Light emitting device including microlens array device

Abstract

A light emitting device (1) comprising a microlens array device (2) having at least one incident microlens array (21) and one exit microlens array (22), the device being characterized in that at least one light circulation channel (5) arranged along a primary optical axis (10) is formed contiguously by an incident microlens (20) and at least one exit microlens (24, 241, 242), the incident microlens (20) is configured to converge a beam of substantially parallel light from the collimator (3) in a convergence region on an exit face of at least one exit microlens (24, 241, 242) associated with the light circulation channel, the at least one exit microlens (24, 241, 242) being configured to image an incident face of the incident microlens (20) associated with the light circulation channel (5).

Description

[0001] This invention relates to the field of light-emitting devices, specifically light-emitting devices that can be equipped on motor vehicles.

[0002] Vehicles, especially motor vehicles, are typically equipped with headlights that enable a variety of luminous functions, such as road lighting or signaling to other road users, including DRL (daytime running light) functions or indicator lights that effectively allow for changes in direction.

[0003] Headlights need to become increasingly compact, and it may be desirable for these headlights to contain a single light-emitting module capable of producing several light-emitting functions, particularly illumination and signaling functions. In this context, the aim is to emit a beam of light specific to each of the light-emitting functions produced by the module through a common illumination area. In other words, to provide visual identification of the vehicle's illumination, it is desired that an observer outside the vehicle sees the same area illuminated, regardless of whether the headlight is performing a illumination or signaling function.

[0004] In addition, the vehicle's light-emitting device can also be used to perform interior lighting functions and / or ground marking functions, particularly to project pictograms onto the road adjacent to the vehicle.

[0005] In some applications, light emitted by a light source is guided into a microlens array (MLA) device to form a beam that allows the light-emitting function to be performed.

[0006] The array device includes an incident microlens array, an exiting microlens array, and a mask inserted between these arrays. The array device is configured to form an optical circulation channel between one of the incident microlenses and one of the exiting microlenses. The mask includes mask segments, each positioned within a corresponding optical circulation channel. Each mask segment has at least one aperture that allows light to pass from the incident microlens to the exiting microlens. The apertures in the mask are configured to impart a shape to the light transmitted by the incident lens array and allow the exiting lens array to project this shape onto a road.

[0007] Specifically, a glass sheet with a perforated opaque coating is used to produce the mask. This glass sheet forms a support with two optical blocks that respectively form an incident microlens array and an exit microlens array. In particular, the microlens array can be molded and solidified on the glass sheet.

[0008] Therefore, there is a need for a light-emitting device that provides the same optical advantages as a microlens array, particularly allowing for great flexibility in the shape of the functional lighting area and thus in the style of headlights equipped with the array, achieved by discretizing the incident and exit microlenses per unit area. Furthermore, a light-emitting device is proposed that is simple to manufacture and allows for the performance of two or more light-emitting functions in the same lighting area where applicable.

[0009] In this context, the present invention proposes a light-emitting device comprising at least a light-emitting device, a collimator, and a microlens array device. The light-emitting device is configured to emit light toward the array device via the collimator. The array device comprises at least an incident microlens array, an exiting microlens array, and a principal optical axis intersecting the two microlens arrays. The incident surface of the incident microlens array faces outward of the array device toward the collimator, and the exiting surface of the exiting microlens array faces outward of the array device opposite to the incident microlens array. A significant feature of the device is that at least one optical circulation channel arranged along the principal optical axis is continuously formed by the incident microlens and at least one exiting microlens. The incident microlens is configured to converge a beam of substantially parallel light rays from the collimator into a convergence region on the exiting surface of the at least one exiting microlens associated with the optical circulation channel. The at least one exiting microlens is configured to image the incident surface of the incident microlens associated with the optical circulation channel.

[0010] A light emitting device may include one or more semiconductor light emitting elements, which may be, for example, a corresponding light-emitting diode.

[0011] Each incident microlens and exit microlens includes a curved surface facing outwards from the array device, and a material thickness extending from the curved surface to another incident microlens array.

[0012] These channels are defined as material strips formed by an incident microlens and at least one exiting microlens arranged facing the incident microlens, if the principal optical axis is taken into account, within an array device. There are no structural elements, such as separators, within the array device that create physical boundaries between two adjacent channels.

[0013] The array device includes a single incident microlens for a given optical circulation channel. According to a variant embodiment, the incident microlens is associated with one or more exiting microlenses in a given optical circulation channel.

[0014] Associating incident microlenses with multiple exiting microlenses allows for an improvement in the appearance of the microlens array when it is open, especially when there is only one light source. Therefore, it should be recognized that the entire or most of the microlens array appears open regardless of the observer's viewing angle; in other words, the microlenses open in a given viewing direction are distributed throughout the entire microlens array.

[0015] Because light rays from the incident microlenses converge toward the exiting microlenses, the light can propagate completely through the array of exiting microlenses, passing between the optical circulation channels, thus efficiently performing its light-emitting function. In other words, the exiting microlenses enable the generation of beam portions with the same profile as the associated incident microlenses within the same optical circulation channel. The light propagates completely because, for a given optical circulation channel, the size of one or more exiting microlenses is chosen such that this size is greater than or equal to the size of the image formed by the collimator and the action of the incident microlenses on the exiting microlenses.

[0016] To avoid any unilluminated areas on the incident surface of the array device, except for the addition of opaque elements to the incident surface to clearly distinguish the boundary between two adjacent incident microlenses, it should be recognized, where applicable, that if the size of the incident microlens is smaller than the average size of all microlenses, then to compensate this, the corresponding size of one of the adjacent microlenses needs to be larger. Therefore, in some cases, one or more channels within the array device are theoretically bounded by the boundary connecting the edge of the incident microlens to the non-parallel edges of one or more associated exiting microlenses.

[0017] The collimator is configured to redirect the passing light rays to form a beam of light that is substantially parallel to each other as the output, and thus guides these rays uniformly toward the microlenses in the incident microlens array. The reference is to a substantially parallel beam of light, because the size of the light source (which is wider than the theoretical point) may cause slight angles between the rays deflected by the collimator.

[0018] "Continuous" refers to the continuity of the material between surfaces, which allows the microlens array to be obtained in a single injection molding step, rather than being produced as two parts arranged on both sides of a glass sheet configured to form a mask within the thickness of the array device.

[0019] "Convergence" means that the purpose is to ensure that all light rays passing through the incident microlens also pass through the exiting microlens so as not to lose luminous efficiency.

[0020] "Imaging" refers to the process where an incident microlens is configured to have an object focal length as close as possible to the incident microlens's incident surface, and accordingly projects light rays passing through that incident microlens to infinity.

[0021] Whether in convergent or focused cases, it should be understood that throughout this specification, error margins are provided regarding the position of the object or, in particular, the image focus of the various optical elements formed by microlenses.

[0022] Each incident microlens is configured such that the entire beam converges on the exit surface of the exit microlens located at the other end of the guide channel, but the convergence point can be in front of or behind the exit surface.

[0023] Conversely, it is important that the focal length of the exiting microlens is positioned as close as possible to that of the incident microlens.

[0024] According to one feature of the invention, for a given guide channel, the focal length of the exit microlens is closer to the incident surface of the incident microlens than the focal length from the incident microlens to the exit surface of the exit microlens.

[0025] The incident microlens array and the exit microlens array consist of microlenses with a size of approximately a few millimeters, ranging from 0.025 mm to 10 mm.

[0026] More specifically, viewed from the front, the microlenses have a size of less than or equal to 10 mm in diameter, height, and / or width. This allows for limitations on the thickness of the microlenses, and thus on the weight of the part. Furthermore, viewed from the front, the dimensions of the microlenses in terms of diameter, height, and / or width are greater than or equal to 0.1 mm for exiting microlenses and greater than or equal to 0.5 mm for incident microlenses. This allows the lenses to be small enough to be distinguishable at typical viewing distances, while also enabling the optical devices to be manufactured using an easily implemented injection molding process.

[0027] According to an optional feature of the invention, the incident microlens has an aspect ratio corresponding to a horizontal elongated rectangle in both the vertical and horizontal planes. The ratio of the maximum size (i.e., the horizontal size) to the minimum size (i.e., the vertical size) is at least 2 to 1. By way of a non-limiting example of the invention, this ratio can more specifically be about 3 or 4 to 1, especially when projecting a light cutoff beam (e.g., low beam) onto a road.

[0028] According to the various optional features to be considered individually or in combination according to the invention, the maximum dimension (i.e., the lateral dimension) is between 0.1 mm and 10 mm, while the minimum dimension (i.e., the vertical dimension) is between 0.025 mm and 2.5 mm. More specifically, the incident microlens may have a vertical dimension of approximately 0.01 mm, while the exiting microlens may have a vertical dimension of approximately 0.25 mm.

[0029] According to an optional feature of the invention, the at least one exiting microlens is eccentrically cut.

[0030] The purpose of the eccentric cutting is to specifically protect the fact that the at least one exiting microlens is a lens portion cut from an aspherical lens to the size of the optical circulation channel, the optical axis of which is substantially parallel to the overall optical axis of the optical system, but offset from the center of the optical circulation channel and the spherical lens portion.

[0031] According to an optional feature of the invention, within the optical circulation channel, the at least one exiting microlens is focused on the edge of the incident surface of the incident microlens.

[0032] This feature is specifically implemented in guide channels through which light participating in the formation of the illumination function, and particularly the low beam function, is passed, for which a clear cutoff line between light and dark is desired in the beam, and the beam is then truncated by the boundary of the aperture where the object focus is located.

[0033] The exiting microlens is configured to have an optical axis vertically aligned on the edge (i.e., the bottom edge) of the incident microlens.

[0034] The exiting microlens is also configured such that the optical axis intersects the incident surface of the incident microlens in a region around a specific point on the edge, whether that specific point is the center of the edge or a bend formed on the edge.

[0035] When generating the near beam portion, the edge of the incident surface in question is the lower edge, because the projected beam must be clearly cut off above it.

[0036] Alternatively, the edge in question of the incident surface is the upper edge when an additional high beam portion is to be generated to supplement the lower portion of the high beam, or the side edge when an array illumination beam portion is to be generated, with the beam being cut into selectively activated juxtaposed lateral strips.

[0037] According to an optional feature of the invention, the edge of the incident surface of the incident microlens on which the at least one exiting microlens is focused has a bend.

[0038] According to an optional feature of the invention, the at least one optical circulation channel is arranged along the main optical axis and is formed on one side by a single incident microlens and on the other side by a plurality of adjacent exiting microlenses.

[0039] According to an optional feature of the invention, adjacent exiting microlenses may be located in an offset elongated plane, wherein a step is formed between the exiting microlenses.

[0040] According to an optional feature of the invention, at least one average size of the incident microlens participating in defining the optical circulation channel is a multiple of the corresponding average size of the exiting microlens participating in defining the optical circulation channel. The average size is obtained by considering a specific size (whether it is height, width, diagonal, or area) of the incident or exiting microlens and calculating the average of that specific size from one longitudinal end to the opposite longitudinal end. For example, when the optical circulation channel extends between one incident microlens and two exiting microlenses, the average area of ​​the incident microlens (in other words, the average area projected into the vertically and horizontally extended plane) is equal to the sum of the corresponding sizes of two adjacent exiting microlenses (in this case, the areas projected into the same plane).

[0041] According to an optional feature of the invention, the exiting microlenses of the same optical circulation channel are juxtaposed in the vertical direction and a bend is formed on the vertical edge of the incident surface, the bend being substantially centered on the edge in the transverse direction perpendicular to the vertical direction.

[0042] According to an optional feature of the invention, the exiting microlenses of the same optical circulation channel are juxtaposed in the lateral direction and have a bend formed on the vertical edge of the incident surface, the bend being laterally eccentrically positioned on the edge so as to face the exiting microlens configured to image the edge of the incident microlens.

[0043] The optical axis of the exiting microlens can be centered on the bend, but it can also be offset, especially in order to find a compromise between the bend center and the opening on the outside of the path of the projected beam, which is needed to find a clearer cutoff line between light and dark in the projected beam.

[0044] According to an optional feature of the invention, the exiting microlens of the same optical circulation channel are configured to have different object focal points positioned on the incident surfaces of the incident microlenses of the optical circulation channel. This feature is particularly advantageous for more easily generating different portions of the luminescent beam.

[0045] According to an optional feature of the invention, one of the exiting microlenses is focused on the edge of the incident microlens, while the other exiting microlens is substantially focused on the center of the incident surface of the incident microlens. Therefore, in each optical circulation channel, a clear image of the incident surface can be obtained in different regions.

[0046] "Substantially at the center" means that the focal point is located away from the edge defining the second aperture, which includes, for example, a position where the focal point is located at two-thirds of the distance between the two opposing edges defining the second aperture. This feature is particularly implemented in guide channels through which light participating in the signaling function passes.

[0047] When the first light source is activated, light rays passing through each incident microlens within its associated optical circulation channel converge onto a first exiting microlens present in that channel. When the second light source is activated, light rays passing through each incident microlens within its associated optical circulation channel converge onto a second exiting microlens present in that channel. Each exiting microlens present in the same channel focuses on a different region of the incident microlens associated with that channel.

[0048] The second exiting microlens is offset from the first incident microlens in the direction of offset of the light source relative to each other. It should be noted that light is easily guided after passing through the incident microlens, allowing it to propagate completely in the direction of one of the exiting microlenses. Therefore, there is little or no light obstruction within the array device, and no loss of light intensity, especially when implementing signal transmission functions.

[0049] According to an optional feature of the invention, only one of the plurality of exiting microlenses in the same optical circulation channel is configured to have an object focus on the incident surface of the incident microlens in the optical circulation channel. In other words, at least one of the exiting microlenses is not focused on the incident surface, such that the exiting microlens does not generate a sharp image of the incident lens. This may be because the focusing plane of the exiting microlens is offset from the plane of the incident surface of the incident microlens in the longitudinal direction, or because the exiting microlens has no focusing plane.

[0050] According to an optional feature of the invention, at least two of the microlenses have different focal lengths between the optical circulation channels.

[0051] In other words, for the first optical circulation channel, the focal length of the microlens, particularly one or more outgoing microlenses, is different from that of the microlens, particularly one or more outgoing microlenses, in the second optical circulation channel.

[0052] According to an optional feature of the invention, the longitudinal dimensions of at least two of these optical circulation channels vary between the optical circulation channels. In particular, this allows the exit surface to be configured such that the exit surface follows a curve suitable for the layout and / or style of the light-emitting device. The change in longitudinal dimension along the array device from one channel to an adjacent channel can be linear, or it can evolve, for example, in a manner that makes it faster on one side of the array device than on the opposite side.

[0053] According to an optional feature of the invention, the exit surface associated with a first optical circulation channel that is longer than the second optical circulation channel is flatter than the exit surface associated with the second optical circulation channel. The flatness of one exit surface compared to the other is more specifically determined by the curvature of these exit surfaces. A flatter exit surface is considered to have a smaller curvature.

[0054] According to an optional feature of the invention, the size of the bend within the incident microlens varies depending on the longitudinal dimension of the optical circulation channel associated with the incident microlens and / or the focal length of the exiting microlens configured to image the incident surface of the incident microlens.

[0055] According to an optional feature of the invention, the optical axis of at least one exiting microlens is offset relative to the central longitudinal axis of the associated optical circulation channel.

[0056] According to an optional feature of the invention, the optical axis of the exiting microlens can be positioned such that it intersects the incident surface of the incident microlens, wherein there is a lateral offset relative to the bend formed on the edge of the incident surface of the microlens.

[0057] According to an optional feature of the invention, the position of the bend formed on the edge of the incident microlens relative to the central longitudinal axis of the associated optical circulation channel varies from one incident microlens to the adjacent incident microlens.

[0058] According to an optional feature of the invention, the channels are arranged side by side in such a way that they form horizontal rows that overlap vertically, and the channels in one row are laterally offset relative to the channels in the adjacent row.

[0059] According to optional features of the present invention, the incident microlens array and the exit microlens array are formed in a single piece as an array device.

[0060] In other words, the incident microlens and the exiting microlens are integrated and form a one-piece assembly. The array device does not include a partially opaque mask in the thickness between the two microlens arrays, and each of the two arrays is attached to the mask. The longitudinal end of the incident microlens array presses directly onto the longitudinal end of the exiting microlens array without any material interruption.

[0061] According to an optional feature of the invention, the two microlens arrays are produced in a single injection molding operation.

[0062] According to an optional feature of the invention, the light-emitting device includes opaque elements arranged against the incident surface of the array device in such a way that their edges overlap with those shared by two adjacent incident microlenses. For example, the opaque plastic can be adhesively bonded to the side of the array device facing the collimator to form a clear boundary between the incident surfaces of each incident microlens. This optical plastic can also be etched, printed, or overmolded onto the incident surface of the array device. It is noteworthy that, in all cases, these opaque elements are not present in the thickness of the array device.

[0063] According to an optional feature of the invention, the light emitting device includes a plurality of light sources, which are particularly selectively addressable, and a collimator shared by the plurality of light sources and configured to shape the light emitted by each light source into a beam of substantially parallel light directed toward the array device, wherein the beam of substantially parallel light has an angle of inclination relative to the optical axis, which varies depending on the activated light source. The light emitting device is notable for including a first light source and a second light source, the activation of which participates in generating a first light emitting function, and the activation of which participates in generating a second light emitting function or an additional portion of the first light emitting function, such that the light emitted by the first light source is focused by an incident microlens of the optical circulation channel onto a first exit microlens of the optical circulation channel, and the light emitted by the second light source is focused by the same incident microlens onto a second exit microlens of the optical circulation channel.

[0064] The ability to selectively address a light source is particularly advantageous for emitting several light-emitting functions. When a light source participates in generating the same light-emitting function, it is advantageous to address the light source only at a time, which simplifies the configuration of the control circuitry for the light source. However, the light source can also be selectively addressed, for example, by gradually activating the light-emitting function.

[0065] According to an optional feature of the invention, the second exiting microlens associated with the optical circulation channel has an optical axis whose relative position within the optical circulation channel differs from the corresponding relative position of the optical axis of the first exiting microlens associated with the optical circulation channel.

[0066] Therefore, an outgoing microlens is set off so that its center is aligned with the aperture or the edge of the aperture to properly deflect the light.

[0067] The light-emitting device according to the invention enables the fulfillment of two light-emitting functions, specifically a DRL (Daytime Running Light) type signaling function and a low-beam type illumination function. Alternatively, the light-emitting device can enable the performance of both a DRL type signaling function and a high-beam type illumination function, wherein two exiting microlenses present in the same guide channel are focused on the center of the associated incident microlens. Furthermore, and in ways that are not exhaustive regarding the possibilities provided by the light-emitting device according to the invention, it is possible to have both a low-beam type illumination function and a high-beam type illumination function.

[0068] The light sources are reportedly selectively addressable because they can be activated independently of each other by electronic control devices. For example, when one light source is activated, one or more other light sources can be deactivated, allowing only one light source to emit light. Alternatively, to increase the uniformity of the open appearance of an area based on the activation of the lights, it is conceivable to keep sources associated with specific functions on while another source is activated. In other words, under certain conditions, at least some, and in particular all, of the light sources can be activated simultaneously, allowing the corresponding associated light-emitting functions to be produced simultaneously. For example, when all light sources are activated simultaneously, some light sources can be activated at variable light intensity levels.

[0069] If the light source is from a first light source, it can perform a first light-emitting function; and if the light source is from a second light source, it can perform a second light-emitting function, or an additional segment for the first light-emitting function can be formed, which allows a specific light-emitting function to be generated through a combination of the two segments. In both cases, the light participating in performing the light-emitting function is emitted from the illumination area formed by the outgoing microlens array.

[0070] Therefore, the array device according to the invention makes it easy and precise to perform different light-emitting functions using the same illumination area.

[0071] It should be noted that "participation in generation" means that the light-emitting device according to the invention can be a single device that allows the generation of a desired illumination beam or signal beam, or that the beam generated by the light-emitting device can be combined with other beams generated by other light-emitting devices to form the beam, regardless of whether these other light-emitting devices are according to the invention.

[0072] According to an optional feature of the invention, a first light source and a second light source are spaced apart from each other and distributed on opposite sides of a defining plane, with the first light source closer to the defining plane than the second light source. Where appropriate, the first source may be partially placed on the defining plane. The defining plane in question is a plane substantially perpendicular to both / or any of the microlens arrays, and this defining plane includes the principal optical axis of the light-emitting device. This defining plane may in particular be the intermediate plane of the collimator, and where appropriate, the plane of symmetry of the collimator. "Spaced apart from each other" means that the light sources do not contact each other and are separated by a sufficient distance, for example, by about 0.5 to 10 times the size of the light source, so that the light rays can have different inclinations when exiting the collimator, depending on which light source emitted the light.

[0073] According to an optional feature of the invention, the collimator is formed by one or more lenses, or by one or more mirrors. In particular, the one or more lenses may be converging lenses.

[0074] According to an optional feature of the invention, the incident microlens and the exiting microlens have corresponding outer surfaces, particularly corresponding curved outer surfaces, facing outwards of the microarray device, and the array device is configured to have an exiting surface formed by a plurality of outer surfaces of the exiting microlens, the exiting surface being inclined relative to the longitudinal direction along which the main optical axis of the light-emitting device extends.

[0075] The incident microlens array and the exit microlens array can be kept in a vertical and horizontal plane perpendicular to the longitudinal direction along which the main optical axis of the light-emitting device extends, wherein the light circulation channel keeps this orientation parallel to the optical axis, and the outer surfaces of the incident microlenses are axially offset from each other in such a way that they form horizontal rows that are axially offset from each other, and thus form stair steps that produce a tilting effect when the entire screen is viewed.

[0076] The present invention also relates to a light-emitting module for a motor vehicle, the light-emitting module comprising a plurality of light-emitting devices according to the present disclosure, each device forming a functional block.

[0077] Each functional block has its own light-emitting device, in other words, a device that emits light in the direction of the collimator associated with that functional block. The collimators and array devices of each of these various functional blocks can be juxtaposed and made as a single piece, and these functional blocks do not interact with each other to project their own beams.

[0078] The present invention also relates to a motor vehicle including at least one light-emitting device according to the present disclosure.

[0079] Further features, details, and advantages of the invention will become clearer, on the one hand, by reading the following description, and on the other hand, by referring to examples of embodiments given in an illustrative rather than limiting manner in the accompanying drawings: [ Figure 1 The invention depicts a light-emitting device, showing a light source, a collimator, and an array device, which in particular includes an incident microlens array and an exit microlens array; [ Figure 2 [Image] is a cross-sectional view of a portion of an array device having three optical circulation channels, with the light rays drawn schematically to illustrate the convergence and focusing characteristics of the light rays; [ Figure 3 [This is a perspective view of a part of the array device, showing in particular the bend formed on the incident microlens of the array device;] [ Figure 4 The image shows three optical circulation channels intended to be adjacent in an array device, wherein the bends formed in the incident microlenses of each channel are located at different positions between the channels, and the images projected by the exiting microlenses are depicted as spaced apart from the optical circulation channels. [ Figure 5 The image shown is an overlay of images projected by three exiting microlenses, illustrating how... Figure 4 The advantages of the described bend position offset; [ Figure 6 The image shows the incident microlens array as seen from the collimator, to depict... Figure 4 The offset of the position of the bend seen in the image; [ Figure 7 ]yes Figure 1 A side view of an array device in which light rays are drawn as lines, and the array device has microlenses with different focal lengths; [ Figure 8 This illustrates how the different sizes of images projected by an array device vary with the focal length of the microlenses in that array device; [ Figure 9 ] in a similar way Figure 4 The view shows a variant of the incident microlens array; [ Figure 10 The second embodiment of the present invention is shown, which includes two light sources and a collimator shared by the two light sources; [ Figure 11 It shows Figure 10 A first alternative implementation of the second embodiment; [ Figure 12 It shows Figure 10 A second alternative implementation of the second embodiment.

[0080] First, it should be noted that although the accompanying drawings illustrate the invention in detail to enable its implementation, these drawings can, where appropriate, be used to better define the invention. It should also be noted that these drawings disclose only examples of embodiments of the invention.

[0081] The features, variations, and different embodiments of the present invention can be combined with each other in various combinations, as long as they are not mutually exclusive or compatible. In particular, it is conceivable that variations of the present invention may include only a portion of the features described below, independent of the other features described, if such portion of the features is sufficient to provide a technical advantage or to distinguish the present invention from the prior art.

[0082] In the accompanying drawings, many elements common to all the drawings are indicated by the same reference numerals.

[0083] In the following description, reference will be made to information regarding such as Figures 1 to 12The axes L, V, and T shown define the orientation of the longitudinal, vertical, and transverse axes, where the longitudinal axis L corresponds to the overall direction of light propagation, and the vertical axis V and transverse axis T define the principal extension planes of the microlens array device that form part of the light-emitting device. The vertical and transverse axes are perpendicular to the longitudinal axis L. More specifically, the vertical axis V and transverse axis T correspond to the height and width of the microlens faces, which will be described in more detail below, respectively, and the width of these faces is greater than their height. The selection of these axes does not limit the orientation that the light-emitting device can adopt, particularly when the light-emitting device is mounted in a motor vehicle.

[0084] Figure 1 The light-emitting device 1 is schematically shown, which includes a microlens array device 2, a collimator 3, and a light-emitting device 4.

[0085] The light emitting device 4 typically includes at least one light source. Figure 1 In the illustrated embodiment, only one light source is used, but specifically in Figures 10 to 12 Other embodiments shown employ multiple light sources; in this case, two light sources are used: a first light source 41 and a second light source 42. As will be described below, the number of light sources can vary, provided the array device is configured accordingly. In particular, the number of light sources affects the number of light-emitting functions that can be implemented by the device according to the invention.

[0086] Figure 1 The light-emitting device 1 in the middle enables the execution of a single light-emitting function. More specifically, the device is advantageous for implementing a low-beam type lighting function, projecting a beam of light with an upper cutoff line onto the road scene upstream of the vehicle, so as to avoid dazzling other road users. However, the device can be used for other functions, such as a high-beam type lighting function without a cutoff line, a signaling function, an interior lighting function, or a ground marking function including the projection of pictograms.

[0087] The light-emitting device 1 has a main optical axis 10, and the light-emitting device is configured to project a light beam to infinity, the optical axis being parallel to the longitudinal axis as a projection reference.

[0088] At least one light source 4 is arranged on or near the defined plane of the main optical axis 10, which includes the light-emitting device.

[0089] Collimator 3 and light emitting device 4 are positioned relative to each other such that light emitted from light source 41 or light source 42 passes through collimator 3. Collimator 3 is configured to capture light emitted by each of the light sources, orient them substantially parallel to each other, and guide them toward array device 2, more specifically toward incident microlens array 21.

[0090] "Substantially parallel" means that the light rays can have an angular offset related to the size of the light source that generates the light. In other words, in an embodiment with one light source, the collimator 3 (which here takes the form of a converging lens, but can alternatively be composed of, for example, several lenses and / or several mirrors) is configured to generate light in the direction of the array device 2, particularly in... Figure 7 The first parallel ray beam visible in the image is used as the output.

[0091] It should be noted that when the light source is activated, if the position of the light source is offset relative to the plane including the principal optical axis, the light rays can have a tilt angle of a first value relative to the principal optical axis 10. It should also be noted that the collimator 3 is configured to deliver a completely different parallel light beam (i.e., a beam with a different tilt angle) as output when the activated light source changes. Then, the collimator 3 can deliver another parallel light beam as output in the direction of the array device 2 when another light source is activated, with all or almost all rays having a tilt angle of a different value relative to the principal optical axis than the first value, as will be referred to below. Figure 10 Explanation.

[0092] The microlens array device 2 includes the incident microlens array 21 and the exiting microlens array 22, each array having an outer surface that is away from the other arrays, namely the incident surface 210 of the incident microlens array 21 and the exiting surface 220 of the exiting microlens array 22.

[0093] In the example shown, each microlens array 21, 22 is primarily located in a vertical and horizontal plane perpendicular to the longitudinal direction L, and the main optical axis 10 of the light-emitting device 1 extends in this longitudinal direction. Alternatively, the array device can be positioned at an angle relative to the main optical axis, particularly to accommodate the curvature of the vehicle to which it is to be integrated. This angle can be achieved by tilting the array device as a whole or by forming a step in the exit surface of the array device, which is formed by the exit surface (in other words, the outside of the exiting microlens array).

[0094] The emitting surface of the array device 2 (i.e., the emitting surface 220 of the emitting microlens array 22) forms the illumination area of ​​the light-emitting device 1, that is, the area through which light is emitted to generate a beam of light outside the vehicle, and this area is shared by each of the light-emitting functions that can be performed by the light-emitting device.

[0095] The incident microlens array 21 is formed by multiple incident microlenses 20, which are arranged side-by-side adjacent to each other in both the vertical and horizontal directions, as shown in... Figure 1As can be seen in the image. Each of these incident microlenses 20 has a curved surface, which are juxtaposed to form the incident surface 210 of the incident microlens array 21. Where appropriate, there is a longitudinal offset that creates a step between the curved surfaces, and each of these curved surfaces has a material thickness that extends between the curved surface and the exiting lens array 22 so that light can propagate between the curved surfaces.

[0096] Equivalent to the arrangement of the incident microlens array 21, the exiting microlens array 22 is formed by multiple exiting microlenses 24, which are arranged side-by-side with each other in both the vertical and horizontal directions, such as... Figure 1 It can be seen in the image.

[0097] Each of these exiting microlenses 24 has a curved surface, which, when appropriate, are juxtaposed to form the exit surface 220 of the exiting microlens array 22, i.e., the exit surface of the array device, which, when appropriate, has a longitudinal offset that creates a step between the curved surfaces, and each of the curved surfaces has a material thickness that extends between the incident microlens array 21 and the curved surface so that light can propagate between the curved surfaces.

[0098] Therefore, each microlens array (incident or exit) has an outer and an inner volume, the outer volume being opposite to another array and formed by multiple outer volumes of the microlenses constituting the array, and the inner volume being formed by the thickness of the material extending from the outer volume to another array.

[0099] exist Figure 1 In the diagram, the junction plane P between the incident microlens 20 and the exiting microlens 24 has been shown in dashed lines. However, it should be noted that this junction plane is indicative, and according to the invention, the array device 2 extends continuously between the incident microlens array 21 and the exiting microlens array 22 without an insert mask.

[0100] The array device 2 according to the invention is configured to include optical circulation channels 5, which extend in a direction parallel to the main optical axis 10 between an incident microlens 20 and at least one exiting microlens 24 (in appropriate cases, several adjacent exiting microlenses as described below), and the number of adjacent exiting microlenses 24 participating in defining the same optical circulation channel depends on the number of different light sources that can be activated and face the same collimator. Figures 10 to 12 In the example shown, two light sources are provided, each light circulation channel 5 extending between an incident microlens 20 and two adjacent exiting microlenses 24, including a first incident microlens 241 and a second exiting microlens 242.

[0101] It should be noted that in the accompanying drawings, which schematically illustrate the array device, only the outer surfaces of the incident and exit microlenses are shown; however, it should also be noted that each microlens is not only formed by a curved surface, but also actually includes the material thickness extending from the curved surface to another microlens arranged along the main optical axis 10 facing the curved surface.

[0102] exist Figure 1 In this diagram, the outer surfaces of the incident and exit microlenses have different curvatures between the optical circulation channels, and the length of the exit microlens 24 is variable, such that a longer optical circulation channel 5 implies a flatter surface. However, it should be noted that this is given by way of example, and this configuration is further different from the diagram below.

[0103] According to the present invention, the array device 2 is particularly characterized in that, for a given optical circulation channel 5, the exiting microlens 24 is focused on the incident microlens 20, while the incident microlens 20 focuses the light onto the exiting microlens 24.

[0104] Specifically, each incident microlens 20 is configured within the array device 2 such that it forms a converging lens, the image focus of which forms a convergence point Pc located near the exit surface of the exiting microlens 24, which is arranged to directly face the incident microlens 20 in the associated optical circulation channel 5. Light rays from the collimator 3 and passing through the incident microlens 20 converge toward the convergence point Pc near the exiting microlens in the optical circulation channel.

[0105] "Near" means that as long as almost all the light rays pass through the exit surface 220 of the exiting microlens 24 and remain in its dedicated optical circulation channel 5, this convergence of light rays can be axially offset. In other words, considering the longitudinal direction, the convergence point Pc of the light rays deflected by the incident microlens can be on the exit surface of the exiting microlens or actually in front of or behind the exit surface of the exiting microlens, as long as the offset has a minimum value relative to the longitudinal extension dimension of the optical circulation channel, for example, at least less than 10% of that extension dimension.

[0106] Furthermore, when considering the projection of the exit surface of the exiting microlens 24 onto a plane perpendicular to the longitudinal direction, the convergence point Pc is essentially centered on the exiting surface.

[0107] Thus, the light rays shaped by the collimator 3 and caused to pass through the incident microlens 20 substantially propagate through the optical circulation channel 5 associated with the incident microlens 20, and are emitted from the array device 2 substantially via one of the exiting microlenses 24 associated with the optical circulation channel, especially by means of the convergence of the light rays caused by the incident microlens 20 on the exiting microlens 24.

[0108] In the example shown, the incident microlenses 20 are identical to each other.

[0109] Each exiting microlens 24 is configured within the array device 2 such that the exiting microlens has an object focal point F on the incident microlens 20 associated with its optical circulation channel 5. Light rays propagating within the array device 2 and passing through the object focal point F are redirected by the corresponding exiting microlens 24 into a beam projected toward the exterior of the vehicle, so as to participate in the formation of an illumination beam or a signal beam in a road scene.

[0110] In other words, the profile of the incident microlens 20 is imaged by the exiting microlens 24 present in the same optical circulation channel 5. This necessitates the precise profiles of the incident microlenses 20, images of which (projected to infinity by their respective associated exiting microlenses 24) are juxtaposed to form a unified beam for emitting light. Therefore, the incident surfaces of the array device are fabricated such that there is no surface continuity between the incident microlens surfaces.

[0111] This can be specifically implemented by having a fully marked rounded corner from one edge of the incident microlens 20 to the adjacent edge of the adjacent incident microlens 20. The discontinuity between the incident microlenses is as follows: Figure 2 The discontinuity of the tangent shown is due to the presence of two converging incident lenses whose optical axes are different from each other. This specifically results in an angle. When the bend is provided on the edge of the incident microlens, a slight longitudinal axial offset may occur locally at the bend due to the shape of the bend being cut into the lens; however, if there is no bend at the edge of the incident microlens, no axial offset is provided.

[0112] Advantageously, to clearly mark the boundaries between the incident surfaces, it is conceivable to form a blocking coating on the incident surface of the array device 2, particularly by depositing an opaque plastic material. It should be understood that this coating should not be considered a mask present in the mask thickness between the microlens arrays according to existing technology. Such a coating also allows for the limitation of stray light because it allows for the masking of manufacturing irregularities on the sharp edges of the incident microlens profiles, and / or because it allows for the masking of any steps on the incident surface of the array device created by cutting out profiles with bent shapes. In the latter case, this prevents the formation of steps on the incident surface, thus limiting stray light within the optical circulation channel. Steps that may exist on the exiting surface of the exiting microlens, in areas where light converges towards points spaced apart from the edges, should be avoided.

[0113] As described, each exiting microlens 24 has an object focus F located on or near the incident microlens 20. More specifically, at least one exiting microlens 24 and Figure 1In this example, each exiting microlens has an object focal point F located on an edge 200 that defines the incident surface 210 of the incident microlens 20, such that this edge forms a sharp cutoff edge in the projected image. When applying near-light type illumination, the edge 200 on which the corresponding exiting microlens 24 is focused is more specifically the lower edge of the incident microlens 20, such that in the projected beam, the upper rays are parallel to the optical axis 11 of the exiting microlens 24 and, here parallel to the principal optical axis 10, and are sharper than other rays. In other words, aligning the optical axis of the exiting microlens with the bottom edge of the corresponding incident microlens ensures that the top edge of the image is projected to infinity, so that, also by means of this alignment of the optical axis in a specific area of ​​the incident microlens, particularly at its edge, the top cutoff line of the entire projected beam remains sharp.

[0114] Therefore, a clear cutoff line that conforms to the standards promoted for producing illumination beams with distinct cutoff lines can be produced. Conversely, as will be described below, the luminescent device is configured with a blurring mechanism, the purpose of which is to misalign the bottom of the image projected by each exiting microlens with respect to infinity by slightly reducing the luminescence intensity, thereby producing blurred edges.

[0115] Of course, if the edge of the incident microlens, which the exiting microlens focuses upon, is a side edge or an upper edge, it should be recognized that the side or lower edge of the projected beam is therefore particularly sharp. This can be particularly advantageous when producing an array illumination function with juxtaposed vertical bars that form a beam and can be selectively opened and closed, or when producing high beams, where the upper portion of the beam is projected to complement the projection of the lower portion of the beam.

[0116] In projection onto a plane perpendicular to the principal optical axis 10, viewed from the front, the optical circulation channel 5 has a size of less than or equal to 10 mm and greater than or equal to 0.1 mm in terms of its diameter, height, and / or width. It should be noted that the shapes of the incident microlens and the exit microlens must be taken into account accordingly.

[0117] The incident microlens advantageously has an aspect ratio corresponding to a horizontal elongated rectangle in both the vertical and horizontal planes. The ratio of the maximum horizontal dimension to the minimum vertical dimension is determined to correspond to the size of the overall beam to be projected onto the road scene, and specifically, when a cutoff beam (e.g., low beam) is projected onto the road, it can be at least 2:1, more specifically, about 3 or 4:1.

[0118] As will be described in more detail below, the exiting microlenses 24 can have different configurations depending on their arrangement in the optical circulation channel 5. In particular, some exiting microlenses 24 can have symmetrical or asymmetrical configurations relative to their respective optical circulation channels and the light-emitting function they must participate in generating, or more specifically, centered or off-center configurations, with the optical axis of the exiting microlens coinciding with or offset from the central axis of the associated optical circulation channel.

[0119] Figure 2 The basic features of the invention are described in particular detail, which enable the emission function to be performed without a mask within the array device, while achieving the optimal luminous efficiency of the system, namely the combination of convergence and proper focusing of the emitting microlenses.

[0120] It should be noted that Figure 2 Depicting and Figure 1 A slightly different embodiment in which the exiting microlenses 24 have the same size and thus have recesses from one exiting microlens 24 to the other, but the concept of this embodiment is the same as that described above in conjunction with the line of light, its convergence and its focusing.

[0121] Each exiting microlens 24 has an exiting surface shaped as part of a sphere, the optical axis 11 of which is substantially parallel to the principal optical axis 10 of the entire device, in this case parallel to the longitudinal axis L. In the depicted example, each exiting microlens is an aspherical lens of the Cartesian ellipse type, in other words, an astigmatic lens for imaging an object in a material. Of course, each exiting microlens can have another shape. A portion of the sphere is cut from one edge to the other corresponding to the optical circulation channel 5 such that the optical axis 11 of the exiting microlens 24 is aligned with a precise point on the incident microlens 20 at the other end of the optical circulation channel 5, more specifically with a precise point on the lower edge 200 of the incident microlens 20 as described below.

[0122] This causes the lower end 240 of the exiting microlens 24 to be axially or longitudinally offset relative to the upper end 245 of the exiting microlens 24, and causes return edges 25 to exist between two adjacent exiting microlenses 24, which are located in the transverse and longitudinal planes and arranged between the adjacent vertical ends of the two adjacent exiting microlenses 24.

[0123] Figure 2 A portion of an array device 2 is depicted, which has four sets of incident microlenses and exit microlenses, with optical circulation channels 5 formed longitudinally in pairs between these four sets of incident and exit microlenses, shown as dashed lines in the figure.

[0124] The light rays are depicted with double arrows to distinguish them from the structural lines of the microlens.

[0125] The actual light rays that pass successively through the collimator (not visible here) and arrive at the incident microlens in substantially parallel form are depicted as solid lines. These rays are deflected by the incident microlens 20 toward a convergence point Pc located near the exit surface 220 of the exit microlens 24. This ensures that almost all the light rays remain in the optical circulation channel 5 associated with the incident microlens 20, thereby improving luminous efficiency.

[0126] In this case, the view is a cross-sectional view in the vertical and longitudinal planes, and the convergence point is essentially at half the width of the exiting microlens. It should be noted that in the transverse and longitudinal cross-sectional planes, the convergence point is essentially at half the width of the exiting microlens. Furthermore, it should be noted that only light rays from the source point are shown here; however, due to the size of the light source, there will be a converging spot rather than a point on the exiting microlens, and it is this converging spot that will be considered the point in the rest of the specification for ease of reading, centered on the exiting microlens, such that all light rays pass through the correct exiting microlens.

[0127] In the depicted example, the convergence point Pc is slightly behind the exiting microlens 24 in the longitudinal direction, that is, slightly outside the microlens array. In particular, in order to illustrate the concept of "converging in the vicinity of", it is intended to cover the convergence point on the exiting surface and slightly in front of or behind the exiting surface.

[0128] The axial offset of the convergence point Pc relative to the emission surface 220 can be as small as a few millimeters, which does not affect the aforementioned luminous efficiency. The greater the thickness (in other words, its axial dimension) of the emission microlens 24, the closer the convergence point Pc must be to the emission surface 220 of the emission microlens 24.

[0129] The focusing characteristics of the exiting microlenses are depicted by shading, and these exiting microlenses focus in this case on the edge 200 of the incident surface 210 corresponding to the incident microlens 20. Each ray of light that first passes through this edge 200 (in this case, the lower edge of the incident microlens) exits parallel to the optical axis 11 of the exiting microlens 24.

[0130] Naturally, the light rays passing through this edge 200 are intended to converge toward the convergence point Pc, as described above. However, it should be noted that in practice, the light rays passing through this edge 200 can be scattered around the convergence point Pc, thus forming a spot of light around that point on the exiting surface. This spot cannot be infinitely small, especially due to the geometry of the light emitting device. It is noteworthy, however, that each of these light rays that have passed through this edge is, in all cases, emitted substantially parallel to the optical axis 11 of the exiting microlens. Therefore, the edge 200, on which the incident microlens 20 and the exiting microlens 24 are focused, is particularly sharp in the projected image, with the optical axis 11 of each exiting microlens being substantially parallel to the principal optical axis 10.

[0131] Figure 3 The concept just mentioned is depicted in the case of low beam functionality (i.e., lighting functionality with an upper beam cutoff line to avoid dazzling other road users), in which case the details of the array device show two adjacent light circulation channels arranged in four rows side by side. Of course, the features described here can affect adjacent light circulation channels throughout the array device.

[0132] In this case, the exiting microlens 24 has a similar Figure 2 The shape depicted is such that each exiting microlens 24 is formed by cutting out an aspherical lens having an optical axis 11 eccentric relative to the central axis of the optical circulation channel 5, and a return edge 25 is arranged between the adjacent vertical ends of two adjacent exiting microlenses 24.

[0133] The overall beam 100 projected to perform the low beam function must have a clear upper cutoff line so as not to dazzle other road users, and the clear cutoff line conventionally has a step 101 so that when the vehicle in question is driven by the right hand, the height of the beam projected to the right or left of the beam can be increased.

[0134] As described, the overall beam 100 projected onto the road by the device of the present invention is an overlap of images from the incident microlenses. More specifically, the steps 101 in the projected overall beam are formed by overlapping the images of the bends 201 formed on each lower edge 200 of the incident microlens 20 projected by each exiting microlens.

[0135] The bend 201 specifically includes an inclined plane that creates a horizontal difference between the first lateral portion 20a and the second lateral portion 20b of the incident microlens. The second lateral portion 20b extends only partially longitudinally, and the remainder of the optical circulation channel is continuously formed by the first lateral portion 20a.

[0136] For example, especially in Figure 3 As can be seen, the second lateral portion 20b formed by the bend 201 of the first optical circulation channel 5a intrudes into the volume of the second optical circulation channel 5b, which is specifically arranged directly below the first optical circulation channel 5a.

[0137] Therefore, considering that the image projected onto the road by the light-emitting device is the inverse image of the shape of the incident microlens to be imaged, the image of the incident microlens 20 projected by the second optical circulation channel 5b has a step 101 in the upper part due to the presence of the bend 201 formed on the lower edge 200 of the incident microlens 20 in the optical circulation channel, and there is also a step in the lower part due to the presence of the bend imposed by the bend formed in the adjacent optical circulation channel.

[0138] In a context where the overall beam 100 projected onto the road is an overlap of all images projected by the outgoing microlenses, the overlap of the images with the unwanted bends in the lower portion of the beam can be visually irritating to the driver, even if this portion of the beam is more blurred than the upper portion.

[0139] It is advantageous to implement a device that has a step visible to the driver at the bottom to prevent low beams.

[0140] One way to manage this is to change the size of one incident surface of the incident microlens 20 relative to the other incident surface, so that the projected images are of different sizes. Therefore, the size of the images projected by each exiting microlens 24 differs between the images, and the overlap of these images in the overall projected beam 100 makes the edges of the beam more blurred because the edge intensity is lower, as there are fewer overlapping images in these beam boundary regions. Since the optical axis 11 of each exiting microlens 24 is always aligned with the lower edge 200 of the corresponding incident microlens 20, and particularly with the bend 201 formed on that lower edge, the size of the step 101 in the overall projected image 100 resulting from the overlap of all images remains the same, and the step 101 remains sharp.

[0141] Other devices for blurring the bottom of the beam can also be implemented, which may be combined with each other and / or with the devices just mentioned, if necessary.

[0142] Figure 4 The image depicts a first blurring device, in which three guide channels arranged vertically and adjacent to each other in an array are shown in a top view. Naturally, the description combining three successively arranged channels can be applied to more channels.

[0143] The first blurring device is located at the position of the bend 201 of the incident microlens relative to the center of the corresponding optical circulation channel 5. The position of the bend varies between the incident microlenses 20 and is related to the specific shape of the exit microlens 24 associated with the optical circulation channel.

[0144] This particular shape is due in particular to the fact that the optical axis 11 specific to the exiting microlens 24 is aligned with the bend 201 formed in the corresponding incident microlens 20 to ensure that the image of the incident microlens is correctly positioned in the direction of the principal optical axis. The exiting microlens 24 maintains a partially spherical shape, wherein the optical axis 11 forms the diameter of the sphere, and the spherical portion is formed by cutting the sphere within the volume formed by the optical circulation channel 5 specific to the exiting microlens 24.

[0145] As in Figure 4As can be seen, this creates a first optical circulation channel 5a, a second optical circulation channel 5b, and a third optical circulation channel 5c. In the first optical circulation channel, the bent portion 201a is in a first position, offset laterally from the center of the optical circulation channel by a first distance in the first direction S1. In the second optical circulation channel, the bent portion 201b is in a second position, offset laterally from the center of the optical circulation channel by a second distance in the second direction S2. In the third optical circulation channel, the bent portion 201c is in a third position, offset laterally from the center of the optical circulation channel by a third distance in the first direction S1.

[0146] For each of these channels, the lateral end of the incident microlens 20 through which light passes and the bend 201 are shown, these rays coinciding with the optical axis 11. These three rays converge at a convergence point Pc near the exit surface 220 of the exit microlens 24, which is located on the optical axis 11 of the exit microlens specific to the optical circulation channel, in other words, facing the bend. Therefore, at a given distance from the vehicle, the images of the bends 201a, 201b, 201c in the upper portion of the projected image (schematically shown on the right side of the figure) form sharp steps 101a, 101b, 101c positioned on the main optical axis 10 of the array device. Their overlap in the overall projected beam 100 allows for the generation of a sharp image of step 101, but the lateral limits of the beam vary between images.

[0147] Furthermore, it should be noted that the effect of laterally shifting the bend 201 on the lower edge 200 of the incident microlens is to laterally shift the bend on the upper edge of the incident microlens located below the incident microlens. This is particularly useful in... Figure 5 As seen in the diagram, this is a front view of the array device as seen from the collimator. For each optical circulation channel 5, the axial offset Dx between the optical axis 11 of the exiting microlens and the bend that is to be weakened in the lower portion of the projected overall beam (i.e., the bend present in the upper edge of the incident microlens) differs from that of the optical circulation channel. This makes... Figure 6 The image of the overall beam of light projected onto the road is visible in the image with image overlap, where several steps are visible at the bottom of the beam, but at a lower intensity, meaning that these steps are not bothersome to the driver.

[0148] Figure 7 and Figure 8 A second device for blurring the bottom of the beam is depicted.

[0149] The second blurring device includes a change in focal length, in other words, a change in the distance between the focal point or object focal point F and the exit surface 220 of the exiting microlens 24 between the exiting microlenses. This involves changing the length of the exiting microlens 24, because according to the invention, each exiting microlens focuses on the incident microlens associated with it in the optical circulation channel, and more specifically, in this case, on the edge 200 of the incident microlens 20.

[0150] exist Figure 7 In, with Figure 1 As in the previous example, the junction plane P between the incident microlens 20 and the exiting microlens 24 has been depicted, specifically to show the change in length of one exiting microlens relative to the other, but considering that the array device 2 according to the invention extends continuously between the incident microlens array 21 and the exiting microlens array 22, no insert mask is used.

[0151] In the depicted example, the length of the exiting microlens 24 gradually increases from one vertical end of the array device 2 to the other, making it repeatable here. Figure 1 The design of the array device in the middle; however, it should be noted that the purpose will be achieved in the same way, with a more random distribution of longer and shorter exit microlens lengths.

[0152] Increasing the focal length of the exiting microlens 24 allows the point where the exiting microlens is focused (i.e., the area of ​​the bend 201) to remain centered and clear, but it also reduces the size of the projected image.

[0153] Figure 8 The effect of focal length on the size of the projected image is depicted. At a small focal length Fp, approximately 1 to 2 times the maximum size of the incident microlens plane, the image projected by the corresponding optical circulation channel is larger than at a large focal length Fg, approximately 10 times the size of the incident microlens plane. To ensure that the steps formed in the image of the overall projected beam are sharp, as... Figure 8 As shown, it may be advantageous to provide a bend 201 in the lower edge 200 of the incident microlens 20. The size of the bend depends on the length of the corresponding optical circulation channel 5. When the focal length of the exiting microlens is longer, the bend is larger between the channels, and therefore the projected image is correspondingly smaller.

[0154] Figure 9 A third device for blurring the bottom of the beam is depicted.

[0155] The perspective in this image is similar to Figure 5The image shows the array device 2 viewed from the front of the collimator 3. The third device provides lateral offset of the optical circulation channels 5 between rows, with the position of the bend 201 maintained centered on the associated optical circulation channel. The fact that the optical circulation channels are staggered means that the center position of the bend on the lower edge of the optical circulation channel is naturally off-center on the upper edge of the adjacent optical circulation channel. In the depicted example, with the guide channels in the same position every other row, the light intensity of the overall beam projected onto the area where the bend is imaged can be reduced by half, thus reducing potential driver annoyance.

[0156] Figures 10 to 12 The second embodiment depicted differs from the one described above in that the light-emitting device no longer includes a single light source in the same light circulation channel, but includes multiple light sources 41, 42 (two in this case) and multiple exiting microlenses 24, the number of which is equal to the number of light sources.

[0157] This second embodiment makes it possible to generate multiple light-emitting functions for the same illumination area formed by the emitting surface of the emitting microlens array.

[0158] Each of the light sources is selectively addressable. In particular, each of the first light source 41 and the second light source 42 is therefore adapted to be turned on and off independently of each other, for example, by electronic control devices.

[0159] In the example shown, there are two outgoing microlenses 241 and 242 in the same channel 5, and the light-emitting device 1 of the present invention performs two light-emitting functions. When the first light source 41 is activated, it participates in generating the first light-emitting function, while the second light source 42 participates in generating the second light-emitting function when it is activated.

[0160] In the example shown, the first luminous function is an illumination function, more specifically in this case, illumination that will not dazzle other road users, referred to as "low beam," which involves a beam of light with a clear cutoff line as described above. The second luminous function can be a position light function with reduced light source power, or a signaling function, more specifically in this case, a light designed to signal the presence of a vehicle, referred to as "daytime running lights."

[0161] The characteristics of light sources 41 and 42 and / or particularly the focusing characteristics of the exiting microlenses depend on the light-emitting function that the light-emitting device is to perform.

[0162] Therefore, the light source associated with the implementation of this type of light-emitting function is selected based on the luminous intensity that the light-emitting function must or must not have in order to comply with motor vehicle regulations. Moreover, the position of the light source relative to the defined plane including the principal optical axis can depend on the light-emitting function to be performed and, in particular, on the sharpness of the outline of the beam to be delivered.

[0163] In particular, in an example of an embodiment where the first light-emitting function is a "low beam" illumination function and the second light-emitting function is a signaling function, the first light source 41, which is allowed to perform the first light-emitting function, may be closer to the defining plane than the second light source 42, which is allowed to perform the second light-emitting function.

[0164] More specifically, the distance of the light source from the defining plane can be determined based on the angle relative to the principal optical axis 10 that is expected to be imparted to the light rays emitted from the collimator when each of the light sources is activated. Therefore, particularly as Figure 10 As shown, the light sources are spaced apart from each other in the vertical direction, but depending on the number and arrangement of the light sources, they are also spaced apart from each other in the horizontal direction. "Spaced apart from each other" means that the light sources do not touch each other.

[0165] Therefore, the light-emitting device 1 in this second embodiment is particularly characterized in that the light-emitting device 4 includes a plurality of selectively addressable light sources 41, 42, wherein a collimator 3 shared by these light sources redirects the emitted light into a beam of parallel light, which illuminates each incident microlens 20 at an incident angle suitable for activating a particular light source. In each optical circulation channel 5, the incident microlens 20 is configured to cause the light to converge toward either a first exiting microlens 241 or a second exiting microlens 242 depending on the tilt of the light entering the optical circulation channel 5. The light converges at each exiting microlens 241, 242 and focuses on the incident microlens 20.

[0166] It is worth noting that for a given optical circulation channel 5, there exists a single incident microlens 20 that affects the propagation of light, regardless of the light-emitting function implemented.

[0167] In this second embodiment, the difference between the first exiting microlens 241 and the associated second exiting microlens 242 in the same optical circulation channel 5 is that the exiting microlenses focus on different regions of the same incident microlens 20, or for a given guide channel, one of the exiting microlenses does not have a focal point or plane, while one of the exiting microlenses is configured as described above to focus on the incident surface of the incident microlens in the optical circulation channel. Thus, at least one of the microlenses produces a clear image of the incident microlens, and for example, a clear image of one of the edges of the incident microlens, while the other exiting microlens does not produce a clear image of the edges or the shape of the incident microlens; in other words, it is not an imaging microlens. Specifically, the first exiting microlens 241 focuses on the edge 200 of the incident surface of the incident microlens 20, which forms the light and dark cutoff line of the projected beam, while the second exiting microlens 242 is substantially focused on the center of the incident microlens 20.

[0168] exist Figures 10 to 12 In the schematic depiction of various light rays, the light rays emitted by the first light source 41 are depicted with thicker lines, while the light rays emitted by the second light source 42 are depicted with thinner lines.

[0169] Collimator 3 is configured such that when light is generated by the first light source 41, the light rays exit from collimator 3 with a principal tilt of a first angle α1 relative to the principal optical axis 10, while allowing the light rays to diverge as described above because the light source is not a point source. Therefore, the light rays illuminate each of the incident microlenses at a first incident angle. In this context, and as in... Figure 11 and Figure 12 As can be seen, the light is deflected by each incident microlens 20 of the optical circulation channel 5 to converge near the first exiting microlens 241 located at the end of the optical circulation channel 5. The first exiting microlens 241 has an object focal point F1 located on the lower edge 200 of the incident microlens 20, more specifically, as shown in the image. Figure 11 As shown, it is located on the bent portion 201 formed on the lower edge 200.

[0170] Therefore, all the light emitted by the first light source 41 is guided toward the first exiting microlens 241, because all the light rays entering the guiding channel of the array converge toward the first exiting microlens 241, and thus there is no leakage between the optical circulation channels. Therefore, all these light rays participate in forming a projected overall beam corresponding to the first luminous function, making the luminous efficiency of that function optimal.

[0171] Furthermore, for each image intended to be superimposed on other images to form the overall projected beam, one portion is sharper than the others—that is, the portion corresponding to the lower edge of the incident surface of the incident microlens on which the exiting microlens focuses. This sharper portion advantageously forms the light-dark cutoff line of the beam.

[0172] The second light source 42 is turned on by appropriate driving of an electronic control device associated with the light-emitting device. The second light source 42 emits light in the direction of the collimator 3, and the collimator collects these light rays and guides them into beams of light that are parallel to each other and transmitted in the direction of the incident microlens array of the array device 2.

[0173] Collimator 3 is configured such that when light is generated by the second light source 42, the light rays exit from collimator 3 with a principal tilt of the principal optical axis 10 at a second angle α2, while also allowing the light rays to diverge as described above since the light source is not a point source. Therefore, the light rays strike each of the incident microlenses at a second incident angle. Against this background, the light rays are deflected by each incident microlens 20 to focus on a second exiting microlens 242 disposed at the end of the optical circulation channel 5. The second exiting microlens 242 has an object focal point F2 centered on the incident microlens 20 and spaced apart from the edge of the incident microlens. Therefore, the edge of the incident microlens is not sharp in the image projected by the exiting microlens, thus avoiding any annoyance when generating the signal transmission function.

[0174] According to the present invention, two different light beams are thus projected onto the same illumination area. When the first light emission function is desired, the light focused by the incident microlens 20 passes through the first exiting microlens 241 of the optical circulation channel. When the second light emission function is desired, the light focused by the incident microlens 20 passes through the second exiting microlens 242 of the same optical circulation channel.

[0175] Therefore, as described above, the first exiting microlens 241 participates in generating a light-emitting function consisting of illumination with a light and dark cutoff line by overlapping all the images projected by the first exiting microlens, particularly a near-light type illumination function.

[0176] The second exiting microlens 242 itself participates in generating (here again by overlapping all images projected by the second exiting microlens) light-emitting functions without sharp outlines and signal-emitting functions such as daytime running lights.

[0177] Of course, in the second embodiment, a device for blurring the bottom of the beam as described above can be provided, and for example, an increase in the focal length of the exiting microlens can be included. In this case, when the light-emitting device is configured such that the first exiting microlens images the edge of the incident microlens and the second exiting microlens images the center of the incident microlens, the focal lengths of the two exiting microlenses in the same optical circulation channel remain the same and change between guide channels. As described above, it is conceivable that, for example, one of the exiting microlenses having the function of performing a signal transmission function is not an imaging microlens, or it is an imaging microlens but its focal length is not equal to the depth of the channel, thereby generating a blurred image. In the latter case, the increase in the focal length of the exiting microlens described at the beginning of this paragraph is considered to be the function of the exiting microlens that images the incident surface.

[0178] Figure 11 A first embodiment of the second embodiment is depicted, wherein the exiting microlenses 241 and 242 of the same optical circulation channel 5 are arranged vertically above and below each other. Figure 11 It describes the lines of light within the array device in more detail, and... Figure 10 Similarly, the light emitted by the first light source 241 is a thicker line, while the light emitted by the second light source 242 is a thinner line.

[0179] In the illustrated example, as described above with respect to at least some of the figures, the lower edge 200 of the incident surface defining the incident microlens 20 includes a bend 201, which is intended to be imaged to form a step 101 with a light-dark cutoff line in the projected bulk beam 100.

[0180] As described above, each incident microlens 20 is configured to converge light rays passing through it onto one or the other of the exiting microlenses 241, 242 arranged at the opposite end of the optical circulation channel 5, depending on the angle of inclination of the light rays entering the incident microlens. In the illustrated example, when the first light source 41 is activated, the first light rays illuminating the incident microlens at a first angle are guided toward a convergence point substantially at the center of the first exiting microlens 241 associated with the optical circulation channel. Figure 11 In the example shown, the first exiting microlens 241 is arranged below the second exiting microlens 242 in the same optical circulation channel.

[0181] When the second light source 42 is activated, the second light rays shine on the incident microlens at a second tilt angle. These second light rays are guided toward the exit surface of the array device, in this case, toward the convergence point at the center of the second exit microlens 242 which is substantially associated with the optical circulation channel.

[0182] Figure 12Different implementations of the second embodiment are depicted, wherein the exit microlenses shared by the same optical circulation channel are laterally juxtaposed. The figure shows, in a top view, two adjacent optical circulation channels in the lateral direction of this lateral juxtaposition.

[0183] In the example shown, the incident microlens 20 is configured to precisely converge light onto the exiting surfaces of the exiting microlenses 241, 242, which does not limit the invention as described above.

[0184] In this figure, with Figure 10 and Figure 11 Similarly, the light emitted by the first light source 41 is shown in thick lines, while the light emitted by the second light source 42 is shown in thinner lines.

[0185] Here, similarly, each incident microlens 20 is configured to converge the light passing through the incident microlens onto one or the other of the exiting microlens 241, 242 arranged at the opposite end of the optical circulation channel 5, depending on the tilt of the light entering the incident microlens.

[0186] In this embodiment, the first exiting microlens 241 is also focused on the edge 200 of the incident surface 210 of the incident microlens 20, the edge including the bend 201, while the second exiting microlens 242 is focused on the center of the incident microlens 20.

[0187] However, it is worth noting that the bent portion 201 is laterally displaced relative to the central portion of the incident microlens 20 so as to face the first exiting microlens 241. The optical axis 11 of the first exiting microlens 241 may be aligned with the bent portion 201 or have a slight lateral offset in order to achieve a compromise between the sharpness of the step in the cutoff line of the beam and the desired lateral range of the projected beam.

[0188] The present invention, as just described, enables the achievement of the objective set, namely, designing a light-emitting device comprising an array of easily manufactured devices, particularly without inserting masks between microlens arrays, thus enabling the generation of at least one light-emitting function.

Claims

1. A light-emitting device (1), comprising at least a light-emitting device (4), a collimator (3), and a microlens array device (2), wherein the light-emitting device (4) is configured to emit light toward the array device (2) via the collimator (3), and the array device (2) comprises at least an incident microlens array (21), an exiting microlens array (22), and a principal optical axis (10), wherein the incident surface of the incident microlens array faces outward of the array device and toward the collimator, and the exiting surface of the exiting microlens array faces outward of the array device and is opposite to the incident microlens array, and the principal optical axis is aligned with the two microlens arrays (21, 22, 23, 24, 25, 26, 27, 28, 29, 20 ... 22) Intersecting, the device is characterized in that at least one optical circulation channel (5) arranged along the main optical axis (10) is continuously formed by an incident microlens (20) and at least one exiting microlens (24, 241, 242), the incident microlens (20) being configured to converge a beam of substantially parallel light from the collimator (3) in a convergence region on the exit surface of the at least one exiting microlens (24, 241, 242) associated with the optical circulation channel, the at least one exiting microlens (24, 241, 242) being configured to image the incident surface of the incident microlens (20) associated with the optical circulation channel (5).

2. The light-emitting device (1) as described in claim 1, characterized in that, Within the optical circulation channel (5), at least one exiting microlens (24, 241) is focused on the edge (200) of the incident surface of the incident microlens (20).

3. The light-emitting device as described in the preceding claim, characterized in that, The incident microlens (20) has a bend (201) at the edge (200) of the incident surface, and at least one exiting microlens (24, 241) is focused on the edge.

4. The light-emitting device (1) as described in any one of the preceding claims, characterized in that, The at least one optical circulation channel (5) is arranged along the main optical axis (10) and is formed on one side by a single incident microlens (20) and on the other side by a plurality of adjacent exiting microlenses (241, 242).

5. The light-emitting device (1) as described in claim 4, characterized in that, The exit microlenses (241, 242) of the same optical circulation channel (5) are configured to have different object focal points (F) on the incident surface of the incident microlens (20) of the optical circulation channel (5).

6. The light-emitting device (1) as described in conjunction with claim 2 or 3 of the preceding claim, wherein, One of the exiting microlenses (241) is focused on the edge (200) of the incident microlens (20), and the other exiting microlens (242) is focused substantially on the center of the incident surface of the incident microlens (20).

7. The light-emitting device (1) as described in claim 4, characterized in that, Of the plurality of exiting microlenses (241, 242) in the same optical circulation channel (5), only one exiting microlens is configured to have an object focus (F) on the incident surface of the incident microlens (20) in the optical circulation channel (5).

8. The light-emitting device (1) as described in any one of the preceding claims, characterized in that, At least two of the microlenses (20, 24, 241, 242) have different focal lengths between the optical circulation channels (5).

9. The light-emitting device (1) as described in the preceding claim, characterized in that, At least two of the optical circulation channels (5) have different longitudinal dimensions between the optical circulation channels.

10. The light-emitting device (1) in conjunction with claim 3 as claimed in any one of claims 8 and 9, characterized in that, The size of the bend (201) within the incident microlens (20) varies depending on the longitudinal dimension of the optical circulation channel (5) associated with the incident microlens (20) and / or the focal length of the exiting microlens (24) configured to image the incident surface of the incident microlens (20).

11. The light-emitting device (1) as described in any one of the preceding claims, characterized in that, The optical axis (11) of at least one outgoing microlens (24, 241, 242) is offset relative to the central longitudinal axis of the associated optical circulation channel (5).

12. The light-emitting device (1) as described in any of the preceding claims in conjunction with claim 3, characterized in that, The position of the bend (201) formed on the edge (200) of the incident microlens (20) relative to the central longitudinal axis of the associated optical circulation channel (5) varies from one incident microlens to the adjacent incident microlens.

13. The light-emitting device (1) as described in any one of the preceding claims, characterized in that, The light-emitting device includes an opaque element arranged against the incident surface of the array device (2) in such a way that it overlaps with the edges shared by two adjacent incident microlenses (20).

14. The light-emitting device as described in any one of the preceding claims, characterized in that, The light emitting device (4) includes a plurality of light sources (41, 42), which are selectively addressable in particular. The collimator (3) is shared by the plurality of light sources (41, 42) and is configured to shape the light emitted by each light source into a beam of substantially parallel light directed toward the array device (2), wherein the tilt angle of the substantially parallel light beam relative to the principal optical axis (10) varies depending on the activated light source. The light emitting device (1) is characterized in that the light source includes a first light source (41) and a second light source (42), the activation of the first light source participating in generating a first light emitting function, and the activation of the second light source participating in generating a second light emitting function or an additional part of the first light emitting function, such that the light emitted by the first light source (41) is focused by the incident microlens (20) of the optical circulation channel (5) onto the first exit microlens (241) of the optical circulation channel, and the light emitted by the second light source (42) is focused by the same incident microlens (20) onto the second exit microlens (242) of the optical circulation channel.

15. A motor vehicle comprising at least one light-emitting device (1) as described in any of the preceding claims.

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