OPTICAL MEASURING DEVICE AND METHOD FOR DETERMINING THE THREE-DIMENSIONAL SHAPE OF AN OBJECT

Description

[0001] The invention relates to an optical measuring device for determining the three-dimensional shape of an object, which has at least one light section sensor which has an illumination unit designed to project a linear marking onto the object and at least one image recording unit for detecting the linear marking projected onto the object, and has a feed detection unit which is designed to detect the feed path of the object moved beneath the light section sensor over time, wherein the optical measuring device is designed to determine height profiles of the object from the linear marking.

[0002] The invention further relates to a method for determining the three-dimensional shape of an object using such an optical measuring device.

[0003] The so-called light section method is known for determining object properties. In this method, a line of light is projected onto the surface of the object to be analyzed, using a laser or line illumination, for example, and the lateral image is captured with an image acquisition unit. From the shape of the current profile line, the object height of a profile point in the current elevation profile can then be directly determined using appropriate calibration. A height profile is also called a scan profile and can also be presented in the form of a cross-sectional profile.

[0004] DE 10 2017 130 909 A1 describes an optical measuring device with a first illumination unit for projecting a linear marking onto an illumination plane and a first image recording unit for capturing the linear marking projected onto the object. Furthermore, a controllable second illumination unit is provided, which is designed to project light in a predetermined light spectrum onto the object in order to capture the light of the second illumination unit reflected back from the object in a location-dependent manner using a second image recording unit and to determine three-dimensional surface information of the object by means of a light section with the linear marking, as well as to determine properties of the object from the location-dependently captured light spectrum of the light of the second illumination unit reflected back from the object.

[0005] DE 10 2017 104 998 A1 describes a conveyor device and a method for determining the surface speed of a transport surface.

[0006] Since the light section method determines 3D data only within the used light plane (=height profile), which corresponds to the light line projected on the current object surface, external information is required about how successive height profiles are related, ie how the object moves through the light line and what distance lies between the height profiles.

[0007] For example, if the sensor is moved over the object at a constant speed, the missing information can be obtained from the direction of movement and the magnitude of the speed.

[0008] Measurements are often performed with the object being measured on a conveyor belt and moving beneath a stationary sensor through its light plane. The known conveyor speed can then be used to determine the relationship between the individual height profiles. If the belt speed is not constant, especially if accelerated movements occur, measurement errors will occur.

[0009] The problem can usually be avoided by using incremental encoders that convert the belt movement into signals corresponding to a constant distance. However, if the objects are uncertain about their adhesion to the transport medium, there may be a slippage between the assumed object movement from the increments and the actual object movement. The resulting measurement uncertainty can be exacerbated by additional belt transitions where the object behavior during transport is not reliably controlled.

[0010] In many transport processes that do not use a controlled transport medium, such as slides, roller conveyors or free fall sections, there is usually no information about the transport path that the measuring object takes between the height profiles.

[0011] EP 2 363 716 A2 discloses contactless path and speed detection based on consecutive images and a correlation analysis between two consecutive images. Such a method can be found in hardware implementation, for example, in today's PC mice, which no longer use a wheel but instead continuously capture images of the surface of the PC mouse with a small CMOS sensor of approximately 16 x 16 to 30 x 30 pixels and determine the current displacements from the correlation of the image content of two consecutive images. However, one of the prerequisites is that the distance practically does not vary and remains constant on average.

[0012] Such a situation does not generally exist with regard to objects to be scanned with a light section sensor, because the aim of a scanning process is to determine changing surfaces and thus changing heights and widths.

[0013] Even if a sharp image can be generated over the occurring height variations and there is no significant change in distance between two images and the product surface has sufficient structures so that successive images of the different distance ranges allow a good correlation analysis, the information as to how a determined displacement in pixels relates to the actual displacement of the object is lost because the image scale changes.

[0014] Based on this, it is the object of the present invention to provide an improved optical measuring device for determining the three-dimensional shape of an object and an improved method for this purpose, which does not require product transport, which takes place in such a controlled manner that the required path information can be derived from the transport medium itself.

[0015] The object is achieved by the optical measuring device having the features of claim 1 and by the method having the features of claim 14. Advantageous embodiments are described in the subclaims.

[0016] It is proposed that the optical measuring device is configured to capture images of the surface of the object captured during the movement of the object, to determine a displacement of features in the images captured of the object surface in a time interval and to determine a displacement of the object in the time interval from the respectively determined displacement of the features in the images of the object surface and from at least one height profile of the object, the respective distances and scales for the images captured of the object surface.

[0017] For this purpose, the respective distance of each surface region captured as an image can be determined from the cross-sectional profiles of the object's surfaces, images of which are captured for feed rate determination, and stored as a distance profile for the captured surface region. If the measuring device is designed so that the scan line crosses the center of the recorded surface region, the distance to this region can be determined particularly easily from the height profile.

[0018] The invention exploits the fact that a combination of the sequence of depth information from the height profiles with a sequence of 2D image sensor information of the object surface leads to a known object movement between the height profiles, because the distance information of the object regions of the recorded 2D images, which is missing at varying distances, can be derived from the height profiles of the light section sensor.

[0019] In simple cases, this allows a distance-dependent adjustment of the conversion factors for the pixel displacement in the recorded images in the image space of the object surface to the actual object displacement of the object in the object space.

[0020] This has the advantage that the actual displacement path of the object in the area of ​​the light section sensor can be detected without any distortion due to slippage or similar, and that even simple, uncontrolled transport media such as slides and roller belts are suitable as measuring sections.

[0021] The optical measuring device can have a data processing unit which is configured as a feed detection unit for evaluating image sections of the images of the object captured by the light section sensor by determining a displacement of features in the image sections.

[0022] The feed detection unit may have at least one 2D image sensor, each of which is configured to capture images of the surface of the object detected during the movement of the object.

[0023] The optical measuring device can be configured to adjust the setting of a lens of the 2D image sensor to quasi-statically changing distance ranges between the lens and the object. The lens and / or the illumination can be automatically adjusted, for example, to adapt to other quasi-static distance ranges (e.g., products of different heights with comparable surface roughness and surface structure).

[0024] The feed detection unit can have multiple 2D image sensors, each configured to capture images of the object's surface as it moves. The multiple 2D image sensors capture different surface areas of the object. The object areas can differ in both height and width due to their different positions. 2D image sensors with the same focus can be aligned to comparably high regions of the object's surface that are spatially offset (or possibly overlapping) from one another at the same height level. It is also conceivable, however, that 2D image sensors have different focuses but are aligned to the same object region, so that the 2D image sensors capture different surface areas in height with respect to the distance between the lens and the respective focused image plane.The optical measuring device is configured to select one of the several surface areas for determining the displacement of the object adapted to height information derived from the height profile recorded with the line intersection sensor.

[0025] If the object varies significantly in width, a fixed-configuration 2D image sensor unit (lens and illumination) may be sufficient to determine the displacement between two height profiles. In some cases, more than one object region may be required for which images are recorded to ensure that an image region is always available on the object's surface. The appropriate image region or associated 2D image sensor can then be selected from the height profile so that the relevant displacement information can be derived.

[0026] The at least one 2D image sensor can be sensitive to a different wavelength than the wavelength of the light section sensor.

[0027] It is advantageous if the light for the 2D image sensors has a different frequency than the light line of the light section sensor, so that no mutual interference occurs. It can also be advantageous if the associated illumination for the 2D image sensors also uses different light frequencies at different distances if a globally suitable illumination cannot be found for all distance ranges.

[0028] The feed detection unit may further have an additional lighting unit for illuminating the detected surface of the object.

[0029] In more complex cases, it is advantageous if the distance information from the light section sensor results in an adjustment of the illumination and, if necessary, the lens of the 2D image sensor.

[0030] The optical measuring device can be configured to adapt the illumination of the image area captured by the surface of the object to quasi-statically changing distance ranges between the lens and the object.

[0031] If the object surface varies in its basic format, but the actual height variation, and thus the distance of the object region to the 2D image sensor, is limited, a quasi-static adjustment of the lens and illumination is sufficient. Thus, no continuous, dynamic adjustment is necessary during the measurement.

[0032] The optical measuring device can be configured to dynamically adjust the lens setting and illumination for distance ranges that dynamically change across the object. This allows for continuous automatic adjustment of the image size and / or object area illumination of the relevant 2D image sensor for dynamically changing distance ranges.

[0033] The optical measuring device can be configured to determine a displacement of features in the images captured of the object surface in an image area intersected by the linear marking. The center—as seen in the transport direction—of the surface region of the 2D image sensor for the relevant distance of this object surface can lie exactly on a height profile line of the light section sensor. Thus, the distance resulting from this height profile already approximately represents the average distance of the object region to the relevant 2D image sensor. This can be ensured by appropriate design and arrangement of the optics of the 2D image sensor and the scanning optics of the light section sensor.

[0034] The optical measuring device can be configured to synchronize the scanning frequency of the light section sensor with the frame rate used to determine an object's displacement from sequentially acquired images. The synchronization can be performed, for example, depending on the requirements of the scanning resolution, scanning speed, and surface smoothness.

[0035] Since only a small change in distance should occur between two images, which is beneficial for the quality of the correlation analysis, the images should be recorded at a sufficient frame rate. Especially when the object surface has only small structural elements, a sufficiently magnified representation of the object area is advantageous. To allow for movement of up to several m / s even in these cases, the recording rate must be sufficiently high.

[0036] For example, for an object speed of 1 m / s and an image region of 30 x 30 pixels with the smallest structural element of 1 mm, this should be sampled with at least two pixels. This results in an object region of 15 mm. Assuming that for good correlation, there should be a maximum displacement of 7.5 mm between two consecutive images, a recording should be taken every 7.5 milliseconds, meaning the frame rate should be at least 134 Hz.

[0037] On the other hand, it makes no sense to generally choose an extremely high frequency, because then no shift would be measured between two recordings.

[0038] The parameters measurement frequency, object area size, structural element size, maximum speed and acceleration and smallest resolvable displacement should be coordinated with each other.

[0039] In addition to the problem of scale changes when the object distance is not constant, these influencing parameters also mean that one cannot assume that a sharp image across the entire height range is sufficient. If one takes an object with a smooth, lightly structured surface as an example, one will need to use a relatively high magnification and small image sections just to achieve a correlation between two consecutive, overlapping images. This will ensure that small structures across the entire image area are clearly visible and that a correlation of the image content can function at all. A lens with a large depth of field would by no means achieve the desired result. In addition, the lighting must be high-contrast but also very uniform, as fluctuations in lighting and strong fluctuations in shadow formation between two images would be detrimental to the correlation analysis.The factors of structures suitable for correlation, sharpness of the image, uniformity of the illumination and no extreme shadows can only be adjusted sufficiently well over a certain working range, which also depends on the surface properties of the object.

[0040] Adjustments to the lenses of the 2D image sensor and the associated illumination are therefore also advantageous. Alternatively, a suitable selection can be made from a variety of 2D image sensors and / or 2D image sensor regions with distance-dependent lenses and illumination.

[0041] Consider the case where only a quasi-static adjustment is required because the changes in the height ratios either only exist in the basic format of the measuring objects. In this case, it is sufficient to automatically adjust the lenses and the illumination to a different working range before starting the measurement. The remaining variation is then small enough that a correction of the pixel shift to the true object shift by distance-dependent scaling is sufficient. Or the product changes so slowly compared to the usual object speed that continuous adjustment is possible without time-related problems.

[0042] If the measuring object has a higher height dynamic, techniques should preferably be used that allow sufficiently fast lens adjustment and illumination adjustment.

[0043] The lighting can usually be adjusted more easily when using LEDs, as it is easier to switch to other or additional array elements.

[0044] A change in the angle of the lighting can also be achieved with relatively small deflections that can be implemented quickly.

[0045] Automatically adjustable lenses, such as liquid lenses, can be used to allow adjustments to be made in a range of a few milliseconds.

[0046] If adjustment during image acquisition is not fast enough, at least two 2D image sensor units with adjustable lenses and illumination could be provided, for example. One measures while the other is adjusted to the new distance conditions and then switches to the other unit after the adjustment process. This assumes that the distance curve for many objects is relatively continuous - i.e., without sudden changes in the respective trend. A cascade of 2D image sensor units is also conceivable, which are preset for different distance regions of the surface areas detected by the feed measuring device; this is also economically feasible if inexpensive PC mouse chips are used.

[0047] Using the distance information obtained from the light section sensor, the result of the 2D image sensor that best matches the determined distance for each of the multiple 2D image sensors can then be accessed during the measurement process.

[0048] It is advantageous to use an integrated circuit designed for use in an optical mouse, comprising an image sensor configured to capture an image pixel matrix and an image evaluation unit for detecting the displacement of features based on the image comparison of image pixel matrices captured sequentially. The optical measuring device can be configured to scale the displacement based on the scale profile derived from the distance profile and to determine the feed path of the object from the scaled displacement.

[0049] For example, several units – with adapted illumination and lenses – could be used as image sensors, such as those used in mice for personal computers (PCs).

[0050] In some cases, however, a CMOS camera could also be suitable, which is intended for the provision of frequency-selective information - such as object colour - e.g. to find special features such as defects on the object surface, whereby suitable sub-regions of this recording sensor are used to obtain a pixel shift in the x and y direction from the aforementioned correlation analyses, which is then converted into path information in x and y, appropriately scaled, based on the distance information from the light section sensor.

[0051] The optical device can have a data memory with distance-dependent correlation parameters and scaling parameters stored in the data memory and can be configured to convert the determined displacement of the features in the images of the object surface into a displacement path of the object using correlation parameters and / or scaling parameters read from the data memory.

[0052] The problem is also solved with a method for determining the three-dimensional shape of an object using such an optical measuring device. The following steps are provided: Determining a height profile of an object conveyed beneath the light section sensor using the light section sensor based on a linear marking projected onto the object, capturing images of the object surface, determining a displacement of features in the images captured of the object surface, and determining a displacement of the object from the determined displacement of the features in the images of the object surface and from the respective distances and scales of the images captured of the object surface derived from the height profile of the object.

[0053] In the method, an adjustment of an optics and / or illumination unit of the optical measuring device can be provided depending on the height profile derived with the light section sensor to the detected areas of the object surface of the object.

[0054] Advantageously, one of several 2D image sensors is selected and / or an illumination unit of the optical measuring device is controlled to illuminate the detected object surface depending on the distance profiles for the 2D image regions with their associated illumination elements derived from the height profiles of the object using the light section sensor.

[0055] It is conceivable that the principle of combining height information, 2D image information and pixel shift based on correlation analysis is realized by a compact hardware unit that uses non-contact distance measurement (time of flight, ultrasound, etc.) to adjust the imaging optics in real time.

[0056] The illumination can be implemented globally, e.g. as telecentric illumination, whose expected reflected intensity is adjusted depending on the distance and is included as a parameter in the correlation calculation, so that a permanently distance-corrected displacement path in x and y is output by this extended hardware.

[0057] Another option is a suitably controlled LED array, which would need to be provided externally for the hardware. The array would be designed to provide illumination suitable for correlation analysis at any distance. However, this would only allow for adaptation to the object's contours within certain limits. Abrupt holes or elevations could then be effectively processed using certain filter mechanisms.

[0058] It is conceivable to perform a kind of averaging over a certain distance of the object in the scanning direction. This can be used to easily and effectively eliminate implausible distance measurements and displacement measurements from a single measurement.

[0059] A special variant could also input the depth images of two light-section sensors, which are at a known fixed distance D from each other in the scanning direction and measure with a known, identical scanning frequency, into the correlation analysis. In this case, the number of height profiles until a correlated overlap area is reached would be the measure of the speed required by the object to cover the distance D and thus the measure of the distance between two height profiles.

[0060] The invention is explained in more detail below using an exemplary embodiment with the accompanying drawings. They show: Figure 1 - Side view sketch of an optical measuring device on a conveyor belt for objects transported beneath a light section sensor; Figure 2 - Top view sketch of an optical measuring device on a conveyor belt for objects transported beneath a light section sensor;

[0061] Figure 1 shows a sketch in side view of an optical measuring device 1 arranged on a conveyor belt 2. The optical measuring device 1 is aligned with the upper side of the conveyor belt 2, on which objects 3 are conveyed in a feed direction V under a light section sensor 4.

[0062] The light section sensor 4 has an illumination unit 5 designed to project a linear marking onto the surface of the object 3 facing the light section sensor 4. Furthermore, the light section sensor 4 has at least one image recording unit 6 for capturing at least part of the linear marking projected onto the object.

[0063] The light section sensor 4 or a data processing unit 7 connected to it is set up, for example, by suitable programming with a computer program designed for execution on the data processing device 7, to determine the respective height of the object 3 in relation to the upper side 8 of the conveyor belt 2 in an image column based on the recorded images with the linear marking on the object 3, which then provides a height profile or a cross-sectional profile of the object 3 for each scanned image. This height profile also results in features such as object width, object height and cross-section. If the object height is determined at a specific point transverse to the transport direction, this results in a distance profile at this point via the sum of height profiles, i.e. over time or over the location along the length of the object 3. In this way, it is also possible for object areas on the object 3, which e.g.are recorded by the feed measuring unit, whose respective height value is determined, from which it can also be determined which image scale is to be expected in order to get from a displacement in the image to a displacement of the corresponding object surface.

[0064] For the feed movement, the conveyor belt 2 is guided along two deflection rollers 9a, 9b arranged at a distance from one another and controlled, for example, by means of the data processing unit 7. To determine the distance profile during the feed movement V, it is now desirable to determine the feed of the object 3 over time t as precisely as possible.

[0065] For this purpose, a feed detection unit is provided which, in the exemplary embodiment, is configured to capture images of the surface of the object 3 moving beneath the light section sensor 4. For this purpose, the 2D image sensor 10 captures images of sections of the surface of the object 3. The displacement path of the object 3 is determined from an image comparison of features of two consecutively captured images of the surface of the object 3. In this case, the displacement of identical features in the pair of images is captured. The feed rate can then be determined taking into account the time difference between the capture of the successive images, i.e., by the time derivative of the displacement.

[0066] The optical measuring device 1 can have a data processing unit 7 that performs the image comparison and determines the displacement path and, if applicable, the feed rate from the result of the image comparison. For this purpose, the images of at least one 2D image sensor 10 or images captured by the image recording unit 6 of the light section sensor 4 can be used.

[0067] It is conceivable that images from a 2D image sensor 10 are transmitted to the data processing unit 7. The displacement path or feed rate is then determined from the successive images by a computer program executed by the data processing unit 7.

[0068] The data processing unit 7 can be configured to derive a scale from the height information acquired by the light section sensor 4 at specific times t, which is used to determine the displacement of the object 3 from the displacement of features in the images of the object surface. For this purpose, the scale can be, for example, a scaling factor by which the displacement of a feature in the image is multiplied. The distance-dependent scaling scale transforms the determined displacement in the image space into the actual displacement of the object 3 in the object space.

[0069] Figure 2shows a top view of the optical measuring device 1 and the conveyor belt 2, on which objects 3 are transported beneath the light section sensor 4. It can be seen that a linear marking L is projected onto the surface of the object 3. The height profile can be determined from the deformation of the linear marking L.

[0070] In this sketch, the feed sensor 10 is aligned with the surface of the object 3.

[0071] It can also be seen that the conveyor belt 2 is driven by a motor 11, which is connected to a deflection roller 9b via a shaft 12. The motor 11 is controlled by the data processing unit 7, which not only evaluates but also performs control functions. It is also conceivable that the object 3 moves on a roller belt with or without a drive.

[0072] The dashed lines on object 3 indicate the peaks and valleys of object 3, ie a specific distance profile.

[0073] From the shape of the current linear marking L, the object height of a profile point in the current cross-sectional image can be directly deduced by means of appropriate calibration. If the object 3 moves along beneath the linear marking L with a known spatial and temporal advance, a sequence of height profiles is obtained, from which the surface of the object 3 facing the light section sensor 4 can be reconstructed.

[0074] The feed V is determined by an optical path measurement using an imaging 2D image sensor 10, which creates images of the surface of the object 3 moving at the feed speed with a sufficient frame rate, wherein at least two consecutive images are compared with each other and the current displacement value is determined from the displacement of the image information.

[0075] For this purpose, the data processing unit 7 is configured, for example, to evaluate the images recorded during the movement of the surface of the object 3, each of which contains overlapping information, by means of a correlation analysis of the successive image contents. If the image contents are shifted relative to one another, the magnitude of the correlation is determined when the image contents match as closely as possible. The shift vector of the image contents for this state with the best possible correlation then corresponds to the shift path.

[0076] The 2D image sensor 10 can be integrated into a commercially available compact sensor. Integrated circuits are available for this purpose, which are used in optical mice for computers and contain the optics with image acquisition unit and an evaluation unit.

[0077] It is conceivable that the feed detection unit with the 2D image sensor 10 additionally has an illumination unit (light source) which illuminates the surface of the object 3 to be recorded in a suitable and as uniform a manner as possible.

[0078] It is also advantageous if the 2D image sensor 10 contains an optic that generates a flat image that is best suited for correlation analysis, depending on the distance conditions and the surface properties (material, roughness, structure, etc.).

[0079] The 2D image sensor 10 is preferably configured to the average surface property of the object 3. For this purpose, both the optics and an optional illumination of the feed detection unit can be permanently adjusted or controlled. It is advantageous if the optics and illumination of the 2D image sensor 10 are permanently adjusted to the average distance of the 2D image sensor 10 from the surface of the object 3 or, preferably, dynamically adjusted depending on the varying conditions of, for example, distance, light, surface structure, etc.

[0080] The measurement frequency of the 2D image sensor 10 should be at least high enough so that no large change in depth occurs for two consecutive images.

[0081] It is conceivable that the optics and illumination of the 2D image sensor 10 can be variably adapted to the surface quality and the distance of the 2D image sensor 10 from the background. If there are differences in the average distances and the average surface quality between different applications, i.e., the average distance of the 2D image sensor 10 from the surface of the object 3 varies or the surface structure is finer or coarser, the distance measurement can be adapted to the other conditions. This ensures that a flat, structured image can be recorded by the 2D image sensor 10 in each case, which is optimally suited for correlation analysis.

[0082] The measurement frequency of the 2D image sensor 10 is preferably variably adjustable. For example, it can be synchronized by the data processing unit 7 with a control signal that determines the feed speed of the conveyor belt 2.

[0083] It is conceivable that the image recording unit 6 of the light section sensor 4 is simultaneously used as an image recording unit for the feed detection unit.

[0084] The optical measuring device 1 can be configured such that, in the event of significant changes in height, the optics and illumination are adjusted based on depth data measured by the 2D image sensor 10 or the light section sensor 4. To determine the feed path, it is sufficient if the surface structures and distances to the surface of the object 3 are constant piecewise. The path measurement can be performed with sufficient accuracy over the entire measuring distance if an adjustment is made depending on the depth data when the distances of the recorded images to the object surfaces change so drastically that an adjustment of the image scale becomes necessary.

[0085] The adjustment is preferably carried out automatically and can be carried out by the data processing unit 7.

[0086] The height information or distance data determined by the light section sensor 4 can be used to mathematically correlate the result data of the path measurement performed by the feed rate determination unit. This allows, for example, a scaling factor to be determined from the height information determined by the light section sensor 4, which is incorporated into the feed rate of the object 3 determined by the feed rate determination unit 10 from the displacement of features of the object surface of an object 3 captured by images.

[0087] The measuring method can also be carried out in such a way that, with an unchanged surface structure, a pure change in distance and the associated changed scaling of the image recorded by the 2D image sensor 10 through the light section sensor 4 is subsequently corrected using software for the distance of the recording area of ​​the image recording unit 6. A large distance means a larger difference in distance between the two successive image recordings for the same pixel shift from the correlation analysis. If a constant distance and thus a constant path scaling is used in the first calculation step, the data can be recalculated using the indexing carried out and the correct distances and thus the correct scaling factors can be used to correct the previously determined path differences. In this way, the true path distance, i.e. the feed path, is subsequently determined despite the changing distance between the 2D image sensor 10 and the surface.

[0088] Correction factors that can be derived from the measurement of the at least one light section sensor 4 can be transferred directly to the data processing unit 7 or determined by it, which then immediately outputs corrected position shifts.

[0089] In the event that only a simple scaling change needs to be considered, the current distance value or the distance change can be continuously transmitted to an advanced correlation hardware, which continuously takes the scaling change to be applied into account and determines and outputs a corrected shift value in real time.

Claims

1. Optical measuring device (1) for determining the three-dimensional shape of an object (3), which has at least one light section sensor (4) which has an illumination unit (5) designed to project a linear marking (L) onto the object (3) and at least one image recording unit (6) for detecting the linear marking (L) projected onto the object (3), and has a feed detection unit which is designed to detect the feed path of the object (3) moving under the light section sensor (4) over time (t), wherein the optical measuring device (1) is designed to determine height profiles of the object from the linear marking (L), and to detect images of the surface detected during the movement of the object (3), characterized in that the optical measuring device (1) is designed to determine a displacement of features in the images captured from the object surface in a time interval and to determine a displacement of the object (3) in the time interval from the respectively determined displacement of the features in the images of the object surface and respective distances and scales derived from at least one height profile of the object (3) for the images captured from the object surface.

2. Optical measuring device (1) according to claim 1, characterized in that the optical measuring device (1) has a data processing unit (7) which is set up as a feed detection unit for evaluating image sections of the images of the object (3) captured with the light section sensor (4) by determining a displacement of features in the image sections.

3. Optical measuring device (1) according to claim 1, characterized in that the feed detection unit has a 2D image sensor (10) which is designed to capture images of the surface of the object (3) captured during the movement of the object (3).

4. Optical measuring device (1) according to claim 3, characterized in that the optical measuring device (1) is designed to adapt the setting of a lens of the 2D image sensor (10) to quasi-statically changing distance ranges between the lens and the surface areas of the object (3) used by the feed detection unit.

5. Optical measuring device (1) according to claim 3 or 4, characterized in that the feed detection unit has a plurality of 2D image sensors (10), each of which is set up to capture images of the surface of the object (3) captured during the movement of the object (3), wherein the plurality of 2D image sensors (10) capture surface areas of the object (3) that are different from one another, and wherein the optical measuring device (1) is set up to select one of the plurality of surface areas for determining the displacement of the object (3) on the basis of the height information on all surface areas captured by the plurality of 2D image sensors (10), which are derived from the height profiles captured with the line intersection sensor (4).

6. Optical measuring device (1) according to claim 3, 4 or 5, characterized in that the at least one 2D image sensor (10) is sensitive to a different wavelength than the wavelength of the light section sensor (4).

7. Optical measuring device (1) according to one of the preceding claims, characterized in that the feed detection unit further has an additional lighting unit for illuminating the detected surface of the object (3).

8. Optical measuring device (1) according to one of the preceding claims, characterized in that the optical measuring device (1) is designed to adapt the illumination of the image area captured by the surface of the object (3) to quasi-statically changing distance ranges between the lens and the surface areas of the object (3) used by the feed detection unit.

9. Optical measuring device (1) according to claim 4 and 8, characterized in that the optical measuring device (1) is designed for dynamic adjustment of the setting of the lens and the illumination for distance ranges of the surface areas used for determining the feed rate which change dynamically across the object (3).

10. Optical measuring device (1) according to one of the preceding claims, characterized in that the optical measuring device (1) is set up to determine a displacement of features in the images captured from the object surface in an image area which is intersected by the linear marking (L).

11. Optical measuring device (1) according to one of the preceding claims, characterized in that the optical measuring device (1) is set up to coordinate the scanning frequency of the light section sensor (4) and the image repetition frequency, which is used to determine a displacement of the object from images acquired one after the other in time.

12. Optical measuring device (1) according to one of the preceding claims, characterized in that the optical measuring device (1) has an integrated circuit designed for use in an optical mouse with an image sensor (10) set up to detect an image pixel matrix and with an image evaluation unit for detecting the displacement of features based on the image comparison of image pixel matrices recorded one after the other, wherein the optical measuring device (1) is set up to scale the displacement of features detected by the image evaluation unit based on the scale derived from at least one height profile in order to determine the object displacement of the object (3) taking place at any given time.

13. Optical measuring device (1) according to one of the preceding claims, characterized in that the optical device (1) has a data memory with distance-dependent correlation parameters and scaling parameters stored in the data memory and is set up to convert the determined displacement of the features in the images of the object surface with correlation parameters and / or scaling parameters read from the data memory into a displacement path of the object (3).

14. Method for determining the three-dimensional shape of an object (3) with an optical measuring device (1) according to one of the preceding claims, comprising the steps of: - determining a height profile of an object (3) conveyed beneath the light section sensor (4) with the light section sensor (4) on the basis of a linear marking (L) projected onto the object (3), - capturing images of the object surface, characterized by: - determining a displacement of features in the images captured of the object surface, and - determining a displacement of the object (3) from the determined displacement of the features in the images of the object surface and from the respective distances and scales of the images captured of the object surface, derived from the height profile of the object (3).

15. Method according to claim 14, characterized by adapting an optics and / or lighting unit (5) and / or frame rate of the optical measuring device (1) depending on the respective distance for the detected area of the object surface of the object (3), which is derived from the height profile detected with the light section sensor (4).

16. Method according to claim 14 or 15, characterized by selecting a 2D image sensor (10) and / or controlling an illumination unit (5) of the optical measuring device (1) for illuminating the detected object surface as a function of the distances for the 2D image regions with their associated illumination elements, each derived from the height profiles of the object (3) using the light section sensor (4).