Lighting device for photosensor for detecting object in monitoring area, and photosensor
By designing a diffusing device with a bent portion to compensate for distortion of the receiving optical device, accurate imaging of the emitted light pattern of the photoelectric sensor on the optical receiver is achieved, and spatial resolution and distance measurement accuracy are improved.
Patent Information
- Application Number
- CN202510035604.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2024-01-09
- Filing Date
- 2025-01-09
- Publication Date
- 2025-07-11
AI Technical Summary
When the lighting device of existing photoelectric sensors generates a bar-shaped emitted light pattern, distortion of the receiving optical device causes the emitted light pattern to be unable to accurately image on the light receiver, affecting the accuracy of spatial resolution and distance measurement.
A diffusing device is designed with an effective area including a bend such that the emitted light pattern produces a curved distortion extension in the angular space to compensate for distortion by receiving the optics, ensuring that the light is imaged on the light receiver as a straight extension without distortion.
Accurate imaging of the emitted light pattern on the light receiver is achieved, the spatial resolution and distance measurement accuracy of the photoelectric sensor are improved, and the reduction of the photoelectric sensor sensitivity in the edge area is avoided.
Smart Images
Figure CN120294857A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to an illumination device for an optoelectronic sensor, which is arranged to detect an object in a monitoring area. The optoelectronic sensor includes: a light emitting device arranged to emit emitted light into the monitoring area, and the light emitting device includes at least one light source; an emission optical device including at least one emission optical element and arranged to focus the emitted light; and a diffusion device including at least one linear diffuser, and the diffusion device is arranged such that the focused emitted light is scattered in a first spatial direction and such that the focused emitted light is substantially not scattered in a second spatial direction orthogonal to the first spatial direction. The light emitting device, the emission optical device and the diffusion device are designed to generate a bar-shaped emitted light pattern on an object present in the monitoring area, and the bar-shaped emitted light pattern includes a plurality of light rays. Background Art
[0002] In the case of an optoelectronic sensor operating according to the principle of a light detector (Lichttaster), the illumination device and a receiving device arranged to detect a received optical signal are located on the same side of the monitoring area. If an object is present in the monitoring area, the emitted light emitted by the light emitting device is emitted on the surface of the object in the direction of the receiving device, i.e., diffusely reflected or specularly reflected. In order to perform spatially resolved detection of the object, the receiving device may include a light receiver having a one-dimensional or two-dimensional array of photosensitive receiving elements and receiving optics, wherein, for example, spatially resolved detection of the imaging of the emitted light pattern projected by the illumination device onto the object can be achieved. A light receiver having a two-dimensional array of photosensitive receiving elements typically has a matrix-like, rectangular and equidistant arrangement of multiple rows of receiving elements.
[0003] In various applications, it is desirable to obtain not only the spatial resolution in one or two lateral dimensions, but also to determine distance information or depth information about the detected object as another dimension. Such a ranging optical sensor or ranging light detector is also referred to as a lidar (Light Detection And Ranging) sensor or lidar system (lidar is an abbreviation of the English "Light Detecting And Ranging"). For this type of sensor, a special light receiver is usually used, which is configured, for example, to determine distance information according to the time-of-flight method (Lichtlaufzeitverfahren). Such a light receiver or sensor array is also called a TOF sensor (TOF is an abbreviation of the English "Time Of Flight", a synonym for "time of flight"). The TOF sensor is designed to record the transit time between the time point of its emission of a light pulse and the time point of detection of the corresponding light pulse reflected on an object, and to record it separately for each photosensitive element of the TOF sensor.
[0004] Such TOF sensors can usually only be read out row by row, which means that for a given time, only one row of photosensitive elements of the TOF sensor can be evaluated. In order to obtain higher energy efficiency when generating the emitted light than full-surface illumination of the monitoring area, and also to avoid unwanted crosstalk effects It is desirable to illuminate only those areas of the monitoring area or the surface of the object to be detected, which can actually also be detected by the corresponding activated rows of the light receiver due to the geometry in the receiving optical path. For this purpose, the light emitting device is configured and operated to generate a bar-shaped emitted light pattern, which includes a plurality of light rays. For this purpose, the imaging characteristics of the light emitting device and the receiving device are coordinated with each other in such a way that each light ray of the emitted light pattern is imaged as concentrated as possible on one row of the light receiver. For example, a plurality of light rays are sequentially generated by sequentially activating the individual light sources of the light emitting device.
[0005] The following refers to Figures 1 to 4 explain the problem underlying the present invention in the case of generating a bar-shaped emitted light pattern using a conventional lighting device.
[0006] According to Figure 1 and Figure 2 As shown, a single light ray can be generated by the lighting device 100. The emission optics 12 is arranged behind the point light source 10, and the emission optics 12 causes the divergent emitted light emitted by the point light source 10 to form a parallel light beam 14. A diffusing device with a so-called one-dimensional (1D) diffuser or linear diffuser 16 is arranged behind the emission optics 12. The linear diffuser 16 expands the parallel light beam 14 into a fan shape by scattering in the first spatial direction (see Figure 2: in the X direction), while in the second spatial direction, at least substantially, i.e., except for an unavoidable degree due to structure and manufacturing technology, there is no influence on the light beam (see Figure 1 : the Y direction). Such a linear diffuser 16 can be designed, for example, as a plate or film having an effective area that includes linear structures that produce a desired fan-shaped expansion of the light beam 14. In accordance with Figures 1 to 3 of the linear diffuser 16, these linear structures extend in the Y direction.
[0007] To generate multiple light rays spaced apart from each other, the lighting device 200 in accordance with Figure 3 can provide multiple point light sources 10 that are arranged laterally spaced apart from each other. In the lighting device 200, exemplarily, three point light sources 10 are provided, which are described as "0", "+1", and "-1", and are spaced apart from each other in the Y direction. When the light beam 14 emitted by the point light source "0" extends along the optical axis OA of the lighting device 200, the light beams 14 emitted by the point light sources "+1" and "-1" extend obliquely downward and upward, respectively. Each of these light beams 14 is fan-shapedly expanded, thereby generating an emitted light pattern that appears in the angular space as a light pattern having multiple linearly extending parallel light rays, which will be explained in more detail below.
[0008] Such an emitted light pattern or emission profile is exemplarily shown in Figure 4 for a lighting device having seven point light sources. The angular distribution of the emission profile (where the polarization angle is plotted relative to the azimuth angle) is represented by a large number of dot-like symbols, which are shown as thinner lines in Figure 4 . The polarization angle corresponds to the respective tilt angle of the light beam 14 emitted by the corresponding point light source 10 with respect to the optical axis OA, and thus corresponds to the Y position of the respective symbol. The azimuth angle corresponds to the respective scattering angle of the fan-shaped expansion, and thus corresponds to the X position of the respective symbol.
[0009] For imaging such an emission profile in the received light pattern on a light receiver having multiple rows of receiving elements, it is preferable to use receiving optics including an equiangular imaging function, also known as a flat-field focusing (F-theta) lens. However, using such receiving optics results in distortion of the imaging of the emission profile. The corresponding angular distribution of such a distorted received light pattern or received profile is shown in Figure 4 by a large number of circular symbols, shown here as thicker lines. It can be clearly seen from Figure 4 that the emission profile (i.e., the angular profile generated by the emission unit) and the received profile are significantly different from each other. Due to this deviation, it is no longer possible to obtain an imaging of the emitted light that is adapted to the rows of the light receiver. Especially at the edges, this deviation causes the corresponding edge portions of the emitted light rays not to be imaged or only partially imaged on the designated rows of the light receiver. SUMMARY OF THE INVENTION
[0010] The object of the present application is to create an illumination device for an optoelectronic sensor, by means of which an emitted light pattern can be generated, which can also be imaged on a light receiver as a received light pattern consisting of rays extending as straight as possible by means of a distorted receiving optical device.
[0011] This object is achieved by an illumination device having the features of claim 1.
[0012] According to the present application, the effective area of the diffusing device includes a bent portion which is designed such that a reference-emitted light pattern (which, when generated by a reference-diffusing device having a flat effective area, includes rays extending straight in an angular space) is distorted in such a way that the rays include a bent and distorted extension in the angular space.
[0013] In the angular space, i.e., in the spatial polar coordinate system described by the polarization angle and the azimuth angle, a ray having a straight extension is understood as such a linear region for which the polarization angle is the same for different azimuth angles. Thus, a ray having a bent and distorted extension in the angular space is understood as such a linear region for which, in the angular space, the polarization angle is different for different azimuth angles.
[0014] In the case of a single linear diffuser, the effective area of the diffusing device corresponds to the effective area or effective surface which causes the aforementioned scattering in one spatial direction. If the diffusing device includes a plurality of linear diffusers, the effective area of the diffusing device consists of the respective effective areas of the different linear diffusers. Thus, the bent portion of the effective area can include a continuous or discrete extension, which will be explained in more detail below.
[0015] In particular, the above-mentioned reference-emitted light pattern is a virtual emitted light pattern introduced in the present application for use as a reference when describing the effect of the bent portion of the diffusing device. The rays of the reference-emitted light pattern (corresponding to Figure 4 the emission profile represented by dot symbols in) extend in the angular space, more precisely, in the imaginary projection on the spherical shell of the polar coordinate system, the straight and in particular also parallel planar effective areas of the reference-diffusing device extend orthogonally with respect to the optical axis of the illumination device in this perspective.
[0016] The above-described curved and distorted extension of the light rays of the "real" emitted light pattern should be understood such that in angular space (i.e., in the imaginary projection on the spherical shell of the polar coordinate system), the light rays or the emitted light pattern have a distortion in the optical sense. This optical distortion is described in particular in such a way that the light rays extend straight through the geometric center of the emitted light pattern, and the light rays that do not extend through the center are curved, where the radius of curvature of the light rays decreases as the distance of the light rays from the center increases (i.e., the bend becomes more curved as the distance increases). If the light rays are convexly curved with respect to the center, it is a cushion distortion; if the light rays are concavely curved, it is a barrel distortion.
[0017] The design of the lighting device according to the present application enables the monitoring area of the optoelectronic sensor to be illuminated by a distorted linear emitted light pattern, such that the distorted emitted light pattern can be imaged by the receiving optics of the receiving device as a received light pattern on the light receiver of the receiving device, and the lines of the received light pattern have a distortion-free and substantially straight extension.
[0018] In principle, the above-described generation of the bar-shaped emitted light pattern should not be uniquely understood such that all the light rays of the emitted light pattern must be generated at the same point in time. On the contrary, it is preferably generated in such a way that multiple light rays can also be generated one after the other in time (i.e., sequentially). This will be explained in more detail below.
[0019] According to a preferred embodiment, the bend of the effective area of the diffusing device extends only in one dimension, where the bend extends in a plane spanned by the optical axis of the lighting device and a second spatial direction, and the optical axis extends through the light emitting device, the emitting optics, and the diffusing device. The optical axis of the light emitting device. Thus, the effective area does not have a spherical bend, but a cylindrical bend. The axis of symmetry or central axis of the cylindrical shape of the effective area extends correspondingly in the above-mentioned first spatial direction.
[0020] Advantageously, the diffusing device is aligned with respect to its bend such that the above-mentioned axis of symmetry extends parallel to the rows of the photosensitive elements of the associated receiving device.
[0021] According to another preferred embodiment, the effective area of the diffusing device is concave-curved with respect to the side of the diffusing device facing the emitting optical device. This results in the emitted light pattern exhibiting barrel distortion in angular space (i.e., in the imaginary projection on the spherical shell of the polar coordinate system). Alternatively, the effective area of the diffusing device can also be convex-curved with respect to the side of the diffusing device facing the emitting optical device. This results in the emitted light pattern exhibiting pincushion distortion in angular space (i.e., in the imaginary projection on the spherical shell of the polar coordinate system). The selection of the convex or concave curvature of the effective area is preferably carried out in such a way that the distortion of the receiving optics of the associated receiving device can be compensated as completely as possible.
[0022] According to another preferred embodiment, the diffusing device includes a linear diffuser that is curved according to a preset curvature of the effective area of the diffusing device. Alternatively, the diffusing device includes a plurality of flat linear diffusers that are arranged and aligned according to a preset curvature of the effective area of the diffusing device. Thus, the curved effective area can be formed in a continuous manner by a single curved linear diffuser or can be formed by the abutting connection of a plurality of flat linear diffusers.
[0023] According to another preferred embodiment, the light-emitting device includes a plurality of light sources that are arranged at intervals from each other in a second spatial direction. In this design, each light source generates its own light beam. Preferably, the plurality of light sources are arranged in a row that extends in the second spatial direction.
[0024] Preferably, the plurality of light sources can be sequentially activated, where preferably only one light source is activated relative to a determined time point. Thus, when the lighting device is used in a ranging optoelectronic TOF sensor, due to technical reasons, only one row of receiving elements is activated relative to a determined time point, which avoids low-energy-efficiency lighting of undetectable parts in the monitoring area.
[0025] Preferably, each light source is assigned a corresponding emitting optical device. Accordingly, the emitting optical device can be designed as a linear array or a microlens array of individual emitting optical devices. Alternatively, a common emitting optical device can be provided for all light sources.
[0026] Furthermore, preferably, each light source is also assigned a corresponding one of the plurality of flat linear diffusers. In principle, the design with a plurality of light sources and / or the design with one or more emitting optical devices can also be combined with the design of the diffusing device with a curved linear diffuser.
[0027] The present application also relates to a photoelectric sensor for detecting an object in a monitored area, the photoelectric sensor comprising an illumination device and a receiving device according to the present application, the receiving device comprising a light receiver and receiving optics, the light receiver having a plurality of photosensitive receiving elements arranged in rows and columns, the receiving optics being configured to image an emitted light pattern as a received light pattern on the light receiver, the emitted light pattern being generated by the illumination device on an object present in the monitored area. The light receiver and the receiving optics are designed and arranged such that corresponding rays of the emitted light pattern are imaged on corresponding rows of the light receiver.
[0028] With the aid of this photoelectric sensor, the concept according to the invention can advantageously be implemented, wherein the design according to the invention of the diffusing device at least largely compensates for the optical distortion caused by the receiving optics of the receiving device. As a result, it is achieved that the lines of the received light pattern generated on the light receiver by the imaging of the emitted light pattern correspond as well as possible to the respective rows of the photosensitive receiving elements, so that the incident light in the edge region of the light receiver can be captured almost completely. Thereby, it is avoided that the sensitivity of the photoelectric sensor is reduced in an undesired manner at least in some regions due to undesired bends of the receiving lines.
[0029] According to a preferred embodiment of the photoelectric sensor, the curvature of the effective area of the diffusing device and / or the distance of the diffusing device from the emission optics are selected such that the distortion of the emitted light pattern caused by the diffusing device cancels out the distortion of the received light pattern caused by the receiving optics. Preferably, the distortion of the emitted light pattern caused by the diffusing device at least substantially completely compensates for the distortion of the received pattern caused by the receiving optics. Thus, the received light pattern has received lines that extend substantially straight.
[0030] The expressions "at least substantially" or "substantially" used in the present application should be understood here as distortion compensation within the framework possible in terms of structure and manufacturing technology. Deviations from an ideally straight extension due to manufacturing technology and structure or, for example, due to the curvature of a real object surface are tolerable. In particular, the selection of the curvature includes, where appropriate, the selection of a suitable curvature direction, i.e., the selection of a convex or concave curvature; and, where appropriate, the selection of a suitable curvature radius. In particular, the selection of the distance of the diffusing device from the emission optics can also include the setting of the desired operating distance of the sensor.
[0031] According to another preferred embodiment of the optoelectronic sensor, an evaluation device is provided, which is connected to a light emitting device and a light receiver. The light emitting device includes a plurality of light sources, which can be sequentially activated by an evaluation unit and are arranged at intervals from each other in a second spatial direction. Each light source is assigned a corresponding row of photosensitive elements of the light receiver. The evaluation device is designed to determine, in a spatially resolved manner, the distance of the impact point of the emitted light pattern on the surface of an object based on the time of flight of light between the respective activated light source and the photosensitive elements of the assigned row of the light receiver. Thus, the optoelectronic sensor defined herein is designed for distance measurement of an object based on the principle of a lidar system.
[0032] Further advantages and advantageous embodiments of the lighting device according to the present application and the optoelectronic sensor according to the present application will be given by the following description with reference to the drawings. Embodiments of the present application are shown in the drawings. The drawings, the description and the claims contain combinations of numerous features. Those skilled in the art will also advantageously consider these features individually and combine them into further meaningful combinations. Description of the Drawings
[0033] Figures 1 to 3 is a schematic, non - to - scale cross - sectional view of a lighting device according to the prior art.
[0034] Figure 4 is a schematic view showing the angular distribution of the reception profile or the emission profile of an optoelectronic sensor according to the prior art.
[0035] Figure 5 and Figure 6 is a schematic, non - to - scale cross - sectional view of a lighting device according to an embodiment having some features of the present application.
[0036] Figure 7 shows, for different tilt angles of a linear diffuser, according to Figure 5 and Figure 6 the angular distribution of the emission profile of the lighting device.
[0037] Figure 8 is a schematic, non - to - scale cross - sectional view of a lighting device according to another exemplary embodiment having some features of the present application.
[0038] Figure 9 shows Figure 8 the angular distribution of the emission profile of the lighting device.
[0039] Figure 10 is a schematic, non - to - scale cross - sectional view of a lighting device according to an embodiment of the present application.
[0040] Figure 11 It shows the Figure 10 angular distribution of the emission profile of the lighting device for different distances of the diffusing device from the emission optical device.
[0041] Description of reference numerals:
[0042] 100, 200, 300, 400, 500 Lighting devices
[0043] 10 Point light source
[0044] 12 Emission optical device
[0045] 14 Emission beam
[0046] 16, 16.1 - 16.4 Linear diffuser
[0047] OA Optical axis Detailed implementation manners
[0048] Hereinafter, the same reference numerals are used for the same or similar elements.
[0049] Figure 5 And Figure 6 shows a schematic cross-sectional view of a lighting device 300 according to an embodiment, which does not have all the features of the present application but is used to better understand the present application. The lighting device 300 is similar to Figure 1 and Figure 2 the lighting device 100 in Figure 5 Therefore, only the substantial differences will be discussed here. In Figure 1 , a side view of the lighting device 300 is shown. Compared with the corresponding Figure 6 , the linear diffuser 16 is arranged obliquely with respect to the optical axis OA, which passes through the center of the point light source 10, the emission optical device 12 and extends through the linear diffuser 16, and coincides with a ray of the emission beam 14. Among them, the axis of inclination or tilting of the linear diffuser 16 extends in the X direction and thus transversely to the linear structure of the linear diffuser 16 or the effective area of the linear diffuser 16. Therefore, Figure 6 the linear diffuser 16 in Figure 5 appears to extend in the Z direction,
[0050] In Figure 7The angular distribution of three emission profiles is shown in the diagram, the three emission profiles being produced by the lighting device 300 for different tilt angles of the linear diffuser 16. Here, the tilt angle is related to the tilt with respect to the vertical line of the optical axis OA. Since in the example considered, the lighting device 300 ( Figure 5 and Figure 6 ) has only one point light source 10 for simplicity, each of the three emission profiles consists of only one ray of light. The ray of the emission light profile shown as a solid line extends straight for a tilt angle of 0° (corresponding to Figure 1 and Figure 2 the lighting device 100 with the linear diffuser 16 vertically aligned with the optical axis OA), and for non-0° tilt angles, the extensions shown as dashed or dotted lines are curved. Among them, the larger the tilt angle, the stronger the curvature of the curved part. Therefore, for a tilt angle of 15°, the curvature of the curved part is weaker than that of the curved part for a tilt angle of 30° (i.e., the bending radius is larger).
[0051] Figure 8 Figure shows a lighting device 400 according to another embodiment, which also does not show all features of the present application and is also intended to be used for better understanding of the present application. Figure 8 The lighting device 400 of Figure 3 corresponds in principle to the combination of the lighting device 200 ( Figure 5 and Figure 6 ) and the lighting device 300 ( Figure 8 ). Therefore, Figure 5 and Figure 6 the lighting device 400 of
[0052] has a total of three point light sources 10, which are marked as "+1", "0" and "-1". Similar to the embodiments according to Figure 8 , the linear diffuser 16 is arranged to be tilted with respect to the optical axis OA, that is, tilted with respect to the vertical line of the optical axis OA. Figure 9 The angular distribution of the emission profiles produced by the lighting device 400 ( Figure 9 ) is shown in Figure 8 . Figure 9 It can be clearly seen from
[0053] Figure 10 Figure shows a lighting device 500 according to an embodiment of the present application. The lighting device 500 is similar to the lighting device 400 ( Figure 8). Among them, the linear diffuser 16 or the effective area of the linear diffuser 16 has a curved extension. The axis of symmetry of this curved portion extends in the X direction. In Figure 10 , the linear diffuser 16 is shown at four different distances from the emission optical device 12, and the reference numerals 16.1 to 16.4 are accordingly provided. Among them, the value of the distance is the relative distance with respect to the focal point of the emission optical device 12 and the bending radius R of the linear diffuser 16. The linear diffuser 16.1 shown by a solid line is located in the region of the focal point of the emission optical device 12, and thus has a distance of 0. The linear diffuser 16.2 shown by a dashed line is arranged at such a position that the distance between this position and the focal point of the emission optical device 12 is half of the bending radius R of the linear diffuser 16. The distance of the linear diffuser 16.3 shown by a dotted line corresponds to the bending radius R, and the distance of the linear diffuser 16.4 shown by a dash-dotted line corresponds to 1.5 times the bending radius R.
[0054] Figure 11 shows the angular distribution corresponding to different distances of the linear diffuser 16 from the emission optical device 12 or the focal point of the emission optical device 12. Among them, the lines of these angular distributions correspond to the lines of the corresponding representations of the linear diffusers 16.1 to 16.4. It can be clearly seen from Figure 10 that the light rays generated by the point light source "0" located on the optical axis OA extend straight for all distances, which corresponds to Figure 11 the middle line in Figure 11 . The light rays generated by the other two point light sources "+1" and "-1" also extend straight for the case where the distance from the linear diffuser 16.1 is 0. For the linear diffusers 16.2 to 16.4 that are farther from the emission optical device 12, the degree of bending of the light rays increases with the increase of the distance, and the bending radius of these light rays decreases accordingly.
[0055] Therefore, Figure 11 shows that by selecting the appropriate distance and bending radius of the linear diffuser 16 or the effective area of the linear diffuser 16, such an emission line pattern can be generated, that is, this emission line pattern is generated corresponding to Figure 10 the embodiment of
[0056] and has barrel distortion. Figure 10 It can be understood that the exemplary number of the three point light sources 10 in the embodiment of
[0057] can be increased in an appropriate manner to adapt to the number of rows of the photosensitive elements present in the assigned light receiver. Figures 5 to 7As explained, the bending radius of the light rays of the emitted light pattern also depends on the tilt angle of the linear diffuser 16 and thus on the effective impact angle (Auftreffwinkel) of the emitted light rays on the effective area of the flat linear diffuser 16. Due to the relationship between the impact angle of the emitted light rays on the effective area of the linear diffuser 16 and the degree of bending of the resulting light rays, a person skilled in the art can, in a suitable manner, select the distance and the bending radius R of the linear diffuser or the effective area of the diffusing device that may consist of a plurality of linear diffusers, corresponding to the curved extension of the light rays on the emitted light pattern. Among them, this selection process can be carried out empirically through appropriate experiments or also through calculations.
Claims
1. An illumination device (200, 300, 400, 500) for a photoelectric sensor, the photoelectric sensor being arranged to detect an object in a monitoring area, the illumination device (200, 300, 400, 500) comprising: A light emitting device arranged to emit emitted light into the monitoring area, and the light emitting device includes at least one light source (10); An emission optical device including at least one emission optical element (12) and arranged for focusing the emitted light; And A diffusion device including at least one linear diffuser (16), and the diffusion device is arranged such that the focused emitted light is scattered in a first spatial direction (X), and such that the focused emitted light is substantially not scattered in a second spatial direction (Y) orthogonal to the first spatial direction (X), wherein the light emitting device, the emission optical device and the diffusion device are designed to produce a bar-shaped emitted light pattern on the object present in the monitoring area, the emitted light pattern including a plurality of light rays, characterized in that the effective area of the diffusion device includes a bent portion designed to cause such a distortion of a reference-emitted light pattern that the light rays include a curved and distorted extension in an angular space, when the reference-emitted light pattern is produced by a reference-diffusion device having a flat effective area, the reference-emitted light pattern including light rays extending straight in the angular space.
2. The illumination device (200, 300, 400, 500) according to claim 1, characterized in that the bent portion of the effective area of the diffusion device extends only in one dimension, wherein the bent portion extends in a plane spanned by an optical axis (OA) of the illumination device (500) and the second spatial direction (Y), the optical axis (OA) extending through the light emitting device, the emission optical device and the diffusion device.
3. The illumination device (200, 300, 400, 500) according to claim 1 or 2, characterized in that the effective area of the diffusion device is curved concavely with respect to a side of the diffusion device facing the emission optical device.
4. The illumination device (200, 300, 400, 500) according to any one of the preceding claims, characterized in that the diffusion device includes a linear diffuser (16) curved according to a preset bent portion of the effective area of the diffusion device, or the diffusion device includes a plurality of flat linear diffusers (16) arranged and aligned according to a preset bent portion of the effective area of the diffusion device.
5. The illumination device (200, 300, 400, 500) according to any one of the preceding claims, characterized in that the light emitting device includes a plurality of light sources (10), and the plurality of light sources (10) are arranged at intervals from each other in the second spatial direction (Y).
6. The lighting device (200, 300, 400, 500) according to claim 5, wherein a plurality of said light sources (10) are sequentially activated.
7. The lighting device (200, 300, 400, 500) according to claim 6, wherein each of said light sources (10) is assigned a corresponding emission optical device (12).
8. An optoelectronic sensor for detecting an object within a monitoring area, characterized in that, Comprising: the lighting device (500) according to any one of the preceding claims; and a receiving device, the receiving device comprising: a light receiver, the light receiver comprising a plurality of photosensitive receiving elements arranged in rows and columns; and receiving optics for imaging an emitted light pattern as a received light pattern on the light receiver, the emitted light pattern being generated by the lighting device (500) on an object present in the monitored area, wherein the light receiver and the receiving optics are designed and arranged such that corresponding rays of the emitted light pattern are imaged on corresponding rows of the light receiver.
9. The optoelectronic sensor according to claim 8, wherein the curvature of the effective area of the diffusing device and / or the distance of the diffusing device from the emission optical device are selected such that the distortion of the emitted light pattern caused by the diffusing device cancels out the distortion of the received light pattern caused by the receiving optics.
10. The optoelectronic sensor according to claim 8 or 9, wherein an evaluation device is provided, the evaluation device being connected to the light emitting device and the light receiver, wherein the light emitting device comprises a plurality of light sources (10), the plurality of light sources (10) can be sequentially activated by the evaluation unit, and the plurality of light sources (10) are arranged spaced apart from each other in the second spatial direction (Y), wherein each light source (10) is assigned a corresponding row of the light receiver, and wherein the evaluation device is configured to determine, in a spatially resolved manner, the distance of the impact point of the emitted light pattern on the surface of the object based on the time of flight of light between the respective activated light sources (10) and the photosensitive elements of the assigned row of the light receiver.