OPTOELECTRONIC SENSOR AND METHOD FOR MANUFACTURING AN OPTOELECTRONIC SENSOR

Description

[0001] The present invention relates to an optoelectronic sensor according to the preamble of claim 1 and to a method for producing an optoelectronic sensor according to claims 12 and 13, respectively.

[0002] Optoelectronic sensors are used for a wide variety of monitoring tasks. Examples of such sensors include photoelectric sensors or retro-reflective sensors, in which a light emitter emits a beam of light that is reflected and captured by a light receiver arranged next to the light emitter. Another type of sensor is a light grid, in which a series of light emitter / receiver pairs are arranged side by side, forming a kind of light curtain.

[0003] Another application of these sensors is the optical determination of distance based on the time-of-flight principle. A light beam with a transmitted pattern is reflected by an object and, after reception in the sensor, compared with an internally generated reference pattern. From this, the light path and thus also the distance can be calculated. In practice, two main methods are used. In one method, the transmitted pattern is a simple light pulse whose transit time is measured. In the other method, the transmitted pattern is a sine modulation, where the phase position of the sine relative to a reference sine corresponds to the transit time modulo the period of the sine.

[0004] Distance measurement can be required, for example, in vehicle safety, logistics or factory automation, or security technology. In particular, a rangefinder based on a reflected light beam can react to a change in the distance of the reflector or the reflecting or remitting target. A special application is a distance-measuring retro-reflective sensor, in which the distance between the light emitter and the reflector is monitored.

[0005] In all of the sensors mentioned, an optical system is assigned to the light transmitter and the light receiver, and this optical system must be correctly aligned. Especially for distance measurements using a laser as the light transmitter, an adjustment is traditionally performed in the production environment. This is intended to set a specific focus position or laser spot diameter. In addition, it may be necessary in a second step to align the transmitter and receiver. In all cases, this adjustment should determine the relative positions of the light transmitter, light receiver, and the two lenses.

[0006] As long as the light receiver and / or the light spot are relatively large, the adjustment doesn't need to be particularly precise. However, with increasing miniaturization, the adjustment requirements become more stringent. The current state-of-the-art method of mounting the receiver as a chip on a circuit board eventually becomes too inaccurate.

[0007] In any case, the manufacturing or, if the adjustment is only carried out in the production environment, the assembly is complex, costly, inconvenient and can even lead to rejects if the sensor can no longer be adjusted correctly.

[0008] For example, multiple components must be joined separately, resulting in increased manufacturing costs. The probability of assembly errors is significantly higher with multiple components than with a single component.

[0009] Individual optical components have positional tolerances relative to each other, which results in poor performance of the overall assembly.

[0010] DE 10 2007 050 096 A1 discloses an optical sensor. This sensor comprises a light source and means for homogenizing the light beam generated by the light source. Several optical elements with different focal distances homogenize the light beam in its propagation direction. To homogenize the light beam transversely to its propagation direction, several optical elements arranged side by side with alternating focal lengths or widths are used. These are preferably designed as an array on a front panel.

[0011] DE 10 2015 121 840 A1 discloses an optoelectronic sensor for detecting an object in a surveillance area, comprising at least one light transmitter for emitting a plurality of separated light beams, a light receiver with a plurality of light receiving elements for generating a respective received signal from the light beams remitted by the object, a receiving optics arranged upstream of the light receiver, and an evaluation unit for obtaining information about the object from the received signals. At least some of the light receiving elements are offset from one another in a direction perpendicular to their receiving surface.

[0012] DE 10 2011 089 866 A1 discloses a measuring device for measuring a distance to a target object, comprising a beam source which is designed as an electro-optical component and emits a transmission beam, a detector which is designed as a further electro-optical component and receives a reception beam reflected and / or scattered by the target object, a beam splitting optic for deflecting the transmission and / or reception beam and / or a beam shaping optic for shaping the transmission and / or reception beam and an optic carrier for receiving the electro-optical components and for receiving the beam splitting optic and / or the beam shaping optic, wherein the optic carrier has a first wafer for receiving the electro-optical components and a second wafer for receiving the beam splitting optic and / or the beam shaping optic.

[0013] US 2016 / 0238443 A1 discloses an optical sensor module, an optical sensor accessory, and an optical sensor device. An optical sensor module consists of a light source, a photodetector, and a substrate. The light source is configured to convert electrical energy into radiant energy and emit light onto an object surface. The photodetector is configured to receive the light from an object surface and convert radiant energy into electrical current or voltage. An optical sensor accessory and an optical sensor device comprise the optical sensor module and other electronic modules for further applications.

[0014] It is therefore an object of the invention to provide an optoelectronic sensor which requires the least possible adjustment effort and also to provide a simplified manufacturing method for a correctly adjusted sensor.

[0015] The object is achieved according to claim 1 by an optoelectronic sensor for object detection, with a sensor housing, with at least one printed circuit board, with a light transmitter and a light receiver arranged at a distance therefrom, wherein the light transmitter and the light receiver are arranged on the printed circuit board, and with at least one first lens which is arranged upstream of the light transmitter and with at least one second lens which is arranged upstream of the light receiver, wherein the first lens and the second lens are integrated in a one-piece optical combination element, wherein the optical combination element has at least one transmitter aperture and at least one receiver aperture.

[0016] The optoelectronic sensor according to the invention with the one-piece optical combination element offers the advantage that the base distances between the light transmitter and light receiver, on the one hand, and between the two associated lenses, on the other, are fixed. This provides a simple optoelectronic sensor with components that are already aligned to one another.

[0017] Since the optical components are implemented in one part, namely the optical combination element, the position tolerances between the optical functional elements are significantly lower than with individual optical elements, which can improve the sensor performance.

[0018] The number of optical components is greatly reduced, which significantly reduces parts and assembly costs.

[0019] The likelihood of assembly errors is lower with a smaller number of components. Furthermore, the risk of components being forgotten during assembly is lower.

[0020] The first lens and / or the second lens are preferably designed as refractive optics. The first lens and / or the second lens are preferably designed as converging lenses.

[0021] Because the apertures, i.e. the transmitter aperture and the receiver aperture, are integrated into the optical combination element, they are positioned more precisely to the lenses, i.e. the first lens and the second lens, which means that they can be better dimensioned in terms of their performance due to smaller tolerances.

[0022] The transmitter aperture or receiver aperture limits the cross-section of beams. The aperture of the light transmitter or receiver is limited by the transmitter aperture or receiver aperture. Because the transmitter aperture and receiver aperture are arranged on the optical combination element, the transmitter aperture can be positioned very precisely relative to the light transmitter, and the receiver aperture can be positioned very precisely relative to the light receiver. This improves the quality of the optical combination element and thus of the optoelectronic sensor.

[0023] A control and evaluation unit is preferably located on the circuit board. The control and evaluation unit can be used to control the light transmitter and evaluate the light receiver. The control and evaluation unit is formed, for example, by a microcontroller or a microprocessor. However, an FPGA or ASIC can also be provided as the control and evaluation unit.

[0024] In a further development of the invention, the optical combination element has at least one diffractive optical element.

[0025] The optical combination element can have one or more diffractive optical elements.

[0026] Diffractive optical elements are elements that exhibit microstructures. In these microstructures, phase modulation occurs due to the different optical path lengths of the partial beams, creating interference patterns. In addition, the amplitude is modulated through constructive and destructive superposition. Thus, with clever design, the intensity patterns in a light beam, especially a laser beam, can be manipulated. A diffractive optical element can preferably create a light beam bundling similar to a refractive lens.

[0027] The microstructure in the diffractive optical element can shape the beam, for example, through the refractive index or height modulation. Efficiencies of 80-99% and transmittances of 95-99% can be achieved.

[0028] For example, the diffractive optical element forms an optical system together with the first lens and / or the second lens.

[0029] In a further development of the invention, the first lens and / or the second lens is designed as a diffractive optical element.

[0030] This allows the optical combination element to be designed very compactly, as the refractive surfaces are minimized or even eliminated entirely. This allows the optoelectronic sensor itself to be miniaturized.

[0031] In a further development of the invention, the optical combination element has at least one bandpass filter.

[0032] In optics, a bandpass filter (also known as a bandwidth filter) is a filter that allows only signals of a specific frequency band to pass through. The frequency ranges below and above the passband are blocked or significantly attenuated. This is an optical bandpass filter.

[0033] Bandpass filters for optical wavelengths include color filters. They consist of interference filters, for example, and can be designed with very narrow bands. In particular, the bandpass filter can be permeable to red or infrared light. In particular, the bandpass filter can be permeable to red or infrared laser light.

[0034] In a further development of the invention, the optical combination element forms a front pane of the optoelectronic sensor, wherein the front pane forms part of an outer surface of the sensor housing.

[0035] According to the further development, the windscreen is implemented as a part of the combination element, which saves additional installation space and further reduces the number of individual parts.

[0036] Since the front screen forms part of the outer surface of the sensor housing, the front screen is preferably designed to be flat and smooth on the outside. The front screen can be made of glass or plastic. The outer side of the front screen can be designed to be scratch-resistant and / or impact-resistant, for example. In particular, the outer side of the front screen can exhibit high chemical resistance.

[0037] In a further development of the invention, positioning elements are arranged between the optical combination element and at least one of the circuit boards in order to position and fix the optical element on the circuit board(s). The positioning elements can preferably be integrally connected to the optical combination element. However, it can also be provided that the positioning elements are integrally connected to the circuit board. For example, the positioning elements can be formed by simple pins or spacers.

[0038] The positioning elements are used to define a position in at least three mutually perpendicular spatial directions. This also establishes a fixation in three spatial angles. The positioning elements are preferably made of plastic.

[0039] In particular, the optical combination element and the circuit board have a similar temperature coefficient.

[0040] In a further development of the invention, an optical carrier is arranged between the optical combination element and the circuit board in order to position and fix the optical element on the circuit board.

[0041] The optics carrier defines a position in at least three mutually perpendicular spatial directions. It also defines a fixation in three solid angles. The optics carrier is preferably made of plastic. The optics carrier can, for example, form a tube. The optics carrier is preferably made of black plastic. In particular, the optics carrier has matte black surfaces to absorb stray or scattered light.

[0042] In a further development of the invention, the optical combination element has an anti-reflective, anti-scratch and / or anti-fog coating.

[0043] The anti-scratch coating makes the optical combination element robust against mechanical influences. The anti-reflective coating makes the optical combination element, and thus the optoelectronic sensor, more robust against optical stray light. The anti-fog coating makes the optical combination element, and thus the optoelectronic sensor, more robust against temperature fluctuations. This allows the sensor to be operated more effectively in outdoor environments and under large temperature fluctuations.

[0044] In a further development of the invention, the optical combination element has optical microstructures. The optical microstructures are geometric structures in the micrometer range. These can be microlenses or similar. For example, microprisms can be provided. This allows optical components, such as the first lens or the second lens, to be designed as optical microlenses. However, additional optical elements can also be designed as microstructure elements. The optical microstructures are, for example, integrally connected to the optical combination element.

[0045] In a further development of the invention, the optical combination element has mechanical microstructures. The mechanical microstructures are geometric structures in the micrometer range. For example, positioning elements, fixing elements, bearing elements, or even static elements can be formed as mechanical microstructures. The mechanical microstructures are, for example, integrally connected to the optical combination element.

[0046] In a further development of the invention, the optical combination element has optical separation means for optically separating the transmission and reception paths.

[0047] This prevents stray light from the light transmitter from passing directly into the light receiver and being received there. The separating agents optically separate the optical transmission path from the optical reception path.

[0048] The optical separating means can be designed, for example, as optical separating layers, optical separating webs, or recesses. Optical separating layers are made, for example, of an opaque material, such as black plastic. Optical separating webs are, for example, so thin or geometrically shaped that the separating webs form an optical barrier. A recess is, for example, a gap in the material of the combination element through which optical wave propagation is impeded.

[0049] In a further development of the invention, the first lens and / or the second lens are Fresnel lenses.

[0050] Fresnel lenses have a particularly low installation height, which saves installation space.

[0051] According to the invention, the optical combination element (8) has at least one bandpass filter (12), wherein the optical combination element (8) is constructed from a plurality of layers (19) and different layers (19) have different components, wherein one layer has the transmitter aperture (9) and the receiver aperture (10) and a layer different from these has the bandpass filter (12).

[0052] In a further development of the invention, the optical combination element is manufactured by injection molding.

[0053] This process allows for the cost-effective production of optical combination elements in large quantities. The tool costs represent a large portion of the necessary investment.

[0054] Injection molding, particularly advanced, specialized processes, allows for virtually unlimited choice of shape and surface structure, such as smooth surfaces or lenses. Injection molding, often referred to as injection molding, is a primary molding process used primarily in plastics processing. An injection molding machine liquefies (plasticizes) the material in question and then injects it under pressure into a mold, the injection molding tool. Within the tool, the material reverts to its solid state through cooling or a crosslinking reaction. After the tool is opened, it is removed as a finished part. The cavity and the tool's hollow space determine the shape and surface structure of the optical combination element.

[0055] In a further development of the invention, the optical combination element is produced by means of a nanoimprint lithography process or nanoprinting lithography process (nanoimprint lithography, abbreviation: NIL).

[0056] Manufacturing using the NIL (nanoimprint lithography) process significantly reduces component costs, as several components can be manufactured simultaneously on large substrates and subsequently separated.

[0057] In particular, Fresnel lenses can be manufactured using the NIL process. These lenses can be produced with significantly higher quality than injection molding.

[0058] The nanoprinting lithography process is a method for producing patterns in the nanometer range using a special stamp.

[0059] It is a simple, low-cost, high-throughput, and high-resolution nanolithography process. It creates patterns through mechanical deformation of the impression varnish and subsequent processes. The impression varnish is typically a monomer or polymer formulation that is cured by heat or UV light during the impression process. The adhesion between the varnish and the stencil is controlled to ensure proper release.

[0060] In particular, it can be provided that the surface structuring step is carried out using nanoimprint lithography. Nanoimprint lithography, often also referred to as nanoimprint lithography, NIL or nanoimprint, is an embossing process that can be used to produce nanostructures. This requires a stamp with the negative, which in turn can be produced using nanoimprint lithography or another nanostructuring process. During the surface structuring step, the stamp is pressed into a positive, whereby the relief of the stamp is embossed into the positive. The positive can be made of plastic, preferably monomers or polymers. The stamp is only removed after the positive has cured. Curing can be carried out, in particular, using UV radiation. When plastic is used as the substrate, the positive can directly be the substrate.Alternatively, the positive can subsequently be etched away, with the positive serving as an etching mask for the underlying material, particularly a glass substrate or a coating. The stamp allows the surface reliefs to be created to be particularly well defined and manufactured with tight tolerances. Furthermore, nanoimprint lithography allows the creation of surface reliefs that allow for a particularly steep transition between individual elevations and depressions.

[0061] There are many different types of nanoimprint lithography, but three are most important: thermoplastic nanoimprint lithography, photo-nanoimprint lithography, and resist-free direct thermal nanoimprint lithography. Thermoplastic nanoimprint lithography:

[0062] Thermoplastic nanoimprint lithography (T-NIL) is the earliest form of nanoimprint lithography. In a standard T-NIL process, a thin layer of a resist (thermoplastic polymer) is spin-coated onto the sample substrate. Then, the mold, which has predefined topological patterns, is brought into contact with the sample, and they are pressed together under a specific pressure. Upon heating above the glass transition temperature of the polymer, the pattern on the mold is pressed into the softened polymer film. After cooling, the mold is separated from the sample, leaving the pattern resist on the substrate. A pattern transfer process (usually reactive ion etching) can be used to transfer the pattern to the underlying substrate.

[0063] Alternatively, cold welding between two metal surfaces could also transfer low-dimensional nanostructured metal without heating (especially for critical sizes of less than approximately 10 nm). By repeating this process, three-dimensional structures can be produced. The cold welding approach has the advantage of reducing contamination or defects at the surface contact without the need for a heating process. Photo-nanoimprint lithography:

[0064] In photo-nanoimprint lithography (P-NIL), a UV-curable liquid resist is applied to the sample substrate. The mold is typically made of a transparent material such as fused silica or PDMS. After the mold and substrate are pressed together, the resist is cured in UV light and solidifies. After mold release, a similar pattern transfer process can be used to transfer the resist pattern to the underlying material. Resist-free direct thermal nanoimprint lithography:

[0065] Unlike the above-mentioned nanoimprinting techniques, resist-free direct thermal nanoimprint lithography does not require an additional etching step to transfer patterns of imprinting resists to the device layer.

[0066] In a typical process, photoresist patterns are first defined using photolithography. A polydimethylsiloxane (PDMS) elastomer stamp is then replicated from the resist patterns. Furthermore, a one-step nanoimprint directly forms thin-film materials into desired device geometries under pressure at elevated temperatures. The printed materials should exhibit suitable softening properties to fill the pattern. Amorphous semiconductors (e.g., chalcogenide glass) with a high refractive index and a wide transparent window are ideal materials for imprinting optical components for the optical combination element.

[0067] A key advantage of nanoimprint lithography is its simplicity. A nanoimprint tool eliminates the need for complex optics or high-energy radiation sources. It also eliminates the need for finely tuned photoresists engineered for both resolution and sensitivity at a specific wavelength. The simplified requirements of the technology result in low costs.

[0068] Master molds can be used for up to several thousand to ten thousand impressions.

[0069] Impression lithography is inherently a three-dimensional patterning process. Impressions can be fabricated with multiple vertically stacked topography layers. The resulting imprints replicate both layers with a single imprinting step. As mentioned above, the printing material does not need to be fine-tuned for high resolution and sensitivity. A wider range of materials with different properties is available for use with impression lithography. The increased material variability gives chemists the freedom to develop new functional materials instead of sacrificially etch-resistant polymers. A functional material can be printed directly to form a layer, eliminating the need for pattern transfer to underlying materials.

[0070] In a further development of the invention, the optical combination element is adjusted and aligned to the circuit board based on an image of the transmitted light.

[0071] Due to small tolerances within the optical combination element or integral component and within the circuit board assembly, an adjustment based on an image of the transmitted light is sufficient to adjust the transmission and reception paths.

[0072] By adjusting the transmitted light path using, for example, image verification on a ground glass screen, the received path is also adjusted, which means that no complex adjustment of the receiver with evaluation of the receiving element is necessary.

[0073] In a further development of the invention, a plurality of optical combination elements are produced in a single substrate and then separated.

[0074] This allows a very cost-effective production of a large number of optical combination elements.

[0075] In a further development of the invention, the separation is carried out by means of a laser separation process.

[0076] Separation using a laser separation process has the advantage of being residue-free. This means that no chips or other waste products are generated during the separation process, as can sometimes be the case with mechanical separation processes. Furthermore, a laser separation process has the advantage of being very precise and accurate, since the laser beam cuts or separates very precisely.

[0077] In a further development of the invention, the substrate takes the form of a CD, a DVD, a Blu-ray disc, or an ultra-high-definition disc. This has the advantage that the substrate is a standard size and can therefore be processed using conventional machines.

[0078] The invention will be explained below with reference to further advantages and features, using exemplary embodiments, with reference to the accompanying drawings. The figures of the drawing show: Figures 1, 1a, 1b and 2 each show an optoelectronic sensor; Figure 3 shows an optical combination element; Figure 4 shows an optoelectronic sensor; Figures 5 to 10 each show an optical combination element.

[0079] In the following figures, identical parts are provided with identical reference numerals.

[0080] Figure 1shows an optoelectronic sensor 1 for object detection of an object 22, with a sensor housing 2, with at least one printed circuit board 3, with a light transmitter 4 and a light receiver 5 arranged at a distance therefrom, wherein the light transmitter 4 and the light receiver 5 are arranged on the printed circuit board 3, and with at least one first lens 6 which is arranged upstream of the light transmitter 4 and with at least one second lens 7 which is arranged upstream of the light receiver 5, wherein the first lens 6 and the second lens 7 are integrated in a one-piece optical combination element 8, wherein the optical combination element 8 has a transmitter aperture 9 and a receiver aperture 10.

[0081] Optionally, the optical combination element 8 has at least one diffractive optical element 11.

[0082] The first lens 6 and / or the second lens 7 are preferably designed as refractive optics. The first lens 6 and / or the second lens 7 are preferably designed as converging lenses.

[0083] Diffractive optical elements 11 are elements that have microstructures. For example, the diffractive optical element 11 forms an optical system together with the first lens 6 and / or the second lens 7.

[0084] The transmitter aperture 9 or receiver aperture 10 limit the cross-section of beams, minimize the propagation of stray light and limit the influence of extraneous light on the receiver 5. The opening width or aperture of the light transmitter 4 or the light receiver 5 is limited by the transmitter aperture 9 or the receiver aperture 10.

[0085] A control and evaluation unit 21 is preferably located on the circuit board 3. By means of the control and evaluation unit 21, the light transmitter 4 can be controlled and the light receiver 5 can be evaluated.

[0086] According to Figure 1a The light transmitter 4 is arranged on a second circuit board 3. On the circuit board 3 with the light receiver 5, an opening is provided for the transmitted light beams. According to Figure 1a two circuit boards 3 are provided.

[0087] According to Figure 1b The light transmitter 4 is arranged on a second circuit board 3. The circuit board with the light receiver 5 is arranged in the same plane as the circuit board 3 with the light transmitter. According to Figure 1b Two circuit boards 3 are provided. This is advantageous, for example, for laser sensors, since separate transmitter or receiver adjustment is necessary.

[0088] According to Figure 2the first lens 6 and / or the second lens 7 is designed as a diffractive optical element 11.

[0089] According to Figure 3 The optical combination element 8 has at least one bandpass filter 12. This is an optical bandpass filter 12.

[0090] Bandpass filters 12 for optical wavelengths are, for example, color filters. They consist, for example, of interference filters and can be designed with very narrow bands. In particular, the bandpass filter 12 can be permeable to red or infrared light. In particular, the bandpass filter 12 can be permeable to red or infrared laser light.

[0091] According to Figure 4 the optical combination element 8 forms a front pane 13 of the optoelectronic sensor 1, wherein the front pane 13 forms part of an outer surface of the sensor housing 2.

[0092] Since the front panel 13 forms part of an outer surface of the sensor housing 2, the front panel 13 is preferably designed to be flat and smooth on the outside. The front panel 13 can be made of glass or plastic. The outer surface of the front panel 13 can be designed to be scratch-resistant and / or impact-resistant, for example. In particular, the outer surface of the front panel 13 can exhibit high chemical resistance.

[0093] According to Figure 5Positioning elements 14 are arranged between the optical combination element 8 and at least one of the circuit boards 3 in order to position and fix the optical combination element 8 on the circuit board(s) 3. The positioning elements 14 can preferably be integrally connected to the optical combination element 8. However, it can also be provided that the positioning elements 14 are integrally connected to the circuit board 3. For example, the positioning elements 14 can be formed by simple pins or spacers.

[0094] The positioning elements 14 define a position in at least three mutually perpendicular spatial directions. This also defines a fixation in three spatial angles. The positioning elements 14 are preferably made of plastic.

[0095] In particular, the optical combination element 8 and the circuit board 3 have a similar temperature coefficient.

[0096] According to Figure 6 An optics carrier 15 is arranged between the optical combination element 8 and the circuit board 3 in order to position and fix the optical combination element 8 on the circuit board 3.

[0097] The optics carrier 15 defines a position in at least three mutually perpendicular spatial directions. This also defines a fixation in three solid angles. The optics carrier 15 is preferably made of plastic. The optics carrier 15 can, for example, form a tube. Preferably, the optics carrier 15 is made of black plastic. In particular, the optics carrier 15 has matte black surfaces so that stray or scattered light is absorbed.

[0098] For example, the optical combination element 8 has an anti-reflective, anti-scratch and / or anti-fog coating.

[0099] According to Figure 7 The optical combination element 8 has optical microstructures 16. The optical microstructures 16 are geometric structures in the micrometer range. These can be microlenses or the like. For example, microprisms can be provided. This allows optical components, such as the first lens 6 or the second lens 7, to be designed as optical microlenses. However, additional optical elements can also be designed as microstructure elements. The optical microstructures 16 are, for example, integrally connected to the optical combination element 8.

[0100] For example, the optical combination element 8 has mechanical microstructures. The mechanical microstructures are geometric structures in the micrometer range. For example, positioning elements 14, fixing elements, bearing elements, or even static elements can be formed as mechanical microstructures. The mechanical microstructures are, for example, integrally connected to the optical combination element 8.

[0101] According to Figure 8 the optical combination element 8 has optical separating means 17 for optically separating the transmission and reception paths.

[0102] This prevents stray light from the light transmitter 4 from passing directly into the light receiver 5 and being received there. The separating means optically separate the optical transmission path from the optical reception path.

[0103] The optical separating means 17 can be designed, for example, as optical separating layers or as optical separating webs. Optical separating layers are made, for example, of an opaque material, such as black plastic. Optical separating webs are, for example, so thin or geometrically shaped that the separating webs form an optical barrier.

[0104] According to Figure 9 The first lens 6 and / or the second lens 7 are Fresnel lenses 18. Fresnel lenses 18 have a particularly low overall height, which saves installation space.

[0105] According to Figure 10The optical combination element 8 is constructed from several layers 19. For example, one layer 19 can comprise the transmitter aperture 9 and the receiver aperture 10. Another layer 19 different from these can comprise, for example, the first lens 6 or the transmitter lens and the second lens 7 or the receiver lens. A further layer 19 different from these can comprise, for example, the optical filters.

[0106] For example, different layers 19 have different components. For example, one layer can have the transmitter aperture 9 and the receiver aperture 10. Another layer 19 different from these can, for example, have the first lens 6 or the transmitter lens and the second lens 7 or the receiver lens. A further layer 19 different from these can, for example, have the optical filters.

[0107] For example, the optical combination element 8 is manufactured by injection molding. Injection molding, especially advanced special processes, allows for a virtually free choice of shape and surface structure, such as smooth surfaces or lenses.

[0108] Injection molding, often referred to as injection molding or injection molding, is a primary molding process primarily used in plastics processing. The material is liquefied (plasticized) using an injection molding machine and injected under pressure into a mold, the injection molding tool. Within the tool, the material reverts to its solid state through cooling or a crosslinking reaction. After the tool is opened, it is removed as a finished part. The cavity of the tool determines the shape and surface structure of the optical combination element.

[0109] For example, the optical combination element 8 is manufactured by means of a nanoimprint lithography process or nano-printing lithography process (nanoimprint lithography, abbreviation: NIL).

[0110] Nano-printing lithography is a process for producing patterns in the nanometer range using a special stamp.

[0111] In particular, it can be provided that the surface structuring step is carried out using nanoimprint lithography. Nanoimprint lithography, often also referred to as nanoimprint lithography, NIL or nanoimprint, is an embossing process that can be used to produce nanostructures. This requires a stamp with the negative, which in turn can be produced using nanoimprint lithography or another nanostructuring process. During the surface structuring step, the stamp is pressed into a positive, whereby the relief of the stamp is embossed into the positive. The positive can be made of plastic, preferably monomers or polymers. The stamp is only removed after the positive has cured. Curing can be carried out, in particular, using UV radiation. When plastic is used as the substrate, the positive can directly be the substrate.Alternatively, the positive can subsequently be etched away, whereby the positive represents an etching mask for the underlying material, in particular a glass substrate or a coating.

[0112] For example, based on an image of the transmitted light, the optical combination element 8 is adjusted and aligned to the circuit board 3.

[0113] By adjusting the transmitted light path using, for example, image checking on a ground glass screen, the received path is also adjusted.

[0114] For example, a plurality of optical combination elements 8 are manufactured in a single substrate and then separated.

[0115] For example, the separation is carried out using a laser separation process.

[0116] For example, the substrate has the shape of a CD, a DVD, a Blu-ray disc or an ultra-high-definition disc. Reference symbol:

[0117] 1 optoelectronic sensor 2 sensor housing 3 circuit board 4 light transmitter 5 light receiver 6 first lens 7 second lens 8 optical combination element 9 transmitter aperture 10 receiver aperture 11 diffractive optical element 12 bandpass filter 13 front screen 14 positioning elements 15 optics carrier 16 optical microstructures 17 optical separation media 18 Fresnel lens 19 layers 21 control and evaluation unit

Claims

1. An optoelectronic sensor (1) for object detection, comprising a sensor housing (2), at least one circuit board (3), a light transmitter (4) and a light receiver (5) arranged at a distance therefrom, wherein the light transmitter (4) and the light receiver (5) are arranged on the circuit board (3), and at least a first lens (6), which is arranged upstream of the light transmitter (4), and at least a second lens (7), which is arranged upstream of the light receiver (5), wherein the first lens (6) and the second lens (7) are integrated in a single-piece optical combination element (8), characterized in that the optical combination element (8) has at least one transmitter diaphragm (9) and at least one receiver diaphragm (10), wherein the optical combination element (8) has at least one bandpass filter (12), wherein the optical combination element (8) is composed of a plurality of layers (19) and different layers (19) have different components, wherein one layer has the transmitter diaphragm (9) and the receiver diaphragm (10) and a layer different therefrom has the bandpass filter (12).

2. An optoelectronic sensor (1) according to claim 1, characterized in that the optical combination element (8) has at least one diffractive optical element (11).

3. An optoelectronic sensor (1) according to claim 2, characterized in that the first lens (6) or the second lens (7) is configured as a diffractive optical element (11).

4. An optoelectronic sensor (1) according to any one of the preceding claims, characterized in that the optical combination element (8) forms a front screen (13) of the optoelectronic sensor (1), wherein the front screen (13) forms a part of an outer surface of the sensor housing (2).

5. An optoelectronic sensor (1) according to any one of the preceding claims, characterized in that positioning elements (14) are arranged between the optical combination element (8) and at least one of the circuit boards (3) in order to position and fix the optical combination element (8) on the circuit board or the circuit boards (3).

6. An optoelectronic sensor (1) according to any one of the preceding claims, characterized in that an optics carrier (15) is arranged between the optical combination element (8) and the circuit board (3) in order to position and fix the optical combination element (8) on the circuit board (3).

7. An optoelectronic sensor (1) according to any one of the preceding claims, characterized in that the optical combination element (8) has an anti-reflective coating, an anti-scratch coating and / or an anti-fog coating.

8. An optoelectronic sensor (1) according to any one of the preceding claims, characterized in that the optical combination element (9) has optical microstructures (16).

9. An optoelectronic sensor (1) according to any one of the preceding claims, characterized in that the optical combination element (9) has mechanical microstructures.

10. An optoelectronic sensor (1) according to any one of the preceding claims, characterized in that the optical combination element (8) has optical separation means (17) for optically separating the transmission path and the reception path.

11. An optoelectronic sensor (1) according to any one of the preceding claims, characterized in that the first lens (6) and / or the second lens (7) is / are Fresnel lenses (18).

12. A method for producing an optoelectronic sensor (1) according to claim 1, characterized in that the optical combination element (8) is produced by means of injection molding.

13. A method for producing an optoelectronic sensor (1) according to claim 1, characterized in that the optical combination element (8) is produced by means of a nanoimprint lithography method.

14. A method according to claim 12 or 13, characterized in that the optical combination element (8) is adjusted to and aligned with the circuit board (3) on the basis of an image of the transmission light.

15. A method according to claim 12 or 13, characterized in that a plurality of optical combination elements (8) are produced in a single substrate and are then separated.

16. A method according to claim 15, characterized in that the separation is performed by means of a laser cutting process.

17. A method according to claim 15, characterized in that the substrate has the form of a CD, a DVD, a blue-ray disk or an ultra-high-definition disk.