Color projection using a multi-lens array projector

Abstract

This disclosure relates to a multi-lens optical element (200), comprising a plurality of optical channels (202), each optical channel (202) defined by a corresponding field lens (204) and a corresponding imaging lens (206), a structured layer (212) configured to define a partial projection projected through each optical channel (202) for each optical channel (202) and to obtain a resulting projection by superimposing the partial projections from the plurality of optical channels (202), and at least one optical channel of the plurality of optical channels (202) A multi-lens optical element (200) comprising an optical coloring layer (216) arranged on a channel (202), wherein the imaging lens optical coloring layer (216) covers a first portion of the imaging lens structuring layer (212) corresponding to at least one optical channel (202) of the imaging lens, but the remaining portion of the imaging lens structuring layer (212) corresponding to at least one optical channel (202) of the imaging lens is left without the imaging lens optical coloring layer (216), and the imaging lens optical coloring layer (216) is configured to impart a predetermined color to the light passing through the imaging lens optical coloring layer (216).

Description

Technical Field

[0001] The present disclosure generally relates to an optical element having a plurality of lenses, an optical element adapted to provide a colored projection, and a projection system including the adapted optical element.

Background Art

[0002] Generally, pattern projection has attracted attention in recent years, particularly in automotive applications. Static or dynamic projection can display various types of information on the inner surface of a vehicle (e.g., the windshield), or on the ground near the vehicle, such as a road. For example, in order to indicate a failure or an emergency, a symbol may be projected onto the road as a warning sign for following vehicles. As another example, a so-called "welcome light carpet" may be projected to welcome a driver or a passenger who has reached the vehicle. The projected pattern thus functions as a decorative function, and also functions as a safety function that illuminates the vicinity around the vehicle to assist the user at night or illuminates an uneven road surface. A common approach relies on a microlens array used as a projection lens in a multi-channel configuration. The projections from each microlens overlap to create a desired projection in the far field, e.g., on a projection surface. Therefore, the improvement of pattern projection, particularly pattern projection through a multi-lens optical element, can be particularly relevant to further advancements in several technologies.

Summary of the Invention

[0003] The present disclosure generally relates to an optical element having a plurality of lenses, an optical element adapted to provide a colored projection, and a projection system including the adapted optical element.

Brief Description of the Drawings

[0004] Identical parts are denoted by the same reference numerals. The drawings are not necessarily to scale, and are generally intended to illustrate the principles of the invention. In the following description, the structure and effects of the present invention will be explained with respect to the attached drawings and the various embodiments shown in the drawings. [Figure 1A] This is a schematic diagram showing a projection optical element having a microlens array. [Figure 1B] This diagram schematically illustrates pattern projection via a projection optical element. [Figure 2A] This diagram schematically illustrates various forms of multi-lens optical elements. [Figure 2B] This section outlines other general features of multi-lens optical elements in various forms. [Figure 2C] A schematic example of lens arrangement in a multi-lens optical element relating to various embodiments is shown. [Figure 2D] An example of a projected image obtained by a multi-lens optical element in various forms is shown. [Figure 3A] A schematic example of a configuration in which a light-colored layer is placed in the optical channel of a multi-lens optical element according to various embodiments is shown. [Figure 3B] This document shows schematic configuration examples for arranging photo-colored layers in different optical channels of multi-lens optical elements according to various embodiments. [Figure 4A] A schematic diagram shows exemplary configurations in which photo-colored layers are arranged in different optical channels of a multi-lens optical element relating to various embodiments. [Figure 4B] A schematic diagram shows exemplary configurations in which photo-colored layers are arranged in different optical channels of a multi-lens optical element relating to various embodiments. [Figure 4C] A schematic diagram shows exemplary configurations in which photo-colored layers are arranged in different optical channels of a multi-lens optical element relating to various embodiments. [Figure 4D] A schematic diagram shows exemplary configurations in which photo-colored layers are arranged in different optical channels of a multi-lens optical element relating to various embodiments. [Figure 5A]This figure shows a schematic example of a configuration for obtaining a color gradient by arranging photo-colored layers in different optical channels of a multi-lens optical element according to various embodiments. [Figure 5B] This figure shows a schematic example of a configuration for obtaining a color gradient by arranging photo-colored layers in different optical channels of a multi-lens optical element according to various embodiments. [Figure 6] A schematic diagram illustrates projection systems using multi-lens optical elements in various configurations. [Modes for carrying out the invention]

[0005] The following detailed description is accompanied by drawings illustrating specific and various details and aspects for carrying out the invention. For ease of explanation, the same reference numerals are used to indicate identical or similar elements. These embodiments are described in sufficient detail to enable a person with professional skill to carry out the invention. Other embodiments may be used and structural, logical, and electrical modifications may be made without departing from the scope of the invention. The above embodiments do not need to be mutually exclusive and may be combined with one or more other embodiments to form new embodiments. Various embodiments are described in terms of methods, and various embodiments are described in terms of apparatus (e.g., multi-lens optical elements, projection systems). However, it is understood that embodiments described in terms of methods are similarly applicable to embodiments described in terms of apparatus, and vice versa.

[0006] In general, projection systems capable of projecting light according to a predetermined pattern play an important role in a variety of applications. Notable examples include the use of projection systems in relation to automobiles, such as integrating them into car doors or car headlights. A common application of such projection systems is the formation of a "welcome light carpet" projecting decorative patterns around the vehicle, such as the vehicle manufacturer's brand or a welcome message to the driver. Other examples include projecting information onto the interior or vicinity of a vehicle, such as warning symbols for the driver or warning symbols for surrounding vehicles or bicycles. Other application scenarios for projection systems include their use in industrial settings to assist robots or drones in factories, and in home settings to project decorative light properties.

[0007] Generally, the method for forming a projection is based on a so-called microlens array, as shown in Figures 1A and 1B. The microlens method makes it possible to realize a compact projection module of a few cubic centimeters, which facilitates integration into host systems such as vehicle interiors, vehicle doors, automated machinery, and home appliances. Generally, the projection optical element 100 may include a plurality of optical channels 102 arranged in parallel to each other. The projections from each optical channel 102 overlap to form a panoramic image in the far field. Considering the microlens method, the projection optical element 100 may have a first microlens array on the illumination side and a second microlens array on the projection side. As an example, the projection optical element 100 may have a plurality of field lenses 104 defining the optical channels 102 and a plurality of imaging lenses 106. The first and second microlens arrays may be arranged on an optical substrate 108, for example, a glass substrate.

[0008] The projection optical element 100 may further have a projection mask 110 for each optical channel 102, each having a corresponding structure that defines the projection from that optical channel. As shown in Figure 1B, the structures of the projection masks corresponding to different optical channels 102 are configured to give a desired projection 112 on a projection surface 114 consisting of a far field, such as a screen, road surface, or wall. For example, the structures of the projection masks corresponding to different optical channels 102 are configured to generate the final projection 112 by superimposing them.

[0009] The microlens system enables miniaturization of the entire projection optical element and the module including the light source compared to single-channel projectors, while achieving high brightness and sharp projection. This multi-channel configuration allows for increased image brightness and sharpness by superimposing multiple projections, and the small diameter and short focal length of individual lenses allows for system miniaturization and easier integration into host equipment. Compared to conventional lenses, the miniaturization of microlenses (e.g., approximately 1 / 100th the size) allows for a greater depth of field (e.g., longer focal length), enabling the synthesis of multiple projections into the distant field.

[0010] While microlens projection systems offer many advantages, they have drawbacks when it comes to projecting colored patterns and images. Conventional configurations require more complex systems or impose constraints that reduce the overall operational flexibility of the projection system. For example, colored projection can be achieved by employing light sources of different colors, such as red, green, and blue light-emitting diodes (LEDs). However, this solution requires the use of multiple light sources, increasing the system's cost, area, and maintenance requirements. Another example is to completely cover an optical channel to impart a specific color to the light propagating through that channel. However, complete covering of an optical channel imposes a somewhat static configuration that fails to fully utilize the potential of a multi-channel system.

[0011] This disclosure may be based on the finding that coating a portion of the optical channels in a multi-lens arrangement to color the light propagating through those channels allows for a wide range of configurations for the resulting projection, thereby improving the capabilities of the projection system compared to a configuration in which the entire optical channel is coated, and without requiring an additional (colored) light source. For example, this disclosure may be based on the finding that placing a light-coloring layer in a dedicated area of ​​the optical channel (e.g., a dedicated area of ​​the aperture of a field lens) can provide a simple yet efficient strategy for adjusting the appearance of the resulting projected image.

[0012] According to this disclosure, one or more optical coloring layers may be included in a dedicated portion of an optical channel (one or more optical channels, e.g., each optical channel). The optical coloring layers in an optical channel may be combined with optical coloring layers in one or more other optical channels within that optical channel to configure, for example, a combination of colors, a color gradient, etc., corresponding to a desired (target) projection (also called the final projection). Such a proposed approach allows for more flexible and finer adaptation of the resulting projection to achieve, for example, complex color patterns, complex color gradients, etc.

[0013] In various embodiments, a multi-lens optical element comprises a plurality of optical channels, each optical channel defined by a corresponding field lens and a corresponding imaging lens; a structured layer configured to define an image projected through each optical channel; and an optical color layer disposed in at least one of the plurality of optical channels, wherein the optical color layer covers a first portion of the structured layer corresponding to at least one optical channel, but the optical color layer is absent from a second portion of the structured layer corresponding to at least one optical channel, and the optical color layer is configured to impart a predetermined color to light passing through it.

[0014] According to various aspects, a multi-lens optical element includes a first lens array having a plurality of field lenses, and a second lens array having a plurality of imaging lenses, wherein each field lens is associated with a corresponding imaging lens to define an optical channel, the first and second lens arrays, a projection mask configured to define a projection pattern of the optical channel, and a color filter disposed at a dedicated location of an aperture of at least one field lens but not disposed at the entire aperture of at least one field lens.

[0015] In a preferred configuration, the multi-lens optical element can have a plurality of microlenses, for example, a first microlens array (as a field lens) on the illumination side and a second microlens array (as an imaging lens) on the projection side. The microlens array provides a convenient implementation of the proposed projection strategy and is advantageous in terms of, for example, miniaturization of the optical module, brightness of the resulting pattern, and established manufacturing techniques. Therefore, in the following, some terms may belong to the specific context of microlenses and microlens arrays (MLAs). However, in principle, it is understood that the proposed method may also be implemented with lenses that are not necessarily "micro" lenses, for example, lenses with a diameter larger than 1 mm.

[0016] The proposed strategy may be particularly relevant in the context of automotive applications, for example, it can be incorporated into a vehicle to project various images and patterns such as warning symbols, instructions to the driver, welcome carpets, etc. Thus, some of the terms below may belong to the specific context of automotive applications related to a potential host device, for example, for a multi-lens optical element or a corresponding projection system. However, in principle, it is understood that the multi-lens optical element or projection system as described herein may be used in any suitable scenario where the projection of an image / pattern can play a role. Other application examples include the industrial market (for example, as part of an automated factory), the home market (for example, as part of smart home appliances), or generally the consumer market (for example, as part of a portable device).

[0017] Figure 2A schematically shows a multi-lens optical element 200 configured according to the proposed strategy, relating to various aspects. Generally, the multi-lens optical element 200 includes a plurality of lenses that define a plurality of optical channels for projecting a pattern, and may have a light coloring layer in a dedicated portion of at least one optical channel. Note that the multi-lens optical element 200 may also be referred to as a multi-lens projector, a multi-channel optical element, or a multi-channel projector. For the sake of brevity, the multi-lens optical element 200 may be described only as the optical element 200. Generally, as will be described in more detail below, the multi-lens optical element 200 may be configured to perform colored projection, for example, as part of a projection system.

[0018] Generally, a multi-lens optical element 200 may include a plurality of optical channels 202 defined by a corresponding pair of lenses 204, 206. In this context, the term “optical channel” may be used to describe the portion of the optical element 200 that contributes to the projection (resulting pattern or image) of a given result of the optical element 200. Thus, “optical channel” can refer to a portion of the optical element 200 that, in combination with other optical channels, defines a corresponding portion of the final projection (e.g., a partial image or pattern). As an example, “optical channel” may be a portion of the multi-lens optical element 200 through which light propagates to project a corresponding projection that is consequently formed (e.g., in the far field) in combination with projections projected through other optical channels.

[0019] As previously described, each optical channel 202 may be defined by a corresponding pair of lenses 204, 206. In this regard, the optical element 200 may comprise a (first) plurality 208 of first lenses 204 and a (second) plurality 210 of second lenses 206. Each first lens 204 may be combined with a corresponding second lens 206 to define a separate optical channel 202. Generally, the first lens 204 and its corresponding second lens 206 may be arranged such that, during the operation of the optical element 200, light passes through the first lens 204 before passing through the second lens 206. For example, the first lens 204 and its corresponding second lens 206 may be arranged coaxially.

[0020] In principle, any suitable arrangement of the first lens 204 and the second lens 206 can be provided depending on system considerations such as the geometric shape of the projection system and the space constraints of the host device. For example, the first lens 204 and the second lens 206 may be arranged in a one-dimensional array such as a column or row of lenses. As another example, the first lens 204 and the second lens 206 may be arranged two-dimensionally, for example in a two-dimensional array. In principle, the first lens 204 and the second lens 206 can be arranged regularly (e.g., in a periodic array) or irregularly (e.g., in a non-periodic array, or in any irregular arrangement in a plane). As an example, the first lens 204 and / or the second lens 206 can be arranged in a square grid array, a rectangular grid array, a hexagonal grid array, a circular array, an elliptical array, etc.

[0021] In this specification, the first lens 204 is also referred to as the illumination lens, field lens, or incident lens. For example, during the operation of the optical element 200, the first lens 204 may be positioned optically upstream of the second lens 206 so that the light illuminating the optical element 200 (the light that produces the desired projection) first enters the first lens 204 before propagating to the second lens 206. In other words, in operation (for example, within a projection system; see also Figure 6), the first lens 204 may be positioned closer to the light source than the second lens 206.

[0022] Correspondingly, in this specification, the second lens 206 is also referred to as the projection lens, photographic lens, or output lens. For example, during the operation of the optical element 200, the second lens 206 may be positioned optically downstream of the first lens 204 with respect to the incident light. In other words, during operation (for example, within a projection system, see also Figure 6), the second lens 206 may be positioned closer to the illumination field (further from the light source) with respect to the first lens 204.

[0023] Generally, the first lens 204 and the second lens 206 may have appropriate configurations for projecting a predetermined pattern / image. The first lens 204 and the second lens 206 may be spherical lenses or aspherical lenses. For example, at least one of the first lenses 204 (e.g., each first lens 204) may be configured as a convex lens, such as a plano-convex lens. As another example, at least one of the second lenses 206 (e.g., each second lens 206) may be configured with a convex surface, such as a plano-convex lens, facing in the opposite direction to the convex surface of the first lens 204. However, it is understood that lenses 204 and 206 may also have other configurations to achieve the projection of a pattern / image.

[0024] In some embodiments, the first lenses 204 may have the same configuration, for example, the same size, focal length, and other parameters. In other embodiments, one or more lens parameters may differ in all of the multiple first lenses 204 (for example, to compensate for distortions in the projection). Correspondingly, the multiple second lenses 206 may have the same configuration or different configurations, and in other embodiments, one or more lens parameters may differ in the multiple second lenses 206.

[0025] In a preferred configuration, the first lens 204 and the second lens 206 may be microlenses. In this specification, the term microlens may generally be used to refer to lens elements having dimensions in the range of micrometers, for example, lens elements with a lateral dimension (e.g., diameter) of less than 1 millimeter (mm). In this configuration, lenses 204, 206 may also be called "lenslets". In this scenario, the first plurality of lenses 208 may constitute a first microlens array, and the second plurality of lenses 210 may constitute a second microlens array. For example, the optical element 200 may have a first two-dimensional array of first microlenses (as field lenses) defining an optical channel 202, and a second two-dimensional array of second microlenses (as photographic lenses).

[0026] The microlens-based configuration provides projection capability with reduced overall dimensions, facilitating the integration of the optical element 200 and the corresponding projection system into a suitable host device (e.g., a headlamp, a vehicle door, etc.). Microlenses can be manufactured by known technologies, such as molding, microfabrication, or wafer-level manufacturing techniques. Lenses 204, 206, including microlenses, may contain or be formed from optionally applicable materials, such as glass, organic polymers, or inorganic polymers. For example, the microlenses may consist of or contain polymethyl methacrylate (PMMA). In some embodiments, lenses 204, 206 may be manufactured by polymer-on-glass manufacturing methods (e.g., on a substrate containing or made of glass (see also Figure 2B)). In this configuration, lenses 204, 206 may be hybrid glass-polymer lenses, where the robustness of the substrate enhances lens stability and facilitates handling during manufacturing. In other embodiments, lenses 204 and 206 may be monolithic polymer lenses (for example, lenses on a substrate containing or made of a polymer, e.g., lenses on a UV-curable polymer), which can simplify the manufacturing process.

[0027] The dimensions of lenses 204, 206 can be adapted to a suitable range depending on system considerations. In a preferred configuration, at least one lens 204, 206 (e.g., each first lens 204 and / or each second lens 206) may have a width in the direction perpendicular to the optical axis of the optical element 200 (e.g., diameter) in the range of 1 μm to 1000 μm, for example, 5 μm to 500 μm, or for example, 10 μm to 300 μm. As another numerical example, at least one lens 204, 206 (e.g., each first lens 204 and / or each second lens 206) may have a lateral spread (e.g., thickness or height) in the direction parallel to the optical axis of the optical element 200 in the range of 1 μm to 200 μm, for example, 5 μm to 100 μm, or for example, 10 μm to 50 μm. However, it should be understood that, in principle, the strategy of this proposal can also be implemented with larger lenses, such as lenses with a diameter greater than 1 mm and / or lenses with a height greater than 1 mm.

[0028] The number of lenses 204 and 206 can be adapted to a suitable range, for example, depending on system considerations. For example, the first lens 204 of the first group 208 and the second lens 206 of the second group are each 2 to 10 6 Within the range of (millions), for example, 10 to 10 5 Within the range of (100,000), for example, 100 to 10 4 This may include each lens count within the range of (10,000).

[0029] Generally, the first lens 204 and the corresponding second lens 206 can be arranged in a suitable configuration to superimpose the light (and corresponding partial patterns) projected through the various optical channels 202. For example, the first lens 204 and the second lens 206 may be configured such that the light projected through the optical channels 202 results in a predetermined projection in the far field. Each optical channel 202 may project a different image / pattern / figure / display, and the final projection includes the superposition of the individual projections of each optical channel 202.

[0030] For example, adjacent first lenses 204 (e.g., in a one-dimensional or two-dimensional array) may be in contact with each other, or adjacent second lenses 206 may be in contact with each other. For example, the center-to-center distance between adjacent (in other words, adjacent) first lenses 204, for example, the array pitch of the first array, can be in the range of 10 μm to 1000 μm, and for example, it may be in the range of 50 μm to 500 μm. Correspondingly, the center-to-center distance between adjacent second lenses 206, for example, the array pitch of the second array, may be in the range of 10 μm to 1000 μm, or it may be in the range of 50 μm to 500 μm.

[0031] The optical element 200 may further have a structured layer 212 that defines an image / pattern to be projected through each optical channel 202, such as a partial projection to obtain a final projection by superimposing it with a partial projection from another optical channel 202. For example, the structured layer 212 may have a structured feature 214 corresponding to each optical channel 202, and shape the light propagating through the optical channel 202 according to the structured feature 214. For example, the structured feature 214 may be a transparent opening through which light can pass freely. In this way, the structured layer 212 may be configured to partially block and partially transmit light to the structured feature 214 for each optical channel 202 during operation of the optical element 200. In this way, the structured feature 214 may define an opening for projecting light through the corresponding optical channel 202 according to its shape and arrangement. Thus, the structured layer 212 may be opaque or non-transparent with respect to light in a predetermined wavelength range, that is, the wavelength range on which the optical element 200 (or the corresponding projection system) should act, for example, the wavelength range of light emitted by the light source of the projection system. In this specification, the structured layer 212 is also referred to as a projection mask, and the structured feature 214 is also referred to as a pattern feature or projection feature. As an example, the structured layer 212 may contain a metal such as chromium (e.g., black chromium), or may be composed of such a metal.

[0032] As is well known, structured features 214 corresponding to each optical channel 202 may be adapted according to the projection obtained in the far field. Furthermore, the structured features 214 may be configured (e.g., shape, arrangement, and size, etc.) for each optical channel 202 to produce the desired result (final projection) when partial projections from the optical channel 202 are superimposed, based on an algorithm or simulation. The representation for each optical channel 202 may be calculated separately according to the optical and geometric setups. Depending on the resulting projection, the structured features 214 corresponding to different optical channels 202 may be identical or slightly different (e.g., gradually changing across the entire array). In principle, the structured layer 212 may be placed at any suitable position within the optical element 200 to define the partial projection onto the optical channel 202. As an example, as shown in Figure 2A, the structured layer 212 may be placed between the first lens 204 and the second lens 206.

[0033] In principle, the structured layer 212 can be configured to define any type of projection achieved through the optical element 200. Generally, the structured layer 212 can be configured to define an image to be projected through the optical channel 202 (for example, by defining a partial image for each optical channel 202). The "image" can be any suitable graphic representation that can be projected through the optical element 202. Generally, the optical element 200 may illuminate with visible light to define a colored projection in the visible spectral region, but it is understood that it may also illuminate with light invisible to the human eye (e.g., infrared light). Therefore, even when the optical element 200 is illuminated with light invisible to the human eye, the embodiments discussed herein can be applied accordingly. For this reason, projection can be applied not only when it is actually visible to the human eye, but also when it is not visible to the human eye (for example, when used in sensing processing such as face recognition or object recognition).

[0034] The projected "image" may be configured (e.g., designed) according to the intended use of the optical element 200. For example, the structured layer 212 may define an image that represents warning symbols indicating vehicle malfunction, dangerous road conditions, speed limits, etc., and may be projected onto the road to warn the driver of the vehicle or drivers of surrounding vehicles. Another example is that when the structured layer 212 defines an image, it may be the logo of the vehicle manufacturer, a welcome message to the driver of the vehicle, or simply a decorative image such as a decorative pattern. Furthermore, the image defined by the structured layer 212 may be instructions to be taken (e.g., "Stop," "Go," "Turn Left," "Turn Right," "Jump," etc.), directions to follow (e.g., as arrows), status information, or any appropriate visual representation of information in different applications.

[0035] In some embodiments, the projection may be a “pattern.” The “pattern” may include a repeating (regular) arrangement of features. For example, the “pattern” may be a geometric pattern containing repeating geometric shapes in one or two dimensions. In some embodiments, the “image” or “pattern” defined by the structured layer 212 may include a regular arrangement of features or elements arranged in a grid. In this specification, the term “image” may be applied in correspondence with “pattern,” or conversely, “pattern” may be applied to “image,” or in general, it may be applied to all types of projections that can be obtained by a multi-lens optical element.

[0036] According to this disclosure, the optical element 200 may further have an optical coloring layer 216 in at least one optical channel 202. Generally, the “optical coloring layer” as described herein may be a layer configured to impart a predetermined color to light passing through the layer. For example, the “optical coloring layer” may be configured to receive incident light of a first color (e.g., white light) and emit outgoing light of a second color defined by the properties of the optical coloring layer. Thus, the “optical coloring layer” may be configured, for example, so that the light output from the optical coloring layer has a predetermined color (e.g., a predetermined range of wavelengths).

[0037] In some embodiments, the "photochromic layer" may be configured to select a predetermined wavelength of light passing through it. In some embodiments, the photochromic layer is configured as a color filter, transmitting light in a predetermined wavelength range and blocking light outside that range. For example, in a scenario where the optical element 200 is illuminated with white light, the photochromic layer may receive the white light as incident light and emit light of a specific color (e.g., red, green, blue, etc.) as outgoing light. As an example, the above-mentioned photochromic layer may be configured as a bandpass color filter. As another example, the photochromic layer may be configured as a lowpass color filter.

[0038] According to the proposed configuration, the optical coloring layer 216 may be placed only in the portion dedicated to the optical channel 202. For example, the optical coloring layer 216 may not be placed over the entire area through which light propagates within the optical channel 202, but rather in a dedicated region through which light propagates within the optical channel 202. In this way, the optical coloring layer 216 may be placed in the structured layer 212 such that it covers a first portion corresponding to at least one optical channel 202, but the optical coloring layer 216 remains absent in a second portion corresponding to at least one optical channel 202. It should be noted that the optical coloring layer 216 only needs to overlap a portion of the structured layer 212, corresponding to at least one optical channel 202.

[0039] In other words, the optically colored layer 216 covers one or more structured features 214 of the structured layer 212 corresponding to at least one optical channel 202, but leaves one or more further structured features 214 of the structured layer 212 corresponding to at least one optical channel 202 without the optically colored layer 216. Another example is that the optically colored layer 216 overlaps with a portion of one structured feature, but leaves a portion of other structured features without the optically colored layer 216. Thus, the optically colored layer 216 can be configured (arranged) to color only a portion of the light propagating through the optical channel 202, for example, only the light passing through a portion of the structured features 214, thereby coloring only a portion of the optical channel 202 with the color defined by the optically colored layer 216. In some embodiments, the optically colored layer 216 is located in a portion of the aperture of the field lens 204 corresponding to the optical channel 202, but the other portions of the aperture of the field lens 204 may be left without the optically colored layer 216.

[0040] Thus, arranging the photo-colored layer 216 in only a portion of the optical channel 202 provides additional flexibility in designing the projection result (various configurations shown in Figures 3A to 5B below). As can be seen in Figure 2A, the configuration is simplified for illustrative purposes to illustrate the principle of the proposed strategy, and the optical element 200 may include one or more such photo-colored layers 216 within the same optical channel 202 or within different optical channels 202 (e.g., each optical channel 202), for example, as described below.

[0041] In principle, the photo-colored layer 216 (and any further photo-colored layers) can be placed at any suitable position within the optical element 200 to color the light passing through the corresponding portion of the optical channel 202. As an example, the photo-colored layer 216 may be placed on the structured layer 212, corresponding to at least one optical channel 202. For example, the photo-colored layer 216 can be directly formed on the structured layer 212 by means of deposition, patterning, hardening, etc. As another example, the lenses 204, 206 of the optical element 200 (for example, each lens 204, 206) have a base layer and a lens portion (for example, in the case of a microlens) placed on the base layer, and the photo-colored layer 216 can be placed on the base layer and overlapping with a part of the lens portion (but not overlapping the entire surface of the lens portion). As an example, the photo-colored layer 216 may be placed between the first lens 204 and the second lens 206 that define the optical channel 202, for example, between the first lens 204 and the structuring layer 212.

[0042] Generally, the photo-colored layer may contain any suitable material capable of imparting photo-coloring properties, or may be formed from such a material. As a preferred configuration that enables a simple and efficient manufacturing process, the photo-colored layer may contain a resin material, such as epoxy, or may be formed from such a material. However, it is understood that other materials, such as thin film materials, plastics, resist materials, etc., may also be used. As an example, the photo-colored layer may contain the same material as the first lens 204 and / or second lens 206 that define the optical channel 202, or may be formed from the same material as the first lens 204 and / or second lens 206, thereby simplifying the manufacturing process.

[0043] The configuration in Figure 2A illustrates a single structured layer 212. However, it is understood that the configuration is also applicable to configurations having two or more structured layers 212, such as a stack of structured layers, or multiple structured layers 212 arranged sequentially. In this scenario, the photo-colored layer can be placed at any suitable position within the array (or stack) of structured layers, depending on the structured features to be colored. The photo-colored layer can be placed before the first structured layer 212, after the last structured layer 212, or at any position in the row of structured layers 212.

[0044] Furthermore, it is understood that the optical element 200 may include other components in addition to those shown in the illustration. For example, the optical element 200 may include further lenses optically positioned upstream of the first lens 204 or downstream of the second lens 206, and may be part of a system including further optical elements such as lenses, mirrors, apertures, etc. As another example, the first lens 204 and / or the second lens 206 may have anti-reflective properties, for example, they may have an anti-reflective layer or coating. For example, the first lens 204 and / or the second lens 206 may have an anti-reflective structure formed on the lens surface, for example, a moth-eye structure, nanopillars, nanorods, etc.

[0045] Figures 2B to 2D show further embodiments of the optical element 200. In some embodiments, as shown in Figure 2B, the optical element 200 may further have an optical substrate 218. In this configuration, a first lens 204 may be disposed on a first surface of the optical substrate 218, and a second lens 206 may be disposed on a second surface of the optical substrate 218 opposite to the first surface (for example, opposite along the optical axis direction of the optical element 200). The first and second surfaces are the main surfaces of the substrate 218 and may have, for example, length and width dimensions greater than the thickness of the substrate 218. The substrate 218 may be provided, for example, in part of a manufacturing process in which the lenses 204 and 206 are formed (e.g., duplicated) on the substrate 218, or in part of a manufacturing process in which a layer (e.g., a PMMA layer) containing the lenses 204 and 206 is placed on the substrate 218.

[0046] In this configuration, a structured layer 212 may be placed on the substrate 218. In a preferred configuration, the structured layer 212 may be placed on the first surface of the optical substrate 218, and exemplary, between the first lens 204 and the substrate 218. This configuration avoids beam clipping of the structured layer 212 due to beam diffusion in the substrate 218. However, it is understood that the structured layer 212 may be placed in other locations. Correspondingly, the optically colored layer 216 may be placed on the substrate 218 (for example, on the structured layer 212 placed on the substrate 218). For example, the optically colored layer 216 may be on the first surface of the optical substrate 218, between the first lens 204 and the substrate 218.

[0047] The substrate 218 may contain or be formed from any suitable refractive material, such as glass (e.g., borosilicate glass, alumina borosilicate glass, etc.), optical filter glass, epoxy, polymer, etc. In some embodiments, the substrate 218 may be a wafer, such as a glass wafer or epoxy wafer. In other embodiments, the substrate 218 may contain or be composed of oxides, nitrides, and oxynitrides, etc. Generally, the substrate 218 may be configured to transmit light, for example, light in the wavelength range on which the optical element 200 operates. For example, the substrate 218 may be configured to transmit light (light having a predetermined range of wavelengths). For example, the predetermined wavelength band may be the visible light band. In other embodiments, the wavelength band may be the infrared and / or near-infrared band, or any other suitable band. In some embodiments, the optical substrate 218 may be configured to block light outside the predetermined wavelength range. For example, the material of the substrate 218 may transmit only the desired wavelength range. As another example, the optical substrate 218 may have a coating that blocks light outside the predetermined wavelength range. Generally, the dimensions of the optical substrate 218 can be appropriately matched to the overall dimensions of the optical element 200, or the overall dimensions of the corresponding imaging device into which the optical element 200 is incorporated, depending on the desired application.

[0048] In this regard, Figure 2C shows examples of the arrangement of lenses 204 and 206, and examples of the dimensions of the optical element 200 (and therefore the substrate). As an example, Figure 2C shows an example configuration of a first lens array and / or a second lens array of the optical element. As an example of dimensions (dimensions in the plane perpendicular to the optical axis of the optical element 200), the lens array (e.g., substrate 218) may have a first dimension 220 (e.g., in the range of 1 mm to 50 mm, e.g., 5 mm to 20 mm, e.g., a first width or first length of approximately 11 mm in width / length). As another numerical example, the lens array (e.g., substrate 218) may have a second dimension 222 in the plane (e.g., in the range of 1 mm to 50 mm, e.g., in the range of 5 mm to 20 mm, e.g., a second width or length of approximately 10 mm in width / length). As a further numerical example, the distance 224 between the corner of the lens array and the boundary of the substrate 218 can be, for example, in the range of 0.1 mm to 10 mm, for example, in the range of 0.5 mm to 5 mm, for example, it can be approximately 3 mm.

[0049] Figure 2D shows three exemplary projections 230a, 230b, and 230c that can be defined by appropriate structuring of the structured layer 212. The coloring (e.g., color gradient) of projections 230a, 230b, and 230c can be obtained by appropriately configuring and arranging an optical coloring layer in the optical element 200, as described in more detail with respect to Figures 3A to 5B.

[0050] Figure 3A shows possible configurations 300a to 300e for arranging the photo-colored layer in the optical channel 302. Note that the representation in Figure 3A is simplified for illustrative purposes, but the optical channel 202 and the first lens 204 described in Figure 2A are represented as individual optical channels 302 having corresponding lenses 304 (e.g., field lenses). It is understood that the embodiments discussed in relation to Figure 3A can be extended to one or more optical channels of the optical element 200. For example, they can be extended to each optical channel of the optical element 200. Furthermore, it is understood that the embodiments described in relation to Figure 3A can also be applied to different arrangements of the lens 304, structured layer 306, and photo-colored layer 310, for example, to different orders. Furthermore, although the various components are shown spaced apart for the sake of clarity in the illustration, it is understood that the descriptions of the above embodiments also apply to configurations in which the lens 304, the structured layer 306, and the photo-colored layer 310 are in contact with each other (for example, on the substrate of an optical element).

[0051] The first configuration 300a represents a scenario in which the optical channel 302 has an optically colored layer 310 located in a dedicated portion of the optical channel 302. For example, the structuring layer 306 defines one or more structuring features 308 (e.g., first to third structuring features 308-1, 308-2, 308-3, or any number of structuring features) corresponding to the optical channel 302, and the optically colored layer 310 may be positioned to cover (exemplarily overlap) a portion of the structuring features 308. For example, the optically colored layer 310 may overlap the first structuring feature 308-1, but the optically colored layer 310 may not be present over other (e.g., second) structuring features 308-2. Furthermore, the embodiment described for a configuration in which the photo-colored layer covers structured feature 308-1, but the other structured features 308-2 and 308-3 remain without the photo-colored layer, is understood to also apply to an embodiment in which the photo-colored layer covers only a portion of (one) structured feature, but the other portion of the structured feature remains without the photo-colored layer.

[0052] The optical channel 302 may, in principle, have two or more optical coloring layers 310. For example, it may have multiple optical coloring layers 310 to color one or more parts of a partial projection with the same color, or to color them with different colors. For example, as shown in the second configuration 300b and the third configuration 300c, the optical channel 302 may include multiple optical coloring layers 310, for example, the first to third optical coloring layers 310-1, 310-2, 310-3, etc., and the number of optical coloring layers 310 may be any appropriate number. Generally, one optical channel 302 may contain more areas with the same coloring filter, or one optical channel 302 may contain more areas with different coloring filters. Thus, the (partial) projection projected through one optical channel 302 may include regions with different colors / wavelengths.

[0053] Each colored layer may be positioned to cover each (partial) portion of the optical channel 302, for example, each portion of the aperture of the field lens 304. For example, as shown in the second configuration 300b above, the optical channel 302 may have a first optical colored layer 310-1 and a second optical colored layer 310-2. The first optical colored layer 310-1 may be positioned on a portion of the optical channel 302, but the first optical colored layer 310-1 may not be present on the remaining portion of the optical channel 302. Correspondingly, the second optical colored layer 310-2 may be positioned on a portion of the optical channel 302, but the second optical colored layer 310-2 may not be present on the remaining portion of the optical channel 302.

[0054] For example, the first optically colored layer 310-1 may cover only the first portion of the structuring layer 306 corresponding to the optical channel 302, the second optically colored layer 310-2 may cover only the second portion of the structuring layer 306 corresponding to the optical channel 302, and the third optically colored layer 310-3 (see configuration 300c) may cover only the third portion of the structuring layer 306 corresponding to the optical channel 302. For example, each optically colored layer may overlap (completely or partially) one or more structuring features 308, but other structuring features 308 may remain without an optically colored layer (and may be covered by other optically colored layers).

[0055] For example, the first optically colored layer 310-1 may cover only the first structured feature 308-1 (or one or more first structured features), the second optically colored layer 310-2 may cover only the second structured feature 308-2 (or one or more second structured features), and the third optically colored layer 310-3 may cover only the third structured feature 308-3 (or one or more third structured features). In principle, all structured features 308 corresponding to the optical channel 302 may be fully or partially covered by their respective optically colored layers 310, and in other configurations, at least one structured feature 308 may not have an optically colored layer 310.

[0056] Generally, the properties of the optical coloring layer 310 should be adapted depending on the color or the desired color to be imparted to the light transmitted through the optical channel 302. For example, the properties of the optical coloring layer 310 should be adapted depending on whether the same color is to be imparted to different structural features 308, or whether different colors are to be imparted to different structural features 308. In this way, it is preferable that the first optical coloring layer 310-1 is configured to impart a first predetermined color to the light passing through the first optical coloring layer 310-1, the second optical coloring layer 310-2 is configured to impart a second predetermined color to the light passing through the second optical coloring layer 310-2, and the third optical coloring layer 310-3 is configured to impart a third predetermined color to the light passing through the third optical coloring layer 310-3.

[0057] Various colors can be arbitrarily chosen. For example, the first predetermined color may be the same as the second predetermined color (and / or the third predetermined color, etc.). As another example, the first predetermined color and the second predetermined color (and / or the third predetermined color, etc.) may be different. For example, the first predetermined color may be the same as the second predetermined color and different from the third predetermined color. As yet another example, the first predetermined color may be different from the second predetermined color, and the first predetermined color and the second predetermined color may be different from the third predetermined color. In addition, other appropriate combinations may be adopted depending on the number of optically colored layers 310 in the optical channel 302.

[0058] Furthermore, according to various embodiments, as shown in the fourth configuration 300d and the fifth configuration 300e, the optical channel 302 can have a configuration in which multiple photo-colored layers 310 are stacked. For example, the optical channel 302 may have a photo-colored laminate having multiple photo-colored layers, for example, a first photo-colored layer 310-1 and a second photo-colored layer 310-2 (or an appropriate number of photo-colored layers). The embodiments discussed with respect to a single layer can be applied in correspondence to a photo-colored laminate. For example, the photo-colored laminate may cover only a part of the optical channel 302, for example, only a part of the structured layer 306, while the other part is without a photo-colored laminate.

[0059] In this configuration, each optically colored layer of the optically colored laminate may be configured to provide a color different from the color defined by the other layers. A configuration having an optically colored laminate may, for example, allow the coloring of the projection to be defined by a more complex combination of colors. As shown in Figure 3A, the optically colored laminate may be provided only in a portion of the optical channel 302, or in combination with other individual optically colored layers 310-3 in other portions of the optical channel 302, or in combination with other optically colored laminates (not shown).

[0060] In principle, each optical channel 302 of the optical element can be adapted to any appropriate configuration depending on the appearance of the desired projected image. Thus, each optical channel 302 may include an appropriate number of optically colored layers or laminates, arranged in an appropriate configuration, depending on the desired configuration of the resulting projection. In this way, each optical channel 302 can be configured in any configuration described with respect to Figure 3A, or in any other possible configuration / arrangement of optically colored layers.

[0061] The configurations of the different optical channels 302 may be adjusted according to the target configuration of the resulting projection, for example, in terms of the number of optical coloring layers, the type of color, the position of the optical coloring layers, etc. For example, they may be adjusted according to the target color or color gradation in the projection obtained by superimposing partial projections from each optical channel 302. As an example configuration, the area of ​​the coloring filter can be different depending on the optical channel 302. As another example configuration, in the projection result on an illuminated surface, different areas of coloring filters from different optical channels 302 may be superimposed. As yet another example configuration, on the resulting illuminated surface, for example, areas with filters of the same color may be superimposed from different optical channels 302.

[0062] Figure 3B shows a configuration 300f in which multiple optical channels 302 are shown, for example, first to third optical channels 302-1, 302-2, 302-3. It is understood that the configuration described with respect to Figure 3B can be extended to any number of optical channels that fit. In Figure 3B, each optical channel 302-1, 302-2, 302-3 is shown as an exemplary configuration having a single photo-colored layer 310 (for example, first to third photo-colored layers 310a, 310b, 310c), but it is understood that each optical channel 302 may have any configuration in Figure 3A (or any other appropriate configuration), for example, having multiple photo-colored layers (defining the same or different colors), or having a photo-colored laminate.

[0063] Depending on the coloring, the optically colored layers 310 of different optical channels 302 may or may be arranged to correspond to the same structured feature 308. In this context, "same structured feature" 308 generally refers to structured features 308 corresponding to different optical channels 302 that contribute to the same area of ​​the resulting projection, for example, structured features 308 that provide the same projected features in the resulting projection. For this reason, "same structured feature" 308 may be the same among different optical channels 302, for example, in terms of shape, size, relative position, etc. However, the same structured feature 308 may differ slightly among different optical channels 302 (for example, in terms of shape, dimensions, relative position) in light of the slight adjustments made to obtain the resulting projection in the far field, but still correspond to the same projected features in the resulting projection. Therefore, generally speaking, the "identical structured features" 308 in different optical channels 302 can be understood as portions of the structured layer 306 in different optical channels 302, where the illumination of the optical element 200 causes their (partial) projections to overlap and constitute a part of the final projection. In contrast, the "different structured features" 308 in different optical channels 302 are generally portions of the structured layer 306 in different optical channels 302, where the illumination of the optical element 200 causes each to correspond to different projections, and these are understood as parts where their (partial) projections do not overlap.

[0064] As shown in the example configuration in Figure 3B, the first optical channel 302-1 may have a first optical color layer 310a (or a laminate), the second optical channel 302-2 may have a second optical color layer 310b (or a laminate), and the third optical channel 302-3 may have a third optical color layer 310c (or a laminate). As an example configuration, each optical channel of the optical element 200 may have at least one optical color layer. In other configurations, at least one optical channel of the optical element 200 may not have an optical color layer at all.

[0065] As an example configuration, the optical coloring layers of light in different optical channels 302 may cover the same structural features of the structuring layer 306. This is shown in Figure 3B for a first optical coloring layer 310a of a first optical channel 302-1 covering a first structural feature 308-1 (or one or more first structural features), and a second optical coloring layer 310b of a second optical channel 302-2 covering the (same) first structural feature 308-1 (or the same one or more first structural features). The first optical coloring layer 310a and the second optical coloring layer 310b may be configured to impart the same color to the light passing through them, or they may be configured to impart different colors to the light passing through them, depending on the desired effect on the resulting projection.

[0066] As an example configuration, the optical coloring layers in each different optical channel 302 may cover each different structural feature of the structural layer 306. This is shown in Figure 3B for a first optical coloring layer 310a in a first optical channel 302-1 covering a first structural feature 308-1 (or one or more first structural features), and a third optical coloring layer 310c in a third optical channel 302-3 covering a different (e.g., second) structural feature 308-2 (or one or more second structural features). The first optical coloring layer 310a and the third optical coloring layer 310c may be configured to impart the same color to the light passing through them, or to impart different colors to the light passing through them, depending on the desired effect on the resulting projection.

[0067] The embodiments discussed with respect to the exemplary configuration in Figure 3B can be similarly extended to cases where the optical channel 302 includes a plurality of photo-colored layers 310. For example, the first optical channel 302-1 may have first and second photo-colored layers, and the second optical channel 302-2 may have third and fourth photo-colored layers. The first photo-colored layer may have the same structural characteristics as the third photo-colored layer, and may define the same or different color as the third photo-colored layer. The second photo-colored layer may have the same structural characteristics as the fourth photo-colored layer, and may define the same or different color as the fourth photo-colored layer (same or different color as the first / third photo-colored layer), and so on.

[0068] In various embodiments (see also Figures 5A and 5B), the photo-colored layer 310 can be configured to define a color gradient in the final projected image. For example, by placing the photo-colored layer 310 in different optical channels 302, a color gradient (e.g., from white light to a constant color, or from an initial color to a final color) can be created in the final projected image obtained through the optical element. A "color gradient" may be understood as meaning that the color (e.g., density) gradually changes (e.g., increases or decreases) along the extension of the resulting projection, such as in the vertical and / or horizontal directions.

[0069] The color gradient may be obtained by having the photo-colored layer 310 cover different portions of the extended portion of the structured feature 308 (for example, the extended portion of the structured layer 306) in each optical channel. This can be achieved, for example, by changing the size of the photo-colored layer 310 in different optical channels 302, or by shifting the position of the photo-colored layer 310 in different optical channels 302, thereby covering more or less of the surface area of ​​the structured feature 308. In this way, the state in which the light projected through different optical channels 302 overlaps may gradually change depending on the number of photo-colored layers 310 overlapping the light transmission holes.

[0070] For example, referring to the configuration in Figure 3B, a color gradient may be achieved by adapting the first optical color layer 310a in the first optical channel 302-1 and the second optical color layer 310b in the second optical channel 302-2 to cover different amounts of the surface area corresponding to the first structured feature 308-1 (or the first structured feature). For example, the first optical color layer 310a may completely cover the first structured feature 308-1 in the first optical channel 302-1, while the second optical color layer 310b may cover only a portion of the first structured feature 308-1 in the second optical channel 302-2 (e.g., 90% of the surface area of ​​the first structured feature 308-1). Further optical color layers 310 in further optical channels may cover even smaller surface areas (e.g., 80% of the surface area) of the first structured feature 308-1 in further optical channels 302, depending on the desired color gradient.

[0071] As previously described, a color gradient may be realized from an initial color to a final color, for example, from white light (or the color of a typical light source) to a color defined by the photochromic layer, or from a first color to a second color. A color gradient from the color of light emitted by a light source to a predetermined color can be realized by allowing the light emitted by the light source to propagate unaffected, while leaving the surface areas of the structured feature not covered by the photochromic layer unaffected by the photochromic layer. A color gradient from a first color to a second color (which may or may not include an intermediate color) may be achieved by covering the surface areas of the structured feature defining the first color that are not covered by the photochromic layer with another photochromic layer defining the second color. In this second scenario, the surface area covered by the first photochromic layer (the layer defining the first color) may gradually increase (or decrease) across different optical channels 302, and the surface area covered by the second photochromic layer (defining the second color) may gradually decrease (or increase) across different optical channels 302.

[0072] For example, referring to the configuration in Figure 3B, a color gradient may be achieved in the first optical channel 302-1 by covering a portion of the first structured feature 308-1 (e.g., 50% of the surface area) with a first optically colored layer that defines a first color, and covering the other portion of the first structured feature 308-1 (e.g., a complementary portion of the surface area, e.g., the remaining 50%) with a second optically colored layer that defines a second color. Furthermore, a color gradient may be achieved by having a second optical channel 302-2 having a third optically colored layer that defines a first color and covers a portion of the first structured feature 308-1 (e.g., a portion that is more or less than the first optically colored layer (e.g., 40% of the surface area)) and a fourth optically colored layer that defines a second color and covers the other portion of the first structured feature 308-1 (e.g., a portion that is a complementary surface area (e.g., a portion that is more or less than the second optically colored layer (e.g., 60% of the surface area))). These embodiments can be extended to further optically colored layers in further optical channels that cover more / less surface areas of the structured feature. These embodiments can also be extended to three or more optically colored layers used to form a gradient according to the structured feature.

[0073] Figures 4A to 4D show an example configuration of the optical coloring layers of different optical channels in a multi-lens optical element. Figures 4A to 4D show an implementation example of the configuration described in Figures 3A and 3B. It should be understood that the representation in Figures 4A to 4D is simplified for illustrative purposes, and that each optical element in the figures may include further components (e.g., field lenses, substrates, etc.) as described in relation to Figure 2A.

[0074] The configuration examples shown in Figures 4A to 4D illustrate possible coloring across four optical channels 402-1, 402-2, 402-3, and 402-4 defined by each imaging lens 404 (and corresponding field lenses, not shown). As an example, Figures 4A to 4D show possible arrangements of the optical coloring layer 410 for structuring the structuring layer 406 that defines the resulting projection 418. The structuring layer 406 may include structuring features 408-1, 408-2, 408-3, and 408-4 that define the projection 418 in the far field (e.g., on a projection surface such as a wall, road surface, windshield, or floor). Each structuring feature 408-1, 408-2, 408-3, and 408-4 may generate corresponding projection features 420-1, 420-2, 420-3, and 420-4 in the resulting projection 418. In general, structured features may have any appropriate configuration (e.g., shape, size, geometry, etc.) depending on the resulting projection image. In the embodiments shown in Figures 4A to 4D, structured features are exemplified as geometric shapes, but it is understood that structured features may have any possible design.

[0075] In the exemplary configuration 400a shown in Figure 4A, optical channels 402-1, 402-2, 402-3, and 402-4 may each have an optically colored layer 410 positioned corresponding to the same structured feature (e.g., a first structured feature 408-1). In this scenario, the corresponding projection feature 420-1 in the resulting projection 418 may be colored according to the color defined by the optically colored layer 410 (e.g., assuming that the optically colored layers 410 of different optical channels define the same color). The optically colored layer 410 may be left absent from the rest of the optical channel (other structured features 408-2, 408-3, and 408-4), and the color defined by the optically colored layer 410 may not be present in the rest of the projection 418 (other projection features 420-2, 420-3, and 420-4) (e.g., the color of light emitted by a light source, e.g., white).

[0076] In the exemplary configuration 400b of Figure 4B, optical channels 402-1, 402-2, 402-3, and 402-4 may each have multiple optical coloring layers, for example, a first optical coloring layer 410-1 corresponding to a first structured feature 408-1 and a second optical coloring layer 410-2 corresponding to a third structured feature 408-3. In this scenario, the corresponding projection feature 420-1 in the resulting projection 418 may be colored by the colors defined by the optical coloring layers 410-1 and 410-2. Thus, the first projection feature 420-1 may be colored by the color defined by the first optical coloring layer 410-1, and the third projection feature 420-3 may be colored by the color defined by the second optical coloring layer 410-2. The other projection features 420-2 and 420-4 do not need to be colored by the optical coloring layers 410-1 and 410-2.

[0077] In configuration 400b shown in Figure 4B, the light-colored layers 410-1 and 410-2 are configured to impart the same color to light, thereby causing the corresponding projection features 420-1 and 420-3 to be the same color. On the other hand, in configuration 400c shown in Figure 4C, if the light-colored layers 410-1 and 410-2 are configured to impart different colors to light, the corresponding projection features 420-1 and 420-3 will be different colors.

[0078] In the somewhat complex configuration 400d shown in Figure 4D, the optically colored layers corresponding to the structured features in different optical channels each define different colorations, thereby providing a combined color in the final projected feature. For example, the first optically colored layer 410-1 in the different optical channels 402-1, 402-2, 402-3, and 402-4 define the same (first) color, and the resulting projected feature 420-1 has the corresponding coloration. The second optically colored layer 410-2, positioned corresponding to the third structured feature 408-3, may define a different color in the different optical channel. For example, the second photo-coloring layer 410-2 in the second optical channel 402-2 and the fourth optical channel 402-4 may define a second color (e.g., yellow), and the second photo-coloring layer 410-2 in the first optical channel 402-1 and the third optical channel 402-3 may define a third color (e.g., blue) that is different from the second color. The (third) projection feature thus obtained may have a fourth color (e.g., green) resulting from a combination of the second and third colors. Such an approach may be extended to any appropriate number of colors to provide a desired hue in the projection 418.

[0079] Figures 5A and 5B show examples of the configurations of the optical coloring layers for different optical channels of a multi-lens optical element. Figures 5A and 5B show an example of the configuration described in Figures 3A and 3B, in particular an example of a configuration that achieves a color gradient in the final projection through the configuration of the optical coloring layer. It should be understood that the representations in Figures 5A and 5B are simplified for illustrative purposes, and that each optical element in the figure may include further components (e.g., field lenses, substrates, etc.) as explained with respect to Figure 2A.

[0080] The configuration examples shown in Figures 5A to 5D illustrate possible coloring across four optical channels 502-1, 502-2, 502-3, and 502-4 defined by each imaging lens 504 (and corresponding field lenses, not shown). As an example, Figures 5A and 5B show possible arrangements of the optical coloring layer for structuring the structuring layer 506 that defines the projection 518. The structuring layer 506 may also include structuring features 508 that define the projection 518 in the far field (e.g., on a projected surface such as a wall, road, windshield, or floor). The structuring features 508 may generate corresponding projection features 520 in the corresponding resulting projection 518. It is understood that the embodiments discussed in relation to Figures 5A and 5B can also be applied to configurations having two or more structuring features per optical channel.

[0081] In the exemplary configuration 500a shown in Figure 5A, optical channels 502-1, 502-2, 502-3, and 502-4 each have photo-colored layers 510-1, 510-2, 510-3, and 510-4, respectively, which are arranged to correspond to the (identical) structured feature 508. The photo-colored layers 510-1, 510-2, 510-3, and 510-4 of different optical channels 502-1, 502-2, 502-3, and 502-4 may cover different parts (exemplary, different amounts of surface area) of the structured feature 508. For example, the photo-colored layers 510-1, 510-2, 510-3, and 510-4 may transmit light of the same color.

[0082] For example, the first optically colored layer 510-1 may cover the first surface region of the structured feature 508 of the structured layer 506 corresponding to the first optical channel 502-1, the second optically colored layer 510-2 may cover the second surface region of the structured feature 508 of the structured layer 506 corresponding to the second optical channel 502-2, the third optically colored layer 510-3 may cover the third surface region of the structured feature 508 of the structured layer 506 corresponding to the third optical channel 502-3, and the fourth optically colored layer 510-4 may cover the fourth surface region of the structured feature 508 of the structured layer 506 corresponding to the fourth optical channel 502-4.

[0083] The configuration 500a in the example shown in Figure 5A may be such that the first surface area covered by the first optically colored layer 510-1 is smaller than the second surface area covered by the second optically colored layer 510-2, the second surface area is smaller than the third surface area covered by the third optically colored layer 510-3, and the third surface area is smaller than the fourth surface area covered by the fourth optically colored layer 510-4. With this configuration, a color gradient in the projection feature 520 can be obtained, from the color of the light source corresponding to the portion of the structured feature 508 not covered by any optically colored layer (e.g., white) to the color defined by the optically colored layer corresponding to the portion of the structured feature 508 covered by the optically colored layer. This change can be gradual in each optical channel 502, depending on the number of optically colored layers covering specific portions of the structured feature 508.

[0084] In the exemplary configuration 500b of Figure 5B, the color gradient may be a gradient from an initial (first) color to a final (second) color defined by multiple photo-colored layers covering the structured feature 508 in each optical channel 502-1, 502-2, 502-3, 502-4. For example, in addition to the photo-colored layers 510-1, 510-2, 510-3, 510-4 described with respect to Figure 5A, optical channels 502-1, 502-2, 502-3, 502-4 may be covered with additional photo-colored layers rather than leaving the complementary portion of the structured feature 508 without any colored layer.

[0085] As an example, the first optical channel 502-1 may further have a fifth photo-colored layer 510-5 arranged to cover a fifth surface area of ​​the structured feature 508 of the structured layer 506 corresponding to the first optical channel 502-1 (e.g., a complementary area of ​​the first surface area to the entire surface area of ​​the structured feature 508). The second optical channel 502-2 may further have a sixth photo-colored layer 510-6 arranged to cover a sixth surface area of ​​the structured feature 508 of the structured layer 506 corresponding to the second optical channel 502-2 (e.g., a complementary area of ​​the second surface area to the entire surface area of ​​the structured feature 508). The third optical channel 502-3 may further have a seventh photo-colored layer 510-7 arranged to cover a seventh surface area of ​​the structured feature 508 of the structured layer 506 corresponding to the third optical channel 502-3 (e.g., a complementary area of ​​the third surface area to the entire surface area of ​​the structured feature 508). The fourth optical channel 502-2 may further include an eighth photo-colored layer 510-8 disposed to cover an eighth surface region of the structured feature 508 of the structured layer 506 corresponding to the fourth optical channel 502-4 (for example, a complementary region of the fourth surface region to the entire surface region of the structured feature 508).

[0086] In the exemplary configuration 500b shown in Figure 5B, the fifth surface area covered by the fifth photochromic layer 510-5 may be larger than the sixth surface area covered by the sixth photochromic layer 510-6, the sixth surface area may be larger than the seventh surface area covered by the seventh photochromic layer 510-7, and the seventh surface area may be larger than the eighth surface area covered by the eighth photochromic layer 510-8. This configuration allows for a color gradient in the projection feature 520 from the colors of the second type of photochromic layers (the fifth to eighth photochromic layers) to the colors of the first type of photochromic layers (the first to fourth photochromic layers s), or vice versa. Such a configuration can be extended to an appropriate number of colors provided in the gradient, as described above.

[0087] Figure 6 schematically shows a projection system 600 including a multi-lens optical element 602 configured as shown herein in various embodiments. The multi-lens optical element 602 may be in any configuration shown in relation to Figures 2A to 5B and performs color projection. The projection system 600 can be integrated into any suitable host device depending on the desired application. For example, the projection system 600 may be integrated into a vehicle (e.g., inside a vehicle door, inside a headlamp, etc.). The proposed method is, in principle, applicable to any platform.

[0088] The projection system 600 may include a light source 604 that illuminates the multi-lens optical element 602 to generate a projection 610 on a far field, for example, on a projection surface. For example, the light source 604 may illuminate the multi-lens optical element 602 and project an image by superimposing a partial projection defined by an optical channel (for example, defined by a structured layer corresponding to the optical channel). It should be noted that the projection system 600 may include two or more light sources for illuminating the multi-lens optical element 602, for example, multiple light sources emitting light of different colors.

[0089] Generally, the light source 604 may be configured to emit collimated light. The light source 604 may have any suitable configuration that can illuminate the multi-lens optical element 602 and generate the projection 610. For example, the light source 604 may be an LED (Light Emitting Diode), or it may include, for example, an array of LEDs arranged in one or two dimensions. As another example, the light source may be a laser light source, for example, a VCSEL (Vertical Cavity Surface Emitting Laser) or a VCSEL array. The light source may be configured to emit light of a predetermined wavelength in the visible region (e.g., about 380 nm to about 700 nm). As yet another example, the light source may be configured to emit light in the infrared and / or near-infrared range (e.g., in the range of about 700 nm to 5000 nm) or ultraviolet range (e.g., in the range of about 100 nm to 400 nm). For example, the light source 604 may be configured to emit white light, but in principle, it may be configured to emit light of different colors. The light source 604 may be configured to emit light in any appropriate manner depending on the desired operation of the projection system 600. For example, the light source 604 may emit continuous light. As another example, the light source 604 may be configured to emit light in pulses, for example, by emitting a series of light pulses.

[0090] The projection system 600 may further include a control circuit 606 (e.g., one or more processors) that controls the emission of light from the light source 604. The control circuit 606 may be configured to trigger the emission of light from the light source 604 and the interruption of the emission of light from the light source 604. For example, the control circuit 606 may be configured to trigger the emission of light from the light source 604 in response to a predetermined trigger event. The control circuit 606 may receive a signal indicating the occurrence of a trigger event (vehicle-related trigger event) and control the light source 604 accordingly to emit light and generate the projection 610.

[0091] The trigger event may correspond to any suitable scenario in which the projection 610 should be generated. For example, a (vehicle-related) trigger event may be the opening of a vehicle door, which may trigger, for example, the projection of a welcome pattern to the driver. Another example is that a (vehicle-related) trigger event may be the approach of a driver / occupant to the vehicle (e.g., approach detected by a proximity sensor). Yet another example is that a (vehicle-related) trigger event may be the detection of a vehicle malfunction or a dangerous situation (e.g., excessive speed, slippery road surface, traffic jam, etc.). While these are understood to be exemplary trigger events related to automobiles, other types of trigger events (e.g., the opening of a refrigerator door, a change in room temperature, a robot completing a task, etc.) may also be provided.

[0092] Therefore, the proposed strategy in this specification may rely on localized coating within the optical channels of a multi-lens optical component. The colored coating may exist only for a dedicated localized region within each optical channel, and may differ for each optical channel. In some embodiments, the coating may be positioned, for example, as part of the lens substrate layer, close to the display area.

[0093] Different configurations may be offered. In the "one-color local coating" configuration, a local transparent colored coating may be applied to at least one optical channel. In the "more-colors local coating" configuration, each optical channel may include one or more local coating regions of the same or different colors, and the colors may be superimposed in the final (resulting) projection.

[0094] In various embodiments, color gradient projections can be provided. Local coatings may be designed separately for each channel (or at least two channels) to create a transition from colored light to white light (or, generally, light defined by the light source). Alternatively, each channel (or at least two channels) may be designed separately to produce a change from one color to another. Multiple transitions and color superpositions are also possible. This allows for a smooth gradient (transition) between multiple colors, or between a color and white light. For example, a gradient may be achieved by gradually changing the size of the coating area to produce a change in color between colors, or between a color and white light.

[0095] Such proposed approaches can be applied to decorative and functional projections such as symbols, warning symbols, graphics, and patterns. The proposed methods could be used, for example, in the automotive, industrial, or consumer markets.

[0096] The proposed method allows for the formation of colored gradients using a white light source (e.g., an LED), and enables the change of projected color without changing the light source (therefore, standard modules can be used). For example, the proposed method makes it possible to project RGB colors using a white light source.

[0097] Therefore, according to the proposed method, a colored coating is applied only to a dedicated local area within each optical channel (e.g., within the substrate layer of the field lens), and the coating color and specific area may differ in each optical channel. As an example, the coating can be implemented via a colored resin (e.g., colored epoxy). A localized color coating within a single optical channel can produce a transition between color and white light, or between two different colors. Localized coatings allow for the use of more colors within a single optical channel, or color mixing across more optical channels. Localized coatings within a single optical channel allow for the projection of only one or more localized portions of a projection pattern / graphic / display colored with one or more colors.

[0098] In this specification, the term "control circuit" (or "processing circuit") may be understood to mean any technical entity that enables the handling of data. A control circuit may handle data depending on one or more specific functions it performs. In this specification, a control circuit may be understood to mean any type of circuit, such as any type of analog or digital circuit. Therefore, a control circuit may be an analog circuit, a digital circuit, a mixed-signal circuit, a logic circuit (e.g., a hardwired logic circuit or a programmable logic circuit), a microprocessor, a central processing unit (CPU), a graphics processing unit (GPU), a digital signal processor (DSP), a field programmable gate array (FPGA), an integrated circuit, an application-specific integrated circuit (ASIC), etc., or any combination thereof, and may include these.

[0099] In this specification, the term “exemplary” is used to mean “given as an example, example, or for illustrative purposes.” Any embodiment or design described using the term “exemplary” in this specification should not necessarily be construed as being preferable or advantageous to other embodiments or designs.

[0100] The phrases "at least one" and "one or more" mean that the set includes one or more numbers (e.g., 1, 2, 3, 4, ...). In this specification, "at least one" in relation to a group of elements means at least one element from a group consisting of multiple elements. For example, when the term "at least one" is used in relation to a group of elements in this specification, it means one of the enumerated elements, multiple of any one of the enumerated elements, multiple individual elements from the enumerated elements, or a selection of multiple individual elements from the enumerated elements.

[0101] All acronyms defined in the above description shall be retained in all claims included in this application.

[0102] Although the present invention has been illustrated and described in particular with reference to certain embodiments, it should be understood by those skilled in the art that various modifications can be made in form and detail without departing from the spirit and scope of the invention as defined by the appended claims. Accordingly, the scope of the invention is indicated by the appended claims, and all modifications that fall within the meaning and scope of the claims are intended to be encompassed. [Explanation of Symbols]

[0103] 100 Projection Optical Elements 102 optical channels 104 Field Lens 106 Imaging lens 108 Optical board 110 Projection Mask 112 Projection 114 Projection plane 200 multi-lens optical elements 202 optical channels 204 First lens 206 Second lens 208 First Multiple Lenses 210 Second set of lenses 212 Structured layer 214 Structured Features 216 Photocolored layer 218 Optical board 220 First dimension 222 Second dimension 224 Third dimension 230a First projection 230b Second projection 230c Third projection 300a First composition 300b Second composition 300c Third configuration 300d Fourth configuration 300e Fifth configuration 300f Sixth configuration 302 optical channels 302-1 First optical channel 302-2 Second optical channel 302-3 Third Optical Channel 304 lens 306 Structured layer 308 Structured Features 308-1 First Structural Feature 308-2 Second Structural Feature 308-3 Third Structural Feature 310 Photocolored layer 310-1 First photo-colored layer 310-2 Second photo-colored layer 310-3 Third photo-colored layer 310a First photo-colored layer 310b Second photo-colored layer 310c Third photo-colored layer 400a First composition 400b Second composition 400c Third configuration 400d Fourth configuration 402-1 First optical channel 402-2 Second optical channel 402-3 Third Optical Channel 402-4 Fourth Optical Channel 404 Imaging Lens 406 Structured layer 408-1 First Structural Feature 408-2 Second Structural Feature 408-3 Third Structural Feature 408-4 Fourth Structural Feature 410 Photocolored layer 410-1 First photochromic layer 410-2 Second photo-colored layer 418 Projection 420-1 First projection feature 420-2 Second projection feature 420-3 Third Projection Feature 420-4 The fourth projection feature 500a First composition 500b Second composition 502-1 First optical channel 502-2 Second optical channel 502-3 Third optical channel 502-4 Fourth Optical Channel 504 Imaging lens 506 Structured layer 508 Structured Features 510-1 First photochromic layer 510-2 Second photo-colored layer 510-3 Third photo-colored layer 510-4 The fourth photochromic layer 510-5 Fifth photochromic layer 510-6 The sixth photochromic layer 510-7 The seventh photo-colored layer 510-8 Eighth photochromic layer 510-1 First photochromic layer 510-2 Second photo-colored layer 510-3 Third photo-colored layer 510-4 The fourth photochromic layer 518 Projection 520 Projection Features 600 Projection System 602 Optical element 604 Light source 606 control circuit 610 Projection

Claims

1. A multi-lens optical element (200), A plurality of optical channels (202), each optical channel (202) defined by a corresponding field lens (204) and a corresponding imaging lens (206), A structured layer (212) is configured to define a partial projection projected through each of the optical channels (202) for each optical channel (202), and to obtain a resulting projection by superimposing the partial projections from the plurality of optical channels (202), The system comprises a photo-colored layer (216) disposed in at least one of the plurality of optical channels (202), The photo-colored layer (216) covers a first portion of the structured layer (212) corresponding to the at least one optical channel (202), but the remaining portion of the structured layer (212) corresponding to the at least one optical channel (202) is left without the photo-colored layer (216). The light-colored layer (216) is configured to impart a predetermined color to the light passing through it. Multi-lens optical element (200).

2. The structured layer (212) corresponding to the at least one optical channel (202) comprises a plurality of structured features (214) configured to define the partial projection, The photo-colored layer (216) covers one or more of the plurality of structured features (214), but is arranged such that the photo-colored layer (216) is not present on one or more of the other structured features (214). The multi-lens optical element (200) according to claim 1.

3. The structured layer (212) corresponding to the at least one optical channel (202) comprises one or more structured features (214) configured to define the partial projection, The photo-colored layer (216) is arranged such that it overlaps with a portion of one of the structured features (214), but the photo-colored layer (216) is not present on another portion of the structured feature (214). A multi-lens optical element (200) according to claim 1 or 2.

4. The light-colored layer (216) is a color filter configured to transmit light in a predetermined wavelength range and block light of wavelengths outside the predetermined wavelength range. A multi-lens optical element (200) according to any one of claims 1 to 3.

5. The at least one optical channel (202) further comprises a second photo-colored layer (310-2) disposed within it. The second photo-colored layer (310-2) is arranged to cover the second portion of the structured layer (212) corresponding to the at least one optical channel (202). A multi-lens optical element (200) according to any one of claims 1 to 4.

6. The second light-colored layer (310-2) is configured to impart a second predetermined color, different from the predetermined color defined by the light-colored layers (216, 310-1), to the light passing through the second light-colored layer (310-2), or The second light-coloring layer (310-2) is configured to impart a second predetermined color, equal to the predetermined color defined by the light-coloring layers (216, 310-1), to the light passing through the second light-coloring layer (310-2). The multi-lens optical element (200) according to claim 5.

7. The system further comprises a further photo-colored layer (310b) disposed in at least one further optical channel (202, 302-2) among the plurality of optical channels (202), The further photo-colored layer (310b) covers a further first portion of the structured layer (212, 306) corresponding to the at least one further optical channel (302-2), but the remaining further portion of the structured layer (212, 306) corresponding to the at least one further optical channel (202, 302-2) is left without the further photo-colored layer (310b). The further photo-colored layer (310b) is configured to impart an additional predetermined color to the light that passes through the further photo-colored layer (310b). A multi-lens optical element (200) according to any one of claims 1 to 6.

8. The predetermined color imparted by the light-colored layer (216, 310a) is the same as the further predetermined color imparted by the further light-colored layer (310b), or The predetermined color imparted by the light-colored layer (216, 310a) is different from the further predetermined color imparted by the further light-colored layer (310b). The multi-lens optical element (200) according to claim 7.

9. The structured layers (212, 306) define structured features (214, 308-1) corresponding to at least one optical channel (202, 302-1), and define further structured features (308-1) corresponding to a further optical channel (302-2). The aforementioned structured feature (308-1) and the further structured feature (308-1) correspond to the same projection feature in the resulting projection, The light-colored layers (216, 310a) are arranged to cover the first surface region of the structured feature (308-1) corresponding to the at least one optical channel (202, 302-1), The further photo-colored layer (310b) is arranged to cover a second surface region of the further structured feature (308-1) corresponding to the further optical channel (302-2), The first surface region is different from the second surface region. The multi-lens optical element (200) according to claim 7 or 8.

10. The light-colored layers (216, 310a) are arranged to completely cover the structured feature (308-1) corresponding to at least one optical channel (202, 302-1), The further photo-colored layer (310b) covers a portion of the further structural feature (308-1) corresponding to the further optical channel (302-2), but the other portion of the further structural feature (308-1) is left without the further photo-colored layer (310b). The multi-lens optical element (200) according to claim 9.

11. The first surface region and the second surface region define mutually complementary parts of the entire surface region of the structured feature (308-1). The multi-lens optical element (200) according to claim 9.

12. The multi-lens optical element (200) includes a first microlens array as a field lens (204), The multi-lens optical element (200) includes a second microlens array as an imaging lens (206). A multi-lens optical element (200) according to any one of claims 1 to 11.

13. The multi-lens optical element (200, 602) according to any one of claims 1 to 12, A light source (604) that illuminates the multi-lens optical elements (200, 602) to obtain the resulting projection by superimposing the partial projections defined by the structured layer (212) in the optical channel (202) of the multi-lens optical elements (200, 602), A projection system (600) equipped with [a specific feature].

14. The light source (604) is configured to emit white light. The projection system (600) according to claim 13.

15. The system further includes a control circuit (606) for controlling the emission of light from the light source (604), The control circuit (606) is configured to trigger the emission of light from the light source (604) in response to a predetermined vehicle-related trigger event. The projection system (600) according to claim 13 or 14.

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