Collimator and projector including such a collimator

Abstract

This collimator comprises a light inlet surface (6), a light outlet surface (8), and an intermediate collimation surface (10) configured to collimate the light from the inlet surface (6) and direct it to the outlet surface (8). The light outlet surface (8) comprises at least one straight prism-shaped groove (20) including a reflection surface (22) configured to reflect the light collimated by the intermediate collimation surface (10) and a refraction surface (24) configured to refract the light reflected by the reflection surface (22). Figure for the abstract: Fig 1

Description

Title of the invention: Collimator and projector comprising such a collimator Technical field

[0001] The technical field of the invention is collimators.

[0002] In particular, the invention relates to a collimator used in a fixed-wing aircraft searchlight and a searchlight comprising such a collimator. Previous techniques

[0003] An aircraft lighting system generally comprises several lighting devices which are activated according to flight or taxiing phases of the aircraft.

[0004] The lighting system comprises landing lights and navigation lights arranged on the wings of the aircraft, lighting devices mounted on the nose landing gear leg of the aircraft, lighting devices providing lateral lighting, and additional lighting devices called "wing engine scan light" in English terms which are used for night inspection of the leading edges and air intakes of the aircraft.

[0005] In the state of the art, such a complementary lighting device consists of a housing arranged on the side of the aircraft upstream of the wings of the aircraft and provided with a glass flush with the fuselage of the aircraft.

[0006] The housing also comprises a support inclined relative to the glass and provided with integrated LED circuits associated with collimators arranged in the housing and making it possible to emit collimated visible light. The light collimated by each collimator propagates parallel to the optical axis of the collimator in the direction of the glass.

[0007] The internal face of the glass arranged inside the housing is provided with grooves forming rectilinear prisms on the internal face of the glass.

[0008] The combined effect of the inclined support and the glass provided with grooves forming rectilinear prisms allows the complementary lighting device to illuminate in a direction inclined relative to the direction normal to the fuselage of the aircraft taken at the location of the complementary lighting device.

[0009] Such a complementary lighting device has a certain number of drawbacks, in particular relating to the fact that the complementary lighting device has a relatively large size and mass.

[0010] The inclined support of the housing increases the depth of the housing and therefore does not promote the bulk and reduction of the mass of the complementary lighting device. The inclined collimators reduce the projected illuminating surface crossing the ice. In fact, the inclined collimators can emit light towards the internal walls of the housing, the light then being lost.

[0011] The glass provided with grooves forming rectilinear prisms of the complementary lighting device is fragile. In addition, the collimated light undergoes two refractions through the grooves forming rectilinear prisms, which generates chromatic dispersion from the complementary lighting device and does not allow for a homogeneous and uniformly white light beam. Statement of the invention

[0012] The present invention therefore aims to overcome all or part of the aforementioned drawbacks and to provide an implementation collimator integrating a deviation function, in particular without chromatic dispersion.

[0013] The invention therefore relates to a collimator, in particular for an aircraft projector, in particular a fixed-wing aircraft, comprising a light entry surface, a light exit surface and an intermediate collimation surface configured to collimate the light coming from the entry surface and direct it towards the exit surface.

[0014] According to a general characteristic of the invention, the light output surface comprises at least one rectilinear prism-shaped groove comprising a reflection surface configured to reflect the light collimated by the intermediate collimation surface and a refraction surface configured to refract the light reflected by the reflection surface.

[0015] Thus, said rectilinear prism-shaped groove is configured to deflect the light collimated by the intermediate collimation surface in a majority direction by a non-zero angle.

[0016] The light collimated by the intermediate collimating surface is collimated along the optical axis of the collimator.

[0017] Said rectilinear groove is transversely in the form of a prism with a triangular section.

[0018] The light collimated by the intermediate collimation surface is reflected by the reflection surface of said rectilinear prism-shaped streak and then transmitted by the refraction surface of said rectilinear prism-shaped streak.

[0019] The reflection surface of said rectilinear prism-shaped streak may be arranged such that the angle between the normal to the reflection surface of said rectilinear prism-shaped streak and the collimation direction of the light collimated by the intermediate collimation surface is greater than a reflection limit angle.

[0020] The reflection surface of said rectilinear prism-shaped streak can form an angle with the light collimated by the intermediate collimation surface of less than 55 degrees, in particular less than 45 degrees, in particular between 25 degrees and 35 degrees.

[0021] The collimator can be obtained by molding a refractive material, in particular by molding a single piece.

[0022] The refraction surface of said rectilinear prism-shaped streak may form an angle relative to the direction of collimation of the light collimated by the intermediate collimation surface of less than 10 degrees, in particular less than 5 degrees, in particular between 2 degrees and 4 degrees.

[0023] The angle formed by the refraction surface of said rectilinear prism-shaped groove relative to the collimation direction of the light collimated by the intermediate collimation surface may correspond to a clearance angle facilitating the demolding of the collimator.

[0024] Reducing the value of the angle formed by the refraction surface of said rectilinear prism-shaped streak relative to the collimation direction of the light collimated by the intermediate collimation surface makes it possible to reduce the quantity of light not leaving the collimator via the refraction surface of said rectilinear prism-shaped streak.

[0025] The output surface may comprise a plurality of prism-shaped rectilinear striations arranged successively such that at least the refractive surface of one rectilinear striation is directly adjacent to the reflective surface of a directly successive rectilinear striation.

[0026] In particular, the output surface is formed solely from the succession of rectilinear prism-shaped striations and does not include a surface orthogonal to the direction of collimation of the light collimated by the intermediate collimation surface.

[0027] The reflection surfaces of the rectilinear prism-shaped striations may be parallel to each other.

[0028] The refractive surfaces of the rectilinear prism-shaped striations may be parallel to each other.

[0029] The invention also relates to a projector comprising a housing provided with a glass and a light source support arranged in the housing and provided with at least one light source and at least one collimator as defined previously associated with said light source.

[0030] The use of such collimators makes it possible to reduce the physical size of the aircraft projector by placing all of the collimators as close as possible to the glass. The quantity of light emitted by the light sources lost in the housing is also reduced, the illuminating surface of the supports being close to the surface of the glass. In addition, the chromatism of such a projector is reduced compared to known solutions of the state of the art.

[0031] Preferably, said collimator is arranged on the light source support of so that the optical axis of said collimator is orthogonal to the glass.

[0032] The glass may comprise two plane surfaces parallel to each other and orthogonal to the direction of collimation of the light collimated by the intermediate collimation surface of said collimator.

[0033] The glass may include a treatment increasing its resistance to abrasion.

[0034] The glass may include a treatment increasing its mechanical resistance.

[0035] The glass may include a treatment increasing its thermal resistance. Brief description of the drawings

[0036] Other aims, characteristics and advantages of the invention will appear on reading the following description, given solely by way of non-limiting example and made with reference to the appended drawings in which:

[0037] [Fig-1] schematically illustrates a section of a collimator according to the invention;

[0038] [Fig.2] schematically illustrates the cross-section of two directly adjacent rectilinear prism-shaped striations of [Fig.l];

[0039] [Fig.3] schematically illustrates a perspective view of an arrangement of three collimators according to the invention; and

[0040] [Fig.4] illustrates a projector according to the invention. Detailed description

[0041] [Fig. 1] represents a collimator 2 comprising a body 4 made in a single piece, by molding a refractive material, for example a plastic material, in particular anti-UV treated polycarbonate suitable for the use of white light-emitting diodes. Such an anti-UV treated polycarbonate lets visible light pass through and resists photo-oxidation.

[0042] The body 4 comprises a light entry surface 6, a light exit surface 8 and an intermediate collimation surface 10.

[0043] The light entry surface 6 forms a housing for housing a light source 12 at the entrance to the collimator 2.

[0044] The light source 12 comprises, for example, a light-emitting diode emitting visible light. Alternatively, it is possible to provide another type of light source 12 emitting in another spectral band.

[0045] The input and intermediate collimation surfaces 6, 10 are surfaces of revolution around the optical axis A of the collimator 2. The optical axis A defines an axial direction, the direction orthogonal to the optical axis A defining a radial direction.

[0046] The input and intermediate collimation surfaces 6, 10 ensure the collimation of light beams delivered by the light source 12 in the form of collimated light beams, the beams being parallel to the optical axis A of the collimator 2.

[0047] The input surface 6 comprises a convex surface 14 centered on the optical axis A forming a convex lens and an inner peripheral surface 16 forming a well. The convex surface 14 forming the convex lens is arranged so that the light source 12 is arranged in the object focus of the convex lens.

[0048] The intermediate collimation surface 10 comprises an outer peripheral surface 18 radially delimiting the body 4.

[0049] The light beams emitted by the light source 12 are refracted by the inner peripheral surface 16 then reflected by the outer peripheral surface 18 or refracted by the convex surface 14 so as to be directed towards the light output surface 8 of the collimator 2.

[0050] The light output surface 8 comprises a plurality of rectilinear streaks 20 with a prismatic section, each comprising a reflection surface 22 and a refraction surface 24. A cross-section of each rectilinear streak 20 in the form of a prism is triangular and is defined by the refraction surface 24 and by the reflection surface 22, each rectilinear streak 20 being in the form of a prism with a triangular section.

[0051] The refractive surface 24 of each rectilinear prism-shaped groove 20 forms an angle with respect to the collimation direction of the light collimated by the intermediate collimation surface 10 of approximately 3 degrees. The refractive surfaces 24 of the rectilinear prism-shaped grooves 20 are parallel to each other.

[0052] The reflection surface 22 of each rectilinear prism-shaped groove 20 forms an angle with the light collimated by the intermediate collimation surface 10 of approximately 30 degrees. The reflection surfaces 22 of the rectilinear prism-shaped grooves 20 are parallel to each other.

[0053] The prism-shaped rectilinear striations 20 are arranged such that, with the exception of the surfaces radially located outside the prism-shaped rectilinear striations 20 located at the end of the collimator 2, each refraction surface 24 of a rectilinear striation 20 is extended by the reflection surface 22 of a directly adjacent rectilinear striation 20.

[0054] As illustrated more visibly in [Fig.2], representing the trajectory of two light rays, the light collimated by the intermediate collimation surface 10 and directed towards the reflection surface 22 of each rectilinear prism-shaped streak 20 is reflected by the reflection surface 22 towards the refraction surface 24 of the rectilinear prism-shaped streak 20.

[0055] Indeed, the reflection surface 22 of each rectilinear prism-shaped groove 20 is arranged so that the angle between the normal to the reflection surface 22 and the collimation direction of the light collimated by the intermediate collimation surface 10 is greater than a reflection limit angle.

[0056] The light reflected by the reflection surface 22 of each rectilinear streak 20 in prism shape towards the refracting surface 24 of the prism-shaped rectilinear groove 20 is then refracted by the refracting surface 24 of the prism-shaped rectilinear groove 20 in particular so as to maximize the extraction of the light reflected by the reflecting surface 22 while avoiding the masking of the light by the directly adjacent prism-shaped rectilinear groove 20.

[0057] The angle values ​​of the reflection and refraction surfaces 22, 24 of each rectilinear prism-shaped groove 20 are determined to obtain a deflection angle of the light collimated by the intermediate collimation surface 10 due to the light exit surface 8 around 45 degrees, in particular between 40 degrees and 50 degrees in particular for a material with a refractive index equal to 1.585. Alternatively, it is possible to adapt these angle values ​​according to the material used and the desired deflection angle of the light collimated by the intermediate collimation surface 10.

[0058] Alternatively, it is possible to provide reflection and refraction surfaces 22, 24 whose angle values ​​vary from one rectilinear prism-shaped groove 20 to another to obtain a collimator 2 deflecting the light in several directions.

[0059] Advantageously, the value of the angle formed by the refraction surface 24 of each rectilinear prism-shaped groove 20 with the collimation direction of the light collimated by the intermediate collimation surface 10 is chosen so as to reduce the quantity of light collimated by the intermediate collimation surface 10 and reflected by the refraction surface 24 of each rectilinear prism-shaped groove 20, and also chosen so as to reduce the quantity of light reflected by the reflection surface 22 and then refracted by the refraction surface 24 of each rectilinear prism-shaped groove 20 striking the reflection surface 22 of the directly adjacent rectilinear prism-shaped groove 20. Thus, the extraction of the light collimated by the intermediate collimation surface 10 is maximized.

[0060] In the example shown, the collimator 2 comprises a plurality of rectilinear streaks 20 in the shape of a prism. Alternatively, the collimator 2 may comprise a single rectilinear streak 20 in the shape of a prism.

[0061] [Fig.3] represents an arrangement 26 of three collimators 2 oriented according to a same direction and in contact with each other, the three collimators 2 being identical here.

[0062] The arrangement 26 comprises three identical fixing feet 28 arranged in a triangular shape in order to fix the arrangement 26 in a stable manner, each foot 28 being arranged between two separate collimators 2. This arrangement 26 makes it possible to share the support feet 28 of the collimators 2, also promoting the luminous efficiency of the arrangement 26 while remaining mechanically reliable and rigid.

[0063] [Fig. 4] represents a projector 30 comprising a housing 32 provided with a glass 34 forming one of the outer faces of the housing 32. The projector 30 is intended to equip an aircraft, in particular a fixed-wing aircraft, so that the glass 34 is flush with the fuselage of the aircraft. In particular, the projector 30 is intended to allow a pilot of the aircraft to inspect the leading edges and the air intakes of the aircraft.

[0064] The window 34 comprises two surfaces parallel to each other, in particular two flat surfaces in the extension of the fuselage of the aircraft.

[0065] The housing 32 comprises a support 36 for light sources arranged in the housing 32 and comprising an upper face facing the glass 34. The support 36 for light sources comprises an integrated circuit carrying light sources 12 and arranged on the upper face of the support 36 for light sources.

[0066] Arrangements 26 of collimators 2 are mounted by means of the fixing feet 28 on the support 36 of light sources so that each light source 12 is associated with a collimator 2.

[0067] The light source support 36 is arranged so that the optical axis A of each collimator 2 is orthogonal to the parallel surfaces of the glass 34.

[0068] Preferably, the glass 34 comprises a treatment in order to strengthen it. For example, the glass 34 comprises a treatment increasing its abrasion resistance and / or a treatment increasing its mechanical resistance and / or a treatment increasing its thermal resistance.

[0069] The use of arrangement 26 of collimators 2 makes it possible to reduce the assembly time of the housing 32.

[0070] In a particular embodiment, the projector 30 comprises a mixture of different arrangements 26 of collimators 2, each arrangement 26 of collimator 2 being adapted to illuminate according to a different deflection angle. Thus, the projector 30 can emit non-uniform radiation and illuminate more areas of interest, for example areas of interest of an aircraft wing, or illuminate a larger volume of space.

Claims

Claims

1. Collimator (2), in particular for an aircraft projector (30), in particular a fixed-wing aircraft, comprising a light input surface (6), a light output surface (8) and an intermediate collimation surface (10) configured to collimate the light coming from the input surface (6) and direct it towards the output surface (8), characterized in that the light output surface (8) comprises at least one rectilinear prism-shaped groove (20) comprising a reflection surface (22) configured to reflect the light collimated by the intermediate collimation surface (10) and a refraction surface (24) configured to refract the light reflected by the reflection surface (22).

2. A collimator (2) according to claim 1, wherein the reflection surface (22) of said prism-shaped rectilinear groove (20) is arranged such that the angle between the normal to the reflection surface (22) of said prism-shaped rectilinear groove (20) and the collimation direction of the light collimated by the intermediate collimation surface (10) is greater than a reflection limit angle.

3. Collimator (2) according to one of claims 1 and 2, in which the reflection surface (22) of said rectilinear streak (20) in the form of a prism forms an angle with the light collimated by the intermediate collimation surface (10) of less than 55 degrees, in particular less than 45 degrees, in particular between 25 degrees and 35 degrees.

4. Collimator (2) according to one of claims 1 to 3, wherein the collimator (2) is obtained by molding a refractive material, in particular by molding in one piece.

5. Collimator (2) according to one of claims 1 to 4, in which the refraction surface (24) of said rectilinear prism-shaped groove (20) forms an angle relative to the direction of collimation of the light collimated by the intermediate collimation surface (10) of less than 10 degrees, in particular of less than 5 degrees, in particular between 2 degrees and 4 degrees.

6. Collimator (2) according to one of claims 1 to 5, in which the output surface (8) comprises a plurality of rectilinear streaks (20) in the form of a prism arranged successively so that at least the refraction surface (24) of a rectilinear streak (20) is extended by the reflection surface (22) of a rectilinear streak (20) directly successive.

7. Collimator (2) according to claim 6, wherein the reflection surfaces (22) of the rectilinear prism-shaped striations (20) are parallel to each other and / or wherein the refraction surfaces (24) of the rectilinear prism-shaped striations (20) are parallel to each other.

8. Projector (30) comprising a housing (32) provided with a glass (34) and a support (36) for light sources (12) arranged in the housing (32) and provided with at least one light source (12) and at least one collimator (2) according to any one of claims 1 to 7 associated with said light source (12).

9. Projector (30) according to claim 8, in which the glass (34) comprises two plane surfaces parallel to each other and orthogonal to the direction of collimation of the light collimated by the intermediate collimation surface (10) of said collimator (2).

10. Projector (30) according to one of claims 8 and 9, in which the glass (34) comprises a treatment increasing its resistance to abrasion and / or a treatment increasing its mechanical resistance and / or a treatment increasing its thermal resistance.

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