sectional plane, of a portion of the optical mixing of the primary optics according to an optical device according to an embodiment of the invention

[0050] [Fig.4] is a simplified three-dimensional representation of a portion of the mixture optics of the primary optics according to an optical device according to an embodiment of the invention.

[0051] The invention relates to a primary optic 12, shown in an exemplary embodiment in [Fig. 2], designed to be interposed between a light source 3, for example an LED, shown in [Fig. 3], and a collimation optic 14, shown in an exemplary embodiment in [Fig. 1]. Said light source is not shown in Figures 1 and 2; it is positioned at a point on an axis 0, represented on [Fig.3], of the primary optic 12, the optical axis 0 being transverse to an extension of the primary optic 12, the light source 3 being positioned on said optical axis 0 on one side of the extension of the primary optic 12, and the collimation optic 14 being positioned on the other side of the extension of the primary optic 12, so that the primary optic 12 is intercalated between the light source 3 and the collimation optic 14.

[0052] The primary optic 12 comprises a mechanical holding part 21 and an optical mixing part 22, the optical mixing part 22 being configured to ensure a mixing of the colors of the light coming from the light source 3. Thus the primary optic has an optical function of color mixing and a mechanical function of assembly, via a mechanical interface 13, to a more complete optical device 10, represented in [Fig.1] according to an example of an embodiment, which includes in particular the collimation optic 14.

[0053] The optical device 10 shown in [Fig.1] thus comprises the primary optic 12, the mechanical interface 13, a collimator, the primary optic 12 being removably mounted on the mechanical interface 13, the collimator also being mounted on the mechanical interface 13, so that the light from the light source 3 passes through the primary optic 12 and then the collimator.

[0054] According to these provisions, the optical device 10 has the major advantage of being modular since it can be standardized and thus any mechanically compatible collimator can be fixed to the primary optics. The mechanical interface ensures co-planarity for the alignment of the collimator and the primary optics.

[0055] According to a particular embodiment of the optical device 10, the collimator comprises a collimating optic 14 and a collimating window 15, the collimating window 15 of the collimator being movable in rotation relative to the mechanical interface 13 around the axis of the primary optic 12, the collimator being configured to provide a variable zoom function as a function of a rotation angle of the collimating window 15. More particularly, the rotation angle of the collimating window is between 10 degrees and 15 degrees.

[0056] In particular, the mechanical retaining part 21 and the optical mixing part 22 of the primary optics 12, form a single monobloc piece.

[0057] According to one embodiment, the primary optic 12 is made of a transparent plastic material so that the primary optic 12 can be manufactured by plastic injection molding. For example, the plastic material is a polycarbonate, so that the mechanical strength and thermal resistance of the material are suitable for the requirement.

[0058] According to one embodiment, the mechanical retaining part 21 of the primary optic 12 includes at least one first fixing member 23, for example a bayonet-type fixing notch, the at least one first fixing member being configured to receive a first complementary fixing member disposed on the mechanical interface 13.

[0059] Thus, at least one first fixing member makes it possible to lock the position of the primary optics relative to the mechanical interface and, consequently, also relative to the collimator mounted on the mechanical interface 13.

[0060] According to a particular embodiment, the mechanical retaining part 21 further comprises at least one second fixing member 24, for example standardized screw holes, configured to fix the primary optic 12 on a support, not shown in the figures, of the light source 3.

[0061] According to a more particular embodiment, the mechanical retaining part 21 further comprises at least one opening 25, for example kidney-shaped, configured to evacuate heat.

[0062] Optionally, the mechanical retaining part 21 has a transverse extension to the axis of the primary optic 12, said extension having a cup shape 26, a lower part of the cup 26 being closer to the light source 3 than the upper part of the cup 26, the optical mixing part 22 being positioned on the lower part of the cup 26. Thus, the optical mixing part 22 is brought closer to the light source 3.

[0063] With reference to Figures 3 and 4 more particularly, an example of an embodiment of the optical mixing part 22 of the primary optics is described below.

[0064] The optical mixing portion 22 comprises two microlens arrays 1, 2, each array 1, 2 being arranged respectively on a hemisphere centered on the point on the axis 0 of the primary optics 12 on which the light source 3 is placed; a microlens 5, 5b, 5c of one microlens array 1 corresponding to a corresponding microlens 6, 6b, 6c of another microlens array 2, the microlens array 1 defining one hemispherical face of the optical mixing portion 22 and forming a partition of said hemispherical face, without free space between two adjacent microlenses, and the other corresponding microlens array 2 defining another hemispherical face of the optical mixing portion 22, and forming a partition of said other hemispherical face without free space between two corresponding adjacent microlenses.

[0065] More particularly, a microlens 5 of the microlens array 1, located along the axis of the primary optic 12, recovers an incident light beam 4 from the light source 3 and projects it towards a corresponding microlens 6 of the other microlens array 2 also located along the axis of the primary optic 12, so that the microlens 5 projects an image of the light source 3 onto the corresponding microlens 6, which projects an emergent collimated and homogeneous light beam 7, so that the corresponding microlens 6 projects an image of the microlens 5 at infinity.

[0066] In particular, a dimension of the microlens 5 of the microlens array 1 is fitted to a dimension of the corresponding microlens 6 of the other microlens array 2 so that a geometric extent of the incident light beam 4 is conserved and corresponds to a geometric extent of the emergent light beam 7.

[0067] To do this, we need to know the following parameters:

[0068] - a radius of curvature (R5) of the microlens 5,

[0069] - a radius of curvature (R6) of the corresponding microlens 6,

[0070] - a distance (E5) separating the microlens 5 from the light source 3,

[0071] - a distance (E6) separating the microlens 5 from the corresponding microlens 6,

[0072] - a useful optical diameter (D5) of the microlens 5,

[0073] - a useful optical diameter (D6) of the corresponding microlens 6.

[0074] To this end, we use the following relationships: A. The distance between the microlens 5 and the light source 3 is arbitrarily defined. An optional value is chosen to limit the field angle of the incident light rays as shown in [Fig. 3]. For example, the distance between the light source 3 and the microlens 5 is defined such that the field angle of the incident beam 4 is less than 20 degrees on either side of the axis of the primary optic 12. B. The radius of curvature (R5) of the microlens 5 is put into equation so as to perform an optical conjugation (of the object / image type) between the light source 3 and the microlens 6. C. The radius of curvature (R6) of the microlens 6 is put into equation so as to perform an optical conjugation (of type focus / infinity) between the microlens 6 and the output space. D. The useful optical diameter (D6) of the microlens 6 is given an equation such that each point on the edge of the light source corresponds to each point on the edge of the microlens 6, as shown in [Fig. 3]. This is possible because there is a conjugate relationship between 3 and 6. E. The right edge of microlens 6 must correspond to the left edge of the immediately adjacent microlens 6. F. Similarly, the right edge of microlens 5 must correspond to the left edge of the immediately adjacent microlens 5.

[0075] Relation (E) implies that, advantageously, one edge of the microlens 5 corresponds to another edge of a corresponding microlens adjacent to the corresponding microlens 5 and,

[0076] relation (F) implies that, advantageously, one edge of the corresponding microlens 6 corresponds to another edge of a corresponding microlens adjacent to the corresponding microlens 6.

[0077] If this is not respected, then light from a microlens 5 might not be collected by the corresponding microlens 6 and leak elsewhere, creating light artifacts.

[0078] Step by step the distance (E6) separating each microlens 5 from each microlens 6 is defined.

[0079] Step by step the useful optical diameter (D5) of each microlens 5 is defined.

[0080] So that, step by step, a useful diameter of each microlens of the microlens array 1 and a useful diameter of the corresponding microlens of the other microlens array 2 are determined

[0081] Conditions (E) and (F) are recurrence relations which require a starting point. The recurrence relations are initiated by means of a global “hidden” parameter which is, for example, an opening angle O of the microlenses 5 and 6; a value of the opening angle of the microlens 5 is chosen for example less than 10 degrees, i.e. 5 degrees on either side of the axis which passes through a center of the microlenses 5 and 6, as illustrated in [Fig.3].

[0082] Thus, six unknowns (R5, R6, E5, E6, D5, D6) and six equations (A, B, C, D, E, F) allow each pair of microlenses 5 and 6 composing the complete array to be determined individually. The embodiment described here is not unique. There are variants where, for example, instead of defining a fixed distance (E5) a priori for each pair of microlenses, a fixed radius of curvature (R6) is defined a priori for each pair of microlenses. Advantageously, a fixed radius of curvature (R6) a priori allows the use of machining techniques that greatly simplify mold manufacturing, such as, for example, the use of a ball end mill calibrated to the value of the radius of curvature (R6). In all cases, one unknown is fixed, then the problem restricted to 5 unknowns and 5 equations, including 2 recurrence relations, is solved.

[0083] A solution to the problem posed above in three dimensions of space further leads to determining the geometric shapes of the microlenses so that the conditions (A, B, C, D, E, F) are satisfied. According to an example implementation, two additional conditions are introduced.

[0084] A first additional condition is that a contour of the projected surfaces of the microlenses 5, 5b, 5c, 6, 6b, 6c of a pair 5, 6, or 5b, 6b, or 5c, 6c of microlenses which correspond on each hemisphere, is substantially symmetric about an axis which passes through the microlens.

[0085] A contour of a surface is said to be substantially symmetrical about an axis if: - the point symmetrical with respect to the axis of any point on the contour is positioned on said contour, or if - The point symmetrical with respect to the axis of any point on the contour is at a distance from the contour less than 10% of a distance to the axis of said point.

[0086] Thus, if the contour of the projected surface is, for example, a rectangle, a regular hexagon, a circle, or an ellipse, and the axis in question passes through the center of the shape in question transversely to a plane containing said contour, then the contour is perfectly symmetrical about the axis. The contour will only be substantially symmetrical about the axis if the contour of one of these perfectly symmetrical shapes is deformed such that the point symmetrical with respect to any point on the contour is at a distance from the contour less than 10% of a distance to the axis of said point.

[0087] To solve in three dimensions the problem represented in two dimensions in [Fig. 3], the second additional condition introduced is as follows: the microlenses are arranged along concentric rings around the optical axis 0 of the primary optic 12, a ring corresponding to a constant angle of emission of the light from the light source 3. Thus, as an example in [Fig. 4], two particular rings are shown, which delimit three portions 1, 2, 3 of surface on a hemispherical face of the optical mixing part 22. The technical effect obtained by this second additional condition is that the conditions (D, E, F) defined above are respected in the plane of [Fig. 3].

[0088] On each hemispherical face which makes up the optical mixing part 22, along each ring thus defined, a number of microlenses is thus adjusted so that the contours of the projected surfaces of the microlenses have axial symmetry according to the first additional condition.

[0089] Thus, according to an exemplary embodiment of the optical mixing portion 22, and with reference to [Fig. 4], the microlens array, or the corresponding other microlens array, comprises at least a first portion 221 and a second portion 222; the first portion 221 comprises the microlenses, or the corresponding microlenses, positioned on the hemispherical face, or the other hemispherical face, of the optical mixing portion 22, along successive concentric rings traced on the hemispherical face, respectively. tively on the other hemispherical face, around the axis of the primary optic 12; said first part 221 extends to a first parallel PI drawn on the hemispherical face, respectively on the other hemispherical face, around the axis of the primary optic 12; the second part 2 comprises the microlenses, respectively the corresponding microlenses, positioned on the hemispherical face, respectively on the other hemispherical face, of the optical mixing part 22, along successive concentric rings drawn on the hemispherical face, respectively on the other hemispherical face, around the axis of the primary optic 12, between the first parallel PI and a second parallel P2 drawn on the hemispherical face, respectively on the other hemispherical face, around the axis of the primary optic 12;a number of microlenses, or respectively a number of corresponding microlenses, positioned on each successive concentric ring being adjusted so that a contour of a surface of a microlens projected onto the hemispherical face, or respectively a contour of a surface of a corresponding microlens projected onto the other hemispherical face, is substantially symmetrical about an axis passing through a center of the microlens and through a center of the corresponding microlens.

[0090] More particularly, the microlens array, respectively the other corresponding microlens array, comprises a third part 223 comprising the microlenses, respectively the corresponding microlenses, positioned on the hemispherical face, respectively on the other hemispherical face, of the optical mixing part 22, along successive concentric rings traced on the hemispherical face, respectively on the other hemispherical face, around the primary optical axis 12, between the second parallel P2 and a third parallel P3 of the optical mixing part 22, the third parallel P3 being coincident with a base of the hemispherical face, respectively of the other hemispherical face.

[0091] More particularly, the microlenses, respectively the corresponding microlenses, of the first part 221 have a first shape, for example substantially hexagonal.In addition, a distance between two adjacent microlenses, respectively between two adjacent corresponding microlenses, of the first part 221, comprises a curvilinear distance between two adjacent microlenses, respectively between two adjacent corresponding microlenses, which belong to two successive rings of the first part, and another curvilinear distance between two adjacent microlenses, respectively between two adjacent corresponding microlenses, of the same ring of the first part, the other curvilinear distance being equal to the curvilinear distance rounded to an integer value so that a number of adjacent microlenses, respectively a number of adjacent corresponding microlenses, of said same ring of the first part, . be whole.

[0092] By convention, a substantially hexagonal shape is a regular hexagon, i.e. one which includes 6 vertices and whose two sides at each vertex form an angle of 120 degrees, or an irregular hexagon, i.e. one which includes 6 vertices and whose two sides at each vertex form an angle between 110 degrees and 130 degrees.

[0093] Furthermore, the microlenses, or corresponding microlenses, of the second part 222 have a second shape, for example substantially hexagonal or substantially rectangular. On the other hand, a number of the microlenses, or corresponding microlenses, adjacent along a ring of the second part 222, is a multiple of 4.

[0094] A substantially rectangular shape is a perfect rectangle, i.e. a quadrilateral comprising a right angle at each vertex, or a quadrilateral whose sides form, at each vertex, an angle between 80 degrees and 100 degrees.

[0095] Even more particularly, the microlenses, respectively the corresponding microlenses, of the third part 223 have a third shape, for example substantially rectangular; a number of the microlenses, respectively a number of the corresponding microlenses, of the third part 223 is constant from one ring to the next.

[0096] According to these provisions, the optical device 10 makes it possible to generate a variable light beam, which combines the performance of fixed-beam RGBW optics, which allow for color mixing with an intense and homogeneous light beam, and the performance of conventional zoom optics. In particular, the primary optic makes it possible to obtain: • A light output greater than 75% • An excellent mix of colors,

[0097] regardless of the setting of a zoom, used in combination and at the output of the primary optic, said zoom being able to go from 10° to 50°.

[0098] The color mixing effect is achieved in particular by the fact that conditions (B) and (C) are met simultaneously. In particular, the fulfillment of conditions (B) and (C) results in the image of the light source seen through the primary optic 12 no longer being the light source but a virtual source corresponding to a superposition of all the microlenses.

Claims

Claims

1. Primary optics (12), comprising a mechanical holding portion (21) and an optical mixing portion (22), the optical mixing portion (22) being configured to provide mixing of the colors of light coming from a light source (3) placed at a point on an axis of the primary optics (12), the mechanical holding portion (21) being configured to be removably fixed on a mechanical interface (13).

2. Primary optic (12) according to claim 1, wherein the mechanical holding portion (21) comprises at least one first fixing member (23), for example a bayonet-type fixing notch, the at least one first fixing member being configured to receive a first complementary fixing member disposed on the mechanical interface (13).

3. Primary optics (12) according to one of the preceding claims, in which the mechanical holding part (21) has an extension transverse to the axis of the primary optics, with a bowl shape (26), a lower part of the bowl (26) being closer to a light source than a higher part of the bowl (26), the optical mixing part (22) being positioned on the lower part of the bowl (26).

4. Primary optics (12) according to one of the preceding claims, wherein the optical mixing part (22) comprises at least two microlens arrays (1, 2), each arranged on a hemisphere centered on the point of the axis of the primary optics (12) on which the light source is placed, a microlens (5, 5b, 5c) of one microlens array (1) among the at least two arrays (1, 2) corresponding to a corresponding microlens (6, 6b, 6c) of another microlens array (2) among the at least two arrays (1, 2), the microlens array (1) defining a hemispherical face of the optical mixing part (22) and forming a partition of said hemispherical face, without free space between two adjacent microlenses, and the other corresponding microlens array (2) defining another hemispherical face of the optical mixing part (22),and forming a partition of said other hemispherical face without free space between two adjacent corresponding microlenses.,

5. Primary optics (12) according to the preceding claim, wherein the microlens array, respectively the other microlens array

6. corresponding, comprises at least a first part (221) and a second part (222), the first part (221) comprising the microlenses, respectively the corresponding microlenses, positioned on the hemispherical face, respectively on the other hemispherical face of the optical mixing part (22), along successive concentric rings traced on the hemispherical face, respectively on the other hemispherical face, around the axis of the primary optics (12), up to a first parallel (PI) traced on the hemispherical face, respectively on the other hemispherical face, around the axis of the primary optics (12), the second part (222) comprising the microlenses, respectively the corresponding microlenses, positioned on the hemispherical face, respectively on the other hemispherical face, of the optical mixing part (22), along successive concentric rings traced on the hemispherical face,respectively on the other hemispherical face, around the axis of the primary optic (12), between the first parallel (PI) and a second parallel (P2) drawn on the hemispherical face, respectively on the other hemispherical face, around the axis of the primary optic (12), a number of microlenses, respectively a number of corresponding microlenses, positioned on each successive concentric crown being adjusted so that a contour of a surface of a microlens projected onto the hemispherical face, respectively a contour of a surface of a corresponding microlens projected onto the other hemispherical face, is substantially symmetrical around an axis passing through a center of the microlens and through a center of the corresponding microlens., Primary optics (12) according to the preceding claim, in which the array of microlenses, respectively the other array of corresponding microlenses, comprises a third part (223) comprising the microlenses, respectively the corresponding microlenses, positioned on the hemispherical face, respectively on the other hemispherical face, of the optical mixing part (22), along successive concentric rings traced on the hemispherical face, respectively on the other hemispherical face, around the axis of the primary optics (12), between the second parallel (P2) and a third parallel (P3) of the optical mixing part (22), the third parallel (P3) being merged with a base of the hemispherical face, respectively of the other hemispherical face.

7. Primary optics (12) according to one of claims 5 or 6, in which the microlenses, respectively the corresponding microlenses, of the first part have a first shape and in which a distance between two adjacent microlenses, respectively between two adjacent corresponding microlenses, of the first part, comprises a curvilinear distance between two adjacent microlenses, respectively between two adjacent corresponding microlenses, which belong to two successive rings of the first part, and another curvilinear distance between two adjacent microlenses, respectively between two adjacent corresponding microlenses, of the same ring of the first part, the other curvilinear distance being equal to the curvilinear distance rounded to an integer value so that a number of adjacent microlenses, respectively a number of corresponding adjacent microlenses,of the said same crown of the first part, either whole.,

8. Primary optics (12) according to one of claims 5 to 7, wherein the microlenses, respectively the corresponding microlenses, of the second part (222) have a second shape, and wherein a number of the microlenses, respectively a number of the corresponding microlenses, adjacent along a crown of the second part, is a multiple of 4.

9. Primary optics (12) according to one of claims 6 to 8, in which the microlenses, respectively the corresponding microlenses, of the third part (223) have a third shape, and in which a number of the microlenses, respectively a number of the corresponding microlenses, is constant from one crown to the next.

10. Primary optics (12) according to one of claims 4 to 9, wherein a microlens (5) of the microlens array (1), located along the axis of the primary optics (12), recovers an incident light beam (4) from the light source (3) and projects it towards a corresponding microlens (6) of the other microlens array (2) also located along the axis of the primary optics (12), so that the microlens (5) projects an image of the light source (3) onto the corresponding microlens (6), which projects a collimated and homogeneous emergent light beam (7), so that the corresponding microlens (6) projects an image of the microlens (5) to infinity.

11. Primary optics (12) according to the preceding claim, wherein a dimension of the microlens (5) of the microlens array (1) is adjusted to a dimension of the corresponding microlens (6) of the other microlens array (2) so that a geometric extent of the incident light beam (4) is preserved and corresponds to a geometric extent of the emerging light beam (7).

12. Primary optics (12) according to the preceding claim, wherein at least one of a radius of curvature R5 of the microlens (5), a radius of curvature R6 of the corresponding microlens (6), a distance E5 separating the microlens (5) from the light source (3), a distance E6 separating the microlens (5) from the corresponding microlens (6), a useful optical diameter D5 of the microlens (5), a useful optical diameter D6 of the corresponding microlens (6), is determined as a function of a distance separating the light source (3) and the microlens (5).

13. Primary optics (12) according to the preceding claim, wherein one edge of the microlens (5) corresponds to another edge of a corresponding microlens adjacent to the corresponding microlens (5), and wherein one edge of the corresponding microlens (6) corresponds to another edge of a corresponding microlens adjacent to the corresponding microlens (6), so that step by step a useful diameter of each microlens of the microlens array (1) and a useful diameter of the corresponding microlens of the other microlens array (2) are determined.

14. An optical device (10) comprising a primary optic (12) according to one of claims 1 to 13, and a mechanical interface (13), the optical device (10) further comprising a collimator, the primary optic (12) being removably mounted on the mechanical interface (13), the collimator also being mounted on the mechanical interface (13), such that light from the light source passes through the primary optic (12) and then the collimator.

15. Optical device (10) according to the preceding claim, in which the collimator comprises a collimation optic (14) and a collimation window (15), the collimation window (15) of the collimator being movable in rotation relative to the mechanical interface (13) around an axis of the primary optic (12), the collimator being configured to provide a variable zoom function as a function of an angle of rotation of the collimation window (15).

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