Method for correcting the scanning field of at least one laser scanner device, laser scanner device, scattering pattern element, scattering pattern holding device, and scanning field correction system
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- NOVANTA EURO GMBH
- Filing Date
- 2022-02-08
- Publication Date
- 2026-08-05
Smart Images
Figure 0007901089000001 
Figure 0007901089000002 
Figure 0007901089000003
Abstract
Description
Technical Field
[0001] The present invention relates to a method for scan field correction of at least one laser scanner device according to claim 1, a laser scanner device according to claim 10, a scattered pattern element according to claim 15, a scattered pattern element holding device according to claim 19, and a scan field correction system according to claim 23.
Background Art
[0002] Conventional scanning modules or laser scanner devices can each position a laser spot in all three directions in space with high accuracy and reproducibility within a specific operating volume. The beam deflections in the x and y directions required for this purpose are generally performed via two deflection mirrors, while the focusing in the z direction is in most cases also performed by displacing the optical system or by changing the setting parameters of a zoom lens.
[0003] Due to design and tolerances, both mechanical operating sequences are non-linear in the spatial coordinates x, y, z and thus introduce distortion errors into the desired trajectory in response to linear control. Therefore, it is necessary to pre-correct the control software accordingly to guide the laser beam in a geometrically correct manner, i.e., without distortion. [[ID=??]]
[0004] Due to high-precision requirements, the corresponding pre-distortion function for scan field correction can only be determined experimentally.
[0005] This type of pre-distortion function for scan field correction needs to be determined manually separately for each laser scanner device. For this purpose, the pattern is applied to paper or metal by a processing laser in various steps and measured in a time-consuming manner.
[0006] There seems to be a missing tag ID in the provided text. I've left it as "??" in the translation for the relevant part. If you can correct that in the original text, the translation will be more accurate.Depending on the requirements of each individual laser scanner device, measurements are performed either by eye or by an external measuring instrument, such as a coordinate measuring machine. Therefore, conventional methods are either relatively inaccurate (by eye) or extremely time-consuming (by coordinate measuring machine). [Overview of the Initiative]
[0007] Therefore, an object of the present invention is to provide a method for performing high-precision scanning field correction of a laser scanner device in a simple and reproducible manner.
[0008] A further object of the present invention is to provide a further developed laser scanner device equipped with a scanning field-correctable deflection unit.
[0009] Furthermore, an object of the present invention is to provide an improved scattering pattern element that can implement, in a particularly advantageous manner, further developed methods for scanning field correction of laser scanner devices.
[0010] Furthermore, an object of the present invention is to identify a scattering pattern holding device particularly well suited for fixing scattering pattern elements, in particular scattering pattern elements according to the present invention, so that a method for correcting the scanning field of a laser scanner device can be carried out in a particularly advantageous manner.
[0011] A further object of the present invention is to identify further developed scanning field correction systems.
[0012] With respect to a method for correcting the scanning field of at least one laser scanner device, the object is solved by the subject matter of claim 1; with respect to the laser scanner device, the object is solved by the subject matter of claim 10; with respect to the scattering pattern element, the object is solved by the subject matter of claim 15; with respect to the scattering pattern element holding device, the object is solved by the subject matter of claim 19; and with respect to the scanning field correction system, the object is solved by the subject matter of claim 23.
[0013] This objective is addressed by a method for correcting the scanning field of at least one laser scanner device, the method comprising the following steps: - A step of providing a scattering pattern element on a processing plane, wherein the scattering pattern element has at least one scattering region arranged in a scattering pattern; - A step of passing or scanning at least a portion of scattering pattern elements on a processing plane with a laser beam of at least one laser scanner device along scanner coordinates, wherein the laser beam passes through at least one window, preferably protective glass, between the deflection unit and the processing plane; - A step of detecting scattered radiation that may be generated by the scattering and / or reflection of the laser beam as it passes over or scans, particularly preferably over, and / or scans over, at least one scattering region; - A step of creating an outline diagram by correlating detected scattered radiation with scanner coordinates; - A step of comparing the contour plot with a reference image of the scattering pattern and determining the deviation of the contour plot from the reference image of the scattering pattern; - A step of calculating a calibration function for calibrated control of the deflection unit based on the determined deviation;
[0014] The essential concept of this invention is that the calibration function or pre-distortion function of a laser scanner device already installed in an operational laser processing machine can be inspected by the operator as needed (or at regular intervals) and adapted as necessary. This is necessary not only for changing components such as the laser source and photodiode, or removing and reinstalling further optical components (e.g., for cleaning purposes), but also for routine inspections after a certain period of operation. Positional deviations caused during operation by thermal or mechanical stresses such as shock or vibration can thus be detected and compensated for.
[0015] Therefore, with high-precision scanning field correction, user effort can be minimized. The necessary measuring instruments (here, scattering pattern elements) can be easily placed on the processing plane, the necessary measurements can be performed and evaluated without further input from the operator, and the calibration function for scanning field correction can be calculated completely automatically based on the contour diagram.
[0016] The contour plot is preferably understood to be an intensity (profile) plot. The amplitude of the contour plot of the amplitude of the photodiode signal (or integrated photodiode signal) is specified, for example, in "counts," or the amplitude is standardized to 1 (standardized to the best photodiode signal).
[0017] A further concept of the present invention is that calibration may be performed by the (processing) laser or the (processing) laser beam itself, rather than by a (separate) calibration laser. This is because an offset from the actual laser beam is usually present when using a calibration laser, and the calibration is not performed "under normal conditions," thus improving accuracy. Therefore, for example, heat generated during processing in the scanning device's optical system (due to high laser power) can be directly taken into account during calibration. Thus, the calibration or scanning field correction becomes virtually invariant to external influences.
[0018] In one embodiment, some of the scattered radiation can spread within the window by reflection and / or scattering between the upper and lower surfaces of the window, at least toward a portion of the window edge, so that the scattered radiation can escape from the window edge and be detected there.
[0019] Reflection at windows and / or transmission of light through windows and / or multiple reflections at the top and bottom surfaces of windows are cost-effective and simple options for attenuating a concentrated laser beam so as not to saturate the corresponding detectors that detect the light. Furthermore, this configuration can be implemented in particularly small spaces.
[0020] Since the entire opening is utilized, a large amount of scattered light can be further collected in this way. In this manner, not only can the scattered radiation (of the scattered pattern element) be collected from the direct field of view of the photodiode, but it is also possible to indirectly detect the scattered radiation through reflection and / or scattering within the window. Therefore, the method or the light detection can each be carried out almost directionally independently.
[0021] In a preferred embodiment, the detection of the scattered radiation is carried out at at least a part of the window edge of the window.
[0022] The detector can be permanently arranged in this way, for example, there is no need to remove it after calibration.
[0023] In one embodiment, the detection of the scattered radiation is carried out by at least one, preferably two, more preferably at least three photodiodes, and several photodiodes are preferably distributed equidistantly.
[0024] In other words, the photodiodes can be arranged along the outer periphery of the window such that in any case the photodiodes are arranged at the same distance from each other.
[0025] The photodiodes can be obtained cost - effectively and can be easily read out. The use of several photodiodes results in the setting of a uniform contour diagram, especially when the photodiodes are arranged equidistantly. The larger the number of photodiodes used, the larger the field of view / detection field of view. For creating a uniform contour diagram, as the number of photodiodes generating the scattered light increases, it becomes less and less important.
[0026] In one embodiment, the amplitude of the contour diagram is essentially proportional to the detected scattered radiation.
[0027] Therefore, optimal and reproducible data evaluation becomes possible because the corresponding contour map has a high signal-to-noise ratio. In this way, the calibration function can be accurately determined. Therefore, a further advantage lies in the interpolation and / or fitting accuracy. The computational effort and the computational time can also be optimized in this way.
[0028] In one embodiment, the contour map has a scattering pattern image, and the scattering pattern image corresponds to a distortion map of the scattering pattern of the scattering pattern elements such that the contour map has at least one scattering region image that can be assigned, particularly clearly assigned, to at least one scattering region of the scattering pattern elements.
[0029] Due to the geometric, preferably clear assignability, the orientation or identification of the scattering pattern elements or at least partial regions of the scattering pattern elements can be reliably determined in a simple manner. The clear assignability that can be easily identified can thus save computational effort and computational time in this way in order to accelerate the calibration process. This is particularly relevant when two or several laser scanner devices use (respectively single or common) scattering pattern elements on, for example, a (common) machining plane and are particularly calibrated with respect to each other or with respect to each other.
[0030] In one embodiment, the step for determining the deviation of the contour map from the scattering pattern includes steps for preferably partial fitting and / or interpolation of the contour map.
[0031] Thereby, it becomes possible to automate the method by means of a computing unit and by means of corresponding instructions for performing the method steps. Therefore, the calibration accuracy can be optimized. The computational time can be further shortened only by partial fitting and / or interpolation (for example, only the relevant part or particularly the high-contrast part of the contour map).
[0032] In one embodiment, the step of determining the deviation of the contour diagram from the scattering pattern includes, in particular, the step of determining the focal and / or center points and / or contour diagram reference points of the shape distortion of several scattering region images of the contour diagram.
[0033] Data evaluation can be further optimized by determining contour plot reference points. Specific (scattering) regions can be easily fitted / interpolated, and therefore in relatively few steps, or with relatively little computational effort, or in relatively short computation time. For example, circles or the centers of circles are relatively unaffected by noisy edges. Thus, data evaluation can be accelerated and accuracy can be improved.
[0034] In one embodiment, the step of determining the deviation of the contour plot from the scattering pattern includes the step of determining the deviation of the contour plot reference points from corresponding reference points in a reference image of the scattering pattern and / or shape distortion.
[0035] Data evaluation can be further optimized by determining reference points in the reference image of the scattering pattern. Specific (scattering) regions can be easily fitted / interpolated, and therefore in relatively few steps, or with relatively little computational effort, or in relatively short computation time. For example, circles or the centers of circles are relatively unaffected by noisy edges. Thus, data evaluation can be accelerated and accuracy can be improved.
[0036] The object of the present invention is similarly solved by a laser scanner device equipped with a scanning field correctable deflection unit, the laser scanner device having the following: - At least one deflection unit formed to pass over or scan a work area with a laser beam along predetermined scanner coordinates, particularly passing over or scanning, particularly preferably over-taking and / or scanning, the deflection unit having at least one scattering region in which scattering pattern elements are positioned on the work plane and in which scattering pattern elements are positioned within a scattering pattern; - At least one window, preferably protective glass, positioned between the deflection unit and the processing area; - At least one photodiode formed to detect scattered radiation that may be generated by the scattering and / or reflection of a laser beam as it passes through at least one scattering region of a scattering pattern element; - A computational unit formed to create a contour plot by correlating detected scattered radiation with scanner coordinates, and to calculate a calibration function for calibrated control of the deflection unit based on the deviation of the contour plot from a reference image of the scattering pattern;
[0037] This brings the same advantages already described in relation to the method. Data evaluation of the contour plot can be performed by the computational unit through fitting and / or interpolation and / or contrast enhancement and / or threshold analysis and further image processing steps.
[0038] In one embodiment, the system comprises two, preferably at least three, photodiodes positioned on a portion of the window frame of the window.
[0039] Photodiodes can be acquired cost-effectively and easily read out. The use of several photodiodes results in the creation of a uniform contour plot, especially when the photodiodes are equidistant from each other. The more photodiodes used, the larger the field of view / detection field becomes. To create a uniform contour plot, this becomes less and less important as the number of photodiodes generating scattered light increases.
[0040] In one embodiment, at least one photodiode, preferably two, more preferably at least three, is formed and / or positioned to detect a portion of the scattered radiation, which spreads within the window by reflection and / or scattering between the upper and lower surfaces of the window, toward a portion of the window edge of the window.
[0041] Reflection or scattering at windows, and / or transmission of light through windows, and / or multiple reflections at the top and bottom surfaces of windows are cost-effective and simple options for weakening a concentrated laser beam so as not to saturate the corresponding detectors that detect the light.
[0042] Furthermore, this configuration can be implemented in a particularly space-saving manner. Because the entire aperture is utilized, a large amount of scattered light can be collected in this way. In this manner, it becomes possible not only to collect scattered radiation (from the scattering pattern elements) from the direct field of view of the photodiode, but also to indirectly detect scattered radiation through reflection and / or scattering within the window. Thus, the method or the photodetection can each be performed almost directionally independently.
[0043] In one embodiment, at least one photodiode is configured to output a measurement signal to a computing unit that is essentially proportional to the detected scattered radiation.
[0044] In one embodiment, the amplitude of the contour diagram is essentially proportional to the detected scattered radiation or the measurement signal of at least one photodiode, respectively.
[0045] Therefore, optimal and reproducible data evaluation of the contour plot becomes possible because the contour plot has a correspondingly high signal-to-noise ratio. In this way, the calibration function can be accurately determined. Thus, a further advantage lies in the interpolation and / or fitting accuracy. Computational effort and computation time can also be optimized in this manner.
[0046] The object of the present invention is similarly solved by the scattering pattern element for scanning field correction of the laser scanner device, particularly by the method described above and / or particularly for the laser scanner device described above.
[0047] The scattering pattern element is preferably formed in the form of a plate from glass or glass ceramic, particularly fused silica, Zerodur®, or Borofloat, and has a scattering pattern, the scattering pattern comprising several scattering regions.
[0048] The scattering regions are formed as roughened and / or imprinted surface regions and / or holes of the scattering pattern element, or within the volume of the scattering pattern element.
[0049] The scattering region is positioned within the scattering pattern so that the image of the scattering pattern or a portion thereof can be clearly identified at each rotation, shape distortion, reflection, scaling, or translation.
[0050] Regarding the scattering pattern elements, it is essential to provide a "target" that will not be destroyed even when exposed to high-power laser irradiation. Therefore, it becomes possible to directly calibrate the laser scanner device with the (processing) laser beam. In advantageous ways, it is possible to omit a separate calibration laser.
[0051] This is not readily possible for all materials due to the high laser power / intensity (e.g., >50W or >100W, e.g., CW, or pulsed, e.g., NIR, focus size (scattering pattern elements), e.g., about 40μm) and target accuracy.
[0052] Static errors in the scattering pattern elements, such as "deflection" due to the self-weight, uniformity, positioning, and manufacturing precision of the scattering region, as well as dynamic errors, such as thermal expansion during the measurement process, must be minimized and / or taken into consideration in the following data evaluation of the contour diagram.
[0053] In one embodiment, the scattering region comprises a first array of first marker regions, preferably essentially circular first marker regions, each of which is surrounded by a second array of a plurality of second marker regions, preferably essentially circular second marker regions (33).
[0054] Therefore, image recognition / image processing or data processing can be optimized accordingly. For example, the difference between the first and second sequences can be selected so that the patterns can be efficiently identified or fitted in the contour diagram, respectively. Thus, a scattering pattern element can be obtained that is easy to manufacture and simplifies data processing due to its scattering pattern. Calibration can be performed quickly and accurately in this way.
[0055] In one embodiment, the second arrangement of a plurality of second marker regions in each of the first marker regions differs in particular in terms of angular arrangement and / or the number of second marker regions.
[0056] Therefore, the scattering pattern or the orientation of the scattering pattern, in particular the scattering pattern or the orientation of the scattering pattern, and especially preferably the scattering pattern and / or the orientation of the scattering pattern, can be detected by the contour diagram.
[0057] In one embodiment, the scattering region includes several polygons, preferably rectangles, where the polygons are of different sizes, and / or some, and especially all, of the polygons preferably have individual marker attachments.
[0058] The orientation of the scattering pattern can be efficiently detected using the contour diagram in this way.
[0059] The object of the present invention is similarly solved, in particular, by a scattering pattern element holding device for holding the scattering pattern elements, in order to provide scattering pattern elements on the processing plane of a laser scanner device. The scattering pattern element holding device has the following: - A base surface and a side wall that rotates around the base surface so as to form a hollow space, wherein the side wall at the upper end is formed to support the scattering pattern element so as to be fixed to the upper end, thereby allowing light from a laser scanner device to be irradiated into the hollow space through the scattering pattern element; - At least one deflection cone disposed on a base surface, wherein the deflection cone is formed and / or positioned such that it absorbs light striking the deflection cone and / or deflects the light toward the inner surface of the side wall, and the inner surface of the side wall is formed such that it absorbs light striking the inner surface of the side wall;
[0060] The speed and accuracy of the aforementioned method for calculating the calibration function for calibrated control of the deflection unit are determined, for example, by the contrast that can be achieved. The contrast is determined by the optionally different surface roughness of the scattering pattern elements and the associated backscatter of the laser radiation in the direction of the photodiode. However, depending on the material of the scattering pattern elements, about 90% to almost 100% of the power of the laser light is transmitted through the scattering pattern elements. Tests have shown that about 10% less light is transmitted in the scattering region. Therefore, how this power is captured is important for contrast and thermal management. Accordingly, according to the present invention, the light is absorbed downstream from the scattering pattern elements on the inner wall of the hollow space of the scattering pattern element holder.
[0061] In one embodiment, the inner surface of the side wall and / or the deflection cone has a plurality of absorbent thin layers. The absorbent thin layers are preferably formed as elements having a triangular cross-section. The absorbent thin layers can have a pyramidal shape.
[0062] This allows for more efficient light absorption. Consequently, the contrast of the contour diagram is further increased, computation time is reduced, and the accuracy of the calibration function is improved.
[0063] In one embodiment, the upper end of the side wall is formed to allow the scattering pattern element to float and be supported. The floating support should be understood as such a support for the scattering pattern element, thereby the scattering pattern element is not fully resting on the lower fastening section. It is preferable that a gap is formed between the scattering pattern element and the deflection cone.
[0064] The upper end of the side wall is preferably formed in a protruding shape so that scattering pattern elements can be placed in this protruding portion.
[0065] The side wall at the upper end has, for example, a chamfer or an insertion groove.
[0066] Similarly, the sidewall may have three or four bearing protrusions, for example, one bearing protrusion on the side of the sidewall, for attaching the scattering pattern element 30.
[0067] The corresponding chamfered portion, insertion groove, or bearing projection can optionally be formed to be recessed (when viewed from the upper end) so that the side wall of the upper end portion 44 can introduce the scattering pattern elements so that they are positioned stabilized or fixed against (undesirable) movement, respectively.
[0068] This allows the scattering pattern elements to be thermally and mechanically detached from the scattering pattern element holder, and the thermal expansion of the scattering pattern element holder does not affect, or cannot affect, the scattering pattern elements.
[0069] In one embodiment, the deflection cone base surface essentially covers the entire base surface, and / or the height of the deflection cone corresponds to at least half, preferably at least 80%, of the height of the side wall.
[0070] In this way, light can be efficiently guided to the inner wall from different impact directions and absorbed there. This results in improved contrast.
[0071] To allow the scattering pattern elements to be positioned at several locations, the scattering pattern elements may preferably be supported in a displaceable manner. For example, the scattering pattern element holder can be supported in a displaceable manner in the XY plane.
[0072] To displaceably support the scattering pattern elements and / or the scattering pattern element holding device, for example, an array can be provided on a cross table or an XY table, respectively.
[0073] Objects of the present invention are similarly addressed by a scanning field correction system, which comprises at least one laser scanner device as described above and at least one scattering pattern element for scanning field correction, and preferably includes at least one scattering pattern element holder as described above.
[0074] At this point, it should be noted that the features and advantages described in relation to the method, laser scanner apparatus, and scattering pattern element according to the present invention also apply to the scanning field correction system according to the present invention.
[0075] The characteristics of the method, particularly those relating to the detection of photodiode signals or the evaluation / analysis of contour diagrams, can be transferred to the correction system according to the present invention, in such a way that the corresponding device is configured to be suitable for performing the characteristics of the corresponding method.
[0076] In one embodiment, the scanning field correction system includes at least two scattering pattern elements that differ in size and / or scattering pattern.
[0077] For example, the calibrated control of the deflection unit can be verified or tested by it. Similarly, the calibration function can be calibrated by a second calibration function. Thus, the accuracy of the deflection unit control can be further improved.
[0078] In one embodiment, the scanning field correction system comprises at least two laser scanner devices whose scanning fields overlap at least partially, and the laser scanner devices can be calibrated relative to each other using scattering pattern elements.
[0079] In some laser scanner devices, each scanning field can be rotated and / or tilted relative to one another, for example, due to the improper (bent) assembly of the corresponding laser scanning heads. The relative accuracy of the beam guidance of several laser beams relative to one another can be optimized, in particular, with the help of a common calibration adapted to each other. Further advantageous developments follow in the dependent claims.
[0080] Furthermore, the present invention is described below in relation to further details, features, and advantages which will be explained in more detail with reference to the figures.
[0081] The features and combinations of features described below, as shown in the drawings and described based on the drawings, can be used not only in their respective specified combinations, but also in other combinations or individually without departing from the scope of the present invention. [Brief explanation of the drawing]
[0082] [Figure 1] A schematic diagram of a typical embodiment of the laser scanner device according to the present invention, which includes three photodiodes, is shown. [Figure 2] A top view of a typical embodiment of the scattering pattern element according to the present invention is shown. [Figure 3]A schematic diagram of a typical embodiment of the arrangement of scattering pattern elements on a processing plane is shown, schematically suggesting scanning of at least a portion of the scattering pattern elements on the processing plane by a laser beam along scanner coordinates. [Figure 4] A schematic diagram of a typical contour line diagram according to an embodiment, obtained by the correlation between detected scattered radiation and scanner coordinates, is shown. [Figure 5] A top view of another typical embodiment of the scattering pattern element according to the present invention is shown. [Figure 6] A schematic diagram of a contour line diagram obtained by the correlation between detected scattered radiation and scanner coordinates, according to another typical embodiment, is shown. [Figure 7] A cross-sectional view of a typical embodiment of the scattering pattern element holding device according to the present invention is shown. [Figure 8] A cross-sectional view of a typical embodiment of a scattering pattern element holding device according to the present invention, which includes a scattering pattern element, is shown. [Figure 9] A cross-sectional view of another typical embodiment of the scattering pattern element holding device according to the present invention is shown. [Figure 10] A schematic top view of the scattering pattern holding device according to the present invention, based on a typical embodiment, is shown. [Figure 11] Typical embodiments of methods for calibration or scanning field correction of a scanning field correction system comprising two laser scanner devices and a common processing plane are shown. [Figure 12] Typical embodiments of methods for calibration or scanning field correction of a scanning field correction system comprising multiple laser scanner devices and a common processing plane are shown. [Figure 13] Another typical embodiment of a method for calibrating or correcting the scanning field of a laser scanner by displacing scattering pattern elements at several positions is shown. [Modes for carrying out the invention]
[0083] Figure 1 shows a schematic diagram of a typical embodiment of the laser scanner device according to the present invention, which comprises the scanning field correction system 200 according to the present invention.
[0084] As a result, the laser scanner device comprises at least one laser light source (not shown in Figure 1) for emitting a laser beam 12 and at least one deflection unit 10.
[0085] The deflection unit 10 may include, for example, a (deflection) mirror and a galvanometer scanner.
[0086] The laser beam 12 can be moved in three spatial coordinates x, y, and z by the deflection unit 10 and optionally by further (not shown) deflection units.
[0087] The movement of the laser beam 12 in the three spatial coordinates x, y, and z should be understood as the spot of the laser beam being moved on the processing plane 11 in the x and y directions (parallel to the processing plane 11 in each case, and optionally perpendicular to each other) by at least one deflection unit 10. The possible focal positions can be moved / displaced in the z direction (perpendicular to the processing plane 11).
[0088] A window 20 is positioned between the deflection unit 10 and the processing plane 11. The window 20 can be, for example, a protective glass that serves the purpose of irradiating the laser beam 12 into the work area where the processing plane 11 is located.
[0089] In one exemplary embodiment, the window serves to protect the inside of the scanner from external contamination (dust, smoke, (water vapor) vapor). In an improved version of the present invention, the laser scanner device can be airtightly closed by the window.
[0090] The scattering pattern element 30 is placed on the processing plane 11 in Figure 1. The scattering pattern element 30 has several scattering regions 31 that can be arranged in pattern M.
[0091] In the exemplary embodiment shown in Figure 1, three photodiodes PD1, PD2, and PD3 are each positioned on the cross-section of the window edge 23 of the window 20.
[0092] Furthermore, there may be a fourth photodiode (not shown) positioned opposite the third photodiode PD3.
[0093] For scanning field correction according to the present invention, the laser beam 12 can be moved or scanned along predetermined scanner coordinates x and y, respectively, along the processing plane 11 or along scattering pattern elements 30 arranged on the processing plane.
[0094] The laser beam is then deflected by the pattern M of the scattering pattern element 30 according to the law of reflection (if the light does not hit any of the scattering regions 31), or scattered (diffusely) by the scattering regions 31 or a part thereof.
[0095] The laser light 13 (generally referred to here as scattered radiation 13, which may also include light reflected backward) that is reflected backward passes through the lower surface 22 of the window.
[0096] Some of the scattered radiation 13 spreads within the window 20 by (repeated) reflection and / or scattering between the upper window surface 21 and the lower window surface 22, at least toward part of the window edge 23 of the window 20, so that the scattered radiation 13 escapes from the window edge 23 of the window 20 and can be detected there.
[0097] Due to the different surface roughness of the scattering pattern elements 30, contrast is generated in the scattered radiation 13 that is reflected / scattered backward.
[0098] This scattered radiation 13 is collected via photodiodes PD1, PD2, and PD3 directed (inward) of window 20 and correlated with scanner coordinates x, y, and z.
[0099] When the photodiode signals from photodiodes PD1, PD2, and PD3 are combined and correlated with scanner coordinates x, y, and z to form a contour diagram K, a distorted and blurred image of the scattering pattern M is generated due to the aforementioned distortion error.
[0100] The required calibration function can be calculated by comparing this contour plot K with a known reference image of the scattering pattern M.
[0101] A typical embodiment of the scattering pattern element 30 having the scattering pattern M according to this typical embodiment will be described in more detail below with reference to Figure 2.
[0102] The scattering pattern element 30 is preferably formed in plate form from glass or glass ceramic, particularly fused silica, Zerodur®, or Borofloat. These materials are particularly suitable for high-performance lasers because they have a high damage threshold. Furthermore, the materials have a low coefficient of thermal expansion, thereby minimizing thermal effects.
[0103] The scattering pattern element 30 shown in Figure 2 is formed in a rectangular shape. However, according to the present invention, the scattering pattern element can also be formed in a circular shape, or it can have any shape, such as a star shape.
[0104] The scattering pattern element 30 is specifically formed to transmit the wavelength of the laser beam 12, for example, to avoid destruction due to light absorption.
[0105] Alternatively, the scattering pattern element 30 may also be made of, for example, paper, cardboard, or metal (for lower laser power).
[0106] The scattering pattern element 30 has a scattering pattern M on its surface, and the scattering pattern M includes several scattering regions 31, which are formed as roughened (e.g., by etching or sandblasting) and / or imprinted (surface) regions of the scattering pattern element (30).
[0107] Alternatively, or in addition to the above, the scattering region 30 can be at least partially located within the volume of the scattering pattern element 30. For example, this type of scattering region can be introduced by laser engraving. It is also conceivable that the scattering region 30 includes holes.
[0108] The scattering region 31 is positioned in the scattering pattern M such that any image of the scattering pattern M has an orientation that is clearly identifiable in each rotation or shape distortion or reflection or scaling or translation. Needless to say, according to the present invention, it is also possible that the scattering region 31 is formed to not scatter, and the remaining region of the scattering pattern element 30 is formed to scatter. Thus, "negative" can also refer to the formation according to the present invention.
[0109] For this purpose, the scattering region 31 may include a first sequence of the first marker region 32 and a second sequence of the second marker region 33.
[0110] In the typical embodiment shown in Figure 2, the first marker region 32 is formed as circles arranged in a regular 3x3 pattern on the surface of the scattering pattern element.
[0111] Here, each of the first marker regions 32 is surrounded by multiple second marker regions 33.
[0112] The second arrangement of the plurality of second marker regions 33 is, with respect to each of the first marker regions 32, at least two, preferably at least three, more different, particularly in terms of angular arrangement and / or in some of the second marker regions 33.
[0113] In this way, each first marker region 32 can be clearly identified. This thus provides clear (geometric) assignability of the pattern M, such that the image of the scattering pattern M has an orientation that can be clearly identified in each rotation, shape distortion and reflection, scaling or translation.
[0114] To simplify the design of image processing / detection and scattering pattern element manufacturing as much as possible, for example, only circles can be selected as marker regions. This allows for any type of mask-related manufacturing (sandblasting, etching), in which case "islands" are not possible. A further advantage lies in the "interpolation" / "fitting accuracy" because the determination of the circle's center point is less affected by noisy edges.
[0115] In a typical embodiment shown in Figure 3, the passage or scanning of at least a portion of the scattering pattern elements 30 on the processing plane 11 by the laser beam 12 of the laser scanner device along scanner coordinates x, y, z or the corresponding trajectory is shown.
[0116] The passage or scanning of scattering pattern elements can be performed more frequently (sequentially), for example, four times, to enhance contrast. The order (or starting point, respectively), the curve shape of the scan, or the scanning speed can also be varied accordingly.
[0117] The contour diagram K is calculated based on the correlation between the scanner coordinates x, y, and z and the photodiode signals detected for this purpose (one photodiode signal dataset for each scanner coordinate x, y, and z).
[0118] Figure 4 shows a schematic diagram of a typical contour diagram K obtained by the correlation between the detected scattered radiation 13 (see Figure 1) and scanner coordinates x, y, z (see Figure 3) in the scattering pattern element 30 of a typical embodiment of Figure 2.
[0119] The contour diagram K has coordinates x', y', and z', where coordinates x' and y' essentially correspond to scanner coordinates x, y, and z (see Figure 3), and z' represents the amplitude of the contour diagram.
[0120] The amplitude z' of the contour diagram K corresponds to the integrated and / or averaged signals (e.g., averaged over several scans) of several photodiodes PD1, PD2, PD3 (see Figure 1).
[0121] For this purpose, a (essentially) conventional analog-to-digital conversion is provided, and as a result, the unit of amplitude z' is specified, for example, in "counts," or the amplitude z' is standardized to 1 (standardized to the best photodiode signal).
[0122] Therefore, the contour diagram K shows the (distorted) image or scattering pattern image M' of the scattering pattern 30, corresponding to the distortion diagram of the scattering pattern M of the scattering pattern element 30.
[0123] Therefore, the contour diagram K has several scattering region images 31, which can preferably be clearly assigned to several scattering regions 31 of the scattering pattern element 30.
[0124] The contour diagram K is compared on the calculation unit with a reference image (not shown) of the scattering pattern element 30.
[0125] A reference image of the scattering pattern element 30 can be generated, for example, by a high-resolution photograph of the scattering pattern element 30, or by measuring the scattering pattern element 30 using a coordinate measuring machine.
[0126] Similarly, for example, raw data (coordinate raw data) could be used as a reference image of the scattering pattern element 30 used in a (laser) printing method for generating the scattering pattern M of the scattering pattern element 30.
[0127] Different fitting and / or interpolation methods can be used to determine the deviation of the scattering pattern M or the scattering pattern element 30 from the reference image of the contour diagram K, respectively. For example, further image processing steps / data processing steps such as contrast enhancement and / or threshold analysis can be optionally performed.
[0128] In particular, in order to determine the deviation using the steps described in the previous paragraph, contour plot reference points are determined, such as the focal and / or center points and / or shape distortion (e.g., "ellipse" instead of "circle") of several scattered region images 31' of contour plot K.
[0129] A grid can be generated from contour plot reference points, in which case each contour plot reference point includes information about its x and y positions as well as its (optimal) focal position.
[0130] The pre-distortion function or calibration function can be calculated by comparing the scattering pattern M of the scattering pattern element 30 (or a predetermined reference point in the reference image) with the contour plot reference point against an undistorted, regular reference image.
[0131] The calibration function serves to compensate for distortion of the winding barrel or other distortions that may occur during the control of the deflection unit 10 (see Figure 1), for example.
[0132] The calibration function, which includes the z-value (= (optimal) focal position), is completed through interpolation between the contour plot reference points and / or the corresponding reference points in the reference image of the scattering pattern M.
[0133] Figure 5 shows a top view of another typical embodiment of the scattering pattern element 30 according to the present invention, which includes the scattering pattern M.
[0134] According to a typical embodiment of the scattering pattern element 30 shown in Figure 5, the scattering pattern element 30 has scattering regions 31 in the form of several polygons 34.
[0135] These polygons may each include, for example, rectangles, lines, or straight lines. Alternatively or in addition, the polygons or scattered regions may also include barcodes, QR codes, or numbers and / or letters.
[0136] Polygons of varying sizes form cascaded arrangements accompanied by reticles.
[0137] Each or some of the polygons 34 preferably have individual marker attachments 35.
[0138] The marker attachment 35 in a typical embodiment shown in Figure 5 is equipped with line markings, and the four rectangles 34 each have one, two, three, or four line markings in any case.
[0139] In this way, a clear (geometric) assignment possibility for pattern M can be provided, and as a result, the image of the scattering pattern M has an orientation that is clearly identifiable in each rotation, shape distortion and reflection, scaling or translation.
[0140] Figure 6 shows a schematic diagram of a typical contour diagram K obtained by the correlation between the detected scattered radiation 13 (see Figure 1) and scanner coordinates x, y, z (see Figure 3) in the scattering pattern element 30 of a typical embodiment of Figure 5.
[0141] For further descriptions and evaluations or analyses, as well as for the pre-distortion or calibration functions that can be calculated therefrom, please refer to the description of Figure 4.
[0142] Figure 7 shows a cross-sectional view of a typical embodiment of the scattering pattern element holding device 40 according to the present invention.
[0143] The speed and accuracy of the aforementioned methods for calculating pre-distortion functions or calibration functions for calibrated control of the deflection unit are determined, for example, by the contrast that can be achieved (in the contour diagram K). The contrast is determined by the (different) surface roughness of the scattering pattern elements 30 and the associated backscatter of the laser radiation 13 in the direction of the photodiodes PD1, PD2, and PD3 (see Figure 1).
[0144] However, depending on the material of the scattering pattern element, approximately 90% to almost 100% of the laser light power is transmitted through the scattering pattern element 30. The test shows that about 10% less light is transmitted in the scattering region.
[0145] Therefore, for contrast and thermal management, it is important how this power is captured and, preferably, not scattered back to the photodiode.
[0146] Therefore, according to the present invention, light is absorbed after passing through the scattering pattern element 30 on the inner wall of the hollow space 43 of the scattering pattern element holding device 40.
[0147] The scattering pattern elements 30 can be placed on the processing plane 11 (see Figure 1) by the scattering pattern element holding device 40. Specifically, for example, with high laser power outputs of 50W or 100W or more, (undesirable) backscattering is (in most cases) avoided or significantly reduced, thereby greatly improving the contrast of the contour diagram.
[0148] The scattering pattern element holding device 40 has a base surface 41 and side walls 42 that rotate around the base surface.
[0149] Therefore, internally, the scattering pattern element holding device 40 forms a hollow space 43.
[0150] The side wall 42 is formed at the upper end so that it can support the scattering pattern element 30 so that it is fixed to the upper end 44.
[0151] The upper end portion 44 of the side wall 42 is located on the opposite side of the end portion where the base surface 41 is adjacent to the side wall 42.
[0152] For this purpose, the side wall 42 may have, for example, a corresponding chamfered portion or insertion groove at its upper end 44. Furthermore, the upper end 44 of the side wall 42 may be formed in a protruding shape.
[0153] Similarly, the side wall 42 may have three or four bearing protrusions, for example, one bearing protrusion on the side of the side wall 42 in either case, for attaching the scattering pattern element 30.
[0154] The corresponding chamfered portion, insertion groove, or bearing projection can optionally be formed to be recessed (as seen from the upper end portion 44) so that the side wall 42 of the upper end portion 44 can introduce the scattering pattern element 30 so that the scattering pattern element is positioned and fixed against (undesirable) movement, respectively.
[0155] The scattering pattern element holding device 40 further includes at least one deflection cone 45 positioned on the base surface 41.
[0156] At least one deflection cone 45 is formed and / or positioned to deflect incident light toward the inner surface 46 of the side wall 42.
[0157] The inner surface 46 of the side wall 42 is formed to absorb light that strikes the inner surface 46.
[0158] For this purpose, the side wall 42 may have an absorbent thin layer 47. Alternatively, or in addition to this, further absorbing or diffusing scattering elements may be provided in the hollow space 43.
[0159] The deflection cone base surface essentially covers the entire base surface 41, or alternatively, the deflection cone base surface can be formed to be slightly smaller than the base surface 41.
[0160] The height of the deflection cone 45 corresponds to at least half the height of the side wall 42, preferably at least 80% of the height of the side wall 42. In this way, incident light can be absorbed over a large range of incident angles.
[0161] A typical embodiment of the scattering element holding device 40 shown in Figure 7 is shown in Figure 8, where the scattering element holding device 40 holds the scattering pattern elements 30.
[0162] Figure 9 shows another typical embodiment of the scattering element holding device 40.
[0163] The “tip” or apex angle of the deflection cone 45 is, in this case, directed toward the base surface 41. In this typical embodiment, the deflection cone 45 may have an absorber layer 47, or the deflection cone 45 (itself) may form the inner surface 46 of the side wall 42.
[0164] Figure 10 shows a schematic top view of a scattering pattern holding device 40 according to a typical embodiment.
[0165] The scattering pattern holding device 40 holds the scattering pattern element 30. The scattering pattern element 30 is formed to transmit the laser wavelength. The portion of the laser light that is not scattered by the photodiodes PD1, PD2, and PD3 (see Figure 1) enters the hollow space 43 (below the scattering pattern element 30) in this way and is absorbed there.
[0166] The scattering pattern element 30 is held in the scattering pattern holding device 40 so as to be completely absorbed without damaging the scattering pattern holding device 40.
[0167] Since the scattering pattern element 30 is further thermally and mechanically separated from the scattering pattern holding device 40, its thermal expansion does not affect the scattering pattern element 30.
[0168] At high laser power, the components may be significantly heated. For example, to avoid curvature resulting from thermal expansion of the scattering pattern element 30 here, the scattering pattern holding device 40 can be (actively) cooled, for example, with water, in a further embodiment of the present invention.
[0169] The scattering pattern element holding device 40 can be made of, for example, (anodic-oxidized) aluminum or another material with good thermal conductivity so as to be able to dissipate heat and not be damaged by the laser output.
[0170] Figure 11 shows a schematic typical embodiment of a method for calibration or scanning field correction of a scanning field correction system 200 comprising two laser scanner devices 300, each having a scattering pattern element 30 and a common processing plane 11.
[0171] The photodiode and window are not shown here. For a description of the corresponding arrangement or features of the scattering pattern element 30, refer explicitly to the typical embodiment described above.
[0172] In this typical embodiment, the calibration function according to the present invention is calculated for each of the two laser scanner devices 300.
[0173] By applying the calibration function, the respective scanning fields 120 and 122 of the corresponding laser scanner device 300 are, in either case, "distorted" or corrected according to the distortion.
[0174] However, in some laser scanner devices 300, the scanning fields 120, 122 can be rotated and / or tilted relative to each other, for example, due to the improper (bent) assembly of the laser scanning head. See the schematically proposed (tilted) scanning fields 120, 122 in the top view on the right-hand side of the processing plane 11 in Figure 11.
[0175] This is why the laser scanner devices 300 still need to be calibrated against each other in order to obtain the most accurate possible calibration of the laser scanning system.
[0176] To compensate for this type of relative error between several laser scanner devices 300, two laser scanner devices 300 scan the same overlapping region 121 on the scattering pattern element 30 (the overlapping region 121 of two scanning fields 120, 122).
[0177] The two resulting contour diagrams K are then matched by rotation / tilting, and the laser scanner device 300 is corrected by the resulting calibration function.
[0178] The method described in relation to the typical embodiment shown in Figure 11 can also be transferred to multiple laser scanner devices 300 (in any arrangement).
[0179] Figure 12 shows a typical embodiment including multiple, for example, six laser scanner devices 300, of the scanning field correction system 200, each including scanning fields 120, 122, 124, 126, 128, and 130. As also described in relation to Figure 11, the overlapping regions 121, 123, 125, 127, and 129 of adjacent scanning fields 120, 122, 124, 126, 128, and 130 can be scanned on the scattering pattern element 30.
[0180] The resulting contour diagrams K are then aligned by rotation / tilting, and the laser scanner device is corrected by the resulting calibration function.
[0181] In the typical embodiments shown in Figures 11 and 12, a relatively large scattering pattern element 30 (compared to the scanning field or processing plane) is used.
[0182] In another typical embodiment shown in Figure 13, the method described above can be used to correct the scanning field of a (large) scanning field 120 by rearranging (using different positions of) the scattering pattern elements 30 on the processing plane 11.
[0183] For the purpose of generalizing each scattering pattern element 30 or the corresponding scattering pattern element holder, or for favorable manufacturability (in terms of manufacturing cost and labor), it may be advantageous to use relatively small scattering pattern elements 30 (compared to the scanning field or processing plane) for scanning field correction of a (significantly) large scanning field 120.
[0184] Nevertheless, the scanning pattern elements 30 are rearranged within the scanning field 120 so that the distortion of the entire or at least a large portion of the scanning field 120 can be measured.
[0185] As a result, the scanning pattern element 30 is first positioned in relation to the scanning field 120, scanned by the laser beam, and the corresponding first calibration function is calculated (Figure 13, top).
[0186] Next, the scattering pattern element 30 is first positioned at a second location relative to the scanning field 120 and scanned by the laser beam, and the corresponding second calibration function is calculated (Figure 13, bottom).
[0187] By performing overlapping measurements (passage / scanning by a laser beam) on the same region of the scattering pattern element 30 or the same scattering region 31, the calibration functions (first and second calibration functions) targeting a portion of the scanning field 120 can be correlated with each other in either case.
[0188] In order to allow the scanning pattern elements 30 to be placed in multiple locations, it is preferable to support the scanning pattern elements 30 in a displaceable manner. For example, the scattering pattern element holding device can be supported in a displaceable manner within the XY plane.
[0189] At this point, it is important to note that all of the above components, individually or in any combination, are claimed to be essential to the present invention, particularly the details shown in the drawings. [Explanation of Symbols]
[0190] 10 Deflection Units 11 Machining plane 12 laser beams 13 Scattered radiation 20 windows 21. Top of the window 22 Below the window 23 Window frame 30 Scattering Pattern Elements 31 Scattering area 31' Scattered region image 32 First Marker Area 33 Second Marker Area 34 Polygon 35 Marker accessories 40 Scattering Pattern Element Holding Device 41 Base surface 42 Side wall 43 Hollow space 44 Upper end 45 Polarizing cone 46. Inner self 47. Thin layer of absorbent material Scanning areas 120, 122, 124, 126, 128, 130 121, 123, 125, 127, 129 Overlapping area 200 Scanning Field Correction System 300 laser scanner devices K Contour Diagram M scattering pattern M' scattering pattern image PD1, PD2, PD3 photodiodes x, y, z scanner coordinates x', y', z' are coordinates of the contour diagram.
Claims
1. A method for correcting the scanning field of at least one laser scanner device (300), - A step of providing a scattering pattern element (30) on a processing plane (11), wherein the scattering pattern element (30) has at least one scattering region (31) arranged in a scattering pattern (M), - A step of passing or scanning at least a portion of the scattering pattern elements (30) on the processing plane (11) with a laser beam (12) of the at least one laser scanner device (300) along scanner coordinates (x, y, z), wherein the laser beam passes through at least one window (20) between the deflection unit (10) and the processing plane (11), - A step of detecting scattered radiation (13) that may be generated by the scattering and / or reflection of the laser beam (12) as it passes through or scans each of the at least one scattering region (31), - A step of creating a contour diagram (K) by correlation between the detected scattered radiation (13) and the scanner coordinates (x, y, z), - A step of comparing the contour diagram (K) with a reference image of the scattering pattern (M) and determining the deviation of the contour diagram (K) from the reference image of the scattering pattern (M), - A step of calculating a calibration function for calibrated control of the deflection unit (10) based on the determined deviation, A method of having.
2. The method according to claim 1, characterized in that a portion of the scattered radiation (13) spreads within the window (20) by reflection and / or scattering between the upper window surface (21) and the lower window surface (22) so that the scattered radiation (13) escapes from the window edge (23) of the window (20) and can be detected there.
3. The method according to claim 2, characterized in that the detection of the scattered radiation (13) is performed on at least a portion of the window edge (23) of the window (20).
4. The method according to any one of claims 1 to 3, characterized in that the detection of the scattered radiation is performed by at least one photodiode.
5. The method according to claim 4, characterized in that the detection of the scattered radiation is performed by at least three photodiodes (PD1, PD2, PD3).
6. The method according to claim 5, characterized in that several of the photodiodes (PD1, PD2, PD3) are distributed at equidistant distances.
7. The method according to any one of claims 1 to 6, characterized in that the amplitude of the outline diagram (K) is essentially proportional to the detected scattered radiation (13).
8. The method according to any one of claims 1 to 7, characterized in that the contour diagram (K) comprises a scattering pattern image (M'), and the scattering pattern image (M') corresponds to a distortion diagram of the scattering pattern (M) of the scattering pattern element (30) such that the contour diagram (K) has at least one scattering region image (31') that can be assigned to the at least one scattering region (31) of the scattering pattern element (30).
9. The method according to claim 8, characterized in that the contour diagram (K) has at least one scattering region image (31') which can be clearly assigned to the at least one scattering region (31) of the scattering pattern element (30).
10. The method according to any one of claims 1 to 9, characterized in that the step for determining the deviation of the contour diagram (K) from the scattering pattern (M) includes a step for fitting and / or interpolating the contour diagram (K).
11. The method according to claim 9 or 10, characterized in that the step for determining the deviation of the contour diagram (K) from the scattering pattern (M) includes the step for determining contour diagram reference points of several scattering region images (31') of the contour diagram (K).
12. The method according to claim 11, wherein the step of determining the deviation of the contour diagram (K) from the scattering pattern (M) includes the step of determining the focal point and / or center point and / or shape distortion in several scattering region images (31') of the contour diagram (K).
13. The method according to any one of claims 1 to 12, characterized in that the step for determining the deviation of the contour diagram (K) from the scattering pattern (M) includes a step for determining the deviation of the contour diagram reference points from the corresponding reference points of the reference image of the scattering pattern (M) and / or shape distortion.
14. A laser scanner device (300) equipped with a scanning field correction deflection unit (10), - At least one deflection unit (10) formed to pass through or scan a processing area (11) by a laser beam (12) along predetermined scanner coordinates (x, y, z), wherein a scattering pattern element (30) can be arranged on the processing plane, and the deflection unit (10) has at least one scattering region (31) in which the scattering pattern element (30) is arranged within a scattering pattern (M), - At least one window (20) is positioned between the deflection unit (10) and the processing area (11), - At least one photodiode (PD) formed to detect scattered radiation (13) that may be generated by the scattering and / or reflection of the laser beam as it passes through the at least one scattering region (31) of the scattering pattern element (30) １ PD ２ PD ３ )and, - A calculation unit formed to create a contour diagram (K) based on the correlation between the detected scattered radiation (13) and the scanner coordinates (x, y, z), and to calculate a calibration function for calibrated control of the deflection unit (10) based on the deviation of the contour diagram (K) from a reference image of the scattering pattern (M), A laser scanner device (300) having the following.
15. The laser scanner device (300) according to claim 14, further comprising two photodiodes positioned on a portion of the window edge (23) of the window (20).
16. The laser scanner device (300) according to claim 15, characterized by comprising at least three photodiodes (PD1, PD2, PD3) arranged on a portion of the window edge (23) of the window (20).
17. The laser scanner device (300) according to any one of claims 14 to 16, wherein the at least one photodiode is formed or positioned to detect a portion of the scattered radiation (13), and the scattered radiation spreads within the window (20) by reflection and / or scattering between the upper window surface (21) and the lower window surface (22) toward a portion of the window edge (23) of the window (20).
18. At least one photodiode (PD) １ PD ２ PD ３ The laser scanner device (300) according to any one of claims 14 to 17, characterized in that the device is configured to output a measurement signal to the calculation unit that is essentially proportional to the detected scattered radiation (13).
19. The amplitude of the contour diagram (K) is essentially proportional to the detected scattered radiation (13) or the measurement signal of the at least one photodiode (PD １ , PD ２ , PD ３ ), respectively. The laser scanner device (300) according to claim 18.
20. A scattering pattern element (30) for carrying out the method described in claims 1 to 13, and / or for a laser scanner device (300) according to any one of claims 14 to 19, The scattering pattern element (30) is formed in a plate shape and has a scattering pattern (M), and the scattering pattern (M) includes several scattering regions (31). The scattering region (31) is formed as a roughened and / or imprinted surface region and / or hole of the scattering pattern element (30), or within the volume of the scattering pattern element (30). The scattering region (31) is positioned within the scattering pattern (M) so that the image of the scattering pattern (M) or a part thereof can be clearly identified in each rotation, shape distortion, reflection, scaling, or translation. The scattering region (31) comprises a first arrangement of the first marker region (32), A scattering pattern element (30) characterized in that each of the first marker regions (32) is surrounded by a second array of a plurality of second marker regions (33).
21. The scattering pattern element (30) according to claim 20, characterized in that the second arrangement of the plurality of second marker regions (33) in at least two of the first marker regions (32) is different.
22. The scattering pattern element (30) according to claim 21, characterized in that the second arrangement of the plurality of second marker regions (33) in at least two of the first marker regions (32) differs in angular arrangement and / or the number of the second marker regions (33).
23. A scattering pattern element holding device (40) for holding the scattering pattern element (30) in order to place the scattering pattern element (30) on the processing plane (11) of a laser scanner device, - A base surface (41) and a side wall (42) that rotates around the base surface (41) such that the base surface (41) and the scattering pattern element holding device (40) form a hollow space (43), wherein the side wall (42) at the upper end (44) is formed to support the scattering pattern element (30) so as to be fixed to the upper end (44), thereby allowing light from the laser scanner device (300) to be irradiated into the hollow space (43) through the scattering pattern element (30), the base surface (41) and the side wall (42), - At least one deflection cone (45) disposed on the base surface (41), wherein the deflection cone (45) is formed and / or positioned such that it absorbs light striking the deflection cone (45) and / or deflects the light toward the inner surface (46) of the side wall (42), and the inner surface (46) of the side wall (42) is formed such that it absorbs light striking the inner surface (46) of the side wall (42), A scattering pattern element holding device (40) having the following:
24. The scattering pattern element holding device (40) according to claim 23, characterized in that the inner surface (46) of the side wall (42) and / or the deflection cone (45) has a plurality of absorber thin layers (47).
25. The scattering pattern element holding device (40) according to claim 23 or 24, characterized in that the upper end portion (44) of the side wall (42) is formed to support the scattering pattern element (30) in a floating manner.
26. A scattering pattern element holding device (40) according to any one of claims 23 to 25, characterized in that the deflection cone base surface essentially covers the entire base surface (41), and / or the height of the deflection cone (45) corresponds to at least half the height of the side wall (42).
27. A scanning field correction system (200) comprising at least one laser scanner device (300) according to any one of claims 14 to 19, and at least one scattering pattern element (30) for scanning field correction according to any one of claims 20 to 22.
28. The scanning field correction system (200) according to claim 27, comprising at least one scattering pattern element holding device (40) according to any one of claims 23 to 26.
29. A scanning field correction system (200) according to claim 27 or 28, comprising at least two laser scanner devices (300) whose scanning fields (120, 122, 124, 126, 128) at least partially overlap, wherein the laser scanner devices (300) can be calibrated relative to each other using the scattering pattern elements (30).