Optical assembly

Abstract

An optical assembly comprising an optical body defining an optical axis, a housing that includes the optical body or is adapted at least to receive the optical body, a circuit board, and an electrically functional member electrically connected to the circuit board, wherein the electrically functional member comprises a heating element and / or an electronic component coupled to the circuit board. The heating element may include an optically transparent conductive layer applied to the optical body, for example, for removing water-based obstructions that may be attached thereto. The electronic component may be, for example, a light source and / or light receiver of a soil detection system for determining optical contamination attached to the optical body. Additionally, the circuit board may possibly comprise an opening or a notch or an indentation adapted for allowing the optical axis to pass through thereof. In this way, at least a portion of the opening, notch or indentation may be arranged therebetween a surface of the optical body and an image sensor in optical communication with the optical body. The optical assembly may be a lens assembly or a camera module comprising a protective cover.

Description

[0001] Optical assembly

[0002] The present disclosure relates to an optical assembly, such as for example a lens assembly for a camera module or a camera module comprising a protective cover for vehicle visual systems and many other applications. The present disclosure particularly concerns to said optical assemblies provided with an electrically functional member comprising at least one of a heating element and an electronic component such as a light source and / or a light receiver e.g., being part of a soil detection system. The light source and / or light receiver may be, for example, part of the soil detection system for determining optical contamination attached to an optically transparent portion of the optical body. The heating element includes an optically transparent conductive layer applied to an optically transparent portion of an optical body, for example, for removing water-based obstructions that may be attached thereto.

[0003] BACKGROUND

[0004] Camera modules are commonly employed in visual systems, for example in the automotive field, and in many other applications where images are to be acquired from surrounding environments, such as in motor vehicles. In the latter case, visual systems are commonly associated with rear view mirrors, backup cameras, front and rear-view cameras, top-view systems, etc. Visual systems include a camera module and an electronic control unit (ECU) typically fitted in vehicle.

[0005] Known camera modules comprise a lens assembly that includes an optical body, e.g., a lens body, with at least one optical element (i.e. lens element) fitted within a lens barrel or lens assembly holder. An image sensor is coupled to an electronics carrier, in optical communication with the optical body. The image sensor should be arranged in optical alignment with the optical body for proper image quality. However, it is not enough for the optical body and the image sensor to be arranged in optical alignment with each other for proper image quality. The optical body is required to be free of optical contamination or optical obstructions.

[0006] At least one portion of a surface of the lens body (or an optically transparent portion of a protective cover known in the automotive industry as glass cover) is arranged facing outwards the motor vehicle and is thus susceptible of being coated by external moisture from the air. This results in optical interference or contamination such that the image captured by the camera module is not sharp. In addition, external moisture may freeze when ambient temperature drops, such that a layer of ice may be created that adheres to the lens body (or the protective cover) at least partially blocking the captured image. Various attempts have been made in the art for removing water-based obstructions that may be attached to a lens surface (or a protective cover). For example, a heating device has been proposed to be provided in a camera module for the purpose of heating a lens surface (or a protective cover).

[0007] Camera modules known in the art comprise a lens assembly, and a camera housing that, in turn, typically includes a front housing and a back housing attached together. The front housing is adapted to receive the lens assembly. Known camera modules may further comprise a heating element for heating the lens assembly. Most known heating elements are configured as a non-transparent ring made of metal fixed to the inner surface of the front housing. As a result, a gap is undesirably created between the ring of the heating element and (an outer circumferential surface of) the lens assembly. This had caused problems and low heating efficiency in prior art camera modules. In order to obtain both high optical efficiency for good image quality and electrical conductivity for suitable lens heating effect, the gap between the heating element and the surface of the lens assembly should be as small as possible. However, reducing the gap is difficult to achieve in practice since it is formed due to manufacturing tolerances and assembly processes of the camera modules that cannot be avoided.

[0008] EP4123357, filed in the name of the present applicant, discloses a lens assembly comprising a lens body and a heating element. The heating element includes an optically transparent coating made of aluminium-doped zinc oxide (AZO) which is applied to at least one portion of the lens body for resistive heating of said at least one portion of the lens body as electric current flows through (Joule effect). It may advantageously cause the removal of any waterbased obstructions that may be attached to the lens body.

[0009] However, EP4123357 does not particularly deal with an optical assembly comprising a transparent heating element that can be mounted and assemble in a quick and cost-effective manner. Also, the present application differs from EP4123357 in that the lens barrel is particularly adapted to allow a conductor to pass through e.g., for providing electric power to the optically transparent coating as required. Further, the present disclosure discloses specific features of the optically transparent coating when comprises AZO for improving its heating performance.

[0010] With regards to the soil detection system, various attempts have been made in the art for determining optical obstructions that may be attached to a lens surface (or a protective cover). For example, computer implemented methods have been proposed to be provided in a camera module for the purpose of determining soil (i.e. optical obstructions) on a lens surface based on trained machine learning. Typically, soil detection systems based on trained machine learning do not provide high accuracy when optical contamination is substantially transparent, for example, containing water. Also, heavy computation may be required. A processor unit may be required to be thus more powerful.

[0011] EP3584567, filed in the name of the present applicant, discloses a soil detection system (i.e. a speckles detection system) for detecting optical obstructions, i.e. speckles, on a surface of a lens surface based on light and not on trained machine learning. The soil detection system proposed in EP3584567 comprises a light source and a light receiver, wherein the light source is configured to emit light towards the lens surface, the lens surface is configured to reflect the emitted light when optical obstructions, i.e. speckles, are located on the lens surface, and wherein the light receiver is configured to receive the reflected light such that speckles on the lens surface may be detected.

[0012] In short, the present optical assembly (e.g., lens assembly or camera module with a protective cover) overcomes the above and other deficiencies found in the prior art. Particularly, the present invention overcomes the drawback of how to provide electric power to the electrically functional member. Preferably, the electrically functional member being configured to determine and / or remove optical obstructions on an (exterior) optical surface.

[0013] SUMMARY

[0014] It is an object of the present invention to provide an optical assembly that supplies electric power to an electrically functional member. Said optical assembly may be mounted in a quick and cost-effective manner in mass-production environments. The electrically functional member may be a heating element and / or an electronic component such as a light operated device (e.g., a light source and / or a light receiver), for example, being part of a soil detection system. Thus, the light source and / or light receiver may be part of a soil detection system for determining optical contamination attached to a portion (e.g., an exterior optical surface) of the optical body. As explained further below, the heating element may include an optically transparent conductive layer applied to a portion of the optical body, for example, for removing water-based obstructions that may be attached thereto.

[0015] The present optical assembly (for vehicles) comprises an optical body and a housing that includes the optical body or is adapted at least to receive the optical body.

[0016] The optical assembly may be a lens assembly or a camera module provided with a protective cover (e.g., a camera cover glass). As explained further below, if the optical assembly is a lens assembly, the optical body is a lens body, and the housing is a lens barrel. Instead, if the optical assembly is a camera module comprising a protective cover, the optical body is an optically transparent portion of the protective cover, and the housing is a protective cover case. The protective cover may be provided for protecting the lens body (and other camera module components) against external factors such as shocks or impacts.

[0017] In the following, reference will be made to an optical axis. The optical axis corresponds, within the meaning of the present disclosure, to a straight line defined by the optical body passing through its geometrical center that creates a path along which the light is propagated through optical elements.

[0018] In use, the optical body is intended to be in optical communication with an image sensor so as to acquire a captured image from an exterior field of view of a vehicle extending at least outside the vehicle. The image sensor may not necessarily be part of the optical assembly. For example, it is possible that the image sensor is arranged out of the optical assembly when the optical assembly is a lens assembly.

[0019] The optical assembly may comprise an exterior optical surface and an internal optical surface spaced apart along the optical axis. The exterior optical surface may be an optical surface arranged closest to the exterior environment (i.e. the outermost surface of the optical body). In use, dirtiness, dust accumulation, mud splashes, water droplets, fog, condensation, frost, snow, ice sheets, etc. of the exterior environment may disadvantageously be present on the exterior optical surface. That is, such exterior optical surface may become dirty due to e.g. dust accumulation, mud splashes, malicious paintings, etc. As a result, image areas covered by contamination do not provide appropriate image data. Further, the internal optical surface may not be in (direct) contact to the exterior environment, for example, arranged closer to the image sensor than the exterior optical surface.

[0020] When the optical assembly is the camera module provided with the protective cover, the exterior optical surface is the (outermost) transparent portion of the protective cover. The internal optical surface may be a surface of the lens body. In this case, the exterior optical surface and the internal optical surface are spaced apart along the optical axis, for example, up to one or two centimetres such as 2 to 5 millimeters. Other distances of course are possible.

[0021] As explained, when the optical assembly is the lens assembly, then the optical body is the lens body. In this case, it is preferred that the optical body may comprise a plurality of optical elements arranged one after the other along the optical axis. The top end of the optical body may be a top end of a first optical element. The bottom end of the optical body may be a bottom end of a last optical element. In use, the first optical element may be the optical element arranged closest to the exterior environment. This is, the first optical element may be the optical element arranged furthest away from the image sensor. In fact, the first optical element may comprise the above-mentioned exterior optical surface. The last optical element may be the optical element arranged closest to the image sensor. In particular, the exterior optical surface is the top end (e.g., front surface) of the first optical element. The internal surface may be a surface of any other subsequent optical element, e.g., a front surface of a second optical element. In this case, the exterior optical surface and the internal optical surface are spaced apart along the optical axis, for example, up to five millimetres, preferably up to three millimeters. Other distances of course are possible.

[0022] As explained, the optical assembly may comprise the electrically functional member. Said electrically functional member may be configured to receive electric power so as to perform an active function with regards to optical contamination attached to the exterior surface.

[0023] The optical assembly, e.g., the electrically functional member, may comprise the heating element. The heating element may include an optically transparent coating that comprises an optically transparent conductive layer. The optically transparent coating may be applied to at least one portion of the optical body for resistive heating of said at least one portion of the optical body as electric current flows through the optically transparent conductive layer (Joule effect). It may advantageously cause the removal of any water-based obstructions that may be attached to the (exterior optical surface of the) optical body.

[0024] Therefore, the optically transparent coating is intended for resistive heating at least one portion of the optical body as electric current flows there through. This allows any water-based obstructions, such as, for example, at least one of fog, condensation, snow, and ice, that may be attached to the lens body, to be efficiently removed. Thus, it is envisaged that heat supplied by the heating element advantageously allows optical contamination such as dirtiness, dust accumulation, mud splashes, water droplets, fog, condensation, frost, snow, ice sheets, etc. present on the optical body to be easily removed, e.g., detached. Particularly, optical contamination that contains water.

[0025] The optically transparent conductive layer may be a homogeneous (e.g. continuous) layer but alternatively it may be a non-homogeneous (e.g. discontinuous) layer, as required. Furthermore, the optically transparent conductive layer that forms the heating element may partially or completely cover at least one portion of a surface of the lens body such as for example a front or external surface thereof. As used herein, the terms coating and layer refer to a thin sheet of material applied to a surface of at least one portion of the optical body such as the lens body or the optically transparent portion of the protective cover. In short, the thin sheet covers or lies over at least a portion of a surface of the optical body.

[0026] It is preferred that the optically transparent conductive layer comprises at least aluminium- doped zinc oxide (AZO). Although AZO is the most preferred conductive element, other suitable materials for the optically transparent conductive layer such as, for example, indium tin oxide (ITO), and any other transparent conducting metal oxide may be used.

[0027] If aluminium-doped zinc oxide material is employed for the optically transparent conductive layer, then the optically transparent conductive layer may specifically have a sheet resistance of 50 - 300 ohm / square. Further, in use, the optically transparent conductive layer may generate a heating output of 1000 - 10000 W / m2.

[0028] Further, the optically transparent conductive layer may have an electrical resistance of 30- 1500 ohms, preferably, 50-1500 ohms. Also, the optically transparent conductive layer may be 50-2500 nm thick, for example, 50-2000 nm, preferably, 50-1500 nm. The operating voltage may be between 5 volts and 40 volts, preferably, between 5 and 20 volts, being more preferred close to 10-15 volts.

[0029] The optical assembly may further comprise a circuit board. A purpose of the circuit board is to facilitate the supply of electric power to the electrically functional member such as the heating element, e.g., the optically transparent conductive layer. By the use of the circuit board, it is possible to provide electric power to the optically transparent coating (and / or the light source and / or light receiver or any other electronic component as explained further below) in an efficient manner. Particularly, the circuit board allows the optical assembly to be mounted and assembled in a quick and cost-effective manner. For example, electrical wires (i.e. electric cables) may be advantageously avoided for connecting an electric power source to the optically transparent conductive layer (and / or the light source and / or light receiver). Attaching electrical wires to the optically transparent conductive layer, for example by means of glue, may be time-consuming and prone to manufacturing errors in mass-production environments. Furthermore, the circuit board may have different purposes such as to receive the electronic component. In fact, the electronic component may be coupled to the circuit board. Attaching the electronic component to the circuit board may be easier than attaching it to a surface of the housing. Further, cables and wires may not particularly be configured to receive the electronic component. (Non-transparent ring) heaters of curse are not adapted for receiving the electronic component. The electronic component may be or comprise at least one of a temperature sensor, a resistor, the light source (emitter), and the light receiver as explained further below.

[0030] The circuit board may comprise an opening or a notch or an indentation. The opening, notch or indentation may be adapted for allowing the optical axis to pass through thereof. For example, the circuit board may comprise a C-shape, a U-shape or an O-shape portion. The opening, notch or indentation may be a cut that at least partially extends around the optical axis (e.g., light that passes through the optical body), for example, a cut that at least partially extends around a portion of the optical body. In use, as stated above, the optical body is in optical communication with the image sensor. The opening, notch or indentation is thus adapted for allowing the optical communication to pass through thereof. That is, (exterior) light may be allowed to pass through the optical body (e.g., the lens body and / or the optically transparent portion of the protective cover) to reach the image sensor. As a consequence, it may be possible to convert light (electromagnetic radiation) into image data of the surroundings of the optical assembly (e.g., of the external environment of a vehicle where the optical assembly is incorporated). In this way, the circuit board may advantageously be arranged as close as possible to the exterior optical surface or even abutting the optically transparent coating, in any case, without interfering with the optical communication.

[0031] It is preferred that at least a portion of the opening, notch or indentation is arranged therebetween a surface of the optical body and the image sensor. Preferably, at least a portion of the opening, notch or indentation is arranged between the exterior optical surface and the image sensor. More preferably, at least a portion of the opening, notch or indentation is arranged between the exterior optical surface and the internal optical surface. For example, that is between the first optical element and the second optical element, or alternatively, between the optically transparent portion of the protective cover and the first optical element.

[0032] Preferably, the circuit board may be arranged within the optical assembly at least partially extending around the optical axis (e.g., the optical body) and optionally between opposite ends of the optical body. Especially, when the optical assembly is the lens assembly. A portion of the optical body may be arranged extending through the circuit board. For this purpose, the opening (notch or indentation) of the circuit board may be a through opening which the optical body or a portion thereof is allowed to extend. This is, the circuit board is crossed by the optical body. It should be noted that, as explained, the optical body (e.g., the lens body) may comprise a plurality of optical elements arranged one after the other along the optical axis with a gap optionally provided therebetween. When the circuit board is provided in said gap, it is to be understood within the scope of the present invention that the circuit board is still at least partially extending around the optical body. In fact, said gap as well as the two or more optical elements may form part of the optical body, i.e. the lens body. In any case, it is preferred that the circuit board is arranged between two optical elements, e.g., the first and second optical elements, which is to be understood as the circuit board is still at least partially extending around the optical body.

[0033] Preferably, the circuit board may comprise a first portion that is at least partially contained in a plane that is substantially perpendicular to the optical axis. The first portion may have a planar geometry. It facilitates the attachment to the heating element or the light operated device, e.g., the light source and / or the light receiver. More preferably, the circuit board may be a flexible (printed) circuit board. It is even more preferred that that the circuit board further comprises a second portion. The second portion may optionally extend in a direction substantially parallel to the optical axis.

[0034] The circuit board may be suitable for carrying electronics for operation of the optical assembly. As stated, the image sensor may be (directly) attached, e.g., coupled, to an electronics carrier. The circuit board may comprise one or more printed circuit boards, PCBs, and optionally any other substrate or segments having (or not) electronics. The circuit board and the electronics carrier (the one supporting the image sensor) may preferably be different components. However, it may be possible to be integrated into a single (flexible) board. In this case, they would be the same component.

[0035] In any case, the electronics carrier may extend in a plane XY that is perpendicular to the optical axis. It is preferred that at least the first portion of the circuit board is arranged therebetween a portion of the optical body and the plane XY. Preferably, the first portion of the circuit board is arranged between a portion of the exterior optical surface and the plane XY. More preferably, the first portion of the circuit board is arranged between (a portion of) the exterior optical surface and the internal optical surface.

[0036] Preferably, the circuit board may be attached to the optical body, and / or is supported by the housing, and / or is sandwiched by the optical body and the housing, and / or is sandwiched by at least two optical surfaces of the optical body.

[0037] It is preferred the circuit board comprises a first main surface and a second main surface oppose (i.e. parallel) to each other. Said first and second main surfaces are connected through an edge, i.e. spaced apart from each other by the circuit board thickness.

[0038] With regards to the first portion of the circuit board, the first main surface may be closer to the exterior environment than the second main surface along the optical axis. Preferably, the second main surface may be closer to the image sensor than the first main surface. The first main surface may be or at least may comprise a planar surface arranged perpendicular to the optical axis. The first main surface may be configured to supply electric power to the electrically functional member. Preferably, the heating element is attached to the first main surface or electrically connected to the circuit board through an electrical connecting means arranged between the heating element and the first main surface. Further, the electronic component may be (directly) attached, i.e. coupled, to the first main surface. The second main surface of the circuit board may or at least comprise also be a planar surface arranged perpendicular to the optical axis. Preferably, the second main surface may be adapted to sit on a (first) coupling surface of the housing. Optionally, the second main surface may be attached to (the first coupling surface of) the housing by, for example, attaching means such as glue. In short, the first main surface of the circuit board may be attached to the heating element (e.g., abutting the first optical element) and / or the second main surface may be attached to the housing, (e.g., the first coupling surface of the housing). It includes being tightly sandwiched between the lens body and the housing and also being tightly sandwiched between two optical elements, e.g., the first and second optical elements.

[0039] The housing may enclose at least a portion of the optical body and the circuit board. Further, the housing may comprise the (first) coupling surface for receiving at least one of the circuit board and the attaching means for fixing the circuit board in the housing. Said attaching means may be an adhesive member such as glue. The attaching means may alternatively or additionally be welding means, clamping pressure means, such as an inner surface of the housing for sandwiching the circuit board, or fastening means, such as screws for attaching the circuit board to the housing. The housing may further comprise a second coupling surface for receiving the optical body. More preferably, the second coupling surface of the housing may be particularly adapted for attaching the optical body and the housing to each other.

[0040] As explained, it is possible that the housing has at least the (first) coupling surface to receive the circuit board. In use, said coupling surface may be arranged perpendicular to the optical axis. The circuit board may include a coupling surface to be fixed on the housing, e.g., to be seated on the coupling surface of the housing. Preferably, the second main surface of the circuit board includes said coupling surface. As stated, there may optionally be the adhesive means such as glue arranged between the coupling surface of the circuit board and the coupling surface of the housing. Also, at least a portion of the optical body is coated by the optically transparent coating that is supplied with electric power. In use, the electric power passes through the circuit board. In this way, the circuit board may receive the sandwiching (clamping) force from the lens body and the housing (or alternatively between the first and second optical elements). In fact, the circuit board may be arranged sandwiched by the optical body and the housing (or alternatively between the first and second optical elements). That is, the circuit board is pressed by the lens body and the coupling surface of the housing (or alternatively by the first and second optical elements). It allows the circuit board to be fixed without fasteners or any additional parts. As explained, the use of additional adhesive means may be advantageously employed. Same applies when the circuit board is pressed by the first optical element and the second optical element.

[0041] As stated, a portion of the circuit board may be arranged therebetween a surface of the optical body and the portion of the housing that supports the circuit board. Preferably, the circuit board may be supported by the housing at least on a continuous portion substantially perpendicular to the optical axis. More preferably, the circuit board may be arranged sandwiched by the optical body and the housing, or between two optical elements (e.g., the first and second optical elements).

[0042] The optical assembly may comprise the electrical connecting means for electrically connecting the circuit board and the electrically functional member, e.g., the heating element. In operation, the electrical connecting means may preferably be arranged therebetween the optically transparent coating and the first main surface of the circuit board. The electrical connecting means may be (an integral) part of or (directly) attached to the circuit board. In other words, the electrical connecting means may be the electric track(s) of the circuit board or an additional component (not being part of the circuit board), e.g., a metallic spring, arranged therebetween the optically transparent coating and the first main surface of the circuit board. The electrical connecting means contacts at least a portion (possible at least two different portions) of the optical body where the optically transparent coating is provided.

[0043] The electrical connecting means may preferably comprise a first connecting portion and a second connecting portion spaced apart to each other (along a direction perpendicular to the optical axis) such that, in use, the first and second connecting portions are adapted for providing electric current to the electrically functional member, e.g., the heating element. In other words, a first portion of the optically transparent coating is in (electrical) contact to the first connecting portion, wherein a second portion of the optically transparent coating is in (electrical) contact to the second connecting portion. It is even more preferred that the first and second connecting portions are arranged opposed to each other with respect to the optical axis or spaced as far as possible to each other (or at least not arranged next to each other). Arranged opposed may be understood as at least a portion of the second connecting portion is in front of a portion of the first connecting portion. If so, electric current flows through the heating element in an improved manner. In particular, the first and second connecting portions are angularly separated by more than 25° (and less than 335°). As shown in figure 3A, it is preferred to be angularly displaced by more than 90° (and less than 270°), for example, 180°. The circuit board may include at least a first and second electric tracks for supplying electric power to the heating element. The first and second electric tracks may comprise or electrical connect to the first and second connecting portions. That is, the first electric track comprises or electrically connects to the first connecting portion, wherein the second electric track comprises or electrically connects to the second connecting portion. The first connecting portion may electrically connect to the light source or to a first portion of the optically transparent coating. Similarly, the second connecting portion may electrically connect to the light receiver or to a second portion of the optically transparent coating. It is possible that the circuit board further comprises one or more additional electric tracks such as a third electric track or a ground line specially when the circuit board is electrically connected to both the heating element and the soil detection system.

[0044] Preferably, the second portion of the circuit board comprises a second portion of the first and / or second electric track(s) that is surrounded by an (electrical) isolation material being part of the (second portion of the) circuit board. It avoids said second portion of the electric tracks from coming into electrical contact with the housing (e.g., a passageway) which may comprise electrically conductive material, for example, metal such as aluminum.

[0045] Light reflexions play a critical role. Therefore, the optically transparent coating may further comprise at least one optically transparent back layer and at least one optically transparent front layer. The at least one optically transparent back layer is arranged between the lens body and the optically transparent conductive layer. The at least one optically transparent front layer is arranged on top of the optically transparent conductive layer. In one example, a number of optically transparent back layers may be combined with the optically transparent conductive layer and a single optically transparent front layer. Other different configurations are possible for the purposes of the present disclosure.

[0046] According to an advantageous example, the optically transparent back layer is an optical antireflective or anti-reflection layer suitable to eliminate or to at least reduce reflections from the lens body. In particular, the optically transparent back layer may comprise at least one high-refractive index layer and at least one low-refractive index layer.

[0047] As it is known in the field of optics, the refractive index (refraction index or index of refraction) is a dimensionless value that corresponds to the measure of bending of a light ray when passing through different media, that is, a measure of how much a path of light is bent, or refracted, when entering a material. For example, a refractive index of 1.333 for water means that light travels 1.333 times slower in water than in a vacuum. Increasing the refractive index corresponds to decreasing the speed of light in the material.

[0048] The high-refractive index layer may have a high refractive index. Further, the high-refractive index layer may preferably comprise a non-conductive and optically transparent metal material or an optically transparent metal oxide with low electrical conductivity such as titanium oxide (TiOx). The low-refractive index layer may have a low refractive index. Further, the low- refractive index layer may preferably comprise an optically transparent dielectric material such as silica (SiO2). Other materials for the high-refractive index layer and the low-refractive index layer are possible.

[0049] Those skilled in the art will readily recognize the meaning of high-refractive index and low- refractive index in the field of optics. Thus, within the meaning of the present disclosure, high- refractive index corresponds to a refractive index above 1.65, more preferably, between 1.7 and 2.9, and still more preferably, between 2.0 and 2.4. Low-refractive index corresponds to a refractive index below 1.65, preferably below 1.60, more preferably, between 1.3 and 1.65, and even more preferably, between 1 .4 and 1 .5.

[0050] For example, at 550 nm light wavelength the refractive index for SiO2 is 1.44-1.52, the refractive index for TiOx is 2.2-2.5, and the refractive index for AZO is 1.8-1.86.

[0051] In general, the optically transparent back layer of the lens assembly includes a number, preferably in pairs, of alternatingly disposed low- and high- refractive index layers to form the optically transparent back layer resulting in an efficient anti-reflective multi-layer coating.

[0052] The optical assembly (e.g., the electrically functional member) may further comprise the above-mentioned electronic component. The electronic component may be preferably coupled, e.g., attached, to the first main surface of the circuit board. It may be preferred that the electronic component is arranged between the first main surface of the circuit board and a portion of the optical body. The electronic component may be arranged below an optical element along the optical axis. It is more preferred the optical body comprises at least two optical elements between which the electronic component is arranged. It is preferred that the electronic component is arranged therebetween the first optical element and the second optical element.

[0053] The electrically functional member, e.g., the electronic component, may comprise a device (i.e. temperature sensor) configured to measure the temperature of the optical body and / or of the environment of the optical body. In this way, the heating element may act a temperature adjustment device thermally configured to adjust the temperature of the optical body to a predetermined temperature as a function of the measured temperature. In this way, thermal expansions and contractions due to temperature change are reduced or at least controlled.

[0054] Preferably, the housing, e.g., lens barrel, may comprise a passageway formed therein for receiving at least one portion of the circuit board. Further, the passageway may extend parallel to the optical axis. Preferably, the passageway may be arranged extending through a lateral side of the lens barrel.

[0055] When the housing is the lens barrel, the lens barrel and the electronics carrier may be attached to each other. It allows an improved alignment between the lens body and the image sensor. In use, it enables the use of an image sensor with greater number of pixels.

[0056] As explained, the present optical assembly (e.g., the electrically functional member) may comprise the heating element and / or the optical contamination detection function (i.e. soil detection system). In turn, the soil detection system may be provided by said electronic component when employs a light operated device, e.g., the light source and / or the light receiver. Said optical contamination detection function may be combined by and coordinated with the heating element and / or an automatic cleaning system. Said automatic cleaning system may include a heating system comprising the heating element. In any case, the electronic component, e.g., the light source, does not necessarily have to be limited to a soil detection system and can therefore be used for another application.

[0057] The present optical assembly is advantageously configured as one-single unit that may include said optical contamination detection system and said heating element that may be mounted, for example, to a camera module. The camera module may be connected to a control unit or controller. The camera module may be part of or connected to a vehicle visual system. Said optical assembly (either as a lens assembly or as a camera module with the protective cover) can be efficiently cleaned. As a result, optical contamination such as dirtiness, dust accumulation, mud splashes, water droplets, fog, condensation, frost, snow, ice sheets, etc. may be efficiently detected and removed by the same one-single unit defined by the present optical assembly. In any case, the camera module may still produce images of good quality. This is particular advantageous in an Advanced Driver Assistance Systems (ADAS).

[0058] For reasons of completeness, the following clauses are provided:

[0059] 1. A lens assembly (10’) comprising:

[0060] - a lens body (100’); - a lens barrel (200’) adapted at least to receive the lens body (100’);

[0061] - a conductor; and

[0062] - an electrically functional member electrically connected to the conductor.

[0063] 2. The lens assembly (10) of clause 1 , wherein the electrically functional member is a heating element (300) and / or an electronic component such as at least one of a temperature sensor, a resistor (R), a light source (301), and / or a light receiver (302). The heating element (300), the temperature sensor, the resistor (R), the light source (301), and the light receiver (302) may be as described throughout the present disclosure.

[0064] 3. The lens assembly (10) of clauses 2, wherein the heating element (300) includes an optically transparent coating (310) that comprises an optically transparent conductive layer (330), wherein the optically transparent coating (310) is applied to at least one portion of the lens body (100’) for resistive heating of said at least one portion of the lens body (100’) as electric current flows through the optically transparent conductive layer (330).

[0065] 4. The lens assembly (10) of clauses 1-3, wherein the lens barrel (200’) and an electronics carrier (580) are (directly) attached to each other, wherein an image sensor (850) is coupled to the electronics carrier (580), wherein the image sensor (850) is in optical communication with the lens body (100’). In this way, the image sensor (850) is surrounded I enclosed (at least) by the lens body (100’) and the electronics carrier (580). Foreign matter is prevented from coming into contact with the image sensor (850). Further, the optical communication is improved and the optical alignment between the lens assembly (10’) and the image sensor (850) is enhanced.

[0066] 5. The lens assembly (10) of clauses 1-4, wherein the lens barrel (200’) comprises a passageway (234) to allow the conductor to pass through. Optionally, the passageway (234) extends parallel to the optical axis (O).

[0067] 6. The lens assembly (10) of clauses 1-5, wherein the lens barrel comprises a first lens barrel (240), a second lens barrel (230), and an attaching member (220) adapted for attaching the first and second lens barrels (240, 230) to each other.

[0068] 7. The lens assembly (10) of clause 6, wherein the first lens barrel (240) and the second lens barrel (230) abut each other. Further, the attaching member (220) (at least partially) surrounds both the first and second lens barrels (240, 230). 8. The lens assembly (10) of clauses 6-7, wherein the first lens barrel (240) and the second lens barrel (230) are press fit together.

[0069] 9. The lens assembly (10) of clauses 6-8, wherein the second lens barrel (230) comprises an inwardly projection (235) arranged on an inner perimeter surface thereof. It prevents a rotational movement between the first and second lens barrels (240, 230).

[0070] 10. The lens assembly (10) of clauses 6-9, wherein the second lens barrel (230) is attached to the electronics carrier (580), wherein the first lens barrel (240) comprises a first passageway (2341), wherein the second lens barrel (230) comprises a second passageway (2342), wherein the first and second passageways (2341 , 2342) are aligned with each other, preferably along a direction parallel to the optical axis (O), optionally, forming a continuous passageway (234).

[0071] 11. The lens assembly (10) of clauses 5-10, wherein the lens barrel comprises a lateral side that gives access (2340) to the passageway (234). Particularly, the second lens barrel (230) comprises the lateral side that gives access (2340) to the passageway (234).

[0072] 12. The lens assembly (10) of clauses 1-11 , wherein the conductor is a circuit board (500). The circuit board (500) may be as described throughout the present disclosure. It is possible the conductor is an electric cable or wire. It is even possible that the conductor is an optical fiber to guide light when the soil detection system is employed. The conductor may be any elongated body capable of guiding electric current (power supply) or light from a first end to a second end. The first end may be located at or near a power source or a light source or a light receiver. The second end may be located at or near the optical body (e.g., the first optical element) or attached to the heating element.

[0073] 13. A camera module (900) comprising: the lens assembly (10’) of clauses 1-12; and a camera housing (400); wherein the lens assembly (10’) comprises a first lens flange (231) projecting outwardly to the optical axis (O), and wherein the camera housing (400) comprises a first housing flange (411) projecting inwardly to the optical axis (O) in which its inner surface abuts (a top surface of) the first lens flange (231). In the camera module assembling process, the first housing flange (411) acts as a stopper when abutting the first lens flange (231) after moving the camera housing (400) and the lens assembly (10’) to each other. Or vice-versa, the first lens flange (231) acts as a stopper when abutting the first housing flange (411) after moving the camera housing (400) and the lens assembly (10’) to each other. It should be noted that the (lens) flanges (231 , 232, 233) of the present disclosure may be continuous or discontinuous.

[0074] 14. The camera module (900) of clause 13, wherein the first lens flange (231) comprises a positioning portion (2310) for (directly) attaching the (second) lens barrel (200’, 230) and the electronics carrier (580) to each other.

[0075] 15. The camera module (900) of clauses 13-14, wherein the lens assembly (10’) comprises a second lens flange (232) projecting outwardly to the optical axis (O) and spaced apart in the direction of the optical axis (O) from the first lens flange (231), optionally the camera housing (400) comprises a second housing flange (430), and wherein an attaching member (440) such as adhesive means is provided in the second lens flange (232) and / or a portion of the lateral side of the camera housing (400) to prevent foreign matter from entering inside the camera module (900). It should be noted that the camera housing (400) comprises an aperture where the lens assembly (10’) is at least partially arranged through. Said aperture on a front surface of the camera housing (400) may the lateral side of the camera housing (400).

[0076] 16. The camera module (900) of clauses 13-15, wherein a lateral side of the camera housing (400) surrounds the lateral side of the lens barrel (200”) that gives access (2340) to the passageway (234). Particularly, the lateral side of the camera housing (400) between the first and second housing flanges surrounds the lateral side of the second lens barrel (230) that gives access (2340) to the passageway (234).

[0077] 17. The camera module (900) of clauses 13-16, wherein the camera housing (400) comprises a first housing part (410) and a second housing part (420) attached to each other defining therein an interior space. The first housing part (410) is a front housing and the second housing part (420) is a back housing. The camera housing (400) is made of electrically conductive material such as metal, for example, comprising aluminium. It allows to reduce the electromagnetic noise (EMC). The first housing part (410) comprises the first and second housing flanges (411 , 430).

[0078] The subject-matter of the above clauses may be combined with other features disclosed in the present application and vice versa, the features disclosed in the present application may specifically be combined with the subject-matter of the above clauses.

[0079] BRIEF DESCRIPTION OF THE DRAWINGS

[0080] Non-limiting examples of the present disclosure will be described in the following, with reference to the appended drawings. In the drawings: Figure 1 is a sectional elevation view of an example of a lens assembly provided with optical elements in which a circuit board is arranged therebetween two optical elements, the circuit board being in electrical connection to a heating element comprising an optically transparent conductive layer applied the one of the two optical elements;

[0081] Figure 2 is an exploded view of the lens assembly;

[0082] Figure 3A is a plant view of an example of the circuit board configured to provide electric current to the heating element;

[0083] Figure 3B is a plant view of an example of the circuit board configured to provide electric current to an electronic component such as a light source and / or a light receiver, the electronic component being coupled to the circuit board;

[0084] Figure 4 is a sectional elevation view of an optical subassembly formed by the lens assembly and an electronics carrier being attached to each other, wherein an image sensor is coupled to the electronics carrier being in optical communication with the lens assembly;

[0085] Figure 5 is a camera module that comprises the optical subassembly of figure 4;

[0086] Figures 6A and 6B is a front view and a perspective view respectively of a lens barrel of the lens assembly;

[0087] Figures 7, 8 and 9 are views of the lens barrel;

[0088] Figure 10 is a view of the lens assembly;

[0089] Figure 11 is a view of the lens barrel showing the interference fit between a first and second lens barrels;

[0090] Figures 12 and 13 are cross-sectional views of a lens body and a heating element comprising an optically transparent coating, wherein a portion of the lens body is coated with the optically transparent coating;

[0091] Figure 14 is a schematic cross-sectional illustration of the optically transparent coating illustrating different layers thereof;

[0092] Figure 15 is a graph indicating the normalized reflectance values of the visible light at different wavelength when passing through the optically transparent coating and the lens body;

[0093] Figures 16A and 16B are views of an example of a camera module including the lens assembly and further comprising a protective cover; and

[0094] Figures 17A and 17B are views showing a soil detection system comprising a light source and a light receiver coupled to the circuit board.

[0095] DETAILED DESCRIPTION OF EXAMPLES

[0096] Examples of an optical assembly 10 are disclosed herein and shown in the figures of the drawings. The optical assembly 10 comprises an optical body 100 and a housing 200 adapted at least to receive the optical body 100. It further comprises a circuit board 500 and a heating element 300 electrically connected to the circuit board 500. Additionally or alternatively to the heating element 300, the optical assembly 10 further comprises an electronic component such as a light source 301 and / or a light receiver 302 coupled to the circuit board 500 (see figures 3B, 17A and 17B). The electronic component will be explained in detail further below.

[0097] The present optical assembly 10 may be a lens assembly 10’ as shown in figures 1-13, or a camera module 900 comprising a protective cover 990 as shown in figures 16A and 16B. When the optical assembly 10 is the lens assembly 10’, the housing 200 is a lens barrel 200’ and the optical body 100 is a lens body 100’. When the optical assembly 10 is the camera module 900 with the protective cover 990, the housing 200 is a protective cover case 200”.

[0098] As shown in figure 5, an aspect of the present disclosure is a camera module 900 comprising the lens assembly 10’. Therefore, the lens assembly 10’ is mounted to the camera module 900. In turn, the camera module 900 may be part of a vehicle visual system incorporated into a motor vehicle.

[0099] The camera module 900 shown in figures 5, 16A and 16B may be fitted for example to a rearview mirror for capturing images from outside a motor vehicle. Other applications of course are not ruled out such as surrounding view systems, back-up cameras for parking, or front and rear-view cameras.

[0100] Lens

[0101] In the shown examples disclosed in figures 1-13, the optical body 100 is the lens body 100’ when the optical assembly 10 is the lens assembly 10’. Figure 1 particularly shows that the lens body 100’ is provided with two or more optical elements (i.e. lens elements) 110, 120, 130, 140, 150. In particular, the lens body 100’ comprises five optical elements 110, 120, 130, 140, 150, arranged one after the other along the direction of the above-mentioned optical axis O. Other different number of optical elements 110, 120, 130, 140, 150 of course may be provided. Each of said optical elements 110, 120, 130, 140, 150 is a (glass) lens element.

[0102] Said optical elements 110, 120, 130, 140, 150 may or may not be in direct contact with each other. For example, the optical elements 110, 120, 130, 140, 150 may be arranged spaced apart a predetermined distance along the optical axis O. Said predetermined distance or gap may be part of the lens body 100’. The plurality of optical elements 110, 120, 130, 140, 150 are received within the lens barrel 200’ that will be described further below. In use, the first optical element 110 is the optical element arranged furthest from the image sensor 850 (see figure 4). Also, the first optical element 110 is arranged closest to the exterior environment. In fact, the first optical element 110 may comprise an exterior optical surface 1110. Furthermore, the second optical element 120 is arranged between the first optical element 110 and the electronics carrier 580 (see figure 4) along the optical axis O. A last optical element 150 is arranged closest to the image sensor 850 (see figure 4).

[0103] The optical assembly 10, e.g., the lens assembly 10’, comprises the exterior optical surface 1110 and an internal optical surface spaced apart along the optical axis. The exterior optical surface 1110 is in contact to the exterior environment. When the optical assembly 10 is the lens assembly 10’, the exterior optical surface 1110 is the front surface 111 of the lens body 100’ (see figure 13). When the optical assembly 10 is the camera module 900 with the protective cover 990, the exterior optical surface 1110 is the exterior surface of an optically transparent portion 100” of the protective cover 990 (see figure 16A). In any case, the internal optical surface is an optically transparent surface not in contact to the exterior environment. In use, the internal optical surface is closer to image sensor 850 than the exterior optical surface 1110 along the optical axis O. When the optical assembly 10 is the lens assembly 10, the interior optical surface is a surface of the optical elements 120, 130, 140, 150 such as 111b (indicated in figure 4), for example, a front surface 121 of the second optical element 120 (indicated in figure 1). As shown in figures 16A and 16B, when the optical assembly 10 is the camera module 900 with the protective cover 990, the internal optical surface is a surface of the lens body 100’ such as the front surface 111 of the lens body 100’.

[0104] Figure 1 shows that the lens body 100’ has a top end 111a and a and bottom end 111b. The optical body 100, e.g., the lens body 100’, extends from said top and bottom ends 111a, 111 b. The top end 111a of the optical body 100 corresponds to a top end of the first optical element 110. The bottom end 111 b of the lens body 100 corresponds to a bottom end of the last optical element 150.

[0105] Figure 17B schematically illustrates the optical body 100, e.g., lens body 100’, including a peripheral surface connecting the top end 111a and the bottom end 111 b. Said peripheral surface has a first diameter located at or near the top end 111a and a second diameter located closer to the bottom end 111 b than the first diameter and at least between the top end 111a and the bottom end 111b. The first diameter is greater than the second diameter. In other words, the diameter of the first optical element 110 is larger than a diameter of at least one of the subsequent optical elements 120, 130, 140, 150. The lens barrel 200’ to be described below may be at least partially arranged around the second diameter.

[0106] The lens body 100 is substantially circular in shape, i.e., the optical body 100 is substantially circular in cross-section. However, other shapes may be possible. In any case, the plurality of optical elements 110, 120, 130, 140, 150 may be coupled to an inner surface of the housing 200, e.g., the lens barrel 200’.

[0107] As shown in figure 13 of the drawings, a first optical element 110 has a back surface comprising a first part 113 which is flat and substantially perpendicular to the optical axis O. Further, the back surface may also comprise a second part 114 which is convex and curves outwards, away from the imager 850 (shown in figures 4 and 5). The optical element 110 has side surfaces 112 extending into the front surface 111 and the back surface 113, 114. The optical axis O does not pass through the side surfaces 112 of the first lens element 110a. The side surfaces 112 of the first optical element 110 may include a plurality of lateral surfaces where the optical axis may not pass through.

[0108] The second part 114 of the back surface and the front surface 111 of the first optical element 110 are surfaces which the lens optical axis O passes through. The side surfaces 112 of the first optical element 110 include at least one lateral surface that is substantially parallel to the optical axis O.

[0109] The first part 113 of the back surface of the first optical element 110 may include a surface arranged at least substantially perpendicular to the optical axis O with the optical axis O not passing there through.

[0110] In a non-limiting example, a surface area of the front surface 111 is within a preferred range of 0.5-10 cm2, for example, of 2 cm2.

[0111] Figures 4 and 5 show that, in use, the optical body 100 is in optical communication with the image sensor 850 along the optical axis O so as to acquire a captured image from an exterior field of view of a motor vehicle extending at least outside the vehicle. Alignment of the optical elements 110, 120, 130, 140, 150 along the optical axis O allows light to be guided from one optical element to another so as to reach the image sensor 850 properly. That is, light coming from the outside of the lens body 100’ is properly guided through the different optical elements 110, 120, 130, 140, 150 until reaching the image sensor 850 where it is converted into a signal that will form an image to be displayed on a screen. The image sensor 850 is connected, e.g., coupled, on the electronics carrier 580, in particular, on its top face 581. Barrel

[0112] Figures 1-2 and 4-12 disclose that the housing 200 is particularly a lens barrel 200’. The lens barrel 200’ is a tube-shaped member encasing therein the plurality of optical elements 110, 120,130, 150, 150. The lens barrel 200’ is thus configured and sized to position and align the optical elements 110, 120,130, 150, 150.

[0113] Figure 4 shows the lens barrel 200’ and the electronics carrier 580 being attached to each other. In this way, a(n) (optical) sub-assembly is formed comprising the lens body 100’, the lens barrel 200’, the electronics carrier 580, and the image sensor 858.

[0114] In the shown examples, the lens barrel 200’ comprises a continuous or discontinuous first lens flange 231 projecting outwardly to the optical axis O, e.g., radially outwards to the optical axis O. It allows an improved attachment between the lens barrel 200’ and the electronics carrier 580. Particularly, greater stability of the attachment is achieved. The attachment of the lens barrel 200’ and the electronics carrier 580 allows an enhanced optical communication (less misalignments in mass-production environments). In practice, it allows the use of more precise image sensors (higher number of pixels). Therefore, the captured image is of higher quality. Also, reduction of material of the lens barrel 200’ may be obtained since perimeter (lateral) walls of the lens barrel 200’ may be thinner.

[0115] Further, the lens barrel 200’ comprises a passageway 234 to allow a conductor to pass through. As shown, the conductor is in particular a circuit board 500 that will be explained in detail further below.

[0116] Figures 1 , 2, 4, 5 and 10 show that the lens barrel 200’ comprises a first lens barrel 240, a second lens barrel 230, and an attaching member 220 adapted for attaching the first and second lens barrels 240, 230 to each other. Figure 9 shows that the first lens barrel 240 is an internal barrel. The second barrel 230 is an external barrel. Also, the first lens barrel 240 and the second lens barrel 230 abut each other (see figures 1 ,2,4 ,5 and 10). In particular, figure 10 shows a top surface 238 of the second lens barrel 230 that directly contacts a surface of the first lens barrel 240.

[0117] As shown, the first lens barrel 240 and the second lens barrel 230 are press fit together. Further, figure 11 shows that the second lens barrel 230 comprises (three) inwardly projections 235 arranged on an inner perimeter surface thereof. It prevents a rotational movement between the first and second lens barrel 240, 230. Figure 7 shows protrusions 243 and 243b on an outer perimeter surface of the first lens barrel 240. In use, protrusions 243 and 243b abut the inner perimeter surface of the second lens barrel 230. It allows to reduce a thickness of a perimeter wall of the first lens barrel 240 while preventing a pivoting movement between the first and second lens barrel 240, 230.

[0118] In particular, figure 4 shows that the second lens barrel 230 is attached to the electronics carrier 580. As indicated in figure 10, the first lens barrel 240 comprises a first passageway 2341. Also, the second lens barrel 230 comprises a second passageway 2342. In use, the first and second passageways 2341 , 2342 are aligned with each other along a direction parallel to the optical axis O. Therefore, the passageway 234 is formed as a continuous passageway.

[0119] As shown, the lens barrel 200’ comprises a lateral side that gives access 2340 to the passageway 234. Particularly, figures 1 , 4 and 10 show the second lens barrel 230 comprises said lateral side that gives access 2340 to the passageway 234. It prevents the conductor (e.g., the circuit board 500) to reach the electronics carrier 580 at a location near the image sensor 850.

[0120] Heating element

[0121] The optical assembly 10, e.g., the electrically functional member, may further comprise a heating element 300. The heating element 300 includes a conductive body for resistive heating of at least a portion of the optical body 100 as electric current flows through. Figure 14 schematically illustrates that the conductive body includes an optically transparent coating 310 arranged on the optical body 100 with an optically transparent conductive layer 330. It is to be noted that the optically transparent coating 310 may be a surface coating applied to the optical body 100 or it may be formed integral therewith. Alternatively, the optically transparent coating 310 may be provided close to the optical body 100 but not in contact with it. In shown examples, the optically transparent coating 310 is in direct contact with at least one portion of the optical body 100, e.g., the first optical element 110.

[0122] The optically transparent coating 310 is suitable for resistive heating of at least one portion of the optical body 100, e.g., the lens body 100’, as electric current flows through. Thus, as an electric current flows through the heating element 300, optical contamination S such as dirtiness, dust accumulation, mud splashes, water droplets, frost, fog, condensation, snow, ice sheets, etc. that may be attached to the exterior optical surface 1110 of the optical body 100 can be efficiently removed from the optical body 100 (without affecting an optical performance of the optical assembly 100). The optically transparent coating 310 may be of a homogeneous and / or continuous or non- homogeneous and / or discontinuous nature depending on optical and heating requirements. The optically transparent coating 310 further comprises an optically transparent conductive layer 330, as stated above, which may be also of a homogeneous and / or continuous or non- homogeneous and / or discontinuous nature depending on optical and heating requirements.

[0123] The optically transparent coating 310 may be directly applied to the lens body 100’, e.g., to any surface of the first optical element 110. In particular, as shown in figures 12 and 13, the optically transparent coating 310 completely or partially covers the back surface 113, 114 the lens body 100’. Optionally, the optically transparent coating 310 may also be applied on the side surfaces 112 of the lens body 100’. According to an example not shown, the optically transparent coating 310 may be directly applied to the front surface 111 and optionally at least on a portion of the side surfaces 112. A drawback to apply the optically transparent coating 310 on the front surface 111 is that may be damaged due to the external environment. Alternatively, figure 16A shows that optically transparent coating 310 is directly applied to an optically transparent portion of the protective cover 990 that will be explained further below.

[0124] In examples, the optically transparent conductive layer 330 of the optically transparent coating 310 comprises at least aluminum-doped zinc oxide (AZO). In one example, the optically transparent coating 310 has an electrical resistance of 50-1500 ohms, providing thus a good tradeoff between a fast-heating process and safety. It may be applied to a curved surface of the first optical element 110. The optically transparent coating 310 has a thickness of between 50nm and 2000nm. The thickness of the transparent conductive AZO layer 330 has a significant impact on the Joule effect for efficiently heating of the optical body 100. The thickness of the AZO layer 330 of the optically transparent coating 310 is large enough for a low electrical resistance and short heating time of the optical body 100. On the other hand, the thickness of the transparent conductive AZO layer 330 is small enough for low reflectance of the optical body 100 for good image quality and safety.

[0125] The optically transparent coating 310 is critically important for a good compromise between the greatest optical transparency for enhanced image acquisition and optimum electrical conductivity for lens heating. As a result, enough high power can be supplied suitably to heat up the optical body 100 quickly, for example to a predefined temperature. Said predefined temperature allows ice adhered to the optical body 100 to be melted, but is not too high (e.g., below 60°C) in order not to compromise safety for avoiding burns and damages if someone touches the optical assembly. A good balance between light transmission (low reflectance), heating speed, and safety is provided. An optically transparent back layer 320 may be provided to eliminate or to at least reduce reflections from the surface of the optical body 100 due to heating action of current flowing therethrough.

[0126] Figure 14 shows that the optically transparent back layer 320 in turn comprises a high- refractive index layer 321 and a low-refractive index layer 322 that is directly applied to the front surface 111 of the first lens element 110. The transparent conductive AZO layer 330 is directly applied to said low-refractive index layer 322.

[0127] The high-refractive index layer 321 has a refractive index of above 1.65. The high-refractive index layer 321 is preferably between 1.7 and 2.9, and still more preferably, between 2.0 and 2.4. The high-refractive index layer 321 is formed of any metal oxide which, according to the example described above, is titanium oxide, TiOx.

[0128] As also shown in figure 14, the low-refractive index layer 322 is formed of silica, SiO2, with a refractive index of below 1.65. The low-refractive index layer 322 is preferably below 1.60, and still more preferably, between 1.3 and 1.65, and even more preferably, between 1.4 and 1.5. The low-refractive index layer 322 is directly applied onto the high-refractive index layer 321 .

[0129] One or more of the high- and low- refractive index layers 321 , 322 of the optically transparent back layer 320 and the optically transparent conductive layer 330 that make up the optically transparent coating 310 are applied on the lens body 100’, e.g., the first optical element 110, by physical vapor deposition (PVD).

[0130] As already explained above, the refractive index (refraction index or index of refraction) is known to be a dimensionless value that corresponds to the measure of bending of a light ray when passing through different media, that is, a measure of how much a path of light is bent, or refracted, when entering a material. For example, a refractive index of 1.333 for water means that light travels 1 .333 times slower in water than in a vacuum. Increasing the refractive index corresponds to decreasing the speed of light in the material.

[0131] On the other hand, reflectance is also known in the field of optics to be the change in direction of an electromagnetic wavefront at an interface between two different media so that the wavefront returns into the medium from which it originated. Generally, it is accepted that optical materials such as glass may have an approximate reflectance of 4% per interface. Hence, an optical material with two interfaces may have a reflectance of around 8%. It is preferred that the low refractive index layer 322 is thicker than the high refractive index layer 321 . In particular, the low refractive index layer 322 is at least twice as thick as the high refractive index layer 321. In particular, the low refractive index layer 322 is between 1.2 and 15 times thicker than the high refractive index layer 321. More in particular, the low refractive index layer 322 is between 1.5 and 10 times thicker than the high refractive index layer 321 and still more particular, between 2 and 5 times.

[0132] The refractive index of the front layer 340 is particularly below 1.65, more in particular, below 1 .60, and still more in particular, between 1 .3 and 1 .65, and even more particular, between 1.4 and 1.5. The front layer 340 is directly applied onto the optically transparent conductive layer 330 as shown in figure 1 .

[0133] It is preferred that the AZO layer 330 is thicker than the high refractive index layer 321 and the low refractive index layer 322. In particular, it is preferred that the AZO layer 330 is at least twice as thick as the optically transparent back layer 320. For example, the AZO layer 330 may be at least twice as thick as the low refractive index layer 322. More in particular, the AZO layer 330 is at least five times thicker than the high refractive index layer 321. In particular, the AZO layer 330 is between 2 and 20 times thicker than the low refractive index layer 322. More in particular, between 2 and 15 times and, still more particular, between 2.5 and 8.5 times thicker than the low refractive index layer 322.

[0134] It is preferred that the front layer 340 is thicker than the high refractive index layer 321. In particular, the front layer 340 may be at least twice as thick as the optically transparent back layer 320. Further, the front layer 340 is thicker than the low refractive index layer 322. In particular, the front layer 340 is at least twice as thick as the high refractive index layer 321. More in particular, the front layer 340 is at least three times thicker than the low refractive index layer 322. In particular, the front layer 340 is between 2 and 6 times thicker than the low refractive index layer 322. More in particular, between 2 and 5 times and, still more particular, between 2.5 and 4 times thicker than the low refractive index layer 322.

[0135] Figure 15 is a graph showing the normalized reflectance of the lens body 100’ with the front and back surfaces 111 , 113, 114 coated with the optically transparent coating 310 at different values of wavelength of light according to a non-limiting example.

[0136] In view of the experimental results, the following thicknesses for the optically transparent coating 310 are preferred for the visible range of 430 nm-700 nm:

[0137] - transparent conductive (AZO) layer (330): 50-2000 nm, particularly, 50-350 nm; - low-refractive index (SiCh) layer (321): 9-90 nm, particularly, 20-40 nm;

[0138] - high-refractive index (TiOx) layer (322): 5-15 nm, particularly, 5-10 nm; and

[0139] - low-refractive index (SiCh) layer (340): 9-90 nm, particularly, 20-40 nm.

[0140] The combinations of thicknesses of layers 321 , 322, 330, 340 shown in figure 14 have been shown to provide a good optical performance in terms of low reflectance. Figure 15 shows that the reflectance is below 4% and even below 2% for the most part of the visible electromagnetic spectrum by the human eye.

[0141] If the lens body 100’ is not coated with the optically transparent coating 310, an unwanted reflection of light may be reflected by a surface of the lens body 100’ which may be approximate at 4%. Further, anti reflection coatings are well known and are extensively used on the surfaces of optical element e.g. lens elements or covers to reduce unwanted reflection, however, known anti refl ection coatings do not include any conductive transparent layer 330 such as AZO layer 330. The tradeoff between optical transparency, electrical conductivity and safety cannot be achieved but simply adding an AZO layer to a known anti refl ection coating. It is desirable that the optically transparent coating 310 of the present disclosure reduces the surface reflectance to a low value over an extended spectral region so as to maintain proper color balance while being highly efficient.

[0142] The above values ensure a reflectance of the lens body 100’ with the optically transparent coating 310 below 0,08 as shown in figure 15. These values provide a good indication for the above-mentioned compromise between the greatest optical transparency and optimum electrical conductivity for the optically transparent coating 310 once arranged on the lens body 100’. When designing a particular coating of the present invention with the above-mentioned four layers, it is to be taken into account that it has eight degrees of freedom (four thicknesses and four refractive indices) so there may be different options within the same general inventive concept. It has been found that thinner layers behave better with wavelength (their reflection varies less) but for the AZO layer 330, for example, a greater thickness is needed to have good electrical conductivity so as to achieve the desired power density. Furthermore, the more extreme the refractive indices (higher the high or lower the low), the smaller thicknesses may be used, as in the case of TiOx compared to what happens with SiO2.

[0143] In the example disclosed herein, the power supply 400 provides electric current. The electric current that goes through the heater element is 5-40V, particularly, 5-20V, more particularly, approximately 5-12 V. As a result, a rapid increase in temperature in the lens body 100’ from 0 °C to 10 °C by the Joule effect in 30 s is obtained. For this purpose, the optically transparent conductive layer 330 has a sheet resistance of 50 - 300 ohm / square. In use, it generates a heating output of 1000 - 10000 W / m2, presenting a good tradeoff between a fast-heating process and safety.

[0144] Circuit board

[0145] Figures 1-4 show the lens assembly 10’ comprising a circuit board 500. Figures 16A and 16B show that the camera module 900 with the protective cover 990 also comprises the circuit board 500. A purpose of the circuit board 500 is to facilitate the supply of electric power to the AZO layer 330 (and to the electronic component such as the light source). By the use of the circuit board 500, it is possible to provide electric power to the optically transparent coating 310 (and / or the electronic component) in an efficient manner. Particularly, the circuit board 500 allows the optical assembly 10 to be mounted and assemble in a quick and cost-effective manner.

[0146] As indicated in figure 4, the circuit board 500 comprises a first main surface 501 opposed to a second main surface 502 separated by its thickness. The first main surface 501 is connected to the second main surface 502 through an edge. In use, the first main surface 501 is closer to the exterior environment than the second main surface 502 along the optical axis O. As shown, the second main surface 502 is closer to the image sensor 850 than the first main surface 501 .

[0147] As shown, the circuit board 500 comprises the first portion 510 contained in a plane that is substantially perpendicular to the optical axis O. Further, the circuit board 500 is a flexible printed circuit board. Also, the circuit board 500 comprises a second portion 520 extending in a direction substantially parallel to an optical axis O.

[0148] Figures 3A shows that the circuit board 500 comprises an opening D1 or a notch or an indentation. Further, the lens body 110 is in optical communication with the image sensor 850 (see figures 4 and 5). The opening D1 , notch or indentation is a cut that allows light that passes through the lens body 110 to pass also through the circuit board 500 so as to reach the image sensor 850. The opening D1 , notch or indentation is adapted thus for allowing the optical communication to pass through thereof. That is, exterior light may be allowed to pass through the lens body 100’ to reach the image sensor 850. In this way, at least a portion of the circuit board 500 at least partially extends around the light that passes through the lens body 100’. For example, the opening D1 , notch or indentation is a cut allowing the circuit board 500 at least partially extending around a portion of the lens body 100’. As a consequence, it may be possible to convert light into image data of the external environment of a vehicle where the lens assembly 10’ is incorporated. In this way, the circuit board 500 is advantageously arranged as close as possible to the exterior optical surface 1110 (or abutting the optically transparent coating 310) without interfering with the optical communication.

[0149] As shown, at least a portion of the opening D1 , notch or indentation is arranged therebetween a surface of the lens body 100’ and the image sensor 850. In particular, at least a portion of the opening D1 , notch or indentation is arranged therebetween the front surface 111 and the image sensor 850, for example, therebetween a back surface 113, 114 and the image sensor 850. More in particular, a portion of the opening D1 , notch or indentation is arranged therebetween the first optical element 110 and the image sensor 850.

[0150] More in particular, at least a portion of the opening D1 , notch or indentation is arranged between the above-mentioned exterior optical surface 1110 and the internal optical surface.

[0151] As shown, the circuit board 500 is arranged within the lens barrel 200’. That is, the lens barrel 200’ encloses at least a portion of the circuit board 500. Further, the circuit board 500 at least partially extends around the lens body 100’ and between opposite ends 111a, 111 b of the lens body. That is, a portion of the lens body 100’ is arranged extending through the circuit board 500. For this purpose, the circuit board 500 comprises a through opening D1 which the lens body 100’ or a portion thereof is allowed to extend. In other words, the circuit board 500 is crossed by the lens body 110.

[0152] Figures 1 and 4 show that the lens body 100’, e.g., the first optical element 110, and the circuit board 500 are attached to each other. In particular, the back surface 113, 114 of the first optical element and a first surface 501 of the circuit board are attached to each other.

[0153] It is possible that the circuit board 500 is supported by the lens barrel 200’, e.g., the first lens barrel 240, at least on a continuous portion substantially perpendicular to the optical axis O. More in particular, the circuit board 500 is arranged sandwiched by the first optical element 110 and the second optical element 120. According to an example not shown, the circuit board 500 may be arranged sandwiched by the lens body 100’, e.g., the first optical element 110, and the lens barrel 200, e.g., the first lens barrel 240.

[0154] The lens barrel 200’ encloses at least a portion of the lens body 100’ and the circuit board 500. Further, the lens barrel 200’, e.g., the first lens barrel 240, comprises a first coupling surface 239 for receiving at least one of the circuit board 500 and an attaching means (not shown) for fixing the circuit board 500 in the lens barrel 200. Said attaching means (not shown) may be an adhesive member such as glue. The lens barrel 200’, e.g., the first lens barrel 240, further comprise a second coupling surface for receiving the lens body 100’. As shown, the second coupling surface of the lens barrel 200’ is particularly adapted for attaching the lens body 100’ and the lens barrel 200 to each other.

[0155] In particular, the circuit board 500 is arranged sandwiched by the first optical element 110, and the second optical element 120. In particular, by the back surface 113, 114 of the first optical element 110 and a front surface of the second optical element 120. Alternatively, it is still possible that the circuit board 500 is arranged sandwiched by the lens body 100’ and the lens barrel 200’. In particular, by the back surface 113, 114 of the first optical element 110 and a first coupling surface 239 of the lens barrel 200’.

[0156] It is therefore possible that the housing 200 has at least a coupling surface 239 to receive the circuit board 500. In use, said coupling surface 239 is arranged perpendicular to the optical axis O. The first main surface 501 includes a coupling surface for fixing it onto the coupling surface 239 of the housing, e.g., to be seated on the coupling surface 239 of the housing.

[0157] According to an example, adhesive means (not shown) such as a glue member is arranged between the first main circuit 501 and the back surface 113, 114 of the first optical element 110 (not shown). According to another example, adhesive means (not shown) such as a glue member is arranged between the second main surface 502 and the coupling surface 239 of the housing.

[0158] The opening D1 , notch or indentation of the circuit board 500 is also applicable of the example of figures 16A and 16B where the camera module 900 comprises the protective cover 990. In this case, light passes through the optically transparent portion 100” of the protective cover 990 and reaches the lens assembly 10’. For example, at least a portion of the opening D1 , notch or indentation is arranged therebetween the optically transparent portion 100” and the image sensor 850. In particular, therebetween the optically transparent portion 100” and the lens assembly 10’.

[0159] Figure 3A additionally shows that the circuit board 500 further comprises notches 557 between the first and second portions 510, 520. This facilitates the bending of the second portion 520 with respect to the first portion 510, for example, about 90°.

[0160] The circuit board 500 may be made of, for example, FR4, especially in case of multilayer board. However other suitable materials with sufficient strength and water resistance may be used, such as, for example, FR2, polyamide, CEM 1 , CEM 3 and other paper-based materials with good electrical insulating properties capable of providing at least one electric path along which current is guided.

[0161] Electrical connecting means

[0162] The optical assembly 10 may comprise the above-mentioned electrical connecting means 700 for electrically connecting the circuit board 500 and the heating element 300 (or the light source 301 and / or light receiver 302). As explained, at least a portion of the lens body 100’ is coated by the optically transparent coating 310 that is supplied with electric power. In use, the electric power passes through the circuit board 500. Further, the lens assembly 10’ is provided with an electrical connecting means 700 that is (an integral) part of or (directly) attached to the circuit board 500. The electrical connecting means 700 contacts at least a portion (possible at least two different portions) of the lens body 100’ where the optically transparent coating 310 is provided.

[0163] Figure 3A shows that the electrical connecting means 700 comprises a first connecting portion 701 and a second connecting portion 702 spaced apart to each other such that, in use, the first and second connecting portions 701 , 702 are adapted for providing electric current to the heating element 300. In particular, each of the first and second connecting portion 701 , 702 is a continuous portion (with a certain surface area) that extends perpendicular to the optical axis O. In other words, the first and second connecting portion 701 , 702 are not merely contact points. More in particular, the first and second connecting portions 701 , 702 are arranged opposite to each other with respect to the optical axis O, or spaced as far as possible to each other. It allows a better distribution of the electric power through the optically transparent and electrically conductive layer 330.

[0164] Figure 3A shows that the circuit board 500 includes at least a first and second electric tracks

[0165] 551 , 552 for supplying electric power to the heating element 300. The first and second electric tracks 551 , 552 comprises or electrical connects to the first and second connecting portions 701 , 702. That is, the circuit board 500 includes at least a first and second electric tracks 551 ,

[0166] 552, wherein the first electric track 551 comprises or electrically connects the first connecting portion 701 , and wherein the second electric track 552 comprises or electrically connects the second connecting portion 702.

[0167] In examples, the second portion 520 of the circuit board comprises the first and second electric tracks 551 , 552 surrounded by an electrical isolation material being part of the circuit board 500. It avoids said second portion 520 of the electric tracks from coming into electrical contact with the housing 200 which may comprise electrically conductive material, for example, metal such as aluminum. Also, the first portion 510 of the circuit board comprises a portion where the first and second electric tracks 551 , 552 are not surrounded by an electrical isolation material being thus exposed so as to electrically connect to the optically transparent conductive layer 330 as required. In this way, electric power is provided to the optically transparent coating 310 in a safe manner without any substantial loss of energy. In examples, the portion where the first and second electric tracks 551 , 552 are not surrounded by the electrical isolation material may correspond to the first and second connecting portions 701 and 702 as shown in figure 3A. The first and second connecting portions 701 , 702 may be a widening of the first and second electric tracks 551 , 552, e.g., a copper layer that is part of the circuit board 500, or a component that is not part of the circuit board 500 attached to the circuit board 500 such as a first conductive pad being the first connecting portion 701 , and a second conductive pad being the second connecting portion 702.

[0168] It is possible that the electrical connecting means 700 is a flexible element or a biasing element such as a metallic spring (not shown). It is adapted to be deformed at least in the direction of the optical axis O. It allows to compensate manufacturing and assembly tolerances along the optical axis O. In examples, each of the first connecting portion 701 and the second connecting portion 702 is a conductive flexible material stacked between the first optical element 110 and the circuit board 500. Alternatively, each of the first and second connecting portions 701 , 702 is a conductive gasket arranged on top of the circuit board 500 and abutting the first optical element 110, for example, on a back surface thereof 113, 114. Further, the circuit board 500 may be electrically connected to a power source (not shown).

[0169] According to an example not shown, attaching means may be provided for attaching the electrical connecting means 700 to the optically transparent coating 310. In use, the electrical connecting means 700 may be electrically connected to the optically transparent conductive layer 330. The attaching means may comprise, for example, a conductive adhesive means that may include a transparent conductive glue. In short, said attaching means are adapted for attaching the optical body 10 and the circuit board 500.

[0170] Passageway

[0171] Figure 4 shows that the lens barrel 200’ and the electronics carrier 580 are attached to each other. In fact, the first lens flange 231 comprises a positioning portion 2310 (see figure 6B) for attaching the second lens barrel 230 and the electronics carrier 580 to each other. As shown, the image sensor 850 is surrounded or enclosed at least by the lens body 100’ and the electronics carrier 580. Foreign matter is prevented from coming into contact with the image sensor 850. Further, the optical communication is improved and the optical alignment between the lens assembly 10 and the image sensor 850 is enhanced. A shown, the lens barrel 200’ includes the above-mentioned passageway 234 for a conductor, e.g., the circuit board 500, to pass through. In particular, the above-mentioned second portion 520 of the circuit board 500 is arranged in the passageway 234.

[0172] Figure 4 and 16A show that the passageway 234 extends within the housing 200 (e.g., the lens barrel 200’ and the protective cover case 200”) so that the first portion 510 of the circuit board 500 can be electrically connected to the optically transparent conductive layer 330 and the second portion 520 of the circuit board 500 can be electrically connected to the power supply (not shown). In examples, the passageway 234 is arranged extending through a lateral side of the housing 200, e.g., the lens barrel 200’.

[0173] As shown in figures 1 and 10, the lens barrel 200’ comprises a first lens barrel 240, a second lens barrel 230, and an attaching member 220 adapted for attaching the first and second lens barrels 240, 230 to each other. Particularly, the attaching member 220 surrounds at least a portion of the outer perimeter surface of the first lens barrel 240 and the second lens barrel 230.

[0174] As shown, the lens barrel 200’ further comprises a continuous or discontinuous third lens flange 233 projecting outwardly to the optical axis O. The first and third lens flanges 231 , 233 are spaced apart in a direction parallel to the optical axis O. The third lens flange 233 is further away from the electronics carrier 580 than the first lens flange 231. A purpose of the third lens flange 233 is to support the attaching member 220.

[0175] Further, the lens barrel 200’ comprises a retainer 210. The retainer 210 at least partially surrounds the first housing barrel. Further, the retainer 210 is attached to the first housing barrel 240, for example, by threading 244. Also, the retainer 210 (optionally in connection with a sealing member 250) prevents foreign matter, e.g., dust, water, etc., from reaching the image sensor 850. Furthermore, the retainer 210 contacts a portion of the lens body 100’, e.g., the front surface 111. It helps to locate the lens body 100’, e.g., the first optical element 110, as required to achieve the optical alignment with the image sensor 850.

[0176] Figure 11 shows that the first lens barrel 240 and the second lens barrel 230 are press fit together. That is, the first lens barrel 240 is at least partially inserted inside the second lens barrel 230 so that they are in interference fit. In other words, the second lens barrel 230 partially surrounds the first lens barrel 240 such that the first lens barrel 240 is fitted into a hole of the second lens barrel 230 being slightly smaller than the first lens barrel 240 and held tight and motionless. Figure 11 also shows that the second les barrel 230 comprises (three) inwardly projections 235 arranged on an inner perimeter surface thereof. It is for preventing a rotational movement between the first and second lens barrel 240, 230.

[0177] As shown, the electronics carrier 580 is particularly attached to the second lens barrel 230. Also, the first lens barrel 240 comprises a first passageway 2341. Further, the second lens barrel 230 comprises a second passageway 2342. In use, the first and second passageways 2341 , 2342 are aligned with each other along a direction parallel to the optical axis O. In this way, the passageway 234 is formed as a continuous passageway, i.e. , the passageway 234 is not discontinuous.

[0178] Figures 1 , 4, 6A, 8, 9, 10 and 11 shows the lens barrel, e.g., the second lens barrel 230, comprises a lateral side that gives access 2340 to the passageway 234. In this way, it prevents interaction between the circuit board 500 and the image sensor 850. Advantageously, optical communication is not influenced by the second portion 520 of the circuit board.

[0179] Camera module

[0180] Figure 5 shows the camera module 900 comprising the above-mentioned (optical) subassembly (i.e. lens assembly 10’ + electronics carrier 580 + image sensor 850) and a camera housing 400. In turn, the camera housing 400 comprises a first housing part 410 and a second housing part 420. The first housing part 410 and the second housing part 420 are attached to each other by an attaching member (not shown) comprising a welding member or a fastener such as two or more screws. Other types of attaching members are of course possible. The first and second housing parts 410, 420 define an interior space when mounted. In particular, as shown, the first housing part 410 is a front housing and the second housing part 420 is a back housing. In any case, the camera housing 400 encloses the electronics carrier 580 and at least a portion of the lens assembly 10’. The second housing part 420 comprises an orifice for receiving a connector-adapter 499. The connector-adapter 499 is electrically connected to the electronics carrier 580. In this way, an image signal can be sent outside the camera module, e.g., to a controller or electronic control unit ECU being part of a vehicle visual system. In fact, the image signal comprises a video feed of at least 15 frames per second (fps). The video feed includes a plurality of captured images. The vehicle visual system may be, for example, a vehicle digital mirror system, a vehicle surrounding view system and many others. The heating element 300 and / or the soiling system may be operated when the vehicle is in operation, e.g., the vehicle is being driven. As shown in figure 5, the camera housing 400 comprises a portion (e.g., an inwards flange 411) that extends over the first lens flange 231 of the lens barrel 200’. In other words, the first housing part 410 comprises the inwards flange 411 (i.e. radially inwards to the optical axis O) that lies over a portion (e.g., the first flange 231) of the lens barrel 200’ so as to partially cover said first flange 231. In this way, the first flange 231 is arranged inside the camera housing 400. In fact, the first lens flange 231 abuts an inner surface of the inwards flange 411. That is, the inwards flange 411 of the first housing part 410 and the first flange 231 of the lens barrel 200’ overlap each other in a direction of the optical axis O (one on top of the other). When mounting the lens assembly 10’ and the camera housing 400, the lens assembly 10’ and the camera housing 400, e.g., the first housing part 410, are moved in opposite directions so approach each other until the inwards flange 411 acts as a stopper or vice-versa, the first flange 231 acts as a stopper.

[0181] Figure 5 shows that the lens barrel 200’ further comprises a continuous or discontinuous second lens flange 232 projecting outwardly to the optical axis O (i.e. radially outwards to the optical axis O). The first and second lens flanges 231 , 232 are spaced apart in a direction parallel to the optical axis O. It allows an improved fixation of the lens assembly 10’ to the camera housing. The second lens flange 232 is arranged between the first lens flange 231 and the third lens flange 233. In use, the access 2340 to the passageway 234 is located between the second lens flange 232 and the electronics carrier 580. The second lens flange 232 is arranged inside the camera housing 400. In fact, the second lens flange 232 abuts an inner surface of the first housing part 410, e.g., an inner lateral surface 412 of the first housing part 410 . The second flange 232 and / or the inner lateral surface 412 is / are adapted for receiving an attaching body 440. In particular, the attaching body 440 is an adhesive body. Other attaching bodies such as welding are not ruled out. In examples, the attaching body 440 is continuously arranged around the lens barrel 200’. As shown in figure 5, the attaching body 440 rests on an upper surface of the second lens flange 232. Particularly, the attaching body 440 is arranged between the lens barrel 200’ and the first housing part 410. More particularly, the attaching body 440 is arranged therebetween the inner lateral surface 412 of the first housing part 410 and the lens barrel 200’, e.g., the second lens flange 232. In this case, the attaching body 440 is particularly located in the spaced enclosed by a lateral outer surface of the lens barrel 200’, the second lens flange 232, and the inner lateral surface of the first housing part 410. It is important to notice that the attaching body 440 may act as a seal, e.g., preventing foreign matter such as dust, dirt, or liquids from passing through between the camera housing 400 (e.g., the first housing part 410) and the lens barrel 200’.

[0182] Figures 16A and 16B show an example where the camera module 900 is provided with the protective cover 990. The protective external cover 990 is configured to protect the lens assembly 10’ against external elements such as dust, water, etc or shocks or impacts. It may be made for example of plastic or glass. The protective cover 990 comprises the optically transparent portion 100” and a protective cover case 200”. The optically transparent portion 100” comprises the exterior optical surface 1110. The protective cover case 200” is adapted for receiving the optically transparent portion 100” or at least includes the optically transparent portion 100”. The protective cover case 200” extends around at least a portion of the lens barrel 200’. As shown, the protective cover case 200” may also extend around at least a portion of the camera housing 400, e.g., the first housing part 410.

[0183] Figure 16A shows that the circuit board 500 is electrically connected to the electrically functional member, e.g., the heating element 300 (shown) and / or the electronic component (not shown) coupled to the circuit board. Furthermore, the opening D1 , notch or indentation of the circuit board 500 is arranged therebetween the optically transparent portion 100” and the lens body 100’. The optically transparent portion 100” allows light of the exterior environment to pass through. Said light passes through the opening D1 so as to reach the lens body 100’. The lens body 100’ guides the light to be received by the image sensor 850. In fact, the circuit board 500 comprises the opening D1 (not shown) or a notch or an indentation adapted for allowing the optical axis O to pass through thereof.

[0184] Electronic component

[0185] As explained, the electronic component may be coupled to the circuit board 500. The electronic component may include a temperature measurement device (i.e. temperature sensor), a light source, or a light receiver. The temperature sensor is configured to measure the temperature of the optical body 100 and / or of the environment of the optical body. For example, it is possible the heating element 300 acts a temperature adjustment device thermally configured to adjust the temperature of the optical body 100 to a predetermined temperature as a function of the measured temperature. In this way, thermal expansions and contractions of the optical body 100, e.g., lens body 100’, due to temperature change are reduced or at least controlled. In examples, the electronic component is arranged therebetween two of the optical elements 110, 120, 130, 140, 150, in particular, between the first and the second optical element. The above-mentioned light source 301 and / or light receiver 302 is / are part of the soil detection system 1000.

[0186] Soil detection system

[0187] When dirtiness in the exterior optical surface is excessive or an ice sheet is present thereon, the camera module 900 may produce images of insufficient quality. Therefore, it may be a concern to determine when the exterior optical element becomes excessively dirty in order to undertake corresponding corrective action(s), such as e.g., activation of the heating element 300, an automatic cleaning system, triggering of an alarm for manual cleaning, etc.

[0188] For this purpose, figures 17A and 17B show a speckles detection system 1000 that is provided in the optical assembly 10. The speckles detection system 1000 comprises one or more light sources 301 configured to emit light towards the optical body 100, such as the lens body 100’ or the optically transparent portion 100” of the protective cover 990. Said optical body 100 then reflects light from said one or more light sources 301 when speckles are located on the exterior optical surface 1110 of the optical body 100. One or more light receivers 302 are provided to receive light reflected by the lens body 100’ or the optically transparent portion 100” of the protective cover 990 such that speckles on the exterior optical surface 1110 of the optical body 100 are detected. For example, when the vehicle is in operation, i.e. when the moto vehicle is being driven. Said one or more light receivers 302 may comprise a broadband detectors including infrared detectors (or UV detectors) configure to operate at a wavelength out of the visible spectrum, for example, over 750 nm o under 400 nm. In this way, it is possible to prevent the emitted light from interfering with an image captured by the camera module 900. In examples, the one or more light sources 301 generates a predetermined emission wavelength centered on absorption bands of atmosphere, for example, at wavelengths at or near 760-800 nm, or 920-960 nm, or 1110-1150 nm, or 1380-1420 nm. Particularly, the light receiver may comprise a photo detector, for example, a CCD (charge-coupled device) sensor.

[0189] As opposed to the device of EP3584567 where light sources and / or light receivers are directly attached to a lens barrel, the present optical assembly 10 provides at least one light source and / or light receiver directly attached to the circuit board 500. As result, a simple and fast assembly process is advantageously obtained, which is of particular relevance in mass production.

[0190] Figure 3B shows the circuit board 500 including three electric tracks 55T, 55’2, 553’ for supplying electric power to the electronic component. The circuit boards of the figure 3A and 3B may be implemented together, i.e. in the same board (not shown). If so, the circuit board 500 is configured to supply electric power to the heating element 300 and the electronic component. As shown in figure 3B, the electronics carrier 500, particularly the second portion 520, comprises three conductive pins 554’, 555’, 556’. Said three conductive pads 554’, 555’, 556’ are located at or near an end of the second portion 520. The conductive pins 554’, 555’, 556’ are depositions of electrically conductive material such as copper, particularly, on the first main surface 501. In examples, the three conductive pads 554’, 555’, 556’ are between 4 and 6 mm long, 1 and 1.5 wide, and 0.1 and 0.2 thick. The first conductive pin 554’ is electrically connected to the first electric track 55T. The second conductive pin 555’ is electrically connected to the second electric track 552’. Same applies to the circuit board 500 of figure 3A (554 and 555 correspond the first and second conductive pins). The third conductive pin 556’ is electrically connected to the third electric track 553’ which is the ground (GND). The conductive pads 554’, 555’, 556’ are electrically connected to the power source (not shown).

[0191] As shown in figure 3B, the circuit board 500, particularly the first portion 510, comprises a resistor device R. In particular, the resistor device R is located on the first main surface 501. The resistor device R is connected at one end to the first electric track 551 and at the other end to the light source 301. The resistor device R is configured to limit the electric current flowing through the light source 301. The light source 301 comprises a diode being, for example, a LED (light-emitting diode) device. The resistor device R has an electrical resistance of between 50 to 800 ohms, particularly, 100 to 400 ohms. The light source 301 , e.g., the LED device, is electrically connected to the resistor device R, the third electric track 553’, and the light receiver 302. The light source 301 and the light receiver 302 are electrically connected through the connecting portion 70T. The electrical connection to the light receiver 302 is made through a further connecting portion 702’. The light receiver 302 is further electrically connected to the second electric track 552’. The second electric track 552’ is electrically connected to second conductive pin 556’. Furthermore, the described electric circuit operates with pulsed current. This is, pulsed current circulates on the electric tracks. In examples, the electrical power is of between 0.2 and 5 watts, particularly, 0.5-1 watts.

[0192] There are several possible placement options for the light source 301 and the light receiver 302, for example opposite each other as shown in figure 17A. Different placement options are possible, but it is preferred not next to each other. In particular, the light source 301 and the light receiver 302 are angularly separated by more than 20°. As shown in figure 3B, it is preferred to be angularly displaced by an angle A of 30° to 60°, for example, 45°.

[0193] When reflected light is received by the one or more light receivers 502, it is determined that the optical body 100 has optical contamination and corrective action(s) such as the activation of a heating element 300, activation of an automatic cleaning system (not shown), triggering of an alarm for manual cleaning, etc. may be performed in response.

[0194] The scope of the present disclosure should not be limited by the particular examples disclosed herein but should be determined only by a fair reading of the claims that follow. Reference signs related to drawings placed in parentheses in a claim are solely for attempting to increase the intelligibility of the claim and shall not be construed as limiting the scope thereof.

Claims

CLAIMS1. An optical assembly (10) comprising:- an optical body (100);- a housing (200) that includes the optical body (100) or is adapted at least to receive the optical body (100);- a circuit board (500); and- an electrically functional member electrically connected to the circuit board (500), wherein the electrically functional member comprises a heating element (300) and / or an electronic component (301 , 302) coupled to the circuit board (500).

2. The optical assembly (10) of claim 1 , wherein the optical body (100) defines an optical axis (O), wherein the circuit board (500) comprises an opening (D1) or a notch or an indentation adapted for allowing the optical axis (O) to pass through thereof.

3. The optical assembly (10) of claim 2, wherein at least a portion of the opening (D1), notch or indentation is arranged therebetween a surface of the optical body (100) and an image sensor (850) in optical communication with the optical body (100).

4. The optical assembly (10) of claims 2-3, wherein it comprises an exterior optical surface (1110) and an internal optical surface spaced apart along the optical axis (O), wherein at least a portion of the opening (D1), notch or indentation is arranged between the exterior optical surface (1110) and the internal optical surface.

5. The optical assembly (10) of any preceding claim, wherein the circuit board (500) is arranged within the optical assembly (10) at least partially extending around the optical axis (O), optionally between opposite ends (111a, 111 b) of the optical body (100).

6. The optical assembly (10) of any preceding claim, wherein the circuit board (500) comprises a first portion (510) at least partially contained in a plane that is substantially perpendicular to the optical axis (O), preferably, the circuit board (500) is a flexible printed circuit board further comprising a second portion (520) that optionally extends in a direction substantially parallel to the optical axis (O).

7. The optical assembly (10) of any preceding claim, wherein the circuit board (500) is attached to the optical body (100), and / or is supported by the housing (200), and / or is sandwiched by the optical body (100) and the housing (200), and / or is sandwiched by at least two optical surfaces of the optical body (100).

8. The optical assembly (10) of any preceding claim, wherein the electrically functional member is the heating element (300), wherein the optical assembly (10) further comprises an electrical connecting means (700) for electrically connecting the circuit board (500) and the heating element (300), optionally, the electrical connecting means (700) comprises a first connecting portion (701) and a second connecting portion (702) spaced apart to each other such that, in use, the first and second connecting portions (701 , 702) are adapted for providing electric current to the heating element (300).

9. The optical assembly (10) of claim 8, wherein the circuit board (500) includes at least a first and second electric tracks (551 , 552), wherein the first electric track (551) comprises or electrically connects to the first connecting portion (701), and wherein the second electric track (553) comprises or electrically connects to the second connecting portion (702), wherein the first connecting portion (701) and the second connecting portion (702) contact the heating element (300) at different portions thereof.

10. The optical assembly (10) of claim 9 when depending on claim 6, wherein the second portion (520) of the circuit board (500) comprises a second portion of the first and / or second electric track(s) (551 , 552) that is surrounded by an isolation material being part of the circuit board (500), wherein the first portion (510) of the circuit board (500) comprises a first portion of the first and / or second electric track(s) (551 , 552) adapted for being electrically connected to the heating element (300).

11. The optical assembly (10) of any preceding claims, wherein the electrically functional member is the heating element (300) that includes an optically transparent coating (310) that comprises an optically transparent conductive layer (330), wherein the optically transparent coating (310) is applied to at least one portion of the optical body (100) for resistive heating of said at least one portion of the optical body (100) as electric current flows through the optically transparent conductive layer (330).

12. The optical assembly (10) of claim 11 , wherein the optically transparent conductive layer (330) comprises at least aluminium-doped zinc oxide, optionally, the optically transparent conductive layer (330) has a sheet resistance of 50 - 300 ohm / square and, in use, generating a heating output of 1000 - 10000 W / m2.

13. The optical assembly (10) of any of the preceding claims, wherein the optical assembly (10) is a lens assembly (10’), the optical body (100) is a lens body (100’), and the housing (200) is a lens barrel (200’).

14. The optical assembly (10) of claim 13, wherein the lens barrel (200’) and an electronics carrier (580) are attached to each other, wherein the image sensor (850) is coupled to the electronics carrier (580), and wherein the lens barrel comprises a passageway (234) to allow the circuit board (500) to pass through.

15. The optical assembly (10) of any claims 1-12, wherein the optical assembly (10) is a camera module (900) comprising a protective cover (990), the optical body (100) is an optically transparent portion of the protective cover (990), and the housing (200) is a protective cover case (200”).

Images