DE102018113847B3 - Holder for mounting a sensor - Google Patents

Abstract

The invention relates to a holder (32) for fastening a sensor (10), in particular a 3D camera, to the ceiling (48), wherein the holder (32) has a ball joint (34, 36) with a ball element (34) and a Holding element (36) which carries the ball element (34) and in which the ball element (34) is rotatable about a vertical axis and tiltably mounted against the vertical axis and is under a tension which counteracts the turning and tilting. In this case, the ball element (34) is configured as a double-sphere element with an upper first part ball element (40) and a lower second part ball element (42) which lie flat on one another, and a tension element (52) is provided, without tools, for the tension of the retaining element (36) optionally to reinforce or reduce.

Description

The invention relates to a holder according to the preamble of claim 1 with a ball joint for mounting a sensor on the ceiling, in particular a 3D camera.

In addition to conventional two-dimensional cameras, 3D sensors are also used for the monitoring. These include, first of all, 3D cameras in different technologies, for example stereoscopy, triangulation, light propagation time or evaluation of the disturbance of passive two-dimensional patterns or of projected illumination patterns. Such 3D sensors, in contrast to a two-dimensional camera, record images that contain a distance or depth value in their pixels. This depth-resolved or three-dimensional image data is also referred to as a depth map. Also known are scanning in two or all three directions laser scanner, which also detect three-dimensional image data on the respective scanning angle and the measured distance. Compared to a two-dimensional image acquisition higher device and evaluation effort for the generation of three-dimensional image data is justified in many applications by the additional information.

A special field of application is safety technology with the function of protecting persons from sources of danger such as, for example, machines in an industrial environment. The machine is monitored by means of sensors, and if there is a situation in which a person threatens to come dangerously close to the machine, an appropriate safeguard is taken. Sensors used in safety technology or for personal protection must work particularly reliably and therefore meet high safety requirements, for example the EN13849 standard for machine safety and the IEC61496 or EN61496 device type for contactless protective devices (ESPE). To meet these safety standards, a series of measures must be taken, such as functional tests, reliable evaluation, in particular by redundant or diversified redundant structures, or monitoring of the contamination of optical components.

A fundamental step in setting up a safety application is to properly mount the sensors. A 3D camera is preferably mounted facing down on the ceiling. The setup is simplified, although the mounted sensor still allows a certain change in perspective in its holder. For a flexible rotation in all degrees of freedom a ball joint mount is in principle suitable. For the assembly in particular of a 3D camera but there are more requirements, such as a simple installation of relatively heavy equipment and adjustability, which is at the same time reasonably smooth, yet reliably fixed during operation.

The DE 10 2006 050 235 B4 discloses a camera system for monitoring a space area. The camera system is attached by means of a mounting part to a wall, a mast or the like. The mounting part is a mounting arm with a plurality of hinges that allow pivoting of the camera system by at least two mutually orthogonal axes of rotation. on a mounting arm with several hinges. Such a multi-part mounting arm is relatively large, and also the individual axes must be fixed after the alignment, what the document but not received.

The EP 1 336 535 A1 discloses a rotatable mount for a mobile phone or the like in a vehicle. In the holder, a ball head snaps into a mating socket, initially providing play in the mutual contact and allowing for rotation. Subsequently, the ball head and socket are pressed together by pulling a guided through a central axis of the bracket band which is fixed in a grid, firmly to hold the current rotational position. This bracket is suitable for a small, lightweight everyday device, where it depends only on a rough alignment, especially since the user in a moving vehicle has to compensate for completely different tolerances. For a safety sensor, which is by no means intended, but the required stability and reliability would not exist.

The CH 142467 A is one of many examples of a ball joint for attaching a camera to a tripod. Here, a union nut ensures that ball and socket are pressed against each other, and in between a rubber insert is provided to increase the friction and thereby fix the rotational position in addition. A precise and at the same time comfortable orientation as well as sufficient fixation for a safety application can not be achieved with such a simple structure.

The EP 2 063 138 B1 discloses a ball joint retainer for a notebook in a vehicle. The ball joint has two balls, and in between a locking member can be selectively pressed or released.

From the DE 201 17 543 U1 For example, a joint for a tripod is known which comprises at least two ball joints.

The DE 20 2014 103 540 U1 describes a camera arrangement in which the camera unit itself is part of a ball joint. As a second ball steering a stand with a ball is provided.

In the DE 41 28 669 A1 A three-dimensionally adjustable ceiling suspension for a surgical microscope is presented. Several rod-shaped connecting elements are connected via ball joints with a platform.

Ball joint mounts are also known from countless other sources, but designed and suitable for completely different devices, assemblies or orientations. It is therefore not or only possible with the conventional solutions to achieve an easily reproducible holding torque for secure fixation of a safety sensor.

It is therefore an object of the invention to improve the mounting of a sensor.

This object is achieved by a holder for mounting a sensor on the ceiling according to claim 1. The sensor, in particular a 3D camera, is preferably mounted on a ceiling construction and then observes its surveillance area from a bird's-eye view. The optical axis, which is referred to here without restricting meaning as Z-axis, thus shows substantially downwards. However, the holder initially also makes it possible to adjust the perspective by turning or tilting, so that the viewing direction of the mounted sensor does not have to point downwards exactly. Incidentally, although the holder is designed for ceiling mounting and particularly suitable, but can also be mounted differently.

The holder has a ball joint with a ball element and a holding element in which the ball element is mounted. The retaining element is at least indirectly fixed to the ceiling, so either mounted itself on the ceiling or at least indirectly fixed by support members, which in turn are attached to the ceiling. The holding element serves as a receptacle for the ball element and carries the ball element and the at least indirectly fixed thereto sensor. The ball element is rotatable in the holding element according to the ball geometry in both degrees of freedom, thus rotatable about the Z-axis and on the other hand tiltable. The holding element is under a tension that counteracts this rotation and thus holds the current rotational position, and is therefore also referred to as a collet.

The invention is based on the basic idea of ensuring both a temporary stabilization of the current rotational position during the orientation of the sensor, as well as their final fixation for the operation by the geometric design of the ball joint and a tool-less change in the voltage of the holding element.

For this purpose, on the one hand, the ball element is designed as a double-sphere element. It has two partial spherical elements, wherein a partial spherical element denotes a sphere cut off by a plane, similar to a hemisphere, but the section is not necessarily made in the equatorial plane, but may be offset parallel thereto. At this interface, the partial spherical elements lie flat against one another, preferably in such a way that, in a basic position of the holder with orientation downwards, the Z-axis runs straight through the centers of the cut surfaces. The dual-sphere member preferably allows rotation about the Z-axis through 360 °, but restricts the tilting movements and makes it easier to stabilize the respective positions.

In addition, a clamping element is provided, which selectively increases or decreases the tension under which the holding element is. In a state of low tension, the ball element can be rotated in the holding element, with a residual stress remains to stabilize the respective rotational positions during alignment. In the case of increased tension, twisting is no longer possible under the forces and moments occurring during operation. The change of voltage is possible without tools.

The invention has the advantage that the user is assisted to align the sensor in a simple manner and then to make a secure fixation. In this case, the holder provides an adequate holding torque both in the alignment and in the operating phase, which initially permits alignment movements, without immediately losing a current alignment position due to too much play, and ensures a sufficient holding torque after assembly, thus the sensor reliably maintain its perspective during operation. The bracket offers in addition to the unmistakable Justage- and assembly concept a very compact design. The tool-free handling of the clamping element manual fixation is very easy. The reliable compliance with an alignment position is particularly important for advantageous embodiments of the sensor as a safety sensor in the sense of the aforementioned or comparable standards of importance. If a security sensor loses its intended perspective, at least its availability is reduced even if security is not impaired by self-monitoring.

Preferably, only the second part ball element is in contact with the holding element. The ball element is thus supported solely on the second part of the ball element. This has the advantage that the retaining element does not have to be adapted to the slightly more complex Doppelsphärengeometrie and thus can be easily designed.

The first part ball element preferably has a smaller radius than the second part ball element. The second, lower part ball element brings the carrying capacity and the largest part of the holding torque against twists from the current orientation.

The partial spherical elements preferably have a common center. The radii and the height at which the partial spherical elements are cut off parallel to the equatorial plane are accordingly matched to one another. Thus, despite the globally no longer spherical geometry with different partial ball elements, the double-sphere element can continue to rotate at least over a certain tilting range like a ball. The rotation about the axis of symmetry, ie the Z-axis, is not impaired anyway by the double-sphere geometry.

The first partial ball element preferably has the geometry of a ball piece larger than a hemisphere and / or the second partial ball element has the geometry of a ball piece smaller than a hemisphere. This allows a common center despite different radii. The offset by the different radii is preferably compensated by different heights of the sectional plane of the partial ball elements relative to the equatorial plane of a sphere. The two partial ball elements have different functions in addition to the rotation about the Z axis. The first part ball element primarily prevents translations on the Z axis. For this purpose, a receptacle for the first part ball element is preferably provided on a side opposite the holding element side of the ball element, which is adapted to its radius. The second partial ball element essentially ensures the holding moment with which the holder opposes a rotation. Due to its geometry, in combination with the configuration of the retaining element, it limits the angular range in which tilting movements are possible, for example to at most 10 °, at most 20 ° or at most 30 °.

The holding element preferably has an adapted to the geometry of a ball inner receptacle for the second part of the ball element, in particular a conical receptacle. The geometry of the holding element can be comparatively simple if it does not come into contact with the entire double-sphere element, but only with the lower second partial-sphere element. It is also not necessary to create a somewhat more elaborate hollow sphere shape with a large contact area. Rather, a preferred conical shape of the receptacle is sufficient to allow and support the rotational and tilting movements.

The retaining element preferably has at least one radial slot. Preferably, a plurality of radially arranged slots are provided. A slot helps to create variable voltages of the support member to resist more or less resistance to rotational movement.

The clamping element preferably has an annular geometry and surrounds the retaining element on its outer circumference. As a result, a uniform, radial force is exerted on the holding element, which is particularly suitable for generating different and well-defined holding moments.

The tensioning element is preferably designed as an eccentric tensioner with a tensioning lever. This is a particularly suitable embodiment of an annular element surrounding the clamping element clamping element. The clamping lever changes the tension without tools, in each case a defined force acts by moving the clamping lever into the open and the closed position.

The tensioning element preferably has an adjusting element for predetermining a residual or prestressing stress. The holding element should also be under a certain tension during the alignment and before the fixation for the operation, so that a provisionally set in the context of adjustment rotational position is maintained. The adjustment element serves to set this residual stress defined, so that on the one hand sufficient stability is maintained, but at the same time can be tried and adjusted alignments without excessive force. The adjusting element has in particular an adjusting screw.

The tensioning element is preferably designed in two parts, in particular of two half-rings, with a closure actuated by the tensioning lever and the adjusting element at the connection points. At one connection point is the closure, which is opened and closed by the clamping lever. At the opposite junction, the adjustment is provided, which can leave a variable gap and so the residual stress varies.

In an advantageous embodiment, an arrangement of a 3D camera, in particular stereo camera, is formed with a holder according to the invention. A 3D camera can be any known Use technology such as a light transit time principle with direct transit time measurement of light signals or phase measurement or a distance estimation from brightness or focus positions (DFF, Depth from Focus, DFD, Depth from Defocus). However, the 3D camera particularly preferably uses a triangulation principle in which two camera images of a moving camera or a stereo camera are correlated with one another, or alternatively an illumination pattern is correlated with a camera image in order to estimate disparities and to determine distances therefrom.

• 1 eine schematische dreidimensionale Darstellung einer 3D-Kamera und ihres Überwachungsbereich;
• 2 eine dreidimensionale Ansicht einer Halterung für eine 3D-Kamera;
• 3 eine weitere dreidimensionale Ansicht der Halterung gemäß 2 aus anderer Perspektive;
• 4 eine Schnittdarstellung der Halterung gemäß 2 und 3;
• 5 eine dreidimensionale Ansicht einer Halterung mit Fixierung des Spannhebels;
• 6 eine dreidimensionale Ansicht einer Halterung mit einer weiteren Ausführungsform eines Spannelements für eine Vorspannung; und
• 7 eine dreidimensionale Ansicht einer weiteren Ausführungsform eines Halteelements für eine Halterung.

The invention will be explained in more detail below with regard to further features and advantages by way of example with reference to embodiments and with reference to the accompanying drawings. The illustrations of the drawing show in:

• 1 a schematic three-dimensional representation of a 3D camera and its surveillance area;
• 2 a three-dimensional view of a holder for a 3D camera;
• 3 a further three-dimensional view of the holder according to 2 from another perspective;
• 4 a sectional view of the holder according to 2 and 3 ;
• 5 a three-dimensional view of a holder with fixation of the clamping lever;
• 6 a three-dimensional view of a holder with a further embodiment of a clamping element for a bias voltage; and
• 7 a three-dimensional view of another embodiment of a holding element for a holder.

1 shows in a schematic three-dimensional representation of the general structure of a stereo camera 10 to record a depth map. The stereo camera 10 serves only as an example of a sensor according to the invention. Likewise conceivable would be other optoelectronic sensors, such as the other mentioned 3-D cameras with determination of the light transit time or an evaluation of the disturbance of passive two-dimensional pattern or with correlation of image and projected illumination patterns, but also 2D cameras and other optoelectronic sensors such as light scanners or laser scanners.

To capture a room area 12 are two camera modules 14a . 14b mounted in a known fixed distance from each other and take pictures of the space area 12 on. In every camera is an image sensor 16a . 16b provided, usually a matrix-shaped recording chip which receives a rectangular pixel image, for example a CCD or a CMOS sensor. The image sensors 16a . 16b is ever a lens 18a . 18b associated with an imaging optics, which may be implemented in practice as any known imaging lens. The maximum viewing angle of these optics is in 1 represented by dashed lines, each with a viewing pyramid 20a . 20b form.

Between the two image sensors 16a . 16b is a lighting unit 22 provided to the room area 12 to illuminate with a structured pattern. The stereoscopic camera shown is therefore designed for active stereoscopy, in which the pattern also imprints a contrast that can be evaluated anywhere in a structureless scene. Alternatively, no or a homogeneous illumination is provided to the natural object structures in the spatial area 12 evaluate, but this regularly leads to additional image errors.

With the two image sensors 16a . 16b and the lighting unit 22 is a control and evaluation unit 24 connected. The control and evaluation unit 24 can be implemented in a variety of hardware, such as digital devices such as microprocessors, Application Specific Integrated Circuit (ASIC), Field Programmable Gate Array (FPGA), Graphics Processing Unit (GPU) or hybrid forms thereof, which are arbitrarily distributable to internal and external components external components can also be integrated via network or a cloud, as long as latencies can be mastered or tolerated. Since the generation of the depth map and its evaluation are very computationally intensive, an at least partially parallel architecture is preferably formed.

The control and evaluation unit 24 generated with the help of the lighting unit 22 the structured illumination pattern and receives image data of the image sensors 16a . 16b , From these image data, it calculates the 3D image data or the depth map of the spatial area with the help of a stereoscopic disparity estimation 12 , The entire detectable space area 12 or workspace can be restricted via a configuration, for example, to hide disturbing or unnecessary areas.

An important safety application of the stereo camera 10 is the monitoring of a machine 26 in the 1 symbolized by a robot. That's what the stereo camera is for 10 preferably fail-safe designed in the sense of safety standards as mentioned in the introduction. The machine 26 can also be much more complex than shown, consist of many parts or even actually be an arrangement of multiple machines, such as multiple robots or robot arms. This machine 26 should through the stereo camera 10 be secured. The safety assessment can be done in the control and evaluation unit 24 or at least partially external and based on a variety of criteria, such as conventional protective fields, which are monitored for the presence of inadmissible objects.

Briefly described, however, is only representative of a distance monitoring, for example, for a human-robot collaboration, taking into account DIN EN ISO 10218 respectively ISO / TS 15066 at which the stereo camera 10 providing secure object detection and a shortest distance determined therefrom, which is then evaluated externally. The starting point are the positions of the machine parts of the machine 26 at least insofar as they are relevant to safety, or hazard points defined on this basis, which may be extended on the basis of reaction and stopping times or other criteria, as well as those of the stereo camera 10 captured objects 28 , The latter is, for example, after appropriate processing steps in the control and evaluation unit 24 in the form of a 2D detection map in front, whose pixels are at positions where an object 28 a minimum size has been recorded, the measured distance value has been entered, and otherwise remains empty. With the help of these object detections, which of course can also be represented differently, distances between the objects become 28 and the machine represented by a danger point 26 certainly.

Via a secure interface 30 becomes the shortest distance of the object nearest a respective danger point 28 issued, either directly to the machine 26 or to an intermediate station such as a secure controller. One to the secure interface 30 connected control, be it a higher-level control or that of the machine 26 , evaluates the shortest distance. In the case of danger, a safety-related reaction is initiated, for example, the machine 26 to stop, slow down or dodge. Whether this is necessary can be next to the shortest distance from other conditions such as the speeds or the nature of the object 28 and machine area 26 depend on the impending collision.

The 2 and 3 show in three-dimensional view from two perspectives and the 4 shows a holder in a sectional view 32 for mounting the stereo camera 10 , The holder 32 is designed for mounting on the ceiling including any bird's-eye view of overhead structures, as this usually provides the best overview and the stereo camera 10 even in this way does not constitute an obstacle. In principle, however, another assembly, for example, on a wall or even on the ground is conceivable, as well as the holder 32 can also be used for mounting other sensors.

The holder 32 , which continues to be exemplary as a holder for a stereo camera 10 is described at the same time allows adjusting the orientation of the stereo camera by a ball joint. All rotatory degrees of freedom are permitted. Due to the design, however, rotations about the X and Y axes are possible only in a limited angular range, while rotations around the Z axis and also around the limited angular range tilted Z axis remain possible without restriction. The coordinate system, which is used here without any restrictive meaning and its central Z-axis according to the viewing direction of the stereo camera 10 runs in a basic position in height direction, is in 4 located.

The actual ball joint, which is best in the sectional view of the 4 can be seen, has as a rotatable part a ball element 34 on that in a holding element 36 is stored. The ball element 34 flows down in a mounting area 38 for the stereo camera 10 whose circular or precise circular cylindrical shape is to be understood only symbolically. The sphere area of the ball element 34 is as a double-spherical element with an upper part ball element 40 and a lower part ball element 42 designed. The two partial ball elements 40 . 42 have a geometry similar to a hemisphere, but are cut off on a plane parallel to the equatorial plane. On this cutting plane are the two partial spherical elements 40 . 42 flat on each other. The first part ball element 40 has a smaller radius and a larger proportion of a sphere than a hemisphere, the second partial sphere element 42 conversely, the larger radius, but only a smaller fraction of a sphere than a hemisphere. This makes it possible that the two partial ball elements 40 . 42 have a common center, which lies in the origin of the drawn coordinate system and the center of rotation for the rotational movements of the ball joint 34 . 36 forms.

Only the second, lower part ball element 42 is preferably in contact with the holding element 36 , It takes over the main part of the holding moment due to the larger radius. The upper, first partial ball element 40 , which has the smaller radius in favor of a more compact design, prevents a pushing up of the ball element 34 ,

The holding element 36 acts as a collet and surrounds the outer periphery of the second part of the ball element 42 , It has a conical inner receptacle, which with the second part of the ball element 42 in contact. An additional ball-like curve for a larger contact surface or a surface adaptation or an intermediate material for greater friction would also be conceivable. The holding element 36 has several star-shaped radial slots 44 so that it is compressed more in externally applied radial force. The holding element 36 carries the ball element 34 and is in its upper part 46 on the ceiling 48 fastened, for example by screw connections 50 , Instead of a one-piece holding element 36 that even in the ceiling 48 screwed, a multi-part construction would be conceivable.

A clamping force which the holding element 36 for closing and clamping the ball element 34 Partial brings, can by a holding element 36 annular clamping element surrounding the outer periphery 52 be applied, the example here as Exzenterspanner with clamping lever 54 and closure 56 is trained. Instead of an eccentric vice, it is also possible to use other constructions which have a variable force, in particular radially inward, on the retaining element 36 exercise, such as a union nut which fixes the retaining element radially.

Depending on whether the tension lever 54 and with it the closure 56 is in the open or closed position, the ball element resists 34 a rotational movement with a low or strong holding torque. The lower holding torque is used to change the rotational position during alignment, while a certain resistance should be maintained so a trial-selected setting is not immediately lost. The strong holding torque fixes the alignment for the operation. The user does not need a tool to switch between these positions nor any in-depth knowledge of the mount 32 , It should only be ensured that the clamping lever for operation has fully applied and that the clamping lever must eventually be secured against loosening.

It is advantageous if the residual or bias voltage with the clamping lever open 54 is changeable or can be set defined. For this purpose, the clamping element 52 preferably on one of the closure 56 opposite side an adjustment 58 . 60 for adjusting the residual voltage. The tensioning element 52 can be made in two parts, with the closure 56 and the adjusting element 58 . 60 as a connection point between two semi-annular parts.

After assembly, so with the ball element 34 in the holding element 36 and if the tensioning element 52 the holding element 36 surrounds, can be used to adjust the residual stress when the clamping lever is open 54 a set screw 58 be tightened with a defined torque. Using a threaded pin 60 becomes the set screw 58 countered and secured against loosening. The residual stress preferably causes a holding torque that is just slightly greater than the load torque. This allows the user to make an adjustment, in which even without manual retention, for example, in adjustment pauses the ball element 34 , especially including stereo camera 10 , stays true to its position and orientation. Optionally, an additional resilient element is provided for this purpose at one point of the power flow, so that the residual stress and thus the Justier-holding torque can be adjusted easily and it decreases less strongly due to time-dependent settling on pressing surfaces.

By the adjusting screw 58 can also achieve that each manufactured holder has approximately the same holding torque at the same lever position. In particular, the residual or preload can be set reproducibly such that, with a correspondingly designed eccentric or clamping element 52 and fully applied tension lever 54 a sufficient or optimal clamping force is achieved, which in turn has a sufficient or optimal holding torque result.

5 shows a further embodiment of a holder 32 in a three-dimensional view. The tension lever 54 is here in its closed state by an additional fixation 62 held, for example in the form of an eye bolt with cross handle nut. About the fixation, so here is a thread, can apply a greater clamping force, and the clamping lever 54 is also secured against accidental opening such as shock or vibration.

6 shows a further embodiment of a holder 32 in a three-dimensional view with a variation of the adjustment 58 . 60 , Here is the set screw 58 not as before the shutter 56 opposite directly into the tab of the clamping element 52 screwed. Instead, the bias on the closure 56 via adjusting screw 58 and mother 64 applied. An adjustment of the bias in this manner is depending on the specific embodiment of the holder 32 more accurate and better reproducible.

7 shows an alternative embodiment of the retaining element 36 , In this illustration is better to see that the slots 44 down to the top 46 can expand. In addition, this example illustrates that a different number of slots 44 and correspondingly provided therefrom elastic fingers can be provided and this number is not fixed as previously on six segments.

In summary, according to the invention, an adjustable holder 32 on ceiling constructions 48 of industrial halls or the like mounted to an optoelectronic sensor and in particular a stereo camera 10 for a security application. The stereo camera 10 observes and secures a room area 12 from a bird's eye view. To the stereo camera 10 to adapt to local geometric conditions, provides the holder 32 Rotational adjustment degrees of freedom ready. The orientation thus set is constant over a long period of time, even under typical industrial environmental conditions, such as temperature changes, changes in air humidity, mechanical vibrations and shocks. The holder according to the invention 36 can be easily and safely installed and used. Care is taken to ensure that the holding forces and moments which fix the orientation are sufficiently large and that the user is informed in a simple manner. The adjustable holder 32 is for a stereo camera 10 described, but also allows the attachment and alignment of other 3D cameras and optoelectronic sensors, in principle, any sensors and even a direction finder or a source of illumination, especially if they are advantageously mounted in a bird's eye view of a ceiling structure.

Claims (12)

Support (32) for mounting a sensor (10) on the ceiling (48), wherein the holder (32) has a ball joint (34, 36) with a ball element (34) and a holding element (36), which the ball element (34 ) and in which the ball element (34) is rotatable about a vertical axis and tiltably mounted against the vertical axis and is under tension, which counteracts the turning and tilting, characterized in that the ball element (34) as a double-bubble element with an upper first part ball element (40) and a lower second part ball element (42) is configured, wherein a part ball element denotes a ball cut off by a plane, that the part ball elements lie flat on this cutting surface, and that a clamping element (52) is provided to the voltage of Holding element (36) without tools to either strengthen or reduce. Retainer (32) after Claim 1 wherein only the second part ball element (42) is in contact with the holding element (36). Retainer (32) after Claim 1 or 2 wherein the first part ball element (40) has a smaller radius than the second part ball element (42). Holder (32) according to one of the preceding claims, wherein the partial ball elements (40, 42) have a common center. Holder (32) according to one of the preceding claims, wherein the first part ball element (40) has the geometry of a ball piece greater than a hemisphere and / or the second part ball element (42) has the geometry of a ball smaller than a hemisphere. Holder (32) according to one of the preceding claims, wherein the holding element (36) has an adapted to the geometry of a ball inner receptacle for the second part ball element (42). Holder (32) according to one of the preceding claims, wherein the holding element (36) has at least one radial slot (44). Holder (32) according to one of the preceding claims, wherein the clamping element (52) has an annular geometry and surrounds the holding element (36) on its outer circumference. Holder (32) according to one of the preceding claims, wherein the clamping element (52) is designed as Exzenterspanner with a clamping lever (54). A bracket (32) as claimed in any preceding claim, wherein the tension member (52) includes an adjustment member (58, 60) for biasing. Retainer (32) after Claim 10 , wherein the clamping element (52) is formed in two parts, with a by the clamping lever (54) actuated closure (56) and the adjusting element (58, 60) at the connection points. 3D camera (10) with a holder (32) according to one of the preceding claims.

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