Optical device for projecting a pattern onto a surface

Abstract

The invention relates to an optical device (20) for projecting a pattern onto a surface (98), the optical device (20) comprising the following: a slide (30), wherein the slide (30), for generating the pattern, refracts and / or diffracts and / or reflects and / or absorbs some of the light radiated into the optical device (20), and a projection optical unit (60), wherein the projection optical unit (60) is designed to image the pattern onto the surface (98), characterised in that the slide (30) and the projection optical unit (60) are designed in a single piece.

Description

[0001] Optical device for projecting a pattern onto a surface

[0002] Description

[0003] The invention relates to an optical device for projecting a pattern onto a surface.

[0004] State of the art

[0005] In difficult-to-access cavities, the flatness of the surface can be measured using a pattern projected onto it using light. For this purpose, light is shone onto the surface using an endoscope, for example, and the projected pattern is optically recorded.

[0006] A slide can be used to create the pattern and a projection lens projects the pattern onto the surface.

[0007] A disadvantage of previously known devices and methods of this type is that the projection optics must be aligned with the slide. Furthermore, the alignment between the slide and the projection optics can change over time, causing the pattern to change.

[0008] Disclosure of the invention

[0009] The invention is based on the object of demonstrating an optical device for projecting a pattern onto a surface, which is technically particularly simple and in which the relative spatial position between a slide of the optical device and a projection optics of the optical device remains reliably unchanged.

[0010] This object is achieved by an optical device for projecting a pattern onto a surface according to claim 1. In particular, the object is achieved by an optical device for projecting a pattern onto a surface, the optical device comprising: a slide, the slide refracting and / or diffracting and / or reflecting and / or absorbing a portion of light radiated into the optical device to generate the pattern, and projection optics, the projection optics being designed to image the pattern onto the surface, characterized in that the slide and the projection optics are formed in one piece.

[0011] One advantage of this is that the optical device is technically very simple. Furthermore, the alignment between the slide and the projection optics cannot change because they are formed as a single piece and thus spatially unchanged. This allows the optical device to project the pattern reliably and precisely. Furthermore, the optical device can be used with incoherent light. This avoids speckle effects. In particular, a multimodal light source with a wide spectral bandwidth can be used to shine the light into the optical device. A further advantage is that the optical device can generate a locally varying intensity distribution and / or angular distribution. In this way, stray light, i.e. unwanted light, can be prevented from contributing to the projected pattern.Portions of the light that are not intended to contribute to the projected pattern can be prevented from reaching the surface onto which the pattern is to be projected by refraction, diffraction, reflection, and / or absorption. The optical device can, in particular, be manufactured in one piece using an additive manufacturing process.

[0012] The invention is also based on the object of demonstrating a light projection device which is technically particularly simple in construction.

[0013] In particular, the object is achieved by a light projection device comprising an optical device as described above and a light source for transmitting light into the optical device, wherein the optical device is arranged on the light source in such a way that, due to refraction and / or diffraction and / or reflection and / or absorption in the slide, only a portion of the light emitted by the light source forms the pattern projected by the optical device. The advantage of this is that the light projection device has a particularly simple technical construction. Furthermore, in the light projection device, the alignment between the slide and the projection optics relative to one another is unchangeable. Since the light from the light source is refracted, diffracted, reflected and / or absorbed by the slide, the light source can emit incoherent light into the optical device. In this way, speckle effects are prevented.

[0014] The invention is also based on the object of demonstrating a method for producing an optical device by means of which an optical device can be produced in a technically simple manner.

[0015] In particular, the object is achieved by a method for producing an optical device, in particular as described above, in an additive manufacturing method, wherein the method comprises the following steps: producing a slide, wherein the slide refracts and / or diffracts and / or reflects and / or absorbs a portion of light radiated into the optical device to produce a pattern on a surface, and - a projection optics, wherein the projection optics are designed to image the pattern onto a surface, wherein the slide and the projection optics are produced in one piece.

[0016] One advantage of this is that the slide and the projection optics can be produced using the same additive manufacturing method. Furthermore, this type of manufacturing ensures the fixed alignment or positioning of the projection optics relative to the slide and vice versa. Shifting, assembly errors during alignment, or similar problems can not occur. Furthermore, the optical device produced using this method can use incoherent (temporally and / or spatially) light. In this way, the speckle effect can be avoided. Furthermore, the manufactured optical device can reliably prevent stray light, i.e. unwanted light, from contributing to the projected pattern or negatively influencing it (e.g., by illuminating dark areas of the pattern with stray light).This can be achieved, for example, by directing the stray light into light traps or absorbing regions within the optics. The additive manufacturing process can, in particular, be a 3D printing process. The invention is also based on the object of demonstrating a method for examining a surface by means of which the properties of the surface can be recorded in a technically simple and reliable manner, even in hard-to-reach areas.

[0017] This object is achieved by a method for examining a surface according to claim 17.

[0018] In particular, the object is achieved by a method for examining a surface, the method comprising the following steps: radiating light through an optical device as described above or from a light projection device as described above or through an optical device produced by a method as described above, to generate a pattern, in particular an at least partially regular pattern, on the surface; detecting the light reflected from the surface; and comparing the reflected light with a target pattern, in particular by means of a machine learning system, to determine properties, in particular unevenness, of the surface.

[0019] The advantage of this method is that it is technically simple and allows the use of incoherent light. This avoids the speckle effect. Furthermore, the method can be carried out reliably and precisely, since the position of the projection optics relative to the slide cannot change, and thus the position and / or shape of the projected pattern cannot change (due to a change in the relative position of the slide to the projection optics). Furthermore, the method enables particularly compact geometries, since the one-piece design eliminates the need for guide or alignment structures.

[0020] According to one embodiment of the optical device, the slide is designed such that the slide is essentially completely transparent to light directed onto the slide. The advantage of this is that all of the light can be used to create the pattern. Thus, very little light is required, and the pattern can be projected onto the surface with particularly high contrast. Also, no light is absorbed by the slide. All of the light or parts of the light can contribute to creating the pattern. Deflected, refracted, diffracted, and / or reflected light can leave the slide in such a way that it does not contribute to creating the pattern. All of the light radiates through the slide in a refracted, diffracted, and / or reflected state.

[0021] According to one embodiment of the optical device, the slide and the projection optics are made of essentially the same, in particular dielectric, material. This is advantageous in that the optical device has an even simpler technical design. Furthermore, the optical device can be manufactured particularly easily. The material can be the same in each case. The material can preferably comprise or be an acrylate-based photopolymer, for example, polymethyl methacrylate (PMMA).

[0022] According to one embodiment of the optical device, the slide is designed such that a portion of the light directed onto the slide is refracted and / or diffracted and / or reflected by the slide in such a way that the refracted and / or diffracted and / or reflected portion of the light radiation does not strike the projection optics. One advantage of this is that unwanted light is not emitted by the optical device in the direction of the surface or the projected pattern. In this way, it can be reliably prevented that the refracted and / or diffracted and / or reflected portion of the light strikes the surface, since it does not even reach the projection optics. Thus, the contrast of the pattern can be particularly high, or a high contrast of the pattern can be achieved even with little light.

[0023] According to one embodiment of the optical device, the projection optics comprises two spaced-apart, particularly aspherical, lenses. This is advantageous in that the focus of the projection optics can be adjusted particularly easily during production, and the projection is particularly distortion-free and generally exhibits fewer image errors. The optical device can comprise more than two spaced-apart, particularly aspherical, lenses.

[0024] According to one embodiment of the optical device, the slide and the projection optics are connected to one another, in particular directly, by a plurality of first webs, wherein the webs are formed integrally with the slide and the projection optics. One advantage of this is that the position of the slide relative to the projection optics is mechanically particularly stable. Thus, the optical device is very robust against mechanical influences. The webs can connect the slide and the projection optics directly to one another, i.e., no further elements are present on the connecting path from the slide to the projection optics other than the first webs.

[0025] According to one embodiment of the optical device, the slide is designed such that at least a first region of the slide refracts and / or diffracts and / or reflects and / or absorbs light of different wavelengths differently. One advantage of this is that different patterns can be projected using light of different wavelengths using the same slide. It is thus conceivable that a first pattern (e.g. a striped pattern with horizontal stripes) can be projected using yellow light and that a second pattern (e.g. a striped pattern with vertical stripes and / or a pattern with one or more circles) that differs from the first pattern can be projected using red light using the same slide. This allows the surface to be examined even more precisely.

[0026] According to one embodiment of the optical device, the slide is designed such that, when white light is irradiated into the optical device, the projected pattern has at least one area with a gray tone. This is advantageous because white light can be used to create not only white and black areas of the pattern, but also areas of the pattern that have a gray tone or different gray tones. Thus, even with white light, the pattern can have more than two colors (where black and white are counted as colors), namely, for example, black, gray, and white.

[0027] According to one embodiment of the light projection device, the optical device is arranged on the light source in such a way that the light emitted by the light source only partially passes through the optical device due to refraction and / or diffraction and / or reflection and / or absorption in the slide. This is advantageous in that unwanted light does not leave the optical device. This ensures that this light does not contribute to or negatively influence the pattern. Furthermore, this ensures that the light projection device projects a pattern with high contrast even in low light.

[0028] According to one embodiment of the light projection device, the light source comprises a, particularly multimodal, fiber optic cable, a waveguide, and / or an LED. This is advantageous in that the light projection device is technically particularly simple and cost-effective. Furthermore, the light projection device can be designed to be particularly compact.

[0029] According to one embodiment of the light projection device, the light source is formed integrally with the optical device. One advantage of this is that the light projection device can be manufactured technically easily. Furthermore, slipping / displacement of the optical device relative to the light source and / or detachment of the optical device from the light source is reliably prevented. This ensures that the light from the light source is always radiated into the optical device at the same angle.

[0030] According to one embodiment of the light projection device, the light source is configured such that the light source emits light onto the optical device in a conical shape, in particular a circular conical shape, with an aperture angle of a maximum of 30°, in particular a maximum of 15°, preferably a maximum of 5°. This allows a particularly detailed pattern to be projected. Thus, the surface can be examined in particularly detailed detail using the light projection device.

[0031] According to one embodiment of the method for manufacturing an optical device, the optical device is additively manufactured directly on a light source for radiating light into the optical device. This is advantageous in that the optical device cannot change its position relative to the light source. In particular, detachment of the optical device from the light source is reliably prevented. Furthermore, this manufacturing method ensures that the light source always radiates the light into the optical device at the same angle. Furthermore, the manufacturing method is technically particularly simple.

[0032] According to one embodiment of the method for manufacturing an optical device, the slide is manufactured in such a way that only a portion of the light radiated into the optical device reaches the projection optics. This is advantageous because unwanted light reliably does not negatively affect the projected pattern. Because part of the light, namely the unwanted part, does not reach the projection optics at all, the pattern is reliably unaffected by this part of the light. Consequently, a particularly high pattern contrast can be achieved.The refraction, diffraction, reflection and / or absorption of the light irradiated into the optical device by the slide can be carried out, for example, by the following measures: refractive deflection by the slide; deflection by total internal reflection within the slide; generation of a point array or intermediate image by means of a lens structure of the slide, wherein the point array is spaced from the slide; reflection based on a Fabry-Perot resonator structure; deflection by a grating of the slide; absorption by absorbing materials of the slide; and / or absorption by fluids, in particular liquids, introduced into the slide after the optical device has been manufactured.

[0033] A pattern can in particular be understood as an at least partially regular structure. The pattern typically comprises simple geometric figures or structures (e.g. straight lines, circles, etc.). For example, the pattern can be a striped pattern and / or a pattern with ellipses and / or circles. The pattern can in particular consist of lighter and darker areas (i.e. areas that are weakly or not at all illuminated). These areas can in particular alternate regularly within the pattern. The pattern does not necessarily have to have repeating structures, but can, for example, only have a single geometric shape (e.g. a circle, an ellipse, a rectangle and / or a triangle). The pattern can have repeating structures (e.g. have a striped pattern). The pattern can also consist, for example, of a pixelated arrangement of gray values ​​that, when put together, create an image.

[0034] The projection optics can, in particular, comprise one or more lenses. The projection optics can focus the light or project the pattern onto the surface. The location of the focus or image can be the surface of the material whose properties are to be captured, or it can be in front of or behind the surface of the material.

[0035] The shape of the projected pattern or patterns is known or can be easily determined. By comparing the visible pattern on the surface and how the pattern should look on a target surface (target pattern) - e.g., if the surface is flat and parallel to the slide or one of the lenses, the projected pattern should correspond exactly to the target pattern - the properties of the surface can be easily determined. Distortions, shifts, or similar of the projected pattern or part of it on the surface allow conclusions to be drawn or determinations to be made about the shape and / or orientation of the surface. For example, the projected pattern or target pattern can be a circle. If this circular pattern on the surface is distorted into an ellipse, or if an ellipse is visible on the surface, the surface is tilted or misaligned relative to a line parallel to the slide or lens.the surface has a non-zero angle to the parallel to the slide or lens.

[0036] The slide may in particular comprise three-dimensional slide structure elements through which the light is partially refracted and / or diffracted and / or reflected and / or absorbed and through which the light is partially transmitted substantially unchanged and substantially unchanged in its propagation direction.

[0037] Preferred embodiments are set out in the dependent claims. The invention is explained in more detail below with reference to drawings of exemplary embodiments.

[0038] Fig. 1 is a schematic side view of an embodiment of the light projection device according to the invention;

[0039] Fig. 2 is a detailed view of a first embodiment of the slide of the light projection device from Fig. 1;

[0040] Fig. 3 is a detailed view of a second embodiment of the slide of the light projection device from Fig. 1;

[0041] Fig. 4 is a detailed view of a third embodiment of the slide of the light projection device from Fig. 1; Fig. 5 is a detailed view of a fourth embodiment of the slide of the light projection device from Fig. 1;

[0042] Fig. 6 is a detailed view of a fifth embodiment of the slide of the light projection device from Fig. 1;

[0043] Fig. 7 is a detailed view of a sixth embodiment of the slide of the light projection device of Fig. 1;

[0044] Fig. 8 is a detailed view of a seventh embodiment of the slide of the light projection device of Fig. 1;

[0045] Fig. 9 is a detailed view of an eighth embodiment of the slide of the light projection device of Fig. 1; and

[0046] Fig. 10 is a detailed view of a ninth embodiment of the slide of the light projection device from Fig. 1.

[0047] In the following description, the same reference numbers are used for identical and equivalent parts.

[0048] Fig. 1 shows a schematic side view of an embodiment of the light projection device 10 according to the invention.

[0049] The light projection device 10 is designed to project a pattern onto a surface 98 of a material 97. The light projection device 10 comprises a light source and an optical device 20. The light source can generate the light itself (e.g., LED) or guide the light from a light-generating device and thus represent a light source. The light source can comprise a, in particular multimodal, glass fiber 90, a waveguide and / or an LED. The light can be (temporally or spatially) incoherent light. The light source, e.g., the glass fiber 90, can have a small diameter (e.g., less than 500 pm). A broad wavelength spectrum can be used. This prevents a speckle effect. For example, the light projection device 10 or the optical device 20 of the light projection device 10 can be arranged on or in a photonic integrated circuit (PIC) or can be a part thereof.

[0050] It is conceivable that the optical device 20 is formed integrally with the light source. Thus, the optical device 20 is immovable relative to the light source.

[0051] The optical device 20 comprises a slide 30 and a projection optic 60. The light from the light source is radiated into the optical device 20. Using the light, the optical device 20 projects a pattern onto a surface 98 of a material 97. The pattern, or the pattern visible on the surface 98, can be optically detected.

[0052] Slide 30 generates a spatially varying intensity or angular distribution. Slide 30 thereby generates the pattern, and projection optics 60 focuses the rays of the pattern or the pattern and / or projects the pattern onto the surface.

[0053] The slide 30 can in particular be designed in the shape of a circular disk.

[0054] The optical device 20 is manufactured in one piece using an additive manufacturing process. The slide 30 and the projection optics 60 are manufactured using the same additive manufacturing process. This means that the slide 30 and the projection optics 60 were formed in a common or single manufacturing process. As a result, no alignment or orientation of the slide 30 relative to the projection optics 60 is necessary after production. Slipping or displacement relative to one another is also not possible. The distance between the slide 30 and the projection optics 60 cannot change either. Thus, the shape of the pattern cannot change due to a change in the position of the projection optics 60 relative to the slide 30. The projection optics 60 can comprise one or more lenses 62, 64. For example, the projection optics 60 has two, in particular aspherical, lenses 62, 64.The projection optics 60 can extend over the entire width or diameter of the slide 30 or have an even greater width or diameter than the slide 30.

[0055] The slide 30 and the projection optics 60, or the lens 62, 64 or lenses 62, 64 of the projection optics 60, can be made of the same material, in particular a dielectric material. This simplifies the manufacturing process through an additive manufacturing process.

[0056] The slide 30 is connected to the projection optics 60 via a plurality of webs 70, 80. The slide 30 can be directly or immediately connected to the projection optics 60 via a plurality of webs 70, 80. This means that the slide 30 is not arranged on a substrate or the like, with the substrate being connected to the projection optics 60, but rather that the slide 30 is directly or immediately connected (without detours or further intermediate elements) to the webs 70, 80, and the webs 70, 80 are directly connected (without detours or further intermediate elements) to the projection optics 60.

[0057] First ridges 70 are arranged between the slide 30 and a first lens 62 of the projection optics 60. Second ridges 80 can be arranged between the first lens 62 and the second lens 64. The ridges 70, 80 are produced using the same additive manufacturing process in which the slide 30 and the projection optics 60 were manufactured. Thus, the slide 30, the projection optics 60, and the ridges 70, 80 are integrally formed or were manufactured using an additive manufacturing process. This makes the optical device 20 particularly robust against mechanical influences.

[0058] The slide 30 has a plurality of slide structure elements 32-38. The slide structure elements 32-38 are located on the side of the slide 30 facing the projection optics 60. This means that the slide 30 can be flat on the side associated with the light source and not flat on the side associated with the projection optics 60, but rather has an uneven or non-flat structure due to the slide structure elements 32-38. The slide structure elements 32-38 refract and / or diffract and / or reflect and / or absorb the light or a portion of the light and / or deflect the light or a portion of the light. It is possible for the slide 30 to have no absorbing slide structure elements 32-38. This means that no portion of the light is absorbed by the slide 30. The light is only refracted and / or diffracted and / or reflected.

[0059] The additive manufacturing process may include a 3D printing process, e.g. multi-jet fusion, fused layer modeling, free-jet material deposition processes such as poly-jet modeling or multi-jet modeling, laser sintering, laser beam melting, electron beam melting, digital light processing, stereolithography and / or two-photon lithography.

[0060] Fig. 2 shows a detailed view of a first embodiment of the slide 30 of the light projection device 10 from Fig. 1. The slide structure elements 32-38 comprise a plurality of elements with a triangular cross-section, which are at an angle to the output surface 95 of the light source and refractively deflect the light, and a plurality of elements with a rectangular cross-section, the surface of which facing away from the light source runs parallel to the output surface 95 of the light source and which transmit the light essentially unhindered and unchanged in its propagation direction. The slide structure elements 32, 33, 35, 36 with a triangular cross-section can have a tetrahedral shape. The slide structure element(s) 34 with a rectangular cross-section can have a cuboid shape and / or a cube shape. The slide 30 or the side of the slide 30 facing the light source runs parallel to the output surface 95 of the light source.

[0061] From the left in Fig. 2, incoming light 50 enters the slide 30. As a result, light exits the slide 30, which projects the pattern or is projected by means of the projection optics 60 (also called useful light 52, 53, 54), which is represented by an arrow pointing horizontally to the right in the upper part of Fig. 2. In addition, part of the light is deflected by the slide 30 (shown by arrows pointing to the top right and bottom right in Fig. 2). This deflected light is not projected onto the surface 98 (also called false light 55-59). It is possible that this deflected light does not reach the projection optics 60 or does not reach the surface 98 of the material 97 from the projection optics 60, at least not directly (i.e. at least not without further reflection and / or refraction and / or diffraction). A first part of the light thus passes through the slide 30 essentially unchanged and unchanged in its direction.This first portion of the light is focused by the projection optics 60 to form the pattern on the surface 98, or this first portion of the light is radiated by the projection optics 60 to image the pattern onto the surface 98. A second portion of the light is refracted, diffracted, absorbed, and / or reflected by the slide 30 in such a way that this second portion either does not reach the projection optics 60 at all, or this second portion is not imaged and / or focused by the projection optics 60 to form the pattern. The second portion of the light therefore does not reach the area of ​​the surface 98 of the pattern onto which the pattern is projected.

[0062] For example, the light projection device 10 can be inserted into an opening of a small-diameter depression in order to examine, for example, the surface 98 of the end of the depression. For this purpose, the pattern is radiated onto the surface 98 of the end of the depression using the light projection device 10. The reflected light from the surface 98 is detected using an optical detection device. The visible pattern or visible reflected light on the surface 98 can be compared with the emitted pattern. This can be carried out either by a person or by a computer or software (e.g., a machine learning system). In this way, the unevenness of the surface 98 can be detected or determined. A tilt of the surface 98 relative to a parallel to a lens 62, 64 or the slide 30 of the projection optics 60 can also be detected.

[0063] In this way, a pattern can be created technically easily. The projection optics 60 focuses the light that reaches the projection optics 60, or images the pattern onto the surface 98. The focus can be on the surface 98 of the material 97. It is also conceivable that the focus lies between the projection optics 60 and the surface 98 of the material 97, i.e., in front of the surface 98. It is also possible for the focus to lie behind the surface 98 of the material 97.

[0064] The projection optics 60 are not shown in Fig. 2 or in the following Figs. 3-10. The projection optics 60 are located to the right of the slide 30 shown in Figs. 2-10. The light source is located to the left of the slide 30 in Figs. 2-10 or can be located to the left of the slide 30 in Fig. 2-10. In Figs. 2-10, only a part or a section of the slide 30 can be shown at a time. This means that there can be several areas through which the light is transmitted essentially unchanged and not just one area, as partially shown in Figs. 2-10. This also means that the number of slide structure elements 32-38 is larger, in particular much larger, than shown in each case in Figs. 2-10. The number of slide structure elements 32-38 can be in the range of hundreds, thousands, tens of thousands, hundreds of thousands or millions.

[0065] The light emerging from slide 30 and contributing to the pattern is also called useful light 52, 53, 54. The light emerging from the slide (refracted, diffracted, reflected) and not contributing to the pattern is also called false light 55-59.

[0066] The slide structure elements 32-38 are manufactured using the additive manufacturing process (together with the projection optics 60). The slide structure elements 32-38 of the slide 30 generate the pattern, which is focused by the projection optics 60 and projected onto the surface 98 of the material 97, or is imaged onto the surface 98 by the projection optics 60. The pattern generated by the slide 30 can, of course, be modified by the projection optics 60, or the pattern can be created by the projection optics 60.

[0067] The pattern visible on the surface 98 of the material 97 can be optically detected. By comparing a target pattern (e.g., the projected pattern on a flat surface parallel to the output surface 95 of the light source) with the optically detected visible pattern on the surface 98, the properties of the surface 98 of the material 97 can be detected. The optical detection can be performed, for example, using an endoscopic camera.

[0068] The properties of surface 98 can, in particular, be unevenness or elevations and / or depressions on surface 98. An angle of surface 98 relative to the parallel of the output surface 95 of the light source can also be determined in this way. The comparison can be performed using a computer or software. A machine learning system can also be used here. The pattern can comprise a striped pattern and / or one or more circles and / or one or more rectangles. The pattern can, in particular, be static.

[0069] The slide 30 or the slide structure elements 32-38 can be manufactured additively, e.g., 3D-printed, directly or immediately on the light source or the output surface 95 of the light source. Thus, the slide 30, the projection optics 60, and the light source are manufactured as a single piece.

[0070] Each slide 30 has a projection optics 60, and vice versa. This means that exactly one slide 30 is assigned to each projection optics 60, and exactly one projection optics 60 is assigned to each slide 30. The slide 30 is thus formed integrally with exactly one projection optics 60, and the projection optics 60 is formed integrally with exactly one slide 30. It is possible for an optical device 20 to have exactly one slide 30 and exactly one projection optics 60.

[0071] The first version of slide 30 allows all the incident light to pass through. It only partially changes the direction of the light.

[0072] Fig. 3 shows a detailed view of a second embodiment of the slide 30 of the light projection device 10 from Fig. 1.

[0073] The second embodiment differs from the first embodiment of the slide 30 in that, in the second embodiment, in contrast to the first embodiment of the slide 30, the slide structure element 32-38 that transmits the light essentially undeflected is arranged on the side facing away from the output surface 95 of the light source (on the right in Fig. 3) at a distance from deflecting elements (elements with a triangular cross-section). A slide structure element 32-38 that transmits the light essentially unchanged is arranged in the center of the slide 30. The second embodiment of the slide 30 also transmits the light radiated into the slide 30 from the light source completely, or is transparent to the light. The direction of a portion of the light is merely changed.

[0074] Fig. 4 shows a detailed view of a third embodiment of the slide 30 of the light projection device 10 from Fig. 1.

[0075] The third embodiment differs from the first embodiment in that the slide structure elements 32-38 (triangular in cross-section) that deflect the light in the third embodiment have a different angle to the output surface 95 of the light source than in the first embodiment, so that the light is deflected multiple times, resulting in total internal reflection. The slide structure element 32-38 (rectangular in cross-section) in Fig. 4, shown in the center of Fig. 4, allows the light to pass unobstructed through the slide 30. Thus, some of the light is totally reflected, while another part of the light is passed through the slide 30 essentially unchanged.

[0076] Fig. 5 shows a detailed view of a fourth embodiment of the slide 30 of the light projection device 10 from Fig. 1. In the fourth embodiment, the slide structure elements 32-38 have at least a partially triangular shape in cross-section. The incident light 50 is initially partially totally reflected, then refracted, and then deflected to the side, so that the light does not reach the projection optics 60. Thus, with appropriate angles of the slide structure elements 32-38, totally reflected light can also exit the slide 30 in the direction of the projection optics 60 and be deflected laterally past the entrance aperture of the projection optics 60. In regions of the slide 30 that do not have a triangular shape in cross-section, the incident light 50 passes through the slide 30 essentially unhindered and unchanged in direction. This light is then useful light 52, 53, 54.

[0077] Fig. 6 shows a detailed view of a fifth embodiment of the slide 30 of the light projection device 10 from Fig. 1. The slide structure elements 32-38 in the fifth embodiment have a lens-like structure. As a result, the light is redistributed, deflected, and / or diffracted in such a way that a type of point array or other intermediate image is generated on a plane spaced from the slide 30, at whose points the light is focused. This point array is projected onto the surface 98 of the material 97 by means of the projection optics 60. No part of the light is deflected, refracted, diffracted, or the like in such a way that it does not contribute to the generation of the pattern. The advantage of this is that all of the light is used to generate the pattern. This allows the pattern to be particularly high-contrast. The pattern that is radiated onto the surface 98 of the material 97 is first generated by the projection optics 60.

[0078] Fig. 7 shows a detailed view of a sixth embodiment of the slide 30 of the light projection device 10 from Fig. 1. The slide 30 comprises a Fabry-Perot resonator, or the slide structure elements 32-38 form Fabry-Perot resonator structures. As a result, the light is essentially completely reflected in one area (left and right of the center in Fig. 6). In the center, the light is passed through the slide 30 essentially unchanged.

[0079] Fig. 8 shows a detailed view of a seventh embodiment of the slide 30 of the light projection device 10 from Fig. 1. In the seventh embodiment, the slide structure elements 32-38 form a grating by which the light is diffracted. In Fig. 7, the formed grating can be seen at the top and bottom of the center. As a result, the light is diffracted (diffraction orders 0) in such a way that the light either does not reach the projection optics 60 at all or, after passing through the projection optics 60, does not contribute to generating the pattern. The deflected light is shown in Fig. 7 by arrows pointing diagonally to the top right and bottom right, respectively. The arrow pointing horizontally to the right in the upper part of Fig. 7 shows the light that generates or projects the pattern.

[0080] Fig. 9 shows a detailed view of an eighth embodiment of the slide 30 of the light projection device 10 from Fig. 1. During the production of the eighth embodiment of the slide 30, the light-absorbing and / or strongly scattering slide structure elements 32-38 are also produced during the additive manufacturing process. Thus, a portion of the light, or the light in designated areas of the slide 30, is absorbed and does not reach the projection optics 60. Another portion of the light is transmitted through the slide 30 essentially unchanged.

[0081] Fig. 10 shows a detailed view of a ninth embodiment of the slide 30 of the light projection device 10 from Fig. 1. In the ninth embodiment, there are regions of the slide 30 or of the slide structure elements 32-38 that have a receiving space. Material that partially or completely absorbs the light can be introduced into this receiving space or into the receiving spaces during the additive production of the slide 30 (and thus also of the projection optics 60). It is also conceivable that the material that partially or completely absorbs the light is introduced into the receiving space or spaces after the additive production of the slide 30 and the projection optics 60. The material can in particular be a fluid, preferably a liquid. This liquid can additionally be curable and, for example, polymerize or dry out.The storage rooms can be lockable so that they are permanently closed or reopenable after the material has been introduced.

[0082] It is possible for the slide 30 or the optical device 20 to produce a black and white pattern. However, it is also conceivable for the slide 30 or the optical device 20 to produce a pattern that includes one or more shades of gray in addition to black and white. For this purpose, the light is only partially absorbed and / or refracted and / or reflected and / or scattered.

[0083] The slide 30 can be designed such that different areas of the slide 30 are permeable to different wavelengths of light or to different colored light, or that the light refracts, bends, reflects, and / or absorbs differently depending on the wavelength. This allows a different pattern to be projected with light of a first wavelength (e.g., blue light) than with light of a second wavelength (e.g., red light). This is possible with all of the above-described embodiments of the slide 30. Thus, different patterns can be projected onto the surface 98 in succession by changing the light.

[0084] It is also conceivable that when white light 50 is irradiated into the optical device 20, colored patterns are projected by the optical device 20.

[0085] List of reference symbols:

[0086] 10 Light projection device

[0087] 20 optical device

[0088] 30 slides

[0089] 32-38 Slide structure element Incident light , 53, 54 Useful light -59 False light Projection optics First lens Second lens First bars Second bars Fiber optic Output surface of the light source Material Surface of the material

Claims

Claims 1. An optical device (20) for projecting a pattern onto a surface (98), the optical device (20) comprising: a slide (30), the slide (30) refracting and / or diffracting and / or reflecting and / or absorbing a portion of light radiated into the optical device (20) to produce the pattern, and projection optics (60), the projection optics (60) being configured to image the pattern onto the surface (98), characterized in that the slide (30) and the projection optics (60) are configured as a single piece.

2. Optical device (20) according to claim 1, wherein the slide (30) is designed such that the slide (30) is substantially completely transparent to light directed onto the slide (30).

3. Optical device (20) according to claim 1 or 2, wherein the slide (30) and the projection optics (60) are formed from substantially the same, in particular dielectric, material.

4. Optical device (20) according to one of the preceding claims, wherein the slide (30) is designed such that a part of the light directed onto the slide (30) is refracted and / or diffracted and / or reflected by the slide (30) such that the refracted and / or diffracted and / or reflected part of the light radiation does not fall onto the projection optics (60).

5. Optical device (20) according to one of the preceding claims, wherein the projection optics (60) comprises two spaced-apart, in particular aspherical, lenses (62, 64).

6. Optical device (20) according to one of the preceding claims, wherein the slide (30) and the projection optics (60) are connected to one another by a plurality of first webs (70), in particular directly, wherein the webs (70) are formed integrally with the slide (30) and the projection optics (60).

7. Optical device (20) according to one of the preceding claims, wherein the slide (30) is designed such that at least a first region of the slide (30) refracts and / or diffracts and / or reflects and / or absorbs light of different wavelengths differently.

8. Optical device (20) according to one of the preceding claims, wherein the slide (30) is designed such that the projected pattern has at least one area with a shade of gray when white light is irradiated into the optical device (20).

9. Light projection device (10) comprising an optical device (20) according to one of the preceding claims, and a light source for transmitting light into the optical device (20), wherein the optical device (20) is arranged on the light source such that the light emitted by the light source forms the pattern projected by the optical device (20) due to refraction and / or diffraction and / or reflection and / or absorption in the slide (30).

10. Light projection device (10) according to claim 9, wherein the optical device (20) is arranged on the light source such that the light emitted by the light source only partially passes through the optical device (20) due to refraction and / or diffraction and / or reflection and / or absorption in the slide (30).

11. Light projection device (10) according to claim 9 or 10, wherein the light source comprises a, in particular multimodal, glass fiber (90), a waveguide and / or an LED.

12. Light projection device (10) according to one of claims 9-11, wherein the light source is formed integrally with the optical device (20).

13. Light projection device (10) according to one of claims 9-12, wherein the light source is designed such that the light source projects light onto the optical device (20) in a conical shape, in particular a circular conical shape, with an opening angle of maximum 30°, in particular maximum 15°, preferably maximum 5°.

14. A method for producing an optical device (20), in particular according to one of claims 1-8, in an additive manufacturing process, the method comprising the following steps: Produce - a slide (30), wherein the slide (30) refracts and / or diffracts and / or reflects and / or absorbs a portion of light radiated into the optical device (20) to produce a pattern on a surface (98), and - a projection optics (60), wherein the projection optics (60) are designed to image the pattern onto a surface (98), wherein the slide (30) and the projection optics (60) are manufactured in one piece.

15. The method according to claim 14, wherein the optical device (20) is additively manufactured directly on a light source for radiating light into the optical device (20).

16. The method according to claim 14 or 15, wherein the slide (30) is manufactured in such a way that only a part of the light radiated into the optical device (20) reaches the projection optics (60).

17. A method for examining a surface (98), the method comprising the following steps: Radiating light through an optical device (20) according to one of claims 1-8 or from a light projection device (10) according to one of claims 9-13 or through an optical device (20) produced by means of a method according to one of claims 14-16, to produce a, in particular at least partially regular, pattern on the surface (98); detecting the light reflected from the surface (98); and Comparing the reflected light with a target pattern, in particular by means of a machine learning system, to determine properties, in particular unevenness, of the surface (98).

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